Changeset - bc4fc1729942
[Not reviewed]
0 11 0
MH - 3 years ago 2022-02-28 13:26:09
contact@maxhenger.nl
WIP: Handling interaction between PDL/runtime for select stmt
9 files changed:
0 comments (0 inline, 0 general)
src/macros.rs
Show inline comments
 
// Utility for performing debug printing within a particular module. Still
 
// requires some extra macros to be defined to be ergonomic.
 
macro_rules! enabled_debug_print {
 
    (false, $name:literal, $format:literal) => {};
 
    (false, $name:literal, $format:literal, $($args:expr),*) => {};
 
    (true, $name:literal, $format:literal) => {
 
        println!("[{}] {}", $name, $format)
 
    };
 
    (true, $name:literal, $format:literal, $($args:expr),*) => {
 
        println!("[{}] {}", $name, format!($format, $($args),*))
 
    };
 
}
 

	
 
// Utility for inserting code only executed in debug mode. Because writing the
 
// conditional cfg is tedious and looks ugly. Still doesn't work for struct
 
// fields, though.
 
macro_rules! dbg_code {
 
    ($code:stmt) => {
 
        #[cfg(debug_assertions)] $code
 
    }
 
}
 

	
 
// Given a function name, return type and variant, will generate the all-so
 
// common `union_value.as_variant()` method.
 
macro_rules! union_cast_method_impl {
 
// common `union_value.as_variant()` method. The return value is the reference
 
// to the embedded union type.
 
macro_rules! union_cast_to_ref_method_impl {
 
    ($func_name:ident, $ret_type:ty, $variant:path) => {
 
        fn $func_name(&self) -> &$ret_type {
 
            match self {
 
                $variant(content) => return content,
 
                _ => unreachable!(),
 
            }
 
        }
 
    }
 
}
 

	
 
// Another union cast, but now returning a copy of the value
 
macro_rules! union_cast_to_value_method_impl {
 
    ($func_name:ident, $ret_type:ty, $variant:path) => {
 
        impl Value {
 
            pub(crate) fn $func_name(&self) -> $ret_type {
 
                match self {
 
                    $variant(v) => *v,
 
                    _ => unreachable!(),
 
                }
 
            }
 
        }
 
    }
 
}
 
\ No newline at end of file
src/protocol/eval/executor.rs
Show inline comments
 

	
 
use std::collections::VecDeque;
 

	
 
use super::value::*;
 
use super::store::*;
 
use super::error::*;
 
use crate::protocol::*;
 
use crate::protocol::ast::*;
 
use crate::protocol::type_table::*;
 

	
 
macro_rules! debug_enabled { () => { false }; }
 
macro_rules! debug_log {
 
    ($format:literal) => {
 
        enabled_debug_print!(false, "exec", $format);
 
    };
 
    ($format:literal, $($args:expr),*) => {
 
        enabled_debug_print!(false, "exec", $format, $($args),*);
 
    };
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub(crate) enum ExprInstruction {
 
    EvalExpr(ExpressionId),
 
    PushValToFront,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub(crate) struct Frame {
 
    pub(crate) definition: ProcedureDefinitionId,
 
    pub(crate) monomorph_type_id: TypeId,
 
    pub(crate) monomorph_index: usize,
 
    pub(crate) position: StatementId,
 
    pub(crate) expr_stack: VecDeque<ExprInstruction>, // hack for expression evaluation, evaluated by popping from back
 
    pub(crate) expr_values: VecDeque<Value>, // hack for expression results, evaluated by popping from front/back
 
    pub(crate) max_stack_size: u32,
 
}
 

	
 
impl Frame {
 
    /// Creates a new execution frame. Does not modify the stack in any way.
 
    pub fn new(heap: &Heap, definition_id: ProcedureDefinitionId, monomorph_type_id: TypeId, monomorph_index: u32) -> Self {
 
        let definition = &heap[definition_id];
 
        let outer_scope_id = definition.scope;
 
        let first_statement_id = definition.body;
 

	
 
        // Another not-so-pretty thing that has to be replaced somewhere in the
 
        // future...
 
        fn determine_max_stack_size(heap: &Heap, scope_id: ScopeId, max_size: &mut u32) {
 
            let scope = &heap[scope_id];
 

	
 
            // Check current block
 
            let cur_size = scope.next_unique_id_in_scope as u32;
 
            if cur_size > *max_size { *max_size = cur_size; }
 

	
 
            // And child blocks
 
            for child_scope in &scope.nested {
 
                determine_max_stack_size(heap, *child_scope, max_size);
 
            }
 
        }
 

	
 
        let mut max_stack_size = 0;
 
        determine_max_stack_size(heap, outer_scope_id, &mut max_stack_size);
 

	
 
        Frame{
 
            definition: definition_id,
 
            monomorph_type_id,
 
            monomorph_index: monomorph_index as usize,
 
            position: first_statement_id.upcast(),
 
            expr_stack: VecDeque::with_capacity(128),
 
            expr_values: VecDeque::with_capacity(128),
 
            max_stack_size,
 
        }
 
    }
 

	
 
    /// Prepares a single expression for execution. This involves walking the
 
    /// expression tree and putting them in the `expr_stack` such that
 
    /// continuously popping from its back will evaluate the expression. The
 
    /// results of each expression will be stored by pushing onto `expr_values`.
 
    pub fn prepare_single_expression(&mut self, heap: &Heap, expr_id: ExpressionId) {
 
        debug_assert!(self.expr_stack.is_empty());
 
        self.expr_values.clear(); // May not be empty if last expression result(s) were discarded
 

	
 
        self.serialize_expression(heap, expr_id);
 
    }
 

	
 
    /// Prepares multiple expressions for execution (i.e. evaluating all
 
    /// function arguments or all elements of an array/union literal). Per
 
    /// expression this works the same as `prepare_single_expression`. However
 
    /// after each expression is evaluated we insert a `PushValToFront`
 
    /// instruction
 
    pub fn prepare_multiple_expressions(&mut self, heap: &Heap, expr_ids: &[ExpressionId]) {
 
        debug_assert!(self.expr_stack.is_empty());
 
        self.expr_values.clear();
 

	
 
        for expr_id in expr_ids {
 
            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
            self.serialize_expression(heap, *expr_id);
 
        }
 
    }
 

	
 
    /// Performs depth-first serialization of expression tree. Let's not care
 
    /// about performance for a temporary runtime implementation
 
    fn serialize_expression(&mut self, heap: &Heap, id: ExpressionId) {
 
        self.expr_stack.push_back(ExprInstruction::EvalExpr(id));
 

	
 
        match &heap[id] {
 
            Expression::Assignment(expr) => {
 
                self.serialize_expression(heap, expr.left);
 
                self.serialize_expression(heap, expr.right);
 
            },
 
            Expression::Binding(expr) => {
 
                self.serialize_expression(heap, expr.bound_to);
 
                self.serialize_expression(heap, expr.bound_from);
 
            },
 
            Expression::Conditional(expr) => {
 
                self.serialize_expression(heap, expr.test);
 
            },
 
            Expression::Binary(expr) => {
 
                self.serialize_expression(heap, expr.left);
 
                self.serialize_expression(heap, expr.right);
 
            },
 
            Expression::Unary(expr) => {
 
                self.serialize_expression(heap, expr.expression);
 
            },
 
            Expression::Indexing(expr) => {
 
                self.serialize_expression(heap, expr.index);
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Slicing(expr) => {
 
                self.serialize_expression(heap, expr.from_index);
 
                self.serialize_expression(heap, expr.to_index);
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Select(expr) => {
 
                self.serialize_expression(heap, expr.subject);
 
            },
 
            Expression::Literal(expr) => {
 
                // Here we only care about literals that have subexpressions
 
                match &expr.value {
 
                    Literal::Null | Literal::True | Literal::False |
 
                    Literal::Character(_) | Literal::String(_) |
 
                    Literal::Integer(_) | Literal::Enum(_) => {
 
                        // No subexpressions
 
                    },
 
                    Literal::Struct(literal) => {
 
                        // Note: fields expressions are evaluated in programmer-
 
                        // specified order. But struct construction expects them
 
                        // in type-defined order. I might want to come back to
 
                        // this.
 
                        let mut _num_pushed = 0;
 
                        for want_field_idx in 0..literal.fields.len() {
 
                            for field in &literal.fields {
 
                                if field.field_idx == want_field_idx {
 
                                    _num_pushed += 1;
 
                                    self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                                    self.serialize_expression(heap, field.value);
 
                                }
 
                            }
 
                        }
 
                        debug_assert_eq!(_num_pushed, literal.fields.len())
 
                    },
 
                    Literal::Union(literal) => {
 
                        for value_expr_id in &literal.values {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    },
 
                    Literal::Array(value_expr_ids) => {
 
                        for value_expr_id in value_expr_ids {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    },
 
                    Literal::Tuple(value_expr_ids) => {
 
                        for value_expr_id in value_expr_ids {
 
                            self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                            self.serialize_expression(heap, *value_expr_id);
 
                        }
 
                    }
 
                }
 
            },
 
            Expression::Cast(expr) => {
 
                self.serialize_expression(heap, expr.subject);
 
            }
 
            Expression::Call(expr) => {
 
                for arg_expr_id in &expr.arguments {
 
                    self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                    self.serialize_expression(heap, *arg_expr_id);
 
                }
 
            },
 
            Expression::Variable(_expr) => {
 
                // No subexpressions
 
            }
 
        }
 
    }
 
}
 

	
 
pub type EvalResult = Result<EvalContinuation, EvalError>;
 

	
 
#[derive(Debug)]
 
pub enum EvalContinuation {
 
    // Returned in both sync and non-sync modes
 
    Stepping,
 
    // Returned only in sync mode
 
    BranchInconsistent,
 
    SyncBlockEnd,
 
    NewFork,
 
    BlockFires(PortId),
 
    BlockGet(PortId),
 
    Put(PortId, ValueGroup),
 
    SelectStart(u32, u32), // (num_cases, num_ports_total)
 
    SelectRegisterPort(u32, u32, PortId), // (case_index, port_index_in_case, port_id)
 
    SelectWait, // wait until select can continue
 
    // Returned only in non-sync mode
 
    ComponentTerminated,
 
    SyncBlockStart,
 
    NewComponent(ProcedureDefinitionId, TypeId, ValueGroup),
 
    NewChannel,
 
}
 

	
 
// Note: cloning is fine, methinks. cloning all values and the heap regions then
 
// we end up with valid "pointers" to heap regions.
 
#[derive(Debug, Clone)]
 
pub struct Prompt {
 
    pub(crate) frames: Vec<Frame>,
 
    pub(crate) store: Store,
 
}
 

	
 
impl Prompt {
 
    pub fn new(types: &TypeTable, heap: &Heap, def: ProcedureDefinitionId, type_id: TypeId, args: ValueGroup) -> Self {
 
        let mut prompt = Self{
 
            frames: Vec::new(),
 
            store: Store::new(),
 
        };
 

	
 
        // Maybe do typechecking in the future?
 
        let monomorph_index = types.get_monomorph(type_id).variant.as_procedure().monomorph_index;
 
        let new_frame = Frame::new(heap, def, type_id, monomorph_index);
 
        let max_stack_size = new_frame.max_stack_size;
 
        prompt.frames.push(new_frame);
 
        args.into_store(&mut prompt.store);
 
        prompt.store.reserve_stack(max_stack_size);
 

	
 
        prompt
 
    }
 

	
 
    /// Big 'ol function right here. Didn't want to break it up unnecessarily.
 
    /// It consists of, in sequence: executing any expressions that should be
 
    /// executed before the next statement can be evaluated, then a section that
 
    /// performs debug printing, and finally a section that takes the next
 
    /// statement and executes it. If the statement requires any expressions to
 
    /// be evaluated, then they will be added such that the next time `step` is
 
    /// called, all of these expressions are indeed evaluated.
 
    pub(crate) fn step(&mut self, types: &TypeTable, heap: &Heap, modules: &[Module], ctx: &mut impl RunContext) -> EvalResult {
 
        // Helper function to transfer multiple values from the expression value
 
        // array into a heap region (e.g. constructing arrays or structs).
 
        fn transfer_expression_values_front_into_heap(cur_frame: &mut Frame, store: &mut Store, num_values: usize) -> HeapPos {
 
            let heap_pos = store.alloc_heap();
 

	
 
            // Do the transformation first (because Rust...)
 
            for val_idx in 0..num_values {
 
                cur_frame.expr_values[val_idx] = store.read_take_ownership(cur_frame.expr_values[val_idx].clone());
 
            }
 

	
 
            // And now transfer to the heap region
 
            let values = &mut store.heap_regions[heap_pos as usize].values;
 
            debug_assert!(values.is_empty());
 
            values.reserve(num_values);
 
            for _ in 0..num_values {
 
                values.push(cur_frame.expr_values.pop_front().unwrap());
 
            }
 

	
 
            heap_pos
 
        }
 

	
 
        // Helper function to make sure that an index into an aray is valid.
 
        fn array_inclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
 
            let array_len = store.heap_regions[array_heap_pos as usize].values.len();
 
            return idx < 0 || idx >= array_len as i64;
 
        }
 

	
 
        fn array_exclusive_index_is_invalid(store: &Store, array_heap_pos: u32, idx: i64) -> bool {
 
            let array_len = store.heap_regions[array_heap_pos as usize].values.len();
 
            return idx < 0 || idx > array_len as i64;
 
        }
 

	
 
        fn construct_array_error(prompt: &Prompt, modules: &[Module], heap: &Heap, expr_id: ExpressionId, heap_pos: u32, idx: i64) -> EvalError {
 
            let array_len = prompt.store.heap_regions[heap_pos as usize].values.len();
 
            return EvalError::new_error_at_expr(
 
                prompt, modules, heap, expr_id,
 
                format!("index {} is out of bounds: array length is {}", idx, array_len)
 
            )
 
        }
 

	
 
        // Checking if we're at the end of execution
 
        let cur_frame = self.frames.last_mut().unwrap();
 
        if cur_frame.position.is_invalid() {
 
            if heap[cur_frame.definition].kind == ProcedureKind::Function {
 
                todo!("End of function without return, return an evaluation error");
 
            }
 
            return Ok(EvalContinuation::ComponentTerminated);
 
        }
 

	
 
        debug_log!("Taking step in '{}'", heap[cur_frame.definition].identifier().value.as_str());
 

	
 
        // Execute all pending expressions
 
        while !cur_frame.expr_stack.is_empty() {
 
            let next = cur_frame.expr_stack.pop_back().unwrap();
 
            debug_log!("Expr stack: {:?}", next);
 
            match next {
 
                ExprInstruction::PushValToFront => {
 
                    cur_frame.expr_values.rotate_right(1);
 
                },
 
                ExprInstruction::EvalExpr(expr_id) => {
 
                    let expr = &heap[expr_id];
 
                    match expr {
 
                        Expression::Assignment(expr) => {
 
                            let to = cur_frame.expr_values.pop_back().unwrap().as_ref();
 
                            let rhs = cur_frame.expr_values.pop_back().unwrap();
 

	
 
                            // Note: although not pretty, the assignment operator takes ownership
 
                            // of the right-hand side value when possible. So we do not drop the
 
                            // rhs's optionally owned heap data.
 
                            let rhs = self.store.read_take_ownership(rhs);
 
                            apply_assignment_operator(&mut self.store, to, expr.operation, rhs);
 
                        },
 
                        Expression::Binding(_expr) => {
 
                            let bind_to = cur_frame.expr_values.pop_back().unwrap();
 
                            let bind_from = cur_frame.expr_values.pop_back().unwrap();
 
                            let bind_to_heap_pos = bind_to.get_heap_pos();
 
                            let bind_from_heap_pos = bind_from.get_heap_pos();
 

	
 
                            let result = apply_binding_operator(&mut self.store, bind_to, bind_from);
 
                            self.store.drop_value(bind_to_heap_pos);
 
                            self.store.drop_value(bind_from_heap_pos);
 
                            cur_frame.expr_values.push_back(Value::Bool(result));
 
                        },
 
                        Expression::Conditional(expr) => {
 
                            // Evaluate testing expression, then extend the
 
                            // expression stack with the appropriate expression
 
                            let test_result = cur_frame.expr_values.pop_back().unwrap().as_bool();
 
                            if test_result {
 
                                cur_frame.serialize_expression(heap, expr.true_expression);
 
                            } else {
 
                                cur_frame.serialize_expression(heap, expr.false_expression);
 
                            }
 
                        },
 
                        Expression::Binary(expr) => {
 
                            let lhs = cur_frame.expr_values.pop_back().unwrap();
 
                            let rhs = cur_frame.expr_values.pop_back().unwrap();
 
                            let result = apply_binary_operator(&mut self.store, &lhs, expr.operation, &rhs);
 
                            cur_frame.expr_values.push_back(result);
 
                            self.store.drop_value(lhs.get_heap_pos());
 
                            self.store.drop_value(rhs.get_heap_pos());
 
                        },
 
                        Expression::Unary(expr) => {
 
                            let val = cur_frame.expr_values.pop_back().unwrap();
 
                            let result = apply_unary_operator(&mut self.store, expr.operation, &val);
 
                            cur_frame.expr_values.push_back(result);
 
                            self.store.drop_value(val.get_heap_pos());
 
                        },
 
                        Expression::Indexing(_expr) => {
 
                            // Evaluate index. Never heap allocated so we do
 
                            // not have to drop it.
 
                            let index = cur_frame.expr_values.pop_back().unwrap();
 
                            let index = self.store.maybe_read_ref(&index);
 

	
 
                            debug_assert!(index.is_integer());
 
                            let index = if index.is_signed_integer() {
 
                                index.as_signed_integer() as i64
 
                            } else {
 
                                index.as_unsigned_integer() as i64
 
                            };
 

	
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 

	
 
                            let (deallocate_heap_pos, value_to_push) = match subject {
 
                                Value::Ref(value_ref) => {
 
                                    // Our expression stack value is a reference to something that
 
                                    // exists in the normal stack/heap. We don't want to deallocate
 
                                    // this thing. Rather we want to return a reference to it.
 
                                    let subject = self.store.read_ref(value_ref);
 
                                    let subject_heap_pos = match subject {
 
                                        Value::String(v) => *v,
 
                                        Value::Array(v) => *v,
 
                                        Value::Message(v) => *v,
 
                                        _ => unreachable!(),
 
                                    };
 

	
 
                                    if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
 
                                        return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
 
                                    }
 

	
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, index as u32)))
 
                                },
 
                                _ => {
 
                                    // Our value lives on the expression stack, hence we need to
 
                                    // clone whatever we're referring to. Then drop the subject.
 
                                    let subject_heap_pos = match &subject {
 
                                        Value::String(v) => *v,
 
                                        Value::Array(v) => *v,
 
                                        Value::Message(v) => *v,
 
                                        _ => unreachable!(),
 
                                    };
 

	
 
                                    if array_inclusive_index_is_invalid(&self.store, subject_heap_pos, index) {
 
                                        return Err(construct_array_error(self, modules, heap, expr_id, subject_heap_pos, index));
 
                                    }
 

	
 
                                    let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, index as u32));
 
                                    (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
 
                                },
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value_to_push);
 
                            self.store.drop_value(deallocate_heap_pos);
 
                        },
 
                        Expression::Slicing(expr) => {
 
                            // Evaluate indices
 
                            let from_index = cur_frame.expr_values.pop_back().unwrap();
 
                            let from_index = self.store.maybe_read_ref(&from_index);
 
                            let to_index = cur_frame.expr_values.pop_back().unwrap();
 
                            let to_index = self.store.maybe_read_ref(&to_index);
 

	
 
                            debug_assert!(from_index.is_integer() && to_index.is_integer());
 
                            let from_index = if from_index.is_signed_integer() {
 
                                from_index.as_signed_integer()
 
                            } else {
 
                                from_index.as_unsigned_integer() as i64
 
                            };
 
                            let to_index = if to_index.is_signed_integer() {
 
                                to_index.as_signed_integer()
 
                            } else {
 
                                to_index.as_unsigned_integer() as i64
 
                            };
 

	
 
                            // Dereference subject if needed
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 
                            let deref_subject = self.store.maybe_read_ref(&subject);
 

	
 
                            // Slicing needs to produce a copy anyway (with the
 
                            // current evaluator implementation)
 
                            enum ValueKind{ Array, String, Message }
 
                            let (value_kind, array_heap_pos) = match deref_subject {
 
                                Value::Array(v) => (ValueKind::Array, *v),
 
                                Value::String(v) => (ValueKind::String, *v),
 
                                Value::Message(v) => (ValueKind::Message, *v),
 
                                _ => unreachable!()
 
                            };
 

	
 
                            if array_inclusive_index_is_invalid(&self.store, array_heap_pos, from_index) {
 
                                return Err(construct_array_error(self, modules, heap, expr.from_index, array_heap_pos, from_index));
 
                            }
 
                            if array_exclusive_index_is_invalid(&self.store, array_heap_pos, to_index) {
 
                                return Err(construct_array_error(self, modules, heap, expr.to_index, array_heap_pos, to_index));
 
                            }
 

	
 
                            // Again: would love to push directly, but rust...
 
                            let new_heap_pos = self.store.alloc_heap();
 
                            debug_assert!(self.store.heap_regions[new_heap_pos as usize].values.is_empty());
 
                            if to_index > from_index {
 
                                let from_index = from_index as usize;
 
                                let to_index = to_index as usize;
 
                                let mut values = Vec::with_capacity(to_index - from_index);
 
                                for idx in from_index..to_index {
 
                                    let value = self.store.heap_regions[array_heap_pos as usize].values[idx].clone();
 
                                    values.push(self.store.clone_value(value));
 
                                }
 

	
 
                                self.store.heap_regions[new_heap_pos as usize].values = values;
 

	
 
                            } // else: empty range
 

	
 
                            cur_frame.expr_values.push_back(match value_kind {
 
                                ValueKind::Array => Value::Array(new_heap_pos),
 
                                ValueKind::String => Value::String(new_heap_pos),
 
                                ValueKind::Message => Value::Message(new_heap_pos),
 
                            });
 

	
 
                            // Dropping the original subject, because we don't
 
                            // want to drop something on the stack
 
                            self.store.drop_value(subject.get_heap_pos());
 
                        },
 
                        Expression::Select(expr) => {
 
                            let subject= cur_frame.expr_values.pop_back().unwrap();
 
                            let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                            let field_idx = mono_data.expr_info[expr.type_index as usize].variant.as_select() as u32;
 

	
 
                            // Note: same as above: clone if value lives on expr stack, simply
 
                            // refer to it if it already lives on the stack/heap.
 
                            let (deallocate_heap_pos, value_to_push) = match subject {
 
                                Value::Ref(value_ref) => {
 
                                    let subject = self.store.read_ref(value_ref);
 
                                    let subject_heap_pos = match expr.kind {
 
                                        SelectKind::StructField(_) => subject.as_struct(),
 
                                        SelectKind::TupleMember(_) => subject.as_tuple(),
 
                                    };
 

	
 
                                    (None, Value::Ref(ValueId::Heap(subject_heap_pos, field_idx)))
 
                                },
 
                                _ => {
 
                                    let subject_heap_pos = match expr.kind {
 
                                        SelectKind::StructField(_) => subject.as_struct(),
 
                                        SelectKind::TupleMember(_) => subject.as_tuple(),
 
                                    };
 
                                    let subject_indexed = Value::Ref(ValueId::Heap(subject_heap_pos, field_idx));
 
                                    (Some(subject_heap_pos), self.store.clone_value(subject_indexed))
 
                                },
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value_to_push);
 
                            self.store.drop_value(deallocate_heap_pos);
 
                        },
 
                        Expression::Literal(expr) => {
 
                            let value = match &expr.value {
 
                                Literal::Null => Value::Null,
 
                                Literal::True => Value::Bool(true),
 
                                Literal::False => Value::Bool(false),
 
                                Literal::Character(lit_value) => Value::Char(*lit_value),
 
                                Literal::String(lit_value) => {
 
                                    let heap_pos = self.store.alloc_heap();
 
                                    let values = &mut self.store.heap_regions[heap_pos as usize].values;
 
                                    let value = lit_value.as_str();
 
                                    debug_assert!(values.is_empty());
 
                                    values.reserve(value.len());
 
                                    for character in value.as_bytes() {
 
                                        debug_assert!(character.is_ascii());
 
                                        values.push(Value::Char(*character as char));
 
                                    }
 
                                    Value::String(heap_pos)
 
                                }
 
                                Literal::Integer(lit_value) => {
 
                                    use ConcreteTypePart as CTP;
 
                                    let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                                    let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
 
                                    let concrete_type = &types.get_monomorph(type_id).concrete_type;
 

	
 
                                    debug_assert_eq!(concrete_type.parts.len(), 1);
 
                                    match concrete_type.parts[0] {
 
                                        CTP::UInt8  => Value::UInt8(lit_value.unsigned_value as u8),
 
                                        CTP::UInt16 => Value::UInt16(lit_value.unsigned_value as u16),
 
                                        CTP::UInt32 => Value::UInt32(lit_value.unsigned_value as u32),
 
                                        CTP::UInt64 => Value::UInt64(lit_value.unsigned_value as u64),
 
                                        CTP::SInt8  => Value::SInt8(lit_value.unsigned_value as i8),
 
                                        CTP::SInt16 => Value::SInt16(lit_value.unsigned_value as i16),
 
                                        CTP::SInt32 => Value::SInt32(lit_value.unsigned_value as i32),
 
                                        CTP::SInt64 => Value::SInt64(lit_value.unsigned_value as i64),
 
                                        _ => unreachable!("got concrete type {:?} for integer literal at expr {:?}", concrete_type, expr_id),
 
                                    }
 
                                }
 
                                Literal::Struct(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.fields.len()
 
                                    );
 
                                    Value::Struct(heap_pos)
 
                                }
 
                                Literal::Enum(lit_value) => {
 
                                    Value::Enum(lit_value.variant_idx as i64)
 
                                }
 
                                Literal::Union(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.values.len()
 
                                    );
 
                                    Value::Union(lit_value.variant_idx as i64, heap_pos)
 
                                }
 
                                Literal::Array(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.len()
 
                                    );
 
                                    Value::Array(heap_pos)
 
                                }
 
                                Literal::Tuple(lit_value) => {
 
                                    let heap_pos = transfer_expression_values_front_into_heap(
 
                                        cur_frame, &mut self.store, lit_value.len()
 
                                    );
 
                                    Value::Tuple(heap_pos)
 
                                }
 
                            };
 

	
 
                            cur_frame.expr_values.push_back(value);
 
                        },
 
                        Expression::Cast(expr) => {
 
                            let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                            let type_id = mono_data.expr_info[expr.type_index as usize].type_id;
 
                            let concrete_type = &types.get_monomorph(type_id).concrete_type;
 

	
 
                            // Typechecking reduced this to two cases: either we
 
                            // have casting noop (same types), or we're casting
 
                            // between integer/bool/char types.
 
                            let subject = cur_frame.expr_values.pop_back().unwrap();
 
                            match apply_casting(&mut self.store, concrete_type, &subject) {
 
                                Ok(value) => cur_frame.expr_values.push_back(value),
 
                                Err(msg) => {
 
                                    return Err(EvalError::new_error_at_expr(self, modules, heap, expr.this.upcast(), msg));
 
                                }
 
                            }
 

	
 
                            self.store.drop_value(subject.get_heap_pos());
 
                        }
 
                        Expression::Call(expr) => {
 
                            // If we're dealing with a builtin we don't do any
 
                            // fancy shenanigans at all, just push the result.
 
                            match expr.method {
 
                                Method::Get => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value = self.store.maybe_read_ref(&value).clone();
 

	
 
                                    let port_id = if let Value::Input(port_id) = value {
 
                                        port_id
 
                                    } else {
 
                                        unreachable!("executor calling 'get' on value {:?}", value)
 
                                    };
 

	
 
                                    match ctx.performed_get(port_id) {
 
                                        Some(result) => {
 
                                            // We have the result. Merge the `ValueGroup` with the
 
                                            // stack/heap storage.
 
                                            debug_assert_eq!(result.values.len(), 1);
 
                                            result.into_stack(&mut cur_frame.expr_values, &mut self.store);
 
                                        },
 
                                        None => {
 
                                            // Don't have the result yet, prepare the expression to
 
                                            // get run again after we've received a message.
 
                                            cur_frame.expr_values.push_front(value.clone());
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockGet(port_id));
 
                                        }
 
                                    }
 
                                },
 
                                Method::Put => {
 
                                    let port_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let deref_port_value = self.store.maybe_read_ref(&port_value).clone();
 

	
 
                                    let port_id = if let Value::Output(port_id) = deref_port_value {
 
                                        port_id
 
                                    } else {
 
                                        unreachable!("executor calling 'put' on value {:?}", deref_port_value)
 
                                    };
 

	
 
                                    let msg_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let deref_msg_value = self.store.maybe_read_ref(&msg_value).clone();
 

	
 
                                    if ctx.performed_put(port_id) {
 
                                        // We're fine, deallocate in case the expression value stack
 
                                        // held an owned value
 
                                        self.store.drop_value(msg_value.get_heap_pos());
 
                                    } else {
 
                                        // Prepare to execute again
 
                                        cur_frame.expr_values.push_front(msg_value);
 
                                        cur_frame.expr_values.push_front(port_value);
 
                                        cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                        let value_group = ValueGroup::from_store(&self.store, &[deref_msg_value]);
 
                                        return Ok(EvalContinuation::Put(port_id, value_group));
 
                                    }
 
                                },
 
                                Method::Fires => {
 
                                    let port_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let port_value_deref = self.store.maybe_read_ref(&port_value).clone();
 

	
 
                                    let port_id = match port_value_deref {
 
                                        Value::Input(port_id) => port_id,
 
                                        Value::Output(port_id) => port_id,
 
                                        _ => unreachable!("executor calling 'fires' on value {:?}", port_value_deref),
 
                                    };
 
                                    let port_id = port_value_deref.as_port_id();
 

	
 
                                    match ctx.fires(port_id) {
 
                                        None => {
 
                                            cur_frame.expr_values.push_front(port_value);
 
                                            cur_frame.expr_stack.push_back(ExprInstruction::EvalExpr(expr_id));
 
                                            return Ok(EvalContinuation::BlockFires(port_id));
 
                                        },
 
                                        Some(value) => {
 
                                            cur_frame.expr_values.push_back(value);
 
                                        }
 
                                    }
 
                                },
 
                                Method::Create => {
 
                                    let length_value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let length_value = self.store.maybe_read_ref(&length_value);
 
                                    let length = if length_value.is_signed_integer() {
 
                                        let length_value = length_value.as_signed_integer();
 
                                        if length_value < 0 {
 
                                            return Err(EvalError::new_error_at_expr(
 
                                                self, modules, heap, expr_id,
 
                                                format!("got length '{}', can only create a message with a non-negative length", length_value)
 
                                            ));
 
                                        }
 

	
 
                                        length_value as u64
 
                                    } else {
 
                                        debug_assert!(length_value.is_unsigned_integer());
 
                                        length_value.as_unsigned_integer()
 
                                    };
 

	
 
                                    let heap_pos = self.store.alloc_heap();
 
                                    let values = &mut self.store.heap_regions[heap_pos as usize].values;
 
                                    debug_assert!(values.is_empty());
 
                                    values.resize(length as usize, Value::UInt8(0));
 
                                    cur_frame.expr_values.push_back(Value::Message(heap_pos));
 
                                },
 
                                Method::Length => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value_heap_pos = value.get_heap_pos();
 
                                    let value = self.store.maybe_read_ref(&value);
 

	
 
                                    let heap_pos = match value {
 
                                        Value::Array(pos) => *pos,
 
                                        Value::String(pos) => *pos,
 
                                        _ => unreachable!("length(...) on {:?}", value),
 
                                    };
 

	
 
                                    let len = self.store.heap_regions[heap_pos as usize].values.len();
 

	
 
                                    // TODO: @PtrInt
 
                                    cur_frame.expr_values.push_back(Value::UInt32(len as u32));
 
                                    self.store.drop_value(value_heap_pos);
 
                                },
 
                                Method::Assert => {
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value = self.store.maybe_read_ref(&value).clone();
 
                                    if !value.as_bool() {
 
                                        return Ok(EvalContinuation::BranchInconsistent)
 
                                    }
 
                                },
 
                                Method::Print => {
 
                                    // Convert the runtime-variant of a string
 
                                    // into an actual string.
 
                                    let value = cur_frame.expr_values.pop_front().unwrap();
 
                                    let value_heap_pos = value.as_string();
 
                                    let elements = &self.store.heap_regions[value_heap_pos as usize].values;
 

	
 
                                    let mut message = String::with_capacity(elements.len());
 
                                    for element in elements {
 
                                        message.push(element.as_char());
 
                                    }
 

	
 
                                    // Drop the heap-allocated value from the
 
                                    // store
 
                                    self.store.drop_heap_pos(value_heap_pos);
 
                                    println!("{}", message);
 
                                },
 
                                Method::SelectStart => {
 
                                    todo!("select start");
 
                                    let num_cases = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 
                                    let num_ports = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 
                                    if !ctx.select_start(num_cases, num_ports) {
 
                                        return Ok(EvalContinuation::SelectStart(num_cases, num_ports))
 
                                    }
 
                                },
 
                                Method::SelectRegisterCasePort => {
 
                                    todo!("select register");
 
                                    let case_index = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 
                                    let port_index = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_uint32();
 
                                    let port_value = self.store.maybe_read_ref(&cur_frame.expr_values.pop_front().unwrap()).as_port_id();
 

	
 
                                    if !ctx.performed_select_start() {
 
                                        return Ok(EvalContinuation::SelectRegisterPort(case_index, port_index, port_value));
 
                                    }
 
                                },
 
                                Method::SelectWait => {
 
                                    todo!("select wait");
 
                                    match ctx.performed_select_wait() {
 
                                        Some(select_index) => {
 
                                            cur_frame.expr_values.push_back(Value::UInt32(select_index));
 
                                        },
 
                                        None => return Ok(EvalContinuation::SelectWait),
 
                                    }
 
                                },
 
                                Method::UserComponent => {
 
                                    // This is actually handled by the evaluation
 
                                    // of the statement.
 
                                    debug_assert_eq!(heap[expr.procedure].parameters.len(), cur_frame.expr_values.len());
 
                                    debug_assert_eq!(heap[cur_frame.position].as_new().expression, expr.this)
 
                                },
 
                                Method::UserFunction => {
 
                                    // Push a new frame. Note that all expressions have
 
                                    // been pushed to the front, so they're in the order
 
                                    // of the definition.
 
                                    let num_args = expr.arguments.len();
 

	
 
                                    // Determine stack boundaries
 
                                    let cur_stack_boundary = self.store.cur_stack_boundary;
 
                                    let new_stack_boundary = self.store.stack.len();
 

	
 
                                    // Push new boundary and function arguments for new frame
 
                                    self.store.stack.push(Value::PrevStackBoundary(cur_stack_boundary as isize));
 
                                    for _ in 0..num_args {
 
                                        let argument = self.store.read_take_ownership(cur_frame.expr_values.pop_front().unwrap());
 
                                        self.store.stack.push(argument);
 
                                    }
 

	
 
                                    // Determine the monomorph index of the function we're calling
 
                                    let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                                    let (type_id, monomorph_index) = mono_data.expr_info[expr.type_index as usize].variant.as_procedure();
 

	
 
                                    // Push the new frame and reserve its stack size
 
                                    let new_frame = Frame::new(heap, expr.procedure, type_id, monomorph_index);
 
                                    let new_stack_size = new_frame.max_stack_size;
 
                                    self.frames.push(new_frame);
 
                                    self.store.cur_stack_boundary = new_stack_boundary;
 
                                    self.store.reserve_stack(new_stack_size);
 

	
 
                                    // To simplify the logic a little bit we will now
 
                                    // return and ask our caller to call us again
 
                                    return Ok(EvalContinuation::Stepping);
 
                                }
 
                            }
 
                        },
 
                        Expression::Variable(expr) => {
 
                            let variable = &heap[expr.declaration.unwrap()];
 
                            let ref_value = if expr.used_as_binding_target {
 
                                Value::Binding(variable.unique_id_in_scope as StackPos)
 
                            } else {
 
                                Value::Ref(ValueId::Stack(variable.unique_id_in_scope as StackPos))
 
                            };
 
                            cur_frame.expr_values.push_back(ref_value);
 
                        }
 
                    }
 
                }
 
            }
 
        }
 

	
 
        debug_log!("Frame [{:?}] at {:?}", cur_frame.definition, cur_frame.position);
 
        if debug_enabled!() {
 
            debug_log!("Expression value stack (size = {}):", cur_frame.expr_values.len());
 
            for (_stack_idx, _stack_val) in cur_frame.expr_values.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
 
            }
 

	
 
            debug_log!("Stack (size = {}):", self.store.stack.len());
 
            for (_stack_idx, _stack_val) in self.store.stack.iter().enumerate() {
 
                debug_log!("  [{:03}] {:?}", _stack_idx, _stack_val);
 
            }
 

	
 
            debug_log!("Heap:");
 
            for (_heap_idx, _heap_region) in self.store.heap_regions.iter().enumerate() {
 
                let _is_free = self.store.free_regions.iter().any(|idx| *idx as usize == _heap_idx);
 
                debug_log!("  [{:03}] in_use: {}, len: {}, vals: {:?}", _heap_idx, !_is_free, _heap_region.values.len(), &_heap_region.values);
 
            }
 
        }
 
        // No (more) expressions to evaluate. So evaluate statement (that may
 
        // depend on the result on the last evaluated expression(s))
 
        let stmt = &heap[cur_frame.position];
 
        let return_value = match stmt {
 
            Statement::Block(stmt) => {
 
                debug_assert!(stmt.statements.is_empty() || stmt.next == stmt.statements[0]);
 
                cur_frame.position = stmt.next;
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndBlock(stmt) => {
 
                let block = &heap[stmt.start_block];
 
                let scope = &heap[block.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Local(stmt) => {
 
                match stmt {
 
                    LocalStatement::Memory(stmt) => {
 
                        dbg_code!({
 
                            let variable = &heap[stmt.variable];
 
                            debug_assert!(match self.store.read_ref(ValueId::Stack(variable.unique_id_in_scope as u32)) {
 
                                Value::Unassigned => false,
 
                                _ => true,
 
                            });
 
                        });
 

	
 
                        cur_frame.position = stmt.next;
 
                        Ok(EvalContinuation::Stepping)
 
                    },
 
                    LocalStatement::Channel(stmt) => {
 
                        // Need to create a new channel by requesting it from
 
                        // the runtime.
 
                        match ctx.created_channel() {
 
                            None => {
 
                                // No channel is pending. So request one
 
                                    Ok(EvalContinuation::NewChannel)
 
                            },
 
                            Some((put_port, get_port)) => {
 
                                self.store.write(ValueId::Stack(heap[stmt.from].unique_id_in_scope as u32), put_port);
 
                                self.store.write(ValueId::Stack(heap[stmt.to].unique_id_in_scope as u32), get_port);
 
                                cur_frame.position = stmt.next;
 
                                Ok(EvalContinuation::Stepping)
 
                            }
 
                        }
 
                    }
 
                }
 
            },
 
            Statement::Labeled(stmt) => {
 
                cur_frame.position = stmt.body;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::If(stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for if statement");
 
                let test_value = cur_frame.expr_values.pop_back().unwrap();
 
                let test_value = self.store.maybe_read_ref(&test_value).as_bool();
 
                if test_value {
 
                    cur_frame.position = stmt.true_case.body;
 
                } else if let Some(false_body) = stmt.false_case {
 
                    cur_frame.position = false_body.body;
 
                } else {
 
                    // Not true, and no false body
 
                    cur_frame.position = stmt.end_if.upcast();
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndIf(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let if_stmt = &heap[stmt.start_if];
 
                debug_assert_eq!(
 
                    heap[if_stmt.true_case.scope].first_unique_id_in_scope,
 
                    heap[if_stmt.false_case.unwrap_or(if_stmt.true_case).scope].first_unique_id_in_scope,
 
                );
 
                let scope = &heap[if_stmt.true_case.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::While(stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for while statement");
 
                let test_value = cur_frame.expr_values.pop_back().unwrap();
 
                let test_value = self.store.maybe_read_ref(&test_value).as_bool();
 
                if test_value {
 
                    cur_frame.position = stmt.body;
 
                } else {
 
                    cur_frame.position = stmt.end_while.upcast();
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndWhile(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_while = &heap[stmt.start_while];
 
                let scope = &heap[start_while.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Break(stmt) => {
 
                cur_frame.position = stmt.target.upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Continue(stmt) => {
 
                cur_frame.position = stmt.target.upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Synchronous(stmt) => {
 
                cur_frame.position = stmt.body;
 

	
 
                Ok(EvalContinuation::SyncBlockStart)
 
            },
 
            Statement::EndSynchronous(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_synchronous = &heap[stmt.start_sync];
 
                let scope = &heap[start_synchronous.scope];
 
                self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 

	
 
                Ok(EvalContinuation::SyncBlockEnd)
 
            },
 
            Statement::Fork(stmt) => {
 
                if stmt.right_body.is_none() {
 
                    // No reason to fork
 
                    cur_frame.position = stmt.left_body;
 
                } else {
 
                    // Need to fork
 
                    if let Some(go_left) = ctx.performed_fork() {
 
                        // Runtime has created a fork
 
                        if go_left {
 
                            cur_frame.position = stmt.left_body;
 
                        } else {
 
                            cur_frame.position = stmt.right_body.unwrap();
 
                        }
 
                    } else {
 
                        // Request the runtime to create a fork of the current
 
                        // branch
 
                        return Ok(EvalContinuation::NewFork);
 
                    }
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndFork(stmt) => {
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Select(_stmt) => {
 
                todo!("implement select evaluation")
 
            Statement::Select(stmt) => {
 
                // This is a trampoline for the statements that were placed by
 
                // the AST transformation pass
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndSelect(stmt) => {
 
                cur_frame.position = stmt.next;
 
                let start_select = &heap[stmt.start_select];
 
                if let Some(select_case) = start_select.cases.first() {
 
                    let scope = &heap[select_case.scope];
 
                    self.store.clear_stack(scope.first_unique_id_in_scope as usize);
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Return(_stmt) => {
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for return statement");
 

	
 
                // The preceding frame has executed a call, so is expecting the
 
                // return expression on its expression value stack. Note that
 
                // we may be returning a reference to something on our stack,
 
                // so we need to read that value and clone it.
 
                let return_value = cur_frame.expr_values.pop_back().unwrap();
 
                let return_value = match return_value {
 
                    Value::Ref(value_id) => self.store.read_copy(value_id),
 
                    _ => return_value,
 
                };
 

	
 
                // Pre-emptively pop our stack frame
 
                self.frames.pop();
 

	
 
                // Clean up our section of the stack
 
                self.store.clear_stack(0);
 
                self.store.stack.truncate(self.store.cur_stack_boundary + 1);
 
                let prev_stack_idx = self.store.stack.pop().unwrap().as_stack_boundary();
 

	
 
                // TODO: Temporary hack for testing, remove at some point
 
                if self.frames.is_empty() {
 
                    debug_assert!(prev_stack_idx == -1);
 
                    debug_assert!(self.store.stack.len() == 0);
 
                    self.store.stack.push(return_value);
 
                    return Ok(EvalContinuation::ComponentTerminated);
 
                }
 

	
 
                debug_assert!(prev_stack_idx >= 0);
 
                // Return to original state of stack frame
 
                self.store.cur_stack_boundary = prev_stack_idx as usize;
 
                let cur_frame = self.frames.last_mut().unwrap();
 
                cur_frame.expr_values.push_back(return_value);
 

	
 
                // We just returned to the previous frame, which might be in
 
                // the middle of evaluating expressions for a particular
 
                // statement. So we don't want to enter the code below.
 
                return Ok(EvalContinuation::Stepping);
 
            },
 
            Statement::Goto(stmt) => {
 
                cur_frame.position = stmt.target.upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::New(stmt) => {
 
                let call_expr = &heap[stmt.expression];
 
                debug_assert_eq!(
 
                    cur_frame.expr_values.len(), heap[call_expr.procedure].parameters.len(),
 
                    "mismatch in expr stack size and number of arguments for new statement"
 
                );
 

	
 
                let mono_data = &heap[cur_frame.definition].monomorphs[cur_frame.monomorph_index];
 
                let type_id = mono_data.expr_info[call_expr.type_index as usize].variant.as_procedure().0;
 

	
 
                // Note that due to expression value evaluation they exist in
 
                // reverse order on the stack.
 
                // TODO: Revise this code, keep it as is to be compatible with current runtime
 
                let mut args = Vec::new();
 
                while let Some(value) = cur_frame.expr_values.pop_front() {
 
                    args.push(value);
 
                }
 

	
 
                // Construct argument group, thereby copying heap regions
 
                let argument_group = ValueGroup::from_store(&self.store, &args);
 

	
 
                // Clear any heap regions
 
                for arg in &args {
 
                    self.store.drop_value(arg.get_heap_pos());
 
                }
 

	
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::NewComponent(call_expr.procedure, type_id, argument_group))
 
            },
 
            Statement::Expression(stmt) => {
 
                // The expression has just been completely evaluated. Some
 
                // values might have remained on the expression value stack.
 
                // cur_frame.expr_values.clear(); PROPER CLEARING
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
        };
 

	
 
        assert!(
 
            cur_frame.expr_values.is_empty(),
 
            "This is a debugging assertion that will fail if you perform expressions without \
 
            assigning to anything. This should be completely valid, and this assertion should be \
 
            replaced by something that clears the expression values if needed, but I'll keep this \
 
            in for now for debugging purposes."
 
        );
 

	
 
        // If the next statement requires evaluating expressions then we push
 
        // these onto the expression stack. This way we will evaluate this
 
        // stack in the next loop, then evaluate the statement using the result
 
        // from the expression evaluation.
 
        if !cur_frame.position.is_invalid() {
 
            let stmt = &heap[cur_frame.position];
 

	
 
            match stmt {
 
                Statement::Local(stmt) => {
 
                    if let LocalStatement::Memory(stmt) = stmt {
 
                        // Setup as unassigned, when we execute the memory
 
                        // statement (after evaluating expression), it should no
 
                        // longer be `Unassigned`.
 
                        let variable = &heap[stmt.variable];
 
                        self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
 
                        cur_frame.prepare_single_expression(heap, stmt.initial_expr.upcast());
 
                    }
 
                },
 
                Statement::If(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
 
                Statement::While(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
 
                Statement::Return(stmt) => {
 
                    debug_assert_eq!(stmt.expressions.len(), 1); // TODO: @ReturnValues
 
                    cur_frame.prepare_single_expression(heap, stmt.expressions[0]);
 
                },
 
                Statement::New(stmt) => {
 
                    // Note that we will end up not evaluating the call itself.
 
                    // Rather we will evaluate its expressions and then
 
                    // instantiate the component upon reaching the "new" stmt.
 
                    let call_expr = &heap[stmt.expression];
 
                    cur_frame.prepare_multiple_expressions(heap, &call_expr.arguments);
 
                },
 
                Statement::Expression(stmt) => {
 
                    cur_frame.prepare_single_expression(heap, stmt.expression);
 
                }
 
                _ => {},
 
            }
 
        }
 

	
 
        return_value
 
    }
 

	
 
    /// Constructs an error at the current expression that lives at the top of
 
    /// the expression stack. Falls back to constructing an error at the current
 
    /// statement if there is no expression.
 
    pub(crate) fn new_error_at_expr(&self, modules: &[Module], heap: &Heap, error_message: String) -> EvalError {
 
        let last_frame = self.frames.last().unwrap();
 
        for instruction in last_frame.expr_stack.iter().rev() {
 
            if let ExprInstruction::EvalExpr(expression_id) = instruction {
 
                return EvalError::new_error_at_expr(
 
                    self, modules, heap, *expression_id, error_message
 
                );
 
            }
 
        }
 

	
 
        // If here then expression stack was empty (cannot have just rotate
 
        // instructions)
 
        panic!("attempted to construct evaluation error without any expressions to evaluate in frame");
 
    }
 
}
 
\ No newline at end of file
src/protocol/eval/value.rs
Show inline comments
 
use std::collections::VecDeque;
 

	
 
use super::store::*;
 
use crate::protocol::ast::{
 
    AssignmentOperator,
 
    BinaryOperator,
 
    UnaryOperator,
 
    ConcreteType,
 
    ConcreteTypePart,
 
};
 
use crate::protocol::parser::token_parsing::*;
 

	
 
pub type StackPos = u32;
 
pub type HeapPos = u32;
 

	
 
#[derive(Debug, Copy, Clone)]
 
pub enum ValueId {
 
    Stack(StackPos), // place on stack
 
    Heap(HeapPos, u32), // allocated region + values within that region
 
}
 

	
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
pub struct PortId{
 
    pub(crate) id: u32
 
}
 

	
 
impl PortId {
 
    pub fn new(id: u32) -> Self {
 
        return Self{ id };
 
    }
 
}
 

	
 
/// Represents a value stored on the stack or on the heap. Some values contain
 
/// a `HeapPos`, implying that they're stored in the store's `Heap`. Clearing
 
/// a `Value` with a `HeapPos` from a stack must also clear the associated
 
/// region from the `Heap`.
 
#[derive(Debug, Clone)]
 
pub enum Value {
 
    // Special types, never encountered during evaluation if the compiler works correctly
 
    Unassigned,                 // Marker when variables are first declared, immediately followed by assignment
 
    PrevStackBoundary(isize),   // Marker for stack frame beginning, so we can pop stack values
 
    Ref(ValueId),               // Reference to a value, used by expressions producing references
 
    Binding(StackPos),          // Reference to a binding variable (reserved on the stack)
 
    // Builtin types
 
    Input(PortId),
 
    Output(PortId),
 
    Message(HeapPos),
 
    Null,
 
    Bool(bool),
 
    Char(char),
 
    String(HeapPos),
 
    UInt8(u8),
 
    UInt16(u16),
 
    UInt32(u32),
 
    UInt64(u64),
 
    SInt8(i8),
 
    SInt16(i16),
 
    SInt32(i32),
 
    SInt64(i64),
 
    Array(HeapPos),
 
    Tuple(HeapPos),
 
    // Instances of user-defined types
 
    Enum(i64),
 
    Union(i64, HeapPos),
 
    Struct(HeapPos),
 
}
 

	
 
macro_rules! impl_union_unpack_as_value {
 
    ($func_name:ident, $variant_name:path, $return_type:ty) => {
 
        impl Value {
 
            pub(crate) fn $func_name(&self) -> $return_type {
 
                match self {
 
                    $variant_name(v) => *v,
 
                    _ => panic!(concat!("called ", stringify!($func_name()), " on {:?}"), self),
 
                }
 
            }
 
        }
 
    }
 
}
 

	
 
impl_union_unpack_as_value!(as_stack_boundary, Value::PrevStackBoundary, isize);
 
impl_union_unpack_as_value!(as_ref,     Value::Ref,     ValueId);
 
impl_union_unpack_as_value!(as_input,   Value::Input,   PortId);
 
impl_union_unpack_as_value!(as_output,  Value::Output,  PortId);
 
impl_union_unpack_as_value!(as_message, Value::Message, HeapPos);
 
impl_union_unpack_as_value!(as_bool,    Value::Bool,    bool);
 
impl_union_unpack_as_value!(as_char,    Value::Char,    char);
 
impl_union_unpack_as_value!(as_string,  Value::String,  HeapPos);
 
impl_union_unpack_as_value!(as_uint8,   Value::UInt8,   u8);
 
impl_union_unpack_as_value!(as_uint16,  Value::UInt16,  u16);
 
impl_union_unpack_as_value!(as_uint32,  Value::UInt32,  u32);
 
impl_union_unpack_as_value!(as_uint64,  Value::UInt64,  u64);
 
impl_union_unpack_as_value!(as_sint8,   Value::SInt8,   i8);
 
impl_union_unpack_as_value!(as_sint16,  Value::SInt16,  i16);
 
impl_union_unpack_as_value!(as_sint32,  Value::SInt32,  i32);
 
impl_union_unpack_as_value!(as_sint64,  Value::SInt64,  i64);
 
impl_union_unpack_as_value!(as_array,   Value::Array,   HeapPos);
 
impl_union_unpack_as_value!(as_tuple,   Value::Tuple,   HeapPos);
 
impl_union_unpack_as_value!(as_enum,    Value::Enum,    i64);
 
impl_union_unpack_as_value!(as_struct,  Value::Struct,  HeapPos);
 
union_cast_to_value_method_impl!(as_stack_boundary, isize, Value::PrevStackBoundary);
 
union_cast_to_value_method_impl!(as_ref, ValueId, Value::Ref);
 
union_cast_to_value_method_impl!(as_input, PortId, Value::Input);
 
union_cast_to_value_method_impl!(as_output, PortId, Value::Output);
 
union_cast_to_value_method_impl!(as_message, HeapPos, Value::Message);
 
union_cast_to_value_method_impl!(as_bool, bool, Value::Bool);
 
union_cast_to_value_method_impl!(as_char, char, Value::Char);
 
union_cast_to_value_method_impl!(as_string, HeapPos, Value::String);
 
union_cast_to_value_method_impl!(as_uint8, u8, Value::UInt8);
 
union_cast_to_value_method_impl!(as_uint16, u16, Value::UInt16);
 
union_cast_to_value_method_impl!(as_uint32, u32, Value::UInt32);
 
union_cast_to_value_method_impl!(as_uint64, u64, Value::UInt64);
 
union_cast_to_value_method_impl!(as_sint8, i8, Value::SInt8);
 
union_cast_to_value_method_impl!(as_sint16, i16, Value::SInt16);
 
union_cast_to_value_method_impl!(as_sint32, i32, Value::SInt32);
 
union_cast_to_value_method_impl!(as_sint64, i64, Value::SInt64);
 
union_cast_to_value_method_impl!(as_array, HeapPos, Value::Array);
 
union_cast_to_value_method_impl!(as_tuple, HeapPos, Value::Tuple);
 
union_cast_to_value_method_impl!(as_enum, i64, Value::Enum);
 
union_cast_to_value_method_impl!(as_struct, HeapPos, Value::Struct);
 

	
 
impl Value {
 
    pub(crate) fn as_union(&self) -> (i64, HeapPos) {
 
        match self {
 
            Value::Union(tag, v) => (*tag, *v),
 
            _ => panic!("called as_union on {:?}", self),
 
        }
 
    }
 

	
 
    pub(crate) fn as_port_id(&self) -> PortId {
 
        match self {
 
            Value::Input(v) => *v,
 
            Value::Output(v) => *v,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    pub(crate) fn is_integer(&self) -> bool {
 
        match self {
 
            Value::UInt8(_) | Value::UInt16(_) | Value::UInt32(_) | Value::UInt64(_) |
 
            Value::SInt8(_) | Value::SInt16(_) | Value::SInt32(_) | Value::SInt64(_) => true,
 
            _ => false
 
        }
 
    }
 

	
 
    pub(crate) fn is_unsigned_integer(&self) -> bool {
 
        match self {
 
            Value::UInt8(_) | Value::UInt16(_) | Value::UInt32(_) | Value::UInt64(_) => true,
 
            _ => false
 
        }
 
    }
 

	
 
    pub(crate) fn is_signed_integer(&self) -> bool {
 
        match self {
 
            Value::SInt8(_) | Value::SInt16(_) | Value::SInt32(_) | Value::SInt64(_) => true,
 
            _ => false
 
        }
 
    }
 

	
 
    pub(crate) fn as_unsigned_integer(&self) -> u64 {
 
        match self {
 
            Value::UInt8(v)  => *v as u64,
 
            Value::UInt16(v) => *v as u64,
 
            Value::UInt32(v) => *v as u64,
 
            Value::UInt64(v) => *v as u64,
 
            _ => unreachable!("called as_unsigned_integer on {:?}", self),
 
        }
 
    }
 

	
 
    pub(crate) fn as_signed_integer(&self) -> i64 {
 
        match self {
 
            Value::SInt8(v)  => *v as i64,
 
            Value::SInt16(v) => *v as i64,
 
            Value::SInt32(v) => *v as i64,
 
            Value::SInt64(v) => *v as i64,
 
            _ => unreachable!("called as_signed_integer on {:?}", self)
 
        }
 
    }
 

	
 
    /// Returns the heap position associated with the value. If the value
 
    /// doesn't store anything in the heap then we return `None`.
 
    pub(crate) fn get_heap_pos(&self) -> Option<HeapPos> {
 
        match self {
 
            Value::Message(v) => Some(*v),
 
            Value::String(v) => Some(*v),
 
            Value::Array(v) => Some(*v),
 
            Value::Tuple(v) => Some(*v),
 
            Value::Union(_, v) => Some(*v),
 
            Value::Struct(v) => Some(*v),
 
            _ => None
 
        }
 
    }
 
}
 

	
 
/// When providing arguments to a new component, or when transferring values
 
/// from one component's store to a newly instantiated component, one has to
 
/// transfer stack and heap values. This `ValueGroup` represents such a
 
/// temporary group of values with potential heap allocations.
 
///
 
/// Constructing such a ValueGroup manually requires some extra care to make
 
/// sure all elements of `values` point to valid elements of `regions`.
 
///
 
/// Again: this is a temporary thing, hopefully removed once we move to a
 
/// bytecode interpreter.
 
#[derive(Clone, Debug)]
 
pub struct ValueGroup {
 
    pub(crate) values: Vec<Value>,
 
    pub(crate) regions: Vec<Vec<Value>>
 
}
 

	
 
impl ValueGroup {
 
    pub(crate) fn new_stack(values: Vec<Value>) -> Self {
 
        debug_assert!(values.iter().all(|v| v.get_heap_pos().is_none()));
 
        Self{
 
            values,
 
            regions: Vec::new(),
 
        }
 
    }
 
    pub(crate) fn from_store(store: &Store, values: &[Value]) -> Self {
 
        let mut group = ValueGroup{
 
            values: Vec::with_capacity(values.len()),
 
            regions: Vec::with_capacity(values.len()), // estimation
 
        };
 

	
 
        for value in values {
 
            let transferred = group.retrieve_value(value, store);
 
            group.values.push(transferred);
 
        }
 

	
 
        group
 
    }
 

	
 
    /// Transfers a provided value from a store into a local value with its
 
    /// heap allocations (if any) stored in the ValueGroup. Calling this
 
    /// function will not store the returned value in the `values` member.
 
    fn retrieve_value(&mut self, value: &Value, from_store: &Store) -> Value {
 
        let value = from_store.maybe_read_ref(value);
 
        if let Some(heap_pos) = value.get_heap_pos() {
 
            // Value points to a heap allocation, so transfer the heap values
 
            // internally.
 
            let from_region = &from_store.heap_regions[heap_pos as usize].values;
 
            let mut new_region = Vec::with_capacity(from_region.len());
 
            for value in from_region {
 
                let transferred = self.retrieve_value(value, from_store);
 
                new_region.push(transferred);
 
            }
 

	
 
            // Region is constructed, store internally and return the new value.
 
            let new_region_idx = self.regions.len() as HeapPos;
 
            self.regions.push(new_region);
 

	
 
            return match value {
 
                Value::Message(_)    => Value::Message(new_region_idx),
 
                Value::String(_)     => Value::String(new_region_idx),
 
                Value::Array(_)      => Value::Array(new_region_idx),
 
                Value::Tuple(_)      => Value::Tuple(new_region_idx),
 
                Value::Union(tag, _) => Value::Union(*tag, new_region_idx),
 
                Value::Struct(_)     => Value::Struct(new_region_idx),
 
                _ => unreachable!(),
 
            };
 
        } else {
 
            return value.clone();
 
        }
 
    }
 

	
 
    /// Transfers the heap values and the stack values into the store. Stack
 
    /// values are pushed onto the Store's stack in the order in which they
 
    /// appear in the value group.
 
    pub(crate) fn into_store(self, store: &mut Store) {
 
        for value in &self.values {
 
            let transferred = self.provide_value(value, store);
 
            store.stack.push(transferred);
 
        }
 
    }
 

	
 
    /// Transfers the heap values into the store, but will put the stack values
 
    /// into the provided `VecDeque`. This is mainly used to merge `ValueGroup`
 
    /// instances retrieved by the code by `get` calls into the expression
 
    /// stack.
 
    pub(crate) fn into_stack(self, stack: &mut VecDeque<Value>, store: &mut Store) {
 
        for value in &self.values {
 
            let transferred = self.provide_value(value, store);
 
            stack.push_back(transferred);
 
        }
 
    }
 

	
 
    fn provide_value(&self, value: &Value, to_store: &mut Store) -> Value {
 
        if let Some(from_heap_pos) = value.get_heap_pos() {
 
            let from_heap_pos = from_heap_pos as usize;
 
            let to_heap_pos = to_store.alloc_heap();
 
            let to_heap_pos_usize = to_heap_pos as usize;
 
            to_store.heap_regions[to_heap_pos_usize].values.reserve(self.regions[from_heap_pos].len());
 

	
 
            for value in &self.regions[from_heap_pos as usize] {
 
                let transferred = self.provide_value(value, to_store);
 
                to_store.heap_regions[to_heap_pos_usize].values.push(transferred);
 
            }
 

	
 
            return match value {
 
                Value::Message(_)    => Value::Message(to_heap_pos),
 
                Value::String(_)     => Value::String(to_heap_pos),
 
                Value::Array(_)      => Value::Array(to_heap_pos),
 
                Value::Tuple(_)      => Value::Tuple(to_heap_pos),
 
                Value::Union(tag, _) => Value::Union(*tag, to_heap_pos),
 
                Value::Struct(_)     => Value::Struct(to_heap_pos),
 
                _ => unreachable!(),
 
            };
 
        } else {
 
            return value.clone();
 
        }
 
    }
 
}
 

	
 
impl Default for ValueGroup {
 
    /// Returns an empty ValueGroup
 
    fn default() -> Self {
 
        Self { values: Vec::new(), regions: Vec::new() }
 
    }
 
}
 

	
 
enum ValueKind { Message, String, Array }
 

	
 
pub(crate) fn apply_assignment_operator(store: &mut Store, lhs: ValueId, op: AssignmentOperator, rhs: Value) {
 
    use AssignmentOperator as AO;
 

	
 
    macro_rules! apply_int_op {
 
        ($lhs:ident, $assignment_tokens:tt, $operator:ident, $rhs:ident) => {
 
            match $lhs {
 
                Value::UInt8(v)  => { *v $assignment_tokens $rhs.as_uint8();  },
 
                Value::UInt16(v) => { *v $assignment_tokens $rhs.as_uint16(); },
 
                Value::UInt32(v) => { *v $assignment_tokens $rhs.as_uint32(); },
 
                Value::UInt64(v) => { *v $assignment_tokens $rhs.as_uint64(); },
 
                Value::SInt8(v)  => { *v $assignment_tokens $rhs.as_sint8();  },
 
                Value::SInt16(v) => { *v $assignment_tokens $rhs.as_sint16(); },
 
                Value::SInt32(v) => { *v $assignment_tokens $rhs.as_sint32(); },
 
                Value::SInt64(v) => { *v $assignment_tokens $rhs.as_sint64(); },
 
                _ => unreachable!("apply_assignment_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs),
 
            }
 
        }
 
    }
 

	
 
    let lhs = store.read_mut_ref(lhs);
 

	
 
    let mut to_dealloc = None;
 
    match op {
 
        AO::Set => {
 
            match lhs {
 
                Value::Unassigned => { *lhs = rhs; },
 
                Value::Input(v)  => { *v = rhs.as_input(); },
 
                Value::Output(v) => { *v = rhs.as_output(); },
 
                Value::Message(v)  => { to_dealloc = Some(*v); *v = rhs.as_message(); },
 
                Value::Bool(v)    => { *v = rhs.as_bool(); },
 
                Value::Char(v) => { *v = rhs.as_char(); },
 
                Value::String(v) => { *v = rhs.as_string().clone(); },
 
                Value::UInt8(v) => { *v = rhs.as_uint8(); },
 
                Value::UInt16(v) => { *v = rhs.as_uint16(); },
 
                Value::UInt32(v) => { *v = rhs.as_uint32(); },
 
                Value::UInt64(v) => { *v = rhs.as_uint64(); },
 
                Value::SInt8(v) => { *v = rhs.as_sint8(); },
 
                Value::SInt16(v) => { *v = rhs.as_sint16(); },
 
                Value::SInt32(v) => { *v = rhs.as_sint32(); },
 
                Value::SInt64(v) => { *v = rhs.as_sint64(); },
 
                Value::Array(v) => { to_dealloc = Some(*v); *v = rhs.as_array(); },
 
                Value::Tuple(v) => { to_dealloc = Some(*v); *v = rhs.as_tuple(); },
 
                Value::Enum(v) => { *v = rhs.as_enum(); },
 
                Value::Union(lhs_tag, lhs_heap_pos) => {
 
                    to_dealloc = Some(*lhs_heap_pos);
 
                    let (rhs_tag, rhs_heap_pos) = rhs.as_union();
 
                    *lhs_tag = rhs_tag;
 
                    *lhs_heap_pos = rhs_heap_pos;
 
                }
 
                Value::Struct(v) => { to_dealloc = Some(*v); *v = rhs.as_struct(); },
 
                _ => unreachable!("apply_assignment_operator {:?} on lhs {:?} and rhs {:?}", op, lhs, rhs),
 
            }
 
        },
 
        AO::Concatenated => {
 
            let lhs_heap_pos = lhs.get_heap_pos().unwrap() as usize;
 
            let rhs_heap_pos = rhs.get_heap_pos().unwrap() as usize;
 

	
 
            // To prevent borrowing crap, swap out heap region with a temp empty array
 
            let mut total = Vec::new();
 
            std::mem::swap(&mut total, &mut store.heap_regions[lhs_heap_pos].values);
 

	
 
            // Push everything onto the swapped vector
 
            let rhs_len = store.heap_regions[rhs_heap_pos].values.len();
 
            total.reserve(rhs_len);
 
            for value_idx in 0..rhs_len {
 
                total.push(store.clone_value(store.heap_regions[rhs_heap_pos].values[value_idx].clone()));
 
            }
 

	
 
            // Swap back in place
 
            std::mem::swap(&mut total, &mut store.heap_regions[lhs_heap_pos].values);
 

	
 
            // We took ownership of the RHS, but we copied it into the LHS, so
 
            // different form assignment we need to drop the RHS heap pos.
 
            to_dealloc = Some(rhs_heap_pos as u32);
 
        },
 
        AO::Multiplied =>   { apply_int_op!(lhs, *=,  op, rhs) },
 
        AO::Divided =>      { apply_int_op!(lhs, /=,  op, rhs) },
 
        AO::Remained =>     { apply_int_op!(lhs, %=,  op, rhs) },
 
        AO::Added =>        { apply_int_op!(lhs, +=,  op, rhs) },
 
        AO::Subtracted =>   { apply_int_op!(lhs, -=,  op, rhs) },
 
        AO::ShiftedLeft =>  { apply_int_op!(lhs, <<=, op, rhs) },
 
        AO::ShiftedRight => { apply_int_op!(lhs, >>=, op, rhs) },
 
        AO::BitwiseAnded => { apply_int_op!(lhs, &=,  op, rhs) },
 
        AO::BitwiseXored => { apply_int_op!(lhs, ^=,  op, rhs) },
 
        AO::BitwiseOred =>  { apply_int_op!(lhs, |=,  op, rhs) },
 
    }
 

	
 
    if let Some(heap_pos) = to_dealloc {
 
        store.drop_heap_pos(heap_pos);
 
    }
 
}
 

	
 
pub(crate) fn apply_binary_operator(store: &mut Store, lhs: &Value, op: BinaryOperator, rhs: &Value) -> Value {
 
    use BinaryOperator as BO;
 

	
 
    macro_rules! apply_int_op_and_return_self {
 
        ($lhs:ident, $operator_tokens:tt, $operator:ident, $rhs:ident) => {
 
            return match $lhs {
 
                Value::UInt8(v)  => { Value::UInt8( *v $operator_tokens $rhs.as_uint8() ) },
 
                Value::UInt16(v) => { Value::UInt16(*v $operator_tokens $rhs.as_uint16()) },
 
                Value::UInt32(v) => { Value::UInt32(*v $operator_tokens $rhs.as_uint32()) },
 
                Value::UInt64(v) => { Value::UInt64(*v $operator_tokens $rhs.as_uint64()) },
 
                Value::SInt8(v)  => { Value::SInt8( *v $operator_tokens $rhs.as_sint8() ) },
 
                Value::SInt16(v) => { Value::SInt16(*v $operator_tokens $rhs.as_sint16()) },
 
                Value::SInt32(v) => { Value::SInt32(*v $operator_tokens $rhs.as_sint32()) },
 
                Value::SInt64(v) => { Value::SInt64(*v $operator_tokens $rhs.as_sint64()) },
 
                _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs)
 
            };
 
        }
 
    }
 

	
 
    macro_rules! apply_int_op_and_return_bool {
 
        ($lhs:ident, $operator_tokens:tt, $operator:ident, $rhs:ident) => {
 
            return match $lhs {
 
                Value::UInt8(v)  => { Value::Bool(*v $operator_tokens $rhs.as_uint8() ) },
 
                Value::UInt16(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint16()) },
 
                Value::UInt32(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint32()) },
 
                Value::UInt64(v) => { Value::Bool(*v $operator_tokens $rhs.as_uint64()) },
 
                Value::SInt8(v)  => { Value::Bool(*v $operator_tokens $rhs.as_sint8() ) },
 
                Value::SInt16(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint16()) },
 
                Value::SInt32(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint32()) },
 
                Value::SInt64(v) => { Value::Bool(*v $operator_tokens $rhs.as_sint64()) },
 
                _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", $operator, $lhs, $rhs)
 
            };
 
        }
 
    }
 

	
 
    // We need to handle concatenate in a special way because it needs the store
 
    // mutably.
 
    if op == BO::Concatenate {
 
        let target_heap_pos = store.alloc_heap();
 
        let lhs_heap_pos;
 
        let rhs_heap_pos;
 

	
 
        let lhs = store.maybe_read_ref(lhs);
 
        let rhs = store.maybe_read_ref(rhs);
 

	
 
        let value_kind;
 

	
 
        match lhs {
 
            Value::Message(lhs_pos) => {
 
                lhs_heap_pos = *lhs_pos;
 
                rhs_heap_pos = rhs.as_message();
 
                value_kind = ValueKind::Message;
 
            },
 
            Value::String(lhs_pos) => {
 
                lhs_heap_pos = *lhs_pos;
 
                rhs_heap_pos = rhs.as_string();
 
                value_kind = ValueKind::String;
 
            },
 
            Value::Array(lhs_pos) => {
 
                lhs_heap_pos = *lhs_pos;
 
                rhs_heap_pos = rhs.as_array();
 
                value_kind = ValueKind::Array;
 
            },
 
            _ => unreachable!("apply_binary_operator {:?} on lhs {:?} and rhs {:?}", op, lhs, rhs)
 
        }
 

	
 
        let lhs_heap_pos = lhs_heap_pos as usize;
 
        let rhs_heap_pos = rhs_heap_pos as usize;
 

	
 
        let mut concatenated = Vec::new();
 
        let lhs_len = store.heap_regions[lhs_heap_pos].values.len();
 
        let rhs_len = store.heap_regions[rhs_heap_pos].values.len();
 
        concatenated.reserve(lhs_len + rhs_len);
 
        for idx in 0..lhs_len {
 
            concatenated.push(store.clone_value(store.heap_regions[lhs_heap_pos].values[idx].clone()));
 
        }
 
        for idx in 0..rhs_len {
 
            concatenated.push(store.clone_value(store.heap_regions[rhs_heap_pos].values[idx].clone()));
 
        }
 

	
 
        store.heap_regions[target_heap_pos as usize].values = concatenated;
 

	
 
        return match value_kind{
 
            ValueKind::Message => Value::Message(target_heap_pos),
 
            ValueKind::String => Value::String(target_heap_pos),
 
            ValueKind::Array => Value::Array(target_heap_pos),
 
        };
 
    }
 

	
 
    // If any of the values are references, retrieve the thing they're referring
 
    // to.
 
    let lhs = store.maybe_read_ref(lhs);
 
    let rhs = store.maybe_read_ref(rhs);
 

	
 
    match op {
 
        BO::Concatenate => unreachable!(),
 
        BO::LogicalOr => {
 
            return Value::Bool(lhs.as_bool() || rhs.as_bool());
 
        },
 
        BO::LogicalAnd => {
 
            return Value::Bool(lhs.as_bool() && rhs.as_bool());
 
        },
 
        BO::BitwiseOr        => { apply_int_op_and_return_self!(lhs, |,  op, rhs); },
 
        BO::BitwiseXor       => { apply_int_op_and_return_self!(lhs, ^,  op, rhs); },
 
        BO::BitwiseAnd       => { apply_int_op_and_return_self!(lhs, &,  op, rhs); },
 
        BO::Equality         => { Value::Bool(apply_equality_operator(store, lhs, rhs)) },
 
        BO::Inequality       => { Value::Bool(apply_inequality_operator(store, lhs, rhs)) },
src/protocol/mod.rs
Show inline comments
 
mod arena;
 
pub(crate) mod eval;
 
pub(crate) mod input_source;
 
mod parser;
 
#[cfg(test)] mod tests;
 

	
 
pub(crate) mod ast;
 
pub(crate) mod ast_printer;
 

	
 
use std::sync::Mutex;
 

	
 
use crate::collections::{StringPool, StringRef};
 
use crate::protocol::ast::*;
 
use crate::protocol::eval::*;
 
use crate::protocol::input_source::*;
 
use crate::protocol::parser::*;
 
use crate::protocol::type_table::*;
 

	
 
pub use parser::type_table::TypeId;
 

	
 
/// A protocol description module
 
pub struct Module {
 
    pub(crate) source: InputSource,
 
    pub(crate) root_id: RootId,
 
    pub(crate) name: Option<StringRef<'static>>,
 
}
 
/// Description of a protocol object, used to configure new connectors.
 
#[repr(C)]
 
pub struct ProtocolDescription {
 
    pub(crate) modules: Vec<Module>,
 
    pub(crate) heap: Heap,
 
    pub(crate) types: TypeTable,
 
    pub(crate) pool: Mutex<StringPool>,
 
}
 
#[derive(Debug, Clone)]
 
pub(crate) struct ComponentState {
 
    pub(crate) prompt: Prompt,
 
}
 

	
 
#[derive(Debug)]
 
pub enum ComponentCreationError {
 
    ModuleDoesntExist,
 
    DefinitionDoesntExist,
 
    DefinitionNotComponent,
 
    InvalidNumArguments,
 
    InvalidArgumentType(usize),
 
    UnownedPort,
 
    InSync,
 
}
 

	
 
impl ProtocolDescription {
 
    pub fn parse(buffer: &[u8]) -> Result<Self, String> {
 
        let source = InputSource::new(String::new(), Vec::from(buffer));
 
        let mut parser = Parser::new();
 
        parser.feed(source).expect("failed to feed source");
 
        
 
        if let Err(err) = parser.parse() {
 
            println!("ERROR:\n{}", err);
 
            return Err(format!("{}", err))
 
        }
 

	
 
        debug_assert_eq!(parser.modules.len(), 1, "only supporting one module here for now");
 
        let modules: Vec<Module> = parser.modules.into_iter()
 
            .map(|module| Module{
 
                source: module.source,
 
                root_id: module.root_id,
 
                name: module.name.map(|(_, name)| name)
 
            })
 
            .collect();
 

	
 
        return Ok(ProtocolDescription {
 
            modules,
 
            heap: parser.heap,
 
            types: parser.type_table,
 
            pool: Mutex::new(parser.string_pool),
 
        });
 
    }
 

	
 
    pub(crate) fn new_component(
 
        &self, module_name: &[u8], identifier: &[u8], arguments: ValueGroup
 
    ) -> Result<Prompt, ComponentCreationError> {
 
        // Find the module in which the definition can be found
 
        let module_root = self.lookup_module_root(module_name);
 
        if module_root.is_none() {
 
            return Err(ComponentCreationError::ModuleDoesntExist);
 
        }
 
        let module_root = module_root.unwrap();
 

	
 
        let root = &self.heap[module_root];
 
        let definition_id = root.get_definition_ident(&self.heap, identifier);
 
        if definition_id.is_none() {
 
            return Err(ComponentCreationError::DefinitionDoesntExist);
 
        }
 
        let definition_id = definition_id.unwrap();
 

	
 
        let ast_definition = &self.heap[definition_id];
 
        if !ast_definition.is_procedure() {
 
            return Err(ComponentCreationError::DefinitionNotComponent);
 
        }
 

	
 
        // Make sure that the types of the provided value group matches that of
 
        // the expected types.
 
        let ast_definition = ast_definition.as_procedure();
 
        if !ast_definition.poly_vars.is_empty() || ast_definition.kind == ProcedureKind::Function {
 
            return Err(ComponentCreationError::DefinitionNotComponent);
 
        }
 

	
 
        // - check number of arguments by retrieving the one instantiated
 
        //   monomorph
 
        let concrete_type = ConcreteType{ parts: vec![ConcreteTypePart::Component(ast_definition.this, 0)] };
 
        let procedure_type_id = self.types.get_procedure_monomorph_type_id(&definition_id, &concrete_type.parts).unwrap();
 
        let procedure_monomorph_index = self.types.get_monomorph(procedure_type_id).variant.as_procedure().monomorph_index;
 
        let monomorph_info = &ast_definition.monomorphs[procedure_monomorph_index as usize];
 
        if monomorph_info.argument_types.len() != arguments.values.len() {
 
            return Err(ComponentCreationError::InvalidNumArguments);
 
        }
 

	
 
        // - for each argument try to make sure the types match
 
        for arg_idx in 0..arguments.values.len() {
 
            let expected_type_id = monomorph_info.argument_types[arg_idx];
 
            let expected_type = &self.types.get_monomorph(expected_type_id).concrete_type;
 
            let provided_value = &arguments.values[arg_idx];
 
            if !self.verify_same_type(expected_type, 0, &arguments, provided_value) {
 
                return Err(ComponentCreationError::InvalidArgumentType(arg_idx));
 
            }
 
        }
 

	
 
        // By now we're sure that all of the arguments are correct. So create
 
        // the connector.
 
        return Ok(Prompt::new(&self.types, &self.heap, ast_definition.this, procedure_type_id, arguments));
 
    }
 

	
 
    fn lookup_module_root(&self, module_name: &[u8]) -> Option<RootId> {
 
        for module in self.modules.iter() {
 
            match &module.name {
 
                Some(name) => if name.as_bytes() == module_name {
 
                    return Some(module.root_id);
 
                },
 
                None => if module_name.is_empty() {
 
                    return Some(module.root_id);
 
                }
 
            }
 
        }
 

	
 
        return None;
 
    }
 

	
 
    fn verify_same_type(&self, expected: &ConcreteType, expected_idx: usize, arguments: &ValueGroup, argument: &Value) -> bool {
 
        use ConcreteTypePart as CTP;
 

	
 
        match &expected.parts[expected_idx] {
 
            CTP::Void | CTP::Message | CTP::Slice | CTP::Pointer | CTP::Function(_, _) | CTP::Component(_, _) => unreachable!(),
 
            CTP::Bool => if let Value::Bool(_) = argument { true } else { false },
 
            CTP::UInt8 => if let Value::UInt8(_) = argument { true } else { false },
 
            CTP::UInt16 => if let Value::UInt16(_) = argument { true } else { false },
 
            CTP::UInt32 => if let Value::UInt32(_) = argument { true } else { false },
 
            CTP::UInt64 => if let Value::UInt64(_) = argument { true } else { false },
 
            CTP::SInt8 => if let Value::SInt8(_) = argument { true } else { false },
 
            CTP::SInt16 => if let Value::SInt16(_) = argument { true } else { false },
 
            CTP::SInt32 => if let Value::SInt32(_) = argument { true } else { false },
 
            CTP::SInt64 => if let Value::SInt64(_) = argument { true } else { false },
 
            CTP::Character => if let Value::Char(_) = argument { true } else { false },
 
            CTP::String => {
 
                // Match outer string type and embedded character types
 
                if let Value::String(heap_pos) = argument {
 
                    for element in &arguments.regions[*heap_pos as usize] {
 
                        if let Value::Char(_) = element {} else {
 
                            return false;
 
                        }
 
                    }
 
                } else {
 
                    return false;
 
                }
 

	
 
                return true;
 
            },
 
            CTP::Array => {
 
                if let Value::Array(heap_pos) = argument {
 
                    let heap_pos = *heap_pos;
 
                    for element in &arguments.regions[heap_pos as usize] {
 
                        if !self.verify_same_type(expected, expected_idx + 1, arguments, element) {
 
                            return false;
 
                        }
 
                    }
 
                    return true;
 
                } else {
 
                    return false;
 
                }
 
            },
 
            CTP::Input => if let Value::Input(_) = argument { true } else { false },
 
            CTP::Output => if let Value::Output(_) = argument { true } else { false },
 
            CTP::Tuple(_) => todo!("implement full type checking on user-supplied arguments"),
 
            CTP::Instance(definition_id, _num_embedded) => {
 
                let definition = self.types.get_base_definition(definition_id).unwrap();
 
                match &definition.definition {
 
                    DefinedTypeVariant::Enum(definition) => {
 
                        if let Value::Enum(variant_value) = argument {
 
                            let is_valid = definition.variants.iter()
 
                                .any(|v| v.value == *variant_value);
 
                            return is_valid;
 
                        }
 
                    },
 
                    _ => todo!("implement full type checking on user-supplied arguments"),
 
                }
 

	
 
                return false;
 
            },
 
        }
 
    }
 
}
 

	
 
pub trait RunContext {
 
    fn performed_put(&mut self, port: PortId) -> bool;
 
    fn performed_get(&mut self, port: PortId) -> Option<ValueGroup>; // None if still waiting on message
 
    fn fires(&mut self, port: PortId) -> Option<Value>; // None if not yet branched
 
    fn performed_fork(&mut self) -> Option<bool>; // None if not yet forked
 
    fn created_channel(&mut self) -> Option<(Value, Value)>; // None if not yet prepared
 
    fn performed_select_start(&mut self) -> bool; // true if performed
 
    fn performed_select_register_port(&mut self) -> bool; // true if registered
 
    fn performed_select_wait(&mut self) -> Option<u32>; // None if not yet notified runtime of select blocker
 
}
 

	
 
pub struct ProtocolDescriptionBuilder {
 
    parser: Parser,
 
}
 

	
 
impl ProtocolDescriptionBuilder {
 
    pub fn new() -> Self {
 
        return Self{
 
            parser: Parser::new(),
 
        }
 
    }
 

	
 
    pub fn add(&mut self, filename: String, buffer: Vec<u8>) -> Result<(), ParseError> {
 
        let input = InputSource::new(filename, buffer);
 
        self.parser.feed(input)?;
 

	
 
        return Ok(())
 
    }
 

	
 
    pub fn compile(mut self) -> Result<ProtocolDescription, ParseError> {
 
        self.parser.parse()?;
 

	
 
        let modules: Vec<Module> = self.parser.modules.into_iter()
 
            .map(|module| Module{
 
                source: module.source,
 
                root_id: module.root_id,
 
                name: module.name.map(|(_, name)| name)
 
            })
 
            .collect();
 

	
 
        return Ok(ProtocolDescription {
 
            modules,
 
            heap: self.parser.heap,
 
            types: self.parser.type_table,
 
            pool: Mutex::new(self.parser.string_pool),
 
        });
 
    }
 
}
src/protocol/parser/pass_rewriting.rs
Show inline comments
 
use crate::collections::*;
 
use crate::protocol::*;
 

	
 
use super::visitor::*;
 

	
 
pub(crate) struct PassRewriting {
 
    current_scope: ScopeId,
 
    current_procedure_id: ProcedureDefinitionId,
 
    definition_buffer: ScopedBuffer<DefinitionId>,
 
    statement_buffer: ScopedBuffer<StatementId>,
 
    call_expr_buffer: ScopedBuffer<CallExpressionId>,
 
    expression_buffer: ScopedBuffer<ExpressionId>,
 
    scope_buffer: ScopedBuffer<ScopeId>,
 
}
 

	
 
impl PassRewriting {
 
    pub(crate) fn new() -> Self {
 
        Self{
 
            current_scope: ScopeId::new_invalid(),
 
            current_procedure_id: ProcedureDefinitionId::new_invalid(),
 
            definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            call_expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
        }
 
    }
 
}
 

	
 
impl Visitor for PassRewriting {
 
    fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
 
        let module = ctx.module();
 
        debug_assert_eq!(module.phase, ModuleCompilationPhase::Typed);
 

	
 
        let root_id = module.root_id;
 
        let root = &ctx.heap[root_id];
 
        let definition_section = self.definition_buffer.start_section_initialized(&root.definitions);
 
        for definition_index in 0..definition_section.len() {
 
            let definition_id = definition_section[definition_index];
 
            self.visit_definition(ctx, definition_id)?;
 
        }
 

	
 
        definition_section.forget();
 
        ctx.module_mut().phase = ModuleCompilationPhase::Rewritten;
 
        return Ok(())
 
    }
 

	
 
    // --- Visiting procedures
 

	
 
    fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
 
        let definition = &ctx.heap[id];
 
        let body_id = definition.body;
 
        self.current_scope = definition.scope;
 
        self.current_procedure_id = id;
 
        return self.visit_block_stmt(ctx, body_id);
 
    }
 

	
 
    // --- Visiting statements (that are not the select statement)
 

	
 
    fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
 
        let block_stmt = &ctx.heap[id];
 
        let stmt_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
 

	
 
        self.current_scope = block_stmt.scope;
 
        for stmt_idx in 0..stmt_section.len() {
 
            self.visit_stmt(ctx, stmt_section[stmt_idx])?;
 
        }
 

	
 
        stmt_section.forget();
 
        return Ok(())
 
    }
 

	
 
    fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
 
        let labeled_stmt = &ctx.heap[id];
 
        let body_id = labeled_stmt.body;
 
        return self.visit_stmt(ctx, body_id);
 
    }
 

	
 
    fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
 
        let if_stmt = &ctx.heap[id];
 
        let true_case = if_stmt.true_case;
 
        let false_case = if_stmt.false_case;
 

	
 
        self.current_scope = true_case.scope;
 
        self.visit_stmt(ctx, true_case.body)?;
 
        if let Some(false_case) = false_case {
 
            self.current_scope = false_case.scope;
 
            self.visit_stmt(ctx, false_case.body)?;
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
 
        let while_stmt = &ctx.heap[id];
 
        let body_id = while_stmt.body;
 
        self.current_scope = while_stmt.scope;
 
        return self.visit_stmt(ctx, body_id);
 
    }
 

	
 
    fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
 
        let sync_stmt = &ctx.heap[id];
 
        let body_id = sync_stmt.body;
 
        self.current_scope = sync_stmt.scope;
 
        return self.visit_stmt(ctx, body_id);
 
    }
 

	
 
    // --- Visiting the select statement
 

	
 
    fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
 
        // Utility for the last stage of rewriting process. Note that caller
 
        // still needs to point the end of the if-statement to the end of the
 
        // replacement statement of the select statement.
 
        fn transform_select_case_code(
 
            ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
 
            select_id: SelectStatementId, case_index: usize,
 
            select_var_id: VariableId, select_var_type_id: TypeIdReference
 
        ) -> (IfStatementId, EndIfStatementId) {
 
            // Retrieve statement IDs associated with case
 
            let case = &ctx.heap[select_id].cases[case_index];
 
            let case_guard_id = case.guard;
 
            let case_body_id = case.body;
 
            let case_scope_id = case.scope;
 

	
 
            // Create the if-statement for the result of the select statement
 
            let compare_expr_id = create_ast_equality_comparison_expr(ctx, containing_procedure_id, select_var_id, select_var_type_id, case_index as u64);
 
            let true_case = IfStatementCase{
 
                body: case_guard_id, // which is linked up to the body
 
                scope: case_scope_id,
 
            };
 
            let (if_stmt_id, end_if_stmt_id) = create_ast_if_stmt(ctx, compare_expr_id.upcast(), true_case, None);
 

	
 
            // Link up body statement to end-if
 
            set_ast_statement_next(ctx, case_body_id, end_if_stmt_id.upcast());
 

	
 
            return (if_stmt_id, end_if_stmt_id)
 
        }
 

	
 
        // Precreate the block that will end up containing all of the
 
        // transformed statements. Also precreate the scope associated with it
 
        let (outer_block_id, outer_end_block_id, outer_scope_id) =
 
            create_ast_block_stmt(ctx, Vec::new());
 

	
 
        // The "select" and the "end select" statement will act like trampolines
 
        // that jump to the replacement block. So set the child/parent
 
        // relationship already.
 
        // --- for the statements
 
        let select_stmt = &mut ctx.heap[id];
 
        select_stmt.next = outer_block_id.upcast();
 
        let end_select_stmt_id = select_stmt.end_select;
 
        let select_stmt_relative_pos = select_stmt.relative_pos_in_parent;
 

	
 
        let outer_end_block_stmt = &mut ctx.heap[outer_end_block_id];
 
        outer_end_block_stmt.next = end_select_stmt_id.upcast();
 

	
 
        // --- for the scopes
 
        link_new_child_to_existing_parent_scope(ctx, &mut self.scope_buffer, self.current_scope, outer_scope_id, select_stmt_relative_pos);
 

	
 
        // Create statements that will create temporary variables for all of the
 
        // ports passed to the "get" calls in the select case guards.
 
        let select_stmt = &ctx.heap[id];
 
        let total_num_cases = select_stmt.cases.len();
 
        let mut total_num_ports = 0;
 
        let end_select_stmt_id = select_stmt.end_select;
 
        let _end_select = &ctx.heap[end_select_stmt_id];
 

	
 
        // Put heap IDs into temporary buffers to handle borrowing rules
 
        let mut call_id_section = self.call_expr_buffer.start_section();
 
        let mut expr_id_section = self.expression_buffer.start_section();
 

	
 
        for case in select_stmt.cases.iter() {
 
            total_num_ports += case.involved_ports.len();
 
            for (call_id, expr_id) in case.involved_ports.iter().copied() {
 
                call_id_section.push(call_id);
 
                expr_id_section.push(expr_id);
 
            }
 
        }
 

	
 
        // Transform all of the call expressions by takings its argument (the
 
        // port from which we `get`) and turning it into a temporary variable.
 
        let mut transformed_stmts = Vec::with_capacity(total_num_ports); // TODO: Recompute this preallocated length, put assert at the end
 
        let mut locals = Vec::with_capacity(total_num_ports);
 

	
 
        for port_var_idx in 0..call_id_section.len() {
 
            let get_call_expr_id = call_id_section[port_var_idx];
 
            let port_expr_id = expr_id_section[port_var_idx];
 
            let port_type_index = ctx.heap[port_expr_id].type_index();
 
            let port_type_ref = TypeIdReference::IndirectSameAsExpr(port_type_index);
 

	
 
            // Move the port expression such that it gets assigned to a temporary variable
 
            let variable_id = create_ast_variable(ctx, outer_scope_id);
 
            let variable_decl_stmt_id = create_ast_variable_declaration_stmt(ctx, self.current_procedure_id, variable_id, port_type_ref, port_expr_id);
 

	
 
            // Replace the original port expression in the call with a reference
 
            // to the replacement variable
 
            let variable_expr_id = create_ast_variable_expr(ctx, self.current_procedure_id, variable_id, port_type_ref);
 
            let call_expr = &mut ctx.heap[get_call_expr_id];
 
            call_expr.arguments[0] = variable_expr_id.upcast();
 

	
 
            transformed_stmts.push(variable_decl_stmt_id.upcast().upcast());
 
            locals.push((variable_id, port_type_ref));
 
        }
 

	
 
        // Insert runtime calls that facilitate the semantics of the select
 
        // block.
 

	
 
        // Create the call that indicates the start of the select block
 
        {
 
            let num_cases_expression_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, total_num_cases as u64);
 
            let num_ports_expression_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, total_num_ports as u64);
 
            let arguments = vec![
 
                num_cases_expression_id.upcast(),
 
                num_ports_expression_id.upcast()
 
            ];
 

	
 
            let call_expression_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectStart, &mut self.expression_buffer, arguments);
 
            let call_statement_id = create_ast_expression_stmt(ctx, call_expression_id.upcast());
 

	
 
            transformed_stmts.push(call_statement_id.upcast());
 
        }
 

	
 
        // Create calls for each select case that will register the ports that
 
        // we are waiting on at the runtime.
 
        {
 
            let mut total_port_index = 0;
 
            for case_index in 0..total_num_cases {
 
                let case = &ctx.heap[id].cases[case_index];
 
                let case_num_ports = case.involved_ports.len();
 

	
 
                for case_port_index in 0..case_num_ports {
 
                    // Arguments to runtime call
 
                    let (port_variable_id, port_variable_type) = locals[total_port_index]; // so far this variable contains the temporary variables for the port expressions
 
                    let case_index_expr_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, case_index as u64);
 
                    let port_index_expr_id = create_ast_literal_integer_expr(ctx, self.current_procedure_id, case_port_index as u64);
 
                    let port_variable_expr_id = create_ast_variable_expr(ctx, self.current_procedure_id, port_variable_id, port_variable_type);
 
                    let runtime_call_arguments = vec![
 
                        case_index_expr_id.upcast(),
 
                        port_index_expr_id.upcast(),
 
                        port_variable_expr_id.upcast()
 
                    ];
 

	
 
                    // Create runtime call, then store it
 
                    let runtime_call_expr_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectRegisterCasePort, &mut self.expression_buffer, runtime_call_arguments);
 
                    let runtime_call_stmt_id = create_ast_expression_stmt(ctx, runtime_call_expr_id.upcast());
 

	
 
                    transformed_stmts.push(runtime_call_stmt_id.upcast());
 

	
 
                    total_port_index += 1;
 
                }
 
            }
 
        }
 

	
 
        // Create the variable that will hold the result of a completed select
 
        // block. Then create the runtime call that will produce this result
 
        let select_variable_id = create_ast_variable(ctx, outer_scope_id);
 
        let select_variable_type = TypeIdReference::DirectTypeId(ctx.arch.uint32_type_id);
 
        locals.push((select_variable_id, select_variable_type));
 

	
 
        {
 
            let runtime_call_expr_id = create_ast_call_expr(ctx, self.current_procedure_id, Method::SelectWait, &mut self.expression_buffer, Vec::new());
 
            let variable_stmt_id = create_ast_variable_declaration_stmt(ctx, self.current_procedure_id, select_variable_id, select_variable_type, runtime_call_expr_id.upcast());
 
            transformed_stmts.push(variable_stmt_id.upcast().upcast());
 
        }
 

	
 
        call_id_section.forget();
 
        expr_id_section.forget();
 

	
 
        // Now we transform each of the select block case's guard and code into
 
        // a chained if-else statement.
 
        if total_num_cases > 0 {
 
            let (if_stmt_id, end_if_stmt_id) = transform_select_case_code(ctx, self.current_procedure_id, id, 0, select_variable_id, select_variable_type);
 
            let first_end_if_stmt = &mut ctx.heap[end_if_stmt_id];
 
            first_end_if_stmt.next = outer_end_block_id.upcast();
 

	
 
            let mut last_if_stmt_id = if_stmt_id;
 
            let mut last_end_if_stmt_id = end_if_stmt_id;
 
            transformed_stmts.push(last_if_stmt_id.upcast());
 

	
 
            for case_index in 1..total_num_cases {
 
                let (if_stmt_id, end_if_stmt_id) = transform_select_case_code(ctx, self.current_procedure_id, id, case_index, select_variable_id, select_variable_type);
 
                let false_case_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(last_if_stmt_id, false)));
 
                set_ast_if_statement_false_body(ctx, last_if_stmt_id, last_end_if_stmt_id, IfStatementCase{ body: if_stmt_id.upcast(), scope: false_case_scope_id });
 

	
 
                let end_if_stmt = &mut ctx.heap[end_if_stmt_id];
 
                end_if_stmt.next = last_end_if_stmt_id.upcast();
 

	
 
                last_if_stmt_id = if_stmt_id;
 
                last_end_if_stmt_id = end_if_stmt_id;
 
            }
 
        }
 

	
 
        // Final steps: set the statements of the replacement block statement,
 
        // and link all of those statements together
 
        let first_stmt_id = transformed_stmts[0];
 
        let mut last_stmt_id = transformed_stmts[0];
 
        for stmt_id in transformed_stmts.iter().skip(1).copied() {
 
            set_ast_statement_next(ctx, last_stmt_id, stmt_id);
 
            last_stmt_id = stmt_id;
 
        }
 

	
 
        let outer_block_stmt = &mut ctx.heap[outer_block_id];
 
        outer_block_stmt.next = first_stmt_id;
 
        outer_block_stmt.statements = transformed_stmts;
 

	
 
        return Ok(())
 
    }
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// Utilities to create compiler-generated AST nodes
 
// -----------------------------------------------------------------------------
 

	
 
#[derive(Clone, Copy)]
 
enum TypeIdReference {
 
    DirectTypeId(TypeId),
 
    IndirectSameAsExpr(i32), // by type index
 
}
 

	
 
fn create_ast_variable(ctx: &mut Ctx, scope_id: ScopeId) -> VariableId {
 
    let variable_id = ctx.heap.alloc_variable(|this| Variable{
 
        this,
 
        kind: VariableKind::Local,
 
        parser_type: ParserType{
 
            elements: Vec::new(),
 
            full_span: InputSpan::new(),
 
        },
 
        identifier: Identifier::new_empty(InputSpan::new()),
 
        relative_pos_in_parent: -1,
 
        unique_id_in_scope: -1,
 
    });
 
    let scope = &mut ctx.heap[scope_id];
 
    scope.variables.push(variable_id);
 

	
 
    return variable_id;
 
}
 

	
 
fn create_ast_variable_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, variable_id: VariableId, variable_type_id: TypeIdReference) -> VariableExpressionId {
 
    let variable_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, variable_type_id);
 
    return ctx.heap.alloc_variable_expression(|this| VariableExpression{
 
        this,
 
        identifier: Identifier::new_empty(InputSpan::new()),
 
        declaration: Some(variable_id),
 
        used_as_binding_target: false,
 
        parent: ExpressionParent::None,
 
        type_index: variable_type_index,
 
    });
 
}
 

	
 
fn create_ast_call_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, method: Method, buffer: &mut ScopedBuffer<ExpressionId>, arguments: Vec<ExpressionId>) -> CallExpressionId {
 
    let call_type_id = match method {
 
        Method::SelectStart => ctx.arch.void_type_id,
 
        Method::SelectRegisterCasePort => ctx.arch.void_type_id,
 
        Method::SelectWait => ctx.arch.uint32_type_id, // TODO: Not pretty, this. Pretty error prone
 
        _ => unreachable!(), // if this goes of, add the appropriate method here.
 
    };
 

	
 
    let expression_ids = buffer.start_section_initialized(&arguments);
 
    let call_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(call_type_id));
 
    let call_expression_id = ctx.heap.alloc_call_expression(|this| CallExpression{
 
        func_span: InputSpan::new(),
 
        this,
 
        full_span: InputSpan::new(),
 
        parser_type: ParserType{
 
            elements: Vec::new(),
 
            full_span: InputSpan::new(),
 
        },
 
        method,
 
        arguments,
 
        procedure: ProcedureDefinitionId::new_invalid(),
 
        parent: ExpressionParent::None,
 
        type_index: call_type_index,
 
    });
 

	
 
    for argument_index in 0..expression_ids.len() {
 
        let argument_id = expression_ids[argument_index];
 
        let argument_expr = &mut ctx.heap[argument_id];
 
        *argument_expr.parent_mut() = ExpressionParent::Expression(call_expression_id.upcast(), argument_index as u32);
 
    }
 

	
 
    return call_expression_id;
 
}
 

	
 
fn create_ast_literal_integer_expr(ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId, unsigned_value: u64) -> LiteralExpressionId {
 
    let literal_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(ctx.arch.uint64_type_id));
 
    return ctx.heap.alloc_literal_expression(|this| LiteralExpression{
 
        this,
 
        span: InputSpan::new(),
 
        value: Literal::Integer(LiteralInteger{
 
            unsigned_value,
 
            negated: false,
 
        }),
 
        parent: ExpressionParent::None,
 
        type_index: literal_type_index,
 
    });
 
}
 

	
 
fn create_ast_equality_comparison_expr(
 
    ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
 
    variable_id: VariableId, variable_type: TypeIdReference, value: u64
 
) -> BinaryExpressionId {
 
    let var_expr_id = create_ast_variable_expr(ctx, containing_procedure_id, variable_id, variable_type);
 
    let int_expr_id = create_ast_literal_integer_expr(ctx, containing_procedure_id, value);
 
    let cmp_type_index = add_new_procedure_expression_type(ctx, containing_procedure_id, TypeIdReference::DirectTypeId(ctx.arch.bool_type_id));
 
    let cmp_expr_id = ctx.heap.alloc_binary_expression(|this| BinaryExpression{
 
        this,
 
        operator_span: InputSpan::new(),
 
        full_span: InputSpan::new(),
 
        left: var_expr_id.upcast(),
 
        operation: BinaryOperator::Equality,
 
        right: int_expr_id.upcast(),
 
        parent: ExpressionParent::None,
 
        type_index: cmp_type_index,
 
    });
 

	
 
    let var_expr = &mut ctx.heap[var_expr_id];
 
    var_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 0);
 
    let int_expr = &mut ctx.heap[int_expr_id];
 
    int_expr.parent = ExpressionParent::Expression(cmp_expr_id.upcast(), 1);
 

	
 
    return cmp_expr_id;
 
}
 

	
 
fn create_ast_expression_stmt(ctx: &mut Ctx, expression_id: ExpressionId) -> ExpressionStatementId {
 
    let statement_id = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
 
        this,
 
        span: InputSpan::new(),
 
        expression: expression_id,
 
        next: StatementId::new_invalid(),
 
    });
 

	
 
    let expression = &mut ctx.heap[expression_id];
 
    *expression.parent_mut() = ExpressionParent::ExpressionStmt(statement_id);
 

	
 
    return statement_id;
 
}
 

	
 
fn create_ast_variable_declaration_stmt(
 
    ctx: &mut Ctx, containing_procedure_id: ProcedureDefinitionId,
 
    variable_id: VariableId, variable_type: TypeIdReference, initial_value_expr_id: ExpressionId
 
) -> MemoryStatementId {
 
    // Create the assignment expression, assigning the initial value to the variable
 
    let variable_expr_id = create_ast_variable_expr(ctx, containing_procedure_id, variable_id, variable_type);
 
    let assignment_expr_id = ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{
 
        this,
 
        operator_span: InputSpan::new(),
 
        full_span: InputSpan::new(),
 
        left: variable_expr_id.upcast(),
 
        operation: AssignmentOperator::Set,
 
        right: initial_value_expr_id,
 
        parent: ExpressionParent::None,
 
        type_index: -1,
 
    });
 

	
 
    // Create the memory statement
 
    let memory_stmt_id = ctx.heap.alloc_memory_statement(|this| MemoryStatement{
 
        this,
 
        span: InputSpan::new(),
 
        variable: variable_id,
 
        initial_expr: assignment_expr_id,
 
        next: StatementId::new_invalid(),
 
    });
 

	
 
    // Set all parents which we can access
 
    let variable_expr = &mut ctx.heap[variable_expr_id];
 
    variable_expr.parent = ExpressionParent::Expression(assignment_expr_id.upcast(), 0);
 
    let value_expr = &mut ctx.heap[initial_value_expr_id];
 
    *value_expr.parent_mut() = ExpressionParent::Expression(assignment_expr_id.upcast(), 1);
 
    let assignment_expr = &mut ctx.heap[assignment_expr_id];
 
    assignment_expr.parent = ExpressionParent::Memory(memory_stmt_id);
 

	
 
    return memory_stmt_id;
 
}
 

	
 
fn create_ast_block_stmt(ctx: &mut Ctx, statements: Vec<StatementId>) -> (BlockStatementId, EndBlockStatementId, ScopeId) {
 
    let block_stmt_id = ctx.heap.alloc_block_statement(|this| BlockStatement{
 
        this,
 
        span: InputSpan::new(),
 
        statements,
 
        end_block: EndBlockStatementId::new_invalid(),
 
        scope: ScopeId::new_invalid(),
 
        next: StatementId::new_invalid(),
 
    });
 
    let end_block_stmt_id = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
 
        this,
 
        start_block: block_stmt_id,
 
        next: StatementId::new_invalid(),
 
    });
 
    let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Block(block_stmt_id)));
 

	
 
    let block_stmt = &mut ctx.heap[block_stmt_id];
 
    block_stmt.end_block = end_block_stmt_id;
 
    block_stmt.scope = scope_id;
 

	
 
    return (block_stmt_id, end_block_stmt_id, scope_id);
 
}
 

	
 
fn create_ast_if_stmt(ctx: &mut Ctx, condition_expression_id: ExpressionId, true_case: IfStatementCase, false_case: Option<IfStatementCase>) -> (IfStatementId, EndIfStatementId) {
 
    // Create if statement and the end-if statement
 
    let if_stmt_id = ctx.heap.alloc_if_statement(|this| IfStatement{
 
        this,
 
        span: InputSpan::new(),
 
        test: condition_expression_id,
 
        true_case,
 
        false_case,
 
        end_if: EndIfStatementId::new_invalid()
 
    });
 

	
 
    let end_if_stmt_id = ctx.heap.alloc_end_if_statement(|this| EndIfStatement{
 
        this,
 
        start_if: if_stmt_id,
 
        next: StatementId::new_invalid(),
 
    });
 

	
 
    // Link the statements up as much as we can
 
    let if_stmt = &mut ctx.heap[if_stmt_id];
 
    if_stmt.end_if = end_if_stmt_id;
 

	
 
    let condition_expr = &mut ctx.heap[condition_expression_id];
 
    *condition_expr.parent_mut() = ExpressionParent::If(if_stmt_id);
 

	
 

	
 

	
 
    return (if_stmt_id, end_if_stmt_id);
 
}
 

	
 
/// Sets the false body for a given
 
fn set_ast_if_statement_false_body(ctx: &mut Ctx, if_statement_id: IfStatementId, end_if_statement_id: EndIfStatementId, false_case: IfStatementCase) {
 
    // Point if-statement to "false body"
 
    let if_stmt = &mut ctx.heap[if_statement_id];
 
    debug_assert!(if_stmt.false_case.is_none()); // simplifies logic, not necessary
 
    if_stmt.false_case = Some(false_case);
 

	
 
    // Point end of false body to the end of the if statement
 
    set_ast_statement_next(ctx, false_case.body, end_if_statement_id.upcast());
 
}
 

	
 
/// Sets the specified AST statement's control flow such that it will be
 
/// followed by the target statement. This may seem obvious, but may imply that
 
/// a statement associated with, but different from, the source statement is
 
/// modified.
 
fn set_ast_statement_next(ctx: &mut Ctx, source_stmt_id: StatementId, target_stmt_id: StatementId) {
 
    let source_stmt = &mut ctx.heap[source_stmt_id];
 
    match source_stmt {
 
        Statement::Block(stmt) => {
 
            let end_id = stmt.end_block;
 
            ctx.heap[end_id].next = target_stmt_id
 
        },
 
        Statement::EndBlock(stmt) => stmt.next = target_stmt_id,
 
        Statement::Local(stmt) => {
 
            match stmt {
 
                LocalStatement::Memory(stmt) => stmt.next = target_stmt_id,
 
                LocalStatement::Channel(stmt) => stmt.next = target_stmt_id,
 
            }
 
        },
 
        Statement::Labeled(stmt) => {
 
            let body_id = stmt.body;
 
            set_ast_statement_next(ctx, body_id, target_stmt_id);
 
        },
 
        Statement::If(stmt) => {
 
            let end_id = stmt.end_if;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndIf(stmt) => stmt.next = target_stmt_id,
 
        Statement::While(stmt) => {
 
            let end_id = stmt.end_while;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndWhile(stmt) => stmt.next = target_stmt_id,
 

	
 
        Statement::Break(_stmt) => {},
 
        Statement::Continue(_stmt) => {},
 
        Statement::Synchronous(stmt) => {
 
            let end_id = stmt.end_sync;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndSynchronous(stmt) => {
 
            stmt.next = target_stmt_id;
 
        },
 
        Statement::Fork(_) | Statement::EndFork(_) => {
 
            todo!("remove fork from language");
 
        },
 
        Statement::Select(stmt) => {
 
            let end_id = stmt.end_select;
 
            ctx.heap[end_id].next = target_stmt_id;
 
        },
 
        Statement::EndSelect(stmt) => stmt.next = target_stmt_id,
 
        Statement::Return(_stmt) => {},
 
        Statement::Goto(_stmt) => {},
 
        Statement::New(stmt) => stmt.next = target_stmt_id,
 
        Statement::Expression(stmt) => stmt.next = target_stmt_id,
 
    }
 
}
 

	
 
/// Links a new scope to an existing scope as its child.
 
fn link_new_child_to_existing_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
 
    let child_scope = &mut ctx.heap[child_scope_id];
 
    debug_assert!(child_scope.parent.is_none());
 

	
 
    child_scope.parent = Some(parent_scope_id);
 
    child_scope.relative_pos_in_parent = relative_pos_hint;
 

	
 
    add_child_scope_to_parent(ctx, scope_buffer, parent_scope_id, child_scope_id, relative_pos_hint);
 
}
 

	
 
/// Relinks an existing scope to a new scope as its child. Will also break the
 
/// link of the child scope's old parent.
 
fn link_existing_child_to_new_parent_scope(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, new_parent_scope_id: ScopeId, child_scope_id: ScopeId, new_relative_pos_in_parent: i32) {
 
    let child_scope = &mut ctx.heap[child_scope_id];
 
    let old_parent_scope_id = child_scope.parent.unwrap();
 
    child_scope.parent = Some(new_parent_scope_id);
 
    child_scope.relative_pos_in_parent = new_relative_pos_in_parent;
 

	
 
    // Remove from old parent
 
    let old_parent = &mut ctx.heap[old_parent_scope_id];
 
    let scope_index = old_parent.nested.iter()
 
        .position(|v| *v == child_scope_id)
 
        .unwrap();
 
    old_parent.nested.remove(scope_index);
 

	
 
    // Add to new parent
 
    add_child_scope_to_parent(ctx, scope_buffer, new_parent_scope_id, child_scope_id, new_relative_pos_in_parent);
 
}
 

	
 
/// Will add a child scope to a parent scope using the relative position hint.
 
fn add_child_scope_to_parent(ctx: &mut Ctx, scope_buffer: &mut ScopedBuffer<ScopeId>, parent_scope_id: ScopeId, child_scope_id: ScopeId, relative_pos_hint: i32) {
 
    let child_scope = &ctx.heap[child_scope_id];
 

	
 
    let existing_scope_ids = scope_buffer.start_section_initialized(&child_scope.nested);
 
    let mut insert_pos = existing_scope_ids.len();
 
    for index in 0..existing_scope_ids.len() {
 
        let existing_scope_id = existing_scope_ids[index];
 
        let existing_scope = &ctx.heap[existing_scope_id];
 
        if relative_pos_hint <= existing_scope.relative_pos_in_parent {
 
            insert_pos = index;
 
            break;
 
        }
 
    }
 
    existing_scope_ids.forget();
 

	
 
    let parent_scope = &mut ctx.heap[parent_scope_id];
 
    parent_scope.nested.insert(insert_pos, child_scope_id);
 
}
 

	
 
fn add_new_procedure_expression_type(ctx: &mut Ctx, procedure_id: ProcedureDefinitionId, type_id: TypeIdReference) -> i32 {
 
    let procedure = &mut ctx.heap[procedure_id];
 
    let type_index = procedure.monomorphs[0].expr_info.len();
 

	
 
    match type_id {
 
        TypeIdReference::DirectTypeId(type_id) => {
 
            for monomorph in procedure.monomorphs.iter_mut() {
 
                debug_assert_eq!(monomorph.expr_info.len(), type_index);
 
                monomorph.expr_info.push(ExpressionInfo{
 
                    type_id,
 
                    variant: ExpressionInfoVariant::Generic
 
                });
 
            }
 
        },
 
        TypeIdReference::IndirectSameAsExpr(source_type_index) => {
 
            for monomorph in procedure.monomorphs.iter_mut() {
 
                debug_assert_eq!(monomorph.expr_info.len(), type_index);
 
                let copied_expr_info = monomorph.expr_info[source_type_index as usize];
 
                monomorph.expr_info.push(copied_expr_info)
 
            }
 
        }
 
    }
 

	
 
    return type_index as i32;
 
}
src/protocol/parser/pass_typing.rs
Show inline comments
 
@@ -491,784 +491,784 @@ impl InferenceType {
 
            }
 

	
 
            if !forced_template {
 
                // We cannot infer anything, but the template may still be
 
                // compatible with the type we're inferring
 
                if let Some(depth_change) = Self::check_part_for_single_type(
 
                    template, &mut template_idx, &to_infer.parts, &mut to_infer_idx
 
                ) {
 
                    depth += depth_change;
 
                    continue;
 
                }
 
            }
 

	
 
            return SingleInferenceResult::Incompatible
 
        }
 

	
 
        if modified {
 
            to_infer.recompute_is_done();
 
            return SingleInferenceResult::Modified;
 
        } else {
 
            return SingleInferenceResult::Unmodified;
 
        }
 
    }
 

	
 
    /// Checks if both types are compatible, doesn't perform any inference
 
    fn check_subtrees(
 
        type_parts_a: &[InferenceTypePart], start_idx_a: usize,
 
        type_parts_b: &[InferenceTypePart], start_idx_b: usize
 
    ) -> bool {
 
        let mut depth = 1;
 
        let mut idx_a = start_idx_a;
 
        let mut idx_b = start_idx_b;
 

	
 
        while depth > 0 {
 
            let part_a = &type_parts_a[idx_a];
 
            let part_b = &type_parts_b[idx_b];
 

	
 
            if part_a == part_b {
 
                let depth_change = part_a.depth_change();
 
                depth += depth_change;
 
                debug_assert_eq!(depth_change, part_b.depth_change());
 
                idx_a += 1;
 
                idx_b += 1;
 
                continue;
 
            }
 
            
 
            if part_a.is_marker() { idx_a += 1; continue; }
 
            if part_b.is_marker() { idx_b += 1; continue; }
 

	
 
            if let Some(depth_change) = Self::check_part_for_single_type(
 
                type_parts_a, &mut idx_a, type_parts_b, &mut idx_b
 
            ) {
 
                depth += depth_change;
 
                continue;
 
            }
 
            if let Some(depth_change) = Self::check_part_for_single_type(
 
                type_parts_b, &mut idx_b, type_parts_a, &mut idx_a
 
            ) {
 
                depth += depth_change;
 
                continue;
 
            }
 

	
 
            return false;
 
        }
 

	
 
        true
 
    }
 

	
 
    /// Performs the conversion of the inference type into a concrete type.
 
    /// By calling this function you must make sure that no unspecified types
 
    /// (e.g. Unknown or IntegerLike) exist in the type. Will not clear or check
 
    /// if the supplied `ConcreteType` is empty, will simply append to the parts
 
    /// vector.
 
    fn write_concrete_type(&self, concrete_type: &mut ConcreteType) {
 
        use InferenceTypePart as ITP;
 
        use ConcreteTypePart as CTP;
 

	
 
        // Make sure inference type is specified but concrete type is not yet specified
 
        debug_assert!(!self.parts.is_empty());
 
        concrete_type.parts.reserve(self.parts.len());
 

	
 
        let mut idx = 0;
 
        while idx < self.parts.len() {
 
            let part = &self.parts[idx];
 
            let converted_part = match part {
 
                ITP::Marker(_) => {
 
                    // Markers are removed when writing to the concrete type.
 
                    idx += 1;
 
                    continue;
 
                },
 
                ITP::Unknown | ITP::NumberLike |
 
                ITP::IntegerLike | ITP::ArrayLike | ITP::PortLike => {
 
                    // Should not happen if type inferencing works correctly: we
 
                    // should have returned a programmer-readable error or have
 
                    // inferred all types.
 
                    unreachable!("attempted to convert inference type part {:?} into concrete type", part);
 
                },
 
                ITP::Void => CTP::Void,
 
                ITP::Message => CTP::Message,
 
                ITP::Bool => CTP::Bool,
 
                ITP::UInt8 => CTP::UInt8,
 
                ITP::UInt16 => CTP::UInt16,
 
                ITP::UInt32 => CTP::UInt32,
 
                ITP::UInt64 => CTP::UInt64,
 
                ITP::SInt8 => CTP::SInt8,
 
                ITP::SInt16 => CTP::SInt16,
 
                ITP::SInt32 => CTP::SInt32,
 
                ITP::SInt64 => CTP::SInt64,
 
                ITP::Character => CTP::Character,
 
                ITP::String => {
 
                    // Inferred type has a 'char' subtype to simplify array
 
                    // checking, we remove it here.
 
                    debug_assert_eq!(self.parts[idx + 1], InferenceTypePart::Character);
 
                    idx += 1;
 
                    CTP::String
 
                },
 
                ITP::Array => CTP::Array,
 
                ITP::Slice => CTP::Slice,
 
                ITP::Input => CTP::Input,
 
                ITP::Output => CTP::Output,
 
                ITP::Tuple(num) => CTP::Tuple(*num),
 
                ITP::Instance(id, num) => CTP::Instance(*id, *num),
 
            };
 

	
 
            concrete_type.parts.push(converted_part);
 
            idx += 1;
 
        }
 
    }
 

	
 
    /// Writes a human-readable version of the type to a string. This is used
 
    /// to display error messages
 
    fn write_display_name(
 
        buffer: &mut String, heap: &Heap, parts: &[InferenceTypePart], mut idx: usize
 
    ) -> usize {
 
        use InferenceTypePart as ITP;
 

	
 
        match &parts[idx] {
 
            ITP::Marker(_marker_idx) => {
 
                if debug_log_enabled!() {
 
                    buffer.push_str(&format!("{{Marker:{}}}", *_marker_idx));
 
                }
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
            },
 
            ITP::Unknown => buffer.push_str("?"),
 
            ITP::NumberLike => buffer.push_str("numberlike"),
 
            ITP::IntegerLike => buffer.push_str("integerlike"),
 
            ITP::ArrayLike => {
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push_str("[?]");
 
            },
 
            ITP::PortLike => {
 
                buffer.push_str("portlike<");
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            }
 
            ITP::Void => buffer.push_str("void"),
 
            ITP::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
 
            ITP::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
 
            ITP::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
 
            ITP::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
 
            ITP::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
 
            ITP::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
 
            ITP::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
 
            ITP::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
 
            ITP::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
 
            ITP::Character => buffer.push_str(KW_TYPE_CHAR_STR),
 
            ITP::String => {
 
                buffer.push_str(KW_TYPE_STRING_STR);
 
                idx += 1; // skip the 'char' subtype
 
            },
 
            ITP::Message => {
 
                buffer.push_str(KW_TYPE_MESSAGE_STR);
 
                buffer.push('<');
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            },
 
            ITP::Array => {
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            ITP::Slice => {
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push_str("[..]");
 
            },
 
            ITP::Input => {
 
                buffer.push_str(KW_TYPE_IN_PORT_STR);
 
                buffer.push('<');
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            },
 
            ITP::Output => {
 
                buffer.push_str(KW_TYPE_OUT_PORT_STR);
 
                buffer.push('<');
 
                idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                buffer.push('>');
 
            },
 
            ITP::Tuple(num_sub) => {
 
                buffer.push('(');
 
                if *num_sub > 0 {
 
                    idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                    for _sub_idx in 1..*num_sub {
 
                        buffer.push_str(", ");
 
                        idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                    }
 
                }
 
                buffer.push(')');
 
            }
 
            ITP::Instance(definition_id, num_sub) => {
 
                let definition = &heap[*definition_id];
 
                buffer.push_str(definition.identifier().value.as_str());
 
                if *num_sub > 0 {
 
                    buffer.push('<');
 
                    idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                    for _sub_idx in 1..*num_sub {
 
                        buffer.push_str(", ");
 
                        idx = Self::write_display_name(buffer, heap, parts, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            },
 
        }
 

	
 
        idx
 
    }
 

	
 
    /// Returns the display name of a (part of) the type tree. Will allocate a
 
    /// string.
 
    fn partial_display_name(heap: &Heap, parts: &[InferenceTypePart]) -> String {
 
        let mut buffer = String::with_capacity(parts.len() * 6);
 
        Self::write_display_name(&mut buffer, heap, parts, 0);
 
        buffer
 
    }
 

	
 
    /// Returns the display name of the full type tree. Will allocate a string.
 
    fn display_name(&self, heap: &Heap) -> String {
 
        Self::partial_display_name(heap, &self.parts)
 
    }
 
}
 

	
 
impl Default for InferenceType {
 
    fn default() -> Self {
 
        Self{
 
            has_marker: false,
 
            is_done: false,
 
            parts: Vec::new(),
 
        }
 
    }
 
}
 

	
 
/// Iterator over the subtrees that follow a marker in an `InferenceType`
 
/// instance. Returns immutable slices over the internal parts
 
struct InferenceTypeMarkerIter<'a> {
 
    parts: &'a [InferenceTypePart],
 
    idx: usize,
 
}
 

	
 
impl<'a> InferenceTypeMarkerIter<'a> {
 
    fn new(parts: &'a [InferenceTypePart]) -> Self {
 
        Self{ parts, idx: 0 }
 
    }
 
}
 

	
 
impl<'a> Iterator for InferenceTypeMarkerIter<'a> {
 
    type Item = (u32, &'a [InferenceTypePart]);
 

	
 
    fn next(&mut self) -> Option<Self::Item> {
 
        // Iterate until we find a marker
 
        while self.idx < self.parts.len() {
 
            if let InferenceTypePart::Marker(marker) = self.parts[self.idx] {
 
                // Found a marker, find the subtree end
 
                let start_idx = self.idx + 1;
 
                let end_idx = InferenceType::find_subtree_end_idx(self.parts, start_idx);
 

	
 
                // Modify internal index, then return items
 
                self.idx = end_idx;
 
                return Some((marker, &self.parts[start_idx..end_idx]));
 
            }
 

	
 
            self.idx += 1;
 
        }
 

	
 
        None
 
    }
 
}
 

	
 
#[derive(Debug, PartialEq, Eq)]
 
enum DualInferenceResult {
 
    Neither,        // neither argument is clarified
 
    First,          // first argument is clarified using the second one
 
    Second,         // second argument is clarified using the first one
 
    Both,           // both arguments are clarified
 
    Incompatible,   // types are incompatible: programmer error
 
}
 

	
 
impl DualInferenceResult {
 
    fn modified_lhs(&self) -> bool {
 
        match self {
 
            DualInferenceResult::First | DualInferenceResult::Both => true,
 
            _ => false
 
        }
 
    }
 
    fn modified_rhs(&self) -> bool {
 
        match self {
 
            DualInferenceResult::Second | DualInferenceResult::Both => true,
 
            _ => false
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, PartialEq, Eq)]
 
enum SingleInferenceResult {
 
    Unmodified,
 
    Modified,
 
    Incompatible
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// PassTyping - Public Interface
 
// -----------------------------------------------------------------------------
 

	
 
type InferNodeIndex = usize;
 
type PolyDataIndex = isize;
 
type VarDataIndex = usize;
 

	
 
pub(crate) struct ResolveQueueElement {
 
    // Note that using the `definition_id` and the `monomorph_idx` one may
 
    // query the type table for the full procedure type, thereby retrieving
 
    // the polymorphic arguments to the procedure.
 
    pub(crate) root_id: RootId,
 
    pub(crate) definition_id: DefinitionId,
 
    pub(crate) reserved_type_id: TypeId,
 
    pub(crate) reserved_monomorph_index: u32,
 
}
 

	
 
pub(crate) type ResolveQueue = VecDeque<ResolveQueueElement>;
 

	
 
struct InferenceNode {
 
    // filled in during type inference
 
    expr_type: InferenceType,               // result type from expression
 
    expr_id: ExpressionId,                  // expression that is evaluated
 
    inference_rule: InferenceRule,          // rule used to infer node type
 
    parent_index: Option<InferNodeIndex>,   // parent of inference node
 
    field_index: i32,                       // index of struct field or tuple member
 
    poly_data_index: PolyDataIndex,         // index to inference data for polymorphic types
 
    // filled in once type inference is done
 
    info_type_id: TypeId,
 
    info_variant: ExpressionInfoVariant,
 
}
 

	
 
impl InferenceNode {
 
    #[inline]
 
    fn as_expression_info(&self) -> ExpressionInfo {
 
        return ExpressionInfo {
 
            type_id: self.info_type_id,
 
            variant: self.info_variant
 
        }
 
    }
 
}
 

	
 
/// Inferencing rule to apply. Some of these are reasonably generic. Other ones
 
/// require so much custom logic that we'll not try to come up with an
 
/// abstraction.
 
enum InferenceRule {
 
    Noop,
 
    MonoTemplate(InferenceRuleTemplate),
 
    BiEqual(InferenceRuleBiEqual),
 
    TriEqualArgs(InferenceRuleTriEqualArgs),
 
    TriEqualAll(InferenceRuleTriEqualAll),
 
    Concatenate(InferenceRuleTwoArgs),
 
    IndexingExpr(InferenceRuleIndexingExpr),
 
    SlicingExpr(InferenceRuleSlicingExpr),
 
    SelectStructField(InferenceRuleSelectStructField),
 
    SelectTupleMember(InferenceRuleSelectTupleMember),
 
    LiteralStruct(InferenceRuleLiteralStruct),
 
    LiteralEnum,
 
    LiteralUnion(InferenceRuleLiteralUnion),
 
    LiteralArray(InferenceRuleLiteralArray),
 
    LiteralTuple(InferenceRuleLiteralTuple),
 
    CastExpr(InferenceRuleCastExpr),
 
    CallExpr(InferenceRuleCallExpr),
 
    VariableExpr(InferenceRuleVariableExpr),
 
}
 

	
 
impl InferenceRule {
 
    union_cast_method_impl!(as_mono_template, InferenceRuleTemplate, InferenceRule::MonoTemplate);
 
    union_cast_method_impl!(as_bi_equal, InferenceRuleBiEqual, InferenceRule::BiEqual);
 
    union_cast_method_impl!(as_tri_equal_args, InferenceRuleTriEqualArgs, InferenceRule::TriEqualArgs);
 
    union_cast_method_impl!(as_tri_equal_all, InferenceRuleTriEqualAll, InferenceRule::TriEqualAll);
 
    union_cast_method_impl!(as_concatenate, InferenceRuleTwoArgs, InferenceRule::Concatenate);
 
    union_cast_method_impl!(as_indexing_expr, InferenceRuleIndexingExpr, InferenceRule::IndexingExpr);
 
    union_cast_method_impl!(as_slicing_expr, InferenceRuleSlicingExpr, InferenceRule::SlicingExpr);
 
    union_cast_method_impl!(as_select_struct_field, InferenceRuleSelectStructField, InferenceRule::SelectStructField);
 
    union_cast_method_impl!(as_select_tuple_member, InferenceRuleSelectTupleMember, InferenceRule::SelectTupleMember);
 
    union_cast_method_impl!(as_literal_struct, InferenceRuleLiteralStruct, InferenceRule::LiteralStruct);
 
    union_cast_method_impl!(as_literal_union, InferenceRuleLiteralUnion, InferenceRule::LiteralUnion);
 
    union_cast_method_impl!(as_literal_array, InferenceRuleLiteralArray, InferenceRule::LiteralArray);
 
    union_cast_method_impl!(as_literal_tuple, InferenceRuleLiteralTuple, InferenceRule::LiteralTuple);
 
    union_cast_method_impl!(as_cast_expr, InferenceRuleCastExpr, InferenceRule::CastExpr);
 
    union_cast_method_impl!(as_call_expr, InferenceRuleCallExpr, InferenceRule::CallExpr);
 
    union_cast_method_impl!(as_variable_expr, InferenceRuleVariableExpr, InferenceRule::VariableExpr);
 
    union_cast_to_ref_method_impl!(as_mono_template, InferenceRuleTemplate, InferenceRule::MonoTemplate);
 
    union_cast_to_ref_method_impl!(as_bi_equal, InferenceRuleBiEqual, InferenceRule::BiEqual);
 
    union_cast_to_ref_method_impl!(as_tri_equal_args, InferenceRuleTriEqualArgs, InferenceRule::TriEqualArgs);
 
    union_cast_to_ref_method_impl!(as_tri_equal_all, InferenceRuleTriEqualAll, InferenceRule::TriEqualAll);
 
    union_cast_to_ref_method_impl!(as_concatenate, InferenceRuleTwoArgs, InferenceRule::Concatenate);
 
    union_cast_to_ref_method_impl!(as_indexing_expr, InferenceRuleIndexingExpr, InferenceRule::IndexingExpr);
 
    union_cast_to_ref_method_impl!(as_slicing_expr, InferenceRuleSlicingExpr, InferenceRule::SlicingExpr);
 
    union_cast_to_ref_method_impl!(as_select_struct_field, InferenceRuleSelectStructField, InferenceRule::SelectStructField);
 
    union_cast_to_ref_method_impl!(as_select_tuple_member, InferenceRuleSelectTupleMember, InferenceRule::SelectTupleMember);
 
    union_cast_to_ref_method_impl!(as_literal_struct, InferenceRuleLiteralStruct, InferenceRule::LiteralStruct);
 
    union_cast_to_ref_method_impl!(as_literal_union, InferenceRuleLiteralUnion, InferenceRule::LiteralUnion);
 
    union_cast_to_ref_method_impl!(as_literal_array, InferenceRuleLiteralArray, InferenceRule::LiteralArray);
 
    union_cast_to_ref_method_impl!(as_literal_tuple, InferenceRuleLiteralTuple, InferenceRule::LiteralTuple);
 
    union_cast_to_ref_method_impl!(as_cast_expr, InferenceRuleCastExpr, InferenceRule::CastExpr);
 
    union_cast_to_ref_method_impl!(as_call_expr, InferenceRuleCallExpr, InferenceRule::CallExpr);
 
    union_cast_to_ref_method_impl!(as_variable_expr, InferenceRuleVariableExpr, InferenceRule::VariableExpr);
 
}
 

	
 
// Note: InferenceRuleTemplate is `Copy`, so don't add dynamically allocated
 
// members in the future (or review places where this struct is copied)
 
#[derive(Clone, Copy)]
 
struct InferenceRuleTemplate {
 
    template: &'static [InferenceTypePart],
 
    application: InferenceRuleTemplateApplication,
 
}
 

	
 
impl InferenceRuleTemplate {
 
    fn new_none() -> Self {
 
        return Self{
 
            template: &[],
 
            application: InferenceRuleTemplateApplication::None,
 
        };
 
    }
 

	
 
    fn new_forced(template: &'static [InferenceTypePart]) -> Self {
 
        return Self{
 
            template,
 
            application: InferenceRuleTemplateApplication::Forced,
 
        };
 
    }
 

	
 
    fn new_template(template: &'static [InferenceTypePart]) -> Self {
 
        return Self{
 
            template,
 
            application: InferenceRuleTemplateApplication::Template,
 
        }
 
    }
 
}
 

	
 
#[derive(Clone, Copy)]
 
enum InferenceRuleTemplateApplication {
 
    None, // do not apply template, silly, but saves some bytes
 
    Forced,
 
    Template,
 
}
 

	
 
/// Type equality applied to 'self' and the argument. An optional template will
 
/// be applied to 'self' first. Example: "bitwise not"
 
struct InferenceRuleBiEqual {
 
    template: InferenceRuleTemplate,
 
    argument_index: InferNodeIndex,
 
}
 

	
 
/// Type equality applied to two arguments. Template can be applied to 'self'
 
/// (generally forced, since this rule does not apply a type equality constraint
 
/// to 'self') and the two arguments. Example: "equality operator"
 
struct InferenceRuleTriEqualArgs {
 
    argument_template: InferenceRuleTemplate,
 
    result_template: InferenceRuleTemplate,
 
    argument1_index: InferNodeIndex,
 
    argument2_index: InferNodeIndex,
 
}
 

	
 
/// Type equality applied to 'self' and two arguments. Template may be
 
/// optionally applied to 'self'. Example: "addition operator"
 
struct InferenceRuleTriEqualAll {
 
    template: InferenceRuleTemplate,
 
    argument1_index: InferNodeIndex,
 
    argument2_index: InferNodeIndex,
 
}
 

	
 
/// Information for an inference rule that is applied to 'self' and two
 
/// arguments, see `InferenceRule` for its meaning.
 
struct InferenceRuleTwoArgs {
 
    argument1_index: InferNodeIndex,
 
    argument2_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleIndexingExpr {
 
    subject_index: InferNodeIndex,
 
    index_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleSlicingExpr {
 
    subject_index: InferNodeIndex,
 
    from_index: InferNodeIndex,
 
    to_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleSelectStructField {
 
    subject_index: InferNodeIndex,
 
    selected_field: Identifier,
 
}
 

	
 
struct InferenceRuleSelectTupleMember {
 
    subject_index: InferNodeIndex,
 
    selected_index: u64,
 
}
 

	
 
struct InferenceRuleLiteralStruct {
 
    element_indices: Vec<InferNodeIndex>,
 
}
 

	
 
struct InferenceRuleLiteralUnion {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleLiteralArray {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleLiteralTuple {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleCastExpr {
 
    subject_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleCallExpr {
 
    argument_indices: Vec<InferNodeIndex>
 
}
 

	
 
/// Data associated with a variable expression: an expression that reads the
 
/// value from a variable.
 
struct InferenceRuleVariableExpr {
 
    var_data_index: VarDataIndex, // shared variable information
 
}
 

	
 
/// This particular visitor will recurse depth-first into the AST and ensures
 
/// that all expressions have the appropriate types.
 
pub(crate) struct PassTyping {
 
    // Current definition we're typechecking.
 
    reserved_type_id: TypeId,
 
    reserved_monomorph_index: u32,
 
    procedure_id: ProcedureDefinitionId,
 
    procedure_kind: ProcedureKind,
 
    poly_vars: Vec<ConcreteType>,
 
    // Temporary variables during construction of inference rulesr
 
    parent_index: Option<InferNodeIndex>,
 
    // Buffers for iteration over various types
 
    var_buffer: ScopedBuffer<VariableId>,
 
    expr_buffer: ScopedBuffer<ExpressionId>,
 
    stmt_buffer: ScopedBuffer<StatementId>,
 
    bool_buffer: ScopedBuffer<bool>,
 
    index_buffer: ScopedBuffer<usize>,
 
    definition_buffer: ScopedBuffer<DefinitionId>,
 
    poly_progress_buffer: ScopedBuffer<u32>,
 
    // Mapping from parser type to inferred type. We attempt to continue to
 
    // specify these types until we're stuck or we've fully determined the type.
 
    infer_nodes: Vec<InferenceNode>,                     // will be transferred to type table at end
 
    poly_data: Vec<PolyData>,       // data for polymorph inference
 
    var_data: Vec<VarData>,
 
    // Keeping track of which expressions need to be reinferred because the
 
    // expressions they're linked to made progression on an associated type
 
    node_queued: DequeSet<InferNodeIndex>,
 
}
 

	
 
/// Generic struct that is used to store inferred types associated with
 
/// polymorphic types.
 
struct PolyData {
 
    first_rule_application: bool,
 
    definition_id: DefinitionId, // the definition, only used for user feedback
 
    /// Inferred types of the polymorphic variables as they are written down
 
    /// at the type's definition.
 
    poly_vars: Vec<InferenceType>,
 
    expr_types: PolyDataTypes,
 
}
 

	
 
// silly structure, just so we can use `PolyDataTypeIndex` ergonomically while
 
// making sure we're still capable of borrowing from `poly_vars`.
 
struct PolyDataTypes {
 
    /// Inferred types of associated types (e.g. struct fields, tuple members,
 
    /// function arguments). These types may depend on the polymorphic variables
 
    /// defined above.
 
    associated: Vec<InferenceType>,
 
    /// Inferred "returned" type (e.g. if a struct field is selected, then this
 
    /// contains the type of the selected field, for a function call it contains
 
    /// the return type). May depend on the polymorphic variables defined above.
 
    returned: InferenceType,
 
}
 

	
 
#[derive(Clone, Copy)]
 
enum PolyDataTypeIndex {
 
    Associated(usize), // indexes into `PolyData.associated`
 
    Returned,
 
}
 

	
 
impl PolyDataTypes {
 
    fn get_type(&self, index: PolyDataTypeIndex) -> &InferenceType {
 
        match index {
 
            PolyDataTypeIndex::Associated(index) => return &self.associated[index],
 
            PolyDataTypeIndex::Returned => return &self.returned,
 
        }
 
    }
 

	
 
    fn get_type_mut(&mut self, index: PolyDataTypeIndex) -> &mut InferenceType {
 
        match index {
 
            PolyDataTypeIndex::Associated(index) => return &mut self.associated[index],
 
            PolyDataTypeIndex::Returned => return &mut self.returned,
 
        }
 
    }
 
}
 

	
 
struct VarData {
 
    var_id: VariableId,
 
    var_type: InferenceType,
 
    used_at: Vec<InferNodeIndex>, // of variable expressions
 
    linked_var: Option<VarDataIndex>,
 
}
 

	
 
impl PassTyping {
 
    pub(crate) fn new() -> Self {
 
        PassTyping {
 
            reserved_type_id: TypeId::new_invalid(),
 
            reserved_monomorph_index: u32::MAX,
 
            procedure_id: ProcedureDefinitionId::new_invalid(),
 
            procedure_kind: ProcedureKind::Function,
 
            poly_vars: Vec::new(),
 
            parent_index: None,
 
            var_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            stmt_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            bool_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            index_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            poly_progress_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            infer_nodes: Vec::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            poly_data: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            var_data: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            node_queued: DequeSet::new(),
 
        }
 
    }
 

	
 
    pub(crate) fn queue_module_definitions(&mut self, ctx: &mut Ctx, queue: &mut ResolveQueue) {
 
        debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::ValidatedAndLinked);
 
        let root_id = ctx.module().root_id;
 
        let root = &ctx.heap.protocol_descriptions[root_id];
 
        let definitions_section = self.definition_buffer.start_section_initialized(&root.definitions);
 

	
 
        for definition_id in definitions_section.iter_copied() {
 
            let definition = &ctx.heap[definition_id];
 

	
 
            let first_concrete_part_and_procedure_id = match definition {
 
                Definition::Procedure(definition) => {
 
                    if definition.poly_vars.is_empty() {
 
                        if definition.kind == ProcedureKind::Function {
 
                            Some((ConcreteTypePart::Function(definition.this, 0), definition.this))
 
                        } else {
 
                            Some((ConcreteTypePart::Component(definition.this, 0), definition.this))
 
                        }
 
                    } else {
 
                        None
 
                    }
 
                }
 
                Definition::Enum(_) | Definition::Struct(_) | Definition::Union(_) => None,
 
            };
 

	
 
            if let Some((first_concrete_part, procedure_id)) = first_concrete_part_and_procedure_id {
 
                let procedure = &mut ctx.heap[procedure_id];
 
                let monomorph_index = procedure.monomorphs.len() as u32;
 
                procedure.monomorphs.push(ProcedureDefinitionMonomorph::new_invalid());
 

	
 
                let concrete_type = ConcreteType{ parts: vec![first_concrete_part] };
 
                let type_id = ctx.types.reserve_procedure_monomorph_type_id(&definition_id, concrete_type, monomorph_index);
 
                queue.push_back(ResolveQueueElement{
 
                    root_id,
 
                    definition_id,
 
                    reserved_type_id: type_id,
 
                    reserved_monomorph_index: monomorph_index,
 
                })
 
            }
 
        }
 

	
 
        definitions_section.forget();
 
    }
 

	
 
    pub(crate) fn handle_module_definition(
 
        &mut self, ctx: &mut Ctx, queue: &mut ResolveQueue, element: ResolveQueueElement
 
    ) -> VisitorResult {
 
        self.reset();
 
        debug_assert_eq!(ctx.module().root_id, element.root_id);
 
        debug_assert!(self.poly_vars.is_empty());
 

	
 
        // Prepare for visiting the definition
 
        self.reserved_type_id = element.reserved_type_id;
 
        self.reserved_monomorph_index = element.reserved_monomorph_index;
 

	
 
        let proc_base = ctx.types.get_base_definition(&element.definition_id).unwrap();
 
        if proc_base.is_polymorph {
 
            let monomorph = ctx.types.get_monomorph(element.reserved_type_id);
 
            for poly_arg in monomorph.concrete_type.embedded_iter(0) {
 
                self.poly_vars.push(ConcreteType{ parts: Vec::from(poly_arg) });
 
            }
 
        }
 

	
 
        // Visit the definition, setting up the type resolving process, then
 
        // (attempt to) resolve all types
 
        self.visit_definition(ctx, element.definition_id)?;
 
        self.resolve_types(ctx, queue)?;
 
        Ok(())
 
    }
 

	
 
    fn reset(&mut self) {
 
        self.reserved_type_id = TypeId::new_invalid();
 
        self.procedure_id = ProcedureDefinitionId::new_invalid();
 
        self.procedure_kind = ProcedureKind::Function;
 
        self.poly_vars.clear();
 
        self.parent_index = None;
 

	
 
        self.infer_nodes.clear();
 
        self.poly_data.clear();
 
        self.var_data.clear();
 
        self.node_queued.clear();
 
    }
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// PassTyping - Visitor-like implementation
 
// -----------------------------------------------------------------------------
 

	
 
type VisitorResult = Result<(), ParseError>;
 
type VisitExprResult = Result<InferNodeIndex, ParseError>;
 

	
 
impl PassTyping {
 
    // Definitions
 

	
 
    fn visit_definition(&mut self, ctx: &mut Ctx, id: DefinitionId) -> VisitorResult {
 
        return visitor_recursive_definition_impl!(self, &ctx.heap[id], ctx);
 
    }
 

	
 
    fn visit_enum_definition(&mut self, _: &mut Ctx, _: EnumDefinitionId) -> VisitorResult { return Ok(()) }
 
    fn visit_struct_definition(&mut self, _: &mut Ctx, _: StructDefinitionId) -> VisitorResult { return Ok(()) }
 
    fn visit_union_definition(&mut self, _: &mut Ctx, _: UnionDefinitionId) -> VisitorResult { return Ok(()) }
 

	
 
    fn visit_procedure_definition(&mut self, ctx: &mut Ctx, id: ProcedureDefinitionId) -> VisitorResult {
 
        let procedure_def = &ctx.heap[id];
 

	
 
        self.procedure_id = id;
 
        self.procedure_kind = procedure_def.kind;
 
        let body_id = procedure_def.body;
 

	
 
        debug_log!("{}", "-".repeat(50));
 
        debug_log!("Visiting procedure: '{}' (id: {}, kind: {:?})", procedure_def.identifier.value.as_str(), id.0.index, procedure_def.kind);
 
        debug_log!("{}", "-".repeat(50));
 

	
 
        // Visit parameters
 
        let section = self.var_buffer.start_section_initialized(procedure_def.parameters.as_slice());
 
        for param_id in section.iter_copied() {
 
            let param = &ctx.heap[param_id];
 
            let var_type = self.determine_inference_type_from_parser_type_elements(&param.parser_type.elements, true);
 
            debug_assert!(var_type.is_done, "expected function arguments to be concrete types");
 
            self.var_data.push(VarData{
 
                var_id: param_id,
 
                var_type,
 
                used_at: Vec::new(),
 
                linked_var: None
 
            })
 
        }
 
        section.forget();
 

	
 
        // Visit all of the expressions within the body
 
        self.parent_index = None;
 
        return self.visit_block_stmt(ctx, body_id);
 
    }
 

	
 
    // Statements
 

	
 
    fn visit_stmt(&mut self, ctx: &mut Ctx, id: StatementId) -> VisitorResult {
 
        return visitor_recursive_statement_impl!(self, &ctx.heap[id], ctx, Ok(()));
 
    }
 

	
 
    fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
 
        // Transfer statements for traversal
 
        let block = &ctx.heap[id];
 

	
 
        let section = self.stmt_buffer.start_section_initialized(block.statements.as_slice());
 
        for stmt_id in section.iter_copied() {
 
            self.visit_stmt(ctx, stmt_id)?;
 
        }
 
        section.forget();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_local_stmt(&mut self, ctx: &mut Ctx, id: LocalStatementId) -> VisitorResult {
 
        return visitor_recursive_local_impl!(self, &ctx.heap[id], ctx);
 
    }
 

	
 
    fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
src/protocol/tests/utils.rs
Show inline comments
 
@@ -886,404 +886,393 @@ impl<'a> ErrorTester<'a> {
 
    }
 

	
 
    /// Seeks the index of the pattern in the context message, then checks if
 
    /// the input position corresponds to that index.
 
    pub (crate) fn assert_occurs_at(self, idx: usize, pattern: &str) -> Self {
 
        let pos = self.error.statements[idx].context.find(pattern);
 
        assert!(
 
            pos.is_some(),
 
            "[{}] incorrect occurs_at: '{}' could not be found in the context for {}",
 
            self.test_name, pattern, self.assert_postfix()
 
        );
 
        let pos = pos.unwrap();
 
        let col = self.error.statements[idx].start_column as usize;
 
        assert_eq!(
 
            pos + 1, col,
 
            "[{}] Expected error to occur at column {}, but found it at {} for {}",
 
            self.test_name, pos + 1, col, self.assert_postfix()
 
        );
 

	
 
        self
 
    }
 

	
 
    fn assert_postfix(&self) -> String {
 
        let mut v = String::new();
 
        v.push_str("error: [");
 
        for (idx, stmt) in self.error.statements.iter().enumerate() {
 
            if idx != 0 {
 
                v.push_str(", ");
 
            }
 

	
 
            v.push_str(&format!("{{ context: {}, message: {} }}", &stmt.context, stmt.message));
 
        }
 
        v.push(']');
 
        v
 
    }
 
}
 

	
 
//------------------------------------------------------------------------------
 
// Generic utilities
 
//------------------------------------------------------------------------------
 

	
 
fn has_equal_num_monomorphs(ctx: TestCtx, num: usize, definition_id: DefinitionId) -> (bool, usize) {
 
    // Again: inefficient, but its testing code
 
    let mut num_on_type = 0;
 

	
 
    for mono in &ctx.types.mono_types {
 
        match &mono.concrete_type.parts[0] {
 
            ConcreteTypePart::Instance(def_id, _) => {
 
                if *def_id == definition_id {
 
                    num_on_type += 1;
 
                }
 
            }
 
            ConcreteTypePart::Function(def_id, _) |
 
            ConcreteTypePart::Component(def_id, _) => {
 
                if def_id.upcast() == definition_id {
 
                    num_on_type += 1;
 
                }
 
            },
 
            _ => {},
 
        };
 
    }
 

	
 
    (num_on_type == num, num_on_type)
 
}
 

	
 
fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph: &str) -> (Option<TypeId>, String) {
 
    // Note: full_buffer is just for error reporting
 
    let mut full_buffer = String::new();
 
    let mut has_match = None;
 

	
 
    full_buffer.push('[');
 
    let mut append_to_full_buffer = |concrete_type: &ConcreteType, type_id: TypeId| {
 
        if full_buffer.len() != 1 {
 
            full_buffer.push_str(", ");
 
        }
 
        full_buffer.push('"');
 

	
 
        let first_idx = full_buffer.len();
 
        full_buffer.push_str(concrete_type.display_name(ctx.heap).as_str());
 
        if &full_buffer[first_idx..] == serialized_monomorph {
 
            has_match = Some(type_id);
 
        }
 

	
 
        full_buffer.push('"');
 
    };
 

	
 
    // Bit wasteful, but this is (temporary?) testing code:
 
    for (_mono_idx, mono) in ctx.types.mono_types.iter().enumerate() {
 
        let got_definition_id = match &mono.concrete_type.parts[0] {
 
            ConcreteTypePart::Instance(v, _) => *v,
 
            ConcreteTypePart::Function(v, _) |
 
            ConcreteTypePart::Component(v, _) => v.upcast(),
 
            _ => DefinitionId::new_invalid(),
 
        };
 
        if got_definition_id == definition_id {
 
            append_to_full_buffer(&mono.concrete_type, mono.type_id);
 
        }
 
    }
 

	
 
    full_buffer.push(']');
 

	
 
    (has_match, full_buffer)
 
}
 

	
 
fn serialize_parser_type(buffer: &mut String, heap: &Heap, parser_type: &ParserType) {
 
    use ParserTypeVariant as PTV;
 

	
 
    fn serialize_variant(buffer: &mut String, heap: &Heap, parser_type: &ParserType, mut idx: usize) -> usize {
 
        match &parser_type.elements[idx].variant {
 
            PTV::Void => buffer.push_str("void"),
 
            PTV::InputOrOutput => {
 
                buffer.push_str("portlike<");
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::ArrayLike => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[???]");
 
            },
 
            PTV::IntegerLike => buffer.push_str("integerlike"),
 
            PTV::Message => buffer.push_str(KW_TYPE_MESSAGE_STR),
 
            PTV::Bool => buffer.push_str(KW_TYPE_BOOL_STR),
 
            PTV::UInt8 => buffer.push_str(KW_TYPE_UINT8_STR),
 
            PTV::UInt16 => buffer.push_str(KW_TYPE_UINT16_STR),
 
            PTV::UInt32 => buffer.push_str(KW_TYPE_UINT32_STR),
 
            PTV::UInt64 => buffer.push_str(KW_TYPE_UINT64_STR),
 
            PTV::SInt8 => buffer.push_str(KW_TYPE_SINT8_STR),
 
            PTV::SInt16 => buffer.push_str(KW_TYPE_SINT16_STR),
 
            PTV::SInt32 => buffer.push_str(KW_TYPE_SINT32_STR),
 
            PTV::SInt64 => buffer.push_str(KW_TYPE_SINT64_STR),
 
            PTV::Character => buffer.push_str(KW_TYPE_CHAR_STR),
 
            PTV::String => buffer.push_str(KW_TYPE_STRING_STR),
 
            PTV::IntegerLiteral => buffer.push_str("int_literal"),
 
            PTV::Inferred => buffer.push_str(KW_TYPE_INFERRED_STR),
 
            PTV::Array => {
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push_str("[]");
 
            },
 
            PTV::Input => {
 
                buffer.push_str(KW_TYPE_IN_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::Output => {
 
                buffer.push_str(KW_TYPE_OUT_PORT_STR);
 
                buffer.push('<');
 
                idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                buffer.push('>');
 
            },
 
            PTV::Tuple(num_embedded) => {
 
                buffer.push('(');
 
                for embedded_idx in 0..*num_embedded {
 
                    if embedded_idx != 0 {
 
                        buffer.push(',');
 
                    }
 
                    idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                }
 
                buffer.push(')');
 
            },
 
            PTV::PolymorphicArgument(definition_id, poly_idx) => {
 
                let definition = &heap[*definition_id];
 
                let poly_arg = &definition.poly_vars()[*poly_idx as usize];
 
                buffer.push_str(poly_arg.value.as_str());
 
            },
 
            PTV::Definition(definition_id, num_embedded) => {
 
                let definition = &heap[*definition_id];
 
                buffer.push_str(definition.identifier().value.as_str());
 

	
 
                let num_embedded = *num_embedded;
 
                if num_embedded != 0 {
 
                    buffer.push('<');
 
                    for embedded_idx in 0..num_embedded {
 
                        if embedded_idx != 0 {
 
                            buffer.push(',');
 
                        }
 
                        idx = serialize_variant(buffer, heap, parser_type, idx + 1);
 
                    }
 
                    buffer.push('>');
 
                }
 
            }
 
        }
 

	
 
        idx
 
    }
 

	
 
    serialize_variant(buffer, heap, parser_type, 0);
 
}
 

	
 
fn seek_def_in_modules<'a>(heap: &Heap, modules: &'a [Module], def_id: DefinitionId) -> Option<&'a Module> {
 
    for module in modules {
 
        let root = &heap.protocol_descriptions[module.root_id];
 
        for definition in &root.definitions {
 
            if *definition == def_id {
 
                return Some(module)
 
            }
 
        }
 
    }
 

	
 
    None
 
}
 

	
 
fn seek_stmt<F: Fn(&Statement) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<StatementId> {
 
    let stmt = &heap[start];
 
    if f(stmt) { return Some(start); }
 

	
 
    // This statement wasn't it, try to recurse
 
    let matched = match stmt {
 
        Statement::Block(block) => {
 
            for sub_id in &block.statements {
 
                if let Some(id) = seek_stmt(heap, *sub_id, f) {
 
                    return Some(id);
 
                }
 
            }
 

	
 
            None
 
        },
 
        Statement::Labeled(stmt) => seek_stmt(heap, stmt.body, f),
 
        Statement::If(stmt) => {
 
            if let Some(id) = seek_stmt(heap, stmt.true_case.body, f) {
 
                return Some(id);
 
            } else if let Some(false_body) = stmt.false_case {
 
                if let Some(id) = seek_stmt(heap, false_body.body, f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::While(stmt) => seek_stmt(heap, stmt.body, f),
 
        Statement::Synchronous(stmt) => seek_stmt(heap, stmt.body, f),
 
        _ => None
 
    };
 

	
 
    matched
 
}
 

	
 
fn seek_scope<F: Fn(&Scope) -> bool>(heap: &Heap, start: ScopeId, f: &F) -> Option<ScopeId> {
 
    let scope = &heap[start];
 
    if f(scope) { return Some(start); }
 

	
 
    for child_scope_id in scope.nested.iter().copied() {
 
        if let Some(result) = seek_scope(heap, child_scope_id, f) {
 
            return Some(result);
 
        }
 
    }
 

	
 
    return None;
 
}
 

	
 
fn seek_expr_in_expr<F: Fn(&Expression) -> bool>(heap: &Heap, start: ExpressionId, f: &F) -> Option<ExpressionId> {
 
    let expr = &heap[start];
 
    if f(expr) { return Some(start); }
 

	
 
    match expr {
 
        Expression::Assignment(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Binding(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_to, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.bound_from, f))
 
        }
 
        Expression::Conditional(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.test, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.true_expression, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.false_expression, f))
 
        },
 
        Expression::Binary(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.left, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.right, f))
 
        },
 
        Expression::Unary(expr) => {
 
            seek_expr_in_expr(heap, expr.expression, f)
 
        },
 
        Expression::Indexing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.index, f))
 
        },
 
        Expression::Slicing(expr) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, expr.subject, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.from_index, f))
 
            .or_else(|| seek_expr_in_expr(heap, expr.to_index, f))
 
        },
 
        Expression::Select(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        },
 
        Expression::Literal(expr) => {
 
            if let Literal::Struct(lit) = &expr.value {
 
                for field in &lit.fields {
 
                    if let Some(id) = seek_expr_in_expr(heap, field.value, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            } else if let Literal::Array(elements) = &expr.value {
 
                for element in elements {
 
                    if let Some(id) = seek_expr_in_expr(heap, *element, f) {
 
                        return Some(id)
 
                    }
 
                }
 
            }
 
            None
 
        },
 
        Expression::Cast(expr) => {
 
            seek_expr_in_expr(heap, expr.subject, f)
 
        }
 
        Expression::Call(expr) => {
 
            for arg in &expr.arguments {
 
                if let Some(id) = seek_expr_in_expr(heap, *arg, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Expression::Variable(_expr) => {
 
            None
 
        }
 
    }
 
}
 

	
 
fn seek_expr_in_stmt<F: Fn(&Expression) -> bool>(heap: &Heap, start: StatementId, f: &F) -> Option<ExpressionId> {
 
    let stmt = &heap[start];
 

	
 
    match stmt {
 
        Statement::Local(stmt) => {
 
            match stmt {
 
                LocalStatement::Memory(stmt) => seek_expr_in_expr(heap, stmt.initial_expr.upcast(), f),
 
                LocalStatement::Channel(_) => None
 
            }
 
        }
 
        Statement::Block(stmt) => {
 
            for stmt_id in &stmt.statements {
 
                if let Some(id) = seek_expr_in_stmt(heap, *stmt_id, f) {
 
                    return Some(id)
 
                }
 
            }
 
            None
 
        },
 
        Statement::Labeled(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body, f)
 
        },
 
        Statement::If(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.true_case.body, f))
 
            .or_else(|| if let Some(false_body) = stmt.false_case {
 
                seek_expr_in_stmt(heap, false_body.body, f)
 
            } else {
 
                None
 
            })
 
        },
 
        Statement::While(stmt) => {
 
            None
 
            .or_else(|| seek_expr_in_expr(heap, stmt.test, f))
 
            .or_else(|| seek_expr_in_stmt(heap, stmt.body, f))
 
        },
 
        Statement::Synchronous(stmt) => {
 
            seek_expr_in_stmt(heap, stmt.body, f)
 
        },
 
        Statement::Return(stmt) => {
 
            for expr_id in &stmt.expressions {
 
                if let Some(id) = seek_expr_in_expr(heap, *expr_id, f) {
 
                    return Some(id);
 
                }
 
            }
 
            None
 
        },
 
        Statement::New(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression.upcast(), f)
 
        },
 
        Statement::Expression(stmt) => {
 
            seek_expr_in_expr(heap, stmt.expression, f)
 
        },
 
        _ => None
 
    }
 
}
 

	
 
struct FakeRunContext{}
 
impl RunContext for FakeRunContext {
 
    fn performed_put(&mut self, _port: PortId) -> bool {
 
        unreachable!("'put' called in compiler testing code")
 
    }
 

	
 
    fn performed_get(&mut self, _port: PortId) -> Option<ValueGroup> {
 
        unreachable!("'get' called in compiler testing code")
 
    }
 

	
 
    fn fires(&mut self, _port: PortId) -> Option<Value> {
 
        unreachable!("'fires' called in compiler testing code")
 
    }
 

	
 
    fn performed_fork(&mut self) -> Option<bool> {
 
        unreachable!("'fork' called in compiler testing code")
 
    }
 

	
 
    fn created_channel(&mut self) -> Option<(Value, Value)> {
 
        unreachable!("channel created in compiler testing code")
 
    }
 
    fn performed_put(&mut self, _port: PortId) -> bool { unreachable!() }
 
    fn performed_get(&mut self, _port: PortId) -> Option<ValueGroup> { unreachable!() }
 
    fn fires(&mut self, _port: PortId) -> Option<Value> { unreachable!() }
 
    fn performed_fork(&mut self) -> Option<bool> { unreachable!() }
 
    fn created_channel(&mut self) -> Option<(Value, Value)> { unreachable!() }
 
    fn performed_select_start(&mut self) -> bool { unreachable!() }
 
    fn performed_select_register_port(&mut self) -> bool { unreachable!() }
 
    fn performed_select_wait(&mut self) -> Option<u32> { unreachable!() }
 
}
 
\ No newline at end of file
src/runtime/connector.rs
Show inline comments
 
// connector.rs
 
//
 
// Represents a component. A component (and the scheduler that is running it)
 
// has many properties that are not easy to subdivide into aspects that are
 
// conceptually handled by particular data structures. That is to say: the code
 
// that we run governs: running PDL code, keeping track of ports, instantiating
 
// new components and transports (i.e. interacting with the runtime), running
 
// a consensus algorithm, etc. But on the other hand, our data is rather
 
// simple: we have a speculative execution tree, a set of ports that we own,
 
// and a bit of code that we should run.
 
//
 
// So currently the code is organized as following:
 
// - The scheduler that is running the component is the authoritative source on
 
//     ports during *non-sync* mode. The consensus algorithm is the
 
//     authoritative source during *sync* mode. They retrieve each other's
 
//     state during the transitions. Hence port data exists duplicated between
 
//     these two datastructures.
 
// - The execution tree is where executed branches reside. But the execution
 
//     tree is only aware of the tree shape itself (and keeps track of some
 
//     queues of branches that are in a particular state), and tends to store
 
//     the PDL program state. The consensus algorithm is also somewhat aware
 
//     of the execution tree, but only in terms of what is needed to complete
 
//     a sync round (for now, that means the port mapping in each branch).
 
//     Hence once more we have properties conceptually associated with branches
 
//     in two places.
 
// - TODO: Write about handling messages, consensus wrapping data
 
// - TODO: Write about way information is exchanged between PDL/component and scheduler through ctx
 

	
 
use std::sync::atomic::AtomicBool;
 

	
 
use crate::ProtocolDescription;
 
use crate::protocol::eval::{EvalContinuation, EvalError, Prompt, Value, PortId, ValueGroup};
 
use crate::protocol::RunContext;
 

	
 
use super::branch::{BranchId, ExecTree, QueueKind, SpeculativeState, PreparedStatement};
 
use super::consensus::{Consensus, Consistency, RoundConclusion, find_ports_in_value_group};
 
use super::inbox::{DataMessage, Message, SyncCompMessage, SyncPortMessage, SyncControlMessage, PublicInbox};
 
use super::native::Connector;
 
use super::port::{PortKind, PortIdLocal};
 
use super::scheduler::{ComponentCtx, SchedulerCtx, MessageTicket};
 

	
 
pub(crate) struct ConnectorPublic {
 
    pub inbox: PublicInbox,
 
    pub sleeping: AtomicBool,
 
}
 

	
 
impl ConnectorPublic {
 
    pub fn new(initialize_as_sleeping: bool) -> Self {
 
        ConnectorPublic{
 
            inbox: PublicInbox::new(),
 
            sleeping: AtomicBool::new(initialize_as_sleeping),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 
enum Mode {
 
    NonSync,    // running non-sync code
 
    Sync,       // running sync code (in potentially multiple branches)
 
    SyncError,  // encountered an unrecoverable error in sync mode
 
    Error,      // encountered an error in non-sync mode (or finished handling the sync mode error).
 
}
 

	
 
#[derive(Debug)]
 
pub(crate) enum ConnectorScheduling {
 
    Immediate,          // Run again, immediately
 
    Later,              // Schedule for running, at some later point in time
 
    NotNow,             // Do not reschedule for running
 
    Exit,               // Connector has exited
 
}
 

	
 
pub(crate) struct ConnectorPDL {
 
    mode: Mode,
 
    eval_error: Option<EvalError>,
 
    tree: ExecTree,
 
    consensus: Consensus,
 
    last_finished_handled: Option<BranchId>,
 
}
 

	
 
struct ConnectorRunContext<'a> {
 
    branch_id: BranchId,
 
    consensus: &'a Consensus,
 
    prepared: PreparedStatement,
 
}
 

	
 
impl<'a> RunContext for ConnectorRunContext<'a>{
 
    fn performed_put(&mut self, _port: PortId) -> bool {
 
        return match self.prepared.take() {
 
            PreparedStatement::None => false,
 
            PreparedStatement::PerformedPut => true,
 
            taken => unreachable!("prepared statement is '{:?}' during 'performed_put()'", taken)
 
        };
 
    }
 

	
 
    fn performed_get(&mut self, _port: PortId) -> Option<ValueGroup> {
 
        return match self.prepared.take() {
 
            PreparedStatement::None => None,
 
            PreparedStatement::PerformedGet(value) => Some(value),
 
            taken => unreachable!("prepared statement is '{:?}' during 'performed_get()'", taken),
 
        };
 
    }
 

	
 
    fn fires(&mut self, _port: PortId) -> Option<Value> {
 
        todo!("Remove fires() now")
 
        // let port_id = PortIdLocal::new(port.id);
 
        // let annotation = self.consensus.get_annotation(self.branch_id, port_id);
 
        // return annotation.expected_firing.map(|v| Value::Bool(v));
 
    }
 

	
 
    fn created_channel(&mut self) -> Option<(Value, Value)> {
 
        return match self.prepared.take() {
 
            PreparedStatement::None => None,
 
            PreparedStatement::CreatedChannel(ports) => Some(ports),
 
            taken => unreachable!("prepared statement is '{:?}' during 'created_channel()'", taken),
 
        };
 
    }
 

	
 
    fn performed_fork(&mut self) -> Option<bool> {
 
        return match self.prepared.take() {
 
            PreparedStatement::None => None,
 
            PreparedStatement::ForkedExecution(path) => Some(path),
 
            taken => unreachable!("prepared statement is '{:?}' during 'performed_fork()'", taken),
 
        };
 
    }
 

	
 
    fn performed_select_start(&mut self) -> bool { unreachable!() }
 
    fn performed_select_register_port(&mut self) -> bool { unreachable!() }
 
    fn performed_select_wait(&mut self) -> Option<u32> { unreachable!() }
 
}
 

	
 
impl Connector for ConnectorPDL {
 
    fn run(&mut self, sched_ctx: SchedulerCtx, comp_ctx: &mut ComponentCtx) -> ConnectorScheduling {
 
        if let Some(scheduling) = self.handle_new_messages(comp_ctx) {
 
            return scheduling;
 
        }
 

	
 
        match self.mode {
 
            Mode::Sync => {
 
                // Run in sync mode
 
                let scheduling = self.run_in_sync_mode(sched_ctx, comp_ctx);
 

	
 
                // Handle any new finished branches
 
                let mut iter_id = self.last_finished_handled.or(self.tree.get_queue_first(QueueKind::FinishedSync));
 
                while let Some(branch_id) = iter_id {
 
                    iter_id = self.tree.get_queue_next(branch_id);
 
                    self.last_finished_handled = Some(branch_id);
 

	
 
                    if let Some(round_conclusion) = self.consensus.handle_new_finished_sync_branch(branch_id, comp_ctx) {
 
                        // Actually found a solution
 
                        return self.enter_non_sync_mode(round_conclusion, comp_ctx);
 
                    }
 

	
 
                    self.last_finished_handled = Some(branch_id);
 
                }
 

	
 
                return scheduling;
 
            },
 
            Mode::NonSync => {
 
                let scheduling = self.run_in_deterministic_mode(sched_ctx, comp_ctx);
 
                return scheduling;
 
            },
 
            Mode::SyncError => {
 
                let scheduling = self.run_in_sync_mode(sched_ctx, comp_ctx);
 
                return scheduling;
 
            },
 
            Mode::Error => {
 
                // This shouldn't really be called. Because when we reach exit
 
                // mode the scheduler should not run the component anymore
 
                unreachable!("called component run() during error-mode");
 
            },
 
        }
 
    }
 
}
 

	
 
impl ConnectorPDL {
 
    pub fn new(initial: Prompt) -> Self {
 
        Self{
 
            mode: Mode::NonSync,
 
            eval_error: None,
 
            tree: ExecTree::new(initial),
 
            consensus: Consensus::new(),
 
            last_finished_handled: None,
 
        }
 
    }
 

	
 
    // --- Handling messages
 

	
 
    pub fn handle_new_messages(&mut self, ctx: &mut ComponentCtx) -> Option<ConnectorScheduling> {
 
        while let Some(ticket) = ctx.get_next_message_ticket() {
 
            let message = ctx.read_message_using_ticket(ticket);
 
            let immediate_result = if let Message::Data(_) = message {
 
                self.handle_new_data_message(ticket, ctx);
 
                None
 
            } else {
 
                match ctx.take_message_using_ticket(ticket) {
 
                    Message::Data(_) => unreachable!(),
 
                    Message::SyncComp(message) => {
 
                        self.handle_new_sync_comp_message(message, ctx)
 
                    },
 
                    Message::SyncPort(message) => {
 
                        self.handle_new_sync_port_message(message, ctx);
 
                        None
 
                    },
 
                    Message::SyncControl(message) => {
 
                        self.handle_new_sync_control_message(message, ctx)
 
                    },
 
                    Message::Control(_) => unreachable!("control message in component"),
 
                }
 
            };
 

	
 
            if let Some(result) = immediate_result {
 
                return Some(result);
 
            }
 
        }
 

	
 
        return None;
 
    }
 

	
 
    pub fn handle_new_data_message(&mut self, ticket: MessageTicket, ctx: &mut ComponentCtx) {
 
        // Go through all branches that are awaiting new messages and see if
 
        // there is one that can receive this message.
 
        if !self.consensus.handle_new_data_message(ticket, ctx) {
 
            // Message should not be handled now
 
            return;
 
        }
 

	
 
        let message = ctx.read_message_using_ticket(ticket).as_data();
 
        let mut iter_id = self.tree.get_queue_first(QueueKind::AwaitingMessage);
 
        while let Some(branch_id) = iter_id {
 
            iter_id = self.tree.get_queue_next(branch_id);
 

	
 
            let branch = &self.tree[branch_id];
 
            if branch.awaiting_port != message.data_header.target_port { continue; }
 
            if !self.consensus.branch_can_receive(branch_id, &message) { continue; }
 

	
 
            // This branch can receive, so fork and given it the message
 
            let receiving_branch_id = self.tree.fork_branch(branch_id);
 
            self.consensus.notify_of_new_branch(branch_id, receiving_branch_id);
 
            let receiving_branch = &mut self.tree[receiving_branch_id];
 

	
 
            debug_assert!(receiving_branch.awaiting_port == message.data_header.target_port);
 
            receiving_branch.awaiting_port = PortIdLocal::new_invalid();
 
            receiving_branch.prepared = PreparedStatement::PerformedGet(message.content.clone());
 
            self.consensus.notify_of_received_message(receiving_branch_id, &message, ctx);
 

	
 
            // And prepare the branch for running
 
            self.tree.push_into_queue(QueueKind::Runnable, receiving_branch_id);
 
        }
 
    }
 

	
 
    pub fn handle_new_sync_comp_message(&mut self, message: SyncCompMessage, ctx: &mut ComponentCtx) -> Option<ConnectorScheduling> {
 
        if let Some(round_conclusion) = self.consensus.handle_new_sync_comp_message(message, ctx) {
 
            return Some(self.enter_non_sync_mode(round_conclusion, ctx));
 
        }
 

	
 
        return None;
 
    }
 

	
 
    pub fn handle_new_sync_port_message(&mut self, message: SyncPortMessage, ctx: &mut ComponentCtx) {
 
        self.consensus.handle_new_sync_port_message(message, ctx);
 
    }
 

	
 
    pub fn handle_new_sync_control_message(&mut self, message: SyncControlMessage, ctx: &mut ComponentCtx) -> Option<ConnectorScheduling> {
 
        if let Some(round_conclusion) = self.consensus.handle_new_sync_control_message(message, ctx) {
 
            return Some(self.enter_non_sync_mode(round_conclusion, ctx));
 
        }
 

	
 
        return None;
 
    }
 

	
 
    // --- Running code
 

	
 
    pub fn run_in_sync_mode(&mut self, sched_ctx: SchedulerCtx, comp_ctx: &mut ComponentCtx) -> ConnectorScheduling {
 
        // Check if we have any branch that needs running
 
        debug_assert!(self.tree.is_in_sync() && self.consensus.is_in_sync());
 
        let branch_id = self.tree.pop_from_queue(QueueKind::Runnable);
 
        if branch_id.is_none() {
 
            return ConnectorScheduling::NotNow;
 
        }
 

	
 
        // Retrieve the branch and run it
 
        let branch_id = branch_id.unwrap();
 
        let branch = &mut self.tree[branch_id];
 

	
 
        let mut run_context = ConnectorRunContext{
 
            branch_id,
 
            consensus: &self.consensus,
 
            prepared: branch.prepared.take(),
 
        };
 

	
 
        let run_result = Self::run_prompt(&mut branch.code_state, &sched_ctx.runtime.protocol_description, &mut run_context);
 
        if let Err(eval_error) = run_result {
 
            self.eval_error = Some(eval_error);
 
            self.mode = Mode::SyncError;
 
            if let Some(conclusion) = self.consensus.notify_of_fatal_branch(branch_id, comp_ctx) {
 
                // We can exit immediately
 
                return self.enter_non_sync_mode(conclusion, comp_ctx);
 
            } else {
 
                // Current branch failed. But we may have other things that are
 
                // running.
 
                return ConnectorScheduling::Immediate;
 
            }
 
        }
 
        let run_result = run_result.unwrap();
 

	
 
        // Handle the returned result. Note that this match statement contains
 
        // explicit returns in case the run result requires that the component's
 
        // code is ran again immediately
 
        match run_result {
 
            EvalContinuation::BranchInconsistent => {
 
                // Branch became inconsistent
 
                branch.sync_state = SpeculativeState::Inconsistent;
 
            },
 
            EvalContinuation::BlockFires(port_id) => {
 
                // Branch called `fires()` on a port that has not been used yet.
 
                let port_id = PortIdLocal::new(port_id.id);
 

	
 
                // Create two forks, one that assumes the port will fire, and
 
                // one that assumes the port remains silent
 
                branch.sync_state = SpeculativeState::HaltedAtBranchPoint;
 

	
 
                let firing_branch_id = self.tree.fork_branch(branch_id);
 
                let silent_branch_id = self.tree.fork_branch(branch_id);
 
                self.consensus.notify_of_new_branch(branch_id, firing_branch_id);
 
                let _result = self.consensus.notify_of_speculative_mapping(firing_branch_id, port_id, true, comp_ctx);
 
                debug_assert_eq!(_result, Consistency::Valid);
 
                self.consensus.notify_of_new_branch(branch_id, silent_branch_id);
 
                let _result = self.consensus.notify_of_speculative_mapping(silent_branch_id, port_id, false, comp_ctx);
 
                debug_assert_eq!(_result, Consistency::Valid);
 

	
 
                // Somewhat important: we push the firing one first, such that
 
                // that branch is ran again immediately.
 
                self.tree.push_into_queue(QueueKind::Runnable, firing_branch_id);
 
                self.tree.push_into_queue(QueueKind::Runnable, silent_branch_id);
 

	
 
                return ConnectorScheduling::Immediate;
 
            },
 
            EvalContinuation::BlockGet(port_id) => {
 
                // Branch performed a `get()` on a port that does not have a
 
                // received message on that port.
 
                let port_id = PortIdLocal::new(port_id.id);
 

	
 
                branch.sync_state = SpeculativeState::HaltedAtBranchPoint;
 
                branch.awaiting_port = port_id;
 
                self.tree.push_into_queue(QueueKind::AwaitingMessage, branch_id);
 

	
 
                // Note: we only know that a branch is waiting on a message when
 
                // it reaches the `get` call. But we might have already received
 
                // a message that targets this branch, so check now.
 
                let mut any_message_received = false;
 
                for message in comp_ctx.get_read_data_messages(port_id) {
 
                    if self.consensus.branch_can_receive(branch_id, &message) {
 
                        // This branch can receive the message, so we do the
 
                        // fork-and-receive dance
 
                        let receiving_branch_id = self.tree.fork_branch(branch_id);
 
                        let branch = &mut self.tree[receiving_branch_id];
 
                        branch.awaiting_port = PortIdLocal::new_invalid();
 
                        branch.prepared = PreparedStatement::PerformedGet(message.content.clone());
 

	
 
                        self.consensus.notify_of_new_branch(branch_id, receiving_branch_id);
 
                        self.consensus.notify_of_received_message(receiving_branch_id, &message, comp_ctx);
 
                        self.tree.push_into_queue(QueueKind::Runnable, receiving_branch_id);
 

	
 
                        any_message_received = true;
 
                    }
 
                }
 

	
 
                if any_message_received {
 
                    return ConnectorScheduling::Immediate;
 
                }
 
            }
 
            EvalContinuation::SyncBlockEnd => {
 
                let consistency = self.consensus.notify_of_finished_branch(branch_id);
 
                if consistency == Consistency::Valid {
 
                    branch.sync_state = SpeculativeState::ReachedSyncEnd;
 
                    self.tree.push_into_queue(QueueKind::FinishedSync, branch_id);
 
                } else {
 
                    branch.sync_state = SpeculativeState::Inconsistent;
 
                }
 
            },
 
            EvalContinuation::NewFork => {
 
                // Like the `NewChannel` result. This means we're setting up
 
                // a branch and putting a marker inside the RunContext for the
 
                // next time we run the PDL code
 
                let left_id = branch_id;
 
                let right_id = self.tree.fork_branch(left_id);
 
                self.consensus.notify_of_new_branch(left_id, right_id);
 
                self.tree.push_into_queue(QueueKind::Runnable, left_id);
 
                self.tree.push_into_queue(QueueKind::Runnable, right_id);
 

	
 
                let left_branch = &mut self.tree[left_id];
 
                left_branch.prepared = PreparedStatement::ForkedExecution(true);
 
                let right_branch = &mut self.tree[right_id];
 
                right_branch.prepared = PreparedStatement::ForkedExecution(false);
 
            }
 
            EvalContinuation::Put(port_id, content) => {
 
                // Branch is attempting to send data
 
                let port_id = PortIdLocal::new(port_id.id);
 
                let (sync_header, data_header) = self.consensus.handle_message_to_send(branch_id, port_id, &content, comp_ctx);
 
                let message = DataMessage{ sync_header, data_header, content };
 
                match comp_ctx.submit_message(Message::Data(message)) {
 
                    Ok(_) => {
 
                        // Message is underway
 
                        branch.prepared = PreparedStatement::PerformedPut;
 
                        self.tree.push_into_queue(QueueKind::Runnable, branch_id);
 
                        return ConnectorScheduling::Immediate;
 
                    },
 
                    Err(_) => {
 
                        // We don't own the port
 
                        let pd = &sched_ctx.runtime.protocol_description;
 
                        let eval_error = branch.code_state.new_error_at_expr(
 
                            &pd.modules, &pd.heap,
 
                            String::from("attempted to 'put' on port that is no longer owned")
 
                        );
 
                        self.eval_error = Some(eval_error);
 
                        self.mode = Mode::SyncError;
 

	
 
                        if let Some(conclusion) = self.consensus.notify_of_fatal_branch(branch_id, comp_ctx) {
 
                            return self.enter_non_sync_mode(conclusion, comp_ctx);
 
                        }
 
                    }
 
                }
 
            },
 
            _ => unreachable!("unexpected run result {:?} in sync mode", run_result),
 
        }
 

	
 
        // If here then the run result did not require a particular action. We
 
        // return whether we have more active branches to run or not.
 
        if self.tree.queue_is_empty(QueueKind::Runnable) {
 
            return ConnectorScheduling::NotNow;
 
        } else {
 
            return ConnectorScheduling::Later;
 
        }
 
    }
 

	
 
    pub fn run_in_deterministic_mode(&mut self, sched_ctx: SchedulerCtx, comp_ctx: &mut ComponentCtx) -> ConnectorScheduling {
 
        debug_assert!(!self.tree.is_in_sync() && !self.consensus.is_in_sync());
 

	
 
        let branch = self.tree.base_branch_mut();
 
        debug_assert!(branch.sync_state == SpeculativeState::RunningNonSync);
 

	
 
        let mut run_context = ConnectorRunContext{
 
            branch_id: branch.id,
 
            consensus: &self.consensus,
 
            prepared: branch.prepared.take(),
 
        };
 
        let run_result = Self::run_prompt(&mut branch.code_state, &sched_ctx.runtime.protocol_description, &mut run_context);
 
        if let Err(eval_error) = run_result {
 
            comp_ctx.push_error(eval_error);
 
            return ConnectorScheduling::Exit
 
        }
 
        let run_result = run_result.unwrap();
 

	
 
        match run_result {
 
            EvalContinuation::ComponentTerminated => {
 
                branch.sync_state = SpeculativeState::Finished;
 
                return ConnectorScheduling::Exit;
 
            },
 
            EvalContinuation::SyncBlockStart => {
 
                comp_ctx.notify_sync_start();
 
                let sync_branch_id = self.tree.start_sync();
 
                debug_assert!(self.last_finished_handled.is_none());
 
                self.consensus.start_sync(comp_ctx);
 
                self.consensus.notify_of_new_branch(BranchId::new_invalid(), sync_branch_id);
 
                self.tree.push_into_queue(QueueKind::Runnable, sync_branch_id);
 
                self.mode = Mode::Sync;
 

	
 
                return ConnectorScheduling::Immediate;
 
            },
 
            EvalContinuation::NewComponent(definition_id, type_id, arguments) => {
 
                // Note: we're relinquishing ownership of ports. But because
 
                // we are in non-sync mode the scheduler will handle and check
 
                // port ownership transfer.
 
                debug_assert!(comp_ctx.workspace_ports.is_empty());
 
                find_ports_in_value_group(&arguments, &mut comp_ctx.workspace_ports);
 

	
 
                let new_prompt = Prompt::new(
 
                    &sched_ctx.runtime.protocol_description.types,
 
                    &sched_ctx.runtime.protocol_description.heap,
 
                    definition_id, type_id, arguments
 
                );
 
                let new_component = ConnectorPDL::new(new_prompt);
 
                comp_ctx.push_component(new_component, comp_ctx.workspace_ports.clone());
 
                comp_ctx.workspace_ports.clear();
 

	
 
                return ConnectorScheduling::Later;
 
            },
 
            EvalContinuation::NewChannel => {
 
                let (getter, putter) = sched_ctx.runtime.create_channel(comp_ctx.id);
 
                debug_assert!(getter.kind == PortKind::Getter && putter.kind == PortKind::Putter);
 
                branch.prepared = PreparedStatement::CreatedChannel((
 
                    Value::Output(PortId::new(putter.self_id.index)),
 
                    Value::Input(PortId::new(getter.self_id.index)),
 
                ));
 

	
 
                comp_ctx.push_port(putter);
 
                comp_ctx.push_port(getter);
 

	
 
                return ConnectorScheduling::Immediate;
 
            },
 
            _ => unreachable!("unexpected run result '{:?}' while running in non-sync mode", run_result),
 
        }
 
    }
 

	
 
    /// Helper that moves the component's state back into non-sync mode, using
 
    /// the provided solution branch ID as the branch that should be comitted to
 
    /// memory. If this function returns false, then the component is supposed
 
    /// to exit.
 
    fn enter_non_sync_mode(&mut self, conclusion: RoundConclusion, ctx: &mut ComponentCtx) -> ConnectorScheduling {
 
        debug_assert!(self.mode == Mode::Sync || self.mode == Mode::SyncError);
 

	
 
        // Depending on local state decide what to do
src/runtime2/component/component_pdl.rs
Show inline comments
 
use crate::protocol::*;
 
use crate::protocol::ast::ProcedureDefinitionId;
 
use crate::protocol::eval::{
 
    PortId as EvalPortId, Prompt,
 
    ValueGroup, Value,
 
    EvalContinuation, EvalResult, EvalError
 
};
 

	
 
use crate::runtime2::scheduler::SchedulerCtx;
 
use crate::runtime2::communication::*;
 

	
 
use super::component_context::*;
 
use super::control_layer::*;
 
use super::consensus::Consensus;
 

	
 
pub enum CompScheduling {
 
    Immediate,
 
    Requeue,
 
    Sleep,
 
    Exit,
 
}
 

	
 
pub enum ExecStmt {
 
    CreatedChannel((Value, Value)),
 
    PerformedPut,
 
    PerformedGet(ValueGroup),
 
    PerformedSelectStart,
 
    PerformedSelectRegister,
 
    PerformedSelectWait(u32),
 
    None,
 
}
 

	
 
impl ExecStmt {
 
    fn take(&mut self) -> ExecStmt {
 
        let mut value = ExecStmt::None;
 
        std::mem::swap(self, &mut value);
 
        return value;
 
    }
 

	
 
    fn is_none(&self) -> bool {
 
        match self {
 
            ExecStmt::None => return true,
 
            _ => return false,
 
        }
 
    }
 
}
 

	
 
pub struct ExecCtx {
 
    stmt: ExecStmt,
 
}
 

	
 
impl RunContext for ExecCtx {
 
    fn performed_put(&mut self, _port: EvalPortId) -> bool {
 
        match self.stmt.take() {
 
            ExecStmt::None => return false,
 
            ExecStmt::PerformedPut => return true,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn performed_get(&mut self, _port: EvalPortId) -> Option<ValueGroup> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::PerformedGet(value) => return Some(value),
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn fires(&mut self, _port: EvalPortId) -> Option<Value> {
 
        todo!("remove fires")
 
    }
 

	
 
    fn performed_fork(&mut self) -> Option<bool> {
 
        todo!("remove fork")
 
    }
 

	
 
    fn created_channel(&mut self) -> Option<(Value, Value)> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::CreatedChannel(ports) => return Some(ports),
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn performed_select_start(&mut self) -> bool {
 
        match self.stmt.take() {
 
            ExecStmt::None => return false,
 
            ExecStmt::PerformedSelectStart => return true,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn performed_select_register_port(&mut self) -> bool {
 
        match self.stmt.take() {
 
            ExecStmt::None => return false,
 
            ExecStmt::PerformedSelectRegister => return true,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn performed_select_wait(&mut self) -> Option<u32> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::PerformedSelectWait(selected_case) => Some(selected_case),
 
            _ => unreachable!(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
pub(crate) enum Mode {
 
    NonSync, // not in sync mode
 
    Sync, // in sync mode, can interact with other components
 
    SyncEnd, // awaiting a solution, i.e. encountered the end of the sync block
 
    BlockedGet,
 
    BlockedPut,
 
    StartExit, // temporary state: if encountered then we start the shutdown process
 
    BusyExit, // temporary state: waiting for Acks for all the closed ports
 
    Exit, // exiting: shutdown process started, now waiting until the reference count drops to 0
 
}
 

	
 
pub(crate) struct CompPDL {
 
    pub mode: Mode,
 
    pub mode_port: PortId, // when blocked on a port
 
    pub mode_value: ValueGroup, // when blocked on a put
 
    pub prompt: Prompt,
 
    pub control: ControlLayer,
 
    pub consensus: Consensus,
 
    pub sync_counter: u32,
 
    pub exec_ctx: ExecCtx,
 
    // TODO: Temporary field, simulates future plans of having one storage place
 
    //  reserved per port.
 
    // Should be same length as the number of ports. Corresponding indices imply
 
    // message is intended for that port.
 
    pub inbox_main: Vec<Option<DataMessage>>,
 
    pub inbox_backup: Vec<DataMessage>,
 
}
 

	
 
impl CompPDL {
 
    pub(crate) fn new(initial_state: Prompt, num_ports: usize) -> Self {
 
        let mut inbox_main = Vec::new();
 
        inbox_main.reserve(num_ports);
 
        for _ in 0..num_ports {
 
            inbox_main.push(None);
 
        }
 

	
 
        return Self{
 
            mode: Mode::NonSync,
 
            mode_port: PortId::new_invalid(),
 
            mode_value: ValueGroup::default(),
 
            prompt: initial_state,
 
            control: ControlLayer::default(),
 
            consensus: Consensus::new(),
 
            sync_counter: 0,
 
            exec_ctx: ExecCtx{
 
                stmt: ExecStmt::None,
 
            },
 
            inbox_main,
 
            inbox_backup: Vec::new(),
 
        }
 
    }
 

	
 
    pub(crate) fn handle_message(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx, mut message: Message) {
 
        sched_ctx.log(&format!("handling message: {:#?}", message));
 
        if let Some(new_target) = self.control.should_reroute(&mut message) {
 
            let mut target = sched_ctx.runtime.get_component_public(new_target);
 
            target.send_message(sched_ctx, message, false); // not waking up: we schedule once we've received all PortPeerChanged Acks
 
            let _should_remove = target.decrement_users();
 
            debug_assert!(_should_remove.is_none());
 
            return;
 
        }
 

	
 
        match message {
 
            Message::Data(message) => {
 
                self.handle_incoming_data_message(sched_ctx, comp_ctx, message);
 
            },
 
            Message::Control(message) => {
 
                self.handle_incoming_control_message(sched_ctx, comp_ctx, message);
 
            },
 
            Message::Sync(message) => {
 
                self.handle_incoming_sync_message(sched_ctx, comp_ctx, message);
 
            }
 
        }
 
    }
 

	
 
    // -------------------------------------------------------------------------
 
    // Running component and handling changes in global component state
 
    // -------------------------------------------------------------------------
 

	
 
    pub(crate) fn run(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx) -> Result<CompScheduling, EvalError> {
 
        use EvalContinuation as EC;
 

	
 
        sched_ctx.log(&format!("Running component (mode: {:?})", self.mode));
 

	
 
        // Depending on the mode don't do anything at all, take some special
 
        // actions, or fall through and run the PDL code.
 
        match self.mode {
 
            Mode::NonSync | Mode::Sync => {},
 
            Mode::SyncEnd | Mode::BlockedGet | Mode::BlockedPut => {
 
                return Ok(CompScheduling::Sleep);
 
            }
 
            Mode::StartExit => {
 
                self.handle_component_exit(sched_ctx, comp_ctx);
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            Mode::BusyExit => {
 
                if self.control.has_acks_remaining() {
 
                    return Ok(CompScheduling::Sleep);
 
                } else {
 
                    self.mode = Mode::Exit;
 
                    return Ok(CompScheduling::Exit);
 
                }
 
            },
 
            Mode::Exit => {
 
                return Ok(CompScheduling::Exit);
 
            }
 
        }
 

	
 
        let run_result = self.execute_prompt(&sched_ctx)?;
 

	
 
        match run_result {
 
            EC::Stepping => unreachable!(), // execute_prompt runs until this is no longer returned
 
            EC::BranchInconsistent | EC::NewFork | EC::BlockFires(_) => todo!("remove these"),
 
            // Results that can be returned in sync mode
 
            EC::SyncBlockEnd => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                self.handle_sync_end(sched_ctx, comp_ctx);
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            EC::BlockGet(port_id) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                debug_assert!(self.exec_ctx.stmt.is_none());
 

	
 
                let port_id = port_id_from_eval(port_id);
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                let port_index = comp_ctx.get_port_index(port_handle);
 
                if let Some(message) = &self.inbox_main[port_index] {
 
                    // Check if we can actually receive the message
 
                    if self.consensus.try_receive_data_message(sched_ctx, comp_ctx, message) {
 
                        // Message was received. Make sure any blocked peers and
 
                        // pending messages are handled.
 
                        let message = self.inbox_main[port_index].take().unwrap();
 
                        self.handle_received_data_message(sched_ctx, comp_ctx, port_handle);
 

	
 
                        self.exec_ctx.stmt = ExecStmt::PerformedGet(message.content);
 
                        return Ok(CompScheduling::Immediate);
 
                    } else {
 
                        todo!("handle sync failure due to message deadlock");
 
                        return Ok(CompScheduling::Sleep);
 
                    }
 
                } else {
 
                    // We need to wait
 
                    self.mode = Mode::BlockedGet;
 
                    self.mode_port = port_id;
 
                    return Ok(CompScheduling::Sleep);
 
                }
 
            },
 
            EC::Put(port_id, value) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                let port_id = port_id_from_eval(port_id);
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                let port_info = comp_ctx.get_port(port_handle);
 
                if port_info.state.is_blocked() {
 
                    self.mode = Mode::BlockedPut;
 
                    self.mode_port = port_id;
 
                    self.mode_value = value;
 
                    self.exec_ctx.stmt = ExecStmt::PerformedPut; // prepare for when we become unblocked
 
                    return Ok(CompScheduling::Sleep);
 
                } else {
 
                    self.send_data_message_and_wake_up(sched_ctx, comp_ctx, port_handle, value);
 
                    self.exec_ctx.stmt = ExecStmt::PerformedPut;
 
                    return Ok(CompScheduling::Immediate);
 
                }
 
            },
 
            EC::SelectStart(num_cases, num_ports) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                todo!("finish handling select start")
 
            },
 
            EC::SelectRegisterPort(case_index, port_index, port_id) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                todo!("finish handling register port")
 
            },
 
            EC::SelectWait => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                self.handle_select_wait(sched_ctx, comp_ctx);
 
                todo!("finish handling select wait")
 
            },
 
            // Results that can be returned outside of sync mode
 
            EC::ComponentTerminated => {
 
                self.mode = Mode::StartExit; // next call we'll take care of the exit
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            EC::SyncBlockStart => {
 
                debug_assert_eq!(self.mode, Mode::NonSync);
 
                self.handle_sync_start(sched_ctx, comp_ctx);
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            EC::NewComponent(definition_id, type_id, arguments) => {
 
                debug_assert_eq!(self.mode, Mode::NonSync);
 
                self.create_component_and_transfer_ports(
 
                    sched_ctx, comp_ctx,
 
                    definition_id, type_id, arguments
 
                );
 
                return Ok(CompScheduling::Requeue);
 
            },
 
            EC::NewChannel => {
 
                debug_assert_eq!(self.mode, Mode::NonSync);
 
                debug_assert!(self.exec_ctx.stmt.is_none());
 
                let channel = comp_ctx.create_channel();
 
                self.exec_ctx.stmt = ExecStmt::CreatedChannel((
 
                    Value::Output(port_id_to_eval(channel.putter_id)),
 
                    Value::Input(port_id_to_eval(channel.getter_id))
 
                ));
 
                self.inbox_main.push(None);
 
                self.inbox_main.push(None);
 
                return Ok(CompScheduling::Immediate);
 
            }
 
        }
 
    }
 

	
 
    fn execute_prompt(&mut self, sched_ctx: &SchedulerCtx) -> EvalResult {
 
        let mut step_result = EvalContinuation::Stepping;
 
        while let EvalContinuation::Stepping = step_result {
 
            step_result = self.prompt.step(
 
                &sched_ctx.runtime.protocol.types, &sched_ctx.runtime.protocol.heap,
 
                &sched_ctx.runtime.protocol.modules, &mut self.exec_ctx,
 
            )?;
 
        }
 

	
 
        return Ok(step_result)
 
    }
 

	
 
    fn handle_sync_start(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
 
        sched_ctx.log("Component starting sync mode");
 
        self.consensus.notify_sync_start(comp_ctx);
 
        debug_assert_eq!(self.mode, Mode::NonSync);
 
        self.mode = Mode::Sync;
 
    }
 

	
 
    /// Handles end of sync. The conclusion to the sync round might arise
 
    /// immediately (and be handled immediately), or might come later through
 
    /// messaging. In any case the component should be scheduled again
 
    /// immediately
 
    fn handle_sync_end(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
 
        sched_ctx.log("Component ending sync mode (now waiting for solution)");
 
        let decision = self.consensus.notify_sync_end(sched_ctx, comp_ctx);
 
        self.mode = Mode::SyncEnd;
 
        self.handle_sync_decision(sched_ctx, comp_ctx, decision);
 
    }
 

	
 
    /// Handles decision from the consensus round. This will cause a change in
 
    /// the internal `Mode`, such that the next call to `run` can take the
 
    /// appropriate next steps.
 
    fn handle_sync_decision(&mut self, sched_ctx: &SchedulerCtx, _comp_ctx: &mut CompCtx, decision: SyncRoundDecision) {
 
        sched_ctx.log(&format!("Handling sync decision: {:?} (in mode {:?})", decision, self.mode));
 
        let is_success = match decision {
 
            SyncRoundDecision::None => {
 
                // No decision yet
 
                return;
 
            },
 
            SyncRoundDecision::Solution => true,
 
            SyncRoundDecision::Failure => false,
 
        };
 

	
 
        // If here then we've reached a decision
 
        debug_assert_eq!(self.mode, Mode::SyncEnd);
 
        if is_success {
 
            self.mode = Mode::NonSync;
 
            self.consensus.notify_sync_decision(decision);
 
        } else {
 
            self.mode = Mode::StartExit;
 
        }
 
    }
 

	
 
    /// Handles the moment where the PDL code has notified the runtime of all
 
    /// the ports it is waiting on.
 
    fn handle_select_wait(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
 
        sched_ctx.log("Component waiting for select conclusion");
 

	
 
    }
 

	
 
    fn handle_component_exit(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
 
        sched_ctx.log("Component exiting");
 
        debug_assert_eq!(self.mode, Mode::StartExit);
 
        self.mode = Mode::BusyExit;
 

	
 
        // Doing this by index, then retrieving the handle is a bit rediculous,
 
        // but Rust is being Rust with its borrowing rules.
 
        for port_index in 0..comp_ctx.num_ports() {
 
            let port = comp_ctx.get_port_by_index_mut(port_index);
 
            if port.state == PortState::Closed {
 
                // Already closed, or in the process of being closed
 
                continue;
 
            }
 

	
 
            // Mark as closed
 
            let port_id = port.self_id;
 
            port.state = PortState::Closed;
 

	
 
            // Notify peer of closing
 
            let port_handle = comp_ctx.get_port_handle(port_id);
 
            let (peer, message) = self.control.initiate_port_closing(port_handle, comp_ctx);
 
            let peer_info = comp_ctx.get_peer(peer);
 
            peer_info.handle.send_message(sched_ctx, Message::Control(message), true);
 
        }
 
    }
 

	
 
    // -------------------------------------------------------------------------
 
    // Handling messages
 
    // -------------------------------------------------------------------------
 

	
 
    fn send_data_message_and_wake_up(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, source_port_handle: LocalPortHandle, value: ValueGroup) {
 
        let port_info = comp_ctx.get_port(source_port_handle);
 
        let peer_handle = comp_ctx.get_peer_handle(port_info.peer_comp_id);
 
        let peer_info = comp_ctx.get_peer(peer_handle);
 
        let annotated_message = self.consensus.annotate_data_message(comp_ctx, port_info, value);
 
        peer_info.handle.send_message(sched_ctx, Message::Data(annotated_message), true);
 
    }
 

	
 
    /// Handles a message that came in through the public inbox. This function
 
    /// will handle putting it in the correct place, and potentially blocking
 
    /// the port in case too many messages are being received.
 
    fn handle_incoming_data_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: DataMessage) {
 
        // Check if we can insert it directly into the storage associated with
 
        // the port
 
        let target_port_id = message.data_header.target_port;
 
        let port_handle = comp_ctx.get_port_handle(target_port_id);
 
        let port_index = comp_ctx.get_port_index(port_handle);
 
        if self.inbox_main[port_index].is_none() {
 
            self.inbox_main[port_index] = Some(message);
 

	
 
            // After direct insertion, check if this component's execution is 
 
            // blocked on receiving a message on that port
 
            debug_assert!(!comp_ctx.get_port(port_handle).state.is_blocked()); // because we could insert directly
 
            if self.mode == Mode::BlockedGet && self.mode_port == target_port_id {
 
                // We were indeed blocked
 
                self.mode = Mode::Sync;
 
                self.mode_port = PortId::new_invalid();
 
            }
 
            
 
            return;
 
        }
 

	
 
        // The direct inbox is full, so the port will become (or was already) blocked
 
        let port_info = comp_ctx.get_port_mut(port_handle);
 
        debug_assert!(port_info.state == PortState::Open || port_info.state.is_blocked());
 

	
 
        if port_info.state == PortState::Open {
 
            comp_ctx.set_port_state(port_handle, PortState::BlockedDueToFullBuffers);
 
            let (peer_handle, message) =
 
                self.control.initiate_port_blocking(comp_ctx, port_handle);
 

	
 
            let peer = comp_ctx.get_peer(peer_handle);
 
            peer.handle.send_message(sched_ctx, Message::Control(message), true);
 
        }
 

	
 
        // But we still need to remember the message, so:
 
        self.inbox_backup.push(message);
 
    }
 

	
 
    /// Handles when a message has been handed off from the inbox to the PDL
 
    /// code. We check to see if there are more messages waiting and, if not,
 
    /// then we handle the case where the port might have been blocked
 
    /// previously.
 
    fn handle_received_data_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, port_handle: LocalPortHandle) {
 
        let port_index = comp_ctx.get_port_index(port_handle);
 
        debug_assert!(self.inbox_main[port_index].is_none()); // this function should be called after the message is taken out
 

	
 
        // Check for any more messages
 
        let port_info = comp_ctx.get_port(port_handle);
 
        for message_index in 0..self.inbox_backup.len() {
 
            let message = &self.inbox_backup[message_index];
 
            if message.data_header.target_port == port_info.self_id {
 
                // One more message for this port
 
                let message = self.inbox_backup.remove(message_index);
 
                debug_assert!(comp_ctx.get_port(port_handle).state.is_blocked()); // since we had >1 message on the port
 
                self.inbox_main[port_index] = Some(message);
 

	
 
                return;
 
            }
 
        }
 

	
 
        // Did not have any more messages. So if we were blocked, then we need
 
        // to send the "unblock" message.
 
        if port_info.state == PortState::BlockedDueToFullBuffers {
 
            comp_ctx.set_port_state(port_handle, PortState::Open);
 
            let (peer_handle, message) = self.control.cancel_port_blocking(comp_ctx, port_handle);
 
            let peer_info = comp_ctx.get_peer(peer_handle);
 
            peer_info.handle.send_message(sched_ctx, Message::Control(message), true);
 
        }
 
    }
 

	
 
    fn handle_incoming_control_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: ControlMessage) {
 
        // Little local utility to send an Ack
 
        fn send_control_ack_message(sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, causer_id: ControlId, peer_handle: LocalPeerHandle) {
 
            let peer_info = comp_ctx.get_peer(peer_handle);
 
            peer_info.handle.send_message(sched_ctx, Message::Control(ControlMessage{
 
                id: causer_id,
 
                sender_comp_id: comp_ctx.id,
 
                target_port_id: None,
 
                content: ControlMessageContent::Ack,
 
            }), true);
 
        }
 

	
 
        // Handle the content of the control message, and optionally Ack it
 
        match message.content {
 
            ControlMessageContent::Ack => {
 
                self.handle_ack(sched_ctx, comp_ctx, message.id);
 
            },
 
            ControlMessageContent::BlockPort(port_id) => {
 
                // On of our messages was accepted, but the port should be
 
                // blocked.
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                let port_info = comp_ctx.get_port(port_handle);
 
                debug_assert_eq!(port_info.kind, PortKind::Putter);
 
                if port_info.state == PortState::Open {
 
                    // only when open: we don't do this when closed, and we we don't do this if we're blocked due to peer changes
 
                    comp_ctx.set_port_state(port_handle, PortState::BlockedDueToFullBuffers);
 
                }
 
            },
 
            ControlMessageContent::ClosePort(port_id) => {
 
                // Request to close the port. We immediately comply and remove
 
                // the component handle as well
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                let peer_comp_id = comp_ctx.get_port(port_handle).peer_comp_id;
 
                let peer_handle = comp_ctx.get_peer_handle(peer_comp_id);
 

	
 
                // One exception to sending an `Ack` is if we just closed the
 
                // port ourselves, meaning that the `ClosePort` messages got
 
                // sent to one another.
 
                if let Some(control_id) = self.control.has_close_port_entry(port_handle, comp_ctx) {
 
                    self.handle_ack(sched_ctx, comp_ctx, control_id);
 
                } else {
 
                    send_control_ack_message(sched_ctx, comp_ctx, message.id, peer_handle);
 
                    comp_ctx.remove_peer(sched_ctx, port_handle, peer_comp_id, false); // do not remove if closed
 
                    comp_ctx.set_port_state(port_handle, PortState::Closed); // now set to closed
 
                }
 
            },
 
            ControlMessageContent::UnblockPort(port_id) => {
 
                // We were previously blocked (or already closed)
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                let port_info = comp_ctx.get_port(port_handle);
 
                debug_assert_eq!(port_info.kind, PortKind::Putter);
 
                if port_info.state == PortState::BlockedDueToFullBuffers {
 
                    self.handle_unblock_port_instruction(sched_ctx, comp_ctx, port_handle);
 
                }
 
            },
 
            ControlMessageContent::PortPeerChangedBlock(port_id) => {
 
                // The peer of our port has just changed. So we are asked to
 
                // temporarily block the port (while our original recipient is
 
                // potentially rerouting some of the in-flight messages) and
 
                // Ack. Then we wait for the `unblock` call.
 
                debug_assert_eq!(message.target_port_id, Some(port_id));
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                comp_ctx.set_port_state(port_handle, PortState::BlockedDueToPeerChange);
 

	
 
                let port_info = comp_ctx.get_port(port_handle);
 
                let peer_handle = comp_ctx.get_peer_handle(port_info.peer_comp_id);
 

	
 
                send_control_ack_message(sched_ctx, comp_ctx, message.id, peer_handle);
 
            },
 
            ControlMessageContent::PortPeerChangedUnblock(new_port_id, new_comp_id) => {
 
                let port_handle = comp_ctx.get_port_handle(message.target_port_id.unwrap());
 
                let port_info = comp_ctx.get_port(port_handle);
 
                debug_assert!(port_info.state == PortState::BlockedDueToPeerChange);
 
                let old_peer_id = port_info.peer_comp_id;
 

	
 
                comp_ctx.remove_peer(sched_ctx, port_handle, old_peer_id, false);
 

	
 
                let port_info = comp_ctx.get_port_mut(port_handle);
 
                port_info.peer_comp_id = new_comp_id;
 
                port_info.peer_port_id = new_port_id;
 
                comp_ctx.add_peer(port_handle, sched_ctx, new_comp_id, None);
 
                self.handle_unblock_port_instruction(sched_ctx, comp_ctx, port_handle);
 
            }
 
        }
 
    }
 

	
 
    fn handle_incoming_sync_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: SyncMessage) {
 
        let decision = self.consensus.receive_sync_message(sched_ctx, comp_ctx, message);
 
        self.handle_sync_decision(sched_ctx, comp_ctx, decision);
 
    }
 

	
 
    /// Little helper that notifies the control layer of an `Ack`, and takes the
 
    /// appropriate subsequent action
 
    fn handle_ack(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, control_id: ControlId) {
 
        let mut to_ack = control_id;
 
        loop {
 
            let (action, new_to_ack) = self.control.handle_ack(to_ack, sched_ctx, comp_ctx);
 
            match action {
 
                AckAction::SendMessage(target_comp, message) => {
 
                    // FIX @NoDirectHandle
 
                    let mut handle = sched_ctx.runtime.get_component_public(target_comp);
 
                    handle.send_message(sched_ctx, Message::Control(message), true);
 
                    let _should_remove = handle.decrement_users();
 
                    debug_assert!(_should_remove.is_none());
 
                },
 
                AckAction::ScheduleComponent(to_schedule) => {
 
                    // FIX @NoDirectHandle
 
                    let mut handle = sched_ctx.runtime.get_component_public(to_schedule);
 

	
 
                    // Note that the component is intentionally not
 
                    // sleeping, so we just wake it up
 
                    debug_assert!(!handle.sleeping.load(std::sync::atomic::Ordering::Acquire));
 
                    let key = unsafe{ to_schedule.upgrade() };
 
                    sched_ctx.runtime.enqueue_work(key);
 
                    let _should_remove = handle.decrement_users();
 
                    debug_assert!(_should_remove.is_none());
 
                },
 
                AckAction::None => {}
 
            }
 

	
 
            match new_to_ack {
 
                Some(new_to_ack) => to_ack = new_to_ack,
 
                None => break,
 
            }
 
        }
 
    }
 

	
 
    // -------------------------------------------------------------------------
 
    // Handling ports
 
    // -------------------------------------------------------------------------
 

	
 
    /// Unblocks a port, potentially continuing execution of the component, in
 
    /// response to a message that told us to unblock a previously blocked
 
    fn handle_unblock_port_instruction(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, port_handle: LocalPortHandle) {
 
        let port_info = comp_ctx.get_port_mut(port_handle);
 
        let port_id = port_info.self_id;
 
        debug_assert!(port_info.state.is_blocked());
 
        port_info.state = PortState::Open;
 

	
 
        if self.mode == Mode::BlockedPut && port_id == self.mode_port {
 
            // We were blocked on the port that just became unblocked, so
 
            // send the message.
 
            debug_assert_eq!(port_info.kind, PortKind::Putter);
 
            let mut replacement = ValueGroup::default();
 
            std::mem::swap(&mut replacement, &mut self.mode_value);
 
            self.send_data_message_and_wake_up(sched_ctx, comp_ctx, port_handle, replacement);
 

	
 
            self.mode = Mode::Sync;
 
            self.mode_port = PortId::new_invalid();
 
        }
 
    }
 

	
 
    fn create_component_and_transfer_ports(
 
        &mut self,
 
        sched_ctx: &SchedulerCtx, creator_ctx: &mut CompCtx,
 
        definition_id: ProcedureDefinitionId, type_id: TypeId, mut arguments: ValueGroup
 
    ) {
 
        struct PortPair{
 
            creator_handle: LocalPortHandle,
 
            creator_id: PortId,
 
            created_handle: LocalPortHandle,
 
            created_id: PortId,
 
        }
 
        let mut port_id_pairs = Vec::new();
 

	
 
        let reservation = sched_ctx.runtime.start_create_pdl_component();
 
        let mut created_ctx = CompCtx::new(&reservation);
 

	
 
        // Take all the ports ID that are in the `args` (and currently belong to
 
        // the creator component) and translate them into new IDs that are
 
        // associated with the component we're about to create
 
        let mut arg_iter = ValueGroupIter::new(&mut arguments);
 
        while let Some(port_reference) = arg_iter.next() {
 
            // Create port entry for new component
 
            let creator_port_id = port_reference.id;
 
            let creator_port_handle = creator_ctx.get_port_handle(creator_port_id);
 
            let creator_port = creator_ctx.get_port(creator_port_handle);
 
            let created_port_handle = created_ctx.add_port(
 
                creator_port.peer_comp_id, creator_port.peer_port_id,
 
                creator_port.kind, creator_port.state
 
            );
 
            let created_port = created_ctx.get_port(created_port_handle);
 
            let created_port_id = created_port.self_id;
 

	
 
            port_id_pairs.push(PortPair{
 
                creator_handle: creator_port_handle,
 
                creator_id: creator_port_id,
 
                created_handle: created_port_handle,
 
                created_id: created_port_id,
 
            });
 

	
 
            // Modify value in arguments (bit dirty, but double vec in ValueGroup causes lifetime issues)
 
            let arg_value = if let Some(heap_pos) = port_reference.heap_pos {
 
                &mut arg_iter.group.regions[heap_pos][port_reference.index]
 
            } else {
 
                &mut arg_iter.group.values[port_reference.index]
 
            };
 
            match arg_value {
 
                Value::Input(id) => *id = port_id_to_eval(created_port_id),
 
                Value::Output(id) => *id = port_id_to_eval(created_port_id),
 
                _ => unreachable!(),
 
            }
 
        }
 

	
 
        // For each transferred port pair set their peer components to the
 
        // correct values. This will only change the values for the ports of
 
        // the new component.
 
        let mut created_component_has_remote_peers = false;
 

	
 
        for pair in port_id_pairs.iter() {
 
            let creator_port_info = creator_ctx.get_port(pair.creator_handle);
 
            let created_port_info = created_ctx.get_port_mut(pair.created_handle);
 

	
 
            if created_port_info.peer_comp_id == creator_ctx.id {
 
                // Port peer is owned by the creator as well
 
                let created_peer_port_index = port_id_pairs
 
                    .iter()
 
                    .position(|v| v.creator_id == creator_port_info.peer_port_id);
 
                match created_peer_port_index {
 
                    Some(created_peer_port_index) => {
 
                        // Peer port moved to the new component as well. So
 
                        // adjust IDs appropriately.
 
                        let peer_pair = &port_id_pairs[created_peer_port_index];
 
                        created_port_info.peer_port_id = peer_pair.created_id;
 
                        created_port_info.peer_comp_id = reservation.id();
 
                        todo!("either add 'self peer', or remove that idea from Ctx altogether")
 
                    },
 
                    None => {
 
                        // Peer port remains with creator component.
 
                        created_port_info.peer_comp_id = creator_ctx.id;
 
                        created_ctx.add_peer(pair.created_handle, sched_ctx, creator_ctx.id, None);
 
                    }
 
                }
 
            } else {
 
                // Peer is a different component. We'll deal with sending the
 
                // appropriate messages later
 
                let peer_handle = creator_ctx.get_peer_handle(created_port_info.peer_comp_id);
 
                let peer_info = creator_ctx.get_peer(peer_handle);
 
                created_ctx.add_peer(pair.created_handle, sched_ctx, peer_info.id, Some(&peer_info.handle));
 
                created_component_has_remote_peers = true;
 
            }
 
        }
 

	
 
        // We'll now actually turn our reservation for a new component into an
 
        // actual component. Note that we initialize it as "not sleeping" as
 
        // its initial scheduling might be performed based on `Ack`s in response
 
        // to message exchanges between remote peers.
 
        let prompt = Prompt::new(
 
            &sched_ctx.runtime.protocol.types, &sched_ctx.runtime.protocol.heap,
 
            definition_id, type_id, arguments,
 
        );
 
        let component = CompPDL::new(prompt, port_id_pairs.len());
 
        let (created_key, component) = sched_ctx.runtime.finish_create_pdl_component(
 
            reservation, component, created_ctx, false,
 
        );
 
        let created_ctx = &component.ctx;
 

	
 
        // Now modify the creator's ports: remove every transferred port and
 
        // potentially remove the peer component. Here is also where we will
 
        // transfer messages in the main inbox.
 
        for pair in port_id_pairs.iter() {
 
            // Remove peer if appropriate
 
            let creator_port_info = creator_ctx.get_port(pair.creator_handle);
 
            let creator_port_index = creator_ctx.get_port_index(pair.creator_handle);
 
            let creator_peer_comp_id = creator_port_info.peer_comp_id;
 
            creator_ctx.remove_peer(sched_ctx, pair.creator_handle, creator_peer_comp_id, false);
 
            creator_ctx.remove_port(pair.creator_handle);
 

	
 
            // Transfer any messages
 
            let created_port_index = created_ctx.get_port_index(pair.created_handle);
 
            let created_port_info = created_ctx.get_port(pair.created_handle);
 
            debug_assert!(component.code.inbox_main[created_port_index].is_none());
 
            if let Some(mut message) = self.inbox_main.remove(creator_port_index) {

Changeset was too big and was cut off... Show full diff anyway

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