CSY/reowolf Changeset - 48a151ff33b5 · Centrum Wiskunde & Informatica (CWI)

Changeset - 48a151ff33b5

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mh - 3 years ago 2022-02-11 09:38:59
contact@maxhenger.nl

Moved scope creation to initial AST construction

3 files changed with 129 insertions and 125 deletions:

src/protocol/ast.rs

src/protocol/parser/pass_definitions.rs

src/protocol/parser/pass_validation_linking.rs

0 comments (0 inline, 0 general)

src/protocol/ast.rs

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@@ @@ -548,384 +548,400 @@ impl Default for ConcreteType { @@
         Self{ parts: Vec::new() }
+    }
+}
 impl ConcreteType {
     /// Returns an iterator over the subtrees that are type arguments (e.g. an
     /// array element's type, or a polymorphic type's arguments) to the
     /// provided parent type (specified by its index in the `parts` array).
     pub(crate) fn embedded_iter(&self, parent_part_idx: usize) -> ConcreteTypeIter {
         return ConcreteTypeIter::new(&self.parts, parent_part_idx);
+    }
     /// Construct a human-readable name for the type. Because this performs
     /// a string allocation don't use it for anything else then displaying the
     /// type to the user.
     pub(crate) fn display_name(&self, heap: &Heap) -> String {
         return Self::type_parts_display_name(self.parts.as_slice(), heap);
+    }
     // --- Utilities that operate on slice of parts
     /// Given the starting position of a type tree, determine the exclusive
     /// ending index.
     pub(crate) fn type_parts_subtree_end_idx(parts: &[ConcreteTypePart], start_idx: usize) -> usize {
         let mut depth = 1;
         let num_parts = parts.len();
         debug_assert!(start_idx < num_parts);
         for part_idx in start_idx..parts.len() {
             let depth_change = parts[part_idx].num_embedded() as i32 - 1;
             depth += depth_change;
             debug_assert!(depth >= 0);
             if depth == 0 {
                 return part_idx + 1;
+            }
+        }
         debug_assert!(false, "incorrectly constructed ConcreteType instance");
         return 0;
+    }
     /// Produces a human-readable representation of the concrete type parts
     fn type_parts_display_name(parts: &[ConcreteTypePart], heap: &Heap) -> String {
         let mut name = String::with_capacity(128);
         let _final_idx = Self::render_type_part_at(parts, heap, 0, &mut name);
         debug_assert_eq!(_final_idx, parts.len());
         return name;
+    }
     /// Produces a human-readable representation of a single type part. Lower
     /// level utility for `type_parts_display_name`.
     fn render_type_part_at(parts: &[ConcreteTypePart], heap: &Heap, mut idx: usize, target: &mut String) -> usize {
         use ConcreteTypePart as CTP;
         use crate::protocol::parser::token_parsing::*;
         let cur_idx = idx;
         idx += 1; // increment by 1, because it always happens
         match parts[cur_idx] {
             CTP::Void => { target.push_str("void"); },
             CTP::Message => { target.push_str(KW_TYPE_MESSAGE_STR); },
             CTP::Bool => { target.push_str(KW_TYPE_BOOL_STR); },
             CTP::UInt8 => { target.push_str(KW_TYPE_UINT8_STR); },
             CTP::UInt16 => { target.push_str(KW_TYPE_UINT16_STR); },
             CTP::UInt32 => { target.push_str(KW_TYPE_UINT32_STR); },
             CTP::UInt64 => { target.push_str(KW_TYPE_UINT64_STR); },
             CTP::SInt8 => { target.push_str(KW_TYPE_SINT8_STR); },
             CTP::SInt16 => { target.push_str(KW_TYPE_SINT16_STR); },
             CTP::SInt32 => { target.push_str(KW_TYPE_SINT32_STR); },
             CTP::SInt64 => { target.push_str(KW_TYPE_SINT64_STR); },
             CTP::Character => { target.push_str(KW_TYPE_CHAR_STR); },
             CTP::String => { target.push_str(KW_TYPE_STRING_STR); },
             CTP::Array | CTP::Slice => {
                 idx = Self::render_type_part_at(parts, heap, idx, target);
                 target.push_str("[]");
             },
             CTP::Input => {
                 target.push_str(KW_TYPE_IN_PORT_STR);
                 target.push('<');
                 idx = Self::render_type_part_at(parts, heap, idx, target);
                 target.push('>');
             },
             CTP::Output => {
                 target.push_str(KW_TYPE_OUT_PORT_STR);
                 target.push('<');
                 idx = Self::render_type_part_at(parts, heap, idx, target);
                 target.push('>');
             },
             CTP::Tuple(num_parts) => {
                 target.push('(');
                 if num_parts != 0 {
                     idx = Self::render_type_part_at(parts, heap, idx, target);
                     for _ in 1..num_parts {
                         target.push(',');
                         idx = Self::render_type_part_at(parts, heap, idx, target);
+                    }
+                }
                 target.push(')');
             },
             CTP::Instance(definition_id, num_poly_args) |
             CTP::Function(definition_id, num_poly_args) |
             CTP::Component(definition_id, num_poly_args) => {
                 let definition = &heap[definition_id];
                 target.push_str(definition.identifier().value.as_str());
                 if num_poly_args != 0 {
                     target.push('<');
                     for poly_arg_idx in 0..num_poly_args {
                         if poly_arg_idx != 0 {
                             target.push(',');
+                        }
                         idx = Self::render_type_part_at(parts, heap, idx, target);
+                    }
                     target.push('>');
+                }
+            }
+        }
         idx
+    }
+}
 #[derive(Debug)]
 pub struct ConcreteTypeIter<'a> {
     parts: &'a [ConcreteTypePart],
     idx_embedded: u32,
     num_embedded: u32,
     part_idx: usize,
+}
 impl<'a> ConcreteTypeIter<'a> {
     pub(crate) fn new(parts: &'a[ConcreteTypePart], parent_idx: usize) -> Self {
         let num_embedded = parts[parent_idx].num_embedded();
         return ConcreteTypeIter{
             parts,
             idx_embedded: 0,
             num_embedded,
             part_idx: parent_idx + 1,
+        }
+    }
+}
 impl<'a> Iterator for ConcreteTypeIter<'a> {
     type Item = &'a [ConcreteTypePart];
     fn next(&mut self) -> Option<Self::Item> {
         if self.idx_embedded == self.num_embedded {
             return None;
+        }
         // Retrieve the subtree of interest
         let start_idx = self.part_idx;
         let end_idx = ConcreteType::type_parts_subtree_end_idx(&self.parts, start_idx);
         self.idx_embedded += 1;
         self.part_idx = end_idx;
         return Some(&self.parts[start_idx..end_idx]);
+    }
+}
 #[derive(Debug, Clone, Copy)]
 pub enum ScopeAssociation {
     Definition(DefinitionId),
     Block(BlockStatementId),
     If(IfStatementId, bool), // if true, then body of "if", otherwise body of "else"
     While(WhileStatementId),
     Synchronous(SynchronousStatementId),
     SelectCase(SelectStatementId, u32), // index is select case
+}
 /// `ScopeNode` is a helper that links scopes in two directions. It doesn't
 /// actually contain any information associated with the scope, this may be
 /// found on the AST elements that `Scope` points to.
 #[derive(Debug, Clone)]
 pub struct Scope {
     // Relation to other scopes
     pub this: ScopeId,
     pub parent: Option<ScopeId>,
     pub nested: Vec<ScopeId>,
     // Locally available variables/labels
     pub association: ScopeAssociation,
     pub variables: Vec<VariableId>,
     pub labels: Vec<LabeledStatementId>,
     // Location trackers/counters
     pub relative_pos_in_parent: i32,
     pub first_unique_id_in_scope: i32,
     pub next_unique_id_in_scope: i32,
+}
 impl Scope {
     pub(crate) fn new(id: ScopeId, association: ScopeAssociation) -> Self {
         return Self{
             this: id,
             parent: None,
             nested: Vec::new(),
             association,
             variables: Vec::new(),
             labels: Vec::new(),
             relative_pos_in_parent: -1,
             first_unique_id_in_scope: -1,
             next_unique_id_in_scope: -1,
+        }
+    }
+}
 impl Scope {
     pub(crate) fn new_invalid(this: ScopeId) -> Self {
         return Self{
             this,
             parent: None,
             nested: Vec::new(),
             association: ScopeAssociation::Definition(DefinitionId::new_invalid()),
             variables: Vec::new(),
             labels: Vec::new(),
             relative_pos_in_parent: -1,
             first_unique_id_in_scope: -1,
             next_unique_id_in_scope: -1,
         };
+    }
+}
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum VariableKind {
     Parameter,      // in parameter list of function/component
     Local,          // declared in function/component body
     Binding,        // may be bound to in a binding expression (determined in validator/linker)
+}
 #[derive(Debug, Clone)]
 pub struct Variable {
     pub this: VariableId,
     // Parsing
     pub kind: VariableKind,
     pub parser_type: ParserType,
     pub identifier: Identifier,
     // Validator/linker
     pub relative_pos_in_parent: i32,
     pub unique_id_in_scope: i32, // Temporary fix until proper bytecode/asm is generated
+}
 #[derive(Debug, Clone)]
 pub enum Definition {
     Struct(StructDefinition),
     Enum(EnumDefinition),
     Union(UnionDefinition),
     Component(ComponentDefinition),
     Function(FunctionDefinition),
+}
 impl Definition {
     pub fn is_struct(&self) -> bool {
         match self {
             Definition::Struct(_) => true,
             _ => false
+        }
+    }
     pub(crate) fn as_struct(&self) -> &StructDefinition {
         match self {
             Definition::Struct(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
+        }
+    }
     pub(crate) fn as_struct_mut(&mut self) -> &mut StructDefinition {
         match self {
             Definition::Struct(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'StructDefinition'"),
+        }
+    }
     pub fn is_enum(&self) -> bool {
         match self {
             Definition::Enum(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_enum(&self) -> &EnumDefinition {
         match self {
             Definition::Enum(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
+        }
+    }
     pub(crate) fn as_enum_mut(&mut self) -> &mut EnumDefinition {
         match self {
             Definition::Enum(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'EnumDefinition'"),
+        }
+    }
     pub fn is_union(&self) -> bool {
         match self {
             Definition::Union(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_union(&self) -> &UnionDefinition {
         match self {
             Definition::Union(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
+        }
+    }
     pub(crate) fn as_union_mut(&mut self) -> &mut UnionDefinition {
         match self {
             Definition::Union(result) => result,
             _ => panic!("Unable to cast 'Definition' to 'UnionDefinition'"),
+        }
+    }
     pub fn is_component(&self) -> bool {
         match self {
             Definition::Component(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_component(&self) -> &ComponentDefinition {
         match self {
             Definition::Component(result) => result,
             _ => panic!("Unable to cast `Definition` to `Component`"),
+        }
+    }
     pub(crate) fn as_component_mut(&mut self) -> &mut ComponentDefinition {
         match self {
             Definition::Component(result) => result,
             _ => panic!("Unable to cast `Definition` to `Component`"),
+        }
+    }
     pub fn is_function(&self) -> bool {
         match self {
             Definition::Function(_) => true,
             _ => false,
+        }
+    }
     pub(crate) fn as_function(&self) -> &FunctionDefinition {
         match self {
             Definition::Function(result) => result,
             _ => panic!("Unable to cast `Definition` to `Function`"),
+        }
+    }
     pub(crate) fn as_function_mut(&mut self) -> &mut FunctionDefinition {
         match self {
             Definition::Function(result) => result,
             _ => panic!("Unable to cast `Definition` to `Function`"),
+        }
+    }
     pub fn parameters(&self) -> &Vec<VariableId> {
         match self {
             Definition::Component(def) => &def.parameters,
             Definition::Function(def) => &def.parameters,
             _ => panic!("Called parameters() on {:?}", self)
+        }
+    }
     pub fn defined_in(&self) -> RootId {
         match self {
             Definition::Struct(def) => def.defined_in,
             Definition::Enum(def) => def.defined_in,
             Definition::Union(def) => def.defined_in,
             Definition::Component(def) => def.defined_in,
             Definition::Function(def) => def.defined_in,
+        }
+    }
     pub fn identifier(&self) -> &Identifier {
         match self {
             Definition::Struct(def) => &def.identifier,
             Definition::Enum(def) => &def.identifier,
             Definition::Union(def) => &def.identifier,
             Definition::Component(def) => &def.identifier,
             Definition::Function(def) => &def.identifier,
+        }
+    }
     pub fn poly_vars(&self) -> &Vec<Identifier> {
         match self {
             Definition::Struct(def) => &def.poly_vars,
             Definition::Enum(def) => &def.poly_vars,
             Definition::Union(def) => &def.poly_vars,
             Definition::Component(def) => &def.poly_vars,
             Definition::Function(def) => &def.poly_vars,
+        }
+    }
+}
 #[derive(Debug, Clone)]
 pub struct StructFieldDefinition {
     pub span: InputSpan,
     pub field: Identifier,
     pub parser_type: ParserType,
+}
 #[derive(Debug, Clone)]
 pub struct StructDefinition {
     pub this: StructDefinitionId,
     pub defined_in: RootId,
     // Symbol scanning
     pub span: InputSpan,
     pub identifier: Identifier,
     pub poly_vars: Vec<Identifier>,
     // Parsing
     pub fields: Vec<StructFieldDefinition>
+}
 impl StructDefinition {
     pub(crate) fn new_empty(

src/protocol/parser/pass_definitions.rs

➞

Show inline comments

@@ @@ -150,719 +150,738 @@ impl PassDefinitions { @@
         struct_def.fields = fields_section.into_vec();
         Ok(())
+    }
     fn visit_enum_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         consume_exact_ident(&module.source, iter, KW_ENUM)?;
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated DefinitionId
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         // Parse enum definition
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         let mut enum_section = self.enum_variants.start_section();
         consume_comma_separated(
             TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
             |source, iter, ctx| {
                 let identifier = consume_ident_interned(source, iter, ctx)?;
                 let value = if iter.next() == Some(TokenKind::Equal) {
                     iter.consume();
                     let (variant_number, _) = consume_integer_literal(source, iter, &mut self.buffer)?;
                     EnumVariantValue::Integer(variant_number as i64) // TODO: @int
                 } else {
                     EnumVariantValue::None
                 };
                 Ok(EnumVariantDefinition{ identifier, value })
             },
             &mut enum_section, "an enum variant", "a list of enum variants", None
         )?;
         // Transfer to definition
         let enum_def = ctx.heap[definition_id].as_enum_mut();
         enum_def.variants = enum_section.into_vec();
         Ok(())
+    }
     fn visit_union_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         consume_exact_ident(&module.source, iter, KW_UNION)?;
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated DefinitionId
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         // Parse union definition
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         let mut variants_section = self.union_variants.start_section();
         consume_comma_separated(
             TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, ctx,
             |source, iter, ctx| {
                 let identifier = consume_ident_interned(source, iter, ctx)?;
                 let mut close_pos = identifier.span.end;
                 let mut types_section = self.parser_types.start_section();
                 let has_embedded = maybe_consume_comma_separated(
                     TokenKind::OpenParen, TokenKind::CloseParen, source, iter, ctx,
                     |source, iter, ctx| {
                         let poly_vars = ctx.heap[definition_id].poly_vars();
                         self.type_parser.consume_parser_type(
                             iter, &ctx.heap, source, &ctx.symbols, poly_vars, definition_id,
                             module_scope, false, None
+                        )
                     },
                     &mut types_section, "an embedded type", Some(&mut close_pos)
                 )?;
                 let value = if has_embedded {
                     types_section.into_vec()
                 } else {
                     types_section.forget();
                     Vec::new()
                 };
                 Ok(UnionVariantDefinition{
                     span: InputSpan::from_positions(identifier.span.begin, close_pos),
                     identifier,
                     value
                 })
             },
             &mut variants_section, "a union variant", "a list of union variants", None
         )?;
         // Transfer to AST
         let union_def = ctx.heap[definition_id].as_union_mut();
         union_def.variants = variants_section.into_vec();
         Ok(())
+    }
     fn visit_function_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         // Retrieve function name
         consume_exact_ident(&module.source, iter, KW_FUNCTION)?;
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated DefinitionId
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         // Parse function's argument list
         let mut parameter_section = self.variables.start_section();
         consume_parameter_list(
             &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
         )?;
         let parameters = parameter_section.into_vec();
         // Consume return types
         consume_token(&module.source, iter, TokenKind::ArrowRight)?;
         let poly_vars = ctx.heap[definition_id].poly_vars();
         let parser_type = self.type_parser.consume_parser_type(
             iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars, definition_id,
             module_scope, false, None
         )?;
         // Consume block and the definition's scope
         let body = self.consume_block_statement(module, iter, ctx)?;
         // Assign everything in the preallocated AST node
         let function = ctx.heap[definition_id].as_function_mut();
         function.return_type = parser_type;
         function.parameters = parameters;
         function.body = body;
         Ok(())
+    }
     fn visit_component_definition(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<(), ParseError> {
         // Consume component variant and name
         let (_variant_text, _) = consume_any_ident(&module.source, iter)?;
         debug_assert!(_variant_text == KW_PRIMITIVE || _variant_text == KW_COMPOSITE);
         let (ident_text, _) = consume_ident(&module.source, iter)?;
         // Retrieve preallocated definition
         let module_scope = SymbolScope::Module(module.root_id);
         let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text)
             .unwrap().variant.as_definition().definition_id;
         self.cur_definition = definition_id;
         consume_polymorphic_vars_spilled(&module.source, iter, ctx)?;
         // Parse component's argument list
         let mut parameter_section = self.variables.start_section();
         consume_parameter_list(
             &mut self.type_parser, &module.source, iter, ctx, &mut parameter_section, module_scope, definition_id
         )?;
         let parameters = parameter_section.into_vec();
         // Consume block
         let body = self.consume_block_statement(module, iter, ctx)?;
         // Assign everything in the AST node
         let component = ctx.heap[definition_id].as_component_mut();
         component.parameters = parameters;
         component.body = body;
         Ok(())
+    }
     /// Consumes a statement and returns a boolean indicating whether it was a
     /// block or not.
     fn consume_statement(&mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx) -> Result<StatementId, ParseError> {
         let next = iter.next().expect("consume_statement has a next token");
         if next == TokenKind::OpenCurly {
             let id = self.consume_block_statement(module, iter, ctx)?;
             return Ok(id.upcast());
         } else if next == TokenKind::Ident {
             let ident = peek_ident(&module.source, iter).unwrap();
             if ident == KW_STMT_IF {
                 // Consume if statement and place end-if statement directly
                 // after it.
                 let id = self.consume_if_statement(module, iter, ctx)?;
                 let end_if = ctx.heap.alloc_end_if_statement(|this| EndIfStatement {
                     this,
                     start_if: id,
                     next: StatementId::new_invalid()
                 });
                 let if_stmt = &mut ctx.heap[id];
                 if_stmt.end_if = end_if;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_WHILE {
                 let id = self.consume_while_statement(module, iter, ctx)?;
                 let end_while = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement {
                     this,
                     start_while: id,
                     next: StatementId::new_invalid()
                 });
                 let while_stmt = &mut ctx.heap[id];
                 while_stmt.end_while = end_while;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_BREAK {
                 let id = self.consume_break_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_CONTINUE {
                 let id = self.consume_continue_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_SYNC {
                 let id = self.consume_synchronous_statement(module, iter, ctx)?;
                 let end_sync = ctx.heap.alloc_end_synchronous_statement(|this| EndSynchronousStatement {
                     this,
                     start_sync: id,
                     next: StatementId::new_invalid()
                 });
                 let sync_stmt = &mut ctx.heap[id];
                 sync_stmt.end_sync = end_sync;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_FORK {
                 let id = self.consume_fork_statement(module, iter, ctx)?;
                 let end_fork = ctx.heap.alloc_end_fork_statement(|this| EndForkStatement {
                     this,
                     start_fork: id,
                     next: StatementId::new_invalid(),
                 });
                 let fork_stmt = &mut ctx.heap[id];
                 fork_stmt.end_fork = end_fork;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_SELECT {
                 let id = self.consume_select_statement(module, iter, ctx)?;
                 let end_select = ctx.heap.alloc_end_select_statement(|this| EndSelectStatement{
                     this,
                     start_select: id,
                     next: StatementId::new_invalid(),
                 });
                 let select_stmt = &mut ctx.heap[id];
                 select_stmt.end_select = end_select;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_RETURN {
                 let id = self.consume_return_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_GOTO {
                 let id = self.consume_goto_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_NEW {
                 let id = self.consume_new_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
             } else if ident == KW_STMT_CHANNEL {
                 let id = self.consume_channel_statement(module, iter, ctx)?;
                 return Ok(id.upcast().upcast());
             } else if iter.peek() == Some(TokenKind::Colon) {
                 let id = self.consume_labeled_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
             } else {
                 // Two fallback possibilities: the first one is a memory
                 // declaration, the other one is to parse it as a normal
                 // expression. This is a bit ugly.
                 if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
                     consume_token(&module.source, iter, TokenKind::SemiColon)?;
                     return Ok(memory_stmt_id.upcast().upcast());
                 } else {
                     let id = self.consume_expression_statement(module, iter, ctx)?;
                     return Ok(id.upcast());
+                }
+            }
         } else if next == TokenKind::OpenParen {
             // Same as above: memory statement or normal expression
             if let Some(memory_stmt_id) = self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
                 consume_token(&module.source, iter, TokenKind::SemiColon)?;
                 return Ok(memory_stmt_id.upcast().upcast());
             } else {
                 let id = self.consume_expression_statement(module, iter, ctx)?;
                 return Ok(id.upcast());
+            }
         } else {
             let id = self.consume_expression_statement(module, iter, ctx)?;
             return Ok(id.upcast());
+        }
+    }
     fn consume_block_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<BlockStatementId, ParseError> {
         let open_curly_span = consume_token(&module.source, iter, TokenKind::OpenCurly)?;
         let mut stmt_section = self.statements.start_section();
         let mut next = iter.next();
         while next != Some(TokenKind::CloseCurly) {
             if next.is_none() {
                 return Err(ParseError::new_error_str_at_pos(
                     &module.source, iter.last_valid_pos(), "expected a statement or '}'"
                 ));
+            }
             let stmt_id = self.consume_statement(module, iter, ctx)?;
             stmt_section.push(stmt_id);
             next = iter.next();
+        }
         let statements = stmt_section.into_vec();
         let mut block_span = consume_token(&module.source, iter, TokenKind::CloseCurly)?;
         block_span.begin = open_curly_span.begin;
-        let id = ctx.heap.alloc_block_statement(|this| BlockStatement{
+        let block_id = ctx.heap.alloc_block_statement(|this| BlockStatement{
             this,
             is_implicit: false,
             span: block_span,
             statements,
             end_block: EndBlockStatementId::new_invalid(),
             scope: ScopeId::new_invalid(),
             next: StatementId::new_invalid(),
         });
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Block(block_id)));
         let end_block = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
             this, start_block: id, next: StatementId::new_invalid()
         let end_block_id = ctx.heap.alloc_end_block_statement(|this| EndBlockStatement{
             this, start_block: block_id, next: StatementId::new_invalid()
         });
         let block_stmt = &mut ctx.heap[id];
         block_stmt.end_block = end_block;
         let block_stmt = &mut ctx.heap[block_id];
         block_stmt.end_block = end_block_id;
         block_stmt.scope = scope_id;
-        Ok(id)
+        Ok(block_id)
+    }
     fn consume_if_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<IfStatementId, ParseError> {
         let if_span = consume_exact_ident(&module.source, iter, KW_STMT_IF)?;
         consume_token(&module.source, iter, TokenKind::OpenParen)?;
         let test = self.consume_expression(module, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::CloseParen)?;
         // Consume bodies of if-statement
         let true_body = IfStatementCase{
             body: self.consume_statement(module, iter, ctx)?,
             scope: ScopeId::new_invalid(),
         };
         let true_body_scope_id = true_body.scope;
         let (false_body, false_body_scope_id) = if has_ident(&module.source, iter, KW_STMT_ELSE) {
             iter.consume();
             let false_body = IfStatementCase{
                 body: self.consume_statement(module, iter, ctx)?,
                 scope: ScopeId::new_invalid(),
             };
             let false_body_scope_id = false_body.scope;
             (Some(false_body), Some(false_body_scope_id))
         } else {
             (None, None)
         };
         // Construct AST elements
         let if_stmt_id = ctx.heap.alloc_if_statement(|this| IfStatement{
             this,
             span: if_span,
             test,
             true_case: true_body,
             false_case: false_body,
             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(),
         });
         let true_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(if_stmt_id, true)));
         let if_stmt = &mut ctx.heap[if_stmt_id];
         if_stmt.end_if = end_if_stmt_id;
         if_stmt.true_case.scope = true_scope_id;
         if let Some(false_case) = &mut if_stmt.false_case {
             let false_scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::If(if_stmt_id, false)));
             false_case.scope = false_scope_id
+        }
         return Ok(if_stmt_id);
+    }
     fn consume_while_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<WhileStatementId, ParseError> {
         let while_span = consume_exact_ident(&module.source, iter, KW_STMT_WHILE)?;
         consume_token(&module.source, iter, TokenKind::OpenParen)?;
         let test = self.consume_expression(module, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::CloseParen)?;
         let body = self.consume_statement(module, iter, ctx)?;
-        Ok(ctx.heap.alloc_while_statement(|this| WhileStatement{
+        let while_stmt_id = ctx.heap.alloc_while_statement(|this| WhileStatement{
             this,
             span: while_span,
             test,
             scope: ScopeId::new_invalid(),
             body,
             end_while: EndWhileStatementId::new_invalid(),
             in_sync: SynchronousStatementId::new_invalid(),
         }))
         });
         let end_while_stmt_id = ctx.heap.alloc_end_while_statement(|this| EndWhileStatement{
             this,
             start_while: while_stmt_id,
             next: StatementId::new_invalid(),
         });
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::While(while_stmt_id)));
         let while_stmt = &mut ctx.heap[while_stmt_id];
         while_stmt.scope = scope_id;
         while_stmt.end_while = end_while_stmt_id;
         Ok(while_stmt_id)
+    }
     fn consume_break_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<BreakStatementId, ParseError> {
         let break_span = consume_exact_ident(&module.source, iter, KW_STMT_BREAK)?;
         let label = if Some(TokenKind::Ident) == iter.next() {
             let label = consume_ident_interned(&module.source, iter, ctx)?;
             Some(label)
         } else {
             None
         };
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         Ok(ctx.heap.alloc_break_statement(|this| BreakStatement{
             this,
             span: break_span,
             label,
             target: EndWhileStatementId::new_invalid(),
         }))
+    }
     fn consume_continue_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ContinueStatementId, ParseError> {
         let continue_span = consume_exact_ident(&module.source, iter, KW_STMT_CONTINUE)?;
         let label=  if Some(TokenKind::Ident) == iter.next() {
             let label = consume_ident_interned(&module.source, iter, ctx)?;
             Some(label)
         } else {
             None
         };
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         Ok(ctx.heap.alloc_continue_statement(|this| ContinueStatement{
             this,
             span: continue_span,
             label,
             target: WhileStatementId::new_invalid(),
         }))
+    }
     fn consume_synchronous_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<SynchronousStatementId, ParseError> {
         let synchronous_span = consume_exact_ident(&module.source, iter, KW_STMT_SYNC)?;
         let body = self.consume_statement(module, iter, ctx)?;
-        Ok(ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
+        let sync_stmt_id = ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
             this,
             span: synchronous_span,
             scope: ScopeId::new_invalid(),
             body,
             end_sync: EndSynchronousStatementId::new_invalid(),
         }))
         });
         let end_sync_stmt_id = ctx.heap.alloc_end_synchronous_statement(|this| EndSynchronousStatement{
             this,
             start_sync: sync_stmt_id,
             next: StatementId::new_invalid(),
         });
         let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::Synchronous(sync_stmt_id)));
         let sync_stmt = &mut ctx.heap[sync_stmt_id];
         sync_stmt.scope = scope_id;
         sync_stmt.end_sync = end_sync_stmt_id;
         return Ok(sync_stmt_id);
+    }
     fn consume_fork_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ForkStatementId, ParseError> {
         let fork_span = consume_exact_ident(&module.source, iter, KW_STMT_FORK)?;
         let left_body = self.consume_statement(module, iter, ctx)?;
         let right_body = if has_ident(&module.source, iter, KW_STMT_OR) {
             iter.consume();
             let right_body = self.consume_statement(module, iter, ctx)?;
             Some(right_body)
         } else {
             None
         };
         Ok(ctx.heap.alloc_fork_statement(|this| ForkStatement{
             this,
             span: fork_span,
             left_body,
             right_body,
             end_fork: EndForkStatementId::new_invalid(),
         }))
+    }
     fn consume_select_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<SelectStatementId, ParseError> {
         let select_span = consume_exact_ident(&module.source, iter, KW_STMT_SELECT)?;
         consume_token(&module.source, iter, TokenKind::OpenCurly)?;
         let mut cases = Vec::new();
         let mut next = iter.next();
         while Some(TokenKind::CloseCurly) != next {
             let guard = match self.maybe_consume_memory_statement_without_semicolon(module, iter, ctx)? {
                 Some(guard_mem_stmt) => guard_mem_stmt.upcast().upcast(),
                 None => {
                     let start_pos = iter.last_valid_pos();
                     let expr = self.consume_expression(module, iter, ctx)?;
                     let end_pos = iter.last_valid_pos();
                     let guard_expr_stmt = ctx.heap.alloc_expression_statement(|this| ExpressionStatement{
                         this,
                         span: InputSpan::from_positions(start_pos, end_pos),
                         expression: expr,
                         next: StatementId::new_invalid(),
                     });
                     guard_expr_stmt.upcast()
                 },
             };
             consume_token(&module.source, iter, TokenKind::ArrowRight)?;
             let block = self.consume_statement(module, iter, ctx)?;
             cases.push(SelectCase{
                 guard,
                 body: block,
                 scope: ScopeId::new_invalid(),
                 involved_ports: Vec::with_capacity(1)
             });
             next = iter.next();
+        }
         consume_token(&module.source, iter, TokenKind::CloseCurly)?;
         Ok(ctx.heap.alloc_select_statement(|this| SelectStatement{
         let num_cases = cases.len();
         let select_stmt_id = ctx.heap.alloc_select_statement(|this| SelectStatement{
             this,
             span: select_span,
             cases,
             end_select: EndSelectStatementId::new_invalid(),
         }))
         });
         let end_select_stmt_id = ctx.heap.alloc_end_select_statement(|this| EndSelectStatement{
             this,
             start_select: select_stmt_id,
             next: StatementId::new_invalid(),
         });
         let select_stmt = &mut ctx.heap[select_stmt_id];
         select_stmt.end_select = end_select_stmt_id;
         for case_index in 0..num_cases {
             let scope_id = ctx.heap.alloc_scope(|this| Scope::new(this, ScopeAssociation::SelectCase(select_stmt_id, case_index as u32)));
             let select_stmt = &mut ctx.heap[select_stmt_id];
             let select_case = &mut select_stmt.cases[case_index];
             select_case.scope = scope_id;
+        }
         return Ok(select_stmt_id)
+    }
     fn consume_return_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ReturnStatementId, ParseError> {
         let return_span = consume_exact_ident(&module.source, iter, KW_STMT_RETURN)?;
         let mut scoped_section = self.expressions.start_section();
         consume_comma_separated_until(
             TokenKind::SemiColon, &module.source, iter, ctx,
             |_source, iter, ctx| self.consume_expression(module, iter, ctx),
             &mut scoped_section, "an expression", None
         )?;
         let expressions = scoped_section.into_vec();
         if expressions.is_empty() {
             return Err(ParseError::new_error_str_at_span(&module.source, return_span, "expected at least one return value"));
         } else if expressions.len() > 1 {
             return Err(ParseError::new_error_str_at_span(&module.source, return_span, "multiple return values are not (yet) supported"))
+        }
         Ok(ctx.heap.alloc_return_statement(|this| ReturnStatement{
             this,
             span: return_span,
             expressions
         }))
+    }
     fn consume_goto_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<GotoStatementId, ParseError> {
         let goto_span = consume_exact_ident(&module.source, iter, KW_STMT_GOTO)?;
         let label = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         Ok(ctx.heap.alloc_goto_statement(|this| GotoStatement{
             this,
             span: goto_span,
             label,
             target: LabeledStatementId::new_invalid(),
         }))
+    }
     fn consume_new_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<NewStatementId, ParseError> {
         let new_span = consume_exact_ident(&module.source, iter, KW_STMT_NEW)?;
         let start_pos = iter.last_valid_pos();
         let expression_id = self.consume_primary_expression(module, iter, ctx)?;
         let expression = &ctx.heap[expression_id];
         let mut valid = false;
         let mut call_id = CallExpressionId::new_invalid();
         if let Expression::Call(expression) = expression {
             // Allow both components and functions, as it makes more sense to
             // check their correct use in the validation and linking pass
             if expression.method == Method::UserComponent || expression.method == Method::UserFunction {
                 call_id = expression.this;
                 valid = true;
+            }
+        }
         if !valid {
             return Err(ParseError::new_error_str_at_span(
                 &module.source, InputSpan::from_positions(start_pos, iter.last_valid_pos()), "expected a call expression"
             ));
+        }
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         debug_assert!(!call_id.is_invalid());
         Ok(ctx.heap.alloc_new_statement(|this| NewStatement{
             this,
             span: new_span,
             expression: call_id,
             next: StatementId::new_invalid(),
         }))
+    }
     fn consume_channel_statement(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<ChannelStatementId, ParseError> {
         // Consume channel specification
         let channel_span = consume_exact_ident(&module.source, iter, KW_STMT_CHANNEL)?;
         let (inner_port_type, end_pos) = if Some(TokenKind::OpenAngle) == iter.next() {
             // Retrieve the type of the channel, we're cheating a bit here by
             // consuming the first '<' and setting the initial angle depth to 1
             // such that our final '>' will be consumed as well.
             let angle_start_pos = iter.next_start_position();
             iter.consume();
             let definition_id = self.cur_definition;
             let poly_vars = ctx.heap[definition_id].poly_vars();
             let parser_type = self.type_parser.consume_parser_type(
                 iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars,
                 definition_id, SymbolScope::Module(module.root_id),
                 true, Some(angle_start_pos)
             )?;
             (parser_type.elements, parser_type.full_span.end)
         } else {
             // Assume inferred
+            (
                 vec![ParserTypeElement{
                     element_span: channel_span,
                     variant: ParserTypeVariant::Inferred
                 }],
                 channel_span.end
+            )
         };
         let from_identifier = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::ArrowRight)?;
         let to_identifier = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::SemiColon)?;
         // Construct ports
         let port_type_span = InputSpan::from_positions(channel_span.begin, end_pos);
         let port_type_len = inner_port_type.len() + 1;
         let mut from_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
         from_port_type.elements.push(ParserTypeElement{
             element_span: channel_span,
             variant: ParserTypeVariant::Output,
         });
         from_port_type.elements.extend_from_slice(&inner_port_type);
         let from = ctx.heap.alloc_variable(|this| Variable{
             this,
             kind: VariableKind::Local,
             identifier: from_identifier,
             parser_type: from_port_type,
             relative_pos_in_parent: 0,
             unique_id_in_scope: -1,
         });
         let mut to_port_type = ParserType{ elements: Vec::with_capacity(port_type_len), full_span: port_type_span };
         to_port_type.elements.push(ParserTypeElement{
             element_span: channel_span,
             variant: ParserTypeVariant::Input
         });
         to_port_type.elements.extend_from_slice(&inner_port_type);
         let to = ctx.heap.alloc_variable(|this|Variable{
             this,
             kind: VariableKind::Local,
             identifier: to_identifier,
             parser_type: to_port_type,
             relative_pos_in_parent: 0,
             unique_id_in_scope: -1,
         });
         // Construct the channel
         Ok(ctx.heap.alloc_channel_statement(|this| ChannelStatement{
             this,
             span: channel_span,
             from, to,
             relative_pos_in_parent: 0,
             next: StatementId::new_invalid(),
         }))
+    }
     fn consume_labeled_statement(&mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx) -> Result<LabeledStatementId, ParseError> {
         let label = consume_ident_interned(&module.source, iter, ctx)?;
         consume_token(&module.source, iter, TokenKind::Colon)?;
         let inner_stmt_id = self.consume_statement(module, iter, ctx)?;
         let stmt_id = ctx.heap.alloc_labeled_statement(|this| LabeledStatement {
             this,
             label,
             body: inner_stmt_id,
             relative_pos_in_parent: 0,
             in_sync: SynchronousStatementId::new_invalid(),
         });
         return Ok(stmt_id);
+    }
     /// Attempts to consume a memory statement (a statement along the lines of
     /// `type var_name = initial_expr`). Will return `Ok(None)` if it didn't
     /// seem like there was a memory statement, `Ok(Some(...))` if there was
     /// one, and `Err(...)` if its reasonable to assume that there was a memory
     /// statement, but we failed to parse it.
     fn maybe_consume_memory_statement_without_semicolon(
         &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx
     ) -> Result<Option<MemoryStatementId>, ParseError> {
         // This is a bit ugly. It would be nicer if we could somehow
         // consume the expression with a type hint if we do get a valid
         // type, but we don't get an identifier following it
         let iter_state = iter.save();
         let definition_id = self.cur_definition;
         let poly_vars = ctx.heap[definition_id].poly_vars();
         let parser_type = self.type_parser.consume_parser_type(
             iter, &ctx.heap, &module.source, &ctx.symbols, poly_vars,
             definition_id, SymbolScope::Definition(definition_id), true, None
         );

src/protocol/parser/pass_validation_linking.rs

➞

Show inline comments

@@ @@ -20,730 +20,741 @@ @@
+ *
  * Setting the `next` statement: the AST is a tree, but during execution we walk
  * a linear path through all statements. So where appropriate a statement may
  * set the "previous statement" field of the pass to itself. When visiting the
  * subsequent statement it will check this "previous statement", and if set, it
  * will link this previous statement up to itself. Not every statement has a
  * previous statement. Hence there are two patterns that occur: assigning the
  * `next` value, then clearing the "previous statement" field. And assigning the
  * `next` value, and then putting the current statement's ID in the "previous
  * statement" field. Because it is so common, this file contain two macros that
  * perform that operation.
+ *
  * To make storing types for polymorphic procedures simpler and more efficient,
  * we assign to each expression in the procedure a unique ID. This is what the
  * "next expression index" field achieves. Each expression simply takes the
  * current value, and then increments this counter.
  */
 use crate::collections::{ScopedBuffer};
 use crate::protocol::ast::*;
 use crate::protocol::input_source::*;
 use crate::protocol::parser::symbol_table::*;
 use crate::protocol::parser::type_table::*;
 use super::visitor::{
     BUFFER_INIT_CAP_SMALL,
     BUFFER_INIT_CAP_LARGE,
     Ctx,
     Visitor,
     VisitorResult
 };
 use crate::protocol::parser::ModuleCompilationPhase;
 #[derive(PartialEq, Eq)]
 enum DefinitionType {
     Primitive(ComponentDefinitionId),
     Composite(ComponentDefinitionId),
     Function(FunctionDefinitionId)
+}
 impl DefinitionType {
     fn is_primitive(&self) -> bool { if let Self::Primitive(_) = self { true } else { false } }
     fn is_composite(&self) -> bool { if let Self::Composite(_) = self { true } else { false } }
     fn is_function(&self) -> bool { if let Self::Function(_) = self { true } else { false } }
     fn definition_id(&self) -> DefinitionId {
         match self {
             DefinitionType::Primitive(v) => v.upcast(),
             DefinitionType::Composite(v) => v.upcast(),
             DefinitionType::Function(v) => v.upcast(),
+        }
+    }
+}
 struct ControlFlowStatement {
     in_sync: SynchronousStatementId,
     in_while: WhileStatementId,
     in_scope: ScopeId,
     statement: StatementId, // of 'break', 'continue' or 'goto'
+}
 /// This particular visitor will go through the entire AST in a recursive manner
 /// and check if all statements and expressions are legal (e.g. no "return"
 /// statements in component definitions), and will link certain AST nodes to
 /// their appropriate targets (e.g. goto statements, or function calls).
 ///
 /// This visitor will not perform control-flow analysis (e.g. making sure that
 /// each function actually returns) and will also not perform type checking. So
 /// the linking of function calls and component instantiations will be checked
 /// and linked to the appropriate definitions, but the return types and/or
 /// arguments will not be checked for validity.
 ///
 /// The main idea is, because we're visiting nodes in a tree, to do as much as
 /// we can while we have the memory in cache.
 pub(crate) struct PassValidationLinking {
     // Traversal state, all valid IDs if inside a certain AST element. Otherwise
     // `id.is_invalid()` returns true.
     in_sync: SynchronousStatementId,
     in_while: WhileStatementId, // to resolve labeled continue/break
     in_select_guard: SelectStatementId, // for detection/rejection of builtin calls
     in_select_arm: u32,
     in_test_expr: StatementId, // wrapping if/while stmt id
     in_binding_expr: BindingExpressionId, // to resolve variable expressions
     in_binding_expr_lhs: bool,
     // Traversal state, current scope (which can be used to find the parent
     // scope) and the definition variant we are considering.
     cur_scope: ScopeId,
     def_type: DefinitionType,
     // "Trailing" traversal state, set be child/prev stmt/expr used by next one
     prev_stmt: StatementId,
     expr_parent: ExpressionParent,
     // Set by parent to indicate that child expression must be assignable. The
     // child will throw an error if it is not assignable. The stored span is
     // used for the error's position
     must_be_assignable: Option<InputSpan>,
     // Keeping track of relative positions and unique IDs.
     relative_pos_in_parent: i32, // of statements: to determine when variables are visible
     next_expr_index: i32, // to arrive at a unique ID for all expressions within a definition
     // Control flow statements that require label resolving
     control_flow_stmts: Vec<ControlFlowStatement>,
     // Various temporary buffers for traversal. Essentially working around
     // Rust's borrowing rules since it cannot understand we're modifying AST
     // members but not the AST container.
     variable_buffer: ScopedBuffer<VariableId>,
     definition_buffer: ScopedBuffer<DefinitionId>,
     statement_buffer: ScopedBuffer<StatementId>,
     expression_buffer: ScopedBuffer<ExpressionId>,
     scope_buffer: ScopedBuffer<ScopeId>,
+}
 impl PassValidationLinking {
     pub(crate) fn new() -> Self {
         Self{
             in_sync: SynchronousStatementId::new_invalid(),
             in_while: WhileStatementId::new_invalid(),
             in_select_guard: SelectStatementId::new_invalid(),
             in_select_arm: 0,
             in_test_expr: StatementId::new_invalid(),
             in_binding_expr: BindingExpressionId::new_invalid(),
             in_binding_expr_lhs: false,
             cur_scope: ScopeId::new_invalid(),
             prev_stmt: StatementId::new_invalid(),
             expr_parent: ExpressionParent::None,
             def_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
             must_be_assignable: None,
             relative_pos_in_parent: 0,
             next_expr_index: 0,
             control_flow_stmts: Vec::with_capacity(BUFFER_INIT_CAP_SMALL),
             variable_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             definition_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
             statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
             scope_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
+        }
+    }
     fn reset_state(&mut self) {
         self.in_sync = SynchronousStatementId::new_invalid();
         self.in_while = WhileStatementId::new_invalid();
         self.in_select_guard = SelectStatementId::new_invalid();
         self.in_test_expr = StatementId::new_invalid();
         self.in_binding_expr = BindingExpressionId::new_invalid();
         self.in_binding_expr_lhs = false;
         self.cur_scope = ScopeId::new_invalid();
         self.def_type = DefinitionType::Function(FunctionDefinitionId::new_invalid());
         self.prev_stmt = StatementId::new_invalid();
         self.expr_parent = ExpressionParent::None;
         self.must_be_assignable = None;
         self.relative_pos_in_parent = 0;
         self.next_expr_index = 0;
         self.control_flow_stmts.clear();
+    }
+}
 macro_rules! assign_then_erase_next_stmt {
     ($self:ident, $ctx:ident, $stmt_id:expr) => {
         if !$self.prev_stmt.is_invalid() {
             $ctx.heap[$self.prev_stmt].link_next($stmt_id);
             $self.prev_stmt = StatementId::new_invalid();
+        }
+    }
+}
 macro_rules! assign_and_replace_next_stmt {
     ($self:ident, $ctx:ident, $stmt_id:expr) => {
         if !$self.prev_stmt.is_invalid() {
             $ctx.heap[$self.prev_stmt].link_next($stmt_id);
+        }
         $self.prev_stmt = $stmt_id;
+    }
+}
 impl Visitor for PassValidationLinking {
     fn visit_module(&mut self, ctx: &mut Ctx) -> VisitorResult {
         debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::TypesAddedToTable);
         let root = &ctx.heap[ctx.module().root_id];
         let section = self.definition_buffer.start_section_initialized(&root.definitions);
         for definition_id in section.iter_copied() {
             self.visit_definition(ctx, definition_id)?;
+        }
         section.forget();
         ctx.module_mut().phase = ModuleCompilationPhase::ValidatedAndLinked;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Definition visitors
     //--------------------------------------------------------------------------
     fn visit_component_definition(&mut self, ctx: &mut Ctx, id: ComponentDefinitionId) -> VisitorResult {
         self.reset_state();
         self.def_type = match &ctx.heap[id].variant {
         let definition = &ctx.heap[id];
         self.def_type = match &definition.variant {
             ComponentVariant::Primitive => DefinitionType::Primitive(id),
             ComponentVariant::Composite => DefinitionType::Composite(id),
         };
         self.expr_parent = ExpressionParent::None;
         // Visit parameters and assign a unique scope ID
         let old_scope = self.push_scope(ctx, ScopeAssociation::Definition(id.upcast()));
         let definition_scope_id = definition.scope;
         let old_scope = self.push_scope(ctx, true, definition_scope_id);
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         let section = self.variable_buffer.start_section_initialized(&definition.parameters);
         for variable_idx in 0..section.len() {
             let variable_id = section[variable_idx];
             self.checked_at_single_scope_add_local(ctx, self.cur_scope, variable_idx as i32, variable_id)?;
+        }
         self.relative_pos_in_parent = section.len() as i32;
         section.forget();
         // Visit statements in component body
         self.visit_block_stmt(ctx, body_id)?;
         self.pop_scope(old_scope);
         // Assign total number of expressions and assign an in-block unique ID
         // to each of the locals in the procedure.
         let definition = &mut ctx.heap[id];
         let definition_scope = definition.scope;
         definition.num_expressions_in_body = self.next_expr_index;
         self.visit_scope_and_assign_local_ids(ctx, definition_scope, 0);
         self.resolve_pending_control_flow_targets(ctx)?;
         Ok(())
+    }
     fn visit_function_definition(&mut self, ctx: &mut Ctx, id: FunctionDefinitionId) -> VisitorResult {
         self.reset_state();
         // Set internal statement indices
         self.def_type = DefinitionType::Function(id);
         self.expr_parent = ExpressionParent::None;
         // Visit parameters and assign a unique scope ID
         let old_scope = self.push_scope(ctx, ScopeAssociation::Definition(id.upcast()));
         let definition = &ctx.heap[id];
         let definition_scope_id = definition.scope;
         let old_scope = self.push_scope(ctx, true, definition_scope_id);
         let definition = &ctx.heap[id];
         let body_id = definition.body;
         let section = self.variable_buffer.start_section_initialized(&definition.parameters);
         for variable_idx in 0..section.len() {
             let variable_id = section[variable_idx];
             self.checked_at_single_scope_add_local(ctx, self.cur_scope, variable_idx as i32, variable_id)?;
+        }
         section.forget();
         // Visit statements in function body
         self.visit_block_stmt(ctx, body_id)?;
         self.pop_scope(old_scope);
         // Assign total number of expressions and assign an in-block unique ID
         // to each of the locals in the procedure.
         let definition = &mut ctx.heap[id];
         let definition_scope = definition.scope;
         definition.num_expressions_in_body = self.next_expr_index;
         self.visit_scope_and_assign_local_ids(ctx, definition_scope, 0);
         self.resolve_pending_control_flow_targets(ctx)?;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Statement visitors
     //--------------------------------------------------------------------------
     fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
         // Get end of block
         let block_stmt = &ctx.heap[id];
         let end_block_id = block_stmt.end_block;
         let scope_id = block_stmt.scope;
         // Traverse statements in block
         let statement_section = self.statement_buffer.start_section_initialized(&block_stmt.statements);
-        let old_scope = self.push_scope(ctx, ScopeAssociation::Block(id));
+        let old_scope = self.push_scope(ctx, false, scope_id);
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         for stmt_idx in 0..statement_section.len() {
             self.relative_pos_in_parent = stmt_idx as i32;
             self.visit_stmt(ctx, statement_section[stmt_idx])?;
+        }
         statement_section.forget();
         assign_and_replace_next_stmt!(self, ctx, end_block_id.upcast());
         self.pop_scope(old_scope);
         Ok(())
+    }
     fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let expr_id = stmt.initial_expr;
         let variable_id = stmt.variable;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, variable_id)?;
         assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::Memory(id);
         self.visit_assignment_expr(ctx, expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let from_id = stmt.from;
         let to_id = stmt.to;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, from_id)?;
         self.checked_add_local(ctx, self.cur_scope, self.relative_pos_in_parent, to_id)?;
         assign_and_replace_next_stmt!(self, ctx, id.upcast().upcast());
         Ok(())
+    }
     fn visit_labeled_stmt(&mut self, ctx: &mut Ctx, id: LabeledStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let body_id = stmt.body;
         self.checked_add_label(ctx, self.relative_pos_in_parent, self.in_sync, id)?;
         self.visit_stmt(ctx, body_id)?;
         Ok(())
+    }
     fn visit_if_stmt(&mut self, ctx: &mut Ctx, id: IfStatementId) -> VisitorResult {
         let if_stmt = &ctx.heap[id];
         let end_if_id = if_stmt.end_if;
         let test_expr_id = if_stmt.test;
         let true_case = if_stmt.true_case;
         let false_case = if_stmt.false_case;
         // Visit test expression
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert!(self.in_test_expr.is_invalid());
         self.in_test_expr = id.upcast();
         self.expr_parent = ExpressionParent::If(id);
         self.visit_expr(ctx, test_expr_id)?;
         self.in_test_expr = StatementId::new_invalid();
         self.expr_parent = ExpressionParent::None;
         // Visit true and false branch. Executor chooses next statement based on
         // test expression, not on if-statement itself. Hence the if statement
         // does not have a static subsequent statement.
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
-        let old_scope = self.push_scope(ctx, ScopeAssociation::If(id, true));
+        let old_scope = self.push_scope(ctx, false, true_case.scope);
         self.visit_stmt(ctx, true_case.body)?;
         self.pop_scope(old_scope);
         assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
         if let Some(false_case) = false_case {
-            let old_scope = self.push_scope(ctx, ScopeAssociation::If(id, false));
+            let old_scope = self.push_scope(ctx, false, false_case.scope);
             self.visit_stmt(ctx, false_case.body)?;
             self.pop_scope(old_scope);
             assign_then_erase_next_stmt!(self, ctx, end_if_id.upcast());
+        }
         self.prev_stmt = end_if_id.upcast();
         Ok(())
+    }
     fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
         let stmt = &ctx.heap[id];
         let end_while_id = stmt.end_while;
         let test_expr_id = stmt.test;
         let body_stmt_id = stmt.body;
         let scope_id = stmt.scope;
         let old_while = self.in_while;
         self.in_while = id;
         // Visit test expression
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert!(self.in_test_expr.is_invalid());
         self.in_test_expr = id.upcast();
         self.expr_parent = ExpressionParent::While(id);
         self.visit_expr(ctx, test_expr_id)?;
         self.in_test_expr = StatementId::new_invalid();
         // Link up to body statement
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.expr_parent = ExpressionParent::None;
-        let old_scope = self.push_scope(ctx, ScopeAssociation::While(id));
+        let old_scope = self.push_scope(ctx, false, scope_id);
         self.visit_stmt(ctx, body_stmt_id)?;
         self.pop_scope(old_scope);
         self.in_while = old_while;
         // Link final entry in while's block statement back to the while. The
         // executor will go to the end-while statement if the test expression
         // is false, so put that in as the new previous stmt
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.prev_stmt = end_while_id.upcast();
         Ok(())
+    }
     fn visit_break_stmt(&mut self, ctx: &mut Ctx, id: BreakStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast()
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_continue_stmt(&mut self, ctx: &mut Ctx, id: ContinueStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast()
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_synchronous_stmt(&mut self, ctx: &mut Ctx, id: SynchronousStatementId) -> VisitorResult {
         // Check for validity of synchronous statement
         let sync_stmt = &ctx.heap[id];
         let end_sync_id = sync_stmt.end_sync;
         let cur_sync_span = sync_stmt.span;
         let scope_id = sync_stmt.scope;
         if !self.in_sync.is_invalid() {
             // Nested synchronous statement
             let old_sync_span = ctx.heap[self.in_sync].span;
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, cur_sync_span, "Illegal nested synchronous statement"
             ).with_info_str_at_span(
                 &ctx.module().source, old_sync_span, "It is nested in this synchronous statement"
             ));
+        }
         if !self.def_type.is_primitive() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, cur_sync_span,
                 "synchronous statements may only be used in primitive components"
             ));
+        }
         // Synchronous statement implicitly moves to its block
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         // Visit block statement. Note that we explicitly push the scope here
         // (and the `visit_block_stmt` will also push, but without effect) to
         // ensure the scope contains the sync ID.
         let sync_body = ctx.heap[id].body;
         debug_assert!(self.in_sync.is_invalid());
         self.in_sync = id;
-        let old_scope = self.push_scope(ctx, ScopeAssociation::Synchronous(id));
+        let old_scope = self.push_scope(ctx, false, scope_id);
         self.visit_stmt(ctx, sync_body)?;
         self.pop_scope(old_scope);
         assign_and_replace_next_stmt!(self, ctx, end_sync_id.upcast());
         self.in_sync = SynchronousStatementId::new_invalid();
         Ok(())
+    }
     fn visit_fork_stmt(&mut self, ctx: &mut Ctx, id: ForkStatementId) -> VisitorResult {
         let fork_stmt = &ctx.heap[id];
         let end_fork_id = fork_stmt.end_fork;
         let left_body_id = fork_stmt.left_body;
         let right_body_id = fork_stmt.right_body;
         // Fork statements may only occur inside sync blocks
         if self.in_sync.is_invalid() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, fork_stmt.span,
                 "Forking may only occur inside sync blocks"
             ));
+        }
         // Visit the respective bodies. Like the if statement, a fork statement
         // does not have a single static subsequent statement. It forks and then
         // each fork has a different next statement.
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         self.visit_stmt(ctx, left_body_id)?;
         assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
         if let Some(right_body_id) = right_body_id {
             self.visit_stmt(ctx, right_body_id)?;
             assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
+        }
         self.prev_stmt = end_fork_id.upcast();
         Ok(())
+    }
     fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
         let select_stmt = &ctx.heap[id];
         let end_select_id = select_stmt.end_select;
         // Select statements may only occur inside sync blocks
         if self.in_sync.is_invalid() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, select_stmt.span,
                 "select statements may only occur inside sync blocks"
             ));
+        }
         if !self.def_type.is_primitive() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, select_stmt.span,
                 "select statements may only be used in primitive components"
             ));
+        }
         // Visit the various arms in the select block
         let mut case_stmt_ids = self.statement_buffer.start_section();
         let mut case_scope_ids = self.scope_buffer.start_section();
         let num_cases = select_stmt.cases.len();
         for case in &select_stmt.cases {
             // We add them in pairs, so the subsequent for-loop retrieves in pairs
             case_stmt_ids.push(case.guard);
             case_stmt_ids.push(case.body);
             case_scope_ids.push(case.scope);
+        }
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         for idx in 0..num_cases {
             let base_idx = 2 * idx;
             let guard_id     = case_stmt_ids[base_idx    ];
             let case_body_id = case_stmt_ids[base_idx + 1];
         for index in 0..num_cases {
             let base_index = 2 * index;
             let guard_id     = case_stmt_ids[base_index];
             let case_body_id = case_stmt_ids[base_index + 1];
             let case_scope_id = case_scope_ids[index];
             // The guard statement ends up belonging to the block statement
             // following the arm. The reason we parse it separately is to
             // extract all of the "get" calls.
-            let old_scope = self.push_scope(ctx, ScopeAssociation::SelectCase(id, idx as u32));
+            let old_scope = self.push_scope(ctx, false, case_scope_id);
             // Visit the guard of this arm
             debug_assert!(self.in_select_guard.is_invalid());
             self.in_select_guard = id;
-            self.in_select_arm = idx as u32;
+            self.in_select_arm = index as u32;
             self.visit_stmt(ctx, guard_id)?;
             self.in_select_guard = SelectStatementId::new_invalid();
             // Visit the code associated with the guard
             self.visit_stmt(ctx, case_body_id)?;
             self.pop_scope(old_scope);
             // Link up last statement in block to EndSelect
             assign_then_erase_next_stmt!(self, ctx, end_select_id.upcast());
+        }
         self.in_select_guard = SelectStatementId::new_invalid();
         self.prev_stmt = end_select_id.upcast();
         Ok(())
+    }
     fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
         // Check if "return" occurs within a function
         let stmt = &ctx.heap[id];
         if !self.def_type.is_function() {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, stmt.span,
                 "return statements may only appear in function bodies"
             ));
+        }
         // If here then we are within a function
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         debug_assert_eq!(ctx.heap[id].expressions.len(), 1);
         self.expr_parent = ExpressionParent::Return(id);
         self.visit_expr(ctx, ctx.heap[id].expressions[0])?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_goto_stmt(&mut self, ctx: &mut Ctx, id: GotoStatementId) -> VisitorResult {
         self.control_flow_stmts.push(ControlFlowStatement{
             in_sync: self.in_sync,
             in_while: self.in_while,
             in_scope: self.cur_scope,
             statement: id.upcast(),
         });
         assign_then_erase_next_stmt!(self, ctx, id.upcast());
         Ok(())
+    }
     fn visit_new_stmt(&mut self, ctx: &mut Ctx, id: NewStatementId) -> VisitorResult {
         // Make sure the new statement occurs inside a composite component
         if !self.def_type.is_composite() {
             let new_stmt = &ctx.heap[id];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, new_stmt.span,
                 "instantiating components may only be done in composite components"
             ));
+        }
         // Recurse into call expression (which will check the expression parent
         // to ensure that the "new" statment instantiates a component)
         let call_expr_id = ctx.heap[id].expression;
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::New(id);
         self.visit_call_expr(ctx, call_expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     fn visit_expr_stmt(&mut self, ctx: &mut Ctx, id: ExpressionStatementId) -> VisitorResult {
         let expr_id = ctx.heap[id].expression;
         assign_and_replace_next_stmt!(self, ctx, id.upcast());
         debug_assert_eq!(self.expr_parent, ExpressionParent::None);
         self.expr_parent = ExpressionParent::ExpressionStmt(id);
         self.visit_expr(ctx, expr_id)?;
         self.expr_parent = ExpressionParent::None;
         Ok(())
+    }
     //--------------------------------------------------------------------------
     // Expression visitors
     //--------------------------------------------------------------------------
     fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         let assignment_expr = &mut ctx.heap[id];
         // Although we call assignment an expression to simplify the compiler's
         // code (mainly typechecking), we disallow nested use in expressions
         match self.expr_parent {
             // Look at us: lying through our teeth while providing error messages.
             ExpressionParent::Memory(_) => {},
             ExpressionParent::ExpressionStmt(_) => {},
             _ => {
                 let assignment_span = assignment_expr.full_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, assignment_span,
                     "assignments are statements, and cannot be used in expressions"
                 ))
             },
+        }
         let left_expr_id = assignment_expr.left;
         let right_expr_id = assignment_expr.right;
         let old_expr_parent = self.expr_parent;
         assignment_expr.parent = old_expr_parent;
         assignment_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
         self.must_be_assignable = Some(assignment_expr.operator_span);
         self.visit_expr(ctx, left_expr_id)?;
         self.expr_parent = ExpressionParent::Expression(upcast_id, 1);
         self.must_be_assignable = None;
         self.visit_expr(ctx, right_expr_id)?;
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> VisitorResult {
         let upcast_id = id.upcast();
         // Check for valid context of binding expression
         if let Some(span) = self.must_be_assignable {
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, span, "cannot assign to the result from a binding expression"
             ));
+        }
         if self.in_test_expr.is_invalid() {
             let binding_expr = &ctx.heap[id];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, binding_expr.full_span,
                 "binding expressions can only be used inside the testing expression of 'if' and 'while' statements"
             ));
+        }
         if !self.in_binding_expr.is_invalid() {
             let binding_expr = &ctx.heap[id];
             let previous_expr = &ctx.heap[self.in_binding_expr];
             return Err(ParseError::new_error_str_at_span(
                 &ctx.module().source, binding_expr.full_span,
                 "nested binding expressions are not allowed"
             ).with_info_str_at_span(
                 &ctx.module().source, previous_expr.operator_span,
                 "the outer binding expression is found here"
             ));
+        }
         let mut seeking_parent = self.expr_parent;
         loop {
             // Perform upward search to make sure only LogicalAnd is applied to
             // the binding expression
             let valid = match seeking_parent {
                 ExpressionParent::If(_) | ExpressionParent::While(_) => {
                     // Every parent expression (if any) were LogicalAnd.
                     break;
+                }
                 ExpressionParent::Expression(parent_id, _) => {
                     let parent_expr = &ctx.heap[parent_id];
                     match parent_expr {
                         Expression::Binary(parent_expr) => {
                             // Set new parent to continue the search. Otherwise
                             // halt and provide an error using the current
                             // parent.
                             if parent_expr.operation == BinaryOperator::LogicalAnd {
                                 seeking_parent = parent_expr.parent;
                                 true
                             } else {
                                 false
+                            }
                         },
                         _ => false,
+                    }
                 },
                 _ => unreachable!(), // nested under if/while, so always expressions as parents
             };
             if !valid {
                 let binding_expr = &ctx.heap[id];
                 let parent_expr = &ctx.heap[seeking_parent.as_expression()];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, binding_expr.full_span,
                     "only the logical-and operator (&&) may be applied to binding expressions"
                 ).with_info_str_at_span(
@@ @@ -1264,449 +1275,407 @@ impl Visitor for PassValidationLinking { @@
         if expecting_no_select_stmt {
             if !self.in_select_guard.is_invalid() {
                 let (call_span, func_name) = get_span_and_name(ctx, id);
                 return Err(ParseError::new_error_at_span(
                     &ctx.module().source, call_span,
                     format!("a call to '{}' may not occur in a select statement's guard", func_name)
                 ));
+            }
+        }
         if expecting_wrapping_new_stmt {
             if !self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "cannot call a component, it can only be instantiated by using 'new'"
                 ));
+            }
         } else {
             if self.expr_parent.is_new() {
                 let call_span = call_expr.func_span;
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, call_span,
                     "only components can be instantiated, this is a function"
                 ));
+            }
+        }
         // Check the number of arguments
         let call_definition = ctx.types.get_base_definition(&call_expr.definition).unwrap();
         let num_expected_args = match &call_definition.definition {
             DefinedTypeVariant::Function(definition) => definition.arguments.len(),
             DefinedTypeVariant::Component(definition) => definition.arguments.len(),
             v => unreachable!("encountered {} type in call expression", v.type_class()),
         };
         let num_provided_args = call_expr.arguments.len();
         if num_provided_args != num_expected_args {
             let argument_text = if num_expected_args == 1 { "argument" } else { "arguments" };
             let call_span = call_expr.full_span;
             return Err(ParseError::new_error_at_span(
                 &ctx.module().source, call_span, format!(
                     "expected {} {}, but {} were provided",
                     num_expected_args, argument_text, num_provided_args
+                )
             ));
+        }
         // Recurse into all of the arguments and set the expression's parent
         let upcast_id = id.upcast();
         let section = self.expression_buffer.start_section_initialized(&call_expr.arguments);
         let old_expr_parent = self.expr_parent;
         call_expr.parent = old_expr_parent;
         call_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         for arg_expr_idx in 0..section.len() {
             let arg_expr_id = section[arg_expr_idx];
             self.expr_parent = ExpressionParent::Expression(upcast_id, arg_expr_idx as u32);
             self.visit_expr(ctx, arg_expr_id)?;
+        }
         section.forget();
         self.expr_parent = old_expr_parent;
         Ok(())
+    }
     fn visit_variable_expr(&mut self, ctx: &mut Ctx, id: VariableExpressionId) -> VisitorResult {
         let var_expr = &ctx.heap[id];
         // Check if declaration was already resolved (this occurs for the
         // variable expr that is on the LHS of the assignment expr that is
         // associated with a variable declaration)
         let mut variable_id = var_expr.declaration;
         let mut is_binding_target = false;
         // Otherwise try to find it
         if variable_id.is_none() {
             variable_id = self.find_variable(ctx, self.relative_pos_in_parent, &var_expr.identifier);
+        }
         // Otherwise try to see if is a variable introduced by a binding expr
         let variable_id = if let Some(variable_id) = variable_id {
             variable_id
         } else {
             if self.in_binding_expr.is_invalid() || !self.in_binding_expr_lhs {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span, "unresolved variable"
                 ));
+            }
             // This is a binding variable, but it may only appear in very
             // specific locations.
             let is_valid_binding = match self.expr_parent {
                 ExpressionParent::Expression(expr_id, idx) => {
                     match &ctx.heap[expr_id] {
                         Expression::Binding(_binding_expr) => {
                             // Nested binding is disallowed, and because of
                             // the check above we know we're directly at the
                             // LHS of the binding expression
                             debug_assert_eq!(_binding_expr.this, self.in_binding_expr);
                             debug_assert_eq!(idx, 0);
                             true
+                        }
                         Expression::Literal(lit_expr) => {
                             // Only struct, unions, tuples and arrays can
                             // have subexpressions, so we're always fine
                             if cfg!(debug_assertions) {
                                 match lit_expr.value {
                                     Literal::Struct(_) | Literal::Union(_) | Literal::Array(_) | Literal::Tuple(_) => {},
                                     _ => unreachable!(),
+                                }
+                            }
                             true
                         },
                         _ => false,
+                    }
                 },
                 _ => {
                     false
+                }
             };
             if !is_valid_binding {
                 let binding_expr = &ctx.heap[self.in_binding_expr];
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, var_expr.identifier.span,
                     "illegal location for binding variable: binding variables may only be nested under a binding expression, or a struct, union or array literal"
                 ).with_info_at_span(
                     &ctx.module().source, binding_expr.operator_span, format!(
                         "'{}' was interpreted as a binding variable because the variable is not declared and it is nested under this binding expression",
                         var_expr.identifier.value.as_str()
+                    )
                 ));
+            }
             // By now we know that this is a valid binding expression. Given
             // that a binding expression must be nested under an if/while
             // statement, we now add the variable to the scope associated with
             // that statement.
             let bound_identifier = var_expr.identifier.clone();
             let bound_variable_id = ctx.heap.alloc_variable(|this| Variable {
                 this,
                 kind: VariableKind::Binding,
                 parser_type: ParserType {
                     elements: vec![ParserTypeElement {
                         element_span: bound_identifier.span,
                         variant: ParserTypeVariant::Inferred
                     }],
                     full_span: bound_identifier.span
                 },
                 identifier: bound_identifier,
                 relative_pos_in_parent: 0,
                 unique_id_in_scope: -1,
             });
             let scope_id = match &ctx.heap[self.in_test_expr] {
                 Statement::If(stmt) => stmt.true_case.scope,
                 Statement::While(stmt) => stmt.scope,
                 _ => unreachable!(),
             };
             self.checked_at_single_scope_add_local(ctx, scope_id, -1, bound_variable_id)?; // add at -1 such that first statement can find the variable if needed
             is_binding_target = true;
             bound_variable_id
         };
         let var_expr = &mut ctx.heap[id];
         var_expr.declaration = Some(variable_id);
         var_expr.used_as_binding_target = is_binding_target;
         var_expr.parent = self.expr_parent;
         var_expr.unique_id_in_definition = self.next_expr_index;
         self.next_expr_index += 1;
         Ok(())
+    }
+}
 impl PassValidationLinking {
     //--------------------------------------------------------------------------
     // Special traversal
     //--------------------------------------------------------------------------
     /// Pushes a new scope associated with a particular statement. If that
     /// statement already has an associated scope (i.e. scope associated with
     /// sync statement or select statement's arm) then we won't do anything.
     /// In all cases the caller must call `pop_statement_scope` with the scope
     /// and relative scope position returned by this function.
     fn push_scope(&mut self, ctx: &mut Ctx, association: ScopeAssociation) -> (ScopeId, i32) {
         // Create new scope and assign as ScopeId to the specified associated
         // statement.
         let is_first_scope = match association {
             ScopeAssociation::Definition(_) => true,
             _ => false,
         };
         let old_scope_id = self.cur_scope.clone();
         let new_scope_id = ctx.heap.alloc_scope(|this| Scope{
             this,
             parent: if is_first_scope { None } else { Some(old_scope_id) },
             nested: Vec::new(),
             association,
             variables: Vec::new(),
             labels: Vec::new(),
             relative_pos_in_parent: self.relative_pos_in_parent,
             first_unique_id_in_scope: -1,
             next_unique_id_in_scope: -1,
         });
         match association {
             ScopeAssociation::Definition(definition_id) => {
                 let def = &mut ctx.heap[definition_id];
                 match def {
                     Definition::Function(def) => def.scope = new_scope_id,
                     Definition::Component(def) => def.scope = new_scope_id,
                     _ => unreachable!(),
+                }
             },
             ScopeAssociation::Block(stmt_id) => {
                 ctx.heap[stmt_id].scope = new_scope_id;
             },
             ScopeAssociation::If(stmt_id, in_true_body) => {
                 let stmt = &mut ctx.heap[stmt_id];
                 if in_true_body {
                     stmt.true_case.scope = new_scope_id;
                 } else {
                     let false_body = stmt.false_case.as_mut().unwrap();
                     false_body.scope = new_scope_id;
+                }
             },
             ScopeAssociation::While(stmt_id) => {
                 ctx.heap[stmt_id].scope = new_scope_id;
             },
             ScopeAssociation::Synchronous(stmt_id) => {
                 ctx.heap[stmt_id].scope = new_scope_id;
             },
             ScopeAssociation::SelectCase(stmt_id, case_index) => {
                 let select_stmt = &mut ctx.heap[stmt_id];
                 select_stmt.cases[case_index as usize].scope = new_scope_id;
+            }
     fn push_scope(&mut self, ctx: &mut Ctx, is_top_level_scope: bool, pushed_scope_id: ScopeId) -> (ScopeId, i32) {
         // Set the properties of the pushed scope (it is already created during
         // AST construction, but most values are not yet set to their correct
         // values)
         let old_scope_id = self.cur_scope;
         let scope = &mut ctx.heap[pushed_scope_id];
         if is_top_level_scope {
             scope.parent = Some(old_scope_id);
+        }
         scope.relative_pos_in_parent = self.relative_pos_in_parent;
         let old_relative_pos = self.relative_pos_in_parent;
         self.relative_pos_in_parent = 0;
         // Link up scopes
-        if !is_first_scope {
+        if !is_top_level_scope {
             let old_scope = &mut ctx.heap[old_scope_id];
-            old_scope.nested.push(new_scope_id);
+            old_scope.nested.push(pushed_scope_id);
+        }
         // Set as current traversal scope, then return old scope
         self.cur_scope = new_scope_id;
         let old_relative_pos = self.relative_pos_in_parent;
         self.relative_pos_in_parent = 0;
         self.cur_scope = pushed_scope_id;
         return (old_scope_id, old_relative_pos)
+    }
     fn pop_scope(&mut self, scope_to_restore: (ScopeId, i32)) {
         self.cur_scope = scope_to_restore.0;
         self.relative_pos_in_parent = scope_to_restore.1;
+    }
     fn visit_scope_and_assign_local_ids(&mut self, ctx: &mut Ctx, scope_id: ScopeId, mut variable_counter: i32) {
         let scope = &mut ctx.heap[scope_id];
         scope.first_unique_id_in_scope = variable_counter;
         let variable_section = self.variable_buffer.start_section_initialized(&scope.variables);
         let child_scope_section = self.scope_buffer.start_section_initialized(&scope.nested);
         let mut variable_index = 0;
         let mut child_scope_index = 0;
         loop {
             // Determine relative positions of variable and scope to determine
             // which one occurs first within the current scope.
             let variable_relative_pos;
             if variable_index < variable_section.len() {
                 let variable_id = variable_section[variable_index];
                 let variable = &ctx.heap[variable_id];
                 variable_relative_pos = variable.relative_pos_in_parent;
             } else {
                 variable_relative_pos = i32::MAX;
+            }
             let child_scope_relative_pos;
             if child_scope_index < child_scope_section.len() {
                 let child_scope_id = child_scope_section[child_scope_index];
                 let child_scope = &ctx.heap[child_scope_id];
                 child_scope_relative_pos = child_scope.relative_pos_in_parent;
             } else {
                 child_scope_relative_pos = i32::MAX;
+            }
             if variable_relative_pos == i32::MAX && child_scope_relative_pos == i32::MAX {
                 // Done, no more elements in the scope to consider
                 break;
+            }
             // Label the variable/scope, whichever comes first. When dealing
             // with binding variables, where both variable and scope are
             // considered to have the same position in the scope, we treat the
             // variable first.
             // TODO: Think about this some more, isn't it correct that we
             //  consider it part of the fresh scope? So we'll have to deal with
             //  the scope first, and add the variable to that scope?
             if variable_relative_pos <= child_scope_relative_pos {
                 let variable = &mut ctx.heap[variable_section[variable_index]];
                 variable.unique_id_in_scope = variable_counter;
                 variable_counter += 1;
                 variable_index += 1;
             } else {
                 let child_scope_id = child_scope_section[child_scope_index];
                 self.visit_scope_and_assign_local_ids(ctx, child_scope_id, variable_counter);
                 child_scope_index += 1;
+            }
+        }
         variable_section.forget();
         child_scope_section.forget();
         let scope = &mut ctx.heap[scope_id];
         scope.next_unique_id_in_scope = variable_counter;
+    }
     fn resolve_pending_control_flow_targets(&mut self, ctx: &mut Ctx) -> Result<(), ParseError> {
         for entry in &self.control_flow_stmts {
             let stmt = &ctx.heap[entry.statement];
             match stmt {
                 Statement::Break(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let target_while_stmt = &ctx.heap[target_while_id];
                     let target_end_while_id = target_while_stmt.end_while;
                     debug_assert!(!target_end_while_id.is_invalid());
                     let break_stmt = &mut ctx.heap[stmt_id];
                     break_stmt.target = target_end_while_id;
                 },
                 Statement::Continue(stmt) => {
                     let stmt_id = stmt.this;
                     let target_while_id = Self::resolve_break_or_continue_target(ctx, entry, stmt.span, &stmt.label)?;
                     let continue_stmt = &mut ctx.heap[stmt_id];
                     continue_stmt.target = target_while_id;
                 },
                 Statement::Goto(stmt) => {
                     let stmt_id = stmt.this;
                     let target_id = Self::find_label(entry.in_scope, ctx, &stmt.label)?;
                     let target_stmt = &ctx.heap[target_id];
                     if entry.in_sync != target_stmt.in_sync {
                         // Nested sync not allowed. And goto can only go to
                         // outer scopes, so we must be escaping from a sync.
                         debug_assert!(target_stmt.in_sync.is_invalid());    // target not in sync
                         debug_assert!(!entry.in_sync.is_invalid()); // but the goto is in sync
                         let goto_stmt = &ctx.heap[stmt_id];
                         let sync_stmt = &ctx.heap[entry.in_sync];
                         return Err(
                             ParseError::new_error_str_at_span(&ctx.module().source, goto_stmt.span, "goto may not escape the surrounding synchronous block")
                             .with_info_str_at_span(&ctx.module().source, target_stmt.label.span, "this is the target of the goto statement")
                             .with_info_str_at_span(&ctx.module().source, sync_stmt.span, "which will jump past this statement")
                         );
+                    }
                     let goto_stmt = &mut ctx.heap[stmt_id];
                     goto_stmt.target = target_id;
                 },
                 _ => unreachable!("cannot resolve control flow target for {:?}", stmt),
+            }
+        }
         return Ok(())
+    }
     //--------------------------------------------------------------------------
     // Utilities
     //--------------------------------------------------------------------------
     /// Adds a local variable to the current scope. It will also annotate the
     /// `Local` in the AST with its relative position in the block.
     fn checked_add_local(&mut self, ctx: &mut Ctx, target_scope_id: ScopeId, target_relative_pos: i32, id: VariableId) -> Result<(), ParseError> {
         let local = &ctx.heap[id];
         // We immediately go to the parent scope. We check the target scope
         // in the call at the end. That is also where we check for collisions
         // with symbols.
         let mut scope = &ctx.heap[target_scope_id];
         let mut cur_relative_pos = scope.relative_pos_in_parent;
         while let Some(scope_parent_id) = scope.parent {
             scope = &ctx.heap[scope_parent_id];
             // Check for collisions
             for variable_id in scope.variables.iter().copied() {
                 let variable = &ctx.heap[variable_id];
                 if variable.identifier == variable.identifier &&
                     variable.this != id &&
                     cur_relative_pos >= variable.relative_pos_in_parent {
                     return Err(
                         ParseError::new_error_str_at_span(
                             &ctx.module().source, local.identifier.span, "Local variable name conflicts with another variable"
                         ).with_info_str_at_span(
                             &ctx.module().source, variable.identifier.span, "Previous variable is found here"
+                        )
                     );
+                }
+            }
             cur_relative_pos = scope.relative_pos_in_parent;
+        }
         // No collisions in any of the parent scope, attempt to add to scope
         self.checked_at_single_scope_add_local(ctx, target_scope_id, target_relative_pos, id)
+    }
     /// Adds a local variable to the specified scope. Will check the specified
     /// scope for variable conflicts and the symbol table for global conflicts.
     /// Will NOT check parent scopes of the specified scope.
     fn checked_at_single_scope_add_local(
         &mut self, ctx: &mut Ctx, scope_id: ScopeId, relative_pos: i32, new_variable_id: VariableId
     ) -> Result<(), ParseError> {
         // Check the symbol table for conflicts
+        {
             let cur_scope = SymbolScope::Definition(self.def_type.definition_id());
             let ident = &ctx.heap[new_variable_id].identifier;
             if let Some(symbol) = ctx.symbols.get_symbol_by_name(cur_scope, &ident.value.as_bytes()) {
                 return Err(ParseError::new_error_str_at_span(
                     &ctx.module().source, ident.span,
                     "local variable declaration conflicts with symbol"
                 ).with_info_str_at_span(
                     &ctx.module().source, symbol.variant.span_of_introduction(&ctx.heap), "the conflicting symbol is introduced here"
                 ));
+            }
+        }
         // Check the specified scope for conflicts
         let new_variable = &ctx.heap[new_variable_id];
         let scope = &ctx.heap[scope_id];
         for variable_id in scope.variables.iter().copied() {
             let old_variable = &ctx.heap[variable_id];
             if new_variable.this != old_variable.this &&
                 // relative_pos >= other_local.relative_pos_in_block &&
                 new_variable.identifier == old_variable.identifier {
                 // Collision
                 return Err(
                     ParseError::new_error_str_at_span(

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