Changeset - 0d171740d3f1
[Not reviewed]
0 4 0
MH - 4 years ago 2021-12-20 18:07:16
contact@maxhenger.nl
Handling select guard variables in validator and typer
4 files changed with 117 insertions and 51 deletions:
0 comments (0 inline, 0 general)
src/protocol/ast.rs
Show inline comments
 
@@ -1269,192 +1269,194 @@ pub struct IfStatement {
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndIfStatement {
 
    pub this: EndIfStatementId,
 
    pub start_if: IfStatementId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct WhileStatement {
 
    pub this: WhileStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "while" keyword
 
    pub test: ExpressionId,
 
    pub body: BlockStatementId,
 
    pub end_while: EndWhileStatementId,
 
    pub in_sync: SynchronousStatementId, // may be invalid
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndWhileStatement {
 
    pub this: EndWhileStatementId,
 
    pub start_while: WhileStatementId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct BreakStatement {
 
    pub this: BreakStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "break" keyword
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: Option<EndWhileStatementId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ContinueStatement {
 
    pub this: ContinueStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "continue" keyword
 
    pub label: Option<Identifier>,
 
    // Phase 2: linker
 
    pub target: Option<WhileStatementId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SynchronousStatement {
 
    pub this: SynchronousStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "sync" keyword
 
    pub body: BlockStatementId,
 
    pub end_sync: EndSynchronousStatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndSynchronousStatement {
 
    pub this: EndSynchronousStatementId,
 
    pub start_sync: SynchronousStatementId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ForkStatement {
 
    pub this: ForkStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "fork" keyword
 
    pub left_body: BlockStatementId,
 
    pub right_body: Option<BlockStatementId>,
 
    pub end_fork: EndForkStatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndForkStatement {
 
    pub this: EndForkStatementId,
 
    pub start_fork: ForkStatementId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SelectStatement {
 
    pub this: SelectStatementId,
 
    pub span: InputSpan, // of the "select" keyword
 
    pub cases: Vec<SelectCase>,
 
    pub end_select: EndSelectStatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct SelectCase {
 
    // The guard statement of a `select` is either a MemoryStatement or an
 
    // ExpressionStatement. Nothing else is allowed by the initial parsing
 
    pub guard: StatementId,
 
    pub block: BlockStatementId,
 
    // Phase 2: Validation and Linking
 
    pub involved_ports: Vec<(CallExpressionId, ExpressionId)>, // call to `get` and its port argument
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndSelectStatement {
 
    pub this: EndSelectStatementId,
 
    pub start_select: SelectStatementId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ReturnStatement {
 
    pub this: ReturnStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "return" keyword
 
    pub expressions: Vec<ExpressionId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct GotoStatement {
 
    pub this: GotoStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "goto" keyword
 
    pub label: Identifier,
 
    // Phase 2: linker
 
    pub target: Option<LabeledStatementId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct NewStatement {
 
    pub this: NewStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "new" keyword
 
    pub expression: CallExpressionId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ExpressionStatement {
 
    pub this: ExpressionStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan,
 
    pub expression: ExpressionId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 
pub enum ExpressionParent {
 
    None, // only set during initial parsing
 
    Memory(MemoryStatementId),
 
    If(IfStatementId),
 
    While(WhileStatementId),
 
    Return(ReturnStatementId),
 
    New(NewStatementId),
 
    ExpressionStmt(ExpressionStatementId),
 
    Expression(ExpressionId, u32) // index within expression (e.g LHS or RHS of expression)
 
}
 

	
 
impl ExpressionParent {
 
    pub fn is_new(&self) -> bool {
 
        match self {
 
            ExpressionParent::New(_) => true,
 
            _ => false,
 
        }
 
    }
 

	
 
    pub fn as_expression(&self) -> ExpressionId {
 
        match self {
 
            ExpressionParent::Expression(id, _) => *id,
 
            _ => panic!("called as_expression() on {:?}", self),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub enum Expression {
 
    Assignment(AssignmentExpression),
 
    Binding(BindingExpression),
 
    Conditional(ConditionalExpression),
 
    Binary(BinaryExpression),
 
    Unary(UnaryExpression),
 
    Indexing(IndexingExpression),
 
    Slicing(SlicingExpression),
 
    Select(SelectExpression),
 
    Literal(LiteralExpression),
 
    Cast(CastExpression),
 
    Call(CallExpression),
 
    Variable(VariableExpression),
 
}
 

	
 
impl Expression {
 
    pub fn as_variable(&self) -> &VariableExpression {
 
        match self {
 
            Expression::Variable(result) => result,
 
            _ => panic!("Unable to cast `Expression` to `VariableExpression`"),
src/protocol/parser/pass_definitions.rs
Show inline comments
 
@@ -620,193 +620,196 @@ impl PassDefinitions {
 
            None
 
        };
 
        consume_token(&module.source, iter, TokenKind::SemiColon)?;
 
        Ok(ctx.heap.alloc_break_statement(|this| BreakStatement{
 
            this,
 
            span: break_span,
 
            label,
 
            target: None,
 
        }))
 
    }
 

	
 
    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: None
 
        }))
 
    }
 

	
 
    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_block_or_wrapped_statement(module, iter, ctx)?;
 

	
 
        Ok(ctx.heap.alloc_synchronous_statement(|this| SynchronousStatement{
 
            this,
 
            span: synchronous_span,
 
            body,
 
            end_sync: EndSynchronousStatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    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_block_or_wrapped_statement(module, iter, ctx)?;
 

	
 
        let right_body = if has_ident(&module.source, iter, KW_STMT_OR) {
 
            iter.consume();
 
            let right_body = self.consume_block_or_wrapped_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_block_or_wrapped_statement(module, iter, ctx)?;
 
            cases.push(SelectCase{ guard, block });
 
            cases.push(SelectCase{
 
                guard, block,
 
                involved_ports: Vec::with_capacity(1)
 
            });
 

	
 
            next = iter.next();
 
        }
 

	
 
        consume_token(&module.source, iter, TokenKind::CloseCurly)?;
 

	
 
        Ok(ctx.heap.alloc_select_statement(|this| SelectStatement{
 
            this,
 
            span: select_span,
 
            cases,
 
            end_select: EndSelectStatementId::new_invalid(),
 
        }))
 
    }
 

	
 
    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: None
 
        }))
 
    }
 

	
 
    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() {
src/protocol/parser/pass_typing.rs
Show inline comments
 
@@ -1082,192 +1082,216 @@ impl Visitor for PassTyping {
 
    fn visit_block_stmt(&mut self, ctx: &mut Ctx, id: BlockStatementId) -> VisitorResult {
 
        // Transfer statements for traversal
 
        let block = &ctx.heap[id];
 

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

	
 
        Ok(())
 
    }
 

	
 
    fn visit_local_memory_stmt(&mut self, ctx: &mut Ctx, id: MemoryStatementId) -> VisitorResult {
 
        let memory_stmt = &ctx.heap[id];
 
        let initial_expr_id = memory_stmt.initial_expr;
 

	
 
        // Setup memory statement inference
 
        let local = &ctx.heap[memory_stmt.variable];
 
        let var_type = self.determine_inference_type_from_parser_type_elements(&local.parser_type.elements, true);
 
        self.var_types.insert(memory_stmt.variable, VarData::new_local(var_type));
 

	
 
        // Process the initial value
 
        self.visit_assignment_expr(ctx, initial_expr_id)?;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_local_channel_stmt(&mut self, ctx: &mut Ctx, id: ChannelStatementId) -> VisitorResult {
 
        let channel_stmt = &ctx.heap[id];
 

	
 
        let from_local = &ctx.heap[channel_stmt.from];
 
        let from_var_type = self.determine_inference_type_from_parser_type_elements(&from_local.parser_type.elements, true);
 
        self.var_types.insert(from_local.this, VarData::new_channel(from_var_type, channel_stmt.to));
 

	
 
        let to_local = &ctx.heap[channel_stmt.to];
 
        let to_var_type = self.determine_inference_type_from_parser_type_elements(&to_local.parser_type.elements, true);
 
        self.var_types.insert(to_local.this, VarData::new_channel(to_var_type, channel_stmt.from));
 

	
 
        Ok(())
 
    }
 

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

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

	
 
        let true_body_id = if_stmt.true_body;
 
        let false_body_id = if_stmt.false_body;
 
        let test_expr_id = if_stmt.test;
 

	
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.visit_block_stmt(ctx, true_body_id)?;
 
        if let Some(false_body_id) = false_body_id {
 
            self.visit_block_stmt(ctx, false_body_id)?;
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_while_stmt(&mut self, ctx: &mut Ctx, id: WhileStatementId) -> VisitorResult {
 
        let while_stmt = &ctx.heap[id];
 

	
 
        let body_id = while_stmt.body;
 
        let test_expr_id = while_stmt.test;
 

	
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.visit_block_stmt(ctx, body_id)?;
 

	
 
        Ok(())
 
    }
 

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

	
 
        self.visit_block_stmt(ctx, body_id)
 
    }
 

	
 
    fn visit_fork_stmt(&mut self, ctx: &mut Ctx, id: ForkStatementId) -> VisitorResult {
 
        let fork_stmt = &ctx.heap[id];
 
        let left_body_id = fork_stmt.left_body;
 
        let right_body_id = fork_stmt.right_body;
 

	
 
        self.visit_block_stmt(ctx, left_body_id)?;
 
        if let Some(right_body_id) = right_body_id {
 
            self.visit_block_stmt(ctx, right_body_id)?;
 
        }
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_select_stmt(&mut self, ctx: &mut Ctx, id: SelectStatementId) -> VisitorResult {
 
        let select_stmt = &ctx.heap[id];
 

	
 
        let mut section = self.stmt_buffer.start_section();
 
        let num_cases = select_stmt.cases.len();
 

	
 
        for case in &select_stmt.cases {
 
            section.push(case.guard);
 
            section.push(case.block.upcast());
 
        }
 

	
 
        for case_index in 0..num_cases {
 
            let base_index = 2 * case_index;
 
            let guard_stmt_id = section[base_index    ];
 
            let block_stmt_id = section[base_index + 1];
 

	
 
            self.visit_stmt(ctx, guard_stmt_id);
 
            self.visit_stmt(ctx, block_stmt_id);
 
        }
 
        section.forget();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
 
        let return_stmt = &ctx.heap[id];
 
        debug_assert_eq!(return_stmt.expressions.len(), 1);
 
        let expr_id = return_stmt.expressions[0];
 

	
 
        self.visit_expr(ctx, expr_id)
 
    }
 

	
 
    fn visit_new_stmt(&mut self, ctx: &mut Ctx, id: NewStatementId) -> VisitorResult {
 
        let new_stmt = &ctx.heap[id];
 
        let call_expr_id = new_stmt.expression;
 

	
 
        self.visit_call_expr(ctx, call_expr_id)
 
    }
 

	
 
    fn visit_expr_stmt(&mut self, ctx: &mut Ctx, id: ExpressionStatementId) -> VisitorResult {
 
        let expr_stmt = &ctx.heap[id];
 
        let subexpr_id = expr_stmt.expression;
 

	
 
        self.visit_expr(ctx, subexpr_id)
 
    }
 

	
 
    // Expressions
 

	
 
    fn visit_assignment_expr(&mut self, ctx: &mut Ctx, id: AssignmentExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let assign_expr = &ctx.heap[id];
 
        let left_expr_id = assign_expr.left;
 
        let right_expr_id = assign_expr.right;
 

	
 
        self.visit_expr(ctx, left_expr_id)?;
 
        self.visit_expr(ctx, right_expr_id)?;
 

	
 
        self.progress_assignment_expr(ctx, id)
 
    }
 

	
 
    fn visit_binding_expr(&mut self, ctx: &mut Ctx, id: BindingExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let binding_expr = &ctx.heap[id];
 
        let bound_to_id = binding_expr.bound_to;
 
        let bound_from_id = binding_expr.bound_from;
 

	
 
        self.visit_expr(ctx, bound_to_id)?;
 
        self.visit_expr(ctx, bound_from_id)?;
 

	
 
        self.progress_binding_expr(ctx, id)
 
    }
 

	
 
    fn visit_conditional_expr(&mut self, ctx: &mut Ctx, id: ConditionalExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let conditional_expr = &ctx.heap[id];
 
        let test_expr_id = conditional_expr.test;
 
        let true_expr_id = conditional_expr.true_expression;
 
        let false_expr_id = conditional_expr.false_expression;
 

	
 
        self.visit_expr(ctx, test_expr_id)?;
 
        self.visit_expr(ctx, true_expr_id)?;
 
        self.visit_expr(ctx, false_expr_id)?;
 

	
 
        self.progress_conditional_expr(ctx, id)
 
    }
 

	
 
    fn visit_binary_expr(&mut self, ctx: &mut Ctx, id: BinaryExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let binary_expr = &ctx.heap[id];
 
        let lhs_expr_id = binary_expr.left;
 
        let rhs_expr_id = binary_expr.right;
 

	
 
        self.visit_expr(ctx, lhs_expr_id)?;
 
        self.visit_expr(ctx, rhs_expr_id)?;
 

	
 
        self.progress_binary_expr(ctx, id)
 
    }
 

	
 
    fn visit_unary_expr(&mut self, ctx: &mut Ctx, id: UnaryExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
 
        self.insert_initial_expr_inference_type(ctx, upcast_id)?;
 

	
 
        let unary_expr = &ctx.heap[id];
 
        let arg_expr_id = unary_expr.expression;
 

	
 
        self.visit_expr(ctx, arg_expr_id)?;
 

	
 
        self.progress_unary_expr(ctx, id)
 
    }
 

	
 
    fn visit_indexing_expr(&mut self, ctx: &mut Ctx, id: IndexingExpressionId) -> VisitorResult {
 
        let upcast_id = id.upcast();
src/protocol/parser/pass_validation_linking.rs
Show inline comments
 
/*
 
 * pass_validation_linking.rs
 
 *
 
 * The pass that will validate properties of the AST statements (one is not
 
 * allowed to nest synchronous statements, instantiating components occurs in
 
 * the right places, etc.) and expressions (assignments may not occur in
 
 * arbitrary expressions).
 
 *
 
 * Furthermore, this pass will also perform "linking", in the sense of: some AST
 
 * nodes have something to do with one another, so we link them up in this pass
 
 * (e.g. setting the parents of expressions, linking the control flow statements
 
 * like `continue` and `break` up to the respective loop statement, etc.).
 
 *
 
 * There are several "confusing" parts about this pass:
 
 *
 
 * Setting expression parents: this is the simplest one. The pass struct acts
 
 * like a little state machine. When visiting an expression it will set the
 
 * "parent expression" field of the pass to itself, then visit its child. The
 
 * child will look at this "parent expression" field to determine its parent.
 
 *
 
 * 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_CAPACITY,
 
    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(),
 
        }
 
    }
 
}
 

	
 
/// 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.
 
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: Scope,
 
    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_block: 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
 
    // 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>,
 
}
 

	
 
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: Scope::Definition(DefinitionId::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_block: 0,
 
            next_expr_index: 0,
 
            variable_buffer: ScopedBuffer::with_capacity(128),
 
            definition_buffer: ScopedBuffer::with_capacity(128),
 
            statement_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
 
            expression_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAPACITY),
 
        }
 
    }
 

	
 
    fn reset_state(&mut self) {
 
        self.in_sync = SynchronousStatementId::new_invalid();
 
        self.in_while = WhileStatementId::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 = Scope::Definition(DefinitionId::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_block = 0;
 
        self.next_expr_index = 0
 
    }
 
}
 

	
 
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 {
 
            ComponentVariant::Primitive => DefinitionType::Primitive(id),
 
            ComponentVariant::Composite => DefinitionType::Composite(id),
 
        };
 
        self.cur_scope = Scope::Definition(id.upcast());
 
        self.expr_parent = ExpressionParent::None;
 

	
 
        // Visit parameters and assign a unique 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];
 
            let variable = &mut ctx.heap[variable_id];
 
            variable.unique_id_in_scope = variable_idx as i32;
 
        }
 
        section.forget();
 

	
 
        // Visit statements in component body
 
        self.visit_block_stmt(ctx, body_id)?;
 

	
 
        // Assign total number of expressions and assign an in-block unique ID
 
        // to each of the locals in the procedure.
 
        ctx.heap[id].num_expressions_in_body = self.next_expr_index;
 
@@ -383,204 +387,226 @@ impl Visitor for PassValidationLinking {
 
        let sync_stmt = &ctx.heap[id];
 
        let end_sync_id = sync_stmt.end_sync;
 
        let cur_sync_span = sync_stmt.span;
 
        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());
 

	
 
        let sync_body = ctx.heap[id].body;
 
        debug_assert!(self.in_sync.is_invalid());
 
        self.in_sync = id;
 
        self.visit_block_stmt_with_hint(ctx, sync_body, Some(id))?;
 
        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_block_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_block_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 num_cases = select_stmt.cases.len();
 
        for case in &select_stmt.cases {
 
            // Note: we add both to the buffer, retrieve them later in indexed
 
            // fashion
 
            case_stmt_ids.push(case.guard);
 
            case_stmt_ids.push(case.block.upcast());
 
        }
 

	
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        // Link up the "Select" with the "EndSelect". If there are no cases then
 
        // runtime will pick the "EndSelect" immediately.
 
        // runtime should pick the "EndSelect" immediately.
 

	
 
        for idx in 0..num_cases {
 
            let base_idx = 2 * idx;
 
            let guard_id     = case_stmt_ids[base_idx    ];
 
            let arm_block_id = case_stmt_ids[base_idx + 1];
 

	
 
            // 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.visit_stmt(ctx, guard_id)?;
 
            self.in_select_guard = SelectStatementId::new_invalid();
 

	
 
            // If the arm declares a variable, then add it to the variables of
 
            // this arm's code block
 
            match &ctx.heap[guard_id] {
 
                Statement::Local(LocalStatement::Memory(stmt)) => {
 
                    debug_assert_eq!(ctx.heap[arm_block_id].as_block().this.upcast(), arm_block_id); // backwards way of saying arm_block_id is a BlockStatementId
 
                    let block_stmt = BlockStatementId(arm_block_id);
 
                    let block_scope =  Scope::Regular(block_stmt);
 
                    self.checked_at_single_scope_add_local(ctx, block_scope, -1, stmt.variable)?;
 
                },
 
                Statement::Expression(_) => {},
 
                _ => unreachable!(), // just to be sure the parser produced the expected AST
 
            }
 

	
 
            // Visit the code associated with the guard
 
            self.visit_stmt(ctx, arm_block_id)?;
 

	
 
            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 {
 
        let target_id = self.find_label(ctx, &ctx.heap[id].label)?;
 
        ctx.heap[id].target = Some(target_id);
 

	
 
        let target = &ctx.heap[target_id];
 
        if self.in_sync != target.in_sync {
 
            // We can only goto the current scope or outer scopes. Because
 
            // nested sync statements are not allowed we must be inside a sync
 
            // statement.
 
            debug_assert!(!self.in_sync.is_invalid());
 
            let goto_stmt = &ctx.heap[id];
 
            let sync_stmt = &ctx.heap[self.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.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")
 
            );
 
        }
 

	
 
        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
 
@@ -1008,278 +1034,289 @@ impl Visitor for PassValidationLinking {
 
            Literal::Union(literal) => {
 
                // Make sure the variant exists
 
                let type_definition = ctx.types.get_base_definition(&literal.definition).unwrap();
 
                let union_definition = type_definition.definition.as_union();
 

	
 
                let variant_idx = union_definition.variants.iter().position(|v| {
 
                    v.identifier == literal.variant
 
                });
 
                if variant_idx.is_none() {
 
                    let literal = ctx.heap[id].value.as_union();
 
                    let ast_definition = ctx.heap[literal.definition].as_union();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, literal.parser_type.full_span, format!(
 
                            "the variant '{}' does not exist on the union '{}'",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str()
 
                        )
 
                    ));
 
                }
 

	
 
                literal.variant_idx = variant_idx.unwrap();
 

	
 
                // Make sure the number of specified values matches the expected
 
                // number of embedded values in the union variant.
 
                let union_variant = &union_definition.variants[literal.variant_idx];
 
                if union_variant.embedded.len() != literal.values.len() {
 
                    let literal = ctx.heap[id].value.as_union();
 
                    let ast_definition = ctx.heap[literal.definition].as_union();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, literal.parser_type.full_span, format!(
 
                            "The variant '{}' of union '{}' expects {} embedded values, but {} were specified",
 
                            literal.variant.value.as_str(), ast_definition.identifier.value.as_str(),
 
                            union_variant.embedded.len(), literal.values.len()
 
                        ),
 
                    ))
 
                }
 

	
 
                // Traverse embedded values of union (if any) and evaluate the
 
                // polymorphic arguments
 
                let upcast_id = id.upcast();
 
                let mut expr_section = self.expression_buffer.start_section();
 
                for value in &literal.values {
 
                    expr_section.push(*value);
 
                }
 

	
 
                for expr_idx in 0..expr_section.len() {
 
                    let expr_id = expr_section[expr_idx];
 
                    self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 

	
 
                expr_section.forget();
 
            },
 
            Literal::Array(literal) | Literal::Tuple(literal) => {
 
                // Visit all expressions in the array
 
                let upcast_id = id.upcast();
 
                let expr_section = self.expression_buffer.start_section_initialized(literal);
 
                for expr_idx in 0..expr_section.len() {
 
                    let expr_id = expr_section[expr_idx];
 
                    self.expr_parent = ExpressionParent::Expression(upcast_id, expr_idx as u32);
 
                    self.visit_expr(ctx, expr_id)?;
 
                }
 

	
 
                expr_section.forget();
 
            }
 
        }
 

	
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_cast_expr(&mut self, ctx: &mut Ctx, id: CastExpressionId) -> VisitorResult {
 
        let cast_expr = &mut ctx.heap[id];
 

	
 
        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 cast expression"
 
            ))
 
        }
 

	
 
        let upcast_id = id.upcast();
 
        let old_expr_parent = self.expr_parent;
 
        cast_expr.parent = old_expr_parent;
 
        cast_expr.unique_id_in_definition = self.next_expr_index;
 
        self.next_expr_index += 1;
 

	
 
        // Recurse into the thing that we're casting
 
        self.expr_parent = ExpressionParent::Expression(upcast_id, 0);
 
        let subject_id = cast_expr.subject;
 
        self.visit_expr(ctx, subject_id)?;
 
        self.expr_parent = old_expr_parent;
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_call_expr(&mut self, ctx: &mut Ctx, id: CallExpressionId) -> VisitorResult {
 
        let call_expr = &mut ctx.heap[id];
 
        let call_expr = &ctx.heap[id];
 

	
 
        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 call expression"
 
            ))
 
        }
 

	
 
        // Check whether the method is allowed to be called within the code's
 
        // context (in sync, definition type, etc.)
 
        let mut expected_wrapping_new_stmt = false;
 
        match &mut call_expr.method {
 
        let mut expecting_wrapping_new_stmt = false;
 
        let mut expecting_primitive_def = false;
 
        let mut expecting_wrapping_sync_stmt = false;
 
        let mut expecting_no_select_stmt = false;
 

	
 
        match call_expr.method {
 
            Method::Get => {
 
                if !self.def_type.is_primitive() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'get' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'get' may only occur inside synchronous blocks"
 
                    ));
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
                if !self.in_select_guard.is_invalid() {
 
                    // In a select guard. Take the argument (i.e. the port we're
 
                    // retrieving from) and add it to the list of involved ports
 
                    // of the guard
 
                    if call_expr.arguments.len() == 1 {
 
                        // We're checking the number of arguments later, for now
 
                        // assume it is correct.
 
                        let argument = call_expr.arguments[0];
 
                        let select_stmt = &mut ctx.heap[self.in_select_guard];
 
                        let select_case = &mut select_stmt.cases[self.in_select_arm as usize];
 
                        select_case.involved_ports.push((id, argument));
 
                    }
 
                }
 
            },
 
            Method::Put => {
 
                if !self.def_type.is_primitive() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'put' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
                if !self.in_select_guard.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'put' may only occur inside synchronous blocks"
 
                        "a call to 'put' may not occur in a select statement's guard"
 
                    ));
 
                }
 
            },
 
            Method::Fires => {
 
                if !self.def_type.is_primitive() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'fires' may only occur in primitive component definitions"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "a call to 'fires' may only occur inside synchronous blocks"
 
                    ));
 
                }
 
                expecting_primitive_def = true;
 
                expecting_wrapping_sync_stmt = true;
 
            },
 
            Method::Create => {},
 
            Method::Length => {},
 
            Method::Assert => {
 
                expecting_wrapping_sync_stmt = true;
 
                expecting_no_select_stmt = true;
 
                if self.def_type.is_function() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "assert statement may only occur in components"
 
                    ));
 
                }
 
                if self.in_sync.is_invalid() {
 
                    let call_span = call_expr.func_span;
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, call_span,
 
                        "assert statements may only occur inside synchronous blocks"
 
                    ));
 
                }
 
            },
 
            Method::Print => {},
 
            Method::UserFunction => {},
 
            Method::UserComponent => {
 
                expected_wrapping_new_stmt = true;
 
                expecting_wrapping_new_stmt = true;
 
            },
 
        }
 

	
 
        if expected_wrapping_new_stmt {
 
        let call_expr = &mut ctx.heap[id];
 

	
 
        fn get_span_and_name<'a>(ctx: &'a Ctx, id: CallExpressionId) -> (InputSpan, String) {
 
            let call = &ctx.heap[id];
 
            let span = call.func_span;
 
            let name = String::from_utf8_lossy(ctx.module().source.section_at_span(span)).to_string();
 
            return (span, name);
 
        }
 
        if expecting_primitive_def {
 
            if !self.def_type.is_primitive() {
 
                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 only occur in primitive component definitions", func_name)
 
                ));
 
            }
 
        }
 

	
 
        if expecting_wrapping_sync_stmt {
 
            if self.in_sync.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 only occur inside synchronous blocks", 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_block, &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) => {
 
@@ -1537,193 +1574,193 @@ impl PassValidationLinking {
 
        let block_stmt = &mut ctx.heap[block_id];
 
        block_stmt.next_unique_id_in_scope = var_counter;
 
    }
 

	
 
    //--------------------------------------------------------------------------
 
    // 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, relative_pos: i32, id: VariableId) -> Result<(), ParseError> {
 
        debug_assert!(self.cur_scope.is_block());
 
        let local = &ctx.heap[id];
 
        let mut scope = &self.cur_scope;
 
        println!("DEBUG: Adding local '{}' at relative_pos {} in scope {:?}", local.identifier.value.as_str(), relative_pos, self.cur_scope);
 

	
 
        loop {
 
            // We immediately go to the parent scope. We check the current scope
 
            // in the call at the end. Likewise for checking the symbol table.
 
            let block = &ctx.heap[scope.to_block()];
 

	
 
            scope = &block.scope_node.parent;
 
            if let Scope::Definition(definition_id) = scope {
 
                // At outer scope, check parameters of function/component
 
                for parameter_id in ctx.heap[*definition_id].parameters() {
 
                    let parameter = &ctx.heap[*parameter_id];
 
                    if local.identifier == parameter.identifier {
 
                        return Err(
 
                            ParseError::new_error_str_at_span(
 
                                &ctx.module().source, local.identifier.span, "Local variable name conflicts with parameter"
 
                            ).with_info_str_at_span(
 
                                &ctx.module().source, parameter.identifier.span, "Parameter definition is found here"
 
                            )
 
                        );
 
                    }
 
                }
 

	
 
                // No collisions
 
                break;
 
            }
 

	
 
            // If here then the parent scope is a block scope
 
            let local_relative_pos = ctx.heap[scope.to_block()].relative_pos_in_parent;
 

	
 
            for other_local_id in &block.locals {
 
                let other_local = &ctx.heap[*other_local_id];
 
                // Position check in case another variable with the same name
 
                // is defined in a higher-level scope, but later than the scope
 
                // in which the current variable resides.
 
                if local.this != *other_local_id &&
 
                    local_relative_pos >= other_local.relative_pos_in_block &&
 
                    local.identifier == other_local.identifier {
 
                    // Collision within this scope
 
                    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, other_local.identifier.span, "Previous variable is found here"
 
                        )
 
                    );
 
                }
 
            }
 
        }
 

	
 
        // No collisions in any of the parent scope, attempt to add to scope
 
        self.checked_at_single_scope_add_local(ctx, self.cur_scope, 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: Scope, relative_pos: i32, id: VariableId
 
    ) -> Result<(), ParseError> {
 
        // Check the symbol table for conflicts
 
        {
 
            let cur_scope = SymbolScope::Definition(self.def_type.definition_id());
 
            let ident = &ctx.heap[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 local = &ctx.heap[id];
 

	
 
        debug_assert!(scope.is_block());
 
        let block = &ctx.heap[scope.to_block()];
 
        for other_local_id in &block.locals {
 
            let other_local = &ctx.heap[*other_local_id];
 
            if local.this != other_local.this &&
 
                relative_pos >= other_local.relative_pos_in_block &&
 
                // relative_pos >= other_local.relative_pos_in_block &&
 
                local.identifier == other_local.identifier {
 
                // Collision
 
                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, other_local.identifier.span, "Previous variable is found here"
 
                    )
 
                );
 
            }
 
        }
 

	
 
        // No collisions
 
        let block = &mut ctx.heap[scope.to_block()];
 
        block.locals.push(id);
 

	
 
        let local = &mut ctx.heap[id];
 
        local.relative_pos_in_block = relative_pos;
 

	
 
        Ok(())
 
    }
 

	
 
    /// Finds a variable in the visitor's scope that must appear before the
 
    /// specified relative position within that block.
 
    fn find_variable(&self, ctx: &Ctx, mut relative_pos: i32, identifier: &Identifier) -> Option<VariableId> {
 
        println!("DEBUG: Calling find_variable for '{}' at relative_pos {}", identifier.value.as_str(), relative_pos);
 
        debug_assert!(self.cur_scope.is_block());
 

	
 
        // No need to use iterator over namespaces if here
 
        let mut scope = &self.cur_scope;
 
        
 
        loop {
 
            debug_assert!(scope.is_block());
 
            let block = &ctx.heap[scope.to_block()];
 
            println!("DEBUG: > Looking in block {:?} at relative_pos {}", scope.to_block().0, relative_pos);
 
            
 
            for local_id in &block.locals {
 
                let local = &ctx.heap[*local_id];
 
                
 
                if local.relative_pos_in_block < relative_pos && identifier == &local.identifier {
 
                    println!("DEBUG: > Matched at local with relative_pos {}", local.relative_pos_in_block);
 
                    return Some(*local_id);
 
                }
 
            }
 

	
 
            scope = &block.scope_node.parent;
 
            if !scope.is_block() {
 
                // Definition scope, need to check arguments to definition
 
                match scope {
 
                    Scope::Definition(definition_id) => {
 
                        let definition = &ctx.heap[*definition_id];
 
                        for parameter_id in definition.parameters() {
 
                            let parameter = &ctx.heap[*parameter_id];
 
                            if identifier == &parameter.identifier {
 
                                return Some(*parameter_id);
 
                            }
 
                        }
 
                    },
 
                    _ => unreachable!(),
 
                }
 

	
 
                // Variable could not be found
 
                return None
 
            } else {
 
                relative_pos = block.relative_pos_in_parent;
 
            }
 
        }
 
    }
 

	
 
    /// Adds a particular label to the current scope. Will return an error if
 
    /// there is another label with the same name visible in the current scope.
 
    fn checked_add_label(&mut self, ctx: &mut Ctx, relative_pos: i32, in_sync: SynchronousStatementId, id: LabeledStatementId) -> Result<(), ParseError> {
 
        debug_assert!(self.cur_scope.is_block());
 

	
 
        // Make sure label is not defined within the current scope or any of the
 
        // parent scope.
 
        let label = &mut ctx.heap[id];
 
        label.relative_pos_in_block = relative_pos;
 
        label.in_sync = in_sync;
 

	
 
        let label = &ctx.heap[id];
 
        let mut scope = &self.cur_scope;
 

	
 
        loop {
 
            debug_assert!(scope.is_block(), "scope is not a block");
 
            let block = &ctx.heap[scope.to_block()];
 
            for other_label_id in &block.labels {
 
                let other_label = &ctx.heap[*other_label_id];
 
                if other_label.label == label.label {
 
                    // Collision
 
                    return Err(ParseError::new_error_str_at_span(
 
                        &ctx.module().source, label.label.span, "label name is used more than once"
 
                    ).with_info_str_at_span(
 
                        &ctx.module().source, other_label.label.span, "the other label is found here"
 
                    ));
 
                }
0 comments (0 inline, 0 general)