Visitor generates type constraints and processes them. More...

#include <TypeConstraintVisitor.h>

Inheritance diagram for TypeConstraintVisitor:

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Collaboration diagram for TypeConstraintVisitor:

Public Member Functions
	TypeConstraintVisitor ()=delete

	TypeConstraintVisitor (SymbolTable *st, std::shared_ptr< ConstraintHandler > handler)

bool	visit (ASTFunction *element) override

void	endVisit (ASTAccessExpr *element) override
	Type constraints for field access. More...

void	endVisit (ASTAllocExpr *element) override
	Type constraints for heap allocation. More...

void	endVisit (ASTAssignStmt *element) override
	Type rules for assignments. More...

void	endVisit (ASTBinaryExpr *element) override
	Type constraints for binary operator. More...

void	endVisit (ASTDeRefExpr *element) override
	Type constraints for pointer dereference. More...

void	endVisit (ASTErrorStmt *element) override
	Type constraints for error statement. More...

void	endVisit (ASTFunAppExpr *element) override
	Type constraints for function application. More...

void	endVisit (ASTFunction *element) override
	Type constraints for function definition. More...

void	endVisit (ASTIfStmt *element) override
	Type constraints for if statement. More...

void	endVisit (ASTInputExpr *element) override
	Type constraints for input statement. More...

void	endVisit (ASTNullExpr *element) override
	Type constraints for null literal. More...

void	endVisit (ASTNumberExpr *element) override
	Type constraints for numeric literal. More...

void	endVisit (ASTOutputStmt *element) override
	Type constraints for output statement. More...

void	endVisit (ASTRecordExpr *element) override
	Type constraints for record expression. More...

void	endVisit (ASTRefExpr *element) override
	Type constraints for address of. More...

void	endVisit (ASTWhileStmt *element) override
	Type constraints for while loop. More...

Public Member Functions inherited from ASTVisitor
virtual bool	visit (ASTProgram *element)

virtual void	endVisit (ASTProgram *element)

virtual bool	visit (ASTNumberExpr *element)

virtual bool	visit (ASTVariableExpr *element)

virtual void	endVisit (ASTVariableExpr *element)

virtual bool	visit (ASTBinaryExpr *element)

virtual bool	visit (ASTInputExpr *element)

virtual bool	visit (ASTFunAppExpr *element)

virtual bool	visit (ASTAllocExpr *element)

virtual bool	visit (ASTRefExpr *element)

virtual bool	visit (ASTDeRefExpr *element)

virtual bool	visit (ASTNullExpr *element)

virtual bool	visit (ASTFieldExpr *element)

virtual void	endVisit (ASTFieldExpr *element)

virtual bool	visit (ASTRecordExpr *element)

virtual bool	visit (ASTAccessExpr *element)

virtual bool	visit (ASTDeclNode *element)

virtual void	endVisit (ASTDeclNode *element)

virtual bool	visit (ASTDeclStmt *element)

virtual void	endVisit (ASTDeclStmt *element)

virtual bool	visit (ASTAssignStmt *element)

virtual bool	visit (ASTWhileStmt *element)

virtual bool	visit (ASTIfStmt *element)

virtual bool	visit (ASTOutputStmt *element)

virtual bool	visit (ASTReturnStmt *element)

virtual void	endVisit (ASTReturnStmt *element)

virtual bool	visit (ASTErrorStmt *element)

virtual bool	visit (ASTBlockStmt *element)

virtual void	endVisit (ASTBlockStmt *element)

Protected Member Functions
std::shared_ptr< TipType >	astToVar (ASTNode *n)

Protected Attributes
std::shared_ptr< ConstraintHandler >	constraintHandler

SymbolTable *	symbolTable

Detailed Description

Visitor generates type constraints and processes them.

This visitor performs a post-order visit of the program AST. It constructs type constraints for each node that requires a type judgement. The constraints are then processed by a concrete implemntation of A ConstraintHandler. This provides flexibility in using the visitor - it can simply record the constraints or it can solve them on the fly.

Constructor & Destructor Documentation

◆ TypeConstraintVisitor() [1/2]

TypeConstraintVisitor::TypeConstraintVisitor ( )

delete

◆ TypeConstraintVisitor() [2/2]

TypeConstraintVisitor::TypeConstraintVisitor	(	SymbolTable *	st,
		std::shared_ptr< ConstraintHandler >	handler
	)

Construct a TypeConstraintVisitor from the given SymbolTable and ConstraintHandler.

Subclasses define the handler (eg. TypeConstraintUnifyVisitor defines the ConstraintUnfier as its handler) and pass it up to the base class during construction. This allows us to not call virtual methods in the constructor.

Scott Meyers defines this pattern in his Effective C++ series. You can read more about it here, https://www.aristeia.com/EC3E/3E_item9.pdf.

Member Function Documentation

◆ astToVar()

std::shared_ptr< TipType > TypeConstraintVisitor::astToVar ( ASTNode * n )

protected

◆ endVisit() [1/16]

void TypeConstraintVisitor::endVisit ( ASTAccessExpr * element )

overridevirtual

Type constraints for field access.

Type rule for "E.X": [[E]] = { f1:v1, ..., fn:vn } where fi is the ith field in the program's global record and vi = [[E.X]] if fi = X and \alpha otherwise

Reimplemented from ASTVisitor.

◆ endVisit() [2/16]

void TypeConstraintVisitor::endVisit ( ASTAllocExpr * element )

overridevirtual

Type constraints for heap allocation.

Type Rules for "alloc E": [[alloc E]] = &[[E]]

Reimplemented from ASTVisitor.

◆ endVisit() [3/16]

void TypeConstraintVisitor::endVisit ( ASTAssignStmt * element )

overridevirtual

Type rules for assignments.

Type rules for "E1 = E": [[E1]] = [[E2]]

Type rules for "*E1 = E2": [[E1]] = &[[E2]]

Note that these are slightly more general than the rules in the SPA book. The first allows for record expressions on the left hand side and the second allows for more complex assignments, e.g., "**p = &x"

Reimplemented from ASTVisitor.

◆ endVisit() [4/16]

void TypeConstraintVisitor::endVisit ( ASTBinaryExpr * element )

overridevirtual

Type constraints for binary operator.

Type rules for "E1 op E2": [[E1 op E2]] = int and if "op" is not equality or disequality [[E1]] = [[E2]] = int otherwise [[E1]] = [[E2]]

Reimplemented from ASTVisitor.

◆ endVisit() [5/16]

void TypeConstraintVisitor::endVisit ( ASTDeRefExpr * element )

overridevirtual

Type constraints for pointer dereference.

Type Rules for "*E": [[E]] = &[[*E]]

Reimplemented from ASTVisitor.

◆ endVisit() [6/16]

void TypeConstraintVisitor::endVisit ( ASTErrorStmt * element )

overridevirtual

Type constraints for error statement.

Type rules for "error E": [[E]] = int

Reimplemented from ASTVisitor.

◆ endVisit() [7/16]

void TypeConstraintVisitor::endVisit ( ASTFunAppExpr * element )

overridevirtual

Type constraints for function application.

Type Rules for "E(E1, ..., En)": [[E]] = ([[E1]], ..., [[En]]) -> [[E(E1, ..., En)]]

Reimplemented from ASTVisitor.

◆ endVisit() [8/16]

void TypeConstraintVisitor::endVisit ( ASTFunction * element )

overridevirtual

Type constraints for function definition.

Type rules for "main(X1, ..., Xn) { ... return E; }": [[X1]] = [[Xn]] = [[E]] = int To express this we will equate all type variables to int.

Type rules for "X(X1, ..., Xn) { ... return E; }": [[X]] = ([[X1]], ..., [[Xn]]) -> [[E]]

Reimplemented from ASTVisitor.

◆ endVisit() [9/16]

void TypeConstraintVisitor::endVisit ( ASTIfStmt * element )

overridevirtual

Type constraints for if statement.

Type rules for "if (E) S1 else S2": [[E]] = int

Reimplemented from ASTVisitor.

◆ endVisit() [10/16]

void TypeConstraintVisitor::endVisit ( ASTInputExpr * element )

overridevirtual

Type constraints for input statement.

Type rules for "input": [[input]] = int

Reimplemented from ASTVisitor.

◆ endVisit() [11/16]

void TypeConstraintVisitor::endVisit ( ASTNullExpr * element )

overridevirtual

Type constraints for null literal.

Type Rules for "null": [[null]] = & \alpha

Reimplemented from ASTVisitor.

◆ endVisit() [12/16]

void TypeConstraintVisitor::endVisit ( ASTNumberExpr * element )

overridevirtual

Type constraints for numeric literal.

Type rules for "I": [[I]] = int

Reimplemented from ASTVisitor.

◆ endVisit() [13/16]

void TypeConstraintVisitor::endVisit ( ASTOutputStmt * element )

overridevirtual

Type constraints for output statement.

Type rules for "output E": [[E]] = int

Reimplemented from ASTVisitor.

◆ endVisit() [14/16]

void TypeConstraintVisitor::endVisit ( ASTRecordExpr * element )

overridevirtual

Type constraints for record expression.

Type rule for "{ X1:E1, ..., Xn:En }": [[{ X1:E1, ..., Xn:En }]] = { f1:v1, ..., fn:vn } where fi is the ith field in the program's global record and vi = [[Ei]] if fi = Xi and \alpha otherwise

Reimplemented from ASTVisitor.

◆ endVisit() [15/16]

void TypeConstraintVisitor::endVisit ( ASTRefExpr * element )

overridevirtual

Type constraints for address of.

Type Rules for "&X": [[&X]] = &[[X]]

Reimplemented from ASTVisitor.

◆ endVisit() [16/16]

void TypeConstraintVisitor::endVisit ( ASTWhileStmt * element )

overridevirtual

Type constraints for while loop.

Type rules for "while (E) S": [[E]] = int

Reimplemented from ASTVisitor.

◆ visit()

bool TypeConstraintVisitor::visit ( ASTFunction * element )

overridevirtual

Reimplemented from ASTVisitor.

Member Data Documentation

◆ constraintHandler

std::shared_ptr<ConstraintHandler> TypeConstraintVisitor::constraintHandler

protected

◆ symbolTable

SymbolTable* TypeConstraintVisitor::symbolTable

protected

The documentation for this class was generated from the following files:

/home/runner/work/tipc/tipc/src/semantic/types/constraints/TypeConstraintVisitor.h
/home/runner/work/tipc/tipc/src/semantic/types/constraints/TypeConstraintVisitor.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ TypeConstraintVisitor() [1/2]

◆ TypeConstraintVisitor() [2/2]

Member Function Documentation

◆ astToVar()

◆ endVisit() [1/16]

◆ endVisit() [2/16]

◆ endVisit() [3/16]

◆ endVisit() [4/16]

◆ endVisit() [5/16]

◆ endVisit() [6/16]

◆ endVisit() [7/16]

◆ endVisit() [8/16]

◆ endVisit() [9/16]

◆ endVisit() [10/16]

◆ endVisit() [11/16]

◆ endVisit() [12/16]

◆ endVisit() [13/16]

◆ endVisit() [14/16]

◆ endVisit() [15/16]

◆ endVisit() [16/16]

◆ visit()

Member Data Documentation

◆ constraintHandler

◆ symbolTable