A class that does preorder or postorder depth-first traversal on the entire Clang AST and visits each node. More...

#include "clang/AST/RecursiveASTVisitor.h"

Inheritance diagram for clang::RecursiveASTVisitor< Derived >:

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Public Types
typedef SmallVectorImpl< llvm::PointerIntPair< Stmt *, 1, bool > >	DataRecursionQueue
	A queue used for performing data recursion over statements. More...

Public Member Functions
Derived &	getDerived ()
	Return a reference to the derived class. More...

bool	shouldVisitTemplateInstantiations () const
	Return whether this visitor should recurse into template instantiations. More...

bool	shouldWalkTypesOfTypeLocs () const
	Return whether this visitor should recurse into the types of TypeLocs. More...

bool	shouldVisitImplicitCode () const
	Return whether this visitor should recurse into implicit code, e.g., implicit constructors and destructors. More...

bool	shouldTraversePostOrder () const
	Return whether this visitor should traverse post-order. More...

bool	TraverseStmt (Stmt S, DataRecursionQueue Queue=nullptr)
	Recursively visit a statement or expression, by dispatching to Traverse*() based on the argument's dynamic type. More...

bool	dataTraverseStmtPre (Stmt *S)
	Invoked before visiting a statement or expression via data recursion. More...

bool	dataTraverseStmtPost (Stmt *S)
	Invoked after visiting a statement or expression via data recursion. More...

bool	TraverseType (QualType T)
	Recursively visit a type, by dispatching to Traverse*Type() based on the argument's getTypeClass() property. More...

bool	TraverseTypeLoc (TypeLoc TL)
	Recursively visit a type with location, by dispatching to Traverse*TypeLoc() based on the argument type's getTypeClass() property. More...

bool	TraverseAttr (Attr *At)
	Recursively visit an attribute, by dispatching to Traverse*Attr() based on the argument's dynamic type. More...

bool	TraverseDecl (Decl *D)
	Recursively visit a declaration, by dispatching to Traverse*Decl() based on the argument's dynamic type. More...

bool	TraverseNestedNameSpecifier (NestedNameSpecifier *NNS)
	Recursively visit a C++ nested-name-specifier. More...

bool	TraverseNestedNameSpecifierLoc (NestedNameSpecifierLoc NNS)
	Recursively visit a C++ nested-name-specifier with location information. More...

bool	TraverseDeclarationNameInfo (DeclarationNameInfo NameInfo)
	Recursively visit a name with its location information. More...

bool	TraverseTemplateName (TemplateName Template)
	Recursively visit a template name and dispatch to the appropriate method. More...

bool	TraverseTemplateArgument (const TemplateArgument &Arg)
	Recursively visit a template argument and dispatch to the appropriate method for the argument type. More...

bool	TraverseTemplateArgumentLoc (const TemplateArgumentLoc &ArgLoc)
	Recursively visit a template argument location and dispatch to the appropriate method for the argument type. More...

bool	TraverseTemplateArguments (const TemplateArgument *Args, unsigned NumArgs)
	Recursively visit a set of template arguments. More...

bool	TraverseCXXBaseSpecifier (const CXXBaseSpecifier &Base)
	Recursively visit a base specifier. More...

bool	TraverseConstructorInitializer (CXXCtorInitializer *Init)
	Recursively visit a constructor initializer. More...

bool	TraverseLambdaCapture (LambdaExpr LE, const LambdaCapture C, Expr *Init)
	Recursively visit a lambda capture. More...

bool	TraverseLambdaBody (LambdaExpr LE, DataRecursionQueue Queue=nullptr)
	Recursively visit the body of a lambda expression. More...

bool	TraverseSynOrSemInitListExpr (InitListExpr S, DataRecursionQueue Queue=nullptr)
	Recursively visit the syntactic or semantic form of an initialization list. More...

bool	VisitAttr (Attr *A)

Stmt::child_range	getStmtChildren (Stmt *S)

bool	WalkUpFromStmt (Stmt *S)

bool	VisitStmt (Stmt *S)

bool	WalkUpFromType (Type *T)

bool	VisitType (Type *T)

bool	WalkUpFromTypeLoc (TypeLoc TL)

bool	VisitTypeLoc (TypeLoc TL)

bool	WalkUpFromQualifiedTypeLoc (QualifiedTypeLoc TL)

bool	VisitQualifiedTypeLoc (QualifiedTypeLoc TL)

bool	WalkUpFromUnqualTypeLoc (UnqualTypeLoc TL)

bool	VisitUnqualTypeLoc (UnqualTypeLoc TL)

bool	WalkUpFromDecl (Decl *D)

bool	VisitDecl (Decl *D)

bool	canIgnoreChildDeclWhileTraversingDeclContext (const Decl *Child) { TRY_TO(TraverseTypeLoc(TL.getValueLoc()))

Detailed Description

template<typename Derived>
class clang::RecursiveASTVisitor< Derived >

A class that does preorder or postorder depth-first traversal on the entire Clang AST and visits each node.

This class performs three distinct tasks:

traverse the AST (i.e. go to each node);
at a given node, walk up the class hierarchy, starting from the node's dynamic type, until the top-most class (e.g. Stmt, Decl, or Type) is reached.
given a (node, class) combination, where 'class' is some base class of the dynamic type of 'node', call a user-overridable function to actually visit the node.

These tasks are done by three groups of methods, respectively:

TraverseDecl(Decl *x) does task #1. It is the entry point for traversing an AST rooted at x. This method simply dispatches (i.e. forwards) to TraverseFoo(Foo *x) where Foo is the dynamic type of *x, which calls WalkUpFromFoo(x) and then recursively visits the child nodes of x. TraverseStmt(Stmt *x) and TraverseType(QualType x) work similarly.
WalkUpFromFoo(Foo *x) does task #2. It does not try to visit any child node of x. Instead, it first calls WalkUpFromBar(x) where Bar is the direct parent class of Foo (unless Foo has no parent), and then calls VisitFoo(x) (see the next list item).
VisitFoo(Foo *x) does task #3.

These three method groups are tiered (Traverse* > WalkUpFrom* > Visit*). A method (e.g. Traverse*) may call methods from the same tier (e.g. other Traverse*) or one tier lower (e.g. WalkUpFrom*). It may not call methods from a higher tier.

Note that since WalkUpFromFoo() calls WalkUpFromBar() (where Bar is Foo's super class) before calling VisitFoo(), the result is that the Visit*() methods for a given node are called in the top-down order (e.g. for a node of type NamespaceDecl, the order will be VisitDecl(), VisitNamedDecl(), and then VisitNamespaceDecl()).

This scheme guarantees that all Visit*() calls for the same AST node are grouped together. In other words, Visit*() methods for different nodes are never interleaved.

Clients of this visitor should subclass the visitor (providing themselves as the template argument, using the curiously recurring template pattern) and override any of the Traverse*, WalkUpFrom*, and Visit* methods for declarations, types, statements, expressions, or other AST nodes where the visitor should customize behavior. Most users only need to override Visit*. Advanced users may override Traverse* and WalkUpFrom* to implement custom traversal strategies. Returning false from one of these overridden functions will abort the entire traversal.

By default, this visitor tries to visit every part of the explicit source code exactly once. The default policy towards templates is to descend into the 'pattern' class or function body, not any explicit or implicit instantiations. Explicit specializations are still visited, and the patterns of partial specializations are visited separately. This behavior can be changed by overriding shouldVisitTemplateInstantiations() in the derived class to return true, in which case all known implicit and explicit instantiations will be visited at the same time as the pattern from which they were produced.

By default, this visitor preorder traverses the AST. If postorder traversal is needed, the shouldTraversePostOrder method needs to be overridden to return true.

Definition at line 151 of file RecursiveASTVisitor.h.

Member Typedef Documentation

◆ DataRecursionQueue

template<typename Derived>

typedef SmallVectorImpl<llvm::PointerIntPair<Stmt *, 1, bool> > clang::RecursiveASTVisitor< Derived >::DataRecursionQueue

A queue used for performing data recursion over statements.

Parameters involving this type are used to implement data recursion over Stmts and Exprs within this class, and should typically not be explicitly specified by derived classes. The bool bit indicates whether the statement has been traversed or not.

Definition at line 159 of file RecursiveASTVisitor.h.

Member Function Documentation

◆ canIgnoreChildDeclWhileTraversingDeclContext()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::canIgnoreChildDeclWhileTraversingDeclContext ( const Decl * Child ) { TRY_TO(TraverseTypeLoc(TL.getValueLoc()))

Definition at line 1374 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::canIgnoreChildDeclWhileTraversingDeclContext().

◆ dataTraverseStmtPost()

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::dataTraverseStmtPost ( Stmt * S )

inline

Invoked after visiting a statement or expression via data recursion.

This is not invoked if the previously invoked dataTraverseStmtPre returned false.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 196 of file RecursiveASTVisitor.h.

◆ dataTraverseStmtPre()

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::dataTraverseStmtPre ( Stmt * S )

inline

Invoked before visiting a statement or expression via data recursion.

Returns: false to skip visiting the node, true otherwise.

Definition at line 189 of file RecursiveASTVisitor.h.

◆ getDerived()

template<typename Derived>

Derived& clang::RecursiveASTVisitor< Derived >::getDerived ( )

inline

Return a reference to the derived class.

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::shouldVisitTemplateInstantiations ( ) const

inline

Return whether this visitor should recurse into template instantiations.

Definition at line 166 of file RecursiveASTVisitor.h.

◆ shouldWalkTypesOfTypeLocs()

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::shouldWalkTypesOfTypeLocs ( ) const

inline

Return whether this visitor should recurse into the types of TypeLocs.

Definition at line 170 of file RecursiveASTVisitor.h.

◆ TraverseAttr()

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::TraverseAttr ( Attr * At )

Recursively visit an attribute, by dispatching to Traverse*Attr() based on the argument's dynamic type.

Returns: false if the visitation was terminated early, true otherwise (including when the argument is a Null type location).

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseConstructorInitializer()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseConstructorInitializer ( CXXCtorInitializer * Init )

Recursively visit a constructor initializer.

This automatically dispatches to another visitor for the initializer expression, but not for the name of the initializer, so may be overridden for clients that need access to the name.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 906 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseCXXBaseSpecifier()

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::TraverseCXXBaseSpecifier ( const CXXBaseSpecifier & Base )

Recursively visit a base specifier.

This can be overridden by a subclass.

Returns: false if the visitation was terminated early, true otherwise.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseDecl()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseDecl ( Decl * D )

Recursively visit a declaration, by dispatching to Traverse*Decl() based on the argument's dynamic type.

Returns: false if the visitation was terminated early, true otherwise (including when the argument is NULL).

Definition at line 706 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::canIgnoreChildDeclWhileTraversingDeclContext(), clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost(), clang::LexicallyOrderedRecursiveASTVisitor< Derived >::getStmtChildren(), clang::if(), and clang::RecursiveASTVisitor< CallGraph >::TraverseLambdaCapture().

◆ TraverseDeclarationNameInfo()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseDeclarationNameInfo ( DeclarationNameInfo NameInfo )

Recursively visit a name with its location information.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 787 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost(), and clang::if().

◆ TraverseLambdaBody()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseLambdaBody	(	LambdaExpr *	LE,
		DataRecursionQueue *	Queue = `nullptr`
	)

Recursively visit the body of a lambda expression.

This provides a hook for visitors that need more context when visiting LE->getBody().

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 930 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseLambdaCapture()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseLambdaCapture	(	LambdaExpr *	LE,
		const LambdaCapture *	C,
		Expr *	Init
	)

Recursively visit a lambda capture.

Init is the expression that will be used to initialize the capture.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 919 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseNestedNameSpecifier()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseNestedNameSpecifier ( NestedNameSpecifier * NNS )

Recursively visit a C++ nested-name-specifier.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 736 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost(), clang::RecursiveASTVisitor< CallGraph >::TraverseNestedNameSpecifier(), and clang::RecursiveASTVisitor< CallGraph >::TraverseTemplateName().

◆ TraverseNestedNameSpecifierLoc()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseNestedNameSpecifierLoc ( NestedNameSpecifierLoc NNS )

Recursively visit a C++ nested-name-specifier with location information.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 761 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost(), clang::if(), and clang::RecursiveASTVisitor< CallGraph >::TraverseNestedNameSpecifierLoc().

◆ TraverseStmt()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseStmt	(	Stmt *	S,
		DataRecursionQueue *	Queue = `nullptr`
	)

Recursively visit a statement or expression, by dispatching to Traverse*() based on the argument's dynamic type.

Returns: false if the visitation was terminated early, true otherwise (including when the argument is nullptr).

Definition at line 625 of file RecursiveASTVisitor.h.

Referenced by clang::if(), clang::RecursiveASTVisitor< CallGraph >::shouldTraversePostOrder(), clang::RecursiveASTVisitor< CallGraph >::TraverseConstructorInitializer(), and clang::RecursiveASTVisitor< CallGraph >::TraverseLambdaCapture().

◆ TraverseSynOrSemInitListExpr()

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::TraverseSynOrSemInitListExpr	(	InitListExpr *	S,
		DataRecursionQueue *	Queue = `nullptr`
	)

Recursively visit the syntactic or semantic form of an initialization list.

Returns: false if the visitation was terminated early, true otherwise.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseTemplateArgument()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseTemplateArgument ( const TemplateArgument & Arg )

Recursively visit a template argument and dispatch to the appropriate method for the argument type.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 826 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseTemplateArgumentLoc()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseTemplateArgumentLoc ( const TemplateArgumentLoc & ArgLoc )

Recursively visit a template argument location and dispatch to the appropriate method for the argument type.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 857 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseTemplateArguments()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseTemplateArguments	(	const TemplateArgument *	Args,
		unsigned	NumArgs
	)

Recursively visit a set of template arguments.

This can be overridden by a subclass, but it's not expected that will be needed – this visitor always dispatches to another.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 896 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost().

◆ TraverseTemplateName()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseTemplateName ( TemplateName Template )

Recursively visit a template name and dispatch to the appropriate method.

Returns: false if the visitation was terminated early, true otherwise.

Definition at line 816 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost(), and clang::RecursiveASTVisitor< CallGraph >::TraverseDeclarationNameInfo().

◆ TraverseType()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseType ( QualType T )

Recursively visit a type, by dispatching to Traverse*Type() based on the argument's getTypeClass() property.

Returns: false if the visitation was terminated early, true otherwise (including when the argument is a Null type).

Definition at line 669 of file RecursiveASTVisitor.h.

Referenced by clang::RecursiveASTVisitor< CallGraph >::dataTraverseStmtPost(), clang::if(), and clang::RecursiveASTVisitor< CallGraph >::TraverseNestedNameSpecifier().

◆ TraverseTypeLoc()

template<typename Derived >

bool clang::RecursiveASTVisitor< Derived >::TraverseTypeLoc ( TypeLoc TL )

Recursively visit a type with location, by dispatching to Traverse*TypeLoc() based on the argument type's getTypeClass() property.

Returns: false if the visitation was terminated early, true otherwise (including when the argument is a Null type location).

inline

Definition at line 458 of file RecursiveASTVisitor.h.

◆ WalkUpFromUnqualTypeLoc()

template<typename Derived>

bool clang::RecursiveASTVisitor< Derived >::WalkUpFromUnqualTypeLoc ( UnqualTypeLoc TL )

inline

Definition at line 467 of file RecursiveASTVisitor.h.

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

include/clang/AST/RecursiveASTVisitor.h

Public Types

Public Member Functions

Detailed Description

template<typename Derived> class clang::RecursiveASTVisitor< Derived >

Member Typedef Documentation

◆ DataRecursionQueue

Member Function Documentation

◆ canIgnoreChildDeclWhileTraversingDeclContext()

◆ dataTraverseStmtPost()

◆ dataTraverseStmtPre()

◆ getDerived()

◆ getStmtChildren()

◆ shouldTraversePostOrder()

◆ shouldVisitImplicitCode()

◆ shouldVisitTemplateInstantiations()

◆ shouldWalkTypesOfTypeLocs()

◆ TraverseAttr()

◆ TraverseConstructorInitializer()

◆ TraverseCXXBaseSpecifier()

◆ TraverseDecl()

◆ TraverseDeclarationNameInfo()

◆ TraverseLambdaBody()

◆ TraverseLambdaCapture()

◆ TraverseNestedNameSpecifier()

◆ TraverseNestedNameSpecifierLoc()

◆ TraverseStmt()

◆ TraverseSynOrSemInitListExpr()

◆ TraverseTemplateArgument()

◆ TraverseTemplateArgumentLoc()

◆ TraverseTemplateArguments()

◆ TraverseTemplateName()

◆ TraverseType()

◆ TraverseTypeLoc()

◆ VisitAttr()

◆ VisitDecl()

◆ VisitQualifiedTypeLoc()

◆ VisitStmt()

◆ VisitType()

◆ VisitTypeLoc()

◆ VisitUnqualTypeLoc()

◆ WalkUpFromDecl()

◆ WalkUpFromQualifiedTypeLoc()

◆ WalkUpFromStmt()

◆ WalkUpFromType()

◆ WalkUpFromTypeLoc()

◆ WalkUpFromUnqualTypeLoc()

template<typename Derived>
class clang::RecursiveASTVisitor< Derived >