1 //===--- EvaluatedExprVisitor.h - Evaluated expression visitor --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the EvaluatedExprVisitor class template, which visits
11 // the potentially-evaluated subexpressions of a potentially-evaluated
14 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H
16 #define LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/StmtVisitor.h"
27 /// \brief Given a potentially-evaluated expression, this visitor visits all
28 /// of its potentially-evaluated subexpressions, recursively.
29 template<template <typename> class Ptr, typename ImplClass>
30 class EvaluatedExprVisitorBase : public StmtVisitorBase<Ptr, ImplClass, void> {
32 const ASTContext &Context;
35 #define PTR(CLASS) typename Ptr<CLASS>::type
37 explicit EvaluatedExprVisitorBase(const ASTContext &Context) : Context(Context) { }
39 // Expressions that have no potentially-evaluated subexpressions (but may have
40 // other sub-expressions).
41 void VisitDeclRefExpr(PTR(DeclRefExpr) E) { }
42 void VisitOffsetOfExpr(PTR(OffsetOfExpr) E) { }
43 void VisitUnaryExprOrTypeTraitExpr(PTR(UnaryExprOrTypeTraitExpr) E) { }
44 void VisitExpressionTraitExpr(PTR(ExpressionTraitExpr) E) { }
45 void VisitBlockExpr(PTR(BlockExpr) E) { }
46 void VisitCXXUuidofExpr(PTR(CXXUuidofExpr) E) { }
47 void VisitCXXNoexceptExpr(PTR(CXXNoexceptExpr) E) { }
49 void VisitMemberExpr(PTR(MemberExpr) E) {
50 // Only the base matters.
51 return this->Visit(E->getBase());
54 void VisitChooseExpr(PTR(ChooseExpr) E) {
55 // Don't visit either child expression if the condition is dependent.
56 if (E->getCond()->isValueDependent())
58 // Only the selected subexpression matters; the other one is not evaluated.
59 return this->Visit(E->getChosenSubExpr());
62 void VisitGenericSelectionExpr(PTR(GenericSelectionExpr) E) {
63 // The controlling expression of a generic selection is not evaluated.
65 // Don't visit either child expression if the condition is type-dependent.
66 if (E->isResultDependent())
68 // Only the selected subexpression matters; the other subexpressions and the
69 // controlling expression are not evaluated.
70 return this->Visit(E->getResultExpr());
73 void VisitDesignatedInitExpr(PTR(DesignatedInitExpr) E) {
74 // Only the actual initializer matters; the designators are all constant
76 return this->Visit(E->getInit());
79 void VisitCXXTypeidExpr(PTR(CXXTypeidExpr) E) {
80 if (E->isPotentiallyEvaluated())
81 return this->Visit(E->getExprOperand());
84 void VisitCallExpr(PTR(CallExpr) CE) {
85 if (!CE->isUnevaluatedBuiltinCall(Context))
86 return static_cast<ImplClass*>(this)->VisitExpr(CE);
89 void VisitLambdaExpr(PTR(LambdaExpr) LE) {
90 // Only visit the capture initializers, and not the body.
91 for (LambdaExpr::const_capture_init_iterator I = LE->capture_init_begin(),
92 E = LE->capture_init_end();
98 /// \brief The basis case walks all of the children of the statement or
99 /// expression, assuming they are all potentially evaluated.
100 void VisitStmt(PTR(Stmt) S) {
101 for (auto *SubStmt : S->children())
103 this->Visit(SubStmt);
109 /// EvaluatedExprVisitor - This class visits 'Expr *'s
110 template<typename ImplClass>
111 class EvaluatedExprVisitor
112 : public EvaluatedExprVisitorBase<make_ptr, ImplClass> {
114 explicit EvaluatedExprVisitor(const ASTContext &Context) :
115 EvaluatedExprVisitorBase<make_ptr, ImplClass>(Context) { }
118 /// ConstEvaluatedExprVisitor - This class visits 'const Expr *'s.
119 template<typename ImplClass>
120 class ConstEvaluatedExprVisitor
121 : public EvaluatedExprVisitorBase<make_const_ptr, ImplClass> {
123 explicit ConstEvaluatedExprVisitor(const ASTContext &Context) :
124 EvaluatedExprVisitorBase<make_const_ptr, ImplClass>(Context) { }
129 #endif // LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H