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/StmtVisitor.h"
19 #include "clang/AST/DeclCXX.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/ExprCXX.h"
27 /// \begin Given a potentially-evaluated expression, this visitor visits all
28 /// of its potentially-evaluated subexpressions, recursively.
29 template<typename ImplClass>
30 class EvaluatedExprVisitor : public StmtVisitor<ImplClass> {
34 explicit EvaluatedExprVisitor(ASTContext &Context) : Context(Context) { }
36 // Expressions that have no potentially-evaluated subexpressions (but may have
37 // other sub-expressions).
38 void VisitDeclRefExpr(DeclRefExpr *E) { }
39 void VisitOffsetOfExpr(OffsetOfExpr *E) { }
40 void VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E) { }
41 void VisitBlockExpr(BlockExpr *E) { }
42 void VisitCXXUuidofExpr(CXXUuidofExpr *E) { }
43 void VisitCXXNoexceptExpr(CXXNoexceptExpr *E) { }
45 void VisitMemberExpr(MemberExpr *E) {
46 // Only the base matters.
47 return this->Visit(E->getBase());
50 void VisitChooseExpr(ChooseExpr *E) {
51 // Only the selected subexpression matters; the other one is not evaluated.
52 return this->Visit(E->getChosenSubExpr(Context));
55 void VisitDesignatedInitExpr(DesignatedInitExpr *E) {
56 // Only the actual initializer matters; the designators are all constant
58 return this->Visit(E->getInit());
61 void VisitCXXTypeidExpr(CXXTypeidExpr *E) {
62 // typeid(expression) is potentially evaluated when the argument is
63 // a glvalue of polymorphic type. (C++ 5.2.8p2-3)
64 if (!E->isTypeOperand() && E->Classify(Context).isGLValue())
65 if (const RecordType *Record
66 = E->getExprOperand()->getType()->template getAs<RecordType>())
67 if (cast<CXXRecordDecl>(Record->getDecl())->isPolymorphic())
68 return this->Visit(E->getExprOperand());
71 /// \brief The basis case walks all of the children of the statement or
72 /// expression, assuming they are all potentially evaluated.
73 void VisitStmt(Stmt *S) {
74 for (Stmt::child_range C = S->children(); C; ++C)
82 #endif // LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H