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//===--- EvaluatedExprVisitor.h - Evaluated expression visitor --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the EvaluatedExprVisitor class template, which visits
// the potentially-evaluated subexpressions of a potentially-evaluated
// expression.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H
#define LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
namespace clang {
class ASTContext;
/// \brief Given a potentially-evaluated expression, this visitor visits all
/// of its potentially-evaluated subexpressions, recursively.
template<typename ImplClass>
class EvaluatedExprVisitor : public StmtVisitor<ImplClass> {
ASTContext &Context;
public:
explicit EvaluatedExprVisitor(ASTContext &Context) : Context(Context) { }
// Expressions that have no potentially-evaluated subexpressions (but may have
// other sub-expressions).
void VisitDeclRefExpr(DeclRefExpr *E) { }
void VisitOffsetOfExpr(OffsetOfExpr *E) { }
void VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E) { }
void VisitExpressionTraitExpr(ExpressionTraitExpr *E) { }
void VisitBlockExpr(BlockExpr *E) { }
void VisitCXXUuidofExpr(CXXUuidofExpr *E) { }
void VisitCXXNoexceptExpr(CXXNoexceptExpr *E) { }
void VisitMemberExpr(MemberExpr *E) {
// Only the base matters.
return this->Visit(E->getBase());
}
void VisitChooseExpr(ChooseExpr *E) {
// Only the selected subexpression matters; the other one is not evaluated.
return this->Visit(E->getChosenSubExpr(Context));
}
void VisitDesignatedInitExpr(DesignatedInitExpr *E) {
// Only the actual initializer matters; the designators are all constant
// expressions.
return this->Visit(E->getInit());
}
void VisitCXXTypeidExpr(CXXTypeidExpr *E) {
// typeid(expression) is potentially evaluated when the argument is
// a glvalue of polymorphic type. (C++ 5.2.8p2-3)
if (!E->isTypeOperand() && E->Classify(Context).isGLValue())
if (const RecordType *Record
= E->getExprOperand()->getType()->template getAs<RecordType>())
if (cast<CXXRecordDecl>(Record->getDecl())->isPolymorphic())
return this->Visit(E->getExprOperand());
}
/// \brief The basis case walks all of the children of the statement or
/// expression, assuming they are all potentially evaluated.
void VisitStmt(Stmt *S) {
for (Stmt::child_range C = S->children(); C; ++C)
if (*C)
this->Visit(*C);
}
};
}
#endif // LLVM_CLANG_AST_EVALUATEDEXPRVISITOR_H