1 //===--- CFGStmtVisitor.h - Visitor for Stmts in a CFG ----------*- 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 CFGStmtVisitor interface, which extends
11 // StmtVisitor. This interface is useful for visiting statements in a CFG
12 // where some statements have implicit control-flow and thus should
13 // be treated specially.
15 //===----------------------------------------------------------------------===//
17 #ifndef LLVM_CLANG_ANALYSIS_CFGSTMTVISITOR_H
18 #define LLVM_CLANG_ANALYSIS_CFGSTMTVISITOR_H
20 #include "clang/AST/StmtVisitor.h"
21 #include "clang/Analysis/CFG.h"
25 #define DISPATCH_CASE(CLASS) \
26 case Stmt::CLASS ## Class: return \
27 static_cast<ImplClass*>(this)->BlockStmt_Visit ## CLASS(static_cast<CLASS*>(S));
29 #define DEFAULT_BLOCKSTMT_VISIT(CLASS) RetTy BlockStmt_Visit ## CLASS(CLASS *S)\
31 static_cast<ImplClass*>(this)->BlockStmt_VisitImplicitControlFlowExpr(\
34 template <typename ImplClass, typename RetTy=void>
35 class CFGStmtVisitor : public StmtVisitor<ImplClass,RetTy> {
41 NullifyStmt(Stmt*& s) : S(s) {}
42 ~NullifyStmt() { S = NULL; }
46 CFGStmtVisitor() : CurrentBlkStmt(NULL) {}
48 Stmt *getCurrentBlkStmt() const { return CurrentBlkStmt; }
50 RetTy Visit(Stmt *S) {
51 if (S == CurrentBlkStmt ||
52 !static_cast<ImplClass*>(this)->getCFG().isBlkExpr(S))
53 return StmtVisitor<ImplClass,RetTy>::Visit(S);
58 /// VisitConditionVariableInit - Handle the initialization of condition
59 /// variables at branches. Valid statements include IfStmt, ForStmt,
60 /// WhileStmt, and SwitchStmt.
61 RetTy VisitConditionVariableInit(Stmt *S) {
65 /// BlockVisit_XXX - Visitor methods for visiting the "root" statements in
66 /// CFGBlocks. Root statements are the statements that appear explicitly in
67 /// the list of statements in a CFGBlock. For substatements, or when there
68 /// is no implementation provided for a BlockStmt_XXX method, we default
69 /// to using StmtVisitor's Visit method.
70 RetTy BlockStmt_Visit(Stmt *S) {
72 NullifyStmt cleanup(CurrentBlkStmt);
74 switch (S->getStmtClass()) {
75 case Stmt::IfStmtClass:
76 case Stmt::ForStmtClass:
77 case Stmt::WhileStmtClass:
78 case Stmt::SwitchStmtClass:
79 return static_cast<ImplClass*>(this)->VisitConditionVariableInit(S);
81 DISPATCH_CASE(StmtExpr)
82 DISPATCH_CASE(ConditionalOperator)
83 DISPATCH_CASE(BinaryConditionalOperator)
84 DISPATCH_CASE(ObjCForCollectionStmt)
85 DISPATCH_CASE(CXXForRangeStmt)
87 case Stmt::BinaryOperatorClass: {
88 BinaryOperator* B = cast<BinaryOperator>(S);
90 return static_cast<ImplClass*>(this)->BlockStmt_VisitLogicalOp(B);
91 else if (B->getOpcode() == BO_Comma)
92 return static_cast<ImplClass*>(this)->BlockStmt_VisitComma(B);
99 static_cast<ImplClass*>(this)->BlockStmt_VisitExpr(cast<Expr>(S));
101 return static_cast<ImplClass*>(this)->BlockStmt_VisitStmt(S);
105 DEFAULT_BLOCKSTMT_VISIT(StmtExpr)
106 DEFAULT_BLOCKSTMT_VISIT(ConditionalOperator)
107 DEFAULT_BLOCKSTMT_VISIT(BinaryConditionalOperator)
109 RetTy BlockStmt_VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
110 return static_cast<ImplClass*>(this)->BlockStmt_VisitStmt(S);
113 RetTy BlockStmt_VisitCXXForRangeStmt(CXXForRangeStmt *S) {
114 return static_cast<ImplClass*>(this)->BlockStmt_VisitStmt(S);
117 RetTy BlockStmt_VisitImplicitControlFlowExpr(Expr *E) {
118 return static_cast<ImplClass*>(this)->BlockStmt_VisitExpr(E);
121 RetTy BlockStmt_VisitExpr(Expr *E) {
122 return static_cast<ImplClass*>(this)->BlockStmt_VisitStmt(E);
125 RetTy BlockStmt_VisitStmt(Stmt *S) {
126 return static_cast<ImplClass*>(this)->Visit(S);
129 RetTy BlockStmt_VisitLogicalOp(BinaryOperator* B) {
131 static_cast<ImplClass*>(this)->BlockStmt_VisitImplicitControlFlowExpr(B);
134 RetTy BlockStmt_VisitComma(BinaryOperator* B) {
136 static_cast<ImplClass*>(this)->BlockStmt_VisitImplicitControlFlowExpr(B);
139 //===--------------------------------------------------------------------===//
140 // Utility methods. Not called by default (but subclasses may use them).
141 //===--------------------------------------------------------------------===//
143 /// VisitChildren: Call "Visit" on each child of S.
144 void VisitChildren(Stmt *S) {
146 switch (S->getStmtClass()) {
150 case Stmt::StmtExprClass: {
151 CompoundStmt *CS = cast<StmtExpr>(S)->getSubStmt();
152 if (CS->body_empty()) return;
153 static_cast<ImplClass*>(this)->Visit(CS->body_back());
157 case Stmt::BinaryOperatorClass: {
158 BinaryOperator* B = cast<BinaryOperator>(S);
159 if (B->getOpcode() != BO_Comma) break;
160 static_cast<ImplClass*>(this)->Visit(B->getRHS());
165 for (Stmt::child_range I = S->children(); I; ++I)
166 if (*I) static_cast<ImplClass*>(this)->Visit(*I);
170 #undef DEFAULT_BLOCKSTMT_VISIT
173 } // end namespace clang