1 //===--- ParentMap.cpp - Mappings from Stmts to their Parents ---*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the ParentMap class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/AST/ParentMap.h"
15 #include "clang/AST/Decl.h"
16 #include "clang/AST/Expr.h"
17 #include "llvm/ADT/DenseMap.h"
18
19 using namespace clang;
20
21 typedef llvm::DenseMap<Stmt*, Stmt*> MapTy;
22
23 enum OpaqueValueMode {
24 OV_Transparent,
25 OV_Opaque
26 };
27
BuildParentMap(MapTy & M,Stmt * S,OpaqueValueMode OVMode=OV_Transparent)28 static void BuildParentMap(MapTy& M, Stmt* S,
29 OpaqueValueMode OVMode = OV_Transparent) {
30
31 switch (S->getStmtClass()) {
32 case Stmt::PseudoObjectExprClass: {
33 assert(OVMode == OV_Transparent && "Should not appear alongside OVEs");
34 PseudoObjectExpr *POE = cast<PseudoObjectExpr>(S);
35
36 M[POE->getSyntacticForm()] = S;
37 BuildParentMap(M, POE->getSyntacticForm(), OV_Transparent);
38
39 for (PseudoObjectExpr::semantics_iterator I = POE->semantics_begin(),
40 E = POE->semantics_end();
41 I != E; ++I) {
42 M[*I] = S;
43 BuildParentMap(M, *I, OV_Opaque);
44 }
45 break;
46 }
47 case Stmt::BinaryConditionalOperatorClass: {
48 assert(OVMode == OV_Transparent && "Should not appear alongside OVEs");
49 BinaryConditionalOperator *BCO = cast<BinaryConditionalOperator>(S);
50
51 M[BCO->getCommon()] = S;
52 BuildParentMap(M, BCO->getCommon(), OV_Transparent);
53
54 M[BCO->getCond()] = S;
55 BuildParentMap(M, BCO->getCond(), OV_Opaque);
56
57 M[BCO->getTrueExpr()] = S;
58 BuildParentMap(M, BCO->getTrueExpr(), OV_Opaque);
59
60 M[BCO->getFalseExpr()] = S;
61 BuildParentMap(M, BCO->getFalseExpr(), OV_Transparent);
62
63 break;
64 }
65 case Stmt::OpaqueValueExprClass:
66 if (OVMode == OV_Transparent) {
67 OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(S);
68 M[OVE->getSourceExpr()] = S;
69 BuildParentMap(M, OVE->getSourceExpr(), OV_Transparent);
70 }
71 break;
72 default:
73 for (Stmt::child_range I = S->children(); I; ++I) {
74 if (*I) {
75 M[*I] = S;
76 BuildParentMap(M, *I, OVMode);
77 }
78 }
79 break;
80 }
81 }
82
ParentMap(Stmt * S)83 ParentMap::ParentMap(Stmt* S) : Impl(0) {
84 if (S) {
85 MapTy *M = new MapTy();
86 BuildParentMap(*M, S);
87 Impl = M;
88 }
89 }
90
~ParentMap()91 ParentMap::~ParentMap() {
92 delete (MapTy*) Impl;
93 }
94
addStmt(Stmt * S)95 void ParentMap::addStmt(Stmt* S) {
96 if (S) {
97 BuildParentMap(*(MapTy*) Impl, S);
98 }
99 }
100
getParent(Stmt * S) const101 Stmt* ParentMap::getParent(Stmt* S) const {
102 MapTy* M = (MapTy*) Impl;
103 MapTy::iterator I = M->find(S);
104 return I == M->end() ? 0 : I->second;
105 }
106
getParentIgnoreParens(Stmt * S) const107 Stmt *ParentMap::getParentIgnoreParens(Stmt *S) const {
108 do { S = getParent(S); } while (S && isa<ParenExpr>(S));
109 return S;
110 }
111
getParentIgnoreParenCasts(Stmt * S) const112 Stmt *ParentMap::getParentIgnoreParenCasts(Stmt *S) const {
113 do {
114 S = getParent(S);
115 }
116 while (S && (isa<ParenExpr>(S) || isa<CastExpr>(S)));
117
118 return S;
119 }
120
getParentIgnoreParenImpCasts(Stmt * S) const121 Stmt *ParentMap::getParentIgnoreParenImpCasts(Stmt *S) const {
122 do {
123 S = getParent(S);
124 } while (S && isa<Expr>(S) && cast<Expr>(S)->IgnoreParenImpCasts() != S);
125
126 return S;
127 }
128
getOuterParenParent(Stmt * S) const129 Stmt *ParentMap::getOuterParenParent(Stmt *S) const {
130 Stmt *Paren = 0;
131 while (isa<ParenExpr>(S)) {
132 Paren = S;
133 S = getParent(S);
134 };
135 return Paren;
136 }
137
isConsumedExpr(Expr * E) const138 bool ParentMap::isConsumedExpr(Expr* E) const {
139 Stmt *P = getParent(E);
140 Stmt *DirectChild = E;
141
142 // Ignore parents that are parentheses or casts.
143 while (P && (isa<ParenExpr>(P) || isa<CastExpr>(P))) {
144 DirectChild = P;
145 P = getParent(P);
146 }
147
148 if (!P)
149 return false;
150
151 switch (P->getStmtClass()) {
152 default:
153 return isa<Expr>(P);
154 case Stmt::DeclStmtClass:
155 return true;
156 case Stmt::BinaryOperatorClass: {
157 BinaryOperator *BE = cast<BinaryOperator>(P);
158 // If it is a comma, only the right side is consumed.
159 // If it isn't a comma, both sides are consumed.
160 return BE->getOpcode()!=BO_Comma ||DirectChild==BE->getRHS();
161 }
162 case Stmt::ForStmtClass:
163 return DirectChild == cast<ForStmt>(P)->getCond();
164 case Stmt::WhileStmtClass:
165 return DirectChild == cast<WhileStmt>(P)->getCond();
166 case Stmt::DoStmtClass:
167 return DirectChild == cast<DoStmt>(P)->getCond();
168 case Stmt::IfStmtClass:
169 return DirectChild == cast<IfStmt>(P)->getCond();
170 case Stmt::IndirectGotoStmtClass:
171 return DirectChild == cast<IndirectGotoStmt>(P)->getTarget();
172 case Stmt::SwitchStmtClass:
173 return DirectChild == cast<SwitchStmt>(P)->getCond();
174 case Stmt::ReturnStmtClass:
175 return true;
176 }
177 }
178
179