clang 10.0.0git

ParentMap.cpp
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1 //===--- ParentMap.cpp - Mappings from Stmts to their Parents ---*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the ParentMap class.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "clang/AST/ParentMap.h"
14 #include "clang/AST/Decl.h"
15 #include "clang/AST/Expr.h"
16 #include "clang/AST/ExprCXX.h"
17 #include "clang/AST/StmtObjC.h"
18 #include "llvm/ADT/DenseMap.h"
19
20 using namespace clang;
21
22 typedef llvm::DenseMap<Stmt*, Stmt*> MapTy;
23
24 enum OpaqueValueMode {
25 OV_Transparent,
26 OV_Opaque
27 };
28
29 static void BuildParentMap(MapTy& M, Stmt* S,
30 OpaqueValueMode OVMode = OV_Transparent) {
31 if (!S)
32 return;
33
34 switch (S->getStmtClass()) {
35 case Stmt::PseudoObjectExprClass: {
36 assert(OVMode == OV_Transparent && "Should not appear alongside OVEs");
37 PseudoObjectExpr *POE = cast<PseudoObjectExpr>(S);
38
39 // If we are rebuilding the map, clear out any existing state.
40 if (M[POE->getSyntacticForm()])
41 for (Stmt *SubStmt : S->children())
42 M[SubStmt] = nullptr;
43
44 M[POE->getSyntacticForm()] = S;
45 BuildParentMap(M, POE->getSyntacticForm(), OV_Transparent);
46
47 for (PseudoObjectExpr::semantics_iterator I = POE->semantics_begin(),
48 E = POE->semantics_end();
49 I != E; ++I) {
50 M[*I] = S;
51 BuildParentMap(M, *I, OV_Opaque);
52 }
53 break;
54 }
55 case Stmt::BinaryConditionalOperatorClass: {
56 assert(OVMode == OV_Transparent && "Should not appear alongside OVEs");
57 BinaryConditionalOperator *BCO = cast<BinaryConditionalOperator>(S);
58
59 M[BCO->getCommon()] = S;
60 BuildParentMap(M, BCO->getCommon(), OV_Transparent);
61
62 M[BCO->getCond()] = S;
63 BuildParentMap(M, BCO->getCond(), OV_Opaque);
64
65 M[BCO->getTrueExpr()] = S;
66 BuildParentMap(M, BCO->getTrueExpr(), OV_Opaque);
67
68 M[BCO->getFalseExpr()] = S;
69 BuildParentMap(M, BCO->getFalseExpr(), OV_Transparent);
70
71 break;
72 }
73 case Stmt::OpaqueValueExprClass: {
74 // FIXME: This isn't correct; it assumes that multiple OpaqueValueExprs
75 // share a single source expression, but in the AST a single
76 // OpaqueValueExpr is shared among multiple parent expressions.
77 // The right thing to do is to give the OpaqueValueExpr its syntactic
78 // parent, then not reassign that when traversing the semantic expressions.
79 OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(S);
80 if (OVMode == OV_Transparent || !M[OVE->getSourceExpr()]) {
81 M[OVE->getSourceExpr()] = S;
82 BuildParentMap(M, OVE->getSourceExpr(), OV_Transparent);
83 }
84 break;
85 }
86 case Stmt::CapturedStmtClass:
87 for (Stmt *SubStmt : S->children()) {
88 if (SubStmt) {
89 M[SubStmt] = S;
90 BuildParentMap(M, SubStmt, OVMode);
91 }
92 }
93 if (Stmt *SubStmt = cast<CapturedStmt>(S)->getCapturedStmt()) {
94 M[SubStmt] = S;
95 BuildParentMap(M, SubStmt, OVMode);
96 }
97 break;
98 default:
99 for (Stmt *SubStmt : S->children()) {
100 if (SubStmt) {
101 M[SubStmt] = S;
102 BuildParentMap(M, SubStmt, OVMode);
103 }
104 }
105 break;
106 }
107 }
108
109 ParentMap::ParentMap(Stmt *S) : Impl(nullptr) {
110 if (S) {
111 MapTy *M = new MapTy();
112 BuildParentMap(*M, S);
113 Impl = M;
114 }
115 }
116
117 ParentMap::~ParentMap() {
118 delete (MapTy*) Impl;
119 }
120
121 void ParentMap::addStmt(Stmt* S) {
122 if (S) {
123 BuildParentMap(*(MapTy*) Impl, S);
124 }
125 }
126
127 void ParentMap::setParent(const Stmt *S, const Stmt *Parent) {
128 assert(S);
129 assert(Parent);
130 MapTy *M = reinterpret_cast<MapTy *>(Impl);
131 M->insert(std::make_pair(const_cast<Stmt *>(S), const_cast<Stmt *>(Parent)));
132 }
133
134 Stmt* ParentMap::getParent(Stmt* S) const {
135 MapTy* M = (MapTy*) Impl;
136 MapTy::iterator I = M->find(S);
137 return I == M->end() ? nullptr : I->second;
138 }
139
140 Stmt *ParentMap::getParentIgnoreParens(Stmt *S) const {
141 do { S = getParent(S); } while (S && isa<ParenExpr>(S));
142 return S;
143 }
144
145 Stmt *ParentMap::getParentIgnoreParenCasts(Stmt *S) const {
146 do {
147 S = getParent(S);
148 }
149 while (S && (isa<ParenExpr>(S) || isa<CastExpr>(S)));
150
151 return S;
152 }
153
154 Stmt *ParentMap::getParentIgnoreParenImpCasts(Stmt *S) const {
155 do {
156 S = getParent(S);
157 } while (S && isa<Expr>(S) && cast<Expr>(S)->IgnoreParenImpCasts() != S);
158
159 return S;
160 }
161
162 Stmt *ParentMap::getOuterParenParent(Stmt *S) const {
163 Stmt *Paren = nullptr;
164 while (isa<ParenExpr>(S)) {
165 Paren = S;
166 S = getParent(S);
167 };
168 return Paren;
169 }
170
171 bool ParentMap::isConsumedExpr(Expr* E) const {
172 Stmt *P = getParent(E);
173 Stmt *DirectChild = E;
174
175 // Ignore parents that don't guarantee consumption.
176 while (P && (isa<ParenExpr>(P) || isa<CastExpr>(P) ||
177 isa<FullExpr>(P))) {
178 DirectChild = P;
179 P = getParent(P);
180 }
181
182 if (!P)
183 return false;
184
185 switch (P->getStmtClass()) {
186 default:
187 return isa<Expr>(P);
188 case Stmt::DeclStmtClass:
189 return true;
190 case Stmt::BinaryOperatorClass: {
191 BinaryOperator *BE = cast<BinaryOperator>(P);
192 // If it is a comma, only the right side is consumed.
193 // If it isn't a comma, both sides are consumed.
194 return BE->getOpcode()!=BO_Comma ||DirectChild==BE->getRHS();
195 }
196 case Stmt::ForStmtClass:
197 return DirectChild == cast<ForStmt>(P)->getCond();
198 case Stmt::WhileStmtClass:
199 return DirectChild == cast<WhileStmt>(P)->getCond();
200 case Stmt::DoStmtClass:
201 return DirectChild == cast<DoStmt>(P)->getCond();
202 case Stmt::IfStmtClass:
203 return DirectChild == cast<IfStmt>(P)->getCond();
204 case Stmt::IndirectGotoStmtClass:
205 return DirectChild == cast<IndirectGotoStmt>(P)->getTarget();
206 case Stmt::SwitchStmtClass:
207 return DirectChild == cast<SwitchStmt>(P)->getCond();
208 case Stmt::ObjCForCollectionStmtClass:
209 return DirectChild == cast<ObjCForCollectionStmt>(P)->getCollection();
210 case Stmt::ReturnStmtClass:
211 return true;
212 }
213 }
214
clang::PseudoObjectExpr::getSyntacticForm
Expr * getSyntacticForm()
Return the syntactic form of this expression, i.e.
Definition: Expr.h:5759
clang::PseudoObjectExpr::semantics_iterator
Expr *const * semantics_iterator
Definition: Expr.h:5781
clang::Stmt
Stmt - This represents one statement.
Definition: Stmt.h:66
clang::BinaryOperator::getOpcode
Opcode getOpcode() const
Definition: Expr.h:3469
P
StringRef P
Definition: ASTMatchersInternal.cpp:485
clang::ParentMap::getParent
Stmt * getParent(Stmt *) const
Definition: ParentMap.cpp:134
MapTy
llvm::DenseMap< Stmt *, Stmt * > MapTy
Definition: ParentMap.cpp:22
clang::ParentMap::isConsumedExpr
bool isConsumedExpr(Expr *E) const
Definition: ParentMap.cpp:171
StmtObjC.h
Defines the Objective-C statement AST node classes.
ExprCXX.h
Defines the clang::Expr interface and subclasses for C++ expressions.
clang::ParentMap::addStmt
void addStmt(Stmt *S)
Adds and/or updates the parent/child-relations of the complete stmt tree of S.
Definition: ParentMap.cpp:121
clang::OpaqueValueExpr::getSourceExpr
Expr * getSourceExpr() const
The source expression of an opaque value expression is the expression which originally generated the ...
Definition: Expr.h:1133
clang::ParentMap::~ParentMap
~ParentMap()
Definition: ParentMap.cpp:117
clang::ParentMap::setParent
void setParent(const Stmt *S, const Stmt *Parent)
Manually sets the parent of S to Parent.
Definition: ParentMap.cpp:127
OV_Opaque
Definition: ParentMap.cpp:26
clang::Stmt::children
child_range children()
Definition: Stmt.cpp:224
clang::PseudoObjectExpr::semantics_end
semantics_iterator semantics_end()
Definition: Expr.h:5789
clang::BinaryOperator
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3434
Parent
NodeId Parent
Definition: ASTDiff.cpp:191
OV_Transparent
Definition: ParentMap.cpp:25
clang::Expr
This represents one expression.
Definition: Expr.h:108
ParentMap.h
BuildParentMap
static void BuildParentMap(MapTy &M, Stmt *S, OpaqueValueMode OVMode=OV_Transparent)
Definition: ParentMap.cpp:29
clang::BinaryConditionalOperator::getTrueExpr
Expr * getTrueExpr() const
getTrueExpr - Return the subexpression which will be evaluated if the condition evaluates to true; th...
Definition: Expr.h:3860
clang::OpaqueValueExpr
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:1075
clang::PseudoObjectExpr
PseudoObjectExpr - An expression which accesses a pseudo-object l-value.
Definition: Expr.h:5715
clang::ParentMap::getParentIgnoreParens
Stmt * getParentIgnoreParens(Stmt *) const
Definition: ParentMap.cpp:140
OpaqueValueMode
OpaqueValueMode
Definition: ParentMap.cpp:24
Paren
Definition: PPMacroExpansion.cpp:629
clang::BinaryConditionalOperator::getFalseExpr
Expr * getFalseExpr() const
getFalseExpr - Return the subexpression which will be evaluated if the condnition evaluates to false;...
Definition: Expr.h:3867
Decl.h
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:21
clang::ParentMap::ParentMap
ParentMap(Stmt *ASTRoot)
Definition: ParentMap.cpp:109
clang::Stmt::getStmtClass
StmtClass getStmtClass() const
Definition: Stmt.h:1109
clang::PseudoObjectExpr::semantics_begin
semantics_iterator semantics_begin()
Definition: Expr.h:5783
clang::ParentMap::getParentIgnoreParenImpCasts
Stmt * getParentIgnoreParenImpCasts(Stmt *) const
Definition: ParentMap.cpp:154
clang::BinaryConditionalOperator::getCond
Expr * getCond() const
getCond - Return the condition expression; this is defined in terms of the opaque value...
Definition: Expr.h:3855
clang::BinaryConditionalOperator
BinaryConditionalOperator - The GNU extension to the conditional operator which allows the middle ope...
Definition: Expr.h:3808
Expr.h
clang::ParentMap::getParentIgnoreParenCasts
Stmt * getParentIgnoreParenCasts(Stmt *) const
Definition: ParentMap.cpp:145
clang::BinaryOperator::getRHS
Expr * getRHS() const
Definition: Expr.h:3476
clang::BinaryConditionalOperator::getCommon
Expr * getCommon() const
getCommon - Return the common expression, written to the left of the condition.
Definition: Expr.h:3848
clang::ParentMap::getOuterParenParent
Stmt * getOuterParenParent(Stmt *) const
Definition: ParentMap.cpp:162