clang  10.0.0svn
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 
27 };
28 
29 static void BuildParentMap(MapTy& M, Stmt* S,
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;
46 
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;
61 
62  M[BCO->getCond()] = S;
63  BuildParentMap(M, BCO->getCond(), OV_Opaque);
64 
65  M[BCO->getTrueExpr()] = S;
67 
68  M[BCO->getFalseExpr()] = S;
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;
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 
118  delete (MapTy*) Impl;
119 }
120 
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 
135  MapTy* M = (MapTy*) Impl;
136  MapTy::iterator I = M->find(S);
137  return I == M->end() ? nullptr : I->second;
138 }
139 
141  do { S = getParent(S); } while (S && isa<ParenExpr>(S));
142  return S;
143 }
144 
146  do {
147  S = getParent(S);
148  }
149  while (S && (isa<ParenExpr>(S) || isa<CastExpr>(S)));
150 
151  return S;
152 }
153 
155  do {
156  S = getParent(S);
157  } while (S && isa<Expr>(S) && cast<Expr>(S)->IgnoreParenImpCasts() != S);
158 
159  return S;
160 }
161 
163  Stmt *Paren = nullptr;
164  while (isa<ParenExpr>(S)) {
165  Paren = S;
166  S = getParent(S);
167  };
168  return Paren;
169 }
170 
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 
Expr * getSyntacticForm()
Return the syntactic form of this expression, i.e.
Definition: Expr.h:5717
Expr *const * semantics_iterator
Definition: Expr.h:5739
Stmt - This represents one statement.
Definition: Stmt.h:66
Opcode getOpcode() const
Definition: Expr.h:3444
StringRef P
Stmt * getParent(Stmt *) const
Definition: ParentMap.cpp:134
llvm::DenseMap< Stmt *, Stmt * > MapTy
Definition: ParentMap.cpp:22
bool isConsumedExpr(Expr *E) const
Definition: ParentMap.cpp:171
Defines the Objective-C statement AST node classes.
Defines the clang::Expr interface and subclasses for C++ expressions.
void addStmt(Stmt *S)
Adds and/or updates the parent/child-relations of the complete stmt tree of S.
Definition: ParentMap.cpp:121
Expr * getSourceExpr() const
The source expression of an opaque value expression is the expression which originally generated the ...
Definition: Expr.h:1108
void setParent(const Stmt *S, const Stmt *Parent)
Manually sets the parent of S to Parent.
Definition: ParentMap.cpp:127
child_range children()
Definition: Stmt.cpp:223
semantics_iterator semantics_end()
Definition: Expr.h:5747
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3409
NodeId Parent
Definition: ASTDiff.cpp:191
This represents one expression.
Definition: Expr.h:108
static void BuildParentMap(MapTy &M, Stmt *S, OpaqueValueMode OVMode=OV_Transparent)
Definition: ParentMap.cpp:29
Expr * getTrueExpr() const
getTrueExpr - Return the subexpression which will be evaluated if the condition evaluates to true; th...
Definition: Expr.h:3832
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:1050
PseudoObjectExpr - An expression which accesses a pseudo-object l-value.
Definition: Expr.h:5673
Stmt * getParentIgnoreParens(Stmt *) const
Definition: ParentMap.cpp:140
OpaqueValueMode
Definition: ParentMap.cpp:24
Expr * getFalseExpr() const
getFalseExpr - Return the subexpression which will be evaluated if the condnition evaluates to false;...
Definition: Expr.h:3839
Dataflow Directional Tag Classes.
ParentMap(Stmt *ASTRoot)
Definition: ParentMap.cpp:109
StmtClass getStmtClass() const
Definition: Stmt.h:1097
semantics_iterator semantics_begin()
Definition: Expr.h:5741
Stmt * getParentIgnoreParenImpCasts(Stmt *) const
Definition: ParentMap.cpp:154
Expr * getCond() const
getCond - Return the condition expression; this is defined in terms of the opaque value...
Definition: Expr.h:3827
BinaryConditionalOperator - The GNU extension to the conditional operator which allows the middle ope...
Definition: Expr.h:3780
Stmt * getParentIgnoreParenCasts(Stmt *) const
Definition: ParentMap.cpp:145
Expr * getRHS() const
Definition: Expr.h:3451
Expr * getCommon() const
getCommon - Return the common expression, written to the left of the condition.
Definition: Expr.h:3820
Stmt * getOuterParenParent(Stmt *) const
Definition: ParentMap.cpp:162