clang  6.0.0svn
ParentMap.cpp
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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 "clang/AST/ExprCXX.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  default:
87  for (Stmt *SubStmt : S->children()) {
88  if (SubStmt) {
89  M[SubStmt] = S;
90  BuildParentMap(M, SubStmt, OVMode);
91  }
92  }
93  break;
94  }
95 }
96 
97 ParentMap::ParentMap(Stmt *S) : Impl(nullptr) {
98  if (S) {
99  MapTy *M = new MapTy();
100  BuildParentMap(*M, S);
101  Impl = M;
102  }
103 }
104 
106  delete (MapTy*) Impl;
107 }
108 
110  if (S) {
111  BuildParentMap(*(MapTy*) Impl, S);
112  }
113 }
114 
115 void ParentMap::setParent(const Stmt *S, const Stmt *Parent) {
116  assert(S);
117  assert(Parent);
118  MapTy *M = reinterpret_cast<MapTy *>(Impl);
119  M->insert(std::make_pair(const_cast<Stmt *>(S), const_cast<Stmt *>(Parent)));
120 }
121 
123  MapTy* M = (MapTy*) Impl;
124  MapTy::iterator I = M->find(S);
125  return I == M->end() ? nullptr : I->second;
126 }
127 
129  do { S = getParent(S); } while (S && isa<ParenExpr>(S));
130  return S;
131 }
132 
134  do {
135  S = getParent(S);
136  }
137  while (S && (isa<ParenExpr>(S) || isa<CastExpr>(S)));
138 
139  return S;
140 }
141 
143  do {
144  S = getParent(S);
145  } while (S && isa<Expr>(S) && cast<Expr>(S)->IgnoreParenImpCasts() != S);
146 
147  return S;
148 }
149 
151  Stmt *Paren = nullptr;
152  while (isa<ParenExpr>(S)) {
153  Paren = S;
154  S = getParent(S);
155  };
156  return Paren;
157 }
158 
160  Stmt *P = getParent(E);
161  Stmt *DirectChild = E;
162 
163  // Ignore parents that don't guarantee consumption.
164  while (P && (isa<ParenExpr>(P) || isa<CastExpr>(P) ||
165  isa<ExprWithCleanups>(P))) {
166  DirectChild = P;
167  P = getParent(P);
168  }
169 
170  if (!P)
171  return false;
172 
173  switch (P->getStmtClass()) {
174  default:
175  return isa<Expr>(P);
176  case Stmt::DeclStmtClass:
177  return true;
178  case Stmt::BinaryOperatorClass: {
179  BinaryOperator *BE = cast<BinaryOperator>(P);
180  // If it is a comma, only the right side is consumed.
181  // If it isn't a comma, both sides are consumed.
182  return BE->getOpcode()!=BO_Comma ||DirectChild==BE->getRHS();
183  }
184  case Stmt::ForStmtClass:
185  return DirectChild == cast<ForStmt>(P)->getCond();
186  case Stmt::WhileStmtClass:
187  return DirectChild == cast<WhileStmt>(P)->getCond();
188  case Stmt::DoStmtClass:
189  return DirectChild == cast<DoStmt>(P)->getCond();
190  case Stmt::IfStmtClass:
191  return DirectChild == cast<IfStmt>(P)->getCond();
192  case Stmt::IndirectGotoStmtClass:
193  return DirectChild == cast<IndirectGotoStmt>(P)->getTarget();
194  case Stmt::SwitchStmtClass:
195  return DirectChild == cast<SwitchStmt>(P)->getCond();
196  case Stmt::ReturnStmtClass:
197  return true;
198  }
199 }
200 
Expr * getSyntacticForm()
Return the syntactic form of this expression, i.e.
Definition: Expr.h:5013
Expr *const * semantics_iterator
Definition: Expr.h:5035
Stmt - This represents one statement.
Definition: Stmt.h:66
Opcode getOpcode() const
Definition: Expr.h:3026
StringRef P
Stmt * getParent(Stmt *) const
Definition: ParentMap.cpp:122
llvm::DenseMap< Stmt *, Stmt * > MapTy
Definition: ParentMap.cpp:22
bool isConsumedExpr(Expr *E) const
Definition: ParentMap.cpp:159
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:109
Expr * getSourceExpr() const
The source expression of an opaque value expression is the expression which originally generated the ...
Definition: Expr.h:926
void setParent(const Stmt *S, const Stmt *Parent)
Manually sets the parent of S to Parent.
Definition: ParentMap.cpp:115
child_range children()
Definition: Stmt.cpp:226
semantics_iterator semantics_end()
Definition: Expr.h:5043
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:2985
NodeId Parent
Definition: ASTDiff.cpp:192
Expr - This represents one expression.
Definition: Expr.h:106
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:3394
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:868
PseudoObjectExpr - An expression which accesses a pseudo-object l-value.
Definition: Expr.h:4969
Stmt * getParentIgnoreParens(Stmt *) const
Definition: ParentMap.cpp:128
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:3401
Dataflow Directional Tag Classes.
ParentMap(Stmt *ASTRoot)
Definition: ParentMap.cpp:97
StmtClass getStmtClass() const
Definition: Stmt.h:378
semantics_iterator semantics_begin()
Definition: Expr.h:5037
Stmt * getParentIgnoreParenImpCasts(Stmt *) const
Definition: ParentMap.cpp:142
Expr * getCond() const
getCond - Return the condition expression; this is defined in terms of the opaque value...
Definition: Expr.h:3389
BinaryConditionalOperator - The GNU extension to the conditional operator which allows the middle ope...
Definition: Expr.h:3342
Stmt * getParentIgnoreParenCasts(Stmt *) const
Definition: ParentMap.cpp:133
Expr * getRHS() const
Definition: Expr.h:3031
Expr * getCommon() const
getCommon - Return the common expression, written to the left of the condition.
Definition: Expr.h:3382
Stmt * getOuterParenParent(Stmt *) const
Definition: ParentMap.cpp:150