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
19using namespace clang;
20
21typedef llvm::DenseMap<Stmt*, Stmt*> MapTy;
22
23enum OpaqueValueMode {
24  OV_Transparent,
25  OV_Opaque
26};
27
28static 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
83ParentMap::ParentMap(Stmt* S) : Impl(0) {
84  if (S) {
85    MapTy *M = new MapTy();
86    BuildParentMap(*M, S);
87    Impl = M;
88  }
89}
90
91ParentMap::~ParentMap() {
92  delete (MapTy*) Impl;
93}
94
95void ParentMap::addStmt(Stmt* S) {
96  if (S) {
97    BuildParentMap(*(MapTy*) Impl, S);
98  }
99}
100
101Stmt* 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
107Stmt *ParentMap::getParentIgnoreParens(Stmt *S) const {
108  do { S = getParent(S); } while (S && isa<ParenExpr>(S));
109  return S;
110}
111
112Stmt *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
121Stmt *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
129Stmt *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
138bool 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