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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 "llvm/ADT/DenseMap.h"
     18 
     19 using namespace clang;
     20 
     21 typedef llvm::DenseMap<Stmt*, Stmt*> MapTy;
     22 
     23 static void BuildParentMap(MapTy& M, Stmt* S) {
     24   for (Stmt::child_range I = S->children(); I; ++I)
     25     if (*I) {
     26       M[*I] = S;
     27       BuildParentMap(M, *I);
     28     }
     29 }
     30 
     31 ParentMap::ParentMap(Stmt* S) : Impl(0) {
     32   if (S) {
     33     MapTy *M = new MapTy();
     34     BuildParentMap(*M, S);
     35     Impl = M;
     36   }
     37 }
     38 
     39 ParentMap::~ParentMap() {
     40   delete (MapTy*) Impl;
     41 }
     42 
     43 void ParentMap::addStmt(Stmt* S) {
     44   if (S) {
     45     BuildParentMap(*(MapTy*) Impl, S);
     46   }
     47 }
     48 
     49 Stmt* ParentMap::getParent(Stmt* S) const {
     50   MapTy* M = (MapTy*) Impl;
     51   MapTy::iterator I = M->find(S);
     52   return I == M->end() ? 0 : I->second;
     53 }
     54 
     55 Stmt *ParentMap::getParentIgnoreParens(Stmt *S) const {
     56   do { S = getParent(S); } while (S && isa<ParenExpr>(S));
     57   return S;
     58 }
     59 
     60 Stmt *ParentMap::getParentIgnoreParenCasts(Stmt *S) const {
     61   do {
     62     S = getParent(S);
     63   }
     64   while (S && (isa<ParenExpr>(S) || isa<CastExpr>(S)));
     65 
     66   return S;
     67 }
     68 
     69 Stmt *ParentMap::getOuterParenParent(Stmt *S) const {
     70   Stmt *Paren = 0;
     71   while (isa<ParenExpr>(S)) {
     72     Paren = S;
     73     S = getParent(S);
     74   };
     75   return Paren;
     76 }
     77 
     78 bool ParentMap::isConsumedExpr(Expr* E) const {
     79   Stmt *P = getParent(E);
     80   Stmt *DirectChild = E;
     81 
     82   // Ignore parents that are parentheses or casts.
     83   while (P && (isa<ParenExpr>(P) || isa<CastExpr>(P))) {
     84     DirectChild = P;
     85     P = getParent(P);
     86   }
     87 
     88   if (!P)
     89     return false;
     90 
     91   switch (P->getStmtClass()) {
     92     default:
     93       return isa<Expr>(P);
     94     case Stmt::DeclStmtClass:
     95       return true;
     96     case Stmt::BinaryOperatorClass: {
     97       BinaryOperator *BE = cast<BinaryOperator>(P);
     98       // If it is a comma, only the right side is consumed.
     99       // If it isn't a comma, both sides are consumed.
    100       return BE->getOpcode()!=BO_Comma ||DirectChild==BE->getRHS();
    101     }
    102     case Stmt::ForStmtClass:
    103       return DirectChild == cast<ForStmt>(P)->getCond();
    104     case Stmt::WhileStmtClass:
    105       return DirectChild == cast<WhileStmt>(P)->getCond();
    106     case Stmt::DoStmtClass:
    107       return DirectChild == cast<DoStmt>(P)->getCond();
    108     case Stmt::IfStmtClass:
    109       return DirectChild == cast<IfStmt>(P)->getCond();
    110     case Stmt::IndirectGotoStmtClass:
    111       return DirectChild == cast<IndirectGotoStmt>(P)->getTarget();
    112     case Stmt::SwitchStmtClass:
    113       return DirectChild == cast<SwitchStmt>(P)->getCond();
    114     case Stmt::ReturnStmtClass:
    115       return true;
    116   }
    117 }
    118 
    119