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//===--- ParentMap.cpp - Mappings from Stmts to their Parents ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ParentMap class.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ParentMap.h"
#include "clang/AST/Decl.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/StmtObjC.h"
#include "llvm/ADT/DenseMap.h"
using namespace clang;
typedef llvm::DenseMap<Stmt*, Stmt*> MapTy;
enum OpaqueValueMode {
OV_Transparent,
OV_Opaque
};
static void BuildParentMap(MapTy& M, Stmt* S,
OpaqueValueMode OVMode = OV_Transparent) {
if (!S)
return;
switch (S->getStmtClass()) {
case Stmt::PseudoObjectExprClass: {
assert(OVMode == OV_Transparent && "Should not appear alongside OVEs");
PseudoObjectExpr *POE = cast<PseudoObjectExpr>(S);
// If we are rebuilding the map, clear out any existing state.
if (M[POE->getSyntacticForm()])
for (Stmt *SubStmt : S->children())
M[SubStmt] = nullptr;
M[POE->getSyntacticForm()] = S;
BuildParentMap(M, POE->getSyntacticForm(), OV_Transparent);
for (PseudoObjectExpr::semantics_iterator I = POE->semantics_begin(),
E = POE->semantics_end();
I != E; ++I) {
M[*I] = S;
BuildParentMap(M, *I, OV_Opaque);
}
break;
}
case Stmt::BinaryConditionalOperatorClass: {
assert(OVMode == OV_Transparent && "Should not appear alongside OVEs");
BinaryConditionalOperator *BCO = cast<BinaryConditionalOperator>(S);
M[BCO->getCommon()] = S;
BuildParentMap(M, BCO->getCommon(), OV_Transparent);
M[BCO->getCond()] = S;
BuildParentMap(M, BCO->getCond(), OV_Opaque);
M[BCO->getTrueExpr()] = S;
BuildParentMap(M, BCO->getTrueExpr(), OV_Opaque);
M[BCO->getFalseExpr()] = S;
BuildParentMap(M, BCO->getFalseExpr(), OV_Transparent);
break;
}
case Stmt::OpaqueValueExprClass: {
// FIXME: This isn't correct; it assumes that multiple OpaqueValueExprs
// share a single source expression, but in the AST a single
// OpaqueValueExpr is shared among multiple parent expressions.
// The right thing to do is to give the OpaqueValueExpr its syntactic
// parent, then not reassign that when traversing the semantic expressions.
OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(S);
if (OVMode == OV_Transparent || !M[OVE->getSourceExpr()]) {
M[OVE->getSourceExpr()] = S;
BuildParentMap(M, OVE->getSourceExpr(), OV_Transparent);
}
break;
}
default:
for (Stmt *SubStmt : S->children()) {
if (SubStmt) {
M[SubStmt] = S;
BuildParentMap(M, SubStmt, OVMode);
}
}
break;
}
}
ParentMap::ParentMap(Stmt *S) : Impl(nullptr) {
if (S) {
MapTy *M = new MapTy();
BuildParentMap(*M, S);
Impl = M;
}
}
ParentMap::~ParentMap() {
delete (MapTy*) Impl;
}
void ParentMap::addStmt(Stmt* S) {
if (S) {
BuildParentMap(*(MapTy*) Impl, S);
}
}
void ParentMap::setParent(const Stmt *S, const Stmt *Parent) {
assert(S);
assert(Parent);
MapTy *M = reinterpret_cast<MapTy *>(Impl);
M->insert(std::make_pair(const_cast<Stmt *>(S), const_cast<Stmt *>(Parent)));
}
Stmt* ParentMap::getParent(Stmt* S) const {
MapTy* M = (MapTy*) Impl;
MapTy::iterator I = M->find(S);
return I == M->end() ? nullptr : I->second;
}
Stmt *ParentMap::getParentIgnoreParens(Stmt *S) const {
do { S = getParent(S); } while (S && isa<ParenExpr>(S));
return S;
}
Stmt *ParentMap::getParentIgnoreParenCasts(Stmt *S) const {
do {
S = getParent(S);
}
while (S && (isa<ParenExpr>(S) || isa<CastExpr>(S)));
return S;
}
Stmt *ParentMap::getParentIgnoreParenImpCasts(Stmt *S) const {
do {
S = getParent(S);
} while (S && isa<Expr>(S) && cast<Expr>(S)->IgnoreParenImpCasts() != S);
return S;
}
Stmt *ParentMap::getOuterParenParent(Stmt *S) const {
Stmt *Paren = nullptr;
while (isa<ParenExpr>(S)) {
Paren = S;
S = getParent(S);
};
return Paren;
}
bool ParentMap::isConsumedExpr(Expr* E) const {
Stmt *P = getParent(E);
Stmt *DirectChild = E;
// Ignore parents that don't guarantee consumption.
while (P && (isa<ParenExpr>(P) || isa<CastExpr>(P) ||
isa<ExprWithCleanups>(P))) {
DirectChild = P;
P = getParent(P);
}
if (!P)
return false;
switch (P->getStmtClass()) {
default:
return isa<Expr>(P);
case Stmt::DeclStmtClass:
return true;
case Stmt::BinaryOperatorClass: {
BinaryOperator *BE = cast<BinaryOperator>(P);
// If it is a comma, only the right side is consumed.
// If it isn't a comma, both sides are consumed.
return BE->getOpcode()!=BO_Comma ||DirectChild==BE->getRHS();
}
case Stmt::ForStmtClass:
return DirectChild == cast<ForStmt>(P)->getCond();
case Stmt::WhileStmtClass:
return DirectChild == cast<WhileStmt>(P)->getCond();
case Stmt::DoStmtClass:
return DirectChild == cast<DoStmt>(P)->getCond();
case Stmt::IfStmtClass:
return DirectChild == cast<IfStmt>(P)->getCond();
case Stmt::IndirectGotoStmtClass:
return DirectChild == cast<IndirectGotoStmt>(P)->getTarget();
case Stmt::SwitchStmtClass:
return DirectChild == cast<SwitchStmt>(P)->getCond();
case Stmt::ObjCForCollectionStmtClass:
return DirectChild == cast<ObjCForCollectionStmt>(P)->getCollection();
case Stmt::ReturnStmtClass:
return true;
}
}