Check in LLVM r95781.
diff --git a/lib/AST/ParentMap.cpp b/lib/AST/ParentMap.cpp
new file mode 100644
index 0000000..48251d5
--- /dev/null
+++ b/lib/AST/ParentMap.cpp
@@ -0,0 +1,94 @@
+//===--- 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 "llvm/ADT/DenseMap.h"
+
+using namespace clang;
+
+typedef llvm::DenseMap<Stmt*, Stmt*> MapTy;
+
+static void BuildParentMap(MapTy& M, Stmt* S) {
+ for (Stmt::child_iterator I=S->child_begin(), E=S->child_end(); I!=E; ++I)
+ if (*I) {
+ M[*I] = S;
+ BuildParentMap(M, *I);
+ }
+}
+
+ParentMap::ParentMap(Stmt* S) : Impl(0) {
+ if (S) {
+ MapTy *M = new MapTy();
+ BuildParentMap(*M, S);
+ Impl = M;
+ }
+}
+
+ParentMap::~ParentMap() {
+ delete (MapTy*) Impl;
+}
+
+Stmt* ParentMap::getParent(Stmt* S) const {
+ MapTy* M = (MapTy*) Impl;
+ MapTy::iterator I = M->find(S);
+ return I == M->end() ? 0 : I->second;
+}
+
+Stmt *ParentMap::getParentIgnoreParens(Stmt *S) const {
+ do { S = getParent(S); } while (S && isa<ParenExpr>(S));
+ return S;
+}
+
+bool ParentMap::isConsumedExpr(Expr* E) const {
+ Stmt *P = getParent(E);
+ Stmt *DirectChild = E;
+
+ // Ignore parents that are parentheses or casts.
+ while (P && (isa<ParenExpr>(P) || isa<CastExpr>(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()!=BinaryOperator::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::ReturnStmtClass:
+ return true;
+ }
+}
+