Add a method for checking whether a function is one of the reserved global

placement allocation or deallocation functions.  These functions cannot be
replaced by the user and are exempt from the normal requirements on
allocation functions (e.g. that they must return unaliased memory).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131386 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 28 insertions, 4 deletions

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index d4df017383..1e98998002 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1475,10 +1475,34 @@ void FunctionDecl::setPure(bool P) {
 }
 
 bool FunctionDecl::isMain() const {
-  ASTContext &Context = getASTContext();
-  return !Context.getLangOptions().Freestanding &&
-    getDeclContext()->getRedeclContext()->isTranslationUnit() &&
-    getIdentifier() && getIdentifier()->isStr("main");
+  const TranslationUnitDecl *tunit =
+    dyn_cast<TranslationUnitDecl>(getDeclContext()->getRedeclContext());
+  return tunit &&
+         tunit->getASTContext().getLangOptions().Freestanding &&
+         getIdentifier() &&
+         getIdentifier()->isStr("main");
+}
+
+bool FunctionDecl::isReservedGlobalPlacementOperator() const {
+  assert(getDeclName().getNameKind() == DeclarationName::CXXOperatorName);
+  assert(getDeclName().getCXXOverloadedOperator() == OO_New ||
+         getDeclName().getCXXOverloadedOperator() == OO_Delete ||
+         getDeclName().getCXXOverloadedOperator() == OO_Array_New ||
+         getDeclName().getCXXOverloadedOperator() == OO_Array_Delete);
+
+  if (isa<CXXRecordDecl>(getDeclContext())) return false;
+  assert(getDeclContext()->getRedeclContext()->isTranslationUnit());
+
+  const FunctionProtoType *proto = getType()->castAs<FunctionProtoType>();
+  if (proto->getNumArgs() != 2 || proto->isVariadic()) return false;
+
+  ASTContext &Context =
+    cast<TranslationUnitDecl>(getDeclContext()->getRedeclContext())
+      ->getASTContext();
+
+  // The result type and first argument type are constant across all
+  // these operators.  The second argument must be exactly void*.
+  return (proto->getArgType(1).getCanonicalType() == Context.VoidPtrTy);
 }
 
 bool FunctionDecl::isExternC() const {