Add __builtin_operator_new and __builtin_operator_delete, which act like calls

to the normal non-placement ::operator new and ::operator delete, but allow
optimizations like new-expressions and delete-expressions do.

llvm-svn: 210137

4 files changed, 43 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 8b62ef0..f705ed8 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1508,6 +1508,12 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
   }
   case Builtin::BI__builtin_addressof:
     return RValue::get(EmitLValue(E->getArg(0)).getAddress());
+  case Builtin::BI__builtin_operator_new:
+    return EmitBuiltinNewDeleteCall(FD->getType()->castAs<FunctionProtoType>(),
+                                    E->getArg(0), false);
+  case Builtin::BI__builtin_operator_delete:
+    return EmitBuiltinNewDeleteCall(FD->getType()->castAs<FunctionProtoType>(),
+                                    E->getArg(0), true);
   case Builtin::BI__noop:
     return RValue::get(nullptr);
   case Builtin::BI_InterlockedCompareExchange: {
diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 762d8e2..0492813 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -1029,6 +1029,23 @@ static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
   return RV;
 }
 
+RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
+                                                 const Expr *Arg,
+                                                 bool IsDelete) {
+  CallArgList Args;
+  const Stmt *ArgS = Arg;
+  EmitCallArgs(Args, *Type->param_type_begin(),
+               ConstExprIterator(&ArgS), ConstExprIterator(&ArgS + 1));
+  // Find the allocation or deallocation function that we're calling.
+  ASTContext &Ctx = getContext();
+  DeclarationName Name = Ctx.DeclarationNames
+      .getCXXOperatorName(IsDelete ? OO_Delete : OO_New);
+  for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name))
+    if (Ctx.hasSameType(cast<FunctionDecl>(Decl)->getType(), QualType(Type, 0)))
+      return EmitNewDeleteCall(*this, cast<FunctionDecl>(Decl), Type, Args);
+  llvm_unreachable("predeclared global operator new/delete is missing");
+}
+
 namespace {
   /// A cleanup to call the given 'operator delete' function upon
   /// abnormal exit from a new expression.
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index d1e63a7..b6c58e0 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1659,6 +1659,9 @@ public:
   void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr,
                       QualType DeleteTy);
 
+  RValue EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
+                                  const Expr *Arg, bool IsDelete);
+
   llvm::Value* EmitCXXTypeidExpr(const CXXTypeidExpr *E);
   llvm::Value *EmitDynamicCast(llvm::Value *V, const CXXDynamicCastExpr *DCE);
   llvm::Value* EmitCXXUuidofExpr(const CXXUuidofExpr *E);
@@ -2641,7 +2644,8 @@ public:
 
   void EmitCallArgs(CallArgList &Args, ArrayRef<QualType> ArgTypes,
                     CallExpr::const_arg_iterator ArgBeg,
-                    CallExpr::const_arg_iterator ArgEnd, bool ForceColumnInfo);
+                    CallExpr::const_arg_iterator ArgEnd,
+                    bool ForceColumnInfo = false);
 
 private:
   const TargetCodeGenInfo &getTargetHooks() const {
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 60514ef..916ce7d 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -296,8 +296,22 @@ Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
     if (SemaBuiltinAddressof(*this, TheCall))
       return ExprError();
     break;
+  case Builtin::BI__builtin_operator_new:
+  case Builtin::BI__builtin_operator_delete:
+    if (!getLangOpts().CPlusPlus) {
+      Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language)
+        << (BuiltinID == Builtin::BI__builtin_operator_new
+                ? "__builtin_operator_new"
+                : "__builtin_operator_delete")
+        << "C++";
+      return ExprError();
+    }
+    // CodeGen assumes it can find the global new and delete to call,
+    // so ensure that they are declared.
+    DeclareGlobalNewDelete();
+    break;
   }
-  
+
   // Since the target specific builtins for each arch overlap, only check those
   // of the arch we are compiling for.
   if (BuiltinID >= Builtin::FirstTSBuiltin) {