Implement the Named Return Value Optimization (NRVO) for Objective-C++

methods. Fixes PR10835 / <rdar://problem/10050178>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139175 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index e0b69814248b20df7e8223d9b3410f45420ac0ec..6a205786d6293747ca1e79705eb46ab24060fbc2 100644 (file)
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -6700,6 +6700,9 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
       DiagnoseUnusedParameters(MD->param_begin(), MD->param_end());
       DiagnoseSizeOfParametersAndReturnValue(MD->param_begin(), MD->param_end(),
                                              MD->getResultType(), MD);
+      
+      if (Body)
+        ComputeNRVO(Body, getCurFunction());
     }
     if (ObjCShouldCallSuperDealloc) {
       Diag(MD->getLocEnd(), diag::warn_objc_missing_super_dealloc);

diff --git a/test/CodeGenObjCXX/nrvo.mm b/test/CodeGenObjCXX/nrvo.mm
new file mode 100644 (file)
index 0000000..d28d54a
--- /dev/null
+++ b/test/CodeGenObjCXX/nrvo.mm
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -emit-llvm -o - %s -O1 -triple x86_64-apple-darwin10.0.0 | FileCheck %s
+
+// PR10835 / <rdar://problem/10050178>
+struct X {
+  X();
+  X(const X&);
+  ~X();
+};
+
+@interface NRVO
+@end
+
+@implementation NRVO
+// CHECK: define internal void @"\01-[NRVO getNRVO]"
+- (X)getNRVO { 
+  X x;
+  // CHECK: tail call void @_ZN1XC1Ev
+  // CHECK-NEXT: ret void
+  return x;
+}
+@end