[PATCH] D88295: [Sema] Fix volatile check when test if a return object can be implicitly move

[Yang Fan via Phabricator via cfe-commits]

nullptr.cpp updated this revision to Diff 301810.
nullptr.cpp added a comment.

make test more clearly


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D88295/new/

https://reviews.llvm.org/D88295

Files:
  clang/lib/Sema/SemaStmt.cpp
  clang/test/CXX/special/class.copy/copy-elision.cpp


Index: clang/test/CXX/special/class.copy/copy-elision.cpp
===================================================================
--- /dev/null
+++ clang/test/CXX/special/class.copy/copy-elision.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -std=c++20 -emit-llvm -triple x86_64-unknown-linux-gnu -o - %s | FileCheck %s
+// RUN: %clang_cc1 -std=c++17 -emit-llvm -triple x86_64-unknown-linux-gnu -o - %s | FileCheck %s
+// RUN: %clang_cc1 -std=c++14 -emit-llvm -triple x86_64-unknown-linux-gnu -o - %s | FileCheck %s
+// RUN: %clang_cc1 -std=c++11 -emit-llvm -triple x86_64-unknown-linux-gnu -o - %s | FileCheck %s
+
+// - volatile object in return statement don't match the rule for using move
+//   operation instead of copy operation. Thus should call the copy constructor
+//   A(const volatile A &).
+//
+// - volatile object in return statement also don't match the rule for copy
+//   elision. Thus the copy constructor A(const volatile A &) cannot be elided.
+namespace test_volatile {
+class A {
+public:
+  A() {}
+  ~A() {}
+  A(const volatile A &);
+  A(volatile A &&);
+};
+
+A test() {
+  volatile A a_copy;
+  // CHECK: call void @_ZN13test_volatile1AC1ERVKS0_
+  return a_copy;
+}
+} // namespace test_volatile
Index: clang/lib/Sema/SemaStmt.cpp
===================================================================
--- clang/lib/Sema/SemaStmt.cpp
+++ clang/lib/Sema/SemaStmt.cpp
@@ -3059,12 +3059,13 @@
   // variable will no longer be used.
   if (VD->hasAttr<BlocksAttr>()) return false;
 
+  // ...non-volatile...
+  if (VD->getType().isVolatileQualified())
+    return false;
+
   if (CESK & CES_AllowDifferentTypes)
     return true;
 
-  // ...non-volatile...
-  if (VD->getType().isVolatileQualified()) return false;
-
   // Variables with higher required alignment than their type's ABI
   // alignment cannot use NRVO.
   if (!VD->getType()->isDependentType() && VD->hasAttr<AlignedAttr>() &&


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