commit 1006a068c63f9df215a29e3185b4c1a0e4a0f83a
author Sven van Haastregt <sven.vanhaastregt@arm.com> Wed Jun 26 13:31:24 2019 +0000
committer Sven van Haastregt <sven.vanhaastregt@arm.com> Wed Jun 26 13:31:24 2019 +0000
tree 2aa6987081b2d36771ad5c7839dabf0ddfdb231f
parent 1a3dc761860d620ac8ed7e32a4285952142f780b

[OpenCL] Improve diagnostic for placement new

Without an explicit declaration for placement new, clang would reject
uses of placement new with "'default new' is not supported in OpenCL
C++".  This may mislead users into thinking that placement new is not
supported, see e.g. PR42060.

Clarify that placement new requires an explicit declaration.

Differential Revision: https://reviews.llvm.org/D63561

llvm-svn: 364423

clang/include/clang/Basic/DiagnosticSemaKinds.td

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 2abf7d7..b9d081c 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8809,6 +8809,9 @@
   "vector component name '%0' is an OpenCL version 2.2 feature">,
   InGroup<OpenCLUnsupportedRGBA>;
 
+def err_openclcxx_placement_new : Error<
+  "use of placement new requires explicit declaration">;
+
 // MIG routine annotations.
 def warn_mig_server_routine_does_not_return_kern_return_t : Warning<
   "'mig_server_routine' attribute only applies to routines that return a kern_return_t">,

clang/lib/Sema/SemaExprCXX.cpp

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index b59f3fa..32b35ba 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -2413,7 +2413,11 @@
     }
 
     if (getLangOpts().OpenCLCPlusPlus && R.empty()) {
-      Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
+      if (PlaceArgs.empty()) {
+        Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
+      } else {
+        Diag(StartLoc, diag::err_openclcxx_placement_new);
+      }
       return true;
     }
 

clang/test/SemaOpenCLCXX/newdelete.cl

diff --git a/clang/test/SemaOpenCLCXX/newdelete.cl b/clang/test/SemaOpenCLCXX/newdelete.cl
index ce6273f..14be455 100644
--- a/clang/test/SemaOpenCLCXX/newdelete.cl
+++ b/clang/test/SemaOpenCLCXX/newdelete.cl
@@ -21,7 +21,7 @@
 void test_default_new_delete(void *buffer, A **pa) {
   A *a = new A;         // expected-error {{'default new' is not supported in OpenCL C++}}
   delete a;             // expected-error {{'default delete' is not supported in OpenCL C++}}
-  *pa = new (buffer) A; // expected-error {{'default new' is not supported in OpenCL C++}}
+  *pa = new (buffer) A; // expected-error {{use of placement new requires explicit declaration}}
 }
 
 // expected-note@+1 {{candidate function not viable: requires 2 arguments, but 1 was provided}}