Sync 'in class initialization of static const double' extension up with GCC,

and split it out of -Wgnu into its own warning flag.

 * In C++11, this is now a hard error (GCC has no extension here in C++11 mode).
   The error can be disabled with -Wno-static-float-init, and has a fixit to
   add 'constexpr'.

 * In C++98, this is still an ExtWarn, but is now controlled by
   -Wstatic-float-init as well as -Wgnu.

llvm-svn: 173414

1 files changed, 14 insertions, 8 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 538434db002..9efcb52d148 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -7128,17 +7128,23 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
 
     // We allow foldable floating-point constants as an extension.
     } else if (DclT->isFloatingType()) { // also permits complex, which is ok
-      Diag(VDecl->getLocation(), diag::ext_in_class_initializer_float_type)
-        << DclT << Init->getSourceRange();
-      if (getLangOpts().CPlusPlus11)
+      // In C++98, this is a GNU extension. In C++11, it is not, but we support
+      // it anyway and provide a fixit to add the 'constexpr'.
+      if (getLangOpts().CPlusPlus11) {
         Diag(VDecl->getLocation(),
-             diag::note_in_class_initializer_float_type_constexpr)
+             diag::ext_in_class_initializer_float_type_cxx11)
+          << DclT << Init->getSourceRange()
           << FixItHint::CreateInsertion(VDecl->getLocStart(), "constexpr ");
+        VDecl->setConstexpr(true);
+      } else {
+        Diag(VDecl->getLocation(), diag::ext_in_class_initializer_float_type)
+          << DclT << Init->getSourceRange();
 
-      if (!Init->isValueDependent() && !Init->isEvaluatable(Context)) {
-        Diag(Init->getExprLoc(), diag::err_in_class_initializer_non_constant)
-          << Init->getSourceRange();
-        VDecl->setInvalidDecl();
+        if (!Init->isValueDependent() && !Init->isEvaluatable(Context)) {
+          Diag(Init->getExprLoc(), diag::err_in_class_initializer_non_constant)
+            << Init->getSourceRange();
+          VDecl->setInvalidDecl();
+        }
       }
 
     // Suggest adding 'constexpr' in C++11 for literal types.