C11 allows typedefs to be redefined. Implement this in C11 mode, and

downgrade the default-error warning to an ExtWarn in
C90/99. <rdar://problem/10668057>

llvm-svn: 147925

1 files changed, 2 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index a2bf48e47a0..588fc140444 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -1463,8 +1463,6 @@ void Sema::MergeTypedefNameDecl(TypedefNameDecl *New, LookupResult &OldDecls) {
 
   // The types match.  Link up the redeclaration chain if the old
   // declaration was a typedef.
-  // FIXME: this is a potential source of weirdness if the type
-  // spellings don't match exactly.
   if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old))
     New->setPreviousDeclaration(Typedef);
 
@@ -1509,8 +1507,8 @@ void Sema::MergeTypedefNameDecl(TypedefNameDecl *New, LookupResult &OldDecls) {
     return New->setInvalidDecl();
   }
 
-  // Modules always permit redefinition of typedefs.
-  if (getLangOptions().Modules)
+  // Modules always permit redefinition of typedefs, as does C11.
+  if (getLangOptions().Modules || getLangOptions().C11)
     return;
   
   // If we have a redefinition of a typedef in C, emit a warning.  This warning