Add back a check removed in r226436

It shouldn't have been removed, the code which replaced it didn't cover
this case.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226442 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 5509b03ab2255441462679b11447ecdc806b7ffb..3e41564a39cad40c333b303d95e49727a7401117 100644 (file)
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3902,6 +3902,8 @@ def warn_missing_variable_declarations : Warning<
 def err_static_data_member_reinitialization :
   Error<"static data member %0 already has an initializer">;
 def err_redefinition : Error<"redefinition of %0">;
+def err_alias_after_tentative :
+  Error<"alias definition of %0 after tentative definition">;
 def err_alias_is_definition :
   Error<"definition %0 cannot also be an alias">;
 def err_definition_of_implicitly_declared_member : Error<

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index da59fb5773235ef3eb052f9776006cfc900fa6c2..9eb5993f2a2db00b63860397438c0759a71b5798 100644 (file)
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2219,8 +2219,18 @@ static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
     const Attr *NewAttribute = NewAttributes[I];
 
     if (isa<AliasAttr>(NewAttribute)) {
-      FunctionDecl *FD = cast<FunctionDecl>(New);
-      S.CheckForFunctionRedefinition(FD, cast<FunctionDecl>(Def));
+      if (FunctionDecl *FD = dyn_cast<FunctionDecl>(New))
+        S.CheckForFunctionRedefinition(FD, cast<FunctionDecl>(Def));
+      else {
+        VarDecl *VD = cast<VarDecl>(New);
+        unsigned Diag = cast<VarDecl>(Def)->isThisDeclarationADefinition() ==
+                                VarDecl::TentativeDefinition
+                            ? diag::err_alias_after_tentative
+                            : diag::err_redefinition;
+        S.Diag(VD->getLocation(), Diag) << VD->getDeclName();
+        S.Diag(Def->getLocation(), diag::note_previous_definition);
+        VD->setInvalidDecl();
+      }
       ++I;
       continue;
     }

diff --git a/test/Sema/alias-redefinition.c b/test/Sema/alias-redefinition.c
index 9f9930dc2a97f4b6fec8e4b604030f5799009afd..c1562c707752cb6e92ca560fed05f384086e290e 100644 (file)
--- a/test/Sema/alias-redefinition.c
+++ b/test/Sema/alias-redefinition.c
@@ -25,3 +25,6 @@ void __attribute((alias("f5"))) fun5(void) {} // expected-error {{redefinition o
 
 int var1 __attribute((alias("v1"))); // expected-error {{definition 'var1' cannot also be an alias}}
 static int var2 __attribute((alias("v2"))) = 2; // expected-error {{definition 'var2' cannot also be an alias}}
+
+extern int var3 __attribute__((alias("C"))); // expected-note{{previous definition is here}}
+int var3 = 3; // expected-error{{redefinition of 'var3'}}