commit 6b90356ab455baca180c74ee67282fd40bf2780c
author David Majnemer <david.majnemer@gmail.com> Mon Jan 19 10:21:22 2015 +0000
committer David Majnemer <david.majnemer@gmail.com> Mon Jan 19 10:21:22 2015 +0000
tree a310b8a756e09ec68a065470837e310cf4eda674
parent 6a1565c7e5c7c7765535684d0188a83aec2967a0

Add back a check removed in r226436

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

llvm-svn: 226442

clang/include/clang/Basic/DiagnosticSemaKinds.td

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 5509b03..3e41564 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3902,6 +3902,8 @@
 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<

clang/lib/Sema/SemaDecl.cpp

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index da59fb5..9eb5993 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2219,8 +2219,18 @@
     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;
     }

clang/test/Sema/alias-redefinition.c

diff --git a/clang/test/Sema/alias-redefinition.c b/clang/test/Sema/alias-redefinition.c
index 9f9930d..c1562c7 100644
--- a/clang/test/Sema/alias-redefinition.c
+++ b/clang/test/Sema/alias-redefinition.c
@@ -25,3 +25,6 @@
 
 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'}}