Check for internal weak decls after merging.

This fixes pr14946. The problem was that the linkage computation was done too
early, so things like "extern int a;" would be given external linkage, even if
a previous declaration was static.

llvm-svn: 172667

2 files changed, 13 insertions, 0 deletions

diff --git a/clang/test/Sema/attr-weak.c b/clang/test/Sema/attr-weak.c
index adedf1231f9..df74554487e 100644
--- a/clang/test/Sema/attr-weak.c
+++ b/clang/test/Sema/attr-weak.c
@@ -16,3 +16,9 @@ static int x __attribute__((weak)); // expected-error {{weak declaration cannot
 // rdar://9538608
 int C; // expected-note {{previous definition is here}}
 extern int C __attribute__((weak_import)); // expected-warning {{an already-declared variable is made a weak_import declaration}}
+
+static int pr14946_x;
+extern int pr14946_x  __attribute__((weak)); // expected-error {{weak declaration cannot have internal linkage}}
+
+static void pr14946_f();
+void pr14946_f() __attribute__((weak)); // expected-error {{weak declaration cannot have internal linkage}}
diff --git a/clang/test/SemaCXX/attr-weak.cpp b/clang/test/SemaCXX/attr-weak.cpp
index b6a9e0aa840..8939a28d75e 100644
--- a/clang/test/SemaCXX/attr-weak.cpp
+++ b/clang/test/SemaCXX/attr-weak.cpp
@@ -21,9 +21,16 @@ namespace {
   };
 }
 
+// GCC rejects the instantiation with the internal type, but some existing
+// code expects it. It is also not that different from giving hidden visibility
+// to parts of a template that have explicit default visibility, so we accept
+// this.
 template <class T> struct Test7 {
   void test7() __attribute__((weak)) {}
+  static int var __attribute__((weak));
 };
+template <class T>
+int Test7<T>::var;
 namespace { class Internal; }
 template struct Test7<Internal>;
 template struct Test7<int>;