Warn about code that uses variables and functions with internal linkage

without defining them.  This should be an error, but I'm paranoid about
"uses" that end up not actually requiring a definition.  I'll revisit later.

Also, teach IR generation to not set internal linkage on variable
declarations, just for safety's sake.  Doing so produces an invalid module
if the variable is not ultimately defined.

Also, fix several places in the test suite where we were using internal
functions without definitions.

llvm-svn: 126016

1 files changed, 21 insertions, 23 deletions

diff --git a/clang/test/CodeGenCXX/thunks.cpp b/clang/test/CodeGenCXX/thunks.cpp
index 238032cc6de..a74cc053dbe 100644
--- a/clang/test/CodeGenCXX/thunks.cpp
+++ b/clang/test/CodeGenCXX/thunks.cpp
@@ -88,31 +88,29 @@ void C::f() { }
 }
 
 // Check that the thunk gets internal linkage.
-namespace {
-
-struct A {
-  virtual void f();
-};
-
-struct B {
-  virtual void f();
-};
-
-struct C : A, B {
-  virtual void c();
-
-  virtual void f();
-};
+namespace Test4B {
+  struct A {
+    virtual void f();
+  };
 
-void C::f() { }
+  struct B {
+    virtual void f();
+  };
 
-}
+  namespace {
+    struct C : A, B {
+      virtual void c();
+      virtual void f();
+    };
+  }
+  void C::c() {}
+  void C::f() {}
 
-// Force C::f to be used.
-void f() { 
-  C c; 
-  
-  c.f();
+  // Force C::f to be used.
+  void f() { 
+    C c; 
+    c.f();
+  }
 }
 
 namespace Test5 {
@@ -283,4 +281,4 @@ namespace Test11 {
 
 // This is from Test5:
 // CHECK: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
-// CHECK: define internal void @_ZThn8_N12_GLOBAL__N_11C1fEv(
+// CHECK: define internal void @_ZThn8_N6Test4B12_GLOBAL__N_11C1fEv(