r203151 - MS ABI: Disambiguate the manglings for global guard variables

[David Majnemer]

Author: majnemer
Date: Thu Mar  6 13:57:36 2014
New Revision: 203151

URL: http://llvm.org/viewvc/llvm-project?rev=203151&view=rev
Log:
MS ABI: Disambiguate the manglings for global guard variables

If a guard variable will be created for an entity at global scope,
then we cannot rely on the scope depth to disambiguate names for us.

Instead, mangle the entire variable into the guard to ensure it's uniqueness.

Modified:
    cfe/trunk/lib/AST/MicrosoftMangle.cpp
    cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp

Modified: cfe/trunk/lib/AST/MicrosoftMangle.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/MicrosoftMangle.cpp?rev=203151&r1=203150&r2=203151&view=diff
==============================================================================
--- cfe/trunk/lib/AST/MicrosoftMangle.cpp (original)
+++ cfe/trunk/lib/AST/MicrosoftMangle.cpp Thu Mar  6 13:57:36 2014
@@ -2280,13 +2280,17 @@ void MicrosoftMangleContextImpl::mangleS
   bool Visible = VD->isExternallyVisible();
   // <operator-name> ::= ?_B # local static guard
   Mangler.getStream() << (Visible ? "\01??_B" : "\01?$S1@");
-  Mangler.mangleNestedName(VD);
+  unsigned ScopeDepth = 0;
+  if (Visible && !getNextDiscriminator(VD, ScopeDepth))
+    // If we do not have a discriminator and are emitting a guard variable for
+    // use at global scope, then mangling the nested name will not be enough to
+    // remove ambiguities.
+    Mangler.mangle(VD, "");
+  else
+    Mangler.mangleNestedName(VD);
   Mangler.getStream() << (Visible ? "@5" : "@4IA");
-  if (Visible) {
-    unsigned ScopeDepth;
-    getNextDiscriminator(VD, ScopeDepth);
+  if (ScopeDepth)
     Mangler.mangleNumber(ScopeDepth);
-  }
 }
 
 void MicrosoftMangleContextImpl::mangleInitFiniStub(const VarDecl *D,

Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp?rev=203151&r1=203150&r2=203151&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp Thu Mar  6 13:57:36 2014
@@ -135,6 +135,8 @@ void force_usage() {
 }
 
 // CHECK: define internal void @"\01??__Efoo@?$B at H@@2VA@@A at YAXXZ"() [[NUW]]
+// CHECK: load i32* @"\01??_Bfoo@?$B at H@@2VA@@A at 5"
+// CHECK: store i32 {{.*}}, i32* @"\01??_Bfoo@?$B at H@@2VA@@A at 5"
 // CHECK: %{{[.0-9A-Z_a-z]+}} = call x86_thiscallcc %class.A* @"\01??0A@@QAE at XZ"
 // CHECK: call i32 @atexit(void ()* @"\01??__Ffoo@?$B at H@@2VA@@A at YAXXZ")
 // CHECK: ret void