[asan] add the name of the module to the description of a global variable. This improves the readability of global-buffer-overflow reports.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146698 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index e4f1978..4cc5727 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -521,7 +521,11 @@
         NewTy, G->getInitializer(),
         Constant::getNullValue(RightRedZoneTy), NULL);
 
-    GlobalVariable *Name = createPrivateGlobalForString(M, G->getName());
+    SmallString<2048> DescriptionOfGlobal = G->getName();
+    DescriptionOfGlobal += " (";
+    DescriptionOfGlobal += M.getModuleIdentifier();
+    DescriptionOfGlobal += ")";
+    GlobalVariable *Name = createPrivateGlobalForString(M, DescriptionOfGlobal);
 
     // Create a new global variable with enough space for a redzone.
     GlobalVariable *NewGlobal = new GlobalVariable(