[PR26550] Use a different TBAA root for C++ vs C.

This commit changes the root from "Simple C/C++ TBAA" to "Simple C++ TBAA" for
C++.

The problem is that the type name in the TBAA nodes is generated differently
for C vs C++. If we link an IR file for C with an IR file for C++, since they
have the same root and the type names are different, accesses to the two type
nodes will be considered no-alias, even though the two type nodes are from
the same type in a header file.

The fix is to use different roots for C and C++. Types from C will be treated
conservatively in respect to types from C++.

Follow-up commits will change the C root to "Simple C TBAA" plus some mangling
change for C types to make it a little more aggresive.

llvm-svn: 260567

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/test/CodeGen/tbaa-class.cpp b/clang/test/CodeGen/tbaa-class.cpp
index f611ae5abb8..7172e05d9e3 100644
--- a/clang/test/CodeGen/tbaa-class.cpp
+++ b/clang/test/CodeGen/tbaa-class.cpp
@@ -199,7 +199,7 @@ uint32_t g12(StructC *C, StructD *D, uint64_t count) {
 }
 
 // CHECK: [[TYPE_char:!.*]] = !{!"omnipotent char", [[TAG_cxx_tbaa:!.*]],
-// CHECK: [[TAG_cxx_tbaa]] = !{!"Simple C/C++ TBAA"}
+// CHECK: [[TAG_cxx_tbaa]] = !{!"Simple C++ TBAA"}
 // CHECK: [[TAG_i32]] = !{[[TYPE_i32:!.*]], [[TYPE_i32]], i64 0}
 // CHECK: [[TYPE_i32]] = !{!"int", [[TYPE_char]],
 // CHECK: [[TAG_i16]] = !{[[TYPE_i16:!.*]], [[TYPE_i16]], i64 0}