[asan] Rename the ABI versioning symbol to '__asan_version_mismatch_check' instead of abusing '__asan_init'

We currently version `__asan_init` and when the ABI version doesn't match, the linker gives a `undefined reference to '__asan_init_v5'` message. From this, it might not be obvious that it's actually a version mismatch error. This patch makes the error message much clearer by changing the name of the undefined symbol to be `__asan_version_mismatch_check_xxx` (followed by the version string). We obviously don't want the initializer to be named like that, so it's a separate symbol that is used only for the purpose of version checking.

Reviewed at http://reviews.llvm.org/D11004

llvm-svn: 243003

1 files changed, 6 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index c7f3cfb8a48..5dde5fed0d2 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -91,7 +91,9 @@ static const char *const kAsanUnregisterGlobalsName =
     "__asan_unregister_globals";
 static const char *const kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
 static const char *const kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
-static const char *const kAsanInitName = "__asan_init_v5";
+static const char *const kAsanInitName = "__asan_init";
+static const char *const kAsanVersionCheckName =
+    "__asan_version_mismatch_check_v6";
 static const char *const kAsanPtrCmp = "__sanitizer_ptr_cmp";
 static const char *const kAsanPtrSub = "__sanitizer_ptr_sub";
 static const char *const kAsanHandleNoReturnName = "__asan_handle_no_return";
@@ -1468,9 +1470,9 @@ bool AddressSanitizer::doInitialization(Module &M) {
 
   if (!CompileKernel) {
     std::tie(AsanCtorFunction, AsanInitFunction) =
-        createSanitizerCtorAndInitFunctions(M, kAsanModuleCtorName, kAsanInitName,
-                                            /*InitArgTypes=*/{},
-                                            /*InitArgs=*/{});
+        createSanitizerCtorAndInitFunctions(
+            M, kAsanModuleCtorName, kAsanInitName,
+            /*InitArgTypes=*/{}, /*InitArgs=*/{}, kAsanVersionCheckName);
     appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndDtorPriority);
   }
   Mapping = getShadowMapping(TargetTriple, LongSize, CompileKernel);