From: Kostya Serebryany <kcc@google.com>
Date: Thu, 17 Nov 2011 23:14:59 +0000 (+0000)
Subject: fall back to explicit list of allowed linkages when instrumenting globals in asan... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7cf2a04361e8613264498e50babe52d65c070473;p=oota-llvm.git

fall back to explicit list of allowed linkages when instrumenting globals in asan; add a test check that asan does not touch linkonce_odr

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144933 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index e858bccdfbb..1f3672e25cd 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -448,8 +448,11 @@ bool AddressSanitizer::insertGlobalRedzones(Module &M) {
 
     if (!Ty->isSized()) continue;
     if (!G->hasInitializer()) continue;
-    if (GlobalVariable::mayBeOverridden(G->getLinkage()) ||
-        G->getLinkage() == GlobalVariable::AppendingLinkage)
+    // Touch only those globals that will not be defined in other modules.
+    // Don't handle ODR type linkages since other modules may be built w/o asan.
+    if (G->getLinkage() != GlobalVariable::GlobalVariable::ExternalLinkage &&
+        G->getLinkage() != GlobalVariable::GlobalVariable::PrivateLinkage &&
+        G->getLinkage() != GlobalVariable::GlobalVariable::InternalLinkage)
       continue;
     // For now, just ignore this Alloca if the alignment is large.
     if (G->getAlignment() > RedzoneSize) continue;
diff --git a/test/Instrumentation/AddressSanitizer/do-not-touch-odr-global.ll b/test/Instrumentation/AddressSanitizer/do-not-touch-odr-global.ll
new file mode 100644
index 00000000000..1687877849c
--- /dev/null
+++ b/test/Instrumentation/AddressSanitizer/do-not-touch-odr-global.ll
@@ -0,0 +1,6 @@
+; RUN: opt < %s -asan -S | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-unknown-linux-gnu"
+; no action should be taken for these globals
+@v1 = linkonce_odr constant i8 1
+; CHECK-NOT: __asan_register_globals