From: Kostya Serebryany <kcc@google.com>
Date: Mon, 18 Mar 2013 07:33:49 +0000 (+0000)
Subject: [asan] don't instrument functions with available_externally linkage. This saves a... 
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=3797adb94fdc6b747cb0e97a64b15b931f2533b8

[asan] don't instrument functions with available_externally linkage. This saves a bit of compile time and reduces the number of redundant global strings generated by asan (https://code.google.com/p/address-sanitizer/issues/detail?id=167)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177250 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 2d212d0ddc7..758c6e7bcb4 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1095,6 +1095,7 @@ bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
 bool AddressSanitizer::runOnFunction(Function &F) {
   if (BL->isIn(F)) return false;
   if (&F == AsanCtorFunction) return false;
+  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
   DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
   initializeCallbacks(*F.getParent());
 
diff --git a/test/Instrumentation/AddressSanitizer/basic.ll b/test/Instrumentation/AddressSanitizer/basic.ll
index c477b199046..fb32e704af8 100644
--- a/test/Instrumentation/AddressSanitizer/basic.ll
+++ b/test/Instrumentation/AddressSanitizer/basic.ll
@@ -128,3 +128,15 @@ define void @i80test(i80* %a, i80* %b) nounwind uwtable sanitize_address {
 ; CHECK: __asan_report_store_n{{.*}}, i64 10)
 ; CHECK: __asan_report_store_n{{.*}}, i64 10)
 ; CHECK: ret void
+
+; asan should not instrument functions with available_externally linkage.
+define available_externally i32 @f_available_externally(i32* %a) sanitize_address  {
+entry:
+  %tmp1 = load i32* %a
+  ret i32 %tmp1
+}
+; CHECK: @f_available_externally
+; CHECK-NOT: __asan_report
+; CHECK: ret i32
+
+