[llvm] r177250 - [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)

[Kostya Serebryany]

Author: kcc
Date: Mon Mar 18 02:33:49 2013
New Revision: 177250

URL: http://llvm.org/viewvc/llvm-project?rev=177250&view=rev
Log:
[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) 

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
    llvm/trunk/test/Instrumentation/AddressSanitizer/basic.ll

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=177250&r1=177249&r2=177250&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Mon Mar 18 02:33:49 2013
@@ -1095,6 +1095,7 @@ bool AddressSanitizer::maybeInsertAsanIn
 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());
 

Modified: llvm/trunk/test/Instrumentation/AddressSanitizer/basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/basic.ll?rev=177250&r1=177249&r2=177250&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/basic.ll (original)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/basic.ll Mon Mar 18 02:33:49 2013
@@ -128,3 +128,15 @@ define void @i80test(i80* %a, i80* %b) n
 ; 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
+
+