[asan] Add a hidden option for Mach-O global metadata liveness tracking

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274578 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 451f497..43d1b37 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -245,6 +245,13 @@ static cl::opt<bool>
                                          " variables"),
                                 cl::Hidden, cl::init(false));
 
+static cl::opt<bool>
+    ClUseMachOGlobalsSection("asan-globals-live-support",
+                             cl::desc("Use linker features to support dead "
+                                      "code stripping of globals "
+                                      "(Mach-O only)"),
+                             cl::Hidden, cl::init(false));
+
 // Debug flags.
 static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
                             cl::init(0));
@@ -1338,6 +1345,9 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
 // binary in order to allow the linker to properly dead strip. This is only
 // supported on recent versions of ld64.
 bool AddressSanitizerModule::ShouldUseMachOGlobalsSection() const {
+  if (!ClUseMachOGlobalsSection)
+    return false;
+
   if (!TargetTriple.isOSBinFormatMachO())
     return false;
 

diff --git a/test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll b/test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll
index 8bf17ca..ea0daee 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll
+++ b/test/Instrumentation/AddressSanitizer/global_metadata_darwin.ll
@@ -2,7 +2,7 @@
 ; allowing dead stripping to be performed, and that the appropriate runtime
 ; routines are invoked.
 
-; RUN: opt < %s -asan -asan-module -S | FileCheck %s
+; RUN: opt < %s -asan -asan-module -asan-globals-live-support -S | FileCheck %s
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.11.0"