[ASan] Fix https://code.google.com/p/address-sanitizer/issues/detail?id=274

by ignoring globals from __TEXT,__cstring,cstring_literals during instrumenation.
Add a regression test.

llvm-svn: 203916

1 files changed, 9 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index e8d2e0a0085..5c35cc8faf8 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -895,7 +895,7 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
   // our redzones get broken.
   if ((G->getName().find("\01L_OBJC_") == 0) ||
       (G->getName().find("\01l_OBJC_") == 0)) {
-    DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G);
+    DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G << "\n");
     return false;
   }
 
@@ -906,7 +906,7 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
     // them.
     if ((Section.find("__OBJC,") == 0) ||
         (Section.find("__DATA, __objc_") == 0)) {
-      DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G);
+      DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
       return false;
     }
     // See http://code.google.com/p/address-sanitizer/issues/detail?id=32
@@ -918,7 +918,13 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
     // Therefore there's no point in placing redzones into __DATA,__cfstring.
     // Moreover, it causes the linker to crash on OS X 10.7
     if (Section.find("__DATA,__cfstring") == 0) {
-      DEBUG(dbgs() << "Ignoring CFString: " << *G);
+      DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
+      return false;
+    }
+    // The linker merges the contents of cstring_literals and removes the
+    // trailing zeroes.
+    if (Section.find("__TEXT,__cstring,cstring_literals") == 0) {
+      DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
       return false;
     }
   }