[Sanitizer] Introduce Allocator::may_return_null bool flag.

Summary:
Turn "allocator_may_return_null" common flag into an
Allocator::may_return_null bool flag. We want to make sure
that common flags are immutable after initialization. There
are cases when we want to change this flag in the allocator
at runtime: e.g. in unit tests and during ASan activation
on Android.

Test Plan: regression test suite, real-life applications

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6623

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@224148 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 6 deletions

diff --git a/lib/sanitizer_common/sanitizer_allocator.cc b/lib/sanitizer_common/sanitizer_allocator.cc
index 47509f836..03b3e8315 100644
--- a/lib/sanitizer_common/sanitizer_allocator.cc
+++ b/lib/sanitizer_common/sanitizer_allocator.cc
@@ -14,7 +14,6 @@
 #include "sanitizer_allocator.h"
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_common.h"
-#include "sanitizer_flags.h"
 
 namespace __sanitizer {
 
@@ -61,7 +60,7 @@ InternalAllocator *internal_allocator() {
     SpinMutexLock l(&internal_alloc_init_mu);
     if (atomic_load(&internal_allocator_initialized, memory_order_relaxed) ==
         0) {
-      internal_allocator_instance->Init();
+      internal_allocator_instance->Init(/* may_return_null*/ false);
       atomic_store(&internal_allocator_initialized, 1, memory_order_release);
     }
   }
@@ -140,14 +139,12 @@ bool CallocShouldReturnNullDueToOverflow(uptr size, uptr n) {
   return (max / size) < n;
 }
 
-void *AllocatorReturnNull() {
-  if (common_flags()->allocator_may_return_null)
-    return 0;
+void NORETURN ReportAllocatorCannotReturnNull() {
   Report("%s's allocator is terminating the process instead of returning 0\n",
          SanitizerToolName);
   Report("If you don't like this behavior set allocator_may_return_null=1\n");
   CHECK(0);
-  return 0;
+  Die();
 }
 
 }  // namespace __sanitizer