[libcxxabi] __cxa_guard_require: test guard byte with != 0 instead of == 1

MaskRay · MaskRay · commit ab4302de162a · 2019-08-16T13:54:44.000Z
git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@369109 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/src/cxa_guard_impl.h b/src/cxa_guard_impl.h
@@ -175,7 +175,7 @@ struct GuardObject {
   /// Implements __cxa_guard_acquire
   AcquireResult cxa_guard_acquire() {
     AtomicInt<uint8_t> guard_byte(guard_byte_address);
-    if (guard_byte.load(std::_AO_Acquire) == COMPLETE_BIT)
+    if (guard_byte.load(std::_AO_Acquire) != UNSET)
       return INIT_IS_DONE;
     return derived()->acquire_init_byte();
   }

Original file line number	Diff line number	Diff line change
`@@ -175,7 +175,7 @@ struct GuardObject {`
`175`	`175`	`/// Implements __cxa_guard_acquire`
`176`	`176`	`AcquireResult cxa_guard_acquire() {`
`177`	`177`	`AtomicInt<uint8_t> guard_byte(guard_byte_address);`
`178`		`- if (guard_byte.load(std::_AO_Acquire) == COMPLETE_BIT)`
	`178`	`+ if (guard_byte.load(std::_AO_Acquire) != UNSET)`
`179`	`179`	`return INIT_IS_DONE;`
`180`	`180`	`return derived()->acquire_init_byte();`
`181`	`181`	`}`