Objective-C's @synchronize synchronization primitive uses calls to objc_sync_enter and objc_sync_exit runtime functions. In most cases, they end up just calling pthread_mutex_lock/pthread_mutex_unlock, but there are some cases where the synchronization from pthread_mutex_lock/pthread_mutex_unlock interceptors isn't enough. Let's add explicit interceptors for objc_sync_enter and objc_sync_exit to handle all cases.
Differential Revision: https://reviews.llvm.org/D45487
llvm-svn: 329982
RTUbsan
CFLAGS ${TSAN_RTL_CFLAGS}
LINK_FLAGS ${SANITIZER_COMMON_LINK_FLAGS} ${WEAK_SYMBOL_LINK_FLAGS}
- LINK_LIBS ${TSAN_LINK_LIBS}
+ LINK_LIBS ${TSAN_LINK_LIBS} objc
PARENT_TARGET tsan)
add_compiler_rt_object_libraries(RTTsan_dynamic
OS ${TSAN_SUPPORTED_OS}
#endif // #if defined(__has_include) && __has_include(<xpc/xpc.h>)
+TSAN_INTERCEPTOR(int, objc_sync_enter, void *obj) {
+ SCOPED_TSAN_INTERCEPTOR(objc_sync_enter, obj);
+ int result = REAL(objc_sync_enter)(obj);
+ if (obj) Acquire(thr, pc, (uptr)obj);
+ return result;
+}
+
+TSAN_INTERCEPTOR(int, objc_sync_exit, void *obj) {
+ SCOPED_TSAN_INTERCEPTOR(objc_sync_enter, obj);
+ if (obj) Release(thr, pc, (uptr)obj);
+ return REAL(objc_sync_exit)(obj);
+}
+
// On macOS, libc++ is always linked dynamically, so intercepting works the
// usual way.
#define STDCXX_INTERCEPTOR TSAN_INTERCEPTOR
--- /dev/null
+// RUN: %clangxx_tsan %s -o %t -framework Foundation -fobjc-arc %darwin_min_target_with_full_runtime_arc_support
+// RUN: %run %t 2>&1 | FileCheck %s
+
+#import <Foundation/Foundation.h>
+
+@interface MyClass : NSObject {
+ long field;
+}
+@property (nonatomic, readonly) long value;
+@end
+
+dispatch_group_t group;
+
+@implementation MyClass
+
+- (void) start {
+ dispatch_queue_t q = dispatch_queue_create(NULL, NULL);
+ dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+ for (int i = 0; i < 1000; i++) {
+ dispatch_async(q, ^{
+ @synchronized(self) {
+ self->field = i;
+ }
+ });
+ }
+ });
+}
+
+- (long) value {
+ @synchronized(self) {
+ return self->field;
+ }
+}
+
+- (void)dealloc {
+ dispatch_group_leave(group);
+}
+
+@end
+
+int main() {
+ group = dispatch_group_create();
+ @autoreleasepool {
+ for (int j = 0; j < 100; ++j) {
+ dispatch_group_enter(group);
+ MyClass *obj = [[MyClass alloc] init];
+ [obj start];
+ long x = obj.value;
+ (void)x;
+ }
+ }
+ dispatch_group_wait(group, DISPATCH_TIME_FOREVER);
+ NSLog(@"Hello world");
+}
+
+// CHECK: Hello world
+// CHECK-NOT: WARNING: ThreadSanitizer