[tsan] Add interceptors for objc_sync_enter and objc_sync_exit

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



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@329982 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 57 insertions, 0 deletions

diff --git a/test/tsan/Darwin/objc-synchronize.mm b/test/tsan/Darwin/objc-synchronize.mm
new file mode 100644
index 000000000..0bf06370a
--- /dev/null
+++ b/test/tsan/Darwin/objc-synchronize.mm
@@ -0,0 +1,57 @@
+// 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