[TSan] Add the WTFAnnotateBenignRaceSized implementation and a test for

WTFAnnotateBenignRaceSized and AnnotateBenignRaceSized.

llvm-svn: 178534

2 files changed, 43 insertions, 0 deletions

diff --git a/compiler-rt/lib/tsan/lit_tests/benign_race.cc b/compiler-rt/lib/tsan/lit_tests/benign_race.cc
new file mode 100644
index 00000000000..a4d4d23c362
--- /dev/null
+++ b/compiler-rt/lib/tsan/lit_tests/benign_race.cc
@@ -0,0 +1,39 @@
+// RUN: %clang_tsan -O1 %s -o %t && %t 2>&1 | FileCheck %s
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int Global;
+int WTFGlobal;
+
+extern "C" {
+void AnnotateBenignRaceSized(const char *f, int l,
+                             void *mem, unsigned int size, const char *desc);
+void WTFAnnotateBenignRaceSized(const char *f, int l,
+                                void *mem, unsigned int size,
+                                const char *desc);
+}
+
+
+void *Thread(void *x) {
+  Global = 42;
+  WTFGlobal = 142;
+  return 0;
+}
+
+int main() {
+  AnnotateBenignRaceSized(__FILE__, __LINE__,
+                          &Global, sizeof(Global), "Race on Global");
+  WTFAnnotateBenignRaceSized(__FILE__, __LINE__,
+                             &WTFGlobal, sizeof(WTFGlobal),
+                             "Race on WTFGlobal");
+  pthread_t t;
+  pthread_create(&t, 0, Thread, 0);
+  sleep(1);
+  Global = 43;
+  WTFGlobal = 143;
+  pthread_join(t, 0);
+  printf("OK\n");
+}
+
+// CHECK-NOT: WARNING: ThreadSanitizer: data race
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cc b/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cc
index f845d8db6cd..257afcf8fa3 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cc
@@ -416,6 +416,9 @@ void INTERFACE_ATTRIBUTE AnnotateThreadName(
   ThreadSetName(thr, name);
 }
 
+// We deliberately omit the implementation of WTFAnnotateHappensBefore() and
+// WTFAnnotateHappensAfter(). Those are being used by Webkit to annotate
+// atomic operations, which should be handled by ThreadSanitizer correctly.
 void INTERFACE_ATTRIBUTE WTFAnnotateHappensBefore(char *f, int l, uptr addr) {
   SCOPED_ANNOTATION(AnnotateHappensBefore);
 }
@@ -427,6 +430,7 @@ void INTERFACE_ATTRIBUTE WTFAnnotateHappensAfter(char *f, int l, uptr addr) {
 void INTERFACE_ATTRIBUTE WTFAnnotateBenignRaceSized(
     char *f, int l, uptr mem, uptr sz, char *desc) {
   SCOPED_ANNOTATION(AnnotateBenignRaceSized);
+  BenignRaceImpl(f, l, mem, 1, desc);
 }
 
 int INTERFACE_ATTRIBUTE RunningOnValgrind() {