tsan: implement suppressions for top frame only

The new suppression type is called "race_top" and is matched only against top frame in report stacks.
This is required for situations when we want to suppress a race in a "thread pool" or "event loop" implementation.
If we simply use "race:ThreadPool::Execute" suppression, that can suppress everything in the program.

Reviewed in http://reviews.llvm.org/D10686

llvm-svn: 240949

compiler-rt/lib/tsan/rtl/tsan_suppressions.cc

@@ -44,8 +44,9 @@ namespace __tsan {
 ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)];
 static SuppressionContext *suppression_ctx = nullptr;
 static const char *kSuppressionTypes[] = {
-    kSuppressionRace,   kSuppressionMutex, kSuppressionThread,
-    kSuppressionSignal, kSuppressionLib,   kSuppressionDeadlock};
+    kSuppressionRace,   kSuppressionRaceTop, kSuppressionMutex,
+    kSuppressionThread, kSuppressionSignal, kSuppressionLib,
+    kSuppressionDeadlock};
 
 void InitializeSuppressions() {
   CHECK_EQ(nullptr, suppression_ctx);
@@ -94,6 +95,18 @@ static const char *conv(ReportType typ) {
   Die();
 }
 
+static uptr IsSuppressed(const char *stype, const AddressInfo &info,
+    Suppression **sp) {
+  if (suppression_ctx->Match(info.function, stype, sp) ||
+      suppression_ctx->Match(info.file, stype, sp) ||
+      suppression_ctx->Match(info.module, stype, sp)) {
+    DPrintf("ThreadSanitizer: matched suppression '%s'\n", (*sp)->templ);
+    (*sp)->hit_count++;
+    return info.address;
+  }
+  return 0;
+}
+
 uptr IsSuppressed(ReportType typ, const ReportStack *stack, Suppression **sp) {
   CHECK(suppression_ctx);
   if (!suppression_ctx->SuppressionCount() || stack == 0 ||
@@ -102,19 +115,14 @@ uptr IsSuppressed(ReportType typ, const ReportStack *stack, Suppression **sp) {
   const char *stype = conv(typ);
   if (0 == internal_strcmp(stype, kSuppressionNone))
     return 0;
-  Suppression *s;
   for (const SymbolizedStack *frame = stack->frames; frame;
-       frame = frame->next) {
-    const AddressInfo &info = frame->info;
-    if (suppression_ctx->Match(info.function, stype, &s) ||
-        suppression_ctx->Match(info.file, stype, &s) ||
-        suppression_ctx->Match(info.module, stype, &s)) {
-      DPrintf("ThreadSanitizer: matched suppression '%s'\n", s->templ);
-      s->hit_count++;
-      *sp = s;
-      return info.address;
-    }
+      frame = frame->next) {
+    uptr pc = IsSuppressed(stype, frame->info, sp);
+    if (pc != 0)
+      return pc;
   }
+  if (0 == internal_strcmp(stype, kSuppressionRace) && stack->frames != nullptr)
+    return IsSuppressed(kSuppressionRaceTop, stack->frames->info, sp);
   return 0;
 }
 

compiler-rt/lib/tsan/rtl/tsan_suppressions.h

@@ -20,6 +20,7 @@ namespace __tsan {
 
 const char kSuppressionNone[] = "none";
 const char kSuppressionRace[] = "race";
+const char kSuppressionRaceTop[] = "race_top";
 const char kSuppressionMutex[] = "mutex";
 const char kSuppressionThread[] = "thread";
 const char kSuppressionSignal[] = "signal";

compiler-rt/test/tsan/race_top_suppression.cc

@@ -0,0 +1,29 @@
+// RUN: echo "race_top:TopFunction" > %t.supp
+// RUN: %clangxx_tsan -O1 %s -o %t
+// RUN: TSAN_OPTIONS="$TSAN_OPTIONS suppressions='%t.supp'" %run %t 2>&1 | FileCheck %s
+// RUN: rm %t.supp
+#include "test.h"
+
+int Global;
+
+void TopFunction(int *p) {
+  *p = 1;
+}
+
+void *Thread(void *x) {
+  barrier_wait(&barrier);
+  TopFunction(&Global);
+  return 0;
+}
+
+int main() {
+  barrier_init(&barrier, 2);
+  pthread_t t;
+  pthread_create(&t, 0, Thread, 0);
+  Global--;
+  barrier_wait(&barrier);
+  pthread_join(t, 0);
+  fprintf(stderr, "DONE\n");
+}
+
+// CHECK-NOT: WARNING: ThreadSanitizer: data race

compiler-rt/test/tsan/race_top_suppression1.cc

@@ -0,0 +1,32 @@
+// RUN: echo "race_top:TopFunction" > %t.supp
+// RUN: %clangxx_tsan -O1 %s -o %t
+// RUN: TSAN_OPTIONS="$TSAN_OPTIONS suppressions='%t.supp'" %deflake %run %t 2>&1 | FileCheck %s
+// RUN: rm %t.supp
+#include "test.h"
+
+int Global;
+
+void AnotherFunction(int *p) {
+  *p = 1;
+}
+
+void TopFunction(int *p) {
+  AnotherFunction(p);
+}
+
+void *Thread(void *x) {
+  barrier_wait(&barrier);
+  TopFunction(&Global);
+  return 0;
+}
+
+int main() {
+  barrier_init(&barrier, 2);
+  pthread_t t;
+  pthread_create(&t, 0, Thread, 0);
+  Global--;
+  barrier_wait(&barrier);
+  pthread_join(t, 0);
+}
+
+// CHECK: WARNING: ThreadSanitizer: data race