From aeb913dd01b0dc4ccdf5f9e05316802a94c1d6f1 Mon Sep 17 00:00:00 2001
From: Peter Dillinger <peterd@fb.com>
Date: Thu, 15 Jul 2021 23:49:12 -0700
Subject: [PATCH] Standardize on GCC for TSAN conditional compilation (#8543)

Summary:
In https://github.com/facebook/rocksdb/issues/8539 I accidentally only checked for GCC TSAN, which is
what I tested locally, while CircleCI and FB CI use clang TSAN. Related:
other existing code like in stack_trace.cc only check for clang TSAN.

I've now standardized these to the GCC convention in port/lang.h, so now

    #ifdef __SANITIZE_THREAD__

can check for any TSAN (assuming lang.h include)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8543

Test Plan:
Put an assert(false) in slice_test and look for the NOTE
about "signal-unsafe call", both GCC and clang. Eventually, CircleCI
TSAN in https://github.com/facebook/rocksdb/issues/8538

Reviewed By: zhichao-cao

Differential Revision: D29728483

Pulled By: pdillinger

fbshipit-source-id: 8a3b8015c2ed48078214c3ee17146a2c3f11c9f7
---
 port/lang.h              | 17 +++++++++++++++++
 port/stack_trace.cc      |  6 +++---
 trace_replay/io_tracer.h | 15 +--------------
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/port/lang.h b/port/lang.h
index eabe44b69..4a601d41c 100644
--- a/port/lang.h
+++ b/port/lang.h
@@ -15,6 +15,8 @@
 #endif
 #endif
 
+// ASAN (Address sanitizer)
+
 #if defined(__clang__)
 #if defined(__has_feature)
 #if __has_feature(address_sanitizer)
@@ -43,3 +45,18 @@
 #else
 #define STATIC_AVOID_DESTRUCTION(Type, name) static Type& name = *new Type
 #endif
+
+// TSAN (Thread sanitizer)
+
+// For simplicity, standardize on the GCC define
+#if defined(__clang__)
+#if defined(__has_feature) && __has_feature(thread_sanitizer)
+#define __SANITIZE_THREAD__ 1
+#endif  // __has_feature(thread_sanitizer)
+#endif  // __clang__
+
+#ifdef __SANITIZE_THREAD__
+#define TSAN_SUPPRESSION __attribute__((no_sanitize("thread")))
+#else
+#define TSAN_SUPPRESSION
+#endif  // TSAN_SUPPRESSION
diff --git a/port/stack_trace.cc b/port/stack_trace.cc
index c82da2a20..15a36bb71 100644
--- a/port/stack_trace.cc
+++ b/port/stack_trace.cc
@@ -36,6 +36,8 @@ void* SaveStack(int* /*num_frames*/, int /*first_frames_to_skip*/) {
 #include <sys/sysctl.h>
 #endif
 
+#include "port/lang.h"
+
 namespace ROCKSDB_NAMESPACE {
 namespace port {
 
@@ -163,8 +165,7 @@ static void StackTraceHandler(int sig) {
 
   // Efforts to fix or suppress TSAN warnings "signal-unsafe call inside of
   // a signal" have failed, so just warn the user about them.
-#if defined(__clang__) && defined(__has_feature)
-#if __has_feature(thread_sanitizer)
+#ifdef __SANITIZE_THREAD__
   fprintf(stderr,
           "==> NOTE: any above warnings about \"signal-unsafe call\" are\n"
           "==> ignorable, as they are expected when generating a stack\n"
@@ -173,7 +174,6 @@ static void StackTraceHandler(int sig) {
           "==> in the TSAN warning can be useful for that. (The stack\n"
           "==> trace printed by the signal handler is likely obscured\n"
           "==> by TSAN output.)\n");
-#endif
 #endif
 
   // re-signal to default handler (so we still get core dump if needed...)
diff --git a/trace_replay/io_tracer.h b/trace_replay/io_tracer.h
index 83bcaee9d..8db6e2a27 100644
--- a/trace_replay/io_tracer.h
+++ b/trace_replay/io_tracer.h
@@ -9,6 +9,7 @@
 #include <fstream>
 
 #include "monitoring/instrumented_mutex.h"
+#include "port/lang.h"
 #include "rocksdb/file_system.h"
 #include "rocksdb/options.h"
 #include "trace_replay/trace_replay.h"
@@ -157,20 +158,6 @@ class IOTracer {
   // mutex and ignore the operation if writer_is null. So its ok if
   // tracing_enabled shows non updated value.
 
-#if defined(__clang__)
-#if defined(__has_feature) && __has_feature(thread_sanitizer)
-#define TSAN_SUPPRESSION __attribute__((no_sanitize("thread")))
-#endif  // __has_feature(thread_sanitizer)
-#else   // __clang__
-#ifdef __SANITIZE_THREAD__
-#define TSAN_SUPPRESSION __attribute__((no_sanitize("thread")))
-#endif  // __SANITIZE_THREAD__
-#endif  // __clang__
-
-#ifndef TSAN_SUPPRESSION
-#define TSAN_SUPPRESSION
-#endif  // TSAN_SUPPRESSION
-
   // Start writing IO operations to the trace_writer.
   TSAN_SUPPRESSION Status
   StartIOTrace(SystemClock* clock, const TraceOptions& trace_options,