From 8833eab4461b4b7050f06a231c3311cc1fa87523 Mon Sep 17 00:00:00 2001
From: Martin Liska <mliska@suse.cz>
Date: Mon, 7 Dec 2020 15:55:59 +0100
Subject: [PATCH] Add -Wtsan.
gcc/ChangeLog:
PR sanitizer/97868
* common.opt: Add new warning -Wtsan.
* doc/invoke.texi: Likewise.
* tsan.c (instrument_builtin_call): Warn users about unsupported
std::atomic_thread_fence.
gcc/testsuite/ChangeLog:
PR sanitizer/97868
* gcc.dg/tsan/atomic-fence.c: New test.
---
gcc/common.opt | 4 ++++
gcc/doc/invoke.texi | 12 +++++++++++-
gcc/testsuite/gcc.dg/tsan/atomic-fence.c | 11 +++++++++++
gcc/tsan.c | 6 ++++++
4 files changed, 32 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/tsan/atomic-fence.c
diff --git a/gcc/common.opt b/gcc/common.opt
index 6645539f5e52..4ab5fe44737d 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -842,6 +842,10 @@ Wvector-operation-performance
Common Var(warn_vector_operation_performance) Warning
Warn when a vector operation is compiled outside the SIMD.
+Wtsan
+Common Var(warn_tsan) Init(1) Warning
+Warn about unsupported features in ThreadSanitizer.
+
Xassembler
Driver Separate
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 2cebe7ab3195..054b83715934 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -387,7 +387,7 @@ Objective-C and Objective-C++ Dialects}.
-Wswitch -Wno-switch-bool -Wswitch-default -Wswitch-enum @gol
-Wno-switch-outside-range -Wno-switch-unreachable -Wsync-nand @gol
-Wsystem-headers -Wtautological-compare -Wtrampolines -Wtrigraphs @gol
--Wtype-limits -Wundef @gol
+-Wtsan -Wtype-limits -Wundef @gol
-Wuninitialized -Wunknown-pragmas @gol
-Wunsuffixed-float-constants -Wunused @gol
-Wunused-but-set-parameter -Wunused-but-set-variable @gol
@@ -8023,6 +8023,16 @@ Note that the code above is invalid in C++11.
This warning is enabled by default.
+@item -Wtsan
+@opindex Wtsan
+@opindex Wno-tsan
+Warn about unsupported features in ThreadSanitizer.
+
+ThreadSanitizer does not support @code{std::atomic_thread_fence} and
+can report false positives.
+
+This warning is enabled by default.
+
@item -Wtype-limits
@opindex Wtype-limits
@opindex Wno-type-limits
diff --git a/gcc/testsuite/gcc.dg/tsan/atomic-fence.c b/gcc/testsuite/gcc.dg/tsan/atomic-fence.c
new file mode 100644
index 000000000000..013720c2969a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tsan/atomic-fence.c
@@ -0,0 +1,11 @@
+/* PR sanitizer/97868 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=thread" } */
+
+int
+main ()
+{
+ __atomic_thread_fence (__ATOMIC_RELAXED); /* { dg-warning ".atomic_thread_fence. is not supported with .-fsanitize=thread." } */
+ return 0;
+}
+
diff --git a/gcc/tsan.c b/gcc/tsan.c
index 4d6223454b57..1bc020e76480 100644
--- a/gcc/tsan.c
+++ b/gcc/tsan.c
@@ -45,6 +45,7 @@ along with GCC; see the file COPYING3. If not see
#include "asan.h"
#include "builtins.h"
#include "target.h"
+#include "diagnostic-core.h"
/* Number of instrumented memory accesses in the current function. */
@@ -500,6 +501,11 @@ instrument_builtin_call (gimple_stmt_iterator *gsi)
continue;
else
{
+ if (fcode == BUILT_IN_ATOMIC_THREAD_FENCE)
+ warning_at (gimple_location (stmt), OPT_Wtsan,
+ "%qs is not supported with %qs", "atomic_thread_fence",
+ "-fsanitize=thread");
+
tree decl = builtin_decl_implicit (tsan_atomic_table[i].tsan_fcode);
if (decl == NULL_TREE)
return;
--
GitLab