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.

diff --git a/gcc/common.opt b/gcc/common.opt
index 6645539f5e52f90f2bc9054de44612c8ac384408..4ab5fe44737d6cefb9cfa06b4617321ec50786d2 100644 (file)
--- 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 2cebe7ab31958c9eda38fcecbb05dde4a18410d3..054b83715934e0b021d83b7e07eded4b91548ccd 100644 (file)
--- 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 (file)
index 0000000..013720c
--- /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 4d6223454b576eb0706b514a2493e48c20c94a15..1bc020e76480a53a363e0e518fa29cedd25ee818 100644 (file)
--- 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;