[PATCH][PR sanitizer/64354] Define __SANITIZE_THREAD__ and __SANITIZE_UNDEFINED__ macros if corresponding switches are enabled.

[Maxim Ostapenko <m dot ostapenko at samsung dot com>]

Hi,

when compiling with -fsanitize=address we define __SANITIZE_ADDRESS__ 
macros, but we don't do this for -fsanitize=thread and 
-fsanitize=undefined. Perhaps we should be more symmetric here and 
define corresponding __SANITIZE_THREAD__ and __SANITIZE_UNDEFINED__ 
macros respectively?

I added two simple test cases to c-c++-common/{ub, t}san/ directories 
that just verify if __SANITIZE_THREAD__ (__SANITIZE_UNDEFINED__) is 
defined. Is that a proper way how we check that the macros defined 
correctly? Does this patch looks reasonable?

-Maxim

gcc/ChangeLog:

2016-05-19  Maxim Ostapenko  <m.ostapenko@samsung.com>

	PR sanitizer/64354
	* cppbuiltin.c (define_builtin_macros_for_compilation_flags): Add new
	builtin __SANITIZE_THREAD__ and __SANITIZE_UNDEFINED__ macros for
	-fsanitize=thread and -fsanitize=undefined switches respectively.
	* doc/cpp.texi: Document new macros.

gcc/testsuite/ChangeLog:

2016-05-19  Maxim Ostapenko  <m.ostapenko@samsung.com>

	PR sanitizer/64354
	* c-c++-common/tsan/sanitize-thread-macro.c: New test.
	* c-c++-common/ubsan/sanitize-undefined-macro.c: Likewise.

diff --git a/gcc/cppbuiltin.c b/gcc/cppbuiltin.c
index 6d494ad..8fd0723 100644
--- a/gcc/cppbuiltin.c
+++ b/gcc/cppbuiltin.c
@@ -92,6 +92,12 @@ define_builtin_macros_for_compilation_flags (cpp_reader *pfile)
   if (flag_sanitize & SANITIZE_ADDRESS)
     cpp_define (pfile, "__SANITIZE_ADDRESS__");
 
+  if (flag_sanitize & SANITIZE_THREAD)
+    cpp_define (pfile, "__SANITIZE_THREAD__");
+
+  if (flag_sanitize & SANITIZE_UNDEFINED)
+    cpp_define (pfile, "__SANITIZE_UNDEFINED__");
+
   if (optimize_size)
     cpp_define (pfile, "__OPTIMIZE_SIZE__");
   if (optimize)
diff --git a/gcc/doc/cpp.texi b/gcc/doc/cpp.texi
index 9f914b2..965795b 100644
--- a/gcc/doc/cpp.texi
+++ b/gcc/doc/cpp.texi
@@ -2362,6 +2362,12 @@ in use.
 This macro is defined, with value 1, when @option{-fsanitize=address}
 or @option{-fsanitize=kernel-address} are in use.
 
+@item __SANITIZE_THREAD__
+This macro is defined, with value 1, when @option{-fsanitize=thread} is in use.
+
+@item __SANITIZE_UNDEFINED__
+This macro is defined, with value 1, when @option{-fsanitize=undefined} is in use.
+
 @item __TIMESTAMP__
 This macro expands to a string constant that describes the date and time
 of the last modification of the current source file. The string constant
diff --git a/gcc/testsuite/c-c++-common/tsan/sanitize-thread-macro.c b/gcc/testsuite/c-c++-common/tsan/sanitize-thread-macro.c
new file mode 100644
index 0000000..2b8a840
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/tsan/sanitize-thread-macro.c
@@ -0,0 +1,12 @@
+/* Check that -fsanitize=thread options defines __SANITIZE_THREAD__ macros.  */
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O0" } } */
+
+int
+main ()
+{
+#ifndef __SANITIZE_THREAD__
+  bad construction
+#endif
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/ubsan/sanitize-undefined-macro.c b/gcc/testsuite/c-c++-common/ubsan/sanitize-undefined-macro.c
new file mode 100644
index 0000000..7461324
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/sanitize-undefined-macro.c
@@ -0,0 +1,13 @@
+/* Check that -fsanitize=undefined options defines __SANITIZE_UNDEFINED__ macros.  */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=undefined" } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O0" } } */
+
+int
+main ()
+{
+#ifndef __SANITIZE_UNDEFINED__
+  bad construction
+#endif
+  return 0;
+}