Fix glibc testing with GCC 4.9 compiler

Message ID 1456513887.29579.238.camel@ubuntu-sellcey
State New, archived
Headers

Commit Message

Steve Ellcey Feb. 26, 2016, 7:11 p.m. UTC
  Here is an updated and tested patch that checks to see if the compiler
understands the -Wmemset-transposed-args option or not.  Tested using
the 4.9.2 debian compiler as well as a 4.8 compiler and a ToT compiler.

OK to checkin?

Steve Ellcey
sellcey@imgtec.com


2016-02-26  Steve Ellcey  <sellcey@imgtec.com>

	* config.h.in (HAVE_MEMSET_WARNING): Add undef.
	* configure.ac: Check if compiler understands -Wmemset-transposed-args.
	* configure: Regenerate.
	* string/tester.c (test_memset): Check HAVE_MEMSET_WARNING instead
	of GCC version.
  

Patch

diff --git a/config.h.in b/config.h.in
index 0147ba3..ec672e6 100644
--- a/config.h.in
+++ b/config.h.in
@@ -45,6 +45,9 @@ 
 /* Define if the compiler supports __builtin_memset.  */
 #undef	HAVE_BUILTIN_MEMSET
 
+/* Define if the compiler accepts -Wmemset-transposed-args.  */
+#undef HAVE_MEMSET_WARNING
+
 /* Define if compiler accepts -ftree-loop-distribute-patterns.  */
 #undef  HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
 
diff --git a/configure.ac b/configure.ac
index 3c766b7..21fa353 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1449,6 +1449,13 @@  if test "$libc_cv_gcc_builtin_memset" = yes ; then
   AC_DEFINE(HAVE_BUILTIN_MEMSET)
 fi
 
+AC_CACHE_CHECK(for -Wmemset-transposed-args, libc_cv_memset_warning, [dnl
+LIBC_TRY_CC_OPTION([-Wmemset-transposed-args], [libc_cv_memset_warning=yes], [libc_cv_memset_warning=no])
+])
+if test "$libc_cv_memset_warning" = yes ; then
+  AC_DEFINE(HAVE_MEMSET_WARNING)
+fi
+
 AC_CACHE_CHECK(for redirection of built-in functions, libc_cv_gcc_builtin_redirection, [dnl
 cat > conftest.c <<\EOF
 extern char *strstr (const char *, const char *) __asm ("my_strstr");
diff --git a/string/tester.c b/string/tester.c
index 7c36591..1659693 100644
--- a/string/tester.c
+++ b/string/tester.c
@@ -1305,7 +1305,7 @@  test_memset (void)
   equal(one, "axxxefgh", 2);		/* Basic test. */
 
   DIAG_PUSH_NEEDS_COMMENT;
-#if __GNUC_PREREQ (5, 0)
+#ifdef HAVE_MEMSET_WARNING
   /* GCC 5.0 warns about a zero-length memset because the arguments to memset
      may be in the wrong order.  But we really want to test this.  */
   DIAG_IGNORE_NEEDS_COMMENT (5.0, "-Wmemset-transposed-args")