Split DIAG_* macros to new header libc-diag.h.

Quite a few tests include libc-internal.h just for the DIAG_* macros.
Split those macros to their own file, which can be included safely in
_ISOMAC mode.  I also moved ignore_value, since it seems logically
related, even though I didn't notice any tests needing it.

Also add -Wnonnull suppressions to two tests that _should_ have them,
but the error is masked when compiling against internal headers.

	* include/libc-diag.h: New file.  Define ignore_value,
	DIAG_PUSH_NEEDS_COMMENT, DIAG_POP_NEEDS_COMMENT,
	DIAG_IGNORE_NEEDS_COMMENT, and DIAG_IGNORE_Os_NEEDS_COMMENT here.

	* include/libc-internal.h: Definitions of above macros moved from
	here.  Include libc-diag.h.  Add copyright notice.

	* malloc/tst-malloc.c, malloc/tst-memcheck.c, malloc/tst-realloc.c
	* misc/tst-error1.c, posix/tst-dir.c, stdio-common/bug21.c
	* stdio-common/scanf14.c, stdio-common/scanf4.c, stdio-common/scanf7.c
	* stdio-common/test-vfprintf.c, stdio-common/tst-printf.c
	* stdio-common/tst-printfsz.c, stdio-common/tst-sprintf.c
	* stdio-common/tst-unlockedio.c, stdio-common/tstdiomisc.c
	* stdlib/bug-getcontext.c, string/tester.c, string/tst-endian.c
	* time/tst-strptime2.c, wcsmbs/tst-wcstof.c:
	Include libc-diag.h instead of libc-internal.h.

	* stdlib/tst-environ.c: Include libc-diag.h.  Suppress -Wnonnull for
	call to unsetenv (NULL).
	* nptl/tst-mutex1.c: Include libc-diag.h.  Suppress -Wnonnull for
	call to pthread_mutexattr_destroy (NULL).

ChangeLog

@@ -1,3 +1,27 @@
+2017-02-25  Zack Weinberg  <zackw@panix.com>
+
+	* include/libc-diag.h: New file.  Define ignore_value,
+	DIAG_PUSH_NEEDS_COMMENT, DIAG_POP_NEEDS_COMMENT,
+	DIAG_IGNORE_NEEDS_COMMENT, and DIAG_IGNORE_Os_NEEDS_COMMENT here.
+
+	* include/libc-internal.h: Definitions of above macros moved from
+	here.  Include libc-diag.h.  Add copyright notice.
+
+	* malloc/tst-malloc.c, malloc/tst-memcheck.c, malloc/tst-realloc.c
+	* misc/tst-error1.c, posix/tst-dir.c, stdio-common/bug21.c
+	* stdio-common/scanf14.c, stdio-common/scanf4.c, stdio-common/scanf7.c
+	* stdio-common/test-vfprintf.c, stdio-common/tst-printf.c
+	* stdio-common/tst-printfsz.c, stdio-common/tst-sprintf.c
+	* stdio-common/tst-unlockedio.c, stdio-common/tstdiomisc.c
+	* stdlib/bug-getcontext.c, string/tester.c, string/tst-endian.c
+	* time/tst-strptime2.c, wcsmbs/tst-wcstof.c:
+	Include libc-diag.h instead of libc-internal.h.
+
+	* stdlib/tst-environ.c: Include libc-diag.h.  Suppress -Wnonnull for
+	call to unsetenv (NULL).
+	* nptl/tst-mutex1.c: Include libc-diag.h.  Suppress -Wnonnull for
+	call to pthread_mutexattr_destroy (NULL).
+
 2017-02-25  Zack Weinberg  <zackw@panix.com>
 
 	* include/features.h (__GLIBC_USE_DEPRECATED_GETS): New macro.

include/libc-diag.h

@@ -0,0 +1,74 @@
+/* Macros for controlling diagnostic output from the compiler.
+   Copyright (C) 2014-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _LIBC_DIAG_H
+#define _LIBC_DIAG_H 1
+
+/* Ignore the value of an expression when a cast to void does not
+   suffice (in particular, for a call to a function declared with
+   attribute warn_unused_result).  */
+#define ignore_value(x) \
+  ({ __typeof__ (x) __ignored_value = (x); (void) __ignored_value; })
+
+/* The macros to control diagnostics are structured like this, rather
+   than a single macro that both pushes and pops diagnostic state and
+   takes the affected code as an argument, because the GCC pragmas
+   work by disabling the diagnostic for a range of source locations
+   and do not work when all the pragmas and the affected code are in a
+   single macro expansion.  */
+
+/* Push diagnostic state.  */
+#define DIAG_PUSH_NEEDS_COMMENT _Pragma ("GCC diagnostic push")
+
+/* Pop diagnostic state.  */
+#define DIAG_POP_NEEDS_COMMENT _Pragma ("GCC diagnostic pop")
+
+#define _DIAG_STR1(s) #s
+#define _DIAG_STR(s) _DIAG_STR1(s)
+
+/* Ignore the diagnostic OPTION.  VERSION is the most recent GCC
+   version for which the diagnostic has been confirmed to appear in
+   the absence of the pragma (in the form MAJOR.MINOR for GCC 4.x,
+   just MAJOR for GCC 5 and later).  Uses of this pragma should be
+   reviewed when the GCC version given is no longer supported for
+   building glibc; the version number should always be on the same
+   source line as the macro name, so such uses can be found with grep.
+   Uses should come with a comment giving more details of the
+   diagnostic, and an architecture on which it is seen if possibly
+   optimization-related and not in architecture-specific code.  This
+   macro should only be used if the diagnostic seems hard to fix (for
+   example, optimization-related false positives).  */
+#define DIAG_IGNORE_NEEDS_COMMENT(version, option)     \
+  _Pragma (_DIAG_STR (GCC diagnostic ignored option))
+
+/* Similar to DIAG_IGNORE_NEEDS_COMMENT the following macro ignores the
+   diagnostic OPTION but only if optimizations for size are enabled.
+   This is required because different warnings may be generated for
+   different optimization levels.  For example a key piece of code may
+   only generate a warning when compiled at -Os, but at -O2 you could
+   still want the warning to be enabled to catch errors.  In this case
+   you would use DIAG_IGNORE_Os_NEEDS_COMMENT to disable the warning
+   only for -Os.  */
+#ifdef __OPTIMIZE_SIZE__
+# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option) \
+  _Pragma (_DIAG_STR (GCC diagnostic ignored option))
+#else
+# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option)
+#endif
+
+#endif /* libc-diag.h */

include/libc-internal.h

@@ -1,5 +1,20 @@
-/* This file contains a number of internal prototype declarations that
-   don't fit anywhere else.  */
+/* Internal prototype declarations that don't fit anywhere else.
+   Copyright (C) 2000-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
 
 #ifndef _LIBC_INTERNAL
 # define _LIBC_INTERNAL 1
@@ -74,56 +89,6 @@ extern __typeof (__profile_frequency) __profile_frequency attribute_hidden;
 #define PTR_ALIGN_UP(base, size) \
   ((__typeof__ (base)) ALIGN_UP ((uintptr_t) (base), (size)))
 
-/* Ignore the value of an expression when a cast to void does not
-   suffice (in particular, for a call to a function declared with
-   attribute warn_unused_result).  */
-#define ignore_value(x) \
-  ({ __typeof__ (x) __ignored_value = (x); (void) __ignored_value; })
-
-/* The macros to control diagnostics are structured like this, rather
-   than a single macro that both pushes and pops diagnostic state and
-   takes the affected code as an argument, because the GCC pragmas
-   work by disabling the diagnostic for a range of source locations
-   and do not work when all the pragmas and the affected code are in a
-   single macro expansion.  */
-
-/* Push diagnostic state.  */
-#define DIAG_PUSH_NEEDS_COMMENT _Pragma ("GCC diagnostic push")
-
-/* Pop diagnostic state.  */
-#define DIAG_POP_NEEDS_COMMENT _Pragma ("GCC diagnostic pop")
-
-#define _DIAG_STR1(s) #s
-#define _DIAG_STR(s) _DIAG_STR1(s)
-
-/* Ignore the diagnostic OPTION.  VERSION is the most recent GCC
-   version for which the diagnostic has been confirmed to appear in
-   the absence of the pragma (in the form MAJOR.MINOR for GCC 4.x,
-   just MAJOR for GCC 5 and later).  Uses of this pragma should be
-   reviewed when the GCC version given is no longer supported for
-   building glibc; the version number should always be on the same
-   source line as the macro name, so such uses can be found with grep.
-   Uses should come with a comment giving more details of the
-   diagnostic, and an architecture on which it is seen if possibly
-   optimization-related and not in architecture-specific code.  This
-   macro should only be used if the diagnostic seems hard to fix (for
-   example, optimization-related false positives).  */
-#define DIAG_IGNORE_NEEDS_COMMENT(version, option)	\
-  _Pragma (_DIAG_STR (GCC diagnostic ignored option))
-
-/* Similar to DIAG_IGNORE_NEEDS_COMMENT the following macro ignores the
-   diagnostic OPTION but only if optimizations for size are enabled.
-   This is required because different warnings may be generated for
-   different optimization levels.  For example a key piece of code may
-   only generate a warning when compiled at -Os, but at -O2 you could
-   still want the warning to be enabled to catch errors.  In this case
-   you would use DIAG_IGNORE_Os_NEEDS_COMMENT to disable the warning
-   only for -Os.  */
-#ifdef __OPTIMIZE_SIZE__
-# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option)	\
-  _Pragma (_DIAG_STR (GCC diagnostic ignored option))
-#else
-# define DIAG_IGNORE_Os_NEEDS_COMMENT(version, option)
-#endif
+#include <libc-diag.h>
 
 #endif /* _LIBC_INTERNAL  */

malloc/tst-malloc.c

@@ -19,7 +19,7 @@
 #include <errno.h>
 #include <malloc.h>
 #include <stdio.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int errors = 0;
 

malloc/tst-mcheck.c

@@ -19,7 +19,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int errors = 0;
 

malloc/tst-realloc.c

@@ -19,7 +19,7 @@
 #include <malloc.h>
 #include <stdio.h>
 #include <string.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int errors = 0;
 

misc/tst-error1.c

@@ -3,7 +3,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <wchar.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int
 do_test (int argc, char *argv[])

nptl/tst-mutex1.c

@@ -20,7 +20,7 @@
 #include <stdio.h>
 #include <errno.h>
 #include <stdbool.h>
-
+#include <libc-diag.h>
 
 #ifndef ATTR
 # define ATTR NULL
@@ -45,11 +45,16 @@ do_test (void)
       return 1;
     }
 
+  /* This deliberately tests supplying a null pointer to a function whose
+     argument is marked __attribute__ ((nonnull)). */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (5, "-Wnonnull");
   if (!ATTR_NULL && pthread_mutexattr_destroy (ATTR) != 0)
     {
       puts ("mutexattr_destroy failed");
       return 1;
     }
+  DIAG_POP_NEEDS_COMMENT;
 
   if (pthread_mutex_lock (&m) != 0)
     {

posix/tst-dir.c

@@ -26,7 +26,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/stat.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 /* We expect four arguments:
    - source directory name

stdio-common/bug21.c

@@ -1,5 +1,5 @@
 #include <stdio.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int
 do_test (void)

stdio-common/scanf14.c

@@ -2,7 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <wchar.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 #define FAIL() \
   do {							\

stdio-common/scanf4.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 int
 main(int arc, char *argv[])

stdio-common/scanf7.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 int
 main (int argc, char *argv[])

stdio-common/test-vfprintf.c

@@ -25,7 +25,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/stat.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 
 const char *locs[] =

stdio-common/tst-printf.c

@@ -26,7 +26,7 @@
 #endif
 
 #include <float.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 /* This whole file is picayune tests of corner cases of printf format strings.
    The compiler warnings are not useful here.  */

stdio-common/tst-printfsz.c

@@ -2,7 +2,7 @@
 #include <printf.h>
 #include <stdio.h>
 #include <string.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 #define V       12345678.12345678
 

stdio-common/tst-sprintf.c

@@ -2,7 +2,7 @@
 #include <stdlib.h>
 #include <locale.h>
 #include <string.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 
 static int

stdio-common/tst-unlockedio.c

@@ -20,7 +20,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 int fd;
 static void do_prepare (void);

stdio-common/tstdiomisc.c

@@ -3,7 +3,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <wchar.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int
 t1 (void)

stdlib/bug-getcontext.c

@@ -5,7 +5,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <ucontext.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int
 do_test (void)

stdlib/tst-environ.c

@@ -19,7 +19,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-
+#include <libc-diag.h>
 
 #define VAR "FOOBAR"
 
@@ -196,12 +196,17 @@ do_test (void)
       result = 1;
     }
 
+  /* This deliberately tests supplying a null pointer to a function whose
+     argument is marked __attribute__ ((nonnull)). */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT(5, "-Wnonnull");
   errno = 0;
   if (unsetenv (NULL) >= 0 || errno != EINVAL)
     {
       puts ("unsetenv #1 failed");
       result = 1;
     }
+  DIAG_POP_NEEDS_COMMENT;
 
   errno = 0;
   if (unsetenv ("") >= 0 || errno != EINVAL)

string/tester.c

@@ -32,7 +32,7 @@
 #include <string.h>
 #include <strings.h>
 #include <fcntl.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 
 #define	STREQ(a, b)	(strcmp((a), (b)) == 0)

string/tst-endian.c

@@ -3,7 +3,7 @@
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdint.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 #if __GNUC_PREREQ (6, 0)
 /* GCC 6.0 warns on big endian systems about:

time/tst-strptime2.c

@@ -4,7 +4,7 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <time.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 /* Dummy string is used to match strptime's %s specifier.  */
 

wcsmbs/tst-wcstof.c

@@ -3,7 +3,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <wctype.h>
-#include <libc-internal.h>
+#include <libc-diag.h>
 
 static int
 do_test (void)