* NEWS: Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H"

rather than "#if HAVE_STDLIB_H", so that it now works with "gcc
-Wundef -Werror".  Problem reported by David Fang in
<http://lists.gnu.org/archive/html/autoconf/2006-08/msg00045.html>.
* doc/autoconf.texi (Header Templates, Default Includes):
(Particular Functions, Generic Functions, Header Portability):
(Particular Headers, Generic Headers, Generic Declarations, Guidelines):
(Obsolete Macros, AC_FOO_IFELSE vs AC_TRY_FOO):
(Present But Cannot Be Compiled, Preprocessor Symbol Index):
Prefer #ifdef to #if.
* lib/autoconf/c.m4 (AC_C_BIGENDIAN): Prefer #ifdef to #if.
* lib/autoconf/functions.m4 (AC_FUNC_ALLOCA, _AC_FUNC_MALLOC_IF):
(AC_FUNC_MKTIME, AC_FUNC_MMAP, _AC_FUNC_REALLOC_IF):
(AC_FUNC_SELECT_ARGTYPES, AC_FUNC_SETVBUF_REVERSED, _AC_FUNC_VFORK):
Likewise.
* lib/autoconf/headers.m4 (_AC_INCLUDES_DEFAULT_REQUIREMENTS):
(AC_HEADER_RESOLV, AC_HEADER_STAT): Likewise.
* lib/autoconf/specific.m4 (AC_DECL_SYS_SYGLIST):
(AC_SYS_RESTARTABLE_SYSCALLS): Likewise.
* lib/autoconf/types.m4 (AC_STRUCT_TIMEZONE): Likewise.
* lib/autoconf/headers.m4 (AC_HEADER_STAT): Don't assume that
S_ISDIR etc. are valid for use in #if; POSIX doesn't guarantee
this.

diff --git a/ChangeLog b/ChangeLog
index e880163954cf40d06e7ea45a79da7c1cd492304f..770fb02691f237f715f9d9a85a6e57d0ed2158cc 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,29 @@
+2006-08-15  Paul Eggert  <eggert@cs.ucla.edu>
+
+       * NEWS: Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H"
+       rather than "#if HAVE_STDLIB_H", so that it now works with "gcc
+       -Wundef -Werror".  Problem reported by David Fang in
+       <http://lists.gnu.org/archive/html/autoconf/2006-08/msg00045.html>.
+       * doc/autoconf.texi (Header Templates, Default Includes):
+       (Particular Functions, Generic Functions, Header Portability):
+       (Particular Headers, Generic Headers, Generic Declarations, Guidelines):
+       (Obsolete Macros, AC_FOO_IFELSE vs AC_TRY_FOO):
+       (Present But Cannot Be Compiled, Preprocessor Symbol Index):
+       Prefer #ifdef to #if.
+       * lib/autoconf/c.m4 (AC_C_BIGENDIAN): Prefer #ifdef to #if.
+       * lib/autoconf/functions.m4 (AC_FUNC_ALLOCA, _AC_FUNC_MALLOC_IF):
+       (AC_FUNC_MKTIME, AC_FUNC_MMAP, _AC_FUNC_REALLOC_IF):
+       (AC_FUNC_SELECT_ARGTYPES, AC_FUNC_SETVBUF_REVERSED, _AC_FUNC_VFORK):
+       Likewise.
+       * lib/autoconf/headers.m4 (_AC_INCLUDES_DEFAULT_REQUIREMENTS):
+       (AC_HEADER_RESOLV, AC_HEADER_STAT): Likewise.
+       * lib/autoconf/specific.m4 (AC_DECL_SYS_SYGLIST):
+       (AC_SYS_RESTARTABLE_SYSCALLS): Likewise.
+       * lib/autoconf/types.m4 (AC_STRUCT_TIMEZONE): Likewise.
+       * lib/autoconf/headers.m4 (AC_HEADER_STAT): Don't assume that
+       S_ISDIR etc. are valid for use in #if; POSIX doesn't guarantee
+       this.
+
 2006-08-14  Paul Eggert  <eggert@cs.ucla.edu>
 
        * doc/autoconf.texi (Limitations of Usual Tools): Document sed

diff --git a/NEWS b/NEWS
index e6fccd74221e9e7b6a94f30e57deb3cbf20d80a3..711e9a90d7864f16e6c070ce377e3cb53f2ff98d 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,9 @@
 ** GNU M4 1.4.5 or later is now recommended.  At least one "make check"
   test fails with earlier versions of M4.
 
+** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
+  "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
+
 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
   by a public and documented macro, AC_COMPUTE_INT.  The parameters to the
   two macros are different, so autoupdate will not change the old private name

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index fa64191f64677c17d44797f3942df5602401e9e4..7e8ac396782f28737173c2b9caf5c25c6ebe5249 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -3007,7 +3007,7 @@ then decode the configuration header using the preprocessor directives:
 @group
 #include <conf.h>
 
-#if HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #else
 /* We are in trouble.  */
@@ -3508,11 +3508,11 @@ protected includes, such as:
 
 @example
 @group
-#if TIME_WITH_SYS_TIME
+#ifdef TIME_WITH_SYS_TIME
 # include <sys/time.h>
 # include <time.h>
 #else
-# if HAVE_SYS_TIME_H
+# ifdef HAVE_SYS_TIME_H
 #  include <sys/time.h>
 # else
 #  include <time.h>
@@ -3536,36 +3536,36 @@ Expand to @var{include-directives} if defined, otherwise to:
 @example
 @group
 #include <stdio.h>
-#if HAVE_SYS_TYPES_H
+#ifdef HAVE_SYS_TYPES_H
 # include <sys/types.h>
 #endif
-#if HAVE_SYS_STAT_H
+#ifdef HAVE_SYS_STAT_H
 # include <sys/stat.h>
 #endif
-#if STDC_HEADERS
+#ifdef STDC_HEADERS
 # include <stdlib.h>
 # include <stddef.h>
 #else
-# if HAVE_STDLIB_H
+# ifdef HAVE_STDLIB_H
 #  include <stdlib.h>
 # endif
 #endif
-#if HAVE_STRING_H
-# if !STDC_HEADERS && HAVE_MEMORY_H
+#ifdef HAVE_STRING_H
+# if !defined STDC_HEADERS && defined HAVE_MEMORY_H
 #  include <memory.h>
 # endif
 # include <string.h>
 #endif
-#if HAVE_STRINGS_H
+#ifdef HAVE_STRINGS_H
 # include <strings.h>
 #endif
-#if HAVE_INTTYPES_H
+#ifdef HAVE_INTTYPES_H
 # include <inttypes.h>
 #endif
-#if HAVE_STDINT_H
+#ifdef HAVE_STDINT_H
 # include <stdint.h>
 #endif
-#if HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
 @end group
@@ -4346,7 +4346,7 @@ like the following, to declare it properly.
 
 @example
 @group
-#if HAVE_ALLOCA_H
+#ifdef HAVE_ALLOCA_H
 # include <alloca.h>
 #elif defined __GNUC__
 # define alloca __builtin_alloca
@@ -4455,7 +4455,7 @@ previous versions of @command{autoconf} you're encouraged to define it
 yourself in new code:
 @example
 @group
-#if !HAVE_WORKING_VFORK
+#ifndef HAVE_WORKING_VFORK
 # define vfork fork
 #endif
 @end group
@@ -4567,7 +4567,7 @@ systems, you must pass 0 to @code{getpgrp}, as it takes an argument and
 behaves like Posix's @code{getpgid}.
 
 @example
-#if GETPGRP_VOID
+#ifdef GETPGRP_VOID
   pid = getpgrp ();
 #else
   pid = getpgrp (0);
@@ -4617,7 +4617,7 @@ Typically, the replacement file @file{malloc.c} should look like (note
 the @samp{#undef malloc}):
 
 @verbatim
-#if HAVE_CONFIG_H
+#ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
 #undef malloc
@@ -5024,7 +5024,7 @@ a convenient shorthand.
 @ovindex LIBOBJS
 Like @code{AC_CHECK_FUNCS}, but uses @samp{AC_LIBOBJ(@var{function})} as
 @var{action-if-not-found}.  You can declare your replacement function by
-enclosing the prototype in @samp{#if !HAVE_@var{function}}.  If the
+enclosing the prototype in @samp{#ifndef HAVE_@var{function}}.  If the
 system has the function, it probably declares it in a header file you
 should be including, so you shouldn't redeclare it lest your declaration
 conflict.
@@ -5089,15 +5089,15 @@ beforehand.  One should run:
 AC_CHECK_HEADERS([sys/socket.h])
 AC_CHECK_HEADERS([net/if.h], [], [],
 [#include <stdio.h>
-#if STDC_HEADERS
+#ifdef STDC_HEADERS
 # include <stdlib.h>
 # include <stddef.h>
 #else
-# if HAVE_STDLIB_H
+# ifdef HAVE_STDLIB_H
 #  include <stdlib.h>
 # endif
 #endif
-#if HAVE_SYS_SOCKET_H
+#ifdef HAVE_SYS_SOCKET_H
 # include <sys/socket.h>
 #endif
 ])
@@ -5112,15 +5112,15 @@ On Darwin, this file requires that @file{stdio.h} and
 AC_CHECK_HEADERS([sys/socket.h])
 AC_CHECK_HEADERS([netinet/if_ether.h], [], [],
 [#include <stdio.h>
-#if STDC_HEADERS
+#ifdef STDC_HEADERS
 # include <stdlib.h>
 # include <stddef.h>
 #else
-# if HAVE_STDLIB_H
+# ifdef HAVE_STDLIB_H
 #  include <stdlib.h>
 # endif
 #endif
-#if HAVE_SYS_SOCKET_H
+#ifdef HAVE_SYS_SOCKET_H
 # include <sys/socket.h>
 #endif
 ])
@@ -5210,13 +5210,13 @@ something like the following:
 #else
 # define dirent direct
 # define NAMLEN(dirent) ((dirent)->d_namlen)
-# if HAVE_SYS_NDIR_H
+# ifdef HAVE_SYS_NDIR_H
 #  include <sys/ndir.h>
 # endif
-# if HAVE_SYS_DIR_H
+# ifdef HAVE_SYS_DIR_H
 #  include <sys/dir.h>
 # endif
-# if HAVE_NDIR_H
+# ifdef HAVE_NDIR_H
 #  include <ndir.h>
 # endif
 #endif
@@ -5258,7 +5258,7 @@ To properly use @file{resolv.h}, your code should contain something like
 the following:
 
 @verbatim
-#if HAVE_SYS_TYPES_H
+#ifdef HAVE_SYS_TYPES_H
 #  include <sys/types.h>
 #endif
 #ifdef HAVE_NETINET_IN_H
@@ -5299,10 +5299,10 @@ If @file{stdbool.h} exists and conforms to C99, define
 @file{system.h} could contain the following code:
 
 @verbatim
-#if HAVE_STDBOOL_H
+#ifdef HAVE_STDBOOL_H
 # include <stdbool.h>
 #else
-# if ! HAVE__BOOL
+# ifndef HAVE__BOOL
 #  ifdef __cplusplus
 typedef bool _Bool;
 #  else
@@ -5383,15 +5383,15 @@ then, in your code, you can use declarations like this:
 @group
 /* This example is obsolescent.
    Nowadays you can just #include <string.h>.  */
-#if STDC_HEADERS
+#ifdef STDC_HEADERS
 # include <string.h>
 #else
-# if !HAVE_STRCHR
+# ifndef HAVE_STRCHR
 #  define strchr index
 #  define strrchr rindex
 # endif
 char *strchr (), *strrchr ();
-# if !HAVE_MEMCPY
+# ifndef HAVE_MEMCPY
 #  define memcpy(d, s, n) bcopy ((s), (d), (n))
 #  define memmove(d, s, n) bcopy ((s), (d), (n))
 # endif
@@ -5425,7 +5425,7 @@ example:
 @example
 @group
 #include <sys/types.h>
-#if HAVE_SYS_WAIT_H
+#ifdef HAVE_SYS_WAIT_H
 # include <sys/wait.h>
 #endif
 #ifndef WEXITSTATUS
@@ -5453,7 +5453,7 @@ The way to check whether the system supports Posix is:
 
 @example
 @group
-#if HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 # include <sys/types.h>
 # include <unistd.h>
 #endif
@@ -5481,11 +5481,11 @@ example, @code{struct timeval} as well as
 
 @example
 @group
-#if TIME_WITH_SYS_TIME
+#ifdef TIME_WITH_SYS_TIME
 # include <sys/time.h>
 # include <time.h>
 #else
-# if HAVE_SYS_TIME_H
+# ifdef HAVE_SYS_TIME_H
 #  include <sys/time.h>
 # else
 #  include <time.h>
@@ -5514,11 +5514,11 @@ Use:
 
 @example
 @group
-#if HAVE_TERMIOS_H
+#ifdef HAVE_TERMIOS_H
 # include <termios.h>
 #endif
 
-#if GWINSZ_IN_SYS_IOCTL
+#ifdef GWINSZ_IN_SYS_IOCTL
 # include <sys/ioctl.h>
 #endif
 @end group
@@ -5578,7 +5578,7 @@ scheme:
 @verbatim
 AC_CHECK_HEADERS([foo.h])
 AC_CHECK_HEADERS([bar.h], [], [],
-[#if HAVE_FOO_H
+[#ifdef HAVE_FOO_H
 # include <foo.h>
 # endif
 ])
@@ -5659,7 +5659,7 @@ Unlike the other @samp{AC_CHECK_*S} macros, when a @var{symbol} is not
 declared, @code{HAVE_DECL_@var{symbol}} is defined to @samp{0} instead
 of leaving @code{HAVE_DECL_@var{symbol}} undeclared.  When you are
 @emph{sure} that the check was performed, use
-@code{HAVE_DECL_@var{symbol}} just like any other result of Autoconf:
+@code{HAVE_DECL_@var{symbol}} in @code{#if}:
 
 @example
 #if !HAVE_DECL_SYMBOL
@@ -7567,12 +7567,18 @@ example, if you call @code{AC_HEADER_STDBOOL}, then later on in
 
 @example
 @group
-#if HAVE_STDBOOL_H
+#ifdef HAVE_STDBOOL_H
 # include <stdbool.h>
 #endif
 @end group
 @end example
 
+Both @code{#if HAVE_STDBOOL_H} and @code{#ifdef HAVE_STDBOOL_H} will
+work with any standard C compiler.  Some developers prefer @code{#if}
+because it is easier to read, while others prefer @code{#ifdef} because
+it avoids diagnostics with picky compilers like @acronym{GCC} with the
+@option{-Wundef} option.
+
 If a test program needs to use or create a data file, give it a name
 that starts with @file{conftest}, such as @file{conftest.data}.  The
 @command{configure} script cleans up by running @samp{rm -f -r conftest*}
@@ -16315,7 +16321,7 @@ equivalent modern code (see above), or better yet, to use
 @code{AC_CHECK_TYPES} together with
 
 @example
-#if !HAVE_LOFF_T
+#ifndef HAVE_LOFF_T
 typedef loff_t off_t;
 #endif
 @end example
@@ -16377,7 +16383,7 @@ Same as:
 AC_CHECK_DECLS([sys_siglist], [], [],
 [#include <signal.h>
 /* NetBSD declares sys_siglist in unistd.h.  */
-#if HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
 ])
@@ -17671,7 +17677,7 @@ The above example, properly written would (i) use
 @example
 @group
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
-[[#if !defined _AIX
+[[#ifndef _AIX
  error: This isn't AIX!
 #endif
 ]])],
@@ -18643,7 +18649,7 @@ The proper way the handle this case is using the fourth argument
 $ @kbd{cat configure.ac}
 AC_INIT([Example], [1.0], [bug-example@@example.org])
 AC_CHECK_HEADERS([number.h pi.h], [], [],
-[[#if HAVE_NUMBER_H
+[[#ifdef HAVE_NUMBER_H
 # include <number.h>
 #endif
 ]])
@@ -18921,7 +18927,7 @@ on how this is done.
 
 This is an alphabetical list of the C preprocessor symbols that the
 Autoconf macros define.  To work with Autoconf, C source code needs to
-use these names in @code{#if} directives.
+use these names in @code{#if} or @code{#ifdef} directives.
 
 @printindex cv
 

diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index dead340b40a85bb8f9ccc448d4919d6e7601117f..84047d15fcd2c13c1468fedb76a0bb2b957fc76f 100644 (file)
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -1316,7 +1316,8 @@ AC_DEFUN([AC_C_BIGENDIAN],
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <sys/types.h>
 #include <sys/param.h>
 ],
-[#if !BYTE_ORDER || !BIG_ENDIAN || !LITTLE_ENDIAN
+[#if  ! (defined BYTE_ORDER && defined BIG_ENDIAN && defined LITTLE_ENDIAN \
+       && BYTE_ORDER && BIG_ENDIAN && LITTLE_ENDIAN)
  bogus endian macros
 #endif
 ])],

diff --git a/lib/autoconf/functions.m4 b/lib/autoconf/functions.m4
index 3ad6b624b582f25f87d351d958b808cb5332fb6b..b4d37c739afc384bf59737730c74f92604dd94fa 100644 (file)
--- a/lib/autoconf/functions.m4
+++ b/lib/autoconf/functions.m4
@@ -370,7 +370,7 @@ AC_CACHE_CHECK([for alloca], ac_cv_func_alloca_works,
 #  include <malloc.h>
 #  define alloca _alloca
 # else
-#  if HAVE_ALLOCA_H
+#  ifdef HAVE_ALLOCA_H
 #   include <alloca.h>
 #  else
 #   ifdef _AIX
@@ -875,7 +875,7 @@ AC_CHECK_HEADERS(stdlib.h)
 AC_CACHE_CHECK([for GNU libc compatible malloc], ac_cv_func_malloc_0_nonnull,
 [AC_RUN_IFELSE(
 [AC_LANG_PROGRAM(
-[[#if STDC_HEADERS || HAVE_STDLIB_H
+[[#if defined STDC_HEADERS || defined HAVE_STDLIB_H
 # include <stdlib.h>
 #else
 char *malloc ();
@@ -977,26 +977,26 @@ AC_CHECK_FUNCS(alarm)
 AC_CACHE_CHECK([for working mktime], ac_cv_func_working_mktime,
 [AC_RUN_IFELSE([AC_LANG_SOURCE(
 [[/* Test program from Paul Eggert and Tony Leneis.  */
-#if TIME_WITH_SYS_TIME
+#ifdef TIME_WITH_SYS_TIME
 # include <sys/time.h>
 # include <time.h>
 #else
-# if HAVE_SYS_TIME_H
+# ifdef HAVE_SYS_TIME_H
 #  include <sys/time.h>
 # else
 #  include <time.h>
 # endif
 #endif
 
-#if HAVE_STDLIB_H
+#ifdef HAVE_STDLIB_H
 # include <stdlib.h>
 #endif
 
-#if HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
 
-#if !HAVE_ALARM
+#ifndef HAVE_ALARM
 # define alarm(X) /* empty */
 #endif
 
@@ -1186,21 +1186,21 @@ AC_CACHE_CHECK(for working mmap, ac_cv_func_mmap_fixed_mapped,
 #include <fcntl.h>
 #include <sys/mman.h>
 
-#if !STDC_HEADERS && !HAVE_STDLIB_H
+#if !defined STDC_HEADERS && !defined HAVE_STDLIB_H
 char *malloc ();
 #endif
 
 /* This mess was copied from the GNU getpagesize.h.  */
-#if !HAVE_GETPAGESIZE
+#ifndef HAVE_GETPAGESIZE
 /* Assume that all systems that can run configure have sys/param.h.  */
-# if !HAVE_SYS_PARAM_H
+# ifndef HAVE_SYS_PARAM_H
 #  define HAVE_SYS_PARAM_H 1
 # endif
 
 # ifdef _SC_PAGESIZE
 #  define getpagesize() sysconf(_SC_PAGESIZE)
 # else /* no _SC_PAGESIZE */
-#  if HAVE_SYS_PARAM_H
+#  ifdef HAVE_SYS_PARAM_H
 #   include <sys/param.h>
 #   ifdef EXEC_PAGESIZE
 #    define getpagesize() EXEC_PAGESIZE
@@ -1335,7 +1335,7 @@ AC_CHECK_HEADERS(stdlib.h)
 AC_CACHE_CHECK([for GNU libc compatible realloc], ac_cv_func_realloc_0_nonnull,
 [AC_RUN_IFELSE(
 [AC_LANG_PROGRAM(
-[[#if STDC_HEADERS || HAVE_STDLIB_H
+[[#if defined STDC_HEADERS || defined HAVE_STDLIB_H
 # include <stdlib.h>
 #else
 char *realloc ();
@@ -1382,10 +1382,10 @@ AC_CACHE_CHECK([types of arguments for select],
    AC_COMPILE_IFELSE(
        [AC_LANG_PROGRAM(
 [AC_INCLUDES_DEFAULT
-#if HAVE_SYS_SELECT_H
+#ifdef HAVE_SYS_SELECT_H
 # include <sys/select.h>
 #endif
-#if HAVE_SYS_SOCKET_H
+#ifdef HAVE_SYS_SOCKET_H
 # include <sys/socket.h>
 #endif
 ],
@@ -1655,14 +1655,14 @@ AC_CACHE_CHECK(whether setvbuf arguments are reversed,
    AC_LINK_IFELSE(
      [AC_LANG_PROGRAM(
        [[#include <stdio.h>
-#        if PROTOTYPES
+#        ifdef PROTOTYPES
           int (setvbuf) (FILE *, int, char *, size_t);
 #        endif]],
        [[char buf; return setvbuf (stdout, _IOLBF, &buf, 1);]])],
      [AC_LINK_IFELSE(
        [AC_LANG_PROGRAM(
           [[#include <stdio.h>
-#           if PROTOTYPES
+#           ifdef PROTOTYPES
              int (setvbuf) (FILE *, int, char *, size_t);
 #           endif]],
           [[char buf; return setvbuf (stdout, &buf, _IOLBF, 1);]])],
@@ -1822,7 +1822,7 @@ AC_DEFUN([_AC_FUNC_VFORK],
 [AC_RUN_IFELSE([AC_LANG_SOURCE([[/* Thanks to Paul Eggert for this test.  */
 ]AC_INCLUDES_DEFAULT[
 #include <sys/wait.h>
-#if HAVE_VFORK_H
+#ifdef HAVE_VFORK_H
 # include <vfork.h>
 #endif
 /* On some sparc systems, changes by the child to local and incoming

diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4
index af8fb4980e5b5ac576d011cd364fceb47d737603..0bbb3a8bb96d70c7242f93ee10d2eca065c13f79 100644 (file)
--- a/lib/autoconf/headers.m4
+++ b/lib/autoconf/headers.m4
@@ -243,36 +243,36 @@ AC_DEFUN([_AC_INCLUDES_DEFAULT_REQUIREMENTS],
 dnl If ever you change this variable, please keep autoconf.texi in sync.
 ac_includes_default="\
 #include <stdio.h>
-#if HAVE_SYS_TYPES_H
+#ifdef HAVE_SYS_TYPES_H
 # include <sys/types.h>
 #endif
-#if HAVE_SYS_STAT_H
+#ifdef HAVE_SYS_STAT_H
 # include <sys/stat.h>
 #endif
-#if STDC_HEADERS
+#ifdef STDC_HEADERS
 # include <stdlib.h>
 # include <stddef.h>
 #else
-# if HAVE_STDLIB_H
+# ifdef HAVE_STDLIB_H
 #  include <stdlib.h>
 # endif
 #endif
-#if HAVE_STRING_H
-# if !STDC_HEADERS && HAVE_MEMORY_H
+#ifdef HAVE_STRING_H
+# if !defined STDC_HEADERS && defined HAVE_MEMORY_H
 #  include <memory.h>
 # endif
 # include <string.h>
 #endif
-#if HAVE_STRINGS_H
+#ifdef HAVE_STRINGS_H
 # include <strings.h>
 #endif
-#if HAVE_INTTYPES_H
+#ifdef HAVE_INTTYPES_H
 # include <inttypes.h>
 #endif
-#if HAVE_STDINT_H
+#ifdef HAVE_STDINT_H
 # include <stdint.h>
 #endif
-#if HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif"
 ])dnl
@@ -483,7 +483,7 @@ AN_HEADER(resolv.h, [AC_HEADER_RESOLV])
 AC_DEFUN([AC_HEADER_RESOLV],
 [AC_CHECK_HEADERS(sys/types.h netinet/in.h arpa/nameser.h netdb.h resolv.h,
                  [], [],
-[[#if HAVE_SYS_TYPES_H
+[[#ifdef HAVE_SYS_TYPES_H
 #  include <sys/types.h>
 #endif
 #ifdef HAVE_NETINET_IN_H
@@ -511,33 +511,25 @@ AN_IDENTIFIER([S_ISSOCK], [AC_HEADER_STAT])
 AC_DEFUN([AC_HEADER_STAT],
 [AC_CACHE_CHECK(whether stat file-mode macros are broken,
   ac_cv_header_stat_broken,
-[AC_EGREP_CPP([You lose], [#include <sys/types.h>
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#include <sys/types.h>
 #include <sys/stat.h>
 
 #if defined S_ISBLK && defined S_IFDIR
-# if S_ISBLK (S_IFDIR)
-You lose.
-# endif
+extern char c1[S_ISBLK (S_IFDIR) ? -1 : 1];
 #endif
 
 #if defined S_ISBLK && defined S_IFCHR
-# if S_ISBLK (S_IFCHR)
-You lose.
-# endif
+extern char c2[S_ISBLK (S_IFCHR) ? -1 : 1];
 #endif
 
 #if defined S_ISLNK && defined S_IFREG
-# if S_ISLNK (S_IFREG)
-You lose.
-# endif
+extern char c3[S_ISLNK (S_IFREG) ? -1 : 1];
 #endif
 
 #if defined S_ISSOCK && defined S_IFREG
-# if S_ISSOCK (S_IFREG)
-You lose.
-# endif
+extern char c4[S_ISSOCK (S_IFREG) ? -1 : 1];
 #endif
-], ac_cv_header_stat_broken=yes, ac_cv_header_stat_broken=no)])
+]])], ac_cv_header_stat_broken=yes, ac_cv_header_stat_broken=no)])
 if test $ac_cv_header_stat_broken = yes; then
   AC_DEFINE(STAT_MACROS_BROKEN, 1,
            [Define to 1 if the `S_IS*' macros in <sys/stat.h> do not

diff --git a/lib/autoconf/specific.m4 b/lib/autoconf/specific.m4
index 8a6c6fa226d25e5e8b921663452a1fda998f58df..5b0dee2fc441c428a471a5e9b020b145edc8dd5e 100644 (file)
--- a/lib/autoconf/specific.m4
+++ b/lib/autoconf/specific.m4
@@ -63,7 +63,7 @@ AU_DEFUN([AC_DECL_SYS_SIGLIST],
 [AC_CHECK_DECLS([sys_siglist],,,
 [#include <signal.h>
 /* NetBSD declares sys_siglist in unistd.h.  */
-#if HAVE_UNISTD_H
+#ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
 ])
@@ -256,7 +256,7 @@ AC_CACHE_CHECK(for restartable system calls, ac_cv_sys_restartable_syscalls,
 
 AC_INCLUDES_DEFAULT
 #include <signal.h>
-#if HAVE_SYS_WAIT_H
+#ifdef HAVE_SYS_WAIT_H
 # include <sys/wait.h>
 #endif
 

diff --git a/lib/autoconf/types.m4 b/lib/autoconf/types.m4
index 1c45101ed7e8144e0a352cc649b60e5005fa5ac6..1ec2a8ceeb4cd646f9e360322dfc2bd7ff6f62ff 100644 (file)
--- a/lib/autoconf/types.m4
+++ b/lib/autoconf/types.m4
@@ -949,7 +949,7 @@ else
   AC_CACHE_CHECK(for tzname, ac_cv_var_tzname,
 [AC_LINK_IFELSE([AC_LANG_PROGRAM(
 [[#include <time.h>
-#if !HAVE_DECL_TZNAME
+#ifndef HAVE_DECL_TZNAME
 extern char *tzname[];
 #endif
 ]],