Eric Blake wrote:
> --- a/lib/unistd.in.h
> +++ b/lib/unistd.in.h
> @@ -33,10 +33,17 @@
> #include <stddef.h>
>
> /* mingw doesn't define the SEEK_* or *_FILENO macros in <unistd.h>. */
> -#if !(defined SEEK_CUR && defined SEEK_END && defined SEEK_SET)
> +/* Cygwin 1.7.1 declares symlinkat in <stdio.h>, not in <unistd.h>. */
> +#if (!(defined SEEK_CUR && defined SEEK_END && defined SEEK_SET) \
> + || @GNULIB_SYMLINKAT@)
> # include <stdio.h>
> #endif
>
> +/* Cygwin 1.7.1 declares unlinkat in <fcntl.h>, not in <unistd.h>. */
> +#if @GNULIB_UNLINKAT@
> +# include <fcntl.h>
> +#endif
Hmm, I'm not so happy to see additional headers being included, even on
glibc systems. This "namespace pollution" has the effect that a developer
will, for example, write code that does
#include <unistd.h>
... { printf (...); }
and get no error because <unistd.h> happens to drag in <stdio.h>. It's
not possible to avoid all possible #include on all platforms - gnulib
provides them precisely because they are necessary on some platforms -,
but for glibc systems, where most developers write and test their programs,
I can make an extra effort to exclude unnecessary headers.
In fact, one example of such a mistake is already present in lib/fcntl.c.
Applying this:
2009-12-24 Bruno Haible <br...@clisp.org>
Reduce namespace pollution on glibc systems.
* lib/inttypes.in.h: Don't include <stdint.h> on glibc systems.
* lib/stdlib.in.h: Don't include <stdint.h>, <unistd.h> on glibc
systems.
* lib/unistd.in.h: Don't include <stdio.h>, <fcntl.h>, <stdlib.h>,
<getopt.h> on glibc systems.
* lib/fcntl.in.h: Don't include <sys/stat.h>, <unistd.h> on glibc
systems.
* lib/fcntl.c: Include <unistd.h> here instead.
--- lib/inttypes.in.h.orig Thu Dec 24 16:57:08 2009
+++ lib/inttypes.in.h Thu Dec 24 16:54:49 2009
@@ -36,8 +36,11 @@
#if ! defined INTTYPES_H && ! defined _GL_JUST_INCLUDE_SYSTEM_INTTYPES_H
#define INTTYPES_H
-/* Include <stdint.h> or the gnulib replacement. */
-#include <stdint.h>
+/* Include <stdint.h> or the gnulib replacement.
+ But avoid namespace pollution on glibc systems. */
+#ifndef __GLIBC__
+# include <stdint.h>
+#endif
/* Get CHAR_BIT. */
#include <limits.h>
--- lib/stdlib.in.h.orig Thu Dec 24 16:57:09 2009
+++ lib/stdlib.in.h Thu Dec 24 16:55:51 2009
@@ -49,8 +49,8 @@
# include <random.h>
#endif
-#if (@GNULIB_RANDOM_R@ || !...@have_struct_random_data@ \
- || defined GNULIB_POSIXCHECK)
+#if !...@have_struct_random_data@ || (@GNULIB_RANDOM_R@ &&
!...@have_random_r@) \
+ || defined GNULIB_POSIXCHECK
# include <stdint.h>
#endif
@@ -67,9 +67,10 @@
};
#endif
-#if @GNULIB_MKSTEMP@ || @GNULIB_GETSUBOPT@ || defined GNULIB_POSIXCHECK
+#if (@GNULIB_MKSTEMP@ || @GNULIB_GETSUBOPT@ || defined GNULIB_POSIXCHECK) && !
defined __GLIBC__
/* On MacOS X 10.3, only <unistd.h> declares mkstemp. */
/* On Cygwin 1.7.1, only <unistd.h> declares getsubopt. */
+/* But avoid namespace pollution on glibc systems. */
# include <unistd.h>
#endif
--- lib/unistd.in.h.orig Thu Dec 24 16:57:09 2009
+++ lib/unistd.in.h Thu Dec 24 16:56:52 2009
@@ -34,20 +34,26 @@
/* mingw doesn't define the SEEK_* or *_FILENO macros in <unistd.h>. */
/* Cygwin 1.7.1 declares symlinkat in <stdio.h>, not in <unistd.h>. */
+/* But avoid namespace pollution on glibc systems. */
#if (!(defined SEEK_CUR && defined SEEK_END && defined SEEK_SET) \
- || @GNULIB_SYMLINKAT@ || defined GNULIB_POSIXCHECK)
+ || (@GNULIB_SYMLINKAT@ || defined GNULIB_POSIXCHECK)) \
+ && ! defined __GLIBC__
# include <stdio.h>
#endif
/* Cygwin 1.7.1 declares unlinkat in <fcntl.h>, not in <unistd.h>. */
-#if @GNULIB_UNLINKAT@ || defined GNULIB_POSIXCHECK
+/* But avoid namespace pollution on glibc systems. */
+#if (@GNULIB_UNLINKAT@ || defined GNULIB_POSIXCHECK) && ! defined __GLIBC__
# include <fcntl.h>
#endif
/* mingw fails to declare _exit in <unistd.h>. */
/* mingw, BeOS, Haiku declare environ in <stdlib.h>, not in <unistd.h>. */
/* Solaris declares getcwd not only in <unistd.h> but also in <stdlib.h>. */
-#include <stdlib.h>
+/* But avoid namespace pollution on glibc systems. */
+#ifndef __GLIBC__
+# include <stdlib.h>
+#endif
/* mingw declares getcwd in <io.h>, not in <unistd.h>. */
#if ((@GNULIB_GETCWD@ || defined GNULIB_POSIXCHECK) \
@@ -63,8 +69,9 @@
# include <sys/types.h>
#endif
-/* Get getopt(), optarg, optind, opterr, optopt. */
-#if @GNULIB_UNISTD_H_GETOPT@ && !defined _GL_SYSTEM_GETOPT
+/* Get getopt(), optarg, optind, opterr, optopt.
+ But avoid namespace pollution on glibc systems. */
+#if @GNULIB_UNISTD_H_GETOPT@ && !defined __GLIBC__ && !defined
_GL_SYSTEM_GETOPT
# include <getopt.h>
#endif
--- lib/fcntl.in.h.orig Thu Dec 24 16:57:08 2009
+++ lib/fcntl.in.h Thu Dec 24 16:54:17 2009
@@ -25,8 +25,10 @@
/* Special invocation convention. */
#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
+#ifndef __GLIBC__ /* Avoid namespace pollution on glibc systems. */
+# include <sys/stat.h>
+# include <unistd.h>
+#endif
#...@include_next@ @NEXT_FCNTL_H@
#else
@@ -35,8 +37,10 @@
#ifndef _GL_FCNTL_H
#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
+#ifndef __GLIBC__ /* Avoid namespace pollution on glibc systems. */
+# include <sys/stat.h>
+# include <unistd.h>
+#endif
/* The include_next requires a split double-inclusion guard. */
#...@include_next@ @NEXT_FCNTL_H@
--- lib/fcntl.c.orig Thu Dec 24 16:57:08 2009
+++ lib/fcntl.c Thu Dec 24 16:43:30 2009
@@ -25,6 +25,7 @@
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
+#include <unistd.h>
#if !HAVE_FCNTL
# define rpl_fcntl fcntl
