Gary V. Vaughan wrote:
> Unfortunately, this compiler and the IBM compiler on aix4.3.3 and aix6.1.0
> (but
> strangely, not 5.1, 5.2 or 5.3) have another peculiar behaviour which breaks
> on
> some headers when include_next.m4 determines that #include_next doesn't work.
>
> $ echo '#include <stdio.h>' > conftest.c
> $ xlc -E conftest.c | grep stdio
> #line 73 "/usr/include/stdio.h"
> int __stdioid;
> #line 259 "/usr/include/stdio.h"
> #line 374 "/usr/include/stdio.h"
> #line 398 "/usr/include/stdio.h"
> #line 434 "/usr/include/stdio.h"
> $ echo '#include <dirent.h>' > conftest.c
> $ xlc -E conftest.c | grep dirent
> struct dirent {
> extern struct dirent *readdir(DIR *);
> extern int readdir_r(DIR *, struct dirent *, struct dirent **);
> extern int scandir(const char *, struct dirent ***,
> int (*)(struct dirent *),
>
> It seems that the compiler sometimes forgets the #line directives.
Thanks for the report. It appears that because the header file <dirent.h>
contains only comments and preprocessor directives, and no non-comment tokens
of its own, AIX xlc "optimizes" some #line directives.
The problem is easy to reproduce, also on AIX 5.1, with a testdir
created through
./gnulib-tool --create-testdir dirent signal poll dirfd fchdir
The scope of the problem could be quite large, since quite some header files
contain only comments and #includes. I found quite a long list below.
Fortunately, GCC and the system compilers on HP-UX, IRIX, OSF/1, Solaris
don't "optimize" the #line directives like this. So only the system compilers
on AIX are affected.
The fix that I found is to use "xlc -E -C" instead of "xlc -E". It has the
effect of turning the config.status lines
S["NEXT_SIGNAL_H"]="\"///usr/include/sys/signal.h\""
S["NEXT_DIRENT_H"]="\"\""
into
S["NEXT_SIGNAL_H"]="\"///usr/include/signal.h\""
S["NEXT_DIRENT_H"]="\"///usr/include/dirent.h\""
I'm applying the patch below.
Bruno
------------------------------------------------------------------------
aix-4.3.2
<ucontext.h> -> <sys/ucontext.h>
<dirent.h> -> <sys/dir.h>
<signal.h> -> <sys/signal.h>
<limits.h> -> <sys/limits.h>
<aio.h> -> <sys/aio.h>
<stropts.h> -> <sys/stropts.h>
<syslog.h> -> <sys/syslog.h>
<poll.h> -> <sys/poll.h>
aix-5.1.0
<ucontext.h> -> <sys/ucontext.h>
<dirent.h> -> <sys/dir.h>
<signal.h> -> <sys/signal.h>
<stropts.h> -> <sys/stropts.h>
<syslog.h> -> <sys/syslog.h>
<poll.h> -> <sys/poll.h>
beos
<stdarg.h>
<strings.h> -> <string.h>
<wchar.h> -> <wchar_t.h>
cygwin
<syslog.h> -> <sys/syslog.h>
<poll.h> -> <sys/poll.h>
<dirent.h> -> <sys/dir.h>
<utime.h> -> <sys/utime.h>
<termios.h> -> <sys/termios.h>
<unistd.h> -> <sys/unistd.h>
<strings.h> -> <sys/strings.h>
freebsd-6.0
semaphore.h -> posix4/semaphore.h
stdarg.h -> machine/stdarg.h
float.h -> machine/float.h
sched.h -> posix4/sched.h
ucontext.h -> sys/ucontext.h
termios.h -> sys/termios.h
stdint.h -> sys/stdint.h
syslog.h -> sys/syslog.h
errno.h -> sys/errno.h
fcntl.h -> sys/fcntl.h
poll.h -> sys/poll.h
aio.h -> sys/aio.h
glibc
<syslog.h> -> <sys/syslog.h>
<poll.h> -> <sys/poll.h>
hpux
unistd.h
dirent.h
stdarg.h
fcntl.h
ucontext.h
stropts.h
termios.h
signal.h
poll.h
semaphore.h
mqueue.h
sched.h
aio.h
pthread.h
interix
stropts.h
irix-6.5
poll.h
termios.h
wctype.h
macosx-10.3
fenv.h
math.h
semaphore.h
setjmp.h
ucontext.h
termios.h
syslog.h
errno.h
fcntl.h
mingw
strings.h
unistd.h
stddef.h
stdarg.h
utime.h
netbsd-3.0
stdarg.h -> machine/stdarg.h
float.h -> machine/float.h
termios.h -> sys/termios.h
stdint.h -> sys/stdint.h
syslog.h -> sys/syslog.h
fcntl.h -> sys/fcntl.h
poll.h -> sys/poll.h
openbsd-3.8
poll.h
float.h -> machine/float.h
termios.h -> sys/termios.h
stdarg.h -> sys/stdarg.h
syslog.h -> sys/syslog.h
errno.h -> sys/errno.h
fcntl.h -> sys/fcntl.h
osf1
fcntl.h
poll.h
solaris-2.10
poll.h
stdint.h
termios.h
-----------------------------------------------------------------------
2008-11-03 Bruno Haible <[EMAIL PROTECTED]>
Make determination of absolute name of header file work with AIX xlc.
* m4/include_next.m4 (gl_CHECK_NEXT_HEADERS): Require
AC_CANONICAL_HOST. On AIX, use "$CPP -C" rather than "$CPP" for
preprocessing.
* m4/absolute-header.m4 (gl_ABSOLUTE_HEADER): Likewise.
Reported by Gary V. Vaughan <[EMAIL PROTECTED]>.
*** m4/include_next.m4.orig 2008-11-04 01:48:26.000000000 +0100
--- m4/include_next.m4 2008-11-04 01:41:45.000000000 +0100
***************
*** 1,4 ****
! # include_next.m4 serial 8
dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # include_next.m4 serial 9
dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
***************
*** 87,92 ****
--- 87,93 ----
AC_DEFUN([gl_CHECK_NEXT_HEADERS],
[
AC_REQUIRE([gl_INCLUDE_NEXT])
+ AC_REQUIRE([AC_CANONICAL_HOST])
AC_CHECK_HEADERS_ONCE([$1])
m4_foreach_w([gl_HEADER_NAME], [$1],
***************
*** 105,115 ****
[AC_LANG_SOURCE(
[[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
)])
! dnl eval is necessary to expand ac_cpp.
dnl Ultrix and Pyramid sh refuse to redirect output of eval,
dnl so use subshell.
AS_VAR_SET([gl_next_header],
! ['"'`(eval "$ac_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{
s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1#
s#^/[^/]#//&#
--- 106,127 ----
[AC_LANG_SOURCE(
[[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
)])
! dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
! dnl that contain only a #include of other header files and no
! dnl non-comment tokens of their own. This leads to a failure to
! dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
! dnl and others. The workaround is to force preservation of comments
! dnl through option -C. This ensures all necessary #line directives
! dnl are present. GCC supports option -C as well.
! case "$host_os" in
! aix*) gl_absname_cpp="$ac_cpp -C" ;;
! *) gl_absname_cpp="$ac_cpp" ;;
! esac
! dnl eval is necessary to expand gl_absname_cpp.
dnl Ultrix and Pyramid sh refuse to redirect output of eval,
dnl so use subshell.
AS_VAR_SET([gl_next_header],
! ['"'`(eval "$gl_absname_cpp conftest.$ac_ext")
2>&AS_MESSAGE_LOG_FD |
sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{
s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1#
s#^/[^/]#//&#
*** m4/absolute-header.m4.orig 2008-11-04 01:48:26.000000000 +0100
--- m4/absolute-header.m4 2008-11-04 01:43:05.000000000 +0100
***************
*** 1,4 ****
! # absolute-header.m4 serial 9
dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # absolute-header.m4 serial 10
dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
***************
*** 20,26 ****
# preprocessing, i.e. it does not only define preprocessor macros but also
# provides some type/enum definitions or function/variable declarations.
AC_DEFUN([gl_ABSOLUTE_HEADER],
! [AC_LANG_PREPROC_REQUIRE()dnl
m4_foreach_w([gl_HEADER_NAME], [$1],
[AS_VAR_PUSHDEF([gl_absolute_header],
[gl_cv_absolute_]m4_quote(m4_defn([gl_HEADER_NAME])))dnl
--- 20,27 ----
# preprocessing, i.e. it does not only define preprocessor macros but also
# provides some type/enum definitions or function/variable declarations.
AC_DEFUN([gl_ABSOLUTE_HEADER],
! [AC_REQUIRE([AC_CANONICAL_HOST])
! AC_LANG_PREPROC_REQUIRE()dnl
m4_foreach_w([gl_HEADER_NAME], [$1],
[AS_VAR_PUSHDEF([gl_absolute_header],
[gl_cv_absolute_]m4_quote(m4_defn([gl_HEADER_NAME])))dnl
***************
*** 31,40 ****
AC_CHECK_HEADERS_ONCE(m4_quote(m4_defn([gl_HEADER_NAME])))dnl
if test AS_VAR_GET(ac_header_exists) = yes; then
AC_LANG_CONFTEST([AC_LANG_SOURCE([[#include
<]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]])])
! dnl eval is necessary to expand ac_cpp.
! dnl Ultrix and Pyramid sh refuse to redirect output of eval, so use subshell.
AS_VAR_SET(gl_absolute_header,
! [`(eval "$ac_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{
s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1#
s#^/[^/]#//&#
--- 32,53 ----
AC_CHECK_HEADERS_ONCE(m4_quote(m4_defn([gl_HEADER_NAME])))dnl
if test AS_VAR_GET(ac_header_exists) = yes; then
AC_LANG_CONFTEST([AC_LANG_SOURCE([[#include
<]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]])])
! dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
! dnl that contain only a #include of other header files and no
! dnl non-comment tokens of their own. This leads to a failure to
! dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
! dnl and others. The workaround is to force preservation of comments
! dnl through option -C. This ensures all necessary #line directives
! dnl are present. GCC supports option -C as well.
! case "$host_os" in
! aix*) gl_absname_cpp="$ac_cpp -C" ;;
! *) gl_absname_cpp="$ac_cpp" ;;
! esac
! dnl eval is necessary to expand gl_absname_cpp.
! dnl Ultrix and Pyramid sh refuse to redirect output of eval,
! dnl so use subshell.
AS_VAR_SET(gl_absolute_header,
! [`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{
s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1#
s#^/[^/]#//&#
