libbsd/configure.ac
Guillem Jover 6faea4d2a0 Force setproctitle() into .init_array section
The GNU .init_array support is an extension over the standard System V
ABI .init_array support, which passes the main() arguments to the init
function.

This support comes in three parts. First the dynamic linker (from glibc)
needs to support it. Then function pointers need to be placed in the
section, for example by using __attribute__((constructor)), that the
compiler (gcc or clang for example) might place in section .ctors and
the linker (from binutils) will move to .init_array on the output
object, or by placing them directly into .init_array by the compiler
when compiling. If this does not happen and the function pointers end
up in .ctors, then they will not get passed the main() arguments, which
we do really need in this case.

But this relies on recent binutils or gcc having native .init_array
support, and not having it disabled through --disable-initfini-array.

To guarantee we get the correct behaviour, let's just place the function
pointer in the .init_array section directly, so we only require a recent
enough glibc.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=65029
2013-06-08 18:09:29 +02:00

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# Process this file with autoconf to produce a configure script.
AC_PREREQ([2.67])
AC_INIT([libbsd], m4_esyscmd([./get-version]), [libbsd@lists.freedesktop.org])
AC_CONFIG_SRCDIR([src/fgetln.c])
AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_MACRO_DIR([m4])
AM_INIT_AUTOMAKE([1.8 foreign nostdinc no-dist-gzip dist-xz])
m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])],
[AC_SUBST([AM_DEFAULT_VERBOSITY], [1])])
# Check and store if we got user supplied variables
user_CFLAGS=${CFLAGS-unset}
# Checks for operating system services and capabilities.
AC_USE_SYSTEM_EXTENSIONS
AC_SYS_LARGEFILE
LT_INIT
# Checks for programs.
AC_PROG_CC
AC_PROG_INSTALL
AC_PROG_LN_S
# Set default compiler variables
if test "$user_CFLAGS" = unset && test "$GCC" = yes; then
CFLAGS="$CFLAGS -Wall -Wextra -Wno-unused-variable -Wno-unused-parameter"
fi
# Checks for libraries.
# Checks for header files.
AC_CHECK_HEADERS([sys/ndir.h sys/dir.h dir.h dirent.h])
# Checks for typedefs, structures, and compiler characteristics.
AC_TYPE_UID_T
AC_C_INLINE
AC_C_TYPEOF
AC_TYPE_INT64_T
AC_TYPE_MODE_T
AC_TYPE_OFF_T
AC_TYPE_PID_T
AC_TYPE_SIZE_T
AC_TYPE_SSIZE_T
AC_CHECK_DECL([F_CLOSEM],
[AC_DEFINE([HAVE_FCNTL_CLOSEM], [1],
[Define to 1 if you have fcntl(F_CLOSEM)])],
[],
[#include <limits.h>
#include <fcntl.h>])
AC_CACHE_CHECK(
[for GNU .init_array section support],
[libbsd_cv_gnu_init_array_support],
[AC_RUN_IFELSE(
[AC_LANG_SOURCE(
[[
static int rc = 1;
static void init(int argc) { if (argc == 1) rc = 0; }
void (*init_func)(int argc) __attribute__((section(".init_array"))) = init;
int main() { return rc; }
]]
)],
[libbsd_cv_gnu_init_array_support=yes],
[libbsd_cv_gnu_init_array_support=no],
[AC_PREPROC_IFELSE(
[AC_LANG_SOURCE(
[[
/* Look for a known libc that supports .init_array with the GNU extension
* to pass main() arguments to the init functions. */
#include <stdlib.h>
#if defined __GLIBC_PREREQ
# if __GLIBC_PREREQ(2, 4)
/* glibc supports GNU .init_array since 2.4. */
# else
# error glibc does not support GNU .init_array
# endif
#else
/*
* Basic SysV ABI .init_array support, init functions do not get arguments:
* - Bionic since its inception.
* - uClibc since 0.9.29.
*/
# error unknown whether libc supports GNU .init_array
#endif
]]
)],
[libbsd_cv_gnu_init_array_support=yes],
[libbsd_cv_gnu_init_array_support=no])
]
)]
)
if test "$libbsd_cv_gnu_init_array_support" = no; then
AC_MSG_ERROR([missing required GNU .init_array section support])
fi
# Checks for library functions.
AC_MSG_CHECKING([for program_invocation_short_name])
AC_LINK_IFELSE(
[AC_LANG_PROGRAM([[#include <errno.h>]],
[[const char *p = program_invocation_short_name;]])],
[AC_DEFINE([HAVE_PROGRAM_INVOCATION_SHORT_NAME], [1],
[Define to 1 if you have program_invocation_short_name])
AC_MSG_RESULT([yes])],
[AC_MSG_RESULT([no])])
AC_MSG_CHECKING([for __progname])
AC_LINK_IFELSE(
[AC_LANG_PROGRAM([[]],
[[extern char *__progname;
const char *p = __progname;]])],
[AC_DEFINE([HAVE___PROGNAME], [1], [Define to 1 if you have __progname])
AC_MSG_RESULT([yes])],
[AC_MSG_RESULT([no])])
AC_CHECK_FUNCS([clearenv dirfd __fpurge getexecname getline sysconf])
AC_CONFIG_FILES([
Makefile
include/Makefile
man/Makefile
src/Makefile
src/libbsd.pc
src/libbsd-overlay.pc
test/Makefile
])
AC_CONFIG_HEADERS([config.h])
AC_OUTPUT