postgresql/config/c-compiler.m4
Peter Eisentraut b120382353 Upgrade to Autoconf 2.61:
- Change configure.in to use Autoconf 2.61 and update generated files.
- Update build system and documentation to support now directory variables
  offered by Autoconf 2.61.
- Replace usages of PGAC_CHECK_ALIGNOF by AC_CHECK_ALIGNOF, now available
  in Autoconf 2.61.
- Drop our patched version of AC_C_INLINE, as Autoconf now has the change.
2008-02-17 16:36:43 +00:00

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# Macros to detect C compiler features
# $PostgreSQL: pgsql/config/c-compiler.m4,v 1.15 2008/02/17 16:36:42 petere Exp $
# PGAC_C_SIGNED
# -------------
# Check if the C compiler understands signed types.
AC_DEFUN([PGAC_C_SIGNED],
[AC_CACHE_CHECK(for signed types, pgac_cv_c_signed,
[AC_TRY_COMPILE([],
[signed char c; signed short s; signed int i;],
[pgac_cv_c_signed=yes],
[pgac_cv_c_signed=no])])
if test x"$pgac_cv_c_signed" = xno ; then
AC_DEFINE(signed,, [Define to empty if the C compiler does not understand signed types.])
fi])# PGAC_C_SIGNED
# PGAC_TYPE_64BIT_INT(TYPE)
# -------------------------
# Check if TYPE is a working 64 bit integer type. Set HAVE_TYPE_64 to
# yes or no respectively, and define HAVE_TYPE_64 if yes.
AC_DEFUN([PGAC_TYPE_64BIT_INT],
[define([Ac_define], [translit([have_$1_64], [a-z *], [A-Z_P])])dnl
define([Ac_cachevar], [translit([pgac_cv_type_$1_64], [ *], [_p])])dnl
AC_CACHE_CHECK([whether $1 is 64 bits], [Ac_cachevar],
[AC_TRY_RUN(
[typedef $1 ac_int64;
/*
* These are globals to discourage the compiler from folding all the
* arithmetic tests down to compile-time constants.
*/
ac_int64 a = 20000001;
ac_int64 b = 40000005;
int does_int64_work()
{
ac_int64 c,d;
if (sizeof(ac_int64) != 8)
return 0; /* definitely not the right size */
/* Do perfunctory checks to see if 64-bit arithmetic seems to work */
c = a * b;
d = (c + b) / b;
if (d != a+1)
return 0;
return 1;
}
main() {
exit(! does_int64_work());
}],
[Ac_cachevar=yes],
[Ac_cachevar=no],
[# If cross-compiling, check the size reported by the compiler and
# trust that the arithmetic works.
AC_COMPILE_IFELSE([AC_LANG_BOOL_COMPILE_TRY([], [sizeof($1) == 8])],
Ac_cachevar=yes,
Ac_cachevar=no)])])
Ac_define=$Ac_cachevar
if test x"$Ac_cachevar" = xyes ; then
AC_DEFINE(Ac_define,, [Define to 1 if `]$1[' works and is 64 bits.])
fi
undefine([Ac_define])dnl
undefine([Ac_cachevar])dnl
])# PGAC_TYPE_64BIT_INT
# PGAC_C_FUNCNAME_SUPPORT
# -----------------------
# Check if the C compiler understands __func__ (C99) or __FUNCTION__ (gcc).
# Define HAVE_FUNCNAME__FUNC or HAVE_FUNCNAME__FUNCTION accordingly.
AC_DEFUN([PGAC_C_FUNCNAME_SUPPORT],
[AC_CACHE_CHECK(for __func__, pgac_cv_funcname_func_support,
[AC_TRY_COMPILE([#include <stdio.h>],
[printf("%s\n", __func__);],
[pgac_cv_funcname_func_support=yes],
[pgac_cv_funcname_func_support=no])])
if test x"$pgac_cv_funcname_func_support" = xyes ; then
AC_DEFINE(HAVE_FUNCNAME__FUNC, 1,
[Define to 1 if your compiler understands __func__.])
else
AC_CACHE_CHECK(for __FUNCTION__, pgac_cv_funcname_function_support,
[AC_TRY_COMPILE([#include <stdio.h>],
[printf("%s\n", __FUNCTION__);],
[pgac_cv_funcname_function_support=yes],
[pgac_cv_funcname_function_support=no])])
if test x"$pgac_cv_funcname_function_support" = xyes ; then
AC_DEFINE(HAVE_FUNCNAME__FUNCTION, 1,
[Define to 1 if your compiler understands __FUNCTION__.])
fi
fi])# PGAC_C_FUNCNAME_SUPPORT
# PGAC_PROG_CC_CFLAGS_OPT
# -----------------------
# Given a string, check if the compiler supports the string as a
# command-line option. If it does, add the string to CFLAGS.
AC_DEFUN([PGAC_PROG_CC_CFLAGS_OPT],
[AC_MSG_CHECKING([if $CC supports $1])
pgac_save_CFLAGS=$CFLAGS
CFLAGS="$pgac_save_CFLAGS $1"
_AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
AC_MSG_RESULT(yes),
[CFLAGS="$pgac_save_CFLAGS"
AC_MSG_RESULT(no)])
])# PGAC_PROG_CC_CFLAGS_OPT