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|
dnl ######################################################################
dnl Common m4sh code for compiler stuff
AC_DEFUN([NTP_COMPILER], [
AC_USE_SYSTEM_EXTENSIONS
# Ralf Wildenhues: With per-target flags we need CC_C_O
# AM_PROG_CC_C_O supersets AC_PROG_CC_C_O
AM_PROG_CC_C_O
AC_PROG_GCC_TRADITIONAL
AC_REQUIRE([AC_PROG_CC_STDC])
dnl AC_REQUIRE([AC_PROG_CC_C89])
dnl AC_REQUIRE([AC_PROG_CC_C99])
CFLAGS_NTP=
CPPFLAGS_NTP=
LDADD_NTP=
LDFLAGS_NTP=
AC_SUBST([CFLAGS_NTP])
AC_SUBST([CPPFLAGS_NTP])
AC_SUBST([LDADD_NTP])
AC_SUBST([LDFLAGS_NTP])
case "$ac_cv_prog_cc_c89" in
no)
AC_MSG_WARN([ANSI C89/ISO C90 is the minimum to compile NTP]
[ version 4.2.5 and higher.])
;;
esac
AC_CACHE_CHECK(
[if $CC can handle @%:@warning],
[ntp_cv_cpp_warning],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([[]], [[#warning foo]])],
[ntp_cv_cpp_warning=yes],
[ntp_cv_cpp_warning=no]
)]
)
case "$ntp_cv_cpp_warning" in
no)
AC_DEFINE([NO_OPTION_NAME_WARNINGS], [1],
[Should we avoid @%:@warning on option name collisions?])
esac
AC_CACHE_CHECK(
[if $CC supports __attribute__((...))],
[ntp_cv_cc_attribute],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[]],
[[void foo(void) __attribute__((__noreturn__));]]
)],
[ntp_cv_cc_attribute=yes],
[ntp_cv_cc_attribute=no]
)]
)
case "$ntp_cv_cc_attribute" in
yes)
AC_DEFINE([HAVE___ATTRIBUTE__], [],
[defined if C compiler supports __attribute__((...))])
esac
AH_VERBATIM(
[HAVE___ATTRIBUTE___VERBATIM],
[
/* define away __attribute__() if unsupported */
#ifndef HAVE___ATTRIBUTE__
# define __attribute__(x) /* empty */
#endif
#define ISC_PLATFORM_NORETURN_PRE
#define ISC_PLATFORM_NORETURN_POST __attribute__((__noreturn__))
]
)
case "$GCC" in
yes)
SAVED_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Wstrict-overflow"
AC_CACHE_CHECK(
[if $CC can handle -Wstrict-overflow],
[ntp_cv_gcc_Wstrict_overflow],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([[]], [[]])],
[ntp_cv_gcc_Wstrict_overflow=yes],
[ntp_cv_gcc_Wstrict_overflow=no]
) ]
)
#
# $ntp_cv_gcc_Wstrict_overflow is tested later to add the
# flag to CFLAGS.
#
CFLAGS="$SAVED_CFLAGS -Winit-self"
AC_CACHE_CHECK(
[if $CC can handle -Winit-self],
[ntp_cv_gcc_Winit_self],
[
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM([[]], [[]])],
[ntp_cv_gcc_Winit_self=yes],
[ntp_cv_gcc_Winit_self=no]
)
]
)
CFLAGS="$SAVED_CFLAGS"
AS_UNSET([SAVED_CFLAGS])
#
# $ntp_cv_gcc_Winit_self is tested later to add the
# flag to CFLAGS_NTP.
#
AC_CACHE_CHECK(
[if linker supports omitting unused code and data],
[ntp_cv_gc_sections_runs],
[
dnl NetBSD will link but likely not run with --gc-sections
dnl http://bugs.ntp.org/1844
dnl http://gnats.netbsd.org/40401
dnl --gc-sections causes attempt to load as linux elf, with
dnl wrong syscalls in place. Test a little gauntlet of
dnl simple stdio read code checking for errors, expecting
dnl enough syscall differences that the NetBSD code will
dnl fail even with Linux emulation working as designed.
dnl A shorter test could be refined by someone with access
dnl to a NetBSD host with Linux emulation working.
origCFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Wl,--gc-sections"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[
#include <stdlib.h>
#include <stdio.h>
]],
[[
FILE * fpC;
char buf[32];
size_t cch;
int read_success_once;
fpC = fopen("conftest.c", "r");
if (NULL == fpC)
exit(1);
do {
cch = fread(buf, sizeof(buf), 1, fpC);
read_success_once |= (0 != cch);
} while (0 != cch);
if (!read_success_once)
exit(2);
if (!feof(fpC))
exit(3);
if (0 != fclose(fpC))
exit(4);
exit(EXIT_SUCCESS);
]]
)],
[
if test "X$cross_compiling" = "Xyes" || grep gc-sections conftest.err ; then
ntp_cv_gc_sections_runs=no
else
ntp_cv_gc_sections_runs=no
./conftest >/dev/null 2>&1 && ntp_cv_gc_sections_runs=yes
fi
],
[ntp_cv_gc_sections_runs=no]
)
CFLAGS="$origCFLAGS"
AS_UNSET([origCFLAGS])
]
)
case "$ntp_cv_gc_sections_runs" in
yes)
LDADD_LIBNTP="-Wl,--gc-sections"
CFLAGS_NTP="$CFLAGS_NTP -ffunction-sections -fdata-sections"
;;
no)
LDADD_LIBNTP=
;;
esac
CFLAGS_NTP="$CFLAGS_NTP -Wall"
CFLAGS_NTP="$CFLAGS_NTP -Wcast-align"
CFLAGS_NTP="$CFLAGS_NTP -Wcast-qual"
# CFLAGS_NTP="$CFLAGS_NTP -Wconversion"
# CFLAGS_NTP="$CFLAGS_NTP -Werror"
# CFLAGS_NTP="$CFLAGS_NTP -Wextra"
# CFLAGS_NTP="$CFLAGS_NTP -Wfloat-equal"
CFLAGS_NTP="$CFLAGS_NTP -Wmissing-prototypes"
CFLAGS_NTP="$CFLAGS_NTP -Wpointer-arith"
CFLAGS_NTP="$CFLAGS_NTP -Wshadow"
# CFLAGS_NTP="$CFLAGS_NTP -Wtraditional"
# CFLAGS_NTP="$CFLAGS_NTP -Wwrite-strings"
case "$ntp_cv_gcc_Winit_self" in
yes)
CFLAGS_NTP="$CFLAGS_NTP -Winit-self"
esac
case "$ntp_cv_gcc_Wstrict_overflow" in
yes)
CFLAGS_NTP="$CFLAGS_NTP -Wstrict-overflow"
esac
# -W[no-]strict-prototypes might be added by NTP_OPENSSL
esac
NTP_OS_CFLAGS
AC_C_BIGENDIAN
AC_C_VOLATILE
AC_PROG_CPP
])dnl
dnl ======================================================================
|
