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libmicrohttpd/m4/mhd_check_cc_cflag.m4
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Christian Grothoff d629ada1a2 -fix typos
2022-06-26 15:24:24 +02:00

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# SYNOPSIS
#
# MHD_CHECK_CC_CFLAG([FLAG-TO-TEST], [VARIABLE-TO-PREPEND-CFLAGS],
# [ACTION-IF-SUPPORTED], [ACTION-IF-NOT-SUPPORTED])
#
# DESCRIPTION
#
# This macro checks whether the specific compiler flag is supported.
# The check is performing by prepending FLAG-TO-TEST to CFLAGS, then
# prepending value of VARIABLE-TO-PREPEND-CFLAGS (if any) to CFLAGS, and
# then performing compile and link test. If test succeed without warnings,
# then the flag is considered to be supported. Otherwise, if compile and link
# without test flag can be done without any warning, the flag is considered
# to be unsuppoted.
#
# Example usage:
#
# MHD_CHECK_CC_CFLAG([-Wshadow], [additional_CFLAGS],
# [additional_CFLAGS="${additional_CFLAGS} -Wshadow"])
#
# Defined cache variable used in check so if any test will not work
# correctly on some platform, user may simply fix it by giving cache
# variable in configure parameters, for example:
#
# ./configure mhd_cv_cc_fl_supp__Wshadow=no
#
# This simplify building from source on exotic platforms as patching
# of configure.ac is not required to change results of tests.
#
# LICENSE
#
# Copyright (c) 2022 Karlson2k (Evgeny Grin) <k2k@narod.ru>
#
# Copying and distribution of this file, with or without modification, are
# permitted in any medium without royalty provided the copyright notice
# and this notice are preserved. This file is offered as-is, without any
# warranty.
#serial 2
AC_DEFUN([MHD_CHECK_CC_CFLAG],[dnl
_MHD_CHECK_CC_XFLAG([$1],[$2],[$3],[$4],[[CFLAGS]])dnl
])
# SYNOPSIS
#
# _MHD_CHECK_CC_XFLAG([FLAG-TO-TEST], [VARIABLE-TO-PREPEND-CFLAGS],
# [ACTION-IF-SUPPORTED], [ACTION-IF-NOT-SUPPORTED],
# [CFLAGS|LDFLAGS])
#
AC_DEFUN([_MHD_CHECK_CC_XFLAG],[dnl
AC_PREREQ([2.64])dnl for AS_VAR_IF, m4_ifnblank
AC_LANG_ASSERT([C])dnl
AC_REQUIRE([AC_PROG_CC])dnl
m4_ifblank([$1], [m4_fatal([$0: First macro argument must not be empty])])dnl
m4_bmatch(m4_normalize([$1]), [\s],dnl
[m4_fatal([$0: First macro argument must not contain whitespaces])])dnl
m4_bmatch(_mhd_norm_expd([$2]), [\s],dnl
[m4_fatal([$0: Second macro argument must not contain whitespaces])])dnl
m4_bmatch([$1], [\$], [m4_fatal([$0: First macro argument must not contain '$'])])dnl
m4_bmatch([$2], [\$], [m4_fatal([$0: Second macro argument must not contain '$'])])dnl
AC_REQUIRE([MHD_FIND_CC_XFLAG_WARNPARAMS])dnl sets 'mhd_xFLAGS_params_warn' variable
m4_bmatch(_mhd_norm_expd([$5]), [^\(CFLAGS\|LDFLAGS\)$],[],dnl
[m4_fatal([$0: Fifth macro argument must be either 'CFLAGS' or 'LDFLAGS; ']_mhd_norm_expd([$5])[' is not supported])])dnl
_MHD_CHECK_CC_XFLAG_BODY([$1],[$2],[$3],[$4],[mhd_xFLAGS_params_warn],[$5])dnl
])
# SYNOPSIS
#
# _MHD_CHECK_CC_XFLAG_BODY([FLAG-TO-TEST], [VARIABLE-TO-PREPEND-CFLAGS],
# [ACTION-IF-SUPPORTED], [ACTION-IF-NOT-SUPPORTED],
# [VARIABLE-TO-ENABLE-WARNS], [CFLAGS|LDFLAGS])
#
AC_DEFUN([_MHD_CHECK_CC_XFLAG_BODY],[dnl
AC_LANG_ASSERT([C])dnl
m4_ifblank([$1], [m4_fatal([$0: First macro argument must not be empty])])dnl
m4_bmatch(_mhd_norm_expd([$1]), [\s],dnl
[m4_fatal([$0: First macro argument must not contain whitespaces])])dnl
m4_bmatch(_mhd_norm_expd([$2]), [\s],dnl
[m4_fatal([$0: Second macro argument must not contain whitespaces])])dnl
m4_bmatch([$1], [\$], [m4_fatal([$0: First macro argument must not contain '$'])])dnl
m4_bmatch([$2], [\$], [m4_fatal([$0: Second macro argument must not contain '$'])])dnl
m4_ifblank([$5], [m4_fatal([$0: Fifth macro argument must not be empty])])dnl
m4_bmatch([$5], [\$], [m4_fatal([$0: Fifth macro argument must not contain '$'])])dnl
m4_bmatch(_mhd_norm_expd([$6]), [^\(CFLAGS\|LDFLAGS\)$],[],dnl
[m4_fatal([$0: Sixth macro argument must be either 'CFLAGS' or 'LDFLAGS; ']_mhd_norm_expd([$6])[' is not supported])])dnl
m4_pushdef([XFLAGS],_mhd_norm_expd([$6]))dnl
dnl Keep uppercase letters to avoid clashes for parameters like -fPIE and -fpie
AS_VAR_PUSHDEF([cv_Var],[mhd_cv_cc_]m4_tolower(m4_substr(_mhd_norm_expd([$6]),0,1))[fl_supp_]m4_bpatsubst(_mhd_norm_expd([$1]),[[^a-zA-Z0-9]],[_]))dnl
AC_CACHE_CHECK([whether $[]CC supports _mhd_norm_expd([$1]) flag], cv_Var,
[dnl
AS_VAR_PUSHDEF([save_xFLAGS_Var], [mhd_check_cc_flag_save_]XFLAGS)dnl
AS_VAR_SET([save_xFLAGS_Var],["${XFLAGS}"])
m4_ifnblank([$2],[dnl
m4_if(_mhd_norm_expd([$2]),[XFLAGS],
[XFLAGS="${save_xFLAGS_Var} _mhd_norm_expd([$1]) $[]{_mhd_norm_expd([$5])}"],
[XFLAGS="$[]{_mhd_norm_expd([$2])} _mhd_norm_expd([$1]) ${save_xFLAGS_Var} $[]{_mhd_norm_expd([$5])}"])
],[dnl
XFLAGS="_mhd_norm_expd([$1]) $[]XFLAGS $[]{_mhd_norm_expd([$5])}"
])dnl
mhd_check_cc_flag_save_c_werror_flag="$ac_c_werror_flag"
ac_c_werror_flag=yes
[#] Reuse the same source for all the checks here
AC_LANG_CONFTEST([AC_LANG_SOURCE([[
int main(void)
{
return 0;
}
]])])
AC_LINK_IFELSE([],
[AS_VAR_SET([cv_Var],["yes"])],
[ [#] Compile and link failed with test flag added
m4_ifnblank([$2],[dnl
m4_if(_mhd_norm_expd([$2]),[XFLAGS],
[XFLAGS="${save_xFLAGS_Var} $[]{_mhd_norm_expd([$5])}"],
[XFLAGS="$[]{_mhd_norm_expd([$2])} ${save_xFLAGS_Var} $[]{_mhd_norm_expd([$5])}"])
],[dnl
XFLAGS="${save_xFLAGS_Var} $[]{_mhd_norm_expd([$5])}"
])dnl
AC_LINK_IFELSE([],
[AS_VAR_SET([cv_Var],["no"])],
[ [#] Compile and link failed with test flag removed as well
m4_ifnblank([$2],[dnl
m4_if(_mhd_norm_expd([$2]),[XFLAGS],
[XFLAGS="${save_xFLAGS_Var} _mhd_norm_expd([$1])"],
[XFLAGS="$[]{_mhd_norm_expd([$2])} _mhd_norm_expd([$1]) ${save_xFLAGS_Var}"])
],[dnl
XFLAGS="_mhd_norm_expd([$1]) ${save_xFLAGS_Var}"
])dnl
ac_c_werror_flag="$mhd_check_cc_flag_save_c_werror_flag"
AC_LINK_IFELSE([],
[AS_VAR_SET([cv_Var],["yes"])],
[AS_VAR_SET([cv_Var],["no"])],
)
]
)
]
)
ac_c_werror_flag="$mhd_check_cc_flag_save_c_werror_flag"
AS_VAR_SET([XFLAGS],["${save_xFLAGS_Var}"])
AS_UNSET(save_xFLAGS_Var)
AS_VAR_POPDEF([save_xFLAGS_Var])dnl
]
)
m4_ifnblank([$3$4],[dnl
AS_VAR_IF([cv_Var], ["yes"], [$3], m4_default_nblank([$4]))
])dnl
AS_VAR_POPDEF([cv_Var])dnl
m4_popdef([XFLAGS])dnl
])
#
# SYNOPSIS
#
# MHD_FIND_CC_XFLAG_WARNPARAMS()
#
AC_DEFUN([MHD_FIND_CC_XFLAG_WARNPARAMS],[dnl
AC_LANG_ASSERT([C])dnl
AC_REQUIRE([MHD_FIND_CC_CFLAG_WWARN])dnl
mhd_xFLAGS_params_warn=''
_MHD_CHECK_CC_XFLAG_BODY([-Wunused-command-line-argument],[],
[
MHD_APPEND_FLAG_TO_VAR([mhd_xFLAGS_params_warn],[-Wunused-command-line-argument])
],[],[mhd_cv_cc_flag_Wwarn],[[CFLAGS]]
)
_MHD_CHECK_CC_XFLAG_BODY([-Wignored-optimization-argument],[],
[
MHD_APPEND_FLAG_TO_VAR([mhd_xFLAGS_params_warn],[-Wignored-optimization-argument])
],[],[mhd_cv_cc_flag_Wwarn],[[CFLAGS]]
)
_MHD_CHECK_CC_XFLAG_BODY([-Winvalid-command-line-argument],[],
[
MHD_APPEND_FLAG_TO_VAR([mhd_xFLAGS_params_warn],[-Winvalid-command-line-argument])
],[],[mhd_cv_cc_flag_Wwarn],[[CFLAGS]]
)
_MHD_CHECK_CC_XFLAG_BODY([-Wunknown-argument],[],
[
MHD_APPEND_FLAG_TO_VAR([mhd_xFLAGS_params_warn],[-Wunknown-argument])
],[],[mhd_cv_cc_flag_Wwarn],[[CFLAGS]]
)
MHD_PREPEND_FLAG_TO_VAR([mhd_xFLAGS_params_warn],[$mhd_cv_cc_flag_Wwarn])
])
#
# SYNOPSIS
#
# MHD_FIND_CC_CFLAG_WWARN()
#
AC_DEFUN([MHD_FIND_CC_CFLAG_WWARN],[dnl
AC_PREREQ([2.64])dnl for AS_VAR_IF, m4_ifnblank
AC_REQUIRE([AC_PROG_CC])dnl
AC_LANG_ASSERT([C])dnl
AC_MSG_CHECKING([for $[]CC flag to warn on unknown -W parameters])
AC_CACHE_VAL([mhd_cv_cc_flag_Wwarn],
[
mhd_check_cc_flagwarn_save_c_werror_flag="$ac_c_werror_flag"
ac_c_werror_flag=yes
mhd_find_cc_Wwarn_save_CFLAGS="$CFLAGS"
AS_UNSET([mhd_cv_cc_flag_Wwarn])
for mhd_cv_cc_flag_Wwarn in '' '-Wunknown-warning-option' '-Werror=unknown-warning-option' ; do
AS_VAR_IF([mhd_cv_cc_flag_Wwarn], ["unknown"], [break])
[#] Reuse the same source for all the checks here
AC_LANG_CONFTEST([AC_LANG_SOURCE([[
int main(void)
{
return 0;
}
]])])
CFLAGS="-Wmhd-noexist-flag $mhd_find_cc_Wwarn_save_CFLAGS $mhd_cv_cc_flag_Wwarn"
AC_LINK_IFELSE([],
[],
[ [#] Compile and link failed if test flag and non-existing flag added
CFLAGS="$mhd_find_cc_Wwarn_save_CFLAGS $mhd_cv_cc_flag_Wwarn"
AC_LINK_IFELSE([],
[ [#] Compile and link succeed if only test flag added
break
]
)
]
)
done
CFLAGS="$mhd_find_cc_Wwarn_save_CFLAGS"
AS_VAR_IF([mhd_cv_cc_flag_Wwarn], ["unknown"],
[
_AS_ECHO_LOG([No suitable flags detected. Check whether default flags are correct.])
AC_LINK_IFELSE([AC_LANG_SOURCE([[
int main(void)
{
return 0;
}
]])],
[:],
[ [#] Compile and link fails (or warns) with default flags
AC_MSG_WARN([Compiler warns (of fails) with default flags!])
AC_MSG_WARN([Check whether compiler and compiler flags are correct.])
]
)
]
)
CFLAGS="$mhd_find_cc_Wwarn_save_CFLAGS"
AS_UNSET([mhd_find_cc_Wwarn_save_CFLAGS])
ac_c_werror_flag="$mhd_check_cc_flagwarn_save_c_werror_flag"
AS_UNSET([mhd_check_cc_flagwarn_save_c_werror_flag])
]
)
AS_IF([test -z "$mhd_cv_cc_flag_Wwarn"],
[AC_MSG_RESULT([none needed])],
[AC_MSG_RESULT([$mhd_cv_cc_flag_Wwarn])])
AS_VAR_IF([mhd_cv_cc_flag_Wwarn], ["unknown"],
[AC_MSG_WARN([Unable to find compiler flags to warn on unsupported -W options. Final compiler options may be suboptimal.])])
])
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