commit 82a26bfed203b84ccccd791575b9185df69fa014
parent a0c836e6680e88ec8a5d96990d9295045e039ac6
Author: Evgeny Grin (Karlson2k) <k2k@narod.ru>
Date: Fri, 1 Apr 2022 13:55:36 +0300
Added autoconf macro for checking compiler parameters/flags
Diffstat:
1 file changed, 254 insertions(+), 0 deletions(-)
diff --git a/m4/mhd_check_cc_flag.m4 b/m4/mhd_check_cc_flag.m4
@@ -0,0 +1,254 @@
+# SYNOPSIS
+#
+# MHD_CHECK_CC_FLAG([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 suppoted. 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_FLAG([-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 1
+
+AC_DEFUN([MHD_CHECK_CC_FLAG],[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_FLAG_WARNPARAMS])dnl sets 'mhd_CFLAGS_params_warn' variable
+ _MHD_CHECK_CC_FLAG_BODY([$1],[$2],[$3],[$4],[mhd_CFLAGS_params_warn])dnl
+])
+
+
+# SYNOPSIS
+#
+# _MHD_CHECK_CC_FLAG_BODY([FLAG-TO-TEST], [VARIABLE-TO-PREPEND-CFLAGS],
+# [ACTION-IF-SUPPORTED], [ACTION-IF-NOT-SUPPORTED],
+# [VARIABLE-TO-ENABLE-WARNS])
+#
+AC_DEFUN([_MHD_CHECK_CC_FLAG_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
+ AS_VAR_PUSHDEF([cv_Var], [mhd_cv_cc_fl_supp_]m4_bpatsubst(m4_tolower(_mhd_norm_expd([$1])),[[^a-z0-9]],[_]))dnl
+ dnl
+ AC_CACHE_CHECK([whether $[]CC supports _mhd_norm_expd([$1]) flag], cv_Var,
+ [dnl
+ AS_VAR_PUSHDEF([save_CFLAGS_Var], [mhd_check_cc_flag_save_CFLAGS])dnl
+ AS_VAR_SET([save_CFLAGS_Var],["${CFLAGS}"])
+ m4_ifnblank([$2],[dnl
+ m4_if(_mhd_norm_expd([$2]),[CFLAGS],
+ [CFLAGS="${save_CFLAGS_Var} _mhd_norm_expd([$1]) $[]{_mhd_norm_expd([$5])}"],
+ [CFLAGS="$[]{_mhd_norm_expd([$2])} _mhd_norm_expd([$1]) ${save_CFLAGS_Var} $[]{_mhd_norm_expd([$5])}"])
+ ],[dnl
+ CFLAGS="_mhd_norm_expd([$1]) $[]CFLAGS $[]{_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 if test flag added
+ m4_ifnblank([$2],[dnl
+ m4_if(_mhd_norm_expd([$2]),[CFLAGS],
+ [CFLAGS="${save_CFLAGS_Var} $[]{_mhd_norm_expd([$5])}"],
+ [CFLAGS="$[]{_mhd_norm_expd([$2])} ${save_CFLAGS_Var} $[]{_mhd_norm_expd([$5])}"])
+ ],[dnl
+ CFLAGS="${save_CFLAGS_Var} $[]{_mhd_norm_expd([$5])}"
+ ])dnl
+ AC_LINK_IFELSE([],
+ [AS_VAR_SET([cv_Var],["no"])],
+ [ [#] Compile and link failed if test flag removed as well
+ m4_ifnblank([$2],[dnl
+ m4_if(_mhd_norm_expd([$2]),[CFLAGS],
+ [CFLAGS="${save_CFLAGS_Var} _mhd_norm_expd([$1])"],
+ [CFLAGS="$[]{_mhd_norm_expd([$2])} _mhd_norm_expd([$1]) ${save_CFLAGS_Var}"])
+ ],[dnl
+ CFLAGS="_mhd_norm_expd([$1]) ${save_CFLAGS_Var}"
+ ])dnl
+ ac_c_werror_flag="$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="$mhd_check_cc_flag_save_c_werror_flag"
+ AS_VAR_SET([CFLAGS],["${save_CFLAGS_Var}"])
+ AS_UNSET(save_CFLAGS_Var)
+ AS_VAR_POPDEF([save_CFLAGS_Var])dnl
+ ]
+ )
+ m4_ifnblank([$3$4],[dnl
+ AS_VAR_IF([cv_Var], ["yes"], [$3], m4_default_nblank([$4]))
+ ])dnl
+ AS_VAR_POPDEF([cv_Var])dnl
+])
+
+
+#
+# SYNOPSIS
+#
+# MHD_FIND_CC_FLAG_WARNPARAMS()
+#
+AC_DEFUN([MHD_FIND_CC_FLAG_WARNPARAMS],[dnl
+ AC_LANG_ASSERT([C])dnl
+ AC_REQUIRE([MHD_FIND_CC_FLAG_WWARN])dnl
+ mhd_CFLAGS_params_warn=''
+ _MHD_CHECK_CC_FLAG_BODY([-Wunused-command-line-argument],[],
+ [
+ AS_IF([test -z "$mhd_CFLAGS_params_warn"],
+ [mhd_CFLAGS_params_warn='-Wunused-command-line-argument'],
+ [mhd_CFLAGS_params_warn="$mhd_CFLAGS_params_warn -Wunused-command-line-argument"]
+ )
+ ],[],[mhd_cv_cc_flag_Wwarn]
+ )
+ _MHD_CHECK_CC_FLAG_BODY([-Wignored-optimization-argument],[],
+ [
+ AS_IF([test -z "$mhd_CFLAGS_params_warn"],
+ [mhd_CFLAGS_params_warn='-Wignored-optimization-argument'],
+ [mhd_CFLAGS_params_warn="$mhd_CFLAGS_params_warn -Wignored-optimization-argument"]
+ )
+ ],[],[mhd_cv_cc_flag_Wwarn]
+ )
+ _MHD_CHECK_CC_FLAG_BODY([-Winvalid-command-line-argument],[],
+ [
+ AS_IF([test -z "$mhd_CFLAGS_params_warn"],
+ [mhd_CFLAGS_params_warn='-Winvalid-command-line-argument'],
+ [mhd_CFLAGS_params_warn="$mhd_CFLAGS_params_warn -Winvalid-command-line-argument"]
+ )
+ ],[],[mhd_cv_cc_flag_Wwarn]
+ )
+ _MHD_CHECK_CC_FLAG_BODY([-Wunknown-argument],[],
+ [
+ AS_IF([test -z "$mhd_CFLAGS_params_warn"],
+ [mhd_CFLAGS_params_warn='-Wunknown-argument'],
+ [mhd_CFLAGS_params_warn="$mhd_CFLAGS_params_warn -Wunknown-argument"]
+ )
+ ],[],[mhd_cv_cc_flag_Wwarn]
+ )
+ AS_IF([test -z "$mhd_CFLAGS_params_warn"],
+ [mhd_CFLAGS_params_warn="$mhd_cv_cc_flag_Wwarn"],
+ [mhd_CFLAGS_params_warn="$mhd_cv_cc_flag_Wwarn $mhd_CFLAGS_params_warn"]
+ )
+])
+
+
+#
+# SYNOPSIS
+#
+# MHD_FIND_CC_FLAG_WWARN()
+#
+AC_DEFUN([MHD_FIND_CC_FLAG_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.])])
+
+])
