mhd_check_func_run.m4: new autoconf macro

m4/mhd_check_func_run.m4

@@ -0,0 +1,120 @@
+# SYNOPSIS
+#
+#   MHD_CHECK_FUNC_RUN(FUNCTION_NAME,
+#                      [INCLUDES=AC_INCLUDES_DEFAULT], CHECK_CODE
+#                      COMMAND_IF_CROSS_COMPILING,
+#                      [ACTION_IF_AVAILABLE], [ACTION_IF_NOT_AVAILABLE],
+#                      [ADDITIONAL_LIBS])
+#
+# DESCRIPTION
+#
+#   This macro checks for presence of specific function by including
+#   specified headers, checking for declaration of the function and then
+#   compiling and linking CHECK_CODE. If all previous steps succeed,
+#   the binary is executed.
+#   The CHECK_CODE is full body of the "main" function and must include
+#   the final "return" keyword.
+#   This checks the declaration, the presence in library and the functionality.
+#   If function is available then macro HAVE_function_name (the name
+#   of the function conveted to all uppercase characters) is defined
+#   automatically.
+#   By using definition from provided headers, this macro ensures that
+#   correct calling convention is used for detection.
+#   The compilation and linking is tried even if cross-compiling. If they
+#   failed then the result is "no".
+#   The COMMAND_IF_CROSS_COMPILING commands are executed if and only if
+#   the compilation and linking succeed. These commands must set 'cacheVar'
+#   variable to "yes", "no", "assuming yes" or "assuming no".
+#   ACTION_IF_SUCCEED is executed if result is "yes" or "assuming yes".
+#   ACTION_IF_FAILED is executed if result is "no" or "assuming no".
+#
+#   Example usage:
+#
+#     MHD_CHECK_FUNC_RUN([memmem],
+#                        [[#include <string.h>]],
+#                        [[const void *ptr = memmem("aa", 2, "a", 1);
+#                          if (((void*)0) == ptr) return 1;
+#                            return 0;]],
+#                        [cacheVar="assuming yes"],
+#                        [var_use_memmem='yes'], [var_use_memmem='no'])
+#
+#   The 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_works_func_memmem=no
+#
+#   This simplifies building from source on exotic platforms as patching
+#   of configure.ac is not required to change the results of the tests.
+#
+# LICENSE
+#
+#   Copyright (c) 2024 Karlson2k (Evgeny Grin) <[email protected]>
+#
+#   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
+
+dnl $1: FUNCTION_NAME
+dnl $2: INCLUDES
+dnl $3: CHECK_CODE
+dnl $4: COMMAND_IF_CROSS_COMPILING
+dnl $5: ACTION_IF_AVAILABLE
+dnl $6: ACTION_IF_NOT_AVAILABLE
+dnl $7: ADDITIONAL_LIBS
+AC_DEFUN([MHD_CHECK_FUNC_RUN],[dnl
+AC_PREREQ([2.64])dnl for AS_VAR_SET_IF, m4_ifblank, m4_ifnblank, m4_default_nblank
+m4_newline([[# Expansion of $0 macro starts here]])
+AC_LANG_ASSERT([C])dnl
+m4_ifblank(m4_translit([$1],[()],[  ]), [m4_fatal([$0: First macro argument ("FUNCTION_NAME") must not be empty])])dnl
+m4_ifblank([$3], [m4_fatal([$0: Third macro argument ("CHECK_CODE") must not be empty])])dnl
+m4_bmatch(m4_normalize([$1]), [\s],dnl
+          [m4_fatal([$0: First macro argument ("FUNCTION_NAME") must not contain whitespaces])])dnl
+m4_if(m4_index([$3], m4_normalize(m4_translit([$1],[()],[  ]))), [-1], dnl
+      [m4_fatal([$0: "CHECK_CODE" macro parameter (third argument) does not contain ']m4_normalize([$1])[' token])])dnl
+m4_if(m4_index([$3],return), [-1], dnl
+      [m4_fatal([$0: "CHECK_CODE" macro parameter (third argument) does not contain 'return' token])])dnl
+m4_bmatch(_mhd_norm_expd([$4]),[\<]cacheVar[\>],[],dnl
+[m4_fatal([$0: The fourth macro argument ("COMMAND_IF_CROSS_COMPILING") must assign ]dnl
+[a value to the cache variable 'cacheVar'. The variable must be not overquoted.])])dnl
+AS_VAR_PUSHDEF([decl_cv_Var],[ac_cv_have_decl_]m4_bpatsubst(_mhd_norm_expd(m4_translit([$1],[()],[  ])),[[^a-zA-Z0-9]],[_]))dnl
+AS_VAR_PUSHDEF([cacheVar],[mhd_cv_works_func_]m4_bpatsubst(_mhd_norm_expd(m4_translit([$1],[()],[  ])),[[^a-zA-Z0-9]],[_]))dnl
+AS_VAR_SET_IF([cacheVar],[],[AC_CHECK_DECL(_mhd_norm_expd([$1]),[],[cacheVar="no"],[$2])])
+AC_CACHE_CHECK([whether '$1' available and works],[cacheVar],dnl
+[
+AC_LANG_CONFTEST([AC_LANG_SOURCE([
+m4_default_nblank([$2],[AC_INCLUDES_DEFAULT])
+
+[int main(void)
+{
+  ]$3[
+}
+]])])
+m4_ifnblank([$7],[dnl
+mhd_check_func_SAVE_LIBS="$LIBS"
+LIBS="_mhd_norm_expd([$7]) $LIBS"
+])dnl m4_ifnblank
+AS_VAR_IF([cross_compiling],["yes"],
+[AC_LINK_IFELSE([],[
+$4
+],[cacheVar='no'])dnl AC_LINK_IFELSE
+],dnl
+[AC_RUN_IFELSE([],[cacheVar='yes'],[cacheVar='no'],[[# Dummy placeholder]])
+])
+rm -f conftest.$ac_ext
+m4_ifnblank([$7],[dnl
+  LIBS="${mhd_check_func_SAVE_LIBS}"
+  AS_UNSET([mhd_check_func_SAVE_LIBS])
+])dnl m4_ifnblank
+])dnl AC_CACHE_CHECK
+m4_ifnblank([$5],[
+AS_IF([test "x$cacheVar" = "xyes" || test "x$cacheVar" = "xassuming yes"],[$5])dnl AS_IF
+])dnl m4_ifnblank
+m4_ifnblank([$6],[
+AS_IF([test "x$cacheVar" = "xno" || test "x$cacheVar" = "xassuming no"],[$6])dnl AS_IF
+])dnl m4_ifnblank
+m4_newline([[# Expansion of $0 macro ends here]])
+])dnl AC_DEFUN MHD_CHECK_FUNC_RUN