libmicrohttpd

HTTP/1.x server C library (MHD 1.x, stable)
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mhd_check_func.m4 (4017B)


      1 # SYNOPSIS
      2 #
      3 #   MHD_CHECK_FUNC([FUNCTION_NAME],
      4 #                  [INCLUDES=AC_INCLUDES_DEFAULT], [CHECK_CODE],
      5 #                  [ACTION-IF-AVAILABLE], [ACTION-IF-NOT-AVAILABLE],
      6 #                  [ADDITIONAL_LIBS])
      7 #
      8 # DESCRIPTION
      9 #
     10 #   This macro checks for presence of specific function by including
     11 #   specified headers, checking for declaration of the function and then
     12 #   compiling and linking CHECK_CODE.
     13 #   This checks both declaration and presence in library.
     14 #   If function is available then macro HAVE_function_name (the name
     15 #   of the function conveted to all uppercase characters) is defined
     16 #   automatically.
     17 #   Unlike AC_CHECK_FUNCS macro, this macro do not produce false
     18 #   negative result if function is declared with specific calling
     19 #   conventions like __stdcall' or attribute like
     20 #   __attribute__((__dllimport__)) and linker failing to build test
     21 #   program due to the different calling conventions.
     22 #   By using definition from provided headers, this macro ensures that
     23 #   correct calling convention is used for detection.
     24 #
     25 #   Example usage:
     26 #
     27 #     MHD_CHECK_FUNC([memmem],
     28 #                    [[#include <string.h>]],
     29 #                    [const void *ptr = memmem("aa", 2, "a", 1); (void)ptr;],
     30 #                    [var_use_memmem='yes'], [var_use_memmem='no'])
     31 #
     32 #   The cache variable used in check so if any test will not work
     33 #   correctly on some platform, user may simply fix it by giving cache
     34 #   variable in configure parameters, for example:
     35 #
     36 #     ./configure mhd_cv_have_func_memmem=no
     37 #
     38 #   This simplifies building from source on exotic platforms as patching
     39 #   of configure.ac is not required to change the results of the tests.
     40 #
     41 # LICENSE
     42 #
     43 #   Copyright (c) 2019-2023 Karlson2k (Evgeny Grin) <k2k@narod.ru>
     44 #
     45 #   Copying and distribution of this file, with or without modification, are
     46 #   permitted in any medium without royalty provided the copyright notice
     47 #   and this notice are preserved. This file is offered as-is, without any
     48 #   warranty.
     49 
     50 #serial 6
     51 
     52 AC_DEFUN([MHD_CHECK_FUNC],[dnl
     53 AC_PREREQ([2.64])dnl for AS_VAR_IF, m4_ifblank, m4_ifnblank
     54 m4_newline([[# Expansion of $0 macro starts here]])
     55 AC_LANG_ASSERT([C])dnl
     56 m4_ifblank(m4_translit([$1],[()],[  ]), [m4_fatal([First macro argument must not be empty])])dnl
     57 m4_ifblank([$3], [m4_fatal([Third macro argument must not be empty])])dnl
     58 m4_bmatch(m4_normalize([$1]), [\s],dnl
     59           [m4_fatal([First macro argument must not contain whitespaces])])dnl
     60 m4_if(m4_index([$3], m4_normalize(m4_translit([$1],[()],[  ]))), [-1], dnl
     61       [m4_fatal([CHECK_CODE parameter (third macro argument) does not contain ']m4_normalize([$1])[' token])])dnl
     62 AS_VAR_PUSHDEF([decl_cv_Var],[ac_cv_have_decl_]m4_bpatsubst(_mhd_norm_expd(m4_translit([$1],[()],[  ])),[[^a-zA-Z0-9]],[_]))dnl
     63 AS_VAR_PUSHDEF([cv_Var],[mhd_cv_have_func_]m4_bpatsubst(_mhd_norm_expd(m4_translit([$1],[()],[  ])),[[^a-zA-Z0-9]],[_]))dnl
     64 AS_VAR_SET_IF([cv_Var],[],[AC_CHECK_DECL(_mhd_norm_expd([$1]),[],[cv_Var="no"],[$2])])
     65 AC_CACHE_CHECK([f][or function $1], [cv_Var],dnl
     66   [dnl
     67     m4_ifnblank([$6],[dnl
     68       mhd_check_func_SAVE_LIBS="$LIBS"
     69       LIBS="_mhd_norm_expd([$6]) $LIBS"
     70     ])dnl
     71     AC_LINK_IFELSE(
     72       [AC_LANG_SOURCE([
     73 m4_default_nblank([$2],[AC_INCLUDES_DEFAULT])
     74 
     75 [int main(void)
     76 {
     77 
     78   ]$3[
     79 
     80   return 0;
     81 }
     82         ]])
     83       ],
     84       [AS_VAR_SET([cv_Var],["yes"])],
     85       [AS_VAR_SET([cv_Var],["no"])]dnl
     86     )
     87     m4_ifnblank([$6],[dnl
     88       LIBS="${mhd_check_func_SAVE_LIBS}"
     89       AS_UNSET([mhd_check_func_SAVE_LIBS])
     90     ])dnl
     91   ],[AS_VAR_SET([cv_Var],["no"])]dnl
     92 )
     93 AS_VAR_IF([cv_Var], ["yes"],
     94           [AC_DEFINE([[HAVE_]]m4_bpatsubst(m4_toupper(_mhd_norm_expd(m4_translit([$1],[()],[  ]))),[[^A-Z0-9]],[_]),
     95                      [1], [Define to 1 if you have the ']_mhd_norm_expd(m4_translit([$1],[()],[  ]))[' function.])
     96           m4_n([$4])dnl
     97           ],[$5])
     98 AS_VAR_POPDEF([cv_Var])dnl
     99 AS_VAR_POPDEF([decl_cv_Var])dnl
    100 m4_newline([[# Expansion of $0 macro ends here]])
    101 ])dnl AC_DEFUN MHD_CHECK_FUNC