libmicrohttpd

HTTP/1.x server C library (MHD 1.x, stable)
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mhd_check_func_run.m4 (5190B)


      1 # SYNOPSIS
      2 #
      3 #   MHD_CHECK_FUNC_RUN(FUNCTION_NAME,
      4 #                      [INCLUDES=AC_INCLUDES_DEFAULT], CHECK_CODE
      5 #                      COMMAND_IF_CROSS_COMPILING,
      6 #                      [ACTION_IF_AVAILABLE], [ACTION_IF_NOT_AVAILABLE],
      7 #                      [ADDITIONAL_LIBS])
      8 #
      9 # DESCRIPTION
     10 #
     11 #   This macro checks for presence of specific function by including
     12 #   specified headers, checking for declaration of the function and then
     13 #   compiling and linking CHECK_CODE. If all previous steps succeed,
     14 #   the binary is executed.
     15 #   The CHECK_CODE is full body of the "main" function and must include
     16 #   the final "return" keyword.
     17 #   This checks the declaration, the presence in library and the functionality.
     18 #   If function is available then macro HAVE_function_name (the name
     19 #   of the function conveted to all uppercase characters) is defined
     20 #   automatically.
     21 #   By using definition from provided headers, this macro ensures that
     22 #   correct calling convention is used for detection.
     23 #   The compilation and linking is tried even if cross-compiling. If they
     24 #   failed then the result is "no".
     25 #   The COMMAND_IF_CROSS_COMPILING commands are executed if and only if
     26 #   the compilation and linking succeed. These commands must set 'cacheVar'
     27 #   variable to "yes", "no", "assuming yes" or "assuming no".
     28 #   ACTION_IF_SUCCEED is executed if result is "yes" or "assuming yes".
     29 #   ACTION_IF_FAILED is executed if result is "no" or "assuming no".
     30 #
     31 #   Example usage:
     32 #
     33 #     MHD_CHECK_FUNC_RUN([memmem],
     34 #                        [[#include <string.h>]],
     35 #                        [[const void *ptr = memmem("aa", 2, "a", 1);
     36 #                          if (((void*)0) == ptr) return 1;
     37 #                            return 0;]],
     38 #                        [cacheVar="assuming yes"],
     39 #                        [var_use_memmem='yes'], [var_use_memmem='no'])
     40 #
     41 #   The cache variable used in check so if any test will not work
     42 #   correctly on some platform, user may simply fix it by giving cache
     43 #   variable in configure parameters, for example:
     44 #
     45 #     ./configure mhd_cv_works_func_memmem=no
     46 #
     47 #   This simplifies building from source on exotic platforms as patching
     48 #   of configure.ac is not required to change the results of the tests.
     49 #
     50 # LICENSE
     51 #
     52 #   Copyright (c) 2024 Karlson2k (Evgeny Grin) <k2k@narod.ru>
     53 #
     54 #   Copying and distribution of this file, with or without modification, are
     55 #   permitted in any medium without royalty provided the copyright notice
     56 #   and this notice are preserved. This file is offered as-is, without any
     57 #   warranty.
     58 
     59 #serial 1
     60 
     61 dnl $1: FUNCTION_NAME
     62 dnl $2: INCLUDES
     63 dnl $3: CHECK_CODE
     64 dnl $4: COMMAND_IF_CROSS_COMPILING
     65 dnl $5: ACTION_IF_AVAILABLE
     66 dnl $6: ACTION_IF_NOT_AVAILABLE
     67 dnl $7: ADDITIONAL_LIBS
     68 AC_DEFUN([MHD_CHECK_FUNC_RUN],[dnl
     69 AC_PREREQ([2.64])dnl for AS_VAR_SET_IF, m4_ifblank, m4_ifnblank, m4_default_nblank
     70 m4_newline([[# Expansion of $0 macro starts here]])
     71 AC_LANG_ASSERT([C])dnl
     72 m4_ifblank(m4_translit([$1],[()],[  ]), [m4_fatal([$0: First macro argument ("FUNCTION_NAME") must not be empty])])dnl
     73 m4_ifblank([$3], [m4_fatal([$0: Third macro argument ("CHECK_CODE") must not be empty])])dnl
     74 m4_bmatch(m4_normalize([$1]), [\s],dnl
     75           [m4_fatal([$0: First macro argument ("FUNCTION_NAME") must not contain whitespaces])])dnl
     76 m4_if(m4_index([$3], m4_normalize(m4_translit([$1],[()],[  ]))), [-1], dnl
     77       [m4_fatal([$0: "CHECK_CODE" macro parameter (third argument) does not contain ']m4_normalize([$1])[' token])])dnl
     78 m4_if(m4_index([$3],return), [-1], dnl
     79       [m4_fatal([$0: "CHECK_CODE" macro parameter (third argument) does not contain 'return' token])])dnl
     80 m4_bmatch(_mhd_norm_expd([$4]),[\<]cacheVar[\>],[],dnl
     81 [m4_fatal([$0: The fourth macro argument ("COMMAND_IF_CROSS_COMPILING") must assign ]dnl
     82 [a value to the cache variable 'cacheVar'. The variable must be not overquoted.])])dnl
     83 AS_VAR_PUSHDEF([decl_cv_Var],[ac_cv_have_decl_]m4_bpatsubst(_mhd_norm_expd(m4_translit([$1],[()],[  ])),[[^a-zA-Z0-9]],[_]))dnl
     84 AS_VAR_PUSHDEF([cacheVar],[mhd_cv_works_func_]m4_bpatsubst(_mhd_norm_expd(m4_translit([$1],[()],[  ])),[[^a-zA-Z0-9]],[_]))dnl
     85 AS_VAR_SET_IF([cacheVar],[],[AC_CHECK_DECL(_mhd_norm_expd([$1]),[],[cacheVar="no"],[$2])])
     86 AC_CACHE_CHECK([whether '$1' available and works],[cacheVar],dnl
     87 [
     88 AC_LANG_CONFTEST([AC_LANG_SOURCE([
     89 m4_default_nblank([$2],[AC_INCLUDES_DEFAULT])
     90 
     91 [int main(void)
     92 {
     93   ]$3[
     94 }
     95 ]])])
     96 m4_ifnblank([$7],[dnl
     97 mhd_check_func_SAVE_LIBS="$LIBS"
     98 LIBS="_mhd_norm_expd([$7]) $LIBS"
     99 ])dnl m4_ifnblank
    100 AS_VAR_IF([cross_compiling],["yes"],
    101 [AC_LINK_IFELSE([],[
    102 $4
    103 ],[cacheVar='no'])dnl AC_LINK_IFELSE
    104 ],dnl
    105 [AC_RUN_IFELSE([],[cacheVar='yes'],[cacheVar='no'],[[# Dummy placeholder]])
    106 ])
    107 rm -f conftest.$ac_ext
    108 m4_ifnblank([$7],[dnl
    109   LIBS="${mhd_check_func_SAVE_LIBS}"
    110   AS_UNSET([mhd_check_func_SAVE_LIBS])
    111 ])dnl m4_ifnblank
    112 ])dnl AC_CACHE_CHECK
    113 m4_ifnblank([$5],[
    114 AS_IF([test "x$cacheVar" = "xyes" || test "x$cacheVar" = "xassuming yes"],[$5])dnl AS_IF
    115 ])dnl m4_ifnblank
    116 m4_ifnblank([$6],[
    117 AS_IF([test "x$cacheVar" = "xno" || test "x$cacheVar" = "xassuming no"],[$6])dnl AS_IF
    118 ])dnl m4_ifnblank
    119 m4_newline([[# Expansion of $0 macro ends here]])
    120 ])dnl AC_DEFUN MHD_CHECK_FUNC_RUN