m4/general.m4

   1 dnl Copyright (C) 1993-2003 Free Software Foundation, Inc.
   2 dnl This file is free software, distributed under the terms of the GNU
   3 dnl General Public License.  As a special exception to the GNU General
   4 dnl Public License, this file may be distributed as part of a program
   5 dnl that contains a configuration script generated by Autoconf, under
   6 dnl the same distribution terms as the rest of that program.
   7
   8 dnl From Bruno Haible, Marcus Daniels, Sam Steingold.
   9
  10 AC_PREREQ(2.13)
  11
  12 dnl without AC_MSG_...:   with AC_MSG_... and caching:
  13 dnl   AC_TRY_CPP          CL_CPP_CHECK
  14 dnl   AC_TRY_COMPILE      CL_COMPILE_CHECK
  15 dnl   AC_TRY_LINK         CL_LINK_CHECK
  16 dnl   AC_TRY_RUN          CL_RUN_CHECK - would require cross-compiling support
  17 dnl Usage:
  18 dnl AC_TRY_CPP(INCLUDES,
  19 dnl            ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND])
  20 dnl CL_CPP_CHECK(ECHO-TEXT, CACHE-ID,
  21 dnl              INCLUDES,
  22 dnl              ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND])
  23 dnl AC_TRY_xxx(INCLUDES, FUNCTION-BODY,
  24 dnl            ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND])
  25 dnl CL_xxx_CHECK(ECHO-TEXT, CACHE-ID,
  26 dnl              INCLUDES, FUNCTION-BODY,
  27 dnl              ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND])
  28
  29 AC_DEFUN([CL_CPP_CHECK],
  30 [AC_MSG_CHECKING(for $1)
  31 AC_CACHE_VAL($2,[
  32 AC_TRY_CPP([$3], $2=yes, $2=no)
  33 ])
  34 AC_MSG_RESULT([$]$2)
  35 if test [$]$2 = yes; then
  36   ifelse([$4], , :, [$4])
  37 ifelse([$5], , , [else
  38   $5
  39 ])dnl
  40 fi
  41 ])
  42
  43 AC_DEFUN([CL_COMPILE_CHECK],
  44 [AC_MSG_CHECKING(for $1)
  45 AC_CACHE_VAL($2,[
  46 AC_TRY_COMPILE([$3],[$4], $2=yes, $2=no)
  47 ])
  48 AC_MSG_RESULT([$]$2)
  49 if test [$]$2 = yes; then
  50   ifelse([$5], , :, [$5])
  51 ifelse([$6], , , [else
  52   $6
  53 ])dnl
  54 fi
  55 ])
  56
  57 AC_DEFUN([CL_LINK_CHECK],
  58 [AC_MSG_CHECKING(for $1)
  59 AC_CACHE_VAL($2,[
  60 AC_TRY_LINK([$3],[$4], $2=yes, $2=no)
  61 ])
  62 AC_MSG_RESULT([$]$2)
  63 if test [$]$2 = yes; then
  64   ifelse([$5], , :, [$5])
  65 ifelse([$6], , , [else
  66   $6
  67 ])dnl
  68 fi
  69 ])
  70
  71 dnl CL_SILENT(ACTION)
  72 dnl performs ACTION, with AC_MSG_CHECKING and AC_MSG_RESULT being defined away.
  73 AC_DEFUN([CL_SILENT],
  74 [pushdef([AC_MSG_CHECKING],[:])dnl
  75 pushdef([AC_CHECKING],[:])dnl
  76 pushdef([AC_MSG_RESULT],[:])dnl
  77 $1[]dnl
  78 popdef([AC_MSG_RESULT])dnl
  79 popdef([AC_CHECKING])dnl
  80 popdef([AC_MSG_CHECKING])dnl
  81 ])
  82
  83 dnl Expands to the "extern ..." prefix used for system declarations.
  84 dnl AC_LANG_EXTERN()
  85 AC_DEFUN([AC_LANG_EXTERN],
  86 [extern
  87 #ifdef __cplusplus
  88 "C"
  89 #endif
  90 ])
  91
  92 AC_DEFUN([CL_CC_WORKS],
  93 [AC_CACHE_CHECK(whether CC works at all, cl_cv_prog_cc_works, [
  94 AC_LANG_SAVE()
  95 AC_LANG_C()
  96 AC_TRY_RUN([int main() { exit(0); }],
  97 cl_cv_prog_cc_works=yes, cl_cv_prog_cc_works=no,
  98 AC_TRY_LINK([], [], cl_cv_prog_cc_works=yes, cl_cv_prog_cc_works=no))
  99 AC_LANG_RESTORE()
 100 ])
 101 case "$cl_cv_prog_cc_works" in
 102   *no) echo "Installation or configuration problem: C compiler cannot create executables."; exit 1;;
 103   *yes) ;;
 104 esac
 105 ])