config/warnings.m4

   1 # Autoconf include file defining macros related to compile-time warnings.
   2
   3 # Copyright 2004, 2005, 2007, 2009, 2011 Free Software Foundation, Inc.
   4
   5 #This file is part of GCC.
   6
   7 #GCC is free software; you can redistribute it and/or modify it under
   8 #the terms of the GNU General Public License as published by the Free
   9 #Software Foundation; either version 3, or (at your option) any later
  10 #version.
  11
  12 #GCC is distributed in the hope that it will be useful, but WITHOUT
  13 #ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 #FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 #for more details.
  16
  17 #You should have received a copy of the GNU General Public License
  18 #along with GCC; see the file COPYING3.  If not see
  19 #<http://www.gnu.org/licenses/>.
  20
  21 # ACX_PROG_CC_WARNING_OPTS(WARNINGS, [VARIABLE = WARN_CFLAGS)
  22 #   Sets @VARIABLE@ to the subset of the given options which the
  23 #   compiler accepts.
  24 AC_DEFUN([ACX_PROG_CC_WARNING_OPTS],
  25 [AC_REQUIRE([AC_PROG_CC])dnl
  26 m4_pushdef([acx_Var], [m4_default([$2], [WARN_CFLAGS])])dnl
  27 AC_SUBST(acx_Var)dnl
  28 m4_expand_once([acx_Var=
  29 ],m4_quote(acx_Var=))dnl
  30 save_CFLAGS="$CFLAGS"
  31 for real_option in $1; do
  32   # Do the check with the no- prefix removed since gcc silently
  33   # accepts any -Wno-* option on purpose
  34   case $real_option in
  35     -Wno-*) option=-W`expr x$real_option : 'x-Wno-\(.*\)'` ;;
  36     *) option=$real_option ;;
  37   esac
  38   AS_VAR_PUSHDEF([acx_Woption], [acx_cv_prog_cc_warning_$option])
  39   AC_CACHE_CHECK([whether $CC supports $option], acx_Woption,
  40     [CFLAGS="$option"
  41     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[])],
  42       [AS_VAR_SET(acx_Woption, yes)],
  43       [AS_VAR_SET(acx_Woption, no)])
  44   ])
  45   AS_IF([test AS_VAR_GET(acx_Woption) = yes],
  46         [acx_Var="$acx_Var${acx_Var:+ }$real_option"])
  47   AS_VAR_POPDEF([acx_Woption])dnl
  48 done
  49 CFLAGS="$save_CFLAGS"
  50 m4_popdef([acx_Var])dnl
  51 ])# ACX_PROG_CC_WARNING_OPTS
  52
  53 # ACX_PROG_CC_WARNING_ALMOST_PEDANTIC(WARNINGS, [VARIABLE = WARN_PEDANTIC])
  54 #   Append to VARIABLE "-pedantic" + the argument, if the compiler is GCC
  55 #   and accepts all of those options simultaneously, otherwise to nothing.
  56 AC_DEFUN([ACX_PROG_CC_WARNING_ALMOST_PEDANTIC],
  57 [AC_REQUIRE([AC_PROG_CC])dnl
  58 m4_pushdef([acx_Var], [m4_default([$2], [WARN_PEDANTIC])])dnl
  59 AC_SUBST(acx_Var)dnl
  60 m4_expand_once([acx_Var=
  61 ],m4_quote(acx_Var=))dnl
  62 # Do the check with the no- prefix removed from the warning options
  63 # since gcc silently accepts any -Wno-* option on purpose
  64 m4_pushdef([acx_Woptions], [m4_bpatsubst([$1], [-Wno-], [-W])])dnl
  65 AS_VAR_PUSHDEF([acx_Pedantic], [acx_cv_prog_cc_pedantic_]acx_Woptions)dnl
  66 AS_IF([test "$GCC" = yes],
  67 [AC_CACHE_CHECK([whether $CC supports -pedantic ]acx_Woptions, acx_Pedantic,
  68 [save_CFLAGS="$CFLAGS"
  69 CFLAGS="-pedantic acx_Woptions"
  70 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[])],
  71    [AS_VAR_SET(acx_Pedantic, yes)],
  72    [AS_VAR_SET(acx_Pedantic, no)])
  73 CFLAGS="$save_CFLAGS"])
  74 AS_IF([test AS_VAR_GET(acx_Pedantic) = yes],
  75       [acx_Var="$acx_Var${acx_Var:+ }-pedantic $1"])
  76 ])
  77 AS_VAR_POPDEF([acx_Pedantic])dnl
  78 m4_popdef([acx_Woptions])dnl
  79 m4_popdef([acx_Var])dnl
  80 ])# ACX_PROG_CC_WARNING_ALMOST_PEDANTIC
  81
  82 # ACX_PROG_CC_WARNINGS_ARE_ERRORS([x.y.z], [VARIABLE = WERROR])
  83 #   sets @VARIABLE@ to "-Werror" if the compiler is GCC >=x.y.z, or if
  84 #   --enable-werror-always was given on the command line, otherwise
  85 #   to nothing.
  86 #   If the argument is the word "manual" instead of a version number,
  87 #   then @VARIABLE@ will be set to -Werror only if --enable-werror-always
  88 #   appeared on the configure command line.
  89 AC_DEFUN([ACX_PROG_CC_WARNINGS_ARE_ERRORS],
  90 [AC_REQUIRE([AC_PROG_CC])dnl
  91 m4_pushdef([acx_Var], [m4_default([$2], [WERROR])])dnl
  92 AC_SUBST(acx_Var)dnl
  93 m4_expand_once([acx_Var=
  94 ],m4_quote(acx_Var=))dnl
  95 AC_ARG_ENABLE(werror-always,
  96     AS_HELP_STRING([--enable-werror-always],
  97                    [enable -Werror despite compiler version]),
  98 [], [enable_werror_always=no])
  99 AS_IF([test $enable_werror_always = yes],
 100       [acx_Var="$acx_Var${acx_Var:+ }-Werror"])
 101  m4_if($1, [manual],,
 102  [AS_VAR_PUSHDEF([acx_GCCvers], [acx_cv_prog_cc_gcc_$1_or_newer])dnl
 103   AC_CACHE_CHECK([whether $CC is GCC >=$1], acx_GCCvers,
 104     [set fnord `echo $1 | tr '.' ' '`
 105      shift
 106      AC_PREPROC_IFELSE(
 107 [#if __GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ \
 108   < [$]1 * 10000 + [$]2 * 100 + [$]3
 109 #error insufficient
 110 #endif],
 111    [AS_VAR_SET(acx_GCCvers, yes)],
 112    [AS_VAR_SET(acx_GCCvers, no)])])
 113  AS_IF([test AS_VAR_GET(acx_GCCvers) = yes],
 114        [acx_Var="$acx_Var${acx_Var:+ }-Werror"])
 115   AS_VAR_POPDEF([acx_GCCvers])])
 116 m4_popdef([acx_Var])dnl
 117 ])# ACX_PROG_CC_WARNINGS_ARE_ERRORS