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Member "libextractor-1.11/m4/size_max.m4" (2 Dec 2018, 3064 Bytes) of package /linux/privat/libextractor-1.11.tar.gz:


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    1 # size_max.m4 serial 10
    2 dnl Copyright (C) 2003, 2005-2006, 2008-2016 Free Software Foundation, Inc.
    3 dnl This file is free software; the Free Software Foundation
    4 dnl gives unlimited permission to copy and/or distribute it,
    5 dnl with or without modifications, as long as this notice is preserved.
    6 
    7 dnl From Bruno Haible.
    8 
    9 AC_DEFUN([gl_SIZE_MAX],
   10 [
   11   AC_CHECK_HEADERS([stdint.h])
   12   dnl First test whether the system already has SIZE_MAX.
   13   AC_CACHE_CHECK([for SIZE_MAX], [gl_cv_size_max], [
   14     gl_cv_size_max=
   15     AC_EGREP_CPP([Found it], [
   16 #include <limits.h>
   17 #if HAVE_STDINT_H
   18 #include <stdint.h>
   19 #endif
   20 #ifdef SIZE_MAX
   21 Found it
   22 #endif
   23 ], [gl_cv_size_max=yes])
   24     if test -z "$gl_cv_size_max"; then
   25       dnl Define it ourselves. Here we assume that the type 'size_t' is not wider
   26       dnl than the type 'unsigned long'. Try hard to find a definition that can
   27       dnl be used in a preprocessor #if, i.e. doesn't contain a cast.
   28       AC_COMPUTE_INT([size_t_bits_minus_1], [sizeof (size_t) * CHAR_BIT - 1],
   29         [#include <stddef.h>
   30 #include <limits.h>], [size_t_bits_minus_1=])
   31       AC_COMPUTE_INT([fits_in_uint], [sizeof (size_t) <= sizeof (unsigned int)],
   32         [#include <stddef.h>], [fits_in_uint=])
   33       if test -n "$size_t_bits_minus_1" && test -n "$fits_in_uint"; then
   34         if test $fits_in_uint = 1; then
   35           dnl Even though SIZE_MAX fits in an unsigned int, it must be of type
   36           dnl 'unsigned long' if the type 'size_t' is the same as 'unsigned long'.
   37           AC_COMPILE_IFELSE(
   38             [AC_LANG_PROGRAM(
   39                [[#include <stddef.h>
   40                  extern size_t foo;
   41                  extern unsigned long foo;
   42                ]],
   43                [[]])],
   44             [fits_in_uint=0])
   45         fi
   46         dnl We cannot use 'expr' to simplify this expression, because 'expr'
   47         dnl works only with 'long' integers in the host environment, while we
   48         dnl might be cross-compiling from a 32-bit platform to a 64-bit platform.
   49         if test $fits_in_uint = 1; then
   50           gl_cv_size_max="(((1U << $size_t_bits_minus_1) - 1) * 2 + 1)"
   51         else
   52           gl_cv_size_max="(((1UL << $size_t_bits_minus_1) - 1) * 2 + 1)"
   53         fi
   54       else
   55         dnl Shouldn't happen, but who knows...
   56         gl_cv_size_max='((size_t)~(size_t)0)'
   57       fi
   58     fi
   59   ])
   60   if test "$gl_cv_size_max" != yes; then
   61     AC_DEFINE_UNQUOTED([SIZE_MAX], [$gl_cv_size_max],
   62       [Define as the maximum value of type 'size_t', if the system doesn't define it.])
   63   fi
   64   dnl Don't redefine SIZE_MAX in config.h if config.h is re-included after
   65   dnl <stdint.h>. Remember that the #undef in AH_VERBATIM gets replaced with
   66   dnl #define by AC_DEFINE_UNQUOTED.
   67   AH_VERBATIM([SIZE_MAX],
   68 [/* Define as the maximum value of type 'size_t', if the system doesn't define
   69    it. */
   70 #ifndef SIZE_MAX
   71 # undef SIZE_MAX
   72 #endif])
   73 ])
   74 
   75 dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
   76 dnl Remove this when we can assume autoconf >= 2.61.
   77 m4_ifdef([AC_COMPUTE_INT], [], [
   78   AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
   79 ])