libiberty/acinclude.m4

   1 dnl Copyright (C) 2000-2022 Free Software Foundation, Inc.
   2 dnl
   3 dnl GCC is free software; you can redistribute it and/or modify
   4 dnl it under the terms of the GNU General Public License as published by
   5 dnl the Free Software Foundation; either version 3, or (at your option)
   6 dnl any later version.
   7 dnl
   8 dnl GCC is distributed in the hope that it will be useful,
   9 dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 dnl GNU General Public License for more details.
  12 dnl
  13 dnl You should have received a copy of the GNU General Public License
  14 dnl along with GCC; see the file COPYING3.  If not see
  15 dnl <http://www.gnu.org/licenses/>.
  16
  17 dnl See whether strncmp reads past the end of its string parameters.
  18 dnl On some versions of SunOS4 at least, strncmp reads a word at a time
  19 dnl but erroneously reads past the end of strings.  This can cause
  20 dnl a SEGV in some cases.
  21 AC_DEFUN([libiberty_AC_FUNC_STRNCMP],
  22 [AC_REQUIRE([AC_FUNC_MMAP])
  23 AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works,
  24 [AC_TRY_RUN([
  25 /* Test by Jim Wilson and Kaveh Ghazi.
  26    Check whether strncmp reads past the end of its string parameters. */
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30
  31 #ifdef HAVE_FCNTL_H
  32 #include <fcntl.h>
  33 #endif
  34
  35 #ifdef HAVE_SYS_MMAN_H
  36 #include <sys/mman.h>
  37 #endif
  38
  39 #ifndef MAP_ANON
  40 #ifdef MAP_ANONYMOUS
  41 #define MAP_ANON MAP_ANONYMOUS
  42 #else
  43 #define MAP_ANON MAP_FILE
  44 #endif
  45 #endif
  46
  47 #ifndef MAP_FILE
  48 #define MAP_FILE 0
  49 #endif
  50 #ifndef O_RDONLY
  51 #define O_RDONLY 0
  52 #endif
  53
  54 #define MAP_LEN 0x10000
  55
  56 int
  57 main (void)
  58 {
  59 #if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)
  60   char *p;
  61   int dev_zero;
  62
  63   dev_zero = open ("/dev/zero", O_RDONLY);
  64   if (dev_zero < 0)
  65     exit (1);
  66
  67   p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
  68                      MAP_ANON|MAP_PRIVATE, dev_zero, 0);
  69   if (p == (char *)-1)
  70     p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
  71                        MAP_ANON|MAP_PRIVATE, -1, 0);
  72   if (p == (char *)-1)
  73     exit (2);
  74   else
  75     {
  76       char *string = "__si_type_info";
  77       char *q = (char *) p + MAP_LEN - strlen (string) - 2;
  78       char *r = (char *) p + 0xe;
  79
  80       strcpy (q, string);
  81       strcpy (r, string);
  82       strncmp (r, q, 14);
  83     }
  84 #endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */
  85   exit (0);
  86 }
  87 ], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no,
  88   ac_cv_func_strncmp_works=yes)
  89 rm -f core core.* *.core])
  90 if test $ac_cv_func_strncmp_works = no ; then
  91   AC_LIBOBJ([strncmp])
  92 fi
  93 ])
  94
  95 dnl See if errno must be declared even when <errno.h> is included.
  96 AC_DEFUN([libiberty_AC_DECLARE_ERRNO],
  97 [AC_CACHE_CHECK(whether errno must be declared, libiberty_cv_declare_errno,
  98 [AC_TRY_COMPILE(
  99 [#include <errno.h>],
 100 [int x = errno;],
 101 libiberty_cv_declare_errno=no,
 102 libiberty_cv_declare_errno=yes)])
 103 if test $libiberty_cv_declare_errno = yes
 104 then AC_DEFINE(NEED_DECLARATION_ERRNO, 1,
 105   [Define if errno must be declared even when <errno.h> is included.])
 106 fi
 107 ])
 108
 109 dnl See whether we need a declaration for a function.
 110 AC_DEFUN([libiberty_NEED_DECLARATION],
 111 [AC_MSG_CHECKING([whether $1 must be declared])
 112 AC_CACHE_VAL(libiberty_cv_decl_needed_$1,
 113 [AC_TRY_COMPILE([
 114 #include "confdefs.h"
 115 #include <stdio.h>
 116 #ifdef HAVE_STRING_H
 117 #include <string.h>
 118 #else
 119 #ifdef HAVE_STRINGS_H
 120 #include <strings.h>
 121 #endif
 122 #endif
 123 #ifdef HAVE_STDLIB_H
 124 #include <stdlib.h>
 125 #endif
 126 #ifdef HAVE_UNISTD_H
 127 #include <unistd.h>
 128 #endif],
 129 [char *(*pfn) = (char *(*)) $1],
 130 libiberty_cv_decl_needed_$1=no, libiberty_cv_decl_needed_$1=yes)])
 131 AC_MSG_RESULT($libiberty_cv_decl_needed_$1)
 132 if test $libiberty_cv_decl_needed_$1 = yes; then
 133   AC_DEFINE([NEED_DECLARATION_]translit($1, [a-z], [A-Z]), 1,
 134             [Define if $1 is not declared in system header files.])
 135 fi
 136 ])dnl
 137
 138 # We always want a C version of alloca() compiled into libiberty,
 139 # because native-compiler support for the real alloca is so !@#$%
 140 # unreliable that GCC has decided to use it only when being compiled
 141 # by GCC.  This is the part of AC_FUNC_ALLOCA that calculates the
 142 # information alloca.c needs.
 143 AC_DEFUN([libiberty_AC_FUNC_C_ALLOCA],
 144 [AC_CACHE_CHECK(whether alloca needs Cray hooks, ac_cv_os_cray,
 145 [AC_EGREP_CPP(webecray,
 146 [#if defined(CRAY) && ! defined(CRAY2)
 147 webecray
 148 #else
 149 wenotbecray
 150 #endif
 151 ], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
 152 if test $ac_cv_os_cray = yes; then
 153   for ac_func in _getb67 GETB67 getb67; do
 154     AC_CHECK_FUNC($ac_func,
 155       [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func,
 156   [Define to one of _getb67, GETB67, getb67 for Cray-2 and Cray-YMP
 157    systems. This function is required for alloca.c support on those
 158    systems.])  break])
 159   done
 160 fi
 161
 162 AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction,
 163 [AC_TRY_RUN([#include <stdlib.h>
 164
 165 int
 166 find_stack_direction (void)
 167 {
 168   static char *addr = 0;
 169   auto char dummy;
 170   if (addr == 0)
 171     {
 172       addr = &dummy;
 173       return find_stack_direction ();
 174     }
 175   else
 176     return (&dummy > addr) ? 1 : -1;
 177 }
 178
 179 int
 180 main (void)
 181 {
 182   exit (find_stack_direction() < 0);
 183 }],
 184   ac_cv_c_stack_direction=1,
 185   ac_cv_c_stack_direction=-1,
 186   ac_cv_c_stack_direction=0)])
 187 AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction,
 188   [Define if you know the direction of stack growth for your system;
 189    otherwise it will be automatically deduced at run-time.
 190         STACK_DIRECTION > 0 => grows toward higher addresses
 191         STACK_DIRECTION < 0 => grows toward lower addresses
 192         STACK_DIRECTION = 0 => direction of growth unknown])
 193 ])