1dnl Copyright (C) 2000-2024 Free Software Foundation, Inc. 2dnl 3dnl GCC is free software; you can redistribute it and/or modify 4dnl it under the terms of the GNU General Public License as published by 5dnl the Free Software Foundation; either version 3, or (at your option) 6dnl any later version. 7dnl 8dnl GCC is distributed in the hope that it will be useful, 9dnl but WITHOUT ANY WARRANTY; without even the implied warranty of 10dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11dnl GNU General Public License for more details. 12dnl 13dnl You should have received a copy of the GNU General Public License 14dnl along with GCC; see the file COPYING3. If not see 15dnl <http://www.gnu.org/licenses/>. 16 17dnl See whether strncmp reads past the end of its string parameters. 18dnl On some versions of SunOS4 at least, strncmp reads a word at a time 19dnl but erroneously reads past the end of strings. This can cause 20dnl a SEGV in some cases. 21AC_DEFUN([libiberty_AC_FUNC_STRNCMP], 22[AC_REQUIRE([AC_FUNC_MMAP]) 23AC_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 56int 57main (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) 89rm -f core core.* *.core]) 90if test $ac_cv_func_strncmp_works = no ; then 91 AC_LIBOBJ([strncmp]) 92fi 93]) 94 95dnl See if errno must be declared even when <errno.h> is included. 96AC_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;], 101libiberty_cv_declare_errno=no, 102libiberty_cv_declare_errno=yes)]) 103if test $libiberty_cv_declare_errno = yes 104then AC_DEFINE(NEED_DECLARATION_ERRNO, 1, 105 [Define if errno must be declared even when <errno.h> is included.]) 106fi 107]) 108 109dnl See whether we need a declaration for a function. 110AC_DEFUN([libiberty_NEED_DECLARATION], 111[AC_MSG_CHECKING([whether $1 must be declared]) 112AC_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], 130libiberty_cv_decl_needed_$1=no, libiberty_cv_decl_needed_$1=yes)]) 131AC_MSG_RESULT($libiberty_cv_decl_needed_$1) 132if test $libiberty_cv_decl_needed_$1 = yes; then 133 AC_DEFINE([NEED_DECLARATION_]translit($1, [a-z], [A-Z]), 1, 134 [Define if $1 is not declared in system header files.]) 135fi 136])dnl 137 138# We always want a C version of alloca() compiled into libiberty, 139# because native-compiler support for the real alloca is so !@#$% 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. 143AC_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) 147webecray 148#else 149wenotbecray 150#endif 151], ac_cv_os_cray=yes, ac_cv_os_cray=no)]) 152if 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 160fi 161 162AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction, 163[AC_TRY_RUN([#include <stdlib.h> 164 165int 166find_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 179int 180main (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)]) 187AC_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]) 194