1sinclude(../config/acx.m4)
2sinclude(../config/no-executables.m4)
3
4dnl See whether strncmp reads past the end of its string parameters.
5dnl On some versions of SunOS4 at least, strncmp reads a word at a time
6dnl but erroneously reads past the end of strings.  This can cause
7dnl a SEGV in some cases.
8AC_DEFUN(libiberty_AC_FUNC_STRNCMP,
9[AC_REQUIRE([AC_FUNC_MMAP])
10AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works,
11[AC_TRY_RUN([
12/* Test by Jim Wilson and Kaveh Ghazi.
13   Check whether strncmp reads past the end of its string parameters. */
14#include <sys/types.h>
15
16#ifdef HAVE_FCNTL_H
17#include <fcntl.h>
18#endif
19
20#ifdef HAVE_SYS_MMAN_H
21#include <sys/mman.h>
22#endif
23
24#ifndef MAP_ANON
25#ifdef MAP_ANONYMOUS
26#define MAP_ANON MAP_ANONYMOUS
27#else
28#define MAP_ANON MAP_FILE
29#endif
30#endif
31
32#ifndef MAP_FILE
33#define MAP_FILE 0
34#endif
35#ifndef O_RDONLY
36#define O_RDONLY 0
37#endif
38
39#define MAP_LEN 0x10000
40
41main ()
42{
43#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)
44  char *p;
45  int dev_zero;
46
47  dev_zero = open ("/dev/zero", O_RDONLY);
48  if (dev_zero < 0)
49    exit (1);
50
51  p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
52		     MAP_ANON|MAP_PRIVATE, dev_zero, 0);
53  if (p == (char *)-1)
54    p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
55		       MAP_ANON|MAP_PRIVATE, -1, 0);
56  if (p == (char *)-1)
57    exit (2);
58  else
59    {
60      char *string = "__si_type_info";
61      char *q = (char *) p + MAP_LEN - strlen (string) - 2;
62      char *r = (char *) p + 0xe;
63
64      strcpy (q, string);
65      strcpy (r, string);
66      strncmp (r, q, 14);
67    }
68#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */
69  exit (0);
70}
71], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no,
72  ac_cv_func_strncmp_works=no)
73rm -f core core.* *.core])
74if test $ac_cv_func_strncmp_works = no ; then
75  AC_LIBOBJ([strncmp])
76fi
77])
78
79dnl See if errno must be declared even when <errno.h> is included.
80AC_DEFUN(libiberty_AC_DECLARE_ERRNO,
81[AC_CACHE_CHECK(whether errno must be declared, libiberty_cv_declare_errno,
82[AC_TRY_COMPILE(
83[#include <errno.h>],
84[int x = errno;],
85libiberty_cv_declare_errno=no,
86libiberty_cv_declare_errno=yes)])
87if test $libiberty_cv_declare_errno = yes
88then AC_DEFINE(NEED_DECLARATION_ERRNO, 1,
89  [Define if errno must be declared even when <errno.h> is included.])
90fi
91])
92
93dnl See whether we need a declaration for a function.
94AC_DEFUN(libiberty_NEED_DECLARATION,
95[AC_MSG_CHECKING([whether $1 must be declared])
96AC_CACHE_VAL(libiberty_cv_decl_needed_$1,
97[AC_TRY_COMPILE([
98#include "confdefs.h"
99#include <stdio.h>
100#ifdef HAVE_STRING_H
101#include <string.h>
102#else
103#ifdef HAVE_STRINGS_H
104#include <strings.h>
105#endif
106#endif
107#ifdef HAVE_STDLIB_H
108#include <stdlib.h>
109#endif
110#ifdef HAVE_UNISTD_H
111#include <unistd.h>
112#endif],
113[char *(*pfn) = (char *(*)) $1],
114libiberty_cv_decl_needed_$1=no, libiberty_cv_decl_needed_$1=yes)])
115AC_MSG_RESULT($libiberty_cv_decl_needed_$1)
116if test $libiberty_cv_decl_needed_$1 = yes; then
117  AC_DEFINE([NEED_DECLARATION_]translit($1, [a-z], [A-Z]), 1,
118            [Define if $1 is not declared in system header files.])
119fi
120])dnl
121
122# We always want a C version of alloca() compiled into libiberty,
123# because native-compiler support for the real alloca is so !@#$%
124# unreliable that GCC has decided to use it only when being compiled
125# by GCC.  This is the part of AC_FUNC_ALLOCA that calculates the
126# information alloca.c needs.
127AC_DEFUN(libiberty_AC_FUNC_C_ALLOCA,
128[AC_CACHE_CHECK(whether alloca needs Cray hooks, ac_cv_os_cray,
129[AC_EGREP_CPP(webecray,
130[#if defined(CRAY) && ! defined(CRAY2)
131webecray
132#else
133wenotbecray
134#endif
135], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
136if test $ac_cv_os_cray = yes; then
137  for ac_func in _getb67 GETB67 getb67; do
138    AC_CHECK_FUNC($ac_func,
139      [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func,
140  [Define to one of _getb67, GETB67, getb67 for Cray-2 and Cray-YMP
141   systems. This function is required for alloca.c support on those
142   systems.])  break])
143  done
144fi
145
146AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction,
147[AC_TRY_RUN([find_stack_direction ()
148{
149  static char *addr = 0;
150  auto char dummy;
151  if (addr == 0)
152    {
153      addr = &dummy;
154      return find_stack_direction ();
155    }
156  else
157    return (&dummy > addr) ? 1 : -1;
158}
159main ()
160{
161  exit (find_stack_direction() < 0);
162}],
163  ac_cv_c_stack_direction=1,
164  ac_cv_c_stack_direction=-1,
165  ac_cv_c_stack_direction=0)])
166AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction,
167  [Define if you know the direction of stack growth for your system;
168   otherwise it will be automatically deduced at run-time.
169        STACK_DIRECTION > 0 => grows toward higher addresses
170        STACK_DIRECTION < 0 => grows toward lower addresses
171        STACK_DIRECTION = 0 => direction of growth unknown])
172])
173
174# AC_LANG_FUNC_LINK_TRY(C)(FUNCTION)
175# ----------------------------------
176# Don't include <ctype.h> because on OSF/1 3.0 it includes
177# <sys/types.h> which includes <sys/select.h> which contains a
178# prototype for select.  Similarly for bzero.
179#
180# This test used to merely assign f=$1 in main(), but that was
181# optimized away by HP unbundled cc A.05.36 for ia64 under +O3,
182# presumably on the basis that there's no need to do that store if the
183# program is about to exit.  Conversely, the AIX linker optimizes an
184# unused external declaration that initializes f=$1.  So this test
185# program has both an external initialization of f, and a use of f in
186# main that affects the exit status.
187#
188m4_define([AC_LANG_FUNC_LINK_TRY(C)],
189[AC_LANG_PROGRAM(
190[/* System header to define __stub macros and hopefully few prototypes,
191    which can conflict with char $1 (); below.
192    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
193    <limits.h> exists even on freestanding compilers.  Under hpux,
194    including <limits.h> includes <sys/time.h> and causes problems
195    checking for functions defined therein.  */
196#if defined (__STDC__) && !defined (_HPUX_SOURCE)
197# include <limits.h>
198#else
199# include <assert.h>
200#endif
201/* Override any gcc2 internal prototype to avoid an error.  */
202#ifdef __cplusplus
203extern "C"
204{
205#endif
206/* We use char because int might match the return type of a gcc2
207   builtin and then its argument prototype would still apply.  */
208char $1 ();
209/* The GNU C library defines this for functions which it implements
210    to always fail with ENOSYS.  Some functions are actually named
211    something starting with __ and the normal name is an alias.  */
212#if defined (__stub_$1) || defined (__stub___$1)
213choke me
214#else
215char (*f) () = $1;
216#endif
217#ifdef __cplusplus
218}
219#endif
220], [return f != $1;])])
221
222