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dnl See whether strncmp reads past the end of its string parameters.

dnl On some versions of SunOS4 at least, strncmp reads a word at a time

dnl but erroneously reads past the end of strings.  This can cause

dnl a SEGV in some cases.

AC_DEFUN(libiberty_AC_FUNC_STRNCMP,

[AC_REQUIRE([AC_FUNC_MMAP])

AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works,

[AC_TRY_RUN([

/* Test by Jim Wilson and Kaveh Ghazi.

   Check whether strncmp reads past the end of its string parameters. */

#include <sys/types.h>

#ifdef HAVE_FCNTL_H

#include <fcntl.h>

#endif

#ifdef HAVE_SYS_MMAN_H

#include <sys/mman.h>

#endif

#ifndef MAP_ANON

#ifdef MAP_ANONYMOUS

#define MAP_ANON MAP_ANONYMOUS

#else

#define MAP_ANON MAP_FILE

#endif

#endif

#ifndef MAP_FILE

#define MAP_FILE 0

#endif

#ifndef O_RDONLY

#define O_RDONLY 0

#endif

#define MAP_LEN 0x10000

main ()

{

#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)

  char *p;

  int dev_zero;

  dev_zero = open ("/dev/zero", O_RDONLY);

  if (dev_zero < 0)

    exit (1);

  p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,

                     MAP_ANON|MAP_PRIVATE, dev_zero, 0);

  if (p == (char *)-1)

    exit (2);

  else

    {

      char *string = "__si_type_info";

      char *q = (char *) p + MAP_LEN - strlen (string) - 2;

      char *r = (char *) p + 0xe;

      strcpy (q, string);

      strcpy (r, string);

      strncmp (r, q, 14);

    }

#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */

  exit (0);

}

], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no,

  ac_cv_func_strncmp_works=no)

rm -f core core.* *.core])

if test $ac_cv_func_strncmp_works = no ; then

  LIBOBJS="$LIBOBJS strncmp.o"

fi

])

dnl See if errno must be declared even when <errno.h> is included.

AC_DEFUN(libiberty_AC_DECLARE_ERRNO,

[AC_CACHE_CHECK(whether errno must be declared, libiberty_cv_declare_errno,

[AC_TRY_COMPILE(

[#include <errno.h>],

[int x = errno;],

libiberty_cv_declare_errno=no,

libiberty_cv_declare_errno=yes)])

if test $libiberty_cv_declare_errno = yes

then AC_DEFINE(NEED_DECLARATION_ERRNO, 1,

  [Define if errno must be declared even when <errno.h> is included.])

fi

])

# FIXME: We temporarily define our own version of AC_PROG_CC.  This is

# copied from autoconf 2.12, but does not call AC_PROG_CC_WORKS.  We

# are probably using a cross compiler, which will not be able to fully

# link an executable.  This should really be fixed in autoconf

# itself.

AC_DEFUN(LIB_AC_PROG_CC,

[AC_BEFORE([$0], [AC_PROG_CPP])dnl

AC_PROVIDE([AC_PROG_CC])

AC_CHECK_PROG(CC, gcc, gcc)

if test -z "$CC"; then

  AC_CHECK_PROG(CC, cc, cc, , , /usr/ucb/cc)

  test -z "$CC" && AC_MSG_ERROR([no acceptable cc found in \$PATH])

fi

AC_PROG_CC_GNU

if test $ac_cv_prog_gcc = yes; then

  GCC=yes

  ac_libiberty_warn_cflags='-W -Wall -Wtraditional -pedantic'

dnl Check whether -g works, even if CFLAGS is set, in case the package

dnl plays around with CFLAGS (such as to build both debugging and

dnl normal versions of a library), tasteless as that idea is.

  ac_test_CFLAGS="${CFLAGS+set}"

  ac_save_CFLAGS="$CFLAGS"

  CFLAGS=

  AC_PROG_CC_G

  if test "$ac_test_CFLAGS" = set; then

    CFLAGS="$ac_save_CFLAGS"

  elif test $ac_cv_prog_cc_g = yes; then

    CFLAGS="-g -O2"

  else

    CFLAGS="-O2"

  fi

else

  GCC=

  ac_libiberty_warn_cflags=

  test "${CFLAGS+set}" = set || CFLAGS="-g"

fi

AC_SUBST(ac_libiberty_warn_cflags)

])

# Work around a bug in autoheader.  This can go away when we switch to

# autoconf >2.50.  The use of define instead of AC_DEFUN is

# deliberate.

define(AC_DEFINE_NOAUTOHEADER,

[cat >> confdefs.h <<\EOF

[#define] $1 ifelse($#, 2, [$2], $#, 3, [$2], 1)

EOF

])

# We always want a C version of alloca() compiled into libiberty,

# because native-compiler support for the real alloca is so !@#$%

# unreliable that GCC has decided to use it only when being compiled

# by GCC.  This is the part of AC_FUNC_ALLOCA that calculates the

# information alloca.c needs.

AC_DEFUN(libiberty_AC_FUNC_C_ALLOCA,

[AC_CACHE_CHECK(whether alloca needs Cray hooks, ac_cv_os_cray,

[AC_EGREP_CPP(webecray,

[#if defined(CRAY) && ! defined(CRAY2)

webecray

#else

wenotbecray

#endif

], ac_cv_os_cray=yes, ac_cv_os_cray=no)])

if test $ac_cv_os_cray = yes; then

  for ac_func in _getb67 GETB67 getb67; do

    AC_CHECK_FUNC($ac_func,

      [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func,

  [Define to one of _getb67, GETB67, getb67 for Cray-2 and Cray-YMP

   systems. This function is required for alloca.c support on those

   systems.])  break])

  done

fi

AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction,

[AC_TRY_RUN([find_stack_direction ()

{

  static char *addr = 0;

  auto char dummy;

  if (addr == 0)

    {

      addr = &dummy;

      return find_stack_direction ();

    }

  else

    return (&dummy > addr) ? 1 : -1;

}

main ()

{

  exit (find_stack_direction() < 0);

}],

  ac_cv_c_stack_direction=1,

  ac_cv_c_stack_direction=-1,

  ac_cv_c_stack_direction=0)])

AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction,

  [Define if you know the direction of stack growth for your system;

   otherwise it will be automatically deduced at run-time.

        STACK_DIRECTION > 0 => grows toward higher addresses

        STACK_DIRECTION < 0 => grows toward lower addresses

        STACK_DIRECTION = 0 => direction of growth unknown])

])