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-rw-r--r--gnu/dist/diffutils/lib/c-stack.c239
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diff --git a/gnu/dist/diffutils/lib/c-stack.c b/gnu/dist/diffutils/lib/c-stack.c
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index 7826573b0c4..00000000000
--- a/gnu/dist/diffutils/lib/c-stack.c
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@@ -1,239 +0,0 @@
-/* $NetBSD: c-stack.c,v 1.1.1.1 2003/01/26 00:43:15 wiz Exp $ */
-
-/* Stack overflow handling.
-
- Copyright (C) 2002 Free Software Foundation, Inc.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
-
-/* Written by Paul Eggert. */
-
-/* This module assumes that each stack frame is smaller than a page.
- If you use alloca, dynamic arrays, or large local variables, your
- program may extend the stack by more than a page at a time. If so,
- the code below may incorrectly report a program error, or worse
- yet, may not detect the overflow at all. To avoid this problem,
- don't use large local arrays. */
-
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-
-#include <errno.h>
-#ifndef ENOTSUP
-# define ENOTSUP EINVAL
-#endif
-
-#if HAVE_INTTYPES_H
-# include <inttypes.h>
-#else
-# if HAVE_STDINT_H
-# include <stdint.h>
-# endif
-#endif
-
-#include <signal.h>
-#include <stdlib.h>
-#include <string.h>
-
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
-#ifndef STDERR_FILENO
-# define STDERR_FILENO 2
-#endif
-
-#include "c-stack.h"
-#include "exitfail.h"
-
-extern char *program_name;
-
-#if HAVE_XSI_STACK_OVERFLOW_HEURISTIC
-
-# include <ucontext.h>
-
-
-/* Storage for the alternate signal stack. */
-static union
-{
- char buffer[SIGSTKSZ];
-
- /* These other members are for proper alignment. There's no
- standard way to guarantee stack alignment, but this seems enough
- in practice. */
- long double ld;
- uintmax_t u;
- void *p;
-} alternate_signal_stack;
-
-
-/* Direction of the C runtime stack. This function is
- async-signal-safe. */
-
-# if STACK_DIRECTION
-# define find_stack_direction(ptr) STACK_DIRECTION
-# else
-static int
-find_stack_direction (char const *addr)
-{
- char dummy;
- return ! addr ? find_stack_direction (&dummy) : addr < &dummy ? 1 : -1;
-}
-# endif
-
-/* The SIGSEGV handler. */
-static void (* volatile segv_action) (int, siginfo_t *, void *);
-
-/* Handle a segmentation violation and exit. This function is
- async-signal-safe. */
-
-static void
-segv_handler (int signo, siginfo_t *info, void *context)
-{
- /* Clear SIGNO if it seems to have been a stack overflow. */
- if (0 < info->si_code)
- {
- /* If the faulting address is within the stack, or within one
- page of the stack end, assume that it is a stack
- overflow. */
- ucontext_t const *user_context = context;
- char const *stack_min = user_context->uc_stack.ss_sp;
- size_t stack_size = user_context->uc_stack.ss_size;
- char const *faulting_address = info->si_addr;
- size_t s = faulting_address - stack_min;
- size_t page_size = sysconf (_SC_PAGESIZE);
- if (find_stack_direction (0) < 0)
- s += page_size;
- if (s < stack_size + page_size)
- signo = 0;
- }
-
- segv_action (signo, info, context);
-}
-
-#endif /* HAVE_XSI_STACK_OVERFLOW_HEURISTIC */
-
-
-/* Translated messages for program errors and stack overflow. Do not
- translate them in the signal handler, since gettext is not
- async-signal-safe. */
-static char const * volatile program_error_message;
-static char const * volatile stack_overflow_message;
-
-/* Output an error message, then exit with status EXIT_FAILURE if it
- appears to have been a stack overflow, or with a core dump
- otherwise. This function is async-signal-safe. */
-
-void
-c_stack_die (int signo, siginfo_t *info, void *context)
-{
- char const *message =
- signo ? program_error_message : stack_overflow_message;
- write (STDERR_FILENO, program_name, strlen (program_name));
- write (STDERR_FILENO, ": ", 2);
- write (STDERR_FILENO, message, strlen (message));
- write (STDERR_FILENO, "\n", 1);
- if (! signo)
- _exit (exit_failure);
-#if HAVE_SIGINFO_T
- if (context && info && 0 <= info->si_code)
- {
- /* Re-raise the exception at the same address. */
- char *addr = info->si_addr;
- *addr = 0;
- }
-#endif
- kill (getpid (), signo);
-}
-
-
-/* Set up ACTION so that it is invoked on C stack overflow. Return -1
- (setting errno) if this cannot be done.
-
- ACTION must invoke only async-signal-safe functions. ACTION
- together with its callees must not require more than SIGSTKSZ bytes
- of stack space. */
-
-int
-c_stack_action (void (*action) (int, siginfo_t *, void *))
-{
-#if ! HAVE_XSI_STACK_OVERFLOW_HEURISTIC
- errno = ENOTSUP;
- return -1;
-#else
- struct sigaction act;
- stack_t st;
- int r;
-
- st.ss_flags = 0;
- st.ss_sp = alternate_signal_stack.buffer;
- st.ss_size = sizeof alternate_signal_stack.buffer;
- r = sigaltstack (&st, 0);
- if (r != 0)
- return r;
-
- program_error_message = _("program error");
- stack_overflow_message = _("stack overflow");
- segv_action = action;
-
- sigemptyset (&act.sa_mask);
-
- /* POSIX 1003.1-2001 says SA_RESETHAND implies SA_NODEFER, but this
- is not true on Solaris 8 at least. It doesn't hurt to use
- SA_NODEFER here, so leave it in. */
- act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
-
- act.sa_sigaction = segv_handler;
- return sigaction (SIGSEGV, &act, 0);
-#endif
-}
-
-#if DEBUG
-
-#include <stdio.h>
-
-int volatile exit_failure;
-
-static long
-recurse (char *p)
-{
- char array[500];
- array[0] = 1;
- return *p + recurse (array);
-}
-
-char *program_name;
-
-int
-main (int argc, char **argv)
-{
- program_name = argv[0];
- c_stack_action (c_stack_die);
- return recurse ("\1");
-}
-
-#endif /* DEBUG */
-
-/*
-Local Variables:
-compile-command: "gcc -D_GNU_SOURCE -DDEBUG \
- -DHAVE_INTTYPES_H -DHAVE_SIGINFO_T \
- -DHAVE_XSI_STACK_OVERFLOW_HEURISTIC -DHAVE_UNISTD_H \
- -Wall -W -g c-stack.c -o c-stack"
-End:
-*/