199b2450f6
Change all references to stdout/stderr to gdb_stdout/gdb_stderr. Replace all calls to stdio output functions with calls to corresponding _unfiltered functions (`fprintf_unfiltered') Replaced calls to fopen for output to gdb_fopen. Added sufficient goo to utils.c and defs.h to make the above work. The net effect is that stdio output functions are only directly used in utils.c. Elsewhere, the _unfiltered and _filtered functions and GDB_FILE type are used. In the near future, GDB_FILE will stop being equivalant to FILE. The semantics of some commands has changed in a very subtle way: called in the right context, they may cause new occurences of prompt_for_continue() behavior. The testsuite doesn't notice anything like this, though. Please respect this change by not reintroducing stdio output dependencies in the main body of gdb code. All output from commands should go to a GDB_FILE. Target-specific code can still use stdio directly to communicate with targets.
309 lines
8.7 KiB
C
309 lines
8.7 KiB
C
/* Fork a Unix child process, and set up to debug it, for GDB.
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Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
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Contributed by Cygnus Support.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "defs.h"
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#include "frame.h" /* required by inferior.h */
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#include "inferior.h"
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#include "target.h"
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#include "wait.h"
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#include "gdbcore.h"
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#include "terminal.h"
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#include "thread.h"
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#include <signal.h>
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#ifdef SET_STACK_LIMIT_HUGE
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#include <sys/time.h>
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#include <sys/resource.h>
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extern int original_stack_limit;
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#endif /* SET_STACK_LIMIT_HUGE */
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extern char **environ;
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/* Start an inferior Unix child process and sets inferior_pid to its pid.
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EXEC_FILE is the file to run.
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ALLARGS is a string containing the arguments to the program.
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ENV is the environment vector to pass. Errors reported with error(). */
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#ifndef SHELL_FILE
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#define SHELL_FILE "/bin/sh"
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#endif
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void
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fork_inferior (exec_file, allargs, env, traceme_fun, init_trace_fun)
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char *exec_file;
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char *allargs;
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char **env;
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void (*traceme_fun) PARAMS ((void));
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void (*init_trace_fun) PARAMS ((int));
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{
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int pid;
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char *shell_command;
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char *shell_file;
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static char default_shell_file[] = SHELL_FILE;
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int len;
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/* Set debug_fork then attach to the child while it sleeps, to debug. */
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static int debug_fork = 0;
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/* This is set to the result of setpgrp, which if vforked, will be visible
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to you in the parent process. It's only used by humans for debugging. */
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static int debug_setpgrp = 657473;
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char **save_our_env;
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/* If no exec file handed to us, get it from the exec-file command -- with
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a good, common error message if none is specified. */
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if (exec_file == 0)
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exec_file = get_exec_file(1);
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/* The user might want tilde-expansion, and in general probably wants
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the program to behave the same way as if run from
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his/her favorite shell. So we let the shell run it for us.
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FIXME, this should probably search the local environment (as
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modified by the setenv command), not the env gdb inherited. */
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shell_file = getenv ("SHELL");
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if (shell_file == NULL)
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shell_file = default_shell_file;
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/* Multiplying the length of exec_file by 4 is to account for the fact
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that it may expand when quoted; it is a worst-case number based on
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every character being '. */
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len = 5 + 4 * strlen (exec_file) + 1 + strlen (allargs) + 1 + /*slop*/ 12;
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/* If desired, concat something onto the front of ALLARGS.
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SHELL_COMMAND is the result. */
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#ifdef SHELL_COMMAND_CONCAT
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shell_command = (char *) alloca (strlen (SHELL_COMMAND_CONCAT) + len);
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strcpy (shell_command, SHELL_COMMAND_CONCAT);
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#else
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shell_command = (char *) alloca (len);
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shell_command[0] = '\0';
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#endif
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strcat (shell_command, "exec ");
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/* Now add exec_file, quoting as necessary. */
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{
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char *p;
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int need_to_quote;
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/* Quoting in this style is said to work with all shells. But csh
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on IRIX 4.0.1 can't deal with it. So we only quote it if we need
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to. */
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p = exec_file;
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while (1)
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{
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switch (*p)
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{
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case '\'':
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case '"':
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case '(':
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case ')':
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case '$':
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case '&':
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case ';':
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case '<':
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case '>':
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case ' ':
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case '\n':
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case '\t':
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need_to_quote = 1;
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goto end_scan;
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case '\0':
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need_to_quote = 0;
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goto end_scan;
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default:
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break;
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}
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++p;
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}
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end_scan:
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if (need_to_quote)
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{
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strcat (shell_command, "'");
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for (p = exec_file; *p != '\0'; ++p)
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{
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if (*p == '\'')
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strcat (shell_command, "'\\''");
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else
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strncat (shell_command, p, 1);
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}
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strcat (shell_command, "'");
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}
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else
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strcat (shell_command, exec_file);
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}
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strcat (shell_command, " ");
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strcat (shell_command, allargs);
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/* exec is said to fail if the executable is open. */
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close_exec_file ();
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/* Retain a copy of our environment variables, since the child will
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replace the value of environ and if we're vforked, we have to
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restore it. */
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save_our_env = environ;
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/* Tell the terminal handling subsystem what tty we plan to run on;
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it will just record the information for later. */
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new_tty_prefork (inferior_io_terminal);
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/* It is generally good practice to flush any possible pending stdio
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output prior to doing a fork, to avoid the possibility of both the
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parent and child flushing the same data after the fork. */
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gdb_flush (gdb_stdout);
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gdb_flush (gdb_stderr);
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#if defined(USG) && !defined(HAVE_VFORK)
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pid = fork ();
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#else
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if (debug_fork)
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pid = fork ();
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else
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pid = vfork ();
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#endif
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if (pid < 0)
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perror_with_name ("vfork");
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if (pid == 0)
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{
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if (debug_fork)
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sleep (debug_fork);
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/* Run inferior in a separate process group. */
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debug_setpgrp = gdb_setpgid ();
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if (debug_setpgrp == -1)
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perror("setpgrp failed in child");
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#ifdef SET_STACK_LIMIT_HUGE
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/* Reset the stack limit back to what it was. */
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{
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struct rlimit rlim;
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getrlimit (RLIMIT_STACK, &rlim);
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rlim.rlim_cur = original_stack_limit;
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setrlimit (RLIMIT_STACK, &rlim);
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}
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#endif /* SET_STACK_LIMIT_HUGE */
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/* Ask the tty subsystem to switch to the one we specified earlier
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(or to share the current terminal, if none was specified). */
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new_tty ();
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/* Changing the signal handlers for the inferior after
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a vfork can also change them for the superior, so we don't mess
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with signals here. See comments in
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initialize_signals for how we get the right signal handlers
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for the inferior. */
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/* "Trace me, Dr. Memory!" */
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(*traceme_fun) ();
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/* There is no execlpe call, so we have to set the environment
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for our child in the global variable. If we've vforked, this
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clobbers the parent, but environ is restored a few lines down
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in the parent. By the way, yes we do need to look down the
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path to find $SHELL. Rich Pixley says so, and I agree. */
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environ = env;
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execlp (shell_file, shell_file, "-c", shell_command, (char *)0);
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fprintf_unfiltered (gdb_stderr, "Cannot exec %s: %s.\n", shell_file,
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safe_strerror (errno));
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gdb_flush (gdb_stderr);
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_exit (0177);
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}
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/* Restore our environment in case a vforked child clob'd it. */
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environ = save_our_env;
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init_thread_list();
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inferior_pid = pid; /* Needed for wait_for_inferior stuff below */
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/* Now that we have a child process, make it our target, and
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initialize anything target-vector-specific that needs initializing. */
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(*init_trace_fun)(pid);
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/* We are now in the child process of interest, having exec'd the
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correct program, and are poised at the first instruction of the
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new program. */
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#ifdef SOLIB_CREATE_INFERIOR_HOOK
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SOLIB_CREATE_INFERIOR_HOOK (pid);
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#endif
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}
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/* Accept NTRAPS traps from the inferior. */
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void
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startup_inferior (ntraps)
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int ntraps;
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{
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int pending_execs = ntraps;
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int terminal_initted;
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/* The process was started by the fork that created it,
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but it will have stopped one instruction after execing the shell.
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Here we must get it up to actual execution of the real program. */
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clear_proceed_status ();
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init_wait_for_inferior ();
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terminal_initted = 0;
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while (1)
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{
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stop_soon_quietly = 1; /* Make wait_for_inferior be quiet */
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wait_for_inferior ();
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if (stop_signal != SIGTRAP)
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{
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/* Let shell child handle its own signals in its own way */
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/* FIXME, what if child has exit()ed? Must exit loop somehow */
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resume (0, stop_signal);
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}
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else
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{
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/* We handle SIGTRAP, however; it means child did an exec. */
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if (!terminal_initted)
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{
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/* Now that the child has exec'd we know it has already set its
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process group. On POSIX systems, tcsetpgrp will fail with
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EPERM if we try it before the child's setpgid. */
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/* Set up the "saved terminal modes" of the inferior
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based on what modes we are starting it with. */
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target_terminal_init ();
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/* Install inferior's terminal modes. */
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target_terminal_inferior ();
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terminal_initted = 1;
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}
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if (0 == --pending_execs)
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break;
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resume (0, 0); /* Just make it go on */
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}
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}
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stop_soon_quietly = 0;
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}
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