X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Ffork-child.c;h=65a189e0487897fc67b3bc5bcff7a545a248398b;hb=5b6d1e4fa4fc6827c7b3f0e99ff120dfa14d65d2;hp=2ea56a35e9ac96a302c56236cb65c16753aca644;hpb=c54cfec8d4215ef2b4f8019a3431749b44ee0247;p=deliverable%2Fbinutils-gdb.git
diff --git a/gdb/fork-child.c b/gdb/fork-child.c
index 2ea56a35e9..65a189e048 100644
--- a/gdb/fork-child.c
+++ b/gdb/fork-child.c
@@ -1,13 +1,14 @@
/* Fork a Unix child process, and set up to debug it, for GDB.
- Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
- 2001 Free Software Foundation, Inc.
+
+ Copyright (C) 1990-2020 Free Software Foundation, Inc.
+
Contributed by Cygnus Support.
This file is part of GDB.
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 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
@@ -16,434 +17,166 @@
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. */
+ along with this program. If not, see . */
#include "defs.h"
-#include "gdb_string.h"
-#include "frame.h" /* required by inferior.h */
#include "inferior.h"
-#include "target.h"
-#include "gdb_wait.h"
-#include "gdb_vfork.h"
-#include "gdbcore.h"
+#include "gdbcmd.h"
#include "terminal.h"
#include "gdbthread.h"
-#include "command.h" /* for dont_repeat () */
+#include "top.h"
+#include "gdbsupport/job-control.h"
+#include "gdbsupport/filestuff.h"
+#include "nat/fork-inferior.h"
+#include "gdbsupport/common-inferior.h"
-#include
+/* The exec-wrapper, if any, that will be used when starting the
+ inferior. */
-/* This just gets used as a default if we can't find SHELL */
-#ifndef SHELL_FILE
-#define SHELL_FILE "/bin/sh"
-#endif
+static char *exec_wrapper = NULL;
-extern char **environ;
+/* See gdbsupport/common-inferior.h. */
-/* This function breaks up an argument string into an argument
- * vector suitable for passing to execvp().
- * E.g., on "run a b c d" this routine would get as input
- * the string "a b c d", and as output it would fill in argv with
- * the four arguments "a", "b", "c", "d".
- */
-static void
-breakup_args (char *scratch, char **argv)
+const char *
+get_exec_wrapper ()
{
- char *cp = scratch;
-
- for (;;)
- {
-
- /* Scan past leading separators */
- while (*cp == ' ' || *cp == '\t' || *cp == '\n')
- {
- cp++;
- }
-
- /* Break if at end of string */
- if (*cp == '\0')
- break;
-
- /* Take an arg */
- *argv++ = cp;
-
- /* Scan for next arg separator */
- cp = strchr (cp, ' ');
- if (cp == NULL)
- cp = strchr (cp, '\t');
- if (cp == NULL)
- cp = strchr (cp, '\n');
-
- /* No separators => end of string => break */
- if (cp == NULL)
- break;
-
- /* Replace the separator with a terminator */
- *cp++ = '\0';
- }
+ return exec_wrapper;
+}
- /* execv requires a null-terminated arg vector */
- *argv = NULL;
+/* See nat/fork-inferior.h. */
+void
+gdb_flush_out_err ()
+{
+ gdb_flush (main_ui->m_gdb_stdout);
+ gdb_flush (main_ui->m_gdb_stderr);
}
+/* The ui structure that will be saved on 'prefork_hook' and
+ restored on 'postfork_hook'. */
+static struct ui *saved_ui = NULL;
-/* Start an inferior Unix child process and sets inferior_ptid to its pid.
- EXEC_FILE is the file to run.
- ALLARGS is a string containing the arguments to the program.
- ENV is the environment vector to pass. SHELL_FILE is the shell file,
- or NULL if we should pick one. Errors reported with error(). */
-
-/* This function is NOT-REENTRANT. Some of the variables have been
- made static to ensure that they survive the vfork() call. */
+/* See nat/fork-inferior.h. */
void
-fork_inferior (char *exec_file_arg, char *allargs, char **env,
- void (*traceme_fun) (void), void (*init_trace_fun) (int),
- void (*pre_trace_fun) (void), char *shell_file_arg)
+prefork_hook (const char *args)
{
- int pid;
- char *shell_command;
- static char default_shell_file[] = SHELL_FILE;
- int len;
- /* Set debug_fork then attach to the child while it sleeps, to debug. */
- static int debug_fork = 0;
- /* This is set to the result of setpgrp, which if vforked, will be visible
- to you in the parent process. It's only used by humans for debugging. */
- static int debug_setpgrp = 657473;
- static char *shell_file;
- static char *exec_file;
- char **save_our_env;
- int shell = 0;
- static char **argv;
-
- /* If no exec file handed to us, get it from the exec-file command -- with
- a good, common error message if none is specified. */
- exec_file = exec_file_arg;
- if (exec_file == 0)
- exec_file = get_exec_file (1);
-
- /* STARTUP_WITH_SHELL is defined in inferior.h.
- * If 0, we'll just do a fork/exec, no shell, so don't
- * bother figuring out what shell.
- */
- shell_file = shell_file_arg;
- if (STARTUP_WITH_SHELL)
- {
- /* Figure out what shell to start up the user program under. */
- if (shell_file == NULL)
- shell_file = getenv ("SHELL");
- if (shell_file == NULL)
- shell_file = default_shell_file;
- shell = 1;
- }
-
- /* Multiplying the length of exec_file by 4 is to account for the fact
- that it may expand when quoted; it is a worst-case number based on
- every character being '. */
- len = 5 + 4 * strlen (exec_file) + 1 + strlen (allargs) + 1 + /*slop */ 12;
- /* If desired, concat something onto the front of ALLARGS.
- SHELL_COMMAND is the result. */
-#ifdef SHELL_COMMAND_CONCAT
- shell_command = (char *) alloca (strlen (SHELL_COMMAND_CONCAT) + len);
- strcpy (shell_command, SHELL_COMMAND_CONCAT);
-#else
- shell_command = (char *) alloca (len);
- shell_command[0] = '\0';
-#endif
-
- if (!shell)
- {
- /* We're going to call execvp. Create argv */
- /* Largest case: every other character is a separate arg */
- argv = (char **) xmalloc (((strlen (allargs) + 1) / (unsigned) 2 + 2) * sizeof (*argv));
- argv[0] = exec_file;
- breakup_args (allargs, &argv[1]);
+ const char *inferior_io_terminal = get_inferior_io_terminal ();
- }
- else
- {
+ gdb_assert (saved_ui == NULL);
+ /* Retain a copy of our UI, since the child will replace this value
+ and if we're vforked, we have to restore it. */
+ saved_ui = current_ui;
- /* We're going to call a shell */
-
- /* Now add exec_file, quoting as necessary. */
-
- char *p;
- int need_to_quote;
-
- strcat (shell_command, "exec ");
-
- /* Quoting in this style is said to work with all shells. But csh
- on IRIX 4.0.1 can't deal with it. So we only quote it if we need
- to. */
- p = exec_file;
- while (1)
- {
- switch (*p)
- {
- case '\'':
- case '!':
- case '"':
- case '(':
- case ')':
- case '$':
- case '&':
- case ';':
- case '<':
- case '>':
- case ' ':
- case '\n':
- case '\t':
- need_to_quote = 1;
- goto end_scan;
-
- case '\0':
- need_to_quote = 0;
- goto end_scan;
-
- default:
- break;
- }
- ++p;
- }
- end_scan:
- if (need_to_quote)
- {
- strcat (shell_command, "'");
- for (p = exec_file; *p != '\0'; ++p)
- {
- if (*p == '\'')
- strcat (shell_command, "'\\''");
- else if (*p == '!')
- strcat (shell_command, "\\!");
- else
- strncat (shell_command, p, 1);
- }
- strcat (shell_command, "'");
- }
- else
- strcat (shell_command, exec_file);
-
- strcat (shell_command, " ");
- strcat (shell_command, allargs);
-
- }
+ /* Tell the terminal handling subsystem what tty we plan to run on;
+ it will just record the information for later. */
+ new_tty_prefork (inferior_io_terminal);
+}
- /* exec is said to fail if the executable is open. */
- close_exec_file ();
+/* See nat/fork-inferior.h. */
- /* Retain a copy of our environment variables, since the child will
- replace the value of environ and if we're vforked, we have to
- restore it. */
- save_our_env = environ;
+void
+postfork_hook (pid_t pid)
+{
+ inferior *inf = current_inferior ();
- /* Tell the terminal handling subsystem what tty we plan to run on;
- it will just record the information for later. */
+ inferior_appeared (inf, pid);
- new_tty_prefork (inferior_io_terminal);
+ /* Needed for wait_for_inferior stuff. */
+ inferior_ptid = ptid_t (pid);
- /* It is generally good practice to flush any possible pending stdio
- output prior to doing a fork, to avoid the possibility of both the
- parent and child flushing the same data after the fork. */
+ gdb_assert (saved_ui != NULL);
+ current_ui = saved_ui;
+ saved_ui = NULL;
- gdb_flush (gdb_stdout);
- gdb_flush (gdb_stderr);
+ new_tty_postfork ();
+}
- /* If there's any initialization of the target layers that must happen
- to prepare to handle the child we're about fork, do it now...
- */
- if (pre_trace_fun != NULL)
- (*pre_trace_fun) ();
+/* See nat/fork-inferior.h. */
- /* Create the child process. Note that the apparent call to vfork()
- below *might* actually be a call to fork() due to the fact that
- autoconf will ``#define vfork fork'' on certain platforms. */
- if (debug_fork)
- pid = fork ();
- else
- pid = vfork ();
+void
+postfork_child_hook ()
+{
+ /* This is set to the result of setpgrp, which if vforked, will be
+ visible to you in the parent process. It's only used by humans
+ for debugging. */
+ static int debug_setpgrp = 657473;
- if (pid < 0)
- perror_with_name ("vfork");
+ /* Make sure we switch to main_ui here in order to be able to
+ use the fprintf_unfiltered/warning/error functions. */
+ current_ui = main_ui;
- if (pid == 0)
+ /* Create a new session for the inferior process, if necessary.
+ It will also place the inferior in a separate process group. */
+ if (create_tty_session () <= 0)
{
- if (debug_fork)
- sleep (debug_fork);
-
- /* Run inferior in a separate process group. */
+ /* No session was created, but we still want to run the inferior
+ in a separate process group. */
debug_setpgrp = gdb_setpgid ();
if (debug_setpgrp == -1)
- perror ("setpgrp failed in child");
-
- /* Ask the tty subsystem to switch to the one we specified earlier
- (or to share the current terminal, if none was specified). */
-
- new_tty ();
-
- /* Changing the signal handlers for the inferior after
- a vfork can also change them for the superior, so we don't mess
- with signals here. See comments in
- initialize_signals for how we get the right signal handlers
- for the inferior. */
-
- /* "Trace me, Dr. Memory!" */
- (*traceme_fun) ();
- /* The call above set this process (the "child") as debuggable
- * by the original gdb process (the "parent"). Since processes
- * (unlike people) can have only one parent, if you are
- * debugging gdb itself (and your debugger is thus _already_ the
- * controller/parent for this child), code from here on out
- * is undebuggable. Indeed, you probably got an error message
- * saying "not parent". Sorry--you'll have to use print statements!
- */
-
- /* There is no execlpe call, so we have to set the environment
- for our child in the global variable. If we've vforked, this
- clobbers the parent, but environ is restored a few lines down
- in the parent. By the way, yes we do need to look down the
- path to find $SHELL. Rich Pixley says so, and I agree. */
- environ = env;
-
- /* If we decided above to start up with a shell,
- * we exec the shell,
- * "-c" says to interpret the next arg as a shell command
- * to execute, and this command is "exec ".
- * "-f" means "fast startup" to the c-shell, which means
- * don't do .cshrc file. Doing .cshrc may cause fork/exec
- * events which will confuse debugger start-up code.
- */
- if (shell)
- {
- execlp (shell_file, shell_file, "-c", shell_command, (char *) 0);
-
- /* If we get here, it's an error */
- fprintf_unfiltered (gdb_stderr, "Cannot exec %s: %s.\n", shell_file,
- safe_strerror (errno));
- gdb_flush (gdb_stderr);
- _exit (0177);
- }
- else
- {
- /* Otherwise, we directly exec the target program with execvp. */
- int i;
- char *errstring;
-
- execvp (exec_file, argv);
-
- /* If we get here, it's an error */
- errstring = safe_strerror (errno);
- fprintf_unfiltered (gdb_stderr, "Cannot exec %s ", exec_file);
-
- i = 1;
- while (argv[i] != NULL)
- {
- if (i != 1)
- fprintf_unfiltered (gdb_stderr, " ");
- fprintf_unfiltered (gdb_stderr, "%s", argv[i]);
- i++;
- }
- fprintf_unfiltered (gdb_stderr, ".\n");
- /* This extra info seems to be useless
- fprintf_unfiltered (gdb_stderr, "Got error %s.\n", errstring);
- */
- gdb_flush (gdb_stderr);
- _exit (0177);
- }
+ perror (_("setpgrp failed in child"));
}
- /* Restore our environment in case a vforked child clob'd it. */
- environ = save_our_env;
+ /* Ask the tty subsystem to switch to the one we specified
+ earlier (or to share the current terminal, if none was
+ specified). */
+ new_tty ();
+}
- init_thread_list ();
+/* See inferior.h. */
- inferior_ptid = pid_to_ptid (pid); /* Needed for wait_for_inferior stuff below */
+ptid_t
+gdb_startup_inferior (pid_t pid, int num_traps)
+{
+ inferior *inf = current_inferior ();
+ process_stratum_target *proc_target = inf->process_target ();
- /* Now that we have a child process, make it our target, and
- initialize anything target-vector-specific that needs initializing. */
+ ptid_t ptid = startup_inferior (proc_target, pid, num_traps, NULL, NULL);
- (*init_trace_fun) (pid);
+ /* Mark all threads non-executing. */
+ set_executing (proc_target, ptid, 0);
- /* We are now in the child process of interest, having exec'd the
- correct program, and are poised at the first instruction of the
- new program. */
+ return ptid;
+}
- /* Allow target dependent code to play with the new process. This might be
- used to have target-specific code initialize a variable in the new process
- prior to executing the first instruction. */
- TARGET_CREATE_INFERIOR_HOOK (pid);
+/* Implement the "unset exec-wrapper" command. */
-#ifdef SOLIB_CREATE_INFERIOR_HOOK
- SOLIB_CREATE_INFERIOR_HOOK (pid);
-#endif
+static void
+unset_exec_wrapper_command (const char *args, int from_tty)
+{
+ xfree (exec_wrapper);
+ exec_wrapper = NULL;
}
-/* Accept NTRAPS traps from the inferior. */
+static void
+show_startup_with_shell (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file,
+ _("Use of shell to start subprocesses is %s.\n"),
+ value);
+}
void
-startup_inferior (int ntraps)
+_initialize_fork_child (void)
{
- int pending_execs = ntraps;
- int terminal_initted;
-
- /* The process was started by the fork that created it,
- but it will have stopped one instruction after execing the shell.
- Here we must get it up to actual execution of the real program. */
-
- clear_proceed_status ();
-
- init_wait_for_inferior ();
-
- terminal_initted = 0;
-
- if (STARTUP_WITH_SHELL)
- inferior_ignoring_startup_exec_events = ntraps;
- else
- inferior_ignoring_startup_exec_events = 0;
- inferior_ignoring_leading_exec_events =
- target_reported_exec_events_per_exec_call () - 1;
-
-#ifdef STARTUP_INFERIOR
- STARTUP_INFERIOR (pending_execs);
-#else
- while (1)
- {
- /* Make wait_for_inferior be quiet */
- stop_soon_quietly = STOP_QUIETLY;
- wait_for_inferior ();
- if (stop_signal != TARGET_SIGNAL_TRAP)
- {
- /* Let shell child handle its own signals in its own way */
- /* FIXME, what if child has exit()ed? Must exit loop somehow */
- resume (0, stop_signal);
- }
- else
- {
- /* We handle SIGTRAP, however; it means child did an exec. */
- if (!terminal_initted)
- {
- /* Now that the child has exec'd we know it has already set its
- process group. On POSIX systems, tcsetpgrp will fail with
- EPERM if we try it before the child's setpgid. */
-
- /* Set up the "saved terminal modes" of the inferior
- based on what modes we are starting it with. */
- target_terminal_init ();
-
- /* Install inferior's terminal modes. */
- target_terminal_inferior ();
-
- terminal_initted = 1;
- }
-
- pending_execs = pending_execs - 1;
- if (0 == pending_execs)
- break;
-
- resume (0, TARGET_SIGNAL_0); /* Just make it go on */
- }
- }
-#endif /* STARTUP_INFERIOR */
- stop_soon_quietly = NO_STOP_QUIETLY;
+ add_setshow_filename_cmd ("exec-wrapper", class_run, &exec_wrapper, _("\
+Set a wrapper for running programs.\n\
+The wrapper prepares the system and environment for the new program."),
+ _("\
+Show the wrapper for running programs."), NULL,
+ NULL, NULL,
+ &setlist, &showlist);
+
+ add_cmd ("exec-wrapper", class_run, unset_exec_wrapper_command,
+ _("Disable use of an execution wrapper."),
+ &unsetlist);
+
+ add_setshow_boolean_cmd ("startup-with-shell", class_support,
+ &startup_with_shell, _("\
+Set use of shell to start subprocesses. The default is on."), _("\
+Show use of shell to start subprocesses."), NULL,
+ NULL,
+ show_startup_with_shell,
+ &setlist, &showlist);
}