X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=gdb%2Ffork-child.c;h=bb173e7cac9ab12606aa56cf6f3673992781b077;hb=8fbca658f0643a6c3d5b61840351ae70e5bf2db6;hp=738898a3eb35118b27e376154866b44f3673c7d6;hpb=87767c29b527515e0b1dbdefaaef86f972e0de9b;p=binutils-gdb.git
diff --git a/gdb/fork-child.c b/gdb/fork-child.c
index 738898a3eb3..bb173e7cac9 100644
--- a/gdb/fork-child.c
+++ b/gdb/fork-child.c
@@ -1,13 +1,16 @@
/* 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, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
+ 2001, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+ 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,
@@ -16,14 +19,12 @@
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 "terminal.h"
#include "target.h"
#include "gdb_wait.h"
#include "gdb_vfork.h"
@@ -31,74 +32,95 @@
#include "terminal.h"
#include "gdbthread.h"
#include "command.h" /* for dont_repeat () */
+#include "gdbcmd.h"
+#include "solib.h"
#include
-/* This just gets used as a default if we can't find SHELL */
-#ifndef SHELL_FILE
+/* This just gets used as a default if we can't find SHELL. */
#define SHELL_FILE "/bin/sh"
-#endif
extern char **environ;
-/* 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 char *exec_wrapper;
+
+/* Break up SCRATCH into an argument vector suitable for passing to
+ execvp and store it in ARGV. 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)
{
- char *cp = scratch;
+ char *cp = scratch, *tmp;
for (;;)
{
-
/* Scan past leading separators */
while (*cp == ' ' || *cp == '\t' || *cp == '\n')
- {
- cp++;
- }
+ cp++;
- /* Break if at end of string */
+ /* Break if at end of string. */
if (*cp == '\0')
break;
- /* Take an arg */
+ /* 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');
+ /* Scan for next arg separator. */
+ tmp = strchr (cp, ' ');
+ if (tmp == NULL)
+ tmp = strchr (cp, '\t');
+ if (tmp == NULL)
+ tmp = strchr (cp, '\n');
- /* No separators => end of string => break */
- if (cp == NULL)
+ /* No separators => end of string => break. */
+ if (tmp == NULL)
break;
+ cp = tmp;
- /* Replace the separator with a terminator */
+ /* Replace the separator with a terminator. */
*cp++ = '\0';
}
- /* execv requires a null-terminated arg vector */
+ /* Null-terminate the vector. */
*argv = NULL;
-
}
+/* When executing a command under the given shell, return non-zero if
+ the '!' character should be escaped when embedded in a quoted
+ command-line argument. */
-/* 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(). */
+static int
+escape_bang_in_quoted_argument (const char *shell_file)
+{
+ const int shell_file_len = strlen (shell_file);
-/* This function is NOT-REENTRANT. Some of the variables have been
- made static to ensure that they survive the vfork() call. */
+ /* Bang should be escaped only in C Shells. For now, simply check
+ that the shell name ends with 'csh', which covers at least csh
+ and tcsh. This should be good enough for now. */
-void
+ if (shell_file_len < 3)
+ return 0;
+
+ if (shell_file[shell_file_len - 3] == 'c'
+ && shell_file[shell_file_len - 2] == 's'
+ && shell_file[shell_file_len - 1] == 'h')
+ return 1;
+
+ return 0;
+}
+
+/* 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. */
+
+/* This function is NOT reentrant. Some of the variables have been
+ made static to ensure that they survive the vfork call. */
+
+int
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)
@@ -107,7 +129,7 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
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. */
+ /* 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. */
@@ -117,21 +139,22 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
char **save_our_env;
int shell = 0;
static char **argv;
+ const char *inferior_io_terminal = get_inferior_io_terminal ();
+ struct inferior *inf;
- /* If no exec file handed to us, get it from the exec-file command -- with
- a good, common error message if none is specified. */
+ /* 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.
- */
+ /* STARTUP_WITH_SHELL is defined in inferior.h. If 0,e 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. */
+ /* Figure out what shell to start up the user program under. */
if (shell_file == NULL)
shell_file = getenv ("SHELL");
if (shell_file == NULL)
@@ -139,44 +162,51 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
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 '. */
+ /* 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
+ if (exec_wrapper)
+ len += strlen (exec_wrapper) + 1;
+
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));
+ /* We're going to call execvp. Create argument vector.
+ Calculate an upper bound on the length of the vector by
+ assuming that every other character is a separate
+ argument. */
+ int argc = (strlen (allargs) + 1) / 2 + 2;
+
+ argv = (char **) xmalloc (argc * sizeof (*argv));
argv[0] = exec_file;
breakup_args (allargs, &argv[1]);
-
}
else
{
-
- /* We're going to call a shell */
-
- /* Now add exec_file, quoting as necessary. */
+ /* We're going to call a shell. */
char *p;
int need_to_quote;
+ const int escape_bang = escape_bang_in_quoted_argument (shell_file);
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. */
+ /* Add any exec wrapper. That may be a program name with arguments, so
+ the user must handle quoting. */
+ if (exec_wrapper)
+ {
+ strcat (shell_command, exec_wrapper);
+ strcat (shell_command, " ");
+ }
+
+ /* Now add exec_file, quoting as necessary. */
+
+ /* 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)
{
@@ -215,7 +245,7 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
{
if (*p == '\'')
strcat (shell_command, "'\\''");
- else if (*p == '!')
+ else if (*p == '!' && escape_bang)
strcat (shell_command, "\\!");
else
strncat (shell_command, p, 1);
@@ -227,59 +257,70 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
strcat (shell_command, " ");
strcat (shell_command, allargs);
-
}
- /* exec is said to fail if the executable is open. */
+ /* On some systems an exec will fail if the executable is open. */
close_exec_file ();
/* Retain a copy of our environment variables, since the child will
- replace the value of environ and if we're vforked, we have to
+ replace the value of environ and if we're vforked, we have to
restore it. */
save_our_env = environ;
/* 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);
/* 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. */
-
+ output prior to doing a fork, to avoid the possibility of both
+ the parent and child flushing the same data after the fork. */
gdb_flush (gdb_stdout);
gdb_flush (gdb_stderr);
- /* 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 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) ();
- /* 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)
+ /* Create the child process. Since the child process is going to
+ exec(3) shortly afterwards, try to reduce the overhead by
+ calling vfork(2). However, if PRE_TRACE_FUN is non-null, it's
+ likely that this optimization won't work since there's too much
+ work to do between the vfork(2) and the exec(3). This is known
+ to be the case on ttrace(2)-based HP-UX, where some handshaking
+ between parent and child needs to happen between fork(2) and
+ exec(2). However, since the parent is suspended in the vforked
+ state, this doesn't work. Also note that the vfork(2) call might
+ actually be a call to fork(2) due to the fact that autoconf will
+ ``#define vfork fork'' on certain platforms. */
+ if (pre_trace_fun || debug_fork)
pid = fork ();
else
pid = vfork ();
if (pid < 0)
- perror_with_name ("vfork");
+ perror_with_name (("vfork"));
if (pid == 0)
{
if (debug_fork)
sleep (debug_fork);
- /* Run 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). */
+ /* 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)
+ {
+ /* 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
@@ -288,16 +329,17 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
initialize_signals for how we get the right signal handlers
for the inferior. */
- /* "Trace me, Dr. Memory!" */
+ /* "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!
- */
+ 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
@@ -306,19 +348,15 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
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 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
+ ". */
if (shell)
{
execlp (shell_file, shell_file, "-c", shell_command, (char *) 0);
- /* If we get here, it's an error */
+ /* 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);
@@ -326,14 +364,14 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
}
else
{
- /* Otherwise, we directly exec the target program with execvp. */
+ /* 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);
+ /* If we get here, it's an error. */
+ safe_strerror (errno);
fprintf_unfiltered (gdb_stderr, "Cannot exec %s ", exec_file);
i = 1;
@@ -345,9 +383,6 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
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);
}
@@ -356,27 +391,34 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env,
/* Restore our environment in case a vforked child clob'd it. */
environ = save_our_env;
- init_thread_list ();
+ if (!have_inferiors ())
+ init_thread_list ();
- inferior_ptid = pid_to_ptid (pid); /* Needed for wait_for_inferior stuff below */
+ inf = current_inferior ();
- /* Now that we have a child process, make it our target, and
- initialize anything target-vector-specific that needs initializing. */
+ inferior_appeared (inf, pid);
+
+ /* Needed for wait_for_inferior stuff below. */
+ inferior_ptid = pid_to_ptid (pid);
+
+ new_tty_postfork ();
- (*init_trace_fun) (pid);
+ /* We have something that executes now. We'll be running through
+ the shell at this point, but the pid shouldn't change. Targets
+ supporting MT should fill this task's ptid with more data as soon
+ as they can. */
+ add_thread_silent (inferior_ptid);
+
+ /* Now that we have a child process, make it our target, and
+ initialize anything target-vector-specific that needs
+ initializing. */
+ if (init_trace_fun)
+ (*init_trace_fun) (pid);
/* 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. */
-
- /* 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);
-
-#ifdef SOLIB_CREATE_INFERIOR_HOOK
- SOLIB_CREATE_INFERIOR_HOOK (pid);
-#endif
+ return pid;
}
/* Accept NTRAPS traps from the inferior. */
@@ -385,44 +427,91 @@ void
startup_inferior (int ntraps)
{
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 ();
+ int terminal_initted = 0;
+ ptid_t resume_ptid;
- init_wait_for_inferior ();
+ if (target_supports_multi_process ())
+ resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
+ else
+ resume_ptid = minus_one_ptid;
- terminal_initted = 0;
+ /* 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. */
- 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;
+ if (exec_wrapper)
+ pending_execs++;
while (1)
{
- /* Make wait_for_inferior be quiet */
- stop_soon = STOP_QUIETLY;
- wait_for_inferior ();
- if (stop_signal != TARGET_SIGNAL_TRAP)
+ enum target_signal resume_signal = TARGET_SIGNAL_0;
+ ptid_t event_ptid;
+
+ struct target_waitstatus ws;
+ memset (&ws, 0, sizeof (ws));
+ event_ptid = target_wait (resume_ptid, &ws, 0);
+
+ if (ws.kind == TARGET_WAITKIND_IGNORE)
+ /* The inferior didn't really stop, keep waiting. */
+ continue;
+
+ switch (ws.kind)
+ {
+ case TARGET_WAITKIND_SPURIOUS:
+ case TARGET_WAITKIND_LOADED:
+ case TARGET_WAITKIND_FORKED:
+ case TARGET_WAITKIND_VFORKED:
+ case TARGET_WAITKIND_SYSCALL_ENTRY:
+ case TARGET_WAITKIND_SYSCALL_RETURN:
+ /* Ignore gracefully during startup of the inferior. */
+ switch_to_thread (event_ptid);
+ break;
+
+ case TARGET_WAITKIND_SIGNALLED:
+ target_terminal_ours ();
+ target_mourn_inferior ();
+ error (_("During startup program terminated with signal %s, %s."),
+ target_signal_to_name (ws.value.sig),
+ target_signal_to_string (ws.value.sig));
+ return;
+
+ case TARGET_WAITKIND_EXITED:
+ target_terminal_ours ();
+ target_mourn_inferior ();
+ if (ws.value.integer)
+ error (_("During startup program exited with code %d."),
+ ws.value.integer);
+ else
+ error (_("During startup program exited normally."));
+ return;
+
+ case TARGET_WAITKIND_EXECD:
+ /* Handle EXEC signals as if they were SIGTRAP signals. */
+ xfree (ws.value.execd_pathname);
+ resume_signal = TARGET_SIGNAL_TRAP;
+ switch_to_thread (event_ptid);
+ break;
+
+ case TARGET_WAITKIND_STOPPED:
+ resume_signal = ws.value.sig;
+ switch_to_thread (event_ptid);
+ break;
+ }
+
+ if (resume_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);
+ /* Let shell child handle its own signals in its own way. */
+ target_resume (resume_ptid, 0, resume_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. */
+ /* 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. */
@@ -434,12 +523,42 @@ startup_inferior (int ntraps)
terminal_initted = 1;
}
- pending_execs = pending_execs - 1;
- if (0 == pending_execs)
+ if (--pending_execs == 0)
break;
- resume (0, TARGET_SIGNAL_0); /* Just make it go on */
+ /* Just make it go on. */
+ target_resume (resume_ptid, 0, TARGET_SIGNAL_0);
}
}
- stop_soon = NO_STOP_QUIETLY;
+
+ /* Mark all threads non-executing. */
+ set_executing (resume_ptid, 0);
+}
+
+/* Implement the "unset exec-wrapper" command. */
+
+static void
+unset_exec_wrapper_command (char *args, int from_tty)
+{
+ xfree (exec_wrapper);
+ exec_wrapper = NULL;
+}
+
+/* Provide a prototype to silence -Wmissing-prototypes. */
+extern initialize_file_ftype _initialize_fork_child;
+
+void
+_initialize_fork_child (void)
+{
+ 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);
}