-/* Start an inferior Unix child process and sets inferior_pid 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. Errors reported with error(). */
-
-#ifndef SHELL_FILE
-#define SHELL_FILE "/bin/sh"
-#endif
-
-void
-child_create_inferior (exec_file, allargs, env)
- char *exec_file;
- char *allargs;
- char **env;
-{
- int pid;
- char *shell_command;
- extern int sys_nerr;
- extern char *sys_errlist[];
- char *shell_file;
- static char default_shell_file[] = SHELL_FILE;
- int len;
- int pending_execs;
- /* 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;
- char **save_our_env;
-
- /* The user might want tilde-expansion, and in general probably wants
- the program to behave the same way as if run from
- his/her favorite shell. So we let the shell run it for us.
- FIXME, this should probably search the local environment (as
- modified by the setenv command), not the env gdb inherited. */
- shell_file = getenv ("SHELL");
- if (shell_file == NULL)
- shell_file = default_shell_file;
-
- len = 5 + strlen (exec_file) + 1 + strlen (allargs) + 1 + /*slop*/ 10;
- /* 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
- strcat (shell_command, "exec ");
- strcat (shell_command, exec_file);
- strcat (shell_command, " ");
- strcat (shell_command, allargs);
-
- /* exec is said to 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
- 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. */
-
- fflush (stdout);
- fflush (stderr);
-
-#if defined(USG) && !defined(HAVE_VFORK)
- pid = fork ();
-#else
- if (debug_fork)
- pid = fork ();
- else
- pid = vfork ();
-#endif
-
- if (pid < 0)
- perror_with_name ("vfork");
-
- if (pid == 0)
- {
- if (debug_fork)
- sleep (debug_fork);
-
-#ifdef TIOCGPGRP
- /* Run inferior in a separate process group. */
-#ifdef NEED_POSIX_SETPGID
- debug_setpgrp = setpgid (0, 0);
-#else
-#if defined(USG) && !defined(SETPGRP_ARGS)
- debug_setpgrp = setpgrp ();
-#else
- debug_setpgrp = setpgrp (getpid (), getpid ());
-#endif /* USG */
-#endif /* NEED_POSIX_SETPGID */
- if (debug_setpgrp == -1)
- perror("setpgrp failed in child");
-#endif /* TIOCGPGRP */
-
-#ifdef SET_STACK_LIMIT_HUGE
- /* Reset the stack limit back to what it was. */
- {
- struct rlimit rlim;
-
- getrlimit (RLIMIT_STACK, &rlim);
- rlim.rlim_cur = original_stack_limit;
- setrlimit (RLIMIT_STACK, &rlim);
- }
-#endif /* SET_STACK_LIMIT_HUGE */
-
- /* 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. */
-
-#ifdef USE_PROC_FS
- proc_set_exec_trap (); /* Use SVR4 /proc interface */
-#else
- call_ptrace (0, 0, 0, 0); /* "Trace me, Dr. Memory!" */
-#endif
-
- /* 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;
- execlp (shell_file, shell_file, "-c", shell_command, (char *)0);
-
- fprintf (stderr, "Cannot exec %s: %s.\n", shell_file,
- errno < sys_nerr ? sys_errlist[errno] : "unknown error");
- fflush (stderr);
- _exit (0177);
- }
-
- /* Restore our environment in case a vforked child clob'd it. */
- environ = save_our_env;
-
- /* Now that we have a child process, make it our target. */
- push_target (&child_ops);
-
-#ifdef CREATE_INFERIOR_HOOK
- CREATE_INFERIOR_HOOK (pid);
-#endif
-
-/* 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. */
-
- inferior_pid = pid; /* Needed for wait_for_inferior stuff below */
-
- clear_proceed_status ();
-
- /* We will get a trace trap after one instruction.
- Continue it automatically. Eventually (after shell does an exec)
- it will get another trace trap. Then insert breakpoints and continue. */
-
-#ifdef START_INFERIOR_TRAPS_EXPECTED
- pending_execs = START_INFERIOR_TRAPS_EXPECTED;
-#else
- pending_execs = 2;
-#endif
-
- init_wait_for_inferior ();
-
- /* 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 ();
-
- while (1)
- {
- stop_soon_quietly = 1; /* Make wait_for_inferior be quiet */
- wait_for_inferior ();
- if (stop_signal != SIGTRAP)
- {
- /* 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 (0 == --pending_execs)
- break;
- resume (0, 0); /* Just make it go on */
- }
- }
- stop_soon_quietly = 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. */
-#ifdef SOLIB_CREATE_INFERIOR_HOOK
- SOLIB_CREATE_INFERIOR_HOOK ();
-#endif
-
- /* Should this perhaps just be a "proceed" call? FIXME */
- insert_step_breakpoint ();
- breakpoints_failed = insert_breakpoints ();
- if (!breakpoints_failed)
- {
- breakpoints_inserted = 1;
- target_terminal_inferior();
- /* Start the child program going on its first instruction, single-
- stepping if we need to. */
- resume (bpstat_should_step (), 0);
- wait_for_inferior ();
- normal_stop ();
- }
-}
-