/* Top level stuff for GDB, the GNU debugger. Copyright 1999, 2000, 2001, 2002, 2004, 2005 Free Software Foundation, Inc. Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions. 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 (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. */ #include "defs.h" #include "top.h" #include "inferior.h" #include "target.h" #include "terminal.h" /* for job_control */ #include "event-loop.h" #include "event-top.h" #include "interps.h" #include <signal.h> #include "exceptions.h" /* For dont_repeat() */ #include "gdbcmd.h" /* readline include files */ #include "readline/readline.h" #include "readline/history.h" /* readline defines this. */ #undef savestring static void rl_callback_read_char_wrapper (gdb_client_data client_data); static void command_line_handler (char *rl); static void command_line_handler_continuation (struct continuation_arg *arg); static void change_line_handler (void); static void change_annotation_level (void); static void command_handler (char *command); static void async_do_nothing (gdb_client_data arg); static void async_disconnect (gdb_client_data arg); static void async_stop_sig (gdb_client_data arg); static void async_float_handler (gdb_client_data arg); /* Signal handlers. */ #ifdef SIGQUIT static void handle_sigquit (int sig); #endif static void handle_sighup (int sig); static void handle_sigfpe (int sig); #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) static void handle_sigwinch (int sig); #endif /* Functions to be invoked by the event loop in response to signals. */ static void async_do_nothing (gdb_client_data); static void async_disconnect (gdb_client_data); static void async_float_handler (gdb_client_data); static void async_stop_sig (gdb_client_data); /* Readline offers an alternate interface, via callback functions. These are all included in the file callback.c in the readline distribution. This file provides (mainly) a function, which the event loop uses as callback (i.e. event handler) whenever an event is detected on the standard input file descriptor. readline_callback_read_char is called (by the GDB event loop) whenever there is a new character ready on the input stream. This function incrementally builds a buffer internal to readline where it accumulates the line read up to the point of invocation. In the special case in which the character read is newline, the function invokes a GDB supplied callback routine, which does the processing of a full command line. This latter routine is the asynchronous analog of the old command_line_input in gdb. Instead of invoking (and waiting for) readline to read the command line and pass it back to command_loop for processing, the new command_line_handler function has the command line already available as its parameter. INPUT_HANDLER is to be set to the function that readline will invoke when a complete line of input is ready. CALL_READLINE is to be set to the function that readline offers as callback to the event_loop. */ void (*input_handler) (char *); void (*call_readline) (gdb_client_data); /* Important variables for the event loop. */ /* This is used to determine if GDB is using the readline library or its own simplified form of readline. It is used by the asynchronous form of the set editing command. ezannoni: as of 1999-04-29 I expect that this variable will not be used after gdb is changed to use the event loop as default engine, and event-top.c is merged into top.c. */ int async_command_editing_p; /* This variable contains the new prompt that the user sets with the set prompt command. */ char *new_async_prompt; /* This is the annotation suffix that will be used when the annotation_level is 2. */ char *async_annotation_suffix; /* This is used to display the notification of the completion of an asynchronous execution command. */ int exec_done_display_p = 0; /* This is the file descriptor for the input stream that GDB uses to read commands from. */ int input_fd; /* This is the prompt stack. Prompts will be pushed on the stack as needed by the different 'kinds' of user inputs GDB is asking for. See event-loop.h. */ struct prompts the_prompts; /* signal handling variables */ /* Each of these is a pointer to a function that the event loop will invoke if the corresponding signal has received. The real signal handlers mark these functions as ready to be executed and the event loop, in a later iteration, calls them. See the function invoke_async_signal_handler. */ void *sigint_token; #ifdef SIGHUP void *sighup_token; #endif #ifdef SIGQUIT void *sigquit_token; #endif void *sigfpe_token; #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) void *sigwinch_token; #endif #ifdef STOP_SIGNAL void *sigtstp_token; #endif /* Structure to save a partially entered command. This is used when the user types '\' at the end of a command line. This is necessary because each line of input is handled by a different call to command_line_handler, and normally there is no state retained between different calls. */ int more_to_come = 0; struct readline_input_state { char *linebuffer; char *linebuffer_ptr; } readline_input_state; /* This hook is called by rl_callback_read_char_wrapper after each character is processed. */ void (*after_char_processing_hook) (); /* Wrapper function for calling into the readline library. The event loop expects the callback function to have a paramter, while readline expects none. */ static void rl_callback_read_char_wrapper (gdb_client_data client_data) { rl_callback_read_char (); if (after_char_processing_hook) (*after_char_processing_hook) (); } /* Initialize all the necessary variables, start the event loop, register readline, and stdin, start the loop. */ void cli_command_loop (void *data /* unused */) { int length; char *a_prompt; char *gdb_prompt = get_prompt (); /* If we are using readline, set things up and display the first prompt, otherwise just print the prompt. */ if (async_command_editing_p) { /* Tell readline what the prompt to display is and what function it will need to call after a whole line is read. This also displays the first prompt. */ length = strlen (PREFIX (0)) + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1; a_prompt = (char *) xmalloc (length); strcpy (a_prompt, PREFIX (0)); strcat (a_prompt, gdb_prompt); strcat (a_prompt, SUFFIX (0)); rl_callback_handler_install (a_prompt, input_handler); } else display_gdb_prompt (0); /* Now it's time to start the event loop. */ start_event_loop (); } /* Change the function to be invoked every time there is a character ready on stdin. This is used when the user sets the editing off, therefore bypassing readline, and letting gdb handle the input itself, via gdb_readline2. Also it is used in the opposite case in which the user sets editing on again, by restoring readline handling of the input. */ static void change_line_handler (void) { /* NOTE: this operates on input_fd, not instream. If we are reading commands from a file, instream will point to the file. However in async mode, we always read commands from a file with editing off. This means that the 'set editing on/off' will have effect only on the interactive session. */ if (async_command_editing_p) { /* Turn on editing by using readline. */ call_readline = rl_callback_read_char_wrapper; input_handler = command_line_handler; } else { /* Turn off editing by using gdb_readline2. */ rl_callback_handler_remove (); call_readline = gdb_readline2; /* Set up the command handler as well, in case we are called as first thing from .gdbinit. */ input_handler = command_line_handler; } } /* Displays the prompt. The prompt that is displayed is the current top of the prompt stack, if the argument NEW_PROMPT is 0. Otherwise, it displays whatever NEW_PROMPT is. This is used after each gdb command has completed, and in the following cases: 1. when the user enters a command line which is ended by '\' indicating that the command will continue on the next line. In that case the prompt that is displayed is the empty string. 2. When the user is entering 'commands' for a breakpoint, or actions for a tracepoint. In this case the prompt will be '>' 3. Other???? FIXME: 2. & 3. not implemented yet for async. */ void display_gdb_prompt (char *new_prompt) { int prompt_length = 0; char *gdb_prompt = get_prompt (); static int stdin_handler_removed = 0; /* Each interpreter has its own rules on displaying the command prompt. */ if (!current_interp_display_prompt_p ()) return; if (target_executing && sync_execution) { /* This is to trick readline into not trying to display the prompt. Even though we display the prompt using this function, readline still tries to do its own display if we don't call rl_callback_handler_install and rl_callback_handler_remove (which readline detects because a global variable is not set). If readline did that, it could mess up gdb signal handlers for SIGINT. Readline assumes that between calls to rl_set_signals and rl_clear_signals gdb doesn't do anything with the signal handlers. Well, that's not the case, because when the target executes we change the SIGINT signal handler. If we allowed readline to display the prompt, the signal handler change would happen exactly between the calls to the above two functions. Calling rl_callback_handler_remove(), does the job. */ delete_file_handler (input_fd); stdin_handler_removed = 1; rl_callback_handler_remove (); return; } if (!new_prompt) { /* Just use the top of the prompt stack. */ prompt_length = strlen (PREFIX (0)) + strlen (SUFFIX (0)) + strlen (gdb_prompt) + 1; new_prompt = (char *) alloca (prompt_length); /* Prefix needs to have new line at end. */ strcpy (new_prompt, PREFIX (0)); strcat (new_prompt, gdb_prompt); /* Suffix needs to have a new line at end and \032 \032 at beginning. */ strcat (new_prompt, SUFFIX (0)); } if (async_command_editing_p) { /* Claim the terminal before we reset it. It is quick if the terminal is already ours, and if not, we are going to lose when we try to install the callback handler otherwise. We can get here with the terminal still belonging to the inferior if it dies an unexpected death, and somebody forgets to clean up properly. Better safe than sorry... */ target_terminal_ours (); if (stdin_handler_removed) { add_file_handler (input_fd, stdin_event_handler, 0); stdin_handler_removed = 0; } rl_callback_handler_remove (); rl_callback_handler_install (new_prompt, input_handler); } /* new_prompt at this point can be the top of the stack or the one passed in */ else if (new_prompt) { /* Don't use a _filtered function here. It causes the assumed character position to be off, since the newline we read from the user is not accounted for. */ fputs_unfiltered (new_prompt, gdb_stdout); gdb_flush (gdb_stdout); } } /* Used when the user requests a different annotation level, with 'set annotate'. It pushes a new prompt (with prefix and suffix) on top of the prompt stack, if the annotation level desired is 2, otherwise it pops the top of the prompt stack when we want the annotation level to be the normal ones (1 or 0). */ static void change_annotation_level (void) { char *prefix, *suffix; if (!PREFIX (0) || !PROMPT (0) || !SUFFIX (0)) { /* The prompt stack has not been initialized to "", we are using gdb w/o the --async switch */ warning (_("Command has same effect as set annotate")); return; } if (annotation_level > 1) { if (!strcmp (PREFIX (0), "") && !strcmp (SUFFIX (0), "")) { /* Push a new prompt if the previous annotation_level was not >1. */ prefix = (char *) alloca (strlen (async_annotation_suffix) + 10); strcpy (prefix, "\n\032\032pre-"); strcat (prefix, async_annotation_suffix); strcat (prefix, "\n"); suffix = (char *) alloca (strlen (async_annotation_suffix) + 6); strcpy (suffix, "\n\032\032"); strcat (suffix, async_annotation_suffix); strcat (suffix, "\n"); push_prompt (prefix, (char *) 0, suffix); } } else { if (strcmp (PREFIX (0), "") && strcmp (SUFFIX (0), "")) { /* Pop the top of the stack, we are going back to annotation < 1. */ pop_prompt (); } } } /* Pushes a new prompt on the prompt stack. Each prompt has three parts: prefix, prompt, suffix. Usually prefix and suffix are empty strings, except when the annotation level is 2. Memory is allocated within savestring for the new prompt. */ void push_prompt (char *prefix, char *prompt, char *suffix) { the_prompts.top++; PREFIX (0) = savestring (prefix, strlen (prefix)); /* Note that this function is used by the set annotate 2 command. This is why we take care of saving the old prompt in case a new one is not specified. */ if (prompt) PROMPT (0) = savestring (prompt, strlen (prompt)); else PROMPT (0) = savestring (PROMPT (-1), strlen (PROMPT (-1))); SUFFIX (0) = savestring (suffix, strlen (suffix)); } /* Pops the top of the prompt stack, and frees the memory allocated for it. */ void pop_prompt (void) { /* If we are not during a 'synchronous' execution command, in which case, the top prompt would be empty. */ if (strcmp (PROMPT (0), "")) /* This is for the case in which the prompt is set while the annotation level is 2. The top prompt will be changed, but when we return to annotation level < 2, we want that new prompt to be in effect, until the user does another 'set prompt'. */ if (strcmp (PROMPT (0), PROMPT (-1))) { xfree (PROMPT (-1)); PROMPT (-1) = savestring (PROMPT (0), strlen (PROMPT (0))); } xfree (PREFIX (0)); xfree (PROMPT (0)); xfree (SUFFIX (0)); the_prompts.top--; } /* When there is an event ready on the stdin file desriptor, instead of calling readline directly throught the callback function, or instead of calling gdb_readline2, give gdb a chance to detect errors and do something. */ void stdin_event_handler (int error, gdb_client_data client_data) { if (error) { printf_unfiltered (_("error detected on stdin\n")); delete_file_handler (input_fd); discard_all_continuations (); /* If stdin died, we may as well kill gdb. */ quit_command ((char *) 0, stdin == instream); } else (*call_readline) (client_data); } /* Re-enable stdin after the end of an execution command in synchronous mode, or after an error from the target, and we aborted the exec operation. One tricky point here. We want to be careful not to stack up enables & disables. This is because we can run the inferior many times in one execution command (for instance if a breakpoint command restarts the inferior). And it is not possible a-priori to know when we find that the inferior has been restarted whether async_disable_stdin has been called (and thus whether we should re-enable it). If we just make sure that we only do things one level deep here, it removes the bookkeeping from callers, which is much better. */ int stdin_enabled = 1; void async_enable_stdin (void *dummy) { if (stdin_enabled) return; stdin_enabled = 1; /* See NOTE in async_disable_stdin() */ /* FIXME: cagney/1999-09-27: Call this before clearing sync_execution. Current target_terminal_ours() implementations check for sync_execution before switching the terminal. */ target_terminal_ours (); pop_prompt (); /* This is bogus... We shouldn't have to lie about the type of execution in order to implement the terminal_ours... sync_execution = 0; */ } /* Disable reads from stdin (the console) marking the command as synchronous. */ void async_disable_stdin (void) { if (!stdin_enabled) return; stdin_enabled = 0; /* Just don't do this... sync_execution = 1; */ push_prompt ("", "", ""); /* FIXME: cagney/1999-09-27: At present this call is technically redundant since infcmd.c and infrun.c both already call target_terminal_inferior(). As the terminal handling (in sync/async mode) is refined, the duplicate calls can be eliminated (Here or in infcmd.c/infrun.c). */ target_terminal_inferior (); /* Add the reinstate of stdin to the list of cleanups to be done in case the target errors out and dies. These cleanups are also done in case of normal successful termination of the execution command, by complete_execution(). */ make_exec_error_cleanup (async_enable_stdin, NULL); } /* Handles a gdb command. This function is called by command_line_handler, which has processed one or more input lines into COMMAND. */ /* NOTE: 1999-04-30 This is the asynchronous version of the command_loop function. The command_loop function will be obsolete when we switch to use the event loop at every execution of gdb. */ static void command_handler (char *command) { struct cleanup *old_chain; int stdin_is_tty = ISATTY (stdin); struct continuation_arg *arg1; struct continuation_arg *arg2; long time_at_cmd_start; #ifdef HAVE_SBRK long space_at_cmd_start = 0; #endif extern int display_time; extern int display_space; quit_flag = 0; if (instream == stdin && stdin_is_tty) reinitialize_more_filter (); old_chain = make_cleanup (null_cleanup, 0); /* If readline returned a NULL command, it means that the connection with the terminal is gone. This happens at the end of a testsuite run, after Expect has hung up but GDB is still alive. In such a case, we just quit gdb killing the inferior program too. */ if (command == 0) quit_command ((char *) 0, stdin == instream); time_at_cmd_start = get_run_time (); if (display_space) { #ifdef HAVE_SBRK char *lim = (char *) sbrk (0); space_at_cmd_start = lim - lim_at_start; #endif } execute_command (command, instream == stdin); /* Set things up for this function to be compete later, once the execution has completed, if we are doing an execution command, otherwise, just go ahead and finish. */ if (target_can_async_p () && target_executing) { arg1 = (struct continuation_arg *) xmalloc (sizeof (struct continuation_arg)); arg2 = (struct continuation_arg *) xmalloc (sizeof (struct continuation_arg)); arg1->next = arg2; arg2->next = NULL; arg1->data.longint = time_at_cmd_start; #ifdef HAVE_SBRK arg2->data.longint = space_at_cmd_start; #endif add_continuation (command_line_handler_continuation, arg1); } /* Do any commands attached to breakpoint we stopped at. Only if we are always running synchronously. Or if we have just executed a command that doesn't start the target. */ if (!target_can_async_p () || !target_executing) { bpstat_do_actions (&stop_bpstat); do_cleanups (old_chain); if (display_time) { long cmd_time = get_run_time () - time_at_cmd_start; printf_unfiltered (_("Command execution time: %ld.%06ld\n"), cmd_time / 1000000, cmd_time % 1000000); } if (display_space) { #ifdef HAVE_SBRK char *lim = (char *) sbrk (0); long space_now = lim - lim_at_start; long space_diff = space_now - space_at_cmd_start; printf_unfiltered (_("Space used: %ld (%c%ld for this command)\n"), space_now, (space_diff >= 0 ? '+' : '-'), space_diff); #endif } } } /* Do any commands attached to breakpoint we stopped at. Only if we are always running synchronously. Or if we have just executed a command that doesn't start the target. */ void command_line_handler_continuation (struct continuation_arg *arg) { extern int display_time; extern int display_space; long time_at_cmd_start = arg->data.longint; long space_at_cmd_start = arg->next->data.longint; bpstat_do_actions (&stop_bpstat); /*do_cleanups (old_chain); *//*?????FIXME????? */ if (display_time) { long cmd_time = get_run_time () - time_at_cmd_start; printf_unfiltered (_("Command execution time: %ld.%06ld\n"), cmd_time / 1000000, cmd_time % 1000000); } if (display_space) { #ifdef HAVE_SBRK char *lim = (char *) sbrk (0); long space_now = lim - lim_at_start; long space_diff = space_now - space_at_cmd_start; printf_unfiltered (_("Space used: %ld (%c%ld for this command)\n"), space_now, (space_diff >= 0 ? '+' : '-'), space_diff); #endif } } /* Handle a complete line of input. This is called by the callback mechanism within the readline library. Deal with incomplete commands as well, by saving the partial input in a global buffer. */ /* NOTE: 1999-04-30 This is the asynchronous version of the command_line_input function. command_line_input will become obsolete once we use the event loop as the default mechanism in GDB. */ static void command_line_handler (char *rl) { static char *linebuffer = 0; static unsigned linelength = 0; char *p; char *p1; extern char *line; extern int linesize; char *nline; char got_eof = 0; int repeat = (instream == stdin); if (annotation_level > 1 && instream == stdin) { printf_unfiltered (("\n\032\032post-")); puts_unfiltered (async_annotation_suffix); printf_unfiltered (("\n")); } if (linebuffer == 0) { linelength = 80; linebuffer = (char *) xmalloc (linelength); } p = linebuffer; if (more_to_come) { strcpy (linebuffer, readline_input_state.linebuffer); p = readline_input_state.linebuffer_ptr; xfree (readline_input_state.linebuffer); more_to_come = 0; pop_prompt (); } #ifdef STOP_SIGNAL if (job_control) signal (STOP_SIGNAL, handle_stop_sig); #endif /* Make sure that all output has been output. Some machines may let you get away with leaving out some of the gdb_flush, but not all. */ wrap_here (""); gdb_flush (gdb_stdout); gdb_flush (gdb_stderr); if (source_file_name != NULL) ++source_line_number; /* If we are in this case, then command_handler will call quit and exit from gdb. */ if (!rl || rl == (char *) EOF) { got_eof = 1; command_handler (0); } if (strlen (rl) + 1 + (p - linebuffer) > linelength) { linelength = strlen (rl) + 1 + (p - linebuffer); nline = (char *) xrealloc (linebuffer, linelength); p += nline - linebuffer; linebuffer = nline; } p1 = rl; /* Copy line. Don't copy null at end. (Leaves line alone if this was just a newline) */ while (*p1) *p++ = *p1++; xfree (rl); /* Allocated in readline. */ if (p > linebuffer && *(p - 1) == '\\') { p--; /* Put on top of '\'. */ readline_input_state.linebuffer = savestring (linebuffer, strlen (linebuffer)); readline_input_state.linebuffer_ptr = p; /* We will not invoke a execute_command if there is more input expected to complete the command. So, we need to print an empty prompt here. */ more_to_come = 1; push_prompt ("", "", ""); display_gdb_prompt (0); return; } #ifdef STOP_SIGNAL if (job_control) signal (STOP_SIGNAL, SIG_DFL); #endif #define SERVER_COMMAND_LENGTH 7 server_command = (p - linebuffer > SERVER_COMMAND_LENGTH) && strncmp (linebuffer, "server ", SERVER_COMMAND_LENGTH) == 0; if (server_command) { /* Note that we don't set `line'. Between this and the check in dont_repeat, this insures that repeating will still do the right thing. */ *p = '\0'; command_handler (linebuffer + SERVER_COMMAND_LENGTH); display_gdb_prompt (0); return; } /* Do history expansion if that is wished. */ if (history_expansion_p && instream == stdin && ISATTY (instream)) { char *history_value; int expanded; *p = '\0'; /* Insert null now. */ expanded = history_expand (linebuffer, &history_value); if (expanded) { /* Print the changes. */ printf_unfiltered ("%s\n", history_value); /* If there was an error, call this function again. */ if (expanded < 0) { xfree (history_value); return; } if (strlen (history_value) > linelength) { linelength = strlen (history_value) + 1; linebuffer = (char *) xrealloc (linebuffer, linelength); } strcpy (linebuffer, history_value); p = linebuffer + strlen (linebuffer); xfree (history_value); } } /* If we just got an empty line, and that is supposed to repeat the previous command, return the value in the global buffer. */ if (repeat && p == linebuffer && *p != '\\') { command_handler (line); display_gdb_prompt (0); return; } for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++); if (repeat && !*p1) { command_handler (line); display_gdb_prompt (0); return; } *p = 0; /* Add line to history if appropriate. */ if (instream == stdin && ISATTY (stdin) && *linebuffer) add_history (linebuffer); /* Note: lines consisting solely of comments are added to the command history. This is useful when you type a command, and then realize you don't want to execute it quite yet. You can comment out the command and then later fetch it from the value history and remove the '#'. The kill ring is probably better, but some people are in the habit of commenting things out. */ if (*p1 == '#') *p1 = '\0'; /* Found a comment. */ /* Save into global buffer if appropriate. */ if (repeat) { if (linelength > linesize) { line = xrealloc (line, linelength); linesize = linelength; } strcpy (line, linebuffer); if (!more_to_come) { command_handler (line); display_gdb_prompt (0); } return; } command_handler (linebuffer); display_gdb_prompt (0); return; } /* Does reading of input from terminal w/o the editing features provided by the readline library. */ /* NOTE: 1999-04-30 Asynchronous version of gdb_readline. gdb_readline will become obsolete when the event loop is made the default execution for gdb. */ void gdb_readline2 (gdb_client_data client_data) { int c; char *result; int input_index = 0; int result_size = 80; static int done_once = 0; /* Unbuffer the input stream, so that, later on, the calls to fgetc fetch only one char at the time from the stream. The fgetc's will get up to the first newline, but there may be more chars in the stream after '\n'. If we buffer the input and fgetc drains the stream, getting stuff beyond the newline as well, a select, done afterwards will not trigger. */ if (!done_once && !ISATTY (instream)) { setbuf (instream, NULL); done_once = 1; } result = (char *) xmalloc (result_size); /* We still need the while loop here, even though it would seem obvious to invoke gdb_readline2 at every character entered. If not using the readline library, the terminal is in cooked mode, which sends the characters all at once. Poll will notice that the input fd has changed state only after enter is pressed. At this point we still need to fetch all the chars entered. */ while (1) { /* Read from stdin if we are executing a user defined command. This is the right thing for prompt_for_continue, at least. */ c = fgetc (instream ? instream : stdin); if (c == EOF) { if (input_index > 0) /* The last line does not end with a newline. Return it, and if we are called again fgetc will still return EOF and we'll return NULL then. */ break; xfree (result); (*input_handler) (0); } if (c == '\n') { if (input_index > 0 && result[input_index - 1] == '\r') input_index--; break; } result[input_index++] = c; while (input_index >= result_size) { result_size *= 2; result = (char *) xrealloc (result, result_size); } } result[input_index++] = '\0'; (*input_handler) (result); } /* Initialization of signal handlers and tokens. There is a function handle_sig* for each of the signals GDB cares about. Specifically: SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These functions are the actual signal handlers associated to the signals via calls to signal(). The only job for these functions is to enqueue the appropriate event/procedure with the event loop. Such procedures are the old signal handlers. The event loop will take care of invoking the queued procedures to perform the usual tasks associated with the reception of the signal. */ /* NOTE: 1999-04-30 This is the asynchronous version of init_signals. init_signals will become obsolete as we move to have to event loop as the default for gdb. */ void async_init_signals (void) { signal (SIGINT, handle_sigint); sigint_token = create_async_signal_handler (async_request_quit, NULL); /* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed to the inferior and breakpoints will be ignored. */ #ifdef SIGTRAP signal (SIGTRAP, SIG_DFL); #endif #ifdef SIGQUIT /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get passed to the inferior, which we don't want. It would be possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but on BSD4.3 systems using vfork, that can affect the GDB process as well as the inferior (the signal handling tables might be in memory, shared between the two). Since we establish a handler for SIGQUIT, when we call exec it will set the signal to SIG_DFL for us. */ signal (SIGQUIT, handle_sigquit); sigquit_token = create_async_signal_handler (async_do_nothing, NULL); #endif #ifdef SIGHUP if (signal (SIGHUP, handle_sighup) != SIG_IGN) sighup_token = create_async_signal_handler (async_disconnect, NULL); else sighup_token = create_async_signal_handler (async_do_nothing, NULL); #endif signal (SIGFPE, handle_sigfpe); sigfpe_token = create_async_signal_handler (async_float_handler, NULL); #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) signal (SIGWINCH, handle_sigwinch); sigwinch_token = create_async_signal_handler (SIGWINCH_HANDLER, NULL); #endif #ifdef STOP_SIGNAL sigtstp_token = create_async_signal_handler (async_stop_sig, NULL); #endif } void mark_async_signal_handler_wrapper (void *token) { mark_async_signal_handler ((struct async_signal_handler *) token); } /* Tell the event loop what to do if SIGINT is received. See event-signal.c. */ void handle_sigint (int sig) { signal (sig, handle_sigint); /* We used to set the quit flag in async_request_quit, which is either called when immediate_quit is 1, or when we get back to the event loop. This is wrong, because you could be running in a loop reading in symfiles or something, and it could be quite a while before you get to the event loop. Instead, set quit_flag to 1 here, then mark the sigint handler as ready. Then if somebody calls QUIT before you get to the event loop, they will unwind as expected. */ quit_flag = 1; /* If immediate_quit is set, we go ahead and process the SIGINT right away, even if we usually would defer this to the event loop. The assumption here is that it is safe to process ^C immediately if immediate_quit is set. If we didn't, SIGINT would be really processed only the next time through the event loop. To get to that point, though, the command that we want to interrupt needs to finish first, which is unacceptable. */ if (immediate_quit) async_request_quit (0); else /* If immediate quit is not set, we process SIGINT the next time through the loop, which is fine. */ mark_async_signal_handler_wrapper (sigint_token); } /* Do the quit. All the checks have been done by the caller. */ void async_request_quit (gdb_client_data arg) { /* If the quit_flag has gotten reset back to 0 by the time we get back here, that means that an exception was thrown to unwind the current command before we got back to the event loop. So there is no reason to call quit again here. I added the check for immediate quit, since that's what prompt_for_continue uses instead of quit_flag to request the quit. Since BOTH quit_flag & immediate_quit get set to zero when we do handle_exception, the check for both zero has the same meaning as for just quit_flag. */ if (quit_flag == 0 && immediate_quit == 0) return; quit (); } #ifdef SIGQUIT /* Tell the event loop what to do if SIGQUIT is received. See event-signal.c. */ static void handle_sigquit (int sig) { mark_async_signal_handler_wrapper (sigquit_token); signal (sig, handle_sigquit); } #endif /* Called by the event loop in response to a SIGQUIT. */ static void async_do_nothing (gdb_client_data arg) { /* Empty function body. */ } #ifdef SIGHUP /* Tell the event loop what to do if SIGHUP is received. See event-signal.c. */ static void handle_sighup (int sig) { mark_async_signal_handler_wrapper (sighup_token); signal (sig, handle_sighup); } /* Called by the event loop to process a SIGHUP */ static void async_disconnect (gdb_client_data arg) { catch_errors (quit_cover, NULL, "Could not kill the program being debugged", RETURN_MASK_ALL); signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */ kill (getpid (), SIGHUP); } #endif #ifdef STOP_SIGNAL void handle_stop_sig (int sig) { mark_async_signal_handler_wrapper (sigtstp_token); signal (sig, handle_stop_sig); } static void async_stop_sig (gdb_client_data arg) { char *prompt = get_prompt (); #if STOP_SIGNAL == SIGTSTP signal (SIGTSTP, SIG_DFL); #if HAVE_SIGPROCMASK { sigset_t zero; sigemptyset (&zero); sigprocmask (SIG_SETMASK, &zero, 0); } #elif HAVE_SIGSETMASK sigsetmask (0); #endif kill (getpid (), SIGTSTP); signal (SIGTSTP, handle_stop_sig); #else signal (STOP_SIGNAL, handle_stop_sig); #endif printf_unfiltered ("%s", prompt); gdb_flush (gdb_stdout); /* Forget about any previous command -- null line now will do nothing. */ dont_repeat (); } #endif /* STOP_SIGNAL */ /* Tell the event loop what to do if SIGFPE is received. See event-signal.c. */ static void handle_sigfpe (int sig) { mark_async_signal_handler_wrapper (sigfpe_token); signal (sig, handle_sigfpe); } /* Event loop will call this functin to process a SIGFPE. */ static void async_float_handler (gdb_client_data arg) { /* This message is based on ANSI C, section 4.7. Note that integer divide by zero causes this, so "float" is a misnomer. */ error (_("Erroneous arithmetic operation.")); } /* Tell the event loop what to do if SIGWINCH is received. See event-signal.c. */ #if defined(SIGWINCH) && defined(SIGWINCH_HANDLER) static void handle_sigwinch (int sig) { mark_async_signal_handler_wrapper (sigwinch_token); signal (sig, handle_sigwinch); } #endif /* Called by do_setshow_command. */ void set_async_editing_command (char *args, int from_tty, struct cmd_list_element *c) { change_line_handler (); } /* Called by do_setshow_command. */ void set_async_annotation_level (char *args, int from_tty, struct cmd_list_element *c) { change_annotation_level (); } /* Called by do_setshow_command. */ void set_async_prompt (char *args, int from_tty, struct cmd_list_element *c) { PROMPT (0) = savestring (new_async_prompt, strlen (new_async_prompt)); } /* Set things up for readline to be invoked via the alternate interface, i.e. via a callback function (rl_callback_read_char), and hook up instream to the event loop. */ void gdb_setup_readline (void) { /* This function is a noop for the sync case. The assumption is that the sync setup is ALL done in gdb_init, and we would only mess it up here. The sync stuff should really go away over time. */ /* APPLE LOCAL begin async */ /* Note also that if instream == NULL, then we don't want to setup readline even IF event_loop_p is true, because we don't have an input source for events yet. This usually only happens if a command is run in the .gdbinit file. */ if (instream == NULL) return; /* APPLE LOCAL end async */ gdb_stdout = stdio_fileopen (stdout); gdb_stderr = stdio_fileopen (stderr); gdb_stdlog = gdb_stderr; /* for moment */ gdb_stdtarg = gdb_stderr; /* for moment */ /* If the input stream is connected to a terminal, turn on editing. */ if (ISATTY (instream)) { /* Tell gdb that we will be using the readline library. This could be overwritten by a command in .gdbinit like 'set editing on' or 'off'. */ async_command_editing_p = 1; /* When a character is detected on instream by select or poll, readline will be invoked via this callback function. */ call_readline = rl_callback_read_char_wrapper; } else { async_command_editing_p = 0; call_readline = gdb_readline2; } /* When readline has read an end-of-line character, it passes the complete line to gdb for processing. command_line_handler is the function that does this. */ input_handler = command_line_handler; /* Tell readline to use the same input stream that gdb uses. */ rl_instream = instream; /* Get a file descriptor for the input stream, so that we can register it with the event loop. */ input_fd = fileno (instream); /* Now we need to create the event sources for the input file descriptor. */ /* At this point in time, this is the only event source that we register with the even loop. Another source is going to be the target program (inferior), but that must be registered only when it actually exists (I.e. after we say 'run' or after we connect to a remote target. */ add_file_handler (input_fd, stdin_event_handler, 0); } /* Disable command input through the standard CLI channels. Used in the suspend proc for interpreters that use the standard gdb readline interface, like the cli & the mi. */ void gdb_disable_readline (void) { /* FIXME - It is too heavyweight to delete and remake these every time you run an interpreter that needs readline. It is probably better to have the interpreters cache these, which in turn means that this needs to be moved into interpreter specific code. */ #if 0 ui_file_delete (gdb_stdout); ui_file_delete (gdb_stderr); gdb_stdlog = NULL; gdb_stdtarg = NULL; #endif rl_callback_handler_remove (); delete_file_handler (input_fd); } /* Don't set up readline now, this is better done in the interpreter's resume method, since we will have to do this coming back & forth among interpreters anyway... */ void _initialize_event_loop (void) { /* Tell gdb to use the cli_command_loop as the main loop. */ if (deprecated_command_loop_hook == NULL) deprecated_command_loop_hook = cli_command_loop; }