/*****************************************************************************
 *
 *  xdbx - X Window System interface to the dbx debugger
 *
 *  Copyright 1989 The University of Texas at Austin
 *  Copyright 1990 Microelectronics and Computer Technology Corporation
 *
 *  Permission to use, copy, modify, and distribute this software and its
 *  documentation for any purpose and without fee is hereby granted,
 *  provided that the above copyright notice appear in all copies and that
 *  both that copyright notice and this permission notice appear in
 *  supporting documentation, and that the name of The University of Texas
 *  and Microelectronics and Computer Technology Corporation (MCC) not be 
 *  used in advertising or publicity pertaining to distribution of
 *  the software without specific, written prior permission.  The
 *  University of Texas and MCC makes no representations about the 
 *  suitability of this software for any purpose.  It is provided "as is" 
 *  without express or implied warranty.
 *
 *  THE UNIVERSITY OF TEXAS AND MCC DISCLAIMS ALL WARRANTIES WITH REGARD TO
 *  THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
 *  FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF TEXAS OR MCC BE LIABLE FOR
 *  ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
 *  RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
 *  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 *  CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *  Author:  	Po Cheung
 *  Created:   	March 10, 1989
 * 
 *****************************************************************************
 * 
 *  xxgdb - X Window System interface to the gdb debugger
 *  
 * 	Copyright 1990 Thomson Consumer Electronics, Inc.
 *  
 *  Permission to use, copy, modify, and distribute this software and its
 *  documentation for any purpose and without fee is hereby granted,
 *  provided that the above copyright notice appear in all copies and that
 *  both that copyright notice and this permission notice appear in
 *  supporting documentation, and that the name of Thomson Consumer
 *  Electronics (TCE) not be used in advertising or publicity pertaining
 *  to distribution of the software without specific, written prior
 *  permission.  TCE makes no representations about the suitability of
 *  this software for any purpose.  It is provided "as is" without express
 *  or implied warranty.
 *
 *  TCE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
 *  ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT
 *  SHALL TCE BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES
 *  OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 *  WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
 *  ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 *  SOFTWARE.
 *
 *  Adaptation to GDB:  Pierre Willard
 *  XXGDB Created:   	December, 1990
 *
 *****************************************************************************/

/*  gdb_parser.c:
 *
 *	WARNING : gdb_parser.c is included by parser.c for GDB.
 *
 *    Parse output messages from dbx using regular expression pattern matching,
 *    and take appropriate action.
 *
 *    parse():		Parse the dbx output and invoke the appropriate action
 *			handler.
 *    filter():		Modify the dbx output before it gets displayed on the
 *			dialog window.
 *    gdb_source_command():	Test for source command.
 */

#include 	<string.h>

extern Boolean	Prompt;			/* True when gdb prompt arrives */

/*--------------------------------------------------------------------------+
|																			|
|	Function to output a message and ring bell when a answer				|
|	from gdb has not been recognized (possibly because of bug				|
|	in xxgdb which does not anticipate this particular answer).				|
|																			|
|	ECHO_ON means that all the output from gdb was displayed				|
|	on the dialog window (so no need to display any error message).			|
|	In particular we can arrive here because the user typed a				|
|	wrong command.															|
|																			|
|	ECHO_OFF means that the gdb command was issued internally by			|
|	xxgdb, and that the user has no knowledge of it.						|
|																			|
|	ECHO_ON and FILTER_ON means that only part of the						|
|	gdb answer to the command is displayed in the dialog window.			|
|	What is displayed or not is chosen by the filter() function.			|
|	In fact, filter() in this case will display gdb error messages			|
|	from the command sent internally by xxgdb.								|
|																			|
|	This function will only display error messages when echo and			|
|	filter are off. This is more for xxgdb debug than for the user.			|
|																			|
+--------------------------------------------------------------------------*/	
void unknown_output (outputstr, command, flags)
char *outputstr;
char *command;
int flags;
{
	if (command)
		{
		if (debug)
			fprintf(stderr, "\noutput from \"%s\" is not recognized\n", command);
	
		/* if the command was completely silent, we output this
		error message */
		
		if ((flags & (ECHO_ON | FILTER_ON)) == 0)
			{
			AppendDialogText("xxgdb error: output from \"");
			AppendDialogText(command);
			AppendDialogText("\" command is not recognized.\n");
			}
		}
		
	if (outputstr)
		if ((flags & (ECHO_ON | FILTER_ON)) == 0)
			AppendDialogText(outputstr);

	bell(0);	/* ring the bell in ALL cases */
}

/*--------------------------------------------------------------------------+
|																			|
|	Function to remove all 'Reading in symbols' message						|
|	from a string.															|
|																			|
|	This function is used in parser() before matching the output			|
|	because this message can happen any time.								|
|																			|
+--------------------------------------------------------------------------*/
void filter_reading_symbols(output)
char *output;
{
struct re_registers regs;
int	r;
char *p1;
char *p2;

		/* test for reading symbols message */
	
	while (re_match(output_pattern[O_READING_SYMBOLS].buf,output,strlen(output),0,&regs) > 0)
		{
		/* we found a "Reading in symbols for 	...done." pattern */
		
		r = output_pattern[O_READING_SYMBOLS].reg_token[TK_MESG];
		p1=  output+regs.start[r];
		p2 = output+regs.end[r];
		
		/* remove "Reading in symbols for 	...done." */
		
		while(*(p1++) = *(p2++));
		}
}

/*--------------------------------------------------------------------------+
|																			|
| *	 This routine first parses the command string.							|
| *	 If the command is one of run, cont, next, step, stop at, stop in,		|
| *	 where, up, or down, it parses the dbx output to decide what action		|
| *	 to take and dispatch it to one of the handlers.						|
| *	 For other commands, the appropriate handler is called.					|
| *																			|
| *	 !!! This routine has to be re-entrant.									|
| *																			|
+--------------------------------------------------------------------------*/
void parse(output, command, flags)
char *output;
char *command;
int flags;
{
    int  command_type;
    char *output_string;

    if (debug) {
    char *temp;
    if(!command)temp="";else temp=command;
	fprintf(stderr, "parse(output = %s, command = %s, flags = %d)\n", output, temp, flags);
    }

    /* Make a local copy of `output' and use that instead */
    output_string = XtNewString(output);
    if (output) strcpy(output, "");

	/* test for GDB start-up */

    if (!command) {
/* (PW)28AUG91 : do no test for O_DEBUG pattern because of gdb 4.0
who most of the times displays nothing before the promt.
if (match(output_pattern, output_string, O_DEBUG) != -1)
*/
		{
   		query_gdb_directories();	/* will tell if running gdb 4.0 */
   		
	    debug_handler();	/* some init to gdb, and try to display main() */
	
	    /* test if a core file was used in input arguments,
	    an display bomb if necessary. */
	
	    if (match(output_pattern, output_string, O_CORE_FILE) != -1)
			core_file_handler();
	    }
	debug_init();			/* read .gdbinit file (if any) */
	XtFree(output_string);
	return;
    }
    
    /* if not GDB start-up */

	if (match(output_pattern, output_string, O_BELL) != -1)
		{
		/* test if this is 'show undefined'. If yes then we are
		not executing the new gdb (4.0).
			(see show_is_undefined in gdb_handler.c)
		*/
		if (match(output_pattern, output_string, O_UNDEF_SHOW) != -1)
			show_is_undefined();
		else
			unknown_output (output_string,command, flags);
    	XtFree(output_string);
		return;
		}
	
    command_type = match(command_pattern, command, C_ANY);
    
    
    /* remove all "Reading in symbols for pw.c...done."  */

	filter_reading_symbols(output_string);
        	
    switch (command_type) {
      	case C_EXEC: 
		case C_FINISH:
		{
		char * message;
		int signal;
		message = 0;
		if (match(output_pattern, output_string, O_RECEIVED_SIGNAL) != -1)
			{
			message = XtNewString(Token.mesg);
			signal = Token.stop;	/* signal number received */
			}
			
		/* warning : the order of the matching tests is important */
		
	    if ((match(output_pattern, output_string, O_EXEC_MESS_AFTER) != -1)
	    	|| (match(output_pattern, output_string, O_EXEC_MESS_BEFORE) != -1)
	    	|| (match(output_pattern, output_string, O_EXEC) != -1))
			{
			exec_handler(message,signal);
			}
	    else 
	    	{
			if (match(output_pattern, output_string, O_DONE) != -1)
				done_handler(message,signal);
			else
				unknown_output(output_string, command, flags);
			}
			
		if (message)
			{
			bell(0);
			XtFree(message);
			}
		}
	    break;
	    
	case C_UPDOWN:
	    if (match(output_pattern, output_string, O_UPDOWN) != -1)
		updown_handler();
	    else
			unknown_output (output_string, command, flags);
	    break;
	case C_SEARCH:
	    if (match(output_pattern, output_string, O_SEARCH) != -1)
		search_handler();
	    else
			unknown_output(output_string, command, flags);
	    break;
	case C_DELETE:
	    delete_handler(); 
	    break;
	case C_LIST:
	    if (match(output_pattern, output_string, O_LIST) != -1)
	        list_handler();
	    else
			unknown_output(output_string, command, flags);
	    break;
	    
	case C_BREAK: 
	    if (match(output_pattern, output_string, O_BREAK) != -1)
			break_handler();
	    else
			unknown_output(output_string, command, flags);
	    break;
	    
	case C_INFO_DIR:
	    if (match(output_pattern, output_string, O_INFO_DIR) != -1)
	        info_dir_handler();
	    else
			unknown_output(output_string, command, flags);
		break;
		
	case C_DIRECTORY:
	    directory_handler(); 
	    break;
	    
	case C_INFO_LINE:
	    if (match(output_pattern, output_string, O_INFO_LINE) != -1)
	    	info_line_handler();		/* command was 'info line' */
	    else
			unknown_output(output_string, command, flags);
	    break;
	    
	case C_INFO_BREAK:
	    info_break_handler(output_string);
	    break;

	case C_DISPLAY:	/* means "display foo\n" command */
		{
	    if ((strcmp(output_string, "") == NULL) ||
	    	(match(output_pattern, output_string, O_DISPLAY) != -1))
	    	display_handler();
	    else
			unknown_output(output_string, command, flags);
		}
	    break;
	    
	case C_UNDISPLAY:
	    if (strcmp(output_string, "") == NULL)
			display_handler();
	    else
			unknown_output(output_string, command, flags);
	    break;

	case C_DISPLAY_INFO: /* means "display\n" command */
		{
	    if ((strcmp(output_string, "") == NULL) ||
	    	(match(output_pattern, output_string, O_DISPLAY_INFO) != -1))
	    	display_info_handler();
	    else
			unknown_output(output_string, command, flags);
		}
	    break;
	    
	case C_CD:
	    if (match(output_pattern, output_string, O_CD) != -1)
	    	cd_handler(Token.mesg); 
	    else
			unknown_output(output_string, command, flags);
	    break;
	    
	case C_PWD:
	    if (match(output_pattern, output_string, O_PWD) != -1)
			pwd_handler(Token.mesg);
	    else
			unknown_output(output_string, command, flags);
	    break;

	case C_FRAME_CURR:
	    if (match(output_pattern, output_string, O_FRAME_CURR) != -1)
			frame_curr_handler();
	    else
			unknown_output(output_string, command, flags);
	    break;

	case C_PRINT:
		{
		/* for GDB, the label of the popup display is the expression
		string which is printed instead of $n */
		char * prtname;
		prtname = 0;
		if ((Token.mesg) && (PopupMode))
			prtname = XtNewString(Token.mesg);
			
	    if (match(output_pattern, output_string, O_PRINT) != -1)
	    	{
	    	if (prtname)
	    		{
				XtFree(Token.mesg);
				Token.mesg = prtname;
				prtname = 0;			/* not to XtFree twice this string */
				}
	    	print_handler(output_string);
	    	}
	    else
			unknown_output(output_string, command, flags);
		
		/* if PopupMode was true but GDB found an error in print
		statement (ie match() returned -1), PopupMode was never reset */
		PopupMode = FALSE;	 
		
		XtFree(prtname);
		}
	    break;
	    
	case C_SYMBOL_FILE:
	case C_FILE:
		debug_handler(); 
	    break;

	case C_SOURCE:	/* WE SHOULD NEVER ARRIVE HERE */
		break;

	case C_EXEC_FILE:
		break;
		
	case C_CORE_FILE:
	    if (match(output_pattern, output_string, O_CORE_FILE) != -1)
			core_file_handler();
	    else
			unknown_output(output_string, command, flags);
	    break;
	    
	/* in case of 'info source', we do not call unknown_output()
	if the pattern is not matched, because we only test for the
	'compilation directory' line. When there is no compilation
	directory, there is no match and there is no error... */
	
	case C_INFO_SOURCE:
	    if (match(output_pattern, output_string, O_INFO_SOURCE) != -1)
	    	info_source_handler(Token.mesg);
	    break;

	default:
	    break;
    }
    XtFree(output_string);
}

#ifdef NEED_STRSTR
/*--------------------------------------------------------------------------+
|																			|
|	Some systems DO NOT have the ANSI strstr function						|
|																			|
+--------------------------------------------------------------------------*/	
char *
strstr (source, substr)
	char *source;
	char *substr;
{
char *src;
char *sub;

	if (!source || !substr)
		return NULL;
		
	while (*source)
		{
		for (src = source, sub = substr;
				(*src) && (*sub) && (*src == *sub);
					src++,sub++);
		if (!*sub)
			return source;
			
		source++;
		}
		
	return NULL;
}
#endif

/*--------------------------------------------------------------------------+
|																			|
|	Function to filter all the display information in a string				|
|																			|
|	input : string pointer.													|
|																			|
|	output : none.															|
|																			|
|	See O_EXEC_DISPLAY in gdb_regex.h for the display pattern.				|
|																			|
|	Take care when GDB send some message after '\032\032...\n'				|
|	which is not a display line.											|
|																			|
| (gdb) finish																|
| Run till exit from #0	 foo (n=1) (pw.c line 9)							|
| main () (pw.c line 41)													|
| /usr1/gnu_sun4/xxgdb/pw.c:41:590:beg:0x232c								|
| 1: i = 1																	|
| Value returned is $1 = 1													|
| (gdb)																		|
|																			|
+--------------------------------------------------------------------------*/
void filter_display_info(output)
char *output;
{
struct re_registers regs;
int	r;
char *p;
char *p1;
char *p2;
char *cp_output;
int begin_struct;

	p = cp_output = XtNewString(output);

	p1 = strstr(p,"\032\032");		/* find beginning of special gdb line */
	
	if ((p1 == 0) || ((p2 = strchr(p1+1,'\n')) == 0))
		{
		AppendDialogText(p);		/* something wrong here */
		XtFree(cp_output);
		return;
		}
		
	*p1 = 0;
	AppendDialogText(p);			/* print everything before that line */
	p = p2 + 1;						/* end of that line + skip \n */

	/* test for beginning of a display */
	
	while (re_match(output_pattern[O_EXEC_DISPLAY].buf,p,strlen(p),0,&regs) > 0)
		{
		/* we found a "X:....\n" pattern */
		
		r = output_pattern[O_EXEC_DISPLAY].reg_token[TK_DISP];
		p1=  p+regs.start[r];
		p2 = p+regs.end[r];
					
		/* count number of { and } : if not equal, the next lines are part of this display */
		begin_struct = 0;
		while (p1 < p2)
			{
			switch(*(p1++))
				{
				case '{':
					begin_struct++;
					break;
				case '}':
					begin_struct--;
					break;
				}
			}
			
		p1=p+regs.start[r];
		*p1 = 0;
		if (p != p1)
			AppendDialogText(p);	/* print what is before display */
		p = p2;						/* skip display text */
					
		if (begin_struct)	/* skip the whole data displayed */
			{
			do				/* find the last '}' */
				{
				switch(*(p++))
					{
					case '{':
						begin_struct++;
						break;
					case '}':
						begin_struct--;
						break;
					}
				}
			while (begin_struct);
			
			/* now skip until end of line */
			while (*(p++) != '\n');
			}
		}
		
	AppendDialogText(p);		/* print what is after display */
	XtFree(cp_output);
}

/*--------------------------------------------------------------------------+
|																			|
| *	 This function edits the dbx output so that unnecessary information is	|
| *	 not displayed on the dialog window.									|
| *	 It filters away the some output returned by the execution commands;	|
| *	 output from the search commands, and the display command.				|
| *	 On Sun dbx, it also filters away part of the output returned by the	|
| *	 up and down commands.													|
| *																			|
+--------------------------------------------------------------------------*/
void filter(string, output, command)
char *string, *output, *command;
{
    struct re_registers regs;
    char 		*p;
    char 		*p2;
    static Boolean	deleteRest = False;
    int			command_type = -1;
	static unsigned int already_taken_care;	

    if (output == NULL || strcmp(output, "") == NULL) 
	return;

/* for GDB, the only things we want to filter are:

	- the line displayed because of the -fullname  option :
	"\032\032/usr1/gnu_sun4/xdbx/pw.c:6:40:beg:0x22b0\n",
	
	- the displayed info which goes into the display window,
	
	- list and search outputs

*/
	if (!string)
		string = "";
		
    if (command)
    	command_type = match(command_pattern, command, C_ANY);
    	
    if ((command_type == C_EXEC)||(command_type == C_FINISH))
    	{
		if ((re_match(output_pattern[O_EXEC_MESS_AFTER].buf,string,strlen(string),0,&regs) > 0)
			|| (re_match(output_pattern[O_EXEC_MESS_BEFORE].buf,string,strlen(string),0,&regs) > 0)
			|| (re_match(output_pattern[O_EXEC].buf,string,strlen(string),0,&regs) > 0))
			{
			/* remember what was the output length was output was matched */
			already_taken_care = strlen(output) - strlen(string);
			
			/* Remove display messages from output and print what is no a display */
			
			if (Prompt)
				filter_display_info(output + already_taken_care);	
		    else
				deleteRest = True;
				
			return;
			}
		else
			{
			if (deleteRest)		
				{
				/* Remove display messages from output and print what is no a display */
				if (Prompt)
					{
					filter_display_info(output + already_taken_care);	
					deleteRest = False;
					}
				return;
				}
			}
		}
		
	/* filter any line starting with \032\032 */
	
	p = strchr(string,'\032');
	if (p && (*(p+1) == '\032') && (p == string || *(p-1) == '\n') && (p2 = strchr(p,'\n')))
		{
		while (*(p++) = *(++p2));
		}
		
	if ((command_type == C_EXEC)||(command_type == C_FINISH))
		{
		AppendDialogText(string);
		return;
		}
		
    if (Prompt)
    	{
		char *s;

		s = XtNewString(output);
		switch (command_type)
			{
			case C_DISPLAY:
			    if (match(output_pattern, s, O_DISPLAY) != -1)
				strcpy(s, "");
			    break;

			case C_DISPLAY_INFO:
   				 /* (PW)7MAY91 : display error messages */
			    if (match(output_pattern, s, O_DISPLAY_INFO) != -1)
					{    
    				if (Token.mesg && strcmp(Token.mesg, ""))	
   				    	{
						AppendDialogText(Token.mesg);
						bell(0);
    					}		
					strcpy(s, "");
    				}
			    break;
			    
			case C_SEARCH:
			    if (match(output_pattern, s, O_SEARCH) != -1)
				strcpy(s, "");
			    break;
			case C_LIST:
   				 /* (PW)22MAY91 : display messages ") */
			    if (match(output_pattern, s, O_LIST) != -1)
					{    
    				if (Token.mesg && strcmp(Token.mesg, ""))	
   				    	{
						AppendDialogText(Token.mesg);
						if (strstr(Token.mesg,"Source file is more recent than executable."))
							bell(0); /* Warn user WYSIWYG not true */
    					}		
					strcpy(s, "");
    				}
			    break;
			case C_PRINT:
				if	(PopupMode &&	/* if print goes in a window, don't display here */
			    	(match(output_pattern, s, O_PRINT) != -1))
				strcpy(s, "");
				break;
				
			default:
				XtFree(s);
			    s = XtNewString(string);		/* append 'string' only */
			    break;
			}
		AppendDialogText(s);
		XtFree(s);
	    }
	else
		{
		switch (command_type)
			{
			case C_DISPLAY:
			case C_DISPLAY_INFO:
			case C_SEARCH:
			case C_LIST:
			case C_PRINT:
				break;
			default:
				AppendDialogText(string);
				break;
			}
		}
}


/*--------------------------------------------------------------------------+
|																			|
|	Function to filter 'source' command										|
|																			|
|	input : command (from .gdbinit or source command or keyboard),			|
|			echo is TRUE if source command must be echoed.					|
|																			|
|	output : TRUE if source command was recognized							|
|																			|
|	In case source command is recognized, it is executed here.				|
|																			|
+--------------------------------------------------------------------------*/
int gdb_source_command(command,echo)
char *command;
int echo;
{
	if (command && (match(command_pattern, command, C_SOURCE) != -1))
		{
		if (echo)
			AppendDialogText(command);
		source_handler();	
		return TRUE;
		}
		
	return FALSE;
}

/*--------------------------------------------------------------------------+
|																			|
|	Function to filter 'define' & 'document' commands						|
|																			|
|	input : command (from .gdbinit or source command),						|
|			fp = file pointer.												|
|																			|
|	output : TRUE if define or document command was recognized				|
|																			|
|	In case the command is recognized, it is executed here.					|
|																			|
+--------------------------------------------------------------------------*/
static int command_sent = 0;	/* flag gdb is busy : send no more command to gdb. */

int gdb_define_command(command,fp)
char *command;
FILE *fp;
{
char s[LINESIZ];
int error_cmd;
int end_found;

	if ((command && (match(command_pattern, command, C_DEFINE) != -1))
		|| (command && (match(command_pattern, command, C_DOCUMENT) != -1)))
		{
		AppendDialogText(command);
		
		/* because silly gdb 4.0 displays nothing with def/doc command when
		confirm is on (possibly a gdb bug) , I just reset confirm to on
		just for this command !. */
		
		if (new_gdb4())
			query_gdb("set confirm on\n",	PARSE_OFF | ECHO_OFF | FILTER_OFF);

		write_dbx (command);
		
/*
				gdb could ask :
			
					"Redefine command \"%s\"? "
					"Really redefine built-in command \"%s\"? "
					
				gdb could display 
				
					"Type commands for definition of \"%s\".\n"
					"End with a line saying just \"end\"
				
				or
					"Type documentation for \"%s\".\n"
					"End with a line saying just \"end\".\n"
					
				or
				 	"Command \"%s\" is built-in."
*/
	
		error_cmd = FALSE;
				
		/* read message from gdb */
		
		while (1)
			if (fgets(s, LINESIZ, dbxfp))
				{
				if (debug)
					fprintf(stderr, "=>%s", s);
				
				if (strstr(s," is built-in."))	/* error for document of built-in command */
					{
					AppendDialogText(s);
					error_cmd = TRUE;
					bell(0);
					break;
					}
			
				if (strstr(s,"Redefine command ")
				 || strstr(s,"Really redefine built-in command "))
					write_dbx ("y\n"); 	/* answer to question if any */
				else
					{
					if (strcmp(s,"End with a line saying just \"end\".\n") == NULL)
						break;
					}
				}
		
		/* write command definition */
		
		end_found = FALSE;
		
		while (fgets (s, LINESIZ, fp))
			{
			if (!error_cmd)
				{
				AppendDialogText(s);
				write_dbx (s);
				}
			
			if (match(command_pattern, s, C_END) != -1)
				{
				end_found = TRUE;
				break;
				}
			}
			
		if ((!error_cmd) && (!end_found))
			{
			AppendDialogText("Error : missing \"end\" in file.\n");
			bell(0);
			write_dbx ("end\n");
			}
		
		command_sent++;				/* flag gdb is busy (because of read_gdb) */
		insert_command("end\n");	/* insert 'end' at head of queue */
		read_until_prompt (PARSE_OFF | ECHO_ON | FILTER_OFF);	/* return when prompt */

		if (new_gdb4()) /* reset confirm to off */
			query_gdb("set confirm off\n",	PARSE_OFF | ECHO_OFF | FILTER_OFF);

		return TRUE;
		}
		
	return FALSE;
}

/*--------------------------------------------------------------------------+
|																			|
|	Read gdb output until fgets returns no string.							|
|																			|
|	The ouptut is process according to flags.								|
|																			|
|	In case the gdb prompt is found, the command on top of the				|
|	command queue (ie, the one which is assumed to correspond				|
|	to this output) is remove from the queue, and 'command_sent'			|
|	is decremented to say that gdb is no longer busy.						|
|																			|
+--------------------------------------------------------------------------*/
static int parse_flags = PARSE_ON | ECHO_ON | FILTER_ON; /* last flags used in read_gdb */

void read_gdb (flags)
int flags;
{
    static char *output = NULL; 	/* buffer for gdb output */
    static char *next_string = NULL;
    static char *command;
    char 	*string = NULL;
    char 	s[LINESIZ];
    Boolean 	more;
	
	parse_flags = flags; 	/* just remember flags for read_dbx() */
	
    more = True;
    while (more) {
	Prompt = False;
	/* keep reading until no more or until prompt arrives */
	while (more = fgets(s, LINESIZ, dbxfp) && !Prompt)
		{
	    if (debug)
			fprintf(stderr, "=>%s", s);
			
	    /* receive prompt? */
	    if (strncmp(s, dbxprompt, strlen(dbxprompt)) == NULL)
	    	{
			Prompt = True;
			
			/* more stuff behind prompt? */
			if (s[strlen(dbxprompt)])
			    /* remember it */
			    next_string = XtNewString(s+strlen(dbxprompt));
			
			/* destroy contents */
			strcpy(s, "");
		    }
		
	    string = concat(string, s);
	    strcpy(s, "");
		}
		
	output = concat(output, string);
	
	command = get_command();			/* read queue's top command  */
		
	if (flags & FILTER_ON)
	    filter(string, output, command);
	
	if ((flags & ECHO_ON) && Prompt)
	    AppendDialogText(xdbxprompt);
	
	if (string) {
	    XtFree(string);
	    string = NULL;
	}
	
	if (next_string) {
	    string = concat(string, next_string);
	    XtFree(next_string);
	    next_string = NULL;
	}
	
	if ((flags & PARSE_ON) && Prompt) {
	    parse (output, command, flags);
	}
	
	/* note : it is important to decrement 'command_sent' AFTER
	parse() is executed, so that no other commands will mix-up
	the commands sent by the function handlers executed by parse().
	*/
	
	if (Prompt) {
	    delete_command();		/* remove top command from queue */
	    if (command && command_sent)
			command_sent--;
	    XtFree(output);
	    output = NULL;
	}
	}
}

/*--------------------------------------------------------------------------+
| *																			|
| *	 This is a callback procedure invoked everytime when input is pending	|
| *	 on the file descriptor to dbx.											|
| *	 o reads all the data available on the file descriptor line by line		|
| *	   into local variable 'string' and global variable 'output'.			|
| *	   'output' records the entire dbx output whereas 'string' records		|
| *	   only the data read in this invocation of read_dbx().					|
| *	 o in Echo mode, the contents in 'string' is edited by filter()			|
| *	   before it gets displayed on the dialog window.						|
| *	 o once the dbx prompt is read, calls parse() to analyse the dbx output |
| *	   and take appropriate action.											|
| *																			|
+--------------------------------------------------------------------------*/
/* ARGSUSED */
void read_dbx(master, source, id)
XtPointer master;
int 	  *source;
XtInputId *id;
{
	read_gdb (parse_flags);
	
	write_dbx_available ();
}

/*--------------------------------------------------------------------------+
|																			|
|	Read gdb output until prompt.											|
|	The ouptut is process according to flags.								|
|																			|
+--------------------------------------------------------------------------*/
void read_until_prompt (flags)
int flags;
{
    Prompt = False;
    while (!Prompt)
        read_gdb (flags);
}

/*--------------------------------------------------------------------------+
|																			|
| *	 Sends a command to gdb and read the corresponding output, directly		|
| *	 invoking the Xt input procedure, read_gdb().							|
| *																			|
| * Same as query_dbx() in dbx.c except that echo, filter and parse.		|
| *	 are passed in argument flags:											|
| * PARSE_ON | PARSE_OFF | ECHO_ON | ECHO_OFF | FILTER_ON | FILTER_OFF		|
| *																			|
+--------------------------------------------------------------------------*/
void query_gdb(command, flags)
char *command;
int flags;
{
	command_sent++;				/* flag gdb is busy */
	
    write_dbx(command);			/* send command to gdb */

    insert_command(command);	/* insert at head of queue */

	read_until_prompt (flags);	/* return when prompt */
	
	/* test if we are at the top command, and if some commands are waiting */
	
	write_dbx_available ();	/* send next waiting command */
}

/*--------------------------------------------------------------------------+
|																			|
|	Function to send the first command of the command queue to gdb only in	|
|	case gdb is waiting for a command.										|
|																			|
|	WARNING : we must test for 'source' command.							|
|																			|
|	The commands in the command queue are from the keyboard and from		|
|	the buttons.															|
|																			|
+--------------------------------------------------------------------------*/
void write_dbx_available()
{
char *command;

	if (command = get_command())
		{
		if (command_sent++ == 0)	
			{
			/* here, the source command is already displayed, say echo command = FALSE */
			
			if (gdb_source_command(command,FALSE))
				{
				delete_command();		/* remove source command from top of queue */
				command_sent--;
				/* tell gdb to send its prompt */
				query_gdb(" \n", PARSE_OFF | ECHO_OFF | FILTER_OFF);
				return;
				}
				
			parse_flags = PARSE_ON | ECHO_ON | FILTER_ON; /* for read_gdb */
			write_dbx (command);
		    Prompt = False;
			return;					/* return with command_sent incremented */
			}
		else
			{
			if (command_sent)	/* should never be zero ! (just to be safe) */
				command_sent--;	/* command is not sent, restore previous value */
			return;
			}
		}
}