Parent Directory
| 
Revision Log
Remove unnecessary CVS $Id$ tags
/* Copyright (c) 2005, David Leonard. All rights reserved. */
/*
* A simple debugger.
*/
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <see/see.h>
#include "shell.h"
#include "debug.h"
/* A breakpoint set by the user */
struct breakpoint {
struct breakpoint *next;
struct SEE_throw_location loc;
int id; /* unique id */
int ignore_counter; /* number of hits to ignore */
int ignore_reset;
int temporary; /* remove this BP when hit */
};
/* The current state of the debugger */
struct debug {
void *save_host_data;
void (*save_trace)(struct SEE_interpreter *,
struct SEE_throw_location *, struct SEE_context *,
enum SEE_trace_event);
int break_immediately;
struct breakpoint *breakpoints;
int next_bp_id;
char *last_command;
struct SEE_throw_location *current_location;
};
/* Command table elements */
struct cmd {
const char *name;
int (*fn)(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *,
char *arg);
const char *doc;
};
/* Prototypes */
static struct breakpoint *bp_add(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, int, int);
static void loc_print(FILE *, struct SEE_throw_location *);
static int bp_delete(struct SEE_interpreter *, struct debug *, int);
static void bp_print(struct SEE_interpreter *, struct breakpoint *, FILE *);
static void trace_callback(struct SEE_interpreter *,
struct SEE_throw_location *, struct SEE_context *,
enum SEE_trace_event);
static int location_matches(struct SEE_interpreter *,
struct SEE_throw_location *, struct SEE_throw_location *);
static int should_break(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, enum SEE_trace_event);
static int location_parse(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_throw_location *, char **);
static int cmd_where(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_step(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_cont(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_list(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_break(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static void bp_show(struct SEE_interpreter *, struct breakpoint *);
static int cmd_show(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_delete(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_eval(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_throw(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_help(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int cmd_info(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *, char *);
static int user_command(struct SEE_interpreter *, struct debug *,
struct SEE_throw_location *, struct SEE_context *);
static int loc_print_line(struct SEE_interpreter *, struct debug *,
FILE *, struct SEE_throw_location *);
static struct cmd cmdtab[] = {
{ "break", cmd_break, "set a breakpoint" },
{ "cont", cmd_cont, "continue running" },
{ "delete", cmd_delete, "delete a breakpoint" },
{ "eval", cmd_eval, "evaluate an expression" },
{ "help", cmd_help, "print this information" },
{ "info", cmd_info, "print context information" },
{ "list", cmd_list, "show nearby lines" },
{ "show", cmd_show, "show current breakpoints" },
{ "step", cmd_step, "run until statement change" },
{ "throw", cmd_throw, "evaluate an expression and throw it" },
{ "where", cmd_where, "show traceback" },
{ NULL }
};
/*
* Public API
*/
/* Allocates a new debugger context. There should only be one per interp. */
struct debug *
debug_new(interp)
struct SEE_interpreter *interp;
{
struct debug *debug;
debug = SEE_NEW(interp, struct debug);
debug->break_immediately = 1;
debug->breakpoints = NULL;
debug->next_bp_id = 0;
return debug;
}
/* Evaluate input inside the debugger */
void
debug_eval(interp, debug, input, res)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_input *input;
struct SEE_value *res;
{
void *save_host_data;
void (*save_trace)(struct SEE_interpreter *,
struct SEE_throw_location *, struct SEE_context *,
enum SEE_trace_event);
SEE_try_context_t ctxt;
fprintf(stderr, "debugger: starting\n");
save_host_data = debug->save_host_data;
save_trace = debug->save_trace;
debug->save_host_data = interp->host_data;
debug->save_trace = interp->trace;
debug->last_command = NULL;
interp->host_data = debug;
interp->trace = trace_callback;
SEE_TRY(interp, ctxt) {
SEE_Global_eval(interp, input, res);
}
/* finally */
interp->host_data = debug->save_host_data;
interp->trace = debug->save_trace;
debug->save_host_data = save_host_data;
debug->save_trace = save_trace;
if (debug->last_command)
free(debug->last_command);
fprintf(stderr, "debugger: exiting\n");
SEE_DEFAULT_CATCH(interp, ctxt);
}
/*
* Internal functions
*/
/* Adds a breakpoint to the breakpoint list, assigning it a unique number */
static struct breakpoint *
bp_add(interp, debug, loc, ignore, temporary)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
int ignore, temporary;
{
struct breakpoint *bp = SEE_NEW(interp, struct breakpoint);
bp->loc.filename = loc->filename;
bp->loc.lineno = loc->lineno;
bp->id = ++debug->next_bp_id;
bp->ignore_counter = bp->ignore_reset = ignore;
bp->temporary = temporary;
bp->next = debug->breakpoints;
debug->breakpoints = bp;
return bp;
}
static void
loc_print(file, loc)
FILE *file;
struct SEE_throw_location *loc;
{
if (!loc || !loc->filename)
fprintf(file, "<nowhere>");
else {
SEE_string_fputs(loc->filename, file);
fprintf(file, ":%d", loc->lineno);
}
}
/* Deletes a breakpoint by its unique number. Returns true if deleted. */
static int
bp_delete(interp, debug, id)
struct SEE_interpreter *interp;
struct debug *debug;
int id;
{
struct breakpoint *bp, **nbp;
for (bp = *(nbp = &debug->breakpoints); bp; bp = *(nbp = &(bp->next)))
if (bp->id == id) {
*nbp = bp->next;
return 1;
}
return 0;
}
/* Prints a breakpoint in human-readable form */
static void
bp_print(interp, bp, file)
struct SEE_interpreter *interp;
struct breakpoint *bp;
FILE *file;
{
fprintf(file, "#%d ", bp->id);
loc_print(file, &bp->loc);
if (bp->ignore_reset)
fprintf(file, " (remain %d reset %d)",
bp->ignore_counter, bp->ignore_reset);
if (bp->temporary)
fprintf(file, "[temp]");
}
/*
* Callback function invoked during each step inside the debugger.
* Transfers control to the user if a breakpoint is hit.
*/
static void
trace_callback(interp, loc, context, event)
struct SEE_interpreter *interp;
struct SEE_throw_location *loc;
struct SEE_context *context;
enum SEE_trace_event event;
{
struct debug *debug;
SEE_try_context_t ctxt;
debug = (struct debug *)interp->host_data;
/* Call any inner trace functions */
if (debug->save_trace) {
interp->host_data = debug->save_host_data;
interp->trace = debug->save_trace;
SEE_TRY(interp, ctxt) {
(*interp->trace)(interp, loc, context, event);
}
interp->host_data = debug;
interp->trace = trace_callback;
SEE_DEFAULT_CATCH(interp, ctxt);
}
/*
fprintf(stderr, "event: %s\n",
event == SEE_TRACE_CALL ? "call" :
event == SEE_TRACE_RETURN ? "return" :
event == SEE_TRACE_STATEMENT ? "statement" :
event == SEE_TRACE_THROW ? "throw" :
"?");
*/
/* Invoke the command prompt on breakpoints */
if (should_break(interp, debug, loc, event)) {
debug->current_location = loc;
loc_print_line(interp, debug, stderr, loc);
while (!user_command(interp, debug, loc, context))
{ /* nothing */ }
}
}
/* Returns true if the current location is matched by the user location */
static int
location_matches(interp, curloc, usrloc)
struct SEE_interpreter *interp;
struct SEE_throw_location *curloc, *usrloc;
{
return usrloc && usrloc->filename && curloc && curloc->filename &&
SEE_string_cmp(curloc->filename, usrloc->filename) == 0 &&
curloc->lineno == usrloc->lineno;
}
/* Returns true if a breakpoint was hit, and the debugger should intercede */
static int
should_break(interp, debug, loc, event)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
enum SEE_trace_event event;
{
struct breakpoint *bp, **lbp;
if (event != SEE_TRACE_STATEMENT)
return 0;
/* Break if the break_immediately flag is set */
if (debug->break_immediately) {
debug->break_immediately = 0;
return 1;
}
/* Scan the breakpoint list for unignoreable bps */
for (bp = *(lbp = &debug->breakpoints); bp; bp = *(lbp = &bp->next))
if (location_matches(interp, loc, &bp->loc)) {
if (bp->ignore_counter)
bp->ignore_counter--;
else {
bp->ignore_counter = bp->ignore_reset;
if (bp->temporary)
*lbp = bp->next;
return 1;
}
}
return 0;
}
/* Parse "[filename:]lineno" into nloc. Returns true if valid */
static int
location_parse(interp, debug, loc, nloc, argp)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc, *nloc;
char **argp;
{
char *p = *argp;
struct SEE_string *filename = loc ? loc->filename : NULL;
int lineno = 0, ok = 0;
if (*p && isdigit(*p) && filename) {
/* pure line number */
while (*p && isdigit(*p)) {
lineno = lineno * 10 + *p - '0';
p++;
}
nloc->filename = filename;
nloc->lineno = lineno;
ok = 1;
} else if (*p && *p != ':') {
char *start = p;
while (*p && !isspace(*p) && *p != ':') p++;
if (*p == ':' && p[1] && isdigit(p[1])) {
filename = SEE_string_sprintf(interp, "%.*s",
p - start, start);
p++;
while (*p && isdigit(*p)) {
lineno = lineno * 10 + *p - '0';
p++;
}
nloc->filename = filename;
nloc->lineno = lineno;
ok = 1;
} else
fprintf(stderr,
"missing ':<lineno>' after filename\n");
} else
fprintf(stderr, "expected <filename>:<lineno>\n");
if (ok) {
while (*p && isspace(*p)) p++;
*argp = p;
}
return ok;
}
static int
cmd_where(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
SEE_PrintTraceback(interp, stderr);
fprintf(stderr, " @ ");
loc_print(stderr, loc);
fprintf(stderr, "\n");
return 0;
}
static int
cmd_step(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
debug->break_immediately = 1;
return 1;
}
static int
cmd_cont(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
return 1;
}
static int
cmd_list(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
struct SEE_throw_location rloc;
int offset;
int printed_something = 0;
memcpy(&rloc, loc, sizeof rloc);
for (offset = -3; offset <= 3; offset++) {
rloc.lineno = loc->lineno + offset;
if (loc_print_line(interp, debug, stderr, &rloc))
printed_something = 1;;
}
if (!printed_something)
fprintf(stderr, "debugger: unable to list source file\n");
return 0;
}
static int
cmd_break(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
struct SEE_throw_location bloc;
struct breakpoint *bp;
if (location_parse(interp, debug, loc, &bloc, &arg)) {
bp = bp_add(interp, debug, &bloc, 0, 0);
fprintf(stderr, "debugger: added breakpoint: ");
bp_print(interp, bp, stderr);
fprintf(stderr, "\n");
}
return 0;
}
void
debug_add_bp(interp, debug, filename, lineno)
struct SEE_interpreter *interp;
struct debug *debug;
const char *filename;
int lineno;
{
struct SEE_throw_location loc;
struct breakpoint *bp;
loc.filename = SEE_string_sprintf(interp, "%s", filename);
loc.lineno = lineno;
bp = bp_add(interp, debug, &loc, 0, 0);
fprintf(stderr, "debugger: added breakpoint: ");
bp_print(interp, bp, stderr);
fprintf(stderr, "\n");
}
/* Show breakpoints in reverse order */
static void
bp_show(interp, bp)
struct SEE_interpreter *interp;
struct breakpoint *bp;
{
if (bp) {
bp_show(interp, bp->next);
fprintf(stderr, " ");
bp_print(interp, bp, stderr);
fprintf(stderr, "\n");
}
}
static int
cmd_show(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
if (!debug->breakpoints)
fprintf(stderr, "debugger: no breakpoints\n");
else {
fprintf(stderr, "debugger: current breakpoints:\n");
bp_show(interp, debug->breakpoints);
}
return 0;
}
static int
cmd_delete(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
char *p;
int id;
p = arg;
if (!*p || !isdigit(*p)) {
fprintf(stderr, "debugger: expected number\n");
return 0;
}
id = 0;
while (*p && isdigit(*p))
id = 10 *id + (*p++ - '0');
if (bp_delete(interp, debug, id))
fprintf(stderr, "debugger: breakpoint #%d deleted\n", id);
else
fprintf(stderr, "debugger: unknown breakpoint #%d\n", id);
return 0;
}
static int
cmd_eval(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
SEE_try_context_t ctxt;
struct SEE_value res;
struct SEE_string *str;
void (*save_trace)(struct SEE_interpreter *,
struct SEE_throw_location *, struct SEE_context *,
enum SEE_trace_event);
if (!*arg) {
fprintf(stderr, "debugger: expected expression text\n");
return 0;
}
str = SEE_string_sprintf(interp, "%s", arg);
save_trace = interp->trace;
interp->trace = NULL;
SEE_TRY(interp, ctxt) {
SEE_context_eval(context, str, &res);
}
interp->trace = save_trace;
if (SEE_CAUGHT(ctxt)) {
fprintf(stderr, "debugger: caught exception ");
SEE_PrintValue(interp, SEE_CAUGHT(ctxt), stderr);
fprintf(stderr, "\n");
} else {
fprintf(stderr, " = ");
SEE_PrintValue(interp, &res, stderr);
fprintf(stderr, "\n");
}
return 0;
}
static int
cmd_throw(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
SEE_try_context_t ctxt;
struct SEE_value res;
struct SEE_string *str;
void (*save_trace)(struct SEE_interpreter *,
struct SEE_throw_location *, struct SEE_context *,
enum SEE_trace_event);
if (!*arg) {
fprintf(stderr, "debugger: missing expression argument\n");
return 0;
}
str = SEE_string_sprintf(interp, "%s", arg);
save_trace = interp->trace;
interp->trace = NULL;
SEE_TRY(interp, ctxt) {
SEE_context_eval(context, str, &res);
}
interp->trace = save_trace;
if (SEE_CAUGHT(ctxt)) {
char *yn;
fprintf(stderr, "debugger: exception while evaluating expr: ");
SEE_PrintValue(interp, SEE_CAUGHT(ctxt), stderr);
fprintf(stderr, "\n");
yn = readline("debugger: throw this exception instead? [n]: ");
if (yn && (*yn == 'y' || *yn == 'Y')) {
fprintf(stderr, "debugger: throwing...\n");
SEE_DEFAULT_CATCH(interp, ctxt);
}
} else {
fprintf(stderr, "debugger: throwing ");
SEE_PrintValue(interp, &res, stderr);
fprintf(stderr, " ...\n");
SEE_THROW(interp, &res);
}
return 0;
}
static int
cmd_help(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
int i;
fprintf(stderr, "debugger: command table follows\n");
for (i = 0; cmdtab[i].name; i++)
fprintf(stderr, " %-20s%s\n",
cmdtab[i].name, cmdtab[i].doc);
return 0;
}
static int
cmd_info(interp, debug, loc, context, arg)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
char *arg;
{
fprintf(stderr, "debugger: context info follows\n");
fprintf(stderr, " activation = ");
SEE_PrintObject(interp, context->activation, stderr);
fprintf(stderr, "\n");
fprintf(stderr, " variable = ");
SEE_PrintObject(interp, context->variable, stderr);
fprintf(stderr, "\n");
fprintf(stderr, " varattr = < %s%s%s%s>\n",
context->varattr & SEE_ATTR_READONLY ? "readonly " : "",
context->varattr & SEE_ATTR_DONTENUM ? "dontenum " : "",
context->varattr & SEE_ATTR_DONTDELETE ? "dontdelete " : "",
context->varattr & SEE_ATTR_INTERNAL ? "internal " : "");
fprintf(stderr, " this = ");
SEE_PrintObject(interp, context->thisobj, stderr);
fprintf(stderr, "\n");
return 0;
}
/* Prompts user for a command, and carry it out.
* Returns true if the command is to resume, false if not.
*/
static int
user_command(interp, debug, loc, context)
struct SEE_interpreter *interp;
struct debug *debug;
struct SEE_throw_location *loc;
struct SEE_context *context;
{
char *line, *p, *cmd;
int i, result;
loc_print(stderr, loc);
line = readline(" % ");
if (!line) {
fprintf(stderr, "debugger: end-of-file received\n");
exit(1);
}
if (!*line) {
if (debug->last_command) {
free(line);
line = strdup(debug->last_command);
}
} else {
if (debug->last_command)
free(debug->last_command);
debug->last_command = strdup(line);
}
p = line;
while (*p && isspace(*p)) p++; /* skip leading whitespace */
cmd = p; /* extract initial command word */
if (*p && !isspace(*p)) p++;
while (*p && isalnum(*p)) p++;
if (*p) *p++ = '\0';
while (*p && isspace(*p)) p++; /* skip following whitespace */
result = 0;
if (*cmd) {
for (i = 0; cmdtab[i].name; i++)
if (strcmp(cmdtab[i].name, cmd) == 0) {
result = (*cmdtab[i].fn)(interp, debug, loc, context, p);
break;
}
if (!cmdtab[i].name)
fprintf(stderr, "debugger: unknown command '%s' (try 'help')\n",
cmd);
}
free(line);
return result;
}
/* Prints the line from a source file, or nothing if it is not found.
* Returns true only if a line is printed. */
static int
loc_print_line(interp, debug, out, loc)
struct SEE_interpreter *interp;
struct debug *debug;
FILE *out;
struct SEE_throw_location *loc;
{
FILE *f;
char path[4096];
int i, ch, lineno;
struct breakpoint *bp;
char clchar, bpchar;
if (!loc->filename)
return 0;
if (loc->filename->length >= sizeof path - 1)
return 0;
for (i = 0; i < loc->filename->length; i++) {
if (loc->filename->data[i] > 0x7f)
return 0;
path[i] = loc->filename->data[i] & 0x7f;
}
path[i] = 0;
f = fopen(path, "r");
if (!f)
return 0;
lineno = 1;
while (lineno != loc->lineno) {
ch = fgetc(f);
if (ch == EOF)
return 0;
if (ch == '\n')
lineno++;
}
/* Put a * at the front if this line is a breakpoint */
bpchar = ' ';
for (bp = debug->breakpoints; bp; bp = bp->next)
if (location_matches(interp, loc, &bp->loc))
bpchar = '*';
clchar = ' ';
if (location_matches(interp, loc, debug->current_location))
clchar = '>';
fprintf(out, "%c%c%3d: ", bpchar, clchar, lineno);
while ((ch = fgetc(f)) != EOF) {
if (ch == '\n')
break;
fputc(ch, out);
}
fputc('\n', out);
fclose(f);
return 1;
}
| David Leonard | ViewVC Help |
| Powered by ViewVC 1.0.9 |