2005-01-12 Andrew Cagney <cagney@gnu.org>

* exceptions.c: Include "gdb_string.h".
	(enum catcher_state, struct catcher): Define.
	(current_catcher): New global, replaces catch_return;
	(catch_return): Delete.
	(throw_exception): Use current_catcher->buf;
	(catcher_init, catcher_pop, catcher_state_machine): New functions.
	(catcher): Delete.
	(struct catch_errors_args): Delete.
	(do_catch_errors): Delete.
	(catch_exceptions): Replace body with call to
	catch_exceptions_with_msg.
	(catcher): Delete.
	(catch_exceptions_with_msg, catch_errors): Re-implement using
	catcher_state_machine.
This commit is contained in:
Andrew Cagney 2005-01-12 19:12:29 +00:00
parent 60250e8b18
commit db5f402d40
2 changed files with 216 additions and 131 deletions

View File

@ -1,5 +1,20 @@
2005-01-12 Andrew Cagney <cagney@gnu.org>
* exceptions.c: Include "gdb_string.h".
(enum catcher_state, struct catcher): Define.
(current_catcher): New global, replaces catch_return;
(catch_return): Delete.
(throw_exception): Use current_catcher->buf;
(catcher_init, catcher_pop, catcher_state_machine): New functions.
(catcher): Delete.
(struct catch_errors_args): Delete.
(do_catch_errors): Delete.
(catch_exceptions): Replace body with call to
catch_exceptions_with_msg.
(catcher): Delete.
(catch_exceptions_with_msg, catch_errors): Re-implement using
catcher_state_machine.
* exceptions.h (enum return_reason, RETURN_MASK)
(RETURN_MASK_QUIT, RETURN_MASK_ERROR, RETURN_MASK_ALL)
(return_mask, throw_exception, catch_exceptions_ftype)

View File

@ -30,6 +30,7 @@
#include "annotate.h"
#include "ui-out.h"
#include "gdb_assert.h"
#include "gdb_string.h"
/* One should use catch_errors rather than manipulating these
directly. */
@ -43,8 +44,184 @@
#define SIGLONGJMP(buf,val) longjmp((buf), (val))
#endif
/* Possible catcher states. */
enum catcher_state {
/* Initial state, a new catcher has just been created. */
CATCHER_CREATED,
/* The catch code is running. */
CATCHER_RUNNING,
CATCHER_RUNNING_1,
/* The catch code threw an exception. */
CATCHER_ABORTING
};
/* Possible catcher actions. */
enum catcher_action {
CATCH_ITER,
CATCH_ITER_1,
CATCH_THROWING
};
struct catcher
{
enum catcher_state state;
/* Scratch variables used when transitioning a state. */
SIGJMP_BUF buf;
int reason;
int val;
/* Saved/current state. */
int mask;
char *saved_error_pre_print;
char *saved_quit_pre_print;
struct ui_out *saved_uiout;
struct cleanup *saved_cleanup_chain;
char **gdberrmsg;
/* Back link. */
struct catcher *prev;
};
/* Where to go for throw_exception(). */
static SIGJMP_BUF *catch_return;
static struct catcher *current_catcher;
static SIGJMP_BUF *
catcher_init (struct ui_out *func_uiout,
char *errstring,
char **gdberrmsg,
return_mask mask)
{
struct catcher *new_catcher = XZALLOC (struct catcher);
new_catcher->gdberrmsg = gdberrmsg;
new_catcher->mask = mask;
/* Override error/quit messages during FUNC. */
new_catcher->saved_error_pre_print = error_pre_print;
new_catcher->saved_quit_pre_print = quit_pre_print;
if (mask & RETURN_MASK_ERROR)
error_pre_print = errstring;
if (mask & RETURN_MASK_QUIT)
quit_pre_print = errstring;
/* Override the global ``struct ui_out'' builder. */
new_catcher->saved_uiout = uiout;
uiout = func_uiout;
/* Prevent error/quit during FUNC from calling cleanups established
prior to here. */
new_catcher->saved_cleanup_chain = save_cleanups ();
/* Push this new catcher on the top. */
new_catcher->prev = current_catcher;
current_catcher = new_catcher;
new_catcher->state = CATCHER_CREATED;
return &new_catcher->buf;
}
static void
catcher_pop (void)
{
struct catcher *old_catcher = current_catcher;
current_catcher = old_catcher->prev;
/* Restore the cleanup chain, the error/quit messages, and the uiout
builder, to their original states. */
restore_cleanups (old_catcher->saved_cleanup_chain);
uiout = old_catcher->saved_uiout;
quit_pre_print = old_catcher->saved_quit_pre_print;
error_pre_print = old_catcher->saved_error_pre_print;
xfree (old_catcher);
}
/* Catcher state machine. Returns non-zero if the m/c should be run
again, zero if it should abort. */
int
catcher_state_machine (enum catcher_action action)
{
switch (current_catcher->state)
{
case CATCHER_CREATED:
switch (action)
{
case CATCH_ITER:
/* Allow the code to run the catcher. */
current_catcher->state = CATCHER_RUNNING;
return 1;
default:
internal_error (__FILE__, __LINE__, "bad state");
}
case CATCHER_RUNNING:
switch (action)
{
case CATCH_ITER:
/* No error/quit has occured. Just clean up. */
catcher_pop ();
return 0;
case CATCH_ITER_1:
current_catcher->state = CATCHER_RUNNING_1;
return 1;
case CATCH_THROWING:
current_catcher->state = CATCHER_ABORTING;
/* See also throw_exception. */
return 1;
default:
internal_error (__FILE__, __LINE__, "bad switch");
}
case CATCHER_RUNNING_1:
switch (action)
{
case CATCH_ITER:
/* The did a "break" from the inner while loop. */
catcher_pop ();
return 0;
case CATCH_ITER_1:
current_catcher->state = CATCHER_RUNNING;
return 0;
case CATCH_THROWING:
current_catcher->state = CATCHER_ABORTING;
/* See also throw_exception. */
return 1;
default:
internal_error (__FILE__, __LINE__, "bad switch");
}
case CATCHER_ABORTING:
switch (action)
{
case CATCH_ITER:
{
int reason = current_catcher->reason;
/* If caller wants a copy of the low-level error message,
make one. This is used in the case of a silent error
whereby the caller may optionally want to issue the
message. */
if (current_catcher->gdberrmsg != NULL)
*(current_catcher->gdberrmsg) = error_last_message ();
if (current_catcher->mask & RETURN_MASK (reason))
{
/* Exit normally if this catcher can handle this
exception. The caller analyses the func return
values. */
catcher_pop ();
return 0;
}
/* The caller didn't request that the event be caught,
relay the event to the next containing
catch_errors(). */
catcher_pop ();
throw_exception (reason);
}
default:
internal_error (__FILE__, __LINE__, "bad state");
}
default:
internal_error (__FILE__, __LINE__, "bad switch");
}
}
/* Return for reason REASON to the nearest containing catch_errors(). */
@ -79,8 +256,9 @@ throw_exception (enum return_reason reason)
/* Jump to the containing catch_errors() call, communicating REASON
to that call via setjmp's return value. Note that REASON can't
be zero, by definition in defs.h. */
(NORETURN void) SIGLONGJMP (*catch_return, (int) reason);
catcher_state_machine (CATCH_THROWING);
current_catcher->reason = reason;
SIGLONGJMP (current_catcher->buf, current_catcher->reason);
}
/* Call FUNC() with args FUNC_UIOUT and FUNC_ARGS, catching any
@ -115,105 +293,6 @@ throw_exception (enum return_reason reason)
be consolidated into a single file instead of being distributed
between utils.c and top.c? */
static void
catcher (catch_exceptions_ftype *func,
struct ui_out *func_uiout,
void *func_args,
int *func_val,
enum return_reason *func_caught,
char *errstring,
char **gdberrmsg,
return_mask mask)
{
SIGJMP_BUF *saved_catch;
SIGJMP_BUF catch;
struct cleanup *saved_cleanup_chain;
char *saved_error_pre_print;
char *saved_quit_pre_print;
struct ui_out *saved_uiout;
/* Return value from SIGSETJMP(): enum return_reason if error or
quit caught, 0 otherwise. */
int caught;
/* Return value from FUNC(): Hopefully non-zero. Explicitly set to
zero if an error quit was caught. */
int val;
/* Override error/quit messages during FUNC. */
saved_error_pre_print = error_pre_print;
saved_quit_pre_print = quit_pre_print;
if (mask & RETURN_MASK_ERROR)
error_pre_print = errstring;
if (mask & RETURN_MASK_QUIT)
quit_pre_print = errstring;
/* Override the global ``struct ui_out'' builder. */
saved_uiout = uiout;
uiout = func_uiout;
/* Prevent error/quit during FUNC from calling cleanups established
prior to here. */
saved_cleanup_chain = save_cleanups ();
/* Call FUNC, catching error/quit events. */
saved_catch = catch_return;
catch_return = &catch;
caught = SIGSETJMP (catch);
if (!caught)
val = (*func) (func_uiout, func_args);
else
{
val = 0;
/* If caller wants a copy of the low-level error message, make one.
This is used in the case of a silent error whereby the caller
may optionally want to issue the message. */
if (gdberrmsg)
*gdberrmsg = error_last_message ();
}
catch_return = saved_catch;
/* FIXME: cagney/1999-11-05: A correct FUNC implementation will
clean things up (restoring the cleanup chain) to the state they
were just prior to the call. Unfortunately, many FUNC's are not
that well behaved. This could be fixed by adding either a
do_cleanups call (to cover the problem) or an assertion check to
detect bad FUNCs code. */
/* Restore the cleanup chain, the error/quit messages, and the uiout
builder, to their original states. */
restore_cleanups (saved_cleanup_chain);
uiout = saved_uiout;
if (mask & RETURN_MASK_QUIT)
quit_pre_print = saved_quit_pre_print;
if (mask & RETURN_MASK_ERROR)
error_pre_print = saved_error_pre_print;
/* Return normally if no error/quit event occurred or this catcher
can handle this exception. The caller analyses the func return
values. */
if (!caught || (mask & RETURN_MASK (caught)))
{
*func_val = val;
*func_caught = caught;
return;
}
/* The caller didn't request that the event be caught, relay the
event to the next containing catch_errors(). */
throw_exception (caught);
}
int
catch_exceptions (struct ui_out *uiout,
catch_exceptions_ftype *func,
@ -221,14 +300,8 @@ catch_exceptions (struct ui_out *uiout,
char *errstring,
return_mask mask)
{
int val;
enum return_reason caught;
catcher (func, uiout, func_args, &val, &caught, errstring, NULL, mask);
gdb_assert (val >= 0);
gdb_assert (caught <= 0);
if (caught < 0)
return caught;
return val;
return catch_exceptions_with_msg (uiout, func, func_args, errstring,
NULL, mask);
}
int
@ -239,9 +312,13 @@ catch_exceptions_with_msg (struct ui_out *uiout,
char **gdberrmsg,
return_mask mask)
{
int val;
int val = 0;
enum return_reason caught;
catcher (func, uiout, func_args, &val, &caught, errstring, gdberrmsg, mask);
SIGJMP_BUF *catch;
catch = catcher_init (uiout, errstring, gdberrmsg, mask);
for (caught = SIGSETJMP ((*catch));
catcher_state_machine (CATCH_ITER);)
val = (*func) (uiout, func_args);
gdb_assert (val >= 0);
gdb_assert (caught <= 0);
if (caught < 0)
@ -249,30 +326,23 @@ catch_exceptions_with_msg (struct ui_out *uiout,
return val;
}
struct catch_errors_args
{
catch_errors_ftype *func;
void *func_args;
};
static int
do_catch_errors (struct ui_out *uiout, void *data)
{
struct catch_errors_args *args = data;
return args->func (args->func_args);
}
int
catch_errors (catch_errors_ftype *func, void *func_args, char *errstring,
return_mask mask)
{
int val;
int val = 0;
enum return_reason caught;
struct catch_errors_args args;
args.func = func;
args.func_args = func_args;
catcher (do_catch_errors, uiout, &args, &val, &caught, errstring,
NULL, mask);
SIGJMP_BUF *catch;
catch = catcher_init (uiout, errstring, NULL, mask);
/* This illustrates how it is possible to nest the mechanism and
hence catch "break". Of course this doesn't address the need to
also catch "return". */
for (caught = SIGSETJMP ((*catch)); catcher_state_machine (CATCH_ITER);)
for (; catcher_state_machine (CATCH_ITER_1);)
{
val = func (func_args);
break;
}
if (caught != 0)
return 0;
return val;