From db5f402d40beac21d890e4b0b8ec85c17ec4c562 Mon Sep 17 00:00:00 2001 From: Andrew Cagney Date: Wed, 12 Jan 2005 19:12:29 +0000 Subject: [PATCH] 2005-01-12 Andrew Cagney * 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. --- gdb/ChangeLog | 15 +++ gdb/exceptions.c | 332 ++++++++++++++++++++++++++++------------------- 2 files changed, 216 insertions(+), 131 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 8fbf8d7ed2..7e4f498a39 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,20 @@ 2005-01-12 Andrew Cagney + * 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) diff --git a/gdb/exceptions.c b/gdb/exceptions.c index bf56eb2470..3ec2128b8e 100644 --- a/gdb/exceptions.c +++ b/gdb/exceptions.c @@ -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;