/* Exception (throw catch) mechanism, for GDB, the GNU debugger.
- Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
- 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
- Free Software Foundation, Inc.
+ Copyright (C) 1986, 1988-2012 Free Software Foundation, Inc.
This file is part of GDB.
#include "gdb_assert.h"
#include "gdb_string.h"
#include "serial.h"
+#include "gdbthread.h"
const struct gdb_exception exception_none = { 0, GDB_NO_ERROR, NULL };
volatile struct gdb_exception *exception;
/* Saved/current state. */
int mask;
- struct ui_out *saved_uiout;
struct cleanup *saved_cleanup_chain;
/* Back link. */
struct catcher *prev;
/* Where to go for throw_exception(). */
static struct catcher *current_catcher;
+/* Return length of current_catcher list. */
+
+static int
+catcher_list_size (void)
+{
+ int size;
+ struct catcher *catcher;
+
+ for (size = 0, catcher = current_catcher;
+ catcher != NULL;
+ catcher = catcher->prev)
+ ++size;
+
+ return size;
+}
+
EXCEPTIONS_SIGJMP_BUF *
-exceptions_state_mc_init (struct ui_out *func_uiout,
- volatile struct gdb_exception *exception,
+exceptions_state_mc_init (volatile struct gdb_exception *exception,
return_mask mask)
{
struct catcher *new_catcher = XZALLOC (struct catcher);
new_catcher->mask = mask;
- /* 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. */
+ prior to here. */
new_catcher->saved_cleanup_chain = save_cleanups ();
/* Push this new catcher on the top. */
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. */
+ builder, to their original states. */
restore_cleanups (old_catcher->saved_cleanup_chain);
- uiout = old_catcher->saved_uiout;
-
xfree (old_catcher);
}
case CATCH_ITER:
{
struct gdb_exception exception = *current_catcher->exception;
+
if (current_catcher->mask & RETURN_MASK (exception.reason))
{
/* Exit normally if this catcher can handle this
}
/* The caller didn't request that the event be caught,
relay the event to the next containing
- catch_errors(). */
+ catch_errors(). */
catcher_pop ();
throw_exception (exception);
}
/* Return EXCEPTION to the nearest containing catch_errors(). */
-NORETURN void
+void
throw_exception (struct gdb_exception exception)
{
- quit_flag = 0;
+ clear_quit_flag ();
immediate_quit = 0;
- /* Perhaps it would be cleaner to do this via the cleanup chain (not sure
- I can think of a reason why that is vital, though). */
- bpstat_clear_actions (stop_bpstat); /* Clear queued breakpoint commands */
-
- disable_current_display ();
- do_cleanups (ALL_CLEANUPS);
- if (target_can_async_p () && !target_executing)
- do_exec_cleanups (ALL_CLEANUPS);
- if (sync_execution)
- do_exec_error_cleanups (ALL_CLEANUPS);
+ do_cleanups (all_cleanups ());
/* 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. */
+ be zero, by definition in defs.h. */
exceptions_state_mc (CATCH_THROWING);
*current_catcher->exception = exception;
EXCEPTIONS_SIGLONGJMP (current_catcher->buf, exception.reason);
}
-static char *last_message;
-
-NORETURN void
+void
deprecated_throw_reason (enum return_reason reason)
{
struct gdb_exception exception;
+
memset (&exception, 0, sizeof exception);
exception.reason = reason;
as that way the MI's behavior is preserved. */
const char *start;
const char *end;
+
for (start = e.message; start != NULL; start = end)
{
end = strchr (start, '\n');
}
}
-void
+static void
print_any_exception (struct ui_file *file, const char *prefix,
struct gdb_exception e)
{
if (e.reason < 0 && e.message != NULL)
{
target_terminal_ours ();
- wrap_here (""); /* Force out any buffered output */
+ wrap_here (""); /* Force out any buffered output. */
gdb_flush (gdb_stdout);
annotate_error_begin ();
}
}
-NORETURN static void ATTR_NORETURN ATTR_FORMAT (printf, 3, 0)
+/* A stack of exception messages.
+ This is needed to handle nested calls to throw_it: we don't want to
+ xfree space for a message before it's used.
+ This can happen if we throw an exception during a cleanup:
+ An outer TRY_CATCH may have an exception message it wants to print,
+ but while doing cleanups further calls to throw_it are made.
+
+ This is indexed by the size of the current_catcher list.
+ It is a dynamically allocated array so that we don't care how deeply
+ GDB nests its TRY_CATCHs. */
+static char **exception_messages;
+
+/* The number of currently allocated entries in exception_messages. */
+static int exception_messages_size;
+
+static void ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (3, 0)
throw_it (enum return_reason reason, enum errors error, const char *fmt,
va_list ap)
{
struct gdb_exception e;
char *new_message;
+ int depth = catcher_list_size ();
- /* Save the message. Create the new message before deleting the
- old, the new message may include the old message text. */
+ gdb_assert (depth > 0);
+
+ /* Note: The new message may use an old message's text. */
new_message = xstrvprintf (fmt, ap);
- xfree (last_message);
- last_message = new_message;
+
+ if (depth > exception_messages_size)
+ {
+ int old_size = exception_messages_size;
+
+ exception_messages_size = depth + 10;
+ exception_messages = (char **) xrealloc (exception_messages,
+ exception_messages_size
+ * sizeof (char *));
+ memset (exception_messages + old_size, 0,
+ (exception_messages_size - old_size) * sizeof (char *));
+ }
+
+ xfree (exception_messages[depth - 1]);
+ exception_messages[depth - 1] = new_message;
/* Create the exception. */
e.reason = reason;
e.error = error;
- e.message = last_message;
+ e.message = new_message;
/* Throw the exception. */
throw_exception (e);
}
-NORETURN void
+void
throw_verror (enum errors error, const char *fmt, va_list ap)
{
throw_it (RETURN_ERROR, error, fmt, ap);
}
-NORETURN void
+void
throw_vfatal (const char *fmt, va_list ap)
{
throw_it (RETURN_QUIT, GDB_NO_ERROR, fmt, ap);
}
-NORETURN void
+void
throw_error (enum errors error, const char *fmt, ...)
{
va_list args;
+
va_start (args, fmt);
throw_it (RETURN_ERROR, error, fmt, args);
va_end (args);
}
-/* Call FUNC() with args FUNC_UIOUT and FUNC_ARGS, catching any
- errors. Set FUNC_CAUGHT to an ``enum return_reason'' if the
- function is aborted (using throw_exception() or zero if the
- function returns normally. Set FUNC_VAL to the value returned by
- the function or 0 if the function was aborted.
+/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
+ handler. If an exception (enum return_reason) is thrown using
+ throw_exception() than all cleanups installed since
+ catch_exceptions() was entered are invoked, the (-ve) exception
+ value is then returned by catch_exceptions. If FUNC() returns
+ normally (with a positive or zero return value) then that value is
+ returned by catch_exceptions(). It is an internal_error() for
+ FUNC() to return a negative value.
+
+ See exceptions.h for further usage details.
Must not be called with immediate_quit in effect (bad things might
happen, say we got a signal in the middle of a memcpy to quit_return).
This is an OK restriction; with very few exceptions immediate_quit can
- be replaced by judicious use of QUIT.
-
- MASK specifies what to catch; it is normally set to
- RETURN_MASK_ALL, if for no other reason than that the code which
- calls catch_errors might not be set up to deal with a quit which
- isn't caught. But if the code can deal with it, it generally
- should be RETURN_MASK_ERROR, unless for some reason it is more
- useful to abort only the portion of the operation inside the
- catch_errors. Note that quit should return to the command line
- fairly quickly, even if some further processing is being done. */
+ be replaced by judicious use of QUIT. */
/* MAYBE: cagney/1999-11-05: catch_errors() in conjunction with
- error() et.al. could maintain a set of flags that indicate the the
+ error() et al. could maintain a set of flags that indicate the
current state of each of the longjmp buffers. This would give the
longjmp code the chance to detect a longjmp botch (before it gets
to longjmperror()). Prior to 1999-11-05 this wasn't possible as
code also randomly used a SET_TOP_LEVEL macro that directly
- initialize the longjmp buffers. */
-
-/* MAYBE: cagney/1999-11-05: Should the catch_errors and cleanups code
- be consolidated into a single file instead of being distributed
- between utils.c and top.c? */
+ initialized the longjmp buffers. */
int
catch_exceptions (struct ui_out *uiout,
return catch_exceptions_with_msg (uiout, func, func_args, NULL, mask);
}
-struct gdb_exception
-catch_exception (struct ui_out *uiout,
- catch_exception_ftype *func,
- void *func_args,
- return_mask mask)
-{
- volatile struct gdb_exception exception;
- TRY_CATCH (exception, mask)
- {
- (*func) (uiout, func_args);
- }
- return exception;
-}
-
int
-catch_exceptions_with_msg (struct ui_out *uiout,
+catch_exceptions_with_msg (struct ui_out *func_uiout,
catch_exceptions_ftype *func,
void *func_args,
char **gdberrmsg,
{
volatile struct gdb_exception exception;
volatile int val = 0;
- TRY_CATCH (exception, mask)
+ struct ui_out *saved_uiout;
+
+ /* Save and override the global ``struct ui_out'' builder. */
+ saved_uiout = current_uiout;
+ current_uiout = func_uiout;
+
+ TRY_CATCH (exception, RETURN_MASK_ALL)
{
- val = (*func) (uiout, func_args);
+ val = (*func) (current_uiout, func_args);
}
+
+ /* Restore the global builder. */
+ current_uiout = saved_uiout;
+
+ if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0)
+ {
+ /* The caller didn't request that the event be caught.
+ Rethrow. */
+ throw_exception (exception);
+ }
+
print_any_exception (gdb_stderr, NULL, exception);
gdb_assert (val >= 0);
gdb_assert (exception.reason <= 0);
return val;
}
+/* This function is superseded by catch_exceptions(). */
+
int
catch_errors (catch_errors_ftype *func, void *func_args, char *errstring,
return_mask mask)
{
volatile int val = 0;
volatile struct gdb_exception exception;
- TRY_CATCH (exception, mask)
+ struct ui_out *saved_uiout;
+
+ /* Save the global ``struct ui_out'' builder. */
+ saved_uiout = current_uiout;
+
+ TRY_CATCH (exception, RETURN_MASK_ALL)
{
val = func (func_args);
}
+
+ /* Restore the global builder. */
+ current_uiout = saved_uiout;
+
+ if (exception.reason < 0 && (mask & RETURN_MASK (exception.reason)) == 0)
+ {
+ /* The caller didn't request that the event be caught.
+ Rethrow. */
+ throw_exception (exception);
+ }
+
print_any_exception (gdb_stderr, errstring, exception);
if (exception.reason != 0)
return 0;
char *arg, int from_tty, return_mask mask)
{
volatile struct gdb_exception e;
+
TRY_CATCH (e, mask)
{
command (arg, from_tty);