Commit ba410f40 authored by Jim Blandy's avatar Jim Blandy
Browse files

* eval.c (unbind_catch): Do the long-jump here. Take a VALUE

	argument, which specifies the value to return to the catch, or the
	data to give to the condition handler.  Renamed to
	unwind_to_catch, to reflect new role.
	(Fsignal, Fthrow): Removed code to set catch tag value and do the
	long-jump; this is taken care of by unwind_to_catch.
parent 5d6533f1
......@@ -879,23 +879,32 @@ internal_catch (tag, func, arg)
return c.val;
/* Discard from the catchlist all catch tags back through CATCH.
Before each catch is discarded, unbind all special bindings
made within that catch. Also, when discarding a catch that
corresponds to a condition handler, discard that handler.
/* Unwind the specbind, catch, and handler stacks back to CATCH, and
jump to that CATCH, returning VALUE as the value of that catch.
At the end, restore some static info saved in CATCH.
This is the guts Fthrow and Fsignal; they differ only in the way
they choose the catch tag to throw to. A catch tag for a
condition-case form has a TAG of Qnil.
This is used for correct unwinding in Fthrow and Fsignal,
before doing the longjmp that actually destroys the stack frames
in which these handlers and catches reside. */
Before each catch is discarded, unbind all special bindings and
execute all unwind-protect clauses made above that catch. Unwind
the handler stack as we go, so that the proper handlers are in
effect for each unwind-protect clause we run. At the end, restore
some static info saved in CATCH, and longjmp to the location
specified in the
This is used for correct unwinding in Fthrow and Fsignal. */
static void
unbind_catch (catch)
unwind_to_catch (catch, value)
struct catchtag *catch;
Lisp_Object value;
register int last_time;
/* Save the value in the tag. */
catch->val = value;
/* Restore the polling-suppression count. */
if (catch->poll_suppress_count > poll_suppress_count)
abort ();
......@@ -917,6 +926,8 @@ unbind_catch (catch)
gcprolist = catch->gcpro;
backtrace_list = catch->backlist;
lisp_eval_depth = catch->lisp_eval_depth;
_longjmp (catch->jmp, 1);
DEFUN ("throw", Fthrow, Sthrow, 2, 2, 0,
......@@ -933,11 +944,7 @@ Both TAG and VALUE are evalled.")
for (c = catchlist; c; c = c->next)
if (EQ (c->tag, tag))
c->val = val;
unbind_catch (c);
_longjmp (c->jmp, 1);
unwind_to_catch (c, val);
tag = Fsignal (Qno_catch, Fcons (tag, Fcons (val, Qnil)));
......@@ -1140,9 +1147,7 @@ See also the function `condition-case'.")
struct handler *h = handlerlist;
handlerlist = allhandlers;
unbind_catch (h->tag);
h->tag->val = Fcons (clause, Fcons (sig, data));
_longjmp (h->tag->jmp, 1);
unwind_to_catch (h->tag, Fcons (clause, Fcons (sig, data)));
......@@ -1195,9 +1200,10 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
if (wants_debugger (Vstack_trace_on_error, conditions))
internal_with_output_to_temp_buffer ("*Backtrace*", Fbacktrace, Qnil);
if (when_entered_debugger < num_nonmacro_input_chars
&& (EQ (sig, Qquit) ? debug_on_quit
: wants_debugger (Vdebug_on_error, conditions)))
if ((EQ (sig, Qquit)
? debug_on_quit
: wants_debugger (Vdebug_on_error, conditions))
&& when_entered_debugger < num_nonmacro_input_chars)
int count = specpdl_ptr - specpdl;
specbind (Qdebug_on_error, Qnil);
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