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-rw-r--r--src/eval.c143
1 files changed, 99 insertions, 44 deletions
diff --git a/src/eval.c b/src/eval.c
index 8ad289fd51f..17e9f7f4360 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -227,6 +227,18 @@ init_eval ()
when_entered_debugger = -1;
}
+/* unwind-protect function used by call_debugger. */
+
+static Lisp_Object
+restore_stack_limits (data)
+ Lisp_Object data;
+{
+ max_specpdl_size = XINT (XCAR (data));
+ max_lisp_eval_depth = XINT (XCDR (data));
+}
+
+/* Call the Lisp debugger, giving it argument ARG. */
+
Lisp_Object
call_debugger (arg)
Lisp_Object arg;
@@ -234,12 +246,22 @@ call_debugger (arg)
int debug_while_redisplaying;
int count = SPECPDL_INDEX ();
Lisp_Object val;
+ int old_max = max_specpdl_size;
+
+ /* Temporarily bump up the stack limits,
+ so the debugger won't run out of stack. */
+
+ max_specpdl_size += 1;
+ record_unwind_protect (restore_stack_limits,
+ Fcons (make_number (old_max),
+ make_number (max_lisp_eval_depth)));
+ max_specpdl_size = old_max;
- if (lisp_eval_depth + 20 > max_lisp_eval_depth)
- max_lisp_eval_depth = lisp_eval_depth + 20;
+ if (lisp_eval_depth + 40 > max_lisp_eval_depth)
+ max_lisp_eval_depth = lisp_eval_depth + 40;
- if (specpdl_size + 40 > max_specpdl_size)
- max_specpdl_size = specpdl_size + 40;
+ if (SPECPDL_INDEX () + 100 > max_specpdl_size)
+ max_specpdl_size = SPECPDL_INDEX () + 100;
#ifdef HAVE_X_WINDOWS
if (display_hourglass_p)
@@ -256,6 +278,7 @@ call_debugger (arg)
specbind (intern ("debugger-may-continue"),
debug_while_redisplaying ? Qnil : Qt);
specbind (Qinhibit_redisplay, Qnil);
+ specbind (Qdebug_on_error, Qnil);
#if 0 /* Binding this prevents execution of Lisp code during
redisplay, which necessarily leads to display problems. */
@@ -783,6 +806,10 @@ usage: (defvar SYMBOL &optional INITVALUE DOCSTRING) */)
register Lisp_Object sym, tem, tail;
sym = Fcar (args);
+ if (SYMBOL_CONSTANT_P (sym))
+ error ("Constant symbol `%s' specified in defvar",
+ SDATA (SYMBOL_NAME (sym)));
+
tail = Fcdr (args);
if (!NILP (Fcdr (Fcdr (tail))))
error ("Too many arguments");
@@ -862,12 +889,24 @@ usage: (defconst SYMBOL INITVALUE [DOCSTRING]) */)
return sym;
}
+/* Error handler used in Fuser_variable_p. */
+static Lisp_Object
+user_variable_p_eh (ignore)
+ Lisp_Object ignore;
+{
+ return Qnil;
+}
+
DEFUN ("user-variable-p", Fuser_variable_p, Suser_variable_p, 1, 1, 0,
- doc: /* Returns t if VARIABLE is intended to be set and modified by users.
+ doc: /* Return t if VARIABLE is intended to be set and modified by users.
\(The alternative is a variable used internally in a Lisp program.)
-Determined by whether the first character of the documentation
-for the variable is `*' or if the variable is customizable (has a non-nil
-value of `standard-value' or of `custom-autoload' on its property list). */)
+A variable is a user variable if
+\(1) the first character of its documentation is `*', or
+\(2) it is customizable (its property list contains a non-nil value
+ of `standard-value' or `custom-autoload'), or
+\(3) it is an alias for another user variable.
+Return nil if VARIABLE is an alias and there is a loop in the
+chain of symbols. */)
(variable)
Lisp_Object variable;
{
@@ -876,23 +915,37 @@ value of `standard-value' or of `custom-autoload' on its property list). */)
if (!SYMBOLP (variable))
return Qnil;
- documentation = Fget (variable, Qvariable_documentation);
- if (INTEGERP (documentation) && XINT (documentation) < 0)
- return Qt;
- if (STRINGP (documentation)
- && ((unsigned char) SREF (documentation, 0) == '*'))
- return Qt;
- /* If it is (STRING . INTEGER), a negative integer means a user variable. */
- if (CONSP (documentation)
- && STRINGP (XCAR (documentation))
- && INTEGERP (XCDR (documentation))
- && XINT (XCDR (documentation)) < 0)
- return Qt;
- /* Customizable? See `custom-variable-p'. */
- if ((!NILP (Fget (variable, intern ("standard-value"))))
- || (!NILP (Fget (variable, intern ("custom-autoload")))))
- return Qt;
- return Qnil;
+ /* If indirect and there's an alias loop, don't check anything else. */
+ if (XSYMBOL (variable)->indirect_variable
+ && NILP (internal_condition_case_1 (indirect_variable, variable,
+ Qt, user_variable_p_eh)))
+ return Qnil;
+
+ while (1)
+ {
+ documentation = Fget (variable, Qvariable_documentation);
+ if (INTEGERP (documentation) && XINT (documentation) < 0)
+ return Qt;
+ if (STRINGP (documentation)
+ && ((unsigned char) SREF (documentation, 0) == '*'))
+ return Qt;
+ /* If it is (STRING . INTEGER), a negative integer means a user variable. */
+ if (CONSP (documentation)
+ && STRINGP (XCAR (documentation))
+ && INTEGERP (XCDR (documentation))
+ && XINT (XCDR (documentation)) < 0)
+ return Qt;
+ /* Customizable? See `custom-variable-p'. */
+ if ((!NILP (Fget (variable, intern ("standard-value"))))
+ || (!NILP (Fget (variable, intern ("custom-autoload")))))
+ return Qt;
+
+ if (!XSYMBOL (variable)->indirect_variable)
+ return Qnil;
+
+ /* An indirect variable? Let's follow the chain. */
+ variable = XSYMBOL (variable)->value;
+ }
}
DEFUN ("let*", FletX, SletX, 1, UNEVALLED, 0,
@@ -1533,7 +1586,16 @@ See also the function `condition-case'. */)
/* This hook is used by edebug. */
if (! NILP (Vsignal_hook_function)
&& ! NILP (error_symbol))
- call2 (Vsignal_hook_function, error_symbol, data);
+ {
+ /* Edebug takes care of restoring these variables when it exits. */
+ if (lisp_eval_depth + 20 > max_lisp_eval_depth)
+ max_lisp_eval_depth = lisp_eval_depth + 20;
+
+ if (SPECPDL_INDEX () + 40 > max_specpdl_size)
+ max_specpdl_size = SPECPDL_INDEX () + 40;
+
+ call2 (Vsignal_hook_function, error_symbol, data);
+ }
conditions = Fget (real_error_symbol, Qerror_conditions);
@@ -1555,12 +1617,6 @@ See also the function `condition-case'. */)
{
register Lisp_Object clause;
- if (lisp_eval_depth + 20 > max_lisp_eval_depth)
- max_lisp_eval_depth = lisp_eval_depth + 20;
-
- if (specpdl_size + 40 > max_specpdl_size)
- max_specpdl_size = specpdl_size + 40;
-
clause = find_handler_clause (handlerlist->handler, conditions,
error_symbol, data, &debugger_value);
@@ -1673,7 +1729,11 @@ skip_debugger (conditions, data)
= SIG is nil, and DATA is (SYMBOL . REST-OF-DATA).
This is for memory-full errors only.
- Store value returned from debugger into *DEBUGGER_VALUE_PTR. */
+ Store value returned from debugger into *DEBUGGER_VALUE_PTR.
+
+ We need to increase max_specpdl_size temporarily around
+ anything we do that can push on the specpdl, so as not to get
+ a second error here in case we're handling specpdl overflow. */
static Lisp_Object
find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
@@ -1691,7 +1751,6 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
|| !NILP (Vdebug_on_signal)) /* This says call debugger even if
there is a handler. */
{
- int count = SPECPDL_INDEX ();
int debugger_called = 0;
Lisp_Object sig_symbol, combined_data;
/* This is set to 1 if we are handling a memory-full error,
@@ -1713,6 +1772,7 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
if (wants_debugger (Vstack_trace_on_error, conditions))
{
+ max_specpdl_size++;
#ifdef PROTOTYPES
internal_with_output_to_temp_buffer ("*Backtrace*",
(Lisp_Object (*) (Lisp_Object)) Fbacktrace,
@@ -1721,6 +1781,7 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
internal_with_output_to_temp_buffer ("*Backtrace*",
Fbacktrace, Qnil);
#endif
+ max_specpdl_size--;
}
if (! no_debugger
&& (EQ (sig_symbol, Qquit)
@@ -1729,7 +1790,6 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
&& ! skip_debugger (conditions, combined_data)
&& when_entered_debugger < num_nonmacro_input_events)
{
- specbind (Qdebug_on_error, Qnil);
*debugger_value_ptr
= call_debugger (Fcons (Qerror,
Fcons (combined_data, Qnil)));
@@ -1739,7 +1799,7 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
if (EQ (handlers, Qerror))
{
if (debugger_called)
- return unbind_to (count, Qlambda);
+ return Qlambda;
return Qt;
}
}
@@ -3019,13 +3079,8 @@ grow_specpdl ()
if (max_specpdl_size < 400)
max_specpdl_size = 400;
if (specpdl_size >= max_specpdl_size)
- {
- if (!NILP (Vdebug_on_error))
- /* Leave room for some specpdl in the debugger. */
- max_specpdl_size = specpdl_size + 100;
- Fsignal (Qerror,
- Fcons (build_string ("Variable binding depth exceeds max-specpdl-size"), Qnil));
- }
+ Fsignal (Qerror,
+ Fcons (build_string ("Variable binding depth exceeds max-specpdl-size"), Qnil));
}
specpdl_size *= 2;
if (specpdl_size > max_specpdl_size)
@@ -3333,7 +3388,7 @@ syms_of_eval ()
{
DEFVAR_INT ("max-specpdl-size", &max_specpdl_size,
doc: /* *Limit on number of Lisp variable bindings & unwind-protects.
-If Lisp code tries to make more than this many at once,
+If Lisp code tries to increase the total number past this amount,
an error is signaled.
You can safely use a value considerably larger than the default value,
if that proves inconveniently small. However, if you increase it too far,
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-26 20:30:30 +0000