#define Bconstant 0300
#define CONSTANTLIM 0100
+
+/* Structure describing a value stack used during byte-code execution
+ in Fbyte_code. */
+
+struct byte_stack
+{
+ /* Program counter. This points into the byte_string below
+ and is relocated when that string is relocated. */
+ unsigned char *pc;
+
+ /* Top and bottom of stack. The bottom points to an area of memory
+ allocated with alloca in Fbyte_code. */
+ Lisp_Object *top, *bottom;
+
+ /* The string containing the byte-code, and its current address.
+ Storing this here protects it from GC because mark_byte_stack
+ marks it. */
+ Lisp_Object byte_string;
+ unsigned char *byte_string_start;
+
+ /* The vector of constants used during byte-code execution. Storing
+ this here protects it from GC because mark_byte_stack marks it. */
+ Lisp_Object constants;
+
+ /* Next entry in byte_stack_list. */
+ struct byte_stack *next;
+};
+
+/* A list of currently active byte-code execution value stacks.
+ Fbyte_code adds an entry to the head of this list before it starts
+ processing byte-code, and it removed the entry again when it is
+ done. Signalling an error truncates the list analoguous to
+ gcprolist. */
+
+struct byte_stack *byte_stack_list;
+
+/* Mark objects on byte_stack_list. Called during GC. */
+
+void
+mark_byte_stack ()
+{
+ struct byte_stack *stack;
+ Lisp_Object *obj;
+
+ for (stack = byte_stack_list; stack; stack = stack->next)
+ {
+ if (!stack->top)
+ abort ();
+
+ for (obj = stack->bottom; obj <= stack->top; ++obj)
+ mark_object (obj);
+
+ mark_object (&stack->byte_string);
+ mark_object (&stack->constants);
+ }
+}
+
+
+/* Relocate program counters in the stacks on byte_stack_list. Called
+ when GC has completed. */
+
+void
+relocate_byte_pcs ()
+{
+ struct byte_stack *stack;
+
+ for (stack = byte_stack_list; stack; stack = stack->next)
+ if (stack->byte_string_start != XSTRING (stack->byte_string)->data)
+ {
+ int offset = stack->pc - stack->byte_string_start;
+ stack->byte_string_start = XSTRING (stack->byte_string)->data;
+ stack->pc = stack->byte_string_start + offset;
+ }
+}
+
+
\f
/* Fetch the next byte from the bytecode stream */
-#define FETCH *pc++
+#define FETCH *stack.pc++
/* Fetch two bytes from the bytecode stream
and make a 16-bit number out of them */
/* Push x onto the execution stack. */
-/* This used to be #define PUSH(x) (*++stackp = (x))
- This oddity is necessary because Alliant can't be bothered to
- compile the preincrement operator properly, as of 4/91. -JimB */
-#define PUSH(x) (stackp++, *stackp = (x))
+/* This used to be #define PUSH(x) (*++stackp = (x)) This oddity is
+ necessary because Alliant can't be bothered to compile the
+ preincrement operator properly, as of 4/91. -JimB */
+
+#define PUSH(x) (top++, *top = (x))
/* Pop a value off the execution stack. */
-#define POP (*stackp--)
+#define POP (*top--)
/* Discard n values from the execution stack. */
-#define DISCARD(n) (stackp -= (n))
+#define DISCARD(n) (top -= (n))
+
+/* Get the value which is at the top of the execution stack, but don't
+ pop it. */
+
+#define TOP (*top)
-/* Get the value which is at the top of the execution stack, but don't pop it. */
+/* Actions that must performed before and after calling a function
+ that might GC. */
-#define TOP (*stackp)
+#define BEFORE_POTENTIAL_GC() stack.top = top
+#define AFTER_POTENTIAL_GC() stack.top = NULL
/* Garbage collect if we have consed enough since the last time.
We do this at every branch, to avoid loops that never GC. */
#define MAYBE_GC() \
if (consing_since_gc > gc_cons_threshold) \
{ \
+ BEFORE_POTENTIAL_GC (); \
Fgarbage_collect (); \
- HANDLE_RELOCATION (); \
+ AFTER_POTENTIAL_GC (); \
} \
else
-/* Relocate BYTESTR if there has been a GC recently. */
-#define HANDLE_RELOCATION() \
- if (! EQ (string_saved, bytestr)) \
- { \
- pc = pc - XSTRING (string_saved)->data + XSTRING (bytestr)->data; \
- string_saved = bytestr; \
- } \
- else
-
/* Check for jumping out of range. */
+
+#ifdef BYTE_CODE_SAFE
+
#define CHECK_RANGE(ARG) \
if (ARG >= bytestr_length) abort ()
+#else
+
+#define CHECK_RANGE(ARG)
+
+#endif
+
+
DEFUN ("byte-code", Fbyte_code, Sbyte_code, 3, 3, 0,
"Function used internally in byte-compiled code.\n\
The first argument, BYTESTR, is a string of byte code;\n\
(bytestr, vector, maxdepth)
Lisp_Object bytestr, vector, maxdepth;
{
- struct gcpro gcpro1, gcpro2, gcpro3;
int count = specpdl_ptr - specpdl;
#ifdef BYTE_CODE_METER
int this_op = 0;
int prev_op;
#endif
- register int op;
- unsigned char *pc;
- Lisp_Object *stack;
- register Lisp_Object *stackp;
- Lisp_Object *stacke;
- register Lisp_Object v1, v2;
- register Lisp_Object *vectorp = XVECTOR (vector)->contents;
+ int op;
+ Lisp_Object v1, v2;
+ Lisp_Object *stackp;
+ Lisp_Object *vectorp = XVECTOR (vector)->contents;
#ifdef BYTE_CODE_SAFE
- register int const_length = XVECTOR (vector)->size;
+ int const_length = XVECTOR (vector)->size;
+ Lisp_Object *stacke;
#endif
- /* Copy of BYTESTR, saved so we can tell if BYTESTR was relocated. */
- Lisp_Object string_saved;
- /* Cached address of beginning of string,
- valid if BYTESTR equals STRING_SAVED. */
- register unsigned char *strbeg;
int bytestr_length = STRING_BYTES (XSTRING (bytestr));
+ struct byte_stack stack;
+ Lisp_Object *top;
CHECK_STRING (bytestr, 0);
if (!VECTORP (vector))
vector = wrong_type_argument (Qvectorp, vector);
CHECK_NUMBER (maxdepth, 2);
- stackp = (Lisp_Object *) alloca (XFASTINT (maxdepth) * sizeof (Lisp_Object));
- bzero (stackp, XFASTINT (maxdepth) * sizeof (Lisp_Object));
- GCPRO3 (bytestr, vector, *stackp);
- gcpro3.nvars = XFASTINT (maxdepth);
-
- --stackp;
- stack = stackp;
- stacke = stackp + XFASTINT (maxdepth);
-
- /* Initialize the saved pc-pointer for fetching from the string. */
- string_saved = bytestr;
- pc = XSTRING (string_saved)->data;
+ stack.byte_string = bytestr;
+ stack.pc = stack.byte_string_start = XSTRING (bytestr)->data;
+ stack.constants = vector;
+ stack.bottom = (Lisp_Object *) alloca (XFASTINT (maxdepth)
+ * sizeof (Lisp_Object));
+ top = stack.bottom - 1;
+ stack.top = NULL;
+ stack.next = byte_stack_list;
+ byte_stack_list = &stack;
+#ifdef BYTE_CODE_SAFE
+ stacke = stack.bottom - 1 + XFASTINT (maxdepth);
+#endif
+
while (1)
{
#ifdef BYTE_CODE_SAFE
- if (stackp > stacke)
+ if (top > stacks)
error ("Byte code stack overflow (byte compiler bug), pc %d, depth %d",
- pc - XSTRING (string_saved)->data, stacke - stackp);
- if (stackp < stack)
+ stack.pc - stack.byte_string_start, stacke - top);
+ else if (top < stack.bottom - 1)
error ("Byte code stack underflow (byte compiler bug), pc %d",
- pc - XSTRING (string_saved)->data);
+ stack.pc - stack.byte_string_start);
#endif
- /* Update BYTESTR if we had a garbage collection. */
- HANDLE_RELOCATION ();
-
#ifdef BYTE_CODE_METER
prev_op = this_op;
this_op = op = FETCH;
}
}
#endif
+ BEFORE_POTENTIAL_GC ();
TOP = Ffuncall (op + 1, &TOP);
+ AFTER_POTENTIAL_GC ();
break;
case Bunbind+6:
case Bunbind+4: case Bunbind+5:
op -= Bunbind;
dounbind:
+ BEFORE_POTENTIAL_GC ();
unbind_to (specpdl_ptr - specpdl - op, Qnil);
+ AFTER_POTENTIAL_GC ();
break;
case Bunbind_all:
/* To unbind back to the beginning of this frame. Not used yet,
but will be needed for tail-recursion elimination. */
+ BEFORE_POTENTIAL_GC ();
unbind_to (count, Qnil);
+ AFTER_POTENTIAL_GC ();
break;
case Bgoto:
QUIT;
op = FETCH2; /* pc = FETCH2 loses since FETCH2 contains pc++ */
CHECK_RANGE (op);
- pc = XSTRING (string_saved)->data + op;
+ stack.pc = stack.byte_string_start + op;
break;
case Bgotoifnil:
{
QUIT;
CHECK_RANGE (op);
- pc = XSTRING (string_saved)->data + op;
+ stack.pc = stack.byte_string_start + op;
}
break;
{
QUIT;
CHECK_RANGE (op);
- pc = XSTRING (string_saved)->data + op;
+ stack.pc = stack.byte_string_start + op;
}
break;
{
QUIT;
CHECK_RANGE (op);
- pc = XSTRING (string_saved)->data + op;
+ stack.pc = stack.byte_string_start + op;
}
else DISCARD (1);
break;
{
QUIT;
CHECK_RANGE (op);
- pc = XSTRING (string_saved)->data + op;
+ stack.pc = stack.byte_string_start + op;
}
else DISCARD (1);
break;
case BRgoto:
MAYBE_GC ();
QUIT;
- pc += (int) *pc - 127;
+ stack.pc += (int) *stack.pc - 127;
break;
case BRgotoifnil:
if (NILP (POP))
{
QUIT;
- pc += (int) *pc - 128;
+ stack.pc += (int) *stack.pc - 128;
}
- pc++;
+ stack.pc++;
break;
case BRgotoifnonnil:
if (!NILP (POP))
{
QUIT;
- pc += (int) *pc - 128;
+ stack.pc += (int) *stack.pc - 128;
}
- pc++;
+ stack.pc++;
break;
case BRgotoifnilelsepop:
MAYBE_GC ();
- op = *pc++;
+ op = *stack.pc++;
if (NILP (TOP))
{
QUIT;
- pc += op - 128;
+ stack.pc += op - 128;
}
else DISCARD (1);
break;
case BRgotoifnonnilelsepop:
MAYBE_GC ();
- op = *pc++;
+ op = *stack.pc++;
if (!NILP (TOP))
{
QUIT;
- pc += op - 128;
+ stack.pc += op - 128;
}
else DISCARD (1);
break;
case Bcondition_case:
v1 = POP;
v1 = Fcons (POP, v1);
+ BEFORE_POTENTIAL_GC ();
TOP = Fcondition_case (Fcons (TOP, v1));
+ AFTER_POTENTIAL_GC ();
break;
case Btemp_output_buffer_setup:
temp_output_buffer_show (TOP);
TOP = v1;
/* pop binding of standard-output */
+ BEFORE_POTENTIAL_GC ();
unbind_to (specpdl_ptr - specpdl - 1, Qnil);
+ AFTER_POTENTIAL_GC ();
break;
case Bnth:
}
exit:
- UNGCPRO;
+
+ byte_stack_list = byte_stack_list->next;
+
/* Binds and unbinds are supposed to be compiled balanced. */
if (specpdl_ptr - specpdl != count)
#ifdef BYTE_CODE_SAFE
#else
abort ();
#endif
+
return v1;
}
projects / emacs.git / commitdiff