/* Frame object implementation */

#include "allobjects.h"

#include "compile.h"
#include "frameobject.h"
#include "opcode.h"
#include "structmember.h"

#define OFF(x) offsetof(frameobject, x)

static struct memberlist frame_memberlist[] = {
	{"f_back",	T_OBJECT,	OFF(f_back)},
	{"f_code",	T_OBJECT,	OFF(f_code)},
	{"f_globals",	T_OBJECT,	OFF(f_globals)},
	{"f_locals",	T_OBJECT,	OFF(f_locals)},
	{NULL}	/* Sentinel */
};

static object *
frame_getattr(f, name)
	frameobject *f;
	char *name;
{
	return getmember((char *)f, frame_memberlist, name);
}

static void
frame_dealloc(f)
	frameobject *f;
{
	XDECREF(f->f_back);
	XDECREF(f->f_code);
	XDECREF(f->f_globals);
	XDECREF(f->f_locals);
	XDEL(f->f_valuestack);
	XDEL(f->f_blockstack);
	DEL(f);
}

typeobject Frametype = {
	OB_HEAD_INIT(&Typetype)
	0,
	"frame",
	sizeof(frameobject),
	0,
	frame_dealloc,	/*tp_dealloc*/
	0,		/*tp_print*/
	frame_getattr,	/*tp_getattr*/
	0,		/*tp_setattr*/
	0,		/*tp_compare*/
	0,		/*tp_repr*/
	0,		/*tp_as_number*/
	0,		/*tp_as_sequence*/
	0,		/*tp_as_mapping*/
};

frameobject *
newframeobject(back, code, globals, locals, nvalues, nblocks)
	frameobject *back;
	codeobject *code;
	object *globals;
	object *locals;
	int nvalues;
	int nblocks;
{
	frameobject *f;
	if ((back != NULL && !is_frameobject(back)) ||
		code == NULL || !is_codeobject(code) ||
		globals == NULL || !is_dictobject(globals) ||
		locals == NULL || !is_dictobject(locals) ||
		nvalues < 0 || nblocks < 0) {
		err_badcall();
		return NULL;
	}
	f = NEWOBJ(frameobject, &Frametype);
	if (f != NULL) {
		if (back)
			INCREF(back);
		f->f_back = back;
		INCREF(code);
		f->f_code = code;
		INCREF(globals);
		f->f_globals = globals;
		INCREF(locals);
		f->f_locals = locals;
		f->f_valuestack = NEW(object *, nvalues+1);
		f->f_blockstack = NEW(block, nblocks+1);
		f->f_nvalues = nvalues;
		f->f_nblocks = nblocks;
		f->f_iblock = 0;
		if (f->f_valuestack == NULL || f->f_blockstack == NULL) {
			err_nomem();
			DECREF(f);
			f = NULL;
		}
	}
	return f;
}

/* Block management */

void
setup_block(f, type, handler, level)
	frameobject *f;
	int type;
	int handler;
	int level;
{
	block *b;
	if (f->f_iblock >= f->f_nblocks) {
		fprintf(stderr, "XXX block stack overflow\n");
		abort();
	}
	b = &f->f_blockstack[f->f_iblock++];
	b->b_type = type;
	b->b_level = level;
	b->b_handler = handler;
}

block *
pop_block(f)
	frameobject *f;
{
	block *b;
	if (f->f_iblock <= 0) {
		fprintf(stderr, "XXX block stack underflow\n");
		abort();
	}
	b = &f->f_blockstack[--f->f_iblock];
	return b;
}