view lwasm/struct.c @ 502:14a40f8bb4eb

Add various operators to lwcc Add various binary and ternary operators to lwcc, but only those which can work with constant operands. Seems like variables are probably required next.
author William Astle <lost@l-w.ca>
date Wed, 25 Sep 2019 20:23:49 -0600
parents 8764142b3192
children
line wrap: on
line source

/*
struct.c
Copyright © 2010 William Astle

This file is part of LWASM.

LWASM is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.

You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.

Contains stuff associated with structure processing
*/

#include <string.h>

#include <lw_alloc.h>
#include <lw_string.h>

#include "lwasm.h"
#include "instab.h"

PARSEFUNC(pseudo_parse_struct)
{
	structtab_t *s;
	
	if (as -> instruct)
	{
		lwasm_register_error(as, l, E_STRUCT_RECURSE);
		return;
	}
	
	if (l -> sym == NULL)
	{
		lwasm_register_error(as, l, E_STRUCT_NOSYMBOL);
		return;
	}
	
	for (s = as -> structs; s; s = s -> next)
	{
		if (!strcmp(s -> name, l -> sym))	
			break;
	}
	
	if (s)
	{
		lwasm_register_error(as, l, E_STRUCT_DUPE);
		return;
	}
	
	as -> instruct = 1;
	
	s = lw_alloc(sizeof(structtab_t));
	s -> name = lw_strdup(l -> sym);
	s -> next = as -> structs;
	s -> fields = NULL;
	s -> size = 0;
	s -> definedat = l;
	as -> structs = s;
	as -> cstruct = s;
	
	skip_operand(p);
	
	l -> len = 0;
	l -> symset = 1;
	
	// save current assembly address and initialize to 0
	as -> savedaddr = l -> addr;
	l -> addr = lw_expr_build(lw_expr_type_int, 0);
}

static void instantiate_struct(asmstate_t *as, line_t *l, structtab_t *s, char *pref, lw_expr_t baseaddr)
{
	int len;
	char *t;
	int plen;
	int addr = 0;
	lw_expr_t te, te2;
	structtab_field_t *e;

	if (baseaddr == NULL)
		baseaddr = l -> addr;
	
	plen = strlen(pref);
	for (e = s -> fields; e; e = e -> next)
	{
		if (e -> name)
		{
			len = plen + strlen(e -> name) + 1;
			t = lw_alloc(len + 1);
			sprintf(t, "%s.%s", pref, e -> name);
		}
		else
		{
			len = plen + 30;
			t = lw_alloc(len + 1);
			sprintf(t, "%s.____%d", pref, addr);
		}

		te = lw_expr_build(lw_expr_type_int, addr);
		te2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_plus, te, baseaddr);
		register_symbol(as, l, t, te2, symbol_flag_nocheck);
		lw_expr_destroy(te);
		
		if (e -> substruct)
		{
			instantiate_struct(as, l, e -> substruct, t, te2);
		}
		
		lw_expr_destroy(te2);
		
		lw_free(t);
		addr += e -> size;
	}
	
	/* register the "sizeof" symbol */
	len = plen + 8;
	t = lw_alloc(len + 1);
	sprintf(t, "sizeof{%s}", pref);
	te = lw_expr_build(lw_expr_type_int, s -> size);
	register_symbol(as, l, t, te, symbol_flag_nocheck);
	lw_expr_destroy(te);
	lw_free(t);
}


PARSEFUNC(pseudo_parse_endstruct)
{
	lw_expr_t te;
		
	if (as -> instruct == 0)
	{
		lwasm_register_error(as, l, W_ENDSTRUCT_WITHOUT);
		skip_operand(p);
		return;
	}

	te = lw_expr_build(lw_expr_type_int, 0);
	
	// make all the relevant generic struct symbols
	instantiate_struct(as, l, as -> cstruct, as -> cstruct -> name, te);
	lw_expr_destroy(te);
	
	l -> soff = as -> cstruct -> size;
	as -> instruct = 0;
	
	skip_operand(p);
	
	lw_expr_destroy(l -> addr);
	l -> addr = as -> savedaddr;
	as -> savedaddr = NULL;
	
	l -> len = 0;
}

void register_struct_entry(asmstate_t *as, line_t *l, int size, structtab_t *ss)
{
	structtab_field_t *e, *e2;
	
	l -> soff = as -> cstruct -> size;
	e = lw_alloc(sizeof(structtab_field_t));
	e -> next = NULL;
	e -> size = size;
	if (l -> sym)
		e -> name = lw_strdup(l -> sym);
	else
		e -> name = NULL;
	e -> substruct = ss;
	if (as -> cstruct -> fields)
	{
		for (e2 = as -> cstruct -> fields; e2 -> next; e2 = e2 -> next)
			/* do nothing */ ;
		e2 -> next = e;
	}
	else
	{
		as -> cstruct -> fields = e;
	}
	as -> cstruct -> size += size;
}

int expand_struct(asmstate_t *as, line_t *l, char **p, char *opc)
{
	structtab_t *s;
	
	debug_message(as, 200, "Checking for structure expansion: %s", opc);

	for (s = as -> structs; s; s = s -> next)
	{
		if (!strcmp(opc, s -> name))
			break;
	}
	
	if (!s)
		return -1;
	
	debug_message(as, 10, "Expanding structure: %s", opc);
	
	if (!(l -> sym))
	{
		lwasm_register_error(as, l, E_STRUCT_NONAME);
		return -1;
	}

	l -> len = s -> size;

	if (as -> instruct)
	{
		/* register substruct here */
		register_struct_entry(as, l, s -> size, s);
		/* mark the symbol consumed */
		l -> symset = 1;
		l -> len = 0;
		return 0;
	}
	else
	{
		/* instantiate the struct here */
		instantiate_struct(as, l, s, l -> sym, NULL);
		return 0;
	}
	
	return 0;
}