view lwasm/pass2.c @ 333:507f442dc71e

Add support for 6800 compatibility instructions. The occasional program uses the 6800 compatibility instructions since they are actually specified by Motorola in at least some documentation. They advertised the 6809 as source compatible with the 6800. This mode is not enabled by default, however. It is my belief that receiving an error when using a non-6809 instruction is more useful since it is unlikely that much 6800 source code is being assembled for the 6809 these days. Nevertheless, the --6809compat option is present for just those purposes so one does not have to resort to using macros (which would work equally well in most cases).
author William Astle <lost@l-w.ca>
date Tue, 15 Apr 2014 10:57:34 -0600
parents 697bc543368c
children 8764142b3192
line wrap: on
line source

/*
pass2.c

Copyright © 2010 William Astle

This file is part of LWTOOLS.

LWTOOLS 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/>.
*/

#include <stdio.h>
#include <string.h>

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

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

/*
pass 2: deal with undefined symbols and do a simplification pass
on all the expressions. Handle PRAGMA_IMPORTUNDEFEXPORT

*/
void do_pass2(asmstate_t *as)
{
	line_t *cl;
	exportlist_t *ex;
	struct symtabe *s;
	importlist_t *im;
	struct line_expr_s *le;

	// verify the export list
	if (as -> output_format == OUTPUT_OBJ)
	{	
		for (ex = as -> exportlist; ex; ex = ex -> next)
		{
			s = lookup_symbol(as, NULL, ex -> symbol);
			if (!s)
			{
				if (CURPRAGMA(ex -> line, PRAGMA_IMPORTUNDEFEXPORT))
				{
					for (im = as -> importlist; im; im = im -> next)
					{
						if (!strcmp(ex -> symbol, im -> symbol))
							break;
					}
					if (!im)
					{
						im = lw_alloc(sizeof(importlist_t));
						im -> symbol = lw_strdup(ex -> symbol);
						im -> next = as -> importlist;
						as -> importlist = im;
					}
				}
				else
				{
					// undefined export - register error
					lwasm_register_error(as, ex -> line, "Undefined exported symbol");
				}
			}
			ex -> se = s;
		}
		if (as -> errorcount > 0)
			return;
	}

	// we want to throw errors on undefined symbols here
	as -> badsymerr = 1;
	
	// now do some reductions on expressions
	for (cl = as -> line_head; cl; cl = cl -> next)
	{
		as -> cl = cl;
		
		// simplify address
		lwasm_reduce_expr(as, cl -> addr);

		// simplify data address
		lwasm_reduce_expr(as, cl -> daddr);
		
		// simplify each expression
		for (le = cl -> exprs; le; le = le -> next)
			lwasm_reduce_expr(as, le -> expr);
	}	
}