view lwasm/pass2.c @ 406:4411a6123716

Add "basic" output format Add "basic" output format. This outputs the code in the form of a Basic program that installs the assembled output. If an execution address is provided to the END pseudo operation, it will transfer control there using the Basic EXEC command. Thanks to Tim Lindner <tlindner@macmess.org> for the original patch. I used it mostly as is except for a couple of minor fixes for coding style and removing a variable declaration from inside a for() statement for portability reasons.
author William Astle <lost@l-w.ca>
date Thu, 03 Mar 2016 21:04:39 -0700
parents 8764142b3192
children
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, E_SYMBOL_UNDEFINED_EXPORT);
				}
			}
			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);
	}	
}