view lwasm/pass2.c @ 258:ebda5c96665e

Improved stack handling for os9 target in lwlink Added "stack" as a valid symbol in the __os9 section. All instances of __os9 are now polled for "stack" symobls and the values added to the stack size set in the linker script. The stack size is then added to the final data size of the module. Also set a default minimum stack size of 32 bytes.
author William Astle <lost@l-w.ca>
date Thu, 31 Jan 2013 19:34:54 -0700
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);
	}	
}