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view lwasm/pass2.c @ 500:733fd05ca2a8
Initialize temporary line structures properly
Apparently, not initializing all elements of a struct can lead to random
problems if something somewhere decides it should reference one of those
uninitialized fields. Who knew. Set the temporary line_t structure to zeroes
before passing it into anything when calculating the stuff for "object"
output which should at least make things predictable.
This seems to fix a crash reported by "strick" in Discord.
author | William Astle <lost@l-w.ca> |
---|---|
date | Thu, 29 Aug 2019 17:00:17 -0600 |
parents | 8764142b3192 |
children |
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/* 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); } }