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view lwasm/pass5.c @ 366:433dbc18fb41
Make byte overflow detection for 8 bit immediate not fail with COM operator
This is a horrible hack. Add a quick and dirty context to expression parsing
so that it knows whether an 8 bit or 16 bit complement is required. The 8
bit complement will just discard anything above bit 7. When returning an
operator back with lwasm_whichop(), the result will still be "COM" which
should allow other things to keep working as they already do.
This does prevent byte overflows when the complement operator is used,
however, and since those were introduced, there were problems building
Nitros9 among other things. This fix allows Nitros9 to build again.
author | William Astle <lost@l-w.ca> |
---|---|
date | Tue, 02 Jun 2015 20:58:14 -0600 |
parents | 697bc543368c |
children | 8764142b3192 |
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/* pass5.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" /* AssignAddresses Pass Force resolution of all line addresses */ static int exprok_aux(lw_expr_t e, void *priv) { asmstate_t *as = priv; if (lw_expr_istype(e, lw_expr_type_int)) return 0; if (lw_expr_istype(e, lw_expr_type_oper)) return 0; if (lw_expr_istype(e, lw_expr_type_special) && as -> output_format == OUTPUT_OBJ) { int t; t = lw_expr_specint(e); if (t == lwasm_expr_secbase) return 0; } return 1; } static int exprok(asmstate_t *as, lw_expr_t e) { if (lw_expr_testterms(e, exprok_aux, as)) return 0; return 1; } void do_pass5(asmstate_t *as) { // int rc; int cnt; int ocnt; line_t *cl, *sl; // struct line_expr_s *le; // first, count the number of non-constant addresses; do // a reduction first on each one for (cnt = 0, cl = as -> line_head; cl; cl = cl -> next) { as -> cl = cl; lwasm_reduce_expr(as, cl -> addr); if (!exprok(as, cl -> addr)) cnt++; lwasm_reduce_expr(as, cl -> daddr); if (!exprok(as, cl -> daddr)) cnt++; } sl = as -> line_head; while (cnt > 0) { ocnt = cnt; // find an unresolved address for ( ; sl && exprok(as, sl -> addr) && exprok(as, sl -> daddr); sl = sl -> next) /* do nothing */ ; // simplify address for (cl = sl; cl; cl = cl -> next) { as -> cl = sl; lwasm_reduce_expr(as, sl -> addr); if (exprok(as, cl -> addr)) { if (0 == --cnt) return; } lwasm_reduce_expr(as, sl -> daddr); if (exprok(as, cl -> addr)) { if (0 == --cnt) return; } } if (cnt == ocnt) break; } if (cnt) { // we have non-resolved line addresses here for (cl = sl; cl; cl = cl -> next) { if (!exprok(as, cl -> addr)) { lwasm_register_error(as, cl, "Cannot resolve line address"); } if (!exprok(as, cl -> daddr)) { lwasm_register_error(as, cl, "Cannot resolve line data address"); } } } }