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view lwasm/pass4.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 | 8beb109dfd69 |
children | 8764142b3192 |
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/* pass4.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" /* Resolve2 Pass Force resolution of instruction sizes. */ void do_pass4_aux(asmstate_t *as, int force) { int rc; int cnt; line_t *cl, *sl; struct line_expr_s *le; int trycount = 0; // first, count the number of unresolved instructions for (cnt = 0, cl = as -> line_head; cl; cl = cl -> next) { if (cl -> len == -1) cnt++; } sl = as -> line_head; while (cnt > 0) { trycount = cnt; debug_message(as, 60, "%d unresolved instructions", cnt); // find an unresolved instruction for ( ; sl && sl -> len != -1; sl = sl -> next) { debug_message(as, 200, "Search line %p", sl); as -> cl = sl; lwasm_reduce_expr(as, sl -> addr); lwasm_reduce_expr(as, sl -> daddr); // simplify each expression for (le = sl -> exprs; le; le = le -> next) lwasm_reduce_expr(as, le -> expr); } debug_message(as, 200, "Found line %p", sl); // simplify address as -> cl = sl; lwasm_reduce_expr(as, sl -> addr); lwasm_reduce_expr(as, sl -> daddr); // simplify each expression for (le = sl -> exprs; le; le = le -> next) lwasm_reduce_expr(as, le -> expr); if (sl -> len == -1 && sl -> insn >= 0 && instab[sl -> insn].resolve) { (instab[sl -> insn].resolve)(as, sl, 1); debug_message(as, 200, "Try resolve = %d/%d", sl -> len, sl -> dlen); if (force && sl -> len == -1 && sl -> dlen == -1) { lwasm_register_error(as, sl, "Instruction failed to resolve."); return; } } if (sl -> len != -1 && sl -> dlen != -1) { cnt--; if (cnt == 0) return; // this one resolved - try looking for the next one instead // of wasting time running through the rest of the lines continue; } do { debug_message(as, 200, "Flatten after..."); rc = 0; for (cl = sl; cl; cl = cl -> next) { debug_message(as, 200, "Flatten line %p", cl); as -> cl = cl; // simplify address lwasm_reduce_expr(as, cl -> addr); lwasm_reduce_expr(as, cl -> daddr); // simplify each expression for (le = cl -> exprs; le; le = le -> next) lwasm_reduce_expr(as, le -> expr); if (cl -> len == -1) { // try resolving the instruction length // but don't force resolution if (cl -> insn >= 0 && instab[cl -> insn].resolve) { (instab[cl -> insn].resolve)(as, cl, 0); if ((cl -> inmod == 0) && cl -> len >= 0 && cl -> dlen >= 0) { if (cl -> len == 0) cl -> len = cl -> dlen; else cl -> dlen = cl -> len; } debug_message(as, 200, "Flatten resolve returns %d", cl -> len); if (cl -> len != -1 && cl -> dlen != -1) { rc++; cnt--; if (cnt == 0) return; } } } } if (as -> errorcount > 0) return; } while (rc > 0); if (trycount == cnt) break; } } void do_pass4(asmstate_t *as) { do_pass4_aux(as, 1); }