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view lwasm/macro.c @ 434:052c5f335a92
Fix bug in like terms collection in expression simplification
Like term collection would lose the actual "variable" part of the term if
the second term collected happened to have no coefficient. This would cause
the expression to take the value of the calculated coefficient which is
obviously wrong.
Thanks to hider <stego@satx.rr.com> for reporting the bug and providing a
proper test case.
Observation: this bug has been present since the first pre-release of
lwtools 3.0 when the algebraic expression system was introduced. Apparently
people tend not to create expressions that trigger the like terms handler.
The specific conditions require the symbol to be undefined and the second
operand to the addition has to have no coefficient so it's likely a fairly
rare scenario. Still, it is somewhat surprising that nobody tripped on it
before now.
author | William Astle <lost@l-w.ca> |
---|---|
date | Mon, 23 Jan 2017 22:58:36 -0700 |
parents | 39490cf2d1c2 |
children | 5524649f4784 |
line wrap: on
line source
/* macro.c Copyright © 2008 William Astle This file is part of LWASM. LWASM 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/>. Contains stuff associated with macro processing */ #include <ctype.h> #include <stdlib.h> #include <string.h> #include <stdio.h> #include <lw_alloc.h> #include <lw_string.h> #include "lwasm.h" #include "input.h" #include "instab.h" PARSEFUNC(pseudo_parse_macro) { macrotab_t *m; char *t; char tc; l -> len = 0; l -> hideline = 1; if (as -> skipcond) { as -> skipmacro = 1; return; } if (as -> inmacro) { lwasm_register_error(as, l, E_MACRO_RECURSE); return; } if (!(l -> sym)) { lwasm_register_error(as, l, E_MACRO_NONAME); return; } for (m = as -> macros; m; m = m -> next) { if (!strcasecmp(m -> name, l -> sym)) break; } if (m) { lwasm_register_error(as, l, E_MACRO_DUPE); return; } m = lw_alloc(sizeof(macrotab_t)); m -> name = lw_strdup(l -> sym); m -> next = as -> macros; m -> lines = NULL; m -> numlines = 0; m -> flags = 0; m -> definedat = l; as -> macros = m; t = *p; while (**p && !isspace(**p)) (*p)++; tc = **p; /* ignore unknown flags */ if (strcasecmp(t, "noexpand") == 0) m -> flags |= macro_noexpand; **p = tc; as -> inmacro = 1; } PARSEFUNC(pseudo_parse_endm) { l -> hideline = 1; l -> len = 0; if (as -> skipcond) { as -> skipmacro = 0; return; } if (!as -> inmacro) { lwasm_register_error(as, l, E_MACRO_ENDM); return; } as -> inmacro = 0; // a macro definition counts as a context break for local symbols as -> context = lwasm_next_context(as); } // the current macro will ALWAYS be the first one in the table int add_macro_line(asmstate_t *as, char *optr) { if (!as -> inmacro) return 0; as -> macros -> lines = lw_realloc(as -> macros -> lines, sizeof(char *) * (as -> macros -> numlines + 1)); as -> macros -> lines[as -> macros -> numlines] = lw_strdup(optr); as -> macros -> numlines += 1; return 1; } void macro_add_to_buff(char **buff, int *loc, int *len, char c) { if (*loc == *len) { *buff = lw_realloc(*buff, *len + 32); *len += 32; } (*buff)[(*loc)++] = c; } // this is just like a regular operation function /* macro args are referenced by "\n" where 1 <= n <= 9 or by "\{n}"; a \ can be included by writing \\ a comma separates argument but one can be included with "\," whitespace ends argument list but can be included with "\ " or the like */ int expand_macro(asmstate_t *as, line_t *l, char **p, char *opc) { int lc; line_t *cl; //, *nl; int oldcontext; macrotab_t *m; char **args = NULL; // macro arguments int nargs = 0; // number of arguments char *p2, *p3; int bloc, blen; char *linebuff; for (m = as -> macros; m; m = m -> next) { if (!strcasecmp(opc, m -> name)) break; } // signal no macro expansion if (!m) return -1; // save current symbol context for after macro expansion oldcontext = as -> context; cl = l; as -> context = lwasm_next_context(as); while (**p && !isspace(**p) && **p) { p2 = *p; while (*p2 && !isspace(*p2) && *p2 != ',') { if (*p2 == '\\') { if (p2[1]) p2++; } p2++; } // have arg here args = lw_realloc(args, sizeof(char *) * (nargs + 1)); args[nargs] = lw_alloc(p2 - *p + 1); args[nargs][p2 - *p] = '\0'; memcpy(args[nargs], *p, p2 - *p); *p = p2; // now collapse out "\" characters for (p3 = p2 = args[nargs]; *p2; p2++, p3++) { if (*p2 == '\\' && p2[1]) { p2++; } *p3 = *p2; } *p3 = '\0'; nargs++; if (**p == ',') (*p)++; } // now create a string for the macro // and push it into the front of the input stack bloc = blen = 0; linebuff = NULL; if (m -> flags & macro_noexpand) { char ctcbuf[100]; char *p; snprintf(ctcbuf, 100, "\001\001SETNOEXPANDSTART\n"); for (p = ctcbuf; *p; p++) macro_add_to_buff(&linebuff, &bloc, &blen, *p); } for (lc = 0; lc < m -> numlines; lc++) { for (p2 = m -> lines[lc]; *p2; p2++) { if (*p2 == '\\' && p2[1] == '*') { int n; /* all arguments */ for (n = 0; n < nargs; n++) { for (p3 = args[n]; *p3; p3++) { macro_add_to_buff(&linebuff, &bloc, &blen, *p3); } if (n != (nargs -1)) { macro_add_to_buff(&linebuff, &bloc, &blen, ','); } } p2++; } else if (*p2 == '\\' && isdigit(p2[1])) { int n; p2++; n = *p2 - '0'; if (n == 0) { for (p3 = m -> name; *p3; p3++) macro_add_to_buff(&linebuff, &bloc, &blen, *p3); continue; } if (n < 1 || n > nargs) continue; for (p3 = args[n - 1]; *p3; p3++) macro_add_to_buff(&linebuff, &bloc, &blen, *p3); continue; } else if (*p2 == '{') { int n = 0, n2; p2++; while (*p2 && isdigit(*p2)) { n2 = *p2 - '0'; if (n2 < 0 || n2 > 9) n2 = 0; n = n * 10 + n2; p2++; } if (*p2 == '}') p2++; if (n == 0) { for (p3 = m -> name; *p3; p3++) macro_add_to_buff(&linebuff, &bloc, &blen, *p3); continue; } if (n < 1 || n > nargs) continue; for (p3 = args[n - 1]; *p3; p3++) macro_add_to_buff(&linebuff, &bloc, &blen, *p3); continue; } else { macro_add_to_buff(&linebuff, &bloc, &blen, *p2); } } macro_add_to_buff(&linebuff, &bloc, &blen, '\n'); } if (m -> flags & macro_noexpand) { char ctcbuf[100]; char *p; snprintf(ctcbuf, 100, "\001\001SETNOEXPANDEND\n"); for (p = ctcbuf; *p; p++) macro_add_to_buff(&linebuff, &bloc, &blen, *p); } { char ctcbuf[100]; char *p; snprintf(ctcbuf, 100, "\001\001SETCONTEXT %d\n\001\001SETLINENO %d\n", oldcontext, cl -> lineno + 1); for (p = ctcbuf; *p; p++) macro_add_to_buff(&linebuff, &bloc, &blen, *p); } macro_add_to_buff(&linebuff, &bloc, &blen, 0); // push the macro into the front of the stream input_openstring(as, opc, linebuff); lw_free(linebuff); // clean up if (args) { while (nargs) { lw_free(args[--nargs]); } lw_free(args); } // indicate a macro was expanded l -> hideline = 1; return 0; }