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view lwar/main.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 | e34c8bd6ea29 |
children | b138b4005125 |
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/* main.c Copyright © 2009 William Astle This file is part of LWAR. LWAR 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/>. Implements the program startup code */ #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/stat.h> #include <lw_cmdline.h> #include <lw_version.h> #include "lwar.h" #ifdef _MSC_VER #include <lw_win.h> // windows build #else #include <unistd.h> #endif // command line option handling #define PROGVER "lwar from " PACKAGE_STRING char *program_name; static int parse_opts(int key, char *arg, void *state) { switch (key) { case 'd': // debug debug_level++; break; case 'n': // filename only, no path filename_flag++; break; case 'a': // add members operation = LWAR_OP_ADD; break; case 'c': // create archive operation = LWAR_OP_CREATE; break; case 'm': mergeflag = 1; break; case 'r': // replace members operation = LWAR_OP_REPLACE; break; case 'l': // list members operation = LWAR_OP_LIST; break; case 'x': // extract members operation = LWAR_OP_EXTRACT; break; case lw_cmdline_key_arg: if (archive_file) { // add archive member to list add_file_name(arg); } else archive_file = arg; break; default: return lw_cmdline_err_unknown; } return 0; } static struct lw_cmdline_options options[] = { { "replace", 'r', 0, 0, "Add or replace archive members" }, { "extract", 'x', 0, 0, "Extract members from the archive" }, { "add", 'a', 0, 0, "Add members to the archive" }, { "list", 'l', 0, 0, "List the contents of the archive" }, { "create", 'c', 0, 0, "Create new archive (or truncate existing one)" }, { "merge", 'm', 0, 0, "Add the contents of archive arguments instead of the archives themselves" }, { "nopaths", 'n', 0, 0, "Store only the filename when adding members and ignore the path, if any, when extracting members" }, { "debug", 'd', 0, 0, "Set debug mode"}, { 0 } }; static struct lw_cmdline_parser argparser = { options, parse_opts, "ARCHIVE [FILE ...]", "lwar, a library file manager for lwlink", PROGVER }; extern void do_list(void); extern void do_add(void); extern void do_remove(void); extern void do_replace(void); extern void do_extract(void); // main function; parse command line, set up assembler state, and run the // assembler on the first file int main(int argc, char **argv) { program_name = argv[0]; lw_cmdline_parse(&argparser, argc, argv, 0, 0, NULL); if (archive_file == NULL) { fprintf(stderr, "You must specify an archive file.\n"); exit(1); } if (operation == 0) { fprintf(stderr, "You must specify an operation.\n"); exit(1); } if (operation == LWAR_OP_LIST || operation == LWAR_OP_REMOVE || operation == LWAR_OP_EXTRACT) { struct stat stbuf; // make sure the archive exists if (stat(archive_file, &stbuf) < 0) { fprintf(stderr, "Cannot open archive file %s:\n", archive_file); perror(""); exit(2); } } if (operation == LWAR_OP_CREATE) { struct stat stbuf; // check if the archive exists if (stat(archive_file, &stbuf) < 0) { if (errno != ENOENT) { fprintf(stderr, "Cannot create archive file %s:\n", archive_file); perror(""); exit(2); } } else { if (unlink(archive_file) < 0) { fprintf(stderr, "Cannot create archive file %s:\n", archive_file); perror(""); exit(2); } } } switch (operation) { case LWAR_OP_LIST: do_list(); break; case LWAR_OP_ADD: case LWAR_OP_CREATE: do_add(); break; case LWAR_OP_REMOVE: do_remove(); break; case LWAR_OP_REPLACE: do_replace(); break; case LWAR_OP_EXTRACT: do_extract(); break; } exit(0); }