X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flanguage%2Fdictionary%2Fdelete-variables.c;h=1c38074f63c13c43be475b9c1fa009dbad01a61a;hb=209f7e5ccf28c97641b9e69ef6b9df81efe4dc38;hp=bd26a7d1f272bc86551db7259448e7d9892122a6;hpb=48386ee68a5283653435d05a9ea4e449710fd370;p=pspp diff --git a/src/language/dictionary/delete-variables.c b/src/language/dictionary/delete-variables.c index bd26a7d1f2..1c38074f63 100644 --- a/src/language/dictionary/delete-variables.c +++ b/src/language/dictionary/delete-variables.c @@ -1,31 +1,29 @@ -/* PSPP - computes sample statistics. - Copyright (C) 2006 Free Software Foundation, Inc. - Written by Ben Pfaff . +/* PSPP - a program for statistical analysis. + Copyright (C) 2006, 2007, 2010, 2011, 2013 Free Software Foundation, Inc. - This program 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 2 of the - License, or (at your option) any later version. + This program 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. + 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, write to the Free Software - Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - 02110-1301, USA. */ + along with this program. If not, see . */ #include #include -#include -#include -#include -#include -#include +#include "data/casereader.h" +#include "data/dataset.h" +#include "data/dictionary.h" +#include "language/command.h" +#include "language/lexer/variable-parser.h" +#include "libpspp/message.h" #include "gettext.h" #define _(msgid) gettext (msgid) @@ -35,28 +33,75 @@ int cmd_delete_variables (struct lexer *lexer, struct dataset *ds) { struct variable **vars; - size_t var_cnt; + size_t n_vars; + bool ok; if (proc_make_temporary_transformations_permanent (ds)) - msg (SE, _("DELETE VARIABLES may not be used after TEMPORARY. " - "Temporary transformations will be made permanent.")); + msg (SE, _("%s may not be used after %s. " + "Temporary transformations will be made permanent."), + "DELETE VARIABLES", "TEMPORARY"); - if (!parse_variables (lexer, dataset_dict (ds), &vars, &var_cnt, - PV_NONE)) + if (!parse_variables (lexer, dataset_dict (ds), &vars, &n_vars, PV_NONE)) goto error; - if (var_cnt == dict_get_var_cnt (dataset_dict (ds))) + if (n_vars == dict_get_n_vars (dataset_dict (ds))) { - msg (SE, _("DELETE VARIABLES may not be used to delete all variables " - "from the active file dictionary. Use NEW FILE instead.")); + msg (SE, _("%s may not be used to delete all variables " + "from the active dataset dictionary. " + "Use %s instead."), "DELETE VARIABLES", "NEW FILE"); goto error; } - if (!procedure (ds, NULL, NULL)) + ok = casereader_destroy (proc_open_filtering (ds, false)); + ok = proc_commit (ds) && ok; + if (!ok) goto error; - - dict_delete_vars (dataset_dict (ds), vars, var_cnt); + + dict_delete_vars (dataset_dict (ds), vars, n_vars); + + /* XXX A bunch of bugs conspire to make executing transformations again here + necessary, even though it shouldn't be. + + Consider the following (which is included in delete-variables.at): + + DATA LIST NOTABLE /s1 TO s2 1-2(A). + BEGIN DATA + 12 + END DATA. + DELETE VARIABLES s1. + NUMERIC n1. + LIST. + + The DATA LIST gives us a caseproto with widths 1,1. DELETE VARIABLES + deletes the first variable so we now have -1,1. This already is + technically a problem because proc_casereader_read() calls + case_unshare_and_resize() from the former to the latter caseproto, and + these caseprotos are not conformable (which is a requirement for + case_resize()). It doesn't cause an assert by default because + case_resize() uses expensive_assert() to check for it though. However, in + practice we don't see a problem yet because case_resize() only does work + if the number of widths in the source and dest caseproto are different. + + Executing NUMERIC adds a third variable, though, so we have -1,1,0. This + makes caseproto_resize() notice that there are fewer strings in the new + caseproto. Therefore it destroys the second one (s2). It should destroy + the first one (s1), but if the caseprotos were really conformable then it + would have destroyed the right one. This mistake eventually causes a bad + memory reference. + + Executing transformations a second time after DELETE VARIABLES, like we do + below, works around the problem because we can never run into a situation + where we've got both new variables (triggering a resize) and deleted + variables (triggering the bad free). + + We should fix this in a better way. Doing it cleanly seems hard. This + seems to work for now. */ + ok = casereader_destroy (proc_open_filtering (ds, false)); + ok = proc_commit (ds) && ok; + if (!ok) + goto error; + free (vars); - + return CMD_SUCCESS; error: