int
cmd_delete_variables (struct lexer *lexer, struct dataset *ds)
{
+ if (proc_has_transformations (ds))
+ {
+ lex_ofs_error (lexer, 0, lex_ofs (lexer) - 1,
+ _("%s may not be used when there are pending "
+ "transformations (use %s to execute transformations)."),
+ "DELETE VARIABLES", "EXECUTE");
+ return CMD_FAILURE;
+ }
+ if (proc_in_temporary_transformations (ds))
+ {
+ lex_ofs_error (lexer, 0, lex_ofs (lexer) - 1,
+ _("%s may not be used after %s."),
+ "DELETE VARIABLES", "TEMPORARY");
+ return CMD_FAILURE;
+ }
+
struct variable **vars;
size_t n_vars;
- bool ok;
-
- if (proc_make_temporary_transformations_permanent (ds))
- lex_ofs_error (lexer, 0, lex_ofs (lexer) - 1,
- _("%s may not be used after %s. "
- "Temporary transformations will be made permanent."),
- "DELETE VARIABLES", "TEMPORARY");
-
if (!parse_variables (lexer, dataset_dict (ds), &vars, &n_vars, PV_NONE))
- goto error;
+ return CMD_FAILURE;
if (n_vars == dict_get_n_vars (dataset_dict (ds)))
{
lex_ofs_error (lexer, 0, lex_ofs (lexer) - 1,
_("%s may not be used to delete all variables "
"from the active dataset dictionary. "
"Use %s instead."), "DELETE VARIABLES", "NEW FILE");
- goto error;
+ free (vars);
+ return CMD_FAILURE;
}
- ok = casereader_destroy (proc_open_filtering (ds, false));
- ok = proc_commit (ds) && ok;
- if (!ok)
- goto error;
-
- 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;
-
+ dataset_delete_vars (ds, vars, n_vars);
free (vars);
return CMD_SUCCESS;
-
- error:
- free (vars);
- return CMD_CASCADING_FAILURE;
}