[Pspp-cvs] pspp doc/flow-control.texi src/language/control...

[Ben Pfaff]

CVSROOT:        /cvsroot/pspp
Module name:    pspp
Changes by:     Ben Pfaff <blp> 06/12/20 16:09:45

Modified files:
        doc            : flow-control.texi 
        src/language/control: ChangeLog loop.c 
        tests          : ChangeLog 
        tests/command  : loop.sh 

Log message:
        Fix bugs in LOOP.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/pspp/doc/flow-control.texi?cvsroot=pspp&r1=1.4&r2=1.5
http://cvs.savannah.gnu.org/viewcvs/pspp/src/language/control/ChangeLog?cvsroot=pspp&r1=1.7&r2=1.8
http://cvs.savannah.gnu.org/viewcvs/pspp/src/language/control/loop.c?cvsroot=pspp&r1=1.13&r2=1.14
http://cvs.savannah.gnu.org/viewcvs/pspp/tests/ChangeLog?cvsroot=pspp&r1=1.73&r2=1.74
http://cvs.savannah.gnu.org/viewcvs/pspp/tests/command/loop.sh?cvsroot=pspp&r1=1.16&r2=1.17

Patches:
Index: doc/flow-control.texi
===================================================================
RCS file: /cvsroot/pspp/pspp/doc/flow-control.texi,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -b -r1.4 -r1.5
--- doc/flow-control.texi       8 May 2006 01:14:16 -0000       1.4
+++ doc/flow-control.texi       20 Dec 2006 16:09:44 -0000      1.5
@@ -145,16 +145,19 @@
 condition is false or missing before the loop contents are executed the
 first time, the loop contents are not executed at all.
 
-If index and condition clauses are both present on @cmd{LOOP}, the index
-clause is always evaluated first.
+If index and condition clauses are both present on @cmd{LOOP}, the
+index variable is always set before the condition is evaluated.  Thus,
+a condition that makes use of the index variable will always see the
+index value to be used in the next execution of the body.
 
 Specify a boolean expression for the condition on @cmd{END LOOP} to cause
-the loop to terminate if the condition is not true after the enclosed
+the loop to terminate if the condition is true after the enclosed
 code block is executed.  The condition is evaluated at the end of the
-loop, not at the beginning.
+loop, not at the beginning, so that the body of a loop with only a
+condition on @cmd{END LOOP} will always execute at least once.
 
-If the index clause and both condition clauses are not present, then the
-loop is executed MXLOOPS (@pxref{SET}) times.
+If neither the index clause nor either condition clause is
+present, then the loop is executed MXLOOPS (@pxref{SET}) times.
 
 @cmd{BREAK} also terminates @cmd{LOOP} execution (@pxref{BREAK}).
 

Index: src/language/control/ChangeLog
===================================================================
RCS file: /cvsroot/pspp/pspp/src/language/control/ChangeLog,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -b -r1.7 -r1.8
--- src/language/control/ChangeLog      10 Dec 2006 04:12:40 -0000      1.7
+++ src/language/control/ChangeLog      20 Dec 2006 16:09:44 -0000      1.8
@@ -1,3 +1,20 @@
+Tue Dec 19 08:12:46 2006  Ben Pfaff  <address@hidden>
+
+       Fix LOOP.  Thanks to Daniel Williams
+       <address@hidden> for reporting one of the bugs
+       fixed here.
+       
+       * loop.c (cmd_loop): Keep track of whether we created the index
+       variable and delete it if parsing fails, instead of creating it
+       after parsing the IF clause.  This allows the index variable to be
+       used in the IF clause.  This incidentally fixes a segfault when no
+       index variable was used.  Also, return CMD_CASCADING_FAILURE if we
+       fail.
+       (parse_if_clause): Don't allow more than one IF clause.
+       (parse_index_clause): Don't allow more than one index clause.
+       Create the index variable if it doesn't exist.
+       (end_loop_trns_proc): Invert the sense of END LOOP's IF clause.
+
 Sat Dec  9 20:12:34 2006  Ben Pfaff  <address@hidden>
 
        * repeat.c (parse_lines): Issue an error when attempting to nest

Index: src/language/control/loop.c
===================================================================
RCS file: /cvsroot/pspp/pspp/src/language/control/loop.c,v
retrieving revision 1.13
retrieving revision 1.14
diff -u -b -r1.13 -r1.14
--- src/language/control/loop.c 15 Dec 2006 00:16:02 -0000      1.13
+++ src/language/control/loop.c 20 Dec 2006 16:09:44 -0000      1.14
@@ -86,8 +86,10 @@
 static trns_free_func loop_trns_free;
 
 static struct loop_trns *create_loop_trns (struct dataset *);
-static bool parse_if_clause (struct lexer *, struct loop_trns *, struct 
expression **);
-static bool parse_index_clause (struct lexer *, struct loop_trns *, char 
index_var_name[]);
+static bool parse_if_clause (struct lexer *,
+                             struct loop_trns *, struct expression **);
+static bool parse_index_clause (struct dataset *, struct lexer *,
+                                struct loop_trns *, bool *created_index_var);
 static void close_loop (void *);
 
 /* LOOP. */
@@ -97,7 +99,7 @@
 cmd_loop (struct lexer *lexer, struct dataset *ds)
 {
   struct loop_trns *loop;
-  char index_var_name[LONG_NAME_LEN + 1];
+  bool created_index_var = false;
   bool ok = true;
 
   loop = create_loop_trns (ds);
@@ -106,21 +108,21 @@
       if (lex_match_id (lexer, "IF")) 
         ok = parse_if_clause (lexer, loop, &loop->loop_condition);
       else
-        ok = parse_index_clause (lexer, loop, index_var_name);
+        ok = parse_index_clause (ds, lexer, loop, &created_index_var);
     }
 
-  /* Find index variable and create if necessary. */
-  if (ok && index_var_name[0] != '\0')
+  /* Clean up if necessary. */
+  if (!ok) 
+    {
+      loop->max_pass_count = 0; 
+      if (loop->index_var != NULL && created_index_var)
     {
-      loop->index_var = dict_lookup_var (dataset_dict (ds), index_var_name);
-      if (loop->index_var == NULL)
-        loop->index_var = dict_create_var (dataset_dict (ds), 
-                                          index_var_name, 0);
+          dict_delete_var (dataset_dict (ds), loop->index_var);
+          loop->index_var = NULL;
+        }
     }
   
-  if (!ok)
-    loop->max_pass_count = 0;
-  return ok ? CMD_SUCCESS : CMD_FAILURE;
+  return ok ? CMD_SUCCESS : CMD_CASCADING_FAILURE;
 }
 
 /* Parses END LOOP. */
@@ -189,22 +191,45 @@
 parse_if_clause (struct lexer *lexer, 
                 struct loop_trns *loop, struct expression **condition) 
 {
+  if (*condition != NULL) 
+    {
+      lex_sbc_only_once ("IF");
+      return false;
+    }
+  
   *condition = expr_parse_pool (lexer, loop->pool, loop->ds, EXPR_BOOLEAN);
   return *condition != NULL;
 }
 
 /* Parses an indexing clause into LOOP.
-   Stores the index variable's name in INDEX_VAR_NAME[].
+   Stores true in *CREATED_INDEX_VAR if the index clause created
+   a new variable, false otherwise.
    Returns true if successful, false on failure. */
 static bool
-parse_index_clause (struct lexer *lexer, struct loop_trns *loop, char 
index_var_name[]) 
+parse_index_clause (struct dataset *ds, struct lexer *lexer,
+                    struct loop_trns *loop, bool *created_index_var) 
 {
+  if (loop->index_var != NULL) 
+    {
+      msg (SE, _("Only one index clause may be specified."));
+      return false;
+    }
+
   if (lex_token (lexer) != T_ID) 
     {
       lex_error (lexer, NULL);
       return false;
     }
-  strcpy (index_var_name, lex_tokid (lexer));
+
+  loop->index_var = dict_lookup_var (dataset_dict (ds), lex_tokid (lexer));
+  if (loop->index_var != NULL)
+    *created_index_var = false;
+  else
+    {
+      loop->index_var = dict_create_var_assert (dataset_dict (ds), 
+                                                lex_tokid (lexer), 0);
+      *created_index_var = true; 
+    }
   lex_get (lexer);
 
   if (!lex_force_match (lexer, '='))
@@ -336,7 +361,7 @@
   struct loop_trns *loop = loop_;
 
   if (loop->end_loop_condition != NULL
-      && expr_evaluate_num (loop->end_loop_condition, c, case_num) != 1.0)
+      && expr_evaluate_num (loop->end_loop_condition, c, case_num) != 0.0)
     goto break_out;
 
   /* MXLOOPS limiter. */

Index: tests/ChangeLog
===================================================================
RCS file: /cvsroot/pspp/pspp/tests/ChangeLog,v
retrieving revision 1.73
retrieving revision 1.74
diff -u -b -r1.73 -r1.74
--- tests/ChangeLog     16 Dec 2006 22:01:19 -0000      1.73
+++ tests/ChangeLog     20 Dec 2006 16:09:45 -0000      1.74
@@ -1,3 +1,7 @@
+Tue Dec 19 08:17:28 2006  Ben Pfaff  <address@hidden>
+
+       * command/loop.sh: Test all the possible combinations of clauses.
+
 Sat Dec 16 14:00:48 2006  Ben Pfaff  <address@hidden>
 
        * command/rank.sh: Fix test to allow string grouping variables.

Index: tests/command/loop.sh
===================================================================
RCS file: /cvsroot/pspp/pspp/tests/command/loop.sh,v
retrieving revision 1.16
retrieving revision 1.17
diff -u -b -r1.16 -r1.17
--- tests/command/loop.sh       7 Nov 2006 13:00:00 -0000       1.16
+++ tests/command/loop.sh       20 Dec 2006 16:09:45 -0000      1.17
@@ -57,17 +57,71 @@
 
 activity="create prog"
 cat > $TEMPDIR/loop.stat <<EOF
-data list /X 1 Y 2 ZOOLOGICAL 3.
+data list notable /x 1 y 2 z 3.
 begin data.
-125
-256
-397
-401
+121
+252
+393
+404
 end data.
-loop iterative_Variable=y to zoological by abs(zoological-y)/(zoological-y).
-print /x iterative_Variable.
-break.         /* Generates warning.
+
+echo 'Loop with index'.
+loop #i=x to y by z.
+print /#i.
+end loop.
+print/'--------'.
+execute.
+
+echo 'Loop with IF condition'.
+compute #j=x.
+loop if #j <= y.
+print /#j.
+compute #j = #j + z.
+end loop.
+print/'--------'.
+execute.
+
+echo 'Loop with END IF condition'.
+compute #k=x.
+loop.
+print /#k.
+compute #k = #k + z.
+end loop if #k > y.
+print/'--------'.
+execute.
+
+echo 'Loop with index and IF condition based on index'.
+loop #m=x to y by z if #m < 4.
+print /#m.
+end loop.
+print/'--------'.
+execute.
+
+echo 'Loop with index and END IF condition based on index'.
+loop #n=x to y by z.
+print /#n.
+end loop if #n >= 4.
+print/'--------'.
+execute.
+
+echo 'Loop with index and IF and END IF condition based on index'.
+loop #o=x to y by z if mod(#o,2) = 0.
+print /#o.
+end loop if #o >= 4.
+print/'--------'.
+execute.
+
+echo 'Loop with no conditions'.
+set mxloops = 2.
+compute #p = x.
+loop.
+print /#p.
+compute #p = #p + z.
+do if #p >= y.
+break.
+end if.
 end loop.
+print/'--------'.
 execute.
 EOF
 if [ $? -ne 0 ] ; then no_result ; fi
@@ -85,18 +139,81 @@
 activity="compare results"
 perl -pi -e 's/^\s*$//g' $TEMPDIR/pspp.list
 diff  -b $TEMPDIR/pspp.list  - <<EOF
-1.1 DATA LIST.  Reading 1 record from INLINE.
-+----------+------+-------+------+
-| Variable |Record|Columns|Format|
-#==========#======#=======#======#
-|X         |     1|  1-  1|F1.0  |
-|Y         |     1|  2-  2|F1.0  |
-|ZOOLOGICAL|     1|  3-  3|F1.0  |
-+----------+------+-------+------+
-1     2.00 
-2     5.00 
-3     9.00 
-4      .00 
+Loop with index
+    1.00 
+    2.00 
+--------
+    2.00 
+    4.00 
+--------
+    3.00 
+    6.00 
+    9.00 
+--------
+--------
+Loop with IF condition
+    1.00 
+    2.00 
+--------
+    2.00 
+    4.00 
+--------
+    3.00 
+    6.00 
+    9.00 
+--------
+--------
+Loop with END IF condition
+    1.00 
+    2.00 
+--------
+    2.00 
+    4.00 
+--------
+    3.00 
+    6.00 
+    9.00 
+--------
+    4.00 
+--------
+Loop with index and IF condition based on index
+    1.00 
+    2.00 
+--------
+    2.00 
+--------
+    3.00 
+--------
+--------
+Loop with index and END IF condition based on index
+    1.00 
+    2.00 
+--------
+    2.00 
+    4.00 
+--------
+    3.00 
+    6.00 
+--------
+--------
+Loop with index and IF and END IF condition based on index
+--------
+    2.00 
+    4.00 
+--------
+--------
+--------
+Loop with no conditions
+    1.00 
+--------
+    2.00 
+    4.00 
+--------
+    3.00 
+    6.00 
+--------
+    4.00 
+--------
 EOF
 if [ $? -ne 0 ] ; then fail ; fi