[Bug fortran/44602] New: [F2008] EXIT: Jump to end of construct

[Bug fortran/44602] New: [F2008] EXIT: Jump to end of construct

[burnus at gcc dot gnu dot org]

Fortran 2003 only had:
   R844 exit-stmt is EXIT [ do-construct-name ]
while Fortran 2008 (FDIS) has:
   R850 exit-stmt is EXIT [ construct-name ]

While with "EXIT" one only exits the innermost construct, F2008 also allows to
exit other constructs; looking at 8.1 one finds the following constructs:
- ASSOCIATE
- BLOCK
- CRITICAL
- DO
- IF
- SELECT CASE
- SELECT TYPE

of which in CRITICAL and DO CONCURRENT it is invalid to jump to their construct
label (or outside the construct) cf. C845. This is already checked for
CRITICAL.


-- 
           Summary: [F2008] EXIT: Jump to end of construct
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602

[Bug fortran/44602] [F2008] EXIT: Jump to end of construct

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2010-06-20 20:52 -------
See below for a match.c patch. However, it will fail as the labels are not
available. In principle, one just needs to add:

  tree exit_label;
  /* The exit label.  */
  exit_label = gfc_build_label_decl (NULL_TREE);
  code->block->backend_decl = tree_cons (NULL, exit_label, NULL);
  stmt = build1_v (LABEL_EXPR, exit_label);
  gfc_add_expr_to_block (&if_se.pre, stmt);

to all constructs (in trans-stmt.c) as then trans_exit's

  exit_label = TREE_VALUE (code->ext.whichloop->backend_decl);

would work. However, this fails for instance for the IF block as there
"code->block" is only available if an ELSE branch exists.


Index: match.c
===================================================================
--- match.c     (Revision 161045)
+++ match.c
@@ -2034,6 +2034,13 @@ match_exit_cycle
                  gfc_ascii_statement (st));
        return MATCH_ERROR;
       }
+    else if (sym == p->sym)
+      {
+       if (gfc_notify_std (GFC_STD_F2008, "Fortran 2008: EXIT with no "
+                           "do-construct-name at %C") == FAILURE)
+         return MATCH_ERROR;
+       break;
+      }

   if (p == NULL)
     {
@@ -2041,7 +2048,7 @@
        gfc_error ("%s statement at %C is not within a loop",
                   gfc_ascii_statement (st));
       else
-       gfc_error ("%s statement at %C is not within loop '%s'",
+       gfc_error ("%s statement at %C is not within construct '%s'",
                   gfc_ascii_statement (st), sym->name);

       return MATCH_ERROR;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602

[Bug fortran/44602] [F2008] EXIT: Jump to end of construct

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2010-06-21 07:41 -------
+    else if (sym == p->sym)

One should check that this does the right thing for
  do
    block
      exit
    end block
  end do
as this should leave the DO construct and not only the BLOCK construct (to be
compatible with older Fortran standard, where EXIT was relative to DO).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602

[Bug fortran/44602] [F2008] EXIT: Jump to end of construct

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2010-07-23 08:55 -------
PR 44709 comment 0 contains a small test case, which also applies here.

(That PR fixed "exit loop_label" in BLOCK and try-finally cleanup in BLOCK.)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602

[Bug fortran/44602] [F2008] EXIT: Jump to end of construct

[domob at gcc dot gnu dot org]

------- Comment #4 from domob at gcc dot gnu dot org  2010-08-30 12:07 -------
Mine.


-- 

domob at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |domob at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-08-30 12:07:54
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602

[Bug fortran/44602] [F2008] EXIT: Jump to end of construct

[domob at gcc dot gnu dot org]

------- Comment #5 from domob at gcc dot gnu dot org  2010-08-30 18:27 -------
Experimental patch here: http://gcc.gnu.org/ml/fortran/2010-08/msg00456.html

It seems to do what it is supposed to (basically) and also runs the full
test-case of PR 44709 comment 0, but there seems to be at least one regression
to work out.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602

[Bug fortran/44602] [F2008] EXIT: Jump to end of construct

[domob at gcc dot gnu dot org]

------- Comment #6 from domob at gcc dot gnu dot org  2010-09-03 08:02 -------
Subject: Bug 44602

Author: domob
Date: Fri Sep  3 08:01:51 2010
New Revision: 163798

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=163798
Log:
2010-09-03  Daniel Kraft  <d@domob.eu>

        PR fortran/44602
        * gfortran.h (struct gfc_code): Renamed `whichloop' to
        `which_construct' as this is no longer restricted to loops.
        * parse.h (struct gfc_state_data): New field `construct'.
        * match.c (match_exit_cycle): Handle EXIT from non-loops.
        * parse.c (push_state): Set `construct' field.
        * resolve.c (resolve_select_type): Extend comment.
        * trans-stmt.c (gfc_trans_if): Add exit label.
        (gfc_trans_block_construct), (gfc_trans_select): Ditto.
        (gfc_trans_simple_do): Store exit/cycle labels on the gfc_code itself.
        (gfc_trans_do), (gfc_trans_do_while): Ditto.
        (gfc_trans_exit): Use new name `which_construct' instead of
`whichloop'.
        (gfc_trans_cycle): Ditto.
        (gfc_trans_if_1): Use fold_build3_loc instead of fold_build3.

2010-09-03  Daniel Kraft  <d@domob.eu>

        PR fortran/44602
        * gfortran.dg/exit_2.f08; Adapt error messages.
        * gfortran.dg/exit_3.f08: New test.
        * gfortran.dg/exit_4.f08: New test.
        * gfortran.dg/exit_5.f03: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/exit_3.f08
    trunk/gcc/testsuite/gfortran.dg/exit_4.f08
    trunk/gcc/testsuite/gfortran.dg/exit_5.f03
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/match.c
    trunk/gcc/fortran/parse.c
    trunk/gcc/fortran/parse.h
    trunk/gcc/fortran/resolve.c
    trunk/gcc/fortran/trans-stmt.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/exit_2.f08


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602

[Bug fortran/44602] [F2008] EXIT: Jump to end of construct

[domob at gcc dot gnu dot org]

------- Comment #7 from domob at gcc dot gnu dot org  2010-09-03 08:04 -------
Fixed.


-- 

domob at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44602