[Bug fortran/66039] New: ICE on incomplete parentheses at rewind, flush, endfile, backspace

[Bug fortran/66039] New: ICE on incomplete parentheses at rewind, flush, endfile, backspace

[gerhard.steinmetz.fortran@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66039

            Bug ID: 66039
           Summary: ICE on incomplete parentheses at rewind, flush,
                    endfile, backspace
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gerhard.steinmetz.fortran@t-online.de
  Target Milestone: ---

Created attachment 35483
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35483&action=edit
more code variants

An ICE occurs with incomplete parentheses at rewind, flush, endfile, backspace.
For example :

   program p
      flush ((
   end

Tested with gfortran -c, versions 4.8.3, 4.9.0, 5.1.1
on SUSE Linux 13.2 (64 bit)

The attachement contains more disrupting variants for rewind, flush, endfile,
backspace.
Interestingly, for that variants there are no ICEs for the statement wait.

Kind regards.

[Bug fortran/66039] ICE on incomplete parentheses at rewind, flush, endfile, backspace

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66039

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-05-06
                 CC|                            |kargl at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from kargl at gcc dot gnu.org ---
Confirmed.

In io.c(gfc_resolve_filepos), the pointer fp->unit is
dereferenced without checking to see if it is NULL.

The issue appears come from match_filepos() where a
condition on checking for a valid expr is not correctly
checked.

Index: io.c
===================================================================
--- io.c        (revision 222724)
+++ io.c        (working copy)
@@ -2382,9 +2382,7 @@ match_filepos (gfc_statement st, gfc_exe
   if (m == MATCH_NO)
     {
       m = gfc_match_expr (&fp->unit);
-      if (m == MATCH_ERROR)
-       goto done;
-      if (m == MATCH_NO)
+      if (m == MATCH_ERROR || m == MATCH_NO)
        goto syntax;
     }

The old 'goto done' in the above patch, branches to a portion of
the code that looks for an end-of-statement,which is found.  Bad
things then ensue.  The above patch appears to fix ICE for the
program in comment #1.

                === gfortran Summary ===

# of expected passes            48475
# of unexpected failures        8
# of unexpected successes       8
# of expected failures          71
# of unresolved testcases       8
# of unsupported tests          70
/mnt/sgk/gcc/obj6/gcc/testsuite/gfortran/../../gfortran  version 6.0.0 20150502
(experimental) (GCC) 

PS: 'unexpected failures' are all related to gfortran.dg/static_linking_1.f

[Bug fortran/66039] ICE on incomplete parentheses at rewind, flush, endfile, backspace

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66039

--- Comment #2 from kargl at gcc dot gnu.org ---
Author: kargl
Date: Mon May 18 21:04:33 2015
New Revision: 223315

URL: https://gcc.gnu.org/viewcvs?rev=223315&root=gcc&view=rev
Log:
2015-05-18  Steven G. Kargl  <kargl@gcc.gnu.org>

        PR fortran/66039
        * io.c (match_filepos): Check for incomplete/mangled REWIND, FLUSH,
        BACKSPACE, and ENDFILE statements

2015-05-18  Steven G. Kargl  <kargl@gcc.gnu.org>

        PR fortran/66039
        * gfortran.dg/filepos1.f90: New test

Added:
    trunk/gcc/testsuite/gfortran.dg/filepos1.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/io.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/66039] ICE on incomplete parentheses at rewind, flush, endfile, backspace

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66039

--- Comment #3 from kargl at gcc dot gnu.org ---
Author: kargl
Date: Tue May 19 17:13:02 2015
New Revision: 223390

URL: https://gcc.gnu.org/viewcvs?rev=223390&root=gcc&view=rev
Log:
2015-05-19  Steven G. Kargl  <kargl@gcc.gnu.org>

        PR fortran/66039
        * io.c (match_filepos): Check for incomplete/mangled REWIND, FLUSH,
        BACKSPACE, and ENDFILE statements

2015-05-19  Steven G. Kargl  <kargl@gcc.gnu.org>

        PR fortran/66039
        * gfortran.dg/filepos1.f90: New test

Added:
    branches/gcc-5-branch/gcc/testsuite/gfortran.dg/filepos1.f90
Modified:
    branches/gcc-5-branch/gcc/fortran/ChangeLog
    branches/gcc-5-branch/gcc/fortran/io.c
    branches/gcc-5-branch/gcc/testsuite/ChangeLog

[Bug fortran/66039] ICE on incomplete parentheses at rewind, flush, endfile, backspace

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66039

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |5.2

--- Comment #4 from kargl at gcc dot gnu.org ---
Fixed on trunk and 5-branch.  Thanks for the bug report.