[Bug fortran/50392] New: SIGSEGV in gfc_trans_label_assign

[Bug fortran/50392] New: SIGSEGV in gfc_trans_label_assign

[zeccav at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

             Bug #: 50392
           Summary: SIGSEGV in gfc_trans_label_assign
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zeccav@gmail.com


Created attachment 25268
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25268
just compile it

SIGSEGV in gfc_trans_label_assign

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-09-14
     Ever Confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-09-14 09:46:41 UTC ---
Confirmed on gfortran 4.4.6, 4.5.3, 4.6.1, and trunk (r178842). The backtrace
is

pr50392.f90:3.20:

      assign 1 to kf
                    1
Warning: Deleted feature: ASSIGN statement at (1)
 kf
Program received signal SIGSEGV, Segmentation fault.
gfc_trans_label_assign (code=<value optimized out>) at
../../work/gcc/fortran/trans-stmt.c:107
107      len = GFC_DECL_STRING_LEN (se.expr);
(gdb) bt
#0  gfc_trans_label_assign (code=<value optimized out>) at
../../work/gcc/fortran/trans-stmt.c:107
#1  0x00000001000b4d48 in trans_code (code=<value optimized out>, cond=<value
optimized out>) at ../../work/gcc/fortran/trans.c:1204
#2  0x00000001000dbb64 in gfc_generate_function_code (ns=<value optimized out>)
at ../../work/gcc/fortran/trans-decl.c:5211
#3  0x0000000100072f5d in gfc_parse_file () at
../../work/gcc/fortran/parse.c:4404
#4  0x00000001000af786 in gfc_be_parse_file () at
../../work/gcc/fortran/f95-lang.c:250
#5  0x00000001007b72bc in toplev_main (argc=2, argv=0x7fff5fbfdc08) at
../../work/gcc/toplev.c:548
#6  0x0000000100001974 in start ()

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-09-14 10:42:55 UTC ---
The code looks valid (Fortran 90) to me. Except that "kf" needs to be
re-defined before returning from the function.


>From Fortran 95's deleted section:

"B.1.4 ASSIGN, assigned GO TO, and assigned FORMAT"
"The definitions of the ASSIGN and assigned GO TO statements are:
   assign-stmt is ASSIGN label TO scalar-int-variable
 Constraint: The label shall be the statement label of a branch target
   statement or format-stmt that appears in the same scoping unit as the
   assign-stmt.
 Constraint: scalar-int-variable shall be named and of type default integer.
[...]
"Execution of an ASSIGN statement causes a statement label to be assigned to an
integer variable. While defined with a statement label value, the integer
variable may be referenced only in the context of an assigned GO TO statement
or as a format specifier in an input/output statement. An integer variable
defined with a statement label value may be redefined with a statement label
value or an integer value."

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-09-14 16:08:16 UTC ---
Patch:

--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -1264,9 +1265,7 @@ gfc_get_symbol_decl (gfc_symbol * sym)

       TREE_USED (sym->backend_decl) = 1;
       if (sym->attr.assign && GFC_DECL_ASSIGN (sym->backend_decl) == 0)
-       {
-         gfc_add_assign_aux_vars (sym);
-       }
+       gfc_add_assign_aux_vars (sym);

       if (sym->attr.dimension
          && DECL_LANG_SPECIFIC (sym->backend_decl)
@@ -1277,6 +1276,10 @@ gfc_get_symbol_decl (gfc_symbol * sym)
       return sym->backend_decl;
     }

+  if (sym->result == sym && sym->attr.assign
+      && GFC_DECL_ASSIGN (sym->backend_decl) == 0)
+    gfc_add_assign_aux_vars (sym);
+
   if (sym->backend_decl)
     return sym->backend_decl;

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-09-14 16:40:08 UTC ---
(In reply to comment #3)
> Patch:

I have accidentally submitted the patch before testing finished. It does not
work. The problem is that it does create the required declaration - but it does
not get used as one later calls  gfc_get_fake_result_decl, which does not
propagate this information on.

That's fixed by applying additionally the following patch, which feels slightly
hackish.

--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -2557,6 +2561,9 @@ gfc_get_fake_result_decl (gfc_symbol * sym, int
parent_flag)
   else
     current_fake_result_decl = build_tree_list (NULL, decl);

+  if (sym->attr.assign)
+    DECL_LANG_SPECIFIC (decl) = DECL_LANG_SPECIFIC (sym->backend_decl);
+
   return decl;
 }


... maybe by moving the  gfc_add_assign_aux_vars  to gfc_get_fake_result_decl -
like below?

@@ -2501,6 +2501,10 @@ gfc_get_fake_result_decl (gfc_symbol * sym, int
parent_flag)
   if (!sym)
     return NULL_TREE;

+  if (sym->attr.assign
+      && GFC_DECL_ASSIGN (sym->backend_decl) == 0)
+    gfc_add_assign_aux_vars (sym);
+
   if (sym->ts.type == BT_CHARACTER)
     {
       if (sym->ts.u.cl->backend_decl == NULL_TREE)

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu.org

--- Comment #5 from kargl at gcc dot gnu.org 2011-09-14 17:10:59 UTC ---
(In reply to comment #4)
> (In reply to comment #3)
> > Patch:
> 
> I have accidentally submitted the patch before testing finished. It does not
> work. The problem is that it does create the required declaration - but it does
> not get used as one later calls  gfc_get_fake_result_decl, which does not
> propagate this information on.
> 
> That's fixed by applying additionally the following patch, which feels slightly
> hackish.

Just a FYI.  The following code works with the current gfortran.

      function kf() result(j)
      assign 3 to j
3     continue
      j = 3
      end

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[zeccav at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

Vittorio Zecca <zeccav at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|4.7.0                       |4.8.0

--- Comment #6 from Vittorio Zecca <zeccav at gmail dot com> 2013-04-16 08:51:08 UTC ---
I still have the same bug on gfortran 4.8.0.

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[zeccav at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #7 from Vittorio Zecca <zeccav at gmail dot com> ---
Still in gfortran 4.8.1.
In trans-stmt.c:105
"  len = GFC_DECL_STRING_LEN (se.expr);" 
the pointer se.expr->decl_common.lang_specific is NULL.
Thus causing the segmentation fault.

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #18 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Mark Eggleston
<markeggleston@gcc.gnu.org>:

https://gcc.gnu.org/g:a7fd43c38f7469a3ef5ee30e889d60e1376d4dfc

commit r11-665-ga7fd43c38f7469a3ef5ee30e889d60e1376d4dfc
Author: Mark Eggleston <markeggleston@gcc.gnu.org>
Date:   Thu May 7 08:15:26 2020 +0100

    Fortran  : ICE in gfc_trans_label_assign PR50392

    A function may contain an assigned goto.  If the the return variable
    is an integer a statement can be assigned to it.  Prior to this fix
    this resulted in an ICE.

    2020-05-27  Tobias Burnus  <tobias@codesourcery.com>

    gcc/fortran/

            PR fortran/50392
            * trans-decl.c (gfc_get_symbol_decl): Remove unnecessary block
            delimiters.  Add auxiliary variables if a label is assigned to
            a return variable. (gfc_gat_fake_result): If the symbol has an
            assign attribute set declaration from the symbol's backend
            declaration.

    2020-05-27  Mark Eggleston  <markeggleston@gnu.gcc.org>

    gcc/testsuite/

            PR fortran/50392
            * gfortran.dg/pr50392.f: New test.

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #19 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Mark Eggleston
<markeggleston@gcc.gnu.org>:

https://gcc.gnu.org/g:4e2c7f9a29c212db4bf428799a2d62f79f392511

commit r10-8196-g4e2c7f9a29c212db4bf428799a2d62f79f392511
Author: Mark Eggleston <markeggleston@gcc.gnu.org>
Date:   Thu May 7 08:15:26 2020 +0100

    Fortran  : ICE in gfc_trans_label_assign PR50392

    A function may contain an assigned goto.  If the the return variable
    is an integer a statement can be assigned to it.  Prior to this fix
    this resulted in an ICE.

    2020-05-28  Tobias Burnus  <tobias@codesourcery.com>

    gcc/fortran/

            PR fortran/50392
            * trans-decl.c (gfc_get_symbol_decl): Remove unnecessary block
            delimiters.  Add auxiliary variables if a label is assigned to
            a return variable. (gfc_gat_fake_result): If the symbol has an
            assign attribute set declaration from the symbol's backend
            declaration.

    2020-05-28  Mark Eggleston  <markeggleston@gnu.gcc.org>

    gcc/testsuite/

            PR fortran/50392
            * gfortran.dg/pr50392.f: New test.

    (cherry picked from commit a7fd43c38f7469a3ef5ee30e889d60e1376d4dfc)

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #20 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Mark Eggleston
<markeggleston@gcc.gnu.org>:

https://gcc.gnu.org/g:c575cd2e0089cf2fcb11ffb7899e5fd472b3780c

commit r9-8631-gc575cd2e0089cf2fcb11ffb7899e5fd472b3780c
Author: Mark Eggleston <markeggleston@gcc.gnu.org>
Date:   Thu May 7 08:15:26 2020 +0100

    Fortran  : ICE in gfc_trans_label_assign PR50392

    A function may contain an assigned goto.  If the the return variable
    is an integer a statement can be assigned to it.  Prior to this fix
    this resulted in an ICE.

    2020-05-28  Tobias Burnus  <tobias@codesourcery.com>

    gcc/fortran/

            PR fortran/50392
            * trans-decl.c (gfc_get_symbol_decl): Remove unnecessary block
            delimiters.  Add auxiliary variables if a label is assigned to
            a return variable. (gfc_gat_fake_result): If the symbol has an
            assign attribute set declaration from the symbol's backend
            declaration.

    2020-05-28  Mark Eggleston  <markeggleston@gnu.gcc.org>

    gcc/testsuite/

            PR fortran/50392
            * gfortran.dg/pr50392.f: New test.

    (cherry picked from commit a7fd43c38f7469a3ef5ee30e889d60e1376d4dfc)

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #21 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-8 branch has been updated by Mark Eggleston
<markeggleston@gcc.gnu.org>:

https://gcc.gnu.org/g:83b84b6ef84ffc0ca25aef5c91720d8f82212a5c

commit r8-10280-g83b84b6ef84ffc0ca25aef5c91720d8f82212a5c
Author: Mark Eggleston <markeggleston@gcc.gnu.org>
Date:   Thu May 7 08:15:26 2020 +0100

    Fortran  : ICE in gfc_trans_label_assign PR50392

    A function may contain an assigned goto.  If the the return variable
    is an integer a statement can be assigned to it.  Prior to this fix
    this resulted in an ICE.

    2020-05-28  Tobias Burnus  <tobias@codesourcery.com>

    gcc/fortran/

            PR fortran/50392
            * trans-decl.c (gfc_get_symbol_decl): Remove unnecessary block
            delimiters.  Add auxiliary variables if a label is assigned to
            a return variable. (gfc_gat_fake_result): If the symbol has an
            assign attribute set declaration from the symbol's backend
            declaration.

    2020-05-28  Mark Eggleston  <markeggleston@gnu.gcc.org>

    gcc/testsuite/

            PR fortran/50392
            * gfortran.dg/pr50392.f: New test.

    (cherry picked from commit a7fd43c38f7469a3ef5ee30e889d60e1376d4dfc)

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[markeggleston at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

markeggleston at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED
                 CC|                            |markeggleston at gcc dot gnu.org

--- Comment #22 from markeggleston at gcc dot gnu.org ---
committed to master and backported

[Bug fortran/50392] SIGSEGV in gfc_trans_label_assign

[zeccav at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50392

--- Comment #23 from Vittorio Zecca <zeccav at gmail dot com> ---
The update proposed in comment #18 fixed the issue.

Thank you!