[Bug fortran/95613] New: ICE in main_block_label, at tree-cfg.c:1455

[Bug fortran/95613] New: ICE in main_block_label, at tree-cfg.c:1455

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

            Bug ID: 95613
           Summary: ICE in main_block_label, at tree-cfg.c:1455
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Affects versions down to at least r5 :


$ cat z1.f90
program p
   select case (0)
 2 end select
   goto 2
end


$ cat z2.f90
program p
   select case (0)
 2 end select
   stop
   goto 2
end


$ cat z3.f90
program p
   select case (0)
   case (2:1)
 2    stop
   end select
   goto 2
end


$ cat z4.f90
program p
   select case (0)
   case (2:1)
      2 stop
   case (3)
      goto 2
   end select
end


$ gfortran-11-20200607 -c z1.f90
z1.f90:3:2:

    3 |  2 end select
      |  1
    4 |    goto 2
      |         2
Warning: Legacy Extension: Label at (1) is not in the same block as the GOTO
statement at (2)
during GIMPLE pass: cfg
z1.f90:1:0:

    1 | program p
      |
internal compiler error: Segmentation fault
0xbc593f crash_signal
        ../../gcc/toplev.c:328
0xbf6d3b main_block_label
        ../../gcc/tree-cfg.c:1455
0xbf7271 cleanup_dead_labels()
        ../../gcc/tree-cfg.c:1639
0xc0186b build_gimple_cfg
        ../../gcc/tree-cfg.c:238
0xc0186b execute_build_cfg
        ../../gcc/tree-cfg.c:369
0xc0186b execute
        ../../gcc/tree-cfg.c:405

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-06-09
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Confirmed.

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu.org
           Priority|P3                          |P4

--- Comment #2 from kargl at gcc dot gnu.org ---
Fortran 66 has not been the standard for 54 years.  Time to enforce numbered
constraints in the Fortran 2018 (and older) standard.

Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c       (revision 280157)
+++ gcc/fortran/resolve.c       (working copy)
@@ -10193,12 +10200,16 @@ resolve_branch (gfc_st_label *label, gfc_code *code)
       return;
     }

-  /* The label is not in an enclosing block, so illegal.  This was
-     allowed in Fortran 66, so we allow it as extension.  No
-     further checks are necessary in this case.  */
-  gfc_notify_std (GFC_STD_LEGACY, "Label at %L is not in the same block "
-                 "as the GOTO statement at %L", &label->where,
-                 &code->loc);
+  /* F2018: C1169 (R1157) The label shall be the statement label of a
+     branch target statement that appears in the same inclusive scope
+     as the goto-stmt.
+
+     F2018: C1170 (R1158) Each label in label-list shall be the statement
+     label of a branch target statement that appears in the same inclusive
+     scope as the computed-goto-stmt.  */
+
+  gfc_error ("Label at %L is not in the same block as the GOTO statement "
+            "at %L", &label->where, &code->loc);
   return;
 }

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

--- Comment #3 from G. Steinmetz <gscfq@t-online.de> ---

And for the sake of completeness, with another incarnation of goto :

$ cat zz2.f90   # etc.
program p
   select case (0)
 2 end select
   stop
   call s(*2)
end

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

kargl at gcc dot gnu.org changed:

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

--- Comment #4 from kargl at gcc dot gnu.org ---
Created attachment 55207
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55207&action=edit
testcase 1

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

--- Comment #5 from kargl at gcc dot gnu.org ---
Created attachment 55208
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55208&action=edit
testcase 2

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

--- Comment #6 from kargl at gcc dot gnu.org ---
Created attachment 55209
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55209&action=edit
testcase 3

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

--- Comment #7 from kargl at gcc dot gnu.org ---
Created attachment 55210
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55210&action=edit
testcase 4

[Bug fortran/95613] ICE in main_block_label, at tree-cfg.c:1455

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95613

--- Comment #8 from kargl at gcc dot gnu.org ---
Created attachment 55211
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55211&action=edit
patch that fixes bug