[Bug fortran/104211] New: ICE in find_array_section, at fortran/expr.cc:1720

[Bug fortran/104211] New: ICE in find_array_section, at fortran/expr.cc:1720

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104211

            Bug ID: 104211
           Summary: ICE in find_array_section, at fortran/expr.cc:1720
           Product: gcc
           Version: 12.0
            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
   type t
      real :: n
   end type
   type(t), parameter :: a(3) = [t(2)]
   type(t), parameter :: b(2) = a(2:3)
end


$ cat z2.f90
program p
   type t
      real :: n
   end type
   type(t), parameter :: a(3) = [t(2)]
   type(t), parameter :: b(2) = [a(2:3)]
end


$ gfortran-12-20220123 -c z1.f90
f951: internal compiler error: in find_array_section, at fortran/expr.cc:1720
0x6f0d75 find_array_section
        ../../gcc/fortran/expr.cc:1720
0x6f231a simplify_const_ref
        ../../gcc/fortran/expr.cc:1925
0x6f2e4e gfc_simplify_expr(gfc_expr*, int)
        ../../gcc/fortran/expr.cc:2316
0x6f30bb simplify_parameter_variable
        ../../gcc/fortran/expr.cc:2145
0x6f2007 gfc_reduce_init_expr(gfc_expr*)
        ../../gcc/fortran/expr.cc:3156
0x6f4f70 gfc_match_init_expr(gfc_expr**)
        ../../gcc/fortran/expr.cc:3202
0x6df324 variable_decl
        ../../gcc/fortran/decl.cc:3004
0x6df324 gfc_match_data_decl()
        ../../gcc/fortran/decl.cc:6299
0x749933 match_word
        ../../gcc/fortran/parse.cc:67
0x749933 decode_statement
        ../../gcc/fortran/parse.cc:378
0x74b37a next_free
        ../../gcc/fortran/parse.cc:1397
0x74b37a next_statement
        ../../gcc/fortran/parse.cc:1629
0x74c90b parse_spec
        ../../gcc/fortran/parse.cc:4168
0x74fa5c parse_progunit
        ../../gcc/fortran/parse.cc:6192
0x751121 gfc_parse_file()
        ../../gcc/fortran/parse.cc:6737
0x79e86f gfc_be_parse_file
        ../../gcc/fortran/f95-lang.cc:216

[Bug fortran/104211] ICE in find_array_section, at fortran/expr.cc:1720

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104211

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2022-01-24
           Priority|P3                          |P4
                 CC|                            |anlauf at gcc dot gnu.org
     Ever confirmed|0                           |1

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

We hit an assert which can be replaced by an error message, such as:

diff --git a/gcc/fortran/expr.cc b/gcc/fortran/expr.cc
index ed82a94022f..78f21c24f43 100644
--- a/gcc/fortran/expr.cc
+++ b/gcc/fortran/expr.cc
@@ -1718,7 +1718,12 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
        }

       cons = gfc_constructor_lookup (base, limit);
-      gcc_assert (cons);
+      if (cons == NULL)
+       {
+         gfc_error ("Bad array constructor at %L", &ref->u.ar.where);
+         t = false;
+         goto cleanup;
+       }
       gfc_constructor_append_expr (&expr->value.constructor,
                                   gfc_copy_expr (cons->expr), NULL);
     }

[Bug fortran/104211] ICE in find_array_section, at fortran/expr.cc:1720

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104211

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |anlauf at gcc dot gnu.org

--- Comment #2 from anlauf at gcc dot gnu.org ---
Submitted: https://gcc.gnu.org/pipermail/fortran/2022-February/057535.html

[Bug fortran/104211] ICE in find_array_section, at fortran/expr.cc:1720

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104211

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Harald Anlauf <anlauf@gcc.gnu.org>:

https://gcc.gnu.org/g:19b517dff37b8e25f6babf8883483be73cad8fb3

commit r12-7232-g19b517dff37b8e25f6babf8883483be73cad8fb3
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Thu Feb 10 21:22:48 2022 +0100

    Fortran: improve error recovery on bad array section

    gcc/fortran/ChangeLog:

            PR fortran/104211
            * expr.cc (find_array_section): Replace assertion by error
            recovery when encountering bad array constructor.

    gcc/testsuite/ChangeLog:

            PR fortran/104211
            * gfortran.dg/pr104211.f90: New test.

[Bug fortran/104211] ICE in find_array_section, at fortran/expr.cc:1720

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104211

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Harald Anlauf
<anlauf@gcc.gnu.org>:

https://gcc.gnu.org/g:3982a308e669cc5537322c83e8c2d49b0144297e

commit r11-9579-g3982a308e669cc5537322c83e8c2d49b0144297e
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Thu Feb 10 21:22:48 2022 +0100

    Fortran: improve error recovery on bad array section

    gcc/fortran/ChangeLog:

            PR fortran/104211
            * expr.c (find_array_section): Replace assertion by error
            recovery when encountering bad array constructor.

    gcc/testsuite/ChangeLog:

            PR fortran/104211
            * gfortran.dg/pr104211.f90: New test.

    (cherry picked from commit 19b517dff37b8e25f6babf8883483be73cad8fb3)

[Bug fortran/104211] ICE in find_array_section, at fortran/expr.cc:1720

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104211

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |11.3

--- Comment #5 from anlauf at gcc dot gnu.org ---
Fixed on mainline and applied to 11-branch.  Closing.

Thanks for the report!