[Bug fortran/56852] New: ICE on invalid: "Bad array reference" for an undeclared loop variable

[Bug fortran/56852] New: ICE on invalid: "Bad array reference" for an undeclared loop variable

[bugs at stellardeath dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

             Bug #: 56852
           Summary: ICE on invalid: "Bad array reference" for an
                    undeclared loop variable
    Classification: Unclassified
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: bugs@stellardeath.org


Created attachment 29811
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29811
Minimal testcase, invalid code, uncomment line 4 to make it valid (and compile)

The following (invalid code) example produces an internal error, hit this with
4.7.2, seems to also affect my self-compiled 4.9.0 (which is used in the
following transcript).

The only thing remotely similar I could find is #55172, which however seems to
involve OOP.

If I declare "i" as integer to make the code valid, it compiles flawlessly.

Here the transcript, minimal.f90 is also appended as attachment:

$> cat minimal.f90
program test
  implicit none
  real :: a(4)
  ! integer :: i
  read(0) (a(i),i=1,4)
end program
$> gfortran minimal.f90 
minimal.f90:5.14:

  read(0) (a(i),i=1,4)
              1
Error: Symbol 'i' at (1) has no IMPLICIT type
minimal.f90:1.12:

program test
            1
Internal Error at (1):
gfc_variable_attr(): Bad array reference
$> gfortran --version
GNU Fortran (GCC) 4.9.0 20130405 (experimental)
Copyright (C) 2013 Free Software Foundation, Inc.

GNU Fortran comes with NO WARRANTY, to the extent permitted by law.
You may redistribute copies of GNU Fortran
under the terms of the GNU General Public License.
For more information about these matters, see the file named COPYING

$>

[Bug fortran/56852] [4.6/4.7/4.8/4.9 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-04-06
            Summary|ICE on invalid: "Bad array  |[4.6/4.7/4.8/4.9
                   |reference" for an           |Regression] ICE on invalid:
                   |undeclared loop variable    |"Bad array reference" for
                   |                            |an undeclared loop variable
     Ever Confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2013-04-06 09:33:10 UTC ---
Confirmed. Revision 164285 (2010-09-14) gives the error

pr56852.f90:5.14:

  read(0) (a(i),i=1,4)
              1
Error: Symbol 'i' at (1) has no IMPLICIT type

without ICE. Revision 164728 (2010-09-29) gives the same error plus the ICE

program test
            1
Internal Error at (1):
gfc_variable_attr(): Bad array reference

Backtrace for revision 197238

#0  gfc_variable_attr (expr=0x141a141d0, ts=0x0) at
../../_clean/gcc/fortran/primary.c:2135
#1  0x00000001000863b0 in gfc_expr_attr (e=<value optimized out>) at
../../_clean/gcc/fortran/primary.c:2267
#2  0x000000010003c5f9 in gfc_check_vardef_context (e=0x141a141d0,
pointer=false, alloc_obj=<value optimized out>, own_scope=<value optimized
out>, 
    context=0x100b3949f "item in READ") at ../../_clean/gcc/fortran/expr.c:4706
#3  0x000000010009cc2d in resolve_code (code=<value optimized out>, ns=<value
optimized out>) at ../../_clean/gcc/fortran/resolve.c:8150
#4  0x000000010009a90c in gfc_resolve_blocks (b=<value optimized out>,
ns=<value optimized out>) at ../../_clean/gcc/fortran/resolve.c:8885
#5  0x000000010009adc2 in resolve_code (code=<value optimized out>, ns=<value
optimized out>) at ../../_clean/gcc/fortran/resolve.c:9557
#6  0x000000010009a90c in gfc_resolve_blocks (b=<value optimized out>,
ns=<value optimized out>) at ../../_clean/gcc/fortran/resolve.c:8885
#7  0x000000010009adc2 in resolve_code (code=<value optimized out>, ns=<value
optimized out>) at ../../_clean/gcc/fortran/resolve.c:9557
#8  0x000000010009dab4 in resolve_codes (ns=<value optimized out>) at
../../_clean/gcc/fortran/resolve.c:14411
#9  0x000000010008e1bd in gfc_resolve (ns=<value optimized out>) at
../../_clean/gcc/fortran/resolve.c:14439
#10 0x00000001000825db in gfc_parse_file () at
../../_clean/gcc/fortran/parse.c:4399
#11 0x00000001000c25c6 in gfc_be_parse_file () at
../../_clean/gcc/fortran/f95-lang.c:189
#12 0x000000010076ce94 in compile_file () at ../../_clean/gcc/toplev.c:543
#13 0x000000010076ef69 in toplev_main (argc=2, argv=0x7fff5fbfd7c8) at
../../_clean/gcc/toplev.c:1864
#14 0x0000000100009b54 in start (pc=<value optimized out>, bases=0x0) at
../../../_clean/libgcc/config/unwind-dw2-fde-darwin.c:272

[Bug fortran/56852] [4.6/4.7/4.8/4.9 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[mikael at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Mikael Morin <mikael at gcc dot gnu.org> changed:

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

--- Comment #3 from Mikael Morin <mikael at gcc dot gnu.org> 2013-04-07 11:47:58 UTC ---
There is a simple fix, may be too big hammer:

diff --git a/resolve.c b/resolve.c
index 835b57f..0b44c98 100644
--- a/resolve.c
+++ b/resolve.c
@@ -14426,6 +14426,7 @@ gfc_resolve (gfc_namespace *ns)
 {
   gfc_namespace *old_ns;
   code_stack *old_cs_base;
+  int errors;

   if (ns->resolved)
     return;
@@ -14435,6 +14436,9 @@ gfc_resolve (gfc_namespace *ns)
   old_cs_base = cs_base;

   resolve_types (ns);
+  gfc_get_errors (NULL, &errors);
+  if (errors > 0)
+    return;
   component_assignment_level = 0;
   resolve_codes (ns);

[Bug fortran/56852] [4.7/4.8/4.9 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
   Target Milestone|---                         |4.7.4

[Bug fortran/56852] [4.7/4.8/4.9/4.10 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.7.4                       |4.8.4

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
The 4.7 branch is being closed, moving target milestone to 4.8.4.

[Bug fortran/56852] [4.8/4.9/5 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.4                       |4.8.5

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.

[Bug fortran/56852] [4.8/4.9/5 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

--- Comment #6 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> There is a simple fix, may be too big hammer:
> ...

The patch in comment 3 fixes the ICE, bur breaks many tests (700+) for error:

FAIL: gfortran.dg/abstract_type_3.f03   -O   (test for errors, line 44)
FAIL: gfortran.dg/abstract_type_6.f03   -O   (test for errors, line 43)
FAIL: gfortran.dg/advance_3.f90   -O   (test for errors, line 8)
FAIL: gfortran.dg/alloc_comp_constraint_1.f90   -O   (test for errors, line 18)
FAIL: gfortran.dg/alloc_comp_constraint_1.f90   -O   (test for errors, line 20)
FAIL: gfortran.dg/allocate_alloc_opt_1.f90   -O   (test for errors, line 19)
...

[Bug fortran/56852] [4.8/4.9/5 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pault at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |pault at gcc dot gnu.org

--- Comment #7 from Paul Thomas <pault at gcc dot gnu.org> ---
Posted patch on list

[Bug fortran/56852] [4.8/4.9/5/6 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.5                       |4.9.3

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
The gcc-4_8-branch is being closed, re-targeting regressions to 4.9.3.

[Bug fortran/56852] [4.9/5/6 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.9.3 has been released.

[Bug fortran/56852] [4.9/5/6 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.9.3                       |4.9.4

[Bug fortran/56852] [4.9 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.9/5 Regression] ICE on   |[4.9 Regression] ICE on
                   |invalid: "Bad array         |invalid: "Bad array
                   |reference" for an           |reference" for an
                   |undeclared loop variable    |undeclared loop variable

--- Comment #11 from Paul Thomas <pault at gcc dot gnu.org> ---
I have just applied the patch to the 4.9 tree and, if it regtests OK, I will
commit tonight.

Paul

[Bug fortran/56852] [4.9 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

--- Comment #12 from Paul Thomas <pault at gcc dot gnu.org> ---
Author: pault
Date: Mon Oct 19 19:32:52 2015
New Revision: 229000

URL: https://gcc.gnu.org/viewcvs?rev=229000&root=gcc&view=rev
Log:
2013-10-19  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/56852
        * primary.c (gfc_variable_attr): Avoid ICE on AR_UNKNOWN if any
        of the index variables are untyped and errors are present.

2013-10-19  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/56852
        * gfortran.dg/pr56852.f90 : New test

Added:
    branches/gcc-4_9-branch/gcc/testsuite/gfortran.dg/pr56852.f90
Modified:
    branches/gcc-4_9-branch/gcc/fortran/ChangeLog
    branches/gcc-4_9-branch/gcc/fortran/primary.c
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog

[Bug fortran/56852] [4.9 Regression] ICE on invalid: "Bad array reference" for an undeclared loop variable

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56852

Paul Thomas <pault at gcc dot gnu.org> changed:

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

--- Comment #13 from Paul Thomas <pault at gcc dot gnu.org> ---
Sorry about the long delay in closing this PR. I have been heavily distracted
by the likes of submodules.

Thanks for the report.

Paul