multidimensional arrays compiled by gfortran are not passed as such to gdb

[jiho]

Hello everyone,

With the help of the guys on the #gdb irc channel we found what is  
apparently a bug in gfortran: multidimensional arrays are not  
recognized as such after compilation. Therefore, in gdb, they are  
only viewed as uni-dimensional arrays and debugging becomes very  
difficult.

Let's see the minimal example:

foo.f:
       program foo

       real a(1,2)

       a(1,1)=3.
       a(1,2)=4.
       write(*,*) a(1,1)

       end


Now with gfortran:

$ gfortran --version
GNU Fortran (GCC) 4.1.2 20070626 (Red Hat 4.1.2-13)
[...]
$ gfortran -g foo.f
$ gdb a.out
GNU gdb 6.6
[...]
(gdb) b foo.f:7
Breakpoint 1 at 0x400747: file foo.f, line 7.
(gdb) r
Breakpoint 1, MAIN__ () at foo.f:7
(gdb) p a
$1 = (3, 4)
(gdb) p a(1,2)
Wrong number of subscripts
(gdb) ptype a
type = real*4 (0:1)

and

$ readelf -wi a.out
[...]
  <2><9d>: Abbrev Number: 3 (DW_TAG_variable)
      DW_AT_name        : a
      DW_AT_decl_file   : 1
      DW_AT_decl_line   : 3
      DW_AT_type        : <bb>
      DW_AT_location    : 2 byte block: 91 60    (DW_OP_fbreg: -32)
[...]



While with g77 (or intel fortran for that mater):

$ g77 --version
GNU Fortran (GCC) 3.4.6 20060404 (Red Hat 3.4.6-4)
[...]
$ g77 -g foo.f
$ gdb a.out
GNU gdb 6.6
[...]
(gdb) b foo.f:7
Breakpoint 1 at 0x400890: file foo.f, line 7.
(gdb) r
Breakpoint 1, MAIN__ () at foo.f:7
(gdb) p a
$1 = (( 3) ( 4) )
(gdb) p a(1,2)
$2 = 4
(gdb) ptype a
type = real*4 (1,2)

and

$ readelf -wi a.out
[...]
  <2><9c>: Abbrev Number: 3 (DW_TAG_variable)
      DW_AT_name        : a
      DW_AT_decl_file   : 1
      DW_AT_decl_line   : 3
      DW_AT_type        : <da>
      DW_AT_location    : 2 byte block: 91 60    (DW_OP_fbreg: -32)
[...]


Is this helpful? Does someone see what the problem can be? Should I  
report a bug properly, via bugzilla?
Cheers,

JiHO
---
http://jo.irisson.free.fr/