Re: gdb can't print array element for fortran

[Jan Kratochvil <jan.kratochvil@redhat.com>]

On Tue, 16 Mar 2010 16:16:21 +0100, Joel Brobecker wrote:
> This seems like a reasonable workaround, especially since we already
> have some special handling of attr->form == DW_FORM_block1 for range
> types.  So I guess we never have block2/block4 or even block attributes
> for the upper bound in practice?

* I cannot imagine a case something else than DW_FORM_block1 would be used but
  sure GDB should handled all the DW_FORM_block* cases to be correct.

* The maintained offtrunk patch archer-jankratochvil-vla is using
  attr_form_is_block() for the full DW_FORM_block* support.

* As the existing FSF GDB code was already limited to DW_FORM_block1.

* The new patch code fragment application scope should match the scope of the
  existing FSF GDB code.

* This patch will need to be reverted/merged-out on future import of some form
  of the archer-jankratochvil-vla branch therefore I wanted to minimize any
  effort for its import as it should have been spent rather on preparing
  archer-jankratochvil-vla for the merge instead.

=> Chose the minimal patchset satisfying Chandru's requirements.


> >    range_type = create_range_type (NULL, base_type, low, high);
> >  
> > +  if (attr && attr->form == DW_FORM_block1)
> > +    TYPE_HIGH_BOUND_UNDEFINED (range_type) = 1;
> 
> Can you add a quick comment, with a FIXME to show that this is temporary?
> There's already some useful comments just slightly earlier in the code,
> perhaps we just ought to refer to that, somehow.

Done (forgot the FIXME keyword I see now, sorry).


> Pre-approved with the addition of the comment.

Checked-in.



Thanks,
Jan


http://sourceware.org/ml/gdb-cvs/2010-03/msg00158.html

--- src/gdb/ChangeLog	2010/03/16 18:47:14	1.11491
+++ src/gdb/ChangeLog	2010/03/16 20:51:23	1.11492
@@ -1,3 +1,10 @@
+2010-03-16  Jan Kratochvil  <jan.kratochvil@redhat.com>
+	    Chandru <chandru@in.ibm.com>
+
+	* dwarf2read.c (read_subrange_type): Set TYPE_HIGH_BOUND_UNDEFINED.
+	* valarith.c (value_subscripted_rvalue): Suppress error if
+	TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED.
+
 2010-03-16  Holger Hans Peter Freyther  <zecke@selfish.org>
 
 	* linux-record.c (record_linux_msghdr): Remove unintended semicolons.
--- src/gdb/dwarf2read.c	2010/03/15 20:49:53	1.368
+++ src/gdb/dwarf2read.c	2010/03/16 20:51:23	1.369
@@ -6074,6 +6074,12 @@
 
   range_type = create_range_type (NULL, base_type, low, high);
 
+  /* Mark arrays with dynamic length at least as an array of unspecified
+     length.  GDB could check the boundary but before it gets implemented at
+     least allow accessing the array elements.  */
+  if (attr && attr->form == DW_FORM_block1)
+    TYPE_HIGH_BOUND_UNDEFINED (range_type) = 1;
+
   name = dwarf2_name (die, cu);
   if (name)
     TYPE_NAME (range_type) = name;
--- src/gdb/valarith.c	2010/02/11 21:45:25	1.81
+++ src/gdb/valarith.c	2010/03/16 20:51:23	1.82
@@ -198,7 +198,8 @@
   unsigned int elt_offs = elt_size * longest_to_int (index - lowerbound);
   struct value *v;
 
-  if (index < lowerbound || elt_offs >= TYPE_LENGTH (array_type))
+  if (index < lowerbound || (!TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (array_type)
+			     && elt_offs >= TYPE_LENGTH (array_type)))
     error (_("no such vector element"));
 
   v = allocate_value (elt_type);