Re: PR10687 Printing c++ class with static array (of same type) can produce infinite output

["Ulrich Weigand" <uweigand@de.ibm.com>]

Chris Moller wrote:

> +  if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
> +    {
> +      struct type **first_dont_print;
> +      int i;
> +      struct type * target_type = TYPE_TARGET_TYPE (type);
> +
> +      first_dont_print
> +	= (struct type **) obstack_base (&dont_print_stat_array_obstack);
> +      i = obstack_object_size (&dont_print_stat_array_obstack)
> +	/ sizeof (CORE_ADDR);
> +
> +      while (--i >= 0)
> +	{
> +	  if (target_type == first_dont_print[i])
> +	    {
> +	      fputs_filtered ("<same as static member of an already"
> +			      " seen type>",
> +			      stream);
> +	      return;
> +	    }
> +	}
> +
> +      obstack_grow (&dont_print_stat_array_obstack, (char *) &target_type,
> +		    sizeof (struct type *));
> +    }

This is broken on platforms where sizeof (CORE_ADDR) != sizeof (struct type *).
As the objects stored into the dont_print_stat_array_obstack are in fact of
type "struct type *", the size computations also need to use this type's size.

I'm seeing this problem on a spu-elf GDB built as 32-bit PowerPC executable.

Fixed by the patch below.

Tested on spu-elf, committed to mainline.

Bye,
Ulrich


ChangeLog:

	* cp-valprint.c (cp_print_static_field): Members of
	dont_print_stat_array_obstack are of type "struct type *".
	(_initialize_cp_valprint): Likewise.

Index: gdb/cp-valprint.c
===================================================================
RCS file: /cvs/src/src/gdb/cp-valprint.c,v
retrieving revision 1.69
diff -u -p -r1.69 cp-valprint.c
--- gdb/cp-valprint.c	11 Jun 2010 15:36:04 -0000	1.69
+++ gdb/cp-valprint.c	14 Jun 2010 16:03:53 -0000
@@ -615,7 +615,7 @@ cp_print_static_field (struct type *type
       first_dont_print
 	= (struct type **) obstack_base (&dont_print_stat_array_obstack);
       i = obstack_object_size (&dont_print_stat_array_obstack)
-	/ sizeof (CORE_ADDR);
+	/ sizeof (struct type *);
 
       while (--i >= 0)
 	{
@@ -764,7 +764,7 @@ Show printing of object's derived type b
 			   show_objectprint,
 			   &setprintlist, &showprintlist);
 
-  obstack_begin (&dont_print_stat_array_obstack, 32 * sizeof (CORE_ADDR));
+  obstack_begin (&dont_print_stat_array_obstack, 32 * sizeof (struct type *));
   obstack_begin (&dont_print_statmem_obstack, 32 * sizeof (CORE_ADDR));
   obstack_begin (&dont_print_vb_obstack, 32 * sizeof (struct type *));
 }

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com