On 05/28/2015 02:53 PM, Aldy Hernandez wrote:
On 05/27/2015 08:39 AM, Jason Merrill wrote:
On 05/20/2015 11:50 AM, Aldy Hernandez wrote:
+ /* Fill in the size of variable-length fields in late dwarf. */
+ if (TREE_ASM_WRITTEN (type)
+ && !early_dwarf_dumping)
+ {
+ tree member;
+ for (member = TYPE_FIELDS (type); member; member = DECL_CHAIN
(member))
+ fill_variable_array_bounds (TREE_TYPE (member));
+ return;
+ }
Why is this happening in late dwarf? I'm concerned that front-end
information that is necessary to do this might be lost by that point.
I thought only after the optimizations had run their course would we be
guaranteed to have accurate bound information. At least, that's what my
experience showed.
Hmm, I'm don't know why optimizations would change the representation of
the array type.
+ /* Variable-length types may be incomplete even if
+ TREE_ASM_WRITTEN. For such types, fall through to
+ gen_array_type_die() and possibly fill in
+ DW_AT_{upper,lower}_bound attributes. */
+ if ((TREE_CODE (type) != ARRAY_TYPE
+ && TREE_CODE (type) != RECORD_TYPE
+ && TREE_CODE (type) != UNION_TYPE
+ && TREE_CODE (type) != QUAL_UNION_TYPE)
+ || (TYPE_SIZE (type)
+ && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST))
Similarly, why check for INTEGER_CST here?
The INTEGER_CST check was supposed to mean "we have bound information
already, no need to look further".
I guess we could have a variable length bound that does not decay to a
constant.
Right. I would expect that to usually be the case with VLAs.
Perhaps I could check the presence of a cached DIE with a
type DIE containing a DW_TAG_subrange_type *and*
DW_AT_{lower,upper}_bound ??. Basically I just want to add bound
information, if available and not already present.
Suggestions?
I'm still not sure why we can't just emit bound info in early dwarf.
Can you be more specific about the optimization thing?
Jason
