Re: [PATCH] gdb: Preserve the operand type in DW_OP_plus_uconst

[Tom Tromey <tom@tromey.com>]

>>>>> Jielun Wu <firmiana402@gmail.com> writes:

> DWARF v5 requires DW_OP_plus_uconst to interpret its unsigned LEB128
> constant as the type of the popped stack entry and push a result of that
> same type.  GDB instead reconstructs the result using address_type,
> discarding an explicit base type.

> Construct the result using the popped value's type.

Thank you for the patch.

> +		DW_AT_location {
> +		    variable _constants
> +		    variable _cu_label
> +
> +		    _op .byte $_constants(DW_OP_const_type)
> +		    _op .uleb128 "$uint32_label - $_cu_label" \
> +			"base type DIE offset"
> +		    _op .byte 4 "constant size"
> +		    _op .4byte 40 "constant data"
> +		    DW_OP_plus_uconst 1
> +		    _op .byte $_constants(DW_OP_const_type)
> +		    _op .uleb128 "$uint32_label - $_cu_label" \
> +			"base type DIE offset"
> +		    _op .byte 4 "constant size"
> +		    _op .4byte 1 "constant data"

I think it would be better to implement direct support for
DW_OP_const_type in dwarf.exp and move this logic there.

The new proc could require a label, which I think is already done in
some cases, e.g., DW_OP_GNU_variable_value.

thanks,
Tom