Re: [PATCH] bitfield-parent-optimized-out: Fix struct definition

[Luis Machado <lgustavo@codesourcery.com>]

On 11/11/2016 01:37 PM, Andreas Arnez wrote:
> The "struct S" type in bitfield-parent-optimized-out.exp is declared to
> have a size of 4 bytes but to hold two 4-byte members: an int-based
> bitfield and a 4-byte int.  Also, both members have the same
> data_member_location 2, causing them to overlap and to reach 2 bytes
> beyond the structure's boundary.
>
> This is fixed by increasing the structure size to 8 and setting the
> first and second member's data_member_location to 0 and 4, respectively.
>
> gdb/testsuite/ChangeLog:
>
> 	* gdb.dwarf2/bitfield-parent-optimized-out.exp: Fix DWARF code for
> 	the definition of struct S.
> ---
>  gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
> index 27d8044..b789970 100644
> --- a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
> +++ b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
> @@ -43,19 +43,18 @@ Dwarf::assemble $asm_file {
>
>  	    struct_label: structure_type {
>  		{name S}
> -		{byte_size 4 DW_FORM_sdata}
> +		{byte_size 8 DW_FORM_sdata}
>  	    } {
>  		member {
>  		    {name bitfield}
>  		    {type :$int_label}
>  		    {bit_size 12 DW_FORM_sdata}
>  		    {bit_offset 20 DW_FORM_sdata}
> -		    {data_member_location 2 DW_FORM_sdata}
>  		}
>  		member {
>  		    {name intfield}
>  		    {type :$int_label}
> -		    {data_member_location 2 DW_FORM_sdata}
> +		    {data_member_location 4 DW_FORM_sdata}
>  		}
>  	    }
>
>

The patch looks good to me, but i'm wondering if Pedro meant for both 
members to overlap (a union) instead of being two separate members?