Re: [RFA] Fix PR gdb/11702, printing of static const member variables

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Sun, 27 Jun 2010 20:24:42 +0200, Doug Evans wrote:
> btw, the dwarf4 standard, as I read it, says static member variables are
> identified by having DW_AT_external.  [4.1 Data Object Entries]
> However, dwarf2_add_field is calling die_is_declaration.

echo 'class C { static const float i = 1; } c;'|g++ -c -o 1.o -Wall -g -x c++ -
    < c>   DW_AT_producer    : (indirect string, offset: 0x11): GNU C++ 4.6.0 20100628 (experimental)   
 <2><33>: Abbrev Number: 3 (DW_TAG_member)
    <34>   DW_AT_name        : i        
    <38>   DW_AT_type        : <0x45>   
    <3c>   DW_AT_external    : 1        
    <3d>   DW_AT_accessibility: 3       (private)
    <3e>   DW_AT_declaration : 1        
    <3f>   DW_AT_const_value : 4 byte block: 0 0 80 3f  

Isn't it primarily a bug in GCC?  There is no other DIE for `i' and it is
a complete definition so there is no place for DW_AT_declaration there.

Just such GCC change will be incompatible with existing GDBs, maybe to make
the GCC change only for -gdwarf-4 upwards which is incompatible with older
GDBs anyway?


> This seems wrong, but I didn't address this here, other than to add
> a note pointing this out (because some new code in new_symbol should match).

I agree it is an issue for a different patch.


> Also, I added a case to new_symbol to handle DW_TAG_member.
> gcc uses DW_TAG_variable but the correct way AIUI is DW_TAG_member,

4.4.5 20100627 uses DW_TAG_variable but 4.5.1 20100627 uses DW_TAG_member.


Otherwise - for the second patch - there are some needless whitespace changes.
Also I would test also `float' const field there using LOC_CONST_BYTES; it
works but just to test it, based on your IRC comments about LOC_CONST_BYTES.


Thanks,
Jan