Static class members & DWARF

Wed Mar 3 20:13:00 GMT 2010

On 03/03/2010 07:48 PM, Keith Seitz wrote:
> Hi,
>> Consider the following simple class:
>> class jvstatic
> {
> public static int STATIC = 1;
> }
>> Looking at the DWARF info for this class, I see:
>> <1><107>: Abbrev Number: 2 (DW_TAG_class_type)
> <108> DW_AT_name : (indirect string, offset: 0xdf): jvstatic
> <10c> DW_AT_byte_size : 4
> <10d> DW_AT_decl_file : 1
> <10e> DW_AT_decl_line : 0
> <10f> DW_AT_containing_type: <0x17b>
> <113> DW_AT_sibling : <0x17b>
> <2><117>: Abbrev Number: 3 (DW_TAG_inheritance)
> <118> DW_AT_type : <0x17b>
> <11c> DW_AT_data_member_location: 2 byte block: 23 0
> (DW_OP_plus_uconst: 0)
> <11f> DW_AT_accessibility: 1 (public)
> <2><120>: Abbrev Number: 4 (DW_TAG_member)
> <121> DW_AT_name : (indirect string, offset: 0x123): STATIC
> <125> DW_AT_decl_file : 1
> <126> DW_AT_decl_line : 0
> <127> DW_AT_MIPS_linkage_name: (indirect string, offset: 0xca):
> _ZN8jvstatic6STATICE
> <12b> DW_AT_type : <0x181>
> <12f> DW_AT_external : 1
> <130> DW_AT_declaration : 1
>> Pursuant to the DWARF3 specification (sec 4.1 #6), I would expect to
> subsequently see a DIE with DW_TAG_variable which refers to DIE <120>
> (via DW_AT_specification). Alas, this DIE does not appear in the debug
> info at all.
>> Does java operate differently from C++ (which follows the DWARF
> specification)?

Only by mistake. gcj itself has no code to generate DWARF: we create the
data structures and hope that the back end will do The Right Thing with
them.
I suppose that the C++ compiler generates something different from gcj.
I don't know why.
Andrew.