freepascal.compiler/compiler/dbgdwarf.pas

{
    Copyright (c) 2003-2006 by Peter Vreman and Florian Klaempfl

    This units contains support for DWARF debug info generation

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 ****************************************************************************
}
{
  This units contains support for DWARF debug info generation.

  Currently a lot of code looks like being mergable with dbgstabs. This might
  change however when improved dwarf info is generated, so the stuff shouldn't be
  merged yet. (FK)

  The easiest way to debug dwarf debug info generation is the usage of
  readelf --debug-dump <executable>
  This works only with elf targets though.
}
unit dbgdwarf;

{$i fpcdefs.inc}

interface

    uses
      cclasses,
      aasmbase,aasmtai,
      symbase,symtype,symdef,
      DbgBase;

    type
      { Tag names and codes.   }
      tdwarf_tag = (DW_TAG_padding := $00,DW_TAG_array_type := $01,
        DW_TAG_class_type := $02,DW_TAG_entry_point := $03,
        DW_TAG_enumeration_type := $04,DW_TAG_formal_parameter := $05,
        DW_TAG_imported_declaration := $08,DW_TAG_label := $0a,
        DW_TAG_lexical_block := $0b,DW_TAG_member := $0d,
        DW_TAG_pointer_type := $0f,DW_TAG_reference_type := $10,
        DW_TAG_compile_unit := $11,DW_TAG_string_type := $12,
        DW_TAG_structure_type := $13,DW_TAG_subroutine_type := $15,
        DW_TAG_typedef := $16,DW_TAG_union_type := $17,
        DW_TAG_unspecified_parameters := $18,
        DW_TAG_variant := $19,DW_TAG_common_block := $1a,
        DW_TAG_common_inclusion := $1b,DW_TAG_inheritance := $1c,
        DW_TAG_inlined_subroutine := $1d,DW_TAG_module := $1e,
        DW_TAG_ptr_to_member_type := $1f,DW_TAG_set_type := $20,
        DW_TAG_subrange_type := $21,DW_TAG_with_stmt := $22,
        DW_TAG_access_declaration := $23,DW_TAG_base_type := $24,
        DW_TAG_catch_block := $25,DW_TAG_const_type := $26,
        DW_TAG_constant := $27,DW_TAG_enumerator := $28,
        DW_TAG_file_type := $29,DW_TAG_friend := $2a,
        DW_TAG_namelist := $2b,DW_TAG_namelist_item := $2c,
        DW_TAG_packed_type := $2d,DW_TAG_subprogram := $2e,
        DW_TAG_template_type_param := $2f,DW_TAG_template_value_param := $30,
        DW_TAG_thrown_type := $31,DW_TAG_try_block := $32,
        DW_TAG_variant_part := $33,DW_TAG_variable := $34,
        DW_TAG_volatile_type := $35,
        { DWARF 3.   }
        DW_TAG_dwarf_procedure := $36,
        DW_TAG_restrict_type := $37,DW_TAG_interface_type := $38,
        DW_TAG_namespace := $39,DW_TAG_imported_module := $3a,
        DW_TAG_unspecified_type := $3b,DW_TAG_partial_unit := $3c,
        DW_TAG_imported_unit := $3d,

        { SGI/MIPS Extensions.   }
        DW_TAG_MIPS_loop := $4081,

        { HP extensions.  See: ftp://ftp.hp.com/pub/lang/tools/WDB/wdb-4.0.tar.gz .   }
        DW_TAG_HP_array_descriptor := $4090,

        { GNU extensions.   }
        { For FORTRAN 77 and Fortran 90.   }
        DW_TAG_format_label := $4101,
        { For C++.   }
        DW_TAG_function_template := $4102,DW_TAG_class_template := $4103,

        DW_TAG_GNU_BINCL := $4104,DW_TAG_GNU_EINCL := $4105,
        { Extensions for UPC.  See: http://upc.gwu.edu/~upc.   }
        DW_TAG_upc_shared_type := $8765,DW_TAG_upc_strict_type := $8766,
        DW_TAG_upc_relaxed_type := $8767,

        { PGI (STMicroelectronics) extensions.  No documentation available.   }
        DW_TAG_PGI_kanji_type := $A000,
        DW_TAG_PGI_interface_block := $A020);

      { Attribute names and codes.   }
      tdwarf_attribute = (DW_AT_sibling := $01,DW_AT_location := $02,
        DW_AT_name := $03,DW_AT_ordering := $09,
        DW_AT_subscr_data := $0a,DW_AT_byte_size := $0b,
        DW_AT_bit_offset := $0c,DW_AT_bit_size := $0d,
        DW_AT_element_list := $0f,DW_AT_stmt_list := $10,
        DW_AT_low_pc := $11,DW_AT_high_pc := $12,
        DW_AT_language := $13,DW_AT_member := $14,
        DW_AT_discr := $15,DW_AT_discr_value := $16,
        DW_AT_visibility := $17,DW_AT_import := $18,
        DW_AT_string_length := $19,DW_AT_common_reference := $1a,
        DW_AT_comp_dir := $1b,DW_AT_const_value := $1c,
        DW_AT_containing_type := $1d,DW_AT_default_value := $1e,
        DW_AT_inline := $20,DW_AT_is_optional := $21,
        DW_AT_lower_bound := $22,DW_AT_producer := $25,
        DW_AT_prototyped := $27,DW_AT_return_addr := $2a,
        DW_AT_start_scope := $2c,DW_AT_stride_size := $2e,
        DW_AT_upper_bound := $2f,DW_AT_abstract_origin := $31,
        DW_AT_accessibility := $32,DW_AT_address_class := $33,
        DW_AT_artificial := $34,DW_AT_base_types := $35,
        DW_AT_calling_convention := $36,DW_AT_count := $37,
        DW_AT_data_member_location := $38,DW_AT_decl_column := $39,
        DW_AT_decl_file := $3a,DW_AT_decl_line := $3b,
        DW_AT_declaration := $3c,DW_AT_discr_list := $3d,
        DW_AT_encoding := $3e,DW_AT_external := $3f,
        DW_AT_frame_base := $40,DW_AT_friend := $41,
        DW_AT_identifier_case := $42,DW_AT_macro_info := $43,
        DW_AT_namelist_items := $44,DW_AT_priority := $45,
        DW_AT_segment := $46,DW_AT_specification := $47,
        DW_AT_static_link := $48,DW_AT_type := $49,
        DW_AT_use_location := $4a,DW_AT_variable_parameter := $4b,
        DW_AT_virtuality := $4c,DW_AT_vtable_elem_location := $4d,

        { DWARF 3 values.   }
        DW_AT_allocated := $4e,DW_AT_associated := $4f,
        DW_AT_data_location := $50,DW_AT_stride := $51,
        DW_AT_entry_pc := $52,DW_AT_use_UTF8 := $53,
        DW_AT_extension := $54,DW_AT_ranges := $55,
        DW_AT_trampoline := $56,DW_AT_call_column := $57,
        DW_AT_call_file := $58,DW_AT_call_line := $59,

        { SGI/MIPS extensions.   }
        DW_AT_MIPS_fde := $2001,DW_AT_MIPS_loop_begin := $2002,
        DW_AT_MIPS_tail_loop_begin := $2003,DW_AT_MIPS_epilog_begin := $2004,
        DW_AT_MIPS_loop_unroll_factor := $2005,
        DW_AT_MIPS_software_pipeline_depth := $2006,
        DW_AT_MIPS_linkage_name := $2007,DW_AT_MIPS_stride := $2008,
        DW_AT_MIPS_abstract_name := $2009,DW_AT_MIPS_clone_origin := $200a,
        DW_AT_MIPS_has_inlines := $200b,

        { HP extensions.   }
        DW_AT_HP_block_index := $2000,
        DW_AT_HP_unmodifiable := $2001,DW_AT_HP_actuals_stmt_list := $2010,
        DW_AT_HP_proc_per_section := $2011,DW_AT_HP_raw_data_ptr := $2012,
        DW_AT_HP_pass_by_reference := $2013,DW_AT_HP_opt_level := $2014,
        DW_AT_HP_prof_version_id := $2015,DW_AT_HP_opt_flags := $2016,
        DW_AT_HP_cold_region_low_pc := $2017,DW_AT_HP_cold_region_high_pc := $2018,
        DW_AT_HP_all_variables_modifiable := $2019,
        DW_AT_HP_linkage_name := $201a,DW_AT_HP_prof_flags := $201b,

        { GNU extensions.   }
        DW_AT_sf_names := $2101,DW_AT_src_info := $2102,
        DW_AT_mac_info := $2103,DW_AT_src_coords := $2104,
        DW_AT_body_begin := $2105,DW_AT_body_end := $2106,
        DW_AT_GNU_vector := $2107,

        { VMS extensions.  }
        DW_AT_VMS_rtnbeg_pd_address := $2201,

        { UPC extension.   }
        DW_AT_upc_threads_scaled := $3210,

        { PGI (STMicroelectronics) extensions.   }
        DW_AT_PGI_lbase := $3a00,
        DW_AT_PGI_soffset := $3a01,DW_AT_PGI_lstride := $3a02
      );

      { Form names and codes.   }
      Tdwarf_form = (DW_FORM_addr := $01,DW_FORM_block2 := $03,
        DW_FORM_block4 := $04,DW_FORM_data2 := $05,
        DW_FORM_data4 := $06,DW_FORM_data8 := $07,
        DW_FORM_string := $08,DW_FORM_block := $09,
        DW_FORM_block1 := $0a,DW_FORM_data1 := $0b,
        DW_FORM_flag := $0c,DW_FORM_sdata := $0d,
        DW_FORM_strp := $0e,DW_FORM_udata := $0f,
        DW_FORM_ref_addr := $10,DW_FORM_ref1 := $11,
        DW_FORM_ref2 := $12,DW_FORM_ref4 := $13,
        DW_FORM_ref8 := $14,DW_FORM_ref_udata := $15,
        DW_FORM_indirect := $16);

      TDebugInfoDwarf = class(TDebugInfo)
      private
        currfileidx : longint;
        currabbrevnumber : longint;

        writing_def_dwarf : boolean;

        { use this defs to create info for variants and file handles }
        vardatadef,
        filerecdef,
        textrecdef : tdef;

        function append_entry(tag : tdwarf_tag;has_children : boolean;data : array of const) : longint;
        procedure append_labelentry(attr : tdwarf_attribute;sym : tasmsymbol);
        procedure append_labelentry_ref(attr : tdwarf_attribute;sym : tasmsymbol);
        procedure append_labelentry_data(attr : tdwarf_attribute;sym : tasmsymbol);
        procedure finish_entry;
        procedure finish_children;

        procedure field_add_dwarftag(p:Tnamedindexitem;arg:pointer);
        procedure method_add_dwarftag(p:Tnamedindexitem;arg:pointer);
        procedure append_procdef(list:taasmoutput;pd:tprocdef);
        procedure append_dwarftag(list:taasmoutput;def:tdef);
        procedure insertsym(list:taasmoutput;sym:tsym);
        procedure write_symtable_syms(list:taasmoutput;st:tsymtable);
        function def_dwarf_lab(def:tdef) : tasmsymbol;
      public
        procedure insertdef(list:taasmoutput;def:tdef);override;

        procedure insertmoduleinfo;override;
        procedure inserttypeinfo;override;
        procedure referencesections(list:taasmoutput);override;
        procedure insertlineinfo(list:taasmoutput);override;
        procedure write_symtable_defs(list:taasmoutput;st:tsymtable);override;
      end;

implementation

    uses
      version,
      cutils,
      globtype,
      globals,
      verbose,
      systems,
      cpubase,
      cgbase,
      finput,
      fmodule,
      defutil,
      symconst,symtable,symsym
      ;

    const
      DW_TAG_lo_user = $4080;
      DW_TAG_hi_user = $ffff;

      { Flag that tells whether entry has a child or not.   }
      DW_children_no = 0;
      DW_children_yes = 1;

    const
      { Implementation-defined range start.   }
      DW_AT_lo_user = $2000;
      { Implementation-defined range end.   }
      DW_AT_hi_user = $3ff0;

    type
      { Source language names and codes.   }
      tdwarf_source_language = (DW_LANG_C89 := $0001,DW_LANG_C := $0002,DW_LANG_Ada83 := $0003,
        DW_LANG_C_plus_plus := $0004,DW_LANG_Cobol74 := $0005,
        DW_LANG_Cobol85 := $0006,DW_LANG_Fortran77 := $0007,
        DW_LANG_Fortran90 := $0008,DW_LANG_Pascal83 := $0009,
        DW_LANG_Modula2 := $000a,DW_LANG_Java := $000b,

        { DWARF 3.   }
        DW_LANG_C99 := $000c,DW_LANG_Ada95 := $000d,
        DW_LANG_Fortran95 := $000e,

        { MIPS.   }
        DW_LANG_Mips_Assembler := $8001,

        { UPC.   }
        DW_LANG_Upc := $8765
      );

    const
      { Implementation-defined range start.   }
      DW_LANG_lo_user = $8000;

      { Implementation-defined range start.   }
      DW_LANG_hi_user = $ffff;

    type
      { Names and codes for macro information.   }
      tdwarf_macinfo_record_type = (DW_MACINFO_define := 1,DW_MACINFO_undef := 2,
        DW_MACINFO_start_file := 3,DW_MACINFO_end_file := 4,
        DW_MACINFO_vendor_ext := 255);


    type
      { Type encodings.   }
      Tdwarf_type = (DW_ATE_void := $0,DW_ATE_address := $1,
        DW_ATE_boolean := $2,DW_ATE_complex_float := $3,
        DW_ATE_float := $4,DW_ATE_signed := $5,
        DW_ATE_signed_char := $6,DW_ATE_unsigned := $7,
        DW_ATE_unsigned_char := $8,DW_ATE_imaginary_float := $9,

        { HP extensions.   }
        DW_ATE_HP_float80 := $80,DW_ATE_HP_complex_float80 := $81,
        DW_ATE_HP_float128 := $82,DW_ATE_HP_complex_float128 := $83,
        DW_ATE_HP_floathpintel := $84,DW_ATE_HP_imaginary_float80 := $85,
        DW_ATE_HP_imaginary_float128 := $86
        );


    const
      DW_ATE_lo_user = $80;
      DW_ATE_hi_user = $ff;


    type
      Tdwarf_array_dim_ordering = (DW_ORD_row_major := 0,DW_ORD_col_major := 1
        );

      { Access attribute.   }
      Tdwarf_access_attribute = (DW_ACCESS_public := 1,DW_ACCESS_protected := 2,
        DW_ACCESS_private := 3);

      { Visibility.   }
      Tdwarf_visibility_attribute = (DW_VIS_local := 1,DW_VIS_exported := 2,
        DW_VIS_qualified := 3);

      { Virtuality.   }
      Tdwarf_virtuality_attribute = (DW_VIRTUALITY_none := 0,DW_VIRTUALITY_virtual := 1,
        DW_VIRTUALITY_pure_virtual := 2);

      { Case sensitivity.   }
      Tdwarf_id_case = (DW_ID_case_sensitive := 0,DW_ID_up_case := 1,
        DW_ID_down_case := 2,DW_ID_case_insensitive := 3
        );

      { Calling convention.   }
      Tdwarf_calling_convention = (DW_CC_normal := $1,DW_CC_program := $2,
        DW_CC_nocall := $3,DW_CC_GNU_renesas_sh := $40
        );

      { Location atom names and codes.   }
      Tdwarf_location_atom = (DW_OP_addr := $03,DW_OP_deref := $06,DW_OP_const1u := $08,
        DW_OP_const1s := $09,DW_OP_const2u := $0a,
        DW_OP_const2s := $0b,DW_OP_const4u := $0c,
        DW_OP_const4s := $0d,DW_OP_const8u := $0e,
        DW_OP_const8s := $0f,DW_OP_constu := $10,
        DW_OP_consts := $11,DW_OP_dup := $12,DW_OP_drop := $13,
        DW_OP_over := $14,DW_OP_pick := $15,DW_OP_swap := $16,
        DW_OP_rot := $17,DW_OP_xderef := $18,DW_OP_abs := $19,
        DW_OP_and := $1a,DW_OP_div := $1b,DW_OP_minus := $1c,
        DW_OP_mod := $1d,DW_OP_mul := $1e,DW_OP_neg := $1f,
        DW_OP_not := $20,DW_OP_or := $21,DW_OP_plus := $22,
        DW_OP_plus_uconst := $23,DW_OP_shl := $24,
        DW_OP_shr := $25,DW_OP_shra := $26,DW_OP_xor := $27,
        DW_OP_bra := $28,DW_OP_eq := $29,DW_OP_ge := $2a,
        DW_OP_gt := $2b,DW_OP_le := $2c,DW_OP_lt := $2d,
        DW_OP_ne := $2e,DW_OP_skip := $2f,DW_OP_lit0 := $30,
        DW_OP_lit1 := $31,DW_OP_lit2 := $32,DW_OP_lit3 := $33,
        DW_OP_lit4 := $34,DW_OP_lit5 := $35,DW_OP_lit6 := $36,
        DW_OP_lit7 := $37,DW_OP_lit8 := $38,DW_OP_lit9 := $39,
        DW_OP_lit10 := $3a,DW_OP_lit11 := $3b,
        DW_OP_lit12 := $3c,DW_OP_lit13 := $3d,
        DW_OP_lit14 := $3e,DW_OP_lit15 := $3f,
        DW_OP_lit16 := $40,DW_OP_lit17 := $41,
        DW_OP_lit18 := $42,DW_OP_lit19 := $43,
        DW_OP_lit20 := $44,DW_OP_lit21 := $45,
        DW_OP_lit22 := $46,DW_OP_lit23 := $47,
        DW_OP_lit24 := $48,DW_OP_lit25 := $49,
        DW_OP_lit26 := $4a,DW_OP_lit27 := $4b,
        DW_OP_lit28 := $4c,DW_OP_lit29 := $4d,
        DW_OP_lit30 := $4e,DW_OP_lit31 := $4f,
        DW_OP_reg0 := $50,DW_OP_reg1 := $51,DW_OP_reg2 := $52,
        DW_OP_reg3 := $53,DW_OP_reg4 := $54,DW_OP_reg5 := $55,
        DW_OP_reg6 := $56,DW_OP_reg7 := $57,DW_OP_reg8 := $58,
        DW_OP_reg9 := $59,DW_OP_reg10 := $5a,DW_OP_reg11 := $5b,
        DW_OP_reg12 := $5c,DW_OP_reg13 := $5d,
        DW_OP_reg14 := $5e,DW_OP_reg15 := $5f,
        DW_OP_reg16 := $60,DW_OP_reg17 := $61,
        DW_OP_reg18 := $62,DW_OP_reg19 := $63,
        DW_OP_reg20 := $64,DW_OP_reg21 := $65,
        DW_OP_reg22 := $66,DW_OP_reg23 := $67,
        DW_OP_reg24 := $68,DW_OP_reg25 := $69,
        DW_OP_reg26 := $6a,DW_OP_reg27 := $6b,
        DW_OP_reg28 := $6c,DW_OP_reg29 := $6d,
        DW_OP_reg30 := $6e,DW_OP_reg31 := $6f,
        DW_OP_breg0 := $70,DW_OP_breg1 := $71,
        DW_OP_breg2 := $72,DW_OP_breg3 := $73,
        DW_OP_breg4 := $74,DW_OP_breg5 := $75,
        DW_OP_breg6 := $76,DW_OP_breg7 := $77,
        DW_OP_breg8 := $78,DW_OP_breg9 := $79,
        DW_OP_breg10 := $7a,DW_OP_breg11 := $7b,
        DW_OP_breg12 := $7c,DW_OP_breg13 := $7d,
        DW_OP_breg14 := $7e,DW_OP_breg15 := $7f,
        DW_OP_breg16 := $80,DW_OP_breg17 := $81,
        DW_OP_breg18 := $82,DW_OP_breg19 := $83,
        DW_OP_breg20 := $84,DW_OP_breg21 := $85,
        DW_OP_breg22 := $86,DW_OP_breg23 := $87,
        DW_OP_breg24 := $88,DW_OP_breg25 := $89,
        DW_OP_breg26 := $8a,DW_OP_breg27 := $8b,
        DW_OP_breg28 := $8c,DW_OP_breg29 := $8d,
        DW_OP_breg30 := $8e,DW_OP_breg31 := $8f,
        DW_OP_regx := $90,DW_OP_fbreg := $91,DW_OP_bregx := $92,
        DW_OP_piece := $93,DW_OP_deref_size := $94,
        DW_OP_xderef_size := $95,DW_OP_nop := $96,

        { DWARF 3 extensions.   }
        DW_OP_push_object_address := $97,DW_OP_call2 := $98,
        DW_OP_call4 := $99,DW_OP_call_ref := $9a,

        { GNU extensions.   }
        DW_OP_GNU_push_tls_address := $e0,

        { HP extensions.   }
        DW_OP_HP_unknown := $e0,
        DW_OP_HP_is_value := $e1,DW_OP_HP_fltconst4 := $e2,
        DW_OP_HP_fltconst8 := $e3,DW_OP_HP_mod_range := $e4,
        DW_OP_HP_unmod_range := $e5,DW_OP_HP_tls := $e6
        );

    const
      { Implementation-defined range start.   }
      DW_OP_lo_user = $e0;
      { Implementation-defined range end.   }
      DW_OP_hi_user = $ff;

    function TDebugInfoDwarf.def_dwarf_lab(def:tdef) : tasmsymbol;
      begin
        { procdefs only need a number, mark them as already written
          so they won't be written implicitly }
        if (def.deftype=procdef) then
          def.dbg_state:=dbg_state_written;
        { dwarf must already be written, or we must be busy writing it }
        if writing_def_dwarf and
           not(def.dbg_state in [dbg_state_writing,dbg_state_written]) then
          internalerror(200601241);
        { Keep track of used dwarf entries, this info is only usefull for dwarf entries
          referenced by the symbols. Definitions will always include all
          required stabs }
        if def.dbg_state=dbg_state_unused then
          def.dbg_state:=dbg_state_used;
        { Need a new label? }
        if def.dwarf_lab=nil then
          begin
            objectlibrary.getdatalabel(def.dwarf_lab);
          end;
        result:=def.dwarf_lab;
      end;


    { writing the data through a few simply procedures allows to create easily extra information
      for debugging of debug info }
    function TDebugInfoDwarf.append_entry(tag : tdwarf_tag;has_children : boolean;data : array of const) : longint;
      var
        i : longint;
      begin
        inc(currabbrevnumber);

        asmlist[al_dwarf_abbrev].concat(tai_comment.Create(strpnew('Abbrev '+tostr(currabbrevnumber))));

        { abbrev number }
        asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(currabbrevnumber));
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(currabbrevnumber));
        { tag }
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(tag)));

        { children? }
        asmlist[al_dwarf_abbrev].concat(tai_const.create_8bit(ord(has_children)));

        i:=0;
        while i<=high(data) do
          begin
            { attribute }
            if data[i].VType=vtInteger then
              begin
                asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(data[i].VInteger));
              end
            else
              internalerror(200601261);
            inc(i);

            { form }
            if data[i].VType=vtInteger then
              begin
                asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(data[i].VInteger));
              end
            else
              internalerror(200601262);
            inc(i);

            { info itself }
            case tdwarf_form(data[i-1].VInteger) of
              DW_FORM_string:
                case data[i].VType of
                  vtChar:
                    asmlist[al_dwarf_info].concat(tai_string.create(data[i].VChar));
                  vtString:
                    asmlist[al_dwarf_info].concat(tai_string.create(data[i].VString^));
                  vtAnsistring:
                    asmlist[al_dwarf_info].concat(tai_string.create(Ansistring(data[i].VAnsiString^)));
                  else
                    internalerror(200601264);
                end;


              DW_FORM_flag:
                asmlist[al_dwarf_info].concat(tai_const.create_8bit(byte(data[i].VBoolean)));
              DW_FORM_data1:
                asmlist[al_dwarf_info].concat(tai_const.create_8bit(data[i].VInteger));
              DW_FORM_data2:
                asmlist[al_dwarf_info].concat(tai_const.create_16bit(data[i].VInteger));
              DW_FORM_data4:
                asmlist[al_dwarf_info].concat(tai_const.create_32bit(data[i].VInteger));
              DW_FORM_data8:
                asmlist[al_dwarf_info].concat(tai_const.create_64bit(data[i].VInteger));

              DW_FORM_sdata:
                case data[i].VType of
                  vtInteger:
                    asmlist[al_dwarf_info].concat(tai_const.create_sleb128bit(data[i].VInteger));
                  vtInt64:
                    asmlist[al_dwarf_info].concat(tai_const.create_sleb128bit(data[i].VInt64^));
                  vtQWord:
                    asmlist[al_dwarf_info].concat(tai_const.create_sleb128bit(data[i].VQWord^));
                  else
                    internalerror(200601285);
                end;

              DW_FORM_udata:
                case data[i].VType of
                  vtInteger:
                    asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(data[i].VInteger));
                  vtInt64:
                    asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(data[i].VInt64^));
                  vtQWord:
                    asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(data[i].VQWord^));
                  else
                    internalerror(200601284);
                end;

              { block gets only the size, the rest is appended manually by the caller }
              DW_FORM_block1:
                asmlist[al_dwarf_info].concat(tai_const.create_8bit(data[i].VInteger));
              else
                internalerror(200601263);
            end;
            inc(i);
          end;
      end;


    procedure TDebugInfoDwarf.append_labelentry(attr : tdwarf_attribute;sym : tasmsymbol);
      begin
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(attr)));
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_addr)));
        asmlist[al_dwarf_info].concat(tai_const.create_sym(sym));
      end;


    procedure TDebugInfoDwarf.append_labelentry_ref(attr : tdwarf_attribute;sym : tasmsymbol);
      begin
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(attr)));
{$ifdef cpu64bit}
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_ref8)));
{$else cpu64bit}
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_ref4)));
{$endif cpu64bit}
        asmlist[al_dwarf_info].concat(tai_const.create_sym(sym));
      end;


    procedure TDebugInfoDwarf.append_labelentry_data(attr : tdwarf_attribute;sym : tasmsymbol);
      begin
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(attr)));
{$ifdef cpu64bit}
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_data8)));
{$else cpu64bit}
        asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_data4)));
{$endif cpu64bit}
        asmlist[al_dwarf_info].concat(tai_const.create_sym(sym));
      end;


    procedure TDebugInfoDwarf.finish_entry;
      begin
        asmlist[al_dwarf_abbrev].concat(tai_const.create_8bit(0));
        asmlist[al_dwarf_abbrev].concat(tai_const.create_8bit(0));
      end;


    procedure TDebugInfoDwarf.finish_children;
      begin
        asmlist[al_dwarf_info].concat(tai_const.create_8bit(0));
      end;


    procedure TDebugInfoDwarf.field_add_dwarftag(p:Tnamedindexitem;arg:pointer);
      begin
        { static variables from objects are like global objects }
        if (tsym(p).typ=fieldvarsym) and
           not(sp_static in Tsym(p).symoptions) then
          begin
            append_entry(DW_TAG_member,false,[
              DW_AT_name,DW_FORM_string,tsym(p).name+#0,
              DW_AT_data_member_location,DW_FORM_block1,1+lengthuleb128(tfieldvarsym(p).fieldoffset)
              ]);
            asmlist[al_dwarf_info].concat(tai_const.create_8bit(ord(DW_OP_plus_uconst)));
            asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(tfieldvarsym(p).fieldoffset));

            append_labelentry_ref(DW_AT_type,def_dwarf_lab(tfieldvarsym(p).vartype.def));
            finish_entry;
          end;
      end;


    procedure TDebugInfoDwarf.method_add_dwarftag(p:Tnamedindexitem;arg:pointer);
      begin
      end;


    procedure TDebugInfoDwarf.append_dwarftag(list:taasmoutput;def:tdef);

      procedure append_dwarftag_orddef(def:torddef);
        begin
          case def.typ of
            s8bit,
            s16bit,
            s32bit :
              begin
                { we should generate a subrange type here }
                if assigned(def.typesym) then
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_signed,
                    DW_AT_byte_size,DW_FORM_data1,def.size
                    ])
                else
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_signed,
                    DW_AT_byte_size,DW_FORM_data1,def.size
                    ]);
                finish_entry;
              end;
            u8bit,
            u16bit,
            u32bit :
              begin
                { we should generate a subrange type here }
                if assigned(def.typesym) then
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                    DW_AT_byte_size,DW_FORM_data1,def.size
                    ])
                else
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                    DW_AT_byte_size,DW_FORM_data1,def.size
                    ]);
                finish_entry;
              end;
            uvoid :
              begin
                { gdb 6.4 doesn't support DW_TAG_unspecified_type so we
                  replace it with a unsigned type with size 0 (FK)
                }
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'Void'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                  DW_AT_byte_size,DW_FORM_data1,0
                ]);
                finish_entry;
              end;
            uchar :
              begin
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'Char'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned_char,
                  DW_AT_byte_size,DW_FORM_data1,1
                  ]);
                finish_entry;
              end;
            uwidechar :
              begin
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'WideChar'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned_char,
                  DW_AT_byte_size,DW_FORM_data1,2
                  ]);
                finish_entry;
              end;
            bool8bit :
              begin
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'Boolean'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned_char,
                  DW_AT_byte_size,DW_FORM_data1,1
                  ]);
                finish_entry;
              end;
            bool16bit :
              begin
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'WordBool'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_boolean,
                  DW_AT_byte_size,DW_FORM_data1,2
                  ]);
                finish_entry;
              end;
            bool32bit :
              begin
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'LongBool'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_boolean,
                  DW_AT_byte_size,DW_FORM_data1,4
                  ]);
                finish_entry;
              end;
            u64bit :
              begin
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'QWord'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                  DW_AT_byte_size,DW_FORM_data1,8
                  ]);
                finish_entry;
              end;
            s64bit :
              begin
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,'Int64'#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_signed,
                  DW_AT_byte_size,DW_FORM_data1,8
                  ]);
                finish_entry;
              end;
            else
              internalerror(200601287);
          end;
        end;

        procedure append_dwarftag_floatdef(def:tfloatdef);
          begin
            case def.typ of
              s32real,
              s64real,
              s80real:
                if assigned(def.typesym) then
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_float,
                    DW_AT_byte_size,DW_FORM_data1,def.size
                    ])
                else
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_float,
                    DW_AT_byte_size,DW_FORM_data1,def.size
                    ]);
              s64currency:
                { we should use DW_ATE_signed_fixed, however it isn't supported yet by GDB (FK) }
                if assigned(def.typesym) then
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_signed,
                    DW_AT_byte_size,DW_FORM_data1,8
                    ])
                else
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_signed,
                    DW_AT_byte_size,DW_FORM_data1,8
                    ]);
              s64comp:
                if assigned(def.typesym) then
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_signed,
                    DW_AT_byte_size,DW_FORM_data1,8
                    ])
                else
                  append_entry(DW_TAG_base_type,false,[
                    DW_AT_encoding,DW_FORM_data1,DW_ATE_signed,
                    DW_AT_byte_size,DW_FORM_data1,8
                    ]);
              else
                internalerror(200601289);
            end;
            finish_entry;
          end;


      procedure append_dwarftag_enumdef(def:tenumdef);
        var
          hp : tenumsym;
        begin
          if assigned(def.typesym) then
            append_entry(DW_TAG_enumeration_type,true,[
              DW_AT_name,DW_FORM_string,def.typesym.name+#0,
              DW_AT_byte_size,DW_FORM_data1,def.size
              ])
          else
            append_entry(DW_TAG_enumeration_type,true,[
              DW_AT_byte_size,DW_FORM_data1,def.size
              ]);
          if assigned(def.basedef) then
            append_labelentry_ref(DW_AT_type,def_dwarf_lab(def.basedef));
          finish_entry;

          { write enum symbols }
          hp:=tenumsym(def.firstenum);
          while assigned(hp) do
            begin
              append_entry(DW_TAG_enumerator,false,[
                DW_AT_name,DW_FORM_string,hp.name+#0,
                DW_AT_const_value,DW_FORM_data4,hp.value
              ]);
              finish_entry;
              hp:=tenumsym(hp).nextenum;
            end;

          finish_children;
        end;


      procedure append_dwarftag_arraydef(def:tarraydef);
        begin
          if assigned(def.typesym) then
            append_entry(DW_TAG_array_type,true,[
              DW_AT_name,DW_FORM_string,def.typesym.name+#0,
              DW_AT_byte_size,DW_FORM_udata,def.size,
              DW_AT_stride_size,DW_FORM_udata,def.elesize*8
              ])
          else
            append_entry(DW_TAG_array_type,true,[
              DW_AT_byte_size,DW_FORM_udata,def.size,
              DW_AT_stride_size,DW_FORM_udata,def.elesize*8
              ]);
          append_labelentry_ref(DW_AT_type,def_dwarf_lab(def.elementtype.def));
          if def.IsDynamicArray then
            begin
              { !!! FIXME !!! }
              { gdb's dwarf implementation sucks, so we can't use DW_OP_push_object here (FK)
              { insert location attribute manually }
              asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(DW_AT_data_location));
              asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(DW_FORM_block1));
              asmlist[al_dwarf_info].concat(tai_const.create_8bit(1));
              asmlist[al_dwarf_info].concat(tai_const.create_8bit(DW_OP_push_object));
              asmlist[al_dwarf_info].concat(tai_const.create_8bit(DW_OP_deref));
              }

              finish_entry;
              { to simplify things, we don't write a multidimensional array here }
              append_entry(DW_TAG_subrange_type,false,[
                DW_AT_lower_bound,DW_FORM_udata,0,
                DW_AT_upper_bound,DW_FORM_udata,0
                ]);
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(def.rangetype.def));
              finish_entry;
            end
          else
            begin
              finish_entry;
              { to simplify things, we don't write a multidimensional array here }
              append_entry(DW_TAG_subrange_type,false,[
                DW_AT_lower_bound,DW_FORM_udata,def.lowrange,
                DW_AT_upper_bound,DW_FORM_udata,def.highrange
                ]);
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(def.rangetype.def));
              finish_entry;

            end;
          finish_children;
        end;


      procedure append_dwarftag_recorddef(def:trecorddef);
        begin
          if assigned(def.typesym) then
            append_entry(DW_TAG_structure_type,true,[
              DW_AT_name,DW_FORM_string,def.typesym.name+#0,
              DW_AT_byte_size,DW_FORM_udata,def.size
              ])
          else
            append_entry(DW_TAG_structure_type,true,[
              DW_AT_byte_size,DW_FORM_udata,def.size
              ]);
          finish_entry;
          def.symtable.foreach(@field_add_dwarftag,nil);
          finish_children;
        end;


      procedure append_dwarftag_objectdef(def:tobjectdef);

        procedure doappend;
          begin
            if assigned(def.objname) then
              append_entry(DW_TAG_structure_type,true,[
                DW_AT_name,DW_FORM_string,def.objname^+#0,
                DW_AT_byte_size,DW_FORM_udata,def.size
                ])
            else
              append_entry(DW_TAG_structure_type,true,[
                DW_AT_byte_size,DW_FORM_udata,def.size
                ]);
            finish_entry;
            if assigned(def.childof) then
              begin
                append_entry(DW_TAG_inheritance,false,[
                  DW_AT_accessibility,DW_FORM_data1,DW_ACCESS_public,
                  DW_AT_data_member_location,DW_FORM_block1,1+lengthuleb128(0)
                ]);
                asmlist[al_dwarf_info].concat(tai_const.create_8bit(ord(DW_OP_plus_uconst)));
                asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(0));
                append_labelentry_ref(DW_AT_type,def_dwarf_lab(def.childof));
                finish_entry;
              end;

            def.symtable.foreach(@field_add_dwarftag,nil);
            def.symtable.foreach(@method_add_dwarftag,nil);

            finish_children;
          end;

        var
          obj : tasmlabel;

        begin
          case def.objecttype of
            odt_cppclass,
            odt_object:
              doappend;
            odt_interfacecom,
            odt_interfacecorba,
            odt_dispinterface,
            odt_class:
              begin
                objectlibrary.getdatalabel(obj);
                { implicit pointer }
                append_entry(DW_TAG_pointer_type,false,[]);
                append_labelentry_ref(DW_AT_type,obj);
                finish_entry;

                asmlist[al_dwarf_info].concat(tai_symbol.create(obj,0));
                doappend;
              end;
            else
              internalerror(200602041);
          end;
        end;


      procedure append_dwarftag_pointerdef(def:tpointerdef);
        begin
          append_entry(DW_TAG_pointer_type,false,[]);
          if not(is_voidpointer(def)) then
            append_labelentry_ref(DW_AT_type,def_dwarf_lab(def.pointertype.def));
          finish_entry;
        end;


      procedure append_dwarftag_stringdef(def:tstringdef);
        var
          slen : aint;
          arr : tasmlabel;
        begin
          case def.string_typ of
            st_shortstring:
              begin
                { fix length of openshortstring }
                slen:=def.len;
                if slen=0 then
                  slen:=255;


                { create a structure with two elements }
                objectlibrary.getdatalabel(arr);
                append_entry(DW_TAG_structure_type,true,[
                  DW_AT_name,DW_FORM_string,'ShortString'#0,
                  DW_AT_byte_size,DW_FORM_data1,2*sizeof(aint)
                ]);
                finish_entry;

                { length entry }
                append_entry(DW_TAG_member,false,[
                  DW_AT_name,DW_FORM_string,'Length'#0,
                  DW_AT_data_member_location,DW_FORM_block1,1+lengthuleb128(0)
                  ]);
                asmlist[al_dwarf_info].concat(tai_const.create_8bit(ord(DW_OP_plus_uconst)));
                asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(0));
                append_labelentry_ref(DW_AT_type,def_dwarf_lab(u8inttype.def));
                finish_entry;

                { self entry }
                append_entry(DW_TAG_member,false,[
                  DW_AT_name,DW_FORM_string,'Data'#0,
                  DW_AT_data_member_location,DW_FORM_block1,1+lengthuleb128(1)
                  ]);
                asmlist[al_dwarf_info].concat(tai_const.create_8bit(ord(DW_OP_plus_uconst)));
                asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(1));
                append_labelentry_ref(DW_AT_type,arr);
                finish_entry;

                finish_children;

                { now the data array }
                asmlist[al_dwarf_info].concat(tai_symbol.create(arr,0));
                append_entry(DW_TAG_array_type,true,[
                  DW_AT_byte_size,DW_FORM_udata,def.size,
                  DW_AT_stride_size,DW_FORM_udata,1*8
                  ]);
                append_labelentry_ref(DW_AT_type,def_dwarf_lab(cchartype.def));
                finish_entry;
                append_entry(DW_TAG_subrange_type,false,[
                  DW_AT_lower_bound,DW_FORM_udata,0,
                  DW_AT_upper_bound,DW_FORM_udata,slen
                  ]);
                append_labelentry_ref(DW_AT_type,def_dwarf_lab(u8inttype.def));
                finish_entry;
              end;
            st_longstring:
              begin
              {
                charst:=def_stab_number(cchartype.def);
                bytest:=def_stab_number(u8inttype.def);
                longst:=def_stab_number(u32inttype.def);
                result:=def_stabstr_evaluate(def,'s$1length:$2,0,32;dummy:$6,32,8;st:ar$2;1;$3;$4,40,$5;;',
                            [tostr(def.len+5),longst,tostr(def.len),charst,tostr(def.len*8),bytest]);
              }
             end;
           st_ansistring:
             { looks like a pchar }
             append_dwarftag(list,cchartype.def);
           st_widestring:
             { looks like a pwidechar }
             append_dwarftag(list,cwidechartype.def);
          end;
        end;

      procedure append_dwarftag_procvardef(def:tprocvardef);

        procedure doappend;
          var
            i : longint;
          begin
            if assigned(def.typesym) then
              append_entry(DW_TAG_subroutine_type,true,[
                DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                DW_AT_prototyped,DW_FORM_flag,true
              ])
            else
              append_entry(DW_TAG_subroutine_type,true,[
                DW_AT_prototyped,DW_FORM_flag,true
              ]);
            if not(is_void(tprocvardef(def).rettype.def)) then
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(tprocvardef(def).rettype.def));
            finish_entry;

            { write parameters }
            for i:=0 to def.paras.count-1 do
              begin
                append_entry(DW_TAG_formal_parameter,false,[
                  DW_AT_name,DW_FORM_string,tparavarsym(def.paras[i]).name+#0
                ]);
                append_labelentry_ref(DW_AT_type,def_dwarf_lab(tparavarsym(def.paras[i]).vartype.def));
                finish_entry;
              end;

            finish_children;
          end;

        var
          proc : tasmlabel;

        begin
          if def.is_methodpointer then
            begin
              { create a structure with two elements }
              objectlibrary.getdatalabel(proc);
              append_entry(DW_TAG_structure_type,true,[
                DW_AT_byte_size,DW_FORM_data1,2*sizeof(aint)
              ]);
              finish_entry;

              { proc entry }
              append_entry(DW_TAG_member,false,[
                DW_AT_name,DW_FORM_string,'Proc'#0,
                DW_AT_data_member_location,DW_FORM_block1,1+lengthuleb128(0)
                ]);
              asmlist[al_dwarf_info].concat(tai_const.create_8bit(ord(DW_OP_plus_uconst)));
              asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(0));
              append_labelentry_ref(DW_AT_type,proc);
              finish_entry;

              { self entry }
              append_entry(DW_TAG_member,false,[
                DW_AT_name,DW_FORM_string,'Self'#0,
                DW_AT_data_member_location,DW_FORM_block1,1+lengthuleb128(sizeof(aint))
                ]);
              asmlist[al_dwarf_info].concat(tai_const.create_8bit(ord(DW_OP_plus_uconst)));
              asmlist[al_dwarf_info].concat(tai_const.create_uleb128bit(sizeof(aint)));
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(class_tobject));
              finish_entry;

              finish_children;

              asmlist[al_dwarf_info].concat(tai_symbol.create(proc,0));
              doappend;
            end
          else
            doappend;
        end;


      begin
        list.concat(tai_symbol.create(def_dwarf_lab(def),0));
        case def.deftype of
          stringdef :
            append_dwarftag_stringdef(tstringdef(def));
          enumdef :
            append_dwarftag_enumdef(tenumdef(def));
          orddef :
            append_dwarftag_orddef(torddef(def));
          pointerdef :
            append_dwarftag_pointerdef(tpointerdef(def));
          floatdef :
            append_dwarftag_floatdef(tfloatdef(def));
          filedef :
            begin
             { gdb 6.4 doesn't support files so far so we use some fake recorddef
             { file recs. are less than 1k so using data2 is enough }
              if assigned(def.typesym) then
                append_entry(DW_TAG_file_type,false,[
                  DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                  DW_AT_byte_size,DW_FORM_data2,def.size
                  ])
              else
                append_entry(DW_TAG_file_type,false,[
                  DW_AT_byte_size,DW_FORM_data2,def.size
                  ]);
              if tfiledef(def).filetyp=ft_typed then
                append_labelentry_ref(DW_AT_type,def_dwarf_lab(tfiledef(def).typedfiletype.def));
              }

              if assigned(def.typesym) then
                append_entry(DW_TAG_structure_type,true,[
                 DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                 DW_AT_byte_size,DW_FORM_udata,def.size
                ])
              else
                append_entry(DW_TAG_structure_type,true,[
                 DW_AT_byte_size,DW_FORM_udata,def.size
                ]);
              finish_entry;
            end;
          recorddef :
            append_dwarftag_recorddef(trecorddef(def));
          variantdef :
            { variants aren't known to dwarf but writting tvardata should be enough }
            append_dwarftag_recorddef(trecorddef(vardatadef));
          classrefdef :
            append_dwarftag_pointerdef(tpointerdef(pvmttype.def));
          setdef :
            begin
              { at least gdb up to 6.4 doesn't support sets in dwarf, there is a patch available to fix this:
                http://sources.redhat.com/ml/gdb-patches/2005-05/msg00278.html (FK)

              if assigned(def.typesym) then
                append_entry(DW_TAG_set_type,false,[
                  DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                  DW_AT_byte_size,DW_FORM_data2,def.size
                  ])
              else
                append_entry(DW_TAG_set_type,false,[
                  DW_AT_byte_size,DW_FORM_data2,def.size
                  ]);
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(tsetdef(def).elementtype.def));
              finish_entry;
              }
              if assigned(def.typesym) then
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_name,DW_FORM_string,def.typesym.name+#0,
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                  DW_AT_byte_size,DW_FORM_data2,def.size
                  ])
              else
                append_entry(DW_TAG_base_type,false,[
                  DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                  DW_AT_byte_size,DW_FORM_data2,def.size
                  ]);
              finish_entry;
            end;
          formaldef :
            begin
              { gdb 6.4 doesn't support DW_TAG_unspecified_type so we
                replace it with a unsigned type with size 0 (FK)
              }
              append_entry(DW_TAG_base_type,false,[
                DW_AT_name,DW_FORM_string,'FormalDef'#0,
                DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                DW_AT_byte_size,DW_FORM_data1,0
              ]);
              finish_entry;
            end;
          arraydef :
            append_dwarftag_arraydef(tarraydef(def));
          procvardef :
            append_dwarftag_procvardef(tprocvardef(def));
          objectdef :
            append_dwarftag_objectdef(tobjectdef(def));
          undefineddef :
            begin
              { gdb 6.4 doesn't support DW_TAG_unspecified_type so we
                replace it with a unsigned type with size 0 (FK)
              }
              append_entry(DW_TAG_base_type,false,[
                DW_AT_name,DW_FORM_string,'FormalDef'#0,
                DW_AT_encoding,DW_FORM_data1,DW_ATE_unsigned,
                DW_AT_byte_size,DW_FORM_data1,0
              ]);
              finish_entry;
            end;
        else
          internalerror(200601281);
        end;
      end;


    procedure TDebugInfoDwarf.insertdef(list:taasmoutput;def:tdef);
      var
        anc : tobjectdef;
        oldtypesym : tsym;
        i : longint;
      begin
        if (def.dbg_state in [dbg_state_writing,dbg_state_written]) then
          exit;
        { never write generic template defs }
        if df_generic in def.defoptions then
          begin
            def.dbg_state:=dbg_state_written;
            exit;
          end;
        { to avoid infinite loops }
        def.dbg_state := dbg_state_writing;
        { write dependencies first }
        case def.deftype of
          stringdef :
            begin
              if tstringdef(def).string_typ=st_widestring then
                insertdef(list,cwidechartype.def)
              else
                begin
                  insertdef(list,cchartype.def);
                  insertdef(list,u8inttype.def);
                end;
            end;
          floatdef :
            insertdef(list,s32inttype.def);
          filedef :
            begin
              insertdef(list,s32inttype.def);
{$ifdef cpu64bit}
              insertdef(list,s64inttype.def);
{$endif cpu64bit}
              insertdef(list,u8inttype.def);
              insertdef(list,cchartype.def);
            end;
          classrefdef :
            insertdef(list,pvmttype.def);
          pointerdef :
            insertdef(list,tpointerdef(def).pointertype.def);
          setdef :
            insertdef(list,tsetdef(def).elementtype.def);
          procvardef:
            begin
              insertdef(list,tprocvardef(def).rettype.def);
              if tprocvardef(def).is_methodpointer then
                insertdef(list,class_tobject);
              { parameters }
              for i:=0 to tprocvardef(def).paras.count-1 do
                insertdef(list,tparavarsym(tprocvardef(def).paras[i]).vartype.def);
            end;
          procdef :
            insertdef(list,tprocdef(def).rettype.def);
          arraydef :
            begin
              insertdef(list,tarraydef(def).rangetype.def);
              insertdef(list,tarraydef(def).elementtype.def);
            end;
          recorddef :
            trecorddef(def).symtable.foreach(@field_write_defs,list);
          variantdef :
            trecorddef(vardatadef).symtable.foreach(@field_write_defs,list);
          objectdef :
            begin
              insertdef(list,vmtarraytype.def);
              { first the parents }
              anc:=tobjectdef(def);
              while assigned(anc.childof) do
                begin
                  anc:=anc.childof;
                  insertdef(list,anc);
                end;
              tobjectdef(def).symtable.foreach(@field_write_defs,list);
              tobjectdef(def).symtable.foreach(@method_write_defs,list);
            end;
        end;

        append_dwarftag(list,def);

        def.dbg_state:=dbg_state_written;
      end;


    procedure TDebugInfoDwarf.write_symtable_defs(list:taasmoutput;st:tsymtable);

       procedure dowritedwarf(list:taasmoutput;st:tsymtable);
         var
           p : tdef;
         begin
           p:=tdef(st.defindex.first);
           while assigned(p) do
             begin
               if (p.dbg_state=dbg_state_used) then
                 insertdef(list,p);
               p:=tdef(p.indexnext);
             end;
         end;

      var
        old_writing_def_dwarf : boolean;
      begin
        case st.symtabletype of
          staticsymtable :
            list.concat(tai_comment.Create(strpnew('Defs - Begin Staticsymtable')));
          globalsymtable :
            list.concat(tai_comment.Create(strpnew('Defs - Begin unit '+st.name^+' has index '+tostr(st.moduleid))));
        end;
        old_writing_def_dwarf:=writing_def_dwarf;
        writing_def_dwarf:=true;
        dowritedwarf(list,st);
        writing_def_dwarf:=old_writing_def_dwarf;
        case st.symtabletype of
          staticsymtable :
            list.concat(tai_comment.Create(strpnew('Defs - End Staticsymtable')));
          globalsymtable :
            list.concat(tai_comment.Create(strpnew('Defs - End unit '+st.name^+' has index '+tostr(st.moduleid))));
        end;
      end;


    procedure TDebugInfoDwarf.append_procdef(list:taasmoutput;pd:tprocdef);
      var
        procendlabel : tasmlabel;
        mangled_length : longint;
        p : pchar;
        hs : string;
      begin
        if assigned(pd.procstarttai) then
          begin
            append_entry(DW_TAG_subprogram,true,
              [DW_AT_name,DW_FORM_string,pd.procsym.name+#0
              { data continues below }
              { problem: base reg isn't known here
                DW_AT_frame_base,DW_FORM_block1,1
              }
              ]);
            { append block data }
            { asmlist[al_dwarf_info].concat(tai_const.create_8bit(dwarf_reg(pd.))); }

            if not(is_void(tprocdef(pd).rettype.def)) then
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(tprocdef(pd).rettype.def));

            { mark end of procedure }
            objectlibrary.getlabel(procendlabel,alt_dbgtype);
            asmlist[al_procedures].insertbefore(tai_label.create(procendlabel),pd.procendtai);

            append_labelentry(DW_AT_low_pc,objectlibrary.newasmsymbol(pd.mangledname,AB_LOCAL,AT_DATA));
            append_labelentry(DW_AT_high_pc,procendlabel);

            {
            if assigned(pd.funcretsym) and
               (tabstractnormalvarsym(pd.funcretsym).refs>0) then
              begin
                if tabstractnormalvarsym(pd.funcretsym).localloc.loc=LOC_REFERENCE then
                  begin
{$warning Need to add gdb support for ret in param register calling}
                    if paramanager.ret_in_param(pd.rettype.def,pd.proccalloption) then
                      hs:='X*'
                    else
                      hs:='X';
                    templist.concat(Tai_stab.create(stab_stabs,strpnew(
                       '"'+pd.procsym.name+':'+hs+def_stab_number(pd.rettype.def)+'",'+
                       tostr(N_tsym)+',0,0,'+tostr(tabstractnormalvarsym(pd.funcretsym).localloc.reference.offset))));
                    if (m_result in aktmodeswitches) then
                      templist.concat(Tai_stab.create(stab_stabs,strpnew(
                         '"RESULT:'+hs+def_stab_number(pd.rettype.def)+'",'+
                         tostr(N_tsym)+',0,0,'+tostr(tabstractnormalvarsym(pd.funcretsym).localloc.reference.offset))));
                  end;
              end;
            }

            finish_entry;
{
            { para types }
            write_def_stabstr(templist,pd);
}

            if assigned(pd.parast) then
              write_symtable_syms(list,pd.parast);
            { local type defs and vars should not be written
              inside the main proc stab }
            if assigned(pd.localst) and
               (pd.localst.symtabletype=localsymtable) then
              write_symtable_syms(list,pd.localst);

            finish_children;
          end;

      end;


    procedure TDebugInfoDwarf.insertsym(list:taasmoutput;sym:tsym);

        procedure append_varsym(sym:tabstractnormalvarsym);
          var
            templist : taasmoutput;
            blocksize : longint;
            regidx : longint;
            tag : tdwarf_tag;
          begin
            { external symbols can't be resolved at link time, so we
              can't generate stabs for them

              not sure if this applies to dwarf as well (FK)
            }
            if vo_is_external in sym.varoptions then
              exit;

            { There is no space allocated for not referenced locals }
            if (sym.owner.symtabletype=localsymtable) and (sym.refs=0) then
              exit;

            templist:=taasmoutput.create;

            case sym.localloc.loc of
              LOC_REGISTER,
              LOC_CREGISTER,
              LOC_MMREGISTER,
              LOC_CMMREGISTER,
              LOC_FPUREGISTER,
              LOC_CFPUREGISTER :
                begin
                  regidx:=findreg_by_number(sym.localloc.register);
                  templist.concat(tai_const.create_8bit(ord(DW_OP_regx)));
                  templist.concat(tai_const.create_uleb128bit(regdwarf_table[regidx]));
                  blocksize:=Lengthuleb128(regdwarf_table[regidx])+1;
                end;
              else
                begin
                  case sym.typ of
                    globalvarsym:
                      begin
                        if (vo_is_thread_var in sym.varoptions) then
                          begin
{$warning !!! FIXME: dwarf for thread vars !!!}
                          end
                        else
                          begin
                            templist.concat(tai_const.create_8bit(3));
                            templist.concat(tai_const.createname(sym.mangledname,AT_DATA,0));
                            blocksize:=1+sizeof(aword);
                          end;
                      end;
                    paravarsym,
                    localvarsym:
                      begin
                        regidx:=findreg_by_number(sym.localloc.reference.base);
                        templist.concat(tai_const.create_8bit(ord(DW_OP_breg0)+regdwarf_table[regidx]));
                        templist.concat(tai_const.create_sleb128bit(sym.localloc.reference.offset));
                        blocksize:=Lengthsleb128(sym.localloc.reference.offset)+1;
                      end
                    else
                      internalerror(200601288);
                  end;
                end;
            end;

            if sym.typ=paravarsym then
              tag:=DW_TAG_formal_parameter
            else
              tag:=DW_TAG_variable;

            append_entry(tag,false,[
              DW_AT_name,DW_FORM_string,sym.name+#0,
              {
              DW_AT_decl_file,DW_FORM_data1,0,
              DW_AT_decl_line,DW_FORM_data1,
              }
              DW_AT_external,DW_FORM_flag,true,
              { data continues below }
              DW_AT_location,DW_FORM_block1,blocksize
              ]);
            { append block data }
            asmlist[al_dwarf_info].concatlist(templist);
            append_labelentry_ref(DW_AT_type,def_dwarf_lab(sym.vartype.def));

            templist.free;

            finish_entry;
          end;


        procedure paravarsym_stabstr(sym:tparavarsym);
          begin
            {
            result:=nil;
            { set loc to LOC_REFERENCE to get somewhat usable debugging info for -Or }
            { while stabs aren't adapted for regvars yet                             }
            if (vo_is_self in sym.varoptions) then
              begin
                case sym.localloc.loc of
                  LOC_REGISTER,
                  LOC_CREGISTER:
                    regidx:=findreg_by_number(sym.localloc.register);
                  LOC_REFERENCE: ;
                  else
                    internalerror(2003091815);
                end;
                if (po_classmethod in tabstractprocdef(sym.owner.defowner).procoptions) or
                   (po_staticmethod in tabstractprocdef(sym.owner.defowner).procoptions) then
                  begin
                    if (sym.localloc.loc=LOC_REFERENCE) then
                      result:=sym_stabstr_evaluate(sym,'"pvmt:p$1",${N_TSYM},0,0,$2',
                        [def_stab_number(pvmttype.def),tostr(sym.localloc.reference.offset)]);
      (*            else
                      result:=sym_stabstr_evaluate(sym,'"pvmt:r$1",${N_RSYM},0,0,$2',
                        [def_stab_number(pvmttype.def),tostr(regstabs_table[regidx])]) *)
                    end
                else
                  begin
                    if not(is_class(tprocdef(sym.owner.defowner)._class)) then
                      c:='v'
                    else
                      c:='p';
                    if (sym.localloc.loc=LOC_REFERENCE) then
                      result:=sym_stabstr_evaluate(sym,'"$$t:$1",${N_TSYM},0,0,$2',
                            [c+def_stab_number(tprocdef(sym.owner.defowner)._class),tostr(sym.localloc.reference.offset)]);
      (*            else
                      result:=sym_stabstr_evaluate(sym,'"$$t:r$1",${N_RSYM},0,0,$2',
                            [c+def_stab_number(tprocdef(sym.owner.defowner)._class),tostr(regstabs_table[regidx])]); *)
                  end;
              end
            else
              begin
                st:=def_stab_number(sym.vartype.def);

                if paramanager.push_addr_param(sym.varspez,sym.vartype.def,tprocdef(sym.owner.defowner).proccalloption) and
                   not(vo_has_local_copy in sym.varoptions) and
                   not is_open_string(sym.vartype.def) then
                  st := 'v'+st { should be 'i' but 'i' doesn't work }
                else
                  st := 'p'+st;
                case sym.localloc.loc of
                  LOC_REGISTER,
                  LOC_CREGISTER,
                  LOC_MMREGISTER,
                  LOC_CMMREGISTER,
                  LOC_FPUREGISTER,
                  LOC_CFPUREGISTER :
                    begin
                      regidx:=findreg_by_number(sym.localloc.register);
                      { "eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi", "eip", "ps", "cs", "ss", "ds", "es", "fs", "gs", }
                      { this is the register order for GDB}
                      if regidx<>0 then
                        result:=sym_stabstr_evaluate(sym,'"${name}:r$1",${N_RSYM},0,${line},$2',[st,tostr(longint(regstabs_table[regidx]))]);
                    end;
                  LOC_REFERENCE :
                    { offset to ebp => will not work if the framepointer is esp
                      so some optimizing will make things harder to debug }
                    result:=sym_stabstr_evaluate(sym,'"${name}:$1",${N_TSYM},0,${line},$2',[st,tostr(sym.localloc.reference.offset)])
                  else
                    internalerror(2003091814);
                end;
              end;
            }
          end;


        procedure append_constsym(sym:tconstsym);
          begin
            append_entry(DW_TAG_constant,false,[
              DW_AT_name,DW_FORM_string,sym.name+#0
              ]);
            { for string constants, consttype isn't set because they have no real type }
            if sym.consttyp<>conststring then
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(sym.consttype.def));
            asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_AT_const_value)));
            case sym.consttyp of
              conststring:
                begin
                  asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_string)));
                  asmlist[al_dwarf_info].concat(tai_string.create(strpas(pchar(sym.value.valueptr))));
                  asmlist[al_dwarf_info].concat(tai_const.create_8bit(0));
                end;
              constord:
                begin
                  asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_sdata)));
                  asmlist[al_dwarf_info].concat(tai_const.create_sleb128bit(sym.value.valueord));
                end;
              constpointer:
                begin
{$ifdef cpu64bit}
                  asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_data8)));
                  asmlist[al_dwarf_info].concat(tai_const.create_64bit(sym.value.valueordptr));
{$else cpu64bit}
                  asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_data4)));
                  asmlist[al_dwarf_info].concat(tai_const.create_32bit(sym.value.valueordptr));
{$endif cpu64bit}
                end;
              constreal:
                begin
                  asmlist[al_dwarf_abbrev].concat(tai_const.create_uleb128bit(ord(DW_FORM_block1)));
                  case tfloatdef(sym.consttype.def).typ of
                    s32real:
                      begin
                        asmlist[al_dwarf_info].concat(tai_const.create_8bit(4));
                        asmlist[al_dwarf_info].concat(tai_real_32bit.create(psingle(sym.value.valueptr)^));
                      end;
                    s64comp,
                    s64currency,
                    s64real:
                      begin
                        asmlist[al_dwarf_info].concat(tai_const.create_8bit(8));
                        asmlist[al_dwarf_info].concat(tai_real_64bit.create(pdouble(sym.value.valueptr)^));
                      end;
                    s80real:
                      begin
                        asmlist[al_dwarf_info].concat(tai_const.create_8bit(10));
                        asmlist[al_dwarf_info].concat(tai_real_80bit.create(pextended(sym.value.valueptr)^));
                      end;
                    else
                      internalerror(200601291);
                  end;
                end;
              else
                internalerror(200601291);
            end;
            finish_entry;
          end;


        procedure append_procsym(sym:tprocsym);
          var
            i : longint;
          begin
            for i:=1 to sym.procdef_count do
              append_procdef(list,sym.procdef[i]);
          end;


        procedure append_absolutesym(sym:tabsolutevarsym);
          var
            templist : taasmoutput;
            blocksize : longint;
            symlist : psymlistitem;
          begin
            templist:=taasmoutput.create;
            case tabsolutevarsym(sym).abstyp of
              toaddr :
                begin
{$ifdef i386}
                   { in theory, we could write a DW_AT_segment entry here for sym.absseg,
                     however I doubt that gdb supports this (FK) }
{$endif i386}
                   templist.concat(tai_const.create_8bit(3));
                   templist.concat(tai_const.create_aint(sym.addroffset));
                   blocksize:=1+sizeof(aword);
                end;
              toasm :
                begin
                  templist.concat(tai_const.create_8bit(3));
                  templist.concat(tai_const.createname(sym.mangledname,AT_DATA,0));
                  blocksize:=1+sizeof(aword);
                end;
              tovar:
                begin
                  symlist:=tabsolutevarsym(sym).ref.firstsym;
                  { can we insert the symbol? }
                  if assigned(symlist) and
                     (symlist^.sltype=sl_load) then
                    insertsym(list,symlist^.sym);

                  templist.free;
                  exit;
                end;
            end;

            append_entry(DW_TAG_variable,false,[
              DW_AT_name,DW_FORM_string,sym.name+#0,
              {
              DW_AT_decl_file,DW_FORM_data1,0,
              DW_AT_decl_line,DW_FORM_data1,
              }
              DW_AT_external,DW_FORM_flag,true,
              { data continues below }
              DW_AT_location,DW_FORM_block1,blocksize
              ]);
            { append block data }
            asmlist[al_dwarf_info].concatlist(templist);
            append_labelentry_ref(DW_AT_type,def_dwarf_lab(sym.vartype.def));

            templist.free;

            finish_entry;
          end;

      begin
        case sym.typ of
          globalvarsym :
            append_varsym(tglobalvarsym(sym));
          unitsym:
            { for now, we ignore unit symbols }
            ;
          procsym :
            append_procsym(tprocsym(sym));
          labelsym :
            { ignore label syms for now, the problem is that a label sym
              can have more than one label associated e.g. in case of
              an inline procedure expansion }
            ;
          localvarsym :
            append_varsym(tlocalvarsym(sym));
          paravarsym :
            append_varsym(tparavarsym(sym));
          typedconstsym :
            begin
              append_entry(DW_TAG_variable,false,[
                DW_AT_name,DW_FORM_string,sym.name+#0,
                {
                DW_AT_decl_file,DW_FORM_data1,0,
                DW_AT_decl_line,DW_FORM_data1,
                }
                DW_AT_external,DW_FORM_flag,true,
                { data continues below }
                DW_AT_location,DW_FORM_block1,1+sizeof(aword)
              ]);
              { append block data }
              asmlist[al_dwarf_info].concat(tai_const.create_8bit(3));
              asmlist[al_dwarf_info].concat(tai_const.createname(sym.mangledname,AT_DATA,0));
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(ttypedconstsym(sym).typedconsttype.def));

              finish_entry;
            end;
          constsym :
            append_constsym(tconstsym(sym));
          typesym :
            begin
              append_entry(DW_TAG_typedef,false,[
                DW_AT_name,DW_FORM_string,sym.name+#0
              ]);
              append_labelentry_ref(DW_AT_type,def_dwarf_lab(ttypesym(sym).restype.def));
              finish_entry;
            end;
          enumsym :
            { ignore enum syms, they are written by the owner }
            ;
          rttisym :
            { ignore rtti syms, they are only of internal use }
            ;
          syssym :
            { ignore sys syms, they are only of internal use }
            ;
          absolutevarsym :
            append_absolutesym(tabsolutevarsym(sym));
          else
            internalerror(200601242);
        end;
        {
        if stabstr<>nil then
          list.concat(Tai_stab.create(stab_stabs,stabstr));
        { For object types write also the symtable entries }
        if (sym.typ=typesym) and (ttypesym(sym).restype.def.deftype=objectdef) then
          write_symtable_syms(list,tobjectdef(ttypesym(sym).restype.def).symtable);
        sym.isstabwritten:=true;
        }
      end;


    procedure TDebugInfoDwarf.write_symtable_syms(list:taasmoutput;st:tsymtable);
      var
        p : tsym;
      begin
        case st.symtabletype of
          staticsymtable :
            list.concat(tai_comment.Create(strpnew('Syms - Begin Staticsymtable')));
          globalsymtable :
            list.concat(tai_comment.Create(strpnew('Syms - Begin unit '+st.name^+' has index '+tostr(st.moduleid))));
        end;
        p:=tsym(st.symindex.first);
        while assigned(p) do
          begin
            if (not p.isstabwritten) then
              insertsym(list,p);
            p:=tsym(p.indexnext);
          end;
        case st.symtabletype of
          staticsymtable :
            list.concat(tai_comment.Create(strpnew('Syms - End Staticsymtable')));
          globalsymtable :
            list.concat(tai_comment.Create(strpnew('Syms - End unit '+st.name^+' has index '+tostr(st.moduleid))));
        end;
      end;


    procedure TDebugInfoDwarf.insertmoduleinfo;
      var
        templist : taasmoutput;
      begin
        { insert .Ltext0 label }
        templist:=taasmoutput.create;
        new_section(templist,sec_code,'',0);
        templist.concat(tai_symbol.createname('.Ltext0',AT_DATA,0));
        asmlist[al_start].insertlist(templist);
        templist.free;

        { insert .Letext0 label }
        templist:=taasmoutput.create;
        new_section(templist,sec_code,'',0);
        templist.concat(tai_symbol.createname('.Letext0',AT_DATA,0));
        asmlist[al_end].insertlist(templist);
        templist.free;

        { insert .Ldebug_abbrev0 label }
        templist:=taasmoutput.create;
        new_section(templist,sec_debug_abbrev,'',0);
        templist.concat(tai_symbol.createname('.Ldebug_abbrev0',AT_DATA,0));
        asmlist[al_start].insertlist(templist);
        templist.free;

        { insert .Ldebug_line0 label }
        templist:=taasmoutput.create;
        new_section(templist,sec_debug_line,'',0);
        templist.concat(tai_symbol.createname('.Ldebug_line0',AT_DATA,0));
        asmlist[al_start].insertlist(templist);
        templist.free;
      end;


    procedure TDebugInfoDwarf.inserttypeinfo;

      function gettypedef(const s : string) : tdef;
        var
          srsym : ttypesym;
        begin
          if not(searchsystype('TVARDATA',srsym)) then
            internalerror(200602022);
          result:=ttypesym(srsym).restype.def;
        end;

      var
        storefilepos  : tfileposinfo;
        lenstartlabel : tasmlabel;
      begin
        storefilepos:=aktfilepos;
        aktfilepos:=current_module.mainfilepos;

        currabbrevnumber:=0;
        writing_def_dwarf:=false;

        vardatadef:=gettypedef('TVARDATA');

        { not exported (FK)
        filerecdef:=gettypedef('FILEREC');
        textrecdef:=gettypedef('TEXTREC');
        }

        { write start labels }
        asmlist[al_dwarf_info].concat(tai_section.create(sec_debug_info,'',0));
        asmlist[al_dwarf_info].concat(tai_symbol.createname('.Ldebug_info0',AT_DATA,0));

        { start abbrev section }
        new_section(asmlist[al_dwarf_abbrev],sec_debug_abbrev,'',0);

        { debug info header }
        objectlibrary.getlabel(lenstartlabel,alt_dbgfile);
        { size }
        asmlist[al_dwarf_info].concat(tai_const.create_rel_sym(aitconst_ptr,
          lenstartlabel,tasmsymbol.create('.Ledebug_info0',AB_COMMON,AT_DATA)));

        asmlist[al_dwarf_info].concat(tai_label.create(lenstartlabel));
        { version }
        asmlist[al_dwarf_info].concat(tai_const.create_16bit(2));
        { abbrev table }
        asmlist[al_dwarf_info].concat(tai_const.createname('.Ldebug_abbrev0',AT_DATA,0));
        { address size }
        asmlist[al_dwarf_info].concat(tai_const.create_8bit(sizeof(aint)));

        append_entry(DW_TAG_compile_unit,true,[
          DW_AT_name,DW_FORM_string,FixFileName(current_module.sourcefiles.get_file(1).name^)+#0,
          DW_AT_producer,DW_FORM_string,'Free Pascal '+full_version_string+' '+date_string+#0,
          DW_AT_comp_dir,DW_FORM_string,BsToSlash(FixPath(current_module.sourcefiles.get_file(1).path^,false))+#0,
          DW_AT_language,DW_FORM_data1,DW_LANG_Pascal83,
          DW_AT_identifier_case,DW_FORM_data1,DW_ID_case_insensitive]);

        { reference to line info section }
        append_labelentry_data(DW_AT_stmt_list,objectlibrary.newasmsymbol('.Ldebug_line0',AB_LOCAL,AT_DATA));
        append_labelentry(DW_AT_low_pc,objectlibrary.newasmsymbol('.Ltext0',AB_LOCAL,AT_DATA));
        append_labelentry(DW_AT_high_pc,objectlibrary.newasmsymbol('.Letext0',AB_LOCAL,AT_DATA));

        finish_entry;

        { first write all global/local symbols. This will flag all required tdefs }
        if assigned(current_module.globalsymtable) then
          write_symtable_syms(asmlist[al_dwarf_info],current_module.globalsymtable);
        if assigned(current_module.localsymtable) then
          write_symtable_syms(asmlist[al_dwarf_info],current_module.localsymtable);

        { reset unit type info flag }
        reset_unit_type_info;

        { write used types from the used units }
        write_used_unit_type_info(asmlist[al_dwarf_info],current_module);

        { last write the types from this unit }
        if assigned(current_module.globalsymtable) then
          write_symtable_defs(asmlist[al_dwarf_info],current_module.globalsymtable);
        if assigned(current_module.localsymtable) then
          write_symtable_defs(asmlist[al_dwarf_info],current_module.localsymtable);

        { close compilation unit entry }
        finish_children;

        { end of debug info table }
        asmlist[al_dwarf_info].concat(tai_const.create_8bit(0));
        asmlist[al_dwarf_info].concat(tai_symbol.createname('.Ledebug_info0',AT_DATA,0));

        aktfilepos:=storefilepos;
      end;


    procedure TDebugInfoDwarf.referencesections(list:taasmoutput);
      begin
      end;


    procedure TDebugInfoDwarf.insertlineinfo(list:taasmoutput);
      var
        currfileinfo,
        lastfileinfo : tfileposinfo;
        currfuncname : pstring;
        currsectype  : tasmsectiontype;
        hlabel       : tasmlabel;
        hp : tai;
        infile : tinputfile;
      begin
        FillChar(lastfileinfo,sizeof(lastfileinfo),0);
        currfuncname:=nil;
        currsectype:=sec_code;
        hp:=Tai(list.first);
        while assigned(hp) do
          begin
            case hp.typ of
              ait_section :
                currsectype:=tai_section(hp).sectype;
              ait_function_name :
                currfuncname:=tai_function_name(hp).funcname;
              ait_force_line :
                lastfileinfo.line:=-1;
            end;

            if (currsectype=sec_code) and
               (hp.typ=ait_instruction) then
              begin
                currfileinfo:=tailineinfo(hp).fileinfo;
                { file changed ? (must be before line info) }
                if (currfileinfo.fileindex<>0) and
                   (lastfileinfo.fileindex<>currfileinfo.fileindex) then
                  begin
                    infile:=current_module.sourcefiles.get_file(currfileinfo.fileindex);
                    if assigned(infile) then
                      begin
                        inc(currfileidx);
                        if (infile.path^<>'') then
                          list.insertbefore(tai_file.create(
                            BsToSlash(FixPath(infile.path^,false)+FixFileName(infile.name^)),currfileidx
                          ),hp)
                        else
                          list.insertbefore(tai_file.create(
                            FixFileName(infile.name^),currfileidx),hp);
                        { force new line info }
                        lastfileinfo.line:=-1;
                      end;
                  end;

                { line changed ? }
                if (lastfileinfo.line<>currfileinfo.line) and (currfileinfo.line<>0) then
                  list.insertbefore(tai_loc.create(
                    currfileidx,currfileinfo.line,currfileinfo.column),hp);
                lastfileinfo:=currfileinfo;
              end;

            hp:=tai(hp.next);
          end;
      end;


    const
      dbg_dwarf_info : tdbginfo =
         (
           id     : dbg_dwarf;
           idtxt  : 'DWARF';
         );

initialization
  RegisterDebugInfo(dbg_dwarf_info,TDebugInfoDwarf);
end.