fpc/compiler/nobj.pas
peter 3cae449fda * moved rtti to ncgrtti
git-svn-id: trunk@5219 -
2006-11-04 10:43:27 +00:00

1467 lines
59 KiB
ObjectPascal

{
Copyright (c) 1998-2002 by Florian Klaempfl
Routines for the code generation of data structures
like VMT, Messages, VTables, Interfaces descs
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.
****************************************************************************
}
unit nobj;
{$i fpcdefs.inc}
interface
uses
cutils,cclasses,
globtype,
symdef,symsym,
aasmbase,aasmtai,aasmdata
;
type
pprocdeftree = ^tprocdeftree;
tprocdeftree = record
data : tprocdef;
nl : tasmlabel;
l,r : pprocdeftree;
end;
pprocdefcoll = ^tprocdefcoll;
tprocdefcoll = record
data : tprocdef;
hidden : boolean;
visible : boolean;
next : pprocdefcoll;
end;
pvmtentry = ^tvmtentry;
tvmtentry = record
hash : longword;
name : pshortstring;
firstprocdef : pprocdefcoll;
next : pvmtentry;
end;
tclassheader=class
private
_Class : tobjectdef;
private
{ message tables }
root : pprocdeftree;
procedure disposeprocdeftree(p : pprocdeftree);
procedure insertmsgint(p:TObject;arg:pointer);
procedure insertmsgstr(p:TObject;arg:pointer);
procedure insertint(p : pprocdeftree;var at : pprocdeftree;var count:longint);
procedure insertstr(p : pprocdeftree;var at : pprocdeftree;var count:longint);
procedure writenames(p : pprocdeftree);
procedure writeintentry(p : pprocdeftree);
procedure writestrentry(p : pprocdeftree);
{$ifdef WITHDMT}
private
{ dmt }
procedure insertdmtentry(p:TObject;arg:pointer);
procedure writedmtindexentry(p : pprocdeftree);
procedure writedmtaddressentry(p : pprocdeftree);
{$endif}
private
{ published methods }
procedure do_count_published_methods(p:TObject;arg:pointer);
procedure do_gen_published_methods(p:TObject;arg:pointer);
private
{ vmt }
firstvmtentry : pvmtentry;
nextvirtnumber : integer;
has_constructor,
has_virtual_method : boolean;
procedure newdefentry(vmtentry:pvmtentry;pd:tprocdef;is_visible:boolean);
function newvmtentry(sym:tprocsym):pvmtentry;
procedure eachsym(sym : TObject;arg:pointer);
procedure disposevmttree;
procedure writevirtualmethods(List:TAsmList);
private
{ interface tables }
function intf_get_vtbl_name(AImplIntf:TImplementedInterface): string;
procedure intf_create_vtbl(rawdata: TAsmList;AImplIntf:TImplementedInterface);
procedure intf_gen_intf_ref(rawdata: TAsmList;AImplIntf:TImplementedInterface);
procedure intf_optimize_vtbls;
procedure intf_write_data;
function intf_search_procdef_by_name(proc: tprocdef;const name: string): tprocdef;
procedure intf_get_procdefs(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
procedure intf_get_procdefs_recursive(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
public
constructor create(c:tobjectdef);
destructor destroy;override;
{ generates the message tables for a class }
function genstrmsgtab : tasmlabel;
function genintmsgtab : tasmlabel;
function genpublishedmethodstable : tasmlabel;
function generate_field_table : tasmlabel;
{ generates a VMT entries }
procedure genvmt;
{$ifdef WITHDMT}
{ generates a DMT for _class }
function gendmt : tasmlabel;
{$endif WITHDMT}
{ interfaces }
function genintftable: tasmlabel;
{ write the VMT to al_globals }
procedure writevmt;
procedure writeinterfaceids;
end;
implementation
uses
SysUtils,
globals,verbose,systems,
symtable,symconst,symtype,defcmp,
dbgbase,
ncgrtti
;
{*****************************************************************************
TClassHeader
*****************************************************************************}
constructor tclassheader.create(c:tobjectdef);
begin
inherited Create;
_Class:=c;
end;
destructor tclassheader.destroy;
begin
disposevmttree;
end;
{**************************************
Message Tables
**************************************}
procedure tclassheader.disposeprocdeftree(p : pprocdeftree);
begin
if assigned(p^.l) then
disposeprocdeftree(p^.l);
if assigned(p^.r) then
disposeprocdeftree(p^.r);
dispose(p);
end;
procedure tclassheader.insertint(p : pprocdeftree;var at : pprocdeftree;var count:longint);
begin
if at=nil then
begin
at:=p;
inc(count);
end
else
begin
if p^.data.messageinf.i<at^.data.messageinf.i then
insertint(p,at^.l,count)
else if p^.data.messageinf.i>at^.data.messageinf.i then
insertint(p,at^.r,count)
else
Message1(parser_e_duplicate_message_label,tostr(p^.data.messageinf.i));
end;
end;
procedure tclassheader.insertstr(p : pprocdeftree;var at : pprocdeftree;var count:longint);
var
i : integer;
begin
if at=nil then
begin
at:=p;
inc(count);
end
else
begin
i:=CompareStr(p^.data.messageinf.str^,at^.data.messageinf.str^);
if i<0 then
insertstr(p,at^.l,count)
else if i>0 then
insertstr(p,at^.r,count)
else
Message1(parser_e_duplicate_message_label,p^.data.messageinf.str^);
end;
end;
procedure tclassheader.insertmsgint(p:TObject;arg:pointer);
var
i : longint;
pd : Tprocdef;
pt : pprocdeftree;
begin
if tsym(p).typ<>procsym then
exit;
for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
begin
pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
if po_msgint in pd.procoptions then
begin
new(pt);
pt^.data:=pd;
pt^.l:=nil;
pt^.r:=nil;
insertint(pt,root,plongint(arg)^);
end;
end;
end;
procedure tclassheader.insertmsgstr(p:TObject;arg:pointer);
var
i : longint;
pd : Tprocdef;
pt : pprocdeftree;
begin
if tsym(p).typ<>procsym then
exit;
for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
begin
pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
if po_msgstr in pd.procoptions then
begin
new(pt);
pt^.data:=pd;
pt^.l:=nil;
pt^.r:=nil;
insertstr(pt,root,plongint(arg)^);
end;
end;
end;
procedure tclassheader.writenames(p : pprocdeftree);
var
ca : pchar;
len : byte;
begin
current_asmdata.getdatalabel(p^.nl);
if assigned(p^.l) then
writenames(p^.l);
current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(aint))));
current_asmdata.asmlists[al_globals].concat(Tai_label.Create(p^.nl));
len:=length(p^.data.messageinf.str^);
current_asmdata.asmlists[al_globals].concat(tai_const.create_8bit(len));
getmem(ca,len+1);
move(p^.data.messageinf.str[1],ca^,len);
ca[len]:=#0;
current_asmdata.asmlists[al_globals].concat(Tai_string.Create_pchar(ca,len));
if assigned(p^.r) then
writenames(p^.r);
end;
procedure tclassheader.writestrentry(p : pprocdeftree);
begin
if assigned(p^.l) then
writestrentry(p^.l);
{ write name label }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(p^.nl));
current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(p^.data.mangledname,0));
if assigned(p^.r) then
writestrentry(p^.r);
end;
function tclassheader.genstrmsgtab : tasmlabel;
var
count : aint;
begin
root:=nil;
count:=0;
{ insert all message handlers into a tree, sorted by name }
_class.symtable.SymList.ForEachCall(@insertmsgstr,@count);
{ write all names }
if assigned(root) then
writenames(root);
{ now start writing of the message string table }
current_asmdata.getdatalabel(result);
current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(aint))));
current_asmdata.asmlists[al_globals].concat(Tai_label.Create(result));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_aint(count));
if assigned(root) then
begin
writestrentry(root);
disposeprocdeftree(root);
end;
end;
procedure tclassheader.writeintentry(p : pprocdeftree);
begin
if assigned(p^.l) then
writeintentry(p^.l);
{ write name label }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(p^.data.messageinf.i));
current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(p^.data.mangledname,0));
if assigned(p^.r) then
writeintentry(p^.r);
end;
function tclassheader.genintmsgtab : tasmlabel;
var
r : tasmlabel;
count : longint;
begin
root:=nil;
count:=0;
{ insert all message handlers into a tree, sorted by name }
_class.symtable.SymList.ForEachCall(@insertmsgint,@count);
{ now start writing of the message string table }
current_asmdata.getdatalabel(r);
current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(aint))));
current_asmdata.asmlists[al_globals].concat(Tai_label.Create(r));
genintmsgtab:=r;
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(count));
if assigned(root) then
begin
writeintentry(root);
disposeprocdeftree(root);
end;
end;
{$ifdef WITHDMT}
{**************************************
DMT
**************************************}
procedure tclassheader.insertdmtentry(p:TObject;arg:pointer);
var
hp : tprocdef;
pt : pprocdeftree;
begin
if tsym(p).typ=procsym then
begin
hp:=tprocsym(p).definition;
while assigned(hp) do
begin
if (po_msgint in hp.procoptions) then
begin
new(pt);
pt^.p:=hp;
pt^.l:=nil;
pt^.r:=nil;
insertint(pt,root);
end;
hp:=hp.nextoverloaded;
end;
end;
end;
procedure tclassheader.writedmtindexentry(p : pprocdeftree);
begin
if assigned(p^.l) then
writedmtindexentry(p^.l);
al_globals.concat(Tai_const.Create_32bit(p^.data.messageinf.i));
if assigned(p^.r) then
writedmtindexentry(p^.r);
end;
procedure tclassheader.writedmtaddressentry(p : pprocdeftree);
begin
if assigned(p^.l) then
writedmtaddressentry(p^.l);
al_globals.concat(Tai_const_symbol.Createname(p^.data.mangledname,0));
if assigned(p^.r) then
writedmtaddressentry(p^.r);
end;
function tclassheader.gendmt : tasmlabel;
var
r : tasmlabel;
begin
root:=nil;
count:=0;
gendmt:=nil;
{ insert all message handlers into a tree, sorted by number }
_class.symtable.SymList.ForEachCall(insertdmtentry);
if count>0 then
begin
current_asmdata.getdatalabel(r);
gendmt:=r;
al_globals.concat(cai_align.create(const_align(sizeof(aint))));
al_globals.concat(Tai_label.Create(r));
{ entries for caching }
al_globals.concat(Tai_const.Create_ptr(0));
al_globals.concat(Tai_const.Create_ptr(0));
al_globals.concat(Tai_const.Create_32bit(count));
if assigned(root) then
begin
writedmtindexentry(root);
writedmtaddressentry(root);
disposeprocdeftree(root);
end;
end;
end;
{$endif WITHDMT}
{**************************************
Published Methods
**************************************}
procedure tclassheader.do_count_published_methods(p:TObject;arg:pointer);
var
i : longint;
pd : tprocdef;
begin
if (tsym(p).typ<>procsym) then
exit;
for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
begin
pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
if (pd.procsym=tsym(p)) and
(sp_published in pd.symoptions) then
inc(plongint(arg)^);
end;
end;
procedure tclassheader.do_gen_published_methods(p:TObject;arg:pointer);
var
i : longint;
l : tasmlabel;
pd : tprocdef;
begin
if (tsym(p).typ<>procsym) then
exit;
for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
begin
pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
if (pd.procsym=tsym(p)) and
(sp_published in pd.symoptions) then
begin
current_asmdata.getdatalabel(l);
current_asmdata.asmlists[al_typedconsts].concat(cai_align.create(const_align(sizeof(aint))));
current_asmdata.asmlists[al_typedconsts].concat(Tai_label.Create(l));
current_asmdata.asmlists[al_typedconsts].concat(Tai_const.Create_8bit(length(tsym(p).realname)));
current_asmdata.asmlists[al_typedconsts].concat(Tai_string.Create(tsym(p).realname));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(l));
if po_abstractmethod in pd.procoptions then
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(pd.mangledname,0));
end;
end;
end;
function tclassheader.genpublishedmethodstable : tasmlabel;
var
l : tasmlabel;
count : longint;
begin
count:=0;
_class.symtable.SymList.ForEachCall(@do_count_published_methods,@count);
if count>0 then
begin
current_asmdata.getdatalabel(l);
current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(aint))));
current_asmdata.asmlists[al_globals].concat(Tai_label.Create(l));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(count));
_class.symtable.SymList.ForEachCall(@do_gen_published_methods,nil);
genpublishedmethodstable:=l;
end
else
genpublishedmethodstable:=nil;
end;
function tclassheader.generate_field_table : tasmlabel;
var
i : longint;
sym : tsym;
fieldtable,
classtable : tasmlabel;
classindex,
fieldcount : longint;
classtablelist : TFPList;
begin
classtablelist:=TFPList.Create;
current_asmdata.getdatalabel(fieldtable);
current_asmdata.getdatalabel(classtable);
maybe_new_object_file(current_asmdata.asmlists[al_rtti]);
new_section(current_asmdata.asmlists[al_rtti],sec_rodata,classtable.name,const_align(sizeof(aint)));
{ retrieve field info fields }
fieldcount:=0;
for i:=0 to _class.symtable.SymList.Count-1 do
begin
sym:=tsym(_class.symtable.SymList[i]);
if (tsym(sym).typ=fieldvarsym) and
(sp_published in tsym(sym).symoptions) then
begin
if tfieldvarsym(sym).vardef.typ<>objectdef then
internalerror(200611032);
classindex:=classtablelist.IndexOf(tfieldvarsym(sym).vardef);
if classindex=-1 then
classtablelist.Add(tfieldvarsym(sym).vardef);
inc(fieldcount);
end;
end;
{ write fields }
current_asmdata.asmlists[al_rtti].concat(Tai_label.Create(fieldtable));
current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_16bit(fieldcount));
{$ifdef cpurequiresproperalignment}
current_asmdata.asmlists[al_rtti].concat(cai_align.Create(sizeof(TConstPtrUInt)));
{$endif cpurequiresproperalignment}
current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_sym(classtable));
for i:=0 to _class.symtable.SymList.Count-1 do
begin
sym:=tsym(_class.symtable.SymList[i]);
if (tsym(sym).typ=fieldvarsym) and
(sp_published in tsym(sym).symoptions) then
begin
{$ifdef cpurequiresproperalignment}
current_asmdata.asmlists[al_rtti].concat(cai_align.Create(sizeof(AInt)));
{$endif cpurequiresproperalignment}
current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_aint(tfieldvarsym(sym).fieldoffset));
classindex:=classtablelist.IndexOf(tfieldvarsym(sym).vardef);
if classindex=-1 then
internalerror(200611033);
current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_16bit(classindex+1));
current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_8bit(length(tfieldvarsym(sym).realname)));
current_asmdata.asmlists[al_rtti].concat(Tai_string.Create(tfieldvarsym(sym).realname));
end;
end;
{ generate the class table }
current_asmdata.asmlists[al_rtti].concat(cai_align.create(const_align(sizeof(aint))));
current_asmdata.asmlists[al_rtti].concat(Tai_label.Create(classtable));
current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_16bit(classtablelist.count));
{$ifdef cpurequiresproperalignment}
current_asmdata.asmlists[al_rtti].concat(cai_align.Create(sizeof(TConstPtrUInt)));
{$endif cpurequiresproperalignment}
for i:=0 to classtablelist.Count-1 do
current_asmdata.asmlists[al_rtti].concat(Tai_const.Createname(tobjectdef(classtablelist[i]).vmt_mangledname,0));
classtablelist.free;
result:=fieldtable;
end;
{**************************************
VMT
**************************************}
procedure tclassheader.newdefentry(vmtentry:pvmtentry;pd:tprocdef;is_visible:boolean);
var
procdefcoll : pprocdefcoll;
begin
if (_class=pd._class) then
begin
{ new entry is needed, override was not possible }
if (po_overridingmethod in pd.procoptions) then
MessagePos1(pd.fileinfo,parser_e_nothing_to_be_overridden,pd.fullprocname(false));
{ check that all methods have overload directive }
if not(m_fpc in current_settings.modeswitches) then
begin
procdefcoll:=vmtentry^.firstprocdef;
while assigned(procdefcoll) do
begin
if (procdefcoll^.data._class=pd._class) and
((po_overload in pd.procoptions)<>(po_overload in procdefcoll^.data.procoptions)) then
begin
MessagePos1(pd.fileinfo,parser_e_no_overload_for_all_procs,pd.procsym.realname);
{ recover }
include(procdefcoll^.data.procoptions,po_overload);
include(pd.procoptions,po_overload);
end;
procdefcoll:=procdefcoll^.next;
end;
end;
end;
{ generate new entry }
new(procdefcoll);
procdefcoll^.data:=pd;
procdefcoll^.hidden:=false;
procdefcoll^.visible:=is_visible;
procdefcoll^.next:=vmtentry^.firstprocdef;
vmtentry^.firstprocdef:=procdefcoll;
{ give virtual method a number }
if (po_virtualmethod in pd.procoptions) then
begin
pd.extnumber:=nextvirtnumber;
inc(nextvirtnumber);
has_virtual_method:=true;
end;
if (pd.proctypeoption=potype_constructor) then
has_constructor:=true;
end;
function tclassheader.newvmtentry(sym:tprocsym):pvmtentry;
begin
{ generate new vmtentry }
new(result);
result^.Hash:=sym.Hash;
result^.name:=stringdup(sym.name);
result^.next:=firstvmtentry;
result^.firstprocdef:=nil;
firstvmtentry:=result;
end;
procedure tclassheader.eachsym(sym : TObject;arg:pointer);
const
po_comp = [po_classmethod,po_virtualmethod,po_staticmethod,po_interrupt,po_iocheck,po_msgstr,po_msgint,
po_exports,po_varargs,po_explicitparaloc,po_nostackframe];
label
handlenextdef;
var
pd : tprocdef;
i : cardinal;
is_visible,
hasoverloads,
pdoverload : boolean;
procdefcoll : pprocdefcoll;
vmtentry : pvmtentry;
_name : string;
_speed : cardinal;
begin
if (tsym(sym).typ<>procsym) then
exit;
{ check the current list of symbols }
_name:=TSym(sym).name;
_speed:=TSym(sym).Hash;
vmtentry:=firstvmtentry;
while assigned(vmtentry) do
begin
{ does the symbol already exist in the list? First
compare speedvalue before doing the string compare to
speed it up a little }
if (_speed=vmtentry^.Hash) and
(_name=vmtentry^.name^) then
begin
hasoverloads:=(Tprocsym(sym).ProcdefList.Count>1);
{ walk through all defs of the symbol }
for i:=0 to Tprocsym(sym).ProcdefList.Count-1 do
begin
pd:=tprocdef(Tprocsym(sym).ProcdefList[i]);
{ is this procdef visible from the class that we are
generating. This will be used to hide the other procdefs.
When the symbol is not visible we don't hide the other
procdefs, because they can be reused in the next class.
The check to skip the invisible methods that are in the
list is futher down in the code }
is_visible:=pd.is_visible_for_object(_class,nil);
if pd.procsym=sym then
begin
pdoverload:=(po_overload in pd.procoptions);
{ compare with all stored definitions }
procdefcoll:=vmtentry^.firstprocdef;
while assigned(procdefcoll) do
begin
{ compare only if the definition is not hidden }
if not procdefcoll^.hidden then
begin
{ check if one of the two methods has virtual }
if (po_virtualmethod in procdefcoll^.data.procoptions) or
(po_virtualmethod in pd.procoptions) then
begin
{ if the current definition has no virtual then hide the
old virtual if the new definition has the same arguments or
when it has no overload directive and no overloads }
if not(po_virtualmethod in pd.procoptions) then
begin
if procdefcoll^.visible and
(not(pdoverload or hasoverloads) or
(compare_paras(procdefcoll^.data.paras,pd.paras,cp_all,[])>=te_equal)) then
begin
if is_visible then
procdefcoll^.hidden:=true;
if (_class=pd._class) and not(po_reintroduce in pd.procoptions) then
MessagePos1(pd.fileinfo,parser_w_should_use_override,pd.fullprocname(false));
end;
end
{ if both are virtual we check the header }
else if (po_virtualmethod in pd.procoptions) and
(po_virtualmethod in procdefcoll^.data.procoptions) then
begin
{ new one has not override }
if is_class(_class) and
not(po_overridingmethod in pd.procoptions) then
begin
{ we start a new virtual tree, hide the old }
if (not(pdoverload or hasoverloads) or
(compare_paras(procdefcoll^.data.paras,pd.paras,cp_all,[])>=te_equal)) and
(procdefcoll^.visible) then
begin
if is_visible then
procdefcoll^.hidden:=true;
if (_class=pd._class) and not(po_reintroduce in pd.procoptions) then
MessagePos1(pd.fileinfo,parser_w_should_use_override,pd.fullprocname(false));
end;
end
{ same parameters }
else if (compare_paras(procdefcoll^.data.paras,pd.paras,cp_all,[])>=te_equal) then
begin
{ overload is inherited }
if (po_overload in procdefcoll^.data.procoptions) then
include(pd.procoptions,po_overload);
{ inherite calling convention when it was force and the
current definition has none force }
if (po_hascallingconvention in procdefcoll^.data.procoptions) and
not(po_hascallingconvention in pd.procoptions) then
begin
pd.proccalloption:=procdefcoll^.data.proccalloption;
include(pd.procoptions,po_hascallingconvention);
end;
{ the flags have to match except abstract and override }
{ only if both are virtual !! }
if (procdefcoll^.data.proccalloption<>pd.proccalloption) or
(procdefcoll^.data.proctypeoption<>pd.proctypeoption) or
((procdefcoll^.data.procoptions*po_comp)<>(pd.procoptions*po_comp)) then
begin
MessagePos1(pd.fileinfo,parser_e_header_dont_match_forward,pd.fullprocname(false));
tprocsym(procdefcoll^.data.procsym).write_parameter_lists(pd);
end;
{ error, if the return types aren't equal }
if not(equal_defs(procdefcoll^.data.returndef,pd.returndef)) and
not((procdefcoll^.data.returndef.typ=objectdef) and
(pd.returndef.typ=objectdef) and
is_class_or_interface(procdefcoll^.data.returndef) and
is_class_or_interface(pd.returndef) and
(tobjectdef(pd.returndef).is_related(
tobjectdef(procdefcoll^.data.returndef)))) then
begin
if not((m_delphi in current_settings.modeswitches) and
is_interface(_class)) then
Message2(parser_e_overridden_methods_not_same_ret,pd.fullprocname(false),
procdefcoll^.data.fullprocname(false))
else
{ Delphi allows changing the result type }
{ of interface methods from anything to }
{ anything (JM) }
Message2(parser_w_overridden_methods_not_same_ret,pd.fullprocname(false),
procdefcoll^.data.fullprocname(false));
end;
{ check if the method to override is visible, check is only needed
for the current parsed class. Parent classes are already validated and
need to include all virtual methods including the ones not visible in the
current class }
if (_class=pd._class) and
(po_overridingmethod in pd.procoptions) and
(not procdefcoll^.visible) then
MessagePos1(pd.fileinfo,parser_e_nothing_to_be_overridden,pd.fullprocname(false));
{ override old virtual method in VMT }
pd.extnumber:=procdefcoll^.data.extnumber;
procdefcoll^.data:=pd;
if is_visible then
procdefcoll^.visible:=true;
goto handlenextdef;
end
{ different parameters }
else
begin
{ when we got an override directive then can search futher for
the procedure to override.
If we are starting a new virtual tree then hide the old tree }
if not(po_overridingmethod in pd.procoptions) and
not pdoverload then
begin
if is_visible then
procdefcoll^.hidden:=true;
if (_class=pd._class) and not(po_reintroduce in pd.procoptions) then
MessagePos1(pd.fileinfo,parser_w_should_use_override,pd.fullprocname(false));
end;
end;
end
else
begin
{ the new definition is virtual and the old static, we hide the old one
if the new defintion has not the overload directive }
if is_visible and
((not(pdoverload or hasoverloads)) or
(compare_paras(procdefcoll^.data.paras,pd.paras,cp_all,[])>=te_equal)) then
procdefcoll^.hidden:=true;
end;
end
else
begin
{ both are static, we hide the old one if the new defintion
has not the overload directive }
if is_visible and
((not pdoverload) or
(compare_paras(procdefcoll^.data.paras,pd.paras,cp_all,[])>=te_equal)) then
procdefcoll^.hidden:=true;
end;
end; { not hidden }
procdefcoll:=procdefcoll^.next;
end;
{ if it isn't saved in the list we create a new entry }
newdefentry(vmtentry,pd,is_visible);
end;
handlenextdef:
end;
exit;
end;
vmtentry:=vmtentry^.next;
end;
{ Generate new procsym entry in vmt }
vmtentry:=newvmtentry(tprocsym(sym));
{ Add procdefs }
for i:=0 to Tprocsym(sym).ProcdefList.Count-1 do
begin
pd:=tprocdef(Tprocsym(sym).ProcdefList[i]);
newdefentry(vmtentry,pd,pd.is_visible_for_object(_class,nil));
end;
end;
procedure tclassheader.disposevmttree;
var
vmtentry : pvmtentry;
procdefcoll : pprocdefcoll;
begin
{ disposes the above generated tree }
vmtentry:=firstvmtentry;
while assigned(vmtentry) do
begin
firstvmtentry:=vmtentry^.next;
stringdispose(vmtentry^.name);
procdefcoll:=vmtentry^.firstprocdef;
while assigned(procdefcoll) do
begin
vmtentry^.firstprocdef:=procdefcoll^.next;
dispose(procdefcoll);
procdefcoll:=vmtentry^.firstprocdef;
end;
dispose(vmtentry);
vmtentry:=firstvmtentry;
end;
end;
procedure tclassheader.genvmt;
procedure do_genvmt(p : tobjectdef);
begin
{ start with the base class }
if assigned(p.childof) then
do_genvmt(p.childof);
{ walk through all public syms }
p.symtable.SymList.ForEachCall(@eachsym,nil);
end;
begin
firstvmtentry:=nil;
nextvirtnumber:=0;
has_constructor:=false;
has_virtual_method:=false;
{ generates a tree of all used methods }
do_genvmt(_class);
if not(is_interface(_class)) and
has_virtual_method and
not(has_constructor) then
Message1(parser_w_virtual_without_constructor,_class.objrealname^);
end;
{**************************************
Interface tables
**************************************}
function tclassheader.intf_get_vtbl_name(AImplIntf:TImplementedInterface): string;
begin
result:=make_mangledname('VTBL',_class.owner,_class.objname^+'_$_'+AImplIntf.IntfDef.objname^);
end;
procedure tclassheader.intf_create_vtbl(rawdata: TAsmList;AImplIntf:TImplementedInterface);
var
pd : tprocdef;
vtblstr,
hs : string;
i : longint;
begin
vtblstr:=intf_get_vtbl_name(AImplIntf);
section_symbol_start(rawdata,vtblstr,AT_DATA,true,sec_data,const_align(sizeof(aint)));
if assigned(AImplIntf.procdefs) then
begin
for i:=0 to AImplIntf.procdefs.count-1 do
begin
pd:=tprocdef(AImplIntf.procdefs[i]);
hs:=make_mangledname('WRPR',_class.owner,_class.objname^+'_$_'+AImplIntf.IntfDef.objname^+'_$_'+
tostr(i)+'_$_'+pd.mangledname);
{ create reference }
rawdata.concat(Tai_const.Createname(hs,0));
end;
end;
section_symbol_end(rawdata,vtblstr);
end;
procedure tclassheader.intf_gen_intf_ref(rawdata: TAsmList;AImplIntf:TImplementedInterface);
var
iidlabel,
guidlabel : tasmlabel;
i: longint;
begin
{ GUID }
if AImplIntf.IntfDef.objecttype in [odt_interfacecom] then
begin
{ label for GUID }
current_asmdata.getdatalabel(guidlabel);
rawdata.concat(cai_align.create(const_align(sizeof(aint))));
rawdata.concat(Tai_label.Create(guidlabel));
with AImplIntf.IntfDef.iidguid^ do
begin
rawdata.concat(Tai_const.Create_32bit(longint(D1)));
rawdata.concat(Tai_const.Create_16bit(D2));
rawdata.concat(Tai_const.Create_16bit(D3));
for i:=Low(D4) to High(D4) do
rawdata.concat(Tai_const.Create_8bit(D4[i]));
end;
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(guidlabel));
end
else
begin
{ nil for Corba interfaces }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
end;
{ VTable }
current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(intf_get_vtbl_name(AImplIntf.VtblImplIntf),0));
{ IOffset field }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_aint(AImplIntf.VtblImplIntf.ioffset));
{ IIDStr }
current_asmdata.getdatalabel(iidlabel);
rawdata.concat(cai_align.create(const_align(sizeof(aint))));
rawdata.concat(Tai_label.Create(iidlabel));
rawdata.concat(Tai_const.Create_8bit(length(AImplIntf.IntfDef.iidstr^)));
if AImplIntf.IntfDef.objecttype=odt_interfacecom then
rawdata.concat(Tai_string.Create(upper(AImplIntf.IntfDef.iidstr^)))
else
rawdata.concat(Tai_string.Create(AImplIntf.IntfDef.iidstr^));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(iidlabel));
{ EntryType }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_aint(aint(AImplIntf.IntfDef.iitype)));
{ EntryOffset }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_aint(aint(AImplIntf.IntfDef.iioffset)));
end;
procedure tclassheader.intf_optimize_vtbls;
type
tcompintfentry = record
weight: longint;
compintf: longint;
end;
{ Max 1000 interface in the class header interfaces it's enough imho }
tcompintfs = array[0..1000] of tcompintfentry;
pcompintfs = ^tcompintfs;
tequals = array[0..1000] of longint;
pequals = ^tequals;
timpls = array[0..1000] of longint;
pimpls = ^timpls;
var
equals: pequals;
compats: pcompintfs;
impls: pimpls;
ImplIntfCount,
w,i,j,k: longint;
ImplIntfI,
ImplIntfJ : TImplementedInterface;
cij: boolean;
cji: boolean;
begin
ImplIntfCount:=_class.ImplementedInterfaces.count;
if ImplIntfCount>=High(tequals) then
Internalerror(200006135);
getmem(compats,sizeof(tcompintfentry)*ImplIntfCount);
getmem(equals,sizeof(longint)*ImplIntfCount);
getmem(impls,sizeof(longint)*ImplIntfCount);
filldword(compats^,(sizeof(tcompintfentry) div sizeof(dword))*ImplIntfCount,dword(-1));
filldword(equals^,ImplIntfCount,dword(-1));
filldword(impls^,ImplIntfCount,dword(-1));
{ ismergepossible is a containing relation
meaning of ismergepossible(a,b,w) =
if implementorfunction map of a is contained implementorfunction map of b
imp(a,b) and imp(b,c) => imp(a,c) ; imp(a,b) and imp(b,a) => a == b
}
{ the order is very important for correct allocation }
for i:=0 to ImplIntfCount-1 do
begin
for j:=i+1 to ImplIntfCount-1 do
begin
ImplIntfI:=TImplementedInterface(_class.ImplementedInterfaces[i]);
ImplIntfJ:=TImplementedInterface(_class.ImplementedInterfaces[j]);
cij:=ImplIntfI.IsImplMergePossible(ImplIntfJ,w);
cji:=ImplIntfJ.IsImplMergePossible(ImplIntfI,w);
if cij and cji then { i equal j }
begin
{ get minimum index of equal }
if equals^[j]=-1 then
equals^[j]:=i;
end
else if cij then
begin
{ get minimum index of maximum weight }
if compats^[i].weight<w then
begin
compats^[i].weight:=w;
compats^[i].compintf:=j;
end;
end
else if cji then
begin
{ get minimum index of maximum weight }
if (compats^[j].weight<w) then
begin
compats^[j].weight:=w;
compats^[j].compintf:=i;
end;
end;
end;
end;
{ Reset, no replacements by default }
for i:=0 to ImplIntfCount-1 do
impls^[i]:=i;
{ Replace vtbls when equal or compat, repeat
until there are no replacements possible anymore. This is
needed for the cases like:
First loop: 2->3, 3->1
Second loop: 2->1 (because 3 was replaced with 1)
}
repeat
k:=0;
for i:=0 to ImplIntfCount-1 do
begin
if compats^[impls^[i]].compintf<>-1 then
impls^[i]:=compats^[impls^[i]].compintf
else if equals^[impls^[i]]<>-1 then
impls^[i]:=equals^[impls^[i]]
else
inc(k);
end;
until k=ImplIntfCount;
{ Update the VtblImplIntf }
for i:=0 to ImplIntfCount-1 do
begin
ImplIntfI:=TImplementedInterface(_class.ImplementedInterfaces[i]);
ImplIntfI.VtblImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[impls^[i]]);
end;
freemem(compats);
freemem(equals);
freemem(impls);
end;
procedure tclassheader.intf_write_data;
var
rawdata : TAsmList;
i : longint;
ImplIntf : TImplementedInterface;
begin
rawdata:=TAsmList.Create;
{ Two pass, one for allocation and vtbl creation }
for i:=0 to _class.ImplementedInterfaces.count-1 do
begin
ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
{ if it implements itself }
if ImplIntf.VtblImplIntf=ImplIntf then
begin
{ allocate a pointer in the object memory }
with tObjectSymtable(_class.symtable) do
begin
datasize:=align(datasize,sizeof(aint));
ImplIntf.Ioffset:=datasize;
inc(datasize,sizeof(aint));
end;
{ write vtbl }
intf_create_vtbl(rawdata,ImplIntf);
end;
end;
{ second pass: for fill interfacetable and remained ioffsets }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_aint(_class.ImplementedInterfaces.count));
for i:=0 to _class.ImplementedInterfaces.count-1 do
begin
ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
{ Update ioffset of current interface with the ioffset from
the interface that is reused to implements this interface }
if ImplIntf.VtblImplIntf<>ImplIntf then
ImplIntf.Ioffset:=ImplIntf.VtblImplIntf.Ioffset;
intf_gen_intf_ref(rawdata,ImplIntf);
end;
current_asmdata.asmlists[al_globals].concatlist(rawdata);
rawdata.free;
end;
function tclassheader.intf_search_procdef_by_name(proc: tprocdef;const name: string): tprocdef;
const
po_comp = [po_classmethod,po_staticmethod,po_interrupt,po_iocheck,po_msgstr,po_msgint,
po_exports,po_varargs,po_explicitparaloc,po_nostackframe];
var
sym: tsym;
implprocdef : Tprocdef;
i: cardinal;
begin
result:=nil;
sym:=tsym(search_class_member(_class,name));
if assigned(sym) and
(sym.typ=procsym) then
begin
{ when the definition has overload directive set, we search for
overloaded definitions in the class, this only needs to be done once
for class entries as the tree keeps always the same }
if (not tprocsym(sym).overloadchecked) and
(po_overload in tprocdef(tprocsym(sym).ProcdefList[0]).procoptions) and
(tprocsym(sym).owner.symtabletype=ObjectSymtable) then
search_class_overloads(tprocsym(sym));
for i:=0 to Tprocsym(sym).ProcdefList.Count-1 do
begin
implprocdef:=tprocdef(Tprocsym(sym).ProcdefList[i]);
if (compare_paras(proc.paras,implprocdef.paras,cp_none,[])>=te_equal) and
(proc.proccalloption=implprocdef.proccalloption) and
(proc.proctypeoption=implprocdef.proctypeoption) and
((proc.procoptions*po_comp)=((implprocdef.procoptions+[po_virtualmethod])*po_comp)) then
begin
result:=implprocdef;
exit;
end;
end;
end;
end;
procedure tclassheader.intf_get_procdefs(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
var
i : longint;
def : tdef;
hs,
prefix,
mappedname: string;
implprocdef: tprocdef;
begin
prefix:=ImplIntf.IntfDef.symtable.name^+'.';
for i:=0 to IntfDef.symtable.DefList.Count-1 do
begin
def:=tdef(IntfDef.symtable.DefList[i]);
if def.typ=procdef then
begin
{ Find implementing procdef
1. Check for mapped name
2. Use symbol name }
implprocdef:=nil;
hs:=prefix+tprocdef(def).procsym.name;
mappedname:=ImplIntf.GetMapping(hs);
if mappedname<>'' then
implprocdef:=intf_search_procdef_by_name(tprocdef(def),mappedname);
if not assigned(implprocdef) then
implprocdef:=intf_search_procdef_by_name(tprocdef(def),tprocdef(def).procsym.name);
{ Add procdef to the implemented interface }
if assigned(implprocdef) then
ImplIntf.AddImplProc(implprocdef)
else
if ImplIntf.IntfDef.iitype = etStandard then
Message1(sym_e_no_matching_implementation_found,tprocdef(def).fullprocname(false));
end;
end;
end;
procedure tclassheader.intf_get_procdefs_recursive(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
begin
if assigned(IntfDef.childof) then
intf_get_procdefs_recursive(ImplIntf,IntfDef.childof);
intf_get_procdefs(ImplIntf,IntfDef);
end;
function tclassheader.genintftable: tasmlabel;
var
ImplIntf : TImplementedInterface;
intftable : tasmlabel;
i : longint;
begin
{ 1. step collect implementor functions into the tImplementedInterface.procdefs }
for i:=0 to _class.ImplementedInterfaces.count-1 do
begin
ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
intf_get_procdefs_recursive(ImplIntf,ImplIntf.IntfDef);
end;
{ 2. Optimize interface tables to reuse wrappers }
intf_optimize_vtbls;
{ 3. Calculate offsets in object map and Write interface tables }
current_asmdata.getdatalabel(intftable);
current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(aint))));
current_asmdata.asmlists[al_globals].concat(Tai_label.Create(intftable));
intf_write_data;
genintftable:=intftable;
end;
{ Write interface identifiers to the data section }
procedure tclassheader.writeinterfaceids;
var
i : longint;
s : string;
begin
if assigned(_class.iidguid) then
begin
s:=make_mangledname('IID',_class.owner,_class.objname^);
maybe_new_object_file(current_asmdata.asmlists[al_globals]);
new_section(current_asmdata.asmlists[al_globals],sec_rodata,s,const_align(sizeof(aint)));
current_asmdata.asmlists[al_globals].concat(Tai_symbol.Createname_global(s,AT_DATA,0));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(longint(_class.iidguid^.D1)));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_16bit(_class.iidguid^.D2));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_16bit(_class.iidguid^.D3));
for i:=Low(_class.iidguid^.D4) to High(_class.iidguid^.D4) do
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_8bit(_class.iidguid^.D4[i]));
end;
maybe_new_object_file(current_asmdata.asmlists[al_globals]);
s:=make_mangledname('IIDSTR',_class.owner,_class.objname^);
new_section(current_asmdata.asmlists[al_globals],sec_rodata,s,0);
current_asmdata.asmlists[al_globals].concat(Tai_symbol.Createname_global(s,AT_DATA,0));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_8bit(length(_class.iidstr^)));
current_asmdata.asmlists[al_globals].concat(Tai_string.Create(_class.iidstr^));
end;
procedure tclassheader.writevirtualmethods(List:TAsmList);
var
vmtentry : pvmtentry;
procdefcoll : pprocdefcoll;
i : longint;
procname : string;
{$ifdef vtentry}
hs : string;
{$endif vtentry}
begin
{ walk trough all numbers for virtual methods and search }
{ the method }
for i:=0 to nextvirtnumber-1 do
begin
{ walk trough all symbols }
vmtentry:=firstvmtentry;
while assigned(vmtentry) do
begin
{ walk trough all methods }
procdefcoll:=vmtentry^.firstprocdef;
while assigned(procdefcoll) do
begin
{ writes the addresses to the VMT }
{ but only this which are declared as virtual }
if (procdefcoll^.data.extnumber=i) and
(po_virtualmethod in procdefcoll^.data.procoptions) then
begin
if (po_abstractmethod in procdefcoll^.data.procoptions) then
procname:='FPC_ABSTRACTERROR'
else
procname:=procdefcoll^.data.mangledname;
List.concat(Tai_const.createname(procname,0));
{$ifdef vtentry}
hs:='VTENTRY'+'_'+_class.vmt_mangledname+'$$'+tostr(_class.vmtmethodoffset(i) div sizeof(aint));
current_asmdata.asmlists[al_globals].concat(tai_symbol.CreateName(hs,AT_DATA,0));
{$endif vtentry}
break;
end;
procdefcoll:=procdefcoll^.next;
end;
vmtentry:=vmtentry^.next;
end;
end;
end;
{ generates the vmt for classes as well as for objects }
procedure tclassheader.writevmt;
var
methodnametable,intmessagetable,
strmessagetable,classnamelabel,
fieldtablelabel : tasmlabel;
{$ifdef WITHDMT}
dmtlabel : tasmlabel;
{$endif WITHDMT}
interfacetable : tasmlabel;
{$ifdef vtentry}
hs: string;
{$endif vtentry}
begin
{$ifdef WITHDMT}
dmtlabel:=gendmt;
{$endif WITHDMT}
{ write tables for classes, this must be done before the actual
class is written, because we need the labels defined }
if is_class(_class) then
begin
current_asmdata.getdatalabel(classnamelabel);
maybe_new_object_file(current_asmdata.asmlists[al_globals]);
new_section(current_asmdata.asmlists[al_globals],sec_rodata,classnamelabel.name,const_align(sizeof(aint)));
{ interface table }
if _class.ImplementedInterfaces.count>0 then
interfacetable:=genintftable;
methodnametable:=genpublishedmethodstable;
fieldtablelabel:=generate_field_table;
{ write class name }
current_asmdata.asmlists[al_globals].concat(Tai_label.Create(classnamelabel));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_8bit(length(_class.objrealname^)));
current_asmdata.asmlists[al_globals].concat(Tai_string.Create(_class.objrealname^));
{ generate message and dynamic tables }
if (oo_has_msgstr in _class.objectoptions) then
strmessagetable:=genstrmsgtab;
if (oo_has_msgint in _class.objectoptions) then
intmessagetable:=genintmsgtab;
end;
{ write debug info }
maybe_new_object_file(current_asmdata.asmlists[al_globals]);
new_section(current_asmdata.asmlists[al_globals],sec_rodata,_class.vmt_mangledname,const_align(sizeof(aint)));
current_asmdata.asmlists[al_globals].concat(Tai_symbol.Createname_global(_class.vmt_mangledname,AT_DATA,0));
{ determine the size with symtable.datasize, because }
{ size gives back 4 for classes }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create(aitconst_ptr,tObjectSymtable(_class.symtable).datasize));
current_asmdata.asmlists[al_globals].concat(Tai_const.Create(aitconst_ptr,-int64(tObjectSymtable(_class.symtable).datasize)));
{$ifdef WITHDMT}
if _class.classtype=ct_object then
begin
if assigned(dmtlabel) then
current_asmdata.asmlists[al_globals].concat(Tai_const_symbol.Create(dmtlabel)))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_ptr(0));
end;
{$endif WITHDMT}
{ write pointer to parent VMT, this isn't implemented in TP }
{ but this is not used in FPC ? (PM) }
{ it's not used yet, but the delphi-operators as and is need it (FK) }
{ it is not written for parents that don't have any vmt !! }
if assigned(_class.childof) and
(oo_has_vmt in _class.childof.objectoptions) then
current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(_class.childof.vmt_mangledname,0))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
{ write extended info for classes, for the order see rtl/inc/objpash.inc }
if is_class(_class) then
begin
{ pointer to class name string }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(classnamelabel));
{ pointer to dynamic table or nil }
if (oo_has_msgint in _class.objectoptions) then
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(intmessagetable))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
{ pointer to method table or nil }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(methodnametable));
{ pointer to field table }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(fieldtablelabel));
{ pointer to type info of published section }
if (oo_can_have_published in _class.objectoptions) then
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(RTTIWriter.get_rtti_label(_class,fullrtti)))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
{ inittable for con-/destruction }
if _class.members_need_inittable then
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(RTTIWriter.get_rtti_label(_class,initrtti)))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
{ auto table }
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
{ interface table }
if _class.ImplementedInterfaces.count>0 then
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(interfacetable))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
{ table for string messages }
if (oo_has_msgstr in _class.objectoptions) then
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(strmessagetable))
else
current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
end;
{ write virtual methods }
writevirtualmethods(current_asmdata.asmlists[al_globals]);
current_asmdata.asmlists[al_globals].concat(Tai_const.create(aitconst_ptr,0));
{ write the size of the VMT }
current_asmdata.asmlists[al_globals].concat(Tai_symbol_end.Createname(_class.vmt_mangledname));
{$ifdef vtentry}
{ write vtinherit symbol to notify the linker of the class inheritance tree }
hs:='VTINHERIT'+'_'+_class.vmt_mangledname+'$$';
if assigned(_class.childof) then
hs:=hs+_class.childof.vmt_mangledname
else
hs:=hs+_class.vmt_mangledname;
current_asmdata.asmlists[al_globals].concat(tai_symbol.CreateName(hs,AT_DATA,0));
{$endif vtentry}
end;
end.