{
Copyright (c) 1998-2002 by Florian Klaempfl
Builds 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
;
type
TVMTBuilder=class
private
_Class : tobjectdef;
handledprotocols: tfpobjectlist;
function is_new_vmt_entry(pd:tprocdef; out overridesclasshelper: boolean):boolean;
procedure add_new_vmt_entry(pd:tprocdef; allowoverridingmethod: boolean);
function check_msg_str(vmtpd, pd: tprocdef):boolean;
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);
procedure prot_get_procdefs_recursive(ImplProt:TImplementedInterface;ProtDef:TObjectDef);
procedure intf_optimize_vtbls;
procedure intf_allocate_vtbls;
procedure create_vmt_def;
procedure build_interface_mappings;
public
constructor create(c:tobjectdef);
procedure build;
end;
{ convenince routine to build the VMT for an objectdef
Note: also ensures that the procdefs of the objectdef have their hidden
parameters inserted }
procedure build_vmt(def:tobjectdef);
implementation
uses
globals,verbose,systems,
node,
symbase,symtable,symconst,symtype,symcpu,
defcmp,
pparautl;
{*****************************************************************************
TVMTBuilder
*****************************************************************************}
constructor TVMTBuilder.create(c:tobjectdef);
begin
inherited Create;
_Class:=c;
end;
procedure TVMTBuilder.add_new_vmt_entry(pd:tprocdef; allowoverridingmethod: boolean);
var
i : longint;
vmtentry : pvmtentry;
vmtpd : tprocdef;
begin
{ new entry is needed, override was not possible }
{ Allowed when overriding a category method for a parent class in a
descendent Objective-C class }
if not allowoverridingmethod and
(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
for i:=0 to _class.vmtentries.count-1 do
begin
vmtentry:=pvmtentry(_class.vmtentries[i]);
vmtpd:=tprocdef(vmtentry^.procdef);
if (vmtpd.procsym=pd.procsym) and
(not(po_overload in pd.procoptions) or
not(po_overload in vmtpd.procoptions)) then
begin
MessagePos1(pd.fileinfo,parser_e_no_overload_for_all_procs,pd.procsym.realname);
{ recover }
include(vmtpd.procoptions,po_overload);
include(pd.procoptions,po_overload);
end;
end;
end;
{ Register virtual method and give it a number }
if (po_virtualmethod in pd.procoptions) then
begin
{ store vmt entry number in procdef }
if (pd.extnumber<>$ffff) and
(pd.extnumber<>_class.VMTEntries.Count) then
internalerror(200810283);
pd.extnumber:=_class.VMTEntries.Count;
new(vmtentry);
vmtentry^.procdef:=pd;
vmtentry^.procdefderef.reset;
vmtentry^.visibility:=pd.visibility;
_class.VMTEntries.Add(vmtentry);
end;
end;
function TVMTBuilder.check_msg_str(vmtpd, pd: tprocdef): boolean;
begin
result:=true;
if not(is_objc_class_or_protocol(_class)) then
begin
{ the only requirement for normal methods is that both either
have a message string or not (the value is irrelevant) }
if ((pd.procoptions * [po_msgstr]) <> (vmtpd.procoptions * [po_msgstr])) then
begin
MessagePos1(pd.fileinfo,parser_e_header_dont_match_forward,pd.fullprocname(false));
tprocsym(vmtpd.procsym).write_parameter_lists(pd);
result:=false;
end
end
else
begin
{ the compiler should have ensured that the protocol or parent
class method has a message name specified }
if not(po_msgstr in vmtpd.procoptions) then
internalerror(2009070601);
if not(po_msgstr in pd.procoptions) then
begin
{ copy the protocol's/parent class' message name to the one in
the class if none has been specified there }
include(pd.procoptions,po_msgstr);
pd.messageinf.str:=stringdup(vmtpd.messageinf.str^);
end
else
begin
{ if both have a message name, make sure they are equal }
if (vmtpd.messageinf.str^<>pd.messageinf.str^) then
begin
MessagePos2(pd.fileinfo,parser_e_objc_message_name_changed,vmtpd.messageinf.str^,pd.messageinf.str^);
result:=false;
end;
end;
end;
end;
function TVMTBuilder.is_new_vmt_entry(pd:tprocdef; out overridesclasshelper: boolean):boolean;
const
po_comp = [po_classmethod,po_virtualmethod,po_staticmethod,po_interrupt,po_iocheck,po_msgint,
po_exports,po_varargs,po_explicitparaloc,po_nostackframe];
var
i : longint;
hasequalpara,
hasoverloads,
pdoverload : boolean;
srsym : tsym;
st : tsymtable;
// returns true if we can stop checking, false if we have to continue
function found_entry(var vmtpd: tprocdef; var vmtentryvis: tvisibility; updatevalues: boolean): boolean;
{$ifdef jvm}
var
javanewtreeok: boolean;
{$endif jvm}
begin
result:=false;
{ ignore hidden entries (e.g. virtual overridden by a static) that are not visible anymore }
if vmtentryvis=vis_hidden then
exit;
{ ignore different names }
if vmtpd.procsym.name<>pd.procsym.name then
exit;
{ hide private methods that are not visible anymore. For this check we
must override the visibility with the highest value in the override chain.
This is required for case (see tw3292) with protected-private-protected where the
same vmtentry is used (PFV) }
if not is_visible_for_object(vmtpd.owner,vmtentryvis,_class) then
exit;
{ inherit overload }
if (po_overload in vmtpd.procoptions) then
begin
include(pd.procoptions,po_overload);
pdoverload:=true;
end;
{ compare parameter types only, no specifiers yet }
hasequalpara:=(compare_paras(vmtpd.paras,pd.paras,cp_none,[cpo_ignoreuniv,cpo_ignorehidden])>=te_equal);
{ check that we are not trying to override a final method }
{ in Java, new virtual inheritance trees can never be started ->
treat all methods as "overriding" in the context of this check
(Java does check whether the mangled names are identical, so if they
are not we can stil get away with it) }
if (po_finalmethod in vmtpd.procoptions) and
hasequalpara and
((po_overridingmethod in pd.procoptions) or
(is_javaclass(_class) and
(pd.mangledname=vmtpd.mangledname))) and
(is_class(_class) or is_objectpascal_helper(_class) or is_javaclass(_class)) then
MessagePos1(pd.fileinfo,parser_e_final_can_no_be_overridden,pd.fullprocname(false))
else
{ old definition has virtual
new definition has no virtual or override }
if (po_virtualmethod in vmtpd.procoptions) and
(
not(po_virtualmethod in pd.procoptions) or
(
{ new one does not have reintroduce in case of an objccategory }
(is_objccategory(_class) and
not(po_reintroduce in pd.procoptions)) or
{ new one does not have override in case of objpas/objc/java class/intf/proto }
((is_class_or_interface_or_objc_or_java(_class) or is_objectpascal_helper(_class)) and
not is_objccategory(_class) and
not(po_overridingmethod in pd.procoptions)
)
)
) then
begin
if (
not(pdoverload or hasoverloads) or
hasequalpara
) then
begin
{$ifdef jvm}
{ if the mangled names are different, the inheritance trees
are different too in Java; exception: when the parent method
is a virtual class method or virtual constructor, because
those are looked up dynamicall by name }
javanewtreeok:=
is_java_class_or_interface(_class) and
(tcpuprocdef(pd).jvmmangledbasename(false)<>tcpuprocdef(vmtpd).jvmmangledbasename(false)) and
((vmtpd.proctypeoption<>potype_constructor) and
not(po_staticmethod in vmtpd.procoptions));
{$endif}
if not(po_reintroduce in pd.procoptions) and
not(po_java_nonvirtual in vmtpd.procoptions) then
if not(is_objc_class_or_protocol(_class))
{$ifdef jvm}
and (not is_java_class_or_interface(_class) or
javanewtreeok)
{$endif jvm}
then
MessagePos1(pd.fileinfo,parser_w_should_use_override,pd.fullprocname(false))
else
begin
{ In Objective-C, you cannot create a new VMT entry to
start a new inheritance tree. We therefore give an
error when the class is implemented in Pascal, to
avoid confusion due to things working differently
with Object Pascal classes.
In case of external classes, we only give a hint,
because requiring override everywhere may make
automated header translation tools too complex.
The same goes for Java. }
{$ifndef jvm}
if hasequalpara then
{$endif}
begin
if not(oo_is_external in _class.objectoptions) then
if not is_objccategory(_class) then
MessagePos1(pd.fileinfo,parser_e_must_use_override,FullTypeName(tdef(vmtpd.owner.defowner),nil))
else
MessagePos1(pd.fileinfo,parser_e_must_use_reintroduce_objc,FullTypeName(tdef(vmtpd.owner.defowner),nil))
{ there may be a lot of these in auto-translated
headers, so only calculate the fulltypename if
the hint will be shown }
else if CheckVerbosity(V_Hint) then
if not is_objccategory(_class) then
MessagePos1(pd.fileinfo,parser_h_should_use_override,FullTypeName(tdef(vmtpd.owner.defowner),nil))
else
MessagePos1(pd.fileinfo,parser_h_should_use_reintroduce_objc,FullTypeName(tdef(vmtpd.owner.defowner),nil));
end;
{ no new entry, but copy the message name if any from
the procdef in the parent class }
if not is_objc_class_or_protocol(_class) or
hasequalpara then
check_msg_str(vmtpd,pd);
if updatevalues then
begin
{ in case of Java, copy the real name from the parent,
since overriding "Destroy" with "destroy" is not
going to work very well }
if is_java_class_or_interface(_class) and
(pd.procsym.realname<>vmtpd.procsym.realname) then
pd.procsym.realname:=vmtpd.procsym.realname;
{ in case we are overriding an abstract method,
decrease the number of abstract methods in this class }
if (po_abstractmethod in vmtpd.procoptions) then
dec(tobjectdef(pd.owner.defowner).abstractcnt);
if (vmtpd.extnumber<>i) then
internalerror(2011083101);
pd.extnumber:=vmtpd.extnumber;
vmtpd:=pd;
end;
result:=true;
exit;
{$ifdef jvm}
end
else
if not javanewtreeok and
is_java_class_or_interface(_class) then
begin
{ mangled names are the same -> can only override }
MessagePos1(pd.fileinfo,parser_e_must_use_override,FullTypeName(tdef(vmtpd.owner.defowner),nil))
{$endif jvm}
end;
{ disable/hide old VMT entry }
if updatevalues then
vmtentryvis:=vis_hidden;
end;
end
{ both are virtual? }
else if (po_virtualmethod in pd.procoptions) and
(po_virtualmethod in vmtpd.procoptions) then
begin
{ same parameter and return types (parameter specifiers will be checked below) }
if hasequalpara and
compatible_childmethod_resultdef(vmtpd.returndef,pd.returndef) then
begin
{ inherite calling convention when it was explicit and the
current definition has none explicit set }
if (po_hascallingconvention in vmtpd.procoptions) and
not(po_hascallingconvention in pd.procoptions) then
begin
pd.proccalloption:=vmtpd.proccalloption;
include(pd.procoptions,po_hascallingconvention);
end;
{ All parameter specifiers and some procedure the flags have to match
except abstract and override }
if (compare_paras(vmtpd.paras,pd.paras,cp_all,[cpo_ignoreuniv,cpo_ignorehidden])<te_equal) or
(vmtpd.proccalloption<>pd.proccalloption) or
(vmtpd.proctypeoption<>pd.proctypeoption) or
((vmtpd.procoptions*po_comp)<>(pd.procoptions*po_comp)) then
begin
MessagePos1(pd.fileinfo,parser_e_header_dont_match_forward,pd.fullprocname(false));
tprocsym(vmtpd.procsym).write_parameter_lists(pd);
end;
check_msg_str(vmtpd,pd);
{ Give a note if the new visibility is lower. For a higher
visibility update the vmt info }
if vmtentryvis>pd.visibility then
begin
if po_auto_raised_visibility in vmtpd.procoptions then
begin
if updatevalues then
begin
pd.visibility:=vmtentryvis;
{ this one's visibility is now also auto-raised }
include(pd.procoptions,po_auto_raised_visibility);
end
end
else
{$ifdef jvm}
MessagePos4(pd.fileinfo,parser_e_method_lower_visibility,
{$else jvm}
MessagePos4(pd.fileinfo,parser_n_ignore_lower_visibility,
{$endif jvm}
pd.fullprocname(false),
visibilityname[pd.visibility],tobjectdef(vmtpd.owner.defowner).objrealname^,visibilityname[vmtentryvis])
end
else if pd.visibility>vmtentryvis then
begin
if updatevalues then
vmtentryvis:=pd.visibility;
end;
{ override old virtual method in VMT }
if updatevalues then
begin
{ in case we are overriding an abstract method,
decrease the number of abstract methods in this class }
if (po_overridingmethod in pd.procoptions) and
(po_abstractmethod in vmtpd.procoptions) then
dec(tobjectdef(pd.owner.defowner).abstractcnt);
if (vmtpd.extnumber<>i) then
internalerror(200611084);
pd.extnumber:=vmtpd.extnumber;
{ in case of Java, copy the real name from the parent,
since overriding "Destroy" with "destroy" is not
going to work very well }
if is_java_class_or_interface(_class) and
(pd.procsym.realname<>vmtpd.procsym.realname) then
pd.procsym.realname:=vmtpd.procsym.realname;
vmtpd:=pd;
end;
result:=true;
exit;
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 or hasoverloads) then
begin
if not(po_reintroduce in pd.procoptions) then
begin
if not is_object(_class) and
not is_objc_class_or_protocol(_class) and
not is_java_class_or_interface(_class) then
MessagePos1(pd.fileinfo,parser_w_should_use_override,pd.fullprocname(false))
else
{ objects don't allow starting a new virtual tree
and neither do Objective-C or Java }
MessagePos1(pd.fileinfo,parser_e_header_dont_match_forward,vmtpd.fullprocname(false));
end;
{ disable/hide old VMT entry }
if updatevalues then
vmtentryvis:=vis_hidden;
end;
end;
end;
end;
function found_category_method(st: tsymtable): boolean;
var
entrycount: longint;
cat: tobjectdef;
vmtpd: tprocdef;
vmtvis: tvisibility;
begin
result:=false;
if is_objccategory(tdef(st.defowner)) then
begin
cat:=tobjectdef(st.defowner);
{ go through all of the category's methods to find the
vmtentry corresponding to the procdef we are handling }
for entrycount:=0 to cat.vmtentries.Count-1 do
begin
vmtpd:=pvmtentry(cat.vmtentries[entrycount])^.procdef;
vmtvis:=pvmtentry(cat.vmtentries[entrycount])^.visibility;
{ don't change the vmtentry of the category }
if found_entry(vmtpd,vmtvis,false) then
begin
result:=true;
exit;
end;
end;
end;
end;
begin
result:=false;
overridesclasshelper:=false;
{ Load other values for easier readability }
hasoverloads:=(tprocsym(pd.procsym).ProcdefList.Count>1);
pdoverload:=(po_overload in pd.procoptions);
{ compare with all stored definitions }
for i:=0 to _class.vmtentries.Count-1 do
begin
if found_entry(pvmtentry(_class.vmtentries[i])^.procdef, pvmtentry(_class.vmtentries[i])^.visibility,true) then
exit;
end;
{ in case of Objective-C, also check the categories that apply to this
class' *parent* for methods to override (don't allow class X to
"override" a method added by a category to class X itself, since in
that case the category method will in fact replace class X'
"overriding" method }
if is_objcclass(_class) and
assigned(_class.childof) and
search_objc_helper(_class.childof,pd.procsym.name,srsym,st) then
begin
overridesclasshelper:=found_category_method(st);
end;
{ No entry found, we need to create a new entry }
result:=true;
end;
function TVMTBuilder.intf_search_procdef_by_name(proc: tprocdef;const name: string): tprocdef;
const
po_comp = [po_classmethod,po_staticmethod,po_interrupt,po_iocheck,po_msgint,
po_exports,po_varargs,po_explicitparaloc,po_nostackframe];
var
implprocdef : Tprocdef;
i: cardinal;
hclass : tobjectdef;
hashedid : THashedIDString;
srsym : tsym;
overload: boolean;
begin
result:=nil;
hashedid.id:=name;
hclass:=_class;
while assigned(hclass) do
begin
srsym:=tsym(hclass.symtable.FindWithHash(hashedid));
if assigned(srsym) and
(srsym.typ=procsym) and
((hclass=_class) or
is_visible_for_object(srsym,_class)) then
begin
overload:=false;
for i:=0 to Tprocsym(srsym).ProcdefList.Count-1 do
begin
implprocdef:=tprocdef(tprocsym(srsym).ProcdefList[i]);
if po_overload in implprocdef.procoptions then
overload:=true;
if (implprocdef.procsym=tprocsym(srsym)) and
(compare_paras(proc.paras,implprocdef.paras,cp_all,[cpo_ignorehidden,cpo_ignoreuniv])>=te_equal) and
(compare_defs(proc.returndef,implprocdef.returndef,nothingn)>=te_equal) and
(proc.proccalloption=implprocdef.proccalloption) and
(proc.proctypeoption=implprocdef.proctypeoption) and
((proc.procoptions*po_comp)=((implprocdef.procoptions+[po_virtualmethod])*po_comp)) and
check_msg_str(proc,implprocdef) then
begin
{ does the interface increase the visibility of the
implementing method? }
if implprocdef.visibility<proc.visibility then
{$ifdef jvm}
MessagePos2(implprocdef.fileinfo,type_e_interface_lower_visibility,proc.fullprocname(false),implprocdef.fullprocname(false));
{$else}
MessagePos2(implprocdef.fileinfo,type_w_interface_lower_visibility,proc.fullprocname(false),implprocdef.fullprocname(false));
{$endif}
result:=implprocdef;
addsymref(result.procsym,result);
exit;
end;
end;
{ like with normal procdef resolution (in htypechk), stop if
we encounter a proc without the overload directive }
if not overload then
exit;
end;
hclass:=hclass.childof;
end;
end;
procedure TVMTBuilder.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 assigned(def) and
(def.typ=procdef) then
begin
{ Find implementing procdef
1. Check for mapped name
2. Use symbol name, but only if there's no mapping,
or we're processing ancestor of interface.
When modifying this code, ensure that webtbs/tw11862, webtbs/tw4950
and webtbf/tw19591 stay correct. }
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
if (mappedname='') or (ImplIntf.IntfDef<>IntfDef) then
implprocdef:=intf_search_procdef_by_name(tprocdef(def),tprocdef(def).procsym.name);
{ Add procdef to the implemented interface }
if assigned(implprocdef) then
begin
if (tobjectdef(implprocdef.struct).objecttype<>odt_objcclass) then
begin
{ in case of Java, copy the real name from the parent,
since overriding "Destroy" with "destroy" is not
going to work very well }
if is_javaclass(implprocdef.struct) and
(implprocdef.procsym.realname<>tprocdef(def).procsym.realname) then
implprocdef.procsym.realname:=tprocdef(def).procsym.realname;
ImplIntf.AddImplProc(implprocdef);
end
else
begin
{ If no message name has been specified for the method
in the objcclass, copy it from the protocol
definition. }
if not(po_msgstr in tprocdef(def).procoptions) then
begin
include(tprocdef(def).procoptions,po_msgstr);
implprocdef.messageinf.str:=stringdup(tprocdef(def).messageinf.str^);
end
else
begin
{ If a message name has been specified in the
objcclass, it has to match the message name in the
protocol definition. }
if (implprocdef.messageinf.str^<>tprocdef(def).messageinf.str^) then
MessagePos2(implprocdef.fileinfo,parser_e_objc_message_name_changed,tprocdef(def).messageinf.str^,implprocdef.messageinf.str^);
end;
end;
end
else
if (ImplIntf.IType=etStandard) and
not(po_optional in tprocdef(def).procoptions) then
MessagePos1(_Class.typesym.fileinfo,sym_e_no_matching_implementation_found,tprocdef(def).fullprocname(false));
end;
end;
end;
procedure TVMTBuilder.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;
procedure TVMTBuilder.prot_get_procdefs_recursive(ImplProt:TImplementedInterface;ProtDef:TObjectDef);
var
i: longint;
begin
{ don't check the same protocol twice }
if handledprotocols.IndexOf(ProtDef)<>-1 then
exit;
handledprotocols.add(ProtDef);
for i:=0 to ProtDef.ImplementedInterfaces.count-1 do
prot_get_procdefs_recursive(ImplProt,TImplementedInterface(ProtDef.ImplementedInterfaces[i]).intfdef);
intf_get_procdefs(ImplProt,ProtDef);
end;
procedure TVMTBuilder.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
aequals: 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(aequals,sizeof(longint)*ImplIntfCount);
getmem(impls,sizeof(longint)*ImplIntfCount);
filldword(compats^,(sizeof(tcompintfentry) div sizeof(dword))*ImplIntfCount,dword(-1));
filldword(aequals^,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 aequals^[j]=-1 then
aequals^[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 aequals^[impls^[i]]<>-1 then
impls^[i]:=aequals^[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(aequals);
freemem(impls);
end;
procedure TVMTBuilder.intf_allocate_vtbls;
var
i : longint;
ImplIntf : TImplementedInterface;
begin
{ Allocation vtbl space }
for i:=0 to _class.ImplementedInterfaces.count-1 do
begin
ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
{ if it implements itself and if it's not implemented by delegation }
if (ImplIntf.VtblImplIntf=ImplIntf) and (ImplIntf.IType=etStandard) then
begin
{ allocate a pointer in the object memory }
with tObjectSymtable(_class.symtable) do
begin
datasize:=align(datasize,voidpointertype.alignment);
ImplIntf.Ioffset:=datasize;
datasize:=datasize+voidpointertype.size;
end;
end;
end;
{ Update ioffset of current interface with the ioffset from
the interface that is reused to implements this interface }
for i:=0 to _class.ImplementedInterfaces.count-1 do
begin
ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
if ImplIntf.VtblImplIntf<>ImplIntf then
ImplIntf.IOffset:=ImplIntf.VtblImplIntf.IOffset;
end;
end;
procedure TVMTBuilder.create_vmt_def;
var
i: longint;
vmtdef: trecorddef;
systemvmt: tdef;
sym: tsym;
begin
{ these types don't have an actual VMT, we only use the other methods
in TVMTBuilder to determine duplicates/overrides }
if _class.objecttype in [
odt_helper,
odt_objcclass,
odt_objccategory,
odt_objcprotocol,
odt_javaclass,
odt_interfacecom_property,
odt_interfacecom_function,
odt_interfacejava] then
exit;
{ don't generate VMT for generics (only use duplicates/overrides detection) }
{ Note: don't use is_generic here as we also need to check nested non-
generic classes }
if df_generic in _class.defoptions then
exit;
{ todo in the future }
if _class.objecttype = odt_cppclass then
exit;
{ create VMT type definition }
vmtdef:=crecorddef.create_internal(
'$vmtdef',
0,
target_info.alignment.recordalignmin,
_class.symtable);
{$ifdef llvm}
{ in case of a class declared in the implementation section of unit
whose method is called from an inline routine -- LLVM needs to be able
to access the vmt def to create signatures }
vmtdef.register_def;
{$endif}
{ standard VMT fields }
case _Class.objecttype of
odt_class:
begin
systemvmt:=search_system_type('TVMT').typedef;
if not assigned(systemvmt) then
Message1(cg_f_internal_type_not_found,'TVMT');
{ does the TVMT type look like we expect? (so that this code is
easily triggered in case the definition of the VMT would
change) }
if (systemvmt.typ<>recorddef) or
(trecorddef(systemvmt).symtable.SymList.count<>27) then
Message1(cg_f_internal_type_does_not_match,'TVMT');
{ system.tvmt is a record that represents the VMT of TObject,
including its virtual methods. We only want the non-method
fields, as the methods will be added automatically based on
the VMT we generated here only add the 12 first fields }
for i:=0 to 11 do
begin
sym:=tsym(trecorddef(systemvmt).symtable.SymList[i]);
if sym.typ in [procsym,propertysym] then
continue;
if sym.typ<>fieldvarsym then
internalerror(2015052602);
vmtdef.add_field_by_def('',tfieldvarsym(sym).vardef);
end;
end;
odt_interfacecom,odt_interfacecorba,odt_dispinterface:
{ nothing }
;
odt_object:
begin
{ size, -size, parent vmt [, dmt ] (same names as for class) }
vmtdef.add_field_by_def('vInstanceSize',sizesinttype);
vmtdef.add_field_by_def('vInstanceSize2',sizesinttype);
vmtdef.add_field_by_def('vParent',voidpointertype);
{$ifdef WITHDMT}
vmtdef.add_field_by_def('',voidpointertype);
{$endif WITHDMT}
end;
else
internalerror(2015052605);
end;
{ now add the methods }
for i:=0 to _class.vmtentries.count-1 do
vmtdef.add_field_by_def('',
cprocvardef.getreusableprocaddr(pvmtentry(_class.vmtentries[i])^.procdef,pc_address_only)
);
{ the VMT ends with a nil pointer }
vmtdef.add_field_by_def('',voidcodepointertype);
end;
procedure TVMTBuilder.build;
var
i : longint;
def : tdef;
old_current_structdef : tabstractrecorddef;
overridesclasshelper : boolean;
begin
old_current_structdef:=current_structdef;
current_structdef:=_class;
{ inherit (copy) VMT from parent object }
if assigned(_class.childof) then
_class.copyvmtentries(_class.childof);
{ process all procdefs, we must process the defs to
keep the same order as that is written in the source
to be compatible with the indexes in the interface vtable (PFV) }
for i:=0 to _class.symtable.DefList.Count-1 do
begin
def:=tdef(_class.symtable.DefList[i]);
if def.typ=procdef then
begin
{ VMT entry }
if is_new_vmt_entry(tprocdef(def),overridesclasshelper) then
add_new_vmt_entry(tprocdef(def),overridesclasshelper);
end;
end;
insert_struct_hidden_paras(_class);
build_interface_mappings;
if assigned(_class.ImplementedInterfaces) and
not(is_objc_class_or_protocol(_class)) and
not(is_java_class_or_interface(_class)) then
begin
{ Optimize interface tables to reuse wrappers }
intf_optimize_vtbls;
{ Allocate interface tables }
intf_allocate_vtbls;
end;
create_vmt_def;
current_structdef:=old_current_structdef;
end;
procedure TVMTBuilder.build_interface_mappings;
var
ImplIntf : TImplementedInterface;
i: longint;
begin
{ Find Procdefs implementing the interfaces (both Objective-C protocols
and Java interfaces can have multiple parent interfaces, but in that
case obviously no implementations are required) }
if assigned(_class.ImplementedInterfaces) and
not(_class.objecttype in [odt_objcprotocol,odt_interfacejava]) and
// abstract java classes do not have to implement all interface
// methods. todo: check that non-abstract descendents do!
not((_class.objecttype=odt_javaclass) and (oo_is_abstract in _class.objectoptions)) then
begin
{ Collect implementor functions into the tImplementedInterface.procdefs }
case _class.objecttype of
odt_class:
begin
for i:=0 to _class.ImplementedInterfaces.count-1 do
begin
ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
intf_get_procdefs_recursive(ImplIntf,ImplIntf.IntfDef)
end;
end;
odt_objcclass,
odt_javaclass:
begin
{ Object Pascal interfaces are afterwards optimized via the
intf_optimize_vtbls() method, but we can't do this for
protocols/Java interfaces -> check for duplicates here
already. }
handledprotocols:=tfpobjectlist.create(false);
for i:=0 to _class.ImplementedInterfaces.count-1 do
begin
ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
prot_get_procdefs_recursive(ImplIntf,ImplIntf.IntfDef);
end;
handledprotocols.free;
end
else
internalerror(2009091801);
end
end;
end;
procedure build_vmt(def:tobjectdef);
var
vmtbuilder : TVMTBuilder;
begin
vmtbuilder:=TVMTBuilder.create(def);
vmtbuilder.build;
vmtbuilder.free;
end;
end.