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|
{
Copyright (c) 2008 by Jonas Maebe
Virtual methods optimizations (devirtualization)
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 optvirt;
{$i fpcdefs.inc}
interface
uses
globtype,
cclasses,
symtype,symdef,
wpobase;
type
{ node in an inheritance tree, contains a link to the parent type (if any) and to all
child types
}
tinheritancetreenode = class
private
fdef: tobjectdef;
fparent: tinheritancetreenode;
fchilds: tfpobjectlist;
fcalledvmtmethods: tbitset;
finstantiated: boolean;
function getchild(index: longint): tinheritancetreenode;
public
constructor create(_parent: tinheritancetreenode; _def: tobjectdef; _instantiated: boolean);
{ destroys both this node and all of its siblings }
destructor destroy; override;
function childcount: longint;
function haschilds: boolean;
property childs[index: longint]: tinheritancetreenode read getchild;
property parent: tinheritancetreenode read fparent;
property def: tobjectdef read fdef;
property instantiated: boolean read finstantiated write finstantiated;
{ if def is not yet a child of this node, add it. In all cases, return node containing
this def (either new or existing one
}
function maybeaddchild(_def: tobjectdef; _instantiated: boolean): tinheritancetreenode;
function findchild(_def: tobjectdef): tinheritancetreenode;
end;
tinheritancetreecallback = procedure(node: tinheritancetreenode; arg: pointer) of object;
tinheritancetree = class
private
{ just a regular node with parent = nil }
froots: tinheritancetreenode;
classrefdefs: tfpobjectlist;
procedure foreachnodefromroot(root: tinheritancetreenode; proctocall: tinheritancetreecallback; arg: pointer);
function registerinstantiatedobjectdefrecursive(def: tobjectdef; instantiated: boolean): tinheritancetreenode;
procedure markvmethods(node: tinheritancetreenode; p: pointer);
procedure printobjectvmtinfo(node: tinheritancetreenode; arg: pointer);
procedure addcalledvmtentries(node: tinheritancetreenode; arg: pointer);
function getnodefordef(def: tobjectdef): tinheritancetreenode;
public
constructor create;
destructor destroy; override;
{ adds an objectdef (the def itself, and all of its parents that do not yet exist) to
the tree, and returns the leaf node
}
procedure registerinstantiatedobjdef(def: tdef);
procedure registerinstantiatedclassrefdef(def: tdef);
procedure registercalledvmtentries(entries: tcalledvmtentries);
procedure checkforclassrefinheritance(def: tdef);
procedure foreachnode(proctocall: tinheritancetreecallback; arg: pointer);
procedure foreachleafnode(proctocall: tinheritancetreecallback; arg: pointer);
procedure optimizevirtualmethods;
procedure printvmtinfo;
end;
{ devirtualisation information for a class }
tclassdevirtinfo = class(tfphashobject)
private
{ array (indexed by vmt entry nr) of replacement statically callable method names }
fstaticmethodnames: tfplist;
{ is this class instantiated by the program? }
finstantiated: boolean;
function isstaticvmtentry(vmtindex: longint; out replacementname: pshortstring): boolean;
public
constructor create(hashobjectlist:tfphashobjectlist;const n: shortstring; instantiated: boolean);
destructor destroy; override;
property instantiated: boolean read finstantiated;
procedure addstaticmethod(vmtindex: longint; const replacementname: shortstring);
end;
{ devirtualisation information for all classes in a unit }
tunitdevirtinfo = class(tfphashobject)
private
{ hashtable of classes }
fclasses: tfphashobjectlist;
public
constructor create(hashobjectlist:tfphashobjectlist;const n: shortstring);reintroduce;
destructor destroy; override;
function addclass(const n: shortstring; instantiated: boolean): tclassdevirtinfo;
function findclass(const n: shortstring): tclassdevirtinfo;
end;
{ devirtualisation information for all units in a program }
{ tprogdevirtinfo }
tprogdevirtinfo = class(twpodevirtualisationhandler)
private
{ hashtable of tunitdevirtinfo (which contain tclassdevirtinfo) }
funits: tfphashobjectlist;
procedure converttreenode(node: tinheritancetreenode; arg: pointer);
function addunitifnew(const n: shortstring): tunitdevirtinfo;
function findunit(const n: shortstring): tunitdevirtinfo;
function getstaticname(forvmtentry: boolean; objdef, procdef: tdef; out staticname: TSymStr): boolean;
procedure documentformat(writer: twposectionwriterintf);
public
constructor create; override;
destructor destroy; override;
class function getwpotype: twpotype; override;
class function generatesinfoforwposwitches: twpoptimizerswitches; override;
class function performswpoforswitches: twpoptimizerswitches; override;
class function sectionname: shortstring; override;
{ information collection }
procedure constructfromcompilerstate; override;
procedure storewpofilesection(writer: twposectionwriterintf); override;
{ information providing }
procedure loadfromwpofilesection(reader: twposectionreaderintf); override;
function staticnameforcallingvirtualmethod(objdef, procdef: tdef; out staticname: TSymStr): boolean; override;
function staticnameforvmtentry(objdef, procdef: tdef; out staticname: TSymStr): boolean; override;
end;
implementation
uses
cutils,
fmodule,
symconst,
symbase,
defcmp,
verbose;
const
DEVIRT_SECTION_NAME = 'contextinsensitive_devirtualization';
{ *************************** tinheritancetreenode ************************* }
constructor tinheritancetreenode.create(_parent: tinheritancetreenode; _def: tobjectdef; _instantiated: boolean);
begin
fparent:=_parent;
fdef:=_def;
finstantiated:=_instantiated;
if assigned(_def) then
fcalledvmtmethods:=tbitset.create(_def.vmtentries.count);
end;
destructor tinheritancetreenode.destroy;
begin
{ fchilds owns its members, so it will free them too }
fchilds.free;
fcalledvmtmethods.free;
inherited destroy;
end;
function tinheritancetreenode.childcount: longint;
begin
if assigned(fchilds) then
result:=fchilds.count
else
result:=0;
end;
function tinheritancetreenode.haschilds: boolean;
begin
result:=assigned(fchilds)
end;
function tinheritancetreenode.getchild(index: longint): tinheritancetreenode;
begin
result:=tinheritancetreenode(fchilds[index]);
end;
function tinheritancetreenode.maybeaddchild(_def: tobjectdef; _instantiated: boolean): tinheritancetreenode;
begin
{ sanity check }
if assigned(_def.childof) then
begin
if (_def.childof<>def) then
internalerror(2008092201);
end
else if assigned(fparent) then
internalerror(2008092202);
if not assigned(fchilds) then
fchilds:=tfpobjectlist.create(true);
{ def already a child -> return }
result:=findchild(_def);
if assigned(result) then
result.finstantiated:=result.finstantiated or _instantiated
else
begin
{ not found, add new child }
result:=tinheritancetreenode.create(self,_def,_instantiated);
fchilds.add(result);
end;
end;
function tinheritancetreenode.findchild(_def: tobjectdef): tinheritancetreenode;
var
i: longint;
begin
result:=nil;
if assigned(fchilds) then
for i := 0 to fchilds.count-1 do
if (tinheritancetreenode(fchilds[i]).def=_def) then
begin
result:=tinheritancetreenode(fchilds[i]);
break;
end;
end;
{ *************************** tinheritancetree ************************* }
constructor tinheritancetree.create;
begin
froots:=tinheritancetreenode.create(nil,nil,false);
classrefdefs:=tfpobjectlist.create(false);
end;
destructor tinheritancetree.destroy;
begin
froots.free;
classrefdefs.free;
inherited destroy;
end;
function tinheritancetree.registerinstantiatedobjectdefrecursive(def: tobjectdef; instantiated: boolean): tinheritancetreenode;
begin
if assigned(def.childof) then
begin
{ recursively add parent, of which we have no info about whether or not it is
instantiated at this point -> default to false (will be overridden by "true"
if this class is instantioted, since then registerinstantiatedobjdef() will
be called for this class as well)
}
result:=registerinstantiatedobjectdefrecursive(def.childof,false);
{ and add ourselves to the parent }
result:=result.maybeaddchild(def,instantiated);
end
else
{ add ourselves to the roots }
result:=froots.maybeaddchild(def,instantiated);
end;
procedure tinheritancetree.registerinstantiatedobjdef(def: tdef);
begin
{ add the def }
if (def.typ=objectdef) then
registerinstantiatedobjectdefrecursive(tobjectdef(def),true)
else
internalerror(2008092401);
end;
procedure tinheritancetree.registerinstantiatedclassrefdef(def: tdef);
begin
{ queue for later checking (these are the objectdefs
to which the classrefdefs point) }
if (def.typ=objectdef) then
classrefdefs.add(def)
else
internalerror(2008101401);
end;
function tinheritancetree.getnodefordef(def: tobjectdef): tinheritancetreenode;
begin
if assigned(def.childof) then
begin
result:=getnodefordef(def.childof);
if assigned(result) then
result:=result.findchild(def);
end
else
result:=froots.findchild(def);
end;
procedure tinheritancetree.registercalledvmtentries(entries: tcalledvmtentries);
var
node: tinheritancetreenode;
begin
node:=getnodefordef(tobjectdef(entries.objdef));
{ it's possible that no instance of this class or its descendants are
instantiated
}
if not assigned(node) then
exit;
{ now mark these methods as (potentially) called for this type and for
all of its descendants
}
addcalledvmtentries(node,entries.calledentries);
foreachnodefromroot(node,@addcalledvmtentries,entries.calledentries);
end;
procedure tinheritancetree.checkforclassrefinheritance(def: tdef);
var
i: longint;
begin
if (def.typ=objectdef) then
begin
{$ifdef debug_devirt}
write(' Checking for classrefdef inheritance of ',def.typename);
{$endif debug_devirt}
for i:=0 to classrefdefs.count-1 do
if def_is_related(tobjectdef(def),tobjectdef(classrefdefs[i])) then
begin
{$ifdef debug_devirt}
writeln('... Found: inherits from Class Of ',tobjectdef(classrefdefs[i]).typename);
{$endif debug_devirt}
registerinstantiatedobjdef(def);
exit;
end;
{$ifdef debug_devirt}
writeln('... Not found!');
{$endif debug_devirt}
end;
end;
procedure tinheritancetree.foreachnodefromroot(root: tinheritancetreenode; proctocall: tinheritancetreecallback; arg: pointer);
procedure process(const node: tinheritancetreenode);
var
i: longint;
begin
for i:=0 to node.childcount-1 do
if node.childs[i].haschilds then
begin
proctocall(node.childs[i],arg);
process(node.childs[i])
end
else
proctocall(node.childs[i],arg);
end;
begin
process(root);
end;
procedure tinheritancetree.foreachnode(proctocall: tinheritancetreecallback; arg: pointer);
begin
foreachnodefromroot(froots,proctocall,arg);
end;
procedure tinheritancetree.foreachleafnode(proctocall: tinheritancetreecallback; arg: pointer);
procedure process(const node: tinheritancetreenode);
var
i: longint;
begin
for i:=0 to node.childcount-1 do
if node.childs[i].haschilds then
process(node.childs[i])
else
proctocall(node.childs[i],arg);
end;
begin
process(froots);
end;
procedure tinheritancetree.markvmethods(node: tinheritancetreenode; p: pointer);
var
currnode: tinheritancetreenode;
pd: tprocdef;
i: longint;
makeallvirtual: boolean;
begin
{$IFDEF DEBUG_DEVIRT}
writeln('processing leaf node ',node.def.typename);
{$ENDIF}
{ todo: also process interfaces (ImplementedInterfaces) }
if (node.def.vmtentries.count=0) then
exit;
{ process all vmt entries for this class/object }
for i:=0 to node.def.vmtentries.count-1 do
begin
currnode:=node;
{ extra tprocdef(tobject(..)) typecasts so that -CR can catch
errors in case the vmtentries are not properly (re)deref'd }
pd:=tprocdef(tobject(pvmtentry(currnode.def.vmtentries[i])^.procdef));
{ abstract methods cannot be called directly }
if (po_abstractmethod in pd.procoptions) then
continue;
{$IFDEF DEBUG_DEVIRT}
writeln(' method ',pd.typename);
{$ENDIF}
{ Now mark all virtual methods static that are the same in parent
classes as in this instantiated child class (only instantiated
classes can be leaf nodes, since only instantiated classes were
added to the tree).
If a first child does not override a parent method while a
a second one does, the first will mark it as statically
callable, but the second will set it to not statically callable.
In the opposite situation, the first will mark it as not
statically callable and the second will leave it alone.
}
makeallvirtual:=false;
repeat
if { stop when this method does not exist in a parent }
(currnode.def.vmtentries.count<=i) then
break;
if not assigned(currnode.def.vmcallstaticinfo) then
currnode.def.vmcallstaticinfo:=allocmem(currnode.def.vmtentries.count*sizeof(tvmcallstatic));
{ if this method cannot be called, we can just mark it as
unreachable. This will cause its static name to be set to
FPC_ABSTRACTERROR later on. Exception: published methods are
always reachable (via RTTI).
}
if (pd.visibility<>vis_published) and
not(currnode.fcalledvmtmethods.isset(i)) then
begin
currnode.def.vmcallstaticinfo^[i]:=vmcs_unreachable;
currnode:=currnode.parent;
end
{ same procdef as in all instantiated childs? (yes or don't know) }
else if (currnode.def.vmcallstaticinfo^[i] in [vmcs_default,vmcs_yes]) then
begin
{ methods in uninstantiated classes can be made static if
they are the same in all instantiated derived classes
}
if ((pvmtentry(currnode.def.vmtentries[i])^.procdef=pd) or
(not currnode.instantiated and
(currnode.def.vmcallstaticinfo^[i]=vmcs_default))) and
not makeallvirtual then
begin
{$IFDEF DEBUG_DEVIRT}
writeln(' marking as static for ',currnode.def.typename);
{$ENDIF}
currnode.def.vmcallstaticinfo^[i]:=vmcs_yes;
{ this is in case of a non-instantiated parent of an instantiated child:
the method declared in the child will always be called here
}
pvmtentry(currnode.def.vmtentries[i])^.procdef:=pd;
end
else
begin
{$IFDEF DEBUG_DEVIRT}
writeln(' marking as non-static for ',currnode.def.typename);
{$ENDIF}
{ this vmt entry must also remain virtual for all parents }
makeallvirtual:=true;
currnode.def.vmcallstaticinfo^[i]:=vmcs_no;
end;
currnode:=currnode.parent;
end
else if (currnode.def.vmcallstaticinfo^[i]=vmcs_no) then
begin
{$IFDEF DEBUG_DEVIRT}
writeln(' not processing parents, already non-static for ',currnode.def.typename);
{$ENDIF}
{ parents are already set to vmcs_no, so no need to continue }
currnode:=nil;
end
else
currnode:=currnode.parent;
until not assigned(currnode) or
not assigned(currnode.def);
end;
end;
procedure tinheritancetree.optimizevirtualmethods;
begin
foreachleafnode(@markvmethods,nil);
end;
procedure tinheritancetree.printobjectvmtinfo(node: tinheritancetreenode; arg: pointer);
var
i,
totaldevirtualised,
totalvirtual,
totalunreachable: ptrint;
begin
totaldevirtualised:=0;
totalvirtual:=0;
totalunreachable:=0;
writeln(node.def.typename);
if (node.def.vmtentries.count=0) then
begin
writeln(' No virtual methods!');
exit;
end;
for i:=0 to node.def.vmtentries.count-1 do
if (po_virtualmethod in pvmtentry(node.def.vmtentries[i])^.procdef.procoptions) then
begin
inc(totalvirtual);
if (node.def.vmcallstaticinfo^[i]=vmcs_yes) then
begin
inc(totaldevirtualised);
writeln(' Devirtualised: ',pvmtentry(node.def.vmtentries[i])^.procdef.typename);
end
else if (node.def.vmcallstaticinfo^[i]=vmcs_unreachable) then
begin
inc(totalunreachable);
writeln(' Unreachable: ',pvmtentry(node.def.vmtentries[i])^.procdef.typename);
end;
end;
writeln('Total devirtualised/unreachable/all: ',totaldevirtualised,'/',totalunreachable,'/',totalvirtual);
writeln;
end;
procedure tinheritancetree.addcalledvmtentries(node: tinheritancetreenode; arg: pointer);
var
vmtentries: tbitset absolute arg;
begin
node.fcalledvmtmethods.addset(vmtentries);
end;
procedure tinheritancetree.printvmtinfo;
begin
foreachnode(@printobjectvmtinfo,nil);
end;
{ helper routines: decompose an object & procdef combo into a unitname, class name and vmtentry number
(unit name where the objectdef is declared, class name of the objectdef, vmtentry number of the
procdef -- procdef does not necessarily belong to objectdef, it may also belong to a descendant
or parent). classprefix is set in case of nested classes.
}
procedure defunitclassname(objdef: tobjectdef; out unitname, classname: pshortstring; out classprefix: shortstring);
const
mainprogname: string[2] = 'P$';
var
mainsymtab,
objparentsymtab : tsymtable;
begin
objparentsymtab:=objdef.symtable;
mainsymtab:=objparentsymtab.defowner.owner;
classprefix:='';
while mainsymtab.symtabletype in [recordsymtable,objectsymtable] do
begin
classprefix:=mainsymtab.name^+'.'+classprefix;
mainsymtab:=mainsymtab.defowner.owner;
end;
{ main symtable must be static or global }
if not(mainsymtab.symtabletype in [staticsymtable,globalsymtable]) then
internalerror(200204177);
if (TSymtable(main_module.localsymtable)=mainsymtab) and
(not main_module.is_unit) then
{ same convention as for mangled names }
unitname:=@mainprogname
else
unitname:=mainsymtab.name;
classname:=tobjectdef(objparentsymtab.defowner).objname;
end;
procedure defsdecompose(objdef: tobjectdef; procdef: tprocdef; out unitname, classname: pshortstring; out classprefix: shortstring; out vmtentry: longint);
begin
defunitclassname(objdef,unitname,classname,classprefix);
vmtentry:=procdef.extnumber;
{ if it's $ffff, this is not a valid virtual method }
if (vmtentry=$ffff) then
internalerror(2008100509);
end;
{ tclassdevirtinfo }
constructor tclassdevirtinfo.create(hashobjectlist:tfphashobjectlist;const n: shortstring; instantiated: boolean);
begin
inherited create(hashobjectlist,n);
finstantiated:=instantiated;
fstaticmethodnames:=tfplist.create;
end;
destructor tclassdevirtinfo.destroy;
var
i: longint;
begin
for i:=0 to fstaticmethodnames.count-1 do
if assigned(fstaticmethodnames[i]) then
freemem(fstaticmethodnames[i]);
fstaticmethodnames.free;
inherited destroy;
end;
procedure tclassdevirtinfo.addstaticmethod(vmtindex: longint;
const replacementname: shortstring);
begin
if (vmtindex>=fstaticmethodnames.count) then
fstaticmethodnames.Count:=vmtindex+10;
fstaticmethodnames[vmtindex]:=stringdup(replacementname);
end;
function tclassdevirtinfo.isstaticvmtentry(vmtindex: longint; out
replacementname: pshortstring): boolean;
begin
result:=false;
if (vmtindex>=fstaticmethodnames.count) then
exit;
replacementname:=fstaticmethodnames[vmtindex];
result:=assigned(replacementname);
end;
{ tunitdevirtinfo }
constructor tunitdevirtinfo.create(hashobjectlist:tfphashobjectlist;const n: shortstring);
begin
inherited create(hashobjectlist,n);
fclasses:=tfphashobjectlist.create(true);
end;
destructor tunitdevirtinfo.destroy;
begin
fclasses.free;
inherited destroy;
end;
function tunitdevirtinfo.addclass(const n: shortstring; instantiated: boolean): tclassdevirtinfo;
begin
result:=findclass(n);
{ can't have two classes with the same name in a single unit }
if assigned(result) then
internalerror(2008100501);
result:=tclassdevirtinfo.create(fclasses,n,instantiated);
end;
function tunitdevirtinfo.findclass(const n: shortstring): tclassdevirtinfo;
begin
result:=tclassdevirtinfo(fclasses.find(n));
end;
{ tprogdevirtinfo }
procedure tprogdevirtinfo.converttreenode(node: tinheritancetreenode; arg: pointer);
var
i: longint;
classprefix: shortstring;
unitid, classid: pshortstring;
unitdevirtinfo: tunitdevirtinfo;
classdevirtinfo: tclassdevirtinfo;
begin
if (not node.instantiated) and
(node.def.vmtentries.count=0) then
exit;
{ always add a class entry for an instantiated class, so we can
fill the vmt's of non-instantiated classes with calls to
FPC_ABSTRACTERROR during the optimisation phase
}
defunitclassname(node.def,unitid,classid,classprefix);
unitdevirtinfo:=addunitifnew(unitid^);
classdevirtinfo:=unitdevirtinfo.addclass(classprefix+classid^,node.instantiated);
if (node.def.vmtentries.count=0) then
exit;
for i:=0 to node.def.vmtentries.count-1 do
if (po_virtualmethod in pvmtentry(node.def.vmtentries[i])^.procdef.procoptions) then
case node.def.vmcallstaticinfo^[i] of
vmcs_yes:
begin
{ add info about devirtualised vmt entry }
classdevirtinfo.addstaticmethod(i,pvmtentry(node.def.vmtentries[i])^.procdef.mangledname);
end;
vmcs_unreachable:
begin
{ static reference to FPC_ABSTRACTERROR }
classdevirtinfo.addstaticmethod(i,'FPC_ABSTRACTERROR');
end;
else
;
end;
end;
constructor tprogdevirtinfo.create;
begin
inherited create;
end;
destructor tprogdevirtinfo.destroy;
begin
funits.free;
inherited destroy;
end;
class function tprogdevirtinfo.getwpotype: twpotype;
begin
result:=wpo_devirtualization_context_insensitive;
end;
class function tprogdevirtinfo.generatesinfoforwposwitches: twpoptimizerswitches;
begin
result:=[cs_wpo_devirtualize_calls,cs_wpo_optimize_vmts];
end;
class function tprogdevirtinfo.performswpoforswitches: twpoptimizerswitches;
begin
result:=[cs_wpo_devirtualize_calls,cs_wpo_optimize_vmts];
end;
class function tprogdevirtinfo.sectionname: shortstring;
begin
result:=DEVIRT_SECTION_NAME;
end;
procedure tprogdevirtinfo.constructfromcompilerstate;
var
hp: tmodule;
i: longint;
inheritancetree: tinheritancetree;
begin
{ register all instantiated class/object types }
hp:=tmodule(loaded_units.first);
while assigned(hp) do
begin
if assigned(hp.wpoinfo.createdobjtypes) then
for i:=0 to hp.wpoinfo.createdobjtypes.count-1 do
tdef(hp.wpoinfo.createdobjtypes[i]).register_created_object_type;
if assigned(hp.wpoinfo.createdclassrefobjtypes) then
for i:=0 to hp.wpoinfo.createdclassrefobjtypes.count-1 do
tobjectdef(hp.wpoinfo.createdclassrefobjtypes[i]).register_created_classref_type;
if assigned(hp.wpoinfo.maybecreatedbyclassrefdeftypes) then
for i:=0 to hp.wpoinfo.maybecreatedbyclassrefdeftypes.count-1 do
tobjectdef(hp.wpoinfo.maybecreatedbyclassrefdeftypes[i]).register_maybe_created_object_type;
hp:=tmodule(hp.next);
end;
inheritancetree:=tinheritancetree.create;
{ add all constructed class/object types to the tree }
{$IFDEF DEBUG_DEVIRT}
writeln('constructed object/class/classreftypes in ',current_module.realmodulename^);
{$ENDIF}
for i := 0 to current_module.wpoinfo.createdobjtypes.count-1 do
begin
inheritancetree.registerinstantiatedobjdef(tdef(current_module.wpoinfo.createdobjtypes[i]));
{$IFDEF DEBUG_DEVIRT}
write(' ',tdef(current_module.wpoinfo.createdobjtypes[i]).GetTypeName);
{$ENDIF}
case tdef(current_module.wpoinfo.createdobjtypes[i]).typ of
objectdef:
case tobjectdef(current_module.wpoinfo.createdobjtypes[i]).objecttype of
odt_object:
{$IFDEF DEBUG_DEVIRT}
writeln(' (object)')
{$ENDIF}
;
odt_class:
{$IFDEF DEBUG_DEVIRT}
writeln(' (class)')
{$ENDIF}
;
else
internalerror(2008092101);
end;
else
internalerror(2008092102);
end;
end;
{ register all instantiated classrefdefs with the tree }
for i := 0 to current_module.wpoinfo.createdclassrefobjtypes.count-1 do
begin
inheritancetree.registerinstantiatedclassrefdef(tdef(current_module.wpoinfo.createdclassrefobjtypes[i]));
{$IFDEF DEBUG_DEVIRT}
write(' Class Of ',tdef(current_module.wpoinfo.createdclassrefobjtypes[i]).GetTypeName);
{$ENDIF}
case tdef(current_module.wpoinfo.createdclassrefobjtypes[i]).typ of
objectdef:
{$IFDEF DEBUG_DEVIRT}
writeln(' (classrefdef)')
{$ENDIF}
;
else
internalerror(2008101101);
end;
end;
{ now add all objectdefs that are referred somewhere (via a
loadvmtaddr node) and that are derived from an instantiated
classrefdef to the tree (as they can, in theory, all
be instantiated as well)
}
for i := 0 to current_module.wpoinfo.maybecreatedbyclassrefdeftypes.count-1 do
begin
inheritancetree.checkforclassrefinheritance(tdef(current_module.wpoinfo.maybecreatedbyclassrefdeftypes[i]));
{$IFDEF DEBUG_DEVIRT}
write(' Class Of ',tdef(current_module.wpoinfo.maybecreatedbyclassrefdeftypes[i]).GetTypeName);
{$ENDIF}
case tdef(current_module.wpoinfo.maybecreatedbyclassrefdeftypes[i]).typ of
objectdef:
{$IFDEF DEBUG_DEVIRT}
writeln(' (classrefdef)')
{$ENDIF}
;
else
internalerror(2008101106);
end;
end;
{ add info about called virtual methods }
hp:=tmodule(loaded_units.first);
while assigned(hp) do
begin
if assigned(hp.wpoinfo.calledvmtentries) then
for i:=0 to hp.wpoinfo.calledvmtentries.count-1 do
inheritancetree.registercalledvmtentries(tcalledvmtentries(hp.wpoinfo.calledvmtentries[i]));
hp:=tmodule(hp.next);
end;
inheritancetree.optimizevirtualmethods;
{$ifdef DEBUG_DEVIRT}
inheritancetree.printvmtinfo;
{$endif DEBUG_DEVIRT}
inheritancetree.foreachnode(@converttreenode,nil);
inheritancetree.free;
end;
function tprogdevirtinfo.addunitifnew(const n: shortstring): tunitdevirtinfo;
begin
if assigned(funits) then
result:=findunit(n)
else
begin
funits:=tfphashobjectlist.create;
result:=nil;
end;
if not assigned(result) then
begin
result:=tunitdevirtinfo.create(funits,n);
end;
end;
function tprogdevirtinfo.findunit(const n: shortstring): tunitdevirtinfo;
begin
result:=tunitdevirtinfo(funits.find(n));
end;
procedure tprogdevirtinfo.loadfromwpofilesection(reader: twposectionreaderintf);
var
unitid,
classid,
vmtentryname: string;
vmttype: string[15];
vmtentrynrstr: string[7];
classinstantiated: string[1];
vmtentry, error: longint;
unitdevirtinfo: tunitdevirtinfo;
classdevirtinfo: tclassdevirtinfo;
instantiated: boolean;
begin
{ format:
# unitname^
unit1^
# classname&
class1&
# instantiated?
1
# vmt type (base or some interface)
basevmt
# vmt entry nr
0
# name of routine to call instead
staticvmtentryforslot0
5
staticvmtentryforslot5
intfvmt1
0
staticvmtentryforslot0
# non-instantiated class (but if we encounter a variable of this
# type, we can optimise class to vmtentry 1)
class2&
0
basevmt
1
staticvmtentryforslot1
# instantiated class without optimisable virtual methods
class3&
1
unit2^
1
class3&
...
currently, only basevmt is supported (no interfaces yet)
}
{ could be empty if no classes or so }
if not reader.sectiongetnextline(unitid) then
exit;
repeat
if (unitid='') or
(unitid[length(unitid)]<>'^') then
internalerror(2008100502);
{ cut off the trailing ^ }
setlength(unitid,length(unitid)-1);
unitdevirtinfo:=addunitifnew(unitid);
{ now read classes }
if not reader.sectiongetnextline(classid) then
internalerror(2008100505);
repeat
if (classid='') or
(classid[length(classid)]<>'&') then
internalerror(2008100503);
{ instantiated? }
if not reader.sectiongetnextline(classinstantiated) then
internalerror(2008101901);
instantiated:=classinstantiated='1';
{ cut off the trailing & }
setlength(classid,length(classid)-1);
classdevirtinfo:=unitdevirtinfo.addclass(classid,instantiated);
{ last class could be an instantiated class without any
optimisable methods. }
if not reader.sectiongetnextline(vmttype) then
exit;
{ any optimisable virtual methods? }
if (vmttype<>'') then
begin
{ interface info is not yet supported }
if (vmttype<>'basevmt') then
internalerror(2008100507);
{ read all vmt entries for this class }
while reader.sectiongetnextline(vmtentrynrstr) and
(vmtentrynrstr<>'') do
begin
val(vmtentrynrstr,vmtentry,error);
if (error<>0) then
internalerror(2008100504);
if not reader.sectiongetnextline(vmtentryname) or
(vmtentryname='') then
internalerror(2008100508);
classdevirtinfo.addstaticmethod(vmtentry,vmtentryname);
end;
end;
{ end of section -> exit }
if not(reader.sectiongetnextline(classid)) then
exit;
until (classid='') or
(classid[length(classid)]='^');
{ next unit, or error }
unitid:=classid;
until false;
end;
procedure tprogdevirtinfo.documentformat(writer: twposectionwriterintf);
begin
writer.sectionputline('# section format:');
writer.sectionputline('# unit1^');
writer.sectionputline('# class1& ; classname&');
writer.sectionputline('# 1 ; instantiated or not');
writer.sectionputline('# basevmt ; vmt type (base or some interface)');
writer.sectionputline('# # vmt entry nr');
writer.sectionputline('# 0 ; vmt entry nr');
writer.sectionputline('# staticvmtentryforslot0 ; name or routine to call instead');
writer.sectionputline('# 5');
writer.sectionputline('# staticvmtentryforslot5');
writer.sectionputline('# intfvmt1');
writer.sectionputline('# 0');
writer.sectionputline('# staticvmtentryforslot0');
writer.sectionputline('#');
writer.sectionputline('# class2&');
writer.sectionputline('# 0 ; non-instantiated class (can be variables of this type, e.g. TObject)');
writer.sectionputline('# basevmt');
writer.sectionputline('# 1');
writer.sectionputline('# staticvmtentryforslot1');
writer.sectionputline('#');
writer.sectionputline('# class3& ; instantiated class without optimisable virtual methods');
writer.sectionputline('# 1');
writer.sectionputline('#');
writer.sectionputline('# unit2^');
writer.sectionputline('# 1');
writer.sectionputline('# class3&');
writer.sectionputline('# ...');
writer.sectionputline('#');
writer.sectionputline('# currently, only basevmt is supported (no interfaces yet)');
writer.sectionputline('#');
end;
procedure tprogdevirtinfo.storewpofilesection(writer: twposectionwriterintf);
var
unitcount,
classcount,
vmtentrycount: longint;
unitdevirtinfo: tunitdevirtinfo;
classdevirtinfo: tclassdevirtinfo;
first: boolean;
begin
writer.startsection(DEVIRT_SECTION_NAME);
{ if there are no optimised virtual methods, we have stored no info }
if not assigned(funits) then
exit;
documentformat(writer);
for unitcount:=0 to funits.count-1 do
begin
unitdevirtinfo:=tunitdevirtinfo(funits[unitcount]);
writer.sectionputline(unitdevirtinfo.name+'^');
for classcount:=0 to unitdevirtinfo.fclasses.count-1 do
begin
classdevirtinfo:=tclassdevirtinfo(tunitdevirtinfo(funits[unitcount]).fclasses[classcount]);
writer.sectionputline(classdevirtinfo.name+'&');
writer.sectionputline(tostr(ord(classdevirtinfo.instantiated)));
first:=true;
for vmtentrycount:=0 to classdevirtinfo.fstaticmethodnames.count-1 do
if assigned(classdevirtinfo.fstaticmethodnames[vmtentrycount]) then
begin
if first then
begin
writer.sectionputline('basevmt');
first:=false;
end;
writer.sectionputline(tostr(vmtentrycount));
writer.sectionputline(pshortstring(classdevirtinfo.fstaticmethodnames[vmtentrycount])^);
end;
writer.sectionputline('');
end;
end;
end;
function tprogdevirtinfo.getstaticname(forvmtentry: boolean; objdef, procdef: tdef; out staticname: TSymStr): boolean;
var
unitid,
classid,
newname: pshortstring;
unitdevirtinfo: tunitdevirtinfo;
classdevirtinfo: tclassdevirtinfo;
vmtentry: longint;
realobjdef: tobjectdef;
classprefix: shortstring;
begin
{ if we don't have any devirtualisation info, exit }
if not assigned(funits) then
begin
result:=false;
exit
end;
{ class methods are in the regular vmt, so we can handle classrefs
the same way as plain objectdefs
}
if (objdef.typ=classrefdef) then
realobjdef:=tobjectdef(tclassrefdef(objdef).pointeddef)
else if (objdef.typ=objectdef) and
(tobjectdef(objdef).objecttype in [odt_class,odt_object]) then
realobjdef:=tobjectdef(objdef)
else
begin
{ we don't support interfaces yet }
result:=false;
exit;
end;
{ if it's for a vmtentry of an objdef and the objdef is
not instantiated, then we can fill the vmt with pointers
to FPC_ABSTRACTERROR, except for published methods
(these can be called via rtti, so always have to point
to the original method)
}
if forvmtentry and
(tprocdef(procdef).visibility=vis_published) then
begin
result:=false;
exit;
end;
{ get the component names for the class/procdef combo }
defsdecompose(realobjdef,tprocdef(procdef),unitid,classid,classprefix,vmtentry);
{ If we don't have information about a particular unit/class/method,
it means that such class cannot be instantiated. So if we are
looking up information for a vmt entry, we can always safely return
FPC_ABSTRACTERROR if we do not find anything, unless it's a
published method (but those are handled already above) or a
class method (can be called even if the class is not instantiated).
}
result:=
forvmtentry and
not(po_classmethod in tprocdef(procdef).procoptions);
staticname:='FPC_ABSTRACTERROR';
{ do we have any info for this unit? }
unitdevirtinfo:=findunit(unitid^);
if not assigned(unitdevirtinfo) then
exit;
{ and for this class? }
classdevirtinfo:=unitdevirtinfo.findclass(classprefix+classid^);
if not assigned(classdevirtinfo) then
exit;
if forvmtentry and
(objdef.typ=objectdef) and
not classdevirtinfo.instantiated and
{ virtual class methods can be called even if the class is not instantiated }
not(po_classmethod in tprocdef(procdef).procoptions) then
begin
{ already set above
staticname:='FPC_ABSTRACTERROR';
}
result:=true;
end
else
begin
{ now check whether it can be devirtualised, and if so to what }
result:=classdevirtinfo.isstaticvmtentry(vmtentry,newname);
if result then
staticname:=newname^;
end;
end;
function tprogdevirtinfo.staticnameforcallingvirtualmethod(objdef, procdef: tdef; out staticname: TSymStr): boolean;
begin
result:=getstaticname(false,objdef,procdef,staticname);
end;
function tprogdevirtinfo.staticnameforvmtentry(objdef, procdef: tdef; out staticname: TSymStr): boolean;
begin
result:=getstaticname(true,objdef,procdef,staticname);
end;
end.
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