fpc/compiler/htypechk.pas
1999-11-06 14:34:16 +00:00

918 lines
32 KiB
ObjectPascal

{
$Id$
Copyright (c) 1996-98 by Florian Klaempfl
This unit exports some help routines for the type checking
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 htypechk;
interface
uses
tree,symtable;
const
{ firstcallparan without varspez we don't count the ref }
count_ref : boolean = true;
get_para_resulttype : boolean = false;
allow_array_constructor : boolean = false;
{ Conversion }
function isconvertable(def_from,def_to : pdef;
var doconv : tconverttype;fromtreetype : ttreetyp;
explicit : boolean) : byte;
{ Register Allocation }
procedure make_not_regable(p : ptree);
procedure left_right_max(p : ptree);
procedure calcregisters(p : ptree;r32,fpu,mmx : word);
{ subroutine handling }
procedure test_protected_sym(sym : psym);
procedure test_protected(p : ptree);
function valid_for_formal_var(p : ptree) : boolean;
function valid_for_formal_const(p : ptree) : boolean;
function is_procsym_load(p:Ptree):boolean;
function is_procsym_call(p:Ptree):boolean;
function assignment_overloaded(from_def,to_def : pdef) : pprocdef;
procedure test_local_to_procvar(from_def:pprocvardef;to_def:pdef);
function valid_for_assign(p:ptree;allowprop:boolean):boolean;
implementation
uses
globtype,systems,tokens,
cobjects,verbose,globals,
symconst,
types,pass_1,
{$ifdef newcg}
cgbase
{$else}
hcodegen
{$endif}
;
{****************************************************************************
Convert
****************************************************************************}
{ Returns:
0 - Not convertable
1 - Convertable
2 - Convertable, but not first choice }
function isconvertable(def_from,def_to : pdef;
var doconv : tconverttype;fromtreetype : ttreetyp;
explicit : boolean) : byte;
{ Tbasetype: uauto,uvoid,uchar,
u8bit,u16bit,u32bit,
s8bit,s16bit,s32,
bool8bit,bool16bit,bool32bit,
u64bit,s64bitint }
type
tbasedef=(bvoid,bchar,bint,bbool);
const
basedeftbl:array[tbasetype] of tbasedef =
(bvoid,bvoid,bchar,
bint,bint,bint,
bint,bint,bint,
bbool,bbool,bbool,bint,bint);
basedefconverts : array[tbasedef,tbasedef] of tconverttype =
((tc_not_possible,tc_not_possible,tc_not_possible,tc_not_possible),
(tc_not_possible,tc_equal,tc_not_possible,tc_not_possible),
(tc_not_possible,tc_not_possible,tc_int_2_int,tc_int_2_bool),
(tc_not_possible,tc_not_possible,tc_bool_2_int,tc_bool_2_bool));
var
b : byte;
hd1,hd2 : pdef;
hct : tconverttype;
begin
{ safety check }
if not(assigned(def_from) and assigned(def_to)) then
begin
isconvertable:=0;
exit;
end;
{ tp7 procvar def support, in tp7 a procvar is always called, if the
procvar is passed explicit a addrn would be there }
if (m_tp_procvar in aktmodeswitches) and
(def_from^.deftype=procvardef) and
(fromtreetype=loadn) then
begin
def_from:=pprocvardef(def_from)^.retdef;
end;
{ we walk the wanted (def_to) types and check then the def_from
types if there is a conversion possible }
b:=0;
case def_to^.deftype of
orddef :
begin
case def_from^.deftype of
orddef :
begin
doconv:=basedefconverts[basedeftbl[porddef(def_from)^.typ],basedeftbl[porddef(def_to)^.typ]];
b:=1;
if (doconv=tc_not_possible) or
((doconv=tc_int_2_bool) and
(not explicit) and
(not is_boolean(def_from))) or
((doconv=tc_bool_2_int) and
(not explicit) and
(not is_boolean(def_to))) then
b:=0;
end;
enumdef :
begin
{ needed for char(enum) }
if explicit then
begin
doconv:=tc_int_2_int;
b:=1;
end;
end;
end;
end;
stringdef :
begin
case def_from^.deftype of
stringdef :
begin
doconv:=tc_string_2_string;
b:=1;
end;
orddef :
begin
{ char to string}
if is_char(def_from) then
begin
doconv:=tc_char_2_string;
b:=1;
end;
end;
arraydef :
begin
{ array of char to string, the length check is done by the firstpass of this node }
if is_chararray(def_from) then
begin
doconv:=tc_chararray_2_string;
if (not(cs_ansistrings in aktlocalswitches) and
is_shortstring(def_to)) or
((cs_ansistrings in aktlocalswitches) and
is_ansistring(def_to)) then
b:=1
else
b:=2;
end;
end;
pointerdef :
begin
{ pchar can be assigned to short/ansistrings }
if is_pchar(def_from) and not(m_tp in aktmodeswitches) then
begin
doconv:=tc_pchar_2_string;
b:=1;
end;
end;
end;
end;
floatdef :
begin
case def_from^.deftype of
orddef :
begin { ordinal to real }
if is_integer(def_from) then
begin
if pfloatdef(def_to)^.typ=f32bit then
doconv:=tc_int_2_fix
else
doconv:=tc_int_2_real;
b:=1;
end;
end;
floatdef :
begin { 2 float types ? }
if pfloatdef(def_from)^.typ=pfloatdef(def_to)^.typ then
doconv:=tc_equal
else
begin
if pfloatdef(def_from)^.typ=f32bit then
doconv:=tc_fix_2_real
else
if pfloatdef(def_to)^.typ=f32bit then
doconv:=tc_real_2_fix
else
doconv:=tc_real_2_real;
end;
b:=1;
end;
end;
end;
enumdef :
begin
if (def_from^.deftype=enumdef) then
begin
if assigned(penumdef(def_from)^.basedef) then
hd1:=penumdef(def_from)^.basedef
else
hd1:=def_from;
if assigned(penumdef(def_to)^.basedef) then
hd2:=penumdef(def_to)^.basedef
else
hd2:=def_to;
if (hd1=hd2) then
b:=1;
end;
end;
arraydef :
begin
{ open array is also compatible with a single element of its base type }
if is_open_array(def_to) and
is_equal(parraydef(def_to)^.definition,def_from) then
begin
doconv:=tc_equal;
b:=1;
end
else
begin
case def_from^.deftype of
arraydef :
begin
{ array constructor -> open array }
if is_open_array(def_to) and
is_array_constructor(def_from) then
begin
if is_equal(parraydef(def_to)^.definition,parraydef(def_from)^.definition) then
begin
doconv:=tc_equal;
b:=1;
end
else
if isconvertable(parraydef(def_to)^.definition,
parraydef(def_from)^.definition,hct,nothingn,false)<>0 then
begin
doconv:=hct;
b:=2;
end;
end;
end;
pointerdef :
begin
if is_zero_based_array(def_to) and
is_equal(ppointerdef(def_from)^.definition,parraydef(def_to)^.definition) then
begin
doconv:=tc_pointer_2_array;
b:=1;
end;
end;
stringdef :
begin
{ string to array of char}
if (not(is_special_array(def_to)) or is_open_array(def_to)) and
is_equal(parraydef(def_to)^.definition,cchardef) then
begin
doconv:=tc_string_2_chararray;
b:=1;
end;
end;
end;
end;
end;
pointerdef :
begin
case def_from^.deftype of
stringdef :
begin
{ string constant to zero terminated string constant }
if (fromtreetype=stringconstn) and
is_pchar(def_to) then
begin
doconv:=tc_cstring_2_pchar;
b:=1;
end;
end;
orddef :
begin
{ char constant to zero terminated string constant }
if (fromtreetype=ordconstn) then
begin
if is_equal(def_from,cchardef) and
is_pchar(def_to) then
begin
doconv:=tc_cchar_2_pchar;
b:=1;
end
else
if is_integer(def_from) then
begin
doconv:=tc_cord_2_pointer;
b:=1;
end;
end;
end;
arraydef :
begin
{ chararray to pointer }
if is_zero_based_array(def_from) and
is_equal(parraydef(def_from)^.definition,ppointerdef(def_to)^.definition) then
begin
doconv:=tc_array_2_pointer;
b:=1;
end;
end;
pointerdef :
begin
{ child class pointer can be assigned to anchestor pointers }
if (
(ppointerdef(def_from)^.definition^.deftype=objectdef) and
(ppointerdef(def_to)^.definition^.deftype=objectdef) and
pobjectdef(ppointerdef(def_from)^.definition)^.is_related(
pobjectdef(ppointerdef(def_to)^.definition))
) or
{ all pointers can be assigned to void-pointer }
is_equal(ppointerdef(def_to)^.definition,voiddef) or
{ in my opnion, is this not clean pascal }
{ well, but it's handy to use, it isn't ? (FK) }
is_equal(ppointerdef(def_from)^.definition,voiddef) then
begin
doconv:=tc_equal;
b:=1;
end;
end;
procvardef :
begin
{ procedure variable can be assigned to an void pointer }
{ Not anymore. Use the @ operator now.}
if not(m_tp_procvar in aktmodeswitches) and
(ppointerdef(def_to)^.definition^.deftype=orddef) and
(porddef(ppointerdef(def_to)^.definition)^.typ=uvoid) then
begin
doconv:=tc_equal;
b:=1;
end;
end;
classrefdef,
objectdef :
begin
{ class types and class reference type
can be assigned to void pointers }
if (
((def_from^.deftype=objectdef) and pobjectdef(def_from)^.is_class) or
(def_from^.deftype=classrefdef)
) and
(ppointerdef(def_to)^.definition^.deftype=orddef) and
(porddef(ppointerdef(def_to)^.definition)^.typ=uvoid) then
begin
doconv:=tc_equal;
b:=1;
end;
end;
end;
end;
setdef :
begin
{ automatic arrayconstructor -> set conversion }
if is_array_constructor(def_from) then
begin
doconv:=tc_arrayconstructor_2_set;
b:=1;
end;
end;
procvardef :
begin
{ proc -> procvar }
if (def_from^.deftype=procdef) then
begin
doconv:=tc_proc_2_procvar;
if proc_to_procvar_equal(pprocdef(def_from),pprocvardef(def_to)) then
b:=1;
end
else
{ for example delphi allows the assignement from pointers }
{ to procedure variables }
if (m_pointer_2_procedure in aktmodeswitches) and
(def_from^.deftype=pointerdef) and
(ppointerdef(def_from)^.definition^.deftype=orddef) and
(porddef(ppointerdef(def_from)^.definition)^.typ=uvoid) then
begin
doconv:=tc_equal;
b:=1;
end
else
{ nil is compatible with procvars }
if (fromtreetype=niln) then
begin
doconv:=tc_equal;
b:=1;
end;
end;
objectdef :
begin
{ object pascal objects }
if (def_from^.deftype=objectdef) {and
pobjectdef(def_from)^.isclass and pobjectdef(def_to)^.isclass }then
begin
doconv:=tc_equal;
if pobjectdef(def_from)^.is_related(pobjectdef(def_to)) then
b:=1;
end
else
{ nil is compatible with class instances }
if (fromtreetype=niln) and (pobjectdef(def_to)^.is_class) then
begin
doconv:=tc_equal;
b:=1;
end;
end;
classrefdef :
begin
{ class reference types }
if (def_from^.deftype=classrefdef) then
begin
doconv:=tc_equal;
if pobjectdef(pclassrefdef(def_from)^.definition)^.is_related(
pobjectdef(pclassrefdef(def_to)^.definition)) then
b:=1;
end
else
{ nil is compatible with class references }
if (fromtreetype=niln) then
begin
doconv:=tc_equal;
b:=1;
end;
end;
filedef :
begin
{ typed files are all equal to the abstract file type
name TYPEDFILE in system.pp in is_equal in types.pas
the problem is that it sholud be also compatible to FILE
but this would leed to a problem for ASSIGN RESET and REWRITE
when trying to find the good overloaded function !!
so all file function are doubled in system.pp
this is not very beautiful !!}
if (def_from^.deftype=filedef) and
(
(
(pfiledef(def_from)^.filetype = ft_typed) and
(pfiledef(def_to)^.filetype = ft_typed) and
(
(pfiledef(def_from)^.typed_as = pdef(voiddef)) or
(pfiledef(def_to)^.typed_as = pdef(voiddef))
)
) or
(
(
(pfiledef(def_from)^.filetype = ft_untyped) and
(pfiledef(def_to)^.filetype = ft_typed)
) or
(
(pfiledef(def_from)^.filetype = ft_typed) and
(pfiledef(def_to)^.filetype = ft_untyped)
)
)
) then
begin
doconv:=tc_equal;
b:=1;
end
end;
else
begin
{ assignment overwritten ?? }
if assignment_overloaded(def_from,def_to)<>nil then
b:=2;
end;
end;
isconvertable:=b;
end;
{****************************************************************************
Register Calculation
****************************************************************************}
{ marks an lvalue as "unregable" }
procedure make_not_regable(p : ptree);
begin
case p^.treetype of
typeconvn :
make_not_regable(p^.left);
loadn :
if p^.symtableentry^.typ=varsym then
pvarsym(p^.symtableentry)^.varoptions:=pvarsym(p^.symtableentry)^.varoptions-[vo_regable,vo_fpuregable];
end;
end;
procedure left_right_max(p : ptree);
begin
if assigned(p^.left) then
begin
if assigned(p^.right) then
begin
p^.registers32:=max(p^.left^.registers32,p^.right^.registers32);
p^.registersfpu:=max(p^.left^.registersfpu,p^.right^.registersfpu);
{$ifdef SUPPORT_MMX}
p^.registersmmx:=max(p^.left^.registersmmx,p^.right^.registersmmx);
{$endif SUPPORT_MMX}
end
else
begin
p^.registers32:=p^.left^.registers32;
p^.registersfpu:=p^.left^.registersfpu;
{$ifdef SUPPORT_MMX}
p^.registersmmx:=p^.left^.registersmmx;
{$endif SUPPORT_MMX}
end;
end;
end;
{ calculates the needed registers for a binary operator }
procedure calcregisters(p : ptree;r32,fpu,mmx : word);
begin
left_right_max(p);
{ Only when the difference between the left and right registers < the
wanted registers allocate the amount of registers }
if assigned(p^.left) then
begin
if assigned(p^.right) then
begin
if (abs(p^.left^.registers32-p^.right^.registers32)<r32) then
inc(p^.registers32,r32);
if (abs(p^.left^.registersfpu-p^.right^.registersfpu)<fpu) then
inc(p^.registersfpu,fpu);
{$ifdef SUPPORT_MMX}
if (abs(p^.left^.registersmmx-p^.right^.registersmmx)<mmx) then
inc(p^.registersmmx,mmx);
{$endif SUPPORT_MMX}
end
else
begin
if (p^.left^.registers32<r32) then
inc(p^.registers32,r32);
if (p^.left^.registersfpu<fpu) then
inc(p^.registersfpu,fpu);
{$ifdef SUPPORT_MMX}
if (p^.left^.registersmmx<mmx) then
inc(p^.registersmmx,mmx);
{$endif SUPPORT_MMX}
end;
end;
{ error CGMessage, if more than 8 floating point }
{ registers are needed }
if p^.registersfpu>8 then
CGMessage(cg_e_too_complex_expr);
end;
{****************************************************************************
Subroutine Handling
****************************************************************************}
{ protected field handling
protected field can not appear in
var parameters of function !!
this can only be done after we have determined the
overloaded function
this is the reason why it is not in the parser, PM }
procedure test_protected_sym(sym : psym);
begin
if (sp_protected in sym^.symoptions) and
((sym^.owner^.symtabletype=unitsymtable) or
((sym^.owner^.symtabletype=objectsymtable) and
(pobjectdef(sym^.owner^.defowner)^.owner^.symtabletype=unitsymtable))
) then
CGMessage(parser_e_cant_access_protected_member);
end;
procedure test_protected(p : ptree);
begin
case p^.treetype of
loadn : test_protected_sym(p^.symtableentry);
typeconvn : test_protected(p^.left);
derefn : test_protected(p^.left);
subscriptn : begin
{ test_protected(p^.left);
Is a field of a protected var
also protected ??? PM }
test_protected_sym(p^.vs);
end;
end;
end;
function valid_for_formal_var(p : ptree) : boolean;
var
v : boolean;
begin
case p^.treetype of
loadn : v:=(p^.symtableentry^.typ in [typedconstsym,varsym]);
typeconvn : v:=valid_for_formal_var(p^.left);
typen : v:=false;
derefn,subscriptn,vecn,
funcretn,selfn : v:=true;
{ procvars are callnodes first }
calln : v:=assigned(p^.right) and not assigned(p^.left);
{ should this depend on mode ? }
addrn : v:=true;
{ no other node accepted (PM) }
else v:=false;
end;
valid_for_formal_var:=v;
end;
function valid_for_formal_const(p : ptree) : boolean;
var
v : boolean;
begin
{ p must have been firstpass'd before }
{ accept about anything but not a statement ! }
v:=true;
if (p^.treetype in [calln,statementn]) then
{ if not assigned(p^.resulttype) or (p^.resulttype=pdef(voiddef)) then }
v:=false;
valid_for_formal_const:=v;
end;
function is_procsym_load(p:Ptree):boolean;
begin
is_procsym_load:=((p^.treetype=loadn) and (p^.symtableentry^.typ=procsym)) or
((p^.treetype=addrn) and (p^.left^.treetype=loadn)
and (p^.left^.symtableentry^.typ=procsym)) ;
end;
{ change a proc call to a procload for assignment to a procvar }
{ this can only happen for proc/function without arguments }
function is_procsym_call(p:Ptree):boolean;
begin
is_procsym_call:=(p^.treetype=calln) and (p^.left=nil) and
(((p^.symtableprocentry^.typ=procsym) and (p^.right=nil)) or
((p^.right<>nil) and (p^.right^.symtableprocentry^.typ=varsym)));
end;
function assignment_overloaded(from_def,to_def : pdef) : pprocdef;
var
passproc : pprocdef;
convtyp : tconverttype;
begin
assignment_overloaded:=nil;
if assigned(overloaded_operators[_assignment]) then
passproc:=overloaded_operators[_assignment]^.definition
else
exit;
while passproc<>nil do
begin
if is_equal(passproc^.retdef,to_def) and
(is_equal(pparaitem(passproc^.para^.first)^.data,from_def) or
(isconvertable(from_def,pparaitem(passproc^.para^.first)^.data,convtyp,ordconstn,false)=1)) then
begin
assignment_overloaded:=passproc;
break;
end;
passproc:=passproc^.nextoverloaded;
end;
end;
{ local routines can't be assigned to procvars }
procedure test_local_to_procvar(from_def:pprocvardef;to_def:pdef);
begin
if (from_def^.symtablelevel>1) and (to_def^.deftype=procvardef) then
CGMessage(type_e_cannot_local_proc_to_procvar);
end;
function valid_for_assign(p:ptree;allowprop:boolean):boolean;
var
hp : ptree;
gotderef : boolean;
begin
valid_for_assign:=false;
gotderef:=false;
hp:=p;
while assigned(hp) do
begin
if (not allowprop) and
(hp^.isproperty) then
begin
CGMessagePos(hp^.fileinfo,type_e_argument_cant_be_assigned);
exit;
end;
case hp^.treetype of
derefn :
begin
gotderef:=true;
hp:=hp^.left;
end;
typeconvn :
begin
{ pchar -> array conversion is done then we need to see it
as a deref, because a ^ is then not required anymore }
if is_chararray(hp^.resulttype) and
is_pchar(hp^.left^.resulttype) then
gotderef:=true;
hp:=hp^.left;
end;
vecn,
asn,
subscriptn :
hp:=hp^.left;
subn,
addn :
begin
{ Allow add/sub operators on a pointer }
if (hp^.resulttype^.deftype=pointerdef) then
valid_for_assign:=true
else
CGMessagePos(hp^.fileinfo,type_e_variable_id_expected);
exit;
end;
addrn :
begin
if not(gotderef) and
not(hp^.procvarload) then
CGMessagePos(hp^.fileinfo,type_e_no_assign_to_addr);
exit;
end;
funcretn :
begin
valid_for_assign:=true;
exit;
end;
calln :
begin
{ only allow writing if it returns a pointer and we've
found a deref }
if (hp^.resulttype^.deftype=pointerdef) and
gotderef then
valid_for_assign:=true
else
CGMessagePos(hp^.fileinfo,type_e_argument_cant_be_assigned);
exit;
end;
loadn :
begin
case hp^.symtableentry^.typ of
absolutesym,
varsym :
begin
if (pvarsym(hp^.symtableentry)^.varspez=vs_const) then
begin
CGMessagePos(hp^.fileinfo,type_e_no_assign_to_const);
exit;
end;
{ Are we at a with symtable, then we need to process the
withrefnode also to check for maybe a const load }
if (hp^.symtable^.symtabletype=withsymtable) then
begin
{ continue with processing the withref node }
hp:=ptree(pwithsymtable(hp^.symtable)^.withrefnode);
end
else
begin
{ set the assigned flag for varsyms }
if (pvarsym(hp^.symtableentry)^.varstate=vs_declared) then
pvarsym(hp^.symtableentry)^.varstate:=vs_assigned;
valid_for_assign:=true;
exit;
end;
end;
funcretsym,
typedconstsym :
begin
valid_for_assign:=true;
exit;
end;
end;
end;
else
begin
CGMessagePos(hp^.fileinfo,type_e_variable_id_expected);
exit;
end;
end;
end;
end;
end.
{
$Log$
Revision 1.45 1999-11-06 14:34:21 peter
* truncated log to 20 revs
Revision 1.44 1999/11/04 23:11:21 peter
* fixed pchar and deref detection for assigning
Revision 1.43 1999/10/27 16:04:45 peter
* valid_for_assign support for calln,asn
Revision 1.42 1999/10/26 12:30:41 peter
* const parameter is now checked
* better and generic check if a node can be used for assigning
* export fixes
* procvar equal works now (it never had worked at least from 0.99.8)
* defcoll changed to linkedlist with pparaitem so it can easily be
walked both directions
Revision 1.41 1999/10/14 14:57:52 florian
- removed the hcodegen use in the new cg, use cgbase instead
Revision 1.40 1999/09/26 21:30:15 peter
+ constant pointer support which can happend with typecasting like
const p=pointer(1)
* better procvar parsing in typed consts
Revision 1.39 1999/09/17 17:14:04 peter
* @procvar fixes for tp mode
* @<id>:= gives now an error
Revision 1.38 1999/08/17 13:26:07 peter
* arrayconstructor -> arrayofconst fixed when arraycosntructor was not
variant.
Revision 1.37 1999/08/16 23:23:38 peter
* arrayconstructor -> openarray type conversions for element types
Revision 1.36 1999/08/06 12:49:36 jonas
* vo_fpuregable is now also removed in make_not_regable
Revision 1.35 1999/08/05 21:50:35 peter
* removed warning
Revision 1.34 1999/08/05 16:52:55 peter
* V_Fatal=1, all other V_ are also increased
* Check for local procedure when assigning procvar
* fixed comment parsing because directives
* oldtp mode directives better supported
* added some messages to errore.msg
Revision 1.33 1999/08/04 13:02:43 jonas
* all tokens now start with an underscore
* PowerPC compiles!!
Revision 1.32 1999/08/03 22:02:53 peter
* moved bitmask constants to sets
* some other type/const renamings
Revision 1.31 1999/07/16 10:04:32 peter
* merged
Revision 1.30 1999/06/28 16:02:30 peter
* merged
Revision 1.27.2.4 1999/07/16 09:52:18 peter
* allow char(enum)
Revision 1.27.2.3 1999/06/28 15:51:27 peter
* tp7 fix
Revision 1.27.2.2 1999/06/18 10:56:58 daniel
- Enumerations no longer compatible with integer types
Revision 1.27.2.1 1999/06/17 12:51:42 pierre
* changed is_assignment_overloaded into
function assignment_overloaded : pprocdef
to allow overloading of assignment with only different result type
Revision 1.27 1999/06/01 19:27:47 peter
* better checks for procvar and methodpointer
}