{
Copyright (c) 1998-2002 by Florian Klaempfl
Compare definitions and parameter lists
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 defcmp;
{$i fpcdefs.inc}
interface
uses
cclasses,
globtype,globals,
node,
symconst,symtype,symdef;
type
{ if acp is cp_all the var const or nothing are considered equal }
tcompare_paras_type = ( cp_none, cp_value_equal_const, cp_all,cp_procvar);
tcompare_paras_option = (cpo_allowdefaults,cpo_ignorehidden,cpo_allowconvert,cpo_comparedefaultvalue);
tcompare_paras_options = set of tcompare_paras_option;
tcompare_defs_option = (cdo_internal,cdo_explicit,cdo_check_operator,cdo_allow_variant,cdo_parameter);
tcompare_defs_options = set of tcompare_defs_option;
tconverttype = (tc_none,
tc_equal,
tc_not_possible,
tc_string_2_string,
tc_char_2_string,
tc_char_2_chararray,
tc_pchar_2_string,
tc_cchar_2_pchar,
tc_cstring_2_pchar,
tc_cstring_2_int,
tc_ansistring_2_pchar,
tc_string_2_chararray,
tc_chararray_2_string,
tc_array_2_pointer,
tc_pointer_2_array,
tc_int_2_int,
tc_int_2_bool,
tc_bool_2_bool,
tc_bool_2_int,
tc_real_2_real,
tc_int_2_real,
tc_real_2_currency,
tc_proc_2_procvar,
tc_nil_2_methodprocvar,
tc_arrayconstructor_2_set,
tc_set_to_set,
tc_cord_2_pointer,
tc_intf_2_string,
tc_intf_2_guid,
tc_class_2_intf,
tc_char_2_char,
tc_dynarray_2_openarray,
tc_pwchar_2_string,
tc_variant_2_dynarray,
tc_dynarray_2_variant,
tc_variant_2_enum,
tc_enum_2_variant,
tc_interface_2_variant,
tc_variant_2_interface,
tc_array_2_dynarray
);
function compare_defs_ext(def_from,def_to : tdef;
fromtreetype : tnodetype;
var doconv : tconverttype;
var operatorpd : tprocdef;
cdoptions:tcompare_defs_options):tequaltype;
{ Returns if the type def_from can be converted to def_to or if both types are equal }
function compare_defs(def_from,def_to:tdef;fromtreetype:tnodetype):tequaltype;
{ Returns true, if def1 and def2 are semantically the same }
function equal_defs(def_from,def_to:tdef):boolean;
{ Checks for type compatibility (subgroups of type)
used for case statements... probably missing stuff
to use on other types }
function is_subequal(def1, def2: tdef): boolean;
{# true, if two parameter lists are equal
if acp is cp_none, all have to match exactly
if acp is cp_value_equal_const call by value
and call by const parameter are assumed as
equal
allowdefaults indicates if default value parameters
are allowed (in this case, the search order will first
search for a routine with default parameters, before
searching for the same definition with no parameters)
}
function compare_paras(para1,para2 : TFPObjectList; acp : tcompare_paras_type; cpoptions: tcompare_paras_options):tequaltype;
{ True if a function can be assigned to a procvar }
{ changed first argument type to pabstractprocdef so that it can also be }
{ used to test compatibility between two pprocvardefs (JM) }
function proc_to_procvar_equal(def1:tabstractprocdef;def2:tprocvardef):tequaltype;
{ Parentdef is the definition of a method defined in a parent class or interface }
{ Childdef is the definition of a method defined in a child class, interface or }
{ a class implementing an interface with parentdef. }
{ Returns true if the resultdef of childdef can be used to implement/override }
{ parentdef's resultdef }
function compatible_childmethod_resultdef(parentretdef, childretdef: tdef): boolean;
implementation
uses
verbose,systems,
symtable,symsym,
defutil,symutil;
function compare_defs_ext(def_from,def_to : tdef;
fromtreetype : tnodetype;
var doconv : tconverttype;
var operatorpd : tprocdef;
cdoptions:tcompare_defs_options):tequaltype;
{ tordtype:
uvoid,
u8bit,u16bit,u32bit,u64bit,
s8bit,s16bit,s32bit,s64bit,
bool8bit,bool16bit,bool32bit,bool64bit,
uchar,uwidechar }
type
tbasedef=(bvoid,bchar,bint,bbool);
const
basedeftbl:array[tordtype] of tbasedef =
(bvoid,
bint,bint,bint,bint,
bint,bint,bint,bint,
bbool,bbool,bbool,bbool,
bchar,bchar,bint);
basedefconvertsimplicit : array[tbasedef,tbasedef] of tconverttype =
{ void, char, int, bool }
((tc_not_possible,tc_not_possible,tc_not_possible,tc_not_possible),
(tc_not_possible,tc_char_2_char,tc_not_possible,tc_not_possible),
(tc_not_possible,tc_not_possible,tc_int_2_int,tc_not_possible),
(tc_not_possible,tc_not_possible,tc_not_possible,tc_bool_2_bool));
basedefconvertsexplicit : array[tbasedef,tbasedef] of tconverttype =
{ void, char, int, bool }
((tc_not_possible,tc_not_possible,tc_not_possible,tc_not_possible),
(tc_not_possible,tc_char_2_char,tc_int_2_int,tc_int_2_bool),
(tc_not_possible,tc_int_2_int,tc_int_2_int,tc_int_2_bool),
(tc_not_possible,tc_bool_2_int,tc_bool_2_int,tc_bool_2_bool));
var
subeq,eq : tequaltype;
hd1,hd2 : tdef;
hct : tconverttype;
hobjdef : tobjectdef;
hpd : tprocdef;
begin
eq:=te_incompatible;
doconv:=tc_not_possible;
{ safety check }
if not(assigned(def_from) and assigned(def_to)) then
begin
compare_defs_ext:=te_incompatible;
exit;
end;
{ same def? then we've an exact match }
if def_from=def_to then
begin
doconv:=tc_equal;
compare_defs_ext:=te_exact;
exit;
end;
{ undefined def? then mark it as equal }
if (def_from.typ=undefineddef) or
(def_to.typ=undefineddef) then
begin
doconv:=tc_equal;
compare_defs_ext:=te_equal;
exit;
end;
{ undefined def? then mark it as equal }
if (def_from.typ=undefineddef) or
(def_to.typ=undefineddef) then
begin
doconv:=tc_equal;
compare_defs_ext:=te_equal;
exit;
end;
{ we walk the wanted (def_to) types and check then the def_from
types if there is a conversion possible }
case def_to.typ of
orddef :
begin
case def_from.typ of
orddef :
begin
if (torddef(def_from).ordtype=torddef(def_to).ordtype) then
begin
case torddef(def_from).ordtype of
uchar,uwidechar,
u8bit,u16bit,u32bit,u64bit,
s8bit,s16bit,s32bit,s64bit:
begin
if (torddef(def_from).low=torddef(def_to).low) and
(torddef(def_from).high=torddef(def_to).high) then
eq:=te_equal
else
begin
doconv:=tc_int_2_int;
eq:=te_convert_l1;
end;
end;
uvoid,
bool8bit,bool16bit,bool32bit,bool64bit:
eq:=te_equal;
else
internalerror(200210061);
end;
end
else
begin
if cdo_explicit in cdoptions then
doconv:=basedefconvertsexplicit[basedeftbl[torddef(def_from).ordtype],basedeftbl[torddef(def_to).ordtype]]
else
doconv:=basedefconvertsimplicit[basedeftbl[torddef(def_from).ordtype],basedeftbl[torddef(def_to).ordtype]];
if (doconv=tc_not_possible) then
eq:=te_incompatible
else
{ "punish" bad type conversions :) (JM) }
if (not is_in_limit(def_from,def_to)) and
(def_from.size > def_to.size) then
eq:=te_convert_l3
else
eq:=te_convert_l1;
end;
end;
enumdef :
begin
{ needed for char(enum) }
if cdo_explicit in cdoptions then
begin
doconv:=tc_int_2_int;
eq:=te_convert_l1;
end;
end;
floatdef :
begin
if is_currency(def_to) then
begin
doconv:=tc_real_2_currency;
eq:=te_convert_l2;
end;
end;
classrefdef,
procvardef,
pointerdef :
begin
if cdo_explicit in cdoptions then
begin
eq:=te_convert_l1;
if (fromtreetype=niln) then
begin
{ will be handled by the constant folding }
doconv:=tc_equal;
end
else
doconv:=tc_int_2_int;
end;
end;
arraydef :
begin
if (m_mac in current_settings.modeswitches) and
(fromtreetype=stringconstn) then
begin
eq:=te_convert_l3;
doconv:=tc_cstring_2_int;
end;
end;
end;
end;
stringdef :
begin
case def_from.typ of
stringdef :
begin
{ Constant string }
if (fromtreetype=stringconstn) then
begin
if (tstringdef(def_from).stringtype=tstringdef(def_to).stringtype) then
eq:=te_equal
else
begin
doconv:=tc_string_2_string;
{ Don't prefer conversions from widestring to a
normal string as we can loose information }
if tstringdef(def_from).stringtype=st_widestring then
eq:=te_convert_l3
else if tstringdef(def_to).stringtype=st_widestring then
eq:=te_convert_l2
else
eq:=te_equal;
end;
end
else
{ Same string type, for shortstrings also the length must match }
if (tstringdef(def_from).stringtype=tstringdef(def_to).stringtype) and
((tstringdef(def_from).stringtype<>st_shortstring) or
(tstringdef(def_from).len=tstringdef(def_to).len)) then
eq:=te_equal
else
begin
doconv:=tc_string_2_string;
case tstringdef(def_from).stringtype of
st_widestring :
begin
{ Prefer conversions to ansistring }
if tstringdef(def_to).stringtype=st_ansistring then
eq:=te_convert_l2
else
eq:=te_convert_l3;
end;
st_shortstring :
begin
{ Prefer shortstrings of different length or conversions
from shortstring to ansistring }
if (tstringdef(def_to).stringtype=st_shortstring) then
eq:=te_convert_l1
else if tstringdef(def_to).stringtype=st_ansistring then
eq:=te_convert_l2
else
eq:=te_convert_l3;
end;
st_ansistring :
begin
{ Prefer conversion to widestrings }
if (tstringdef(def_to).stringtype=st_widestring) then
eq:=te_convert_l2
else
eq:=te_convert_l3;
end;
end;
end;
end;
orddef :
begin
{ char to string}
if is_char(def_from) or
is_widechar(def_from) then
begin
doconv:=tc_char_2_string;
eq:=te_convert_l1;
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) or is_open_chararray(def_from) then
begin
{ "Untyped" stringconstn is an array of char }
if fromtreetype=stringconstn then
begin
doconv:=tc_string_2_string;
{ prefered string type depends on the $H switch }
if not(cs_ansistrings in current_settings.localswitches) and
(tstringdef(def_to).stringtype=st_shortstring) then
eq:=te_equal
else if (cs_ansistrings in current_settings.localswitches) and
(tstringdef(def_to).stringtype=st_ansistring) then
eq:=te_equal
else if tstringdef(def_to).stringtype=st_widestring then
eq:=te_convert_l3
else
eq:=te_convert_l1;
end
else
begin
doconv:=tc_chararray_2_string;
if is_open_array(def_from) then
begin
if is_ansistring(def_to) then
eq:=te_convert_l1
else if is_widestring(def_to) then
eq:=te_convert_l3
else
eq:=te_convert_l2;
end
else
begin
if is_shortstring(def_to) then
begin
{ Only compatible with arrays that fit
smaller than 255 chars }
if (def_from.size <= 255) then
eq:=te_convert_l1;
end
else if is_ansistring(def_to) then
begin
if (def_from.size > 255) then
eq:=te_convert_l1
else
eq:=te_convert_l2;
end
else if is_widestring(def_to) then
eq:=te_convert_l3
else
eq:=te_convert_l2;
end;
end;
end
else
{ array of widechar to string, the length check is done by the firstpass of this node }
if is_widechararray(def_from) or is_open_widechararray(def_from) then
begin
doconv:=tc_chararray_2_string;
if is_widestring(def_to) then
eq:=te_convert_l1
else
{ size of widechar array is double due the sizeof a widechar }
if not(is_shortstring(def_to) and (def_from.size>255*sizeof(widechar))) then
eq:=te_convert_l3
else
eq:=te_convert_l2;
end;
end;
pointerdef :
begin
{ pchar can be assigned to short/ansistrings,
but not in tp7 compatible mode }
if not(m_tp7 in current_settings.modeswitches) then
begin
if is_pchar(def_from) then
begin
doconv:=tc_pchar_2_string;
{ prefer ansistrings because pchars can overflow shortstrings, }
{ but only if ansistrings are the default (JM) }
if (is_shortstring(def_to) and
not(cs_ansistrings in current_settings.localswitches)) or
(is_ansistring(def_to) and
(cs_ansistrings in current_settings.localswitches)) then
eq:=te_convert_l1
else
eq:=te_convert_l2;
end
else if is_pwidechar(def_from) then
begin
doconv:=tc_pwchar_2_string;
if is_widestring(def_to) then
eq:=te_convert_l1
else
eq:=te_convert_l3;
end;
end;
end;
end;
end;
floatdef :
begin
case def_from.typ of
orddef :
begin { ordinal to real }
{ only for implicit and internal typecasts in tp/delphi }
if (([cdo_explicit,cdo_internal] * cdoptions <> [cdo_explicit]) or
([m_tp7,m_delphi] * current_settings.modeswitches = [])) and
(is_integer(def_from) or
(is_currency(def_from) and
(s64currencytype.typ = floatdef))) then
begin
doconv:=tc_int_2_real;
eq:=te_convert_l1;
end
else if is_currency(def_from)
{ and (s64currencytype.typ = orddef)) } then
begin
{ prefer conversion to orddef in this case, unless }
{ the orddef < currency (then it will get convert l3, }
{ and conversion to float is favoured) }
doconv:=tc_int_2_real;
eq:=te_convert_l2;
end;
end;
floatdef :
begin
if tfloatdef(def_from).floattype=tfloatdef(def_to).floattype then
eq:=te_equal
else
begin
if (fromtreetype=realconstn) or
not((cdo_explicit in cdoptions) and
(m_delphi in current_settings.modeswitches)) then
begin
doconv:=tc_real_2_real;
{ do we loose precision? }
if def_to.size<def_from.size then
eq:=te_convert_l2
else
eq:=te_convert_l1;
end;
end;
end;
end;
end;
enumdef :
begin
case def_from.typ of
enumdef :
begin
if cdo_explicit in cdoptions then
begin
eq:=te_convert_l1;
doconv:=tc_int_2_int;
end
else
begin
hd1:=def_from;
while assigned(tenumdef(hd1).basedef) do
hd1:=tenumdef(hd1).basedef;
hd2:=def_to;
while assigned(tenumdef(hd2).basedef) do
hd2:=tenumdef(hd2).basedef;
if (hd1=hd2) then
begin
eq:=te_convert_l1;
{ because of packenum they can have different sizes! (JM) }
doconv:=tc_int_2_int;
end
else
begin
{ assignment of an enum symbol to an unique type? }
if (fromtreetype=ordconstn) and
(tenumsym(tenumdef(hd1).firstenum)=tenumsym(tenumdef(hd2).firstenum)) then
begin
{ because of packenum they can have different sizes! (JM) }
eq:=te_convert_l1;
doconv:=tc_int_2_int;
end;
end;
end;
end;
orddef :
begin
if cdo_explicit in cdoptions then
begin
eq:=te_convert_l1;
doconv:=tc_int_2_int;
end;
end;
variantdef :
begin
eq:=te_convert_l1;
doconv:=tc_variant_2_enum;
end;
pointerdef :
begin
{ ugly, but delphi allows it }
if (cdo_explicit in cdoptions) and
(m_delphi in current_settings.modeswitches) and
(eq=te_incompatible) then
begin
doconv:=tc_int_2_int;
eq:=te_convert_l1;
end;
end;
end;
end;
arraydef :
begin
{ open array is also compatible with a single element of its base type.
the extra check for deftyp is needed because equal defs can also return
true if the def types are not the same, for example with dynarray to pointer. }
if is_open_array(def_to) and
(def_from.typ=tarraydef(def_to).elementdef.typ) and
equal_defs(def_from,tarraydef(def_to).elementdef) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end
else
begin
case def_from.typ of
arraydef :
begin
{ from/to packed array -- packed chararrays are }
{ strings in ISO Pascal (at least if the lower bound }
{ is 1, but GPC makes all equal-length chararrays }
{ compatible), so treat those the same as regular }
{ char arrays }
if (is_packed_array(def_from) and
not is_chararray(def_from) and
not is_widechararray(def_from)) xor
(is_packed_array(def_to) and
not is_chararray(def_to) and
not is_widechararray(def_to)) then
{ both must be packed }
begin
compare_defs_ext:=te_incompatible;
exit;
end
{ to dynamic array }
else if is_dynamic_array(def_to) then
begin
if equal_defs(tarraydef(def_from).elementdef,tarraydef(def_to).elementdef) then
begin
{ dynamic array -> dynamic array }
if is_dynamic_array(def_from) then
eq:=te_equal
{ fpc modes only: array -> dyn. array }
else if (current_settings.modeswitches*[m_objfpc,m_fpc]<>[]) and
not(is_special_array(def_from)) and
is_zero_based_array(def_from) then
begin
eq:=te_convert_l2;
doconv:=tc_array_2_dynarray;
end;
end
end
else
{ to open array }
if is_open_array(def_to) then
begin
{ array constructor -> open array }
if is_array_constructor(def_from) then
begin
if is_void(tarraydef(def_from).elementdef) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end
else
begin
subeq:=compare_defs_ext(tarraydef(def_from).elementdef,
tarraydef(def_to).elementdef,
{ reason for cdo_allow_variant: see webtbs/tw7070a and webtbs/tw7070b }
arrayconstructorn,hct,hpd,[cdo_check_operator,cdo_allow_variant]);
if (subeq>=te_equal) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end
else
if (subeq>te_incompatible) then
begin
doconv:=hct;
eq:=te_convert_l2;
end;
end;
end
else
{ dynamic array -> open array }
if is_dynamic_array(def_from) and
equal_defs(tarraydef(def_from).elementdef,tarraydef(def_to).elementdef) then
begin
doconv:=tc_dynarray_2_openarray;
eq:=te_convert_l2;
end
else
{ open array -> open array }
if is_open_array(def_from) and
equal_defs(tarraydef(def_from).elementdef,tarraydef(def_to).elementdef) then
eq:=te_equal
else
{ array -> open array }
if not(cdo_parameter in cdoptions) and
equal_defs(tarraydef(def_from).elementdef,tarraydef(def_to).elementdef) then
eq:=te_equal;
end
else
{ to array of const }
if is_array_of_const(def_to) then
begin
if is_array_of_const(def_from) or
is_array_constructor(def_from) then
begin
eq:=te_equal;
end
else
{ array of tvarrec -> array of const }
if equal_defs(tarraydef(def_to).elementdef,tarraydef(def_from).elementdef) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end;
end
else
{ to array of char, from "Untyped" stringconstn (array of char) }
if (fromtreetype=stringconstn) and
(is_chararray(def_to) or
is_widechararray(def_to)) then
begin
eq:=te_convert_l1;
doconv:=tc_string_2_chararray;
end
else
{ other arrays }
begin
{ open array -> array }
if not(cdo_parameter in cdoptions) and
is_open_array(def_from) and
equal_defs(tarraydef(def_from).elementdef,tarraydef(def_to).elementdef) then
begin
eq:=te_equal
end
else
{ array -> array }
if not(m_tp7 in current_settings.modeswitches) and
not(m_delphi in current_settings.modeswitches) and
(tarraydef(def_from).lowrange=tarraydef(def_to).lowrange) and
(tarraydef(def_from).highrange=tarraydef(def_to).highrange) and
equal_defs(tarraydef(def_from).elementdef,tarraydef(def_to).elementdef) and
equal_defs(tarraydef(def_from).rangedef,tarraydef(def_to).rangedef) then
begin
eq:=te_equal
end;
end;
end;
pointerdef :
begin
{ nil and voidpointers are compatible with dyn. arrays }
if is_dynamic_array(def_to) and
((fromtreetype=niln) or
is_voidpointer(def_from)) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end
else
if is_zero_based_array(def_to) and
equal_defs(tpointerdef(def_from).pointeddef,tarraydef(def_to).elementdef) then
begin
doconv:=tc_pointer_2_array;
eq:=te_convert_l1;
end;
end;
stringdef :
begin
{ string to char array }
if (not is_special_array(def_to)) and
(is_char(tarraydef(def_to).elementdef)or
is_widechar(tarraydef(def_to).elementdef)) then
begin
doconv:=tc_string_2_chararray;
eq:=te_convert_l1;
end;
end;
orddef:
begin
if is_chararray(def_to) and
is_char(def_from) then
begin
doconv:=tc_char_2_chararray;
eq:=te_convert_l2;
end;
end;
recorddef :
begin
{ tvarrec -> array of const }
if is_array_of_const(def_to) and
equal_defs(def_from,tarraydef(def_to).elementdef) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end;
end;
variantdef :
begin
if is_dynamic_array(def_to) then
begin
doconv:=tc_variant_2_dynarray;
eq:=te_convert_l1;
end;
end;
end;
end;
end;
variantdef :
begin
if (cdo_allow_variant in cdoptions) then
begin
case def_from.typ of
enumdef :
begin
doconv:=tc_enum_2_variant;
eq:=te_convert_l1;
end;
arraydef :
begin
if is_dynamic_array(def_from) then
begin
doconv:=tc_dynarray_2_variant;
eq:=te_convert_l1;
end;
end;
objectdef :
begin
if is_interface(def_from) then
begin
doconv:=tc_interface_2_variant;
eq:=te_convert_l1;
end;
end;
variantdef :
begin
{ doing this in the compiler avoids a lot of unncessary
copying }
if (tvariantdef(def_from).varianttype=vt_olevariant) and
(tvariantdef(def_to).varianttype=vt_normalvariant) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end;
end;
end;
end;
end;
pointerdef :
begin
case def_from.typ of
stringdef :
begin
{ string constant (which can be part of array constructor)
to zero terminated string constant }
if (((fromtreetype = arrayconstructorn) and
{ can't use is_chararray, because returns false for }
{ array constructors }
is_char(tarraydef(def_from).elementdef)) or
(fromtreetype = stringconstn)) and
(is_pchar(def_to) or is_pwidechar(def_to)) then
begin
doconv:=tc_cstring_2_pchar;
eq:=te_convert_l2;
end
else
if cdo_explicit in cdoptions then
begin
{ pchar(ansistring) }
if is_pchar(def_to) and
is_ansistring(def_from) then
begin
doconv:=tc_ansistring_2_pchar;
eq:=te_convert_l1;
end
else
{ pwidechar(widestring) }
if is_pwidechar(def_to) and
is_widestring(def_from) then
begin
doconv:=tc_ansistring_2_pchar;
eq:=te_convert_l1;
end;
end;
end;
orddef :
begin
{ char constant to zero terminated string constant }
if (fromtreetype in [ordconstn,arrayconstructorn]) then
begin
if (is_char(def_from) or is_widechar(def_from)) and
(is_pchar(def_to) or is_pwidechar(def_to)) then
begin
doconv:=tc_cchar_2_pchar;
eq:=te_convert_l1;
end
else
if (m_delphi in current_settings.modeswitches) and is_integer(def_from) then
begin
doconv:=tc_cord_2_pointer;
eq:=te_convert_l2;
end;
end;
{ allow explicit typecasts from ordinals to pointer.
Support for delphi compatibility
Support constructs like pointer(cardinal-cardinal) or pointer(longint+cardinal) where
the result of the ordinal operation is int64 also on 32 bit platforms.
It is also used by the compiler internally for inc(pointer,ordinal) }
if (eq=te_incompatible) and
not is_void(def_from) and
(
(
(cdo_explicit in cdoptions) and
(
(m_delphi in current_settings.modeswitches) or
{ Don't allow pchar(char) in fpc modes }
is_integer(def_from)
)
) or
(cdo_internal in cdoptions)
) then
begin
doconv:=tc_int_2_int;
eq:=te_convert_l1;
end;
end;
{
enumdef :
begin
{ allow explicit typecasts from enums to pointer.
Support for delphi compatibility
}
if (eq=te_incompatible) and
(((cdo_explicit in cdoptions) and
(m_delphi in current_settings.modeswitches)
) or
(cdo_internal in cdoptions)
) then
begin
doconv:=tc_int_2_int;
eq:=te_convert_l1;
end;
end;
}
arraydef :
begin
{ string constant (which can be part of array constructor)
to zero terminated string constant }
if (((fromtreetype = arrayconstructorn) and
{ can't use is_chararray, because returns false for }
{ array constructors }
is_char(tarraydef(def_from).elementdef)) or
(fromtreetype = stringconstn)) and
(is_pchar(def_to) or is_pwidechar(def_to)) then
begin
doconv:=tc_cstring_2_pchar;
eq:=te_convert_l2;
end
else
{ chararray to pointer }
if (is_zero_based_array(def_from) or
is_open_array(def_from)) and
equal_defs(tarraydef(def_from).elementdef,tpointerdef(def_to).pointeddef) then
begin
doconv:=tc_array_2_pointer;
{ don't prefer the pchar overload when a constant
string was passed }
if fromtreetype=stringconstn then
eq:=te_convert_l2
else
eq:=te_convert_l1;
end
else
{ dynamic array to pointer, delphi only }
if (m_delphi in current_settings.modeswitches) and
is_dynamic_array(def_from) then
begin
eq:=te_equal;
end;
end;
pointerdef :
begin
{ check for far pointers }
if (tpointerdef(def_from).is_far<>tpointerdef(def_to).is_far) then
begin
eq:=te_incompatible;
end
else
{ the types can be forward type, handle before normal type check !! }
if assigned(def_to.typesym) and
(tpointerdef(def_to).pointeddef.typ=forwarddef) then
begin
if (def_from.typesym=def_to.typesym) then
eq:=te_equal
end
else
{ same types }
if equal_defs(tpointerdef(def_from).pointeddef,tpointerdef(def_to).pointeddef) then
begin
eq:=te_equal
end
else
{ child class pointer can be assigned to anchestor pointers }
if (
(tpointerdef(def_from).pointeddef.typ=objectdef) and
(tpointerdef(def_to).pointeddef.typ=objectdef) and
tobjectdef(tpointerdef(def_from).pointeddef).is_related(
tobjectdef(tpointerdef(def_to).pointeddef))
) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end
else
{ all pointers can be assigned to void-pointer }
if is_void(tpointerdef(def_to).pointeddef) then
begin
doconv:=tc_equal;
{ give pwidechar,pchar a penalty so it prefers
conversion to ansistring }
if is_pchar(def_from) or
is_pwidechar(def_from) then
eq:=te_convert_l2
else
eq:=te_convert_l1;
end
else
{ all pointers can be assigned from void-pointer }
if is_void(tpointerdef(def_from).pointeddef) or
{ all pointers can be assigned from void-pointer or formaldef pointer, check
tw3777.pp if you change this }
(tpointerdef(def_from).pointeddef.typ=formaldef) then
begin
doconv:=tc_equal;
{ give pwidechar a penalty so it prefers
conversion to pchar }
if is_pwidechar(def_to) then
eq:=te_convert_l2
else
eq:=te_convert_l1;
end;
end;
procvardef :
begin
{ procedure variable can be assigned to an void pointer,
this not allowed for methodpointers }
if (is_void(tpointerdef(def_to).pointeddef) or
(m_mac_procvar in current_settings.modeswitches)) and
tprocvardef(def_from).is_addressonly then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end;
end;
procdef :
begin
{ procedure variable can be assigned to an void pointer,
this not allowed for methodpointers }
if (m_mac_procvar in current_settings.modeswitches) and
tprocdef(def_from).is_addressonly then
begin
doconv:=tc_proc_2_procvar;
eq:=te_convert_l2;
end;
end;
classrefdef,
objectdef :
begin
{ class types and class reference type
can be assigned to void pointers, but it is less
preferred than assigning to a related objectdef }
if (
is_class_or_interface_or_dispinterface(def_from) or
(def_from.typ=classrefdef)
) and
(tpointerdef(def_to).pointeddef.typ=orddef) and
(torddef(tpointerdef(def_to).pointeddef).ordtype=uvoid) then
begin
doconv:=tc_equal;
eq:=te_convert_l2;
end;
end;
end;
end;
setdef :
begin
case def_from.typ of
setdef :
begin
if assigned(tsetdef(def_from).elementdef) and
assigned(tsetdef(def_to).elementdef) then
begin
{ sets with the same element base type and the same range are equal }
if equal_defs(tsetdef(def_from).elementdef,tsetdef(def_to).elementdef) and
(tsetdef(def_from).setbase=tsetdef(def_to).setbase) and
(tsetdef(def_from).setmax=tsetdef(def_to).setmax) then
eq:=te_equal
else if is_subequal(tsetdef(def_from).elementdef,tsetdef(def_to).elementdef) then
begin
eq:=te_convert_l1;
doconv:=tc_set_to_set;
end;
end
else
begin
{ empty set is compatible with everything }
eq:=te_convert_l1;
doconv:=tc_set_to_set;
end;
end;
arraydef :
begin
{ automatic arrayconstructor -> set conversion }
if is_array_constructor(def_from) then
begin
doconv:=tc_arrayconstructor_2_set;
eq:=te_convert_l1;
end;
end;
end;
end;
procvardef :
begin
case def_from.typ of
procdef :
begin
{ proc -> procvar }
if (m_tp_procvar in current_settings.modeswitches) or
(m_mac_procvar in current_settings.modeswitches) then
begin
subeq:=proc_to_procvar_equal(tprocdef(def_from),tprocvardef(def_to));
if subeq>te_incompatible then
begin
doconv:=tc_proc_2_procvar;
eq:=te_convert_l1;
end;
end;
end;
procvardef :
begin
{ procvar -> procvar }
eq:=proc_to_procvar_equal(tprocvardef(def_from),tprocvardef(def_to));
end;
pointerdef :
begin
{ nil is compatible with procvars }
if (fromtreetype=niln) then
begin
if not Tprocvardef(def_to).is_addressonly then
{Nil to method pointers requires to convert a single
pointer nil value to a two pointer procvardef.}
doconv:=tc_nil_2_methodprocvar
else
doconv:=tc_equal;
eq:=te_convert_l1;
end
else
{ for example delphi allows the assignement from pointers }
{ to procedure variables }
if (m_pointer_2_procedure in current_settings.modeswitches) and
is_void(tpointerdef(def_from).pointeddef) and
tprocvardef(def_to).is_addressonly then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end;
end;
end;
end;
objectdef :
begin
{ object pascal objects }
if (def_from.typ=objectdef) and
(tobjectdef(def_from).is_related(tobjectdef(def_to))) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end
else
{ Class/interface specific }
if is_class_or_interface_or_dispinterface(def_to) then
begin
{ void pointer also for delphi mode }
if (m_delphi in current_settings.modeswitches) and
is_voidpointer(def_from) then
begin
doconv:=tc_equal;
{ prefer pointer-pointer assignments }
eq:=te_convert_l2;
end
else
{ nil is compatible with class instances and interfaces }
if (fromtreetype=niln) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end
{ classes can be assigned to interfaces }
else if is_interface(def_to) and
is_class(def_from) and
assigned(tobjectdef(def_from).ImplementedInterfaces) then
begin
{ we've to search in parent classes as well }
hobjdef:=tobjectdef(def_from);
while assigned(hobjdef) do
begin
if hobjdef.find_implemented_interface(tobjectdef(def_to))<>nil then
begin
doconv:=tc_class_2_intf;
{ don't prefer this over objectdef->objectdef }
eq:=te_convert_l2;
break;
end;
hobjdef:=hobjdef.childof;
end;
end
{ Interface 2 GUID handling }
else if (def_to=tdef(rec_tguid)) and
(fromtreetype=typen) and
is_interface(def_from) and
assigned(tobjectdef(def_from).iidguid) then
begin
eq:=te_convert_l1;
doconv:=tc_equal;
end
else if (def_from.typ=variantdef) and is_interface(def_to) then
begin
doconv:=tc_variant_2_interface;
eq:=te_convert_l2;
end
{ ugly, but delphi allows it }
else if (eq=te_incompatible) and
(def_from.typ=orddef) and
(m_delphi in current_settings.modeswitches) and
(cdo_explicit in cdoptions) then
begin
doconv:=tc_int_2_int;
eq:=te_convert_l1;
end;
end;
end;
classrefdef :
begin
{ similar to pointerdef wrt forwards }
if assigned(def_to.typesym) and
(tclassrefdef(def_to).pointeddef.typ=forwarddef) then
begin
if (def_from.typesym=def_to.typesym) then
eq:=te_equal;
end
else
{ class reference types }
if (def_from.typ=classrefdef) then
begin
if equal_defs(tclassrefdef(def_from).pointeddef,tclassrefdef(def_to).pointeddef) then
begin
eq:=te_equal;
end
else
begin
doconv:=tc_equal;
if (cdo_explicit in cdoptions) or
tobjectdef(tclassrefdef(def_from).pointeddef).is_related(
tobjectdef(tclassrefdef(def_to).pointeddef)) then
eq:=te_convert_l1;
end;
end
else
{ nil is compatible with class references }
if (fromtreetype=niln) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
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.typ=filedef) then
begin
if (tfiledef(def_from).filetyp=tfiledef(def_to).filetyp) then
begin
if
(
(tfiledef(def_from).typedfiledef=nil) and
(tfiledef(def_to).typedfiledef=nil)
) or
(
(tfiledef(def_from).typedfiledef<>nil) and
(tfiledef(def_to).typedfiledef<>nil) and
equal_defs(tfiledef(def_from).typedfiledef,tfiledef(def_to).typedfiledef)
) or
(
(tfiledef(def_from).filetyp = ft_typed) and
(tfiledef(def_to).filetyp = ft_typed) and
(
(tfiledef(def_from).typedfiledef = tdef(voidtype)) or
(tfiledef(def_to).typedfiledef = tdef(voidtype))
)
) then
begin
eq:=te_equal;
end;
end
else
if ((tfiledef(def_from).filetyp = ft_untyped) and
(tfiledef(def_to).filetyp = ft_typed)) or
((tfiledef(def_from).filetyp = ft_typed) and
(tfiledef(def_to).filetyp = ft_untyped)) then
begin
doconv:=tc_equal;
eq:=te_convert_l1;
end;
end;
end;
recorddef :
begin
{ interface -> guid }
if is_interface(def_from) and
(def_to=rec_tguid) then
begin
doconv:=tc_intf_2_guid;
eq:=te_convert_l1;
end;
end;
formaldef :
begin
doconv:=tc_equal;
if (def_from.typ=formaldef) then
eq:=te_equal
else
{ Just about everything can be converted to a formaldef...}
if not (def_from.typ in [abstractdef,errordef]) then
eq:=te_convert_l2;
end;
end;
{ if we didn't find an appropriate type conversion yet
then we search also the := operator }
if (eq=te_incompatible) and
{ make sure there is not a single variant if variants }
{ are not allowed (otherwise if only cdo_check_operator }
{ and e.g. fromdef=stringdef and todef=variantdef, then }
{ the test will still succeed }
((cdo_allow_variant in cdoptions) or
((def_from.typ<>variantdef) and (def_to.typ<>variantdef))
) and
(
{ Check for variants? }
(
(cdo_allow_variant in cdoptions) and
((def_from.typ=variantdef) or (def_to.typ=variantdef))
) or
{ Check for operators? }
(
(cdo_check_operator in cdoptions) and
((def_from.typ in [objectdef,recorddef,arraydef,stringdef]) or
(def_to.typ in [objectdef,recorddef,arraydef,stringdef]))
)
) then
begin
operatorpd:=search_assignment_operator(def_from,def_to);
if assigned(operatorpd) then
eq:=te_convert_operator;
end;
{ update convtype for te_equal when it is not yet set }
if (eq=te_equal) and
(doconv=tc_not_possible) then
doconv:=tc_equal;
compare_defs_ext:=eq;
end;
function equal_defs(def_from,def_to:tdef):boolean;
var
convtyp : tconverttype;
pd : tprocdef;
begin
{ Compare defs with nothingn and no explicit typecasts and
searching for overloaded operators is not needed }
equal_defs:=(compare_defs_ext(def_from,def_to,nothingn,convtyp,pd,[])>=te_equal);
end;
function compare_defs(def_from,def_to:tdef;fromtreetype:tnodetype):tequaltype;
var
doconv : tconverttype;
pd : tprocdef;
begin
compare_defs:=compare_defs_ext(def_from,def_to,fromtreetype,doconv,pd,[cdo_check_operator,cdo_allow_variant]);
end;
function is_subequal(def1, def2: tdef): boolean;
var
basedef1,basedef2 : tenumdef;
Begin
is_subequal := false;
if assigned(def1) and assigned(def2) then
Begin
if (def1.typ = orddef) and (def2.typ = orddef) then
Begin
{ see p.47 of Turbo Pascal 7.01 manual for the separation of types }
{ range checking for case statements is done with testrange }
case torddef(def1).ordtype of
u8bit,u16bit,u32bit,u64bit,
s8bit,s16bit,s32bit,s64bit :
is_subequal:=(torddef(def2).ordtype in [s64bit,u64bit,s32bit,u32bit,u8bit,s8bit,s16bit,u16bit]);
bool8bit,bool16bit,bool32bit,bool64bit :
is_subequal:=(torddef(def2).ordtype in [bool8bit,bool16bit,bool32bit,bool64bit]);
uchar :
is_subequal:=(torddef(def2).ordtype=uchar);
uwidechar :
is_subequal:=(torddef(def2).ordtype=uwidechar);
end;
end
else
Begin
{ Check if both basedefs are equal }
if (def1.typ=enumdef) and (def2.typ=enumdef) then
Begin
{ get both basedefs }
basedef1:=tenumdef(def1);
while assigned(basedef1.basedef) do
basedef1:=basedef1.basedef;
basedef2:=tenumdef(def2);
while assigned(basedef2.basedef) do
basedef2:=basedef2.basedef;
is_subequal:=(basedef1=basedef2);
end;
end;
end;
end;
function compare_paras(para1,para2 : TFPObjectList; acp : tcompare_paras_type; cpoptions: tcompare_paras_options):tequaltype;
var
currpara1,
currpara2 : tparavarsym;
eq,lowesteq : tequaltype;
hpd : tprocdef;
convtype : tconverttype;
cdoptions : tcompare_defs_options;
i1,i2 : byte;
begin
compare_paras:=te_incompatible;
cdoptions:=[cdo_parameter,cdo_check_operator,cdo_allow_variant];
{ we need to parse the list from left-right so the
not-default parameters are checked first }
lowesteq:=high(tequaltype);
i1:=0;
i2:=0;
if cpo_ignorehidden in cpoptions then
begin
while (i1<para1.count) and
(vo_is_hidden_para in tparavarsym(para1[i1]).varoptions) do
inc(i1);
while (i2<para2.count) and
(vo_is_hidden_para in tparavarsym(para2[i2]).varoptions) do
inc(i2);
end;
while (i1<para1.count) and (i2<para2.count) do
begin
eq:=te_incompatible;
currpara1:=tparavarsym(para1[i1]);
currpara2:=tparavarsym(para2[i2]);
{ Unique types must match exact }
if ((df_unique in currpara1.vardef.defoptions) or (df_unique in currpara2.vardef.defoptions)) and
(currpara1.vardef<>currpara2.vardef) then
exit;
{ Handle hidden parameters separately, because self is
defined as voidpointer for methodpointers }
if (vo_is_hidden_para in currpara1.varoptions) or
(vo_is_hidden_para in currpara2.varoptions) then
begin
{ both must be hidden }
if (vo_is_hidden_para in currpara1.varoptions)<>(vo_is_hidden_para in currpara2.varoptions) then
exit;
eq:=te_equal;
if not(vo_is_self in currpara1.varoptions) and
not(vo_is_self in currpara2.varoptions) then
begin
if (currpara1.varspez<>currpara2.varspez) then
exit;
eq:=compare_defs_ext(currpara1.vardef,currpara2.vardef,nothingn,
convtype,hpd,cdoptions);
end;
end
else
begin
case acp of
cp_value_equal_const :
begin
if (
(currpara1.varspez<>currpara2.varspez) and
((currpara1.varspez in [vs_var,vs_out]) or
(currpara2.varspez in [vs_var,vs_out]))
) then
exit;
eq:=compare_defs_ext(currpara1.vardef,currpara2.vardef,nothingn,
convtype,hpd,cdoptions);
end;
cp_all :
begin
if (currpara1.varspez<>currpara2.varspez) then
exit;
eq:=compare_defs_ext(currpara1.vardef,currpara2.vardef,nothingn,
convtype,hpd,cdoptions);
end;
cp_procvar :
begin
if (currpara1.varspez<>currpara2.varspez) then
exit;
eq:=compare_defs_ext(currpara1.vardef,currpara2.vardef,nothingn,
convtype,hpd,cdoptions);
{ Parameters must be at least equal otherwise the are incompatible }
if (eq<te_equal) then
eq:=te_incompatible;
end;
else
eq:=compare_defs_ext(currpara1.vardef,currpara2.vardef,nothingn,
convtype,hpd,cdoptions);
end;
end;
{ check type }
if eq=te_incompatible then
exit;
if eq<lowesteq then
lowesteq:=eq;
{ also check default value if both have it declared }
if (cpo_comparedefaultvalue in cpoptions) and
assigned(currpara1.defaultconstsym) and
assigned(currpara2.defaultconstsym) then
begin
if not equal_constsym(tconstsym(currpara1.defaultconstsym),tconstsym(currpara2.defaultconstsym)) then
exit;
end;
inc(i1);
inc(i2);
if cpo_ignorehidden in cpoptions then
begin
while (i1<para1.count) and
(vo_is_hidden_para in tparavarsym(para1[i1]).varoptions) do
inc(i1);
while (i2<para2.count) and
(vo_is_hidden_para in tparavarsym(para2[i2]).varoptions) do
inc(i2);
end;
end;
{ when both lists are empty then the parameters are equal. Also
when one list is empty and the other has a parameter with default
value assigned then the parameters are also equal }
if ((i1>=para1.count) and (i2>=para2.count)) or
((cpo_allowdefaults in cpoptions) and
(((i1<para1.count) and assigned(tparavarsym(para1[i1]).defaultconstsym)) or
((i2<para2.count) and assigned(tparavarsym(para2[i2]).defaultconstsym)))) then
compare_paras:=lowesteq;
end;
function proc_to_procvar_equal(def1:tabstractprocdef;def2:tprocvardef):tequaltype;
var
eq : tequaltype;
po_comp : tprocoptions;
begin
proc_to_procvar_equal:=te_incompatible;
if not(assigned(def1)) or not(assigned(def2)) then
exit;
{ check for method pointer }
if (def1.is_methodpointer xor def2.is_methodpointer) or
(def1.is_addressonly xor def2.is_addressonly) then
exit;
{ check return value and options, methodpointer is already checked }
po_comp:=[po_staticmethod,po_interrupt,
po_iocheck,po_varargs];
if (m_delphi in current_settings.modeswitches) then
exclude(po_comp,po_varargs);
if (def1.proccalloption=def2.proccalloption) and
((po_comp * def1.procoptions)= (po_comp * def2.procoptions)) and
equal_defs(def1.returndef,def2.returndef) then
begin
{ return equal type based on the parameters, but a proc->procvar
is never exact, so map an exact match of the parameters to
te_equal }
eq:=compare_paras(def1.paras,def2.paras,cp_procvar,[]);
if eq=te_exact then
eq:=te_equal;
proc_to_procvar_equal:=eq;
end;
end;
function compatible_childmethod_resultdef(parentretdef, childretdef: tdef): boolean;
begin
compatible_childmethod_resultdef :=
(equal_defs(parentretdef,childretdef)) or
((parentretdef.typ=objectdef) and
(childretdef.typ=objectdef) and
is_class_or_interface(parentretdef) and
is_class_or_interface(childretdef) and
(tobjectdef(childretdef).is_related(tobjectdef(parentretdef))))
end;
end.
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