fpc/compiler/htypechk.pas
peter 1a2eedd767 * self moved to hidden parameter
* removed hdisposen,hnewn,selfn
2003-05-09 17:47:02 +00:00

1102 lines
40 KiB
ObjectPascal

{
$Id$
Copyright (c) 1998-2002 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;
{$i fpcdefs.inc}
interface
uses
tokens,
node,
symtype,symdef;
type
Ttok2nodeRec=record
tok : ttoken;
nod : tnodetype;
op_overloading_supported : boolean;
end;
const
tok2nodes=25;
tok2node:array[1..tok2nodes] of ttok2noderec=(
(tok:_PLUS ;nod:addn;op_overloading_supported:true), { binary overloading supported }
(tok:_MINUS ;nod:subn;op_overloading_supported:true), { binary and unary overloading supported }
(tok:_STAR ;nod:muln;op_overloading_supported:true), { binary overloading supported }
(tok:_SLASH ;nod:slashn;op_overloading_supported:true), { binary overloading supported }
(tok:_EQUAL ;nod:equaln;op_overloading_supported:true), { binary overloading supported }
(tok:_GT ;nod:gtn;op_overloading_supported:true), { binary overloading supported }
(tok:_LT ;nod:ltn;op_overloading_supported:true), { binary overloading supported }
(tok:_GTE ;nod:gten;op_overloading_supported:true), { binary overloading supported }
(tok:_LTE ;nod:lten;op_overloading_supported:true), { binary overloading supported }
(tok:_SYMDIF ;nod:symdifn;op_overloading_supported:true), { binary overloading supported }
(tok:_STARSTAR;nod:starstarn;op_overloading_supported:true), { binary overloading supported }
(tok:_OP_AS ;nod:asn;op_overloading_supported:false), { binary overloading NOT supported }
(tok:_OP_IN ;nod:inn;op_overloading_supported:false), { binary overloading NOT supported }
(tok:_OP_IS ;nod:isn;op_overloading_supported:false), { binary overloading NOT supported }
(tok:_OP_OR ;nod:orn;op_overloading_supported:true), { binary overloading supported }
(tok:_OP_AND ;nod:andn;op_overloading_supported:true), { binary overloading supported }
(tok:_OP_DIV ;nod:divn;op_overloading_supported:true), { binary overloading supported }
(tok:_OP_NOT ;nod:notn;op_overloading_supported:true), { unary overloading supported }
(tok:_OP_MOD ;nod:modn;op_overloading_supported:true), { binary overloading supported }
(tok:_OP_SHL ;nod:shln;op_overloading_supported:true), { binary overloading supported }
(tok:_OP_SHR ;nod:shrn;op_overloading_supported:true), { binary overloading supported }
(tok:_OP_XOR ;nod:xorn;op_overloading_supported:true), { binary overloading supported }
(tok:_ASSIGNMENT;nod:assignn;op_overloading_supported:true), { unary overloading supported }
(tok:_CARET ;nod:caretn;op_overloading_supported:false), { binary overloading NOT supported }
(tok:_UNEQUAL ;nod:unequaln;op_overloading_supported:false) { binary overloading NOT supported overload = instead }
);
const
{ firstcallparan without varspez we don't count the ref }
{$ifdef extdebug}
count_ref : boolean = true;
{$endif def extdebug}
get_para_resulttype : boolean = false;
allow_array_constructor : boolean = false;
{ is overloading of this operator allowed for this
binary operator }
function isbinaryoperatoroverloadable(treetyp:tnodetype;ld:tdef;lt:tnodetype;rd:tdef;rt:tnodetype) : boolean;
{ is overloading of this operator allowed for this
unary operator }
function isunaryoperatoroverloadable(rd,dd : tdef; treetyp : tnodetype) : boolean;
{ check operator args and result type }
function isoperatoracceptable(pf : tprocdef; optoken : ttoken) : boolean;
function isbinaryoverloaded(var t : tnode) : boolean;
{ Register Allocation }
procedure make_not_regable(p : tnode);
procedure calcregisters(p : tbinarynode;r32,fpu,mmx : word);
{ subroutine handling }
function is_procsym_load(p:tnode):boolean;
procedure test_local_to_procvar(from_def:tprocvardef;to_def:tdef);
{
type
tvarstaterequire = (vsr_can_be_undefined,vsr_must_be_valid,
vsr_is_used_after,vsr_must_be_valid_and_is_used_after); }
{ sets varsym varstate field correctly }
procedure unset_varstate(p : tnode);
procedure set_varstate(p : tnode;must_be_valid : boolean);
{ sets the callunique flag, if the node is a vecn, }
{ takes care of type casts etc. }
procedure set_unique(p : tnode);
function valid_for_formal_var(p : tnode) : boolean;
function valid_for_formal_const(p : tnode) : boolean;
function valid_for_var(p:tnode):boolean;
function valid_for_assignment(p:tnode):boolean;
implementation
uses
globtype,systems,
cutils,verbose,globals,
symconst,symsym,symtable,
defutil,defcmp,cpubase,
ncnv,nld,
nmem,ncal,nmat,
cginfo,cgbase
;
type
TValidAssign=(Valid_Property,Valid_Void);
TValidAssigns=set of TValidAssign;
function isbinaryoperatoroverloadable(treetyp:tnodetype;ld:tdef;lt:tnodetype;rd:tdef;rt:tnodetype) : boolean;
function internal_check(treetyp:tnodetype;ld:tdef;lt:tnodetype;rd:tdef;rt:tnodetype;var allowed:boolean):boolean;
begin
internal_check:=true;
case ld.deftype of
recorddef,
variantdef :
begin
allowed:=true;
end;
procvardef :
begin
if (rd.deftype in [pointerdef,procdef,procvardef]) and
(treetyp in [equaln,unequaln]) then
begin
allowed:=false;
exit;
end;
allowed:=true;
end;
pointerdef :
begin
if ((rd.deftype in [pointerdef,classrefdef,procvardef]) or
is_class_or_interface(rd)) and
(treetyp in [equaln,unequaln,gtn,gten,ltn,lten,addn,subn]) then
begin
allowed:=false;
exit;
end;
{ don't allow operations on pointer/integer }
if is_integer(rd) then
begin
allowed:=false;
exit;
end;
{ don't allow pchar+string }
if is_pchar(ld) and
(treetyp in [addn,equaln,unequaln,gtn,gten,ltn,lten]) and
(is_chararray(rd) or
is_char(rd) or
(rd.deftype=stringdef)) then
begin
allowed:=false;
exit;
end;
allowed:=true;
end;
arraydef :
begin
{ not mmx }
if (cs_mmx in aktlocalswitches) and
is_mmx_able_array(ld) then
begin
allowed:=false;
exit;
end;
{ not chararray+[char,string,chararray] }
if is_chararray(ld) and
(treetyp in [addn,equaln,unequaln,gtn,gten,ltn,lten]) and
(is_char(rd) or
is_pchar(rd) or
is_integer(rd) or
(rd.deftype=stringdef) or
is_chararray(rd) or
(rt=niln)) then
begin
allowed:=false;
exit;
end;
{ dynamic array compare with niln }
if is_dynamic_array(ld) and
(rt=niln) and
(treetyp in [equaln,unequaln]) then
begin
allowed:=false;
exit;
end;
allowed:=true;
end;
objectdef :
begin
{ <> and = are defined for classes }
if (treetyp in [equaln,unequaln]) and
is_class_or_interface(ld) then
begin
allowed:=false;
exit;
end;
allowed:=true;
end;
stringdef :
begin
if ((rd.deftype=stringdef) or
is_char(rd) or
is_pchar(rd) or
is_chararray(rd)) and
(treetyp in [addn,equaln,unequaln,gtn,gten,ltn,lten]) then
begin
allowed:=false;
exit;
end;
allowed:=true;
end;
else
internal_check:=false;
end;
end;
var
allowed : boolean;
begin
{ power ** is always possible }
if (treetyp=starstarn) then
begin
isbinaryoperatoroverloadable:=true;
exit;
end;
{ order of arguments does not matter so we have to check also
the reversed order }
allowed:=false;
if not internal_check(treetyp,ld,lt,rd,rt,allowed) then
internal_check(treetyp,rd,rt,ld,lt,allowed);
isbinaryoperatoroverloadable:=allowed;
end;
function isunaryoperatoroverloadable(rd,dd : tdef; treetyp : tnodetype) : boolean;
var
eq : tequaltype;
conv : tconverttype;
pd : tprocdef;
begin
isunaryoperatoroverloadable:=false;
case treetyp of
assignn :
begin
eq:=compare_defs_ext(rd,dd,nothingn,true,false,conv,pd);
if eq<>te_incompatible then
begin
isunaryoperatoroverloadable:=false;
exit;
end;
isunaryoperatoroverloadable:=true;
end;
subn :
begin
if is_integer(rd) or
(rd.deftype=floatdef) then
begin
isunaryoperatoroverloadable:=false;
exit;
end;
{$ifdef SUPPORT_MMX}
if (cs_mmx in aktlocalswitches) and
is_mmx_able_array(rd) then
begin
isunaryoperatoroverloadable:=false;
exit;
end;
{$endif SUPPORT_MMX}
isunaryoperatoroverloadable:=true;
end;
notn :
begin
if is_integer(rd) or
is_boolean(rd) then
begin
isunaryoperatoroverloadable:=false;
exit;
end;
{$ifdef SUPPORT_MMX}
if (cs_mmx in aktlocalswitches) and
is_mmx_able_array(rd) then
begin
isunaryoperatoroverloadable:=false;
exit;
end;
{$endif SUPPORT_MMX}
isunaryoperatoroverloadable:=true;
end;
end;
end;
function isoperatoracceptable(pf : tprocdef; optoken : ttoken) : boolean;
var
ld,rd,dd : tdef;
i : longint;
begin
case pf.parast.symindex.count of
2 : begin
isoperatoracceptable:=false;
for i:=1 to tok2nodes do
if tok2node[i].tok=optoken then
begin
ld:=tvarsym(pf.parast.symindex.first).vartype.def;
rd:=tvarsym(pf.parast.symindex.first.indexnext).vartype.def;
dd:=pf.rettype.def;
isoperatoracceptable:=
tok2node[i].op_overloading_supported and
isbinaryoperatoroverloadable(tok2node[i].nod,ld,nothingn,rd,nothingn);
break;
end;
end;
1 : begin
rd:=tvarsym(pf.parast.symindex.first).vartype.def;
dd:=pf.rettype.def;
for i:=1 to tok2nodes do
if tok2node[i].tok=optoken then
begin
isoperatoracceptable:=
tok2node[i].op_overloading_supported and
isunaryoperatoroverloadable(rd,dd,tok2node[i].nod);
break;
end;
end;
else
isoperatoracceptable:=false;
end;
end;
function isbinaryoverloaded(var t : tnode) : boolean;
var
rd,ld : tdef;
optoken : ttoken;
operpd : tprocdef;
ht : tnode;
begin
isbinaryoverloaded:=false;
operpd:=nil;
{ load easier access variables }
ld:=tbinarynode(t).left.resulttype.def;
rd:=tbinarynode(t).right.resulttype.def;
if isbinaryoperatoroverloadable(t.nodetype,ld,tbinarynode(t).left.nodetype,rd,tbinarynode(t).right.nodetype) then
begin
isbinaryoverloaded:=true;
case t.nodetype of
equaln,
unequaln :
optoken:=_EQUAL;
addn:
optoken:=_PLUS;
subn:
optoken:=_MINUS;
muln:
optoken:=_STAR;
starstarn:
optoken:=_STARSTAR;
slashn:
optoken:=_SLASH;
ltn:
optoken:=tokens._lt;
gtn:
optoken:=tokens._gt;
lten:
optoken:=_lte;
gten:
optoken:=_gte;
symdifn :
optoken:=_SYMDIF;
modn :
optoken:=_OP_MOD;
orn :
optoken:=_OP_OR;
xorn :
optoken:=_OP_XOR;
andn :
optoken:=_OP_AND;
divn :
optoken:=_OP_DIV;
shln :
optoken:=_OP_SHL;
shrn :
optoken:=_OP_SHR;
else
exit;
end;
{ check if the operator contains overloaded procdefs }
if overloaded_operators[optoken]=nil then
begin
CGMessage(parser_e_operator_not_overloaded);
isbinaryoverloaded:=false;
exit;
end;
{ Check if the assignment is available, if not then
give a message that the types are not compatible }
if optoken in [_EQUAL] then
begin
operpd:=overloaded_operators[optoken].search_procdef_binary_operator(ld,rd);
if not assigned(operpd) then
begin
CGMessage2(type_e_incompatible_types,ld.typename,rd.typename);
isbinaryoverloaded:=false;
exit;
end;
end;
{ the nil as symtable signs firstcalln that this is
an overloaded operator }
inc(overloaded_operators[optoken].refs);
ht:=ccallnode.create(nil,overloaded_operators[optoken],nil,nil);
{ we already know the procdef to use for equal, so it can
skip the overload choosing in callnode.det_resulttype }
if assigned(operpd) then
tcallnode(ht).procdefinition:=operpd;
{ we need copies, because the originals will be destroyed when we give a }
{ changed node back to firstpass! (JM) }
if assigned(tbinarynode(t).left) then
if assigned(tbinarynode(t).right) then
tcallnode(ht).left :=
ccallparanode.create(tbinarynode(t).right.getcopy,
ccallparanode.create(tbinarynode(t).left.getcopy,nil))
else
tcallnode(ht).left :=
ccallparanode.create(nil,
ccallparanode.create(tbinarynode(t).left.getcopy,nil))
else if assigned(tbinarynode(t).right) then
tcallnode(ht).left :=
ccallparanode.create(tbinarynode(t).right.getcopy,
ccallparanode.create(nil,nil));
if t.nodetype=unequaln then
ht:=cnotnode.create(ht);
t:=ht;
end;
end;
{****************************************************************************
Register Calculation
****************************************************************************}
{ marks an lvalue as "unregable" }
procedure make_not_regable(p : tnode);
begin
case p.nodetype of
typeconvn :
make_not_regable(ttypeconvnode(p).left);
loadn :
if tloadnode(p).symtableentry.typ=varsym then
tvarsym(tloadnode(p).symtableentry).varoptions:=tvarsym(tloadnode(p).symtableentry).varoptions-[vo_regable,vo_fpuregable];
end;
end;
{ calculates the needed registers for a binary operator }
procedure calcregisters(p : tbinarynode;r32,fpu,mmx : word);
begin
p.left_right_max;
{ 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
{ the location must be already filled in because we need it to }
{ calculate the necessary number of registers (JM) }
if p.expectloc = LOC_INVALID then
internalerror(200110101);
if (abs(p.left.registers32-p.right.registers32)<r32) or
((p.expectloc = LOC_FPUREGISTER) and
(p.right.registersfpu <= p.left.registersfpu) and
((p.right.registersfpu <> 0) or (p.left.registersfpu <> 0)) and
(p.left.registers32 < p.right.registers32)) 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);
{$endif SUPPORT_MMX}
{ the following is a little bit guessing but I think }
{ it's the only way to solve same internalerrors: }
{ if the left and right node both uses registers }
{ and return a mem location, but the current node }
{ doesn't use an integer register we get probably }
{ trouble when restoring a node }
if (p.left.registers32=p.right.registers32) and
(p.registers32=p.left.registers32) and
(p.registers32>0) and
(p.left.expectloc in [LOC_REFERENCE,LOC_CREFERENCE]) and
(p.right.expectloc in [LOC_REFERENCE,LOC_CREFERENCE]) then
inc(p.registers32);
end
else
begin
if (p.left.registers32<r32) then
inc(p.registers32,r32);
if (p.left.registersfpu<fpu) then
inc(p.registersfpu,fpu);
{$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>maxfpuregs then
CGMessage(cg_e_too_complex_expr); now pushed if needed PM }
end;
{****************************************************************************
Subroutine Handling
****************************************************************************}
function is_procsym_load(p:tnode):boolean;
begin
{ ignore vecn,subscriptn }
repeat
case p.nodetype of
vecn :
p:=tvecnode(p).left;
subscriptn :
p:=tsubscriptnode(p).left;
else
break;
end;
until false;
is_procsym_load:=((p.nodetype=loadn) and (tloadnode(p).symtableentry.typ=procsym)) or
((p.nodetype=addrn) and (taddrnode(p).left.nodetype=loadn)
and (tloadnode(taddrnode(p).left).symtableentry.typ=procsym)) ;
end;
{ local routines can't be assigned to procvars }
procedure test_local_to_procvar(from_def:tprocvardef;to_def:tdef);
begin
if (from_def.parast.symtablelevel>normal_function_level) and
(to_def.deftype=procvardef) then
CGMessage(type_e_cannot_local_proc_to_procvar);
end;
procedure set_varstate(p : tnode;must_be_valid : boolean);
var
hsym : tvarsym;
begin
while assigned(p) do
begin
if (nf_varstateset in p.flags) then
exit;
include(p.flags,nf_varstateset);
case p.nodetype of
typeconvn :
begin
case ttypeconvnode(p).convtype of
tc_cchar_2_pchar,
tc_cstring_2_pchar,
tc_array_2_pointer :
must_be_valid:=false;
tc_pchar_2_string,
tc_pointer_2_array :
must_be_valid:=true;
end;
p:=tunarynode(p).left;
end;
subscriptn :
p:=tunarynode(p).left;
vecn:
begin
set_varstate(tbinarynode(p).right,true);
if not(tunarynode(p).left.resulttype.def.deftype in [stringdef,arraydef]) then
must_be_valid:=true;
p:=tunarynode(p).left;
end;
{ do not parse calln }
calln :
break;
callparan :
begin
set_varstate(tbinarynode(p).right,must_be_valid);
p:=tunarynode(p).left;
end;
loadn :
begin
if (tloadnode(p).symtableentry.typ=varsym) then
begin
hsym:=tvarsym(tloadnode(p).symtableentry);
if must_be_valid and (nf_first_use in p.flags) then
begin
if (hsym.varstate=vs_declared_and_first_found) or
(hsym.varstate=vs_set_but_first_not_passed) then
begin
if (assigned(hsym.owner) and
assigned(current_procdef) and
(hsym.owner=current_procdef.localst)) then
begin
if (vo_is_funcret in hsym.varoptions) then
CGMessage(sym_w_function_result_not_set)
else
if tloadnode(p).symtable.symtabletype=localsymtable then
CGMessage1(sym_n_uninitialized_local_variable,hsym.realname)
else
CGMessage1(sym_n_uninitialized_variable,hsym.realname);
end;
end;
end;
if (nf_first_use in p.flags) then
begin
if hsym.varstate=vs_declared_and_first_found then
begin
{ this can only happen at left of an assignment, no ? PM }
if (parsing_para_level=0) and not must_be_valid then
hsym.varstate:=vs_assigned
else
hsym.varstate:=vs_used;
end
else
if hsym.varstate=vs_set_but_first_not_passed then
hsym.varstate:=vs_used;
exclude(p.flags,nf_first_use);
end
else
begin
if (hsym.varstate=vs_assigned) and
(must_be_valid or (parsing_para_level>0) or
(p.resulttype.def.deftype=procvardef)) then
hsym.varstate:=vs_used;
if (hsym.varstate=vs_declared_and_first_found) and
(must_be_valid or (parsing_para_level>0) or
(p.resulttype.def.deftype=procvardef)) then
hsym.varstate:=vs_set_but_first_not_passed;
end;
end;
break;
end;
else
break;
end;{case }
end;
end;
procedure unset_varstate(p : tnode);
begin
while assigned(p) do
begin
exclude(p.flags,nf_varstateset);
case p.nodetype of
typeconvn,
subscriptn,
vecn :
p:=tunarynode(p).left;
else
break;
end;
end;
end;
procedure set_unique(p : tnode);
begin
while assigned(p) do
begin
case p.nodetype of
vecn:
begin
include(p.flags,nf_callunique);
break;
end;
typeconvn,
subscriptn,
derefn:
p:=tunarynode(p).left;
else
break;
end;
end;
end;
function valid_for_assign(p:tnode;opts:TValidAssigns):boolean;
var
hp : tnode;
gotwith,
gotsubscript,
gotpointer,
gotvec,
gotclass,
gotderef : boolean;
fromdef,
todef : tdef;
begin
valid_for_assign:=false;
gotsubscript:=false;
gotvec:=false;
gotderef:=false;
gotclass:=false;
gotpointer:=false;
gotwith:=false;
hp:=p;
if not(valid_void in opts) and
is_void(hp.resulttype.def) then
begin
CGMessagePos(hp.fileinfo,type_e_argument_cant_be_assigned);
exit;
end;
while assigned(hp) do
begin
{ property allowed? calln has a property check itself }
if (nf_isproperty in hp.flags) then
begin
if (valid_property in opts) then
valid_for_assign:=true
else
begin
{ check return type }
case hp.resulttype.def.deftype of
pointerdef :
gotpointer:=true;
objectdef :
gotclass:=is_class_or_interface(hp.resulttype.def);
recorddef, { handle record like class it needs a subscription }
classrefdef :
gotclass:=true;
end;
{ 1. if it returns a pointer and we've found a deref,
2. if it returns a class or record and a subscription or with is found }
if (gotpointer and gotderef) or
(gotclass and (gotsubscript or gotwith)) then
valid_for_assign:=true
else
CGMessagePos(hp.fileinfo,type_e_argument_cant_be_assigned);
end;
exit;
end;
case hp.nodetype of
temprefn :
begin
valid_for_assign := true;
exit;
end;
derefn :
begin
gotderef:=true;
hp:=tderefnode(hp).left;
end;
typeconvn :
begin
{ typecast sizes must match, exceptions:
- from formaldef
- from void
- typecast from pointer to array }
fromdef:=ttypeconvnode(hp).left.resulttype.def;
todef:=hp.resulttype.def;
if not((fromdef.deftype=formaldef) or
is_void(fromdef) or
((fromdef.deftype=pointerdef) and (todef.deftype=arraydef)) or
((fromdef.deftype = objectdef) and (todef.deftype = objectdef) and
(tobjectdef(fromdef).is_related(tobjectdef(todef))))) and
(fromdef.size<>todef.size) then
begin
{ in TP it is allowed to typecast to smaller types }
if not(m_tp7 in aktmodeswitches) or
(todef.size>fromdef.size) then
CGMessagePos2(hp.fileinfo,type_e_typecast_wrong_size_for_assignment,tostr(fromdef.size),tostr(todef.size));
end;
case hp.resulttype.def.deftype of
pointerdef :
gotpointer:=true;
objectdef :
gotclass:=is_class_or_interface(hp.resulttype.def);
classrefdef :
gotclass:=true;
arraydef :
begin
{ pointer -> array conversion is done then we need to see it
as a deref, because a ^ is then not required anymore }
if (ttypeconvnode(hp).left.resulttype.def.deftype=pointerdef) then
gotderef:=true;
end;
end;
hp:=ttypeconvnode(hp).left;
end;
vecn :
begin
gotvec:=true;
hp:=tunarynode(hp).left;
end;
asn :
hp:=tunarynode(hp).left;
subscriptn :
begin
gotsubscript:=true;
{ a class/interface access is an implicit }
{ dereferencing }
hp:=tsubscriptnode(hp).left;
if is_class_or_interface(hp.resulttype.def) then
gotderef:=true;
end;
subn,
addn :
begin
{ Allow add/sub operators on a pointer, or an integer
and a pointer typecast and deref has been found }
if ((hp.resulttype.def.deftype=pointerdef) or
(is_integer(hp.resulttype.def) and gotpointer)) and
gotderef then
valid_for_assign:=true
else
CGMessagePos(hp.fileinfo,type_e_variable_id_expected);
exit;
end;
addrn :
begin
if gotderef or
(nf_procvarload in hp.flags) then
valid_for_assign:=true
else
CGMessagePos(hp.fileinfo,type_e_no_assign_to_addr);
exit;
end;
calln :
begin
{ check return type }
case hp.resulttype.def.deftype of
arraydef :
begin
{ dynamic arrays are allowed when there is also a
vec node }
if is_dynamic_array(hp.resulttype.def) and
gotvec then
begin
gotderef:=true;
gotpointer:=true;
end;
end;
pointerdef :
gotpointer:=true;
objectdef :
gotclass:=is_class_or_interface(hp.resulttype.def);
recorddef, { handle record like class it needs a subscription }
classrefdef :
gotclass:=true;
end;
{ 1. if it returns a pointer and we've found a deref,
2. if it returns a class or record and a subscription or with is found }
if (gotpointer and gotderef) or
(gotclass and (gotsubscript or gotwith)) then
valid_for_assign:=true
else
CGMessagePos(hp.fileinfo,type_e_argument_cant_be_assigned);
exit;
end;
loadn :
begin
case tloadnode(hp).symtableentry.typ of
absolutesym,
varsym :
begin
if (tvarsym(tloadnode(hp).symtableentry).varspez=vs_const) then
begin
{ allow p^:= constructions with p is const parameter }
if gotderef then
valid_for_assign:=true
else
CGMessagePos(tloadnode(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 (tloadnode(hp).symtable.symtabletype=withsymtable) then
begin
{ continue with processing the withref node }
hp:=tnode(twithsymtable(tloadnode(hp).symtable).withrefnode);
gotwith:=true;
end
else
begin
{ set the assigned flag for varsyms }
if (tvarsym(tloadnode(hp).symtableentry).varstate=vs_declared) then
tvarsym(tloadnode(hp).symtableentry).varstate:=vs_assigned;
valid_for_assign:=true;
exit;
end;
end;
typedconstsym :
begin
if ttypedconstsym(tloadnode(hp).symtableentry).is_writable then
valid_for_assign:=true
else
CGMessagePos(hp.fileinfo,type_e_no_assign_to_const);
exit;
end;
else
begin
CGMessagePos(hp.fileinfo,type_e_variable_id_expected);
exit;
end;
end;
end;
else
begin
CGMessagePos(hp.fileinfo,type_e_variable_id_expected);
exit;
end;
end;
end;
end;
function valid_for_var(p:tnode):boolean;
begin
valid_for_var:=valid_for_assign(p,[]);
end;
function valid_for_formal_var(p : tnode) : boolean;
begin
valid_for_formal_var:=valid_for_assign(p,[valid_void]);
end;
function valid_for_formal_const(p : tnode) : boolean;
var
v : boolean;
begin
{ p must have been firstpass'd before }
{ accept about anything but not a statement ! }
case p.nodetype of
calln,
statementn,
addrn :
begin
{ addrn is not allowed as this generate a constant value,
but a tp procvar are allowed (PFV) }
if nf_procvarload in p.flags then
v:=true
else
v:=false;
end;
else
v:=true;
end;
valid_for_formal_const:=v;
end;
function valid_for_assignment(p:tnode):boolean;
begin
valid_for_assignment:=valid_for_assign(p,[valid_property]);
end;
end.
{
$Log$
Revision 1.63 2003-05-09 17:47:02 peter
* self moved to hidden parameter
* removed hdisposen,hnewn,selfn
Revision 1.62 2003/04/27 11:21:32 peter
* aktprocdef renamed to current_procdef
* procinfo renamed to current_procinfo
* procinfo will now be stored in current_module so it can be
cleaned up properly
* gen_main_procsym changed to create_main_proc and release_main_proc
to also generate a tprocinfo structure
* fixed unit implicit initfinal
Revision 1.61 2003/04/27 07:29:50 peter
* current_procdef cleanup, current_procdef is now always nil when parsing
a new procdef declaration
* aktprocsym removed
* lexlevel removed, use symtable.symtablelevel instead
* implicit init/final code uses the normal genentry/genexit
* funcret state checking updated for new funcret handling
Revision 1.60 2003/04/25 20:59:33 peter
* removed funcretn,funcretsym, function result is now in varsym
and aliases for result and function name are added using absolutesym
* vs_hidden parameter for funcret passed in parameter
* vs_hidden fixes
* writenode changed to printnode and released from extdebug
* -vp option added to generate a tree.log with the nodetree
* nicer printnode for statements, callnode
Revision 1.59 2003/04/22 23:50:22 peter
* firstpass uses expectloc
* checks if there are differences between the expectloc and
location.loc from secondpass in EXTDEBUG
Revision 1.58 2003/01/03 17:17:26 peter
* use compare_def_ext to test if assignn operator is allowed
Revision 1.57 2003/01/02 22:21:19 peter
* fixed previous operator change
Revision 1.56 2003/01/02 19:50:21 peter
* fixed operator checking for objects
* made binary operator checking simpeler
Revision 1.55 2002/12/27 18:06:32 peter
* fix overload error for dynarr:=nil
Revision 1.54 2002/12/22 16:34:49 peter
* proc-procvar crash fixed (tw2277)
Revision 1.53 2002/12/11 22:39:24 peter
* better error message when no operator is found for equal
Revision 1.52 2002/11/27 22:11:59 peter
* rewrote isbinaryoverloadable to use a case. it's now much easier
to understand what is happening
Revision 1.51 2002/11/25 17:43:17 peter
* splitted defbase in defutil,symutil,defcmp
* merged isconvertable and is_equal into compare_defs(_ext)
* made operator search faster by walking the list only once
Revision 1.50 2002/10/07 20:12:08 peter
* ugly hack to fix tb0411
Revision 1.49 2002/10/05 00:47:03 peter
* support dynamicarray<>nil
Revision 1.48 2002/10/04 21:13:59 peter
* ignore vecn,subscriptn when checking for a procvar loadn
Revision 1.47 2002/09/16 18:09:34 peter
* set_funcret_valid fixed when result was already used in a nested
procedure
Revision 1.46 2002/07/20 11:57:53 florian
* types.pas renamed to defbase.pas because D6 contains a types
unit so this would conflicts if D6 programms are compiled
+ Willamette/SSE2 instructions to assembler added
Revision 1.45 2002/05/18 13:34:08 peter
* readded missing revisions
Revision 1.44 2002/05/16 19:46:37 carl
+ defines.inc -> fpcdefs.inc to avoid conflicts if compiling by hand
+ try to fix temp allocation (still in ifdef)
+ generic constructor calls
+ start of tassembler / tmodulebase class cleanup
Revision 1.42 2002/04/02 17:11:28 peter
* tlocation,treference update
* LOC_CONSTANT added for better constant handling
* secondadd splitted in multiple routines
* location_force_reg added for loading a location to a register
of a specified size
* secondassignment parses now first the right and then the left node
(this is compatible with Kylix). This saves a lot of push/pop especially
with string operations
* adapted some routines to use the new cg methods
Revision 1.41 2002/01/16 09:33:46 jonas
* no longer allow assignments to pointer expressions (unless there's a
deref), reported by John Lee
}