freepascal.compiler/compiler/pdecvar.pas

{
    $Id$
    Copyright (c) 1998-2000 by Florian Klaempfl

    Parses variable declarations. Used for var statement and record
    definitions

    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 pdecvar;

{$i defines.inc}

{$define UseUnionSymtable}

interface

    procedure read_var_decs(is_record,is_object,is_threadvar:boolean);


implementation

    uses
       { common }
       cutils,cobjects,
       { global }
       globtype,globals,tokens,verbose,
       systems,cpuinfo,
       { aasm }
       aasm,
       { symtable }
       symconst,symbase,symtype,symdef,symsym,symtable,types,fmodule,
{$ifdef GDB}
       gdb,
{$endif}
       { pass 1 }
       node,pass_1,htypechk,
       nmat,nadd,ncal,nmem,nset,ncnv,ninl,ncon,nld,nflw,
       { parser }
       scanner,
       pbase,pexpr,ptype,ptconst,pdecsub,
       { link }
       import,
       { codegen }
{$ifdef newcg}
       cgbase
{$else}
       hcodegen
{$endif}
       ;

    const
       variantrecordlevel : longint = 0;

    procedure read_var_decs(is_record,is_object,is_threadvar:boolean);
    { reads the filed of a record into a        }
    { symtablestack, if record=false        }
    { variants are forbidden, so this procedure }
    { can be used to read object fields  }
    { if absolute is true, ABSOLUTE and file    }
    { types are allowed                  }
    { => the procedure is also used to read     }
    { a sequence of variable declaration        }

      procedure insert_syms(st : psymtable;sc : pstringcontainer;tt : ttype;is_threadvar : boolean);
      { inserts the symbols of sc in st with def as definition or sym as ptypesym, sc is disposed }
        var
           s : string;
           filepos : tfileposinfo;
           ss : pvarsym;
        begin
           filepos:=akttokenpos;
           while not sc^.empty do
             begin
                s:=sc^.get_with_tokeninfo(akttokenpos);
                ss:=new(pvarsym,init(s,tt));
                if is_threadvar then
                  include(ss^.varoptions,vo_is_thread_var);
                st^.insert(ss);
                { static data fields are inserted in the globalsymtable }
                if (st^.symtabletype=objectsymtable) and
                   (sp_static in current_object_option) then
                  begin
                     s:=lower(st^.name^)+'_'+s;
                     st^.defowner^.owner^.insert(new(pvarsym,init(s,tt)));
                  end;
             end;
{$ifdef fixLeaksOnError}
             if strContStack.pop <> sc then
               writeln('problem with strContStack in pdecl (2)');
{$endif fixLeaksOnError}
           dispose(sc,done);
           akttokenpos:=filepos;
        end;

      var
         sc : pstringcontainer;
         s : stringid;
         old_block_type : tblock_type;
         declarepos,storetokenpos : tfileposinfo;
         symdone : boolean;
         { to handle absolute }
         abssym : pabsolutesym;
         l    : longint;
         code : integer;
         { c var }
         newtype : ptypesym;
         is_dll,
         is_gpc_name,is_cdecl,extern_aktvarsym,export_aktvarsym : boolean;
         old_current_object_option : tsymoptions;
         dll_name,
         C_name : string;
         tt,casetype : ttype;
         { Delphi initialized vars }
         pconstsym : ptypedconstsym;
         { maxsize contains the max. size of a variant }
         { startvarrec contains the start of the variant part of a record }
         maxsize,maxalignment,startvarrecalign,startvarrecsize : longint;
         pt : tnode;
{$ifdef UseUnionSymtable}
         unionsymtable : psymtable;
         offset : longint;
         uniondef : precorddef;
         unionsym : pvarsym;
         uniontype : ttype;
{$endif UseUnionSymtable}
      begin
         old_current_object_option:=current_object_option;
         { all variables are public if not in a object declaration }
         if not is_object then
          current_object_option:=[sp_public];
         old_block_type:=block_type;
         block_type:=bt_type;
         is_gpc_name:=false;
         { Force an expected ID error message }
         if not (token in [_ID,_CASE,_END]) then
          consume(_ID);
         { read vars }
         while (token=_ID) and
               not(is_object and (idtoken in [_PUBLIC,_PRIVATE,_PUBLISHED,_PROTECTED])) do
           begin
             C_name:=orgpattern;
             sc:=idlist;
{$ifdef fixLeaksOnError}
             strContStack.push(sc);
{$endif fixLeaksOnError}
             consume(_COLON);
             if (m_gpc in aktmodeswitches) and
                not(is_record or is_object or is_threadvar) and
                (token=_ID) and (orgpattern='__asmname__') then
               begin
                 consume(_ID);
                 C_name:=pattern;
                 if token=_CCHAR then
                  consume(_CCHAR)
                 else
                  consume(_CSTRING);
                 Is_gpc_name:=true;
               end;
             { this is needed for Delphi mode at least
               but should be OK for all modes !! (PM) }
             ignore_equal:=true;
             read_type(tt,'');
             if (variantrecordlevel>0) and tt.def^.needs_inittable then
               Message(parser_e_cant_use_inittable_here);
             ignore_equal:=false;
             symdone:=false;
             if is_gpc_name then
               begin
                  storetokenpos:=akttokenpos;
                  s:=sc^.get_with_tokeninfo(akttokenpos);
                  if not sc^.empty then
                   Message(parser_e_absolute_only_one_var);
{$ifdef fixLeaksOnError}
                   if strContStack.pop <> sc then
                     writeln('problem with strContStack in pdecl (3)');
{$endif fixLeaksOnError}
                  dispose(sc,done);
                  aktvarsym:=new(pvarsym,init_C(s,target_os.Cprefix+C_name,tt));
                  include(aktvarsym^.varoptions,vo_is_external);
                  symtablestack^.insert(aktvarsym);
                  akttokenpos:=storetokenpos;
                  symdone:=true;
               end;
             { check for absolute }
             if not symdone and
                (idtoken=_ABSOLUTE) and not(is_record or is_object or is_threadvar) then
              begin
                consume(_ABSOLUTE);
                { only allowed for one var }
                s:=sc^.get_with_tokeninfo(declarepos);
                if not sc^.empty then
                 Message(parser_e_absolute_only_one_var);
{$ifdef fixLeaksOnError}
                 if strContStack.pop <> sc then
                   writeln('problem with strContStack in pdecl (4)');
{$endif fixLeaksOnError}
                dispose(sc,done);
                { parse the rest }
                if token=_ID then
                 begin
                   getsym(pattern,true);
                   consume(_ID);
                   { support unit.variable }
                   if srsym^.typ=unitsym then
                    begin
                      consume(_POINT);
                      getsymonlyin(punitsym(srsym)^.unitsymtable,pattern);
                      consume(_ID);
                    end;
                   { we should check the result type of srsym }
                   if not (srsym^.typ in [varsym,typedconstsym,funcretsym]) then
                     Message(parser_e_absolute_only_to_var_or_const);
                   storetokenpos:=akttokenpos;
                   akttokenpos:=declarepos;
                   abssym:=new(pabsolutesym,init(s,tt));
                   abssym^.abstyp:=tovar;
                   abssym^.ref:=pstoredsym(srsym);
                   symtablestack^.insert(abssym);
                   akttokenpos:=storetokenpos;
                 end
                else
                 if (token=_CSTRING) or (token=_CCHAR) then
                  begin
                    storetokenpos:=akttokenpos;
                    akttokenpos:=declarepos;
                    abssym:=new(pabsolutesym,init(s,tt));
                    s:=pattern;
                    consume(token);
                    abssym^.abstyp:=toasm;
                    abssym^.asmname:=stringdup(s);
                    symtablestack^.insert(abssym);
                    akttokenpos:=storetokenpos;
                  end
                else
                { absolute address ?!? }
                 if token=_INTCONST then
                  begin
                    if (target_info.target=target_i386_go32v2) then
                     begin
                       storetokenpos:=akttokenpos;
                       akttokenpos:=declarepos;
                       abssym:=new(pabsolutesym,init(s,tt));
                       abssym^.abstyp:=toaddr;
                       abssym^.absseg:=false;
                       s:=pattern;
                       consume(_INTCONST);
                       val(s,abssym^.address,code);
                       if token=_COLON then
                        begin
                          consume(token);
                          s:=pattern;
                          consume(_INTCONST);
                          val(s,l,code);
                          abssym^.address:=abssym^.address shl 4+l;
                          abssym^.absseg:=true;
                        end;
                       symtablestack^.insert(abssym);
                       akttokenpos:=storetokenpos;
                     end
                    else
                     Message(parser_e_absolute_only_to_var_or_const);
                  end
                else
                 Message(parser_e_absolute_only_to_var_or_const);
                symdone:=true;
              end;
             { Handling of Delphi typed const = initialized vars ! }
             { When should this be rejected ?
               - in parasymtable
               - in record or object
               - ... (PM) }
             if (m_delphi in aktmodeswitches) and (token=_EQUAL) and
                not (symtablestack^.symtabletype in [parasymtable]) and
                not is_record and not is_object then
               begin
                  storetokenpos:=akttokenpos;
                  s:=sc^.get_with_tokeninfo(akttokenpos);
                  if not sc^.empty then
                    Message(parser_e_initialized_only_one_var);
                  pconstsym:=new(ptypedconstsym,inittype(s,tt,false));
                  symtablestack^.insert(pconstsym);
                  akttokenpos:=storetokenpos;
                  consume(_EQUAL);
                  readtypedconst(tt.def,pconstsym,false);
                  symdone:=true;
               end;
             { for a record there doesn't need to be a ; before the END or ) }
             if not((is_record or is_object) and (token in [_END,_RKLAMMER])) then
               consume(_SEMICOLON);
             { procvar handling }
             if (tt.def^.deftype=procvardef) and (tt.def^.typesym=nil) then
               begin
                  newtype:=new(ptypesym,init('unnamed',tt));
                  parse_var_proc_directives(psym(newtype));
                  newtype^.restype.def:=nil;
                  tt.def^.typesym:=nil;
                  dispose(newtype,done);
               end;
             { Check for variable directives }
             if not symdone and (token=_ID) then
              begin
                { Check for C Variable declarations }
                if (m_cvar_support in aktmodeswitches) and
                   not(is_record or is_object or is_threadvar) and
                   (idtoken in [_EXPORT,_EXTERNAL,_PUBLIC,_CVAR]) then
                 begin
                   { only allowed for one var }
                   s:=sc^.get_with_tokeninfo(declarepos);
                   if not sc^.empty then
                    Message(parser_e_absolute_only_one_var);
{$ifdef fixLeaksOnError}
                   if strContStack.pop <> sc then
                     writeln('problem with strContStack in pdecl (5)');
{$endif fixLeaksOnError}
                   dispose(sc,done);
                   { defaults }
                   is_dll:=false;
                   is_cdecl:=false;
                   extern_aktvarsym:=false;
                   export_aktvarsym:=false;
                   { cdecl }
                   if idtoken=_CVAR then
                    begin
                      consume(_CVAR);
                      consume(_SEMICOLON);
                      is_cdecl:=true;
                      C_name:=target_os.Cprefix+C_name;
                    end;
                   { external }
                   if idtoken=_EXTERNAL then
                    begin
                      consume(_EXTERNAL);
                      extern_aktvarsym:=true;
                    end;
                   { export }
                   if idtoken in [_EXPORT,_PUBLIC] then
                    begin
                      consume(_ID);
                      if extern_aktvarsym or
                         (symtablestack^.symtabletype in [parasymtable,localsymtable]) then
                       Message(parser_e_not_external_and_export)
                      else
                       export_aktvarsym:=true;
                    end;
                   { external and export need a name after when no cdecl is used }
                   if not is_cdecl then
                    begin
                      { dll name ? }
                      if (extern_aktvarsym) and (idtoken<>_NAME) then
                       begin
                         is_dll:=true;
                         dll_name:=get_stringconst;
                       end;
                      consume(_NAME);
                      C_name:=get_stringconst;
                    end;
                   { consume the ; when export or external is used }
                   if extern_aktvarsym or export_aktvarsym then
                    consume(_SEMICOLON);
                   { insert in the symtable }
                   storetokenpos:=akttokenpos;
                   akttokenpos:=declarepos;
                   if is_dll then
                    aktvarsym:=new(pvarsym,init_dll(s,tt))
                   else
                    aktvarsym:=new(pvarsym,init_C(s,C_name,tt));
                   { set some vars options }
                   if export_aktvarsym then
                    begin
                      inc(aktvarsym^.refs);
                      include(aktvarsym^.varoptions,vo_is_exported);
                    end;
                   if extern_aktvarsym then
                    include(aktvarsym^.varoptions,vo_is_external);
                   { insert in the stack/datasegment }
                   symtablestack^.insert(aktvarsym);
                   akttokenpos:=storetokenpos;
                   { now we can insert it in the import lib if its a dll, or
                     add it to the externals }
                   if extern_aktvarsym then
                    begin
                      if is_dll then
                       begin
                         if not(current_module^.uses_imports) then
                          begin
                            current_module^.uses_imports:=true;
                            importlib^.preparelib(current_module^.modulename^);
                          end;
                         importlib^.importvariable(aktvarsym^.mangledname,dll_name,C_name)
                       end
                    end;
                   symdone:=true;
                 end
                else
                 if (is_object) and (cs_static_keyword in aktmoduleswitches) and (idtoken=_STATIC) then
                  begin
                    include(current_object_option,sp_static);
                    insert_syms(symtablestack,sc,tt,false);
                    exclude(current_object_option,sp_static);
                    consume(_STATIC);
                    consume(_SEMICOLON);
                    symdone:=true;
                  end;
              end;
             { insert it in the symtable, if not done yet }
             if not symdone then
               begin
                  { save object option, because we can turn of the sp_published }
                  if (sp_published in current_object_option) and
                    not(is_class(tt.def)) then
                   begin
                     Message(parser_e_cant_publish_that);
                     exclude(current_object_option,sp_published);
                   end
                  else
                   if (sp_published in current_object_option) and
                      not(oo_can_have_published in pobjectdef(tt.def)^.objectoptions) then
                    begin
                      Message(parser_e_only_publishable_classes_can__be_published);
                      exclude(current_object_option,sp_published);
                    end;
                  insert_syms(symtablestack,sc,tt,is_threadvar);
                  current_object_option:=old_current_object_option;
               end;
           end;
         { Check for Case }
         if is_record and (token=_CASE) then
           begin
              maxsize:=0;
              maxalignment:=0;
              consume(_CASE);
              s:=pattern;
              getsym(s,false);
              { may be only a type: }
              if assigned(srsym) and (srsym^.typ in [typesym,unitsym]) then
                read_type(casetype,'')
              else
                begin
                  consume(_ID);
                  consume(_COLON);
                  read_type(casetype,'');
                  symtablestack^.insert(new(pvarsym,init(s,casetype)));
                end;
              if not(is_ordinal(casetype.def)) or is_64bitint(casetype.def)  then
               Message(type_e_ordinal_expr_expected);
              consume(_OF);
{$ifdef UseUnionSymtable}
              UnionSymtable:=new(pstoredsymtable,init(recordsymtable));
              UnionSymtable^.next:=symtablestack;
              registerdef:=false;
              UnionDef:=new(precorddef,init(unionsymtable));
              registerdef:=true;
              symtablestack:=UnionSymtable;
{$endif UseUnionSymtable}
              startvarrecsize:=symtablestack^.datasize;
              startvarrecalign:=symtablestack^.dataalignment;
              repeat
                repeat
                  pt:=comp_expr(true);
                  do_firstpass(pt);
                  if not(pt.nodetype=ordconstn) then
                    Message(cg_e_illegal_expression);
                  pt.free;
                  if token=_COMMA then
                   consume(_COMMA)
                  else
                   break;
                until false;
                consume(_COLON);
                { read the vars }
                consume(_LKLAMMER);
                inc(variantrecordlevel);
                if token<>_RKLAMMER then
                  read_var_decs(true,false,false);
                dec(variantrecordlevel);
                consume(_RKLAMMER);
                { calculates maximal variant size }
                maxsize:=max(maxsize,symtablestack^.datasize);
                maxalignment:=max(maxalignment,symtablestack^.dataalignment);
                { the items of the next variant are overlayed }
                symtablestack^.datasize:=startvarrecsize;
                symtablestack^.dataalignment:=startvarrecalign;
                if (token<>_END) and (token<>_RKLAMMER) then
                  consume(_SEMICOLON)
                else
                  break;
              until (token=_END) or (token=_RKLAMMER);
              { at last set the record size to that of the biggest variant }
              symtablestack^.datasize:=maxsize;
              symtablestack^.dataalignment:=maxalignment;
{$ifdef UseUnionSymtable}
              uniontype.def:=uniondef;
              uniontype.sym:=nil;
              UnionSym:=new(pvarsym,init('case',uniontype));
              symtablestack:=symtablestack^.next;
              { we do NOT call symtablestack^.insert
               on purpose PM }
              offset:=align_from_size(symtablestack^.datasize,maxalignment);
              symtablestack^.datasize:=offset+unionsymtable^.datasize;
              if maxalignment>symtablestack^.dataalignment then
                symtablestack^.dataalignment:=maxalignment;
              pstoredsymtable(UnionSymtable)^.Insert_in(symtablestack,offset);
              UnionSym^.owner:=nil;
              dispose(unionsym,done);
              dispose(uniondef,done);
{$endif UseUnionSymtable}
           end;
         block_type:=old_block_type;
         current_object_option:=old_current_object_option;
      end;

end.
{
  $Log$
  Revision 1.3  2000-11-04 14:25:20  florian
    + merged Attila's changes for interfaces, not tested yet

  Revision 1.2  2000/10/31 22:02:49  peter
    * symtable splitted, no real code changes

  Revision 1.1  2000/10/14 10:14:51  peter
    * moehrendorf oct 2000 rewrite

}