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}

interface

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


implementation

    uses
       { common }
       cutils,
       { global }
       globtype,globals,tokens,verbose,
       systems,
       { symtable }
       symconst,symbase,symtype,symdef,symsym,symtable,types,fmodule,
       { pass 1 }
       node,
       nmat,nadd,ncal,nset,ncnv,ninl,ncon,nld,nflw,
       { parser }
       scanner,
       pbase,pexpr,ptype,ptconst,pdecsub,
       { link }
       import;

    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 : tsymtable;sc : tidstringlist;tt : ttype;is_threadvar : boolean);
      { inserts the symbols of sc in st with def as definition or sym as ttypesym, sc is disposed }
        var
           s : string;
           filepos : tfileposinfo;
           ss : tvarsym;
        begin
           filepos:=akttokenpos;
           while not sc.empty do
             begin
                s:=sc.get(akttokenpos);
                ss:=tvarsym.Create(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:='$'+lower(st.name^)+'_'+upper(s);
                     st.defowner.owner.insert(tvarsym.create(s,tt));
                  end;
             end;
{$ifdef fixLeaksOnError}
             if strContStack.pop <> sc then
               writeln('problem with strContStack in pdecl (2)');
{$endif fixLeaksOnError}
           sc.free;
           akttokenpos:=filepos;
        end;

      var
         sc : tidstringList;
         s : stringid;
         old_block_type : tblock_type;
         declarepos,storetokenpos : tfileposinfo;
         oldsymtablestack : tsymtable;
         symdone : boolean;
         { to handle absolute }
         abssym : tabsolutesym;
         { c var }
         newtype : ttypesym;
         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 }
         tconstsym : ttypedconstsym;
         { maxsize contains the max. size of a variant }
         { startvarrec contains the start of the variant part of a record }
         usedalign,
         maxsize,minalignment,maxalignment,startvarrecalign,startvarrecsize : longint;
         pt : tnode;
         srsym : tsym;
         srsymtable : tsymtable;
         unionsymtable : tsymtable;
         offset : longint;
         uniondef : trecorddef;
         unionsym : tvarsym;
         uniontype : ttype;
         dummysymoptions : tsymoptions;
      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:=consume_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:=get_stringconst;
                 Is_gpc_name:=true;
               end;
             { this is needed for Delphi mode at least
               but should be OK for all modes !! (PM) }
             ignore_equal:=true;
             if is_record then
              begin
                { for records, don't search the recordsymtable for
                  the symbols of the types }
                oldsymtablestack:=symtablestack;
                symtablestack:=symtablestack.next;
                read_type(tt,'');
                symtablestack:=oldsymtablestack;
              end
             else
              read_type(tt,'');
             { types that use init/final are not allowed in variant parts, but
               classes are allowed }
             if (variantrecordlevel>0) and
                (tt.def.needs_inittable and not is_class(tt.def)) then
               Message(parser_e_cant_use_inittable_here);
             ignore_equal:=false;
             symdone:=false;
             if is_gpc_name then
               begin
                  storetokenpos:=akttokenpos;
                  s:=sc.get(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}
                  sc.free;
                  aktvarsym:=tvarsym.create_C(s,target_info.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(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}
                sc.free;
                { parse the rest }
                pt:=expr;
                if (pt.nodetype=stringconstn) or (is_constcharnode(pt)) then
                 begin
                   storetokenpos:=akttokenpos;
                   akttokenpos:=declarepos;
                   abssym:=tabsolutesym.create(s,tt);
                   if pt.nodetype=stringconstn then
                     s:=strpas(tstringconstnode(pt).value_str)
                   else
                     s:=chr(tordconstnode(pt).value);
                   consume(token);
                   abssym.abstyp:=toasm;
                   abssym.asmname:=stringdup(s);
                   symtablestack.insert(abssym);
                   akttokenpos:=storetokenpos;
                   symdone:=true;
                 end;
                if not symdone then
                 begin
                   { variable }
                   if (pt.nodetype=loadn) then
                    begin
                      { we should check the result type of srsym }
                      if not (tloadnode(pt).symtableentry.typ in [varsym,typedconstsym,funcretsym]) then
                        Message(parser_e_absolute_only_to_var_or_const);
                      storetokenpos:=akttokenpos;
                      akttokenpos:=declarepos;
                      abssym:=tabsolutesym.create(s,tt);
                      abssym.abstyp:=tovar;
                      abssym.ref:=tstoredsym(tloadnode(pt).symtableentry);
                      symtablestack.insert(abssym);
                      akttokenpos:=storetokenpos;
                      symdone:=true;
                    end
                   { funcret }
                   else if (pt.nodetype=funcretn) then
                    begin
                      storetokenpos:=akttokenpos;
                      akttokenpos:=declarepos;
                      abssym:=tabsolutesym.create(s,tt);
                      abssym.abstyp:=tovar;
                      abssym.ref:=tstoredsym(tfuncretnode(pt).funcretsym);
                      symtablestack.insert(abssym);
                      akttokenpos:=storetokenpos;
                      symdone:=true;
                    end;
                   { address }
                   if (not symdone) and
                      ((target_info.target=target_i386_go32v2) or
                       (m_objfpc in aktmodeswitches) or
                       (m_delphi in aktmodeswitches)) then
                    begin
                      if is_constintnode(pt) then
                       begin
                         storetokenpos:=akttokenpos;
                         akttokenpos:=declarepos;
                         abssym:=tabsolutesym.create(s,tt);
                         abssym.abstyp:=toaddr;
                         abssym.absseg:=false;
                         abssym.address:=tordconstnode(pt).value;
                         if (token=_COLON) and
                            (target_info.target=target_i386_go32v2) then
                          begin
                            consume(token);
                            pt:=expr;
                            if is_constintnode(pt) then
                              begin
                                abssym.address:=abssym.address shl 4+tordconstnode(pt).value;
                                abssym.absseg:=true;
                              end
                            else
                               Message(parser_e_absolute_only_to_var_or_const);
                          end;
                         symtablestack.insert(abssym);
                         akttokenpos:=storetokenpos;
                       end
                      else
                       Message(parser_e_absolute_only_to_var_or_const);
                    end;
                 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(akttokenpos);
                  if not sc.empty then
                    Message(parser_e_initialized_only_one_var);
                  tconstsym:=ttypedconstsym.createtype(s,tt,false);
                  symtablestack.insert(tconstsym);
                  akttokenpos:=storetokenpos;
                  consume(_EQUAL);
                  readtypedconst(tt,tconstsym,false);
                  symdone:=true;
               end;
             { hint directive }
             {$warning hintdirective not stored in syms}
             dummysymoptions:=[];
             try_consume_hintdirective(dummysymoptions);
             { for a record there doesn't need to be a ; before the END or ) }
             if not((is_record or is_object) and (token in [_END,_RKLAMMER])) then
               consume(_SEMICOLON);
             { procvar handling }
             if (tt.def.deftype=procvardef) and (tt.def.typesym=nil) then
               begin
                  newtype:=ttypesym.create('unnamed',tt);
                  parse_var_proc_directives(tsym(newtype));
                  newtype.restype.def:=nil;
                  tt.def.typesym:=nil;
                  newtype.free;
               end;
             { Check for variable directives }
             if not symdone and (token=_ID) then
              begin
                { Check for C Variable declarations }
                if (m_cvar_support in aktmodeswitches) and
                   not(is_record or is_object or is_threadvar) and
                   (idtoken in [_EXPORT,_EXTERNAL,_PUBLIC,_CVAR]) then
                 begin
                   { only allowed for one var }
                   s:=sc.get(declarepos);
                   if not sc.empty then
                    Message(parser_e_absolute_only_one_var);
{$ifdef fixLeaksOnError}
                   if strContStack.pop <> sc then
                     writeln('problem with strContStack in pdecl (5)');
{$endif fixLeaksOnError}
                   sc.free;
                   { 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_info.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:=tvarsym.create_dll(s,tt)
                   else
                    aktvarsym:=tvarsym.create_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
                      else
                       if target_info.DllScanSupported then
                        current_module.Externals.insert(tExternalsItem.create(aktvarsym.mangledname));
                    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 tobjectdef(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;
              searchsym(s,srsym,srsymtable);
              { may be only a type: }
              if assigned(srsym) and (srsym.typ in [typesym,unitsym]) then
               begin
                 { for records, don't search the recordsymtable for
                   the symbols of the types }
                 oldsymtablestack:=symtablestack;
                 symtablestack:=symtablestack.next;
                 read_type(casetype,'');
                 symtablestack:=oldsymtablestack;
               end
              else
                begin
                  consume(_ID);
                  consume(_COLON);
                  { for records, don't search the recordsymtable for
                    the symbols of the types }
                  oldsymtablestack:=symtablestack;
                  symtablestack:=symtablestack.next;
                  read_type(casetype,'');
                  symtablestack:=oldsymtablestack;
                  symtablestack.insert(tvarsym.create(s,casetype));
                end;
              if not(is_ordinal(casetype.def)) or is_64bitint(casetype.def)  then
               Message(type_e_ordinal_expr_expected);
              consume(_OF);
              UnionSymtable:=trecordsymtable.create;
              Unionsymtable.next:=symtablestack;
              registerdef:=false;
              UnionDef:=trecorddef.create(unionsymtable);
              registerdef:=true;
              symtablestack:=UnionSymtable;
              startvarrecsize:=symtablestack.datasize;
              startvarrecalign:=symtablestack.dataalignment;
              repeat
                repeat
                  pt:=comp_expr(true);
                  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;
              uniontype.def:=uniondef;
              uniontype.sym:=nil;
              UnionSym:=tvarsym.create('case',uniontype);
              symtablestack:=symtablestack.next;
              { we do NOT call symtablestack.insert
               on purpose PM }
              if aktalignment.recordalignmax=-1 then
               begin
{$ifdef i386}
                 if maxalignment>2 then
                  minalignment:=4
                 else if maxalignment>1 then
                  minalignment:=2
                 else
                  minalignment:=1;
{$else}
{$ifdef m68k}
                 minalignment:=2;
{$endif}
                 minalignment:=1;
{$endif}
               end
              else
               minalignment:=maxalignment;
              usedalign:=used_align(maxalignment,minalignment,maxalignment);
              offset:=align(symtablestack.datasize,usedalign);
              symtablestack.datasize:=offset+unionsymtable.datasize;
              if maxalignment>symtablestack.dataalignment then
                symtablestack.dataalignment:=maxalignment;
              trecordsymtable(Unionsymtable).Insert_in(symtablestack,offset);
              Unionsym.owner:=nil;
              unionsym.free;
              uniondef.free;
           end;
         block_type:=old_block_type;
         current_object_option:=old_current_object_option;
      end;

end.
{
  $Log$
  Revision 1.20  2001-09-30 21:15:48  peter
    * merged absolute support for constants

  Revision 1.19  2001/08/30 20:13:53  peter
    * rtti/init table updates
    * rttisym for reusable global rtti/init info
    * support published for interfaces

  Revision 1.18  2001/07/01 20:16:16  peter
    * alignmentinfo record added
    * -Oa argument supports more alignment settings that can be specified
      per type: PROC,LOOP,VARMIN,VARMAX,CONSTMIN,CONSTMAX,RECORDMIN
      RECORDMAX,LOCALMIN,LOCALMAX. It is possible to set the mimimum
      required alignment and the maximum usefull alignment. The final
      alignment will be choosen per variable size dependent on these
      settings

  Revision 1.17  2001/06/03 21:57:36  peter
    + hint directive parsing support

  Revision 1.16  2001/04/18 22:01:57  peter
    * registration of targets and assemblers

  Revision 1.15  2001/04/13 01:22:12  peter
    * symtable change to classes
    * range check generation and errors fixed, make cycle DEBUG=1 works
    * memory leaks fixed

  Revision 1.14  2001/04/04 22:43:52  peter
    * remove unnecessary calls to firstpass

  Revision 1.13  2001/04/04 21:30:45  florian
    * applied several fixes to get the DD8 Delphi Unit compiled
     e.g. "forward"-interfaces are working now

  Revision 1.12  2001/04/02 21:20:33  peter
    * resulttype rewrite

  Revision 1.11  2001/03/11 22:58:50  peter
    * getsym redesign, removed the globals srsym,srsymtable

  Revision 1.10  2001/03/06 18:28:02  peter
    * patch from Pavel with a new and much faster DLL Scanner for
      automatic importing so $linklib works for DLLs. Thanks Pavel!

  Revision 1.9  2001/02/20 21:42:54  peter
    * record and object declaration with same field as type fixed

  Revision 1.7  2001/02/20 11:19:45  marco
   * Fix passing tvarrec to array of const

  Revision 1.6  2000/12/25 00:07:27  peter
    + new tlinkedlist class (merge of old tstringqueue,tcontainer and
      tlinkedlist objects)

  Revision 1.5  2000/12/17 14:00:18  peter
    * fixed static variables

  Revision 1.4  2000/11/29 00:30:36  florian
    * unused units removed from uses clause
    * some changes for widestrings

  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

}