{
    $Id: rappcgas.pas,v 1.19 2005/02/14 17:13:10 peter Exp $
    Copyright (c) 1998-2002 by Carl Eric Codere and Peter Vreman

    Does the parsing for the PowerPC GNU AS styled inline assembler.

    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 rappcgas;

{$I fpcdefs.inc}

interface

uses
  raatt, rappc;

type
  tppcattreader = class(tattreader)
    function is_asmopcode(const s: string): boolean; override;
    procedure handleopcode; override;
    procedure BuildReference(oper: tppcoperand);
    procedure BuildOperand(oper: tppcoperand);
    procedure BuildOpCode(instr: tppcinstruction);
    procedure ReadAt(oper: tppcoperand);
    procedure ReadSym(oper: tppcoperand);
    procedure ConvertCalljmp(instr: tppcinstruction);
  end;

implementation

uses
  { helpers }
  cutils,
  { global }
  globtype, verbose,
  systems,
  { aasm }
  cpubase, aasmbase, aasmtai,aasmdata, aasmcpu,
  { symtable }
  symconst, symsym,
  { parser }
  procinfo,
  rabase, rautils,
  cgbase, cgobj
  ;

procedure tppcattreader.ReadSym(oper: tppcoperand);
var
  tempstr, mangledname: string;
  typesize, l, k: aint;
begin
  tempstr := actasmpattern;
  Consume(AS_ID);
  { typecasting? }
  if (actasmtoken = AS_LPAREN) and
    SearchType(tempstr, typesize) then
  begin
    oper.hastype := true;
    Consume(AS_LPAREN);
    BuildOperand(oper);
    Consume(AS_RPAREN);
    if oper.opr.typ in [OPR_REFERENCE, OPR_LOCAL] then
      oper.SetSize(typesize, true);
  end
  else if not oper.SetupVar(tempstr, false) then
    Message1(sym_e_unknown_id, tempstr);
  { record.field ? }
  if actasmtoken = AS_DOT then
  begin
    BuildRecordOffsetSize(tempstr, l, k, mangledname, false);
    if (mangledname<>'') then
      Message(asmr_e_invalid_reference_syntax);
    inc(oper.opr.ref.offset, l);
  end;
end;

procedure tppcattreader.ReadAt(oper: tppcoperand);
begin
  { check for ...@ }
  if actasmtoken = AS_AT then
  begin
    if (oper.opr.ref.symbol = nil) and
      (oper.opr.ref.offset = 0) then
      Message(asmr_e_invalid_reference_syntax);
    Consume(AS_AT);
    if actasmtoken = AS_ID then
    begin
      if upper(actasmpattern) = 'L' then
        oper.opr.ref.refaddr := addr_low
      else if upper(actasmpattern) = 'HA' then
        oper.opr.ref.refaddr := addr_higha
      else if upper(actasmpattern) = 'H' then
        oper.opr.ref.refaddr := addr_high
      else if upper(actasmpattern) = 'HIGHERA' then
        oper.opr.ref.refaddr := addr_highera
      else if upper(actasmpattern) = 'HIGHESTA' then
        oper.opr.ref.refaddr := addr_highesta        
      else if upper(actasmpattern) = 'HIGHER' then
        oper.opr.ref.refaddr := addr_higher
      else if upper(actasmpattern) = 'HIGHEST' then
        oper.opr.ref.refaddr := addr_highest                
      else
        Message(asmr_e_invalid_reference_syntax);
      Consume(AS_ID);
    end
    else
      Message(asmr_e_invalid_reference_syntax);
  end;
end;

procedure tppcattreader.BuildReference(oper: tppcoperand);

  procedure Consume_RParen;
  begin
    if actasmtoken <> AS_RPAREN then
    begin
      Message(asmr_e_invalid_reference_syntax);
      RecoverConsume(true);
    end
    else
    begin
      Consume(AS_RPAREN);
      if not (actasmtoken in [AS_COMMA, AS_SEPARATOR, AS_END]) then
      begin
        Message(asmr_e_invalid_reference_syntax);
        RecoverConsume(true);
      end;
    end;
  end;

var
  l: aint;

begin
  Consume(AS_LPAREN);
  case actasmtoken of
    AS_INTNUM,
      AS_MINUS,
      AS_PLUS:
      begin
        { offset(offset) is invalid }
        if oper.opr.Ref.Offset <> 0 then
        begin
          Message(asmr_e_invalid_reference_syntax);
          RecoverConsume(true);
        end
        else
        begin
          oper.opr.Ref.Offset := BuildConstExpression(false, true);
          Consume(AS_RPAREN);
          if actasmtoken = AS_AT then
            ReadAt(oper);
        end;
        exit;
      end;
    AS_REGISTER: { (reg ...  }
      begin
        if ((oper.opr.typ = OPR_REFERENCE) and (oper.opr.ref.base <> NR_NO)) or
          ((oper.opr.typ = OPR_LOCAL) and (oper.opr.localsym.localloc.loc <>
            LOC_REGISTER)) then
          message(asmr_e_cannot_index_relative_var);
        oper.opr.ref.base := actasmregister;
        Consume(AS_REGISTER);
        { can either be a register or a right parenthesis }
        { (reg)        }
        if actasmtoken = AS_RPAREN then
        begin
          Consume_RParen;
          exit;
        end;
        { (reg,reg ..  }
        Consume(AS_COMMA);
        if (actasmtoken = AS_REGISTER) and
          (oper.opr.Ref.Offset = 0) then
        begin
          oper.opr.ref.index := actasmregister;
          Consume(AS_REGISTER);
          Consume_RParen;
        end
        else
        begin
          Message(asmr_e_invalid_reference_syntax);
          RecoverConsume(false);
        end;
      end; {end case }
    AS_ID:
      begin
        ReadSym(oper);
        { add a constant expression? }
        if (actasmtoken = AS_PLUS) then
        begin
          l := BuildConstExpression(true, true);
          case oper.opr.typ of
            OPR_CONSTANT:
              inc(oper.opr.val, l);
            OPR_LOCAL:
              inc(oper.opr.localsymofs, l);
            OPR_REFERENCE:
              inc(oper.opr.ref.offset, l);
          else
            internalerror(200309202);
          end;
        end;
        Consume(AS_RPAREN);
        if actasmtoken = AS_AT then
          ReadAt(oper);
      end;
    AS_COMMA: { (, ...  can either be scaling, or index }
      begin
        Consume(AS_COMMA);
        { Index }
        if (actasmtoken = AS_REGISTER) then
        begin
          oper.opr.ref.index := actasmregister;
          Consume(AS_REGISTER);
          { check for scaling ... }
          Consume_RParen;
        end
        else
        begin
          Message(asmr_e_invalid_reference_syntax);
          RecoverConsume(false);
        end;
      end;
  else
    begin
      Message(asmr_e_invalid_reference_syntax);
      RecoverConsume(false);
    end;
  end;
end;

procedure tppcattreader.BuildOperand(oper: tppcoperand);
var
  expr: string;
  typesize, l: aint;

  procedure AddLabelOperand(hl: tasmlabel);
  begin
    if not (actasmtoken in [AS_PLUS, AS_MINUS, AS_LPAREN]) and
      is_calljmp(actopcode) then
    begin
      oper.opr.typ := OPR_SYMBOL;
      oper.opr.symbol := hl;
    end
    else
    begin
      oper.InitRef;
      oper.opr.ref.symbol := hl;
    end;
  end;

  procedure MaybeRecordOffset;
  var
    mangledname : string;
    hasdot: boolean;
    l,
      toffset,
      tsize: aint;
  begin
    if not (actasmtoken in [AS_DOT, AS_PLUS, AS_MINUS]) then
      exit;
    l := 0;
    hasdot := (actasmtoken = AS_DOT);
    if hasdot then
    begin
      if expr <> '' then
      begin
        BuildRecordOffsetSize(expr, toffset, tsize, mangledname, false);
        if (oper.opr.typ<>OPR_CONSTANT) and
           (mangledname<>'') then
          Message(asmr_e_wrong_sym_type);
        inc(l, toffset);
        oper.SetSize(tsize, true);
      end;
    end;
    if actasmtoken in [AS_PLUS, AS_MINUS] then
      inc(l, BuildConstExpression(true, false));
    case oper.opr.typ of
      OPR_LOCAL:
        begin
          { don't allow direct access to fields of parameters, because that
            will generate buggy code. Allow it only for explicit typecasting }
          if hasdot and
            (not oper.hastype) and
            (tabstractvarsym(oper.opr.localsym).owner.symtabletype =
              parasymtable) and
            (current_procinfo.procdef.proccalloption <> pocall_register) then
            Message(asmr_e_cannot_access_field_directly_for_parameters);
          inc(oper.opr.localsymofs, l)
        end;
      OPR_CONSTANT:
        if (mangledname<>'') then
          begin
            if (oper.opr.val<>0) then
              Message(asmr_e_wrong_sym_type);
            oper.opr.typ:=OPR_SYMBOL;
            oper.opr.symbol:=current_asmdata.RefAsmSymbol(mangledname);
          end
        else
          inc(oper.opr.val,l);
      OPR_REFERENCE:
        inc(oper.opr.ref.offset, l);
      OPR_SYMBOL:
        Message(asmr_e_invalid_symbol_ref);
    else
      internalerror(200309221);
    end;
  end;

  function MaybeBuildReference: boolean;
    { Try to create a reference, if not a reference is found then false
      is returned }
  begin
    MaybeBuildReference := true;
    case actasmtoken of
      AS_INTNUM,
        AS_MINUS,
        AS_PLUS:
        begin
          oper.opr.ref.offset := BuildConstExpression(True, False);
          if actasmtoken <> AS_LPAREN then
            Message(asmr_e_invalid_reference_syntax)
          else
            BuildReference(oper);
        end;
      AS_LPAREN:
        BuildReference(oper);
      AS_ID: { only a variable is allowed ... }
        begin
          ReadSym(oper);
          case actasmtoken of
            AS_END,
              AS_SEPARATOR,
              AS_COMMA: ;
            AS_LPAREN:
              BuildReference(oper);
          else
            begin
              Message(asmr_e_invalid_reference_syntax);
              Consume(actasmtoken);
            end;
          end; {end case }
        end;
    else
      MaybeBuildReference := false;
    end; { end case }
  end;

var
  tempreg: tregister;
  hl: tasmlabel;
  ofs: aint;
begin
  expr := '';
  case actasmtoken of
    AS_LPAREN: { Memory reference or constant expression }
      begin
        oper.InitRef;
        BuildReference(oper);
      end;

    AS_INTNUM,
      AS_MINUS,
      AS_PLUS:
      begin
        { Constant memory offset }
        { This must absolutely be followed by (  }
        oper.InitRef;
        oper.opr.ref.offset := BuildConstExpression(True, False);
        if actasmtoken <> AS_LPAREN then
        begin
          ofs := oper.opr.ref.offset;
          BuildConstantOperand(oper);
          inc(oper.opr.val, ofs);
        end
        else
          BuildReference(oper);
      end;

    AS_ID: { A constant expression, or a Variable ref.  }
      begin
        { Local Label ? }
        if is_locallabel(actasmpattern) then
        begin
          CreateLocalLabel(actasmpattern, hl, false);
          Consume(AS_ID);
          AddLabelOperand(hl);
        end
        else
          { Check for label } if SearchLabel(actasmpattern, hl, false) then
          begin
            Consume(AS_ID);
            AddLabelOperand(hl);
          end
          else
            { probably a variable or normal expression }
            { or a procedure (such as in CALL ID)      }
          begin
            { is it a constant ? }
            if SearchIConstant(actasmpattern, l) then
            begin
              if not (oper.opr.typ in [OPR_NONE, OPR_CONSTANT]) then
                Message(asmr_e_invalid_operand_type);
              BuildConstantOperand(oper);
            end
            else
            begin
              expr := actasmpattern;
              Consume(AS_ID);
              { typecasting? }
              if (actasmtoken = AS_LPAREN) and
                SearchType(expr, typesize) then
              begin
                oper.hastype := true;
                Consume(AS_LPAREN);
                BuildOperand(oper);
                Consume(AS_RPAREN);
                if oper.opr.typ in [OPR_REFERENCE, OPR_LOCAL] then
                  oper.SetSize(typesize, true);
              end
              else
              begin
                if oper.SetupVar(expr, false) then
                  ReadAt(oper)
                else
                begin
                  { look for special symbols ... }
                  if expr = '__HIGH' then
                  begin
                    consume(AS_LPAREN);
                    if not oper.setupvar('high' + actasmpattern, false) then
                      Message1(sym_e_unknown_id, 'high' + actasmpattern);
                    consume(AS_ID);
                    consume(AS_RPAREN);
                  end
                  else if expr = '__RESULT' then
                    oper.SetUpResult
                  else if expr = '__SELF' then
                    oper.SetupSelf
                  else if expr = '__OLDEBP' then
                    oper.SetupOldEBP
                  else
                    Message1(sym_e_unknown_id, expr);
                end;
              end;
            end;
            if actasmtoken = AS_DOT then
              MaybeRecordOffset;
            { add a constant expression? }
            if (actasmtoken = AS_PLUS) then
            begin
              l := BuildConstExpression(true, false);
              case oper.opr.typ of
                OPR_CONSTANT:
                  inc(oper.opr.val, l);
                OPR_LOCAL:
                  inc(oper.opr.localsymofs, l);
                OPR_REFERENCE:
                  inc(oper.opr.ref.offset, l);
              else
                internalerror(200309202);
              end;
            end
          end;
        { Do we have a indexing reference, then parse it also }
        if actasmtoken = AS_LPAREN then
          BuildReference(oper);
      end;

    AS_REGISTER: { Register, a variable reference or a constant reference  }
      begin
        { save the type of register used. }
        tempreg := actasmregister;
        Consume(AS_REGISTER);
        if (actasmtoken in [AS_END, AS_SEPARATOR, AS_COMMA]) then
          if is_condreg(tempreg) and
            ((actopcode = A_BC) or
            (actopcode = A_BCCTR) or
            (actopcode = A_BCLR) or
            (actopcode = A_TW) or
            (actopcode = A_TWI)) then
          begin
            { it isn't a real operand, everything is stored in the condition }
            oper.opr.typ := OPR_NONE;
            actcondition.cr := getsupreg(tempreg);
          end
          else
          begin
            if not (oper.opr.typ in [OPR_NONE, OPR_REGISTER]) then
              Message(asmr_e_invalid_operand_type);
            oper.opr.typ := OPR_REGISTER;
            oper.opr.reg := tempreg;
          end
        else if is_condreg(tempreg) then
        begin
          if not (actcondition.cond in [C_T..C_DZF]) then
            Message(asmr_e_syn_operand);
          if actasmtoken = AS_STAR then
          begin
            consume(AS_STAR);
            if (actasmtoken = AS_INTNUM) then
            begin
              consume(AS_INTNUM);
              if actasmtoken = AS_PLUS then
              begin
                consume(AS_PLUS);
                if (actasmtoken = AS_ID) then
                begin
                  oper.opr.typ := OPR_NONE;
                  if actasmpattern = 'LT' then
                    actcondition.crbit := (getsupreg(tempreg) - (RS_CR0)) * 4
                  else if actasmpattern = 'GT' then
                    actcondition.crbit := (getsupreg(tempreg) - (RS_CR0)) * 4 + 1
                  else if actasmpattern = 'EQ' then
                    actcondition.crbit := (getsupreg(tempreg) - (RS_CR0)) * 4 + 2
                  else if actasmpattern = 'SO' then
                    actcondition.crbit := (getsupreg(tempreg) - (RS_CR0)) * 4 + 3
                  else
                    Message(asmr_e_syn_operand);
                  consume(AS_ID);
                end
                else
                  Message(asmr_e_syn_operand);
              end
              else
                Message(asmr_e_syn_operand);
            end
            else
              Message(asmr_e_syn_operand);
          end
          else
            Message(asmr_e_syn_operand);
        end
        else
          Message(asmr_e_syn_operand);
      end;
    AS_END,
      AS_SEPARATOR,
      AS_COMMA: ;
  else
    begin
      Message(asmr_e_syn_operand);
      Consume(actasmtoken);
    end;
  end; { end case }
end;

{*****************************************************************************
                                tppcattreader
*****************************************************************************}

procedure tppcattreader.BuildOpCode(instr: tppcinstruction);
var
  operandnum: longint;
begin
  { opcode }
  if (actasmtoken <> AS_OPCODE) then
  begin
    Message(asmr_e_invalid_or_missing_opcode);
    RecoverConsume(true);
    exit;
  end;
  { Fill the instr object with the current state }
  with instr do
  begin
    Opcode := ActOpcode;
    condition := ActCondition;
  end;

  { We are reading operands, so opcode will be an AS_ID }
  operandnum := 1;
  Consume(AS_OPCODE);
  { Zero operand opcode ?  }
  if actasmtoken in [AS_SEPARATOR, AS_END] then
  begin
    operandnum := 0;
    exit;
  end;
  { Read the operands }
  repeat
    case actasmtoken of
      AS_COMMA: { Operand delimiter }
        begin
          if operandnum > Max_Operands then
            Message(asmr_e_too_many_operands)
          else
          begin
            { condition operands doesn't set the operand but write to the
              condition field of the instruction
            }
            if instr.Operands[operandnum].opr.typ <> OPR_NONE then
              Inc(operandnum);
          end;
          Consume(AS_COMMA);
        end;
      AS_SEPARATOR,
        AS_END: { End of asm operands for this opcode  }
        begin
          break;
        end;
    else
      BuildOperand(instr.Operands[operandnum] as tppcoperand);
    end; { end case }
  until false;
  if (operandnum = 1) and (instr.Operands[operandnum].opr.typ = OPR_NONE) then
    dec(operandnum);
  instr.Ops := operandnum;
end;

function tppcattreader.is_asmopcode(const s: string): boolean;
var
  cond: tasmcondflag;
  hs: string;

begin
  { making s a value parameter would break other assembler readers }
  hs := s;
  is_asmopcode := false;

  { clear op code }
  actopcode := A_None;
  { clear condition }
  fillchar(actcondition, sizeof(actcondition), 0);

  { check for direction hint }
  if hs[length(s)] = '-' then
  begin
    dec(ord(hs[0]));
    actcondition.dirhint := DH_Minus;
  end
  else if hs[length(s)] = '+' then
  begin
    dec(ord(hs[0]));
    actcondition.dirhint := DH_Plus;
  end;
  actopcode := tasmop(ptrint(iasmops.Find(hs)));
  if actopcode <> A_NONE then
  begin
    if actcondition.dirhint <> DH_None then
      message1(asmr_e_unknown_opcode, actasmpattern);
    actasmtoken := AS_OPCODE;
    is_asmopcode := true;
    exit;
  end;
  { not found, check branch instructions }
  if hs[1] = 'B' then
  begin
    { we can search here without an extra table which is sorted by string length
      because we take the whole remaining string without the leading B }
    if copy(hs, length(s) - 1, 2) = 'LR' then
    begin
      actopcode := A_BCLR;
      setlength(hs, length(hs) - 2)
    end
    else if copy(hs, length(s) - 2, 3) = 'CTR' then
    begin
      actopcode := A_BCCTR;
      setlength(hs, length(hs) - 3)
    end
    else
      actopcode := A_BC;
    for cond := low(TAsmCondFlag) to high(TAsmCondFlag) do
      if copy(hs, 2, length(s) - 1) = UpperAsmCondFlag2Str[cond] then
      begin
        actcondition.simple := true;
        actcondition.cond := cond;
        if (cond in [C_LT, C_LE, C_EQ, C_GE, C_GT, C_NL, C_NE, C_NG, C_SO, C_NS,
          C_UN, C_NU]) then
          actcondition.cr := RS_CR0;
        actasmtoken := AS_OPCODE;
        is_asmopcode := true;
        exit;
      end;
  end;
end;

procedure tppcattreader.ConvertCalljmp(instr: tppcinstruction);
begin
  if instr.Operands[1].opr.typ = OPR_CONSTANT then begin
    if (instr.operands[1].opr.val > 31) or
      (instr.operands[2].opr.typ <> OPR_CONSTANT) or
      (instr.operands[2].opr.val > 31) or
      not(instr.operands[3].opr.typ in [OPR_REFERENCE,OPR_SYMBOL]) then
      Message(asmr_e_syn_operand);
      { BO/BI notation }
    instr.condition.simple := false;
    instr.condition.bo := instr.operands[1].opr.val;
    instr.condition.bi := instr.operands[2].opr.val;
    instr.operands[1].free;
    instr.operands[2].free;
    instr.operands[2] := nil;
    instr.operands[1] := instr.operands[3];
    instr.operands[3] := nil;
    instr.ops := 1;
  end;
  if instr.Operands[1].opr.typ = OPR_REFERENCE then begin
    instr.Operands[1].opr.ref.refaddr:=addr_full;
    if (instr.Operands[1].opr.ref.base<>NR_NO) or
      (instr.Operands[1].opr.ref.index<>NR_NO) then
      Message(asmr_e_syn_operand);
  end;
end;

procedure tppcattreader.handleopcode;
var
  instr: tppcinstruction;
begin
  instr := TPPCInstruction.Create(TPPCOperand);
  BuildOpcode(instr);
  instr.condition := actcondition;
  if is_calljmp(instr.opcode) then
    ConvertCalljmp(instr);
  {
  instr.AddReferenceSizes;
  instr.SetInstructionOpsize;
  instr.CheckOperandSizes;
  }
  instr.ConcatInstruction(curlist);
  instr.Free;
end;

{*****************************************************************************
                                     Initialize
*****************************************************************************}

const
  asmmode_ppc_att_info: tasmmodeinfo =
  (
    id: asmmode_ppc_gas;
    idtxt: 'GAS';
    casmreader: tppcattreader;
    );

  asmmode_ppc_standard_info: tasmmodeinfo =
  (
    id: asmmode_standard;
    idtxt: 'STANDARD';
    casmreader: tppcattreader;
    );

initialization
  RegisterAsmMode(asmmode_ppc_att_info);
  RegisterAsmMode(asmmode_ppc_standard_info);
end.

