{
 ***************************************************************************
 *                                                                         *
 *   This source 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 code 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.                              *
 *                                                                         *
 *   A copy of the GNU General Public License is available on the World    *
 *   Wide Web at <http://www.gnu.org/copyleft/gpl.html>. You can also      *
 *   obtain it by writing to the Free Software Foundation,                 *
 *   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.        *
 *                                                                         *
 ***************************************************************************

  Author: Mattias Gaertner

  Abstract:
    A simple C parser.
}
unit CCodeParserTool;

{$mode objfpc}{$H+}

interface

{$I codetools.inc}

uses
  {$IFDEF MEM_CHECK}
  MemCheck,
  {$ENDIF}
  Classes, SysUtils, FileProcs, CodeToolsStructs, BasicCodeTools,
  KeywordFuncLists, LinkScanner, CodeAtom, CodeCache, AVL_Tree,
  CodeTree, NonPascalCodeTools;

type
  TCCodeNodeDesc = word;

const
  // descriptors
  ccnBase           = 1000;
  ccnNone           =  0+ccnBase;
  
  ccnRoot           =  1+ccnBase;
  ccnDirective      =  2+ccnBase;// e.g. "#define a" ,can be multiple lines, without line end
  ccnExtern         =  3+ccnBase;// e.g. extern "C" {}
  ccnEnums          =  4+ccnBase;// e.g. enum {};
  ccnEnum           =  5+ccnBase;// e.g. name = value;
  ccnConstant       =  6+ccnBase;// e.g. 1
  ccnTypedef        =  7+ccnBase;// e.g. typedef int TInt;
  ccnStruct         =  8+ccnBase;// e.g. struct{};
  ccnVariable       =  9+ccnBase;// e.g. int i
  ccnVariableName   = 10+ccnBase;// e.g. i
  ccnFuncParamList  = 11+ccnBase;// e.g. ()
  ccnStatementBlock = 12+ccnBase;// e.g. {}

type
  TCCodeParserTool = class;

  { ECCodeParserException }

  ECCodeParserException = class(Exception)
  public
    Sender: TCCodeParserTool;
    constructor Create(ASender: TCCodeParserTool; const AMessage: string);
  end;

  { TCCodeParserTool }

  TCCodeParserTool = class
  private
    FChangeStep: integer;
    FDefaultTokenList: TKeyWordFunctionList;

    function OtherToken: boolean;
    function DirectiveToken: boolean;
    function EnumToken: boolean;
    function ExternToken: boolean;
    function CurlyBracketCloseToken: boolean;
    function TypedefToken: boolean;
    function StructToken: boolean;
    procedure InitKeyWordList;

    procedure InitParser;
    procedure CreateChildNode(Desc: TCCodeNodeDesc);
    procedure EndChildNode;
    procedure CloseNodes;
    
    procedure ReadEnum;
    procedure ReadStruct(NeedIdentifier: boolean);
    procedure ReadConstant;
    procedure ReadVariable;
    
    procedure RaiseException(const AMessage: string);
    procedure RaiseExpectedButAtomFound(const AToken: string);
  public
    Code: TCodeBuffer;
    Src: string;
    SrcLen: integer;
    Tree: TCodeTree;
    CurNode: TCodeTreeNode;
    SrcPos: Integer;
    AtomStart: integer;
    ParseChangeStep: integer;
    
    LastSrcPos: integer;
    LastAtomStart: integer;

    constructor Create;
    destructor Destroy; override;
    procedure Clear;

    procedure Parse;
    procedure Parse(aCode: TCodeBuffer);
    function UpdateNeeded: boolean;
    
    procedure MoveCursorToPos(p: integer);
    procedure ReadNextAtom;
    procedure UndoReadNextAtom;
    function ReadTilBracketClose(ExceptionOnNotFound: boolean): boolean;
    function AtomIs(const s: shortstring): boolean;
    function AtomIsChar(const c: char): boolean;
    function UpAtomIs(const s: shortstring): boolean;
    function AtomIsIdentifier: boolean;
    function AtomIsStringConstant: boolean;
    function GetAtom: string;

    procedure Replace(FromPos, ToPos: integer; const NewSrc: string);

    procedure IncreaseChangeStep;
    procedure WriteDebugReport;
    
    property ChangeStep: integer read FChangeStep;
  end;
  
function CCNodeDescAsString(Desc: TCCodeNodeDesc): string;
procedure InitCCodeKeyWordLists;

var
  IsCCodeFunctionModifier: TKeyWordFunctionList = nil;
  IsCCodeCustomOperator: TKeyWordFunctionList = nil;

implementation

var
  KeyWordLists: TFPList;

function CCNodeDescAsString(Desc: TCCodeNodeDesc): string;
begin
  case Desc of
  ccnNone     : Result:='None';
  ccnRoot     : Result:='Root';
  ccnDirective: Result:='Directive';
  else          Result:='?';
  end;
end;

procedure InitCCodeKeyWordLists;
begin
  if KeyWordLists<>nil then exit;
  KeyWordLists:=TFPList.Create;
  
  IsCCodeFunctionModifier:=TKeyWordFunctionList.Create;
  KeyWordLists.Add(IsCCodeFunctionModifier);
  with IsCCodeFunctionModifier do begin
    Add('static'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('inline'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
  end;

  IsCCodeCustomOperator:=TKeyWordFunctionList.Create;
  KeyWordLists.Add(IsCCodeCustomOperator);
  with IsCCodeCustomOperator do begin
    Add('+'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('-'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('*'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('/'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('|'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('&'     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('='     ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('++'    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('--'    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('+='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('-='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('*='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('/='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('&='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('|='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('=='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
    Add('!='    ,{$ifdef FPC}@{$endif}AllwaysTrue);
  end;
end;

{ ECCodeParserException }

constructor ECCodeParserException.Create(ASender: TCCodeParserTool;
  const AMessage: string);
begin
  inherited Create(AMessage);
  Sender:=ASender;
end;

{ TCCodeParserTool }

function TCCodeParserTool.OtherToken: boolean;
begin
  Result:=true;
  if AtomIsChar(';') then
    // ignore
  else if AtomIsIdentifier then begin
    ReadVariable;
  end else
    RaiseException('unexpected token '+GetAtom);
end;

function TCCodeParserTool.DirectiveToken: boolean;
begin
  Result:=true;
  CreateChildNode(ccnDirective);
  // read til end of line
  ReadTilCLineEnd(Src,SrcPos);
  AtomStart:=SrcPos;
  EndChildNode;
end;

function TCCodeParserTool.EnumToken: boolean;
begin
  Result:=true;
  ReadEnum;
  // read semicolon
  ReadNextAtom;
  if not AtomIsChar(';') then
    RaiseExpectedButAtomFound(';');
end;

function TCCodeParserTool.ExternToken: boolean;
begin
  Result:=true;
  CreateChildNode(ccnExtern);
  ReadNextAtom;
  if not AtomIsStringConstant then
    RaiseExpectedButAtomFound('string constant');
  ReadNextAtom;
  if not AtomIsChar('{') then
    RaiseExpectedButAtomFound('{');
end;

function TCCodeParserTool.CurlyBracketCloseToken: boolean;
begin
  Result:=true;

end;

procedure TCCodeParserTool.ReadEnum;
(* For example:
  enum {
    TEST_ENUM1 = 1, /* Enum starts at 1 */
    TEST_ENUM2,
    TEST_ENUM3
  };
  enum e1{dark, light};

*)
begin
  CreateChildNode(ccnEnums);
  ReadNextAtom;
  // read optional name
  if AtomIsIdentifier then
    ReadNextAtom;
  if not AtomIsChar('{') then
    RaiseExpectedButAtomFound('{');
  // read enums. Examples
  // name,
  // name = constant,
  ReadNextAtom;
  repeat
    if AtomIsIdentifier then begin
      // read enum
      CreateChildNode(ccnEnum);
      CurNode.EndPos:=SrcPos;
      ReadNextAtom;
      if AtomIsChar('=') then begin
        // read value
        ReadNextAtom;
        ReadConstant;
        CurNode.EndPos:=SrcPos;
        ReadNextAtom;
      end;
      EndChildNode;
    end;
    if AtomIsChar(',') then begin
      // next enum
      ReadNextAtom;
      if not AtomIsIdentifier then
        RaiseExpectedButAtomFound('identifier');
    end else if AtomIsChar('}') then begin
      break;
    end else
      RaiseExpectedButAtomFound('}');
  until false;
  EndChildNode;
end;

procedure TCCodeParserTool.ReadStruct(NeedIdentifier: boolean);
(*  Example for NeedIdentifier=false:
  typedef struct {
    uint8_t b[6]; // implicit type
  } __attribute__((packed)) bdaddr_t;

  Example for NeedIdentifier=true:
    struct hidp_connadd_req {
      int ctrl_sock;
    }
    struct hidp_conninfo *ci;

  typedef struct _sdp_list sdp_list_t;
*)
begin
  CreateChildNode(ccnStruct);
  
  ReadNextAtom;
  if NeedIdentifier then begin
    // read type name
    if not AtomIsIdentifier then
      RaiseExpectedButAtomFound('identifier');
    ReadNextAtom;
  end;
  
  if AtomIsChar('{') then begin
    // read block {}
    repeat
      ReadNextAtom;
      // read variables
      if AtomIsIdentifier then begin
        ReadVariable;
        ReadNextAtom;
        if AtomIsChar('}') then
          break
        else if AtomIsChar(';') then begin
          // next identifier
        end else
          RaiseExpectedButAtomFound('}');
      end else if AtomIsChar('}') then
        break
      else
        RaiseExpectedButAtomFound('identifier');
    until false;
    // read attributes
    ReadNextAtom;
    if AtomIs('__attribute__') then begin
      ReadNextAtom;
      if not AtomIsChar('(') then
        RaiseExpectedButAtomFound('(');
      ReadTilBracketClose(true);
    end else begin
      UndoReadNextAtom;
    end;
  end else if AtomIsIdentifier then begin
    // using another struct
  end else
    RaiseExpectedButAtomFound('{');

  // close node
  EndChildNode;
end;

function TCCodeParserTool.TypedefToken: boolean;
begin
  Result:=true;
  CreateChildNode(ccnTypedef);
  // read type
  ReadNextAtom;
  if AtomIs('enum') then
    ReadEnum
  else if AtomIs('struct') then
    ReadStruct(false)
  else if AtomIsIdentifier then begin

  end else
    RaiseExpectedButAtomFound('identifier');
  // read typedef name
  ReadNextAtom;
  if not AtomIsIdentifier then
    RaiseExpectedButAtomFound('identifier');
  // read semicolon
  ReadNextAtom;
  if not AtomIsChar(';') then
    RaiseExpectedButAtomFound(';');
  EndChildNode;
end;

function TCCodeParserTool.StructToken: boolean;
begin
  Result:=true;
  ReadStruct(true);
end;

procedure TCCodeParserTool.InitKeyWordList;
begin
  if FDefaultTokenList=nil then begin
    FDefaultTokenList:=TKeyWordFunctionList.Create;
    with FDefaultTokenList do begin
      Add('#',{$ifdef FPC}@{$endif}DirectiveToken);
      Add('extern',{$ifdef FPC}@{$endif}ExternToken);
      Add('}',{$ifdef FPC}@{$endif}CurlyBracketCloseToken);
      Add('enum',{$ifdef FPC}@{$endif}EnumToken);
      Add('typedef',{$ifdef FPC}@{$endif}TypedefToken);
      Add('struct',{$ifdef FPC}@{$endif}StructToken);
      DefaultKeyWordFunction:={$ifdef FPC}@{$endif}OtherToken;
    end;
  end;
end;

procedure TCCodeParserTool.InitParser;
begin
  ParseChangeStep:=Code.ChangeStep;
  IncreaseChangeStep;
  InitKeyWordList;
  Src:=Code.Source;
  SrcLen:=length(Src);
  if Tree=nil then
    Tree:=TCodeTree.Create
  else
    Tree.Clear;
  SrcPos:=1;
  AtomStart:=1;
  CurNode:=nil;
  CreateChildNode(ccnRoot);
end;

procedure TCCodeParserTool.CreateChildNode(Desc: TCCodeNodeDesc);
var
  NewNode: TCodeTreeNode;
begin
  NewNode:=NodeMemManager.NewNode;
  Tree.AddNodeAsLastChild(CurNode,NewNode);
  NewNode.Desc:=Desc;
  CurNode:=NewNode;
  CurNode.StartPos:=AtomStart;
  DebugLn([GetIndentStr(CurNode.GetLevel*2),'TCCodeParserTool.CreateChildNode ']);
end;

procedure TCCodeParserTool.EndChildNode;
begin
  DebugLn([GetIndentStr(CurNode.GetLevel*2),'TCCodeParserTool.EndChildNode ']);
  if CurNode.EndPos<=0 then
    CurNode.EndPos:=SrcPos;
  CurNode:=CurNode.Parent;
end;

procedure TCCodeParserTool.CloseNodes;
var
  Node: TCodeTreeNode;
begin
  Node:=CurNode;
  while Node<>nil do begin
    Node.EndPos:=AtomStart;
    Node:=Node.Parent;
  end;
end;

procedure TCCodeParserTool.ReadConstant;
begin
  if AtomIsChar(',') or AtomIsChar(';') then
    RaiseExpectedButAtomFound('identifier');
  CreateChildNode(ccnConstant);
  repeat
    if AtomIsChar('(') or AtomIsChar('[') then
      ReadTilBracketClose(true);
    CurNode.EndPos:=SrcPos;
    ReadNextAtom;
    if AtomIsChar(',') or AtomIsChar(';')
    or AtomIsChar(')') or AtomIsChar(']') or AtomIsChar('}')
    then
      break;
  until false;
  UndoReadNextAtom;
  EndChildNode;
end;

procedure TCCodeParserTool.ReadVariable;
(* Read  type name [specifiers]

  Examples:

  int i
  uint8_t b[6]
  int y = 7;

  static inline int bacmp(const bdaddr_t *ba1, const bdaddr_t *ba2)
  {
        return memcmp(ba1, ba2, sizeof(bdaddr_t));
  }
  bdaddr_t *strtoba(const char *str);

  complex operator+(complex, complex);
*)
var
  IsFunction: Boolean;
  NeedEnd: Boolean;
begin
  DebugLn(['TCCodeParserTool.ReadVariable ']);
  CreateChildNode(ccnVariable);
  IsFunction:=false;
  if AtomIs('struct') then begin
    ReadNextAtom;
  end else if AtomIs('union') then begin
    ReadNextAtom;
    if not AtomIsChar('{') then
      RaiseExpectedButAtomFound('{');
    ReadTilBracketClose(true);
  end else if IsCCodeFunctionModifier.DoItCaseSensitive(Src,AtomStart,SrcPos-AtomStart)
  then begin
    // read function modifiers
    while IsCCodeFunctionModifier.DoItCaseSensitive(Src,AtomStart,SrcPos-AtomStart)
    do begin
      IsFunction:=true;
      ReadNextAtom;
      if not AtomIsIdentifier then
        RaiseExpectedButAtomFound('identifier');
    end;
  end;
  CreateChildNode(ccnVariableName);

  // possible:
  // int, short int, short signed int
  // char, signed char, unsigned char
  // long, long long, signed long, signed long long, unsigned long, unsigned long long
  repeat
    if AtomIs('short') then
      ReadNextAtom
    else if AtomIs('signed') then
      ReadNextAtom
    else if AtomIs('unsigned') then
      ReadNextAtom
    else if AtomIs('long') then begin
      // check if 'long long'
      ReadNextAtom;
      if not (AtomIs('long') or AtomIs('unsigned')) then begin
        UndoReadNextAtom;
        break;
      end;
    end else
      break;
   until false;

  // read name
  ReadNextAtom;
  if AtomIs('operator') then begin
    IsFunction:=true;
    // read operator
    ReadNextAtom;
    if not IsCCodeCustomOperator.DoItCaseSensitive(Src,AtomStart,SrcPos-AtomStart)
    then
      RaiseExpectedButAtomFound('operator');
  end else if AtomIsChar('(') then begin
    // example: int (*fp)(char*);
    //   pointer to function taking a char* argument; returns an int
    ReadNextAtom;
    while AtomIsChar('*') do begin
      // pointer
      ReadNextAtom;
    end;
    DebugLn(['TCCodeParserTool.ReadVariable name=',GetAtom]);
    if not AtomIsIdentifier then
      RaiseExpectedButAtomFound('identifier');
    ReadNextAtom;
    if not AtomIsChar(')') then
      RaiseExpectedButAtomFound(')');
  end else begin
    while AtomIsChar('*') do begin
      // pointer
      ReadNextAtom;
    end;

    DebugLn(['TCCodeParserTool.ReadVariable name=',GetAtom]);
    if not AtomIsIdentifier then
      RaiseExpectedButAtomFound('identifier');
  end;
  EndChildNode;

  ReadNextAtom;
  if IsFunction and (not AtomIsChar('(')) then
    RaiseExpectedButAtomFound('(');
  NeedEnd:=true;
  if AtomIsChar('(') then begin
    // this is a function => read parameter list
    CreateChildNode(ccnFuncParamList);
    ReadTilBracketClose(true);
    CurNode.EndPos:=SrcPos;
    EndChildNode;
    ReadNextAtom;
    if AtomIsChar('{') then begin
      // read statements {}
      CreateChildNode(ccnStatementBlock);
      ReadTilBracketClose(true);
      CurNode.EndPos:=SrcPos;
      EndChildNode;
    end else if not AtomIsChar(';') then begin
      // functions without statements are external and must end with a semicolon
      RaiseExpectedButAtomFound(';');
    end;
    NeedEnd:=false;
    ReadNextAtom;
  end else if AtomIsChar('[') then begin
    // read array brackets
    ReadTilBracketClose(true);
    ReadNextAtom;
  end;
  
  // read initial constant
  if AtomIsChar('=') then begin
    ReadNextAtom;
    ReadConstant;
    ReadNextAtom;
    NeedEnd:=true;
  end;
  
  // sanity check
  if (SrcPos<=SrcLen) and NeedEnd
  and not (AtomIsChar(';') or AtomIsChar(',') or AtomIsChar(')')) then
    RaiseExpectedButAtomFound('"end of variable"');
    
  UndoReadNextAtom;

  EndChildNode;
end;

procedure TCCodeParserTool.RaiseException(const AMessage: string);
begin
  CloseNodes;
  raise ECCodeParserException.Create(Self,AMessage);
end;

procedure TCCodeParserTool.RaiseExpectedButAtomFound(const AToken: string);
begin
  RaiseException(AToken+' expected, but '+GetAtom+' found');
end;

constructor TCCodeParserTool.Create;
begin
  Tree:=TCodeTree.Create;
  InitCCOdeKeyWordLists;
end;

destructor TCCodeParserTool.Destroy;
begin
  FreeAndNil(Tree);
  inherited Destroy;
end;

procedure TCCodeParserTool.Clear;
begin
  Tree.Clear;
end;

procedure TCCodeParserTool.Parse;
begin
  Parse(Code);
end;

procedure TCCodeParserTool.Parse(aCode: TCodeBuffer);
begin
  if (Code=aCode) and (not UpdateNeeded) then
    exit;
  Code:=aCode;
  InitParser;
  repeat
    ReadNextAtom;
    if SrcPos<=SrcLen then begin
      FDefaultTokenList.DoItCaseSensitive(Src,AtomStart,SrcPos-AtomStart);
    end else begin
      break;
    end;
  until false;
  CloseNodes;
end;

function TCCodeParserTool.UpdateNeeded: boolean;
begin
  Result:=true;
  if (Code=nil) or (Tree=nil) or (Tree.Root=nil) then exit;
  if Code.ChangeStep<>ParseChangeStep then exit;
  Result:=false;
end;

procedure TCCodeParserTool.MoveCursorToPos(p: integer);
begin
  SrcPos:=p;
  AtomStart:=p;
  LastAtomStart:=0;
  LastSrcPos:=0;
end;

procedure TCCodeParserTool.ReadNextAtom;
begin
  DebugLn(['TCCodeParserTool.ReadNextAtom START ',AtomStart,'-',SrcPos,' ',Src[SrcPos]]);
  LastSrcPos:=SrcPos;
  LastAtomStart:=AtomStart;
  repeat
    ReadRawNextCAtom(Src,SrcPos,AtomStart);
  until (SrcPos>SrcLen) or (not (Src[AtomStart] in [#10,#13]));
  DebugLn(['TCCodeParserTool.ReadNextAtom END ',AtomStart,'-',SrcPos,' "',copy(Src,AtomStart,SrcPos-AtomStart),'"']);
end;

procedure TCCodeParserTool.UndoReadNextAtom;
begin
  if LastSrcPos>0 then begin
    SrcPos:=LastSrcPos;
    AtomStart:=LastAtomStart;
    LastSrcPos:=0;
    LastAtomStart:=0;
  end else begin
    SrcPos:=AtomStart;
  end;
end;

function TCCodeParserTool.ReadTilBracketClose(
  ExceptionOnNotFound: boolean): boolean;
// AtomStart must be on bracket open
// after reading AtomStart is on closing bracket
var
  CloseBracket: Char;
  StartPos: LongInt;
begin
  case Src[AtomStart] of
  '{': CloseBracket:='}';
  '[': CloseBracket:=']';
  '(': CloseBracket:=')';
  '<': CloseBracket:='>';
  else
    if ExceptionOnNotFound then
      RaiseExpectedButAtomFound('(');
    exit(false);
  end;
  StartPos:=AtomStart;
  {$IFOPT R+}{$DEFINE RangeChecking}{$ENDIF}
  {$R-}
  repeat
    ReadRawNextCAtom(Src,SrcPos,AtomStart);
    if AtomStart>SrcLen then begin
      AtomStart:=StartPos;
      SrcPos:=AtomStart+1;
      if ExceptionOnNotFound then
        RaiseException('closing bracket not found');
      exit;
    end;
    case Src[AtomStart] of
    '{','(','[':
      // skip nested bracketss
      begin
        if not ReadTilBracketClose(ExceptionOnNotFound) then
          exit;
      end;
    else
      if Src[AtomStart]=CloseBracket then exit(true);
    end;
  until false;
  {$IFDEF RangeChecking}{$R+}{$UNDEF RangeChecking}{$ENDIF}
end;

function TCCodeParserTool.AtomIs(const s: shortstring): boolean;
var
  len: Integer;
  i: Integer;
begin
  len:=length(s);
  if (len<>SrcPos-AtomStart) then exit(false);
  if SrcPos>SrcLen then exit(false);
  for i:=1 to len do
    if Src[AtomStart+i-1]<>s[i] then exit(false);
  Result:=true;
end;

function TCCodeParserTool.AtomIsChar(const c: char): boolean;
begin
  if SrcPos-AtomStart<>1 then exit(false);
  if SrcPos>SrcLen then exit(false);
  if Src[AtomStart]<>c then exit(false);
  Result:=true;
end;

function TCCodeParserTool.UpAtomIs(const s: shortstring): boolean;
var
  len: Integer;
  i: Integer;
begin
  len:=length(s);
  if (len<>SrcPos-AtomStart) then exit(false);
  if SrcPos>SrcLen then exit(false);
  for i:=1 to len do
    if UpChars[Src[AtomStart+i-1]]<>s[i] then exit(false);
  Result:=true;
end;

function TCCodeParserTool.AtomIsIdentifier: boolean;
var
  p: Integer;
begin
  if (AtomStart>=SrcPos) then exit(false);
  if (SrcPos>SrcLen) or (SrcPos-AtomStart>255) then exit(false);
  if not IsIdentStartChar[Src[AtomStart]] then exit(false);
  p:=AtomStart+1;
  while (p<SrcPos) do begin
    if not IsIdentChar[Src[p]] then exit(false);
    inc(p);
  end;
  Result:=true;
end;

function TCCodeParserTool.AtomIsStringConstant: boolean;
begin
  Result:=(AtomStart<SrcLen) and (Src[AtomStart]='"');
end;

function TCCodeParserTool.GetAtom: string;
begin
  Result:=copy(Src,AtomStart,SrcPos-AtomStart);
end;

procedure TCCodeParserTool.Replace(FromPos, ToPos: integer; const NewSrc: string
  );
var
  Node: TCodeTreeNode;
  DiffPos: Integer;
begin
  DebugLn(['TCCodeParserTool.Replace ',FromPos,'-',ToPos,' Old="',copy(Src,FromPos,ToPos-FromPos),'" New="',NewSrc,'"']);
  IncreaseChangeStep;
  Code.Replace(FromPos,ToPos-FromPos,NewSrc);
  Src:=Code.Source;
  SrcLen:=length(Src);
  // update positions
  DiffPos:=length(NewSrc)-(ToPos-FromPos);
  if DiffPos<>0 then begin
    Node:=Tree.Root;
    while Node<>nil do begin
      AdjustPositionAfterInsert(Node.StartPos,true,FromPos,ToPos,DiffPos);
      AdjustPositionAfterInsert(Node.EndPos,false,FromPos,ToPos,DiffPos);
      Node:=Node.Next;
    end;
  end;
end;

procedure TCCodeParserTool.IncreaseChangeStep;
begin
  if FChangeStep<>$7fffffff then
    inc(FChangeStep)
  else
    FChangeStep:=-$7fffffff;
end;

procedure TCCodeParserTool.WriteDebugReport;
var
  Node: TCodeTreeNode;
begin
  DebugLn(['TCCodeParserTool.WriteDebugReport ']);
  if Tree<>nil then begin
    Node:=Tree.Root;
    while Node<>nil do begin
      DebugLn([GetIndentStr(Node.GetLevel*2)+CCNodeDescAsString(Node.Desc)]);
      Node:=Node.Next;
    end;
  end;
end;

procedure InternalFinal;
var
  i: Integer;
begin
  if KeyWordLists<>nil then begin
    for i:=0 to KeyWordLists.Count-1 do
      TObject(KeyWordLists[i]).Free;
    FreeAndNil(KeyWordLists);
  end;
end;

finalization
  InternalFinal;

end.