diff --git a/.gitattributes b/.gitattributes
index 286868663b..a6836001c1 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -580,6 +580,7 @@ components/codetools/ide/codystrconsts.pas svneol=native#text/pascal
 components/codetools/ide/codyutils.pas svneol=native#text/pascal
 components/codetools/ide/declarevardlg.lfm svneol=native#text/plain
 components/codetools/ide/declarevardlg.pas svneol=native#text/pascal
+components/codetools/ide/identifierdictionary.pas svneol=native#text/plain
 components/codetools/ide/languages/codystrconsts.it.po svneol=native#text/plain
 components/codetools/ide/languages/codystrconsts.po svneol=native#text/plain
 components/codetools/ide/languages/codystrconsts.pt_BR.po svneol=native#text/plain
diff --git a/components/codetools/ide/cody.lpk b/components/codetools/ide/cody.lpk
index a2ff3509b5..2d6aab4088 100644
--- a/components/codetools/ide/cody.lpk
+++ b/components/codetools/ide/cody.lpk
@@ -4,7 +4,7 @@
     <Name Value="Cody"/>
     <Author Value="Mattias Gaertner - mattias@freepascal.org"/>
     <CompilerOptions>
-      <Version Value="10"/>
+      <Version Value="11"/>
       <SearchPaths>
         <UnitOutputDirectory Value="lib/$(TargetCPU)-$(TargetOS)"/>
       </SearchPaths>
@@ -19,7 +19,7 @@
     <Description Value="IDE extensions using Codetools."/>
     <License Value="GPL2"/>
     <Version Major="1" Minor="1"/>
-    <Files Count="11">
+    <Files Count="12">
       <Item1>
         <Filename Value="ppulistdlg.pas"/>
         <UnitName Value="PPUListDlg"/>
@@ -65,6 +65,10 @@
         <Filename Value="addwithblockdlg.pas"/>
         <UnitName Value="addwithblockdlg"/>
       </Item11>
+      <Item12>
+        <Filename Value="identifierdictionary.pas"/>
+        <UnitName Value="identifierdictionary"/>
+      </Item12>
     </Files>
     <LazDoc Paths="doc"/>
     <i18n>
diff --git a/components/codetools/ide/cody.pas b/components/codetools/ide/cody.pas
index a14973f05a..273daa0e93 100644
--- a/components/codetools/ide/cody.pas
+++ b/components/codetools/ide/cody.pas
@@ -9,7 +9,8 @@ interface
 uses
   PPUListDlg, CodyStrConsts, AddAssignMethodDlg, CodyCtrls, CodyFrm, 
   CodyRegistration, DeclareVarDlg, CodyUtils, CodyNodeInfoDlg, 
-  CodyCopyDeclaration, AddWithBlockDlg, LazarusPackageIntf;
+  CodyCopyDeclaration, AddWithBlockDlg, IdentifierDictionary, 
+  LazarusPackageIntf;
 
 implementation
 
diff --git a/components/codetools/ide/identifierdictionary.pas b/components/codetools/ide/identifierdictionary.pas
new file mode 100644
index 0000000000..1354f226a6
--- /dev/null
+++ b/components/codetools/ide/identifierdictionary.pas
@@ -0,0 +1,275 @@
+{
+ ***************************************************************************
+ *                                                                         *
+ *   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:
+    Quick lookup database for identifiers in units.
+}
+unit IdentifierDictionary;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, AVL_Tree, BasicCodeTools, FileProcs;
+
+type
+  TUDIdentifier = class;
+  TUDUnit = class;
+  TUnitDictionary = class;
+
+  { TUDItem }
+
+  TUDItem = class
+  public
+    Name: string;
+  end;
+
+  { TUDFileItem }
+
+  TUDFileItem = class(TUDItem)
+  public
+    Filename: string;
+    constructor Create(const aName, aFilename: string);
+  end;
+
+  { TUDUnitGroup }
+
+  TUDUnitGroup = class(TUDFileItem)
+  public
+    Dictionary: TUnitDictionary;
+    Units: TAVLTree; // tree of TIDUnit sorted with CompareIDItems
+    constructor Create(const aName, aFilename: string);
+    destructor Destroy; override;
+    function AddUnit(NewUnit: TUDUnit): TUDUnit; overload;
+    function AddUnit(const aName, aFilename: string): TUDUnit; overload;
+  end;
+
+  { TUDUnit }
+
+  TUDUnit = class(TUDFileItem)
+  public
+    FileAge: longint;
+    FirstIdentifier: TUDIdentifier;
+    UnitGroups: TAVLTree; // tree of TUDUnitGroup sorted with CompareIDItems
+    constructor Create(const aName, aFilename: string);
+    destructor Destroy; override;
+    function AddIdentifier(aName: PChar): TUDIdentifier;
+  end;
+
+  { TUDIdentifier }
+
+  TUDIdentifier = class(TUDItem)
+  public
+    DUnit: TUDUnit;
+    NextInUnit: TUDIdentifier;
+    constructor Create(const aName: string); overload;
+    constructor Create(aName: PChar); overload;
+  end;
+
+  { TUnitDictionary }
+
+  TUnitDictionary = class
+  private
+    FIdentifiers: TAVLTree; // tree of TUDIdentifier sorted with CompareIDItems
+    FUnitsByName: TAVLTree; // tree of TUDUnit sorted with CompareIDItems
+    FUnitsByFilename: TAVLTree; // tree of TUDUnit sorted with CompareIDFileItems
+    FUnitGroupsByName: TAVLTree; // tree of TUDUnitGroup sorted with CompareIDItems
+    FUnitGroupsByFilename: TAVLTree; // tree of TUDUnitGroup sorted with CompareIDFileItems
+  public
+    constructor Create;
+    destructor Destroy; override;
+    procedure Clear;
+    function AddUnitGroup(Group: TUDUnitGroup): TUDUnitGroup; overload;
+    function AddUnitGroup(const aName, aFilename: string): TUDUnitGroup; overload;
+  end;
+
+function CompareNameWithIDItem(NamePChar, Item: Pointer): integer;
+function CompareIDItems(Item1, Item2: Pointer): integer;
+function CompareFileNameWithIDFileItem(NameAnsiString, Item: Pointer): integer;
+function CompareIDFileItems(Item1, Item2: Pointer): integer;
+
+procedure IDCheckUnitNameAndFilename(const aName, aFilename: string);
+
+implementation
+
+function CompareNameWithIDItem(NamePChar, Item: Pointer): integer;
+var
+  i: TUDItem absolute Item;
+begin
+  Result:=CompareDottedIdentifiers(PChar(NamePChar),PChar(Pointer(i.Name)));
+end;
+
+function CompareIDItems(Item1, Item2: Pointer): integer;
+var
+  i1: TUDItem absolute Item1;
+  i2: TUDItem absolute Item2;
+begin
+  Result:=CompareDottedIdentifiers(PChar(Pointer(i1.Name)),PChar(Pointer(i2.Name)));
+end;
+
+function CompareFileNameWithIDFileItem(NameAnsiString, Item: Pointer): integer;
+var
+  i: TUDFileItem absolute Item;
+begin
+  Result:=CompareFilenames(AnsiString(NameAnsiString),i.Filename);
+end;
+
+function CompareIDFileItems(Item1, Item2: Pointer): integer;
+var
+  i1: TUDFileItem absolute Item1;
+  i2: TUDFileItem absolute Item2;
+begin
+  Result:=CompareFilenames(i1.Filename,i2.Filename);
+end;
+
+procedure IDCheckUnitNameAndFilename(const aName, aFilename: string);
+
+  procedure InvalidName;
+  begin
+    raise Exception.Create('invalid UnitName="'+aName+'" Filename="'+aFilename+'"');
+  end;
+
+var
+  ShortName: String;
+begin
+  ShortName:=ExtractFileNameOnly(aFilename);
+  if CompareDottedIdentifiers(PChar(Pointer(aName)),PChar(Pointer(ShortName)))<>0
+  then
+    InvalidName;
+end;
+
+{ TUDIdentifier }
+
+constructor TUDIdentifier.Create(const aName: string);
+begin
+  Name:=aName;
+end;
+
+constructor TUDIdentifier.Create(aName: PChar);
+begin
+  Name:=GetIdentifier(aName);
+end;
+
+constructor TUDUnit.Create(const aName, aFilename: string);
+begin
+  IDCheckUnitNameAndFilename(aName,aFilename);
+  inherited Create(aName,aFilename);
+  UnitGroups:=TAVLTree.Create(@CompareIDItems);
+end;
+
+destructor TUDUnit.Destroy;
+begin
+  // the groups are freed by the TUnitDictionary
+  FreeAndNil(UnitGroups);
+  inherited Destroy;
+end;
+
+function TUDUnit.AddIdentifier(aName: PChar): TUDIdentifier;
+begin
+  Result:=TUDIdentifier.Create(aName);
+end;
+
+{ TUDUnitGroup }
+
+constructor TUDUnitGroup.Create(const aName, aFilename: string);
+begin
+  IDCheckUnitNameAndFilename(aName,aFilename);
+  inherited Create(aName,aFilename);
+  Units:=TAVLTree.Create(@CompareIDItems);
+end;
+
+destructor TUDUnitGroup.Destroy;
+begin
+  // the units are freed by the TIdentifierDictionary
+  FreeAndNil(Units);
+  inherited Destroy;
+end;
+
+function TUDUnitGroup.AddUnit(NewUnit: TUDUnit): TUDUnit;
+begin
+  Result:=NewUnit;
+  Units.Add(Result);
+end;
+
+function TUDUnitGroup.AddUnit(const aName, aFilename: string): TUDUnit;
+begin
+  Result:=AddUnit(TUDUnit.Create(aName,aFilename));
+end;
+
+{ TUDFileItem }
+
+constructor TUDFileItem.Create(const aName, aFilename: string);
+begin
+  Name:=aName;
+  Filename:=aFilename;
+end;
+
+{ TUnitDictionary }
+
+constructor TUnitDictionary.Create;
+begin
+  FIdentifiers:=TAVLTree.Create(@CompareIDItems);
+  FUnitsByName:=TAVLTree.Create(@CompareIDItems);
+  FUnitsByFilename:=TAVLTree.Create(@CompareIDFileItems);
+  FUnitGroupsByName:=TAVLTree.Create(@CompareIDItems);
+  FUnitGroupsByFilename:=TAVLTree.Create(@CompareIDFileItems);
+end;
+
+destructor TUnitDictionary.Destroy;
+begin
+  Clear;
+  FreeAndNil(FIdentifiers);
+  FreeAndNil(FUnitsByName);
+  FreeAndNil(FUnitsByFilename);
+  FreeAndNil(FUnitGroupsByName);
+  FreeAndNil(FUnitGroupsByFilename);
+  inherited Destroy;
+end;
+
+procedure TUnitDictionary.Clear;
+begin
+  FUnitGroupsByFilename.Clear;
+  FUnitGroupsByName.FreeAndClear;
+  FUnitsByFilename.Clear;
+  FUnitsByName.FreeAndClear;
+  FIdentifiers.FreeAndClear;
+end;
+
+function TUnitDictionary.AddUnitGroup(Group: TUDUnitGroup): TUDUnitGroup;
+begin
+  if Group.Dictionary<>nil then
+    raise Exception.Create('TIdentifierDictionary.AddUnitGroup Group.Dictionary<>nil');
+  Result:=Group;
+  Result.Dictionary:=Self;
+  FUnitGroupsByName.Add(Result);
+  FUnitGroupsByFilename.Add(Result);
+end;
+
+function TUnitDictionary.AddUnitGroup(const aName, aFilename: string
+  ): TUDUnitGroup;
+begin
+  Result:=AddUnitGroup(TUDUnitGroup.Create(aName,aFilename));
+end;
+
+end.
+