TDM#10: BorDebug – Return of the Giant

"The Delphi linker has always had the option of including so-called Turbo Debugger (TD32) debug information (on the Linker page of the Project Options dialog). The internal IDE Debugger does not normally use this information (Delphi 4 and 5 uses it when debugging external DLLs and EXE files), but instead relies on internal compiler structures build during an interactive compile.

External tools such as Borland’s Turbo Debugger[i] does rely on the TD32 information tacked at the end of the EXE or DLL file to enable symbolic debugging. This information is also used by a number of third party tools such as Numega’s BoundsChecker[ii], Turbo Power’s suite of Sleuth QA[iii] tools, Atanas Stoyanov’s freeware MemProof memory checking tool[iv], AutomatedQA’s QTime profiler[v], and Intel’s VTune sampling profiler [vi]

In this article we will see how we can utilise a relatively new DLL from Borland, BorDebug.DLL, to read and interpret the TD32 debug information in our own applications. [...]

We will discuss the functionality provided by the BorDebug DLL, present an import unit that gives us access to it from our Delphi applications, look at a set of wrapper classes to simplify the usage and show some simple demonstration programs."

H. Vassbotn, TDM, November 2000

unit HVBorDebug;
{
    Simplified class interface for the BorDebug API
    Written by Hallvard Vassbotn (hallvard.vassbotn@c2i.net),
    April 1999 - September 2000

    History:
    15.04.99 HV Created
    30.09.00 HV Updated and revised
}
interface

uses
 Windows, Classes, TypInfo, BorDebug, SysUtils;

type
 // ... removed a lot of stuff - see the code on disk
 TBorDebug = class(TObject)
 public
   constructor Create(const aFilename: string = '');
   destructor Destroy; override;
   procedure Open;
   procedure Close;
   property Handle: TBorDebHandle read GetHandle;
   property FileName: string;
   property SkipNames: boolean;
   property CacheNames: boolean;
   property Active: boolean;
   property NameCount: TItemCount;
   property Names[Index: TNameIndex]: string;
   property UnmangledNames[Index: TNameIndex]: string;
   property RegisterName[RegIndex: TRegNameIndex]: string;
   property SubSectionCount: TItemCount;
   property SubSections[Index: TSubSectionIndex]: TBorDebugSubSection;
   function CreateModule(const SubSection: TBorDebugSubSection): TBorDebugModule;
   function CreateSrcModule(const SubSection: TBorDebugSubSection ): TBorDebugSrcModule;
   procedure StartSymbols(const SubSection: TBorDebugSubSection);
   function GetNextSymbol(var Symbol: TBorDebugSymbol): boolean;
   function CreateSymbolInfo(const Symbol: TBorDebugSymbol): TSymbolInfo;
   function CreateTypeInfo(const aType: TBorDebugType): TTypeInfo;
   property TypeFromIndex[TypeIndex: TTypeIndex]: TBorDebugType;
   property TypeFromOffset[Offset: TFileOffset]: TBorDebugType;
   property TypeName[TypeIndex: TTypeIndex]: string;
   property GlobalSymbols[const SubSection: TBorDebugSubSection]: TBorDebugGlobalSymbol;
   property TypeCount: TItemCount;
   property TypesSignature: TSignature;
   property SubSectionDirectoryOffset: TFileOffset;
 end;

 TBorDebugModule = class(TBorDebugObject)
 public
   constructor Create(BorDebug: TBorDebug; Offset: TFileOffset);
   destructor Destroy; override;
   property Overlay            : TOverlayIndex  ;
   property LibIndex           : TLibraryIndex  ;
   property Style              : TDebuggingStyle;
   property TimeStamp          : TBDTimeStamp   ;
   property SegmentCount       : TItemCount     ;
   property NameIndex          : TNameIndex     ;
   property Name               : string         ;
   property ModuleSegmentList  : TList          ;
   property Segments[Index: integer]: TModuleSegment;
 end;

 TBorDebugSrcModule = class(TBorDebugObject)
 public
   constructor Create(BorDebug: TBorDebug; Offset: TFileOffset);
   destructor Destroy; override;
   property RangeCount         : TItemCount     ;
   property RangeSegments      : PSegmentIndices;
   property RangeSegmentStarts : PSegmentOffsets;
   property RangeSegmentEnds   : PSegmentOffsets;
   property SourceCount        : TItemCount     ;
   property SourceOffsets      : PFileOffsets   ;
   property NameIndices        : PNameIndices   ;
   property RangeCounts        : PItemCounts    ;
   property SourceFileList     : TList          ;
   property SourceFiles[Index: integer]: TSourceFileEntry;
   property SourceNames[Index: integer]: string;
 end;

 TModuleSegment = class(TObject)
 public
   constructor Create(Module: TBorDebugModule; SegmentIndex: TSegmentIndex);
   property LinkerSegment     : TLinkerSegmentIndex;
   property Offset            : TFileOffset        ;
   property Size              : TByteCount         ;
   property Flags             : TSegmentFlags      ;
 end;

 TSourceFileEntry = class(TObject)
 public
   constructor Create(SrcModule: TBorDebugSrcModule; SourceFileIndex: TSourceFileIndex);
   destructor Destroy; override;
   property BorDebug           : TBorDebug       ;
   property Handle             : TBorDebHandle   ;
   property Offset             : TFileOffset     ;
   property SrcModule          : TBorDebugSrcModule;
   property Name               : string          ;
   property NameIndex          : TNameIndex      ;
   property SourceFileIndex    : TSourceFileIndex;
   property RangeSegments      : PSegmentIndices ;
   property RangeSegmentStarts : PSegmentOffsets ;
   property RangeSegmentEnds   : PSegmentOffsets ;
   property LineNumberCounts   : PItemCounts     ;
   property LineNumerOffsetList: TList           ;
   property RangeCount         : TItemCount      ;
   property RangeLineNumbers[Index: integer]: TLineNumberOffsets;
 end;

 TLineNumberOffsets = class(TObject)
 public
   constructor Create(SourceFile: TSourceFileEntry; RangeIndex: TRangeIndex);
   destructor Destroy; override;
   property SourceFile  : TSourceFileEntry;
   property LineNumbers : PLineNumbers    ;
   property LineOffsets : PSegmentOffsets ;
   property LineCount   : TItemCount      ;
   property RangeIndex  : TRangeIndex     ;
 end;

 TSymbolInfo = class(TObject)
 public
   constructor Create(BorDebug: TBorDebug; Symbol: TBorDebugSymbol);
   destructor Destroy; override;
   function GetTypeIndex(var TypeIndex: TTypeIndex): boolean;
   function GetNameIndex(var NameIndex: TNameIndex): boolean;
   property Symbol        : TBorDebugSymbol;
   property SymbolOffset  : TFileOffset    ;
   property Len           : TByteCount     ;
   property Kind          : TSymbolKind    ;
   property Info          : TSymbolInfoRec ;
   property KindAsString  : string         ;
 end;

 TTypeInfo = class(TObject)
 public
   constructor Create(BorDebug: TBorDebug; aType: TBorDebugType);
   destructor Destroy; override;
   property BDType        : TBorDebugType  ;
   property TypeIndex     : TTypeIndex     ;
   property TypeOffset    : TFileOffset    ;
   property Length        : TByteCount     ;
   property TypeKind      : TTypeKind      ;
   property Info          : TTypeInfoRec   ;
   property NameIndex     : TNameIndex     ;
   property KindAsString  : string         ;
 end;

As usual you can read the full article (PDF) and download the full, original code (zip). Enjoy! ;)

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[i] Turbo Debugger, a free download: http://www.borland.com/bcppbuilder/turbodebugger/

[ii] Numega BoundsChecker for Delphi: http://www.numega.com/products/aed/del.shtml

[iii] Turbo Power Sleuth QA Suite: http://www.turbopower.com/products/sleuthqa/

[iv] Atanas Stoyanov’s MemProof home page: http://www.totalqa.com/downloads/memproof.asp

[v] QTime: http://www.totalqa.com/index.asp

[vi] VTune: http://developer.intel.com/vtune/