diff --git a/components/fpdebug/fpdbgdwarf.pas b/components/fpdebug/fpdbgdwarf.pas
index ff1d756865..2f33ce98f2 100644
--- a/components/fpdebug/fpdbgdwarf.pas
+++ b/components/fpdebug/fpdbgdwarf.pas
@@ -508,22 +508,22 @@ type
 
   TFpValueDwarfString  = class(TFpValueDwarf)
   private
-    FValue: String;
-    FValueDone: Boolean;
     FLenSize: TFpDbgValueSize;
     FHasLenSize, FLenSizeDone: Boolean;
   protected
+    FValue: String;
+    FValueDone: Boolean;
     function GetLenSize(out ASize: TFpDbgValueSize): boolean;
-    function GetStringLen: Int64;
+    function GetStringLen(out ALen: Int64): boolean;
 
     function GetFieldFlags: TFpValueFieldFlags; override;
     function GetAsString: AnsiString; override;
     function GetAsWideString: WideString; override;
+  public
     function GetSubString(AStartIndex, ALen: Int64; out ASubStr: AnsiString;
       AIgnoreBounds: Boolean = False): Boolean; override;
     function GetSubWideString(AStartIndex, ALen: Int64; out ASubStr: WideString;
       AIgnoreBounds: Boolean = False): Boolean; override;
-  public
     procedure Reset; override;
   end;
 
@@ -4092,14 +4092,15 @@ begin
   Result := FHasLenSize;
 end;
 
-function TFpValueDwarfString.GetStringLen: Int64;
+function TFpValueDwarfString.GetStringLen(out ALen: Int64): boolean;
 var
   t: TFpSymbolDwarfType;
-  HasSize: Boolean;
-  ASize: TFpDbgValueSize;
+  HasLenSize: Boolean;
+  LenSize: TFpDbgValueSize;
   ALenLoc: TFpDbgMemLocation;
 begin
-  Result := -1;
+  Result := False;
+  ALen := -1;
 
   t := TypeInfo;
   if t <> nil then
@@ -4107,23 +4108,25 @@ begin
   if (t = nil) or not(t is TFpSymbolDwarfTypeString) then
     exit;
 
-  HasSize := GetLenSize(ASize);
+  HasLenSize := GetLenSize(LenSize);
 
   if TFpSymbolDwarfTypeString(t).DoReadLengthLocation(Self, ALenLoc) then begin
-    if not HasSize then
-      ASize := SizeVal(AddressSize);
-    if not Context.ReadSignedInt(ALenLoc, ASize, Result) then begin
+    if not HasLenSize then
+      LenSize := SizeVal(AddressSize);
+    Result := Context.ReadSignedInt(ALenLoc, LenSize, ALen);
+    if not Result then begin
       SetLastError(Context.LastMemError);
-      Result := -1;
+      ALen := -1;
     end;
   end
   else
-  if HasSize then begin
-    Result := SizeToFullBytes(ASize);
+  if HasLenSize then begin
+    ALen := SizeToFullBytes(LenSize);
+    Result := True;
   end
   else begin
     SetLastError(CreateError(fpErrAnyError));
-    Result := -1;
+    ALen := -1;
   end;
 end;
 
@@ -4140,6 +4143,7 @@ function TFpValueDwarfString.GetAsString: AnsiString;
 var
   ALen: Int64;
   WResult: WideString;
+  RResult: RawByteString;
 begin
   if FValueDone then
     exit(FValue);
@@ -4148,32 +4152,20 @@ begin
   FValue := '';
   FValueDone := True;
 
-  ALen := GetStringLen;
-  if ALen <= 0 then
-    exit;
-
-  if (MemManager.MemLimits.MaxStringLen > 0) and
-     (QWord(ALen) > MemManager.MemLimits.MaxStringLen)
-  then
-    ALen := MemManager.MemLimits.MaxStringLen;
+  if not GetStringLen(ALen) then
+    exit; // Error should be set by GetStringLen
 
   if Kind = skWideString then begin
-    SetLength(WResult, ALen);
-    if not (Context.ReadMemory(DataAddress, SizeVal(ALen*2), @WResult[1]))
-    then begin
-      SetLastError(Context.LastMemError);
-      Result := '';
-    end
+    if not Context.ReadWString(DataAddress, ALen, WResult) then
+      SetLastError(Context.LastMemError)
     else
       Result := WResult;
   end
   else begin
-    SetLength(Result, ALen);
-    if not (Context.ReadMemory(DataAddress, SizeVal(ALen), @Result[1]))
-    then begin
-      SetLastError(Context.LastMemError);
-      Result := '';
-    end;
+    if not Context.ReadString(DataAddress, ALen, RResult) then
+      SetLastError(Context.LastMemError)
+    else
+      Result := RResult;
   end;
 
   FValue := Result;
@@ -4189,6 +4181,7 @@ function TFpValueDwarfString.GetSubString(AStartIndex, ALen: Int64; out
 var
   AFullLen: Int64;
   WResult: WideString;
+  RResult: RawByteString;
 begin
   // TODO: if FValueDone, and covers selected range, then use FValue;
   ASubStr := '';
@@ -4203,8 +4196,7 @@ begin
     AStartIndex := 0;
   end;
 
-  AFullLen := GetStringLen;
-  if AFullLen <= 0 then begin
+  if (not GetStringLen(AFullLen)) or (AFullLen <= 0) then begin
     Result := AIgnoreBounds;
     exit;
   end;
@@ -4217,30 +4209,21 @@ begin
   if ALen <= 0 then
     exit;
 
-  if (MemManager.MemLimits.MaxStringLen > 0) and
-     (QWord(ALen) > MemManager.MemLimits.MaxStringLen)
-  then
-    ALen := MemManager.MemLimits.MaxStringLen;
-
   if Kind = skWideString then begin
-    SetLength(WResult, ALen);
-    if not (Context.ReadMemory(DataAddress + AStartIndex*2, SizeVal(ALen*2), @WResult[1]))
-    then begin
-      SetLastError(Context.LastMemError);
-      WResult := '';
-      exit;
-    end
+    {$PUSH}{$Q-}{$R-}
+    if not Context.ReadWString(DataAddress+AStartIndex*2, ALen, WResult, True) then
+    {$POP}
+      SetLastError(Context.LastMemError)
     else
       ASubStr := WResult;
   end
   else begin
-    SetLength(ASubStr, ALen);
-    if not (Context.ReadMemory(DataAddress + AStartIndex, SizeVal(ALen), @ASubStr[1]))
-    then begin
-      SetLastError(Context.LastMemError);
-      ASubStr := '';
-      exit;
-    end;
+    {$PUSH}{$Q-}{$R-}
+    if not Context.ReadString(DataAddress+AStartIndex, ALen, RResult, True) then
+    {$POP}
+      SetLastError(Context.LastMemError)
+    else
+      ASubStr := RResult;
   end;
 end;
 
diff --git a/components/fpdebug/fpdbgdwarffreepascal.pas b/components/fpdebug/fpdbgdwarffreepascal.pas
index 2cf16b4411..adb474db6b 100644
--- a/components/fpdebug/fpdbgdwarffreepascal.pas
+++ b/components/fpdebug/fpdbgdwarffreepascal.pas
@@ -254,13 +254,15 @@ type
     function IsValidTypeCast: Boolean; override;
     function GetFieldFlags: TFpValueFieldFlags; override;
     function GetKind: TDbgSymbolKind; override;
-    //function GetAsString: AnsiString; override;
+    function GetAsString: AnsiString; override;
     //function GetAsWideString: WideString; override;
     function GetMemberCount: Integer; override;
     procedure SetAsCardinal(AValue: QWord); override;
     function GetAsCardinal: QWord; override;
-    //function GetSubString(AStartIndex, ALen: Int64; out ASubStr: AnsiString;
-    //  AIgnoreBounds: Boolean = False): Boolean; override;
+  public
+    function GetFpcRefCount(out ARefCount: Int64): Boolean; override;
+    function GetSubString(AStartIndex, ALen: Int64; out ASubStr: AnsiString;
+      AIgnoreBounds: Boolean = False): Boolean; override;
     //function GetSubWideString(AStartIndex, ALen: Int64; out ASubStr: WideString;
     //  AIgnoreBounds: Boolean = False): Boolean; override;
   end;
@@ -289,13 +291,13 @@ type
     FValueDone, FBoundsDone: Boolean;
     FDynamicCodePage: TSystemCodePage;
     function GetCodePage: TSystemCodePage;
-    function ObtainDynamicCodePage(Addr: TFpDbgMemLocation; out Codepage: TSystemCodePage): Boolean;
     procedure CalcBounds;
     // check if this is a string, and return bounds
     function CheckTypeAndGetAddr(out AnAddr: TFpDbgMemLocation): boolean;
   protected
     function IsValidTypeCast: Boolean; override;
     function GetFieldFlags: TFpValueFieldFlags; override;
+    function GetStringLen(out ALen: Int64): boolean; inline;
     function GetAsString: AnsiString; override;
     function GetAsWideString: WideString; override;
     procedure SetAsCardinal(AValue: QWord); override;
@@ -340,6 +342,34 @@ uses
 var
   FPDBG_DWARF_VERBOSE: PLazLoggerLogGroup;
 
+function ObtainDynamicCodePage(Addr: TFpDbgMemLocation; AContext: TFpDbgLocationContext;
+  TypeInfo: TFpSymbolDwarfType; out Codepage: TSystemCodePage): Boolean;
+var
+  CodepageOffset: SmallInt;
+  v: Cardinal;
+begin
+  // Only call this function for non-empty strings!
+  Result := False;
+  if not IsTargetNotNil(Addr) then
+    exit;
+
+  // Only AnsiStrings in fpc 3.0.0 and higher have a dynamic codepage.
+  v := TFpDwarfFreePascalSymbolClassMapDwarf3(TypeInfo.CompilationUnit.DwarfSymbolClassMap).FCompilerVersion;
+  if (v >= $030000) then begin
+    // Too bad the debug-information does not deliver this information. So we
+    // use these hardcoded information, and hope that FPC does not change and
+    // we never reach this point for a compilationunit that is not compiled by
+    // fpc.
+    if v >= $030300 { $030301 } then
+      CodepageOffset := TypeInfo.CompilationUnit.AddressSize + SizeOf(Longint) + SizeOf(Word) + SizeOf(Word)
+    else
+      CodepageOffset := TypeInfo.CompilationUnit.AddressSize * 3;
+    Addr.Address := Addr.Address - CodepageOffset;
+    if AContext.ReadMemory(Addr, SizeVal(2), @Codepage) then
+      Result := CodePageToCodePageName(Codepage) <> '';
+  end;
+end;
+
 { TFpDwarfFreePascalSymbolClassMap }
 
 function TFpDwarfFreePascalSymbolClassMap.CanHandleCompUnit(
@@ -632,8 +662,6 @@ function TFpDwarfFreePascalSymbolScope.FindExportedSymbolInUnits(
 var
   i: Integer;
   CU: TDwarfCompilationUnit;
-  FoundInfoEntry: TDwarfInformationEntry;
-  FndIsExternal: Boolean;
   s: String;
 begin
   if not FSearchSpecialCuDone then begin
@@ -1318,7 +1346,7 @@ begin
   len := LenSym.AsCardinal;
   LenSym.ReleaseReference;
 
-  if not GetSize(Size) then begin;
+  if not GetSize(Size) then begin
     SetLastError(CreateError(fpErrAnyError));
     exit('');
   end;
@@ -1569,6 +1597,51 @@ begin
     Result := skAnsiString;
 end;
 
+function TFpValueDwarfFreePascalString.GetAsString: AnsiString;
+var
+  ALen: Int64;
+  WResult: WideString;
+  RResult: RawByteString;
+  Codepage: TSystemCodePage;
+begin
+  if FValueDone then
+    exit(FValue);
+
+  Result := '';
+  FValue := '';
+  FValueDone := True;
+
+  if not GetStringLen(ALen) then
+    exit;
+
+  if Kind = skWideString then begin
+    if not Context.ReadWString(DataAddress, ALen, WResult) then
+      SetLastError(Context.LastMemError)
+    else
+      Result := WResult;
+  end
+  else
+  if Kind = skAnsiString then begin
+    if not Context.ReadString(DataAddress, ALen, RResult) then begin
+      SetLastError(Context.LastMemError);
+    end
+    else begin
+      if ObtainDynamicCodePage(DataAddress, Context, TypeInfo, Codepage) then
+        SetCodePage(RResult, Codepage, False);
+      Result := RResult;
+    end;
+  end
+  else begin
+    // ShortString;
+    if not Context.ReadString(DataAddress, ALen, RResult) then
+      SetLastError(Context.LastMemError)
+    else
+      Result := RResult;
+  end;
+
+  FValue := Result;
+end;
+
 function TFpValueDwarfFreePascalString.GetMemberCount: Integer;
 var
   ALen: Int64;
@@ -1598,6 +1671,105 @@ begin
     Result := inherited GetAsCardinal;
 end;
 
+function TFpValueDwarfFreePascalString.GetFpcRefCount(out ARefCount: Int64): Boolean;
+var
+  Addr: TFpDbgMemLocation;
+begin
+  ARefCount := 0;
+  Result := (Kind = skAnsiString);
+  if not Result then
+    exit;
+
+  GetDwarfDataAddress(Addr);
+  if (not IsValidLoc(Addr)) and
+     (HasTypeCastInfo) and
+     (svfOrdinal in TypeCastSourceValue.FieldFlags)
+  then
+    Addr := TargetLoc(TypeCastSourceValue.AsCardinal);
+
+  Result := IsTargetNil(Addr);
+  if Result then
+    exit;
+
+  if not MemManager.MemModel.IsReadableLocation(Addr) then
+    exit;
+
+  if TFpDwarfFreePascalSymbolClassMap(TypeInfo.CompilationUnit.DwarfSymbolClassMap).FCompilerVersion >= $030301
+  then begin
+    Addr:= Addr - AddressSize - 4;
+    Result := Context.ReadSignedInt(Addr, SizeVal(4), ARefCount);
+  end
+  else begin
+    Addr:= Addr - (AddressSize * 2);
+    Result := Context.ReadSignedInt(Addr, SizeVal(AddressSize), ARefCount);
+  end;
+end;
+
+function TFpValueDwarfFreePascalString.GetSubString(AStartIndex, ALen: Int64; out
+  ASubStr: AnsiString; AIgnoreBounds: Boolean): Boolean;
+var
+  AFullLen: Int64;
+  WResult: WideString;
+  RResult: RawByteString;
+  Codepage: TSystemCodePage;
+begin
+  // TODO: if FValueDone, and covers selected range, then use FValue;
+  ASubStr := '';
+  Result := True;
+  if ALen <= 0 then
+    exit;
+
+  dec(AStartIndex);
+  if AStartIndex < 0 then begin // not supported, return partial
+    Result := AIgnoreBounds;
+    ALen := ALen + AStartIndex;
+    AStartIndex := 0;
+  end;
+
+  if (not GetStringLen(AFullLen)) or (AFullLen <= 0) then begin
+    Result := AIgnoreBounds;
+    exit;
+  end;
+
+  if AStartIndex + ALen > AFullLen then begin
+    Result := AIgnoreBounds;
+    ALen := AFullLen - AStartIndex;
+  end;
+
+  if ALen <= 0 then
+    exit;
+
+  if Kind = skWideString then begin
+    {$PUSH}{$Q-}{$R-}
+    if not Context.ReadWString(DataAddress+AStartIndex*2, ALen, WResult, True) then
+    {$POP}
+      SetLastError(Context.LastMemError)
+    else
+      ASubStr := WResult;
+  end
+  else
+  if Kind = skAnsiString then begin
+    {$PUSH}{$Q-}{$R-}
+    if not Context.ReadString(DataAddress+AStartIndex, ALen, RResult) then begin
+    {$POP}
+      SetLastError(Context.LastMemError);
+    end
+    else begin
+      if ObtainDynamicCodePage(DataAddress, Context, TypeInfo, Codepage) then
+        SetCodePage(RResult, Codepage, False);
+      ASubStr := RResult;
+    end;
+  end
+  else begin
+    {$PUSH}{$Q-}{$R-}
+    if not Context.ReadString(DataAddress+AStartIndex, ALen, RResult, True) then
+    {$POP}
+      SetLastError(Context.LastMemError)
+    else
+      ASubStr := RResult;
+  end;
+end;
+
 { TFpSymbolDwarfV3FreePascalSymbolTypeArray }
 
 function TFpSymbolDwarfV3FreePascalSymbolTypeArray.GetInternalStringType: TArrayOrStringType;
@@ -1765,12 +1937,24 @@ begin
   end;
 end;
 
+function TFpValueDwarfV3FreePascalString.GetStringLen(out ALen: Int64): boolean;
+begin
+  ALen := 0;
+  Result := True; // Todo: add error checks
+  CalcBounds;
+  if FHighBound < FLowBound then
+    exit; // empty string
+  {$PUSH}{$Q-}{$R-}
+  ALen := FHighBound-FLowBound+1;
+  {$POP}
+  Result := True;
+end;
+
 function TFpValueDwarfV3FreePascalString.GetSubString(AStartIndex, ALen: Int64;
   out ASubStr: AnsiString; AIgnoreBounds: Boolean): Boolean;
 var
-  Addr: TFpDbgMemLocation;
+  Addr, StartAddr: TFpDbgMemLocation;
   FullLen: Int64;
-  t: TFpSymbol;
   WResult: WideString;
   RResult: RawByteString;
   Codepage: TSystemCodePage;
@@ -1784,13 +1968,7 @@ begin
     AStartIndex := 1;
   end;
 
-  // get length
-  CalcBounds;
-  if FHighBound < FLowBound then
-    exit; // empty string
-  {$PUSH}{$Q-}{$R-}
-  FullLen := FHighBound-FLowBound+1;
-  {$POP}
+  GetStringLen(FullLen);
 
   if AStartIndex - 1 + ALen > FullLen then begin
     Result := AIgnoreBounds;
@@ -1814,22 +1992,11 @@ begin
     exit(False);
 
 
-  if (MemManager.MemLimits.MaxStringLen > 0) and
-     (QWord(ALen) > MemManager.MemLimits.MaxStringLen)
-  then
-    ALen := MemManager.MemLimits.MaxStringLen;
-
-  if ALen <= 0 then
-    exit;
-
-  t := TypeInfo;
-  if t.Kind = skWideString then begin
+  if Kind = skWideString then begin
     {$PUSH}{$Q-}{$R-}
     Addr.Address := Addr.Address + (AStartIndex - 1) * 2;
     {$POP}
-    if not ( (MemManager.SetLength(WResult, ALen)) and
-             (Context.ReadMemory(Addr, SizeVal(ALen*2), @WResult[1])) )
-    then
+    if not Context.ReadWString(Addr, ALen, WResult, True) then
       SetLastError(Context.LastMemError)
     else
       ASubStr := WResult;
@@ -1839,23 +2006,20 @@ begin
     {$PUSH}{$Q-}{$R-}
     Addr.Address := Addr.Address + AStartIndex - 1;
     {$POP}
-    if not ( (MemManager.SetLength(ASubStr, ALen)) and
-             (Context.ReadMemory(Addr, SizeVal(ALen), @ASubStr[1])) )
-    then begin
-      ASubStr := '';
-      SetLastError(Context.LastMemError);
-    end;
+    if not Context.ReadString(Addr, ALen, RResult, True) then
+      SetLastError(Context.LastMemError)
+    else
+      ASubStr := RResult;
   end
   else begin
+    StartAddr := Addr;
     {$PUSH}{$Q-}{$R-}
     Addr.Address := Addr.Address + QWord(AStartIndex - 1);
     {$POP}
-    if not ( (MemManager.SetLength(RResult, ALen)) and
-             (Context.ReadMemory(Addr, SizeVal(ALen), @RResult[1])) )
-    then begin
+    if not Context.ReadString(Addr, ALen, RResult, True) then begin
       SetLastError(Context.LastMemError);
     end else begin
-      if ObtainDynamicCodePage(Addr, Codepage) then
+      if ObtainDynamicCodePage(StartAddr, Context, TypeInfo, Codepage) then
         begin
         SetCodePage(RResult, Codepage, False);
         FDynamicCodePage:=Codepage;
@@ -1876,7 +2040,6 @@ end;
 
 function TFpValueDwarfV3FreePascalString.GetAsString: AnsiString;
 var
-  t: TFpSymbol;
   Len: Int64;
   Addr: TFpDbgMemLocation;
   WResult: WideString;
@@ -1894,45 +2057,26 @@ begin
   if not CheckTypeAndGetAddr(Addr) then
     exit;
 
-  // get length
-  CalcBounds;
-  if FHighBound < FLowBound then
-    exit; // empty string
-  {$PUSH}{$Q-}{$R-}
-  Len := FHighBound-FLowBound+1;
-  {$POP}
+  GetStringLen(Len);
 
-  if (MemManager.MemLimits.MaxStringLen > 0) and
-     (QWord(Len) > MemManager.MemLimits.MaxStringLen)
-  then
-      Len := MemManager.MemLimits.MaxStringLen;
-
-
-  t := TypeInfo;
-  if t.Kind = skWideString then begin
-    if not ( (MemManager.SetLength(WResult, Len)) and
-             (Context.ReadMemory(Addr, SizeVal(Len*2), @WResult[1])) )
-    then
+  if Kind = skWideString then begin
+    if not Context.ReadWString(Addr, Len, WResult) then
       SetLastError(Context.LastMemError)
     else
       Result := WResult;
   end else
   if Addr.Address = Address.Address + 1 then begin
     // shortstring
-    if not ( (MemManager.SetLength(Result, Len)) and
-             (Context.ReadMemory(Addr, SizeVal(Len), @Result[1])) )
-    then begin
-      Result := '';
-      SetLastError(Context.LastMemError);
-    end;
+    if not Context.ReadString(Addr, Len, RResult) then
+      SetLastError(Context.LastMemError)
+    else
+      Result := RResult;
   end
   else begin
-    if not ( (MemManager.SetLength(RResult, Len)) and
-             (Context.ReadMemory(Addr, SizeVal(Len), @RResult[1])) )
-    then begin
+    if not Context.ReadString(Addr, Len, RResult) then begin
       SetLastError(Context.LastMemError);
     end else begin
-      if ObtainDynamicCodePage(Addr, Codepage) then
+      if ObtainDynamicCodePage(Addr, Context, TypeInfo, Codepage) then
         begin
         SetCodePage(RResult, Codepage, False);
         FDynamicCodePage:=Codepage;
@@ -1982,7 +2126,7 @@ var
   Addr: TFpDbgMemLocation;
 begin
   ARefCount := 0;
-  Result := (TypeInfo.Kind = skString);
+  Result := (TypeInfo.Kind in [skString, skAnsiString]); // todo only skAnsiString;
   if not Result then
     exit;
 
@@ -2011,32 +2155,6 @@ begin
   end;
 end;
 
-function TFpValueDwarfV3FreePascalString.ObtainDynamicCodePage(Addr: TFpDbgMemLocation; out
-  Codepage: TSystemCodePage): Boolean;
-var
-  CodepageOffset: SmallInt;
-begin
-  // Only call this function for non-empty strings!
-  Result := False;
-  if not IsTargetNotNil(Addr) then
-    exit;
-
-  // Only AnsiStrings in fpc 3.0.0 and higher have a dynamic codepage.
-  if (TypeInfo.Kind = skString) and (TFpDwarfFreePascalSymbolClassMapDwarf3(TypeInfo.CompilationUnit.DwarfSymbolClassMap).FCompilerVersion >= $030000) then begin
-    // Too bad the debug-information does not deliver this information. So we
-    // use these hardcoded information, and hope that FPC does not change and
-    // we never reach this point for a compilationunit that is not compiled by
-    // fpc.
-    if TFpDwarfFreePascalSymbolClassMapDwarf3(TypeInfo.CompilationUnit.DwarfSymbolClassMap).FCompilerVersion >= $030300 { $030301 } then
-      CodepageOffset := AddressSize + SizeOf(Longint) + SizeOf(Word) + SizeOf(Word)
-    else
-      CodepageOffset := AddressSize * 3;
-    Addr.Address := Addr.Address - CodepageOffset;
-    if Context.ReadMemory(Addr, SizeVal(2), @Codepage) then
-      Result := CodePageToCodePageName(Codepage) <> '';
-  end;
-end;
-
 procedure TFpValueDwarfV3FreePascalString.CalcBounds;
 var
   t, t2: TFpSymbol;
@@ -2070,7 +2188,7 @@ begin
   if not MemManager.MemModel.IsReadableLocation(Addr) then
     exit;
 
-  assert((TypeInfo <> nil) and (TypeInfo.CompilationUnit <> nil) and (TypeInfo.CompilationUnit.DwarfSymbolClassMap is TFpDwarfFreePascalSymbolClassMapDwarf3), 'TFpValueDwarfV3FreePascalString.GetAsString: (Owner <> nil) and (Owner.CompilationUnit <> nil) and (TypeInfo.CompilationUnit.DwarfSymbolClassMap is TFpDwarfFreePascalSymbolClassMapDwarf3)');
+  assert((TypeInfo <> nil) and (TypeInfo.CompilationUnit <> nil) and (TypeInfo.CompilationUnit.DwarfSymbolClassMap is TFpDwarfFreePascalSymbolClassMapDwarf3), 'TFpValueDwarfV3FreePascalString.CalcBounds: (Owner <> nil) and (Owner.CompilationUnit <> nil) and (TypeInfo.CompilationUnit.DwarfSymbolClassMap is TFpDwarfFreePascalSymbolClassMapDwarf3)');
   if (TFpDwarfFreePascalSymbolClassMapDwarf3(TypeInfo.CompilationUnit.DwarfSymbolClassMap).FCompilerVersion > 0) and
      (TFpDwarfFreePascalSymbolClassMapDwarf3(TypeInfo.CompilationUnit.DwarfSymbolClassMap).FCompilerVersion < $030100)
   then begin
diff --git a/components/fpdebug/fpdmemorytools.pas b/components/fpdebug/fpdmemorytools.pas
index eae2f20c51..e05201f832 100644
--- a/components/fpdebug/fpdmemorytools.pas
+++ b/components/fpdebug/fpdmemorytools.pas
@@ -163,6 +163,9 @@ type
     //function ReadFloat      (const ALocation: TFpDbgMemLocation; ASize: TFpDbgValueSize;
     //                         out AValue: Extended;
     //                         AnOpts: TFpDbgMemReadOptions): Boolean; inline;
+
+    function ReadString(const ALocation: TFpDbgMemLocation; ALen: Int64; out AValue: RawByteString; AnIgnoreMaxStringLen: boolean = False): Boolean;
+    function ReadWString(const ALocation: TFpDbgMemLocation; ALen: Int64; out AValue: WideString; AnIgnoreMaxStringLen: boolean = False): Boolean;
   end;
 
 
@@ -1104,6 +1107,56 @@ begin
   Result := MemManager.ReadMemory(rdtfloat, ALocation, ASize, @AValue, (SizeOf(AValue)), Self);
 end;
 
+function TFpDbgLocationContext.ReadString(const ALocation: TFpDbgMemLocation; ALen: Int64; out
+  AValue: RawByteString; AnIgnoreMaxStringLen: boolean): Boolean;
+begin
+  Result := False;
+  AValue := '';
+
+  if (not AnIgnoreMaxStringLen) and
+     (MemManager.MemLimits.MaxStringLen > 0) and
+     (ALen > MemManager.MemLimits.MaxStringLen)
+  then
+    ALen := MemManager.MemLimits.MaxStringLen;
+
+  if ALen = 0 then begin
+    Result := True;
+    exit;
+  end;
+
+  if not MemManager.SetLength(AValue, ALen) then
+    exit;
+
+  Result := ReadMemory(ALocation, SizeVal(Length(AValue)), @AValue[1]);
+  if not Result then
+    AValue := ''
+end;
+
+function TFpDbgLocationContext.ReadWString(const ALocation: TFpDbgMemLocation; ALen: Int64; out
+  AValue: WideString; AnIgnoreMaxStringLen: boolean): Boolean;
+begin
+  Result := False;
+  AValue := '';
+
+  if (not AnIgnoreMaxStringLen) and
+     (MemManager.MemLimits.MaxStringLen > 0) and
+     (ALen > MemManager.MemLimits.MaxStringLen)
+  then
+    ALen := MemManager.MemLimits.MaxStringLen;
+
+  if ALen = 0 then begin
+    Result := True;
+    exit;
+  end;
+
+  if not MemManager.SetLength(AValue, ALen) then
+    exit;
+
+  Result := ReadMemory(ALocation, SizeVal(Length(AValue)*2), @AValue[1]);
+  if not Result then
+    AValue := ''
+end;
+
 { TFpDbgMemLimits }
 
 procedure TFpDbgMemLimits.SetMaxMemReadSize(AValue: QWord);
@@ -2013,7 +2066,9 @@ function TFpDbgMemManager.SetLength(var ADest: RawByteString; ALength: Int64
   ): Boolean;
 begin
   Result := False;
-  if (FMemLimits.MaxMemReadSize > 0) and (ALength > FMemLimits.MaxMemReadSize) then begin
+  if (ALength < 0) or
+     ( (FMemLimits.MaxMemReadSize > 0) and (ALength > FMemLimits.MaxMemReadSize) )
+  then begin
     FLastError := CreateError(fpErrReadMemSizeLimit);
     exit;
   end;
@@ -2025,7 +2080,9 @@ function TFpDbgMemManager.SetLength(var ADest: AnsiString; ALength: Int64
   ): Boolean;
 begin
   Result := False;
-  if (FMemLimits.MaxMemReadSize > 0) and (ALength > FMemLimits.MaxMemReadSize) then begin
+  if (ALength < 0) or
+     ( (FMemLimits.MaxMemReadSize > 0) and (ALength > FMemLimits.MaxMemReadSize) )
+  then begin
     FLastError := CreateError(fpErrReadMemSizeLimit);
     exit;
   end;
@@ -2037,7 +2094,9 @@ function TFpDbgMemManager.SetLength(var ADest: WideString; ALength: Int64
   ): Boolean;
 begin
   Result := False;
-  if (FMemLimits.MaxMemReadSize > 0) and (ALength * 2 > FMemLimits.MaxMemReadSize) then begin
+  if (ALength < 0) or
+     ( (FMemLimits.MaxMemReadSize > 0) and (ALength * 2 > FMemLimits.MaxMemReadSize) )
+  then begin
     FLastError := CreateError(fpErrReadMemSizeLimit);
     exit;
   end;