#56 FastMM4 crashes on win64 platform

[Anonymous]

Simple application to produce crash (Access Violation)
FastMM4 must be used in FullDebugMode

program CrashFastMM4;

uses
FastMM4,
Generics.Defaults;

type

IMyInterface = interface
['{DA9A7D06-C9D8-4220-9981-4E48EDC3CEEB}']
end;

TMyInterfaceImplementation = class(TSingletonImplementation, IMyInterface)
end;

TMyObject = class(TObject, IMyInterface)
private
FMyInterface: TMyInterfaceImplementation;
function GetMyInterface: TMyInterfaceImplementation;
public
constructor Create;
destructor Destroy; override;

property MyInterface: TMyInterfaceImplementation read GetMyInterface implements IMyInterface;
end;

constructor TMyObject.Create;
var I: IMyInterface;
begin
I:=Self;
end;

destructor TMyObject.Destroy;
begin
FMyInterface.Free;
inherited;
end;

function TMyObject.GetMyInterface: TMyInterfaceImplementation;
begin
if FMyInterface=nil then
FMyInterface:=TMyInterfaceImplementation.Create; // <-----------CrashPoint @ system._GetMem (MemoryManager.GetMem(Size));
Result:=FMyInterface;
end;

begin
TMyObject.Create.Free;
end.

[Pierre le Riche]

Hi,

I've traced the crash to a Windows API call (CaptureStackBackTrace). At this point I suspect that the 64-bit compiler is doing something wrong with the stack frame setup, because I would not expect CaptureStackBackTrace to crash. I'll investigate further and open a QC report if need be.

Thanks,
Pierre

[Pierre le Riche]

The following code also produces the crash (without FastMM4):

program x64InterfaceCrash;

{$APPTYPE CONSOLE}

uses
Vcl.Dialogs,
Generics.Defaults;

type

IMyInterface = interface
end;

TMyInterfaceImplementation = class(TSingletonImplementation, IMyInterface)
end;

TMyObject = class(TObject, IMyInterface)
private
FMyInterface: TMyInterfaceImplementation;
function GetMyInterface: TMyInterfaceImplementation;
public
constructor Create;

property MyInterface: TMyInterfaceImplementation read GetMyInterface implements IMyInterface;
end;

constructor TMyObject.Create;
var
I: IMyInterface;
begin
I := Self;
end;

function TMyObject.GetMyInterface: TMyInterfaceImplementation;
var
LStackTrace: Pointer;
begin
ShowMessage('This crashes under x64.');
Result := nil;
end;

begin
TMyObject.Create;
end.