Re: [Boost-users] Boost.Function __stdcall, __fastcall, etc

Subject: Re: [Boost-users] Boost.Function __stdcall, __fastcall, etc
From: Brian Rowlett (brianjrowlett_at_[hidden])
Date: 2010-04-26 09:23:35

On Sun, Apr 25, 2010 at 11:34 PM, Steven Watanabe <watanabesj_at_[hidden]>wrote:

> AMDG
>
>
> Brian Rowlett wrote:
>
>> I am writing a DLL that gets injected into another process, and creates
>> pointers to the target processes functions. The target process uses all 3
>> calling conventions, __stdcall, __fastcall and __cdecl.
>>  I have created a class whos constructor gets the address of the function,
>> and passes it to the base class boost::function:
>>
>>    template <typename _Signature, enum LibraryId _LibraryId, int _Offset>
>>    class FunctionPointer: protected OffsetPointer, public
>>    boost::function<_Signature>
>>    {
>>    public:
>>        FunctionPointer(void)
>>        :
>>    boost::function<_Signature>( OffsetPointer::_getOffset(_LibraryId,
>>    _Offset )
>>        { return; }
>>    };
>>
>>  I instantiate this with:
>>
>>    FunctionPointer<return_type__stdcall( argument_types ), LibraryId,
>>    Offset> Function;
>>
>>    FunctionPointer<return_type __cdecl( argument_types ), LibraryId,
>>    Offset> Function;
>>
>>  Whatever calling convention Visual Studio is setup to use (__cdecl by
>> default), works just fine. But trying to instantiate it with another calling
>> convention gives the following error:
>>
>>    Error 1 error C2504: 'boost::function<Signature>' : base class
>>    undefined
>>
>>  It seems weird that it would work for some calling conventions, and not
>> others..
>>  Any ideas?
>>
>
> Don't try to specify a calling convention for Boost.Function.
> return_type __cdecl(argument_types) works because it
> is equivalent to return_type(argument_types) which is
> what Boost.Function accepts.  A boost::function should
> be able to store function pointers that use /any/ calling
> convention.
>
> In Christ,
> Steven Watanabe
>
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>

When I don't specify a calling convention, and I compile a Debug build, I
get the following runtime error:

> Run-Time Check Failure #0 - The value of ESP was not properly saved across
> a function call. This is usually a result of calling a function with one
> calling convention with a function pointer declared with a different calling
> convention.
>
I have the option of Aborting, Retrying, and Ignoring.
When I click Retry, it works..

If I compile a Release build instead of a Debug build, it works just fine.
I wonder if it is still having a problem, but is silent about it because its
not a Debug build...

-- 
+ Brian J. Rowlett