Fix Missing api-ms-win-core-path-l1-1-0.dll #224

[takuya-takeuchi]

Hi guys!!
I want to merge my source code to fix #224.
I believe that you have already checked my source code on issue board.
Just in case, please check once again.

I checked my source code by build it on Windows 7 and running on Windows 7, 8.1 and 10.

Check method is the following.
https://github.com/Microsoft/CNTK/wiki/Setup-CNTK-on-Windows#trying-cntk-with-cpu

Test, train and write is completed.

NOTE
On Windows 8 which have no Visual Studio, OS requires Visual C++ Redistributable for Visual Studio 2012. Is it correct? I thought CNTK requires only VS2013 C++.

I never pull request.
So if you have any problem, let me know.

Thank you!!

[msftclas]

Hi @takuya-takeuchi, I'm your friendly neighborhood Microsoft Pull Request Bot (You can call me MSBOT). Thanks for your contribution!

This seems like a small (but important) contribution, so no Contribution License Agreement is required at this point. Real humans will now evaluate your PR.

TTYL, MSBOT;

[alexeyo26]

Takuya, thank you. But this needs a little revision. PathRemoveFileSpec is depreciated and for the good reason: it could cause a buffer overrun. At the same time PathCchRemoveFileSpec, its replacement relies on the dll that was introduced in Win 8.

So, I believe the fix should check OS version and in case its "6.2." or greater, then PathCchRemoveFileSpec should be use. Otherwise PathRemoveFileSpec for older versions. See https://msdn.microsoft.com/en-us/library/windows/desktop/ms724832(v=vs.85).aspx and https://msdn.microsoft.com/en-us/library/windows/desktop/ms724429(v=vs.85).aspx on detecting OS Version

Thank you,
Alexey

[alexeyo26]

Takuya, one more thing. You wrote

On Windows 8 which have no Visual Studio, OS requires Visual C++ Redistributable for Visual Studio 2012. Is it correct? I thought CNTK requires only VS2013 C++.

Are you sure you were compiling on VS 2013 and (even more important) you don't have a mix of VS2012 and VS2013 on your system?

[takuya-takeuchi]

I'm sorry to trouble you.
To brush up source code, please give me your hand.

Are you sure you were compiling on VS 2013 and (even more important) you don't have a mix of VS2012 and VS2013 on your system?

Oh really? I did not know. I never see this condition in wiki.
My system is mix of 2008, 2010, 2012, 2013 and 2015.
OK, but i can prepare system which include only 2013.

Thank you.

[alexeyo26]

Takuya, terribly sorry, This VC++ 2012 dependency has nothing to do with your system and being generated by ACML. I will update setup instructions right away.

Anyway we do NOT recommend of having a mixture of different Visual Studio installations on one machine (don't mix with different VC++ runtime, which is perfectly fine). We mention it here https://github.com/Microsoft/CNTK/wiki/Setup-CNTK-on-Windows#building-cntk

Thank you,
Alexey

[takuya-takeuchi]

Hi Alexey. Thank you for your kindly support.

So, I believe the fix should check OS version and in case its "6.2." or greater, then PathCchRemoveFileSpec should be use. Otherwise PathRemoveFileSpec for older versions.

I tried the following source code on Windows 7.

    if (IsWindows8OrGreater())
    {
        auto hr = PathCchRemoveFileSpec(&path[0], path.size());
        if (hr == S_OK) // done
            path.resize(wcslen(&path[0]));
        else if (hr == S_FALSE) // nothing to remove: use .
            path = L".";
    }
    else
    {
        auto hr = PathRemoveFileSpec(&path[0]);
        if (hr != 0) // done
            path.resize(wcslen(&path[0]));
        else
            path = L".";
    }

But this code occur application crash.
Windows7 does not have api-ms-win-core-path-l1-1-0.dll.
So even if developer was successful to build CNTK on Windows 7, application will crash.

So we cannot use the above code and resolution.

I am not familiar with C++. I guess I may resolve use LoadLibrary to call 2 function based on OS version. Is it ok?
Do you have any idea?

[alexeyo26]

Takuya, then try a different approach based upon dynamic linking. I.e. try to load the dll in question and base the logic on whether you can load it like shown in this example https://msdn.microsoft.com/en-us/library/windows/desktop/ms686944(v=vs.85).aspx

[alexeyo26]

Takuya, thank you a lot! In fact BOTH of your fixes work. The reason the 1st one crashed is the necessity to add api-ms-win-core-path-l1-1-0.dll in "Delay Loaded Dlls" in CNTK project properties (Linker Section).

Your code generated a couple of ideas about a couple of other things we need to fix. We're implementing it now and will tell, when it's there.

And one more thing. When you're working on a Pull Request and make a new Commit, please place a new comment about it in "Conversation" (i.e. here). The reason is GitHub does not notify about new commits to Pull Request, that's why I spotted your new contribution just today and not on Saturday when you have actually made it.

Thank you one more time. We'll tell you about the progress.
Alexey

[takuya-takeuchi]

You are welcome.

A few weeks, I have been excited that I may be able to contribute for open source community.
At same time, It was anxiety. My modification may break something? I may take other developer's time to support to me...

But that was a very good experience.

Thank you, too!!

[alexeyo26]

Takuya, after internal consideration we decided we want to implement _your_ fix, but during these days Master changed in such a way, that our system can't build your pull request (it's based on the version of Master, that is too old). Please, update the master in your fork and submit a new commit - we'll proceed with it ASAP.

Use the code, that is in your second commit (with LoadLibrary())

Thank you,
Alexey

[takuya-takeuchi]

OK, I retrieved latest source and pushed again.

[takuya-takeuchi]

Use the code, that is in your second commit (with LoadLibrary())

Oh, I'm very sorry. I missed the following direction... what should I do?

[alexeyo26]

You did everything right. Don't worry, We're working with your pull request now...

[alexeyo26]

Attention MS Reviewer: Build 3484

[wolfma61]

👍

[alexeyo26]

Attention MS Reviewer: Build 3485

[alexeyo26]

Takuya, thank you a lot for the contribution - it's in Master now. Enjoy CNTK!