Visual Studio 2015 运行时依赖项或如何摆脱 Universal CRT？

Question

Compiled couple of .dll's using visual studio 2015, and tried to deploy on some older windows 7 / 64 bit. Tried also to guess which dll's are needed for application to start and copied MSVCP140.DLL & VCRUNTIME140.DLL - but application could not load vs2015 dll. Started to analyze what is wrong - and dependency walker showed dependencies from following dll's:

API-MS-WIN-CRT-MATH-L1-1-0.DLL
API-MS-WIN-CRT-HEAP-L1-1-0.DLL
API-MS-WIN-CRT-CONVERT-L1-1-0.DLL
API-MS-WIN-CRT-STRING-L1-1-0.DLL
API-MS-WIN-CRT-STDIO-L1-1-0.DLL
API-MS-WIN-CRT-RUNTIME-L1-1-0.DLL
API-MS-WIN-CRT-FILESYSTEM-L1-1-0.DLL
API-MS-WIN-CRT-TIME-L1-1-0.DLL

This was especially surprising since to my best understanding CRT is responsible for starting dll/exe, it does not provide any higher level services.

Ok, tried to figure out how to get rid of them or at least to minimize.

Found one article: https://blogs.msdn.microsoft.com/vcblog/2015/03/03/introducing-the-universal-crt/

It mentions about release static libraries - so I thought that I could link against them and get rid from *L1-1-0.DLL* dependency hell, but no matter what I have tried - I had no success. I've tried to link against libvcruntime.lib, libucrt.lib, libcmt.lib, tried to disable using linker option "/nodefaultlib:vcruntime.lib", and even tried to add include directory $(UniversalCRT_IncludePath), and also overriding some of define's as I have tried to guess they works - none of my attempts helped.

As an intermediate solution I've fall back to using Visual studio 2013, where CRT dll's are only two: msvcp120.dll, msvcr120.dll.

Of course you will probably recommend to install Visual studio 2015 run-times, but one of our requirement is to support standalone executable - which works without any installation - so additional installation is out of question for now.

Can you recommend me anything else than to wait Visual studio 2017 to arrive ?

Answer 1

I was able to solve this by setting the C/C++ > Code Generation > Runtime Library compiler option

• For Debug: from /MDd to /MTd
• For Release: from /MD to /MT

This removed all the API-MS-WIN-CRT-* and runtime dll references and caused all the CRT code to be statically linked.

Details on the new VS2015 Universal CRT (dynamic and static) are here: https://msdn.microsoft.com/en-us/library/abx4dbyh.aspx

Answer 2

I too was fighting with statically linking a solution with multiple components/project library dependencies importing functions from various parts of the MSVCRT, UCRT and Kernel. The hope was the resulting EXE could be just copied around where it was needed (it was no product which would justify a full MSI installation).

After almost giving-up I found the best solution was the follow the guidelines hidden in the Universal C Runtime announcement , specifically:

We strongly recommend against static linking of the Visual C++ libraries, for both performance and serviceability reasons

Just remove all the "special" linker options you tried, drop-back to /MT|/MD (Multi-Threaded CRT DLL Release|Debug) runtime library choice and it works everywhere, eg newer Windows 10 workstations, 2012 R2 servers and Windows 7). Just install/redistribute MSVCRT (VC_Redist*.exe) and KB2999226 (UCRT via Windows Update) as Microsoft tell us to do, because as they also say:

The Universal CRT is a component of the Windows operating system . It is included as a part of Windows 10, starting with the January Technical Preview, and it is available for older versions of the operating system via Windows Update.

So logically the only additional deployment dependency our C++ solutions add for the customer is the MSVCRT, because the UCRT should already be there on up-to-date/well maintained machines. Of course it adds a bit of uncertainty; you can't just copy the EXE and run on any machine, good or bad.

If you produce a decent deployment package like an MSI then it's straightforward to include when you have tools like WIX. Also to note is since the recent SDK you can include the 40-odd DLLs locally, but that doesn't satisfy the security update principle so I wouldn't do that.

This is really the only supported way to do it, see another example here . This article also suggests we link against "mincore_downlevel.lib" which is an important tip, crucial to whether you get these "api-ms-win*" missing DLL errors. For example:

1. Project SDK version set to 10, link with mincore.lib = Runs only on Windows 10, but not 8.1/2012 R2 or Windows 7/2008 R2 server.
2. Project SDK version set to 8.1, link with mincore.lib = Runs on both Windows 10 and 8.1/2012 R2 server, but not Windows 7/2008 R2 server.
3. Project SDK version set to 10, link with mincore_downlevel.lib = Runs on all!

In summary:

1. Do not link statically, leave the default DLL C runtimes selected in the project settings.
2. You don't need the old SDKs, can develop with the latest Windows 10 SDK, but you must link with "mincore_downlevel.lib" not "mincore.lib" if you want to support older Windows versions.
3. For ease of use, add this to your targetver.h or stdafx.h which also documents your choice (remove the other line):

// Libraries
#pragma comment(lib, "mincore.lib")             // Lowest OS support is same as SDK
#pragma comment(lib, "mincore_downlevel.lib")   // Support OS older than SDK

Answer 3

(Updated 11.10.2016).

It's possible to get rid of universal CRT by linking it statically, I'll get to it later on, but let's take a look if you continue to use universal CRT as such.

According to article https://blogs.msdn.microsoft.com/vcblog/2015/03/03/introducing-the-universal-crt/ - it's possible to launch your application using universal crt dll distributables from following folder: C:\\Program Files (x86)\\Windows Kits\\10\\Redist\\ucrt\u003c/code>

There are 41 files totally in list with 1.8 Mb size in total. (example for 64-bit platform)

Of course it's not enough, you will need additionally vcruntime140.dll & msvcp140.dll coming from following folder: C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\redist\\x64\\Microsoft.VC140.CRT

So after that you will ship totally 43 additional dll's besides your application.

It's also possible to statically compile ucrt library inside your application after which you will not need 43 dll's - but whether static link will for after linking or not - depends on your application - how many dll's and which api's are in use. Generally after ucrt gets linked into two different dll's they don't necessarily share same globals with each other - which can results in errors.

You need to link against vcruntime.lib / msvcrt.lib, but it's not sufficient - there are extra _VCRTIMP= and _ACRTIMP= defines which needs to be disabled from pulling functions from ucrt.

If you're using premake5 you can configure your project like this:

defines { "_VCRTIMP="}
linkoptions { "/nodefaultlib:vcruntime.lib" }
links { "libvcruntime.lib" }

followed by:

defines { "_ACRTIMP="}
linkoptions { "/nodefaultlib:msvcrt.lib" }
links { "libcmt.lib" }

Defines are not documented by Microsoft - so it's possible that it's subject to change in future.

Besides your own projects, you will need to re-compile all static libraries which are in use in your projects.

As for boost libraries - I've managed to compile boost as well, using b2.exe boostrapper

boost>call b2 threading=multi toolset=msvc-14.0 address-model=64 --stagedir=release_64bit --build-dir=intermediate_64but release link=static,shared --with-atomic --with-thread --with-date_time --with-filesystem define=_VCRTIMP= define=_ACRTIMP=

When troubleshooting linking problems - notice that unresolved __imp* function names from because of dllimport keyword usage - and if you link against libvcruntime.lib, you should not have any __imp* references.

Answer 4

I was too struggled a lot finding out the run time DLLs required to run an application which was built in Visual Studio 2015.

Here I found the following things which allow VS-2015 built application to run.

• Download the redistributable from https://www.microsoft.com/en-us/download/details.aspx?id=52685
• Place the msvcp140d.dll, vccorlib140d.dll, vcruntime140d.dll & ucrtbased.dll.

Note : Place the dlls versions according to your system processor's architecture(x86, x64..).

Answer 5

设置：配置属性 - 高级 - MFC 的使用 - “在静态库中使用 MFC”对我有用（使用控制台应用程序 - 而不是 MFC/ATL 应用程序本身）。

Answer 6

If you're not trying to replace the Runtime with your own then it doesn't matter whether

• You have Runtime Typing enabled/disabled
• You have C++ Exceptions enabled/disabled
• Whether you have the Runtime Library set to Multithreaded DLL or not (setting it to non-DLL is still building it into your binary)

The only thing you need to ensure is that you don't use any of its capabilities and Visual Studio automatically doesn't link to it. Ie. No asserts, no calls to anything in string.h or stdio.h, nothing. Anything the compiler can replace with its own intrinsics tho is ok, as are compiler checks like static_assert.