Add OpenSSL static lib to Visual Studio 2017 project - c++

Question

Do NuGets modify the include and linking paths when added to a project?
My background is with CMake where this stuff was trivial, but I'm now at a company that builds solution files from the ground up and I'm unsure how to properly add the static OpenSSL libs to my project. I'm posting the question to make sure I don't duplicate something or otherwise mess it up.
When I add the openssl-vc141-static-x86_64 to my project, it builds the .lib files and everything, but does not modify the include or linker paths.
I can manually add the linker paths, but because the project I was given doesn't have the typical Release/Debug configurations, I can't use the $(Configuration) macro to point at the target libs - so I end of just pointing at Release. The build works though.
I see there is a .targets file, but it doesn't seem to do anything.
(update)
To be specific, I'm basically building boost's http_server_async.cpp. The linker errors I'm getting are:
Error LNK2019 unresolved external symbol _BIO_free referenced in function "public: __thiscall boost::asio::ssl::context::bio_cleanup::~bio_cleanup(void)" (??1bio_cleanup#context#ssl#asio#boost##QAE#XZ) ESOIPDataScope C:\gitrepo\ALIDB\ESOIPDataScope\DataHandler.obj
Error LNK2001 unresolved external symbol _BIO_free ESOIPDataScope C:\gitrepo\ALIDB\ESOIPDataScope\Listener.obj
... (48 more like this)
When I manually add $(SolutionDir)packages\openssl-vc141-static-x86_64.1.1.0\build\native\lib\Win32\static\Release\libcrypto.lib and
$(SolutionDir)packages\openssl-vc141-static-x86_64.1.1.0\build\native\lib\Win32\static\Release\libssl.lib to be additional dependencies the project compiles.
(/update)
Just for contrast, I added a freeglut NuGet, and noticed that gave my more configuration options (Configuration Properties → Referenced Projects), also, boost seems to have added its linker directories to my project (though I only see that in MSBuild output, not in Configuration Properties->Linker->Command Line)
Is there a proper way to add these projects that I'm missing? Or a proper way to use the targets file? Or maybe the OpenSSL static NuGet just missing something? Or maybe I should just look into vcpkg?

Answer 1

Do NuGets modify the include and linking paths when added to a
project?
Sure. I can tell you explicitly that the nuget imports additional properties into the project through <package_id>.targets or <package_id>.props file, instead of manually adding include path again.
This is a mechanism for nuget packaging to add additional project properties such as library path directly to the project during the installation of the nuget package. More info you can refer to this link.
The <package_id>.targets was created during the process of packing the nuget package.
In other words, this method was designed by the author of the nuget package. And in my side, the file openssl-vc141-static-x86_64.targets exists in this path:
C:\Users\Admin\source\repos\ConsoleApplication25\packages\openssl-vc141-static-x86_64.1.1.0\build\native
also, boost seems to have added its linker directories to my project
(though I only see that in MSBuild output, not in Configuration
Properties->Linker->Command Line)
l think the issue is related to the difference between <package_id>.targets and <package_id>.props. Although using <package_id>.targets does not appear on the property UI, it still works for the whole project.
In more detail
When you install the nuget package into the project, these files are automatically executed. <target_id>.props file is added at the top of the file while .targets is added at the bottom.
When initializing the xxx.vcxproj file, because <package_id> .props is at the head of the file, the property UI can capture the properties in the file, and <package_id> .targets is at the end, so the initialization cannot be captured but still In the project. For the nuget, it uses openssl-vc141-static-x86_64.targets.
In openssl-vc141-static-x86_64.targets file, you can see this:
<ClCompile>
<AdditionalIncludeDirectories>$(MSBuildThisFileDirectory)include\;%
(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
<PreprocessorDefinitions>HAS_LIBTHRIFT;%(PreprocessorDefinitions)
</PreprocessorDefinitions>
</ClCompile>
And l have set the output log to Diagnostic and build the project and found this:
The library path has been added into AdditionalIncludeDirectories by the openssl-vc141-static-x86_64.targets file automatically. So you do not have to worry about it.
Is there a proper way to add these projects that I'm missing? Or a
proper way to use the targets file? Or maybe the OpenSSL static NuGet
just missing something? Or maybe I should just look into vcpkg?
You do not need to worry about it and do not add the include path into project property. This is superfluous and when you have finished installing this nuget package, use it in cpp files directly.
In addition,
For c++ packages installed by nuget, you don't need to add any paths to the project property.
Update 1
The issue is related to your project rather than the nuget package. Exactly because your current project does not have $(Configuration), so in openssl-vc141-static-x86_64.targets, you can see these：
<ItemDefinitionGroup Label="Win32 and vc141 and Debug" Condition="'$(Platform)' == 'Win32' And ( $(PlatformToolset.IndexOf('v141')) > -1 Or '$(PlatformToolset)' == 'WindowsKernelModeDriver8.0' Or '$(PlatformToolset)' == 'WindowsApplicationForDrivers8.0' Or '$(PlatformToolset)' == 'WindowsUserModeDriver8.0' ) And '$(Configuration)' == 'Debug'">
<Link>
<AdditionalLibraryDirectories>$(MSBuildThisFileDirectory)lib\Win32\static\Debug\;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
<AdditionalDependencies>libssl.lib;libcrypto.lib;%(AdditionalDependencies)</AdditionalDependencies>
</Link>
<PostBuildEvent>
<Command>xcopy /Y "$(MSBuildThisFileDirectory)\lib\Win32\dynamic\*-1_1.dll" "$(OutDir)"</Command>
</PostBuildEvent>
</ItemDefinitionGroup>
This is the operation to import specific libssl.lib and libcrypto.Lib into the AdditionalDependencies node. But you can find out that there is a judge condition And '$(Configuration)' == 'Debug', since you do not have $(Configuration),therefore, it always returns false and these libs cannot be automatically imported into AdditionalDependencies.
As a workaround, you should add these lib path manually just as you said.
And l am sure that if you use a project which contains $(Configuration)(Debug or Release), you will not encouter this issue. And most of the C++ nuget packages can be used directly in the project which contains the Configuration node.
l am sure that if you use the $(Configuration) into your project and then reinstall this package(please clean the nuget cache before doing it), you will not face this error.
Also, your screen shot, where did you get that? I don't see anything
like that in the VS output console, or when I run msbuild on the
command line. Is there some way I might have accidentally broken the
default behaviour?
You can set MSBuild project build output verbosity to Diagnostic by Tools-->Options-->Projects and Solutions-->Build and Run.
When you build your project,the Output Window shows thw whole build process and records all the information and then you can search the key fields by the search box on the Output Window.