VSG Linking issue

[John38F]

Hello ,

I'm starting to learn VSG , so please forgive me if I missed something obvious...
I'm facing an issue when trying to link against VSG in my app.

I'm developing under Windows 10 with VS2022.
I've complied latest VSG release with VS2022 and "vsg.lib" has successfully been generated (both Release and Debug).

I've also added "vsg.lib" in VS2022 linker params "Additional Dependencies" of my app.
Compilation is smooth, so headers are found.

But I got many linker errors :

Severity Code Description Project File Line Suppression State Details
Error LNK2001 unresolved external symbol vkCmdPushConstants eView C:\eView\vsg.lib(RecordTraversal.obj) 1
Error LNK2001 unresolved external symbol vkCmdPushConstants eView C:\eView\vsg.lib(PushConstants.obj) 1
Error LNK2001 unresolved external symbol vkBeginCommandBuffer eView C:\eView\vsg.lib(CommandGraph.obj) 1

I can't figure out where the issue comes from .
Any suggestion would be greatly appreciated ... :)

Many thanks !
John F

[AnyOldName3]

That looks like you're not linking with vulkan-1.lib, which should be something CMake sets up automatically. What did you do to set up your build system in the first place?

[John38F]

You're definitely right !!
I've added vulkan-1lin to dependencies list : works like a charm now :)

Many thanks for your help !

[AnyOldName3]

If you're adding it manually, it's almost certainly going to break again the next time a build requires CMake to re-run. You need to work out why it wasn't added automatically like it was supposed to be.

[John38F]

I meant the vulkan-1.lib linking dependency was missing in my app Property/Linker/Input.

[AnyOldName3]

So you made your own solution files instead of having CMake do it for you? That's generally considered a bad idea exactly for this kind of reason. The VSG's CMake generates files like vsgConfig.cmake that are supposed to explain to your app's CMake what settings must be set, and it's typically much more reliable and less effort to let it do that than to try and figure everything out yourself.

[John38F]

Works fine now.

[John38F]

Hello, thanks for your answer.

As you guessed, I'm not familiar with CMake.
So, I'm not sure I fully understand what you explain.

Here is exactly what I made.
I wanted to add 3D capabilities to an existing app.
So I've installed LunarG SDK and I've compiled VSG.

Then, I've modified my existing C++ app the "good old way" :

• I've added path to VSG headers.
• I've added paths to the new required VSG and Vulkan libs.
• I've added vsg.lib and vulkan-1.lib linking dependencies to my app.
  It works fine.

From your message, I understand that CMake is able to perform those 3 steps in an easier and more reliable way, correct?
If yes, I have no idea to how to let VS2022 know that I want to use vsgConfig.cmake ...

Regards,

[AnyOldName3]

It might not be the most straightforward approach for an existing app, but it's usual to put the information that would go in a .sln/.vcxproj file into a CMake script (except for the bits that CMake can figure out on its own), and have CMake generate the Visual Studio solution for you. Microsoft seem to be keen on phasing out handmade solution files in favour of CMake-generated ones, and their documentation for including libraries built with CMake is all written under the assumption your application uses CMake, too.

That would mean that you'd write CMake to replace your existing build system.

Another, slightly hacky option is to create a dummy CMake project that includes VSG and see which flags it uses. E.g. from a directory with a CMakeLists.txt containing

cmake_minimum_required(VERSION 3.20)
project(Dummy LANGUAGES CXX)
find_package(vsg CONFIG REQUIRED)
add_executable(Dummy dummy.cpp)
target_link_libraries(Dummy PRIVATE vsg::vsg)

and dummy.cpp containing

int main()
{
    return 0;
}

you can run

cmake -DCMAKE_PREFIX_PATH=C:\path\to\VSG .
echo "Debug build flags:"
cmake --build . --config Debug -- -clp:ShowCommandLine
echo "Release build flags:"
cmake --build . --config Release -- -clp:ShowCommandLine

and it'll tell you the right flags.