[vcpkg] VCPKG_APPINSTALL_DEPS install dependencies on install #1653

[sandercox]

This fixes the issue of #1653 - CMake: provide option to deploy DLLs on install() like VCPKG_APPLOCAL_DEPS

The option is VCPKG_APPINSTALL_DEPS only works on Windows platforms and takes the logic used in the add_executable / add_library part of the post build step to determine the libraries during install.

[BillyONeal]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[BillyONeal]

Can you add a test of some sort?

[BillyONeal]

Instead of using OutVariable and ignoring the results you probably want to record this and print the output on failure. (using OUTPUT_VARIABLE and RESULT_VARIABLE)

[BillyONeal]

Should this powershell be the one vcpkg fetch grabs somehow?

[sandercox]

Maybe better, but this is just some copy & paste from the code in add_executable with minimal changes.

[BillyONeal]

Quoth @ras0219 @ras0219-msft perhaps we should create a new function to do this rather than overriding install.

[ras0219]

Thanks for the PR!

I think it would be best to first introduce this functionality as an explicit function users can call -- this does mean it won't "just work", but there are some additional considerations with the install command that don't apply to our existing build-only behavior (e.g. how does it interact with cpack?).

If it proves successful, then we can look at making it more automatic.

[sandercox]

I must confess that I have no experience with CPack myself so I have no idea if this might interfere. I'm ok with a separate command (but that would probably just mean I'd override install in my own projects CMakeLists).

What do you think of the following name and usage for that:
vcpkg_instal_local_dependencies(<list of targets> [DESTINATION path])
So you give it a list of targets (like install is taking and have the option to specify the DESTINATION path for these targets. We can then use the built-in cmake parser for arguments to it would clean up the code quite a bit.

[BillyONeal]

Ping @ras0219

[ras0219]

That would be fine, though please name it x_vcpkg_install_local_dependencies() to clarify that it is an experimental community component.

I'd also recommend that the list of targets is grouped into a "TARGETS" parameter

[sandercox]

Using TARGETS parameter as suggested. Renamed function and done some cleanup. Also made the optional config setting an experimental one with the x_ prefix.

Wondering though if we should drop the setting as the command is now experimental anyway and no automatic install is happening as we're not overriding the default cmake install function anymore.

[BillyONeal]

Thanks for your contribution!