make cmake work on macos

[nathantsoi]

Summary

cmake's downloads (ctags and toolchain) were not working on macos.

Validation

tested on mac os 13.4.1 and cmake 3.26.4

[nathantsoi]

One caveat here. I found that the ctags for macOS on the Arduino github releases page is not 64-bit, however, the ctags binary distributed in the Arduino app is... so I also had to:

cp /Applications/Arduino.app/Contents/Java/tools-builder/ctags/5.8-arduino11/ctags ~/.Arduino_Core_STM32_dl/d726370579d207be3e43211ba220e5b1/dist/ctags

I'm not sure if a 64-bit ctags binary is available outside of the Arduino installer, but this would be a better solution.

[massonal]

From cmake_host_system_information, redirecting to CMAKE_HOST_SYSTEM_NAME:

Name of the OS CMake is running on.

On systems that have the uname command, this variable is set to the output of uname -s. Linux,
Windows, and Darwin for macOS are the values found on the big three operating systems.

Did you really observe the value "macOS"?! (That's fine, but it would mean the docs are confusing...)

As for the caveat you outline: ctags-5.8-arduino11-x86_64-apple-darwin.zip is what you're looking for, no? Or do you mean they packaged a 32-bits app with a 64-bits name?

[fpistm]

As an extra information: which Mac-OS version you used ?

[nathantsoi]

MacOS version is Ventura 13.4.1

And yes, @massonal, the x86_64 zip contains an i386 executable:

$ wget https://github.com/arduino/ctags/releases/download/5.8-arduino11/ctags-5.8-arduino11-x86_64-apple-darwin.zip
$ unzip ctags-5.8-arduino11-x86_64-apple-darwin
Archive:  ctags-5.8-arduino11-x86_64-apple-darwin.zip
  inflating: ctags
$ file ctags
ctags: Mach-O executable i386

vs. The correct, 64-bit version included with the arduino app:

$ file /Applications/Arduino.app/Contents/Java/tools-builder/ctags/5.8-arduino11/ctags
/Applications/Arduino.app/Contents/Java/tools-builder/ctags/5.8-arduino11/ctags: Mach-O 64-bit executable x86_64

[fpistm]

@nathantsoi you don't answer this question from @massonal

Did you really observe the value "macOS"?! (That's fine, but it would mean the docs are confusing...)

On our side a MacBook Pro with Monterey v12.6.1 is used to validate and result of uname -s is Darwin.
It seems strange the result was changed and CMAKE documentation was not updated.
Looking on Ventura, it is always based on Darwin kernel. Ventura version 13.4.1 is based on 22.5.0 Darwin kernel.

[nathantsoi]

Correct, I get the string macOS:

(Snippet from FindArduinoCtags.cmake)

cmake_host_system_information(
  RESULT HOSTINFO
  QUERY OS_NAME OS_PLATFORM
)
list(GET HOSTINFO 0 HOST_OS)
list(GET HOSTINFO 1 HOST_ARCH)
message(HOST_OS=${HOST_OS})

Results in:

HOST_OS=macOS

[massonal]

Thanks for the confirmation @nathantsoi.
Then, it seems like it's a bug on CMake side (they probably forgot to update the doc at some point? 🤷 )
I suggest you raise a ticket by them... https://github.com/Kitware/CMake#reporting-bugs

As for the issue you have with ctags, do you see any functional impact from the 32-bits version?
I think here we'll try to stick to official releases as much as possible...
You can nonetheless raise an issue there too to ask for clarification! https://github.com/arduino/ctags

My final take on this PR: it does not introduce any bug, so it may be merged safely.
I'll let @fpistm decide on whether to merge it or wait on upstream fixes in the tools.

[massonal]

This code is bug-less and harm-less.
Merging it is a matter of policy.

[nathantsoi]

Re. the macOS string, I'll open a ticket w/ cmake.

Re. ctags, I should clarify that the 32-bit version of ctags will not run on macOS 13.x.

Using the https://github.com/arduino/ctags binary results in this error:

/bin/sh: /Users/ntsoi/.Arduino_Core_STM32_dl/d726370579d207be3e43211ba220e5b1/dist/ctags/ctags: Bad CPU type in executable

Hence the need to copy in the 64-bit version from the Arduino.app

Perhaps this can be noted in the cmake setup documentation for now? I am happy to do this if you would like.

[nathantsoi]

Actually, @massonal, I just checked

message(CMAKE_HOST_SYSTEM_NAME=${CMAKE_HOST_SYSTEM_NAME})

And this does yield the documented result: CMAKE_HOST_SYSTEM_NAME=Darwin

Note, this is different from the snippets in ensure_core_deps.cmake and FindArduinoCtags.cmake (#2060 (comment))

[massonal]

That last item with CMAKE_HOST_SYSTEM_NAME really is confusing... cmake_host_system_information does redirect to it.

OS_NAME
New in version 3.10.

See CMAKE_HOST_SYSTEM_NAME

Definitely mention that in the ticket you write to CMake!

[fpistm]

Perhaps this can be noted in the cmake setup documentation for now? I am happy to do this if you would like.

Feel free to submit a PR for that 😉