iOS status and how-to

[izzyreal]

What is the status of iOS support? I see some issues about iOS and something was merged back in 2020, but the https://github.com/thestk/rtmidi frontpage does not list iOS (yet?).

If (partial) iOS support is already implemented, how does this work? I'm including the following in my CMakeLists.txt:

set(RTMIDI_BUILD_STATIC_LIBS ON)
set(BUILD_SHARED_LIBS OFF)
set(RTMIDI_BUILD_TESTING OFF)
set(RTMIDI_TARGETNAME_UNINSTALL "rtmidi_uninstall")

FetchContent_Declare(rtmidi
    GIT_REPOSITORY https://github.com/thestk/rtmidi.git
    GIT_TAG        5.0.0
    SOURCE_DIR     ${CMAKE_SOURCE_DIR}/deps/rtmidi
)

FetchContent_MakeAvailable(rtmidi)

target_link_libraries(MyProject rtmidi)

This works fine for macOS, but when I build for iOS I get

/foo/rtmidi/RtMidi.cpp:43:6: warning: 'TARGET_OS_IPHONE' is not defined, evaluates to 0 [-Wundef-prefix=TARGET_OS_]
#if (TARGET_OS_IPHONE == 1)
     ^
/foo/rtmidi/RtMidi.cpp:890:16: error: use of undeclared identifier 'AudioGetCurrentHostTime'
        time = AudioGetCurrentHostTime();
               ^
/foo/rtmidi/RtMidi.cpp:893:14: error: use of undeclared identifier 'AudioConvertHostTimeToNanos'
      time = AudioConvertHostTimeToNanos( time );

and a bunch more errors.

Many thanks in advance.

[izzyreal]

For anyone reading this, for now I've resolved this by doing the below in my CMakeLists.txt:

if (IOS)
    target_compile_definitions(rtmidi PRIVATE TARGET_OS_IPHONE=1)
endif()

But setting this is actually the responsibility of #include <TargetConditionals.h> as far as I know. So I doubt this is the way to go. Not sure if I should do something different on my end, or if there's in issue in rtmidi.

PS: I first tried to #include <TargetConditionals.h> before including RtMidi.h, but this did not help.

[GarrettFleischer]

I'm completely lost here... Could you perhaps give some more details on how to set this up? Thank you

[izzyreal]

@GarrettFleischer What is your issue precisely? For what it's worth, here's my static lib's CMakeLists.txt where you can see

target_compile_definitions(rtmidi PRIVATE TARGET_OS_IPHONE=1)

in context: https://github.com/izzyreal/mpc/blob/ee500b24c64b3bff438c533711c539541343c8ef/CMakeLists.txt#L127

[GarrettFleischer]

@izzyreal thank you for the response, I was able to do it through creating a new xcode project