Xcode: Control emission of EFFECTIVE_PLATFORM_NAME
When building with multiple SDKs within one project Xcode requires the usage of ${EFFECTIVE_PLATFORM_NAME} to put temporary and build outout into separate directories. For example an iOS device and simulator build use two different SDKs (iphoneos and iphonesimulator).
In the past cmake tries to detect embedded toolchains that could possibly use simulators and emitted EFFECTIVE_PLATFORM_NAME (EPN) at the proper locations. In #16253 (closed) Mark noticed that if he uses macosx and iphoneos in combination the necessary EPN is not emitted. This is because CMake by default assumes macosx SDK which does not trigger EPN emission.
The fist naive approach - enabling EPN unconditionally revealed that
then the EPN leaks into generator expressions like $<TARGET_FILE:xxx>
which might be a regression and thus is unacceptable.
The next approach was to add an CMake property to enable EPN emission unconditionally. This solved the reported problem.
But the EPN leakage also happened for the embedded toolchains already without anyone noticing. So the control property was turned into a tri-state one:
- No definition: EPN is activated for embedded toolchains like before
- ON: EPN is always emitted
- OFF: EPN is never emitted
That approach gives the user the chance to disable EPN for embedded toolchains and restores generator expression functionality for those.
Closes #16253 (closed)