Should the 5.0 branch currently report a language version of at least 5.0?

bjhomer · October 10, 2018, 4:23pm

I'm working on the implementation of a change that would go into Swift 5. It appears that the following check is failing:

 if (cs.getTypeChecker().getLangOpts().isSwiftVersionAtLeast(5)) {
   // Do something
}

So it appears that the compiler does not believe that the Swift version is at least 5 on the swift-5.0-branch. Is that expected? Is there a better way to be checking for the Swift language version?

Alejandro · October 10, 2018, 4:28pm

github.com

apple/swift/blob/swift-5.0-branch/CMakeLists.txt#L131


   FALSE)


set(SWIFT_ANALYZE_CODE_COVERAGE FALSE CACHE STRING
"Build Swift with code coverage instrumenting enabled [FALSE, NOT-MERGED, MERGED]")
set_property(CACHE SWIFT_ANALYZE_CODE_COVERAGE PROPERTY
STRINGS FALSE "NOT-MERGED" "MERGED")


# SWIFT_VERSION is deliberately /not/ cached so that an existing build directory
# can be reused when a new version of Swift comes out (assuming the user hasn't
# manually set it as part of their own CMake configuration).
set(SWIFT_VERSION "4.2")


set(SWIFT_VENDOR "" CACHE STRING
"The vendor name of the Swift compiler")
set(SWIFT_COMPILER_VERSION "" CACHE STRING
"The internal version of the Swift compiler")
set(CLANG_COMPILER_VERSION "" CACHE STRING
"The internal version of the Clang compiler")


# Indicate whether Swift should attempt to use the lld linker.
set(SWIFT_ENABLE_LLD_LINKER TRUE CACHE BOOL

The compiler has not yet been bumped to Swift 5 yet. The same is on master.

benrimmington · October 10, 2018, 4:28pm

https://github.com/apple/swift/pull/18853

hamishknight · October 10, 2018, 4:37pm

Note also that you're checking the effective language version, which takes into account compatibility mode versions. Therefore, passing the option -swift-version 5 will allow the check to succeed even though the compiler version hasn't been bumped yet.

bjhomer · October 10, 2018, 4:39pm

That's true. It does mean, however, that my tests are failing because I'm writing them under the expectation of Swift 5 behavior. Is there a better way to handle this? It seems like most of the SILGen tests, at least, are just operating on the latest standard version of Swift.

hamishknight · October 10, 2018, 6:52pm

Does passing -swift-version 5 to your tests not solve the problem? e.g (from generic_casts.swift):

// RUN: %target-swift-emit-silgen -swift-version 5 -module-name generic_casts -Xllvm -sil-full-demangle -enable-sil-ownership %s | %FileCheck --check-prefix=CHECK --check-prefix=CHECK-%target-runtime %s

It's worth noting that currently tests by default use -swift-version 4, so even if the compiler version were bumped, you would still need to pass -swift-version 5 to test a Swift 5 mode specific change.

bjhomer · October 10, 2018, 6:40pm

Ah, I see. I hadn't seen how to update the swift-version on a test-by-test basis. Thanks for pointing me in the right direction.

hamishknight · October 10, 2018, 6:53pm

No worries, sorry I should have provided an example (just edited to provide one that'll hopefully be of use to someone else).