[stdlib] adds nullability type specifier to NSStringGetCStringTrampoline

[nordicio]

Adds missing nullability specifier to the buffer passed to _swift_stdlib_NSStringGetCStringTrampoline.

Output from building from scratch on macOS 10.14.1 with the toolchain from Xcode 10.1 (10B61).

[108/1619] Building CXX object stdlib/...cosx-x86_64.dir/FoundationHelpers.mm.o
In file included from <path>swift/stdlib/public/stubs/FoundationHelpers.mm:23:
<path>swift/stdlib/public/stubs/../SwiftShims/CoreFoundationShims.h:137:61: warning: pointer is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified) [-Wnullability-completeness]
                                         _swift_shims_UInt8 *buffer,
                                                            ^
<path>swift/stdlib/public/stubs/../SwiftShims/CoreFoundationShims.h:137:61: note: insert '_Nullable' if the pointer may be null
                                         _swift_shims_UInt8 *buffer,
                                                            ^
                                                              _Nullable 
<path>swift/stdlib/public/stubs/../SwiftShims/CoreFoundationShims.h:137:61: note: insert '_Nonnull' if the pointer should never be null
                                         _swift_shims_UInt8 *buffer,
                                                            ^
                                                              _Nonnull 
1 warning generated.

According to documentation and auto-completion in Xcode this pointer should be _Nonnull:

[@"" getCString:(nonnull char *) maxLength:(NSUInteger) encoding:(NSStringEncoding)];

[Catfish-Man]

Yup, thanks for catching this! Unclear how it compiled when I landed that >.<

[Catfish-Man]

@swift-ci please test and merge

[Catfish-Man]

@swift-ci please test and merge

[compnerd]

@swift-ci please test Linux platform

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 452230a

[nordicio]

/usr/bin/ld.gold: error: /home/buildnode/jenkins/workspace/swift-PR-Linux/branch-master/buildbot_linux/none-swift_package_sandbox_linux-x86_64/usr/lib/swift_static/linux/libdispatch.a(apply.c.o): requires unsupported dynamic reloc 11; recompile with -fPIC

🤔 Not sure what to do about that?

[harlanhaskins]

@swift-ci please test Linux platform

[harlanhaskins]

Tests pass on macOS and Linux.

[harlanhaskins]

Thanks @nordicio!

[nordicio]

Thank you, @harlanhaskins and @Catfish-Man :)