Extensions on system types (like `stat` or `time_t`) go missing in importing module

[helje5]

Macro (and NIO) itself works fine, but stat and timespec extensions in xsys and fs do not make it through to connect in MacroExpress.

swift build --destination /usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/destination.json
/Users/helge/dev/Swift/Macro/MacroExpress/Sources/connect/ServeStatic.swift:129:16: error: value of type 'stat_struct' (aka 'stat') has no member 'isDirectory'
      if lStat.isDirectory() {
         ~~~~~ ^~~~~~~~~~~

This is declared just fine in Macro/fs/Utils/StatStruct.swift.

[helje5]

This can be reproduced with two simple packages:

mkdir LibBase LibDep
cd LibBase && swift package init --type library && git init && cd ..
cd LibDep && swift package init --type library && cd ..

LibBase.swift:

#if os(Windows)
  import WinSDK
#elseif os(Linux)
  import struct Glibc.timespec
  public typealias timespec = Glibc.timespec
  
  public extension timespec {
    static func demo() -> timespec { return timespec() }
  }
#else // Darwin
  import struct Darwin.timespec
  public typealias timespec = Darwin.timespec
  
  public extension timespec {
    static func demo() -> timespec { return timespec() }
  }
#endif // Darwin

libdep Package.swift:

// swift-tools-version:5.3
import PackageDescription

let package = Package(
    name: "LibDep",
    dependencies: [ .package(url: "../LibBase", .branch("master")) ],
    targets: [ .target(name: "LibDep", dependencies: [ "LibBase" ]) ]
)

LibDep.swift:

import LibBase

func doIt() {
  let x = timespec.demo()
  print("X:", x)
}

Compile:

brew install spmdestinations/tap/spm-dest-5.3-x86_64-ubuntu16.04
swift build --destination \
  /usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/destination.json
Zini18:LibDep helge$ swift build --destination /usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/destination.json
/Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/Sources/LibDep/LibDep.swift:4:20: error: type 'timespec' has no member 'demo'
  let x = timespec.demo()
          ~~~~~~~~ ^~~~

Doing the compilation on the host (or in Docker) works just fine.

[helje5]

Call one looks good (--emit-module mode?):

/usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/swift.xctoolchain/usr/bin/swiftc \
  -module-name LibDep -incremental -emit-dependencies -emit-module \
  -emit-module-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.swiftmodule \
  -output-file-map /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.build/output-file-map.json \
  -parse-as-library \
  -c /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/Sources/LibDep/LibDep.swift \
  -I /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug \
  -target x86_64-unknown-linux -swift-version 5 -enable-batch-mode \
  -index-store-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/index/store \
  -use-ld=lld \
  -tools-directory /usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/swift.xctoolchain/usr/bin \
  -sdk /usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/x86_64-ubuntu16.04.sdk \
  -Onone -enable-testing -g -j12 -DSWIFT_PACKAGE -DDEBUG \
  -module-cache-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/ModuleCache \
  -parseable-output -color-diagnostics

Seems to have the right switches on.

Call two fails:

/usr/local/Cellar/spm-dest-5.3-x86_64-ubuntu16.04/2020-07-31/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/swift.xctoolchain/usr/bin/swift \
  -frontend -c \
  -primary-file /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/Sources/LibDep/LibDep.swift \
  -emit-module-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.build/LibDep~partial.swiftmodule \
  -emit-module-doc-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.build/LibDep~partial.swiftdoc \
  -emit-module-source-info-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.build/LibDep~partial.swiftsourceinfo \
  -emit-dependencies-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.build/LibDep.d \
  -emit-reference-dependencies-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.build/LibDep.swiftdeps \
  -target x86_64-unknown-linux \
  -disable-objc-interop \
  -sdk /usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/x86_64-ubuntu16.04.sdk \
  -I /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug \
  -color-diagnostics -enable-testing -g \
  -module-cache-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/ModuleCache \
  -swift-version 5 -Onone -D SWIFT_PACKAGE -D DEBUG \
  -enable-anonymous-context-mangled-names \
  -parse-as-library \
  -module-name LibDep \
  -o /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/LibDep.build/LibDep.swift.o \
  -index-store-path /Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/.build/x86_64-unknown-linux/debug/index/store \
  -index-system-modules
/Users/helge/Dropbox/dev/Tests/RepoXIssue/LibDep/Sources/LibDep/LibDep.swift:4:20: error: type 'timespec' has no member 'demo'
  let x = timespec.demo()
          ~~~~~~~~ ^~~~

Though it does pretty much correct as well? 🤔

[helje5]

Ready to use tarball to demo the issue: https://helgehess.eu/patches/RepoXIssue-2020-08-04-1.tgz

[helje5]

It's not related to the ifdef's, same error w/ this LibBase.swift:

import Glibc
public typealias timespec = Glibc.timespec
public extension timespec {
  static func demo() -> timespec { return timespec() }
}

[helje5]

Hm, it is restricted to such libc types though, e.g. an extension to Formatter DOES work.

[helje5]

Adding

  -resource-dir /usr/local/lib/swift/dst/x86_64-unknown-linux/swift-5.3-ubuntu16.04.xtoolchain/x86_64-ubuntu16.04.sdk/usr/lib/swift \

gives

<unknown>:0: error: missing required module 'SwiftShims'

Looks like the Ubuntu SDK is missing the shims.