[SR-15690] Static linking on linux fails when using new Concurrency features without importing Dispatch

[swift-ci]

Previous ID	SR-15690
Radar	rdar://problem/87165056
Original Reporter	t089 (JIRA User)
Type	Bug

Environment

Swift version 5.5.2

Docker: swift:5.5.2-focal

Additional Detail from JIRA

Votes	1
Component/s
Labels	Bug
Assignee	@drexin
Priority	Medium

md5: 419a2a530bb784aa387000ea2cfc2cf0

Issue Description:

Given this swift executable program

# app.swift
@main
struct App {
  static func main() async throws {
    print("Hello")
    try await Task.sleep(nanoseconds: 1_000_000_000)
    print("Bye!")
  }
}

On linux, you cannot build a binary with{{}}

swift build -c release --static-swift-stdlib

{{}}Because of

error: link command failed with exit code 1 (use -v to see invocation)
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalImpl(swift::Job*): error: undefined reference to '_dispatch_queue_attr_concurrent'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalImpl(swift::Job*): error: undefined reference to '_dispatch_queue_attr_concurrent'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalImpl(swift::Job*): error: undefined reference to 'dispatch_queue_attr_make_with_qos_class'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalImpl(swift::Job*): error: undefined reference to 'dispatch_queue_create'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalImpl(swift::Job*): error: undefined reference to 'dispatch_queue_set_width'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalImpl(swift::Job*): error: undefined reference to 'dispatch_release'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to 'dispatch_time'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to 'dispatch_after_f'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to '_dispatch_queue_attr_concurrent'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to '_dispatch_queue_attr_concurrent'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to 'dispatch_queue_attr_make_with_qos_class'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to 'dispatch_queue_create'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to 'dispatch_queue_set_width'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueGlobalWithDelayImpl(unsigned long long, swift::Job*): error: undefined reference to 'dispatch_release'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueMainExecutor: error: undefined reference to '_dispatch_main_q'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueMainExecutor: error: undefined reference to '_dispatch_main_q'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueMainExecutorImpl(swift::Job*): error: undefined reference to '_dispatch_main_q'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function swift_task_enqueueMainExecutorImpl(swift::Job*): error: undefined reference to '_dispatch_main_q'
/usr/lib/swift_static/linux/libswift_Concurrency.a(GlobalExecutor.cpp.o):GlobalExecutor.cpp:function dispatchEnqueueDispatchAsync(dispatch_queue_s*, void*, unsigned int): error: undefined reference to 'dispatch_async_f'
/usr/lib/swift_static/linux/libswift_Concurrency.a(Task.cpp.o):Task.cpp:function swift_task_asyncMainDrainQueueImpl(): error: undefined reference to 'dispatch_main'
clang-10: error: linker command failed with exit code 1 (use -v to see invocation)

It works if you explicitly import Dispatch.

Swift version 5.5.2

[drexin]

@swift-ci create

[MaxDesiatov]

While you can see this in Swift 5.8.1, it's no longer reproducible on either swiftlang/swift:nightly-jammy swift-DEVELOPMENT-SNAPSHOT-2023-08-27-a, Swift version 5.9-dev (LLVM b8e7c8ee79d44fb, Swift 898f9ef) or swiftlang/swift:nightly-5.9-jammy swift-5.9-DEVELOPMENT-SNAPSHOT-2023-08-25-a Swift version 5.9-dev (LLVM 46ac717ed0ec21c, Swift a129287) Docker images.

Closing as resolved.