Merge pull request swiftlang#1549 from al45tair/eng/PR-123442522

Update driver for fully static Linux.

Author: al45tair

Sources/SwiftDriver/Jobs/GenericUnixToolchain+LinkerSupport.swift

@@ -18,7 +18,8 @@ import struct TSCBasic.AbsolutePath
 extension GenericUnixToolchain {
  private func defaultLinker(for targetTriple: Triple) -> String? {
  if targetTriple.os == .openbsd || targetTriple.os == .freeBSD ||
- targetTriple.environment == .android {
+ targetTriple.environment == .android ||
+ targetTriple.isFullyStaticLinux {
  return "lld"
  }
 

Sources/SwiftDriver/Utilities/Triple+Platforms.swift

@@ -292,7 +292,21 @@ extension Triple {
  return conflatingDarwin ? "darwin" : darwinPlatform.platformName
 
  case .linux:
- return environment == .android ? "android" : "linux"
+ switch environment {
+ case .musl:
+ // The triple for linux-static is <arch>-swift-linux-musl, to distinguish
+ // it from a "normal" musl set-up (ala Alpine).
+ if vendor == .swift {
+ return "linux-static"
+ }
+ fallthrough
+ case .musl, .musleabihf, .musleabi:
+ return "musl"
+ case .android:
+ return "android"
+ default:
+ return "linux"
+ }
  case .freeBSD:
  return "freebsd"
  case .openbsd:

Sources/SwiftDriver/Utilities/Triple.swift

@@ -1032,6 +1032,7 @@ extension Triple {
  case mesa
  case suse
  case openEmbedded = "oe"
+ case swift
 
  fileprivate static func parse(_ component: Substring) -> Triple.Vendor? {
  switch component {
@@ -1067,6 +1068,8 @@ extension Triple {
  return .suse
  case "oe":
  return .openEmbedded
+ case "swift":
+ return .swift
  default:
  return nil
  }
@@ -1711,13 +1714,21 @@ fileprivate extension Array {
  }
 }
 
-// MARK: - Linker support
+// MARK: - Fully static Linux support
 
 extension Triple {
- /// Returns `true` if a given triple supports producing fully statically linked executables by providing `-static`
- /// flag to the linker. This implies statically linking platform's libc, and of those that Swift supports currently
- /// only Musl allows that reliably.
- var supportsStaticExecutables: Bool {
- self.environment == .musl
- }
+ /// Returns `true` if this is the triple for Swift's fully statically
+ /// linked Linux target.
+ var isFullyStaticLinux: Bool {
+ self.vendor == .swift && self.environment == .musl
+ }
+
+ /// Returns `true` if a given triple supports producing fully
+ /// statically linked executables by providing `-static` flag to
+ /// the linker. This implies statically linking platform's libc,
+ /// and of those that Swift supports currently only Musl allows
+ /// that reliably.
+ var supportsStaticExecutables: Bool {
+ self.isFullyStaticLinux
+ }
 }