Merge pull request swiftlang#555 from drexin/wip-static-linking

Use library search group when linking statically

Author: drexin

Sources/SwiftDriver/Jobs/GenericUnixToolchain+LinkerSupport.swift

@@ -152,6 +152,14 @@ extension GenericUnixToolchain {
  )
  commandLine.appendPath(swiftrtPath)
 
+ // If we are linking statically, we need to add all
+ // dependencies to a library search group to resolve
+ // potential circular dependencies
+ if staticStdlib || staticExecutable {
+ commandLine.appendFlag(.Xlinker)
+ commandLine.appendFlag("--start-group")
+ }
+
  let inputFiles: [Job.ArgTemplate] = inputs.compactMap { input in
  // Autolink inputs are handled specially
  if input.type == .autolink {
@@ -166,6 +174,11 @@ extension GenericUnixToolchain {
  }
  commandLine.append(contentsOf: inputFiles)
 
+ if staticStdlib || staticExecutable {
+ commandLine.appendFlag(.Xlinker)
+ commandLine.appendFlag("--end-group")
+ }
+
  let fSystemArgs = parsedOptions.arguments(for: .F, .Fsystem)
  for opt in fSystemArgs {
  if opt.option == .Fsystem {

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -1289,8 +1289,43 @@ final class SwiftDriverTests: XCTestCase {
  XCTAssertFalse(cmd.contains(.flag("-dylib")))
  XCTAssertFalse(cmd.contains(.flag("-static")))
  XCTAssertFalse(cmd.contains(.flag("-shared")))
+ XCTAssertFalse(cmd.contains(.flag("--start-group")))
+ XCTAssertFalse(cmd.contains(.flag("--end-group")))
  }
 
+ // /usr/lib/swift_static/linux/static-stdlib-args.lnk is required for static
+ // linking on Linux, but is not present in macOS toolchains
+ #if os(Linux)
+ do {
+ // executable linking linux static stdlib
+ var driver = try Driver(args: commonArgs + ["-emit-executable", "-static-stdlib", "-target", "x86_64-unknown-linux"], env: env)
+ let plannedJobs = try driver.planBuild()
+
+ XCTAssertEqual(plannedJobs.count, 4)
+
+ let autolinkExtractJob = plannedJobs[2]
+ XCTAssertEqual(autolinkExtractJob.kind, .autolinkExtract)
+
+ let autolinkCmd = autolinkExtractJob.commandLine
+ XCTAssertTrue(autolinkCmd.contains(.path(.temporary(RelativePath("foo.o")))))
+ XCTAssertTrue(autolinkCmd.contains(.path(.temporary(RelativePath("bar.o")))))
+ XCTAssertTrue(autolinkCmd.contains(.path(.temporary(RelativePath("Test.autolink")))))
+
+ let linkJob = plannedJobs[3]
+ let cmd = linkJob.commandLine
+ XCTAssertTrue(cmd.contains(.flag("-o")))
+ XCTAssertTrue(cmd.contains(.path(.temporary(RelativePath("foo.o")))))
+ XCTAssertTrue(cmd.contains(.path(.temporary(RelativePath("bar.o")))))
+ XCTAssertTrue(cmd.contains(.flag("--start-group")))
+ XCTAssertTrue(cmd.contains(.flag("--end-group")))
+ XCTAssertEqual(linkJob.outputs[0].file, try VirtualPath(path: "Test"))
+
+ XCTAssertFalse(cmd.contains(.flag("-static")))
+ XCTAssertFalse(cmd.contains(.flag("-dylib")))
+ XCTAssertFalse(cmd.contains(.flag("-shared")))
+ }
+ #endif
+
  do {
  // static WASM linking
  var driver = try Driver(args: commonArgs + ["-emit-library", "-static", "-target", "wasm32-unknown-wasi"], env: env)