Merge pull request #48 from DougGregor/self-hosting

Add test for self-hosting

Author: aciidgh

Package.swift

@@ -22,7 +22,7 @@ let package = Package(
       dependencies: ["SwiftToolsSupport-auto", "llbuildSwift"]),
     .testTarget(
       name: "SwiftDriverTests",
-      dependencies: ["SwiftDriver"]),
+      dependencies: ["SwiftDriver", "swift-driver"]),
 
     /// The primary driver executable.
     .target(

README.md

@@ -24,6 +24,22 @@ $ swift build -Xcc -I/path/to/build/Ninja-ReleaseAssert/swift-.../include --prod
 
 ```
 
+## Testing
+
+Test using command-line SwiftPM or Xcode.
+
+```
+$ swift test --parallel
+```
+
+Integration tests are costly to run and are disable by default. Enable them
+using `SWIFT_DRIVER_ENABLE_INTEGRATION_TESTS` environment variable. In Xcode,
+you can set this variable in the scheme's test action.
+
+```
+$ SWIFT_DRIVER_ENABLE_INTEGRATION_TESTS=1 swift test --parallel
+```
+
 ## Using with SwiftPM
 
 Create a symlink of the `swift-driver` binary called `swiftc` and export that

Tests/SwiftDriverTests/IntegrationTests.swift

@@ -0,0 +1,53 @@
+import XCTest
+import TSCBasic
+
+import SwiftDriver
+
+#if os(macOS)
+private func bundleRoot() -> AbsolutePath {
+    for bundle in Bundle.allBundles where bundle.bundlePath.hasSuffix(".xctest") {
+        return AbsolutePath(bundle.bundlePath).parentDirectory
+    }
+    fatalError()
+}
+#endif
+
+
+final class IntegrationTests: IntegrationTestCase {
+  func testSelfHosting() throws {
+  #if os(macOS)
+    try withTemporaryDirectory() { path in
+      let binDir = bundleRoot()
+      let driver = binDir.appending(component: "swift-driver")
+      let compiler = path.appending(component: "swiftc")
+      try createSymlink(compiler, pointingAt: driver, relative: false)
+
+      let pkg = AbsolutePath(#file).parentDirectory.parentDirectory.parentDirectory
+
+      var env = ProcessEnv.vars
+      env["SWIFT_EXEC"] = compiler.pathString
+
+      let buildPath = path.appending(component: "build")
+      let result = try TSCBasic.Process.checkNonZeroExit(
+        arguments: [
+          "swift", "build", "--package-path", pkg.pathString,
+          "--build-path", buildPath.pathString
+        ],
+        environment: env
+      )
+
+      XCTAssertTrue(localFileSystem.isExecutableFile(buildPath.appending(RelativePath("debug/swift-driver"))), result)
+    }
+  #endif
+  }
+}
+
+/// A helper class for optionally running integration tests.
+open class IntegrationTestCase: XCTestCase {
+  override open class var defaultTestSuite: XCTestSuite {
+    if ProcessEnv.vars.keys.contains("SWIFT_DRIVER_ENABLE_INTEGRATION_TESTS") {
+      return super.defaultTestSuite
+    }
+    return XCTestSuite(name: String(describing: type(of: self)))
+  }
+}