add --destination option support

Author: dragomirecky

Package.swift

@@ -75,7 +75,7 @@ let package = Package(
       // useful to any Swift package. Similar in spirit to SwiftPM's Basic module.
       .target(
         name: "SKSupport",
-        dependencies: ["SPMUtility"]),
+        dependencies: ["SwiftPM-auto", "SPMUtility"]),
       .testTarget(
         name: "SKSupportTests",
         dependencies: ["SKSupport", "SKTestSupport"]),

Sources/SKCore/BuildSetup.swift

@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 import Basic
+import Workspace
 import SPMUtility
 import SKSupport
 
@@ -31,9 +32,13 @@ public struct BuildSetup {
   /// Additional build flags
   public let flags: BuildFlags
 
-  public init(configuration: BuildConfiguration, path: AbsolutePath?, flags: BuildFlags) {
+  /// Custom compilation destination, if different from host
+  public let customDestination: Destination?
+
+  public init(configuration: BuildConfiguration, path: AbsolutePath?, flags: BuildFlags, customDestination: Destination? = nil) {
     self.configuration = configuration
     self.path = path
     self.flags = flags
+    self.customDestination = customDestination
   }
 }

Sources/SKSwiftPMWorkspace/SwiftPMWorkspace.swift

@@ -73,22 +73,23 @@ public final class SwiftPMWorkspace {
         throw Error.cannotDetermineHostToolchain
     }
 
-    let destination = try Destination.hostDestination(destinationToolchainBinDir)
-    let toolchain = try UserToolchain(destination: destination)
+    let hostDestination = try Destination.hostDestination(destinationToolchainBinDir)
+    let manifestToolchain = try UserToolchain(destination: hostDestination)
+    let targetDestination = buildSetup.customDestination ?? hostDestination
+    let targetToolchain = try UserToolchain(destination: targetDestination)
 
     let buildPath: AbsolutePath = buildSetup.path ?? packageRoot.appending(component: ".build")
 
+
     self.workspace = Workspace(
       dataPath: buildPath,
       editablesPath: packageRoot.appending(component: "Packages"),
       pinsFile: packageRoot.appending(component: "Package.resolved"),
-      manifestLoader: ManifestLoader(manifestResources: toolchain.manifestResources, cacheDir: buildPath),
+      manifestLoader: ManifestLoader(manifestResources: manifestToolchain.manifestResources, cacheDir: buildPath),
       delegate: BuildSettingProviderWorkspaceDelegate(),
       fileSystem: fileSystem,
       skipUpdate: true)
 
-    let triple = Triple.hostTriple
-
     let swiftPMConfiguration: PackageModel.BuildConfiguration
     switch buildSetup.configuration {
     case .debug:
@@ -98,9 +99,10 @@ public final class SwiftPMWorkspace {
     }
 
     self.buildParameters = BuildParameters(
-      dataPath: buildPath.appending(component: triple.tripleString),
+      dataPath: buildPath.appending(component: targetDestination.target.tripleString),
       configuration: swiftPMConfiguration,
-      toolchain: toolchain,
+      toolchain: targetToolchain,
+      destinationTriple: targetDestination.target,
       flags: buildSetup.flags)
 
     self.packageGraph = PackageGraph(rootPackages: [], requiredDependencies: [])

Sources/sourcekit-lsp/main.swift

@@ -20,6 +20,7 @@ import Dispatch
 import Basic
 import SPMUtility
 import Foundation
+import Workspace
 import sourcekitd // Not needed here, but fixes debugging...
 
 func parseArguments() throws -> BuildSetup {
@@ -28,6 +29,7 @@ func parseArguments() throws -> BuildSetup {
   let loggingOption = parser.add(option: "--log-level", kind: LogLevel.self, usage: "Set the logging level (debug|info|warning|error) [default: \(LogLevel.default)]")
   let buildConfigurationOption = parser.add(option: "--configuration", shortName: "-c", kind: BuildConfiguration.self, usage: "Build with configuration (debug|release) [default: debug]")
   let buildPathOption = parser.add(option: "--build-path", kind: PathArgument.self, usage: "Specify build/cache directory")
+  let destinationOption = parser.add(option: "--destination", kind: PathArgument.self)
   let buildFlagsCc = parser.add(option: "-Xcc", kind: [String].self, strategy: .oneByOne, usage: "Pass flag through to all C compiler invocations")
   let buildFlagsCxx = parser.add(option: "-Xcxx", kind: [String].self, strategy: .oneByOne, usage: "Pass flag through to all C++ compiler invocations")
   let buildFlagsLinker = parser.add(option: "-Xlinker", kind: [String].self, strategy: .oneByOne, usage: "Pass flag through to all linker invocations")
@@ -41,6 +43,10 @@ func parseArguments() throws -> BuildSetup {
   buildFlags.linkerFlags = parsedArguments.get(buildFlagsLinker) ?? []
   buildFlags.swiftCompilerFlags = parsedArguments.get(buildFlagsSwift) ?? []
 
+  let customDestination = try parsedArguments.get(destinationOption).map {
+    return try Destination(fromFile: $0.path)
+  }
+
   if let logLevel = parsedArguments.get(loggingOption) {
     Logger.shared.currentLevel = logLevel
   } else {
@@ -50,7 +56,8 @@ func parseArguments() throws -> BuildSetup {
   return BuildSetup(
     configuration: parsedArguments.get(buildConfigurationOption) ?? BuildSetup.default.configuration,
     path: parsedArguments.get(buildPathOption)?.path,
-    flags: buildFlags)
+    flags: buildFlags,
+    customDestination: customDestination)
 }
 
 let clientConnection = JSONRPCConection(inFD: STDIN_FILENO, outFD: STDOUT_FILENO, closeHandler: {