Disuse unversioned triples on non-Darwin platforms.

The target flag should take the versioned triple, otherwise on platforms
with versioned triples, the standard library won't be found.

On Darwin, the unversioned triple should still be used throughout. This
necessitates special-casing in the bootstrap script and when making
subdirectories during the build.

See TSC pr #229.

Author: 3405691582

Sources/Commands/SwiftTool.swift

@@ -656,7 +656,14 @@ public class SwiftTool {
             // FIXME: At the moment we just pass the built products directory for the host. We will need to extend this
             // with a map of the names of tools available to each plugin. In particular this would not work with any
             // binary targets.
-            let builtToolsDir = dataDir.appending(components: try self._hostToolchain.get().triple.tripleString, buildEnvironment.configuration.dirname)
+            let hostTriple = try self._hostToolchain.get().triple
+            let tripleString: String
+            if hostTriple.isDarwin() {
+                tripleString = hostTriple.tripleString(forPlatformVersion: "")
+            } else {
+                tripleString = hostTriple.tripleString
+            }
+            let builtToolsDir = dataDir.appending(components: tripleString, buildEnvironment.configuration.dirname)
             let diagnostics = DiagnosticsEngine()
 
             // Create the cache directory, if needed.
@@ -768,8 +775,14 @@ public class SwiftTool {
             // Use "apple" as the subdirectory because in theory Xcode build system
             // can be used to build for any Apple platform and it has it's own
             // conventions for build subpaths based on platforms.
-            let dataPath = buildPath.appending(
-                 component: options.buildSystem == .xcode ? "apple" : triple.tripleString)
+            let subdir: String
+            if triple.isDarwin() {
+                let unversionedTriple = triple.tripleString(forPlatformVersion: "")
+                subdir = options.buildSystem == .xcode ? "apple" : unversionedTriple
+            } else {
+                subdir = triple.tripleString
+            }
+            let dataPath = buildPath.appending(component: subdir)
             return BuildParameters(
                 dataPath: dataPath,
                 configuration: options.configuration,

Utilities/bootstrap

@@ -291,7 +291,9 @@ def get_build_target(args, cross_compile=False):
         target_info_json = subprocess.check_output(command,
                                stderr=subprocess.PIPE, universal_newlines=True).strip()
         args.target_info = json.loads(target_info_json)
-        return args.target_info["target"]["unversionedTriple"]
+        if platform.system() == 'Darwin':
+          return args.target_info["target"]["unversionedTriple"]
+        return args.target_info["target"]["triple"]
     except Exception as e:
         # Temporary fallback for Darwin.
         if platform.system() == 'Darwin':