[DNM] Refactor Path APIs with SwiftSystem

CMakeLists.txt

@@ -25,6 +25,10 @@ set(CMAKE_DISABLE_IN_SOURCE_BUILD YES)
 
 option(BUILD_SHARED_LIBS "Build shared libraries by default" YES)
 
+if(FIND_PM_DEPS)
+  find_package(SwiftSystem CONFIG REQUIRED)
+endif()
+
 find_package(dispatch QUIET)
 find_package(Foundation QUIET)
 find_package(Threads QUIET)

Package.swift

@@ -44,7 +44,6 @@ let package = Package(
             name: "TSCTestSupport",
             targets: ["TSCTestSupport"]),
     ],
-    dependencies: [],
     targets: [
 
         // MARK: Tools support core targets
@@ -67,7 +66,8 @@ let package = Package(
               "TSCclibc",
               .product(name: "SystemPackage", package: "swift-system"),
             ],
-            exclude: CMakeFiles + ["README.md"]),
+            exclude: CMakeFiles + ["README.md"],
+            cxxSettings: [.define("_CRT_SECURE_NO_WARNINGS")]),
         .target(
             /** Abstractions for common operations, should migrate to TSCBasic */
             name: "TSCUtility",
@@ -102,27 +102,14 @@ let package = Package(
 )
 
 /// When not using local dependencies, the branch to use for llbuild and TSC repositories.
- let relatedDependenciesBranch = "main"
-
- if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
-     package.dependencies += [
-         .package(url: "https://github.com/apple/swift-system.git", .upToNextMinor(from: "1.1.1")),
-     ]
- } else {
-     package.dependencies += [
-         .package(path: "../swift-system"),
-     ]
- }
-
-// FIXME: conditionalise these flags since SwiftPM 5.3 and earlier will crash
-// for platforms they don't know about.
-#if os(Windows)
-  if let TSCBasic = package.targets.first(where: { $0.name == "TSCBasic" }) {
-    TSCBasic.cxxSettings = [
-      .define("_CRT_SECURE_NO_WARNINGS", .when(platforms: [.windows])),
+let relatedDependenciesBranch = "main"
+
+if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
+    package.dependencies += [
+        .package(url: "https://github.com/apple/swift-system.git", .upToNextMinor(from: "1.1.1")),
     ]
-    TSCBasic.linkerSettings = [
-      .linkedLibrary("Pathcch", .when(platforms: [.windows])),
+} else {
+    package.dependencies += [
+        .package(path: "../swift-system"),
     ]
-  }
-#endif
+}

Sources/TSCBasic/CMakeLists.txt

@@ -60,15 +60,13 @@ target_link_libraries(TSCBasic PUBLIC
   SwiftSystem::SystemPackage
   TSCLibc)
 target_link_libraries(TSCBasic PRIVATE
-   TSCclibc)
+  TSCclibc)
 if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
   if(Foundation_FOUND)
     target_link_libraries(TSCBasic PUBLIC
       Foundation)
   endif()
 endif()
-target_link_libraries(TSCBasic PRIVATE
-  $<$<PLATFORM_ID:Windows>:Pathcch>)
 # NOTE(compnerd) workaround for CMake not setting up include flags yet
 set_target_properties(TSCBasic PROPERTIES
   INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_Swift_MODULE_DIRECTORY})

Sources/TSCBasic/FileSystem.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift.org open source project
 
- Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+ Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See http://swift.org/LICENSE.txt for license information
@@ -409,7 +409,7 @@ private class LocalFileSystem: FileSystem {
     }
 
     func createSymbolicLink(_ path: AbsolutePath, pointingAt destination: AbsolutePath, relative: Bool) throws {
-        let destString = relative ? destination.relative(to: path.parentDirectory).pathString : destination.pathString
+        let destString = relative ? try destination.relative(to: path.parentDirectory).pathString : destination.pathString
         try FileManager.default.createSymbolicLink(atPath: path.pathString, withDestinationPath: destString)
     }
 
@@ -846,7 +846,7 @@ public class InMemoryFileSystem: FileSystem {
                 throw FileSystemError(.alreadyExistsAtDestination, path)
             }
 
-            let destination = relative ? destination.relative(to: path.parentDirectory).pathString : destination.pathString
+            let destination = relative ? try destination.relative(to: path.parentDirectory).pathString : destination.pathString
 
             contents.entries[path.basename] = Node(.symlink(destination))
         }
@@ -1024,11 +1024,11 @@ public class RerootedFileSystemView: FileSystem {
 
     /// Adjust the input path for the underlying file system.
     private func formUnderlyingPath(_ path: AbsolutePath) -> AbsolutePath {
-        if path == AbsolutePath.root {
+        if path.isRoot {
             return root
         } else {
             // FIXME: Optimize?
-            return root.appending(RelativePath(String(path.pathString.dropFirst(1))))
+            return root.appending(RelativePath(path.filepath.removingRoot()))
         }
     }