Fixed for Cygwin

Sources/Basic/TerminalController.swift

@@ -80,9 +80,11 @@ public final class TerminalController {
 
         // Try determining using ioctl.
         var ws = winsize()
+#if !CYGWIN
         if ioctl(1, UInt(TIOCGWINSZ), &ws) == 0 {
             return Int(ws.ws_col)
         }
+#endif
         return nil
     }
 

Sources/Build/Command.link(ClangModule).swift

@@ -36,6 +36,8 @@ extension Command {
         // Linux doesn't search executable directory for shared libs so embed runtime search path.
       #if os(Linux)
         args += ["-Xlinker", "-rpath=$ORIGIN"]
+      #elseif CYGWIN
+        args += ["-Xlinker", "--allow-multiple-definition"]
       #endif
         args += linkFlags
         args += objects.map{ $0.asString }

Sources/Build/Command.link(SwiftModule).swift

@@ -56,12 +56,21 @@ extension Command {
             args += ["-L\(prefix.asString)"]
             args += ["-o", outpath.asString]
 
+          #if CYGWIN
+            args += ["-Xlinker", "--allow-multiple-definition"]
+          #endif
+
         case .Library(.Static):
             let inputs = buildables.map{ $0.targetName } + objects.map{ $0.asString }
             let outputs = [outpath.asString]
             return Command(name: product.targetName, tool: ArchiveTool(inputs: inputs, outputs: outputs))
         }
 
+      #if CYGWIN
+        args += ["-D", "CYGWIN"]
+        args += ["-I", "/usr/include"]
+      #endif
+
         switch product.type {
         case .Library(.Static):
             args.append(outpath.asString)

Sources/POSIX/popen.swift

@@ -30,7 +30,7 @@ public func popen(_ arguments: [String], redirectStandardError: Bool = false, en
         }
 
         // Create the file actions to use for spawning.
-#if os(macOS)
+#if os(macOS) || CYGWIN
         var fileActions: posix_spawn_file_actions_t? = nil
 #else
         var fileActions = posix_spawn_file_actions_t()

Sources/POSIX/system.swift

@@ -42,7 +42,7 @@ public func system(_ arguments: [String], environment: [String:String]? = nil) t
 public func system() {}
 
 
-#if os(macOS)
+#if os(macOS) || CYGWIN
 typealias swiftpm_posix_spawn_file_actions_t = posix_spawn_file_actions_t?
 #else
 typealias swiftpm_posix_spawn_file_actions_t = posix_spawn_file_actions_t
@@ -90,7 +90,16 @@ private func WEXITSTATUS(_ status: CInt) -> CInt {
 func waitpid(_ pid: pid_t) throws -> Int32 {
     while true {
         var exitStatus: Int32 = 0
+#if CYGWIN
+        var rv : Int32 = -1
+        withUnsafeMutablePointer(to: &exitStatus) {
+            exitStatusPtr in
+            let exitStatusPtrWrapper = __wait_status_ptr_t(__int_ptr: exitStatusPtr) 
+            rv = waitpid(pid, exitStatusPtrWrapper, 0)
+        }
+#else
         let rv = waitpid(pid, &exitStatus, 0)
+#endif
 
         if rv != -1 {
             if WIFEXITED(exitStatus) {

Sources/PackageDescription/Package.swift

@@ -8,7 +8,7 @@
  See http://swift.org/CONTRIBUTORS.txt for Swift project authors
 */
 
-#if os(Linux)
+#if os(Linux) || CYGWIN
 import Glibc
 #else
 import Darwin.C

Sources/PackageLoading/ManifestLoader.swift

@@ -165,6 +165,10 @@ public final class ManifestLoader: ManifestLoaderProtocol {
         var cmd = [resources.swiftCompilerPath.asString]
         cmd += ["--driver-mode=swift"]
         cmd += verbosity.ccArgs
+    #if CYGWIN
+        cmd += ["-D", "CYGWIN"]
+        cmd += ["-I", "/usr/include"]
+    #endif
         cmd += ["-I", resources.libraryPath.asString]
 
         // When running from Xcode, load PackageDescription.framework

Sources/PackageModel/Product.swift

@@ -78,6 +78,8 @@ public class Product {
     // configuration.
 #if os(macOS)
     public static let dynamicLibraryExtension = "dylib"
+#elseif CYGWIN
+    public static let dynamicLibraryExtension = "dll"
 #else
     public static let dynamicLibraryExtension = "so"
 #endif

Sources/libc/dirent.swift

@@ -11,7 +11,7 @@
  This file defines a common type alias for the result of opendir().
 */
 
-#if os(Linux)
+#if os(Linux) || CYGWIN
 public typealias DirHandle = OpaquePointer
 #else
 public typealias DirHandle = UnsafeMutablePointer<DIR>

Utilities/bootstrap

@@ -116,6 +116,8 @@ if platform.system() == 'Darwin':
 
 if platform.system() == 'Linux':
     g_shared_lib_ext = ".so"
+elif platform.system().startswith('CYGWIN'):
+    g_shared_lib_ext = ".dll"
 else:
     g_shared_lib_ext = ".dylib"
 
@@ -321,10 +323,10 @@ def parse_manifest():
     # We have a *very* strict format for our manifest to make parsing more
     # robust.  We use this to determine the target and product definitions.
     target_pattern = re.compile(
-        r'Target\(.*?name: "(.*?)",\n *dependencies: (\[.*?\])\)',
+        r'Target\(.*?name: "(.*?)",\r?\n? *dependencies: (\[.*?\])\)',
         re.DOTALL | re.MULTILINE)
     product_pattern = re.compile(
-        r'Library\([\n ]*name: \"(.*?)\",[\n ]*type: (.*?),[\n ]*targets: (\[.*?\])[\n ]*\)',
+        r'Library\([\r\n ]*name: \"(.*?)\",[\r\n ]*type: (.*?),[\r\n ]*targets: (\[.*?\])[\r\n ]*\)',
         re.DOTALL | re.MULTILINE)
 
     # Load the manifest as a string (we always assume UTF-8 encoding).
@@ -560,6 +562,8 @@ def create_bootstrap_files(sandbox_path, args):
                 link_command.extend(["-L", args.foundation_path])
             if args.libdispatch_build_dir:
                 link_command.extend(["-L", os.path.join(args.libdispatch_build_dir, "src", ".libs")])
+        if not target.is_library and platform.system().startswith("CYGWIN"):
+            link_command.extend(["-Xlinker", "--allow-multiple-definition"])
 
         # Write out the link command.
         if target.is_library:
@@ -644,12 +648,21 @@ def process_runtime_libraries(build_path, args, bootstrap=False):
         # We include an RPATH entry so that the Swift libraries can be found
         # relative to where it will be installed (in 'lib/swift/pm/...').
         runtime_lib_path = os.path.join(lib_path, "libPackageDescription.so")
+
+        # Change shared object extension for Cygwin
+        if platform.system().startswith("CYGWIN"):
+            runtime_lib_path = os.path.join(lib_path, "libPackageDescription.dll") 
+
         cmd = [args.swiftc_path, "-Xlinker", "-shared", "-o", runtime_lib_path,
                "-Xlinker", "--whole-archive",
                "-Xlinker", input_lib_path,
                "-Xlinker", "--no-whole-archive", "-lswiftGlibc",
                "-Xlinker", "-rpath=$ORIGIN/../linux"]
 
+        # Add link flags for Cygwin
+        if platform.system().startswith("CYGWIN"):
+            cmd.extend(["-Xlinker", "--allow-multiple-definition"])
+
         # We need to pass one swift file here to bypass the "no input files"
         # error.
         tf = tempfile.NamedTemporaryFile(suffix=".swift")
@@ -895,6 +908,8 @@ def main():
     # libraries.
     if platform.system() == 'Linux':
         embed_rpath = "$ORIGIN/../lib/swift/linux"
+    elif platform.system().startswith('CYGWIN'):
+        embed_rpath = "$ORIGIN/../lib/swift/cygwin"
     else:
         embed_rpath = "@executable_path/../lib/swift/macosx"
     build_flags.extend(["-Xlinker", "-rpath", "-Xlinker", embed_rpath])