Compiler: Cygwin is identified by os(Cygwin) instead of os(Windows)

Since MinGW, Cygwin and MSVC are definitely vary greatly in ABI and C language
level behavior, it is neccessary to distinguish each other in Swift. (In target
name, MSVC is x86_64-*-windows-msvc, Cygwin is x86_64-*-windows-cygnus)

Before change, os(Windows) was *-*-windows-*, and now,
os(Cygwin) is for *-*-windows-cygnus, and os(Windows) is for *-*-windows-msvc.

The platform name for Cygwin was also renamed to 'cygwin' from 'windows'.

Author: tinysun212

lib/Basic/LangOptions.cpp

@@ -31,7 +31,8 @@ static const StringRef SupportedConditionalCompilationOSs[] = {
   "Linux",
   "FreeBSD",
   "Windows",
-  "Android"
+  "Android",
+  "Cygwin"
 };
 
 static const StringRef SupportedConditionalCompilationArches[] = {
@@ -126,8 +127,10 @@ std::pair<bool, bool> LangOptions::setTarget(llvm::Triple triple) {
     addPlatformConditionValue("os", "Linux");
   else if (triple.isOSFreeBSD())
     addPlatformConditionValue("os", "FreeBSD");
-  else if (triple.isOSWindows())
+  else if (triple.isWindowsMSVCEnvironment())
     addPlatformConditionValue("os", "Windows");
+  else if (triple.isWindowsCygwinEnvironment())
+    addPlatformConditionValue("os", "Cygwin");
   else {
     UnsupportedOS = true;
   }

lib/Basic/Platform.cpp

@@ -97,9 +97,12 @@ StringRef swift::getPlatformNameForTriple(const llvm::Triple &triple) {
   if (triple.isOSFreeBSD())
     return "freebsd";
 
-  if (triple.isOSWindows())
+  if (triple.isKnownWindowsMSVCEnvironment())
     return  "windows";
 
+  if (triple.isWindowsCygwinEnvironment())
+    return  "cygwin";
+
   return "";
 }
 

stdlib/public/Platform/Platform.swift

@@ -98,8 +98,7 @@ public var errno : Int32 {
   get {
 #if os(OSX) || os(iOS) || os(watchOS) || os(tvOS) || os(FreeBSD)
     return __error().pointee
-// FIXME: os(Windows) should be replaced, such as triple(Cygwin)
-#elseif os(Android) || os(Windows)
+#elseif os(Android) || os(Cygwin)
     return __errno().pointee
 #else
     return __errno_location().pointee
@@ -108,7 +107,7 @@ public var errno : Int32 {
   set(val) {
 #if os(OSX) || os(iOS) || os(watchOS) || os(tvOS) || os(FreeBSD)
     return __error().pointee = val
-#elseif os(Android) || os(Windows)
+#elseif os(Android) || os(Cygwin)
     return __errno().pointee = val
 #else
     return __errno_location().pointee = val
@@ -302,8 +301,8 @@ public var SIG_DFL: sig_t? { return nil }
 public var SIG_IGN: sig_t { return unsafeBitCast(1, to: sig_t.self) }
 public var SIG_ERR: sig_t { return unsafeBitCast(-1, to: sig_t.self) }
 public var SIG_HOLD: sig_t { return unsafeBitCast(5, to: sig_t.self) }
-#elseif os(Linux) || os(FreeBSD) || os(Android) || os(Windows)
-#if os(Windows)
+#elseif os(Linux) || os(FreeBSD) || os(Android) || os(Cygwin)
+#if os(Cygwin)
 // In Cygwin, the below SIG_* have the same value with Linux.
 // Verified with libstdc++6 v5.3.0 in Cygwin v2.4.1 64bit.
 public typealias sighandler_t = _sig_func_ptr
@@ -334,7 +333,7 @@ public var SEM_FAILED: UnsafeMutablePointer<sem_t>? {
 #if os(OSX) || os(iOS) || os(watchOS) || os(tvOS)
   // The value is ABI.  Value verified to be correct for OS X, iOS, watchOS, tvOS.
   return UnsafeMutablePointer<sem_t>(bitPattern: -1)
-#elseif os(Linux) || os(FreeBSD) || os(Android) || os(Windows)
+#elseif os(Linux) || os(FreeBSD) || os(Android) || os(Cygwin)
   // The value is ABI.  Value verified to be correct on Glibc.
   return UnsafeMutablePointer<sem_t>(bitPattern: 0)
 #else

stdlib/public/Platform/tgmath.swift.gyb

@@ -247,7 +247,7 @@ public func scalbn(_ x: ${T}, _ n: Int) -> ${T} {
 
 % # This is AllFloatTypes not OverlayFloatTypes because of the tuple return.
 % for T, CT, f in AllFloatTypes():
-#if os(Linux) || os(FreeBSD) || os(Android) || os(Windows)
+#if os(Linux) || os(FreeBSD) || os(Android) || os(Cygwin)
 @_transparent
 public func lgamma(_ x: ${T}) -> (${T}, Int) {
   var sign = CInt(0)

stdlib/public/core/CTypes.swift

@@ -43,10 +43,18 @@ public typealias CShort = Int16
 public typealias CInt = Int32
 
 /// The C 'long' type.
+#if os(Windows) && arch(x86_64)
+public typealias CLong = Int32
+#else
 public typealias CLong = Int
+#endif
 
 /// The C 'long long' type.
+#if os(Windows) && arch(x86_64)
+public typealias CLongLong = Int
+#else
 public typealias CLongLong = Int64
+#endif
 
 /// The C 'float' type.
 public typealias CFloat = Float

stdlib/public/core/FloatingPoint.swift.gyb

@@ -583,7 +583,7 @@ public protocol BinaryFloatingPoint: FloatingPoint, FloatLiteralConvertible {
   /// `value` rounded to the closest representable `Self`.
   init(_ value: Double)
 
-#if !os(Windows) && (arch(i386) || arch(x86_64))
+#if !os(Windows) && !os(Cygwin) && (arch(i386) || arch(x86_64))
   /// `value` rounded to the closest representable `Self`.
   init(_ value: Float80)
 #endif

stdlib/public/core/FloatingPointParsing.swift.gyb

@@ -38,7 +38,7 @@ internal func _isspace_clocale(_ u: UTF16.CodeUnit) -> Bool {
 %   Self = floatName(bits)
 
 % if bits == 80:
-#if !os(Windows) && (arch(i386) || arch(x86_64))
+#if !os(Windows) && !os(Cygwin) && (arch(i386) || arch(x86_64))
 % end
 
 //===--- Parsing ----------------------------------------------------------===//

stdlib/public/core/Policy.swift

@@ -88,7 +88,7 @@ public typealias StringLiteralType = String
 // IEEE Binary64, and we need 1 bit to represent the sign.  Instead of using
 // 1025, we use the next round number -- 2048.
 public typealias _MaxBuiltinIntegerType = Builtin.Int2048
-#if !os(Windows) && (arch(i386) || arch(x86_64))
+#if !os(Windows) && !os(Cygwin) && (arch(i386) || arch(x86_64))
 public typealias _MaxBuiltinFloatType = Builtin.FPIEEE80
 #else
 public typealias _MaxBuiltinFloatType = Builtin.FPIEEE64

stdlib/public/core/Runtime.swift.gyb

@@ -338,7 +338,7 @@ internal struct _Buffer72 {
 % for bits in [ 32, 64, 80 ]:
 
 % if bits == 80:
-#if !os(Windows) && (arch(i386) || arch(x86_64))
+#if !os(Windows) && !os(Cygwin) && (arch(i386) || arch(x86_64))
 % end
 
 @_silgen_name("swift_float${bits}ToString")

test/Parse/ConditionalCompilation/x64CygwinTarget.swift

@@ -0,0 +1,8 @@
+// RUN: %swift -parse %s -verify -D FOO -D BAR -target x86_64-unknown-windows-cygnus -disable-objc-interop -D FOO -parse-stdlib
+// RUN: %swift-ide-test -test-input-complete -source-filename=%s -target x86_64-unknown-windows-cygnus
+
+#if arch(x86_64) && os(Cygwin) && _runtime(_Native)
+class C {}
+var x = C()
+#endif
+var y = x