bumping master to Swift 5.0

CMakeLists.txt

@@ -128,7 +128,7 @@ set_property(CACHE SWIFT_ANALYZE_CODE_COVERAGE PROPERTY
 # SWIFT_VERSION is deliberately /not/ cached so that an existing build directory
 # can be reused when a new version of Swift comes out (assuming the user hasn't
 # manually set it as part of their own CMake configuration).
-set(SWIFT_VERSION "4.2")
+set(SWIFT_VERSION "5.0")
 
 set(SWIFT_VENDOR "" CACHE STRING
     "The vendor name of the Swift compiler")

lib/Basic/Version.cpp

@@ -317,28 +317,25 @@ Optional<Version> Version::getEffectiveLanguageVersion() const {
     return None;
   }
 
-  // FIXME: When we switch to Swift 5 by default, the "4" case should return
-  // a version newer than any released 4.x compiler, and the
-  // "5" case should start returning getCurrentLanguageVersion. We should
-  // also check for the presence of SWIFT_VERSION_PATCHLEVEL, and if that's
-  // set apply it to the "3" case, so that Swift 4.0.1 will automatically
-  // have a compatibility mode of 3.2.1.
-  switch (Components[0]) {
+   // FIXME: When switching to a new major version by default---say, Swift 4---
+   // the "3" case should return a version newer than any released 3.x compiler,
+   // and the "4" case should start returning getCurrentLanguageVersion.  switch (Components[0]) {
   case 3:
 #ifdef SWIFT_VERSION_PATCHLEVEL
     return Version{3, 4, SWIFT_VERSION_PATCHLEVEL};
 #else
     return Version{3, 4};
 #endif
   case 4:
-    static_assert(SWIFT_VERSION_MAJOR == 4,
-                  "getCurrentLanguageVersion is no longer correct here");
     // Version '4' on its own implies '4.1.50'.
     if (size() == 1)
       return Version{4, 1, 50};
     return Version::getCurrentLanguageVersion();
   case 5:
-    return Version{5, 0};
+  	static_assert(SWIFT_VERSION_MAJOR == 5,
+                  "getCurrentLanguageVersion is no longer correct here");
+
+    return Version::getCurrentLanguageVersion();
   default:
     return None;
   }

test/Driver/swift-version-default.swift

@@ -31,6 +31,18 @@ htn
 #endif
 
 #if swift(>=5)
+aoeu // expected-error {{use of unresolved identifier}}
+#else
+htn
+#endif
+
+#if swift(>=5.1)
+aoeu
+#else
+htn // expected-error {{use of unresolved identifier}}
+#endif
+
+#if swift(>=6)
 aoeu
 #else
 htn // expected-error {{use of unresolved identifier}}

test/SILOptimizer/cast_foldings.sil

@@ -145,7 +145,7 @@ bb0(%0 : $*AnyObject):
 // CHECK:  store [[TMP]] to %0 : $*Optional<AnyObject>
 sil @testIOU : $@convention(thin) (@in Optional<AnyObject>) -> (@out Optional<AnyObject>) {
 bb0(%0 : $*Optional<AnyObject>, %1: $*Optional<AnyObject>):
-  unconditional_checked_cast_addr ImplicitlyUnwrappedOptional<AnyObject> in %1 : $*Optional<AnyObject> to Optional<AnyObject> in %0 : $*Optional<AnyObject>
+  unconditional_checked_cast_addr Swift.ImplicitlyUnwrappedOptional<AnyObject> in %1 : $*Optional<AnyObject> to Optional<AnyObject> in %0 : $*Optional<AnyObject>
   %2 = tuple ()
   return %2 : $()
 }

utils/build_swift/defaults.py

@@ -40,7 +40,7 @@
 CMAKE_GENERATOR = 'Ninja'
 
 COMPILER_VENDOR = 'none'
-SWIFT_USER_VISIBLE_VERSION = CompilerVersion('4.2')
+SWIFT_USER_VISIBLE_VERSION = CompilerVersion('5.0')
 CLANG_USER_VISIBLE_VERSION = CompilerVersion('6.0.0')
 SWIFT_ANALYZE_CODE_COVERAGE = 'false'