Sema: Finish staging back in availability checking in synthesized functions

Remove the suppression of deprecation and potential unavailability diagnostics in
synthesized functions. We still suppress some explicit unavailability diagnostics -- those
in synthesized functions in synthesized functions that are lexically contained in
declarations that are themselves annotated as unavailable. For these cases, the right
solution <rdar://problem/20491640> is to not synthesize the bodies of these functions in
the first place.

rdar://problem/20024980

Swift SVN r27203

include/swift/Basic/LangOptions.h

@@ -79,11 +79,6 @@ namespace swift {
     /// \brief Enable experimental treatment of potentially unavailable
     /// symbols as optionals.
     bool EnableExperimentalUnavailableAsOptional = false;
-
-    /// \brief Enable availability checking in implicit functions.
-    /// This is a temporary flag to help testing while staging in
-    /// availability diagnostics on synthesized code.
-    bool EnableAvailabilityCheckingInImplicitFunctions = false;
     
     /// \brief Enable support for native C function pointer types.
     bool EnableCFunctionPointers = false;

lib/Frontend/CompilerInvocation.cpp

@@ -608,9 +608,6 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
   
   Opts.EnableExperimentalUnavailableAsOptional |=
       Args.hasArg(OPT_enable_experimental_unavailable_as_optional);
-
-  Opts.EnableAvailabilityCheckingInImplicitFunctions |=
-      Args.hasArg(OPT_enable_availability_checking_in_implicit_functions);
   
   Opts.EnableCFunctionPointers |=
       Args.hasArg(OPT_enable_c_function_pointers);

lib/Sema/MiscDiagnostics.cpp

@@ -548,18 +548,6 @@ static bool diagAvailability(TypeChecker &TC, const ValueDecl *D,
   if (!D)
     return false;
 
-  // Suppress the error if the reference is inside an
-  // implicit function. This avoids spurious errors for synthesized
-  // methods (for example, for nil literal conformances of unavailable
-  // imported enums) but also erroneously allows some references
-  // to unavailable symbols (for example, a synthesized call to
-  // to an unavailable default constructor of a super class).
-  // We need to handle these properly. rdar://problem/20024980 tracks this.
-  if (!TC.getLangOpts().EnableAvailabilityCheckingInImplicitFunctions &&
-      TC.isInsideImplicitFunction(R, DC)) {
-    return false;
-  }
-
   if (diagnoseExplicitUnavailability(TC, D, R, DC))
     return true;
 

lib/Sema/TypeChecker.cpp

@@ -2049,22 +2049,6 @@ void TypeChecker::diagnoseDeprecated(SourceRange ReferenceRange,
                                      const DeclContext *ReferenceDC,
                                      const AvailabilityAttr *Attr,
                                      DeclName Name) {
-
-  // Suppress the warning if the reference is inside an
-  // implicit function. This avoids spurious warnings for synthesized
-  // methods (for example, for nil literal conformances of deprecated
-  // imported enums) but also erroneously allows some references
-  // to deprecated symbols (for example, a synthesized call to
-  // to a deprecated default constructor of a super class).
-  // We should emit special-case diagnostics for those cases
-  // where the compiler will synthesize a reference to
-  // a deprecated API element. rdar://problem/20024980 tracks these
-  // special-case diagnostics.
-  if (!getLangOpts().EnableAvailabilityCheckingInImplicitFunctions &&
-      isInsideImplicitFunction(ReferenceRange, ReferenceDC)) {
-    return;
-  }
-
   // We match the behavior of clang to not report deprecation warnigs
   // inside declarations that are themselves deprecated on all deployment
   // targets.

test/ClangModules/availability_implicit_macosx.swift

@@ -1,5 +1,5 @@
-// RUN: %swift -parse -verify -target x86_64-apple-macosx10.10 -enable-experimental-availability-checking -enable-availability-checking-in-implicit-functions %clang-importer-sdk -I %S/Inputs/custom-modules %s
+// RUN: %swift -parse -verify -target x86_64-apple-macosx10.10 -enable-experimental-availability-checking %clang-importer-sdk -I %S/Inputs/custom-modules %s
-// RUN: not %swift -parse -target x86_64-apple-macosx10.10 -enable-experimental-availability-checking -enable-availability-checking-in-implicit-functions %clang-importer-sdk -I %S/Inputs/custom-modules %s 2>&1 | FileCheck %s '--implicit-check-not=<unknown>:0'
+// RUN: not %swift -parse -target x86_64-apple-macosx10.10 -enable-experimental-availability-checking %clang-importer-sdk -I %S/Inputs/custom-modules %s 2>&1 | FileCheck %s '--implicit-check-not=<unknown>:0'
 
 // REQUIRES: OS=macosx
 
@@ -20,6 +20,14 @@ func useClassThatTriggersImportOfDeprecatedEnum() {
   let _ = NSClassWithDeprecatedOptionsInMethodSignature.sharedInstance()
 }
 
+func useClassThatTriggersImportOExplicitlyUnavailableOptions() {
+  let _ = NSClassWithPotentiallyUnavailableOptionsInMethodSignature.sharedInstance()
+}
+
+func useClassThatTriggersImportOfPotentiallyUnavailableOptions() {
+  let _ = NSClassWithExplicitlyUnavailableOptionsInMethodSignature.sharedInstance()
+}
+
 func directUseShouldStillTriggerDeprecationWarning() {
   let _ = NSDeprecatedOptions.First // expected-warning {{'NSDeprecatedOptions' was deprecated in OS X 10.10: Use a different API}}
   let _ = NSDeprecatedEnum.First    // expected-warning {{'NSDeprecatedEnum' was deprecated in OS X 10.10: Use a different API}}

test/IDE/print_clang_framework.swift

@@ -34,9 +34,9 @@
 //
 // REQUIRES: OS=macosx
 
-// FOUNDATION-LABEL: {{^}}/// Aaa.  NSUnavailableOptions.  Bbb.
+// FOUNDATION-LABEL: {{^}}/// Aaa.  NSPotentiallyUnavailableOptions.  Bbb.
 // FOUNDATION-NEXT: {{^}}@availability(OSX, introduced=10.10){{$}}
-// FOUNDATION-NEXT: {{^}}struct NSUnavailableOptions : RawOptionSetType {{{$}}
+// FOUNDATION-NEXT: {{^}}struct NSPotentiallyUnavailableOptions : RawOptionSetType {{{$}}
 
 // FOUNDATION-LABEL: {{^}}/// Aaa.  NSOptionsWithUnavailableElement.  Bbb.
 // FOUNDATION-NEXT: {{^}}struct NSOptionsWithUnavailableElement : RawOptionSetType {{{$}}

test/Inputs/clang-importer-sdk/usr/include/Foundation.h

@@ -440,11 +440,11 @@ typedef NS_OPTIONS(NSUInteger, NSABitmapFormat5) {
   NSAB32d,
 };
 
-/// Aaa.  NSUnavailableOptions.  Bbb.
+/// Aaa.  NSPotentiallyUnavailableOptions.  Bbb.
-typedef NS_OPTIONS(NSUInteger, NSUnavailableOptions) {
+typedef NS_OPTIONS(NSUInteger, NSPotentiallyUnavailableOptions) {
-  NSUnavailableOptionsFirst   = (1 << 0),
+  NSPotentiallyUnavailableOptionsFirst   = (1 << 0),
-  NSUnavailableOptionsSecond  = (1 << 1),
+  NSPotentiallyUnavailableOptionsSecond  = (1 << 1),
-  NSUnavailableOptionsThird   = (1 << 2),
+  NSPotentiallyUnavailableOptionsThird   = (1 << 2),
 }  __attribute__((availability(macosx, introduced=10.10)));
 
 /// Aaa.  NSOptionsWithUnavailableElement.  Bbb.
@@ -506,6 +506,11 @@ typedef NS_OPTIONS(NSUInteger, NSExplicitlyUnavailableOnOSXOptions) {
   - (void)someMethodWithUnavailableOptionsOnOSX:(NSExplicitlyUnavailableOnOSXOptions)options __attribute__((availability(macosx, unavailable, message="Use a different API")));
 @end
 
+@interface NSClassWithPotentiallyUnavailableOptionsInMethodSignature : NSObject
++ (NSClassWithPotentiallyUnavailableOptionsInMethodSignature *) sharedInstance;
+- (void)someMethodWithPotentiallyUnavailableOptions:(NSPotentiallyUnavailableOptions)options __attribute__((availability(macosx, introduced=10.11)));
+@end
+
 @protocol NSWobbling
 -(void)wobble;
 

test/Sema/availability_versions_objc_api.swift

@@ -53,7 +53,7 @@ class ClassAdoptingUnavailableProtocol : NSProtocolAvailableOn10_10 { // expecte
 
 // Enums from Objective-C
 
-let _: NSUnavailableOptions = .First // expected-error {{'NSUnavailableOptions' is only available on OS X 10.10 or newer}}
+let _: NSPotentiallyUnavailableOptions = .First // expected-error {{'NSPotentiallyUnavailableOptions' is only available on OS X 10.10 or newer}}
     // expected-note@-1 {{guard with version check}}
 
 let _: NSOptionsWithUnavailableElement = .Third // expected-error {{'Third' is only available on OS X 10.10 or newer}}