[ASTPrinter][IDE] Print PlatformKind::OSX as "macOS" rather than "OSX" in generated interfaces

This adds a new "PreferMacOSSpelling" option to PrintOptions that is set when
printing for sourcekitd generated interfaces so the OSX PlatformKind is printed
as "macOS" in availability attributes.

Resolves rdar://problem/64667960

Author: Nathan Hawes

include/swift/AST/Attr.h

@@ -814,8 +814,8 @@ class AvailableAttr : public DeclAttribute {
   }
 
   /// Returns the string for the platform of the attribute.
-  StringRef platformString() const {
-    return swift::platformString(Platform);
+  StringRef platformString(bool PreferMacOSSpelling = false) const {
+    return swift::platformString(Platform, PreferMacOSSpelling);
   }
 
   /// Returns the human-readable string for the platform of the attribute.

include/swift/AST/PlatformKind.h

@@ -35,7 +35,9 @@ enum class PlatformKind: uint8_t {
 
 /// Returns the short string representing the platform, suitable for
 /// use in availability specifications (e.g., "OSX").
-StringRef platformString(PlatformKind platform);
+///
+/// \param useMacOSSpelling whether use the "macOS" spelling in place of "OSX".
+StringRef platformString(PlatformKind platform, bool useMacOSSpelling = false);
 
 /// Returns the platform kind corresponding to the passed-in short platform name
 /// or None if such a platform kind does not exist.

include/swift/AST/PrintOptions.h

@@ -442,6 +442,8 @@ struct PrintOptions {
   /// (e.g.  MyFramework).
   bool MapCrossImportOverlaysToDeclaringModule = false;
 
+  bool PreferMacOSSpelling = false;
+
   bool PrintAsMember = false;
 
   /// Whether to print parameter specifiers as 'let' and 'var'.
@@ -530,6 +532,7 @@ struct PrintOptions {
     result.SkipUnderscoredKeywords = true;
     result.EnumRawValues = EnumRawValueMode::PrintObjCOnly;
     result.MapCrossImportOverlaysToDeclaringModule = true;
+    result.PreferMacOSSpelling = true;
     return result;
   }
 

lib/AST/Attr.cpp

@@ -427,7 +427,8 @@ static void printShortFormAvailable(ArrayRef<const DeclAttribute *> Attrs,
       assert(AvailAttr->Introduced.hasValue());
       if (isShortFormAvailabilityImpliedByOther(AvailAttr, Attrs))
         continue;
-      Printer << platformString(AvailAttr->Platform) << " "
+      Printer << platformString(AvailAttr->Platform,
+                                Options.PreferMacOSSpelling) << " "
               << AvailAttr->Introduced.getValue().getAsString() << ", ";
     }
     Printer << "*)";
@@ -844,8 +845,8 @@ bool DeclAttribute::printImpl(ASTPrinter &Printer, const PrintOptions &Options,
     Printer << "(module: ";
     auto Attr = cast<OriginallyDefinedInAttr>(this);
     Printer << "\"" << Attr->OriginalModuleName << "\", ";
-    Printer << platformString(Attr->Platform) << " " <<
-      Attr->MovedVersion.getAsString();
+    Printer << platformString(Attr->Platform, Options.PreferMacOSSpelling) <<
+      " " << Attr->MovedVersion.getAsString();
     Printer << ")";
     break;
   }
@@ -859,7 +860,7 @@ bool DeclAttribute::printImpl(ASTPrinter &Printer, const PrintOptions &Options,
     else if (Attr->isPackageDescriptionVersionSpecific())
       Printer << "_PackageDescription";
     else
-      Printer << Attr->platformString();
+      Printer << Attr->platformString(Options.PreferMacOSSpelling);
 
     if (Attr->isUnconditionallyUnavailable())
       Printer << ", unavailable";

lib/AST/PlatformKind.cpp

@@ -23,7 +23,18 @@
 
 using namespace swift;
 
-StringRef swift::platformString(PlatformKind platform) {
+StringRef swift::platformString(PlatformKind platform, bool useMacOSSpelling) {
+  if (useMacOSSpelling) {
+    switch (platform) {
+    case PlatformKind::OSX:
+      return "macOS";
+    case PlatformKind::OSXApplicationExtension:
+      return "macOSApplicationExtension";
+    default:
+      break;
+    }
+  }
+
   switch (platform) {
   case PlatformKind::none:
     return "*";

test/IDE/print_swift_module_with_available.swift

@@ -14,8 +14,8 @@ public extension C1 {
   func ext_foo() {}
 }
 
-// CHECK1: @available(OSX 10.11, iOS 8.0, *)
+// CHECK1: @available(macOS 10.11, iOS 8.0, *)
 // CHECK1-NEXT: public class C1 {
 
-// CHECK1: @available(OSX 10.12, *)
+// CHECK1: @available(macOS 10.12, *)
 // CHECK1-NEXT: extension C1 {

test/IDE/print_synthesized_extensions_nomerge.swift

@@ -15,7 +15,7 @@ public extension S1 {
   func bar() {}
 }
 
-// CHECK1: <decl:Extension>@available(OSX 10.15, *)
+// CHECK1: <decl:Extension>@available(macOS 10.15, *)
 // CHECK1:  extension <loc><ref:Struct>S1</ref></loc> {
 // CHECK1: <decl:Extension>@available(iOS 13, *)
 // CHECK1: extension <loc><ref:Struct>S1</ref></loc> {

test/SourceKit/DocSupport/doc_swift_module.swift.response

@@ -2169,7 +2169,7 @@ func shouldPrintAnyAsKeyword(x x: Any)
   },
   {
     key.kind: source.lang.swift.decl.extension.class,
-    key.doc.full_as_xml: "<Other><Name></Name><Declaration>@available(OSX 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *)\nextension C1</Declaration><CommentParts><Abstract><Para>some comments</Para></Abstract></CommentParts></Other>",
+    key.doc.full_as_xml: "<Other><Name></Name><Declaration>@available(macOS 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *)\nextension C1</Declaration><CommentParts><Abstract><Para>some comments</Para></Abstract></CommentParts></Other>",
     key.offset: 473,
     key.length: 37,
     key.extends: {
@@ -2426,7 +2426,7 @@ func shouldPrintAnyAsKeyword(x x: Any)
   },
   {
     key.kind: source.lang.swift.decl.extension.class,
-    key.doc.full_as_xml: "<Other><Name></Name><Declaration>@available(OSX 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *)\nextension C2</Declaration><CommentParts><Abstract><Para>some comments</Para></Abstract></CommentParts></Other>",
+    key.doc.full_as_xml: "<Other><Name></Name><Declaration>@available(macOS 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *)\nextension C2</Declaration><CommentParts><Abstract><Para>some comments</Para></Abstract></CommentParts></Other>",
     key.offset: 982,
     key.length: 37,
     key.extends: {