<rdar://43616773> Add swift::tripleHasSwiftInTheOS helper.

Author: graydon

include/swift/Basic/Platform.h

@@ -46,6 +46,10 @@ namespace swift {
   /// Return true if the given triple represents any simulator.
   bool tripleIsAnySimulator(const llvm::Triple &triple);
 
+  /// Returns true if the given triple represents an OS that ships with ABI-stable
+  /// swift libraries (eg. in /usr/lib/swift).
+  bool tripleHasSwiftInTheOS(const llvm::Triple &triple);
+
   /// Returns the platform name for a given target triple.
   ///
   /// For example, the iOS simulator has the name "iphonesimulator", while real

lib/Basic/Platform.cpp

@@ -54,6 +54,25 @@ bool swift::tripleIsAnySimulator(const llvm::Triple &triple) {
     tripleIsAppleTVSimulator(triple);
 }
 
+
+bool swift::tripleHasSwiftInTheOS(const llvm::Triple &triple) {
+  unsigned major, minor, revision;
+  if (triple.isMacOSX()) {
+    triple.getMacOSXVersion(major, minor, revision);
+    return llvm::VersionTuple(major, minor, revision) >=
+      llvm::VersionTuple(10, 14, 4);
+  } else if (triple.isiOS()) {
+    triple.getiOSVersion(major, minor, revision);
+    return llvm::VersionTuple(major, minor, revision) >=
+      llvm::VersionTuple(12, 2);
+  } else if (triple.isWatchOS()) {
+    triple.getOSVersion(major, minor, revision);
+    return llvm::VersionTuple(major, minor, revision) >=
+      llvm::VersionTuple(5, 2);
+  }
+  return false;
+}
+
 DarwinPlatformKind swift::getDarwinPlatformKind(const llvm::Triple &triple) {
   if (triple.isiOS()) {
     if (triple.isTvOS()) {