Merge pull request #24787 from apple/on-the-rpath-to-greatness

Upstream Driver changes for Swift-in-Apple-OSs

Author: jrose-apple

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 tripleRequiresRPathForSwiftInOS(const llvm::Triple &triple);
+
   /// Returns the platform name for a given target triple.
   ///
   /// For example, the iOS simulator has the name "iphonesimulator", while real

include/swift/Option/Options.td

@@ -502,6 +502,12 @@ def static_stdlib: Flag<["-"], "static-stdlib">,
 def no_static_stdlib: Flag<["-"], "no-static-stdlib">,
   Flags<[HelpHidden,DoesNotAffectIncrementalBuild]>,
   HelpText<"Don't statically link the Swift standard library">;
+def toolchain_stdlib_rpath: Flag<["-"], "toolchain-stdlib-rpath">,
+  Flags<[HelpHidden,DoesNotAffectIncrementalBuild]>,
+  HelpText<"Add an rpath entry for the toolchain's standard library, rather than the OS's">;
+def no_stdlib_rpath: Flag<["-"], "no-stdlib-rpath">,
+  Flags<[HelpHidden,DoesNotAffectIncrementalBuild]>,
+  HelpText<"Don't add any rpath entries.">;
 
 def static_executable : Flag<["-"], "static-executable">,
   HelpText<"Statically link the executable">;

lib/Basic/Platform.cpp

@@ -54,6 +54,24 @@ bool swift::tripleIsAnySimulator(const llvm::Triple &triple) {
     tripleIsAppleTVSimulator(triple);
 }
 
+
+bool swift::tripleRequiresRPathForSwiftInOS(const llvm::Triple &triple) {
+  if (triple.isMacOSX()) {
+    // macOS 10.14.4 contains a copy of Swift, but the linker will still use an
+    // rpath-based install name until 10.15.
+    return triple.isMacOSXVersionLT(10, 15);
+
+  } else if (triple.isiOS()) {
+    return triple.isOSVersionLT(12, 2);
+
+  } else if (triple.isWatchOS()) {
+    return triple.isOSVersionLT(5, 2);
+  }
+
+  // Other platforms don't have Swift installed as part of the OS by default.
+  return false;
+}
+
 DarwinPlatformKind swift::getDarwinPlatformKind(const llvm::Triple &triple) {
   if (triple.isiOS()) {
     if (triple.isTvOS()) {