Merge commit '60a355db7da1' from apple/stable/20200108 into swift/release/5.3

Author: git apple-llvm automerger

lldb/include/lldb/Target/Platform.h

@@ -432,9 +432,7 @@ class Platform : public PluginInterface {
     return lldb_private::ConstString();
   }
 
-  virtual std::string GetSDKPath(lldb_private::XcodeSDK sdk) {
-    return {};
-  }
+  virtual llvm::StringRef GetSDKPath(lldb_private::XcodeSDK sdk) { return {}; }
 
   const std::string &GetRemoteURL() const { return m_remote_url; }
 

lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp

@@ -1761,12 +1761,12 @@ PlatformDarwin::FindXcodeContentsDirectoryInPath(llvm::StringRef path) {
   return {};
 }
 
-std::string PlatformDarwin::GetSDKPath(XcodeSDK sdk) {
+llvm::StringRef PlatformDarwin::GetSDKPath(XcodeSDK sdk) {
   std::lock_guard<std::mutex> guard(m_sdk_path_mutex);
   std::string &path = m_sdk_path[sdk.GetString()];
-  if (!path.empty())
-    return path;
-  return HostInfo::GetXcodeSDK(sdk);
+  if (path.empty())
+    path = HostInfo::GetXcodeSDK(sdk);
+  return path;
 }
 
 FileSpec PlatformDarwin::GetXcodeContentsDirectory() {

lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.h

@@ -90,7 +90,7 @@ class PlatformDarwin : public PlatformPOSIX {
   llvm::Expected<lldb_private::StructuredData::DictionarySP>
   FetchExtendedCrashInformation(lldb_private::Process &process) override;
 
-  std::string GetSDKPath(lldb_private::XcodeSDK sdk) override;
+  llvm::StringRef GetSDKPath(lldb_private::XcodeSDK sdk) override;
 
   static lldb_private::FileSpec GetXcodeContentsDirectory();
   static lldb_private::FileSpec GetXcodeDeveloperDirectory();