[SourceKit] Add a test case for fast code completion

Author: rintaro

include/swift/AST/DiagnosticsFrontend.def

@@ -214,6 +214,9 @@ ERROR(repl_must_be_initialized,none,
 ERROR(error_doing_code_completion,none,
       "compiler is in code completion mode (benign diagnostic)", ())
 
+WARNING(completion_reusing_astcontext,none,
+        "completion reusing previous ASTContext (benign diagnostic)", ())
+
 ERROR(verify_encountered_fatal,none,
       "fatal error encountered while in -verify mode", ())
 

lib/IDE/CompletionInstance.cpp

@@ -14,6 +14,7 @@
 
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/DiagnosticEngine.h"
+#include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/SourceFile.h"
 #include "swift/Basic/LangOptions.h"
@@ -290,6 +291,11 @@ CompilerInstance *CompletionInstance::getReusingCompilerInstance(
     AFD->setBodyDelayed(AFD->getBodySourceRange());
   if (DiagC)
     CachedCI->addDiagnosticConsumer(DiagC);
+
+  CachedCI->getDiags().diagnose(
+      SM.getLocForOffset(BufferID, newInfo.StartOffset),
+      diag::completion_reusing_astcontext);
+
   return CachedCI.get();
 }
 

tools/SourceKit/tools/sourcekitd-test/sourcekitd-test.cpp

@@ -573,6 +573,7 @@ static int handleTestInvocation(TestOptions Opts, TestOptions &InitOpts) {
   case SourceKitRequest::CodeComplete:
     sourcekitd_request_dictionary_set_uid(Req, KeyRequest, RequestCodeComplete);
     sourcekitd_request_dictionary_set_int64(Req, KeyOffset, ByteOffset);
+    addCodeCompleteOptions(Req, Opts);
     break;
 
   case SourceKitRequest::CodeCompleteOpen: