[clang-tidy] Get ClangTidyContext out of the business of storing diagnostics. NFC

Summary:
Currently ClangTidyContext::diag() sends the diagnostics to a
DiagnosticsEngine, which probably delegates to a ClangTidyDiagnosticsConsumer,
which is supposed to go back and populate ClangTidyContext::Errors.

After this patch, the diagnostics are stored in the ClangTidyDiagnosticsConsumer
itself and can be retrieved from there.

Why?
 - the round-trip from context -> engine -> consumer -> context is confusing
   and makes it harder to establish layering between these things.
 - context does too many things, and makes it hard to use clang-tidy as a library
 - everyone who actually wants the diagnostics has access to the ClangTidyDiagnosticsConsumer

The most natural implementation (ClangTidyDiagnosticsConsumer::take()
finalizes diagnostics) causes a test failure: clang-tidy-run-with-database.cpp
asserts that clang-tidy exits successfully when trying to process a file
that doesn't exist.
In clang-tidy today, this happens because finish() is never called, so the
diagnostic is never flushed. This looks like a bug to me.
For now, this patch carefully preserves that behavior, but I'll ping the
authors to see whether it's deliberate and worth preserving.

Reviewers: hokein

Subscribers: xazax.hun, cfe-commits, alexfh

Differential Revision: https://reviews.llvm.org/D53953

llvm-svn: 345961

1 files changed, 4 insertions, 4 deletions

diff --git a/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h b/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h
index 2d2675489aa..f6e8e8efdcf 100644
--- a/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h
+++ b/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h
@@ -118,15 +118,15 @@ runCheckOnCode(StringRef Code, std::vector<ClangTidyError> *Errors = nullptr,
   Invocation.setDiagnosticConsumer(&DiagConsumer);
   if (!Invocation.run()) {
     std::string ErrorText;
-    for (const auto &Error : Context.getErrors()) {
+    for (const auto &Error : DiagConsumer.take()) {
       ErrorText += Error.Message.Message + "\n";
     }
     llvm::report_fatal_error(ErrorText);
   }
 
-  DiagConsumer.finish();
   tooling::Replacements Fixes;
-  for (const ClangTidyError &Error : Context.getErrors()) {
+  std::vector<ClangTidyError> Diags = DiagConsumer.take();
+  for (const ClangTidyError &Error : Diags) {
     for (const auto &FileAndFixes : Error.Fix) {
       for (const auto &Fix : FileAndFixes.second) {
         auto Err = Fixes.add(Fix);
@@ -139,7 +139,7 @@ runCheckOnCode(StringRef Code, std::vector<ClangTidyError> *Errors = nullptr,
     }
   }
   if (Errors)
-    *Errors = Context.getErrors();
+    *Errors = std::move(Diags);
   auto Result = tooling::applyAllReplacements(Code, Fixes);
   if (!Result) {
     // FIXME: propogate the error.