Make DiagnosticsEngine::takeClient return std::unique_ptr<>

Summary:
Make DiagnosticsEngine::takeClient return std::unique_ptr<>. Updated
callers to store conditional ownership using a pair of pointer and unique_ptr
instead of a pointer + bool. Updated code that temporarily registers clients to
use the non-owning registration (+ removed extra calls to takeClient).

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6294

llvm-svn: 222193

1 files changed, 6 insertions, 6 deletions

diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index c7d3d3f..a3998fa 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -589,6 +589,7 @@ class CaptureDroppedDiagnostics {
   DiagnosticsEngine &Diags;
   StoredDiagnosticConsumer Client;
   DiagnosticConsumer *PreviousClient;
+  std::unique_ptr<DiagnosticConsumer> OwningPreviousClient;
 
 public:
   CaptureDroppedDiagnostics(bool RequestCapture, DiagnosticsEngine &Diags,
@@ -596,16 +597,15 @@ public:
     : Diags(Diags), Client(StoredDiags), PreviousClient(nullptr)
   {
     if (RequestCapture || Diags.getClient() == nullptr) {
-      PreviousClient = Diags.takeClient();
-      Diags.setClient(&Client);
+      OwningPreviousClient = Diags.takeClient();
+      PreviousClient = Diags.getClient();
+      Diags.setClient(&Client, false);
     }
   }
 
   ~CaptureDroppedDiagnostics() {
-    if (Diags.getClient() == &Client) {
-      Diags.takeClient();
-      Diags.setClient(PreviousClient);
-    }
+    if (Diags.getClient() == &Client)
+      Diags.setClient(PreviousClient, !!OwningPreviousClient.release());
   }
 };