r338962 - Use Optional instead of unique_ptr; NFC

[George Burgess IV via cfe-commits]

Author: gbiv
Date: Sat Aug  4 18:37:07 2018
New Revision: 338962

URL: http://llvm.org/viewvc/llvm-project?rev=338962&view=rev
Log:
Use Optional instead of unique_ptr; NFC

Looks like the only reason we use a unique_ptr here is so that we can
conditionally construct a LogicalErrorHandler. It's a small type, and
Optional can do the same thing with 100% fewer heap allocations.

Modified:
    cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp

Modified: cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp?rev=338962&r1=338961&r2=338962&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp (original)
+++ cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp Sat Aug  4 18:37:07 2018
@@ -2068,11 +2068,11 @@ AnalysisBasedWarnings::IssueWarnings(sem
   }
 
   // Install the logical handler for -Wtautological-overlap-compare
-  std::unique_ptr<LogicalErrorHandler> LEH;
+  llvm::Optional<LogicalErrorHandler> LEH;
   if (!Diags.isIgnored(diag::warn_tautological_overlap_comparison,
                        D->getLocStart())) {
-    LEH.reset(new LogicalErrorHandler(S));
-    AC.getCFGBuildOptions().Observer = LEH.get();
+    LEH.emplace(S);
+    AC.getCFGBuildOptions().Observer = &*LEH;
   }
 
   // Emit delayed diagnostics.