[analyzer] Fix analyzer warnings on analyzer.

Write tests for the actual crash that was found. Write comments and refactor
code around 17 style bugs and suppress 3 false positives.

Differential Revision: https://reviews.llvm.org/D66847

llvm-svn: 370246

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp b/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
index 54d4e48ab8d..f0dd0bf813a 100644
--- a/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
@@ -260,12 +260,13 @@ static llvm::Optional<DereferenceInfo> dereference(ProgramStateRef State,
       break;
   }
 
-  while (R->getAs<CXXBaseObjectRegion>()) {
+  while (isa<CXXBaseObjectRegion>(R)) {
     NeedsCastBack = true;
-
-    if (!isa<TypedValueRegion>(R->getSuperRegion()))
+    const auto *SuperR = dyn_cast<TypedValueRegion>(R->getSuperRegion());
+    if (!SuperR)
       break;
-    R = R->getSuperRegion()->getAs<TypedValueRegion>();
+
+    R = SuperR;
   }
 
   return DereferenceInfo{R, NeedsCastBack, /*IsCyclic*/ false};