diff --git a/clang/include/clang/AST/RawCommentList.h b/clang/include/clang/AST/RawCommentList.h
--- a/clang/include/clang/AST/RawCommentList.h
+++ b/clang/include/clang/AST/RawCommentList.h
@@ -173,7 +173,7 @@
   SourceRange Range;
 
   mutable StringRef RawText;
-  mutable const char *BriefText;
+  mutable const char *BriefText = nullptr;
 
   mutable bool RawTextValid : 1;   ///< True if RawText is valid
   mutable bool BriefTextValid : 1; ///< True if BriefText is valid
diff --git a/clang/include/clang/AST/Redeclarable.h b/clang/include/clang/AST/Redeclarable.h
--- a/clang/include/clang/AST/Redeclarable.h
+++ b/clang/include/clang/AST/Redeclarable.h
@@ -240,7 +240,7 @@
   class redecl_iterator {
     /// Current - The current declaration.
     decl_type *Current = nullptr;
-    decl_type *Starter;
+    decl_type *Starter = nullptr;
     bool PassedFirst = false;
 
   public:
diff --git a/clang/include/clang/CodeGen/CodeGenAction.h b/clang/include/clang/CodeGen/CodeGenAction.h
--- a/clang/include/clang/CodeGen/CodeGenAction.h
+++ b/clang/include/clang/CodeGen/CodeGenAction.h
@@ -83,7 +83,7 @@
 
   CodeGenerator *getCodeGenerator() const;
 
-  BackendConsumer *BEConsumer;
+  BackendConsumer *BEConsumer = nullptr;
 };
 
 class EmitAssemblyAction : public CodeGenAction {
diff --git a/clang/include/clang/Sema/HLSLExternalSemaSource.h b/clang/include/clang/Sema/HLSLExternalSemaSource.h
--- a/clang/include/clang/Sema/HLSLExternalSemaSource.h
+++ b/clang/include/clang/Sema/HLSLExternalSemaSource.h
@@ -23,7 +23,7 @@
 class HLSLExternalSemaSource : public ExternalSemaSource {
   Sema *SemaPtr = nullptr;
   NamespaceDecl *HLSLNamespace = nullptr;
-  CXXRecordDecl *ResourceDecl;
+  CXXRecordDecl *ResourceDecl = nullptr;
 
   using CompletionFunction = std::function<void(CXXRecordDecl *)>;
   llvm::DenseMap<CXXRecordDecl *, CompletionFunction> Completions;
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -937,7 +937,7 @@
   class DelayedDiagnostics;
 
   class DelayedDiagnosticsState {
-    sema::DelayedDiagnosticPool *SavedPool;
+    sema::DelayedDiagnosticPool *SavedPool = nullptr;
     friend class Sema::DelayedDiagnostics;
   };
   typedef DelayedDiagnosticsState ParsingDeclState;
diff --git a/clang/include/clang/Serialization/ModuleFile.h b/clang/include/clang/Serialization/ModuleFile.h
--- a/clang/include/clang/Serialization/ModuleFile.h
+++ b/clang/include/clang/Serialization/ModuleFile.h
@@ -196,7 +196,7 @@
 
   /// The memory buffer that stores the data associated with
   /// this AST file, owned by the InMemoryModuleCache.
-  llvm::MemoryBuffer *Buffer;
+  llvm::MemoryBuffer *Buffer = nullptr;
 
   /// The size of this file, in bits.
   uint64_t SizeInBits = 0;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -318,10 +318,10 @@
 
   /// CurFuncDecl - Holds the Decl for the current outermost
   /// non-closure context.
-  const Decl *CurFuncDecl;
+  const Decl *CurFuncDecl = nullptr;
   /// CurCodeDecl - This is the inner-most code context, which includes blocks.
-  const Decl *CurCodeDecl;
-  const CGFunctionInfo *CurFnInfo;
+  const Decl *CurCodeDecl = nullptr;
+  const CGFunctionInfo *CurFnInfo = nullptr;
   QualType FnRetTy;
   llvm::Function *CurFn = nullptr;
 
@@ -748,11 +748,11 @@
 
     /// An i1 variable indicating whether or not the @finally is
     /// running for an exception.
-    llvm::AllocaInst *ForEHVar;
+    llvm::AllocaInst *ForEHVar = nullptr;
 
     /// An i8* variable into which the exception pointer to rethrow
     /// has been saved.
-    llvm::AllocaInst *SavedExnVar;
+    llvm::AllocaInst *SavedExnVar = nullptr;
 
   public:
     void enter(CodeGenFunction &CGF, const Stmt *Finally,
diff --git a/clang/lib/Format/SortJavaScriptImports.cpp b/clang/lib/Format/SortJavaScriptImports.cpp
--- a/clang/lib/Format/SortJavaScriptImports.cpp
+++ b/clang/lib/Format/SortJavaScriptImports.cpp
@@ -217,8 +217,8 @@
   }
 
 private:
-  FormatToken *Current;
-  FormatToken *LineEnd;
+  FormatToken *Current = nullptr;
+  FormatToken *LineEnd = nullptr;
 
   FormatToken invalidToken;
 
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -478,7 +478,7 @@
 /// been merged into the same redeclaration chain.
 template<typename DeclT>
 class MergedRedeclIterator {
-  DeclT *Start;
+  DeclT *Start = nullptr;
   DeclT *Canonical = nullptr;
   DeclT *Current = nullptr;
 
diff --git a/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp b/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
@@ -754,7 +754,7 @@
 
 ObjCDeallocChecker::ObjCDeallocChecker()
     : NSObjectII(nullptr), SenTestCaseII(nullptr), XCTestCaseII(nullptr),
-      CIFilterII(nullptr) {
+      Block_releaseII(nullptr), CIFilterII(nullptr) {
 
   MissingReleaseBugType.reset(
       new BugType(this, "Missing ivar release (leak)",
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
@@ -25,7 +25,7 @@
 private:
   BugType Bug{this, "Lambda capture of uncounted variable",
               "WebKit coding guidelines"};
-  mutable BugReporter *BR;
+  mutable BugReporter *BR = nullptr;
 
 public:
   void checkASTDecl(const TranslationUnitDecl *TUD, AnalysisManager &MGR,