diff --git a/clang/include/clang/Analysis/Analyses/Consumed.h b/clang/include/clang/Analysis/Analyses/Consumed.h
index 7da4f75ecc027..3e2788cac3c9c 100644
--- a/clang/include/clang/Analysis/Analyses/Consumed.h
+++ b/clang/include/clang/Analysis/Analyses/Consumed.h
@@ -244,7 +244,7 @@ namespace consumed {
     ConsumedBlockInfo BlockInfo;
     std::unique_ptr<ConsumedStateMap> CurrStates;
 
-    ConsumedState ExpectedReturnState;
+    ConsumedState ExpectedReturnState = CS_None;
 
     void determineExpectedReturnState(AnalysisDeclContext &AC,
                                       const FunctionDecl *D);
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index 84669e68a696a..c706482aec983 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -1188,7 +1188,7 @@ class Parser : public CodeCompletionHandler {
   /// RAII object used to modify the scope flags for the current scope.
   class ParseScopeFlags {
     Scope *CurScope;
-    unsigned OldFlags;
+    unsigned OldFlags = 0;
     ParseScopeFlags(const ParseScopeFlags &) = delete;
     void operator=(const ParseScopeFlags &) = delete;
 
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 8b1e59f13d1f3..d108a58a2ed66 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -1294,7 +1294,7 @@ namespace {
   class SpeculativeEvaluationRAII {
     EvalInfo *Info = nullptr;
     Expr::EvalStatus OldStatus;
-    unsigned OldSpeculativeEvaluationDepth;
+    unsigned OldSpeculativeEvaluationDepth = 0;
 
     void moveFromAndCancel(SpeculativeEvaluationRAII &&Other) {
       Info = Other.Info;
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.h b/clang/lib/CodeGen/CGOpenMPRuntime.h
index bd27642867719..b1164dc3f7290 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.h
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.h
@@ -232,7 +232,7 @@ class CGOpenMPRuntime {
   /// as those marked as `omp declare target`.
   class DisableAutoDeclareTargetRAII {
     CodeGenModule &CGM;
-    bool SavedShouldMarkAsGlobal;
+    bool SavedShouldMarkAsGlobal = false;
 
   public:
     DisableAutoDeclareTargetRAII(CodeGenModule &CGM);
diff --git a/clang/lib/CodeGen/ConstantEmitter.h b/clang/lib/CodeGen/ConstantEmitter.h
index 1a7a181ca7f03..a55da0dcad792 100644
--- a/clang/lib/CodeGen/ConstantEmitter.h
+++ b/clang/lib/CodeGen/ConstantEmitter.h
@@ -42,7 +42,7 @@ class ConstantEmitter {
 
   /// The AST address space where this (non-abstract) initializer is going.
   /// Used for generating appropriate placeholders.
-  LangAS DestAddressSpace;
+  LangAS DestAddressSpace = LangAS::Default;
 
   llvm::SmallVector<std::pair<llvm::Constant *, llvm::GlobalVariable*>, 4>
     PlaceholderAddresses;
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 2c1c43dad1603..2f052a5817a6f 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -89,7 +89,7 @@ namespace clang {
     using RecordData = ASTReader::RecordData;
 
     TypeID DeferredTypeID = 0;
-    unsigned AnonymousDeclNumber;
+    unsigned AnonymousDeclNumber = 0;
     GlobalDeclID NamedDeclForTagDecl = 0;
     IdentifierInfo *TypedefNameForLinkage = nullptr;
 
diff --git a/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp
index c8ddf3b2c14f1..ada802394758d 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp
@@ -184,7 +184,7 @@ class MoveChecker
     bool Found;
   };
 
-  AggressivenessKind Aggressiveness;
+  AggressivenessKind Aggressiveness = AK_KnownsAndLocals;
 
 public:
   void setAggressiveness(StringRef Str, CheckerManager &Mgr) {
diff --git a/clang/lib/StaticAnalyzer/Checkers/STLAlgorithmModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/STLAlgorithmModeling.cpp
index e9d5d306cc06b..788f2875863c3 100644
--- a/clang/lib/StaticAnalyzer/Checkers/STLAlgorithmModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/STLAlgorithmModeling.cpp
@@ -61,7 +61,7 @@ class STLAlgorithmModeling : public Checker<eval::Call> {
 public:
   STLAlgorithmModeling() = default;
 
-  bool AggressiveStdFindModeling;
+  bool AggressiveStdFindModeling = false;
 
   bool evalCall(const CallEvent &Call, CheckerContext &C) const;
 }; //