diff --git a/llvm/include/llvm/CodeGen/MachineSSAContext.h b/llvm/include/llvm/CodeGen/MachineSSAContext.h
--- a/llvm/include/llvm/CodeGen/MachineSSAContext.h
+++ b/llvm/include/llvm/CodeGen/MachineSSAContext.h
@@ -36,7 +36,7 @@
 
 template <> class GenericSSAContext<MachineFunction> {
   const MachineRegisterInfo *RegInfo = nullptr;
-  MachineFunction *MF;
+  MachineFunction *MF = nullptr;
 
 public:
   using BlockT = MachineBasicBlock;
diff --git a/llvm/include/llvm/MC/MCContext.h b/llvm/include/llvm/MC/MCContext.h
--- a/llvm/include/llvm/MC/MCContext.h
+++ b/llvm/include/llvm/MC/MCContext.h
@@ -101,7 +101,7 @@
   Triple TT;
 
   /// The SourceMgr for this object, if any.
-  const SourceMgr *SrcMgr;
+  const SourceMgr *SrcMgr = nullptr;
 
   /// The SourceMgr for inline assembly, if any.
   std::unique_ptr<SourceMgr> InlineSrcMgr;
@@ -110,16 +110,16 @@
   DiagHandlerTy DiagHandler;
 
   /// The MCAsmInfo for this target.
-  const MCAsmInfo *MAI;
+  const MCAsmInfo *MAI = nullptr;
 
   /// The MCRegisterInfo for this target.
-  const MCRegisterInfo *MRI;
+  const MCRegisterInfo *MRI = nullptr;
 
   /// The MCObjectFileInfo for this target.
-  const MCObjectFileInfo *MOFI;
+  const MCObjectFileInfo *MOFI = nullptr;
 
   /// The MCSubtargetInfo for this target.
-  const MCSubtargetInfo *MSTI;
+  const MCSubtargetInfo *MSTI = nullptr;
 
   std::unique_ptr<CodeViewContext> CVContext;
 
diff --git a/llvm/include/llvm/MC/MCFragment.h b/llvm/include/llvm/MC/MCFragment.h
--- a/llvm/include/llvm/MC/MCFragment.h
+++ b/llvm/include/llvm/MC/MCFragment.h
@@ -311,7 +311,7 @@
   unsigned MaxBytesToEmit;
 
   /// When emitting Nops some subtargets have specific nop encodings.
-  const MCSubtargetInfo *STI;
+  const MCSubtargetInfo *STI = nullptr;
 
 public:
   MCAlignFragment(Align Alignment, int64_t Value, unsigned ValueSize,
diff --git a/llvm/include/llvm/MC/MCParser/MCAsmParserExtension.h b/llvm/include/llvm/MC/MCParser/MCAsmParserExtension.h
--- a/llvm/include/llvm/MC/MCParser/MCAsmParserExtension.h
+++ b/llvm/include/llvm/MC/MCParser/MCAsmParserExtension.h
@@ -22,7 +22,7 @@
 /// which is implemented by target and object file assembly parser
 /// implementations.
 class MCAsmParserExtension {
-  MCAsmParser *Parser;
+  MCAsmParser *Parser = nullptr;
 
 protected:
   MCAsmParserExtension();
diff --git a/llvm/include/llvm/MC/MCPseudoProbe.h b/llvm/include/llvm/MC/MCPseudoProbe.h
--- a/llvm/include/llvm/MC/MCPseudoProbe.h
+++ b/llvm/include/llvm/MC/MCPseudoProbe.h
@@ -235,7 +235,8 @@
   std::vector<ProbeType> &getProbes() { return Probes; }
   void addProbes(ProbeType Probe) { Probes.push_back(Probe); }
   // Caller node of the inline site
-  MCPseudoProbeInlineTreeBase<ProbeType, DerivedProbeInlineTreeType> *Parent;
+  MCPseudoProbeInlineTreeBase<ProbeType, DerivedProbeInlineTreeType> *Parent =
+      nullptr;
   DerivedProbeInlineTreeType *getOrAddNode(const InlineSite &Site) {
     auto Ret = Children.emplace(
         Site, std::make_unique<DerivedProbeInlineTreeType>(Site));
diff --git a/llvm/include/llvm/MC/MCWinEH.h b/llvm/include/llvm/MC/MCWinEH.h
--- a/llvm/include/llvm/MC/MCWinEH.h
+++ b/llvm/include/llvm/MC/MCWinEH.h
@@ -68,7 +68,7 @@
     int64_t Offset;
     int64_t Length;
     bool HasProlog;
-    MCSymbol *Symbol;
+    MCSymbol *Symbol = nullptr;
     // Map an Epilog's symbol to its offset within the function.
     MapVector<MCSymbol *, int64_t> Epilogs;
 
diff --git a/llvm/include/llvm/Object/COFF.h b/llvm/include/llvm/Object/COFF.h
--- a/llvm/include/llvm/Object/COFF.h
+++ b/llvm/include/llvm/Object/COFF.h
@@ -1259,7 +1259,7 @@
   BinaryByteStream BBS;
 
   SectionRef Section;
-  const COFFObjectFile *Obj;
+  const COFFObjectFile *Obj = nullptr;
 
   std::vector<const coff_relocation *> Relocs;
 
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -197,7 +197,7 @@
 }
 
 class WasmObjectWriter : public MCObjectWriter {
-  support::endian::Writer *W;
+  support::endian::Writer *W = nullptr;
 
   /// The target specific Wasm writer instance.
   std::unique_ptr<MCWasmObjectTargetWriter> TargetObjectWriter;
diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -154,7 +154,7 @@
   bool UseBigObj;
   bool UseOffsetLabels = false;
 
-  MCSectionCOFF *AddrsigSection;
+  MCSectionCOFF *AddrsigSection = nullptr;
 
   MCSectionCOFF *CGProfileSection = nullptr;