Reapply [Coverity] Fix explicit null dereferences

[akshaykhadse]

Summary

This change fixes static code analysis errors

[akshaykhadse]

Remove the erroneous change

[skan]

patch.diff

1 ↗

(On Diff #518814)

Drop this

[akshaykhadse]

Remove the *.diff file

[akshaykhadse]

patch.diff

1 ↗

(On Diff #518814)

Oops. I will.

[skan]

LGTM

[akshaykhadse]

This comment was removed by akshaykhadse.

llvm/include/llvm/ADT/SparseSet.h

public:
 
   /// findIndex - Find an element by its index.
   ///
   /// @param   Idx A valid index to find.
   /// @returns An iterator to the element identified by key, or end().
   ///
   iterator findIndex(unsigned Idx) {
     assert(Idx < Universe && "Key out of range");
+    assert(Sparse != nullptr && "Invalid sparse type");
     const unsigned Stride = std::numeric_limits<SparseT>::max() + 1u;
     for (unsigned i = Sparse[Idx], e = size(); i < e; i += Stride) {
       const unsigned FoundIdx = ValIndexOf(Dense[i]);
       assert(FoundIdx < Universe && "Invalid key in set. Did object mutate?");
       if (Idx == FoundIdx)
         return begin() + i;
       // Stride is 0 when SparseT >= unsigned.  We don't need to loop.
       if (!Stride)

llvm/include/llvm/CodeGen/PBQP/CostAllocator.h

public:
   template <typename ValueKeyT> PoolRef getValue(ValueKeyT ValueKey) {
     typename EntrySetT::iterator I = EntrySet.find_as(ValueKey);
 
     if (I != EntrySet.end())
       return PoolRef((*I)->shared_from_this(), &(*I)->getValue());
 
     auto P = std::make_shared<PoolEntry>(*this, std::move(ValueKey));
     EntrySet.insert(P.get());
-    return PoolRef(std::move(P), &P->getValue());
+    return PoolRef(P, &P->getValue());
   }
 };
 
 template <typename VectorT, typename MatrixT> class PoolCostAllocator {
 private:
   using VectorCostPool = ValuePool<VectorT>;
   using MatrixCostPool = ValuePool<MatrixT>;
 

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

AsmPrinter::getFunctionCFISectionType(const Function &F) const {
   // Ignore functions that won't get emitted.
   if (F.isDeclarationForLinker())
     return CFISection::None;
 
   if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
       F.needsUnwindTableEntry())
     return CFISection::EH;
 
+  assert(MMI != nullptr && "Invalid machine module info");
   if (MMI->hasDebugInfo() || TM.Options.ForceDwarfFrameSection)
     return CFISection::Debug;
 
   return CFISection::None;
 }
 
 AsmPrinter::CFISection
 AsmPrinter::getFunctionCFISectionType(const MachineFunction &MF) const {

llvm/lib/CodeGen/ScheduleDAG.cpp

void ScheduleDAGTopologicalSort::AddSUnitWithoutPredecessors(const SUnit *SU) {
   assert(SU->NumPreds == 0 && "Can only add SU's with no predecessors");
   Node2Index.push_back(Index2Node.size());
   Index2Node.push_back(SU->NodeNum);
   Visited.resize(Node2Index.size());
 }
 
 bool ScheduleDAGTopologicalSort::IsReachable(const SUnit *SU,
                                              const SUnit *TargetSU) {
+  assert(TargetSU != nullptr && "Invalid target SUnit");
+  assert(SU != nullptr && "Invalid SUnit");
   FixOrder();
   // If insertion of the edge SU->TargetSU would create a cycle
   // then there is a path from TargetSU to SU.
   int UpperBound, LowerBound;
   LowerBound = Node2Index[TargetSU->NodeNum];
   UpperBound = Node2Index[SU->NodeNum];
   bool HasLoop = false;
   // Is Ord(TargetSU) < Ord(SU) ?

llvm/lib/CodeGen/ValueTypes.cpp

Type *EVT::getTypeForEVT(LLVMContext &Context) const {
   }
   // clang-format on
 }
 
 /// Return the value type corresponding to the specified type.  This returns all
 /// pointers as MVT::iPTR.  If HandleUnknown is true, unknown types are returned
 /// as Other, otherwise they are invalid.
 MVT MVT::getVT(Type *Ty, bool HandleUnknown){
+  assert(Ty != nullptr && "Invalid type");
   switch (Ty->getTypeID()) {
   default:
     if (HandleUnknown) return MVT(MVT::Other);
     llvm_unreachable("Unknown type!");
   case Type::VoidTyID:
     return MVT::isVoid;
   case Type::IntegerTyID:
     return getIntegerVT(cast<IntegerType>(Ty)->getBitWidth());

llvm/lib/IR/Mangler.cpp

static void addByteCountSuffix(raw_ostream &OS, const Function *F,
   }
 
   OS << '@' << ArgWords;
 }
 
 void Mangler::getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV,
                                 bool CannotUsePrivateLabel) const {
   ManglerPrefixTy PrefixTy = Default;
+  assert(GV != nullptr && "Invalid Global Value");
   if (GV->hasPrivateLinkage()) {
     if (CannotUsePrivateLabel)
       PrefixTy = LinkerPrivate;
     else
       PrefixTy = Private;
   }
 
   const DataLayout &DL = GV->getParent()->getDataLayout();

llvm/lib/TableGen/Record.cpp

RecTy *llvm::resolveTypes(RecTy *T1, RecTy *T2) {
   if (T1 == T2)
     return T1;
 
   if (RecordRecTy *RecTy1 = dyn_cast<RecordRecTy>(T1)) {
     if (RecordRecTy *RecTy2 = dyn_cast<RecordRecTy>(T2))
       return resolveRecordTypes(RecTy1, RecTy2);
   }
 
+  assert(T1 != nullptr && "Invalid record type");
   if (T1->typeIsConvertibleTo(T2))
     return T2;
+
+  assert(T2 != nullptr && "Invalid record type");
   if (T2->typeIsConvertibleTo(T1))
     return T1;
 
   if (ListRecTy *ListTy1 = dyn_cast<ListRecTy>(T1)) {
     if (ListRecTy *ListTy2 = dyn_cast<ListRecTy>(T2)) {
       RecTy* NewType = resolveTypes(ListTy1->getElementType(),
                                     ListTy2->getElementType());
       if (NewType)

llvm/lib/Target/X86/X86InstrInfo.cpp

 static unsigned getLoadStoreRegOpcode(Register Reg,
                                       const TargetRegisterClass *RC,
                                       bool IsStackAligned,
                                       const X86Subtarget &STI, bool Load) {
   bool HasAVX = STI.hasAVX();
   bool HasAVX512 = STI.hasAVX512();
   bool HasVLX = STI.hasVLX();
 
+  assert(RC != nullptr && "Invalid target register class");
   switch (STI.getRegisterInfo()->getSpillSize(*RC)) {
   default:
     llvm_unreachable("Unknown spill size");
   case 1:
     assert(X86::GR8RegClass.hasSubClassEq(RC) && "Unknown 1-byte regclass");
     if (STI.is64Bit())
       // Copying to or from a physical H register on x86-64 requires a NOREX
       // move.  Otherwise use a normal move.

llvm/utils/TableGen/GlobalISelEmitter.cpp

if (Predicate.isStore()) {
     if (Predicate.isNonTruncStore()) {
       // We need to check the sizes match here otherwise we could incorrectly
       // match truncating stores with non-truncating ones.
       InsnMatcher.addPredicate<MemoryVsLLTSizePredicateMatcher>(
           0, MemoryVsLLTSizePredicateMatcher::EqualTo, 0);
     }
   }
 
+  assert(SrcGIEquivOrNull != nullptr && "Invalid SrcGIEquivOrNull value");
   // No check required. We already did it by swapping the opcode.
   if (!SrcGIEquivOrNull->isValueUnset("IfSignExtend") &&
       Predicate.isSignExtLoad())
     return InsnMatcher;
 
   // No check required. We already did it by swapping the opcode.
   if (!SrcGIEquivOrNull->isValueUnset("IfZeroExtend") &&
       Predicate.isZeroExtLoad())