Extract the load/store type verification to a separate function.

[filcab]

Summary

Added isLoadableOrStorableType to PointerType.

We were doing some checks in some places, occasionally assert()ing instead
of telling the caller. With this patch, I'm putting all type checking in
the same place for load/store type instructions, and verifying the same
thing every time.

I also added a check for load/store of a function type.

Applied extracted check to Load, Store, and Cmpxcg.

I don't have exhaustive tests for all of these, but all Error() calls in
TypeCheckLoadStoreInst are being tested (in invalid.test).

[rnk]

lgtm

include/llvm/IR/DerivedTypes.h

public:
   static PointerType *getUnqual(Type *ElementType) {
     return PointerType::get(ElementType, 0);
   }
 
   /// isValidElementType - Return true if the specified type is valid as a
   /// element type.
   static bool isValidElementType(Type *ElemTy);
 
+  /// Return true if we can load or store from a pointer to this type.
+  static bool isLoadableOrStorableType(Type *ElemTy);
+
   /// @brief Return the address space of the Pointer type.
   inline unsigned getAddressSpace() const { return getSubclassData(); }
 
   /// Implement support type inquiry through isa, cast, and dyn_cast.
   static inline bool classof(const Type *T) {
     return T->getTypeID() == PointerTyID;
   }
 };
 
 } // End llvm namespace
 
 #endif

lib/Bitcode/Reader/BitcodeReader.cpp

static std::error_code Error(DiagnosticHandlerFunction DiagnosticHandler,
   return EC;
 }
 
 static std::error_code Error(DiagnosticHandlerFunction DiagnosticHandler,
                              std::error_code EC) {
   return Error(DiagnosticHandler, EC, EC.message());
 }
 
+static std::error_code Error(DiagnosticHandlerFunction DiagnosticHandler,
+                             const Twine &Message) {
+  return Error(DiagnosticHandler,
+               make_error_code(BitcodeError::CorruptedBitcode), Message);
+}
+
 std::error_code BitcodeReader::Error(BitcodeError E, const Twine &Message) {
   return ::Error(DiagnosticHandler, make_error_code(E), Message);
 }
 
 std::error_code BitcodeReader::Error(const Twine &Message) {
   return ::Error(DiagnosticHandler,
                  make_error_code(BitcodeError::CorruptedBitcode), Message);
 }
case bitc::METADATA_ATTACHMENT: {
           InstsWithTBAATag.push_back(Inst);
       }
       break;
     }
     }
   }
 }
 
+static std::error_code TypeCheckLoadStoreInst(DiagnosticHandlerFunction DH,
+                                              Type *ValType, Type *PtrType) {
+  if (!isa<PointerType>(PtrType))
+    return Error(DH, "Load/Store operand is not a pointer type");
+  Type *ElemType = cast<PointerType>(PtrType)->getElementType();
+
+  if (ValType && ValType != ElemType)
+    return Error(DH, "Explicit load/store type does not match pointee type of "
+                     "pointer operand");
+  if (!PointerType::isLoadableOrStorableType(ElemType))
+    return Error(DH, "Cannot load/store from pointer");
+  return std::error_code();
+}
+
 /// ParseFunctionBody - Lazily parse the specified function body block.
 std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
   if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
     return Error("Invalid record");
 
   InstructionList.clear();
   unsigned ModuleValueListSize = ValueList.size();
   unsigned ModuleMDValueListSize = MDValueList.size();
case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
       Value *Op;
       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
           (OpNum + 2 != Record.size() && OpNum + 3 != Record.size()))
         return Error("Invalid record");
 
       Type *Ty = nullptr;
       if (OpNum + 3 == Record.size())
         Ty = getTypeByID(Record[OpNum++]);
-      if (!isa<PointerType>(Op->getType()))
-        return Error("Load operand is not a pointer type");
+      if (std::error_code EC =
+              TypeCheckLoadStoreInst(DiagnosticHandler, Ty, Op->getType()))
+        return EC;
       if (!Ty)
         Ty = cast<PointerType>(Op->getType())->getElementType();
-      else if (Ty != cast<PointerType>(Op->getType())->getElementType())
-        return Error("Explicit load type does not match pointee type of "
-                     "pointer operand");
 
       unsigned Align;
       if (std::error_code EC = parseAlignmentValue(Record[OpNum], Align))
         return EC;
       I = new LoadInst(Ty, Op, "", Record[OpNum + 1], Align);
 
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_LOADATOMIC: {
        // LOADATOMIC: [opty, op, align, vol, ordering, synchscope]
       unsigned OpNum = 0;
       Value *Op;
       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
           (OpNum + 4 != Record.size() && OpNum + 5 != Record.size()))
         return Error("Invalid record");
 
       Type *Ty = nullptr;
       if (OpNum + 5 == Record.size())
         Ty = getTypeByID(Record[OpNum++]);
+      if (std::error_code EC =
+              TypeCheckLoadStoreInst(DiagnosticHandler, Ty, Op->getType()))
+        return EC;
+      if (!Ty)
+        Ty = cast<PointerType>(Op->getType())->getElementType();
 
       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
       if (Ordering == NotAtomic || Ordering == Release ||
           Ordering == AcquireRelease)
         return Error("Invalid record");
       if (Ordering != NotAtomic && Record[OpNum] == 0)
         return Error("Invalid record");
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
 
       unsigned Align;
       if (std::error_code EC = parseAlignmentValue(Record[OpNum], Align))
         return EC;
       I = new LoadInst(Op, "", Record[OpNum+1], Align, Ordering, SynchScope);
 
-      (void)Ty;
-      assert((!Ty || Ty == I->getType()) &&
-             "Explicit type doesn't match pointee type of the first operand");
-
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_STORE:
     case bitc::FUNC_CODE_INST_STORE_OLD: { // STORE2:[ptrty, ptr, val, align, vol]
       unsigned OpNum = 0;
       Value *Val, *Ptr;
       if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
           (BitCode == bitc::FUNC_CODE_INST_STORE
                ? getValueTypePair(Record, OpNum, NextValueNo, Val)
                : popValue(Record, OpNum, NextValueNo,
                           cast<PointerType>(Ptr->getType())->getElementType(),
                           Val)) ||
           OpNum + 2 != Record.size())
         return Error("Invalid record");
+
+      if (std::error_code EC = TypeCheckLoadStoreInst(
+              DiagnosticHandler, Val->getType(), Ptr->getType()))
+        return EC;
       unsigned Align;
       if (std::error_code EC = parseAlignmentValue(Record[OpNum], Align))
         return EC;
       I = new StoreInst(Val, Ptr, Record[OpNum+1], Align);
       InstructionList.push_back(I);
       break;
     }
     case bitc::FUNC_CODE_INST_STOREATOMIC:
     case bitc::FUNC_CODE_INST_STOREATOMIC_OLD: {
       // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, synchscope]
       unsigned OpNum = 0;
       Value *Val, *Ptr;
       if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
           (BitCode == bitc::FUNC_CODE_INST_STOREATOMIC
                ? getValueTypePair(Record, OpNum, NextValueNo, Val)
                : popValue(Record, OpNum, NextValueNo,
                           cast<PointerType>(Ptr->getType())->getElementType(),
                           Val)) ||
           OpNum + 4 != Record.size())
         return Error("Invalid record");
 
+      if (std::error_code EC = TypeCheckLoadStoreInst(
+              DiagnosticHandler, Val->getType(), Ptr->getType()))
+        return EC;
       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
       if (Ordering == NotAtomic || Ordering == Acquire ||
           Ordering == AcquireRelease)
         return Error("Invalid record");
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
       if (Ordering != NotAtomic && Record[OpNum] == 0)
         return Error("Invalid record");
 
case bitc::FUNC_CODE_INST_CMPXCHG: {
           popValue(Record, OpNum, NextValueNo, Cmp->getType(), New) ||
           Record.size() < OpNum + 3 || Record.size() > OpNum + 5)
         return Error("Invalid record");
       AtomicOrdering SuccessOrdering = GetDecodedOrdering(Record[OpNum+1]);
       if (SuccessOrdering == NotAtomic || SuccessOrdering == Unordered)
         return Error("Invalid record");
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
 
+      if (std::error_code EC = TypeCheckLoadStoreInst(
+              DiagnosticHandler, Cmp->getType(), Ptr->getType()))
+        return EC;
       AtomicOrdering FailureOrdering;
       if (Record.size() < 7)
         FailureOrdering =
             AtomicCmpXchgInst::getStrongestFailureOrdering(SuccessOrdering);
       else
         FailureOrdering = GetDecodedOrdering(Record[OpNum+3]);
 
       I = new AtomicCmpXchgInst(Ptr, Cmp, New, SuccessOrdering, FailureOrdering,

lib/IR/Type.cpp

 PointerType *Type::getPointerTo(unsigned addrs) {
   return PointerType::get(this, addrs);
 }
 
 bool PointerType::isValidElementType(Type *ElemTy) {
   return !ElemTy->isVoidTy() && !ElemTy->isLabelTy() &&
          !ElemTy->isMetadataTy();
 }
+
+bool PointerType::isLoadableOrStorableType(Type *ElemTy) {
+  return isValidElementType(ElemTy) && !ElemTy->isFunctionTy();
+}

test/Bitcode/invalid.test

 INVALID-ENCODING: Invalid encoding
 BAD-ABBREV: Abbreviation starts with an Array or a Blob
 UNEXPECTED-EOF: Unexpected end of file
 BAD-ABBREV-NUMBER: Invalid abbrev number
 BAD-TYPE-TABLE-FORWARD-REF: Invalid TYPE table: Only named structs can be forward referenced
 BAD-BITWIDTH: Bitwidth for integer type out of range
 BAD-ALIGN: Invalid alignment value
 MISMATCHED-EXPLICIT-GEP: Explicit gep type does not match pointee type of pointer operand
-MISMATCHED-EXPLICIT-LOAD: Explicit load type does not match pointee type of pointer operand
+MISMATCHED-EXPLICIT-LOAD: Explicit load/store type does not match pointee type of pointer operand
 MISMATCHED-EXPLICIT-GEP-OPERATOR: Explicit gep operator type does not match pointee type of pointer operand
 MISMATCHED-EXPLICIT-CALL: Explicit call type does not match pointee type of callee operand
 NON-FUNCTION-EXPLICIT-CALL: Explicit call type is not a function type
 MISMATCHED-EXPLICIT-INVOKE: Explicit invoke type does not match pointee type of callee operand
 NON-FUNCTION-EXPLICIT-INVOKE: Explicit invoke type is not a function type
 
 RUN: not llvm-dis -disable-output %p/Inputs/invalid-extractval-array-idx.bc 2>&1 | \
 RUN:   FileCheck --check-prefix=EXTRACT-ARRAY %s

 RUN: not llvm-dis -disable-output %p/Inputs/invalid-too-big-fwdref.bc 2>&1 | \
 RUN:   FileCheck --check-prefix=HUGE-FWDREF %s
 
 HUGE-FWDREF: Invalid record
 
 RUN: not llvm-dis -disable-output %p/Inputs/invalid-load-pointer-type.bc 2>&1 | \
 RUN:   FileCheck --check-prefix=LOAD-BAD-TYPE %s
 
-LOAD-BAD-TYPE: Load operand is not a pointer type
+LOAD-BAD-TYPE: Load/Store operand is not a pointer type
 
 RUN: not llvm-dis -disable-output %p/Inputs/invalid-GCTable-overflow.bc 2>&1 | \
 RUN:   FileCheck --check-prefix=GCTABLE-OFLOW %s
 
 GCTABLE-OFLOW: Invalid ID
+
+RUN: not llvm-dis -disable-output %p/Inputs/invalid-load-ptr-type.bc 2>&1 | \
+RUN:   FileCheck --check-prefix=BAD-LOAD-PTR-TYPE %s
+
+BAD-LOAD-PTR-TYPE: Cannot load/store from pointer