X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FBitcode%2FReader%2FBitcodeReader.cpp;h=66426c83c6693e68aa2307ce332e740933367da7;hb=1e97329f2725fb5b5e88f7be99da07da6cf9fe62;hp=524a1a8bd6dea7a13dc08461b537e6fef8ed1600;hpb=c8a1169c935ad9d3dfbdd4f72d80abf8f5acb03c;p=oota-llvm.git

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 524a1a8bd6d..66426c83c66 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -31,11 +31,37 @@ enum {
   SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
 };
 
-void BitcodeReader::materializeForwardReferencedFunctions() {
-  while (!BlockAddrFwdRefs.empty()) {
-    Function *F = BlockAddrFwdRefs.begin()->first;
-    F->Materialize();
+std::error_code BitcodeReader::materializeForwardReferencedFunctions() {
+  if (WillMaterializeAllForwardRefs)
+    return std::error_code();
+
+  // Prevent recursion.
+  WillMaterializeAllForwardRefs = true;
+
+  while (!BasicBlockFwdRefQueue.empty()) {
+    Function *F = BasicBlockFwdRefQueue.front();
+    BasicBlockFwdRefQueue.pop_front();
+    assert(F && "Expected valid function");
+    if (!BasicBlockFwdRefs.count(F))
+      // Already materialized.
+      continue;
+
+    // Check for a function that isn't materializable to prevent an infinite
+    // loop.  When parsing a blockaddress stored in a global variable, there
+    // isn't a trivial way to check if a function will have a body without a
+    // linear search through FunctionsWithBodies, so just check it here.
+    if (!F->isMaterializable())
+      return Error(BitcodeError::NeverResolvedFunctionFromBlockAddress);
+
+    // Try to materialize F.
+    if (std::error_code EC = Materialize(F))
+      return EC;
   }
+  assert(BasicBlockFwdRefs.empty() && "Function missing from queue");
+
+  // Reset state.
+  WillMaterializeAllForwardRefs = false;
+  return std::error_code();
 }
 
 void BitcodeReader::FreeState() {
@@ -51,7 +77,8 @@ void BitcodeReader::FreeState() {
   DeferredFunctionInfo.clear();
   MDKindMap.clear();
 
-  assert(BlockAddrFwdRefs.empty() && "Unresolved blockaddress fwd references");
+  assert(BasicBlockFwdRefs.empty() && "Unresolved blockaddress fwd references");
+  BasicBlockFwdRefQueue.clear();
 }
 
 //===----------------------------------------------------------------------===//
@@ -487,10 +514,10 @@ static void decodeLLVMAttributesForBitcode(AttrBuilder &B,
 
 std::error_code BitcodeReader::ParseAttributeBlock() {
   if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   if (!MAttributes.empty())
-    return Error(InvalidMultipleBlocks);
+    return Error(BitcodeError::InvalidMultipleBlocks);
 
   SmallVector<uint64_t, 64> Record;
 
@@ -503,7 +530,7 @@ std::error_code BitcodeReader::ParseAttributeBlock() {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
     case BitstreamEntry::Record:
@@ -519,7 +546,7 @@ std::error_code BitcodeReader::ParseAttributeBlock() {
     case bitc::PARAMATTR_CODE_ENTRY_OLD: { // ENTRY: [paramidx0, attr0, ...]
       // FIXME: Remove in 4.0.
       if (Record.size() & 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
         AttrBuilder B;
@@ -588,6 +615,8 @@ static Attribute::AttrKind GetAttrFromCode(uint64_t Code) {
     return Attribute::NonLazyBind;
   case bitc::ATTR_KIND_NON_NULL:
     return Attribute::NonNull;
+  case bitc::ATTR_KIND_DEREFERENCEABLE:
+    return Attribute::Dereferenceable;
   case bitc::ATTR_KIND_NO_RED_ZONE:
     return Attribute::NoRedZone;
   case bitc::ATTR_KIND_NO_RETURN:
@@ -635,16 +664,16 @@ std::error_code BitcodeReader::ParseAttrKind(uint64_t Code,
                                              Attribute::AttrKind *Kind) {
   *Kind = GetAttrFromCode(Code);
   if (*Kind == Attribute::None)
-    return Error(InvalidValue);
+    return Error(BitcodeError::InvalidValue);
   return std::error_code();
 }
 
 std::error_code BitcodeReader::ParseAttributeGroupBlock() {
   if (Stream.EnterSubBlock(bitc::PARAMATTR_GROUP_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   if (!MAttributeGroups.empty())
-    return Error(InvalidMultipleBlocks);
+    return Error(BitcodeError::InvalidMultipleBlocks);
 
   SmallVector<uint64_t, 64> Record;
 
@@ -655,7 +684,7 @@ std::error_code BitcodeReader::ParseAttributeGroupBlock() {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
     case BitstreamEntry::Record:
@@ -670,7 +699,7 @@ std::error_code BitcodeReader::ParseAttributeGroupBlock() {
       break;
     case bitc::PARAMATTR_GRP_CODE_ENTRY: { // ENTRY: [grpid, idx, a0, a1, ...]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       uint64_t GrpID = Record[0];
       uint64_t Idx = Record[1]; // Index of the object this attribute refers to.
@@ -683,14 +712,16 @@ std::error_code BitcodeReader::ParseAttributeGroupBlock() {
             return EC;
 
           B.addAttribute(Kind);
-        } else if (Record[i] == 1) { // Align attribute
+        } else if (Record[i] == 1) { // Integer attribute
           Attribute::AttrKind Kind;
           if (std::error_code EC = ParseAttrKind(Record[++i], &Kind))
             return EC;
           if (Kind == Attribute::Alignment)
             B.addAlignmentAttr(Record[++i]);
-          else
+          else if (Kind == Attribute::StackAlignment)
             B.addStackAlignmentAttr(Record[++i]);
+          else if (Kind == Attribute::Dereferenceable)
+            B.addDereferenceableAttr(Record[++i]);
         } else {                     // String attribute
           assert((Record[i] == 3 || Record[i] == 4) &&
                  "Invalid attribute group entry");
@@ -723,14 +754,14 @@ std::error_code BitcodeReader::ParseAttributeGroupBlock() {
 
 std::error_code BitcodeReader::ParseTypeTable() {
   if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   return ParseTypeTableBody();
 }
 
 std::error_code BitcodeReader::ParseTypeTableBody() {
   if (!TypeList.empty())
-    return Error(InvalidMultipleBlocks);
+    return Error(BitcodeError::InvalidMultipleBlocks);
 
   SmallVector<uint64_t, 64> Record;
   unsigned NumRecords = 0;
@@ -744,10 +775,10 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       if (NumRecords != TypeList.size())
-        return Error(MalformedBlock);
+        return Error(BitcodeError::MalformedBlock);
       return std::error_code();
     case BitstreamEntry::Record:
       // The interesting case.
@@ -759,12 +790,12 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
     Type *ResultTy = nullptr;
     switch (Stream.readRecord(Entry.ID, Record)) {
     default:
-      return Error(InvalidValue);
+      return Error(BitcodeError::InvalidValue);
     case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
       // TYPE_CODE_NUMENTRY contains a count of the number of types in the
       // type list.  This allows us to reserve space.
       if (Record.size() < 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       TypeList.resize(Record[0]);
       continue;
     case bitc::TYPE_CODE_VOID:      // VOID
@@ -799,20 +830,20 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
       break;
     case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
       if (Record.size() < 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       ResultTy = IntegerType::get(Context, Record[0]);
       break;
     case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
                                     //          [pointee type, address space]
       if (Record.size() < 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       unsigned AddressSpace = 0;
       if (Record.size() == 2)
         AddressSpace = Record[1];
       ResultTy = getTypeByID(Record[0]);
       if (!ResultTy)
-        return Error(InvalidType);
+        return Error(BitcodeError::InvalidType);
       ResultTy = PointerType::get(ResultTy, AddressSpace);
       break;
     }
@@ -820,7 +851,7 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
       // FIXME: attrid is dead, remove it in LLVM 4.0
       // FUNCTION: [vararg, attrid, retty, paramty x N]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SmallVector<Type*, 8> ArgTys;
       for (unsigned i = 3, e = Record.size(); i != e; ++i) {
         if (Type *T = getTypeByID(Record[i]))
@@ -831,7 +862,7 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
 
       ResultTy = getTypeByID(Record[2]);
       if (!ResultTy || ArgTys.size() < Record.size()-3)
-        return Error(InvalidType);
+        return Error(BitcodeError::InvalidType);
 
       ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
       break;
@@ -839,7 +870,7 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
     case bitc::TYPE_CODE_FUNCTION: {
       // FUNCTION: [vararg, retty, paramty x N]
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SmallVector<Type*, 8> ArgTys;
       for (unsigned i = 2, e = Record.size(); i != e; ++i) {
         if (Type *T = getTypeByID(Record[i]))
@@ -850,14 +881,14 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
 
       ResultTy = getTypeByID(Record[1]);
       if (!ResultTy || ArgTys.size() < Record.size()-2)
-        return Error(InvalidType);
+        return Error(BitcodeError::InvalidType);
 
       ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
       break;
     }
     case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
       if (Record.size() < 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SmallVector<Type*, 8> EltTys;
       for (unsigned i = 1, e = Record.size(); i != e; ++i) {
         if (Type *T = getTypeByID(Record[i]))
@@ -866,21 +897,21 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
           break;
       }
       if (EltTys.size() != Record.size()-1)
-        return Error(InvalidType);
+        return Error(BitcodeError::InvalidType);
       ResultTy = StructType::get(Context, EltTys, Record[0]);
       break;
     }
     case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
       if (ConvertToString(Record, 0, TypeName))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       continue;
 
     case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
       if (Record.size() < 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       if (NumRecords >= TypeList.size())
-        return Error(InvalidTYPETable);
+        return Error(BitcodeError::InvalidTYPETable);
 
       // Check to see if this was forward referenced, if so fill in the temp.
       StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
@@ -899,17 +930,17 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
           break;
       }
       if (EltTys.size() != Record.size()-1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Res->setBody(EltTys, Record[0]);
       ResultTy = Res;
       break;
     }
     case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
       if (Record.size() != 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       if (NumRecords >= TypeList.size())
-        return Error(InvalidTYPETable);
+        return Error(BitcodeError::InvalidTYPETable);
 
       // Check to see if this was forward referenced, if so fill in the temp.
       StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
@@ -924,24 +955,24 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
     }
     case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       if ((ResultTy = getTypeByID(Record[1])))
         ResultTy = ArrayType::get(ResultTy, Record[0]);
       else
-        return Error(InvalidType);
+        return Error(BitcodeError::InvalidType);
       break;
     case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       if ((ResultTy = getTypeByID(Record[1])))
         ResultTy = VectorType::get(ResultTy, Record[0]);
       else
-        return Error(InvalidType);
+        return Error(BitcodeError::InvalidType);
       break;
     }
 
     if (NumRecords >= TypeList.size())
-      return Error(InvalidTYPETable);
+      return Error(BitcodeError::InvalidTYPETable);
     assert(ResultTy && "Didn't read a type?");
     assert(!TypeList[NumRecords] && "Already read type?");
     TypeList[NumRecords++] = ResultTy;
@@ -950,7 +981,7 @@ std::error_code BitcodeReader::ParseTypeTableBody() {
 
 std::error_code BitcodeReader::ParseValueSymbolTable() {
   if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   SmallVector<uint64_t, 64> Record;
 
@@ -962,7 +993,7 @@ std::error_code BitcodeReader::ParseValueSymbolTable() {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
     case BitstreamEntry::Record:
@@ -977,10 +1008,10 @@ std::error_code BitcodeReader::ParseValueSymbolTable() {
       break;
     case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
       if (ConvertToString(Record, 1, ValueName))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       unsigned ValueID = Record[0];
       if (ValueID >= ValueList.size() || !ValueList[ValueID])
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Value *V = ValueList[ValueID];
 
       V->setName(StringRef(ValueName.data(), ValueName.size()));
@@ -989,10 +1020,10 @@ std::error_code BitcodeReader::ParseValueSymbolTable() {
     }
     case bitc::VST_CODE_BBENTRY: {
       if (ConvertToString(Record, 1, ValueName))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       BasicBlock *BB = getBasicBlock(Record[0]);
       if (!BB)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       BB->setName(StringRef(ValueName.data(), ValueName.size()));
       ValueName.clear();
@@ -1006,7 +1037,7 @@ std::error_code BitcodeReader::ParseMetadata() {
   unsigned NextMDValueNo = MDValueList.size();
 
   if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   SmallVector<uint64_t, 64> Record;
 
@@ -1017,7 +1048,7 @@ std::error_code BitcodeReader::ParseMetadata() {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
     case BitstreamEntry::Record:
@@ -1048,7 +1079,7 @@ std::error_code BitcodeReader::ParseMetadata() {
       for (unsigned i = 0; i != Size; ++i) {
         MDNode *MD = dyn_cast_or_null<MDNode>(MDValueList.getValueFwdRef(Record[i]));
         if (!MD)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         NMD->addOperand(MD);
       }
       break;
@@ -1058,14 +1089,14 @@ std::error_code BitcodeReader::ParseMetadata() {
       // fall-through
     case bitc::METADATA_NODE: {
       if (Record.size() % 2 == 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       unsigned Size = Record.size();
       SmallVector<Value*, 8> Elts;
       for (unsigned i = 0; i != Size; i += 2) {
         Type *Ty = getTypeByID(Record[i]);
         if (!Ty)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         if (Ty->isMetadataTy())
           Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
         else if (!Ty->isVoidTy())
@@ -1087,14 +1118,14 @@ std::error_code BitcodeReader::ParseMetadata() {
     }
     case bitc::METADATA_KIND: {
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       unsigned Kind = Record[0];
       SmallString<8> Name(Record.begin()+1, Record.end());
 
       unsigned NewKind = TheModule->getMDKindID(Name.str());
       if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
-        return Error(ConflictingMETADATA_KINDRecords);
+        return Error(BitcodeError::ConflictingMETADATA_KINDRecords);
       break;
     }
     }
@@ -1132,7 +1163,7 @@ std::error_code BitcodeReader::ResolveGlobalAndAliasInits() {
       if (Constant *C = dyn_cast_or_null<Constant>(ValueList[ValID]))
         GlobalInitWorklist.back().first->setInitializer(C);
       else
-        return Error(ExpectedConstant);
+        return Error(BitcodeError::ExpectedConstant);
     }
     GlobalInitWorklist.pop_back();
   }
@@ -1145,7 +1176,7 @@ std::error_code BitcodeReader::ResolveGlobalAndAliasInits() {
       if (Constant *C = dyn_cast_or_null<Constant>(ValueList[ValID]))
         AliasInitWorklist.back().first->setAliasee(C);
       else
-        return Error(ExpectedConstant);
+        return Error(BitcodeError::ExpectedConstant);
     }
     AliasInitWorklist.pop_back();
   }
@@ -1158,7 +1189,7 @@ std::error_code BitcodeReader::ResolveGlobalAndAliasInits() {
       if (Constant *C = dyn_cast_or_null<Constant>(ValueList[ValID]))
         FunctionPrefixWorklist.back().first->setPrefixData(C);
       else
-        return Error(ExpectedConstant);
+        return Error(BitcodeError::ExpectedConstant);
     }
     FunctionPrefixWorklist.pop_back();
   }
@@ -1176,7 +1207,7 @@ static APInt ReadWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
 
 std::error_code BitcodeReader::ParseConstants() {
   if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   SmallVector<uint64_t, 64> Record;
 
@@ -1189,10 +1220,10 @@ std::error_code BitcodeReader::ParseConstants() {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       if (NextCstNo != ValueList.size())
-        return Error(InvalidConstantReference);
+        return Error(BitcodeError::InvalidConstantReference);
 
       // Once all the constants have been read, go through and resolve forward
       // references.
@@ -1214,9 +1245,9 @@ std::error_code BitcodeReader::ParseConstants() {
       break;
     case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
       if (Record.empty())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       if (Record[0] >= TypeList.size() || !TypeList[Record[0]])
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       CurTy = TypeList[Record[0]];
       continue;  // Skip the ValueList manipulation.
     case bitc::CST_CODE_NULL:      // NULL
@@ -1224,12 +1255,12 @@ std::error_code BitcodeReader::ParseConstants() {
       break;
     case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
       if (!CurTy->isIntegerTy() || Record.empty())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       V = ConstantInt::get(CurTy, decodeSignRotatedValue(Record[0]));
       break;
     case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
       if (!CurTy->isIntegerTy() || Record.empty())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       APInt VInt = ReadWideAPInt(Record,
                                  cast<IntegerType>(CurTy)->getBitWidth());
@@ -1239,7 +1270,7 @@ std::error_code BitcodeReader::ParseConstants() {
     }
     case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
       if (Record.empty())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       if (CurTy->isHalfTy())
         V = ConstantFP::get(Context, APFloat(APFloat::IEEEhalf,
                                              APInt(16, (uint16_t)Record[0])));
@@ -1269,7 +1300,7 @@ std::error_code BitcodeReader::ParseConstants() {
 
     case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
       if (Record.empty())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       unsigned Size = Record.size();
       SmallVector<Constant*, 16> Elts;
@@ -1297,7 +1328,7 @@ std::error_code BitcodeReader::ParseConstants() {
     case bitc::CST_CODE_STRING:    // STRING: [values]
     case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
       if (Record.empty())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       SmallString<16> Elts(Record.begin(), Record.end());
       V = ConstantDataArray::getString(Context, Elts,
@@ -1306,7 +1337,7 @@ std::error_code BitcodeReader::ParseConstants() {
     }
     case bitc::CST_CODE_DATA: {// DATA: [n x value]
       if (Record.empty())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       Type *EltTy = cast<SequentialType>(CurTy)->getElementType();
       unsigned Size = Record.size();
@@ -1351,14 +1382,14 @@ std::error_code BitcodeReader::ParseConstants() {
         else
           V = ConstantDataArray::get(Context, Elts);
       } else {
-        return Error(InvalidTypeForValue);
+        return Error(BitcodeError::InvalidTypeForValue);
       }
       break;
     }
 
     case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
       if (Opc < 0) {
         V = UndefValue::get(CurTy);  // Unknown binop.
@@ -1389,14 +1420,14 @@ std::error_code BitcodeReader::ParseConstants() {
     }
     case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       int Opc = GetDecodedCastOpcode(Record[0]);
       if (Opc < 0) {
         V = UndefValue::get(CurTy);  // Unknown cast.
       } else {
         Type *OpTy = getTypeByID(Record[1]);
         if (!OpTy)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
         V = UpgradeBitCastExpr(Opc, Op, CurTy);
         if (!V) V = ConstantExpr::getCast(Opc, Op, CurTy);
@@ -1406,12 +1437,12 @@ std::error_code BitcodeReader::ParseConstants() {
     case bitc::CST_CODE_CE_INBOUNDS_GEP:
     case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
       if (Record.size() & 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SmallVector<Constant*, 16> Elts;
       for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
         Type *ElTy = getTypeByID(Record[i]);
         if (!ElTy)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
       }
       ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
@@ -1422,7 +1453,7 @@ std::error_code BitcodeReader::ParseConstants() {
     }
     case bitc::CST_CODE_CE_SELECT: {  // CE_SELECT: [opval#, opval#, opval#]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       Type *SelectorTy = Type::getInt1Ty(Context);
 
@@ -1441,22 +1472,22 @@ std::error_code BitcodeReader::ParseConstants() {
     case bitc::CST_CODE_CE_EXTRACTELT
         : { // CE_EXTRACTELT: [opty, opval, opty, opval]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       VectorType *OpTy =
         dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
       if (!OpTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
       Constant *Op1 = nullptr;
       if (Record.size() == 4) {
         Type *IdxTy = getTypeByID(Record[2]);
         if (!IdxTy)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         Op1 = ValueList.getConstantFwdRef(Record[3], IdxTy);
       } else // TODO: Remove with llvm 4.0
         Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
       if (!Op1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       V = ConstantExpr::getExtractElement(Op0, Op1);
       break;
     }
@@ -1464,7 +1495,7 @@ std::error_code BitcodeReader::ParseConstants() {
         : { // CE_INSERTELT: [opval, opval, opty, opval]
       VectorType *OpTy = dyn_cast<VectorType>(CurTy);
       if (Record.size() < 3 || !OpTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
       Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
                                                   OpTy->getElementType());
@@ -1472,19 +1503,19 @@ std::error_code BitcodeReader::ParseConstants() {
       if (Record.size() == 4) {
         Type *IdxTy = getTypeByID(Record[2]);
         if (!IdxTy)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         Op2 = ValueList.getConstantFwdRef(Record[3], IdxTy);
       } else // TODO: Remove with llvm 4.0
         Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
       if (!Op2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
       break;
     }
     case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
       VectorType *OpTy = dyn_cast<VectorType>(CurTy);
       if (Record.size() < 3 || !OpTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
       Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
       Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
@@ -1498,7 +1529,7 @@ std::error_code BitcodeReader::ParseConstants() {
       VectorType *OpTy =
         dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
       if (Record.size() < 4 || !RTy || !OpTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
       Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
       Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
@@ -1509,10 +1540,10 @@ std::error_code BitcodeReader::ParseConstants() {
     }
     case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
       if (Record.size() < 4)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *OpTy = getTypeByID(Record[0]);
       if (!OpTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
       Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
 
@@ -1526,16 +1557,16 @@ std::error_code BitcodeReader::ParseConstants() {
     // FIXME: Remove with the 4.0 release.
     case bitc::CST_CODE_INLINEASM_OLD: {
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       std::string AsmStr, ConstrStr;
       bool HasSideEffects = Record[0] & 1;
       bool IsAlignStack = Record[0] >> 1;
       unsigned AsmStrSize = Record[1];
       if (2+AsmStrSize >= Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       unsigned ConstStrSize = Record[2+AsmStrSize];
       if (3+AsmStrSize+ConstStrSize > Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       for (unsigned i = 0; i != AsmStrSize; ++i)
         AsmStr += (char)Record[2+i];
@@ -1550,17 +1581,17 @@ std::error_code BitcodeReader::ParseConstants() {
     // inteldialect).
     case bitc::CST_CODE_INLINEASM: {
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       std::string AsmStr, ConstrStr;
       bool HasSideEffects = Record[0] & 1;
       bool IsAlignStack = (Record[0] >> 1) & 1;
       unsigned AsmDialect = Record[0] >> 2;
       unsigned AsmStrSize = Record[1];
       if (2+AsmStrSize >= Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       unsigned ConstStrSize = Record[2+AsmStrSize];
       if (3+AsmStrSize+ConstStrSize > Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       for (unsigned i = 0; i != AsmStrSize; ++i)
         AsmStr += (char)Record[2+i];
@@ -1574,35 +1605,43 @@ std::error_code BitcodeReader::ParseConstants() {
     }
     case bitc::CST_CODE_BLOCKADDRESS:{
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *FnTy = getTypeByID(Record[0]);
       if (!FnTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Function *Fn =
         dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
       if (!Fn)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
+
+      // Don't let Fn get dematerialized.
+      BlockAddressesTaken.insert(Fn);
 
       // If the function is already parsed we can insert the block address right
       // away.
+      BasicBlock *BB;
+      unsigned BBID = Record[2];
+      if (!BBID)
+        // Invalid reference to entry block.
+        return Error(BitcodeError::InvalidID);
       if (!Fn->empty()) {
         Function::iterator BBI = Fn->begin(), BBE = Fn->end();
-        for (size_t I = 0, E = Record[2]; I != E; ++I) {
+        for (size_t I = 0, E = BBID; I != E; ++I) {
           if (BBI == BBE)
-            return Error(InvalidID);
+            return Error(BitcodeError::InvalidID);
           ++BBI;
         }
-        V = BlockAddress::get(Fn, BBI);
+        BB = BBI;
       } else {
         // Otherwise insert a placeholder and remember it so it can be inserted
         // when the function is parsed.
-        GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
-                                                    Type::getInt8Ty(Context),
-                                            false, GlobalValue::InternalLinkage,
-                                                    nullptr, "");
-        BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
-        V = FwdRef;
+        BB = BasicBlock::Create(Context);
+        auto &FwdBBs = BasicBlockFwdRefs[Fn];
+        if (FwdBBs.empty())
+          BasicBlockFwdRefQueue.push_back(Fn);
+        FwdBBs.emplace_back(BBID, BB);
       }
+      V = BlockAddress::get(Fn, BB);
       break;
     }
     }
@@ -1614,18 +1653,17 @@ std::error_code BitcodeReader::ParseConstants() {
 
 std::error_code BitcodeReader::ParseUseLists() {
   if (Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
-    return Error(InvalidRecord);
-
-  SmallVector<uint64_t, 64> Record;
+    return Error(BitcodeError::InvalidRecord);
 
   // Read all the records.
+  SmallVector<uint64_t, 64> Record;
   while (1) {
     BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
 
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
     case BitstreamEntry::Record:
@@ -1635,14 +1673,42 @@ std::error_code BitcodeReader::ParseUseLists() {
 
     // Read a use list record.
     Record.clear();
+    bool IsBB = false;
     switch (Stream.readRecord(Entry.ID, Record)) {
     default:  // Default behavior: unknown type.
       break;
-    case bitc::USELIST_CODE_ENTRY: { // USELIST_CODE_ENTRY: TBD.
+    case bitc::USELIST_CODE_BB:
+      IsBB = true;
+      // fallthrough
+    case bitc::USELIST_CODE_DEFAULT: {
       unsigned RecordLength = Record.size();
-      if (RecordLength < 1)
-        return Error(InvalidRecord);
-      UseListRecords.push_back(Record);
+      if (RecordLength < 3)
+        // Records should have at least an ID and two indexes.
+        return Error(BitcodeError::InvalidRecord);
+      unsigned ID = Record.back();
+      Record.pop_back();
+
+      Value *V;
+      if (IsBB) {
+        assert(ID < FunctionBBs.size() && "Basic block not found");
+        V = FunctionBBs[ID];
+      } else
+        V = ValueList[ID];
+      unsigned NumUses = 0;
+      SmallDenseMap<const Use *, unsigned, 16> Order;
+      for (const Use &U : V->uses()) {
+        if (++NumUses > Record.size())
+          break;
+        Order[&U] = Record[NumUses - 1];
+      }
+      if (Order.size() != Record.size() || NumUses > Record.size())
+        // Mismatches can happen if the functions are being materialized lazily
+        // (out-of-order), or a value has been upgraded.
+        break;
+
+      V->sortUseList([&](const Use &L, const Use &R) {
+        return Order.lookup(&L) < Order.lookup(&R);
+      });
       break;
     }
     }
@@ -1655,7 +1721,7 @@ std::error_code BitcodeReader::ParseUseLists() {
 std::error_code BitcodeReader::RememberAndSkipFunctionBody() {
   // Get the function we are talking about.
   if (FunctionsWithBodies.empty())
-    return Error(InsufficientFunctionProtos);
+    return Error(BitcodeError::InsufficientFunctionProtos);
 
   Function *Fn = FunctionsWithBodies.back();
   FunctionsWithBodies.pop_back();
@@ -1666,7 +1732,7 @@ std::error_code BitcodeReader::RememberAndSkipFunctionBody() {
 
   // Skip over the function block for now.
   if (Stream.SkipBlock())
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
   return std::error_code();
 }
 
@@ -1674,7 +1740,7 @@ std::error_code BitcodeReader::GlobalCleanup() {
   // Patch the initializers for globals and aliases up.
   ResolveGlobalAndAliasInits();
   if (!GlobalInits.empty() || !AliasInits.empty())
-    return Error(MalformedGlobalInitializerSet);
+    return Error(BitcodeError::MalformedGlobalInitializerSet);
 
   // Look for intrinsic functions which need to be upgraded at some point
   for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
@@ -1703,7 +1769,7 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
   if (Resume)
     Stream.JumpToBit(NextUnreadBit);
   else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   SmallVector<uint64_t, 64> Record;
   std::vector<std::string> SectionTable;
@@ -1715,7 +1781,7 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return GlobalCleanup();
 
@@ -1723,11 +1789,11 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
       switch (Entry.ID) {
       default:  // Skip unknown content.
         if (Stream.SkipBlock())
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         break;
       case bitc::BLOCKINFO_BLOCK_ID:
         if (Stream.ReadBlockInfoBlock())
-          return Error(MalformedBlock);
+          return Error(BitcodeError::MalformedBlock);
         break;
       case bitc::PARAMATTR_BLOCK_ID:
         if (std::error_code EC = ParseAttributeBlock())
@@ -1797,12 +1863,12 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
     default: break;  // Default behavior, ignore unknown content.
     case bitc::MODULE_CODE_VERSION: {  // VERSION: [version#]
       if (Record.size() < 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       // Only version #0 and #1 are supported so far.
       unsigned module_version = Record[0];
       switch (module_version) {
         default:
-          return Error(InvalidValue);
+          return Error(BitcodeError::InvalidValue);
         case 0:
           UseRelativeIDs = false;
           break;
@@ -1815,21 +1881,21 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
     case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
       std::string S;
       if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       TheModule->setTargetTriple(S);
       break;
     }
     case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
       std::string S;
       if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       TheModule->setDataLayout(S);
       break;
     }
     case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
       std::string S;
       if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       TheModule->setModuleInlineAsm(S);
       break;
     }
@@ -1837,27 +1903,27 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
       // FIXME: Remove in 4.0.
       std::string S;
       if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       // Ignore value.
       break;
     }
     case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
       std::string S;
       if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SectionTable.push_back(S);
       break;
     }
     case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
       std::string S;
       if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       GCTable.push_back(S);
       break;
     }
     case bitc::MODULE_CODE_COMDAT: { // COMDAT: [selection_kind, name]
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Comdat::SelectionKind SK = getDecodedComdatSelectionKind(Record[0]);
       unsigned ComdatNameSize = Record[1];
       std::string ComdatName;
@@ -1874,12 +1940,12 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
     //             unnamed_addr, dllstorageclass]
     case bitc::MODULE_CODE_GLOBALVAR: {
       if (Record.size() < 6)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *Ty = getTypeByID(Record[0]);
       if (!Ty)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       if (!Ty->isPointerTy())
-        return Error(InvalidTypeForValue);
+        return Error(BitcodeError::InvalidTypeForValue);
       unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
       Ty = cast<PointerType>(Ty)->getElementType();
 
@@ -1889,7 +1955,7 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
       std::string Section;
       if (Record[5]) {
         if (Record[5]-1 >= SectionTable.size())
-          return Error(InvalidID);
+          return Error(BitcodeError::InvalidID);
         Section = SectionTable[Record[5]-1];
       }
       GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
@@ -1942,16 +2008,16 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
     //             dllstorageclass]
     case bitc::MODULE_CODE_FUNCTION: {
       if (Record.size() < 8)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *Ty = getTypeByID(Record[0]);
       if (!Ty)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       if (!Ty->isPointerTy())
-        return Error(InvalidTypeForValue);
+        return Error(BitcodeError::InvalidTypeForValue);
       FunctionType *FTy =
         dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
       if (!FTy)
-        return Error(InvalidTypeForValue);
+        return Error(BitcodeError::InvalidTypeForValue);
 
       Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
                                         "", TheModule);
@@ -1964,7 +2030,7 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
       Func->setAlignment((1 << Record[5]) >> 1);
       if (Record[6]) {
         if (Record[6]-1 >= SectionTable.size())
-          return Error(InvalidID);
+          return Error(BitcodeError::InvalidID);
         Func->setSection(SectionTable[Record[6]-1]);
       }
       // Local linkage must have default visibility.
@@ -1973,7 +2039,7 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
         Func->setVisibility(GetDecodedVisibility(Record[7]));
       if (Record.size() > 8 && Record[8]) {
         if (Record[8]-1 > GCTable.size())
-          return Error(InvalidID);
+          return Error(BitcodeError::InvalidID);
         Func->setGC(GCTable[Record[8]-1].c_str());
       }
       bool UnnamedAddr = false;
@@ -2008,13 +2074,13 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
     // ALIAS: [alias type, aliasee val#, linkage, visibility, dllstorageclass]
     case bitc::MODULE_CODE_ALIAS: {
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *Ty = getTypeByID(Record[0]);
       if (!Ty)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       auto *PTy = dyn_cast<PointerType>(Ty);
       if (!PTy)
-        return Error(InvalidTypeForValue);
+        return Error(BitcodeError::InvalidTypeForValue);
 
       auto *NewGA =
           GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(),
@@ -2040,7 +2106,7 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
     case bitc::MODULE_CODE_PURGEVALS:
       // Trim down the value list to the specified size.
       if (Record.size() < 1 || Record[0] > ValueList.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       ValueList.shrinkTo(Record[0]);
       break;
     }
@@ -2061,7 +2127,7 @@ std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
       Stream.Read(4) != 0xC ||
       Stream.Read(4) != 0xE ||
       Stream.Read(4) != 0xD)
-    return Error(InvalidBitcodeSignature);
+    return Error(BitcodeError::InvalidBitcodeSignature);
 
   // We expect a number of well-defined blocks, though we don't necessarily
   // need to understand them all.
@@ -2074,7 +2140,7 @@ std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
 
@@ -2082,12 +2148,12 @@ std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
       switch (Entry.ID) {
       case bitc::BLOCKINFO_BLOCK_ID:
         if (Stream.ReadBlockInfoBlock())
-          return Error(MalformedBlock);
+          return Error(BitcodeError::MalformedBlock);
         break;
       case bitc::MODULE_BLOCK_ID:
         // Reject multiple MODULE_BLOCK's in a single bitstream.
         if (TheModule)
-          return Error(InvalidMultipleBlocks);
+          return Error(BitcodeError::InvalidMultipleBlocks);
         TheModule = M;
         if (std::error_code EC = ParseModule(false))
           return EC;
@@ -2096,7 +2162,7 @@ std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
         break;
       default:
         if (Stream.SkipBlock())
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         break;
       }
       continue;
@@ -2111,17 +2177,18 @@ std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
           Stream.AtEndOfStream())
         return std::error_code();
 
-      return Error(InvalidRecord);
+      return Error(BitcodeError::InvalidRecord);
     }
   }
 }
 
-std::error_code BitcodeReader::ParseModuleTriple(std::string &Triple) {
+ErrorOr<std::string> BitcodeReader::parseModuleTriple() {
   if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   SmallVector<uint64_t, 64> Record;
 
+  std::string Triple;
   // Read all the records for this module.
   while (1) {
     BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
@@ -2129,9 +2196,9 @@ std::error_code BitcodeReader::ParseModuleTriple(std::string &Triple) {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
-      return std::error_code();
+      return Triple;
     case BitstreamEntry::Record:
       // The interesting case.
       break;
@@ -2143,16 +2210,17 @@ std::error_code BitcodeReader::ParseModuleTriple(std::string &Triple) {
     case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
       std::string S;
       if (ConvertToString(Record, 0, S))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Triple = S;
       break;
     }
     }
     Record.clear();
   }
+  llvm_unreachable("Exit infinite loop");
 }
 
-std::error_code BitcodeReader::ParseTriple(std::string &Triple) {
+ErrorOr<std::string> BitcodeReader::parseTriple() {
   if (std::error_code EC = InitStream())
     return EC;
 
@@ -2163,7 +2231,7 @@ std::error_code BitcodeReader::ParseTriple(std::string &Triple) {
       Stream.Read(4) != 0xC ||
       Stream.Read(4) != 0xE ||
       Stream.Read(4) != 0xD)
-    return Error(InvalidBitcodeSignature);
+    return Error(BitcodeError::InvalidBitcodeSignature);
 
   // We expect a number of well-defined blocks, though we don't necessarily
   // need to understand them all.
@@ -2172,17 +2240,17 @@ std::error_code BitcodeReader::ParseTriple(std::string &Triple) {
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
 
     case BitstreamEntry::SubBlock:
       if (Entry.ID == bitc::MODULE_BLOCK_ID)
-        return ParseModuleTriple(Triple);
+        return parseModuleTriple();
 
       // Ignore other sub-blocks.
       if (Stream.SkipBlock())
-        return Error(MalformedBlock);
+        return Error(BitcodeError::MalformedBlock);
       continue;
 
     case BitstreamEntry::Record:
@@ -2195,7 +2263,7 @@ std::error_code BitcodeReader::ParseTriple(std::string &Triple) {
 /// ParseMetadataAttachment - Parse metadata attachments.
 std::error_code BitcodeReader::ParseMetadataAttachment() {
   if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   SmallVector<uint64_t, 64> Record;
   while (1) {
@@ -2204,7 +2272,7 @@ std::error_code BitcodeReader::ParseMetadataAttachment() {
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       return std::error_code();
     case BitstreamEntry::Record:
@@ -2220,14 +2288,14 @@ std::error_code BitcodeReader::ParseMetadataAttachment() {
     case bitc::METADATA_ATTACHMENT: {
       unsigned RecordLength = Record.size();
       if (Record.empty() || (RecordLength - 1) % 2 == 1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Instruction *Inst = InstructionList[Record[0]];
       for (unsigned i = 1; i != RecordLength; i = i+2) {
         unsigned Kind = Record[i];
         DenseMap<unsigned, unsigned>::iterator I =
           MDKindMap.find(Kind);
         if (I == MDKindMap.end())
-          return Error(InvalidID);
+          return Error(BitcodeError::InvalidID);
         Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
         Inst->setMetadata(I->second, cast<MDNode>(Node));
         if (I->second == LLVMContext::MD_tbaa)
@@ -2242,7 +2310,7 @@ std::error_code BitcodeReader::ParseMetadataAttachment() {
 /// ParseFunctionBody - Lazily parse the specified function body block.
 std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
   if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
-    return Error(InvalidRecord);
+    return Error(BitcodeError::InvalidRecord);
 
   InstructionList.clear();
   unsigned ModuleValueListSize = ValueList.size();
@@ -2265,7 +2333,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:
-      return Error(MalformedBlock);
+      return Error(BitcodeError::MalformedBlock);
     case BitstreamEntry::EndBlock:
       goto OutOfRecordLoop;
 
@@ -2273,7 +2341,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       switch (Entry.ID) {
       default:  // Skip unknown content.
         if (Stream.SkipBlock())
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         break;
       case bitc::CONSTANTS_BLOCK_ID:
         if (std::error_code EC = ParseConstants())
@@ -2292,6 +2360,10 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         if (std::error_code EC = ParseMetadata())
           return EC;
         break;
+      case bitc::USELIST_BLOCK_ID:
+        if (std::error_code EC = ParseUseLists())
+          return EC;
+        break;
       }
       continue;
 
@@ -2306,16 +2378,46 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     unsigned BitCode = Stream.readRecord(Entry.ID, Record);
     switch (BitCode) {
     default: // Default behavior: reject
-      return Error(InvalidValue);
-    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
+      return Error(BitcodeError::InvalidValue);
+    case bitc::FUNC_CODE_DECLAREBLOCKS: {   // DECLAREBLOCKS: [nblocks]
       if (Record.size() < 1 || Record[0] == 0)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       // Create all the basic blocks for the function.
       FunctionBBs.resize(Record[0]);
-      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
-        FunctionBBs[i] = BasicBlock::Create(Context, "", F);
+
+      // See if anything took the address of blocks in this function.
+      auto BBFRI = BasicBlockFwdRefs.find(F);
+      if (BBFRI == BasicBlockFwdRefs.end()) {
+        for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
+          FunctionBBs[i] = BasicBlock::Create(Context, "", F);
+      } else {
+        auto &BBRefs = BBFRI->second;
+        std::sort(BBRefs.begin(), BBRefs.end(),
+                  [](const std::pair<unsigned, BasicBlock *> &LHS,
+                     const std::pair<unsigned, BasicBlock *> &RHS) {
+          return LHS.first < RHS.first;
+        });
+        unsigned R = 0, RE = BBRefs.size();
+        for (unsigned I = 0, E = FunctionBBs.size(); I != E; ++I)
+          if (R != RE && BBRefs[R].first == I) {
+            assert(I != 0 && "Invalid reference to entry block");
+            BasicBlock *BB = BBRefs[R++].second;
+            BB->insertInto(F);
+            FunctionBBs[I] = BB;
+          } else {
+            FunctionBBs[I] = BasicBlock::Create(Context, "", F);
+          }
+        // Check for invalid basic block references.
+        if (R != RE)
+          return Error(BitcodeError::InvalidID);
+
+        // Erase from the table.
+        BasicBlockFwdRefs.erase(BBFRI);
+      }
+
       CurBB = FunctionBBs[0];
       continue;
+    }
 
     case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
       // This record indicates that the last instruction is at the same
@@ -2330,7 +2432,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         I = &FunctionBBs[CurBBNo-1]->back();
 
       if (!I)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       I->setDebugLoc(LastLoc);
       I = nullptr;
       continue;
@@ -2343,7 +2445,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
                !FunctionBBs[CurBBNo-1]->empty())
         I = &FunctionBBs[CurBBNo-1]->back();
       if (!I || Record.size() < 4)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       unsigned Line = Record[0], Col = Record[1];
       unsigned ScopeID = Record[2], IAID = Record[3];
@@ -2363,11 +2465,11 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
           popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
           OpNum+1 > Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
       if (Opc == -1)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
       InstructionList.push_back(I);
       if (OpNum < Record.size()) {
@@ -2409,12 +2511,12 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       Value *Op;
       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
           OpNum+2 != Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       Type *ResTy = getTypeByID(Record[OpNum]);
       int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
       if (Opc == -1 || !ResTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Instruction *Temp = nullptr;
       if ((I = UpgradeBitCastInst(Opc, Op, ResTy, Temp))) {
         if (Temp) {
@@ -2432,13 +2534,13 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       unsigned OpNum = 0;
       Value *BasePtr;
       if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       SmallVector<Value*, 16> GEPIdx;
       while (OpNum != Record.size()) {
         Value *Op;
         if (getValueTypePair(Record, OpNum, NextValueNo, Op))
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         GEPIdx.push_back(Op);
       }
 
@@ -2454,14 +2556,14 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       unsigned OpNum = 0;
       Value *Agg;
       if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       SmallVector<unsigned, 4> EXTRACTVALIdx;
       for (unsigned RecSize = Record.size();
            OpNum != RecSize; ++OpNum) {
         uint64_t Index = Record[OpNum];
         if ((unsigned)Index != Index)
-          return Error(InvalidValue);
+          return Error(BitcodeError::InvalidValue);
         EXTRACTVALIdx.push_back((unsigned)Index);
       }
 
@@ -2475,17 +2577,17 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       unsigned OpNum = 0;
       Value *Agg;
       if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Value *Val;
       if (getValueTypePair(Record, OpNum, NextValueNo, Val))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       SmallVector<unsigned, 4> INSERTVALIdx;
       for (unsigned RecSize = Record.size();
            OpNum != RecSize; ++OpNum) {
         uint64_t Index = Record[OpNum];
         if ((unsigned)Index != Index)
-          return Error(InvalidValue);
+          return Error(BitcodeError::InvalidValue);
         INSERTVALIdx.push_back((unsigned)Index);
       }
 
@@ -2502,7 +2604,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
           popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
           popValue(Record, OpNum, NextValueNo, Type::getInt1Ty(Context), Cond))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       I = SelectInst::Create(Cond, TrueVal, FalseVal);
       InstructionList.push_back(I);
@@ -2517,18 +2619,18 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
           popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
           getValueTypePair(Record, OpNum, NextValueNo, Cond))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       // select condition can be either i1 or [N x i1]
       if (VectorType* vector_type =
           dyn_cast<VectorType>(Cond->getType())) {
         // expect <n x i1>
         if (vector_type->getElementType() != Type::getInt1Ty(Context))
-          return Error(InvalidTypeForValue);
+          return Error(BitcodeError::InvalidTypeForValue);
       } else {
         // expect i1
         if (Cond->getType() != Type::getInt1Ty(Context))
-          return Error(InvalidTypeForValue);
+          return Error(BitcodeError::InvalidTypeForValue);
       }
 
       I = SelectInst::Create(Cond, TrueVal, FalseVal);
@@ -2541,7 +2643,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       Value *Vec, *Idx;
       if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
           getValueTypePair(Record, OpNum, NextValueNo, Idx))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       I = ExtractElementInst::Create(Vec, Idx);
       InstructionList.push_back(I);
       break;
@@ -2554,7 +2656,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           popValue(Record, OpNum, NextValueNo,
                    cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
           getValueTypePair(Record, OpNum, NextValueNo, Idx))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       I = InsertElementInst::Create(Vec, Elt, Idx);
       InstructionList.push_back(I);
       break;
@@ -2565,10 +2667,10 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       Value *Vec1, *Vec2, *Mask;
       if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
           popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec2))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       I = new ShuffleVectorInst(Vec1, Vec2, Mask);
       InstructionList.push_back(I);
       break;
@@ -2586,7 +2688,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
           popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
           OpNum+1 != Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       if (LHS->getType()->isFPOrFPVectorTy())
         I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
@@ -2608,9 +2710,9 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         unsigned OpNum = 0;
         Value *Op = nullptr;
         if (getValueTypePair(Record, OpNum, NextValueNo, Op))
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         if (OpNum != Record.size())
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
 
         I = ReturnInst::Create(Context, Op);
         InstructionList.push_back(I);
@@ -2618,10 +2720,10 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       }
     case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
       if (Record.size() != 1 && Record.size() != 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       BasicBlock *TrueDest = getBasicBlock(Record[0]);
       if (!TrueDest)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       if (Record.size() == 1) {
         I = BranchInst::Create(TrueDest);
@@ -2632,7 +2734,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         Value *Cond = getValue(Record, 2, NextValueNo,
                                Type::getInt1Ty(Context));
         if (!FalseDest || !Cond)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         I = BranchInst::Create(TrueDest, FalseDest, Cond);
         InstructionList.push_back(I);
       }
@@ -2652,7 +2754,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         Value *Cond = getValue(Record, 2, NextValueNo, OpTy);
         BasicBlock *Default = getBasicBlock(Record[3]);
         if (!OpTy || !Cond || !Default)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
 
         unsigned NumCases = Record[4];
 
@@ -2704,12 +2806,12 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       // Old SwitchInst format without case ranges.
 
       if (Record.size() < 3 || (Record.size() & 1) == 0)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *OpTy = getTypeByID(Record[0]);
       Value *Cond = getValue(Record, 1, NextValueNo, OpTy);
       BasicBlock *Default = getBasicBlock(Record[2]);
       if (!OpTy || !Cond || !Default)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       unsigned NumCases = (Record.size()-3)/2;
       SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
       InstructionList.push_back(SI);
@@ -2719,7 +2821,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
         if (!CaseVal || !DestBB) {
           delete SI;
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         }
         SI->addCase(CaseVal, DestBB);
       }
@@ -2728,11 +2830,11 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     }
     case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
       if (Record.size() < 2)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *OpTy = getTypeByID(Record[0]);
       Value *Address = getValue(Record, 1, NextValueNo, OpTy);
       if (!OpTy || !Address)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       unsigned NumDests = Record.size()-2;
       IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
       InstructionList.push_back(IBI);
@@ -2741,7 +2843,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           IBI->addDestination(DestBB);
         } else {
           delete IBI;
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         }
       }
       I = IBI;
@@ -2751,7 +2853,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     case bitc::FUNC_CODE_INST_INVOKE: {
       // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
       if (Record.size() < 4)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       AttributeSet PAL = getAttributes(Record[0]);
       unsigned CCInfo = Record[1];
       BasicBlock *NormalBB = getBasicBlock(Record[2]);
@@ -2760,7 +2862,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       unsigned OpNum = 4;
       Value *Callee;
       if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
       FunctionType *FTy = !CalleeTy ? nullptr :
@@ -2769,25 +2871,25 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       // Check that the right number of fixed parameters are here.
       if (!FTy || !NormalBB || !UnwindBB ||
           Record.size() < OpNum+FTy->getNumParams())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       SmallVector<Value*, 16> Ops;
       for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
         Ops.push_back(getValue(Record, OpNum, NextValueNo,
                                FTy->getParamType(i)));
         if (!Ops.back())
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
       }
 
       if (!FTy->isVarArg()) {
         if (Record.size() != OpNum)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
       } else {
         // Read type/value pairs for varargs params.
         while (OpNum != Record.size()) {
           Value *Op;
           if (getValueTypePair(Record, OpNum, NextValueNo, Op))
-            return Error(InvalidRecord);
+            return Error(BitcodeError::InvalidRecord);
           Ops.push_back(Op);
         }
       }
@@ -2803,7 +2905,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       unsigned Idx = 0;
       Value *Val = nullptr;
       if (getValueTypePair(Record, Idx, NextValueNo, Val))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       I = ResumeInst::Create(Val);
       InstructionList.push_back(I);
       break;
@@ -2814,10 +2916,10 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       break;
     case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
       if (Record.size() < 1 || ((Record.size()-1)&1))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *Ty = getTypeByID(Record[0]);
       if (!Ty)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
       InstructionList.push_back(PN);
@@ -2833,7 +2935,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           V = getValue(Record, 1+i, NextValueNo, Ty);
         BasicBlock *BB = getBasicBlock(Record[2+i]);
         if (!V || !BB)
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         PN->addIncoming(V, BB);
       }
       I = PN;
@@ -2844,13 +2946,13 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
       unsigned Idx = 0;
       if (Record.size() < 4)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *Ty = getTypeByID(Record[Idx++]);
       if (!Ty)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Value *PersFn = nullptr;
       if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       bool IsCleanup = !!Record[Idx++];
       unsigned NumClauses = Record[Idx++];
@@ -2863,7 +2965,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
 
         if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
           delete LP;
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
         }
 
         assert((CT != LandingPadInst::Catch ||
@@ -2882,15 +2984,19 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
 
     case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
       if (Record.size() != 4)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       PointerType *Ty =
         dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
       Type *OpTy = getTypeByID(Record[1]);
       Value *Size = getFnValueByID(Record[2], OpTy);
-      unsigned Align = Record[3];
+      unsigned AlignRecord = Record[3];
+      bool InAlloca = AlignRecord & (1 << 5);
+      unsigned Align = AlignRecord & ((1 << 5) - 1);
       if (!Ty || !Size)
-        return Error(InvalidRecord);
-      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
+        return Error(BitcodeError::InvalidRecord);
+      AllocaInst *AI = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
+      AI->setUsedWithInAlloca(InAlloca);
+      I = AI;
       InstructionList.push_back(I);
       break;
     }
@@ -2899,7 +3005,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       Value *Op;
       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
           OpNum+2 != Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
       InstructionList.push_back(I);
@@ -2911,15 +3017,14 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       Value *Op;
       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
           OpNum+4 != Record.size())
-        return Error(InvalidRecord);
-
+        return Error(BitcodeError::InvalidRecord);
 
       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
       if (Ordering == NotAtomic || Ordering == Release ||
           Ordering == AcquireRelease)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       if (Ordering != NotAtomic && Record[OpNum] == 0)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
 
       I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1,
@@ -2934,7 +3039,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           popValue(Record, OpNum, NextValueNo,
                     cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
           OpNum+2 != Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
       InstructionList.push_back(I);
@@ -2948,15 +3053,15 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           popValue(Record, OpNum, NextValueNo,
                     cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
           OpNum+4 != Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
       if (Ordering == NotAtomic || Ordering == Acquire ||
           Ordering == AcquireRelease)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
       if (Ordering != NotAtomic && Record[OpNum] == 0)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1,
                         Ordering, SynchScope);
@@ -2974,10 +3079,10 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           popValue(Record, OpNum, NextValueNo,
                     cast<PointerType>(Ptr->getType())->getElementType(), New) ||
           (Record.size() < OpNum + 3 || Record.size() > OpNum + 5))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       AtomicOrdering SuccessOrdering = GetDecodedOrdering(Record[OpNum+1]);
       if (SuccessOrdering == NotAtomic || SuccessOrdering == Unordered)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
 
       AtomicOrdering FailureOrdering;
@@ -3012,14 +3117,14 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           popValue(Record, OpNum, NextValueNo,
                     cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
           OpNum+4 != Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       AtomicRMWInst::BinOp Operation = GetDecodedRMWOperation(Record[OpNum]);
       if (Operation < AtomicRMWInst::FIRST_BINOP ||
           Operation > AtomicRMWInst::LAST_BINOP)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
       if (Ordering == NotAtomic || Ordering == Unordered)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
       I = new AtomicRMWInst(Operation, Ptr, Val, Ordering, SynchScope);
       cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
@@ -3028,11 +3133,11 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     }
     case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
       if (2 != Record.size())
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
       if (Ordering == NotAtomic || Ordering == Unordered ||
           Ordering == Monotonic)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
       I = new FenceInst(Context, Ordering, SynchScope);
       InstructionList.push_back(I);
@@ -3041,7 +3146,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     case bitc::FUNC_CODE_INST_CALL: {
       // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       AttributeSet PAL = getAttributes(Record[0]);
       unsigned CCInfo = Record[1];
@@ -3049,13 +3154,13 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       unsigned OpNum = 2;
       Value *Callee;
       if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
       FunctionType *FTy = nullptr;
       if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
       if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
 
       SmallVector<Value*, 16> Args;
       // Read the fixed params.
@@ -3066,18 +3171,18 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
           Args.push_back(getValue(Record, OpNum, NextValueNo,
                                   FTy->getParamType(i)));
         if (!Args.back())
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
       }
 
       // Read type/value pairs for varargs params.
       if (!FTy->isVarArg()) {
         if (OpNum != Record.size())
-          return Error(InvalidRecord);
+          return Error(BitcodeError::InvalidRecord);
       } else {
         while (OpNum != Record.size()) {
           Value *Op;
           if (getValueTypePair(Record, OpNum, NextValueNo, Op))
-            return Error(InvalidRecord);
+            return Error(BitcodeError::InvalidRecord);
           Args.push_back(Op);
         }
       }
@@ -3097,12 +3202,12 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     }
     case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
       if (Record.size() < 3)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       Type *OpTy = getTypeByID(Record[0]);
       Value *Op = getValue(Record, 1, NextValueNo, OpTy);
       Type *ResTy = getTypeByID(Record[2]);
       if (!OpTy || !Op || !ResTy)
-        return Error(InvalidRecord);
+        return Error(BitcodeError::InvalidRecord);
       I = new VAArgInst(Op, ResTy);
       InstructionList.push_back(I);
       break;
@@ -3113,7 +3218,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
     // this file.
     if (!CurBB) {
       delete I;
-      return Error(InvalidInstructionWithNoBB);
+      return Error(BitcodeError::InvalidInstructionWithNoBB);
     }
     CurBB->getInstList().push_back(I);
 
@@ -3140,32 +3245,13 @@ OutOfRecordLoop:
           delete A;
         }
       }
-      return Error(NeverResolvedValueFoundInFunction);
+      return Error(BitcodeError::NeverResolvedValueFoundInFunction);
     }
   }
 
   // FIXME: Check for unresolved forward-declared metadata references
   // and clean up leaks.
 
-  // See if anything took the address of blocks in this function.  If so,
-  // resolve them now.
-  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
-    BlockAddrFwdRefs.find(F);
-  if (BAFRI != BlockAddrFwdRefs.end()) {
-    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
-    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
-      unsigned BlockIdx = RefList[i].first;
-      if (BlockIdx >= FunctionBBs.size())
-        return Error(InvalidID);
-
-      GlobalVariable *FwdRef = RefList[i].second;
-      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
-      FwdRef->eraseFromParent();
-    }
-
-    BlockAddrFwdRefs.erase(BAFRI);
-  }
-
   // Trim the value list down to the size it was before we parsed this function.
   ValueList.shrinkTo(ModuleValueListSize);
   MDValueList.shrinkTo(ModuleMDValueListSize);
@@ -3179,7 +3265,7 @@ std::error_code BitcodeReader::FindFunctionInStream(
     DenseMap<Function *, uint64_t>::iterator DeferredFunctionInfoIterator) {
   while (DeferredFunctionInfoIterator->second == 0) {
     if (Stream.AtEndOfStream())
-      return Error(CouldNotFindFunctionInStream);
+      return Error(BitcodeError::CouldNotFindFunctionInStream);
     // ParseModule will parse the next body in the stream and set its
     // position in the DeferredFunctionInfo map.
     if (std::error_code EC = ParseModule(true))
@@ -3234,13 +3320,21 @@ std::error_code BitcodeReader::Materialize(GlobalValue *GV) {
     }
   }
 
-  return std::error_code();
+  // Bring in any functions that this function forward-referenced via
+  // blockaddresses.
+  return materializeForwardReferencedFunctions();
 }
 
 bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
   const Function *F = dyn_cast<Function>(GV);
   if (!F || F->isDeclaration())
     return false;
+
+  // Dematerializing F would leave dangling references that wouldn't be
+  // reconnected on re-materialization.
+  if (BlockAddressesTaken.count(F))
+    return false;
+
   return DeferredFunctionInfo.count(const_cast<Function*>(F));
 }
 
@@ -3259,6 +3353,10 @@ void BitcodeReader::Dematerialize(GlobalValue *GV) {
 std::error_code BitcodeReader::MaterializeModule(Module *M) {
   assert(M == TheModule &&
          "Can only Materialize the Module this BitcodeReader is attached to.");
+
+  // Promise to materialize all forward references.
+  WillMaterializeAllForwardRefs = true;
+
   // Iterate over the module, deserializing any functions that are still on
   // disk.
   for (Module::iterator F = TheModule->begin(), E = TheModule->end();
@@ -3274,6 +3372,11 @@ std::error_code BitcodeReader::MaterializeModule(Module *M) {
   if (NextUnreadBit)
     ParseModule(true);
 
+  // Check that all block address forward references got resolved (as we
+  // promised above).
+  if (!BasicBlockFwdRefs.empty())
+    return Error(BitcodeError::NeverResolvedFunctionFromBlockAddress);
+
   // Upgrade any intrinsic calls that slipped through (should not happen!) and
   // delete the old functions to clean up. We can't do this unless the entire
   // module is materialized because there could always be another function body
@@ -3310,18 +3413,14 @@ std::error_code BitcodeReader::InitStreamFromBuffer() {
   const unsigned char *BufPtr = (const unsigned char*)Buffer->getBufferStart();
   const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
 
-  if (Buffer->getBufferSize() & 3) {
-    if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
-      return Error(InvalidBitcodeSignature);
-    else
-      return Error(BitcodeStreamInvalidSize);
-  }
+  if (Buffer->getBufferSize() & 3)
+    return Error(BitcodeError::InvalidBitcodeSignature);
 
   // If we have a wrapper header, parse it and ignore the non-bc file contents.
   // The magic number is 0x0B17C0DE stored in little endian.
   if (isBitcodeWrapper(BufPtr, BufEnd))
     if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
-      return Error(InvalidBitcodeWrapperHeader);
+      return Error(BitcodeError::InvalidBitcodeWrapperHeader);
 
   StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
   Stream.init(*StreamFile);
@@ -3338,10 +3437,10 @@ std::error_code BitcodeReader::InitLazyStream() {
 
   unsigned char buf[16];
   if (Bytes->readBytes(0, 16, buf) == -1)
-    return Error(BitcodeStreamInvalidSize);
+    return Error(BitcodeError::InvalidBitcodeSignature);
 
   if (!isBitcode(buf, buf + 16))
-    return Error(InvalidBitcodeSignature);
+    return Error(BitcodeError::InvalidBitcodeSignature);
 
   if (isBitcodeWrapper(buf, buf + 4)) {
     const unsigned char *bitcodeStart = buf;
@@ -3359,45 +3458,45 @@ class BitcodeErrorCategoryType : public std::error_category {
     return "llvm.bitcode";
   }
   std::string message(int IE) const override {
-    BitcodeReader::ErrorType E = static_cast<BitcodeReader::ErrorType>(IE);
+    BitcodeError E = static_cast<BitcodeError>(IE);
     switch (E) {
-    case BitcodeReader::BitcodeStreamInvalidSize:
-      return "Bitcode stream length should be >= 16 bytes and a multiple of 4";
-    case BitcodeReader::ConflictingMETADATA_KINDRecords:
+    case BitcodeError::ConflictingMETADATA_KINDRecords:
       return "Conflicting METADATA_KIND records";
-    case BitcodeReader::CouldNotFindFunctionInStream:
+    case BitcodeError::CouldNotFindFunctionInStream:
       return "Could not find function in stream";
-    case BitcodeReader::ExpectedConstant:
+    case BitcodeError::ExpectedConstant:
       return "Expected a constant";
-    case BitcodeReader::InsufficientFunctionProtos:
+    case BitcodeError::InsufficientFunctionProtos:
       return "Insufficient function protos";
-    case BitcodeReader::InvalidBitcodeSignature:
+    case BitcodeError::InvalidBitcodeSignature:
       return "Invalid bitcode signature";
-    case BitcodeReader::InvalidBitcodeWrapperHeader:
+    case BitcodeError::InvalidBitcodeWrapperHeader:
       return "Invalid bitcode wrapper header";
-    case BitcodeReader::InvalidConstantReference:
+    case BitcodeError::InvalidConstantReference:
       return "Invalid ronstant reference";
-    case BitcodeReader::InvalidID:
+    case BitcodeError::InvalidID:
       return "Invalid ID";
-    case BitcodeReader::InvalidInstructionWithNoBB:
+    case BitcodeError::InvalidInstructionWithNoBB:
       return "Invalid instruction with no BB";
-    case BitcodeReader::InvalidRecord:
+    case BitcodeError::InvalidRecord:
       return "Invalid record";
-    case BitcodeReader::InvalidTypeForValue:
+    case BitcodeError::InvalidTypeForValue:
       return "Invalid type for value";
-    case BitcodeReader::InvalidTYPETable:
+    case BitcodeError::InvalidTYPETable:
       return "Invalid TYPE table";
-    case BitcodeReader::InvalidType:
+    case BitcodeError::InvalidType:
       return "Invalid type";
-    case BitcodeReader::MalformedBlock:
+    case BitcodeError::MalformedBlock:
       return "Malformed block";
-    case BitcodeReader::MalformedGlobalInitializerSet:
+    case BitcodeError::MalformedGlobalInitializerSet:
       return "Malformed global initializer set";
-    case BitcodeReader::InvalidMultipleBlocks:
+    case BitcodeError::InvalidMultipleBlocks:
       return "Invalid multiple blocks";
-    case BitcodeReader::NeverResolvedValueFoundInFunction:
+    case BitcodeError::NeverResolvedValueFoundInFunction:
       return "Never resolved value found in function";
-    case BitcodeReader::InvalidValue:
+    case BitcodeError::NeverResolvedFunctionFromBlockAddress:
+      return "Never resolved function from blockaddress";
+    case BitcodeError::InvalidValue:
       return "Invalid value";
     }
     llvm_unreachable("Unknown error type!");
@@ -3405,7 +3504,7 @@ class BitcodeErrorCategoryType : public std::error_category {
 };
 }
 
-const std::error_category &BitcodeReader::BitcodeErrorCategory() {
+const std::error_category &llvm::BitcodeErrorCategory() {
   static BitcodeErrorCategoryType O;
   return O;
 }
@@ -3414,24 +3513,42 @@ const std::error_category &BitcodeReader::BitcodeErrorCategory() {
 // External interface
 //===----------------------------------------------------------------------===//
 
-/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
+/// \brief Get a lazy one-at-time loading module from bitcode.
 ///
-ErrorOr<Module *> llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
-                                             LLVMContext &Context) {
+/// This isn't always used in a lazy context.  In particular, it's also used by
+/// \a parseBitcodeFile().  If this is truly lazy, then we need to eagerly pull
+/// in forward-referenced functions from block address references.
+///
+/// \param[in] WillMaterializeAll Set to \c true if the caller promises to
+/// materialize everything -- in particular, if this isn't truly lazy.
+static ErrorOr<Module *> getLazyBitcodeModuleImpl(MemoryBuffer *Buffer,
+                                                  LLVMContext &Context,
+                                                  bool WillMaterializeAll) {
   Module *M = new Module(Buffer->getBufferIdentifier(), Context);
   BitcodeReader *R = new BitcodeReader(Buffer, Context);
   M->setMaterializer(R);
-  if (std::error_code EC = R->ParseBitcodeInto(M)) {
+
+  auto cleanupOnError = [&](std::error_code EC) {
     R->releaseBuffer(); // Never take ownership on error.
     delete M;  // Also deletes R.
     return EC;
-  }
+  };
+
+  if (std::error_code EC = R->ParseBitcodeInto(M))
+    return cleanupOnError(EC);
 
-  R->materializeForwardReferencedFunctions();
+  if (!WillMaterializeAll)
+    // Resolve forward references from blockaddresses.
+    if (std::error_code EC = R->materializeForwardReferencedFunctions())
+      return cleanupOnError(EC);
 
   return M;
 }
 
+ErrorOr<Module *> llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
+                                             LLVMContext &Context) {
+  return getLazyBitcodeModuleImpl(Buffer, Context, false);
+}
 
 Module *llvm::getStreamedBitcodeModule(const std::string &name,
                                        DataStreamer *streamer,
@@ -3451,7 +3568,8 @@ Module *llvm::getStreamedBitcodeModule(const std::string &name,
 
 ErrorOr<Module *> llvm::parseBitcodeFile(MemoryBuffer *Buffer,
                                          LLVMContext &Context) {
-  ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModule(Buffer, Context);
+  ErrorOr<Module *> ModuleOrErr =
+      getLazyBitcodeModuleImpl(Buffer, Context, true);
   if (!ModuleOrErr)
     return ModuleOrErr;
   Module *M = ModuleOrErr.get();
@@ -3468,16 +3586,12 @@ ErrorOr<Module *> llvm::parseBitcodeFile(MemoryBuffer *Buffer,
 }
 
 std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
-                                         LLVMContext& Context,
-                                         std::string *ErrMsg) {
+                                         LLVMContext &Context) {
   BitcodeReader *R = new BitcodeReader(Buffer, Context);
-
-  std::string Triple("");
-  if (std::error_code EC = R->ParseTriple(Triple))
-    if (ErrMsg)
-      *ErrMsg = EC.message();
-
+  ErrorOr<std::string> Triple = R->parseTriple();
   R->releaseBuffer();
   delete R;
-  return Triple;
+  if (Triple.getError())
+    return "";
+  return Triple.get();
 }