1 //===- ValueList.cpp - Internal BitcodeReader implementation --------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "ValueList.h" 10 #include "llvm/IR/Argument.h" 11 #include "llvm/IR/Constant.h" 12 #include "llvm/IR/Constants.h" 13 #include "llvm/IR/GlobalValue.h" 14 #include "llvm/IR/Instruction.h" 15 #include "llvm/IR/Type.h" 16 #include "llvm/IR/User.h" 17 #include "llvm/IR/Value.h" 18 #include "llvm/Support/Casting.h" 19 #include "llvm/Support/Error.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #include <cstddef> 22 23 using namespace llvm; 24 25 Error BitcodeReaderValueList::assignValue(unsigned Idx, Value *V, 26 unsigned TypeID) { 27 if (Idx == size()) { 28 push_back(V, TypeID); 29 return Error::success(); 30 } 31 32 if (Idx >= size()) 33 resize(Idx + 1); 34 35 auto &Old = ValuePtrs[Idx]; 36 if (!Old.first) { 37 Old.first = V; 38 Old.second = TypeID; 39 return Error::success(); 40 } 41 42 assert(!isa<Constant>(&*Old.first) && "Shouldn't update constant"); 43 // If there was a forward reference to this value, replace it. 44 Value *PrevVal = Old.first; 45 if (PrevVal->getType() != V->getType()) 46 return createStringError( 47 std::errc::illegal_byte_sequence, 48 "Assigned value does not match type of forward declaration"); 49 Old.first->replaceAllUsesWith(V); 50 PrevVal->deleteValue(); 51 return Error::success(); 52 } 53 54 Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty, 55 unsigned TyID, 56 BasicBlock *ConstExprInsertBB) { 57 // Bail out for a clearly invalid value. 58 if (Idx >= RefsUpperBound) 59 return nullptr; 60 61 if (Idx >= size()) 62 resize(Idx + 1); 63 64 if (Value *V = ValuePtrs[Idx].first) { 65 // If the types don't match, it's invalid. 66 if (Ty && Ty != V->getType()) 67 return nullptr; 68 69 Expected<Value *> MaybeV = MaterializeValueFn(Idx, ConstExprInsertBB); 70 if (!MaybeV) { 71 // TODO: We might want to propagate the precise error message here. 72 consumeError(MaybeV.takeError()); 73 return nullptr; 74 } 75 return MaybeV.get(); 76 } 77 78 // No type specified, must be invalid reference. 79 if (!Ty) 80 return nullptr; 81 82 // Create and return a placeholder, which will later be RAUW'd. 83 Value *V = new Argument(Ty); 84 ValuePtrs[Idx] = {V, TyID}; 85 return V; 86 } 87