| //===-- Bitcode/Reader/ValueList.h - Number values --------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This class gives values and types Unique ID's. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_LIB_BITCODE_READER_VALUELIST_H |
| #define LLVM_LIB_BITCODE_READER_VALUELIST_H |
| |
| #include "llvm/IR/ValueHandle.h" |
| #include <cassert> |
| #include <utility> |
| #include <vector> |
| |
| namespace llvm { |
| |
| class Constant; |
| class LLVMContext; |
| class Type; |
| class Value; |
| |
| class BitcodeReaderValueList { |
| std::vector<WeakTrackingVH> ValuePtrs; |
| |
| /// Struct containing fully-specified copies of the type of each |
| /// value. When pointers are opaque, this will be contain non-opaque |
| /// variants so that restructuring instructions can determine their |
| /// type correctly even if being loaded from old bitcode where some |
| /// types are implicit. |
| std::vector<Type *> FullTypes; |
| |
| /// As we resolve forward-referenced constants, we add information about them |
| /// to this vector. This allows us to resolve them in bulk instead of |
| /// resolving each reference at a time. See the code in |
| /// ResolveConstantForwardRefs for more information about this. |
| /// |
| /// The key of this vector is the placeholder constant, the value is the slot |
| /// number that holds the resolved value. |
| using ResolveConstantsTy = std::vector<std::pair<Constant *, unsigned>>; |
| ResolveConstantsTy ResolveConstants; |
| LLVMContext &Context; |
| |
| /// Maximum number of valid references. Forward references exceeding the |
| /// maximum must be invalid. |
| unsigned RefsUpperBound; |
| |
| public: |
| BitcodeReaderValueList(LLVMContext &C, size_t RefsUpperBound) |
| : Context(C), |
| RefsUpperBound(std::min((size_t)std::numeric_limits<unsigned>::max(), |
| RefsUpperBound)) {} |
| |
| ~BitcodeReaderValueList() { |
| assert(ResolveConstants.empty() && "Constants not resolved?"); |
| } |
| |
| // vector compatibility methods |
| unsigned size() const { return ValuePtrs.size(); } |
| void resize(unsigned N) { |
| ValuePtrs.resize(N); |
| FullTypes.resize(N); |
| } |
| void push_back(Value *V, Type *Ty) { |
| ValuePtrs.emplace_back(V); |
| FullTypes.emplace_back(Ty); |
| } |
| |
| void clear() { |
| assert(ResolveConstants.empty() && "Constants not resolved?"); |
| ValuePtrs.clear(); |
| FullTypes.clear(); |
| } |
| |
| Value *operator[](unsigned i) const { |
| assert(i < ValuePtrs.size()); |
| return ValuePtrs[i]; |
| } |
| |
| Value *back() const { return ValuePtrs.back(); } |
| void pop_back() { |
| ValuePtrs.pop_back(); |
| FullTypes.pop_back(); |
| } |
| bool empty() const { return ValuePtrs.empty(); } |
| |
| void shrinkTo(unsigned N) { |
| assert(N <= size() && "Invalid shrinkTo request!"); |
| ValuePtrs.resize(N); |
| FullTypes.resize(N); |
| } |
| |
| Constant *getConstantFwdRef(unsigned Idx, Type *Ty); |
| Value *getValueFwdRef(unsigned Idx, Type *Ty, Type **FullTy = nullptr); |
| |
| void assignValue(Value *V, unsigned Idx, Type *FullTy); |
| |
| /// Once all constants are read, this method bulk resolves any forward |
| /// references. |
| void resolveConstantForwardRefs(); |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_LIB_BITCODE_READER_VALUELIST_H |