1 //===-- Bitcode/Reader/ValueList.h - Number values --------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This class gives values and types Unique ID's. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_BITCODE_READER_VALUELIST_H 15 #define LLVM_LIB_BITCODE_READER_VALUELIST_H 16 17 #include "llvm/IR/ValueHandle.h" 18 #include <cassert> 19 #include <utility> 20 #include <vector> 21 22 namespace llvm { 23 24 class Constant; 25 class LLVMContext; 26 class Type; 27 class Value; 28 29 class BitcodeReaderValueList { 30 std::vector<WeakTrackingVH> ValuePtrs; 31 32 /// As we resolve forward-referenced constants, we add information about them 33 /// to this vector. This allows us to resolve them in bulk instead of 34 /// resolving each reference at a time. See the code in 35 /// ResolveConstantForwardRefs for more information about this. 36 /// 37 /// The key of this vector is the placeholder constant, the value is the slot 38 /// number that holds the resolved value. 39 using ResolveConstantsTy = std::vector<std::pair<Constant *, unsigned>>; 40 ResolveConstantsTy ResolveConstants; 41 LLVMContext &Context; 42 43 public: BitcodeReaderValueList(LLVMContext & C)44 BitcodeReaderValueList(LLVMContext &C) : Context(C) {} 45 ~BitcodeReaderValueList()46 ~BitcodeReaderValueList() { 47 assert(ResolveConstants.empty() && "Constants not resolved?"); 48 } 49 50 // vector compatibility methods size()51 unsigned size() const { return ValuePtrs.size(); } resize(unsigned N)52 void resize(unsigned N) { ValuePtrs.resize(N); } push_back(Value * V)53 void push_back(Value *V) { ValuePtrs.emplace_back(V); } 54 clear()55 void clear() { 56 assert(ResolveConstants.empty() && "Constants not resolved?"); 57 ValuePtrs.clear(); 58 } 59 60 Value *operator[](unsigned i) const { 61 assert(i < ValuePtrs.size()); 62 return ValuePtrs[i]; 63 } 64 back()65 Value *back() const { return ValuePtrs.back(); } pop_back()66 void pop_back() { ValuePtrs.pop_back(); } empty()67 bool empty() const { return ValuePtrs.empty(); } 68 shrinkTo(unsigned N)69 void shrinkTo(unsigned N) { 70 assert(N <= size() && "Invalid shrinkTo request!"); 71 ValuePtrs.resize(N); 72 } 73 74 Constant *getConstantFwdRef(unsigned Idx, Type *Ty); 75 Value *getValueFwdRef(unsigned Idx, Type *Ty); 76 77 void assignValue(Value *V, unsigned Idx); 78 79 /// Once all constants are read, this method bulk resolves any forward 80 /// references. 81 void resolveConstantForwardRefs(); 82 }; 83 84 } // end namespace llvm 85 86 #endif // LLVM_LIB_BITCODE_READER_VALUELIST_H 87