llvm/lib/Bitcode/Reader/ValueList.h

   1 //===-- Bitcode/Reader/ValueList.h - Number values --------------*- C++ -*-===//
   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 // This class gives values and types Unique ID's.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_BITCODE_READER_VALUELIST_H
  14 #define LLVM_LIB_BITCODE_READER_VALUELIST_H
  15
  16 #include "llvm/IR/ValueHandle.h"
  17 #include "llvm/Support/Error.h"
  18 #include <cassert>
  19 #include <utility>
  20 #include <vector>
  21
  22 namespace llvm {
  23
  24 class Error;
  25 class Type;
  26 class Value;
  27
  28 class BitcodeReaderValueList {
  29   /// Maps Value ID to pair of Value* and Type ID.
  30   std::vector<std::pair<WeakTrackingVH, unsigned>> ValuePtrs;
  31
  32   /// Maximum number of valid references. Forward references exceeding the
  33   /// maximum must be invalid.
  34   unsigned RefsUpperBound;
  35
  36   using MaterializeValueFnTy =
  37       std::function<Expected<Value *>(unsigned, BasicBlock *)>;
  38   MaterializeValueFnTy MaterializeValueFn;
  39
  40 public:
  41   BitcodeReaderValueList(size_t RefsUpperBound,
  42                          MaterializeValueFnTy MaterializeValueFn)
  43       : RefsUpperBound(std::min((size_t)std::numeric_limits<unsigned>::max(),
  44                                 RefsUpperBound)),
  45         MaterializeValueFn(MaterializeValueFn) {}
  46
  47   // vector compatibility methods
  48   unsigned size() const { return ValuePtrs.size(); }
  49   void resize(unsigned N) {
  50     ValuePtrs.resize(N);
  51   }
  52   void push_back(Value *V, unsigned TypeID) {
  53     ValuePtrs.emplace_back(V, TypeID);
  54   }
  55
  56   void clear() {
  57     ValuePtrs.clear();
  58   }
  59
  60   Value *operator[](unsigned i) const {
  61     assert(i < ValuePtrs.size());
  62     return ValuePtrs[i].first;
  63   }
  64
  65   unsigned getTypeID(unsigned ValNo) const {
  66     assert(ValNo < ValuePtrs.size());
  67     return ValuePtrs[ValNo].second;
  68   }
  69
  70   Value *back() const { return ValuePtrs.back().first; }
  71   void pop_back() {
  72     ValuePtrs.pop_back();
  73   }
  74   bool empty() const { return ValuePtrs.empty(); }
  75
  76   void shrinkTo(unsigned N) {
  77     assert(N <= size() && "Invalid shrinkTo request!");
  78     ValuePtrs.resize(N);
  79   }
  80
  81   void replaceValueWithoutRAUW(unsigned ValNo, Value *NewV) {
  82     assert(ValNo < ValuePtrs.size());
  83     ValuePtrs[ValNo].first = NewV;
  84   }
  85
  86   Value *getValueFwdRef(unsigned Idx, Type *Ty, unsigned TyID,
  87                         BasicBlock *ConstExprInsertBB);
  88
  89   Error assignValue(unsigned Idx, Value *V, unsigned TypeID);
  90 };
  91
  92 } // end namespace llvm
  93
  94 #endif // LLVM_LIB_BITCODE_READER_VALUELIST_H