1 //===- BitcodeReader.h - Internal BitcodeReader impl ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Chris Lattner and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header defines the BitcodeReader class.
12 //===----------------------------------------------------------------------===//
14 #ifndef BITCODE_READER_H
15 #define BITCODE_READER_H
17 #include "llvm/ModuleProvider.h"
18 #include "llvm/Type.h"
19 #include "llvm/User.h"
20 #include "llvm/Bitcode/BitstreamReader.h"
21 #include "llvm/Bitcode/LLVMBitCodes.h"
22 #include "llvm/ADT/DenseMap.h"
29 class BitcodeReaderValueList : public User {
30 std::vector<Use> Uses;
32 BitcodeReaderValueList() : User(Type::VoidTy, Value::ArgumentVal, 0, 0) {}
34 // vector compatibility methods
35 unsigned size() const { return getNumOperands(); }
36 void push_back(Value *V) {
37 Uses.push_back(Use(V, this));
38 OperandList = &Uses[0];
43 std::vector<Use>().swap(Uses);
46 Value *operator[](unsigned i) const { return getOperand(i); }
48 Value *back() const { return Uses.back(); }
49 void pop_back() { Uses.pop_back(); --NumOperands; }
50 bool empty() const { return NumOperands == 0; }
51 void shrinkTo(unsigned N) {
52 assert(N <= NumOperands && "Invalid shrinkTo request!");
56 virtual void print(std::ostream&) const {}
58 Constant *getConstantFwdRef(unsigned Idx, const Type *Ty);
59 Value *getValueFwdRef(unsigned Idx, const Type *Ty);
61 void AssignValue(Value *V, unsigned Idx) {
64 } else if (Value *OldV = getOperand(Idx)) {
65 // If there was a forward reference to this value, replace it.
67 OldV->replaceAllUsesWith(V);
75 void initVal(unsigned Idx, Value *V) {
76 assert(Uses[Idx] == 0 && "Cannot init an already init'd Use!");
77 Uses[Idx].init(V, this);
82 class BitcodeReader : public ModuleProvider {
84 BitstreamReader Stream;
86 const char *ErrorString;
88 std::vector<PATypeHolder> TypeList;
89 BitcodeReaderValueList ValueList;
90 std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
91 std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
93 /// ParamAttrs - The set of parameter attributes by index. Index zero in the
94 /// file is for null, and is thus not represented here. As such all indices
96 std::vector<const ParamAttrsList*> ParamAttrs;
98 /// FunctionBBs - While parsing a function body, this is a list of the basic
99 /// blocks for the function.
100 std::vector<BasicBlock*> FunctionBBs;
102 // When reading the module header, this list is populated with functions that
103 // have bodies later in the file.
104 std::vector<Function*> FunctionsWithBodies;
106 // After the module header has been read, the FunctionsWithBodies list is
107 // reversed. This keeps track of whether we've done this yet.
108 bool HasReversedFunctionsWithBodies;
110 /// DeferredFunctionInfo - When function bodies are initially scanned, this
111 /// map contains info about where to find deferred function body (in the
112 /// stream) and what linkage the original function had.
113 DenseMap<Function*, std::pair<uint64_t, unsigned> > DeferredFunctionInfo;
115 BitcodeReader(MemoryBuffer *buffer) : Buffer(buffer), ErrorString(0) {
116 HasReversedFunctionsWithBodies = false;
124 /// releaseMemoryBuffer - This causes the reader to completely forget about
125 /// the memory buffer it contains, which prevents the buffer from being
126 /// destroyed when it is deleted.
127 void releaseMemoryBuffer() {
131 virtual bool materializeFunction(Function *F, std::string *ErrInfo = 0);
132 virtual Module *materializeModule(std::string *ErrInfo = 0);
133 virtual void dematerializeFunction(Function *F);
134 virtual Module *releaseModule(std::string *ErrInfo = 0);
136 bool Error(const char *Str) {
140 const char *getErrorString() const { return ErrorString; }
142 /// @brief Main interface to parsing a bitcode buffer.
143 /// @returns true if an error occurred.
146 const Type *getTypeByID(unsigned ID, bool isTypeTable = false);
147 Value *getFnValueByID(unsigned ID, const Type *Ty) {
148 return ValueList.getValueFwdRef(ID, Ty);
150 BasicBlock *getBasicBlock(unsigned ID) const {
151 if (ID >= FunctionBBs.size()) return 0; // Invalid ID
152 return FunctionBBs[ID];
154 const ParamAttrsList *getParamAttrs(unsigned i) const {
155 if (i-1 < ParamAttrs.size())
156 return ParamAttrs[i-1];
160 /// getValueTypePair - Read a value/type pair out of the specified record from
161 /// slot 'Slot'. Increment Slot past the number of slots used in the record.
162 /// Return true on failure.
163 bool getValueTypePair(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
164 unsigned InstNum, Value *&ResVal) {
165 if (Slot == Record.size()) return true;
166 unsigned ValNo = (unsigned)Record[Slot++];
167 if (ValNo < InstNum) {
168 // If this is not a forward reference, just return the value we already
170 ResVal = getFnValueByID(ValNo, 0);
172 } else if (Slot == Record.size()) {
176 unsigned TypeNo = (unsigned)Record[Slot++];
177 ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
180 bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
181 const Type *Ty, Value *&ResVal) {
182 if (Slot == Record.size()) return true;
183 unsigned ValNo = (unsigned)Record[Slot++];
184 ResVal = getFnValueByID(ValNo, Ty);
189 bool ParseModule(const std::string &ModuleID);
190 bool ParseParamAttrBlock();
191 bool ParseTypeTable();
192 bool ParseTypeSymbolTable();
193 bool ParseValueSymbolTable();
194 bool ParseConstants();
195 bool RememberAndSkipFunctionBody();
196 bool ParseFunctionBody(Function *F);
197 bool ResolveGlobalAndAliasInits();
200 } // End llvm namespace