1 //===- BitcodeReader.h - Internal BitcodeReader impl ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // 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/Attributes.h"
19 #include "llvm/Type.h"
20 #include "llvm/OperandTraits.h"
21 #include "llvm/Bitcode/BitstreamReader.h"
22 #include "llvm/Bitcode/LLVMBitCodes.h"
23 #include "llvm/Support/ValueHandle.h"
24 #include "llvm/ADT/DenseMap.h"
31 //===----------------------------------------------------------------------===//
32 // BitcodeReaderValueList Class
33 //===----------------------------------------------------------------------===//
35 class BitcodeReaderValueList {
36 std::vector<WeakVH> ValuePtrs;
38 /// ResolveConstants - As we resolve forward-referenced constants, we add
39 /// information about them to this vector. This allows us to resolve them in
40 /// bulk instead of resolving each reference at a time. See the code in
41 /// ResolveConstantForwardRefs for more information about this.
43 /// The key of this vector is the placeholder constant, the value is the slot
44 /// number that holds the resolved value.
45 typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy;
46 ResolveConstantsTy ResolveConstants;
49 BitcodeReaderValueList(LLVMContext& C) : Context(C) {}
50 ~BitcodeReaderValueList() {
51 assert(ResolveConstants.empty() && "Constants not resolved?");
54 // vector compatibility methods
55 unsigned size() const { return ValuePtrs.size(); }
56 void resize(unsigned N) { ValuePtrs.resize(N); }
57 void push_back(Value *V) {
58 ValuePtrs.push_back(V);
62 assert(ResolveConstants.empty() && "Constants not resolved?");
66 Value *operator[](unsigned i) const {
67 assert(i < ValuePtrs.size());
71 Value *back() const { return ValuePtrs.back(); }
72 void pop_back() { ValuePtrs.pop_back(); }
73 bool empty() const { return ValuePtrs.empty(); }
74 void shrinkTo(unsigned N) {
75 assert(N <= size() && "Invalid shrinkTo request!");
79 Constant *getConstantFwdRef(unsigned Idx, const Type *Ty);
80 Value *getValueFwdRef(unsigned Idx, const Type *Ty);
82 void AssignValue(Value *V, unsigned Idx);
84 /// ResolveConstantForwardRefs - Once all constants are read, this method bulk
85 /// resolves any forward references.
86 void ResolveConstantForwardRefs();
90 //===----------------------------------------------------------------------===//
91 // BitcodeReaderMDValueList Class
92 //===----------------------------------------------------------------------===//
94 class BitcodeReaderMDValueList {
95 std::vector<WeakVH> MDValuePtrs;
99 BitcodeReaderMDValueList(LLVMContext& C) : Context(C) {}
101 // vector compatibility methods
102 unsigned size() const { return MDValuePtrs.size(); }
103 void resize(unsigned N) { MDValuePtrs.resize(N); }
104 void push_back(Value *V) { MDValuePtrs.push_back(V); }
105 void clear() { MDValuePtrs.clear(); }
106 Value *back() const { return MDValuePtrs.back(); }
107 void pop_back() { MDValuePtrs.pop_back(); }
108 bool empty() const { return MDValuePtrs.empty(); }
110 Value *operator[](unsigned i) const {
111 assert(i < MDValuePtrs.size());
112 return MDValuePtrs[i];
115 void shrinkTo(unsigned N) {
116 assert(N <= size() && "Invalid shrinkTo request!");
117 MDValuePtrs.resize(N);
120 Value *getValueFwdRef(unsigned Idx);
121 void AssignValue(Value *V, unsigned Idx);
124 class BitcodeReader : public ModuleProvider {
125 LLVMContext &Context;
126 MemoryBuffer *Buffer;
127 BitstreamReader StreamFile;
128 BitstreamCursor Stream;
130 const char *ErrorString;
132 std::vector<PATypeHolder> TypeList;
133 BitcodeReaderValueList ValueList;
134 BitcodeReaderMDValueList MDValueList;
135 SmallVector<Instruction *, 64> InstructionList;
137 std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
138 std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
140 /// MAttributes - The set of attributes by index. Index zero in the
141 /// file is for null, and is thus not represented here. As such all indices
143 std::vector<AttrListPtr> MAttributes;
145 /// FunctionBBs - While parsing a function body, this is a list of the basic
146 /// blocks for the function.
147 std::vector<BasicBlock*> FunctionBBs;
149 // When reading the module header, this list is populated with functions that
150 // have bodies later in the file.
151 std::vector<Function*> FunctionsWithBodies;
153 // When intrinsic functions are encountered which require upgrading they are
154 // stored here with their replacement function.
155 typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
156 UpgradedIntrinsicMap UpgradedIntrinsics;
158 // After the module header has been read, the FunctionsWithBodies list is
159 // reversed. This keeps track of whether we've done this yet.
160 bool HasReversedFunctionsWithBodies;
162 /// DeferredFunctionInfo - When function bodies are initially scanned, this
163 /// map contains info about where to find deferred function body (in the
164 /// stream) and what linkage the original function had.
165 DenseMap<Function*, std::pair<uint64_t, unsigned> > DeferredFunctionInfo;
167 /// BlockAddrFwdRefs - These are blockaddr references to basic blocks. These
168 /// are resolved lazily when functions are loaded.
169 typedef std::pair<unsigned, GlobalVariable*> BlockAddrRefTy;
170 DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs;
173 explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext& C)
174 : Context(C), Buffer(buffer), ErrorString(0), ValueList(C), MDValueList(C) {
175 HasReversedFunctionsWithBodies = false;
183 /// releaseMemoryBuffer - This causes the reader to completely forget about
184 /// the memory buffer it contains, which prevents the buffer from being
185 /// destroyed when it is deleted.
186 void releaseMemoryBuffer() {
190 virtual bool materializeFunction(Function *F, std::string *ErrInfo = 0);
191 virtual Module *materializeModule(std::string *ErrInfo = 0);
192 virtual void dematerializeFunction(Function *F);
193 virtual Module *releaseModule(std::string *ErrInfo = 0);
195 bool Error(const char *Str) {
199 const char *getErrorString() const { return ErrorString; }
201 /// @brief Main interface to parsing a bitcode buffer.
202 /// @returns true if an error occurred.
205 const Type *getTypeByID(unsigned ID, bool isTypeTable = false);
206 Value *getFnValueByID(unsigned ID, const Type *Ty) {
207 if (Ty == Type::getMetadataTy(Context))
208 return MDValueList.getValueFwdRef(ID);
210 return ValueList.getValueFwdRef(ID, Ty);
212 BasicBlock *getBasicBlock(unsigned ID) const {
213 if (ID >= FunctionBBs.size()) return 0; // Invalid ID
214 return FunctionBBs[ID];
216 AttrListPtr getAttributes(unsigned i) const {
217 if (i-1 < MAttributes.size())
218 return MAttributes[i-1];
219 return AttrListPtr();
222 /// getValueTypePair - Read a value/type pair out of the specified record from
223 /// slot 'Slot'. Increment Slot past the number of slots used in the record.
224 /// Return true on failure.
225 bool getValueTypePair(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
226 unsigned InstNum, Value *&ResVal) {
227 if (Slot == Record.size()) return true;
228 unsigned ValNo = (unsigned)Record[Slot++];
229 if (ValNo < InstNum) {
230 // If this is not a forward reference, just return the value we already
232 ResVal = getFnValueByID(ValNo, 0);
234 } else if (Slot == Record.size()) {
238 unsigned TypeNo = (unsigned)Record[Slot++];
239 ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
242 bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
243 const Type *Ty, Value *&ResVal) {
244 if (Slot == Record.size()) return true;
245 unsigned ValNo = (unsigned)Record[Slot++];
246 ResVal = getFnValueByID(ValNo, Ty);
251 bool ParseModule(const std::string &ModuleID);
252 bool ParseAttributeBlock();
253 bool ParseTypeTable();
254 bool ParseTypeSymbolTable();
255 bool ParseValueSymbolTable();
256 bool ParseConstants();
257 bool RememberAndSkipFunctionBody();
258 bool ParseFunctionBody(Function *F);
259 bool ResolveGlobalAndAliasInits();
260 bool ParseMetadata();
261 bool ParseMetadataAttachment();
264 } // End llvm namespace