Land the long talked about "type system rewrite" patch. This
[llvm/stm8.git] / lib / Bitcode / Reader / BitcodeReader.h
blob1b3bf1a1854a133c38657a3886d01617e03c220b
1 //===- BitcodeReader.h - Internal BitcodeReader impl ------------*- 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 header defines the BitcodeReader class.
12 //===----------------------------------------------------------------------===//
14 #ifndef BITCODE_READER_H
15 #define BITCODE_READER_H
17 #include "llvm/GVMaterializer.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"
25 #include <vector>
27 namespace llvm {
28 class MemoryBuffer;
29 class LLVMContext;
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.
42 ///
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;
47 LLVMContext &Context;
48 public:
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);
61 void clear() {
62 assert(ResolveConstants.empty() && "Constants not resolved?");
63 ValuePtrs.clear();
66 Value *operator[](unsigned i) const {
67 assert(i < ValuePtrs.size());
68 return ValuePtrs[i];
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!");
76 ValuePtrs.resize(N);
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;
97 LLVMContext &Context;
98 public:
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 GVMaterializer {
125 LLVMContext &Context;
126 Module *TheModule;
127 MemoryBuffer *Buffer;
128 bool BufferOwned;
129 BitstreamReader StreamFile;
130 BitstreamCursor Stream;
132 const char *ErrorString;
134 std::vector<Type*> TypeList;
135 BitcodeReaderValueList ValueList;
136 BitcodeReaderMDValueList MDValueList;
137 SmallVector<Instruction *, 64> InstructionList;
139 std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
140 std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
142 /// MAttributes - The set of attributes by index. Index zero in the
143 /// file is for null, and is thus not represented here. As such all indices
144 /// are off by one.
145 std::vector<AttrListPtr> MAttributes;
147 /// FunctionBBs - While parsing a function body, this is a list of the basic
148 /// blocks for the function.
149 std::vector<BasicBlock*> FunctionBBs;
151 // When reading the module header, this list is populated with functions that
152 // have bodies later in the file.
153 std::vector<Function*> FunctionsWithBodies;
155 // When intrinsic functions are encountered which require upgrading they are
156 // stored here with their replacement function.
157 typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
158 UpgradedIntrinsicMap UpgradedIntrinsics;
160 // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
161 DenseMap<unsigned, unsigned> MDKindMap;
163 // After the module header has been read, the FunctionsWithBodies list is
164 // reversed. This keeps track of whether we've done this yet.
165 bool HasReversedFunctionsWithBodies;
167 /// DeferredFunctionInfo - When function bodies are initially scanned, this
168 /// map contains info about where to find deferred function body in the
169 /// stream.
170 DenseMap<Function*, uint64_t> DeferredFunctionInfo;
172 /// BlockAddrFwdRefs - These are blockaddr references to basic blocks. These
173 /// are resolved lazily when functions are loaded.
174 typedef std::pair<unsigned, GlobalVariable*> BlockAddrRefTy;
175 DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs;
177 public:
178 explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C)
179 : Context(C), TheModule(0), Buffer(buffer), BufferOwned(false),
180 ErrorString(0), ValueList(C), MDValueList(C) {
181 HasReversedFunctionsWithBodies = false;
183 ~BitcodeReader() {
184 FreeState();
187 void FreeState();
189 /// setBufferOwned - If this is true, the reader will destroy the MemoryBuffer
190 /// when the reader is destroyed.
191 void setBufferOwned(bool Owned) { BufferOwned = Owned; }
193 virtual bool isMaterializable(const GlobalValue *GV) const;
194 virtual bool isDematerializable(const GlobalValue *GV) const;
195 virtual bool Materialize(GlobalValue *GV, std::string *ErrInfo = 0);
196 virtual bool MaterializeModule(Module *M, std::string *ErrInfo = 0);
197 virtual void Dematerialize(GlobalValue *GV);
199 bool Error(const char *Str) {
200 ErrorString = Str;
201 return true;
203 const char *getErrorString() const { return ErrorString; }
205 /// @brief Main interface to parsing a bitcode buffer.
206 /// @returns true if an error occurred.
207 bool ParseBitcodeInto(Module *M);
209 /// @brief Cheap mechanism to just extract module triple
210 /// @returns true if an error occurred.
211 bool ParseTriple(std::string &Triple);
212 private:
213 Type *getTypeByID(unsigned ID);
214 Type *getTypeByIDOrNull(unsigned ID);
215 Value *getFnValueByID(unsigned ID, const Type *Ty) {
216 if (Ty && Ty->isMetadataTy())
217 return MDValueList.getValueFwdRef(ID);
218 return ValueList.getValueFwdRef(ID, Ty);
220 BasicBlock *getBasicBlock(unsigned ID) const {
221 if (ID >= FunctionBBs.size()) return 0; // Invalid ID
222 return FunctionBBs[ID];
224 AttrListPtr getAttributes(unsigned i) const {
225 if (i-1 < MAttributes.size())
226 return MAttributes[i-1];
227 return AttrListPtr();
230 /// getValueTypePair - Read a value/type pair out of the specified record from
231 /// slot 'Slot'. Increment Slot past the number of slots used in the record.
232 /// Return true on failure.
233 bool getValueTypePair(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
234 unsigned InstNum, Value *&ResVal) {
235 if (Slot == Record.size()) return true;
236 unsigned ValNo = (unsigned)Record[Slot++];
237 if (ValNo < InstNum) {
238 // If this is not a forward reference, just return the value we already
239 // have.
240 ResVal = getFnValueByID(ValNo, 0);
241 return ResVal == 0;
242 } else if (Slot == Record.size()) {
243 return true;
246 unsigned TypeNo = (unsigned)Record[Slot++];
247 ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
248 return ResVal == 0;
250 bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
251 const Type *Ty, Value *&ResVal) {
252 if (Slot == Record.size()) return true;
253 unsigned ValNo = (unsigned)Record[Slot++];
254 ResVal = getFnValueByID(ValNo, Ty);
255 return ResVal == 0;
259 bool ParseModule();
260 bool ParseAttributeBlock();
261 bool ParseTypeTable();
262 bool ParseOldTypeTable(); // FIXME: Remove in LLVM 3.1
263 bool ParseTypeTableBody();
265 bool ParseOldTypeSymbolTable(); // FIXME: Remove in LLVM 3.1
266 bool ParseValueSymbolTable();
267 bool ParseConstants();
268 bool RememberAndSkipFunctionBody();
269 bool ParseFunctionBody(Function *F);
270 bool ResolveGlobalAndAliasInits();
271 bool ParseMetadata();
272 bool ParseMetadataAttachment();
273 bool ParseModuleTriple(std::string &Triple);
276 } // End llvm namespace
278 #endif