summaryrefslogtreecommitdiffstats
path: root/bcinfo/BitReader_3_0/BitcodeReader.h
blob: 9caee57ff33bab880137fef0adf745af39e24d56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
//===- BitcodeReader.h - Internal BitcodeReader impl ------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header defines the BitcodeReader class.
//
//===----------------------------------------------------------------------===//

#ifndef BITCODE_READER_H
#define BITCODE_READER_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/Bitcode/BitstreamReader.h"
#include "llvm/Bitcode/LLVMBitCodes.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/GVMaterializer.h"
#include "llvm/IR/OperandTraits.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/ValueHandle.h"
#include <vector>

namespace llvm {
  class MemoryBuffer;
  class LLVMContext;
}

namespace llvm_3_0 {

using namespace llvm;

//===----------------------------------------------------------------------===//
//                          BitcodeReaderValueList Class
//===----------------------------------------------------------------------===//

class BitcodeReaderValueList {
  std::vector<WeakVH> ValuePtrs;

  /// ResolveConstants - As we resolve forward-referenced constants, we add
  /// information about them to this vector.  This allows us to resolve them in
  /// bulk instead of resolving each reference at a time.  See the code in
  /// ResolveConstantForwardRefs for more information about this.
  ///
  /// The key of this vector is the placeholder constant, the value is the slot
  /// number that holds the resolved value.
  typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy;
  ResolveConstantsTy ResolveConstants;
  LLVMContext &Context;
public:
  BitcodeReaderValueList(LLVMContext &C) : Context(C) {}
  ~BitcodeReaderValueList() {
    assert(ResolveConstants.empty() && "Constants not resolved?");
  }

  // vector compatibility methods
  unsigned size() const { return ValuePtrs.size(); }
  void resize(unsigned N) { ValuePtrs.resize(N); }
  void push_back(Value *V) {
    ValuePtrs.push_back(V);
  }

  void clear() {
    assert(ResolveConstants.empty() && "Constants not resolved?");
    ValuePtrs.clear();
  }

  Value *operator[](unsigned i) const {
    assert(i < ValuePtrs.size());
    return ValuePtrs[i];
  }

  Value *back() const { return ValuePtrs.back(); }
    void pop_back() { ValuePtrs.pop_back(); }
  bool empty() const { return ValuePtrs.empty(); }
  void shrinkTo(unsigned N) {
    assert(N <= size() && "Invalid shrinkTo request!");
    ValuePtrs.resize(N);
  }

  Constant *getConstantFwdRef(unsigned Idx, Type *Ty);
  Value *getValueFwdRef(unsigned Idx, Type *Ty);

  void AssignValue(Value *V, unsigned Idx);

  /// ResolveConstantForwardRefs - Once all constants are read, this method bulk
  /// resolves any forward references.
  void ResolveConstantForwardRefs();
};


//===----------------------------------------------------------------------===//
//                          BitcodeReaderMDValueList Class
//===----------------------------------------------------------------------===//

class BitcodeReaderMDValueList {
  std::vector<WeakVH> MDValuePtrs;

  LLVMContext &Context;
public:
  BitcodeReaderMDValueList(LLVMContext& C) : Context(C) {}

  // vector compatibility methods
  unsigned size() const       { return MDValuePtrs.size(); }
  void resize(unsigned N)     { MDValuePtrs.resize(N); }
  void push_back(Value *V)    { MDValuePtrs.push_back(V);  }
  void clear()                { MDValuePtrs.clear();  }
  Value *back() const         { return MDValuePtrs.back(); }
  void pop_back()             { MDValuePtrs.pop_back(); }
  bool empty() const          { return MDValuePtrs.empty(); }

  Value *operator[](unsigned i) const {
    assert(i < MDValuePtrs.size());
    return MDValuePtrs[i];
  }

  void shrinkTo(unsigned N) {
    assert(N <= size() && "Invalid shrinkTo request!");
    MDValuePtrs.resize(N);
  }

  Value *getValueFwdRef(unsigned Idx);
  void AssignValue(Value *V, unsigned Idx);
};

class BitcodeReader : public GVMaterializer {
  LLVMContext &Context;
  Module *TheModule;
  MemoryBuffer *Buffer;
  bool BufferOwned;
  std::unique_ptr<BitstreamReader> StreamFile;
  BitstreamCursor Stream;
  DataStreamer *LazyStreamer;
  uint64_t NextUnreadBit;
  bool SeenValueSymbolTable;

  std::vector<Type*> TypeList;
  BitcodeReaderValueList ValueList;
  BitcodeReaderMDValueList MDValueList;
  SmallVector<Instruction *, 64> InstructionList;

  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;

  /// MAttributes - The set of attributes by index.  Index zero in the
  /// file is for null, and is thus not represented here.  As such all indices
  /// are off by one.
  std::vector<AttributeSet> MAttributes;

  /// \brief The set of attribute groups.
  std::map<unsigned, AttributeSet> MAttributeGroups;

  /// FunctionBBs - While parsing a function body, this is a list of the basic
  /// blocks for the function.
  std::vector<BasicBlock*> FunctionBBs;

  // When reading the module header, this list is populated with functions that
  // have bodies later in the file.
  std::vector<Function*> FunctionsWithBodies;

  // When intrinsic functions are encountered which require upgrading they are
  // stored here with their replacement function.
  typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
  UpgradedIntrinsicMap UpgradedIntrinsics;

  // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
  DenseMap<unsigned, unsigned> MDKindMap;

  // Several operations happen after the module header has been read, but
  // before function bodies are processed. This keeps track of whether
  // we've done this yet.
  bool SeenFirstFunctionBody;

  /// DeferredFunctionInfo - When function bodies are initially scanned, this
  /// map contains info about where to find deferred function body in the
  /// stream.
  DenseMap<Function*, uint64_t> DeferredFunctionInfo;

  /// BlockAddrFwdRefs - These are blockaddr references to basic blocks.  These
  /// are resolved lazily when functions are loaded.
  typedef std::pair<unsigned, GlobalVariable*> BlockAddrRefTy;
  DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs;

  static const std::error_category &BitcodeErrorCategory();

public:
  enum ErrorType {
    BitcodeStreamInvalidSize,
    ConflictingMETADATA_KINDRecords,
    CouldNotFindFunctionInStream,
    ExpectedConstant,
    InsufficientFunctionProtos,
    InvalidBitcodeSignature,
    InvalidBitcodeWrapperHeader,
    InvalidConstantReference,
    InvalidID, // A read identifier is not found in the table it should be in.
    InvalidInstructionWithNoBB,
    InvalidRecord, // A read record doesn't have the expected size or structure
    InvalidTypeForValue, // Type read OK, but is invalid for its use
    InvalidTYPETable,
    InvalidType, // We were unable to read a type
    MalformedBlock, // We are unable to advance in the stream.
    MalformedGlobalInitializerSet,
    InvalidMultipleBlocks, // We found multiple blocks of a kind that should
                           // have only one
    NeverResolvedValueFoundInFunction,
    InvalidValue // Invalid version, inst number, attr number, etc
  };

  std::error_code Error(ErrorType E) {
    return std::error_code(E, BitcodeErrorCategory());
  }

  explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C)
    : Context(C), TheModule(0), Buffer(buffer), BufferOwned(false),
      LazyStreamer(0), NextUnreadBit(0), SeenValueSymbolTable(false),
      ValueList(C), MDValueList(C),
      SeenFirstFunctionBody(false) {
  }
  ~BitcodeReader() {
    FreeState();
  }

  void FreeState();

  /// setBufferOwned - If this is true, the reader will destroy the MemoryBuffer
  /// when the reader is destroyed.
  void setBufferOwned(bool Owned) { BufferOwned = Owned; }

  void releaseBuffer() {
    Buffer = nullptr;
  }

  virtual bool isMaterializable(const GlobalValue *GV) const;
  virtual bool isDematerializable(const GlobalValue *GV) const;
  virtual std::error_code Materialize(GlobalValue *GV);
  virtual std::error_code MaterializeModule(Module *M);
  virtual void Dematerialize(GlobalValue *GV);

  /// @brief Main interface to parsing a bitcode buffer.
  /// @returns true if an error occurred.
  std::error_code ParseBitcodeInto(Module *M);

  /// @brief Cheap mechanism to just extract module triple
  /// @returns true if an error occurred.
  std::error_code ParseTriple(std::string &Triple);

  static uint64_t decodeSignRotatedValue(uint64_t V);

private:
  Type *getTypeByID(unsigned ID);
  Type *getTypeByIDOrNull(unsigned ID);
  Value *getFnValueByID(unsigned ID, Type *Ty) {
    if (Ty && Ty->isMetadataTy())
      return MDValueList.getValueFwdRef(ID);
    return ValueList.getValueFwdRef(ID, Ty);
  }
  BasicBlock *getBasicBlock(unsigned ID) const {
    if (ID >= FunctionBBs.size()) return 0; // Invalid ID
    return FunctionBBs[ID];
  }
  AttributeSet getAttributes(unsigned i) const {
    if (i-1 < MAttributes.size())
      return MAttributes[i-1];
    return AttributeSet();
  }

  /// getValueTypePair - Read a value/type pair out of the specified record from
  /// slot 'Slot'.  Increment Slot past the number of slots used in the record.
  /// Return true on failure.
  bool getValueTypePair(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
                        unsigned InstNum, Value *&ResVal) {
    if (Slot == Record.size()) return true;
    unsigned ValNo = (unsigned)Record[Slot++];
    if (ValNo < InstNum) {
      // If this is not a forward reference, just return the value we already
      // have.
      ResVal = getFnValueByID(ValNo, 0);
      return ResVal == 0;
    } else if (Slot == Record.size()) {
      return true;
    }

    unsigned TypeNo = (unsigned)Record[Slot++];
    ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
    return ResVal == 0;
  }
  bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
                Type *Ty, Value *&ResVal) {
    if (Slot == Record.size()) return true;
    unsigned ValNo = (unsigned)Record[Slot++];
    ResVal = getFnValueByID(ValNo, Ty);
    return ResVal == 0;
  }


  std::error_code ParseModule(bool Resume);
  std::error_code ParseAttributeBlock();
  std::error_code ParseTypeTable();
  std::error_code ParseOldTypeTable();         // FIXME: Remove in LLVM 3.1
  std::error_code ParseTypeTableBody();

  std::error_code ParseOldTypeSymbolTable();   // FIXME: Remove in LLVM 3.1
  std::error_code ParseValueSymbolTable();
  std::error_code ParseConstants();
  std::error_code RememberAndSkipFunctionBody();
  std::error_code ParseFunctionBody(Function *F);
  std::error_code GlobalCleanup();
  std::error_code ResolveGlobalAndAliasInits();
  std::error_code ParseMetadata();
  std::error_code ParseMetadataAttachment();
  std::error_code ParseModuleTriple(std::string &Triple);
  std::error_code InitStream();
  std::error_code InitStreamFromBuffer();
  std::error_code InitLazyStream();
};

} // End llvm_3_0 namespace

#endif