/Users/buildslave/jenkins/sharedspace/clang-stage2-coverage-R@2/llvm/include/llvm/Bitcode/BitstreamReader.h
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1 | | //===- BitstreamReader.h - Low-level bitstream reader interface -*- 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 BitstreamReader class. This class can be used to |
11 | | // read an arbitrary bitstream, regardless of its contents. |
12 | | // |
13 | | //===----------------------------------------------------------------------===// |
14 | | |
15 | | #ifndef LLVM_BITCODE_BITSTREAMREADER_H |
16 | | #define LLVM_BITCODE_BITSTREAMREADER_H |
17 | | |
18 | | #include "llvm/ADT/ArrayRef.h" |
19 | | #include "llvm/ADT/SmallVector.h" |
20 | | #include "llvm/Bitcode/BitCodes.h" |
21 | | #include "llvm/Support/Endian.h" |
22 | | #include "llvm/Support/ErrorHandling.h" |
23 | | #include "llvm/Support/MathExtras.h" |
24 | | #include "llvm/Support/MemoryBuffer.h" |
25 | | #include <algorithm> |
26 | | #include <cassert> |
27 | | #include <climits> |
28 | | #include <cstddef> |
29 | | #include <cstdint> |
30 | | #include <memory> |
31 | | #include <string> |
32 | | #include <utility> |
33 | | #include <vector> |
34 | | |
35 | | namespace llvm { |
36 | | |
37 | | /// This class maintains the abbreviations read from a block info block. |
38 | | class BitstreamBlockInfo { |
39 | | public: |
40 | | /// This contains information emitted to BLOCKINFO_BLOCK blocks. These |
41 | | /// describe abbreviations that all blocks of the specified ID inherit. |
42 | | struct BlockInfo { |
43 | | unsigned BlockID; |
44 | | std::vector<std::shared_ptr<BitCodeAbbrev>> Abbrevs; |
45 | | std::string Name; |
46 | | std::vector<std::pair<unsigned, std::string>> RecordNames; |
47 | | }; |
48 | | |
49 | | private: |
50 | | std::vector<BlockInfo> BlockInfoRecords; |
51 | | |
52 | | public: |
53 | | /// If there is block info for the specified ID, return it, otherwise return |
54 | | /// null. |
55 | 2.10M | const BlockInfo *getBlockInfo(unsigned BlockID) const { |
56 | 2.10M | // Common case, the most recent entry matches BlockID. |
57 | 2.10M | if (!BlockInfoRecords.empty() && 2.10M BlockInfoRecords.back().BlockID == BlockID2.07M ) |
58 | 655k | return &BlockInfoRecords.back(); |
59 | 2.10M | |
60 | 1.45M | for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size()); |
61 | 3.11M | i != e3.11M ; ++i1.66M ) |
62 | 2.61M | if (2.61M BlockInfoRecords[i].BlockID == BlockID2.61M ) |
63 | 955k | return &BlockInfoRecords[i]; |
64 | 495k | return nullptr; |
65 | 2.10M | } |
66 | | |
67 | 34.2k | BlockInfo &getOrCreateBlockInfo(unsigned BlockID) { |
68 | 34.2k | if (const BlockInfo *BI = getBlockInfo(BlockID)) |
69 | 30 | return *const_cast<BlockInfo*>(BI); |
70 | 34.2k | |
71 | 34.2k | // Otherwise, add a new record. |
72 | 34.2k | BlockInfoRecords.emplace_back(); |
73 | 34.2k | BlockInfoRecords.back().BlockID = BlockID; |
74 | 34.2k | return BlockInfoRecords.back(); |
75 | 34.2k | } |
76 | | }; |
77 | | |
78 | | /// This represents a position within a bitstream. There may be multiple |
79 | | /// independent cursors reading within one bitstream, each maintaining their |
80 | | /// own local state. |
81 | | class SimpleBitstreamCursor { |
82 | | ArrayRef<uint8_t> BitcodeBytes; |
83 | | size_t NextChar = 0; |
84 | | |
85 | | public: |
86 | | /// This is the current data we have pulled from the stream but have not |
87 | | /// returned to the client. This is specifically and intentionally defined to |
88 | | /// follow the word size of the host machine for efficiency. We use word_t in |
89 | | /// places that are aware of this to make it perfectly explicit what is going |
90 | | /// on. |
91 | | using word_t = size_t; |
92 | | |
93 | | private: |
94 | | word_t CurWord = 0; |
95 | | |
96 | | /// This is the number of bits in CurWord that are valid. This is always from |
97 | | /// [0...bits_of(size_t)-1] inclusive. |
98 | | unsigned BitsInCurWord = 0; |
99 | | |
100 | | public: |
101 | | static const size_t MaxChunkSize = sizeof(word_t) * 8; |
102 | | |
103 | 38.8k | SimpleBitstreamCursor() = default; |
104 | | explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes) |
105 | 23.4k | : BitcodeBytes(BitcodeBytes) {} |
106 | | explicit SimpleBitstreamCursor(StringRef BitcodeBytes) |
107 | | : BitcodeBytes(reinterpret_cast<const uint8_t *>(BitcodeBytes.data()), |
108 | 38.0k | BitcodeBytes.size()) {} |
109 | | explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes) |
110 | 0 | : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {} |
111 | | |
112 | 319k | bool canSkipToPos(size_t pos) const { |
113 | 319k | // pos can be skipped to if it is a valid address or one byte past the end. |
114 | 319k | return pos <= BitcodeBytes.size(); |
115 | 319k | } |
116 | | |
117 | 58.1M | bool AtEndOfStream() { |
118 | 4.57M | return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar; |
119 | 58.1M | } |
120 | | |
121 | | /// Return the bit # of the bit we are reading. |
122 | 1.00M | uint64_t GetCurrentBitNo() const { |
123 | 1.00M | return NextChar*CHAR_BIT - BitsInCurWord; |
124 | 1.00M | } |
125 | | |
126 | | // Return the byte # of the current bit. |
127 | 39.0k | uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; } |
128 | | |
129 | 38.1k | ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; } |
130 | | |
131 | | /// Reset the stream to the specified bit number. |
132 | 1.62M | void JumpToBit(uint64_t BitNo) { |
133 | 1.62M | size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1); |
134 | 1.62M | unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1)); |
135 | 1.62M | assert(canSkipToPos(ByteNo) && "Invalid location"); |
136 | 1.62M | |
137 | 1.62M | // Move the cursor to the right word. |
138 | 1.62M | NextChar = ByteNo; |
139 | 1.62M | BitsInCurWord = 0; |
140 | 1.62M | |
141 | 1.62M | // Skip over any bits that are already consumed. |
142 | 1.62M | if (WordBitNo) |
143 | 1.39M | Read(WordBitNo); |
144 | 1.62M | } |
145 | | |
146 | | /// Get a pointer into the bitstream at the specified byte offset. |
147 | 176k | const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) { |
148 | 176k | return BitcodeBytes.data() + ByteNo; |
149 | 176k | } |
150 | | |
151 | | /// Get a pointer into the bitstream at the specified bit offset. |
152 | | /// |
153 | | /// The bit offset must be on a byte boundary. |
154 | 176k | const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) { |
155 | 176k | assert(!(BitNo % 8) && "Expected bit on byte boundary"); |
156 | 176k | return getPointerToByte(BitNo / 8, NumBytes); |
157 | 176k | } |
158 | | |
159 | 61.4M | void fillCurWord() { |
160 | 61.4M | if (NextChar >= BitcodeBytes.size()) |
161 | 0 | report_fatal_error("Unexpected end of file"); |
162 | 61.4M | |
163 | 61.4M | // Read the next word from the stream. |
164 | 61.4M | const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar; |
165 | 61.4M | unsigned BytesRead; |
166 | 61.4M | if (BitcodeBytes.size() >= NextChar + sizeof(word_t)61.4M ) { |
167 | 61.4M | BytesRead = sizeof(word_t); |
168 | 61.4M | CurWord = |
169 | 61.4M | support::endian::read<word_t, support::little, support::unaligned>( |
170 | 61.4M | NextCharPtr); |
171 | 61.4M | } else { |
172 | 33.7k | // Short read. |
173 | 33.7k | BytesRead = BitcodeBytes.size() - NextChar; |
174 | 33.7k | CurWord = 0; |
175 | 168k | for (unsigned B = 0; B != BytesRead168k ; ++B135k ) |
176 | 135k | CurWord |= uint64_t(NextCharPtr[B]) << (B * 8); |
177 | 33.7k | } |
178 | 61.4M | NextChar += BytesRead; |
179 | 61.4M | BitsInCurWord = BytesRead * 8; |
180 | 61.4M | } |
181 | | |
182 | 629M | word_t Read(unsigned NumBits) { |
183 | 629M | static const unsigned BitsInWord = MaxChunkSize; |
184 | 629M | |
185 | 629M | assert(NumBits && NumBits <= BitsInWord && |
186 | 629M | "Cannot return zero or more than BitsInWord bits!"); |
187 | 629M | |
188 | 629M | static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f0 : 0x1f629M ; |
189 | 629M | |
190 | 629M | // If the field is fully contained by CurWord, return it quickly. |
191 | 629M | if (BitsInCurWord >= NumBits629M ) { |
192 | 568M | word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits)); |
193 | 568M | |
194 | 568M | // Use a mask to avoid undefined behavior. |
195 | 568M | CurWord >>= (NumBits & Mask); |
196 | 568M | |
197 | 568M | BitsInCurWord -= NumBits; |
198 | 568M | return R; |
199 | 568M | } |
200 | 629M | |
201 | 61.4M | word_t R = BitsInCurWord ? 61.4M CurWord44.2M : 017.1M ; |
202 | 61.4M | unsigned BitsLeft = NumBits - BitsInCurWord; |
203 | 61.4M | |
204 | 61.4M | fillCurWord(); |
205 | 61.4M | |
206 | 61.4M | // If we run out of data, abort. |
207 | 61.4M | if (BitsLeft > BitsInCurWord) |
208 | 0 | report_fatal_error("Unexpected end of file"); |
209 | 61.4M | |
210 | 61.4M | word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft)); |
211 | 61.4M | |
212 | 61.4M | // Use a mask to avoid undefined behavior. |
213 | 61.4M | CurWord >>= (BitsLeft & Mask); |
214 | 61.4M | |
215 | 61.4M | BitsInCurWord -= BitsLeft; |
216 | 61.4M | |
217 | 61.4M | R |= R2 << (NumBits - BitsLeft); |
218 | 61.4M | |
219 | 61.4M | return R; |
220 | 629M | } |
221 | | |
222 | 62.4M | uint32_t ReadVBR(unsigned NumBits) { |
223 | 62.4M | uint32_t Piece = Read(NumBits); |
224 | 62.4M | if ((Piece & (1U << (NumBits-1))) == 0) |
225 | 57.6M | return Piece; |
226 | 62.4M | |
227 | 4.85M | uint32_t Result = 0; |
228 | 4.85M | unsigned NextBit = 0; |
229 | 9.72M | while (true9.72M ) { |
230 | 9.72M | Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit; |
231 | 9.72M | |
232 | 9.72M | if ((Piece & (1U << (NumBits-1))) == 0) |
233 | 4.85M | return Result; |
234 | 9.72M | |
235 | 4.86M | NextBit += NumBits-1; |
236 | 4.86M | Piece = Read(NumBits); |
237 | 4.86M | } |
238 | 62.4M | } |
239 | | |
240 | | // Read a VBR that may have a value up to 64-bits in size. The chunk size of |
241 | | // the VBR must still be <= 32 bits though. |
242 | 157M | uint64_t ReadVBR64(unsigned NumBits) { |
243 | 157M | uint32_t Piece = Read(NumBits); |
244 | 157M | if ((Piece & (1U << (NumBits-1))) == 0) |
245 | 88.4M | return uint64_t(Piece); |
246 | 157M | |
247 | 68.6M | uint64_t Result = 0; |
248 | 68.6M | unsigned NextBit = 0; |
249 | 144M | while (true144M ) { |
250 | 144M | Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit; |
251 | 144M | |
252 | 144M | if ((Piece & (1U << (NumBits-1))) == 0) |
253 | 68.6M | return Result; |
254 | 144M | |
255 | 75.7M | NextBit += NumBits-1; |
256 | 75.7M | Piece = Read(NumBits); |
257 | 75.7M | } |
258 | 157M | } |
259 | | |
260 | 4.52M | void SkipToFourByteBoundary() { |
261 | 4.52M | // If word_t is 64-bits and if we've read less than 32 bits, just dump |
262 | 4.52M | // the bits we have up to the next 32-bit boundary. |
263 | 4.52M | if (sizeof(word_t) > 4 && |
264 | 4.52M | BitsInCurWord >= 324.52M ) { |
265 | 2.42M | CurWord >>= BitsInCurWord-32; |
266 | 2.42M | BitsInCurWord = 32; |
267 | 2.42M | return; |
268 | 2.42M | } |
269 | 4.52M | |
270 | 2.09M | BitsInCurWord = 0; |
271 | 2.09M | } |
272 | | |
273 | | /// Skip to the end of the file. |
274 | 0 | void skipToEnd() { NextChar = BitcodeBytes.size(); } |
275 | | }; |
276 | | |
277 | | /// When advancing through a bitstream cursor, each advance can discover a few |
278 | | /// different kinds of entries: |
279 | | struct BitstreamEntry { |
280 | | enum { |
281 | | Error, // Malformed bitcode was found. |
282 | | EndBlock, // We've reached the end of the current block, (or the end of the |
283 | | // file, which is treated like a series of EndBlock records. |
284 | | SubBlock, // This is the start of a new subblock of a specific ID. |
285 | | Record // This is a record with a specific AbbrevID. |
286 | | } Kind; |
287 | | |
288 | | unsigned ID; |
289 | | |
290 | 5.64k | static BitstreamEntry getError() { |
291 | 5.64k | BitstreamEntry E; E.Kind = Error; return E; |
292 | 5.64k | } |
293 | | |
294 | 2.09M | static BitstreamEntry getEndBlock() { |
295 | 2.09M | BitstreamEntry E; E.Kind = EndBlock; return E; |
296 | 2.09M | } |
297 | | |
298 | 1.54M | static BitstreamEntry getSubBlock(unsigned ID) { |
299 | 1.54M | BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E; |
300 | 1.54M | } |
301 | | |
302 | 51.6M | static BitstreamEntry getRecord(unsigned AbbrevID) { |
303 | 51.6M | BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E; |
304 | 51.6M | } |
305 | | }; |
306 | | |
307 | | /// This represents a position within a bitcode file, implemented on top of a |
308 | | /// SimpleBitstreamCursor. |
309 | | /// |
310 | | /// Unlike iterators, BitstreamCursors are heavy-weight objects that should not |
311 | | /// be passed by value. |
312 | | class BitstreamCursor : SimpleBitstreamCursor { |
313 | | // This is the declared size of code values used for the current block, in |
314 | | // bits. |
315 | | unsigned CurCodeSize = 2; |
316 | | |
317 | | /// Abbrevs installed at in this block. |
318 | | std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs; |
319 | | |
320 | | struct Block { |
321 | | unsigned PrevCodeSize; |
322 | | std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs; |
323 | | |
324 | 2.12M | explicit Block(unsigned PCS) : PrevCodeSize(PCS) {} |
325 | | }; |
326 | | |
327 | | /// This tracks the codesize of parent blocks. |
328 | | SmallVector<Block, 8> BlockScope; |
329 | | |
330 | | BitstreamBlockInfo *BlockInfo = nullptr; |
331 | | |
332 | | public: |
333 | | static const size_t MaxChunkSize = sizeof(word_t) * 8; |
334 | | |
335 | 38.8k | BitstreamCursor() = default; |
336 | | explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes) |
337 | 23.4k | : SimpleBitstreamCursor(BitcodeBytes) {} |
338 | | explicit BitstreamCursor(StringRef BitcodeBytes) |
339 | 0 | : SimpleBitstreamCursor(BitcodeBytes) {} |
340 | | explicit BitstreamCursor(MemoryBufferRef BitcodeBytes) |
341 | 0 | : SimpleBitstreamCursor(BitcodeBytes) {} |
342 | | |
343 | | using SimpleBitstreamCursor::canSkipToPos; |
344 | | using SimpleBitstreamCursor::AtEndOfStream; |
345 | | using SimpleBitstreamCursor::getBitcodeBytes; |
346 | | using SimpleBitstreamCursor::GetCurrentBitNo; |
347 | | using SimpleBitstreamCursor::getCurrentByteNo; |
348 | | using SimpleBitstreamCursor::getPointerToByte; |
349 | | using SimpleBitstreamCursor::JumpToBit; |
350 | | using SimpleBitstreamCursor::fillCurWord; |
351 | | using SimpleBitstreamCursor::Read; |
352 | | using SimpleBitstreamCursor::ReadVBR; |
353 | | using SimpleBitstreamCursor::ReadVBR64; |
354 | | |
355 | | /// Return the number of bits used to encode an abbrev #. |
356 | 647k | unsigned getAbbrevIDWidth() const { return CurCodeSize; } |
357 | | |
358 | | /// Flags that modify the behavior of advance(). |
359 | | enum { |
360 | | /// If this flag is used, the advance() method does not automatically pop |
361 | | /// the block scope when the end of a block is reached. |
362 | | AF_DontPopBlockAtEnd = 1, |
363 | | |
364 | | /// If this flag is used, abbrev entries are returned just like normal |
365 | | /// records. |
366 | | AF_DontAutoprocessAbbrevs = 2 |
367 | | }; |
368 | | |
369 | | /// Advance the current bitstream, returning the next entry in the stream. |
370 | 55.3M | BitstreamEntry advance(unsigned Flags = 0) { |
371 | 55.7M | while (true55.7M ) { |
372 | 55.7M | if (AtEndOfStream()) |
373 | 5.63k | return BitstreamEntry::getError(); |
374 | 55.7M | |
375 | 55.7M | unsigned Code = ReadCode(); |
376 | 55.7M | if (Code == bitc::END_BLOCK55.7M ) { |
377 | 2.09M | // Pop the end of the block unless Flags tells us not to. |
378 | 2.09M | if (!(Flags & AF_DontPopBlockAtEnd) && 2.09M ReadBlockEnd()2.09M ) |
379 | 6 | return BitstreamEntry::getError(); |
380 | 2.09M | return BitstreamEntry::getEndBlock(); |
381 | 2.09M | } |
382 | 55.7M | |
383 | 53.6M | if (53.6M Code == bitc::ENTER_SUBBLOCK53.6M ) |
384 | 1.54M | return BitstreamEntry::getSubBlock(ReadSubBlockID()); |
385 | 53.6M | |
386 | 52.0M | if (52.0M Code == bitc::DEFINE_ABBREV && |
387 | 52.0M | !(Flags & AF_DontAutoprocessAbbrevs)578k ) { |
388 | 393k | // We read and accumulate abbrev's, the client can't do anything with |
389 | 393k | // them anyway. |
390 | 393k | ReadAbbrevRecord(); |
391 | 393k | continue; |
392 | 393k | } |
393 | 52.0M | |
394 | 51.6M | return BitstreamEntry::getRecord(Code); |
395 | 55.7M | } |
396 | 55.3M | } |
397 | | |
398 | | /// This is a convenience function for clients that don't expect any |
399 | | /// subblocks. This just skips over them automatically. |
400 | 30.4M | BitstreamEntry advanceSkippingSubblocks(unsigned Flags = 0) { |
401 | 30.4M | while (true30.4M ) { |
402 | 30.4M | // If we found a normal entry, return it. |
403 | 30.4M | BitstreamEntry Entry = advance(Flags); |
404 | 30.4M | if (Entry.Kind != BitstreamEntry::SubBlock) |
405 | 30.4M | return Entry; |
406 | 30.4M | |
407 | 30.4M | // If we found a sub-block, just skip over it and check the next entry. |
408 | 2.31k | if (2.31k SkipBlock()2.31k ) |
409 | 0 | return BitstreamEntry::getError(); |
410 | 30.4M | } |
411 | 30.4M | } |
412 | | |
413 | 56.0M | unsigned ReadCode() { |
414 | 56.0M | return Read(CurCodeSize); |
415 | 56.0M | } |
416 | | |
417 | | // Block header: |
418 | | // [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen] |
419 | | |
420 | | /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block. |
421 | 1.54M | unsigned ReadSubBlockID() { |
422 | 1.54M | return ReadVBR(bitc::BlockIDWidth); |
423 | 1.54M | } |
424 | | |
425 | | /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body |
426 | | /// of this block. If the block record is malformed, return true. |
427 | 119k | bool SkipBlock() { |
428 | 119k | // Read and ignore the codelen value. Since we are skipping this block, we |
429 | 119k | // don't care what code widths are used inside of it. |
430 | 119k | ReadVBR(bitc::CodeLenWidth); |
431 | 119k | SkipToFourByteBoundary(); |
432 | 119k | unsigned NumFourBytes = Read(bitc::BlockSizeWidth); |
433 | 119k | |
434 | 119k | // Check that the block wasn't partially defined, and that the offset isn't |
435 | 119k | // bogus. |
436 | 119k | size_t SkipTo = GetCurrentBitNo() + NumFourBytes*4*8; |
437 | 119k | if (AtEndOfStream() || 119k !canSkipToPos(SkipTo/8)119k ) |
438 | 6 | return true; |
439 | 119k | |
440 | 119k | JumpToBit(SkipTo); |
441 | 119k | return false; |
442 | 119k | } |
443 | | |
444 | | /// Having read the ENTER_SUBBLOCK abbrevid, enter the block, and return true |
445 | | /// if the block has an error. |
446 | | bool EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr); |
447 | | |
448 | 2.09M | bool ReadBlockEnd() { |
449 | 2.09M | if (BlockScope.empty()2.09M ) return true6 ; |
450 | 2.09M | |
451 | 2.09M | // Block tail: |
452 | 2.09M | // [END_BLOCK, <align4bytes>] |
453 | 2.09M | SkipToFourByteBoundary(); |
454 | 2.09M | |
455 | 2.09M | popBlockScope(); |
456 | 2.09M | return false; |
457 | 2.09M | } |
458 | | |
459 | | private: |
460 | 2.09M | void popBlockScope() { |
461 | 2.09M | CurCodeSize = BlockScope.back().PrevCodeSize; |
462 | 2.09M | |
463 | 2.09M | CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs); |
464 | 2.09M | BlockScope.pop_back(); |
465 | 2.09M | } |
466 | | |
467 | | //===--------------------------------------------------------------------===// |
468 | | // Record Processing |
469 | | //===--------------------------------------------------------------------===// |
470 | | |
471 | | public: |
472 | | /// Return the abbreviation for the specified AbbrevId. |
473 | 34.4M | const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) { |
474 | 34.4M | unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV; |
475 | 34.4M | if (AbbrevNo >= CurAbbrevs.size()) |
476 | 0 | report_fatal_error("Invalid abbrev number"); |
477 | 34.4M | return CurAbbrevs[AbbrevNo].get(); |
478 | 34.4M | } |
479 | | |
480 | | /// Read the current record and discard it, returning the code for the record. |
481 | | unsigned skipRecord(unsigned AbbrevID); |
482 | | |
483 | | unsigned readRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals, |
484 | | StringRef *Blob = nullptr); |
485 | | |
486 | | //===--------------------------------------------------------------------===// |
487 | | // Abbrev Processing |
488 | | //===--------------------------------------------------------------------===// |
489 | | void ReadAbbrevRecord(); |
490 | | |
491 | | /// Read and return a block info block from the bitstream. If an error was |
492 | | /// encountered, return None. |
493 | | /// |
494 | | /// \param ReadBlockInfoNames Whether to read block/record name information in |
495 | | /// the BlockInfo block. Only llvm-bcanalyzer uses this. |
496 | | Optional<BitstreamBlockInfo> |
497 | | ReadBlockInfoBlock(bool ReadBlockInfoNames = false); |
498 | | |
499 | | /// Set the block info to be used by this BitstreamCursor to interpret |
500 | | /// abbreviated records. |
501 | 11.5k | void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; } |
502 | | }; |
503 | | |
504 | | } // end llvm namespace |
505 | | |
506 | | #endif // LLVM_BITCODE_BITSTREAMREADER_H |