//
//===----------------------------------------------------------------------===//
-#ifndef BITSTREAM_READER_H
-#define BITSTREAM_READER_H
+#ifndef LLVM_BITCODE_BITSTREAMREADER_H
+#define LLVM_BITCODE_BITSTREAMREADER_H
#include "llvm/Bitcode/BitCodes.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/StreamableMemoryObject.h"
#include <climits>
+#include <string>
#include <vector>
namespace llvm {
class Deserializer;
+/// BitstreamReader - This class is used to read from an LLVM bitcode stream,
+/// maintaining information that is global to decoding the entire file. While
+/// a file is being read, multiple cursors can be independently advanced or
+/// skipped around within the file. These are represented by the
+/// BitstreamCursor class.
class BitstreamReader {
- const unsigned char *NextChar;
- const unsigned char *LastChar;
+public:
+ /// BlockInfo - This contains information emitted to BLOCKINFO_BLOCK blocks.
+ /// These describe abbreviations that all blocks of the specified ID inherit.
+ struct BlockInfo {
+ unsigned BlockID;
+ std::vector<BitCodeAbbrev*> Abbrevs;
+ std::string Name;
+
+ std::vector<std::pair<unsigned, std::string> > RecordNames;
+ };
+private:
+ std::unique_ptr<StreamableMemoryObject> BitcodeBytes;
+
+ std::vector<BlockInfo> BlockInfoRecords;
+
+ /// IgnoreBlockInfoNames - This is set to true if we don't care about the
+ /// block/record name information in the BlockInfo block. Only llvm-bcanalyzer
+ /// uses this.
+ bool IgnoreBlockInfoNames;
+
+ BitstreamReader(const BitstreamReader&) LLVM_DELETED_FUNCTION;
+ void operator=(const BitstreamReader&) LLVM_DELETED_FUNCTION;
+public:
+ BitstreamReader() : IgnoreBlockInfoNames(true) {
+ }
+
+ BitstreamReader(const unsigned char *Start, const unsigned char *End) {
+ IgnoreBlockInfoNames = true;
+ init(Start, End);
+ }
+
+ BitstreamReader(StreamableMemoryObject *bytes) {
+ BitcodeBytes.reset(bytes);
+ }
+
+ void init(const unsigned char *Start, const unsigned char *End) {
+ assert(((End-Start) & 3) == 0 &&"Bitcode stream not a multiple of 4 bytes");
+ BitcodeBytes.reset(getNonStreamedMemoryObject(Start, End));
+ }
+
+ StreamableMemoryObject &getBitcodeBytes() { return *BitcodeBytes; }
+
+ ~BitstreamReader() {
+ // Free the BlockInfoRecords.
+ while (!BlockInfoRecords.empty()) {
+ BlockInfo &Info = BlockInfoRecords.back();
+ // Free blockinfo abbrev info.
+ for (unsigned i = 0, e = static_cast<unsigned>(Info.Abbrevs.size());
+ i != e; ++i)
+ Info.Abbrevs[i]->dropRef();
+ BlockInfoRecords.pop_back();
+ }
+ }
+
+ /// CollectBlockInfoNames - This is called by clients that want block/record
+ /// name information.
+ void CollectBlockInfoNames() { IgnoreBlockInfoNames = false; }
+ bool isIgnoringBlockInfoNames() { return IgnoreBlockInfoNames; }
+
+ //===--------------------------------------------------------------------===//
+ // Block Manipulation
+ //===--------------------------------------------------------------------===//
+
+ /// hasBlockInfoRecords - Return true if we've already read and processed the
+ /// block info block for this Bitstream. We only process it for the first
+ /// cursor that walks over it.
+ bool hasBlockInfoRecords() const { return !BlockInfoRecords.empty(); }
+
+ /// getBlockInfo - If there is block info for the specified ID, return it,
+ /// otherwise return null.
+ const BlockInfo *getBlockInfo(unsigned BlockID) const {
+ // Common case, the most recent entry matches BlockID.
+ if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
+ return &BlockInfoRecords.back();
+
+ for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
+ i != e; ++i)
+ if (BlockInfoRecords[i].BlockID == BlockID)
+ return &BlockInfoRecords[i];
+ return nullptr;
+ }
+
+ BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
+ if (const BlockInfo *BI = getBlockInfo(BlockID))
+ return *const_cast<BlockInfo*>(BI);
+
+ // Otherwise, add a new record.
+ BlockInfoRecords.push_back(BlockInfo());
+ BlockInfoRecords.back().BlockID = BlockID;
+ return BlockInfoRecords.back();
+ }
+};
+
+
+/// BitstreamEntry - When advancing through a bitstream cursor, each advance can
+/// discover a few different kinds of entries:
+/// Error - Malformed bitcode was found.
+/// EndBlock - We've reached the end of the current block, (or the end of the
+/// file, which is treated like a series of EndBlock records.
+/// SubBlock - This is the start of a new subblock of a specific ID.
+/// Record - This is a record with a specific AbbrevID.
+///
+struct BitstreamEntry {
+ enum {
+ Error,
+ EndBlock,
+ SubBlock,
+ Record
+ } Kind;
+
+ unsigned ID;
+
+ static BitstreamEntry getError() {
+ BitstreamEntry E; E.Kind = Error; return E;
+ }
+ static BitstreamEntry getEndBlock() {
+ BitstreamEntry E; E.Kind = EndBlock; return E;
+ }
+ static BitstreamEntry getSubBlock(unsigned ID) {
+ BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
+ }
+ static BitstreamEntry getRecord(unsigned AbbrevID) {
+ BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
+ }
+};
+
+/// BitstreamCursor - This represents a position within a bitcode file. There
+/// may be multiple independent cursors reading within one bitstream, each
+/// maintaining their own local state.
+///
+/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
+/// be passed by value.
+class BitstreamCursor {
friend class Deserializer;
+ BitstreamReader *BitStream;
+ size_t NextChar;
- /// CurWord - This is the current data we have pulled from the stream but have
- /// not returned to the client.
- uint32_t CurWord;
+
+ /// CurWord/word_t - This is the current data we have pulled from the stream
+ /// but have not returned to the client. This is specifically and
+ /// intentionally defined to follow the word size of the host machine for
+ /// efficiency. We use word_t in places that are aware of this to make it
+ /// perfectly explicit what is going on.
+ typedef uint32_t word_t;
+ word_t CurWord;
/// BitsInCurWord - This is the number of bits in CurWord that are valid. This
- /// is always from [0...31] inclusive.
+ /// is always from [0...31/63] inclusive (depending on word size).
unsigned BitsInCurWord;
// CurCodeSize - This is the declared size of code values used for the current
/// BlockScope - This tracks the codesize of parent blocks.
SmallVector<Block, 8> BlockScope;
- /// BlockInfo - This contains information emitted to BLOCKINFO_BLOCK blocks.
- /// These describe abbreviations that all blocks of the specified ID inherit.
- struct BlockInfo {
- unsigned BlockID;
- std::vector<BitCodeAbbrev*> Abbrevs;
- };
- std::vector<BlockInfo> BlockInfoRecords;
- /// FirstChar - This remembers the first byte of the stream.
- const unsigned char *FirstChar;
public:
- BitstreamReader() {
- NextChar = FirstChar = LastChar = 0;
+ BitstreamCursor() : BitStream(nullptr), NextChar(0) {}
+ BitstreamCursor(const BitstreamCursor &RHS)
+ : BitStream(nullptr), NextChar(0) {
+ operator=(RHS);
+ }
+
+ explicit BitstreamCursor(BitstreamReader &R) : BitStream(&R) {
+ NextChar = 0;
CurWord = 0;
BitsInCurWord = 0;
- CurCodeSize = 0;
+ CurCodeSize = 2;
}
- BitstreamReader(const unsigned char *Start, const unsigned char *End) {
- init(Start, End);
- }
+ void init(BitstreamReader &R) {
+ freeState();
- void init(const unsigned char *Start, const unsigned char *End) {
- NextChar = FirstChar = Start;
- LastChar = End;
- assert(((End-Start) & 3) == 0 &&"Bitcode stream not a multiple of 4 bytes");
+ BitStream = &R;
+ NextChar = 0;
CurWord = 0;
BitsInCurWord = 0;
CurCodeSize = 2;
}
- ~BitstreamReader() {
- // Abbrevs could still exist if the stream was broken. If so, don't leak
- // them.
- for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
- i != e; ++i)
- CurAbbrevs[i]->dropRef();
+ ~BitstreamCursor() {
+ freeState();
+ }
- for (unsigned S = 0, e = static_cast<unsigned>(BlockScope.size());
- S != e; ++S) {
- std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
- for (unsigned i = 0, e = static_cast<unsigned>(Abbrevs.size());
- i != e; ++i)
- Abbrevs[i]->dropRef();
- }
+ void operator=(const BitstreamCursor &RHS);
- // Free the BlockInfoRecords.
- while (!BlockInfoRecords.empty()) {
- BlockInfo &Info = BlockInfoRecords.back();
- // Free blockinfo abbrev info.
- for (unsigned i = 0, e = static_cast<unsigned>(Info.Abbrevs.size());
- i != e; ++i)
- Info.Abbrevs[i]->dropRef();
- BlockInfoRecords.pop_back();
- }
+ void freeState();
+
+ bool isEndPos(size_t pos) {
+ return BitStream->getBitcodeBytes().isObjectEnd(static_cast<uint64_t>(pos));
+ }
+
+ bool canSkipToPos(size_t pos) const {
+ // pos can be skipped to if it is a valid address or one byte past the end.
+ return pos == 0 || BitStream->getBitcodeBytes().isValidAddress(
+ static_cast<uint64_t>(pos - 1));
+ }
+
+ uint32_t getWord(size_t pos) {
+ uint8_t buf[4] = { 0xFF, 0xFF, 0xFF, 0xFF };
+ BitStream->getBitcodeBytes().readBytes(pos, sizeof(buf), buf);
+ return *reinterpret_cast<support::ulittle32_t *>(buf);
}
- bool AtEndOfStream() const {
- return NextChar == LastChar && BitsInCurWord == 0;
+ bool AtEndOfStream() {
+ return BitsInCurWord == 0 && isEndPos(NextChar);
}
+ /// getAbbrevIDWidth - Return the number of bits used to encode an abbrev #.
+ unsigned getAbbrevIDWidth() const { return CurCodeSize; }
+
/// GetCurrentBitNo - Return the bit # of the bit we are reading.
uint64_t GetCurrentBitNo() const {
- return (NextChar-FirstChar)*CHAR_BIT + ((32-BitsInCurWord) & 31);
+ return NextChar*CHAR_BIT - BitsInCurWord;
+ }
+
+ BitstreamReader *getBitStreamReader() {
+ return BitStream;
+ }
+ const BitstreamReader *getBitStreamReader() const {
+ return BitStream;
+ }
+
+ /// Flags that modify the behavior of advance().
+ enum {
+ /// AF_DontPopBlockAtEnd - If this flag is used, the advance() method does
+ /// not automatically pop the block scope when the end of a block is
+ /// reached.
+ AF_DontPopBlockAtEnd = 1,
+
+ /// AF_DontAutoprocessAbbrevs - If this flag is used, abbrev entries are
+ /// returned just like normal records.
+ AF_DontAutoprocessAbbrevs = 2
+ };
+
+ /// advance - Advance the current bitstream, returning the next entry in the
+ /// stream.
+ BitstreamEntry advance(unsigned Flags = 0) {
+ while (1) {
+ unsigned Code = ReadCode();
+ if (Code == bitc::END_BLOCK) {
+ // Pop the end of the block unless Flags tells us not to.
+ if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
+ return BitstreamEntry::getError();
+ return BitstreamEntry::getEndBlock();
+ }
+
+ if (Code == bitc::ENTER_SUBBLOCK)
+ return BitstreamEntry::getSubBlock(ReadSubBlockID());
+
+ if (Code == bitc::DEFINE_ABBREV &&
+ !(Flags & AF_DontAutoprocessAbbrevs)) {
+ // We read and accumulate abbrev's, the client can't do anything with
+ // them anyway.
+ ReadAbbrevRecord();
+ continue;
+ }
+
+ return BitstreamEntry::getRecord(Code);
+ }
+ }
+
+ /// advanceSkippingSubblocks - This is a convenience function for clients that
+ /// don't expect any subblocks. This just skips over them automatically.
+ BitstreamEntry advanceSkippingSubblocks(unsigned Flags = 0) {
+ while (1) {
+ // If we found a normal entry, return it.
+ BitstreamEntry Entry = advance(Flags);
+ if (Entry.Kind != BitstreamEntry::SubBlock)
+ return Entry;
+
+ // If we found a sub-block, just skip over it and check the next entry.
+ if (SkipBlock())
+ return BitstreamEntry::getError();
+ }
}
/// JumpToBit - Reset the stream to the specified bit number.
void JumpToBit(uint64_t BitNo) {
- uintptr_t ByteNo = uintptr_t(BitNo/8) & ~3;
- uintptr_t WordBitNo = uintptr_t(BitNo) & 31;
- assert(ByteNo < (uintptr_t)(LastChar-FirstChar) && "Invalid location");
+ uintptr_t ByteNo = uintptr_t(BitNo/8) & ~(sizeof(word_t)-1);
+ unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
+ assert(canSkipToPos(ByteNo) && "Invalid location");
// Move the cursor to the right word.
- NextChar = FirstChar+ByteNo;
+ NextChar = ByteNo;
BitsInCurWord = 0;
CurWord = 0;
// Skip over any bits that are already consumed.
if (WordBitNo) {
- NextChar -= 4;
- Read(static_cast<unsigned>(WordBitNo));
+ if (sizeof(word_t) > 4)
+ Read64(WordBitNo);
+ else
+ Read(WordBitNo);
}
}
- /// GetAbbrevIDWidth - Return the number of bits used to encode an abbrev #.
- unsigned GetAbbrevIDWidth() const { return CurCodeSize; }
uint32_t Read(unsigned NumBits) {
+ assert(NumBits && NumBits <= 32 &&
+ "Cannot return zero or more than 32 bits!");
+
// If the field is fully contained by CurWord, return it quickly.
if (BitsInCurWord >= NumBits) {
- uint32_t R = CurWord & ((1U << NumBits)-1);
+ uint32_t R = uint32_t(CurWord) & (~0U >> (32-NumBits));
CurWord >>= NumBits;
BitsInCurWord -= NumBits;
return R;
}
// If we run out of data, stop at the end of the stream.
- if (NextChar == LastChar) {
+ if (isEndPos(NextChar)) {
CurWord = 0;
BitsInCurWord = 0;
return 0;
}
- unsigned R = CurWord;
+ uint32_t R = uint32_t(CurWord);
// Read the next word from the stream.
- CurWord = (NextChar[0] << 0) | (NextChar[1] << 8) |
- (NextChar[2] << 16) | (NextChar[3] << 24);
- NextChar += 4;
+ uint8_t Array[sizeof(word_t)] = {0};
+
+ BitStream->getBitcodeBytes().readBytes(NextChar, sizeof(Array), Array);
+
+ // Handle big-endian byte-swapping if necessary.
+ support::detail::packed_endian_specific_integral
+ <word_t, support::little, support::unaligned> EndianValue;
+ memcpy(&EndianValue, Array, sizeof(Array));
+
+ CurWord = EndianValue;
+
+ NextChar += sizeof(word_t);
// Extract NumBits-BitsInCurWord from what we just read.
unsigned BitsLeft = NumBits-BitsInCurWord;
- // Be careful here, BitsLeft is in the range [1..32] inclusive.
- R |= (CurWord & (~0U >> (32-BitsLeft))) << BitsInCurWord;
+ // Be careful here, BitsLeft is in the range [1..32]/[1..64] inclusive.
+ R |= uint32_t((CurWord & (word_t(~0ULL) >> (sizeof(word_t)*8-BitsLeft)))
+ << BitsInCurWord);
- // BitsLeft bits have just been used up from CurWord.
- if (BitsLeft != 32)
+ // BitsLeft bits have just been used up from CurWord. BitsLeft is in the
+ // range [1..32]/[1..64] so be careful how we shift.
+ if (BitsLeft != sizeof(word_t)*8)
CurWord >>= BitsLeft;
else
CurWord = 0;
- BitsInCurWord = 32-BitsLeft;
+ BitsInCurWord = sizeof(word_t)*8-BitsLeft;
return R;
}
}
}
+ // ReadVBR64 - Read a VBR that may have a value up to 64-bits in size. The
+ // chunk size of the VBR must still be <= 32 bits though.
uint64_t ReadVBR64(unsigned NumBits) {
- uint64_t Piece = Read(NumBits);
+ uint32_t Piece = Read(NumBits);
if ((Piece & (1U << (NumBits-1))) == 0)
- return Piece;
+ return uint64_t(Piece);
uint64_t Result = 0;
unsigned NextBit = 0;
while (1) {
- Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
+ Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
if ((Piece & (1U << (NumBits-1))) == 0)
return Result;
}
}
- void SkipToWord() {
+private:
+ void SkipToFourByteBoundary() {
+ // If word_t is 64-bits and if we've read less than 32 bits, just dump
+ // the bits we have up to the next 32-bit boundary.
+ if (sizeof(word_t) > 4 &&
+ BitsInCurWord >= 32) {
+ CurWord >>= BitsInCurWord-32;
+ BitsInCurWord = 32;
+ return;
+ }
+
BitsInCurWord = 0;
CurWord = 0;
}
-
+public:
unsigned ReadCode() {
return Read(CurCodeSize);
}
- //===--------------------------------------------------------------------===//
- // Block Manipulation
- //===--------------------------------------------------------------------===//
-
-private:
- /// getBlockInfo - If there is block info for the specified ID, return it,
- /// otherwise return null.
- BlockInfo *getBlockInfo(unsigned BlockID) {
- // Common case, the most recent entry matches BlockID.
- if (!BlockInfoRecords.empty() && BlockInfoRecords.back().BlockID == BlockID)
- return &BlockInfoRecords.back();
-
- for (unsigned i = 0, e = static_cast<unsigned>(BlockInfoRecords.size());
- i != e; ++i)
- if (BlockInfoRecords[i].BlockID == BlockID)
- return &BlockInfoRecords[i];
- return 0;
- }
-public:
-
// Block header:
// [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
// Read and ignore the codelen value. Since we are skipping this block, we
// don't care what code widths are used inside of it.
ReadVBR(bitc::CodeLenWidth);
- SkipToWord();
- unsigned NumWords = Read(bitc::BlockSizeWidth);
+ SkipToFourByteBoundary();
+ unsigned NumFourBytes = Read(bitc::BlockSizeWidth);
// Check that the block wasn't partially defined, and that the offset isn't
// bogus.
- if (AtEndOfStream() || NextChar+NumWords*4 > LastChar)
+ size_t SkipTo = GetCurrentBitNo() + NumFourBytes*4*8;
+ if (AtEndOfStream() || !canSkipToPos(SkipTo/8))
return true;
- NextChar += NumWords*4;
+ JumpToBit(SkipTo);
return false;
}
/// EnterSubBlock - Having read the ENTER_SUBBLOCK abbrevid, enter
- /// the block, and return true if the block is valid.
- bool EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = 0) {
- // Save the current block's state on BlockScope.
- BlockScope.push_back(Block(CurCodeSize));
- BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
-
- // Add the abbrevs specific to this block to the CurAbbrevs list.
- if (BlockInfo *Info = getBlockInfo(BlockID)) {
- for (unsigned i = 0, e = static_cast<unsigned>(Info->Abbrevs.size());
- i != e; ++i) {
- CurAbbrevs.push_back(Info->Abbrevs[i]);
- CurAbbrevs.back()->addRef();
- }
- }
-
- // Get the codesize of this block.
- CurCodeSize = ReadVBR(bitc::CodeLenWidth);
- SkipToWord();
- unsigned NumWords = Read(bitc::BlockSizeWidth);
- if (NumWordsP) *NumWordsP = NumWords;
-
- // Validate that this block is sane.
- if (CurCodeSize == 0 || AtEndOfStream() || NextChar+NumWords*4 > LastChar)
- return true;
-
- return false;
- }
+ /// the block, and return true if the block has an error.
+ bool EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
bool ReadBlockEnd() {
if (BlockScope.empty()) return true;
// Block tail:
// [END_BLOCK, <align4bytes>]
- SkipToWord();
+ SkipToFourByteBoundary();
- PopBlockScope();
+ popBlockScope();
return false;
}
private:
- void PopBlockScope() {
+
+ void popBlockScope() {
CurCodeSize = BlockScope.back().PrevCodeSize;
// Delete abbrevs from popped scope.
//===--------------------------------------------------------------------===//
private:
- void ReadAbbreviatedLiteral(const BitCodeAbbrevOp &Op,
- SmallVectorImpl<uint64_t> &Vals) {
- assert(Op.isLiteral() && "Not a literal");
- // If the abbrev specifies the literal value to use, use it.
- Vals.push_back(Op.getLiteralValue());
- }
-
- void ReadAbbreviatedField(const BitCodeAbbrevOp &Op,
- SmallVectorImpl<uint64_t> &Vals) {
- assert(!Op.isLiteral() && "Use ReadAbbreviatedLiteral for literals!");
-
- // Decode the value as we are commanded.
- switch (Op.getEncoding()) {
- default: assert(0 && "Unknown encoding!");
- case BitCodeAbbrevOp::Fixed:
- Vals.push_back(Read((unsigned)Op.getEncodingData()));
- break;
- case BitCodeAbbrevOp::VBR:
- Vals.push_back(ReadVBR64((unsigned)Op.getEncodingData()));
- break;
- case BitCodeAbbrevOp::Char6:
- Vals.push_back(BitCodeAbbrevOp::DecodeChar6(Read(6)));
- break;
- }
- }
+ void readAbbreviatedLiteral(const BitCodeAbbrevOp &Op,
+ SmallVectorImpl<uint64_t> &Vals);
+ void readAbbreviatedField(const BitCodeAbbrevOp &Op,
+ SmallVectorImpl<uint64_t> &Vals);
+ void skipAbbreviatedField(const BitCodeAbbrevOp &Op);
+
public:
- unsigned ReadRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals) {
- if (AbbrevID == bitc::UNABBREV_RECORD) {
- unsigned Code = ReadVBR(6);
- unsigned NumElts = ReadVBR(6);
- for (unsigned i = 0; i != NumElts; ++i)
- Vals.push_back(ReadVBR64(6));
- return Code;
- }
+ /// getAbbrev - Return the abbreviation for the specified AbbrevId.
+ const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
unsigned AbbrevNo = AbbrevID-bitc::FIRST_APPLICATION_ABBREV;
assert(AbbrevNo < CurAbbrevs.size() && "Invalid abbrev #!");
- BitCodeAbbrev *Abbv = CurAbbrevs[AbbrevNo];
-
- for (unsigned i = 0, e = Abbv->getNumOperandInfos(); i != e; ++i) {
- const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
- if (Op.isLiteral()) {
- ReadAbbreviatedLiteral(Op, Vals);
- } else if (Op.getEncoding() == BitCodeAbbrevOp::Array) {
- // Array case. Read the number of elements as a vbr6.
- unsigned NumElts = ReadVBR(6);
-
- // Get the element encoding.
- assert(i+2 == e && "array op not second to last?");
- const BitCodeAbbrevOp &EltEnc = Abbv->getOperandInfo(++i);
-
- // Read all the elements.
- for (; NumElts; --NumElts)
- ReadAbbreviatedField(EltEnc, Vals);
- } else if (Op.getEncoding() == BitCodeAbbrevOp::Blob) {
- // Blob case. Read the number of bytes as a vbr6.
- unsigned NumElts = ReadVBR(6);
- SkipToWord(); // 32-bit alignment
-
- // Figure out where the end of this blob will be including tail padding.
- const unsigned char *NewEnd = NextChar+((NumElts+3)&~3);
-
- // If this would read off the end of the bitcode file, just set the
- // record to empty and return.
- if (NewEnd > LastChar) {
- Vals.append(NumElts, 0);
- NextChar = LastChar;
- break;
- }
-
- // Otherwise, read the number of bytes.
- for (; NumElts; ++NextChar, --NumElts)
- Vals.push_back(*NextChar);
- // Skip over tail padding.
- NextChar = NewEnd;
- } else {
- ReadAbbreviatedField(Op, Vals);
- }
- }
-
- unsigned Code = (unsigned)Vals[0];
- Vals.erase(Vals.begin());
- return Code;
+ return CurAbbrevs[AbbrevNo];
}
- //===--------------------------------------------------------------------===//
- // Abbrev Processing
- //===--------------------------------------------------------------------===//
+ /// skipRecord - Read the current record and discard it.
+ void skipRecord(unsigned AbbrevID);
- void ReadAbbrevRecord() {
- BitCodeAbbrev *Abbv = new BitCodeAbbrev();
- unsigned NumOpInfo = ReadVBR(5);
- for (unsigned i = 0; i != NumOpInfo; ++i) {
- bool IsLiteral = Read(1) ? true : false;
- if (IsLiteral) {
- Abbv->Add(BitCodeAbbrevOp(ReadVBR64(8)));
- continue;
- }
-
- BitCodeAbbrevOp::Encoding E = (BitCodeAbbrevOp::Encoding)Read(3);
- if (BitCodeAbbrevOp::hasEncodingData(E))
- Abbv->Add(BitCodeAbbrevOp(E, ReadVBR64(5)));
- else
- Abbv->Add(BitCodeAbbrevOp(E));
- }
- CurAbbrevs.push_back(Abbv);
- }
+ unsigned readRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals,
+ StringRef *Blob = nullptr);
//===--------------------------------------------------------------------===//
- // BlockInfo Block Reading
+ // Abbrev Processing
//===--------------------------------------------------------------------===//
+ void ReadAbbrevRecord();
-private:
- BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
- if (BlockInfo *BI = getBlockInfo(BlockID))
- return *BI;
-
- // Otherwise, add a new record.
- BlockInfoRecords.push_back(BlockInfo());
- BlockInfoRecords.back().BlockID = BlockID;
- return BlockInfoRecords.back();
- }
-
-public:
-
- bool ReadBlockInfoBlock() {
- if (EnterSubBlock(bitc::BLOCKINFO_BLOCK_ID)) return true;
-
- SmallVector<uint64_t, 64> Record;
- BlockInfo *CurBlockInfo = 0;
-
- // Read all the records for this module.
- while (1) {
- unsigned Code = ReadCode();
- if (Code == bitc::END_BLOCK)
- return ReadBlockEnd();
- if (Code == bitc::ENTER_SUBBLOCK) {
- ReadSubBlockID();
- if (SkipBlock()) return true;
- continue;
- }
-
- // Read abbrev records, associate them with CurBID.
- if (Code == bitc::DEFINE_ABBREV) {
- if (!CurBlockInfo) return true;
- ReadAbbrevRecord();
-
- // ReadAbbrevRecord installs the abbrev in CurAbbrevs. Move it to the
- // appropriate BlockInfo.
- BitCodeAbbrev *Abbv = CurAbbrevs.back();
- CurAbbrevs.pop_back();
- CurBlockInfo->Abbrevs.push_back(Abbv);
- continue;
- }
-
- // Read a record.
- Record.clear();
- switch (ReadRecord(Code, Record)) {
- default: break; // Default behavior, ignore unknown content.
- case bitc::BLOCKINFO_CODE_SETBID:
- if (Record.size() < 1) return true;
- CurBlockInfo = &getOrCreateBlockInfo((unsigned)Record[0]);
- break;
- }
- }
- }
+ bool ReadBlockInfoBlock();
};
} // End llvm namespace
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