class Deserializer;
class BitstreamReader {
- const unsigned char *NextChar;
- const unsigned char *LastChar;
- friend class Deserializer;
+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;
+ };
+private:
+ /// FirstChar/LastChar - This remembers the first and last bytes of the
+ /// stream.
+ const unsigned char *FirstChar, *LastChar;
+
+ std::vector<BlockInfo> BlockInfoRecords;
+
+public:
+ BitstreamReader() : FirstChar(0), LastChar(0) {
+ }
+
+ BitstreamReader(const unsigned char *Start, const unsigned char *End) {
+ init(Start, End);
+ }
+
+ void init(const unsigned char *Start, const unsigned char *End) {
+ FirstChar = Start;
+ LastChar = End;
+ assert(((End-Start) & 3) == 0 &&"Bitcode stream not a multiple of 4 bytes");
+ }
+
+ ~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();
+ }
+ }
+
+ const unsigned char *getFirstChar() const { return FirstChar; }
+ const unsigned char *getLastChar() const { return LastChar; }
+
+ //===--------------------------------------------------------------------===//
+ // Block Manipulation
+ //===--------------------------------------------------------------------===//
+
+ /// 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;
+ }
+
+ 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();
+ }
+
+};
+
+class BitstreamCursor {
+ friend class Deserializer;
+ BitstreamReader *BitStream;
+ const unsigned char *NextChar;
+
/// CurWord - This is the current data we have pulled from the stream but have
/// not returned to the client.
uint32_t CurWord;
-
+
/// BitsInCurWord - This is the number of bits in CurWord that are valid. This
/// is always from [0...31] inclusive.
unsigned BitsInCurWord;
-
+
// CurCodeSize - This is the declared size of code values used for the current
// block, in bits.
unsigned CurCodeSize;
-
+
/// CurAbbrevs - Abbrevs installed at in this block.
std::vector<BitCodeAbbrev*> CurAbbrevs;
-
+
struct Block {
unsigned PrevCodeSize;
std::vector<BitCodeAbbrev*> PrevAbbrevs;
explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
};
-
+
/// 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;
+
+ BitstreamCursor(const BitstreamCursor&); // NOT YET IMPLEMENTED.
+ void operator=(const BitstreamCursor&); // NOT YET IMPLEMENTED.
public:
- BitstreamReader() {
- NextChar = FirstChar = LastChar = 0;
+ BitstreamCursor() : BitStream(0), NextChar(0) {
+ }
+ explicit BitstreamCursor(BitstreamReader &R) : BitStream(&R) {
+ NextChar = R.getFirstChar();
+ assert(NextChar && "Bitstream not initialized yet");
CurWord = 0;
BitsInCurWord = 0;
- CurCodeSize = 0;
- }
-
- BitstreamReader(const unsigned char *Start, const unsigned char *End) {
- init(Start, End);
+ CurCodeSize = 2;
}
-
- 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");
+
+ void init(BitstreamReader &R) {
+ freeState();
+
+ BitStream = &R;
+ NextChar = R.getFirstChar();
+ assert(NextChar && "Bitstream not initialized yet");
CurWord = 0;
BitsInCurWord = 0;
CurCodeSize = 2;
}
-
- ~BitstreamReader() {
- // Abbrevs could still exist if the stream was broken. If so, don't leak
- // them.
+
+ ~BitstreamCursor() {
+ freeState();
+ }
+
+ void freeState() {
+ // Free all the Abbrevs.
for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
i != e; ++i)
CurAbbrevs[i]->dropRef();
-
+ CurAbbrevs.clear();
+
+ // Free all the Abbrevs in the block scope.
for (unsigned S = 0, e = static_cast<unsigned>(BlockScope.size());
S != e; ++S) {
std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
i != e; ++i)
Abbrevs[i]->dropRef();
}
-
- // 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();
- }
+ BlockScope.clear();
}
-
+
+ /// GetAbbrevIDWidth - Return the number of bits used to encode an abbrev #.
+ unsigned GetAbbrevIDWidth() const { return CurCodeSize; }
+
bool AtEndOfStream() const {
- return NextChar == LastChar && BitsInCurWord == 0;
+ return NextChar == BitStream->getLastChar() && BitsInCurWord == 0;
}
-
+
/// GetCurrentBitNo - Return the bit # of the bit we are reading.
uint64_t GetCurrentBitNo() const {
- return (NextChar-FirstChar)*CHAR_BIT + ((32-BitsInCurWord) & 31);
+ return (NextChar-BitStream->getFirstChar())*CHAR_BIT - BitsInCurWord;
}
-
+
+
/// 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");
-
+ assert(ByteNo <= (uintptr_t)(BitStream->getLastChar()-
+ BitStream->getFirstChar()) &&
+ "Invalid location");
+
// Move the cursor to the right word.
- NextChar = FirstChar+ByteNo;
+ NextChar = BitStream->getFirstChar()+ByteNo;
BitsInCurWord = 0;
CurWord = 0;
-
+
// Skip over any bits that are already consumed.
- if (WordBitNo) {
- NextChar -= 4;
+ if (WordBitNo)
Read(static_cast<unsigned>(WordBitNo));
- }
}
-
- /// GetAbbrevIDWidth - Return the number of bits used to encode an abbrev #.
- unsigned GetAbbrevIDWidth() const { return CurCodeSize; }
-
+
+
uint32_t Read(unsigned NumBits) {
// If the field is fully contained by CurWord, return it quickly.
if (BitsInCurWord >= NumBits) {
}
// If we run out of data, stop at the end of the stream.
- if (NextChar == LastChar) {
+ if (NextChar == BitStream->getLastChar()) {
CurWord = 0;
BitsInCurWord = 0;
return 0;
CurWord = 0;
}
-
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]
// Check that the block wasn't partially defined, and that the offset isn't
// bogus.
- if (AtEndOfStream() || NextChar+NumWords*4 > LastChar)
+ if (AtEndOfStream() || NextChar+NumWords*4 > BitStream->getLastChar())
return true;
NextChar += NumWords*4;
BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
// Add the abbrevs specific to this block to the CurAbbrevs list.
- if (BlockInfo *Info = getBlockInfo(BlockID)) {
+ if (BitstreamReader::BlockInfo *Info = BitStream->getBlockInfo(BlockID)) {
for (unsigned i = 0, e = static_cast<unsigned>(Info->Abbrevs.size());
i != e; ++i) {
CurAbbrevs.push_back(Info->Abbrevs[i]);
if (NumWordsP) *NumWordsP = NumWords;
// Validate that this block is sane.
- if (CurCodeSize == 0 || AtEndOfStream() || NextChar+NumWords*4 > LastChar)
+ if (CurCodeSize == 0 || AtEndOfStream() ||
+ NextChar+NumWords*4 > BitStream->getLastChar())
return true;
return false;
BlockScope.pop_back();
}
- //===--------------------------------------------------------------------===//
+ //===--------------------------------------------------------------------===//
// Record Processing
//===--------------------------------------------------------------------===//
}
}
public:
- unsigned ReadRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals) {
+
+ /// 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 #!");
+ return CurAbbrevs[AbbrevNo];
+ }
+
+ unsigned ReadRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals,
+ const char **BlobStart = 0, unsigned *BlobLen = 0) {
if (AbbrevID == bitc::UNABBREV_RECORD) {
unsigned Code = ReadVBR(6);
unsigned NumElts = ReadVBR(6);
return Code;
}
- unsigned AbbrevNo = AbbrevID-bitc::FIRST_APPLICATION_ABBREV;
- assert(AbbrevNo < CurAbbrevs.size() && "Invalid abbrev #!");
- BitCodeAbbrev *Abbv = CurAbbrevs[AbbrevNo];
+ const BitCodeAbbrev *Abbv = getAbbrev(AbbrevID);
for (unsigned i = 0, e = Abbv->getNumOperandInfos(); i != e; ++i) {
const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
// If this would read off the end of the bitcode file, just set the
// record to empty and return.
- if (NewEnd > LastChar) {
+ if (NewEnd > BitStream->getLastChar()) {
Vals.append(NumElts, 0);
- NextChar = LastChar;
+ NextChar = BitStream->getLastChar();
break;
}
- // Otherwise, read the number of bytes.
- for (; NumElts; ++NextChar, --NumElts)
- Vals.push_back(*NextChar);
+ // Otherwise, read the number of bytes. If we can return a reference to
+ // the data, do so to avoid copying it.
+ if (BlobStart) {
+ *BlobStart = (const char*)NextChar;
+ *BlobLen = NumElts;
+ } else {
+ for (; NumElts; ++NextChar, --NumElts)
+ Vals.push_back(*NextChar);
+ }
// Skip over tail padding.
NextChar = NewEnd;
} else {
return Code;
}
+ unsigned ReadRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals,
+ const char *&BlobStart, unsigned &BlobLen) {
+ return ReadRecord(AbbrevID, Vals, &BlobStart, &BlobLen);
+ }
+
+
//===--------------------------------------------------------------------===//
// Abbrev Processing
//===--------------------------------------------------------------------===//
}
CurAbbrevs.push_back(Abbv);
}
-
- //===--------------------------------------------------------------------===//
- // BlockInfo Block Reading
- //===--------------------------------------------------------------------===//
-
-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;
+ BitstreamReader::BlockInfo *CurBlockInfo = 0;
// Read all the records for this module.
while (1) {
default: break; // Default behavior, ignore unknown content.
case bitc::BLOCKINFO_CODE_SETBID:
if (Record.size() < 1) return true;
- CurBlockInfo = &getOrCreateBlockInfo((unsigned)Record[0]);
+ CurBlockInfo = &BitStream->getOrCreateBlockInfo((unsigned)Record[0]);
break;
}
}
}
};
-
+
} // End llvm namespace
#endif
projects / oota-llvm.git / blobdiff