#define BITSTREAM_READER_H
#include "llvm/Bitcode/BitCodes.h"
+#include <vector>
namespace llvm {
+ class Deserializer;
+
class BitstreamReader {
const unsigned char *NextChar;
const unsigned char *LastChar;
+ friend class Deserializer;
/// CurWord - This is the current data we have pulled from the stream but have
/// not returned to the client.
// 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<unsigned, 8> BlockScope;
+ 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(const unsigned char *Start, const unsigned char *End)
- : NextChar(Start), LastChar(End) {
+ BitstreamReader() {
+ NextChar = FirstChar = LastChar = 0;
+ CurWord = 0;
+ BitsInCurWord = 0;
+ CurCodeSize = 0;
+ }
+
+ BitstreamReader(const unsigned char *Start, const unsigned char *End) {
+ init(Start, End);
+ }
+
+ 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");
CurWord = 0;
BitsInCurWord = 0;
CurCodeSize = 2;
}
- bool AtEndOfStream() const { return NextChar == LastChar; }
+ ~BitstreamReader() {
+ // Abbrevs could still exist if the stream was broken. If so, don't leak
+ // them.
+ for (unsigned i = 0, e = CurAbbrevs.size(); i != e; ++i)
+ CurAbbrevs[i]->dropRef();
+
+ for (unsigned S = 0, e = BlockScope.size(); S != e; ++S) {
+ std::vector<BitCodeAbbrev*> &Abbrevs = BlockScope[S].PrevAbbrevs;
+ for (unsigned i = 0, e = Abbrevs.size(); 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 = Info.Abbrevs.size(); i != e; ++i)
+ Info.Abbrevs[i]->dropRef();
+ BlockInfoRecords.pop_back();
+ }
+ }
+
+ bool AtEndOfStream() const {
+ return NextChar == LastChar && BitsInCurWord == 0;
+ }
+
+ /// GetCurrentBitNo - Return the bit # of the bit we are reading.
+ uint64_t GetCurrentBitNo() const {
+ return (NextChar-FirstChar)*8 + ((32-BitsInCurWord) & 31);
+ }
+
+ /// 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");
+
+ // Move the cursor to the right word.
+ NextChar = FirstChar+ByteNo;
+ BitsInCurWord = 0;
+ CurWord = 0;
+
+ // Skip over any bits that are already consumed.
+ if (WordBitNo) {
+ NextChar -= 4;
+ Read(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.
return R;
}
+ uint64_t Read64(unsigned NumBits) {
+ if (NumBits <= 32) return Read(NumBits);
+
+ uint64_t V = Read(32);
+ return V | (uint64_t)Read(NumBits-32) << 32;
+ }
+
uint32_t ReadVBR(unsigned NumBits) {
uint32_t Piece = Read(NumBits);
if ((Piece & (1U << (NumBits-1))) == 0)
// 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 = BlockInfoRecords.size(); i != e; ++i)
+ if (BlockInfoRecords[i].BlockID == BlockID)
+ return &BlockInfoRecords[i];
+ return 0;
+ }
+public:
+
+
// Block header:
// [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
return false;
}
- /// EnterSubBlock - Having read the ENTER_SUBBLOCK abbrevid, read and enter
- /// the block, returning the BlockID of the block we just entered.
- bool EnterSubBlock() {
- BlockScope.push_back(CurCodeSize);
+ /// 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 = 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)
// Block tail:
// [END_BLOCK, <align4bytes>]
SkipToWord();
- CurCodeSize = BlockScope.back();
- BlockScope.pop_back();
+
+ PopBlockScope();
return false;
}
+private:
+ void PopBlockScope() {
+ CurCodeSize = BlockScope.back().PrevCodeSize;
+
+ // Delete abbrevs from popped scope.
+ for (unsigned i = 0, e = CurAbbrevs.size(); i != e; ++i)
+ CurAbbrevs[i]->dropRef();
+
+ BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
+ BlockScope.pop_back();
+ }
+
//===--------------------------------------------------------------------===//
// Record Processing
//===--------------------------------------------------------------------===//
+private:
+ void ReadAbbreviatedField(const BitCodeAbbrevOp &Op,
+ SmallVectorImpl<uint64_t> &Vals) {
+ if (Op.isLiteral()) {
+ // If the abbrev specifies the literal value to use, use it.
+ Vals.push_back(Op.getLiteralValue());
+ } else {
+ // 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;
+ }
+ }
+ }
+public:
unsigned ReadRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals) {
if (AbbrevID == bitc::UNABBREV_RECORD) {
unsigned Code = ReadVBR(6);
return Code;
}
- assert(0 && "Reading with abbrevs not implemented!");
- return 0;
+ 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() || Op.getEncoding() != BitCodeAbbrevOp::Array) {
+ ReadAbbreviatedField(Op, Vals);
+ } else {
+ // 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);
+ }
+ }
+
+ unsigned Code = (unsigned)Vals[0];
+ Vals.erase(Vals.begin());
+ return Code;
}
+ //===--------------------------------------------------------------------===//
+ // Abbrev Processing
+ //===--------------------------------------------------------------------===//
+
+ 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);
+ }
+
+ //===--------------------------------------------------------------------===//
+ // 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;
+
+ // 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;
+ }
+ }
+ }
};
} // End llvm namespace
projects / oota-llvm.git / blobdiff