X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FBitcode%2FBitstreamReader.h;h=779ef5fa2d839b7cb832ffe68c3c5d5a1eb7de33;hb=70c2fc0823bcc3970fdebf18ba69449d7822af86;hp=c6394b6c99a539109f55dfe7564838005f9f48a1;hpb=a2d0ad4fe26df1e32610ccd99d084a98daeb5c67;p=oota-llvm.git diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h index c6394b6c99a..779ef5fa2d8 100644 --- a/include/llvm/Bitcode/BitstreamReader.h +++ b/include/llvm/Bitcode/BitstreamReader.h @@ -2,8 +2,8 @@ // // The LLVM Compiler Infrastructure // -// This file was developed by Chris Lattner and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // @@ -16,13 +16,113 @@ #define BITSTREAM_READER_H #include "llvm/Bitcode/BitCodes.h" +#include +#include #include namespace llvm { - + + class Deserializer; + class BitstreamReader { +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 Abbrevs; + std::string Name; + + std::vector > RecordNames; + }; +private: + /// FirstChar/LastChar - This remembers the first and last bytes of the + /// stream. + const unsigned char *FirstChar, *LastChar; + + std::vector 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&); // NOT IMPLEMENTED + void operator=(const BitstreamReader&); // NOT IMPLEMENTED +public: + BitstreamReader() : FirstChar(0), LastChar(0), IgnoreBlockInfoNames(true) { + } + + BitstreamReader(const unsigned char *Start, const unsigned char *End) { + IgnoreBlockInfoNames = true; + 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(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; } + + /// 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(BlockInfoRecords.size()); + i != e; ++i) + if (BlockInfoRecords[i].BlockID == BlockID) + return &BlockInfoRecords[i]; + return 0; + } + + BlockInfo &getOrCreateBlockInfo(unsigned BlockID) { + if (const BlockInfo *BI = getBlockInfo(BlockID)) + return *const_cast(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; - const unsigned char *LastChar; /// CurWord - This is the current data we have pulled from the stream but have /// not returned to the client. @@ -35,7 +135,7 @@ class BitstreamReader { // 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 CurAbbrevs; @@ -47,40 +147,121 @@ class BitstreamReader { /// BlockScope - This tracks the codesize of parent blocks. SmallVector BlockScope; - - /// 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), FirstChar(Start) { - assert(((End-Start) & 3) == 0 &&"Bitcode stream not a multiple of 4 bytes"); + BitstreamCursor() : BitStream(0), NextChar(0) { + } + BitstreamCursor(const BitstreamCursor &RHS) : BitStream(0), NextChar(0) { + operator=(RHS); + } + + explicit BitstreamCursor(BitstreamReader &R) : 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. - for (unsigned i = 0, e = CurAbbrevs.size(); i != e; ++i) - delete CurAbbrevs[i]; - - for (unsigned S = 0, e = BlockScope.size(); S != e; ++S) { + void init(BitstreamReader &R) { + freeState(); + + BitStream = &R; + NextChar = R.getFirstChar(); + assert(NextChar && "Bitstream not initialized yet"); + CurWord = 0; + BitsInCurWord = 0; + CurCodeSize = 2; + } + + ~BitstreamCursor() { + freeState(); + } + + void operator=(const BitstreamCursor &RHS) { + freeState(); + + BitStream = RHS.BitStream; + NextChar = RHS.NextChar; + CurWord = RHS.CurWord; + BitsInCurWord = RHS.BitsInCurWord; + CurCodeSize = RHS.CurCodeSize; + + // Copy abbreviations, and bump ref counts. + CurAbbrevs = RHS.CurAbbrevs; + for (unsigned i = 0, e = static_cast(CurAbbrevs.size()); + i != e; ++i) + CurAbbrevs[i]->addRef(); + + // Copy block scope and bump ref counts. + for (unsigned S = 0, e = static_cast(BlockScope.size()); + S != e; ++S) { + std::vector &Abbrevs = BlockScope[S].PrevAbbrevs; + for (unsigned i = 0, e = static_cast(Abbrevs.size()); + i != e; ++i) + Abbrevs[i]->addRef(); + } + } + + void freeState() { + // Free all the Abbrevs. + for (unsigned i = 0, e = static_cast(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(BlockScope.size()); + S != e; ++S) { std::vector &Abbrevs = BlockScope[S].PrevAbbrevs; - for (unsigned i = 0, e = Abbrevs.size(); i != e; ++i) - delete Abbrevs[i]; + for (unsigned i = 0, e = static_cast(Abbrevs.size()); + i != e; ++i) + Abbrevs[i]->dropRef(); } + BlockScope.clear(); } - bool AtEndOfStream() const { return NextChar == LastChar; } + /// GetAbbrevIDWidth - Return the number of bits used to encode an abbrev #. + unsigned GetAbbrevIDWidth() const { return CurCodeSize; } + + bool AtEndOfStream() const { + return NextChar == BitStream->getLastChar() && BitsInCurWord == 0; + } /// GetCurrentBitNo - Return the bit # of the bit we are reading. uint64_t GetCurrentBitNo() const { - return (NextChar-FirstChar)*8 + (32-BitsInCurWord); + return (NextChar-BitStream->getFirstChar())*CHAR_BIT - BitsInCurWord; + } + + BitstreamReader *getBitStreamReader() { + return BitStream; + } + const BitstreamReader *getBitStreamReader() const { + return BitStream; + } + + + /// 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)(BitStream->getLastChar()- + BitStream->getFirstChar()) && + "Invalid location"); + + // Move the cursor to the right word. + NextChar = BitStream->getFirstChar()+ByteNo; + BitsInCurWord = 0; + CurWord = 0; + + // Skip over any bits that are already consumed. + if (WordBitNo) + Read(static_cast(WordBitNo)); } uint32_t Read(unsigned NumBits) { + assert(NumBits <= 32 && "Cannot return 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); @@ -90,25 +271,25 @@ public: } // If we run out of data, stop at the end of the stream. - if (LastChar == NextChar) { + if (NextChar == BitStream->getLastChar()) { CurWord = 0; BitsInCurWord = 0; return 0; } - + unsigned R = CurWord; // Read the next word from the stream. CurWord = (NextChar[0] << 0) | (NextChar[1] << 8) | (NextChar[2] << 16) | (NextChar[3] << 24); NextChar += 4; - + // 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; - + // BitsLeft bits have just been used up from CurWord. if (BitsLeft != 32) CurWord >>= BitsLeft; @@ -117,14 +298,14 @@ public: BitsInCurWord = 32-BitsLeft; 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) @@ -137,25 +318,27 @@ public: if ((Piece & (1U << (NumBits-1))) == 0) return Result; - + NextBit += NumBits-1; Piece = Read(NumBits); } } - + + // 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; - + NextBit += NumBits-1; Piece = Read(NumBits); } @@ -166,15 +349,11 @@ public: CurWord = 0; } - unsigned ReadCode() { return Read(CurCodeSize); } - //===--------------------------------------------------------------------===// - // Block Manipulation - //===--------------------------------------------------------------------===// - + // Block header: // [ENTER_SUBBLOCK, blockid, newcodelen, , blocklen] @@ -183,7 +362,7 @@ public: unsigned ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); } - + /// SkipBlock - Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip /// over the body of this block. If the block record is malformed, return /// true. @@ -193,56 +372,112 @@ public: ReadVBR(bitc::CodeLenWidth); SkipToWord(); unsigned NumWords = Read(bitc::BlockSizeWidth); - + // 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; 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() { + + /// 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 (const BitstreamReader::BlockInfo *Info = + BitStream->getBlockInfo(BlockID)) { + for (unsigned i = 0, e = static_cast(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) + if (CurCodeSize == 0 || AtEndOfStream() || + NextChar+NumWords*4 > BitStream->getLastChar()) return true; - + return false; } - + bool ReadBlockEnd() { if (BlockScope.empty()) return true; - + // Block tail: // [END_BLOCK, ] SkipToWord(); + + 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) - delete CurAbbrevs[i]; - + for (unsigned i = 0, e = static_cast(CurAbbrevs.size()); + i != e; ++i) + CurAbbrevs[i]->dropRef(); + BlockScope.back().PrevAbbrevs.swap(CurAbbrevs); BlockScope.pop_back(); - return false; } - - //===--------------------------------------------------------------------===// + + //===--------------------------------------------------------------------===// // Record Processing //===--------------------------------------------------------------------===// + +private: + void ReadAbbreviatedLiteral(const BitCodeAbbrevOp &Op, + SmallVectorImpl &Vals) { + assert(Op.isLiteral() && "Not a literal"); + // If the abbrev specifies the literal value to use, use it. + Vals.push_back(Op.getLiteralValue()); + } - unsigned ReadRecord(unsigned AbbrevID, SmallVectorImpl &Vals) { + void ReadAbbreviatedField(const BitCodeAbbrevOp &Op, + SmallVectorImpl &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; + } + } +public: + + /// 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 &Vals, + const char **BlobStart = 0, unsigned *BlobLen = 0) { if (AbbrevID == bitc::UNABBREV_RECORD) { unsigned Code = ReadVBR(6); unsigned NumElts = ReadVBR(6); @@ -250,60 +485,158 @@ public: Vals.push_back(ReadVBR64(6)); return Code; } - - unsigned AbbrevNo = AbbrevID-bitc::FIRST_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 (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::FixedWidth: - Vals.push_back(Read(Op.getEncodingData())); - break; - case BitCodeAbbrevOp::VBR: - Vals.push_back(ReadVBR64(Op.getEncodingData())); + 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 > BitStream->getLastChar()) { + Vals.append(NumElts, 0); + NextChar = BitStream->getLastChar(); break; } + + // 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 { + ReadAbbreviatedField(Op, Vals); } } - - unsigned Code = Vals[0]; + + unsigned Code = (unsigned)Vals[0]; Vals.erase(Vals.begin()); return Code; } + + unsigned ReadRecord(unsigned AbbrevID, SmallVectorImpl &Vals, + const char *&BlobStart, unsigned &BlobLen) { + return ReadRecord(AbbrevID, Vals, &BlobStart, &BlobLen); + } + //===--------------------------------------------------------------------===// // Abbrev Processing //===--------------------------------------------------------------------===// - + void ReadAbbrevRecord() { BitCodeAbbrev *Abbv = new BitCodeAbbrev(); unsigned NumOpInfo = ReadVBR(5); for (unsigned i = 0; i != NumOpInfo; ++i) { - bool IsLiteral = Read(1); + 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)) { + if (BitCodeAbbrevOp::hasEncodingData(E)) Abbv->Add(BitCodeAbbrevOp(E, ReadVBR64(5))); - } else { - assert(0 && "unimp"); - } + else + Abbv->Add(BitCodeAbbrevOp(E)); } CurAbbrevs.push_back(Abbv); } -}; + +public: + + bool ReadBlockInfoBlock() { + // If this is the second stream to get to the block info block, skip it. + if (BitStream->hasBlockInfoRecords()) + return SkipBlock(); + + if (EnterSubBlock(bitc::BLOCKINFO_BLOCK_ID)) return true; + + SmallVector Record; + BitstreamReader::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 = &BitStream->getOrCreateBlockInfo((unsigned)Record[0]); + break; + case bitc::BLOCKINFO_CODE_BLOCKNAME: { + if (!CurBlockInfo) return true; + if (BitStream->isIgnoringBlockInfoNames()) break; // Ignore name. + std::string Name; + for (unsigned i = 0, e = Record.size(); i != e; ++i) + Name += (char)Record[i]; + CurBlockInfo->Name = Name; + break; + } + case bitc::BLOCKINFO_CODE_SETRECORDNAME: { + if (!CurBlockInfo) return true; + if (BitStream->isIgnoringBlockInfoNames()) break; // Ignore name. + std::string Name; + for (unsigned i = 1, e = Record.size(); i != e; ++i) + Name += (char)Record[i]; + CurBlockInfo->RecordNames.push_back(std::make_pair((unsigned)Record[0], + Name)); + break; + } + } + } + } +}; + } // End llvm namespace #endif