diff options
Diffstat (limited to 'include/llvm/Bitcode/BitstreamReader.h')
| -rw-r--r-- | include/llvm/Bitcode/BitstreamReader.h | 99 |
1 files changed, 61 insertions, 38 deletions
diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h index 0437f53134dc..65868294403c 100644 --- a/include/llvm/Bitcode/BitstreamReader.h +++ b/include/llvm/Bitcode/BitstreamReader.h @@ -15,7 +15,10 @@ #ifndef BITSTREAM_READER_H #define BITSTREAM_READER_H +#include "llvm/ADT/OwningPtr.h" #include "llvm/Bitcode/BitCodes.h" +#include "llvm/Support/Endian.h" +#include "llvm/Support/StreamableMemoryObject.h" #include <climits> #include <string> #include <vector> @@ -36,9 +39,7 @@ public: std::vector<std::pair<unsigned, std::string> > RecordNames; }; private: - /// FirstChar/LastChar - This remembers the first and last bytes of the - /// stream. - const unsigned char *FirstChar, *LastChar; + OwningPtr<StreamableMemoryObject> BitcodeBytes; std::vector<BlockInfo> BlockInfoRecords; @@ -47,10 +48,10 @@ private: /// uses this. bool IgnoreBlockInfoNames; - BitstreamReader(const BitstreamReader&); // NOT IMPLEMENTED - void operator=(const BitstreamReader&); // NOT IMPLEMENTED + BitstreamReader(const BitstreamReader&); // DO NOT IMPLEMENT + void operator=(const BitstreamReader&); // DO NOT IMPLEMENT public: - BitstreamReader() : FirstChar(0), LastChar(0), IgnoreBlockInfoNames(true) { + BitstreamReader() : IgnoreBlockInfoNames(true) { } BitstreamReader(const unsigned char *Start, const unsigned char *End) { @@ -58,12 +59,17 @@ public: init(Start, End); } + BitstreamReader(StreamableMemoryObject *bytes) { + BitcodeBytes.reset(bytes); + } + 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"); + BitcodeBytes.reset(getNonStreamedMemoryObject(Start, End)); } + StreamableMemoryObject &getBitcodeBytes() { return *BitcodeBytes; } + ~BitstreamReader() { // Free the BlockInfoRecords. while (!BlockInfoRecords.empty()) { @@ -75,9 +81,6 @@ public: 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. @@ -122,7 +125,7 @@ public: class BitstreamCursor { friend class Deserializer; BitstreamReader *BitStream; - const unsigned char *NextChar; + size_t NextChar; /// CurWord - This is the current data we have pulled from the stream but have /// not returned to the client. @@ -156,8 +159,7 @@ public: } explicit BitstreamCursor(BitstreamReader &R) : BitStream(&R) { - NextChar = R.getFirstChar(); - assert(NextChar && "Bitstream not initialized yet"); + NextChar = 0; CurWord = 0; BitsInCurWord = 0; CurCodeSize = 2; @@ -167,8 +169,7 @@ public: freeState(); BitStream = &R; - NextChar = R.getFirstChar(); - assert(NextChar && "Bitstream not initialized yet"); + NextChar = 0; CurWord = 0; BitsInCurWord = 0; CurCodeSize = 2; @@ -225,13 +226,39 @@ public: /// 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; + 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)); + } + + unsigned char getByte(size_t pos) { + uint8_t byte = -1; + BitStream->getBitcodeBytes().readByte(pos, &byte); + return byte; + } + + uint32_t getWord(size_t pos) { + uint8_t buf[sizeof(uint32_t)]; + memset(buf, 0xFF, sizeof(buf)); + BitStream->getBitcodeBytes().readBytes(pos, + sizeof(buf), + buf, + NULL); + return *reinterpret_cast<support::ulittle32_t *>(buf); + } + + bool AtEndOfStream() { + return isEndPos(NextChar) && BitsInCurWord == 0; } /// GetCurrentBitNo - Return the bit # of the bit we are reading. uint64_t GetCurrentBitNo() const { - return (NextChar-BitStream->getFirstChar())*CHAR_BIT - BitsInCurWord; + return NextChar*CHAR_BIT - BitsInCurWord; } BitstreamReader *getBitStreamReader() { @@ -246,12 +273,10 @@ public: 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"); + assert(canSkipToPos(ByteNo) && "Invalid location"); // Move the cursor to the right word. - NextChar = BitStream->getFirstChar()+ByteNo; + NextChar = ByteNo; BitsInCurWord = 0; CurWord = 0; @@ -272,7 +297,7 @@ public: } // If we run out of data, stop at the end of the stream. - if (NextChar == BitStream->getLastChar()) { + if (isEndPos(NextChar)) { CurWord = 0; BitsInCurWord = 0; return 0; @@ -281,8 +306,7 @@ public: unsigned R = CurWord; // Read the next word from the stream. - CurWord = (NextChar[0] << 0) | (NextChar[1] << 8) | - (NextChar[2] << 16) | (NextChar[3] << 24); + CurWord = getWord(NextChar); NextChar += 4; // Extract NumBits-BitsInCurWord from what we just read. @@ -376,9 +400,8 @@ public: // Check that the block wasn't partially defined, and that the offset isn't // bogus. - const unsigned char *const SkipTo = NextChar + NumWords*4; - if (AtEndOfStream() || SkipTo > BitStream->getLastChar() || - SkipTo < BitStream->getFirstChar()) + size_t SkipTo = NextChar + NumWords*4; + if (AtEndOfStream() || !canSkipToPos(SkipTo)) return true; NextChar = SkipTo; @@ -409,8 +432,7 @@ public: if (NumWordsP) *NumWordsP = NumWords; // Validate that this block is sane. - if (CurCodeSize == 0 || AtEndOfStream() || - NextChar+NumWords*4 > BitStream->getLastChar()) + if (CurCodeSize == 0 || AtEndOfStream()) return true; return false; @@ -455,10 +477,10 @@ private: 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!"); + default: llvm_unreachable("Unknown encoding!"); case BitCodeAbbrevOp::Fixed: Vals.push_back(Read((unsigned)Op.getEncodingData())); break; @@ -512,24 +534,25 @@ public: 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); + size_t 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()) { + if (!canSkipToPos(NewEnd)) { Vals.append(NumElts, 0); - NextChar = BitStream->getLastChar(); + NextChar = BitStream->getBitcodeBytes().getExtent(); 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; + *BlobStart = (const char*)BitStream->getBitcodeBytes().getPointer( + NextChar, NumElts); *BlobLen = NumElts; } else { for (; NumElts; ++NextChar, --NumElts) - Vals.push_back(*NextChar); + Vals.push_back(getByte(NextChar)); } // Skip over tail padding. NextChar = NewEnd; |