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-rw-r--r--include/llvm/Bitcode/BitstreamReader.h332
1 files changed, 147 insertions, 185 deletions
diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h
index 6f478b7..ecf8235 100644
--- a/include/llvm/Bitcode/BitstreamReader.h
+++ b/include/llvm/Bitcode/BitstreamReader.h
@@ -17,39 +17,37 @@
#include "llvm/Bitcode/BitCodes.h"
#include "llvm/Support/Endian.h"
-#include "llvm/Support/StreamableMemoryObject.h"
+#include "llvm/Support/StreamingMemoryObject.h"
#include <climits>
#include <string>
#include <vector>
namespace llvm {
- class Deserializer;
+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.
+/// 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 {
public:
- /// BlockInfo - This contains information emitted to BLOCKINFO_BLOCK blocks.
- /// These describe abbreviations that all blocks of the specified ID inherit.
+ /// 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<IntrusiveRefCntPtr<BitCodeAbbrev>> Abbrevs;
std::string Name;
std::vector<std::pair<unsigned, std::string> > RecordNames;
};
private:
- std::unique_ptr<StreamableMemoryObject> BitcodeBytes;
+ std::unique_ptr<MemoryObject> 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.
+ /// 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;
@@ -58,36 +56,35 @@ public:
BitstreamReader() : IgnoreBlockInfoNames(true) {
}
- BitstreamReader(const unsigned char *Start, const unsigned char *End) {
- IgnoreBlockInfoNames = true;
+ BitstreamReader(const unsigned char *Start, const unsigned char *End)
+ : IgnoreBlockInfoNames(true) {
init(Start, End);
}
- BitstreamReader(StreamableMemoryObject *bytes) {
+ BitstreamReader(MemoryObject *bytes) : IgnoreBlockInfoNames(true) {
BitcodeBytes.reset(bytes);
}
+ BitstreamReader(BitstreamReader &&Other) {
+ *this = std::move(Other);
+ }
+
+ BitstreamReader &operator=(BitstreamReader &&Other) {
+ BitcodeBytes = std::move(Other.BitcodeBytes);
+ // Explicitly swap block info, so that nothing gets destroyed twice.
+ std::swap(BlockInfoRecords, Other.BlockInfoRecords);
+ IgnoreBlockInfoNames = Other.IgnoreBlockInfoNames;
+ return *this;
+ }
+
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();
- }
- }
+ MemoryObject &getBitcodeBytes() { return *BitcodeBytes; }
- /// CollectBlockInfoNames - This is called by clients that want block/record
- /// name information.
+ /// This is called by clients that want block/record name information.
void CollectBlockInfoNames() { IgnoreBlockInfoNames = false; }
bool isIgnoringBlockInfoNames() { return IgnoreBlockInfoNames; }
@@ -95,13 +92,13 @@ public:
// 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.
+ /// 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.
+ /// 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)
@@ -123,23 +120,26 @@ public:
BlockInfoRecords.back().BlockID = BlockID;
return BlockInfoRecords.back();
}
-};
+ /// Takes block info from the other bitstream reader.
+ ///
+ /// This is a "take" operation because BlockInfo records are non-trivial, and
+ /// indeed rather expensive.
+ void takeBlockInfo(BitstreamReader &&Other) {
+ assert(!hasBlockInfoRecords());
+ BlockInfoRecords = std::move(Other.BlockInfoRecords);
+ }
+};
-/// 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.
-///
+/// When advancing through a bitstream cursor, each advance can discover a few
+/// different kinds of entries:
struct BitstreamEntry {
enum {
- Error,
- EndBlock,
- SubBlock,
- Record
+ 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.
} Kind;
unsigned ID;
@@ -158,9 +158,9 @@ struct BitstreamEntry {
}
};
-/// 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.
+/// 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.
@@ -169,92 +169,74 @@ class BitstreamCursor {
BitstreamReader *BitStream;
size_t NextChar;
+ // The size of the bicode. 0 if we don't know it yet.
+ size_t Size;
- /// 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;
+ /// 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 size_t word_t;
word_t CurWord;
- /// BitsInCurWord - This is the number of bits in CurWord that are valid. This
- /// is always from [0...31/63] inclusive (depending on word size).
+ /// This is the number of bits in CurWord that are valid. This is always from
+ /// [0...bits_of(size_t)-1] inclusive.
unsigned BitsInCurWord;
- // CurCodeSize - This is the declared size of code values used for the current
- // block, in bits.
+ // 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;
+ /// Abbrevs installed at in this block.
+ std::vector<IntrusiveRefCntPtr<BitCodeAbbrev>> CurAbbrevs;
struct Block {
unsigned PrevCodeSize;
- std::vector<BitCodeAbbrev*> PrevAbbrevs;
+ std::vector<IntrusiveRefCntPtr<BitCodeAbbrev>> PrevAbbrevs;
explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
};
- /// BlockScope - This tracks the codesize of parent blocks.
+ /// This tracks the codesize of parent blocks.
SmallVector<Block, 8> BlockScope;
public:
- BitstreamCursor() : BitStream(nullptr), NextChar(0) {}
- BitstreamCursor(const BitstreamCursor &RHS)
- : BitStream(nullptr), NextChar(0) {
- operator=(RHS);
- }
+ BitstreamCursor() { init(nullptr); }
- explicit BitstreamCursor(BitstreamReader &R) : BitStream(&R) {
- NextChar = 0;
- CurWord = 0;
- BitsInCurWord = 0;
- CurCodeSize = 2;
- }
+ explicit BitstreamCursor(BitstreamReader &R) { init(&R); }
- void init(BitstreamReader &R) {
+ void init(BitstreamReader *R) {
freeState();
- BitStream = &R;
+ BitStream = R;
NextChar = 0;
- CurWord = 0;
+ Size = 0;
BitsInCurWord = 0;
CurCodeSize = 2;
}
- ~BitstreamCursor() {
- freeState();
- }
-
- void operator=(const BitstreamCursor &RHS);
-
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() {
- return BitsInCurWord == 0 && isEndPos(NextChar);
+ if (BitsInCurWord != 0)
+ return false;
+ if (Size != 0)
+ return Size == NextChar;
+ fillCurWord();
+ return BitsInCurWord == 0;
}
- /// getAbbrevIDWidth - Return the number of bits used to encode an abbrev #.
+ /// 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.
+ /// Return the bit # of the bit we are reading.
uint64_t GetCurrentBitNo() const {
return NextChar*CHAR_BIT - BitsInCurWord;
}
@@ -268,19 +250,17 @@ public:
/// 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.
+ /// 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.
+ /// 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) {
+ /// 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) {
@@ -305,8 +285,8 @@ public:
}
}
- /// advanceSkippingSubblocks - This is a convenience function for clients that
- /// don't expect any subblocks. This just skips over them automatically.
+ /// 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.
@@ -320,7 +300,7 @@ public:
}
}
- /// JumpToBit - Reset the stream to the specified bit number.
+ /// Reset the stream to the specified bit number.
void JumpToBit(uint64_t BitNo) {
uintptr_t ByteNo = uintptr_t(BitNo/8) & ~(sizeof(word_t)-1);
unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
@@ -329,77 +309,74 @@ public:
// Move the cursor to the right word.
NextChar = ByteNo;
BitsInCurWord = 0;
- CurWord = 0;
// Skip over any bits that are already consumed.
- if (WordBitNo) {
- if (sizeof(word_t) > 4)
- Read64(WordBitNo);
- else
- Read(WordBitNo);
+ if (WordBitNo)
+ Read(WordBitNo);
+ }
+
+ void fillCurWord() {
+ assert(Size == 0 || NextChar < (unsigned)Size);
+
+ // Read the next word from the stream.
+ uint8_t Array[sizeof(word_t)] = {0};
+
+ uint64_t BytesRead =
+ BitStream->getBitcodeBytes().readBytes(Array, sizeof(Array), NextChar);
+
+ // If we run out of data, stop at the end of the stream.
+ if (BytesRead == 0) {
+ Size = NextChar;
+ return;
}
+
+ CurWord =
+ support::endian::read<word_t, support::little, support::unaligned>(
+ Array);
+ NextChar += BytesRead;
+ BitsInCurWord = BytesRead * 8;
}
+ word_t Read(unsigned NumBits) {
+ static const unsigned BitsInWord = sizeof(word_t) * 8;
- uint32_t Read(unsigned NumBits) {
- assert(NumBits && NumBits <= 32 &&
- "Cannot return zero or more than 32 bits!");
+ assert(NumBits && NumBits <= BitsInWord &&
+ "Cannot return zero or more than BitsInWord bits!");
+
+ static const unsigned Mask = sizeof(word_t) > 4 ? 0x3f : 0x1f;
// If the field is fully contained by CurWord, return it quickly.
if (BitsInCurWord >= NumBits) {
- uint32_t R = uint32_t(CurWord) & (~0U >> (32-NumBits));
- CurWord >>= NumBits;
+ word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
+
+ // Use a mask to avoid undefined behavior.
+ CurWord >>= (NumBits & Mask);
+
BitsInCurWord -= NumBits;
return R;
}
- // If we run out of data, stop at the end of the stream.
- if (isEndPos(NextChar)) {
- CurWord = 0;
- BitsInCurWord = 0;
- return 0;
- }
-
- uint32_t R = uint32_t(CurWord);
-
- // Read the next word from the stream.
- uint8_t Array[sizeof(word_t)] = {0};
+ word_t R = BitsInCurWord ? CurWord : 0;
+ unsigned BitsLeft = NumBits - BitsInCurWord;
- BitStream->getBitcodeBytes().readBytes(NextChar, sizeof(Array), Array);
+ fillCurWord();
- // 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));
+ // If we run out of data, stop at the end of the stream.
+ if (BitsLeft > BitsInCurWord)
+ return 0;
- CurWord = EndianValue;
+ word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
- NextChar += sizeof(word_t);
+ // Use a mask to avoid undefined behavior.
+ CurWord >>= (BitsLeft & Mask);
- // Extract NumBits-BitsInCurWord from what we just read.
- unsigned BitsLeft = NumBits-BitsInCurWord;
+ BitsInCurWord -= BitsLeft;
- // 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);
+ R |= R2 << (NumBits - BitsLeft);
- // 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 = sizeof(word_t)*8-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)
@@ -418,8 +395,8 @@ public:
}
}
- // 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.
+ // 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) {
uint32_t Piece = Read(NumBits);
if ((Piece & (1U << (NumBits-1))) == 0)
@@ -450,7 +427,6 @@ private:
}
BitsInCurWord = 0;
- CurWord = 0;
}
public:
@@ -462,15 +438,13 @@ public:
// Block header:
// [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
- /// ReadSubBlockID - Having read the ENTER_SUBBLOCK code, read the BlockID for
- /// the block.
+ /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
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.
+ /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body
+ /// of this block. If the block record is malformed, return true.
bool SkipBlock() {
// Read and ignore the codelen value. Since we are skipping this block, we
// don't care what code widths are used inside of it.
@@ -488,8 +462,8 @@ public:
return false;
}
- /// EnterSubBlock - Having read the ENTER_SUBBLOCK abbrevid, enter
- /// the block, and return true if the block has an error.
+ /// Having read the ENTER_SUBBLOCK abbrevid, enter the block, and return true
+ /// if the block has an error.
bool EnterSubBlock(unsigned BlockID, unsigned *NumWordsP = nullptr);
bool ReadBlockEnd() {
@@ -508,12 +482,7 @@ private:
void popBlockScope() {
CurCodeSize = BlockScope.back().PrevCodeSize;
- // Delete abbrevs from popped scope.
- for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
- i != e; ++i)
- CurAbbrevs[i]->dropRef();
-
- BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
+ CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
BlockScope.pop_back();
}
@@ -521,23 +490,16 @@ private:
// Record Processing
//===--------------------------------------------------------------------===//
-private:
- void readAbbreviatedLiteral(const BitCodeAbbrevOp &Op,
- SmallVectorImpl<uint64_t> &Vals);
- void readAbbreviatedField(const BitCodeAbbrevOp &Op,
- SmallVectorImpl<uint64_t> &Vals);
- void skipAbbreviatedField(const BitCodeAbbrevOp &Op);
-
public:
- /// getAbbrev - Return the abbreviation for the specified AbbrevId.
+ /// 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];
+ return CurAbbrevs[AbbrevNo].get();
}
- /// skipRecord - Read the current record and discard it.
+ /// Read the current record and discard it.
void skipRecord(unsigned AbbrevID);
unsigned readRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals,
generated by cgit v1.1 at 2024-05-20 16:50:31 +0000