vendor/llvm/llvm-trunk-r366426

1 files changed, 0 insertions, 506 deletions

diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h
deleted file mode 100644
index 72e7619d9e1c..000000000000
--- a/include/llvm/Bitcode/BitstreamReader.h
+++ /dev/null
@@ -1,506 +0,0 @@
-//===- BitstreamReader.h - Low-level bitstream reader interface -*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This header defines the BitstreamReader class.  This class can be used to
-// read an arbitrary bitstream, regardless of its contents.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_BITCODE_BITSTREAMREADER_H
-#define LLVM_BITCODE_BITSTREAMREADER_H
-
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Bitcode/BitCodes.h"
-#include "llvm/Support/Endian.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include <algorithm>
-#include <cassert>
-#include <climits>
-#include <cstddef>
-#include <cstdint>
-#include <memory>
-#include <string>
-#include <utility>
-#include <vector>
-
-namespace llvm {
-
-/// This class maintains the abbreviations read from a block info block.
-class BitstreamBlockInfo {
-public:
-  /// 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<std::shared_ptr<BitCodeAbbrev>> Abbrevs;
-    std::string Name;
-    std::vector<std::pair<unsigned, std::string>> RecordNames;
-  };
-
-private:
-  std::vector<BlockInfo> BlockInfoRecords;
-
-public:
-  /// 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<unsigned>(BlockInfoRecords.size());
-         i != e; ++i)
-      if (BlockInfoRecords[i].BlockID == BlockID)
-        return &BlockInfoRecords[i];
-    return nullptr;
-  }
-
-  BlockInfo &getOrCreateBlockInfo(unsigned BlockID) {
-    if (const BlockInfo *BI = getBlockInfo(BlockID))
-      return *const_cast<BlockInfo*>(BI);
-
-    // Otherwise, add a new record.
-    BlockInfoRecords.emplace_back();
-    BlockInfoRecords.back().BlockID = BlockID;
-    return BlockInfoRecords.back();
-  }
-};
-
-/// This represents a position within a bitstream. There may be multiple
-/// independent cursors reading within one bitstream, each maintaining their
-/// own local state.
-class SimpleBitstreamCursor {
-  ArrayRef<uint8_t> BitcodeBytes;
-  size_t NextChar = 0;
-
-public:
-  /// 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.
-  using word_t = size_t;
-
-private:
-  word_t CurWord = 0;
-
-  /// This is the number of bits in CurWord that are valid. This is always from
-  /// [0...bits_of(size_t)-1] inclusive.
-  unsigned BitsInCurWord = 0;
-
-public:
-  static const size_t MaxChunkSize = sizeof(word_t) * 8;
-
-  SimpleBitstreamCursor() = default;
-  explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
-      : BitcodeBytes(BitcodeBytes) {}
-  explicit SimpleBitstreamCursor(StringRef BitcodeBytes)
-      : BitcodeBytes(reinterpret_cast<const uint8_t *>(BitcodeBytes.data()),
-                     BitcodeBytes.size()) {}
-  explicit SimpleBitstreamCursor(MemoryBufferRef BitcodeBytes)
-      : SimpleBitstreamCursor(BitcodeBytes.getBuffer()) {}
-
-  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 <= BitcodeBytes.size();
-  }
-
-  bool AtEndOfStream() {
-    return BitsInCurWord == 0 && BitcodeBytes.size() <= NextChar;
-  }
-
-  /// Return the bit # of the bit we are reading.
-  uint64_t GetCurrentBitNo() const {
-    return NextChar*CHAR_BIT - BitsInCurWord;
-  }
-
-  // Return the byte # of the current bit.
-  uint64_t getCurrentByteNo() const { return GetCurrentBitNo() / 8; }
-
-  ArrayRef<uint8_t> getBitcodeBytes() const { return BitcodeBytes; }
-
-  /// Reset the stream to the specified bit number.
-  void JumpToBit(uint64_t BitNo) {
-    size_t ByteNo = size_t(BitNo/8) & ~(sizeof(word_t)-1);
-    unsigned WordBitNo = unsigned(BitNo & (sizeof(word_t)*8-1));
-    assert(canSkipToPos(ByteNo) && "Invalid location");
-
-    // Move the cursor to the right word.
-    NextChar = ByteNo;
-    BitsInCurWord = 0;
-
-    // Skip over any bits that are already consumed.
-    if (WordBitNo)
-      Read(WordBitNo);
-  }
-
-  /// Get a pointer into the bitstream at the specified byte offset.
-  const uint8_t *getPointerToByte(uint64_t ByteNo, uint64_t NumBytes) {
-    return BitcodeBytes.data() + ByteNo;
-  }
-
-  /// Get a pointer into the bitstream at the specified bit offset.
-  ///
-  /// The bit offset must be on a byte boundary.
-  const uint8_t *getPointerToBit(uint64_t BitNo, uint64_t NumBytes) {
-    assert(!(BitNo % 8) && "Expected bit on byte boundary");
-    return getPointerToByte(BitNo / 8, NumBytes);
-  }
-
-  void fillCurWord() {
-    if (NextChar >= BitcodeBytes.size())
-      report_fatal_error("Unexpected end of file");
-
-    // Read the next word from the stream.
-    const uint8_t *NextCharPtr = BitcodeBytes.data() + NextChar;
-    unsigned BytesRead;
-    if (BitcodeBytes.size() >= NextChar + sizeof(word_t)) {
-      BytesRead = sizeof(word_t);
-      CurWord =
-          support::endian::read<word_t, support::little, support::unaligned>(
-              NextCharPtr);
-    } else {
-      // Short read.
-      BytesRead = BitcodeBytes.size() - NextChar;
-      CurWord = 0;
-      for (unsigned B = 0; B != BytesRead; ++B)
-        CurWord |= uint64_t(NextCharPtr[B]) << (B * 8);
-    }
-    NextChar += BytesRead;
-    BitsInCurWord = BytesRead * 8;
-  }
-
-  word_t Read(unsigned NumBits) {
-    static const unsigned BitsInWord = MaxChunkSize;
-
-    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) {
-      word_t R = CurWord & (~word_t(0) >> (BitsInWord - NumBits));
-
-      // Use a mask to avoid undefined behavior.
-      CurWord >>= (NumBits & Mask);
-
-      BitsInCurWord -= NumBits;
-      return R;
-    }
-
-    word_t R = BitsInCurWord ? CurWord : 0;
-    unsigned BitsLeft = NumBits - BitsInCurWord;
-
-    fillCurWord();
-
-    // If we run out of data, abort.
-    if (BitsLeft > BitsInCurWord)
-      report_fatal_error("Unexpected end of file");
-
-    word_t R2 = CurWord & (~word_t(0) >> (BitsInWord - BitsLeft));
-
-    // Use a mask to avoid undefined behavior.
-    CurWord >>= (BitsLeft & Mask);
-
-    BitsInCurWord -= BitsLeft;
-
-    R |= R2 << (NumBits - BitsLeft);
-
-    return R;
-  }
-
-  uint32_t ReadVBR(unsigned NumBits) {
-    uint32_t Piece = Read(NumBits);
-    if ((Piece & (1U << (NumBits-1))) == 0)
-      return Piece;
-
-    uint32_t Result = 0;
-    unsigned NextBit = 0;
-    while (true) {
-      Result |= (Piece & ((1U << (NumBits-1))-1)) << NextBit;
-
-      if ((Piece & (1U << (NumBits-1))) == 0)
-        return Result;
-
-      NextBit += NumBits-1;
-      Piece = Read(NumBits);
-    }
-  }
-
-  // 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)
-      return uint64_t(Piece);
-
-    uint64_t Result = 0;
-    unsigned NextBit = 0;
-    while (true) {
-      Result |= uint64_t(Piece & ((1U << (NumBits-1))-1)) << NextBit;
-
-      if ((Piece & (1U << (NumBits-1))) == 0)
-        return Result;
-
-      NextBit += NumBits-1;
-      Piece = Read(NumBits);
-    }
-  }
-
-  void SkipToFourByteBoundary() {
-    // If word_t is 64-bits and if we've read less than 32 bits, just dump
-    // the bits we have up to the next 32-bit boundary.
-    if (sizeof(word_t) > 4 &&
-        BitsInCurWord >= 32) {
-      CurWord >>= BitsInCurWord-32;
-      BitsInCurWord = 32;
-      return;
-    }
-
-    BitsInCurWord = 0;
-  }
-
-  /// Skip to the end of the file.
-  void skipToEnd() { NextChar = BitcodeBytes.size(); }
-};
-
-/// When advancing through a bitstream cursor, each advance can discover a few
-/// different kinds of entries:
-struct BitstreamEntry {
-  enum {
-    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;
-
-  static BitstreamEntry getError() {
-    BitstreamEntry E; E.Kind = Error; return E;
-  }
-
-  static BitstreamEntry getEndBlock() {
-    BitstreamEntry E; E.Kind = EndBlock; return E;
-  }
-
-  static BitstreamEntry getSubBlock(unsigned ID) {
-    BitstreamEntry E; E.Kind = SubBlock; E.ID = ID; return E;
-  }
-
-  static BitstreamEntry getRecord(unsigned AbbrevID) {
-    BitstreamEntry E; E.Kind = Record; E.ID = AbbrevID; return E;
-  }
-};
-
-/// This represents a position within a bitcode file, implemented on top of a
-/// SimpleBitstreamCursor.
-///
-/// Unlike iterators, BitstreamCursors are heavy-weight objects that should not
-/// be passed by value.
-class BitstreamCursor : SimpleBitstreamCursor {
-  // This is the declared size of code values used for the current block, in
-  // bits.
-  unsigned CurCodeSize = 2;
-
-  /// Abbrevs installed at in this block.
-  std::vector<std::shared_ptr<BitCodeAbbrev>> CurAbbrevs;
-
-  struct Block {
-    unsigned PrevCodeSize;
-    std::vector<std::shared_ptr<BitCodeAbbrev>> PrevAbbrevs;
-
-    explicit Block(unsigned PCS) : PrevCodeSize(PCS) {}
-  };
-
-  /// This tracks the codesize of parent blocks.
-  SmallVector<Block, 8> BlockScope;
-
-  BitstreamBlockInfo *BlockInfo = nullptr;
-
-public:
-  static const size_t MaxChunkSize = sizeof(word_t) * 8;
-
-  BitstreamCursor() = default;
-  explicit BitstreamCursor(ArrayRef<uint8_t> BitcodeBytes)
-      : SimpleBitstreamCursor(BitcodeBytes) {}
-  explicit BitstreamCursor(StringRef BitcodeBytes)
-      : SimpleBitstreamCursor(BitcodeBytes) {}
-  explicit BitstreamCursor(MemoryBufferRef BitcodeBytes)
-      : SimpleBitstreamCursor(BitcodeBytes) {}
-
-  using SimpleBitstreamCursor::canSkipToPos;
-  using SimpleBitstreamCursor::AtEndOfStream;
-  using SimpleBitstreamCursor::getBitcodeBytes;
-  using SimpleBitstreamCursor::GetCurrentBitNo;
-  using SimpleBitstreamCursor::getCurrentByteNo;
-  using SimpleBitstreamCursor::getPointerToByte;
-  using SimpleBitstreamCursor::JumpToBit;
-  using SimpleBitstreamCursor::fillCurWord;
-  using SimpleBitstreamCursor::Read;
-  using SimpleBitstreamCursor::ReadVBR;
-  using SimpleBitstreamCursor::ReadVBR64;
-
-  /// Return the number of bits used to encode an abbrev #.
-  unsigned getAbbrevIDWidth() const { return CurCodeSize; }
-
-  /// Flags that modify the behavior of advance().
-  enum {
-    /// 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,
-
-    /// If this flag is used, abbrev entries are returned just like normal
-    /// records.
-    AF_DontAutoprocessAbbrevs = 2
-  };
-
-  /// Advance the current bitstream, returning the next entry in the stream.
-  BitstreamEntry advance(unsigned Flags = 0) {
-    while (true) {
-      if (AtEndOfStream())
-        return BitstreamEntry::getError();
-
-      unsigned Code = ReadCode();
-      if (Code == bitc::END_BLOCK) {
-        // Pop the end of the block unless Flags tells us not to.
-        if (!(Flags & AF_DontPopBlockAtEnd) && ReadBlockEnd())
-          return BitstreamEntry::getError();
-        return BitstreamEntry::getEndBlock();
-      }
-
-      if (Code == bitc::ENTER_SUBBLOCK)
-        return BitstreamEntry::getSubBlock(ReadSubBlockID());
-
-      if (Code == bitc::DEFINE_ABBREV &&
-          !(Flags & AF_DontAutoprocessAbbrevs)) {
-        // We read and accumulate abbrev's, the client can't do anything with
-        // them anyway.
-        ReadAbbrevRecord();
-        continue;
-      }
-
-      return BitstreamEntry::getRecord(Code);
-    }
-  }
-
-  /// 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 (true) {
-      // If we found a normal entry, return it.
-      BitstreamEntry Entry = advance(Flags);
-      if (Entry.Kind != BitstreamEntry::SubBlock)
-        return Entry;
-
-      // If we found a sub-block, just skip over it and check the next entry.
-      if (SkipBlock())
-        return BitstreamEntry::getError();
-    }
-  }
-
-  unsigned ReadCode() {
-    return Read(CurCodeSize);
-  }
-
-  // Block header:
-  //    [ENTER_SUBBLOCK, blockid, newcodelen, <align4bytes>, blocklen]
-
-  /// Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
-  unsigned ReadSubBlockID() {
-    return ReadVBR(bitc::BlockIDWidth);
-  }
-
-  /// 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.
-    ReadVBR(bitc::CodeLenWidth);
-    SkipToFourByteBoundary();
-    size_t NumFourBytes = Read(bitc::BlockSizeWidth);
-
-    // Check that the block wasn't partially defined, and that the offset isn't
-    // bogus.
-    size_t SkipTo = GetCurrentBitNo() + NumFourBytes*4*8;
-    if (AtEndOfStream() || !canSkipToPos(SkipTo/8))
-      return true;
-
-    JumpToBit(SkipTo);
-    return false;
-  }
-
-  /// 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() {
-    if (BlockScope.empty()) return true;
-
-    // Block tail:
-    //    [END_BLOCK, <align4bytes>]
-    SkipToFourByteBoundary();
-
-    popBlockScope();
-    return false;
-  }
-
-private:
-  void popBlockScope() {
-    CurCodeSize = BlockScope.back().PrevCodeSize;
-
-    CurAbbrevs = std::move(BlockScope.back().PrevAbbrevs);
-    BlockScope.pop_back();
-  }
-
-  //===--------------------------------------------------------------------===//
-  // Record Processing
-  //===--------------------------------------------------------------------===//
-
-public:
-  /// Return the abbreviation for the specified AbbrevId.
-  const BitCodeAbbrev *getAbbrev(unsigned AbbrevID) {
-    unsigned AbbrevNo = AbbrevID - bitc::FIRST_APPLICATION_ABBREV;
-    if (AbbrevNo >= CurAbbrevs.size())
-      report_fatal_error("Invalid abbrev number");
-    return CurAbbrevs[AbbrevNo].get();
-  }
-
-  /// Read the current record and discard it, returning the code for the record.
-  unsigned skipRecord(unsigned AbbrevID);
-
-  unsigned readRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals,
-                      StringRef *Blob = nullptr);
-
-  //===--------------------------------------------------------------------===//
-  // Abbrev Processing
-  //===--------------------------------------------------------------------===//
-  void ReadAbbrevRecord();
-
-  /// Read and return a block info block from the bitstream. If an error was
-  /// encountered, return None.
-  ///
-  /// \param ReadBlockInfoNames Whether to read block/record name information in
-  /// the BlockInfo block. Only llvm-bcanalyzer uses this.
-  Optional<BitstreamBlockInfo>
-  ReadBlockInfoBlock(bool ReadBlockInfoNames = false);
-
-  /// Set the block info to be used by this BitstreamCursor to interpret
-  /// abbreviated records.
-  void setBlockInfo(BitstreamBlockInfo *BI) { BlockInfo = BI; }
-};
-
-} // end llvm namespace
-
-#endif // LLVM_BITCODE_BITSTREAMREADER_H