diff options
| author | robot-piglet <[email protected]> | 2025-03-05 13:38:11 +0300 |
|---|---|---|
| committer | robot-piglet <[email protected]> | 2025-03-05 13:49:53 +0300 |
| commit | 9eed360f02de773a5ed2de5d2a3e81fc7f06acfa (patch) | |
| tree | 744a4054e64eb443073c7c6ad36b29cedcf9c2e6 /contrib/libs/llvm14/include/llvm/Bitstream/BitstreamReader.h | |
| parent | c141a5c40bda2eed1a68b0626ffdae5fd19359a6 (diff) | |
Intermediate changes
commit_hash:2ec2671384dd8e604d41bc5c52c2f7858e4afea6
Diffstat (limited to 'contrib/libs/llvm14/include/llvm/Bitstream/BitstreamReader.h')
| -rw-r--r-- | contrib/libs/llvm14/include/llvm/Bitstream/BitstreamReader.h | 569 |
1 files changed, 0 insertions, 569 deletions
diff --git a/contrib/libs/llvm14/include/llvm/Bitstream/BitstreamReader.h b/contrib/libs/llvm14/include/llvm/Bitstream/BitstreamReader.h deleted file mode 100644 index 82aab050972..00000000000 --- a/contrib/libs/llvm14/include/llvm/Bitstream/BitstreamReader.h +++ /dev/null @@ -1,569 +0,0 @@ -#pragma once - -#ifdef __GNUC__ -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wunused-parameter" -#endif - -//===- BitstreamReader.h - Low-level bitstream reader interface -*- C++ -*-===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This header defines the BitstreamReader class. This class can be used to -// read an arbitrary bitstream, regardless of its contents. -// -//===----------------------------------------------------------------------===// - -#ifndef LLVM_BITSTREAM_BITSTREAMREADER_H -#define LLVM_BITSTREAM_BITSTREAMREADER_H - -#include "llvm/ADT/ArrayRef.h" -#include "llvm/ADT/SmallVector.h" -#include "llvm/Bitstream/BitCodes.h" -#include "llvm/Support/Endian.h" -#include "llvm/Support/Error.h" -#include "llvm/Support/ErrorHandling.h" -#include "llvm/Support/MemoryBufferRef.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 = 0; - 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 constexpr size_t MaxChunkSize = sizeof(word_t) * 8; - - SimpleBitstreamCursor() = default; - explicit SimpleBitstreamCursor(ArrayRef<uint8_t> BitcodeBytes) - : BitcodeBytes(BitcodeBytes) {} - explicit SimpleBitstreamCursor(StringRef BitcodeBytes) - : BitcodeBytes(arrayRefFromStringRef(BitcodeBytes)) {} - 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. - Error 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) { - if (Expected<word_t> Res = Read(WordBitNo)) - return Error::success(); - else - return Res.takeError(); - } - - return Error::success(); - } - - /// 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); - } - - Error fillCurWord() { - if (NextChar >= BitcodeBytes.size()) - return createStringError(std::errc::io_error, - "Unexpected end of file reading %u of %u bytes", - NextChar, BitcodeBytes.size()); - - // 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; - return Error::success(); - } - - Expected<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; - - if (Error fillResult = fillCurWord()) - return std::move(fillResult); - - // If we run out of data, abort. - if (BitsLeft > BitsInCurWord) - return createStringError(std::errc::io_error, - "Unexpected end of file reading %u of %u bits", - BitsInCurWord, BitsLeft); - - 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; - } - - Expected<uint32_t> ReadVBR(unsigned NumBits) { - Expected<unsigned> MaybeRead = Read(NumBits); - if (!MaybeRead) - return MaybeRead; - uint32_t Piece = MaybeRead.get(); - - 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; - MaybeRead = Read(NumBits); - if (!MaybeRead) - return MaybeRead; - Piece = MaybeRead.get(); - } - } - - // 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. - Expected<uint64_t> ReadVBR64(unsigned NumBits) { - Expected<uint64_t> MaybeRead = Read(NumBits); - if (!MaybeRead) - return MaybeRead; - uint32_t Piece = MaybeRead.get(); - - 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; - MaybeRead = Read(NumBits); - if (!MaybeRead) - return MaybeRead; - Piece = MaybeRead.get(); - } - } - - 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; - } - - /// Return the size of the stream in bytes. - size_t SizeInBytes() const { return BitcodeBytes.size(); } - - /// 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::AtEndOfStream; - using SimpleBitstreamCursor::canSkipToPos; - using SimpleBitstreamCursor::fillCurWord; - using SimpleBitstreamCursor::getBitcodeBytes; - using SimpleBitstreamCursor::GetCurrentBitNo; - using SimpleBitstreamCursor::getCurrentByteNo; - using SimpleBitstreamCursor::getPointerToByte; - using SimpleBitstreamCursor::JumpToBit; - using SimpleBitstreamCursor::Read; - using SimpleBitstreamCursor::ReadVBR; - using SimpleBitstreamCursor::ReadVBR64; - using SimpleBitstreamCursor::SizeInBytes; - using SimpleBitstreamCursor::skipToEnd; - - /// 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. - Expected<BitstreamEntry> advance(unsigned Flags = 0) { - while (true) { - if (AtEndOfStream()) - return BitstreamEntry::getError(); - - Expected<unsigned> MaybeCode = ReadCode(); - if (!MaybeCode) - return MaybeCode.takeError(); - unsigned Code = MaybeCode.get(); - - 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) { - if (Expected<unsigned> MaybeSubBlock = ReadSubBlockID()) - return BitstreamEntry::getSubBlock(MaybeSubBlock.get()); - else - return MaybeSubBlock.takeError(); - } - - if (Code == bitc::DEFINE_ABBREV && - !(Flags & AF_DontAutoprocessAbbrevs)) { - // We read and accumulate abbrev's, the client can't do anything with - // them anyway. - if (Error Err = ReadAbbrevRecord()) - return std::move(Err); - continue; - } - - return BitstreamEntry::getRecord(Code); - } - } - - /// This is a convenience function for clients that don't expect any - /// subblocks. This just skips over them automatically. - Expected<BitstreamEntry> advanceSkippingSubblocks(unsigned Flags = 0) { - while (true) { - // If we found a normal entry, return it. - Expected<BitstreamEntry> MaybeEntry = advance(Flags); - if (!MaybeEntry) - return MaybeEntry; - BitstreamEntry Entry = MaybeEntry.get(); - - if (Entry.Kind != BitstreamEntry::SubBlock) - return Entry; - - // If we found a sub-block, just skip over it and check the next entry. - if (Error Err = SkipBlock()) - return std::move(Err); - } - } - - Expected<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. - Expected<unsigned> ReadSubBlockID() { return ReadVBR(bitc::BlockIDWidth); } - - /// Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body - /// of this block. - Error SkipBlock() { - // Read and ignore the codelen value. - if (Expected<uint32_t> Res = ReadVBR(bitc::CodeLenWidth)) - ; // Since we are skipping this block, we don't care what code widths are - // used inside of it. - else - return Res.takeError(); - - SkipToFourByteBoundary(); - Expected<unsigned> MaybeNum = Read(bitc::BlockSizeWidth); - if (!MaybeNum) - return MaybeNum.takeError(); - size_t NumFourBytes = MaybeNum.get(); - - // Check that the block wasn't partially defined, and that the offset isn't - // bogus. - size_t SkipTo = GetCurrentBitNo() + NumFourBytes * 4 * 8; - if (AtEndOfStream()) - return createStringError(std::errc::illegal_byte_sequence, - "can't skip block: already at end of stream"); - if (!canSkipToPos(SkipTo / 8)) - return createStringError(std::errc::illegal_byte_sequence, - "can't skip to bit %zu from %" PRIu64, SkipTo, - GetCurrentBitNo()); - - if (Error Res = JumpToBit(SkipTo)) - return Res; - - return Error::success(); - } - - /// Having read the ENTER_SUBBLOCK abbrevid, and enter the block. - Error 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. - Expected<unsigned> skipRecord(unsigned AbbrevID); - - Expected<unsigned> readRecord(unsigned AbbrevID, - SmallVectorImpl<uint64_t> &Vals, - StringRef *Blob = nullptr); - - //===--------------------------------------------------------------------===// - // Abbrev Processing - //===--------------------------------------------------------------------===// - Error 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. - Expected<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_BITSTREAM_BITSTREAMREADER_H - -#ifdef __GNUC__ -#pragma GCC diagnostic pop -#endif |
