BBAddrMapYAML.cpp

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//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file defines the YAMLIO mappings for the format-agnostic BB address
/// map YAML types declared in BBAddrMapYAML.h.
///
//===----------------------------------------------------------------------===//
 
#include "llvm/ObjectYAML/BBAddrMapYAML.h"
#include "llvm/Object/BBAddrMap.h"
#include "llvm/ObjectYAML/ContiguousBlobAccumulator.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/WithColor.h"
 
namespace llvm {
namespace yaml {
 
void MappingTraits<BBAddrMapYAML::BBAddrMapEntry>::mapping(
    IO &IO, BBAddrMapYAML::BBAddrMapEntry &E) {
  assert(IO.getContext() && "The IO context is not initialized");
  IO.mapRequired("Version", E.Version);
  IO.mapOptional("Feature", E.Feature, Hex16(0));
  IO.mapOptional("FuncGUID", E.FuncGUID);
  IO.mapOptional("NumBBRanges", E.NumBBRanges);
  IO.mapOptional("BBRanges", E.BBRanges);
}
 
void MappingTraits<BBAddrMapYAML::BBAddrMapEntry::BBRangeEntry>::mapping(
    IO &IO, BBAddrMapYAML::BBAddrMapEntry::BBRangeEntry &E) {
  IO.mapOptional("BaseAddress", E.BaseAddress, Hex64(0));
  IO.mapOptional("NumBlocks", E.NumBlocks);
  IO.mapOptional("BBEntries", E.BBEntries);
}
 
void MappingTraits<BBAddrMapYAML::BBAddrMapEntry::BBEntry>::mapping(
    IO &IO, BBAddrMapYAML::BBAddrMapEntry::BBEntry &E) {
  assert(IO.getContext() && "The IO context is not initialized");
  IO.mapOptional("ID", E.ID);
  IO.mapRequired("AddressOffset", E.AddressOffset);
  IO.mapRequired("Size", E.Size);
  IO.mapRequired("Metadata", E.Metadata);
  IO.mapOptional("CallsiteEndOffsets", E.CallsiteEndOffsets);
  IO.mapOptional("Hash", E.Hash);
}
 
void MappingTraits<BBAddrMapYAML::PGOAnalysisMapEntry>::mapping(
    IO &IO, BBAddrMapYAML::PGOAnalysisMapEntry &E) {
  assert(IO.getContext() && "The IO context is not initialized");
  IO.mapOptional("FuncEntryCount", E.FuncEntryCount);
  IO.mapOptional("PGOBBEntries", E.PGOBBEntries);
}
 
void MappingTraits<BBAddrMapYAML::PGOAnalysisMapEntry::PGOBBEntry>::mapping(
    IO &IO, BBAddrMapYAML::PGOAnalysisMapEntry::PGOBBEntry &E) {
  assert(IO.getContext() && "The IO context is not initialized");
  IO.mapOptional("BBFreq", E.BBFreq);
  IO.mapOptional("PostLinkBBFreq", E.PostLinkBBFreq);
  IO.mapOptional("Successors", E.Successors);
}
 
void MappingTraits<
    BBAddrMapYAML::PGOAnalysisMapEntry::PGOBBEntry::SuccessorEntry>::
    mapping(IO &IO,
            BBAddrMapYAML::PGOAnalysisMapEntry::PGOBBEntry::SuccessorEntry &E) {
  assert(IO.getContext() && "The IO context is not initialized");
  IO.mapRequired("ID", E.ID);
  IO.mapRequired("BrProb", E.BrProb);
  IO.mapOptional("PostLinkBrFreq", E.PostLinkBrFreq);
}
 
} // end namespace yaml
 
namespace BBAddrMapYAML {
 
void encodePayload(ArrayRef<BBAddrMapEntry> Entries,
                   const std::vector<PGOAnalysisMapEntry> *PGOAnalyses,
                   yaml::ContiguousBlobAccumulator &CBA,
                   llvm::endianness Endian, unsigned AddressSize) {
  assert((AddressSize == 4 || AddressSize == 8) && "invalid address size");
  for (const auto &[Idx, E] : llvm::enumerate(Entries)) {
    // Write version and feature values.
    if (E.Version > 6)
      WithColor::warning() << "unsupported BB address map version: "
                           << static_cast<int>(E.Version)
                           << "; encoding using the most recent version";
    CBA.write(E.Version);
    if (E.Version < 5)
      CBA.write(static_cast<uint8_t>(E.Feature));
    else
      CBA.write<uint16_t>(E.Feature, Endian);
    auto FeatureOrErr = llvm::object::BBAddrMap::Features::decode(E.Feature);
    if (!FeatureOrErr) {
      // Invalid feature: warn and skip the entry.
      WithColor::warning() << toString(FeatureOrErr.takeError());
      continue;
    }
    // Write the function GUID. This is emitted when either the feature is
    // enabled or 'FuncGUID' is specified, which allows testing mismatches.
    if (!FeatureOrErr->FuncGUID && E.FuncGUID.has_value())
      WithColor::warning() << "feature value(" << E.Feature
                           << ") does not support function GUID.";
    if (FeatureOrErr->FuncGUID || E.FuncGUID.has_value())
      CBA.write<uint64_t>(E.FuncGUID.value_or(llvm::yaml::Hex64(0)), Endian);
    bool MultiBBRangeFeatureEnabled = FeatureOrErr->MultiBBRange;
    bool MultiBBRange =
        MultiBBRangeFeatureEnabled ||
        (E.NumBBRanges.has_value() && E.NumBBRanges.value() != 1) ||
        (E.BBRanges && E.BBRanges->size() != 1);
    if (MultiBBRange && !MultiBBRangeFeatureEnabled)
      WithColor::warning() << "feature value(" << E.Feature
                           << ") does not support multiple BB ranges.";
    if (MultiBBRange) {
      // Write the number of basic block ranges, which is overridden by the
      // 'NumBBRanges' field when specified.
      uint64_t NumBBRanges =
          E.NumBBRanges.value_or(E.BBRanges ? E.BBRanges->size() : 0);
      CBA.writeULEB128(NumBBRanges);
    }
    if (!E.BBRanges)
      continue;
    uint64_t TotalNumBlocks = 0;
    bool EmitCallsiteEndOffsets =
        FeatureOrErr->CallsiteEndOffsets || E.hasAnyCallsiteEndOffsets();
    for (const BBAddrMapEntry::BBRangeEntry &BBR : *E.BBRanges) {
      // Write the pointer-sized base address of the range.
      if (AddressSize == 8)
        CBA.write<uint64_t>(BBR.BaseAddress, Endian);
      else
        CBA.write<uint32_t>(static_cast<uint32_t>(BBR.BaseAddress), Endian);
      // Write number of BBEntries (number of basic blocks in this basic block
      // range). This is overridden by the 'NumBlocks' YAML field when
      // specified.
      uint64_t NumBlocks =
          BBR.NumBlocks.value_or(BBR.BBEntries ? BBR.BBEntries->size() : 0);
      CBA.writeULEB128(NumBlocks);
      // Write all BBEntries in this BBRange.
      if (!BBR.BBEntries || FeatureOrErr->OmitBBEntries)
        continue;
      for (const BBAddrMapEntry::BBEntry &BBE : *BBR.BBEntries) {
        ++TotalNumBlocks;
        if (E.Version > 1)
          CBA.writeULEB128(BBE.ID);
        CBA.writeULEB128(BBE.AddressOffset);
        if (EmitCallsiteEndOffsets) {
          size_t NumCallsiteEndOffsets =
              BBE.CallsiteEndOffsets ? BBE.CallsiteEndOffsets->size() : 0;
          CBA.writeULEB128(NumCallsiteEndOffsets);
          if (BBE.CallsiteEndOffsets) {
            for (uint32_t Offset : *BBE.CallsiteEndOffsets)
              CBA.writeULEB128(Offset);
          }
        }
        CBA.writeULEB128(BBE.Size);
        CBA.writeULEB128(BBE.Metadata);
        if (FeatureOrErr->BBHash || BBE.Hash.has_value()) {
          uint64_t Hash =
              BBE.Hash.has_value() ? BBE.Hash.value() : llvm::yaml::Hex64(0);
          CBA.write<uint64_t>(Hash, Endian);
        }
      }
    }
    if (!PGOAnalyses)
      continue;
    const PGOAnalysisMapEntry &PGOEntry = PGOAnalyses->at(Idx);
 
    if (PGOEntry.FuncEntryCount)
      CBA.writeULEB128(*PGOEntry.FuncEntryCount);
 
    if (!PGOEntry.PGOBBEntries)
      continue;
 
    const auto &PGOBBEntries = PGOEntry.PGOBBEntries.value();
    if (TotalNumBlocks != PGOBBEntries.size()) {
      WithColor::warning() << "PGOBBEntries must be the same length as "
                              "BBEntries in the BB address map.\n"
                           << "Mismatch on function with address: "
                           << E.getFunctionAddress();
      continue;
    }
 
    for (const auto &PGOBBE : PGOBBEntries) {
      if (PGOBBE.BBFreq)
        CBA.writeULEB128(*PGOBBE.BBFreq);
      if (FeatureOrErr->PostLinkCfg || PGOBBE.PostLinkBBFreq.has_value())
        CBA.writeULEB128(PGOBBE.PostLinkBBFreq.value_or(0));
      if (PGOBBE.Successors) {
        CBA.writeULEB128(PGOBBE.Successors->size());
        for (const auto &[ID, BrProb, PostLinkBrFreq] : *PGOBBE.Successors) {
          CBA.writeULEB128(ID);
          CBA.writeULEB128(BrProb);
          if (FeatureOrErr->PostLinkCfg || PostLinkBrFreq.has_value())
            CBA.writeULEB128(PostLinkBrFreq.value_or(0));
        }
      }
    }
  }
}
 
Error decodePayload(
    ArrayRef<uint8_t> Content, llvm::endianness Endian, unsigned AddressSize,
    std::optional<std::vector<BBAddrMapEntry>> &Entries,
    std::optional<std::vector<PGOAnalysisMapEntry>> &PGOAnalyses) {
  assert((AddressSize == 4 || AddressSize == 8) && "invalid address size");
  DataExtractor Data(Content, Endian == llvm::endianness::little);
 
  std::vector<BBAddrMapEntry> DecodedEntries;
  bool HasAnyPGOAnalysisMapEntry = false;
  std::vector<PGOAnalysisMapEntry> DecodedPGOAnalyses;
  DataExtractor::Cursor Cur(0);
  uint8_t Version = 0;
  uint16_t Feature = 0;
  uint64_t Address = 0;
  while (Cur && Cur.tell() < Content.size()) {
    Version = Data.getU8(Cur);
    if (Cur && Version > 6)
      return createStringError(
          errc::invalid_argument,
          "invalid SHT_LLVM_BB_ADDR_MAP section version: " +
              Twine(static_cast<int>(Version)));
    Feature = Version < 5 ? Data.getU8(Cur) : Data.getU16(Cur);
    if (!Cur)
      break;
    uint64_t NumBBRanges = 1;
    uint64_t NumBlocks = 0;
    uint32_t TotalNumBlocks = 0;
    auto FeatureOrErr = llvm::object::BBAddrMap::Features::decode(Feature);
    if (!FeatureOrErr)
      return FeatureOrErr.takeError();
    std::optional<llvm::yaml::Hex64> FuncGUID;
    if (FeatureOrErr->FuncGUID)
      FuncGUID = Data.getU64(Cur);
    if (FeatureOrErr->MultiBBRange) {
      NumBBRanges = Data.getULEB128(Cur);
    } else {
      Address = Data.getUnsigned(Cur, AddressSize);
      NumBlocks = Data.getULEB128(Cur);
    }
    std::vector<BBAddrMapEntry::BBRangeEntry> BBRanges;
    uint64_t BaseAddress = 0;
    for (uint64_t BBRangeN = 0; Cur && BBRangeN != NumBBRanges; ++BBRangeN) {
      if (FeatureOrErr->MultiBBRange) {
        BaseAddress = Data.getUnsigned(Cur, AddressSize);
        NumBlocks = Data.getULEB128(Cur);
      } else {
        BaseAddress = Address;
      }
 
      std::vector<BBAddrMapEntry::BBEntry> BBEntries;
      // Read the specified number of BB entries, or until decoding fails.
      for (uint64_t BlockIndex = 0; Cur && BlockIndex < NumBlocks;
           ++BlockIndex) {
        uint32_t ID = Version >= 2 ? Data.getULEB128(Cur) : BlockIndex;
        uint64_t Offset = Data.getULEB128(Cur);
        std::optional<std::vector<llvm::yaml::Hex64>> CallsiteEndOffsets;
        if (FeatureOrErr->CallsiteEndOffsets) {
          uint32_t NumCallsites = Data.getULEB128(Cur);
          CallsiteEndOffsets = std::vector<llvm::yaml::Hex64>(NumCallsites, 0);
          for (uint32_t CallsiteIndex = 0; Cur && CallsiteIndex < NumCallsites;
               ++CallsiteIndex) {
            (*CallsiteEndOffsets)[CallsiteIndex] = Data.getULEB128(Cur);
          }
        }
        uint64_t Size = Data.getULEB128(Cur);
        uint64_t Metadata = Data.getULEB128(Cur);
        std::optional<llvm::yaml::Hex64> Hash;
        if (FeatureOrErr->BBHash)
          Hash = Data.getU64(Cur);
        BBEntries.push_back(
            {ID, Offset, Size, Metadata, std::move(CallsiteEndOffsets), Hash});
      }
      TotalNumBlocks += BBEntries.size();
      BBRanges.push_back({BaseAddress, /*NumBlocks=*/{}, BBEntries});
    }
    DecodedEntries.push_back(
        {Version, Feature, FuncGUID, /*NumBBRanges=*/{}, std::move(BBRanges)});
 
    PGOAnalysisMapEntry &PGOAnalysis = DecodedPGOAnalyses.emplace_back();
    if (FeatureOrErr->hasPGOAnalysis()) {
      HasAnyPGOAnalysisMapEntry = true;
 
      if (FeatureOrErr->FuncEntryCount)
        PGOAnalysis.FuncEntryCount = Data.getULEB128(Cur);
 
      if (FeatureOrErr->hasPGOAnalysisBBData()) {
        auto &PGOBBEntries = PGOAnalysis.PGOBBEntries.emplace();
        for (uint64_t BlockIndex = 0; Cur && BlockIndex < TotalNumBlocks;
             ++BlockIndex) {
          auto &PGOBBEntry = PGOBBEntries.emplace_back();
          if (FeatureOrErr->BBFreq) {
            PGOBBEntry.BBFreq = Data.getULEB128(Cur);
            if (FeatureOrErr->PostLinkCfg)
              PGOBBEntry.PostLinkBBFreq = Data.getULEB128(Cur);
            if (!Cur)
              break;
          }
 
          if (FeatureOrErr->BrProb) {
            auto &SuccEntries = PGOBBEntry.Successors.emplace();
            uint64_t SuccCount = Data.getULEB128(Cur);
            for (uint64_t SuccIdx = 0; Cur && SuccIdx < SuccCount; ++SuccIdx) {
              uint32_t ID = Data.getULEB128(Cur);
              uint32_t BrProb = Data.getULEB128(Cur);
              std::optional<uint32_t> PostLinkBrFreq;
              if (FeatureOrErr->PostLinkCfg)
                PostLinkBrFreq = Data.getULEB128(Cur);
              SuccEntries.push_back({ID, BrProb, PostLinkBrFreq});
            }
          }
        }
      }
    }
  }
 
  if (!Cur) {
    consumeError(Cur.takeError());
    return Error::success();
  }
  Entries = std::move(DecodedEntries);
  if (HasAnyPGOAnalysisMapEntry)
    PGOAnalyses = std::move(DecodedPGOAnalyses);
  return Error::success();
}
 
} // end namespace BBAddrMapYAML
} // end namespace llvm