lib/XRay/FDRRecordProducer.cpp

   1 //===- FDRRecordProducer.cpp - XRay FDR Mode Record Producer --------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 #include "llvm/XRay/FDRRecordProducer.h"
  10 #include "llvm/Support/DataExtractor.h"
  11
  12 namespace llvm {
  13 namespace xray {
  14
  15 namespace {
  16
  17 Expected<std::unique_ptr<Record>>
  18 metadataRecordType(const XRayFileHeader &Header, uint8_t T) {
  19   // Keep this in sync with the values written in the XRay FDR mode runtime in
  20   // compiler-rt.
  21   enum MetadataRecordKinds : uint8_t {
  22     NewBufferKind,
  23     EndOfBufferKind,
  24     NewCPUIdKind,
  25     TSCWrapKind,
  26     WalltimeMarkerKind,
  27     CustomEventMarkerKind,
  28     CallArgumentKind,
  29     BufferExtentsKind,
  30     TypedEventMarkerKind,
  31     PidKind,
  32     // This is an end marker, used to identify the upper bound for this enum.
  33     EnumEndMarker,
  34   };
  35
  36   if (T >= static_cast<uint8_t>(MetadataRecordKinds::EnumEndMarker))
  37     return createStringError(std::make_error_code(std::errc::invalid_argument),
  38                              "Invalid metadata record type: %d", T);
  39   switch (T) {
  40   case MetadataRecordKinds::NewBufferKind:
  41     return make_unique<NewBufferRecord>();
  42   case MetadataRecordKinds::EndOfBufferKind:
  43     if (Header.Version >= 2)
  44       return createStringError(
  45           std::make_error_code(std::errc::executable_format_error),
  46           "End of buffer records are no longer supported starting version "
  47           "2 of the log.");
  48     return make_unique<EndBufferRecord>();
  49   case MetadataRecordKinds::NewCPUIdKind:
  50     return make_unique<NewCPUIDRecord>();
  51   case MetadataRecordKinds::TSCWrapKind:
  52     return make_unique<TSCWrapRecord>();
  53   case MetadataRecordKinds::WalltimeMarkerKind:
  54     return make_unique<WallclockRecord>();
  55   case MetadataRecordKinds::CustomEventMarkerKind:
  56     return make_unique<CustomEventRecord>();
  57   case MetadataRecordKinds::CallArgumentKind:
  58     return make_unique<CallArgRecord>();
  59   case MetadataRecordKinds::BufferExtentsKind:
  60     return make_unique<BufferExtents>();
  61   case MetadataRecordKinds::TypedEventMarkerKind:
  62     return createStringError(std::make_error_code(std::errc::invalid_argument),
  63                              "Encountered an unsupported TypedEventMarker.");
  64   case MetadataRecordKinds::PidKind:
  65     return make_unique<PIDRecord>();
  66   case MetadataRecordKinds::EnumEndMarker:
  67     llvm_unreachable("Invalid MetadataRecordKind");
  68   }
  69   llvm_unreachable("Unhandled MetadataRecordKinds enum value");
  70 }
  71
  72 } // namespace
  73
  74 Expected<std::unique_ptr<Record>> FileBasedRecordProducer::produce() {
  75   // At the top level, we read one byte to determine the type of the record to
  76   // create. This byte will comprise of the following bits:
  77   //
  78   //   - offset 0: A '1' indicates a metadata record, a '0' indicates a function
  79   //     record.
  80   //   - offsets 1-7: For metadata records, this will indicate the kind of
  81   //     metadata record should be loaded.
  82   //
  83   // We read first byte, then create the appropriate type of record to consume
  84   // the rest of the bytes.
  85   auto PreReadOffset = OffsetPtr;
  86   uint8_t FirstByte = E.getU8(&OffsetPtr);
  87   std::unique_ptr<Record> R;
  88
  89   // For metadata records, handle especially here.
  90   if (FirstByte & 0x01) {
  91     auto LoadedType = FirstByte >> 1;
  92     auto MetadataRecordOrErr = metadataRecordType(Header, LoadedType);
  93     if (!MetadataRecordOrErr)
  94       return joinErrors(
  95           MetadataRecordOrErr.takeError(),
  96           createStringError(
  97               std::make_error_code(std::errc::executable_format_error),
  98               "Encountered an unsupported metadata record (%d) at offset %d.",
  99               LoadedType, PreReadOffset));
 100     R = std::move(MetadataRecordOrErr.get());
 101   } else {
 102     R = llvm::make_unique<FunctionRecord>();
 103   }
 104   RecordInitializer RI(E, OffsetPtr);
 105
 106   if (auto Err = R->apply(RI))
 107     return std::move(Err);
 108
 109   assert(R != nullptr);
 110   return std::move(R);
 111 }
 112
 113 } // namespace xray
 114 } // namespace llvm