//===- Trace.cpp - XRay Trace Loading implementation. ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// XRay log reader implementation.
//
//===----------------------------------------------------------------------===//
#include "llvm/XRay/Trace.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/XRay/YAMLXRayRecord.h"
using namespace llvm;
using namespace llvm::xray;
using llvm::yaml::Input;
using XRayRecordStorage =
std::aligned_storage<sizeof(XRayRecord), alignof(XRayRecord)>::type;
Error NaiveLogLoader(StringRef Data, XRayFileHeader &FileHeader,
std::vector<XRayRecord> &Records) {
// FIXME: Maybe deduce whether the data is little or big-endian using some
// magic bytes in the beginning of the file?
// First 32 bytes of the file will always be the header. We assume a certain
// format here:
//
// (2) uint16 : version
// (2) uint16 : type
// (4) uint32 : bitfield
// (8) uint64 : cycle frequency
// (16) - : padding
//
if (Data.size() < 32)
return make_error<StringError>(
"Not enough bytes for an XRay log.",
std::make_error_code(std::errc::invalid_argument));
if (Data.size() - 32 == 0 || Data.size() % 32 != 0)
return make_error<StringError>(
"Invalid-sized XRay data.",
std::make_error_code(std::errc::invalid_argument));
DataExtractor HeaderExtractor(Data, true, 8);
uint32_t OffsetPtr = 0;
FileHeader.Version = HeaderExtractor.getU16(&OffsetPtr);
FileHeader.Type = HeaderExtractor.getU16(&OffsetPtr);
uint32_t Bitfield = HeaderExtractor.getU32(&OffsetPtr);
FileHeader.ConstantTSC = Bitfield & 1uL;
FileHeader.NonstopTSC = Bitfield & 1uL << 1;
FileHeader.CycleFrequency = HeaderExtractor.getU64(&OffsetPtr);
if (FileHeader.Version != 1)
return make_error<StringError>(
Twine("Unsupported XRay file version: ") + Twine(FileHeader.Version),
std::make_error_code(std::errc::invalid_argument));
// Each record after the header will be 32 bytes, in the following format:
//
// (2) uint16 : record type
// (1) uint8 : cpu id
// (1) uint8 : type
// (4) sint32 : function id
// (8) uint64 : tsc
// (4) uint32 : thread id
// (12) - : padding
for (auto S = Data.drop_front(32); !S.empty(); S = S.drop_front(32)) {
DataExtractor RecordExtractor(S, true, 8);
uint32_t OffsetPtr = 0;
Records.emplace_back();
auto &Record = Records.back();
Record.RecordType = RecordExtractor.getU16(&OffsetPtr);
Record.CPU = RecordExtractor.getU8(&OffsetPtr);
auto Type = RecordExtractor.getU8(&OffsetPtr);
switch (Type) {
case 0:
Record.Type = RecordTypes::ENTER;
break;
case 1:
Record.Type = RecordTypes::EXIT;
break;
default:
return make_error<StringError>(
Twine("Unknown record type '") + Twine(int{Type}) + "'",
std::make_error_code(std::errc::executable_format_error));
}
Record.FuncId = RecordExtractor.getSigned(&OffsetPtr, sizeof(int32_t));
Record.TSC = RecordExtractor.getU64(&OffsetPtr);
Record.TId = RecordExtractor.getU32(&OffsetPtr);
}
return Error::success();
}
Error YAMLLogLoader(StringRef Data, XRayFileHeader &FileHeader,
std::vector<XRayRecord> &Records) {
// Load the documents from the MappedFile.
YAMLXRayTrace Trace;
Input In(Data);
In >> Trace;
if (In.error())
return make_error<StringError>("Failed loading YAML Data.", In.error());
FileHeader.Version = Trace.Header.Version;
FileHeader.Type = Trace.Header.Type;
FileHeader.ConstantTSC = Trace.Header.ConstantTSC;
FileHeader.NonstopTSC = Trace.Header.NonstopTSC;
FileHeader.CycleFrequency = Trace.Header.CycleFrequency;
if (FileHeader.Version != 1)
return make_error<StringError>(
Twine("Unsupported XRay file version: ") + Twine(FileHeader.Version),
std::make_error_code(std::errc::invalid_argument));
Records.clear();
std::transform(Trace.Records.begin(), Trace.Records.end(),
std::back_inserter(Records), [&](const YAMLXRayRecord &R) {
return XRayRecord{R.RecordType, R.CPU, R.Type,
R.FuncId, R.TSC, R.TId};
});
return Error::success();
}
Expected<Trace> llvm::xray::loadTraceFile(StringRef Filename, bool Sort) {
int Fd;
if (auto EC = sys::fs::openFileForRead(Filename, Fd)) {
return make_error<StringError>(
Twine("Cannot read log from '") + Filename + "'", EC);
}
// Attempt to get the filesize.
uint64_t FileSize;
if (auto EC = sys::fs::file_size(Filename, FileSize)) {
return make_error<StringError>(
Twine("Cannot read log from '") + Filename + "'", EC);
}
if (FileSize < 4) {
return make_error<StringError>(
Twine("File '") + Filename + "' too small for XRay.",
std::make_error_code(std::errc::executable_format_error));
}
// Attempt to mmap the file.
std::error_code EC;
sys::fs::mapped_file_region MappedFile(
Fd, sys::fs::mapped_file_region::mapmode::readonly, FileSize, 0, EC);
if (EC) {
return make_error<StringError>(
Twine("Cannot read log from '") + Filename + "'", EC);
}
// Attempt to detect the file type using file magic. We have a slight bias
// towards the binary format, and we do this by making sure that the first 4
// bytes of the binary file is some combination of the following byte
// patterns:
//
// 0x0001 0x0000 - version 1, "naive" format
// 0x0001 0x0001 - version 1, "flight data recorder" format
//
// YAML files dont' typically have those first four bytes as valid text so we
// try loading assuming YAML if we don't find these bytes.
//
// Only if we can't load either the binary or the YAML format will we yield an
// error.
StringRef Magic(MappedFile.data(), 4);
DataExtractor HeaderExtractor(Magic, true, 8);
uint32_t OffsetPtr = 0;
uint16_t Version = HeaderExtractor.getU16(&OffsetPtr);
uint16_t Type = HeaderExtractor.getU16(&OffsetPtr);
Trace T;
if (Version == 1 && (Type == 0 || Type == 1)) {
if (auto E = NaiveLogLoader(StringRef(MappedFile.data(), MappedFile.size()),
T.FileHeader, T.Records))
return std::move(E);
} else {
if (auto E = YAMLLogLoader(StringRef(MappedFile.data(), MappedFile.size()),
T.FileHeader, T.Records))
return std::move(E);
}
if (Sort)
std::sort(T.Records.begin(), T.Records.end(),
[&](const XRayRecord &L, const XRayRecord &R) {
return L.TSC < R.TSC;
});
return std::move(T);
}