llvm-project/llvm/tools/llvm-profgen/PerfReader.cpp

132 lines
4.4 KiB
C++

//===-- PerfReader.cpp - perfscript reader ---------------------*- 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
//
//===----------------------------------------------------------------------===//
#include "PerfReader.h"
static cl::opt<bool> ShowMmapEvents("show-mmap-events", cl::ReallyHidden,
cl::init(false), cl::ZeroOrMore,
cl::desc("Print binary load events."));
namespace llvm {
namespace sampleprof {
PerfReader::PerfReader(cl::list<std::string> &BinaryFilenames) {
// Load the binaries.
for (auto Filename : BinaryFilenames)
loadBinary(Filename, /*AllowNameConflict*/ false);
}
ProfiledBinary &PerfReader::loadBinary(const StringRef BinaryPath,
bool AllowNameConflict) {
// The binary table is currently indexed by the binary name not the full
// binary path. This is because the user-given path may not match the one
// that was actually executed.
StringRef BinaryName = llvm::sys::path::filename(BinaryPath);
// Call to load the binary in the ctor of ProfiledBinary.
auto Ret = BinaryTable.insert({BinaryName, ProfiledBinary(BinaryPath)});
if (!Ret.second && !AllowNameConflict) {
std::string ErrorMsg = "Binary name conflict: " + BinaryPath.str() +
" and " + Ret.first->second.getPath().str() + " \n";
exitWithError(ErrorMsg);
}
return Ret.first->second;
}
void PerfReader::updateBinaryAddress(const MMapEvent &Event) {
// Load the binary.
StringRef BinaryPath = Event.BinaryPath;
StringRef BinaryName = llvm::sys::path::filename(BinaryPath);
auto I = BinaryTable.find(BinaryName);
// Drop the event which doesn't belong to user-provided binaries
// or if its image is loaded at the same address
if (I == BinaryTable.end() || Event.BaseAddress == I->second.getBaseAddress())
return;
ProfiledBinary &Binary = I->second;
// A binary image could be uploaded and then reloaded at different
// place, so update the address map here
AddrToBinaryMap.erase(Binary.getBaseAddress());
AddrToBinaryMap[Event.BaseAddress] = &Binary;
// Update binary load address.
Binary.setBaseAddress(Event.BaseAddress);
}
void PerfReader::parseMMap2Event(TraceStream &TraceIt) {
// Parse a line like:
// PERF_RECORD_MMAP2 2113428/2113428: [0x7fd4efb57000(0x204000) @ 0
// 08:04 19532229 3585508847]: r-xp /usr/lib64/libdl-2.17.so
constexpr static const char *const Pattern =
"PERF_RECORD_MMAP2 ([0-9]+)/[0-9]+: "
"\\[(0x[a-f0-9]+)\\((0x[a-f0-9]+)\\) @ "
"(0x[a-f0-9]+|0) .*\\]: [-a-z]+ (.*)";
// Field 0 - whole line
// Field 1 - PID
// Field 2 - base address
// Field 3 - mmapped size
// Field 4 - page offset
// Field 5 - binary path
enum EventIndex {
WHOLE_LINE = 0,
PID = 1,
BASE_ADDRESS = 2,
MMAPPED_SIZE = 3,
PAGE_OFFSET = 4,
BINARY_PATH = 5
};
Regex RegMmap2(Pattern);
SmallVector<StringRef, 6> Fields;
bool R = RegMmap2.match(TraceIt.getCurrentLine(), &Fields);
if (!R) {
std::string ErrorMsg = "Cannot parse mmap event: Line" +
Twine(TraceIt.getLineNumber()).str() + ": " +
TraceIt.getCurrentLine().str() + " \n";
exitWithError(ErrorMsg);
}
MMapEvent Event;
Fields[PID].getAsInteger(10, Event.PID);
Fields[BASE_ADDRESS].getAsInteger(0, Event.BaseAddress);
Fields[MMAPPED_SIZE].getAsInteger(0, Event.Size);
Fields[PAGE_OFFSET].getAsInteger(0, Event.Offset);
Event.BinaryPath = Fields[BINARY_PATH];
updateBinaryAddress(Event);
if (ShowMmapEvents) {
outs() << "Mmap: Binary " << Event.BinaryPath << " loaded at "
<< format("0x%" PRIx64 ":", Event.BaseAddress) << " \n";
}
}
void PerfReader::parseEvent(TraceStream &TraceIt) {
if (TraceIt.getCurrentLine().startswith("PERF_RECORD_MMAP2"))
parseMMap2Event(TraceIt);
TraceIt.advance();
}
void PerfReader::parseTrace(StringRef Filename) {
// Trace line iterator
TraceStream TraceIt(Filename);
while (!TraceIt.isAtEoF()) {
parseEvent(TraceIt);
}
}
void PerfReader::parsePerfTraces(cl::list<std::string> &PerfTraceFilenames) {
// Parse perf traces.
for (auto Filename : PerfTraceFilenames)
parseTrace(Filename);
}
} // end namespace sampleprof
} // end namespace llvm