Files
clang-p2996/lldb/source/Plugins/Trace/common/ThreadPostMortemTrace.cpp
Walter Erquinigo fc5ef57c7d [trace][intelpt] Support system-wide tracing [12] - Support multi-core trace load and save
:q!
This diff is massive, but it's because it connects the client with lldb-server
and also ensures that the postmortem case works.

- Flatten the postmortem trace schema. The reason is that the schema has become quite complex due to the new multicore case, which defeats the original purpose of having a schema that could work for every trace plug-in. At this point, it's better that each trace plug-in defines it's own full schema. This means that the only common field is "type".
-- Because of this new approach, I merged the "common" trace load and saving functionalities into the IntelPT one. This simplified the code quite a bit. If we eventually implement another trace plug-in, we can see then what we could reuse.
-- The new schema, which is flattened, has now better comments and is parsed better. A change I did was to disallow hex addresses, because they are a bit error prone. I'm asking now to print the address in decimal.
-- Renamed "intel" to "GenuineIntel" in the schema because that's what you see in /proc/cpuinfo.
- Implemented reading the context switch trace data buffer. I had to do
some refactors to do that cleanly.
-- A major change that I did here was to simplify the perf_event circular buffer reading logic. It was too complex. Maybe the original Intel author had something different in mind.
- Implemented all the necessary bits to read trace.json files with per-core data.
- Implemented all the necessary bits to save to disk per-core trace session.
- Added a test that ensures that parsing and saving to disk works.

Differential Revision: https://reviews.llvm.org/D126015
2022-06-15 13:28:36 -07:00

43 lines
1.3 KiB
C++

//===-- ThreadPostMortemTrace.cpp -----------------------------------------===//
//
// 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 "ThreadPostMortemTrace.h"
#include <memory>
#include "Plugins/Process/Utility/RegisterContextHistory.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
using namespace lldb;
using namespace lldb_private;
using namespace llvm;
void ThreadPostMortemTrace::RefreshStateAfterStop() {}
RegisterContextSP ThreadPostMortemTrace::GetRegisterContext() {
if (!m_reg_context_sp)
m_reg_context_sp = CreateRegisterContextForFrame(nullptr);
return m_reg_context_sp;
}
RegisterContextSP
ThreadPostMortemTrace::CreateRegisterContextForFrame(StackFrame *frame) {
// Eventually this will calculate the register context based on the current
// trace position.
return std::make_shared<RegisterContextHistory>(
*this, 0, GetProcess()->GetAddressByteSize(), LLDB_INVALID_ADDRESS);
}
bool ThreadPostMortemTrace::CalculateStopInfo() { return false; }
const Optional<FileSpec> &ThreadPostMortemTrace::GetTraceFile() const {
return m_trace_file;
}