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1//===-- LibiptDecoder.h --======---------------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLDB_SOURCE_PLUGINS_TRACE_LIBIPT_DECODER_H10#define LLDB_SOURCE_PLUGINS_TRACE_LIBIPT_DECODER_H11 12#include "DecodedThread.h"13#include "PerfContextSwitchDecoder.h"14#include "forward-declarations.h"15#include "intel-pt.h"16#include <optional>17 18namespace lldb_private {19namespace trace_intel_pt {20 21/// This struct represents a contiguous section of a trace that starts at a PSB22/// and ends right before the next PSB or the end of the trace.23struct PSBBlock {24 /// The memory offset of a PSB packet that is a synchronization point for the25 /// decoder. A decoder normally looks first for a PSB packet and then it26 /// starts decoding.27 uint64_t psb_offset;28 /// The timestamp associated with the PSB packet above.29 std::optional<uint64_t> tsc;30 /// Size in bytes of this block31 uint64_t size;32 /// The first ip for this PSB block.33 /// This is \a std::nullopt if tracing was disabled when the PSB block was34 /// emitted. This means that eventually there's be an enablement event that35 /// will come with an ip.36 std::optional<lldb::addr_t> starting_ip;37};38 39/// This struct represents a continuous execution of a thread in a cpu,40/// delimited by a context switch in and out, and a list of Intel PT subtraces41/// that belong to this execution.42struct IntelPTThreadContinousExecution {43 ThreadContinuousExecution thread_execution;44 std::vector<PSBBlock> psb_blocks;45 46 IntelPTThreadContinousExecution(47 const ThreadContinuousExecution &thread_execution)48 : thread_execution(thread_execution) {}49 50 /// Comparator by time51 bool operator<(const IntelPTThreadContinousExecution &o) const;52};53 54/// Decode a raw Intel PT trace for a single thread given in \p buffer and55/// append the decoded instructions and errors in \p decoded_thread. It uses the56/// low level libipt library underneath.57///58/// \return59/// An \a llvm::Error if the decoder couldn't be properly set up.60llvm::Error DecodeSingleTraceForThread(DecodedThread &decoded_thread,61 TraceIntelPT &trace_intel_pt,62 llvm::ArrayRef<uint8_t> buffer);63 64/// Decode a raw Intel PT trace for a single thread that was collected in a per65/// cpu core basis.66///67/// \param[out] decoded_thread68/// All decoded instructions, errors and events will be appended to this69/// object.70///71/// \param[in] trace_intel_pt72/// The main Trace object that contains all the information related to the73/// trace session.74///75/// \param[in] buffers76/// A map from cpu core id to raw intel pt buffers.77///78/// \param[in] executions79/// A list of chunks of timed executions of the same given thread. It is used80/// to identify if some executions have missing intel pt data and also to81/// determine in which core a certain part of the execution ocurred.82///83/// \return84/// An \a llvm::Error if the decoder couldn't be properly set up, i.e. no85/// instructions were attempted to be decoded.86llvm::Error DecodeSystemWideTraceForThread(87 DecodedThread &decoded_thread, TraceIntelPT &trace_intel_pt,88 const llvm::DenseMap<lldb::cpu_id_t, llvm::ArrayRef<uint8_t>> &buffers,89 const std::vector<IntelPTThreadContinousExecution> &executions);90 91/// Given an intel pt trace, split it in chunks delimited by PSB packets. Each92/// of these chunks is guaranteed to have been executed continuously.93///94/// \param[in] trace_intel_pt95/// The main Trace object that contains all the information related to the96/// trace session.97///98/// \param[in] buffer99/// The intel pt buffer that belongs to a single thread or to a single cpu100/// core.101///102/// \param[in] expect_tscs103/// If \b true, an error is return if a packet without TSC is found.104///105/// \return106/// A list of continuous executions sorted by time, or an \a llvm::Error in107/// case of failures.108llvm::Expected<std::vector<PSBBlock>>109SplitTraceIntoPSBBlock(TraceIntelPT &trace_intel_pt,110 llvm::ArrayRef<uint8_t> buffer, bool expect_tscs);111 112/// Find the lowest TSC in the given trace.113///114/// \return115/// The lowest TSC value in this trace if available, \a std::nullopt if the116/// trace is empty or the trace contains no timing information, or an \a117/// llvm::Error if it was not possible to set up the decoder.118llvm::Expected<std::optional<uint64_t>>119FindLowestTSCInTrace(TraceIntelPT &trace_intel_pt,120 llvm::ArrayRef<uint8_t> buffer);121 122} // namespace trace_intel_pt123} // namespace lldb_private124 125#endif // LLDB_SOURCE_PLUGINS_TRACE_LIBIPT_DECODER_H126