1 //===-- ThreadDecoder.cpp --======-----------------------------------------===//
2 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
3 // See https://llvm.org/LICENSE.txt for license information.
4 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
5 //
6 //===----------------------------------------------------------------------===//
7 
8 #include "ThreadDecoder.h"
9 
10 #include "llvm/Support/MemoryBuffer.h"
11 
12 #include "../common/ThreadPostMortemTrace.h"
13 #include "LibiptDecoder.h"
14 #include "TraceIntelPT.h"
15 
16 #include <utility>
17 
18 using namespace lldb;
19 using namespace lldb_private;
20 using namespace lldb_private::trace_intel_pt;
21 using namespace llvm;
22 
23 // ThreadDecoder ====================
24 
25 DecodedThreadSP ThreadDecoder::Decode() {
26   if (!m_decoded_thread.hasValue())
27     m_decoded_thread = DoDecode();
28   return *m_decoded_thread;
29 }
30 
31 // LiveThreadDecoder ====================
32 
33 LiveThreadDecoder::LiveThreadDecoder(Thread &thread, TraceIntelPT &trace)
34     : m_thread_sp(thread.shared_from_this()), m_trace(trace) {}
35 
36 DecodedThreadSP LiveThreadDecoder::DoDecode() {
37   DecodedThreadSP decoded_thread_sp =
38       std::make_shared<DecodedThread>(m_thread_sp);
39 
40   Expected<std::vector<uint8_t>> buffer =
41       m_trace.GetLiveThreadBuffer(m_thread_sp->GetID());
42   if (!buffer) {
43     decoded_thread_sp->AppendError(buffer.takeError());
44     return decoded_thread_sp;
45   }
46 
47   decoded_thread_sp->SetRawTraceSize(buffer->size());
48   DecodeTrace(*decoded_thread_sp, m_trace, MutableArrayRef<uint8_t>(*buffer));
49   return decoded_thread_sp;
50 }
51 
52 // PostMortemThreadDecoder =======================
53 
54 PostMortemThreadDecoder::PostMortemThreadDecoder(
55     const lldb::ThreadPostMortemTraceSP &trace_thread, TraceIntelPT &trace)
56     : m_trace_thread(trace_thread), m_trace(trace) {}
57 
58 DecodedThreadSP PostMortemThreadDecoder::DoDecode() {
59   DecodedThreadSP decoded_thread_sp =
60       std::make_shared<DecodedThread>(m_trace_thread);
61 
62   ErrorOr<std::unique_ptr<MemoryBuffer>> trace_or_error =
63       MemoryBuffer::getFile(m_trace_thread->GetTraceFile().GetPath());
64   if (std::error_code err = trace_or_error.getError()) {
65     decoded_thread_sp->AppendError(errorCodeToError(err));
66     return decoded_thread_sp;
67   }
68 
69   MemoryBuffer &trace = **trace_or_error;
70   MutableArrayRef<uint8_t> trace_data(
71       // The libipt library does not modify the trace buffer, hence the
72       // following cast is safe.
73       reinterpret_cast<uint8_t *>(const_cast<char *>(trace.getBufferStart())),
74       trace.getBufferSize());
75   decoded_thread_sp->SetRawTraceSize(trace_data.size());
76 
77   DecodeTrace(*decoded_thread_sp, m_trace, trace_data);
78   return decoded_thread_sp;
79 }
80