contrib/llvm/tools/lldb/source/Plugins/Process/Utility/HistoryUnwind.cpp

   1 //===-- HistoryUnwind.cpp ---------------------------------------*- 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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "lldb/lldb-private.h"
  10
  11 #include "Plugins/Process/Utility/HistoryUnwind.h"
  12 #include "Plugins/Process/Utility/RegisterContextHistory.h"
  13
  14 #include "lldb/Target/Process.h"
  15 #include "lldb/Target/StackFrame.h"
  16 #include "lldb/Target/Target.h"
  17 #include "lldb/Target/Thread.h"
  18
  19 #include <memory>
  20
  21 using namespace lldb;
  22 using namespace lldb_private;
  23
  24 // Constructor
  25
  26 HistoryUnwind::HistoryUnwind(Thread &thread, std::vector<lldb::addr_t> pcs)
  27     : Unwind(thread), m_pcs(pcs) {}
  28
  29 // Destructor
  30
  31 HistoryUnwind::~HistoryUnwind() {}
  32
  33 void HistoryUnwind::DoClear() {
  34   std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
  35   m_pcs.clear();
  36 }
  37
  38 lldb::RegisterContextSP
  39 HistoryUnwind::DoCreateRegisterContextForFrame(StackFrame *frame) {
  40   RegisterContextSP rctx;
  41   if (frame) {
  42     addr_t pc = frame->GetFrameCodeAddress().GetLoadAddress(
  43         &frame->GetThread()->GetProcess()->GetTarget());
  44     if (pc != LLDB_INVALID_ADDRESS) {
  45       rctx = std::make_shared<RegisterContextHistory>(
  46           *frame->GetThread().get(), frame->GetConcreteFrameIndex(),
  47           frame->GetThread()->GetProcess()->GetAddressByteSize(), pc);
  48     }
  49   }
  50   return rctx;
  51 }
  52
  53 bool HistoryUnwind::DoGetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa,
  54                                           lldb::addr_t &pc) {
  55   // FIXME do not throw away the lock after we acquire it..
  56   std::unique_lock<std::recursive_mutex> guard(m_unwind_mutex);
  57   guard.unlock();
  58   if (frame_idx < m_pcs.size()) {
  59     cfa = frame_idx;
  60     pc = m_pcs[frame_idx];
  61     return true;
  62   }
  63   return false;
  64 }
  65
  66 uint32_t HistoryUnwind::DoGetFrameCount() { return m_pcs.size(); }