82 lines · cpp
1//===-- HistoryUnwind.cpp -------------------------------------------------===//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#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 21using namespace lldb;22using namespace lldb_private;23 24// Constructor25 26HistoryUnwind::HistoryUnwind(Thread &thread, std::vector<lldb::addr_t> pcs,27 HistoryPCType pc_type)28 : Unwind(thread), m_pcs(pcs), m_pc_type(pc_type) {}29 30// Destructor31 32HistoryUnwind::~HistoryUnwind() = default;33 34void HistoryUnwind::DoClear() {35 std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);36 m_pcs.clear();37}38 39lldb::RegisterContextSP40HistoryUnwind::DoCreateRegisterContextForFrame(StackFrame *frame) {41 RegisterContextSP rctx;42 if (frame) {43 addr_t pc = frame->GetFrameCodeAddress().GetLoadAddress(44 &frame->GetThread()->GetProcess()->GetTarget());45 if (pc != LLDB_INVALID_ADDRESS) {46 rctx = std::make_shared<RegisterContextHistory>(47 *frame->GetThread().get(), frame->GetConcreteFrameIndex(),48 frame->GetThread()->GetProcess()->GetAddressByteSize(), pc);49 }50 }51 return rctx;52}53 54static bool BehavesLikeZerothFrame(HistoryPCType pc_type, uint32_t frame_idx) {55 switch (pc_type) {56 case HistoryPCType::Returns:57 return (frame_idx == 0);58 case HistoryPCType::ReturnsNoZerothFrame:59 return false;60 case HistoryPCType::Calls:61 return true;62 }63 llvm_unreachable("Fully covered switch above");64}65 66bool HistoryUnwind::DoGetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa,67 lldb::addr_t &pc,68 bool &behaves_like_zeroth_frame) {69 // FIXME do not throw away the lock after we acquire it..70 std::unique_lock<std::recursive_mutex> guard(m_unwind_mutex);71 guard.unlock();72 if (frame_idx < m_pcs.size()) {73 cfa = frame_idx;74 pc = m_pcs[frame_idx];75 behaves_like_zeroth_frame = BehavesLikeZerothFrame(m_pc_type, frame_idx);76 return true;77 }78 return false;79}80 81uint32_t HistoryUnwind::DoGetFrameCount() { return m_pcs.size(); }82