vendor/llvm-project/llvmorg-11-init-20887-g2e10b7a39b9vendor/llvm-project/master

1 files changed, 0 insertions, 519 deletions

diff --git a/lldb/source/Plugins/Process/Utility/UnwindLLDB.cpp b/lldb/source/Plugins/Process/Utility/UnwindLLDB.cpp
deleted file mode 100644
index 74fc90e88547..000000000000
--- a/lldb/source/Plugins/Process/Utility/UnwindLLDB.cpp
+++ /dev/null
@@ -1,519 +0,0 @@
-//===-- UnwindLLDB.cpp -------------------------------------*- C++ -*-===//
-//
-// 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 "lldb/Core/Module.h"
-#include "lldb/Symbol/FuncUnwinders.h"
-#include "lldb/Symbol/Function.h"
-#include "lldb/Symbol/UnwindPlan.h"
-#include "lldb/Target/ABI.h"
-#include "lldb/Target/Process.h"
-#include "lldb/Target/RegisterContext.h"
-#include "lldb/Target/Target.h"
-#include "lldb/Target/Thread.h"
-#include "lldb/Utility/Log.h"
-
-#include "RegisterContextLLDB.h"
-#include "UnwindLLDB.h"
-
-using namespace lldb;
-using namespace lldb_private;
-
-UnwindLLDB::UnwindLLDB(Thread &thread)
-    : Unwind(thread), m_frames(), m_unwind_complete(false),
-      m_user_supplied_trap_handler_functions() {
-  ProcessSP process_sp(thread.GetProcess());
-  if (process_sp) {
-    Args args;
-    process_sp->GetTarget().GetUserSpecifiedTrapHandlerNames(args);
-    size_t count = args.GetArgumentCount();
-    for (size_t i = 0; i < count; i++) {
-      const char *func_name = args.GetArgumentAtIndex(i);
-      m_user_supplied_trap_handler_functions.push_back(ConstString(func_name));
-    }
-  }
-}
-
-uint32_t UnwindLLDB::DoGetFrameCount() {
-  if (!m_unwind_complete) {
-//#define DEBUG_FRAME_SPEED 1
-#if DEBUG_FRAME_SPEED
-#define FRAME_COUNT 10000
-    using namespace std::chrono;
-    auto time_value = steady_clock::now();
-#endif
-    if (!AddFirstFrame())
-      return 0;
-
-    ProcessSP process_sp(m_thread.GetProcess());
-    ABI *abi = process_sp ? process_sp->GetABI().get() : nullptr;
-
-    while (AddOneMoreFrame(abi)) {
-#if DEBUG_FRAME_SPEED
-      if ((m_frames.size() % FRAME_COUNT) == 0) {
-        const auto now = steady_clock::now();
-        const auto delta_t = now - time_value;
-        printf("%u frames in %.9f ms (%g frames/sec)\n", FRAME_COUNT,
-               duration<double, std::milli>(delta_t).count(),
-               (float)FRAME_COUNT / duration<double>(delta_t).count());
-        time_value = now;
-      }
-#endif
-    }
-  }
-  return m_frames.size();
-}
-
-bool UnwindLLDB::AddFirstFrame() {
-  if (m_frames.size() > 0)
-    return true;
-
-  ProcessSP process_sp(m_thread.GetProcess());
-  ABI *abi = process_sp ? process_sp->GetABI().get() : nullptr;
-
-  // First, set up the 0th (initial) frame
-  CursorSP first_cursor_sp(new Cursor());
-  RegisterContextLLDBSP reg_ctx_sp(new RegisterContextLLDB(
-      m_thread, RegisterContextLLDBSP(), first_cursor_sp->sctx, 0, *this));
-  if (reg_ctx_sp.get() == nullptr)
-    goto unwind_done;
-
-  if (!reg_ctx_sp->IsValid())
-    goto unwind_done;
-
-  if (!reg_ctx_sp->GetCFA(first_cursor_sp->cfa))
-    goto unwind_done;
-
-  if (!reg_ctx_sp->ReadPC(first_cursor_sp->start_pc))
-    goto unwind_done;
-
-  // Everything checks out, so release the auto pointer value and let the
-  // cursor own it in its shared pointer
-  first_cursor_sp->reg_ctx_lldb_sp = reg_ctx_sp;
-  m_frames.push_back(first_cursor_sp);
-
-  // Update the Full Unwind Plan for this frame if not valid
-  UpdateUnwindPlanForFirstFrameIfInvalid(abi);
-
-  return true;
-
-unwind_done:
-  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
-  if (log) {
-    LLDB_LOGF(log, "th%d Unwind of this thread is complete.",
-              m_thread.GetIndexID());
-  }
-  m_unwind_complete = true;
-  return false;
-}
-
-UnwindLLDB::CursorSP UnwindLLDB::GetOneMoreFrame(ABI *abi) {
-  assert(m_frames.size() != 0 &&
-         "Get one more frame called with empty frame list");
-
-  // If we've already gotten to the end of the stack, don't bother to try
-  // again...
-  if (m_unwind_complete)
-    return nullptr;
-
-  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
-
-  CursorSP prev_frame = m_frames.back();
-  uint32_t cur_idx = m_frames.size();
-
-  CursorSP cursor_sp(new Cursor());
-  RegisterContextLLDBSP reg_ctx_sp(new RegisterContextLLDB(
-      m_thread, prev_frame->reg_ctx_lldb_sp, cursor_sp->sctx, cur_idx, *this));
-
-  uint64_t max_stack_depth = m_thread.GetMaxBacktraceDepth();
-
-  // We want to detect an unwind that cycles erroneously and stop backtracing.
-  // Don't want this maximum unwind limit to be too low -- if you have a
-  // backtrace with an "infinitely recursing" bug, it will crash when the stack
-  // blows out and the first 35,000 frames are uninteresting - it's the top
-  // most 5 frames that you actually care about.  So you can't just cap the
-  // unwind at 10,000 or something. Realistically anything over around 200,000
-  // is going to blow out the stack space. If we're still unwinding at that
-  // point, we're probably never going to finish.
-  if (cur_idx >= max_stack_depth) {
-    LLDB_LOGF(log,
-              "%*sFrame %d unwound too many frames, assuming unwind has "
-              "gone astray, stopping.",
-              cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-    return nullptr;
-  }
-
-  if (reg_ctx_sp.get() == nullptr) {
-    // If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to
-    // that and return true.  Subsequent calls to TryFallbackUnwindPlan() will
-    // return false.
-    if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) {
-      // TryFallbackUnwindPlan for prev_frame succeeded and updated
-      // reg_ctx_lldb_sp field of prev_frame. However, cfa field of prev_frame
-      // still needs to be updated. Hence updating it.
-      if (!(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
-        return nullptr;
-
-      return GetOneMoreFrame(abi);
-    }
-
-    LLDB_LOGF(log, "%*sFrame %d did not get a RegisterContext, stopping.",
-              cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-    return nullptr;
-  }
-
-  if (!reg_ctx_sp->IsValid()) {
-    // We failed to get a valid RegisterContext. See if the regctx below this
-    // on the stack has a fallback unwind plan it can use. Subsequent calls to
-    // TryFallbackUnwindPlan() will return false.
-    if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) {
-      // TryFallbackUnwindPlan for prev_frame succeeded and updated
-      // reg_ctx_lldb_sp field of prev_frame. However, cfa field of prev_frame
-      // still needs to be updated. Hence updating it.
-      if (!(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
-        return nullptr;
-
-      return GetOneMoreFrame(abi);
-    }
-
-    LLDB_LOGF(log,
-              "%*sFrame %d invalid RegisterContext for this frame, "
-              "stopping stack walk",
-              cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-    return nullptr;
-  }
-  if (!reg_ctx_sp->GetCFA(cursor_sp->cfa)) {
-    // If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to
-    // that and return true.  Subsequent calls to TryFallbackUnwindPlan() will
-    // return false.
-    if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) {
-      // TryFallbackUnwindPlan for prev_frame succeeded and updated
-      // reg_ctx_lldb_sp field of prev_frame. However, cfa field of prev_frame
-      // still needs to be updated. Hence updating it.
-      if (!(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
-        return nullptr;
-
-      return GetOneMoreFrame(abi);
-    }
-
-    LLDB_LOGF(log,
-              "%*sFrame %d did not get CFA for this frame, stopping stack walk",
-              cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-    return nullptr;
-  }
-  if (abi && !abi->CallFrameAddressIsValid(cursor_sp->cfa)) {
-    // On Mac OS X, the _sigtramp asynchronous signal trampoline frame may not
-    // have its (constructed) CFA aligned correctly -- don't do the abi
-    // alignment check for these.
-    if (!reg_ctx_sp->IsTrapHandlerFrame()) {
-      // See if we can find a fallback unwind plan for THIS frame.  It may be
-      // that the UnwindPlan we're using for THIS frame was bad and gave us a
-      // bad CFA. If that's not it, then see if we can change the UnwindPlan
-      // for the frame below us ("NEXT") -- see if using that other UnwindPlan
-      // gets us a better unwind state.
-      if (!reg_ctx_sp->TryFallbackUnwindPlan() ||
-          !reg_ctx_sp->GetCFA(cursor_sp->cfa) ||
-          !abi->CallFrameAddressIsValid(cursor_sp->cfa)) {
-        if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) {
-          // TryFallbackUnwindPlan for prev_frame succeeded and updated
-          // reg_ctx_lldb_sp field of prev_frame. However, cfa field of
-          // prev_frame still needs to be updated. Hence updating it.
-          if (!(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
-            return nullptr;
-
-          return GetOneMoreFrame(abi);
-        }
-
-        LLDB_LOGF(log,
-                  "%*sFrame %d did not get a valid CFA for this frame, "
-                  "stopping stack walk",
-                  cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-        return nullptr;
-      } else {
-        LLDB_LOGF(log,
-                  "%*sFrame %d had a bad CFA value but we switched the "
-                  "UnwindPlan being used and got one that looks more "
-                  "realistic.",
-                  cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-      }
-    }
-  }
-  if (!reg_ctx_sp->ReadPC(cursor_sp->start_pc)) {
-    // If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to
-    // that and return true.  Subsequent calls to TryFallbackUnwindPlan() will
-    // return false.
-    if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) {
-      // TryFallbackUnwindPlan for prev_frame succeeded and updated
-      // reg_ctx_lldb_sp field of prev_frame. However, cfa field of prev_frame
-      // still needs to be updated. Hence updating it.
-      if (!(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
-        return nullptr;
-
-      return GetOneMoreFrame(abi);
-    }
-
-    LLDB_LOGF(log,
-              "%*sFrame %d did not get PC for this frame, stopping stack walk",
-              cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-    return nullptr;
-  }
-  if (abi && !abi->CodeAddressIsValid(cursor_sp->start_pc)) {
-    // If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to
-    // that and return true.  Subsequent calls to TryFallbackUnwindPlan() will
-    // return false.
-    if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) {
-      // TryFallbackUnwindPlan for prev_frame succeeded and updated
-      // reg_ctx_lldb_sp field of prev_frame. However, cfa field of prev_frame
-      // still needs to be updated. Hence updating it.
-      if (!(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
-        return nullptr;
-
-      return GetOneMoreFrame(abi);
-    }
-
-    LLDB_LOGF(log, "%*sFrame %d did not get a valid PC, stopping stack walk",
-              cur_idx < 100 ? cur_idx : 100, "", cur_idx);
-    return nullptr;
-  }
-  // Infinite loop where the current cursor is the same as the previous one...
-  if (prev_frame->start_pc == cursor_sp->start_pc &&
-      prev_frame->cfa == cursor_sp->cfa) {
-    LLDB_LOGF(log,
-              "th%d pc of this frame is the same as the previous frame and "
-              "CFAs for both frames are identical -- stopping unwind",
-              m_thread.GetIndexID());
-    return nullptr;
-  }
-
-  cursor_sp->reg_ctx_lldb_sp = reg_ctx_sp;
-  return cursor_sp;
-}
-
-void UnwindLLDB::UpdateUnwindPlanForFirstFrameIfInvalid(ABI *abi) {
-  // This function is called for First Frame only.
-  assert(m_frames.size() == 1 && "No. of cursor frames are not 1");
-
-  bool old_m_unwind_complete = m_unwind_complete;
-  CursorSP old_m_candidate_frame = m_candidate_frame;
-
-  // Try to unwind 2 more frames using the Unwinder. It uses Full UnwindPlan
-  // and if Full UnwindPlan fails, then uses FallBack UnwindPlan. Also update
-  // the cfa of Frame 0 (if required).
-  AddOneMoreFrame(abi);
-
-  // Remove all the frames added by above function as the purpose of using
-  // above function was just to check whether Unwinder of Frame 0 works or not.
-  for (uint32_t i = 1; i < m_frames.size(); i++)
-    m_frames.pop_back();
-
-  // Restore status after calling AddOneMoreFrame
-  m_unwind_complete = old_m_unwind_complete;
-  m_candidate_frame = old_m_candidate_frame;
-  return;
-}
-
-bool UnwindLLDB::AddOneMoreFrame(ABI *abi) {
-  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_UNWIND));
-
-  // Frame zero is a little different
-  if (m_frames.empty())
-    return false;
-
-  // If we've already gotten to the end of the stack, don't bother to try
-  // again...
-  if (m_unwind_complete)
-    return false;
-
-  CursorSP new_frame = m_candidate_frame;
-  if (new_frame == nullptr)
-    new_frame = GetOneMoreFrame(abi);
-
-  if (new_frame == nullptr) {
-    LLDB_LOGF(log, "th%d Unwind of this thread is complete.",
-              m_thread.GetIndexID());
-    m_unwind_complete = true;
-    return false;
-  }
-
-  m_frames.push_back(new_frame);
-
-  // If we can get one more frame further then accept that we get back a
-  // correct frame.
-  m_candidate_frame = GetOneMoreFrame(abi);
-  if (m_candidate_frame)
-    return true;
-
-  // We can't go further from the frame returned by GetOneMore frame. Lets try
-  // to get a different frame with using the fallback unwind plan.
-  if (!m_frames[m_frames.size() - 2]
-           ->reg_ctx_lldb_sp->TryFallbackUnwindPlan()) {
-    // We don't have a valid fallback unwind plan. Accept the frame as it is.
-    // This is a valid situation when we are at the bottom of the stack.
-    return true;
-  }
-
-  // Remove the possibly incorrect frame from the frame list and try to add a
-  // different one with the newly selected fallback unwind plan.
-  m_frames.pop_back();
-  CursorSP new_frame_v2 = GetOneMoreFrame(abi);
-  if (new_frame_v2 == nullptr) {
-    // We haven't got a new frame from the fallback unwind plan. Accept the
-    // frame from the original unwind plan. This is a valid situation when we
-    // are at the bottom of the stack.
-    m_frames.push_back(new_frame);
-    return true;
-  }
-
-  // Push the new frame to the list and try to continue from this frame. If we
-  // can get a new frame then accept it as the correct one.
-  m_frames.push_back(new_frame_v2);
-  m_candidate_frame = GetOneMoreFrame(abi);
-  if (m_candidate_frame) {
-    // If control reached here then TryFallbackUnwindPlan had succeeded for
-    // Cursor::m_frames[m_frames.size() - 2]. It also succeeded to Unwind next
-    // 2 frames i.e. m_frames[m_frames.size() - 1] and a frame after that. For
-    // Cursor::m_frames[m_frames.size() - 2], reg_ctx_lldb_sp field was already
-    // updated during TryFallbackUnwindPlan call above. However, cfa field
-    // still needs to be updated. Hence updating it here and then returning.
-    return m_frames[m_frames.size() - 2]->reg_ctx_lldb_sp->GetCFA(
-        m_frames[m_frames.size() - 2]->cfa);
-  }
-
-  // The new frame hasn't helped in unwinding. Fall back to the original one as
-  // the default unwind plan is usually more reliable then the fallback one.
-  m_frames.pop_back();
-  m_frames.push_back(new_frame);
-  return true;
-}
-
-bool UnwindLLDB::DoGetFrameInfoAtIndex(uint32_t idx, addr_t &cfa, addr_t &pc,
-                                       bool &behaves_like_zeroth_frame) {
-  if (m_frames.size() == 0) {
-    if (!AddFirstFrame())
-      return false;
-  }
-
-  ProcessSP process_sp(m_thread.GetProcess());
-  ABI *abi = process_sp ? process_sp->GetABI().get() : nullptr;
-
-  while (idx >= m_frames.size() && AddOneMoreFrame(abi))
-    ;
-
-  if (idx < m_frames.size()) {
-    cfa = m_frames[idx]->cfa;
-    pc = m_frames[idx]->start_pc;
-    if (idx == 0) {
-      // Frame zero always behaves like it.
-      behaves_like_zeroth_frame = true;
-    } else if (m_frames[idx - 1]->reg_ctx_lldb_sp->IsTrapHandlerFrame()) {
-      // This could be an asynchronous signal, thus the
-      // pc might point to the interrupted instruction rather
-      // than a post-call instruction
-      behaves_like_zeroth_frame = true;
-    } else if (m_frames[idx]->reg_ctx_lldb_sp->IsTrapHandlerFrame()) {
-      // This frame may result from signal processing installing
-      // a pointer to the first byte of a signal-return trampoline
-      // in the return address slot of the frame below, so this
-      // too behaves like the zeroth frame (i.e. the pc might not
-      // be pointing just past a call in it)
-      behaves_like_zeroth_frame = true;
-    } else {
-      behaves_like_zeroth_frame = false;
-    }
-    return true;
-  }
-  return false;
-}
-
-lldb::RegisterContextSP
-UnwindLLDB::DoCreateRegisterContextForFrame(StackFrame *frame) {
-  lldb::RegisterContextSP reg_ctx_sp;
-  uint32_t idx = frame->GetConcreteFrameIndex();
-
-  if (idx == 0) {
-    return m_thread.GetRegisterContext();
-  }
-
-  if (m_frames.size() == 0) {
-    if (!AddFirstFrame())
-      return reg_ctx_sp;
-  }
-
-  ProcessSP process_sp(m_thread.GetProcess());
-  ABI *abi = process_sp ? process_sp->GetABI().get() : nullptr;
-
-  while (idx >= m_frames.size()) {
-    if (!AddOneMoreFrame(abi))
-      break;
-  }
-
-  const uint32_t num_frames = m_frames.size();
-  if (idx < num_frames) {
-    Cursor *frame_cursor = m_frames[idx].get();
-    reg_ctx_sp = frame_cursor->reg_ctx_lldb_sp;
-  }
-  return reg_ctx_sp;
-}
-
-UnwindLLDB::RegisterContextLLDBSP
-UnwindLLDB::GetRegisterContextForFrameNum(uint32_t frame_num) {
-  RegisterContextLLDBSP reg_ctx_sp;
-  if (frame_num < m_frames.size())
-    reg_ctx_sp = m_frames[frame_num]->reg_ctx_lldb_sp;
-  return reg_ctx_sp;
-}
-
-bool UnwindLLDB::SearchForSavedLocationForRegister(
-    uint32_t lldb_regnum, lldb_private::UnwindLLDB::RegisterLocation &regloc,
-    uint32_t starting_frame_num, bool pc_reg) {
-  int64_t frame_num = starting_frame_num;
-  if (static_cast<size_t>(frame_num) >= m_frames.size())
-    return false;
-
-  // Never interrogate more than one level while looking for the saved pc
-  // value. If the value isn't saved by frame_num, none of the frames lower on
-  // the stack will have a useful value.
-  if (pc_reg) {
-    UnwindLLDB::RegisterSearchResult result;
-    result = m_frames[frame_num]->reg_ctx_lldb_sp->SavedLocationForRegister(
-        lldb_regnum, regloc);
-    return result == UnwindLLDB::RegisterSearchResult::eRegisterFound;
-  }
-  while (frame_num >= 0) {
-    UnwindLLDB::RegisterSearchResult result;
-    result = m_frames[frame_num]->reg_ctx_lldb_sp->SavedLocationForRegister(
-        lldb_regnum, regloc);
-
-    // We descended down to the live register context aka stack frame 0 and are
-    // reading the value out of a live register.
-    if (result == UnwindLLDB::RegisterSearchResult::eRegisterFound &&
-        regloc.type ==
-            UnwindLLDB::RegisterLocation::eRegisterInLiveRegisterContext) {
-      return true;
-    }
-
-    // If we have unwind instructions saying that register N is saved in
-    // register M in the middle of the stack (and N can equal M here, meaning
-    // the register was not used in this function), then change the register
-    // number we're looking for to M and keep looking for a concrete  location
-    // down the stack, or an actual value from a live RegisterContext at frame
-    // 0.
-    if (result == UnwindLLDB::RegisterSearchResult::eRegisterFound &&
-        regloc.type == UnwindLLDB::RegisterLocation::eRegisterInRegister &&
-        frame_num > 0) {
-      result = UnwindLLDB::RegisterSearchResult::eRegisterNotFound;
-      lldb_regnum = regloc.location.register_number;
-    }
-
-    if (result == UnwindLLDB::RegisterSearchResult::eRegisterFound)
-      return true;
-    if (result == UnwindLLDB::RegisterSearchResult::eRegisterIsVolatile)
-      return false;
-    frame_num--;
-  }
-  return false;
-}