1 files changed, 254 insertions, 0 deletions
diff --git a/contrib/llvm-project/lldb/source/Symbol/UnwindTable.cpp b/contrib/llvm-project/lldb/source/Symbol/UnwindTable.cpp
new file mode 100644
index 000000000000..11bedf3d6052
--- /dev/null
+++ b/contrib/llvm-project/lldb/source/Symbol/UnwindTable.cpp
@@ -0,0 +1,254 @@
+//===-- UnwindTable.cpp ---------------------------------------------------===//
+//
+// 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/Symbol/UnwindTable.h"
+
+#include <cstdio>
+#include <optional>
+
+#include "lldb/Core/Module.h"
+#include "lldb/Core/Section.h"
+#include "lldb/Symbol/ArmUnwindInfo.h"
+#include "lldb/Symbol/CallFrameInfo.h"
+#include "lldb/Symbol/CompactUnwindInfo.h"
+#include "lldb/Symbol/DWARFCallFrameInfo.h"
+#include "lldb/Symbol/FuncUnwinders.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Symbol/SymbolContext.h"
+#include "lldb/Symbol/SymbolVendor.h"
+
+// There is one UnwindTable object per ObjectFile. It contains a list of Unwind
+// objects -- one per function, populated lazily -- for the ObjectFile. Each
+// Unwind object has multiple UnwindPlans for different scenarios.
+
+using namespace lldb;
+using namespace lldb_private;
+
+UnwindTable::UnwindTable(Module &module)
+    : m_module(module), m_unwinds(), m_initialized(false), m_mutex(),
+      m_object_file_unwind_up(), m_eh_frame_up(), m_compact_unwind_up(),
+      m_arm_unwind_up() {}
+
+// We can't do some of this initialization when the ObjectFile is running its
+// ctor; delay doing it until needed for something.
+
+void UnwindTable::Initialize() {
+  if (m_initialized)
+    return;
+
+  std::lock_guard<std::mutex> guard(m_mutex);
+
+  if (m_initialized) // check again once we've acquired the lock
+    return;
+  m_initialized = true;
+  ObjectFile *object_file = m_module.GetObjectFile();
+  if (!object_file)
+    return;
+
+  m_object_file_unwind_up = object_file->CreateCallFrameInfo();
+
+  SectionList *sl = m_module.GetSectionList();
+  if (!sl)
+    return;
+
+  SectionSP sect = sl->FindSectionByType(eSectionTypeEHFrame, true);
+  if (sect.get()) {
+    m_eh_frame_up = std::make_unique<DWARFCallFrameInfo>(
+        *object_file, sect, DWARFCallFrameInfo::EH);
+  }
+
+  sect = sl->FindSectionByType(eSectionTypeDWARFDebugFrame, true);
+  if (sect) {
+    m_debug_frame_up = std::make_unique<DWARFCallFrameInfo>(
+        *object_file, sect, DWARFCallFrameInfo::DWARF);
+  }
+
+  sect = sl->FindSectionByType(eSectionTypeCompactUnwind, true);
+  if (sect) {
+    m_compact_unwind_up =
+        std::make_unique<CompactUnwindInfo>(*object_file, sect);
+  }
+
+  sect = sl->FindSectionByType(eSectionTypeARMexidx, true);
+  if (sect) {
+    SectionSP sect_extab = sl->FindSectionByType(eSectionTypeARMextab, true);
+    if (sect_extab.get()) {
+      m_arm_unwind_up =
+          std::make_unique<ArmUnwindInfo>(*object_file, sect, sect_extab);
+    }
+  }
+}
+
+void UnwindTable::Update() {
+  if (!m_initialized)
+    return Initialize();
+
+  std::lock_guard<std::mutex> guard(m_mutex);
+
+  ObjectFile *object_file = m_module.GetObjectFile();
+  if (!object_file)
+    return;
+
+  if (!m_object_file_unwind_up)
+    m_object_file_unwind_up = object_file->CreateCallFrameInfo();
+
+  SectionList *sl = m_module.GetSectionList();
+  if (!sl)
+    return;
+
+  SectionSP sect = sl->FindSectionByType(eSectionTypeEHFrame, true);
+  if (!m_eh_frame_up && sect) {
+    m_eh_frame_up = std::make_unique<DWARFCallFrameInfo>(
+        *object_file, sect, DWARFCallFrameInfo::EH);
+  }
+
+  sect = sl->FindSectionByType(eSectionTypeDWARFDebugFrame, true);
+  if (!m_debug_frame_up && sect) {
+    m_debug_frame_up = std::make_unique<DWARFCallFrameInfo>(
+        *object_file, sect, DWARFCallFrameInfo::DWARF);
+  }
+
+  sect = sl->FindSectionByType(eSectionTypeCompactUnwind, true);
+  if (!m_compact_unwind_up && sect) {
+    m_compact_unwind_up =
+        std::make_unique<CompactUnwindInfo>(*object_file, sect);
+  }
+
+  sect = sl->FindSectionByType(eSectionTypeARMexidx, true);
+  if (!m_arm_unwind_up && sect) {
+    SectionSP sect_extab = sl->FindSectionByType(eSectionTypeARMextab, true);
+    if (sect_extab.get()) {
+      m_arm_unwind_up =
+          std::make_unique<ArmUnwindInfo>(*object_file, sect, sect_extab);
+    }
+  }
+}
+
+UnwindTable::~UnwindTable() = default;
+
+std::optional<AddressRange>
+UnwindTable::GetAddressRange(const Address &addr, const SymbolContext &sc) {
+  AddressRange range;
+
+  // First check the unwind info from the object file plugin
+  if (m_object_file_unwind_up &&
+      m_object_file_unwind_up->GetAddressRange(addr, range))
+    return range;
+
+  // Check the symbol context
+  if (sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0,
+                         false, range) &&
+      range.GetBaseAddress().IsValid())
+    return range;
+
+  // Does the eh_frame unwind info has a function bounds for this addr?
+  if (m_eh_frame_up && m_eh_frame_up->GetAddressRange(addr, range))
+    return range;
+
+  // Try debug_frame as well
+  if (m_debug_frame_up && m_debug_frame_up->GetAddressRange(addr, range))
+    return range;
+
+  return std::nullopt;
+}
+
+FuncUnwindersSP
+UnwindTable::GetFuncUnwindersContainingAddress(const Address &addr,
+                                               SymbolContext &sc) {
+  Initialize();
+
+  std::lock_guard<std::mutex> guard(m_mutex);
+
+  // There is an UnwindTable per object file, so we can safely use file handles
+  addr_t file_addr = addr.GetFileAddress();
+  iterator end = m_unwinds.end();
+  iterator insert_pos = end;
+  if (!m_unwinds.empty()) {
+    insert_pos = m_unwinds.lower_bound(file_addr);
+    iterator pos = insert_pos;
+    if ((pos == m_unwinds.end()) ||
+        (pos != m_unwinds.begin() &&
+         pos->second->GetFunctionStartAddress() != addr))
+      --pos;
+
+    if (pos->second->ContainsAddress(addr))
+      return pos->second;
+  }
+
+  auto range_or = GetAddressRange(addr, sc);
+  if (!range_or)
+    return nullptr;
+
+  FuncUnwindersSP func_unwinder_sp(new FuncUnwinders(*this, *range_or));
+  m_unwinds.insert(insert_pos,
+                   std::make_pair(range_or->GetBaseAddress().GetFileAddress(),
+                                  func_unwinder_sp));
+  return func_unwinder_sp;
+}
+
+// Ignore any existing FuncUnwinders for this function, create a new one and
+// don't add it to the UnwindTable.  This is intended for use by target modules
+// show-unwind where we want to create new UnwindPlans, not re-use existing
+// ones.
+FuncUnwindersSP UnwindTable::GetUncachedFuncUnwindersContainingAddress(
+    const Address &addr, const SymbolContext &sc) {
+  Initialize();
+
+  auto range_or = GetAddressRange(addr, sc);
+  if (!range_or)
+    return nullptr;
+
+  return std::make_shared<FuncUnwinders>(*this, *range_or);
+}
+
+void UnwindTable::Dump(Stream &s) {
+  std::lock_guard<std::mutex> guard(m_mutex);
+  s.Format("UnwindTable for '{0}':\n", m_module.GetFileSpec());
+  const_iterator begin = m_unwinds.begin();
+  const_iterator end = m_unwinds.end();
+  for (const_iterator pos = begin; pos != end; ++pos) {
+    s.Printf("[%u] 0x%16.16" PRIx64 "\n", (unsigned)std::distance(begin, pos),
+             pos->first);
+  }
+  s.EOL();
+}
+
+lldb_private::CallFrameInfo *UnwindTable::GetObjectFileUnwindInfo() {
+  Initialize();
+  return m_object_file_unwind_up.get();
+}
+
+DWARFCallFrameInfo *UnwindTable::GetEHFrameInfo() {
+  Initialize();
+  return m_eh_frame_up.get();
+}
+
+DWARFCallFrameInfo *UnwindTable::GetDebugFrameInfo() {
+  Initialize();
+  return m_debug_frame_up.get();
+}
+
+CompactUnwindInfo *UnwindTable::GetCompactUnwindInfo() {
+  Initialize();
+  return m_compact_unwind_up.get();
+}
+
+ArmUnwindInfo *UnwindTable::GetArmUnwindInfo() {
+  Initialize();
+  return m_arm_unwind_up.get();
+}
+
+SymbolFile *UnwindTable::GetSymbolFile() { return m_module.GetSymbolFile(); }
+
+ArchSpec UnwindTable::GetArchitecture() { return m_module.GetArchitecture(); }
+
+bool UnwindTable::GetAllowAssemblyEmulationUnwindPlans() {
+  if (ObjectFile *object_file = m_module.GetObjectFile())
+    return object_file->AllowAssemblyEmulationUnwindPlans();
+  return false;
+}