Remove Go debugger plugin

In January Davide sent an e-mail to the mailing list to suggest removing
unmaintained language plugins such as Go and Java. The plan was to have
some cool down period to allow users to speak up, however after that the
plugins were never actually removed.

This patch removes the Go debugger plugin.

The plugin can be added again in the future if it is mature enough both
in terms of testing and maintenance commitment.

Discussion on the mailing list:
http://lists.llvm.org/pipermail/lldb-dev/2018-January/013171.html

Differential revision: https://reviews.llvm.org/D54057

llvm-svn: 346157

1 files changed, 0 insertions, 497 deletions

diff --git a/lldb/source/Plugins/OperatingSystem/Go/OperatingSystemGo.cpp b/lldb/source/Plugins/OperatingSystem/Go/OperatingSystemGo.cpp
deleted file mode 100644
index 600a67fc6f8..00000000000
--- a/lldb/source/Plugins/OperatingSystem/Go/OperatingSystemGo.cpp
+++ /dev/null
@@ -1,497 +0,0 @@
-//===-- OperatingSystemGo.cpp -----------------------------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-// C Includes
-// C++ Includes
-#include <unordered_map>
-
-// Other libraries and framework includes
-// Project includes
-#include "OperatingSystemGo.h"
-
-#include "Plugins/Process/Utility/DynamicRegisterInfo.h"
-#include "Plugins/Process/Utility/RegisterContextMemory.h"
-#include "Plugins/Process/Utility/ThreadMemory.h"
-#include "lldb/Core/Debugger.h"
-#include "lldb/Core/Module.h"
-#include "lldb/Core/PluginManager.h"
-#include "lldb/Core/Section.h"
-#include "lldb/Core/ValueObjectVariable.h"
-#include "lldb/Interpreter/CommandInterpreter.h"
-#include "lldb/Interpreter/OptionGroupBoolean.h"
-#include "lldb/Interpreter/OptionGroupUInt64.h"
-#include "lldb/Interpreter/OptionValueProperties.h"
-#include "lldb/Interpreter/Options.h"
-#include "lldb/Interpreter/Property.h"
-#include "lldb/Symbol/ObjectFile.h"
-#include "lldb/Symbol/Type.h"
-#include "lldb/Symbol/VariableList.h"
-#include "lldb/Target/Process.h"
-#include "lldb/Target/StopInfo.h"
-#include "lldb/Target/Target.h"
-#include "lldb/Target/Thread.h"
-#include "lldb/Target/ThreadList.h"
-#include "lldb/Utility/DataBufferHeap.h"
-#include "lldb/Utility/RegisterValue.h"
-#include "lldb/Utility/StreamString.h"
-
-using namespace lldb;
-using namespace lldb_private;
-
-namespace {
-
-static constexpr PropertyDefinition g_properties[] = {
-    {"enable", OptionValue::eTypeBoolean, true, true, nullptr, {},
-     "Specify whether goroutines should be treated as threads."}};
-
-enum {
-  ePropertyEnableGoroutines,
-};
-
-class PluginProperties : public Properties {
-public:
-  PluginProperties() : Properties() {
-    m_collection_sp.reset(new OptionValueProperties(GetSettingName()));
-    m_collection_sp->Initialize(g_properties);
-  }
-
-  ~PluginProperties() override = default;
-
-  static ConstString GetSettingName() {
-    return OperatingSystemGo::GetPluginNameStatic();
-  }
-
-  bool GetEnableGoroutines() {
-    const uint32_t idx = ePropertyEnableGoroutines;
-    return m_collection_sp->GetPropertyAtIndexAsBoolean(
-        NULL, idx, g_properties[idx].default_uint_value);
-  }
-
-  bool SetEnableGoroutines(bool enable) {
-    const uint32_t idx = ePropertyEnableGoroutines;
-    return m_collection_sp->SetPropertyAtIndexAsUInt64(NULL, idx, enable);
-  }
-};
-
-typedef std::shared_ptr<PluginProperties> OperatingSystemGoPropertiesSP;
-
-static const OperatingSystemGoPropertiesSP &GetGlobalPluginProperties() {
-  static OperatingSystemGoPropertiesSP g_settings_sp;
-  if (!g_settings_sp)
-    g_settings_sp.reset(new PluginProperties());
-  return g_settings_sp;
-}
-
-class RegisterContextGo : public RegisterContextMemory {
-public:
-  RegisterContextGo(lldb_private::Thread &thread, uint32_t concrete_frame_idx,
-                    DynamicRegisterInfo &reg_info, lldb::addr_t reg_data_addr)
-      : RegisterContextMemory(thread, concrete_frame_idx, reg_info,
-                              reg_data_addr) {
-    const RegisterInfo *sp = reg_info.GetRegisterInfoAtIndex(
-        reg_info.ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,
-                                                     LLDB_REGNUM_GENERIC_SP));
-    const RegisterInfo *pc = reg_info.GetRegisterInfoAtIndex(
-        reg_info.ConvertRegisterKindToRegisterNumber(eRegisterKindGeneric,
-                                                     LLDB_REGNUM_GENERIC_PC));
-    size_t byte_size = std::max(sp->byte_offset + sp->byte_size,
-                                pc->byte_offset + pc->byte_size);
-
-    DataBufferSP reg_data_sp(new DataBufferHeap(byte_size, 0));
-    m_reg_data.SetData(reg_data_sp);
-  }
-
-  ~RegisterContextGo() override = default;
-
-  bool ReadRegister(const lldb_private::RegisterInfo *reg_info,
-                    lldb_private::RegisterValue &reg_value) override {
-    switch (reg_info->kinds[eRegisterKindGeneric]) {
-    case LLDB_REGNUM_GENERIC_SP:
-    case LLDB_REGNUM_GENERIC_PC:
-      return RegisterContextMemory::ReadRegister(reg_info, reg_value);
-    default:
-      reg_value.SetValueToInvalid();
-      return true;
-    }
-  }
-
-  bool WriteRegister(const lldb_private::RegisterInfo *reg_info,
-                     const lldb_private::RegisterValue &reg_value) override {
-    switch (reg_info->kinds[eRegisterKindGeneric]) {
-    case LLDB_REGNUM_GENERIC_SP:
-    case LLDB_REGNUM_GENERIC_PC:
-      return RegisterContextMemory::WriteRegister(reg_info, reg_value);
-    default:
-      return false;
-    }
-  }
-
-private:
-  DISALLOW_COPY_AND_ASSIGN(RegisterContextGo);
-};
-
-} // anonymous namespace
-
-struct OperatingSystemGo::Goroutine {
-  uint64_t m_lostack;
-  uint64_t m_histack;
-  uint64_t m_goid;
-  addr_t m_gobuf;
-  uint32_t m_status;
-};
-
-void OperatingSystemGo::Initialize() {
-  PluginManager::RegisterPlugin(GetPluginNameStatic(),
-                                GetPluginDescriptionStatic(), CreateInstance,
-                                DebuggerInitialize);
-}
-
-void OperatingSystemGo::DebuggerInitialize(Debugger &debugger) {
-  if (!PluginManager::GetSettingForOperatingSystemPlugin(
-          debugger, PluginProperties::GetSettingName())) {
-    const bool is_global_setting = true;
-    PluginManager::CreateSettingForOperatingSystemPlugin(
-        debugger, GetGlobalPluginProperties()->GetValueProperties(),
-        ConstString("Properties for the goroutine thread plug-in."),
-        is_global_setting);
-  }
-}
-
-void OperatingSystemGo::Terminate() {
-  PluginManager::UnregisterPlugin(CreateInstance);
-}
-
-OperatingSystem *OperatingSystemGo::CreateInstance(Process *process,
-                                                   bool force) {
-  if (!force) {
-    TargetSP target_sp = process->CalculateTarget();
-    if (!target_sp)
-      return nullptr;
-    ModuleList &module_list = target_sp->GetImages();
-    std::lock_guard<std::recursive_mutex> guard(module_list.GetMutex());
-    const size_t num_modules = module_list.GetSize();
-    bool found_go_runtime = false;
-    for (size_t i = 0; i < num_modules; ++i) {
-      Module *module = module_list.GetModulePointerAtIndexUnlocked(i);
-      const SectionList *section_list = module->GetSectionList();
-      if (section_list) {
-        SectionSP section_sp(
-            section_list->FindSectionByType(eSectionTypeGoSymtab, true));
-        if (section_sp) {
-          found_go_runtime = true;
-          break;
-        }
-      }
-    }
-    if (!found_go_runtime)
-      return nullptr;
-  }
-  return new OperatingSystemGo(process);
-}
-
-OperatingSystemGo::OperatingSystemGo(lldb_private::Process *process)
-    : OperatingSystem(process), m_reginfo(new DynamicRegisterInfo) {}
-
-OperatingSystemGo::~OperatingSystemGo() = default;
-
-ConstString OperatingSystemGo::GetPluginNameStatic() {
-  static ConstString g_name("goroutines");
-  return g_name;
-}
-
-const char *OperatingSystemGo::GetPluginDescriptionStatic() {
-  return "Operating system plug-in that reads runtime data-structures for "
-         "goroutines.";
-}
-
-bool OperatingSystemGo::Init(ThreadList &threads) {
-  if (threads.GetSize(false) < 1)
-    return false;
-  TargetSP target_sp = m_process->CalculateTarget();
-  if (!target_sp)
-    return false;
-  // Go 1.6 stores goroutines in a slice called runtime.allgs
-  ValueObjectSP allgs_sp = FindGlobal(target_sp, "runtime.allgs");
-  if (allgs_sp) {
-    m_allg_sp = allgs_sp->GetChildMemberWithName(ConstString("array"), true);
-    m_allglen_sp = allgs_sp->GetChildMemberWithName(ConstString("len"), true);
-  } else {
-    // Go 1.4 stores goroutines in the variable runtime.allg.
-    m_allg_sp = FindGlobal(target_sp, "runtime.allg");
-    m_allglen_sp = FindGlobal(target_sp, "runtime.allglen");
-  }
-
-  if (m_allg_sp && !m_allglen_sp) {
-    StreamSP error_sp = target_sp->GetDebugger().GetAsyncErrorStream();
-    error_sp->Printf("Unsupported Go runtime version detected.");
-    return false;
-  }
-
-  if (!m_allg_sp)
-    return false;
-
-  RegisterContextSP real_registers_sp =
-      threads.GetThreadAtIndex(0, false)->GetRegisterContext();
-
-  std::unordered_map<size_t, ConstString> register_sets;
-  for (size_t set_idx = 0; set_idx < real_registers_sp->GetRegisterSetCount();
-       ++set_idx) {
-    const RegisterSet *set = real_registers_sp->GetRegisterSet(set_idx);
-    ConstString name(set->name);
-    for (size_t reg_idx = 0; reg_idx < set->num_registers; ++reg_idx) {
-      register_sets[reg_idx] = name;
-    }
-  }
-  TypeSP gobuf_sp = FindType(target_sp, "runtime.gobuf");
-  if (!gobuf_sp) {
-    Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
-
-    if (log)
-      log->Printf("OperatingSystemGo unable to find struct Gobuf");
-    return false;
-  }
-  CompilerType gobuf_type(gobuf_sp->GetLayoutCompilerType());
-  for (size_t idx = 0; idx < real_registers_sp->GetRegisterCount(); ++idx) {
-    RegisterInfo reg = *real_registers_sp->GetRegisterInfoAtIndex(idx);
-    int field_index = -1;
-    if (reg.kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_SP) {
-      field_index = 0;
-    } else if (reg.kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_PC) {
-      field_index = 1;
-    }
-    if (field_index == -1) {
-      reg.byte_offset = ~0;
-    } else {
-      std::string field_name;
-      uint64_t bit_offset = 0;
-      CompilerType field_type = gobuf_type.GetFieldAtIndex(
-          field_index, field_name, &bit_offset, nullptr, nullptr);
-      reg.byte_size = field_type.GetByteSize(nullptr);
-      reg.byte_offset = bit_offset / 8;
-    }
-    ConstString name(reg.name);
-    ConstString alt_name(reg.alt_name);
-    m_reginfo->AddRegister(reg, name, alt_name, register_sets[idx]);
-  }
-  return true;
-}
-
-//------------------------------------------------------------------
-// PluginInterface protocol
-//------------------------------------------------------------------
-ConstString OperatingSystemGo::GetPluginName() { return GetPluginNameStatic(); }
-
-uint32_t OperatingSystemGo::GetPluginVersion() { return 1; }
-
-bool OperatingSystemGo::UpdateThreadList(ThreadList &old_thread_list,
-                                         ThreadList &real_thread_list,
-                                         ThreadList &new_thread_list) {
-  new_thread_list = real_thread_list;
-  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
-
-  if (!(m_allg_sp || Init(real_thread_list)) || (m_allg_sp && !m_allglen_sp) ||
-      !GetGlobalPluginProperties()->GetEnableGoroutines()) {
-    return new_thread_list.GetSize(false) > 0;
-  }
-
-  if (log)
-    log->Printf("OperatingSystemGo::UpdateThreadList(%d, %d, %d) fetching "
-                "thread data from Go for pid %" PRIu64,
-                old_thread_list.GetSize(false), real_thread_list.GetSize(false),
-                new_thread_list.GetSize(0), m_process->GetID());
-  uint64_t allglen = m_allglen_sp->GetValueAsUnsigned(0);
-  if (allglen == 0) {
-    return new_thread_list.GetSize(false) > 0;
-  }
-  std::vector<Goroutine> goroutines;
-  // The threads that are in "new_thread_list" upon entry are the threads from
-  // the lldb_private::Process subclass, no memory threads will be in this
-  // list.
-
-  Status err;
-  for (uint64_t i = 0; i < allglen; ++i) {
-    goroutines.push_back(CreateGoroutineAtIndex(i, err));
-    if (err.Fail()) {
-      LLDB_LOG(log, "error: {0}", err);
-      return new_thread_list.GetSize(false) > 0;
-    }
-  }
-  // Make a map so we can match goroutines with backing threads.
-  std::map<uint64_t, ThreadSP> stack_map;
-  for (uint32_t i = 0; i < real_thread_list.GetSize(false); ++i) {
-    ThreadSP thread = real_thread_list.GetThreadAtIndex(i, false);
-    stack_map[thread->GetRegisterContext()->GetSP()] = thread;
-  }
-  for (const Goroutine &goroutine : goroutines) {
-    if (0 /* Gidle */ == goroutine.m_status ||
-        6 /* Gdead */ == goroutine.m_status) {
-      continue;
-    }
-    ThreadSP memory_thread =
-        old_thread_list.FindThreadByID(goroutine.m_goid, false);
-    if (memory_thread && IsOperatingSystemPluginThread(memory_thread) &&
-        memory_thread->IsValid()) {
-      memory_thread->ClearBackingThread();
-    } else {
-      memory_thread.reset(new ThreadMemory(*m_process, goroutine.m_goid, "", "",
-                                           goroutine.m_gobuf));
-    }
-    // Search for the backing thread if the goroutine is running.
-    if (2 == (goroutine.m_status & 0xfff)) {
-      auto backing_it = stack_map.lower_bound(goroutine.m_lostack);
-      if (backing_it != stack_map.end()) {
-        if (goroutine.m_histack >= backing_it->first) {
-          if (log)
-            log->Printf(
-                "OperatingSystemGo::UpdateThreadList found backing thread "
-                "%" PRIx64 " (%" PRIx64 ") for thread %" PRIx64 "",
-                backing_it->second->GetID(),
-                backing_it->second->GetProtocolID(), memory_thread->GetID());
-          memory_thread->SetBackingThread(backing_it->second);
-          new_thread_list.RemoveThreadByID(backing_it->second->GetID(), false);
-        }
-      }
-    }
-    new_thread_list.AddThread(memory_thread);
-  }
-
-  return new_thread_list.GetSize(false) > 0;
-}
-
-void OperatingSystemGo::ThreadWasSelected(Thread *thread) {}
-
-RegisterContextSP
-OperatingSystemGo::CreateRegisterContextForThread(Thread *thread,
-                                                  addr_t reg_data_addr) {
-  RegisterContextSP reg_ctx_sp;
-  if (!thread)
-    return reg_ctx_sp;
-
-  if (!IsOperatingSystemPluginThread(thread->shared_from_this()))
-    return reg_ctx_sp;
-
-  reg_ctx_sp.reset(
-      new RegisterContextGo(*thread, 0, *m_reginfo, reg_data_addr));
-  return reg_ctx_sp;
-}
-
-StopInfoSP
-OperatingSystemGo::CreateThreadStopReason(lldb_private::Thread *thread) {
-  StopInfoSP stop_info_sp;
-  return stop_info_sp;
-}
-
-lldb::ThreadSP OperatingSystemGo::CreateThread(lldb::tid_t tid,
-                                               addr_t context) {
-  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
-
-  if (log)
-    log->Printf("OperatingSystemGo::CreateThread (tid = 0x%" PRIx64
-                ", context = 0x%" PRIx64 ") not implemented",
-                tid, context);
-
-  return ThreadSP();
-}
-
-ValueObjectSP OperatingSystemGo::FindGlobal(TargetSP target, const char *name) {
-  VariableList variable_list;
-
-  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
-
-  if (log) {
-    log->Printf(
-        "exe: %s",
-        target->GetExecutableModule()->GetSpecificationDescription().c_str());
-    log->Printf("modules: %zu", target->GetImages().GetSize());
-  }
-
-  uint32_t match_count = target->GetImages().FindGlobalVariables(
-      ConstString(name), 1, variable_list);
-  if (match_count > 0) {
-    ExecutionContextScope *exe_scope = target->GetProcessSP().get();
-    if (exe_scope == NULL)
-      exe_scope = target.get();
-    return ValueObjectVariable::Create(exe_scope,
-                                       variable_list.GetVariableAtIndex(0));
-  }
-  return ValueObjectSP();
-}
-
-TypeSP OperatingSystemGo::FindType(TargetSP target_sp, const char *name) {
-  ConstString const_typename(name);
-  SymbolContext sc;
-  const bool exact_match = false;
-
-  const ModuleList &module_list = target_sp->GetImages();
-  size_t count = module_list.GetSize();
-  for (size_t idx = 0; idx < count; idx++) {
-    ModuleSP module_sp(module_list.GetModuleAtIndex(idx));
-    if (module_sp) {
-      TypeSP type_sp(module_sp->FindFirstType(sc, const_typename, exact_match));
-      if (type_sp)
-        return type_sp;
-    }
-  }
-  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OS));
-
-  if (log)
-    log->Printf("OperatingSystemGo::FindType(%s): not found", name);
-  return TypeSP();
-}
-
-OperatingSystemGo::Goroutine
-OperatingSystemGo::CreateGoroutineAtIndex(uint64_t idx, Status &err) {
-  err.Clear();
-  Goroutine result = {};
-  ValueObjectSP g =
-      m_allg_sp->GetSyntheticArrayMember(idx, true)->Dereference(err);
-  if (err.Fail()) {
-    return result;
-  }
-
-  ConstString name("goid");
-  ValueObjectSP val = g->GetChildMemberWithName(name, true);
-  bool success = false;
-  result.m_goid = val->GetValueAsUnsigned(0, &success);
-  if (!success) {
-    err.SetErrorToGenericError();
-    err.SetErrorString("unable to read goid");
-    return result;
-  }
-  name.SetCString("atomicstatus");
-  val = g->GetChildMemberWithName(name, true);
-  result.m_status = (uint32_t)val->GetValueAsUnsigned(0, &success);
-  if (!success) {
-    err.SetErrorToGenericError();
-    err.SetErrorString("unable to read atomicstatus");
-    return result;
-  }
-  name.SetCString("sched");
-  val = g->GetChildMemberWithName(name, true);
-  result.m_gobuf = val->GetAddressOf(false);
-  name.SetCString("stack");
-  val = g->GetChildMemberWithName(name, true);
-  name.SetCString("lo");
-  ValueObjectSP child = val->GetChildMemberWithName(name, true);
-  result.m_lostack = child->GetValueAsUnsigned(0, &success);
-  if (!success) {
-    err.SetErrorToGenericError();
-    err.SetErrorString("unable to read stack.lo");
-    return result;
-  }
-  name.SetCString("hi");
-  child = val->GetChildMemberWithName(name, true);
-  result.m_histack = child->GetValueAsUnsigned(0, &success);
-  if (!success) {
-    err.SetErrorToGenericError();
-    err.SetErrorString("unable to read stack.hi");
-    return result;
-  }
-  return result;
-}