Add an OperatingSystem plugin to support goroutines

The Go runtime schedules user level threads (goroutines) across real threads.
This adds an OS plugin to create memory threads for goroutines.
It supports the 1.4 and 1.5 go runtime.

Differential Revision: http://reviews.llvm.org/D5871

llvm-svn: 247852

1 files changed, 560 insertions, 0 deletions

diff --git a/lldb/source/Plugins/OperatingSystem/Go/OperatingSystemGo.cpp b/lldb/source/Plugins/OperatingSystem/Go/OperatingSystemGo.cpp
new file mode 100644
index 00000000000..2709afc2743
--- /dev/null
+++ b/lldb/source/Plugins/OperatingSystem/Go/OperatingSystemGo.cpp
@@ -0,0 +1,560 @@
+//===-- OperatingSystemGo.cpp --------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "OperatingSystemGo.h"
+
+// C Includes
+// C++ Includes
+#include <unordered_map>
+
+// Other libraries and framework includes
+#include "lldb/Core/DataBufferHeap.h"
+#include "lldb/Core/Debugger.h"
+#include "lldb/Core/Module.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Core/RegisterValue.h"
+#include "lldb/Core/Section.h"
+#include "lldb/Core/StreamString.h"
+#include "lldb/Core/ValueObjectVariable.h"
+#include "lldb/Interpreter/CommandInterpreter.h"
+#include "lldb/Interpreter/OptionValueProperties.h"
+#include "lldb/Interpreter/Options.h"
+#include "lldb/Interpreter/OptionGroupBoolean.h"
+#include "lldb/Interpreter/OptionGroupUInt64.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/ThreadList.h"
+#include "lldb/Target/Thread.h"
+#include "Plugins/Process/Utility/DynamicRegisterInfo.h"
+#include "Plugins/Process/Utility/RegisterContextMemory.h"
+#include "Plugins/Process/Utility/ThreadMemory.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace
+{
+
+static PropertyDefinition g_properties[] = {{"enable", OptionValue::eTypeBoolean, true, true, nullptr, nullptr,
+                                             "Specify whether goroutines should be treated as threads."},
+                                            {NULL, OptionValue::eTypeInvalid, false, 0, NULL, NULL, NULL}};
+
+enum
+{
+    ePropertyEnableGoroutines,
+};
+
+class PluginProperties : public Properties
+{
+  public:
+    static ConstString
+    GetSettingName()
+    {
+        return OperatingSystemGo::GetPluginNameStatic();
+    }
+
+    PluginProperties()
+        : Properties()
+    {
+        m_collection_sp.reset(new OptionValueProperties(GetSettingName()));
+        m_collection_sp->Initialize(g_properties);
+    }
+
+    virtual ~PluginProperties() {}
+
+    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:
+    //------------------------------------------------------------------
+    // Constructors and Destructors
+    //------------------------------------------------------------------
+    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);
+    }
+
+    virtual ~RegisterContextGo() {}
+
+    virtual bool
+    ReadRegister(const lldb_private::RegisterInfo *reg_info, lldb_private::RegisterValue &reg_value)
+    {
+        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;
+        }
+    }
+
+    virtual bool
+    WriteRegister(const lldb_private::RegisterInfo *reg_info, const lldb_private::RegisterValue &reg_value)
+    {
+        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);
+};
+
+}  // 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();
+        Mutex::Locker modules_locker(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);
+}
+
+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.";
+}
+
+OperatingSystemGo::OperatingSystemGo(lldb_private::Process *process)
+    : OperatingSystem(process)
+    , m_reginfo(new DynamicRegisterInfo)
+{
+}
+
+OperatingSystemGo::~OperatingSystemGo()
+{
+}
+
+bool
+OperatingSystemGo::Init(ThreadList &threads)
+{
+    if (threads.GetSize(false) < 1)
+        return false;
+    TargetSP target_sp = m_process->CalculateTarget();
+    if (!target_sp)
+        return false;
+    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.
+
+    Error err;
+    for (uint64_t i = 0; i < allglen; ++i)
+    {
+        goroutines.push_back(CreateGoroutineAtIndex(i, err));
+        if (err.Fail())
+        {
+            err.PutToLog(log, "OperatingSystemGo::UpdateThreadList");
+            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, nullptr, nullptr, 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;
+    const bool append = true;
+
+    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), append, 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, Error &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;
+}