Add a new Process plugin for Linux.

This component is still at an early stage, but allows for simple
breakpoint/step-over operations and basic process control.

The makefiles are set up to build the plugin under Linux only.



git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@109318 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Plugins/Process/Linux/ProcessLinux.cpp b/source/Plugins/Process/Linux/ProcessLinux.cpp
new file mode 100644
index 0000000..ce12ee9
--- /dev/null
+++ b/source/Plugins/Process/Linux/ProcessLinux.cpp
@@ -0,0 +1,443 @@
+//===-- ProcessLinux.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
+// Other libraries and framework includes
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Host/Host.h"
+#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Target/Target.h"
+
+#include "ProcessLinux.h"
+#include "ProcessMonitor.h"
+#include "LinuxThread.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+//------------------------------------------------------------------------------
+// Static functions.
+
+Process*
+ProcessLinux::CreateInstance(Target& target, Listener &listener)
+{
+    return new ProcessLinux(target, listener);
+}
+
+void
+ProcessLinux::Initialize()
+{
+    static bool g_initialized = false;
+
+    if (!g_initialized)
+    {
+        PluginManager::RegisterPlugin(GetPluginNameStatic(),
+                                      GetPluginDescriptionStatic(),
+                                      CreateInstance);
+        g_initialized = true;
+    }
+}
+
+void
+ProcessLinux::Terminate()
+{
+}
+
+const char *
+ProcessLinux::GetPluginNameStatic()
+{
+    return "plugin.process.linux";
+}
+
+const char *
+ProcessLinux::GetPluginDescriptionStatic()
+{
+    return "Process plugin for Linux";
+}
+
+
+//------------------------------------------------------------------------------
+// Constructors and destructors.
+
+ProcessLinux::ProcessLinux(Target& target, Listener &listener)
+    : Process(target, listener),
+      m_monitor(NULL),
+      m_module(NULL)
+{
+    // FIXME: Putting this code in the ctor and saving the byte order in a
+    // member variable is a hack to avoid const qual issues in GetByteOrder.
+    ObjectFile *obj_file = GetTarget().GetExecutableModule()->GetObjectFile();
+    m_byte_order = obj_file->GetByteOrder();
+}
+
+ProcessLinux::~ProcessLinux()
+{
+    delete m_monitor;
+}
+
+//------------------------------------------------------------------------------
+// Process protocol.
+
+bool
+ProcessLinux::CanDebug(Target &target)
+{
+    // For now we are just making sure the file exists for a given module
+    ModuleSP exe_module_sp(target.GetExecutableModule());
+    if (exe_module_sp.get())
+        return exe_module_sp->GetFileSpec().Exists();
+    return false;
+}
+
+Error
+ProcessLinux::DoAttachToProcessWithID(lldb::pid_t pid)
+{
+    return Error(1, eErrorTypeGeneric);
+}
+
+Error
+ProcessLinux::DoLaunch(Module *module,
+                       char const *argv[],
+                       char const *envp[],
+                       const char *stdin_path,
+                       const char *stdout_path,
+                       const char *stderr_path)
+{
+    Error error;
+    assert(m_monitor == NULL);
+
+    SetPrivateState(eStateLaunching);
+    m_monitor = new ProcessMonitor(this, module,
+                                   argv, envp,
+                                   stdin_path, stdout_path, stderr_path,
+                                   error);
+
+    m_module = module;
+
+    if (!error.Success())
+        return error;
+
+    return error;
+}
+
+void
+ProcessLinux::DidLaunch()
+{
+    UpdateLoadedSections();
+}
+
+Error
+ProcessLinux::DoResume()
+{
+    assert(GetPrivateState() == eStateStopped && "Bad state for DoResume!");
+
+    // Set our state to running.  This ensures inferior threads do not post a
+    // state change first.
+    SetPrivateState(eStateRunning);
+
+    bool did_resume = false;
+    uint32_t thread_count = m_thread_list.GetSize(false);
+    for (uint32_t i = 0; i < thread_count; ++i)
+    {
+        LinuxThread *thread = static_cast<LinuxThread*>(
+            m_thread_list.GetThreadAtIndex(i, false).get());
+        did_resume = thread->Resume() || did_resume;
+    }
+    assert(did_resume && "Process resume failed!");
+
+    return Error();
+}
+
+Error
+ProcessLinux::DoHalt()
+{
+    return Error(1, eErrorTypeGeneric);
+}
+
+Error
+ProcessLinux::DoDetach()
+{
+    return Error(1, eErrorTypeGeneric);
+}
+
+Error
+ProcessLinux::DoSignal(int signal)
+{
+    return Error(1, eErrorTypeGeneric);
+}
+
+Error
+ProcessLinux::DoDestroy()
+{
+    Error error;
+
+    if (!HasExited())
+    {
+        // Shut down the private state thread as we will syncronize with events
+        // ourselves.  Discard all current thread plans.
+        PausePrivateStateThread();
+        GetThreadList().DiscardThreadPlans();
+
+        // Bringing the inferior into limbo will be caught by our monitor
+        // thread, in turn updating the process state.
+        if (!m_monitor->BringProcessIntoLimbo())
+        {
+            error.SetErrorToGenericError();
+            error.SetErrorString("Process termination failed.");
+            return error;
+        }
+
+        // Wait for the event to arrive.  This guaranteed to be an exit event.
+        StateType state;
+        EventSP event;
+        do {
+            state = WaitForStateChangedEventsPrivate(NULL, event);
+        } while (state != eStateExited);
+
+        // Restart standard event handling and send the process the final kill,
+        // driving it out of limbo.
+        ResumePrivateStateThread();
+    }
+
+    if (kill(m_monitor->GetPID(), SIGKILL))
+        error.SetErrorToErrno();
+    return error;
+}
+
+void
+ProcessLinux::SendMessage(const ProcessMessage &message)
+{
+    Mutex::Locker lock(m_message_mutex);
+    m_message_queue.push(message);
+
+    switch (message.GetKind())
+    {
+    default:
+        SetPrivateState(eStateStopped);
+        break;
+
+    case ProcessMessage::eExitMessage:
+        SetExitStatus(message.GetExitStatus(), NULL);
+        break;
+
+    case ProcessMessage::eSignalMessage:
+        SetExitStatus(-1, NULL);
+        break;
+    }
+}
+
+void
+ProcessLinux::RefreshStateAfterStop()
+{
+    Mutex::Locker lock(m_message_mutex);
+    if (m_message_queue.empty())
+        return;
+
+    ProcessMessage &message = m_message_queue.front();
+
+    // Resolve the thread this message corresponds to.
+    lldb::tid_t tid = message.GetTID();
+    LinuxThread *thread = static_cast<LinuxThread*>(
+        GetThreadList().FindThreadByID(tid, false).get());
+
+    switch (message.GetKind())
+    {
+    default:
+        assert(false && "Unexpected message kind!");
+        break;
+
+    case ProcessMessage::eExitMessage:
+    case ProcessMessage::eSignalMessage:
+        thread->ExitNotify();
+        break;
+
+    case ProcessMessage::eTraceMessage:
+        thread->TraceNotify();
+        break;
+
+    case ProcessMessage::eBreakpointMessage:
+        thread->BreakNotify();
+        break;
+    }
+
+    m_message_queue.pop();
+}
+
+bool
+ProcessLinux::IsAlive()
+{
+    StateType state = GetPrivateState();
+    return state != eStateExited && state != eStateInvalid;
+}
+
+size_t
+ProcessLinux::DoReadMemory(addr_t vm_addr,
+                           void *buf, size_t size, Error &error)
+{
+    return m_monitor->ReadMemory(vm_addr, buf, size, error);
+}
+
+size_t
+ProcessLinux::DoWriteMemory(addr_t vm_addr, const void *buf, size_t size,
+                            Error &error)
+{
+    return m_monitor->WriteMemory(vm_addr, buf, size, error);
+}
+
+addr_t
+ProcessLinux::DoAllocateMemory(size_t size, uint32_t permissions,
+                               Error &error)
+{
+    return 0;
+}
+
+addr_t
+ProcessLinux::AllocateMemory(size_t size, uint32_t permissions, Error &error)
+{
+    return 0;
+}
+
+Error
+ProcessLinux::DoDeallocateMemory(lldb::addr_t ptr)
+{
+    return Error(1, eErrorTypeGeneric);
+}
+
+size_t
+ProcessLinux::GetSoftwareBreakpointTrapOpcode(BreakpointSite* bp_site)
+{
+    static const uint8_t g_i386_opcode[] = { 0xCC };
+
+    ArchSpec arch = GetTarget().GetArchitecture();
+    const uint8_t *opcode = NULL;
+    size_t opcode_size = 0;
+
+    switch (arch.GetGenericCPUType())
+    {
+    default:
+        assert(false && "CPU type not supported!");
+        break;
+
+    case ArchSpec::eCPU_i386:
+    case ArchSpec::eCPU_x86_64:
+        opcode = g_i386_opcode;
+        opcode_size = sizeof(g_i386_opcode);
+        break;
+    }
+
+    bp_site->SetTrapOpcode(opcode, opcode_size);
+    return opcode_size;
+}
+
+Error
+ProcessLinux::EnableBreakpoint(BreakpointSite *bp_site)
+{
+    return EnableSoftwareBreakpoint(bp_site);
+}
+
+Error
+ProcessLinux::DisableBreakpoint(BreakpointSite *bp_site)
+{
+    return DisableSoftwareBreakpoint(bp_site);
+}
+
+uint32_t
+ProcessLinux::UpdateThreadListIfNeeded()
+{
+    // Do not allow recursive updates.
+    return m_thread_list.GetSize(false);
+}
+
+ByteOrder
+ProcessLinux::GetByteOrder() const
+{
+    // FIXME: We should be able to extract this value directly.  See comment in
+    // ProcessLinux().
+    return m_byte_order;
+}
+
+//------------------------------------------------------------------------------
+// ProcessInterface protocol.
+
+const char *
+ProcessLinux::GetPluginName()
+{
+    return "process.linux";
+}
+
+const char *
+ProcessLinux::GetShortPluginName()
+{
+    return "process.linux";
+}
+
+uint32_t
+ProcessLinux::GetPluginVersion()
+{
+    return 1;
+}
+
+void
+ProcessLinux::GetPluginCommandHelp(const char *command, Stream *strm)
+{
+}
+
+Error
+ProcessLinux::ExecutePluginCommand(Args &command, Stream *strm)
+{
+    return Error(1, eErrorTypeGeneric);
+}
+
+Log *
+ProcessLinux::EnablePluginLogging(Stream *strm, Args &command)
+{
+    return NULL;
+}
+
+//------------------------------------------------------------------------------
+// Utility functions.
+
+void
+ProcessLinux::UpdateLoadedSections()
+{
+    ObjectFile *obj_file = m_module->GetObjectFile();
+    SectionList *sections = obj_file->GetSectionList();
+
+    // FIXME: SectionList provides iterator types, but no begin/end methods.
+    size_t num_sections = sections->GetSize();
+    for (unsigned i = 0; i < num_sections; ++i)
+    {
+        Section *section = sections->GetSectionAtIndex(i).get();
+
+        lldb::addr_t new_load_addr = section->GetFileAddress();
+        lldb::addr_t old_load_addr = GetSectionLoadAddress(section);
+
+        if (old_load_addr == LLDB_INVALID_ADDRESS ||
+            old_load_addr != new_load_addr)
+            SectionLoaded(section, new_load_addr);
+    }
+}
+
+bool
+ProcessLinux::HasExited()
+{
+    switch (GetPrivateState())
+    {
+    default:
+        break;
+
+    case eStateUnloaded:
+    case eStateCrashed:
+    case eStateDetached:
+    case eStateExited:
+        return true;
+    }
+
+    return false;
+}