lldb/source/Plugins/Process/Darwin/NativeProcessDarwin.h

//===-- NativeProcessDarwin.h --------------------------------- -*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef NativeProcessDarwin_h
#define NativeProcessDarwin_h

// NOTE: this code should only be compiled on Apple Darwin systems.  It is
// not cross-platform code and is not intended to build on any other platform.
// Therefore, platform-specific headers and code are okay here.

// C includes
#include <mach/mach_types.h>

// C++ includes
#include <mutex>
#include <unordered_set>

// Other libraries and framework includes
#include "lldb/Core/ArchSpec.h"
#include "lldb/lldb-types.h"
#include "lldb/Host/common/NativeProcessProtocol.h"
#include "lldb/Host/Debug.h"
#include "lldb/Host/FileSpec.h"
#include "lldb/Host/HostThread.h"
#include "lldb/Host/Pipe.h"
#include "lldb/Target/MemoryRegionInfo.h"

#include "NativeThreadListDarwin.h"
#include "LaunchFlavor.h"
#include "MachException.h"
#include "NativeThreadDarwin.h"

namespace lldb_private {
    class Error;
    class Scalar;

    namespace process_darwin {

        /// @class NativeProcessDarwin
        /// @brief Manages communication with the inferior (debugee) process.
        ///
        /// Upon construction, this class prepares and launches an inferior
        /// process for debugging.
        ///
        /// Changes in the inferior process state are broadcasted.
        class NativeProcessDarwin: public NativeProcessProtocol
        {
            friend Error
            NativeProcessProtocol::Launch(ProcessLaunchInfo &launch_info,
                                          NativeDelegate &native_delegate,
                                          MainLoop &mainloop,
                                          NativeProcessProtocolSP &process_sp);

            friend Error
            NativeProcessProtocol::Attach(lldb::pid_t pid,
                                          NativeProcessProtocol::NativeDelegate
                                          &native_delegate,
                                          MainLoop &mainloop,
                                          NativeProcessProtocolSP &process_sp);

        public:

            ~NativeProcessDarwin() override;

            // -----------------------------------------------------------------
            // NativeProcessProtocol Interface
            // -----------------------------------------------------------------
            Error
            Resume(const ResumeActionList &resume_actions) override;

            Error
            Halt() override;

            Error
            Detach() override;

            Error
            Signal(int signo) override;

            Error
            Interrupt() override;

            Error
            Kill() override;

            Error
            GetMemoryRegionInfo(lldb::addr_t load_addr, MemoryRegionInfo
                                &range_info) override;

            Error
            ReadMemory(lldb::addr_t addr, void *buf, size_t size,
                       size_t &bytes_read) override;

            Error
            ReadMemoryWithoutTrap(lldb::addr_t addr, void *buf, size_t size,
                                  size_t &bytes_read) override;

            Error
            WriteMemory(lldb::addr_t addr, const void *buf, size_t size,
                        size_t &bytes_written) override;

            Error
            AllocateMemory(size_t size, uint32_t permissions,
                           lldb::addr_t &addr) override;

            Error
            DeallocateMemory(lldb::addr_t addr) override;

            lldb::addr_t
            GetSharedLibraryInfoAddress() override;

            size_t
            UpdateThreads() override;

            bool
            GetArchitecture(ArchSpec &arch) const override;

            Error
            SetBreakpoint(lldb::addr_t addr, uint32_t size,
                          bool hardware) override;

            void
            DoStopIDBumped(uint32_t newBumpId) override;

            Error
            GetLoadedModuleFileSpec(const char* module_path,
                                    FileSpec& file_spec) override;

            Error
            GetFileLoadAddress(const llvm::StringRef& file_name,
                               lldb::addr_t& load_addr) override;

            NativeThreadDarwinSP
            GetThreadByID(lldb::tid_t id);

            task_t
            GetTask() const
            {
                return m_task;
            }

            // -----------------------------------------------------------------
            // Interface used by NativeRegisterContext-derived classes.
            // -----------------------------------------------------------------
            static Error
            PtraceWrapper(int req,
                          lldb::pid_t pid,
                          void *addr = nullptr,
                          void *data = nullptr,
                          size_t data_size = 0,
                          long *result = nullptr);

            bool
            SupportHardwareSingleStepping() const;

        protected:
            // -----------------------------------------------------------------
            // NativeProcessProtocol protected interface
            // -----------------------------------------------------------------
            Error
            GetSoftwareBreakpointTrapOpcode(size_t trap_opcode_size_hint,
                                            size_t &actual_opcode_size,
                                            const uint8_t *&trap_opcode_bytes)
            override;

        private:

            // -----------------------------------------------------------------
            /// Mach task-related Member Variables
            // -----------------------------------------------------------------

            // The task port for the inferior process.
            mutable task_t  m_task;

            // True if the inferior process did an exec since we started
            // monitoring it.
            bool  m_did_exec;

            // The CPU type of this process.
            mutable cpu_type_t  m_cpu_type;

            // -----------------------------------------------------------------
            /// Exception/Signal Handling Member Variables
            // -----------------------------------------------------------------

            // Exception port on which we will receive child exceptions
            mach_port_t  m_exception_port;

            // Saved state of the child exception port prior to us installing
            // our own intercepting port.
            MachException::PortInfo  m_exc_port_info;

            // The thread that runs the Mach exception read and reply handler.
            pthread_t  m_exception_thread;

            // TODO see if we can remove this if we get the exception collection
            // and distribution to happen in a single-threaded fashion.
            std::recursive_mutex  m_exception_messages_mutex;

            // A collection of exception messages caught when listening to the
            // exception port.
            MachException::Message::collection  m_exception_messages;

            // When we call MachProcess::Interrupt(), we want to send this
            // signal (if non-zero).
            int  m_sent_interrupt_signo;

            // If we resume the process and still haven't received our
            // interrupt signal (if this is non-zero).
            int  m_auto_resume_signo;

            // -----------------------------------------------------------------
            /// Thread-related Member Variables
            // -----------------------------------------------------------------
            NativeThreadListDarwin  m_thread_list;
            ResumeActionList        m_thread_actions;

            // -----------------------------------------------------------------
            /// Process Lifetime Member Variable
            // -----------------------------------------------------------------

            // The pipe over which the waitpid thread and the main loop will
            // communicate.
            Pipe  m_waitpid_pipe;

            // The thread that runs the waitpid handler.
            pthread_t  m_waitpid_thread;

            // waitpid reader callback handle.
            MainLoop::ReadHandleUP m_waitpid_reader_handle;

#if 0
            ArchSpec m_arch;

            LazyBool m_supports_mem_region;
            std::vector<MemoryRegionInfo> m_mem_region_cache;

            lldb::tid_t m_pending_notification_tid;

            // List of thread ids stepping with a breakpoint with the address of
            // the relevan breakpoint
            std::map<lldb::tid_t, lldb::addr_t>
            m_threads_stepping_with_breakpoint;
#endif

            // -----------------------------------------------------------------
            // Private Instance Methods
            // -----------------------------------------------------------------
            NativeProcessDarwin(lldb::pid_t pid, int pty_master_fd);

            // -----------------------------------------------------------------
            /// Finalize the launch.
            ///
            /// This method associates the NativeProcessDarwin instance with
            /// the host process that was just launched.  It peforms actions
            /// like attaching a listener to the inferior exception port,
            /// ptracing the process, and the like.
            ///
            /// @param[in] launch_flavor
            ///     The launch flavor that was used to launch the process.
            ///
            /// @param[in] main_loop
            ///     The main loop that will run the process monitor.  Work
            ///     that needs to be done (e.g. reading files) gets registered
            ///     here along with callbacks to process the work.
            ///
            /// @return
            ///     Any error that occurred during the aforementioned
            ///     operations.  Failure here will force termination of the
            ///     launched process and debugging session.
            // -----------------------------------------------------------------
            Error
            FinalizeLaunch(LaunchFlavor launch_flavor, MainLoop &main_loop);

            Error
            SaveExceptionPortInfo();

            void
            ExceptionMessageReceived(const MachException::Message &message);

            void
            MaybeRaiseThreadPriority();

            Error
            StartExceptionThread();

            Error
            SendInferiorExitStatusToMainLoop(::pid_t pid, int status);

            Error
            HandleWaitpidResult();

            bool
            ProcessUsingSpringBoard() const;

            bool
            ProcessUsingBackBoard() const;

            static void*
            ExceptionThread(void *arg);

            void*
            DoExceptionThread();

            lldb::addr_t
            GetDYLDAllImageInfosAddress(Error &error) const;

            static uint32_t
            GetCPUTypeForLocalProcess(::pid_t pid);

            uint32_t
            GetCPUType() const;

            task_t
            ExceptionMessageBundleComplete();

            void
            StartSTDIOThread();

            Error
            StartWaitpidThread(MainLoop &main_loop);

            static void*
            WaitpidThread(void *arg);

            void*
            DoWaitpidThread();

            task_t
            TaskPortForProcessID(Error &error, bool force = false) const;

            /// Attaches to an existing process.  Forms the
            /// implementation of Process::DoAttach.
            void
            AttachToInferior(MainLoop &mainloop, lldb::pid_t pid, Error &error);

            ::pid_t
            Attach(lldb::pid_t pid, Error &error);

            Error
            PrivateResume();

            Error
            ReplyToAllExceptions();

            Error
            ResumeTask();

            bool
            IsTaskValid() const;

            bool
            IsTaskValid(task_t task) const;

            mach_port_t
            GetExceptionPort() const;

            bool
            IsExceptionPortValid () const;

            Error
            GetTaskBasicInfo(task_t task, struct task_basic_info *info) const;

            Error
            SuspendTask();

            static Error
            SetDefaultPtraceOpts(const lldb::pid_t);

            static void *
            MonitorThread(void *baton);

            void
            MonitorCallback(lldb::pid_t pid, bool exited, int signal,
                            int status);

            void
            WaitForNewThread(::pid_t tid);

            void
            MonitorSIGTRAP(const siginfo_t &info, NativeThreadDarwin &thread);

            void
            MonitorTrace(NativeThreadDarwin &thread);

            void
            MonitorBreakpoint(NativeThreadDarwin &thread);

            void
            MonitorWatchpoint(NativeThreadDarwin &thread, uint32_t wp_index);

            void
            MonitorSignal(const siginfo_t &info, NativeThreadDarwin &thread,
                          bool exited);

            Error
            SetupSoftwareSingleStepping(NativeThreadDarwin &thread);

#if 0
            static ::ProcessMessage::CrashReason
            GetCrashReasonForSIGSEGV(const siginfo_t *info);

            static ::ProcessMessage::CrashReason
            GetCrashReasonForSIGILL(const siginfo_t *info);

            static ::ProcessMessage::CrashReason
            GetCrashReasonForSIGFPE(const siginfo_t *info);

            static ::ProcessMessage::CrashReason
            GetCrashReasonForSIGBUS(const siginfo_t *info);
#endif

            bool
            HasThreadNoLock(lldb::tid_t thread_id);

            bool
            StopTrackingThread(lldb::tid_t thread_id);

            NativeThreadDarwinSP
            AddThread(lldb::tid_t thread_id);

            Error
            GetSoftwareBreakpointPCOffset(uint32_t &actual_opcode_size);

            Error
            FixupBreakpointPCAsNeeded(NativeThreadDarwin &thread);

            /// Writes a siginfo_t structure corresponding to the given thread
            /// ID to the memory region pointed to by @p siginfo.
            Error
            GetSignalInfo(lldb::tid_t tid, void *siginfo);
            
            /// Writes the raw event message code (vis-a-vis PTRACE_GETEVENTMSG)
            /// corresponding to the given thread ID to the memory pointed to
            /// by @p message.
            Error
            GetEventMessage(lldb::tid_t tid, unsigned long *message);
            
            void
            NotifyThreadDeath(lldb::tid_t tid);
            
            Error
            Detach(lldb::tid_t tid);
            
            
            // This method is requests a stop on all threads which are still
            // running. It sets up a deferred delegate notification, which will
            // fire once threads report as stopped. The triggerring_tid will be
            // set as the current thread (main stop reason).
            void
            StopRunningThreads(lldb::tid_t triggering_tid);
            
            // Notify the delegate if all threads have stopped.
            void SignalIfAllThreadsStopped();
            
            // Resume the given thread, optionally passing it the given signal.
            // The type of resume operation (continue, single-step) depends on
            // the state parameter.
            Error
            ResumeThread(NativeThreadDarwin &thread, lldb::StateType state,
                         int signo);
            
            void
            ThreadWasCreated(NativeThreadDarwin &thread);
            
            void
            SigchldHandler();
        };
        
    } // namespace process_darwin
} // namespace lldb_private

#endif /* NativeProcessDarwin_h */