lldb/Target/Platform.h

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

#ifndef liblldb_Platform_h_
#define liblldb_Platform_h_

// C Includes
// C++ Includes
#include <map>
#include <string>
#include <vector>

// Other libraries and framework includes
// Project includes
#include "lldb/lldb-public.h"
#include "lldb/Core/ArchSpec.h"
#include "lldb/Core/ConstString.h"
#include "lldb/Core/PluginInterface.h"
#include "lldb/Host/Mutex.h"

namespace lldb_private {

    //----------------------------------------------------------------------
    /// @class Platform Platform.h "lldb/Target/Platform.h"
    /// @brief A plug-in interface definition class for debug platform that
    /// includes many platform abilities such as:
    ///     @li getting platform information such as supported architectures,
    ///         supported binary file formats and more
    ///     @li launching new processes
    ///     @li attaching to existing processes
    ///     @li download/upload files
    ///     @li execute shell commands
    ///     @li listing and getting info for existing processes
    ///     @li attaching and possibly debugging the platform's kernel
    //----------------------------------------------------------------------
    class Platform : public PluginInterface
    {
    public:

        //------------------------------------------------------------------
        /// Get the native host platform plug-in.
        ///
        /// There should only be one of these for each host that LLDB runs
        /// upon that should be statically compiled in and registered using
        /// preprocessor macros or other similar build mechanisms in a
        /// PlatformSubclass::Initialize() function.
        ///
        /// This platform will be used as the default platform when launching
        /// or attaching to processes unless another platform is specified.
        //------------------------------------------------------------------
        static lldb::PlatformSP
        GetDefaultPlatform ();

        static lldb::PlatformSP
        GetPlatformForArchitecture (const ArchSpec &arch,
                                    ArchSpec *platform_arch_ptr);

        static const char *
        GetHostPlatformName ();

        static void
        SetDefaultPlatform (const lldb::PlatformSP &platform_sp);

        static lldb::PlatformSP
        Create (const char *platform_name, Error &error);

        static lldb::PlatformSP
        Create (const ArchSpec &arch, ArchSpec *platform_arch_ptr, Error &error);

        static uint32_t
        GetNumConnectedRemotePlatforms ();

        static lldb::PlatformSP
        GetConnectedRemotePlatformAtIndex (uint32_t idx);

        //------------------------------------------------------------------
        /// Default Constructor
        //------------------------------------------------------------------
        Platform (bool is_host_platform);

        //------------------------------------------------------------------
        /// Destructor.
        ///
        /// The destructor is virtual since this class is designed to be
        /// inherited from by the plug-in instance.
        //------------------------------------------------------------------
        virtual
        ~Platform();

        //------------------------------------------------------------------
        /// Set the target's executable based off of the existing
        /// architecture information in \a target given a path to an
        /// executable \a exe_file.
        ///
        /// Each platform knows the architectures that it supports and can
        /// select the correct architecture slice within \a exe_file by
        /// inspecting the architecture in \a target. If the target had an
        /// architecture specified, then in can try and obey that request
        /// and optionally fail if the architecture doesn't match up.
        /// If no architecture is specified, the platform should select the
        /// default architecture from \a exe_file. Any application bundles
        /// or executable wrappers can also be inspected for the actual
        /// application binary within the bundle that should be used.
        ///
        /// @return
        ///     Returns \b true if this Platform plug-in was able to find
        ///     a suitable executable, \b false otherwise.
        //------------------------------------------------------------------
        virtual Error
        ResolveExecutable (const FileSpec &exe_file,
                           const ArchSpec &arch,
                           lldb::ModuleSP &module_sp,
                           const FileSpecList *module_search_paths_ptr);

        //------------------------------------------------------------------
        /// Resolves the FileSpec to a (possibly) remote path. Remote
        /// platforms must override this to resolve to a path on the remote
        /// side.
        //------------------------------------------------------------------
        virtual bool
        ResolveRemotePath (const FileSpec &platform_path,
                           FileSpec &resolved_platform_path);

        bool
        GetOSVersion (uint32_t &major,
                      uint32_t &minor,
                      uint32_t &update);

        bool
        SetOSVersion (uint32_t major,
                      uint32_t minor,
                      uint32_t update);

        bool
        GetOSBuildString (std::string &s);

        bool
        GetOSKernelDescription (std::string &s);

        // Returns the the hostname if we are connected, else the short plugin
        // name.
        const char *
        GetName ();

        virtual const char *
        GetHostname ();

        virtual const char *
        GetDescription () = 0;

        //------------------------------------------------------------------
        /// Report the current status for this platform.
        ///
        /// The returned string usually involves returning the OS version
        /// (if available), and any SDK directory that might be being used
        /// for local file caching, and if connected a quick blurb about
        /// what this platform is connected to.
        //------------------------------------------------------------------
        virtual void
        GetStatus (Stream &strm);

        //------------------------------------------------------------------
        // Subclasses must be able to fetch the current OS version
        //
        // Remote classes must be connected for this to succeed. Local
        // subclasses don't need to override this function as it will just
        // call the Host::GetOSVersion().
        //------------------------------------------------------------------
        virtual bool
        GetRemoteOSVersion ()
        {
            return false;
        }

        virtual bool
        GetRemoteOSBuildString (std::string &s)
        {
            s.clear();
            return false;
        }

        virtual bool
        GetRemoteOSKernelDescription (std::string &s)
        {
            s.clear();
            return false;
        }

        // Remote Platform subclasses need to override this function
        virtual ArchSpec
        GetRemoteSystemArchitecture ()
        {
            return ArchSpec(); // Return an invalid architecture
        }

        virtual const char *
        GetUserName (uint32_t uid);

        virtual const char *
        GetGroupName (uint32_t gid);

        //------------------------------------------------------------------
        /// Locate a file for a platform.
        ///
        /// The default implementation of this function will return the same
        /// file patch in \a local_file as was in \a platform_file.
        ///
        /// @param[in] platform_file
        ///     The platform file path to locate and cache locally.
        ///
        /// @param[in] uuid_ptr
        ///     If we know the exact UUID of the file we are looking for, it
        ///     can be specified. If it is not specified, we might now know
        ///     the exact file. The UUID is usually some sort of MD5 checksum
        ///     for the file and is sometimes known by dynamic linkers/loaders.
        ///     If the UUID is known, it is best to supply it to platform
        ///     file queries to ensure we are finding the correct file, not
        ///     just a file at the correct path.
        ///
        /// @param[out] local_file
        ///     A locally cached version of the platform file. For platforms
        ///     that describe the current host computer, this will just be
        ///     the same file. For remote platforms, this file might come from
        ///     and SDK directory, or might need to be sync'ed over to the
        ///     current machine for efficient debugging access.
        ///
        /// @return
        ///     An error object.
        //------------------------------------------------------------------
        virtual Error
        GetFile (const FileSpec &platform_file,
                 const UUID *uuid_ptr,
                 FileSpec &local_file);

        virtual Error
        GetSharedModule (const ModuleSpec &module_spec,
                         lldb::ModuleSP &module_sp,
                         const FileSpecList *module_search_paths_ptr,
                         lldb::ModuleSP *old_module_sp_ptr,
                         bool *did_create_ptr);

        virtual Error
        ConnectRemote (Args& args);

        virtual Error
        DisconnectRemote ();

        //------------------------------------------------------------------
        /// Get the platform's supported architectures in the order in which
        /// they should be searched.
        ///
        /// @param[in] idx
        ///     A zero based architecture index
        ///
        /// @param[out] arch
        ///     A copy of the archgitecture at index if the return value is
        ///     \b true.
        ///
        /// @return
        ///     \b true if \a arch was filled in and is valid, \b false
        ///     otherwise.
        //------------------------------------------------------------------
        virtual bool
        GetSupportedArchitectureAtIndex (uint32_t idx, ArchSpec &arch) = 0;

        virtual size_t
        GetSoftwareBreakpointTrapOpcode (Target &target,
                                         BreakpointSite *bp_site) = 0;

        //------------------------------------------------------------------
        /// Launch a new process on a platform, not necessarily for
        /// debugging, it could be just for running the process.
        //------------------------------------------------------------------
        virtual Error
        LaunchProcess (ProcessLaunchInfo &launch_info);

        //------------------------------------------------------------------
        /// Lets a platform answer if it is compatible with a given
        /// architecture and the target triple contained within.
        //------------------------------------------------------------------
        virtual bool
        IsCompatibleArchitecture (const ArchSpec &arch, ArchSpec *compatible_arch_ptr = NULL);

        //------------------------------------------------------------------
        /// Not all platforms will support debugging a process by spawning
        /// somehow halted for a debugger (specified using the
        /// "eLaunchFlagDebug" launch flag) and then attaching. If your
        /// platform doesn't support this, override this function and return
        /// false.
        //------------------------------------------------------------------
        virtual bool
        CanDebugProcess ()
        {
            return true;
        }

        //------------------------------------------------------------------
        /// Subclasses should NOT need to implement this function as it uses
        /// the Platform::LaunchProcess() followed by Platform::Attach ()
        //------------------------------------------------------------------
        lldb::ProcessSP
        DebugProcess (ProcessLaunchInfo &launch_info,
                      Debugger &debugger,
                      Target *target,       // Can be NULL, if NULL create a new target, else use existing one
                      Listener &listener,
                      Error &error);

        //------------------------------------------------------------------
        /// Attach to an existing process using a process ID.
        ///
        /// Each platform subclass needs to implement this function and
        /// attempt to attach to the process with the process ID of \a pid.
        /// The platform subclass should return an appropriate ProcessSP
        /// subclass that is attached to the process, or an empty shared
        /// pointer with an appriopriate error.
        ///
        /// @param[in] pid
        ///     The process ID that we should attempt to attach to.
        ///
        /// @return
        ///     An appropriate ProcessSP containing a valid shared pointer
        ///     to the default Process subclass for the platform that is
        ///     attached to the process, or an empty shared pointer with an
        ///     appriopriate error fill into the \a error object.
        //------------------------------------------------------------------
        virtual lldb::ProcessSP
        Attach (ProcessAttachInfo &attach_info,
                Debugger &debugger,
                Target *target,       // Can be NULL, if NULL create a new target, else use existing one
                Listener &listener,
                Error &error) = 0;

        //------------------------------------------------------------------
        /// Attach to an existing process by process name.
        ///
        /// This function is not meant to be overridden by Process
        /// subclasses. It will first call
        /// Process::WillAttach (const char *) and if that returns \b
        /// true, Process::DoAttach (const char *) will be called to
        /// actually do the attach. If DoAttach returns \b true, then
        /// Process::DidAttach() will be called.
        ///
        /// @param[in] process_name
        ///     A process name to match against the current process list.
        ///
        /// @return
        ///     Returns \a pid if attaching was successful, or
        ///     LLDB_INVALID_PROCESS_ID if attaching fails.
        //------------------------------------------------------------------
//        virtual lldb::ProcessSP
//        Attach (const char *process_name,
//                bool wait_for_launch,
//                Error &error) = 0;

        //------------------------------------------------------------------
        // The base class Platform will take care of the host platform.
        // Subclasses will need to fill in the remote case.
        //------------------------------------------------------------------
        virtual uint32_t
        FindProcesses (const ProcessInstanceInfoMatch &match_info,
                       ProcessInstanceInfoList &proc_infos);

        virtual bool
        GetProcessInfo (lldb::pid_t pid, ProcessInstanceInfo &proc_info);

        //------------------------------------------------------------------
        // Set a breakpoint on all functions that can end up creating a thread
        // for this platform. This is needed when running expressions and
        // also for process control.
        //------------------------------------------------------------------
        virtual lldb::BreakpointSP
        SetThreadCreationBreakpoint (Target &target);


        const std::string &
        GetRemoteURL () const
        {
            return m_remote_url;
        }

        bool
        IsHost () const
        {
            return m_is_host;    // Is this the default host platform?
        }

        bool
        IsRemote () const
        {
            return !m_is_host;
        }

        virtual bool
        IsConnected () const
        {
            // Remote subclasses should override this function
            return IsHost();
        }

        const ArchSpec &
        GetSystemArchitecture();

        void
        SetSystemArchitecture (const ArchSpec &arch)
        {
            m_system_arch = arch;
            if (IsHost())
                m_os_version_set_while_connected = m_system_arch.IsValid();
        }

        // Used for column widths
        uint32_t
        GetMaxUserIDNameLength() const
        {
            return m_max_uid_name_len;
        }
        // Used for column widths
        uint32_t
        GetMaxGroupIDNameLength() const
        {
            return m_max_gid_name_len;
        }

        const ConstString &
        GetSDKRootDirectory () const
        {
            return m_sdk_sysroot;
        }

        void
        SetSDKRootDirectory (const ConstString &dir)
        {
            m_sdk_sysroot = dir;
        }

        const ConstString &
        GetSDKBuild () const
        {
            return m_sdk_build;
        }

        void
        SetSDKBuild (const ConstString &sdk_build)
        {
            m_sdk_build = sdk_build;
        }

        // There may be modules that we don't want to find by default for operations like "setting breakpoint by name".
        // The platform will return "true" from this call if the passed in module happens to be one of these.

        virtual bool
        ModuleIsExcludedForNonModuleSpecificSearches (Target &target, const lldb::ModuleSP &module_sp)
        {
            return false;
        }

    protected:
        bool m_is_host;
        // Set to true when we are able to actually set the OS version while
        // being connected. For remote platforms, we might set the version ahead
        // of time before we actually connect and this version might change when
        // we actually connect to a remote platform. For the host platform this
        // will be set to the once we call Host::GetOSVersion().
        bool m_os_version_set_while_connected;
        bool m_system_arch_set_while_connected;
        ConstString m_sdk_sysroot; // the root location of where the SDK files are all located
        ConstString m_sdk_build;
        std::string m_remote_url;
        std::string m_name;
        uint32_t m_major_os_version;
        uint32_t m_minor_os_version;
        uint32_t m_update_os_version;
        ArchSpec m_system_arch; // The architecture of the kernel or the remote platform
        typedef std::map<uint32_t, ConstString> IDToNameMap;
        Mutex m_uid_map_mutex;
        Mutex m_gid_map_mutex;
        IDToNameMap m_uid_map;
        IDToNameMap m_gid_map;
        uint32_t m_max_uid_name_len;
        uint32_t m_max_gid_name_len;

        const char *
        GetCachedUserName (uint32_t uid)
        {
            Mutex::Locker locker (m_uid_map_mutex);
            IDToNameMap::iterator pos = m_uid_map.find (uid);
            if (pos != m_uid_map.end())
            {
                // return the empty string if our string is NULL
                // so we can tell when things were in the negative
                // cached (didn't find a valid user name, don't keep
                // trying)
                return pos->second.AsCString("");
            }
            return NULL;
        }

        const char *
        SetCachedUserName (uint32_t uid, const char *name, size_t name_len)
        {
            Mutex::Locker locker (m_uid_map_mutex);
            ConstString const_name (name);
            m_uid_map[uid] = const_name;
            if (m_max_uid_name_len < name_len)
                m_max_uid_name_len = name_len;
            // Const strings lives forever in our const string pool, so we can return the const char *
            return const_name.GetCString();
        }

        void
        SetUserNameNotFound (uint32_t uid)
        {
            Mutex::Locker locker (m_uid_map_mutex);
            m_uid_map[uid] = ConstString();
        }


        void
        ClearCachedUserNames ()
        {
            Mutex::Locker locker (m_uid_map_mutex);
            m_uid_map.clear();
        }

        const char *
        GetCachedGroupName (uint32_t gid)
        {
            Mutex::Locker locker (m_gid_map_mutex);
            IDToNameMap::iterator pos = m_gid_map.find (gid);
            if (pos != m_gid_map.end())
            {
                // return the empty string if our string is NULL
                // so we can tell when things were in the negative
                // cached (didn't find a valid group name, don't keep
                // trying)
                return pos->second.AsCString("");
            }
            return NULL;
        }

        const char *
        SetCachedGroupName (uint32_t gid, const char *name, size_t name_len)
        {
            Mutex::Locker locker (m_gid_map_mutex);
            ConstString const_name (name);
            m_gid_map[gid] = const_name;
            if (m_max_gid_name_len < name_len)
                m_max_gid_name_len = name_len;
            // Const strings lives forever in our const string pool, so we can return the const char *
            return const_name.GetCString();
        }

        void
        SetGroupNameNotFound (uint32_t gid)
        {
            Mutex::Locker locker (m_gid_map_mutex);
            m_gid_map[gid] = ConstString();
        }

        void
        ClearCachedGroupNames ()
        {
            Mutex::Locker locker (m_gid_map_mutex);
            m_gid_map.clear();
        }

    private:
        DISALLOW_COPY_AND_ASSIGN (Platform);
    };


    class PlatformList
    {
    public:
        PlatformList() :
            m_mutex (Mutex::eMutexTypeRecursive),
            m_platforms (),
            m_selected_platform_sp()
        {
        }

        ~PlatformList()
        {
        }

        void
        Append (const lldb::PlatformSP &platform_sp, bool set_selected)
        {
            Mutex::Locker locker (m_mutex);
            m_platforms.push_back (platform_sp);
            if (set_selected)
                m_selected_platform_sp = m_platforms.back();
        }

        size_t
        GetSize()
        {
            Mutex::Locker locker (m_mutex);
            return m_platforms.size();
        }

        lldb::PlatformSP
        GetAtIndex (uint32_t idx)
        {
            lldb::PlatformSP platform_sp;
            {
                Mutex::Locker locker (m_mutex);
                if (idx < m_platforms.size())
                    platform_sp = m_platforms[idx];
            }
            return platform_sp;
        }

        //------------------------------------------------------------------
        /// Select the active platform.
        ///
        /// In order to debug remotely, other platform's can be remotely
        /// connected to and set as the selected platform for any subsequent
        /// debugging. This allows connection to remote targets and allows
        /// the ability to discover process info, launch and attach to remote
        /// processes.
        //------------------------------------------------------------------
        lldb::PlatformSP
        GetSelectedPlatform ()
        {
            Mutex::Locker locker (m_mutex);
            if (!m_selected_platform_sp && !m_platforms.empty())
                m_selected_platform_sp = m_platforms.front();

            return m_selected_platform_sp;
        }

        void
        SetSelectedPlatform (const lldb::PlatformSP &platform_sp)
        {
            if (platform_sp)
            {
                Mutex::Locker locker (m_mutex);
                const size_t num_platforms = m_platforms.size();
                for (size_t idx=0; idx<num_platforms; ++idx)
                {
                    if (m_platforms[idx].get() == platform_sp.get())
                    {
                        m_selected_platform_sp = m_platforms[idx];
                        return;
                    }
                }
                m_platforms.push_back (platform_sp);
                m_selected_platform_sp = m_platforms.back();
            }
        }

    protected:
        typedef std::vector<lldb::PlatformSP> collection;
        mutable Mutex m_mutex;
        collection m_platforms;
        lldb::PlatformSP m_selected_platform_sp;

    private:
        DISALLOW_COPY_AND_ASSIGN (PlatformList);
    };
} // namespace lldb_private

#endif  // liblldb_Platform_h_