aboutsummaryrefslogtreecommitdiffstats
path: root/include/lldb/Target/Platform.h
blob: 6f643df53d1ed6c9f210fea12712d5a572ff7b24 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
//===-- Platform.h ----------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef liblldb_Platform_h_
#define liblldb_Platform_h_

#include <functional>
#include <map>
#include <memory>
#include <mutex>
#include <string>
#include <vector>

#include "lldb/Core/PluginInterface.h"
#include "lldb/Core/UserSettingsController.h"
#include "lldb/Host/File.h"
#include "lldb/Interpreter/Options.h"
#include "lldb/Utility/ArchSpec.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/Timeout.h"
#include "lldb/Utility/UserIDResolver.h"
#include "lldb/lldb-private-forward.h"
#include "lldb/lldb-public.h"
#include "llvm/Support/VersionTuple.h"

namespace lldb_private {

class ProcessInstanceInfo;
class ProcessInstanceInfoList;
class ProcessInstanceInfoMatch;

class ModuleCache;
enum MmapFlags { eMmapFlagsPrivate = 1, eMmapFlagsAnon = 2 };

class PlatformProperties : public Properties {
public:
  PlatformProperties();

  static ConstString GetSettingName();

  bool GetUseModuleCache() const;
  bool SetUseModuleCache(bool use_module_cache);

  FileSpec GetModuleCacheDirectory() const;
  bool SetModuleCacheDirectory(const FileSpec &dir_spec);
};

typedef std::shared_ptr<PlatformProperties> PlatformPropertiesSP;
typedef llvm::SmallVector<lldb::addr_t, 6> MmapArgList;

/// \class Platform Platform.h "lldb/Target/Platform.h"
/// 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:
  /// 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.
  ~Platform() override;

  static void Initialize();

  static void Terminate();

  static const PlatformPropertiesSP &GetGlobalPlatformProperties();

  /// 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 GetHostPlatform();

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

  static const char *GetHostPlatformName();

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

  // Find an existing platform plug-in by name
  static lldb::PlatformSP Find(ConstString name);

  static lldb::PlatformSP Create(ConstString name, Status &error);

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

  /// Augments the triple either with information from platform or the host
  /// system (if platform is null).
  static ArchSpec GetAugmentedArchSpec(Platform *platform,
                                       llvm::StringRef triple);

  /// Find a platform plugin for a given process.
  ///
  /// Scans the installed Platform plug-ins and tries to find an instance that
  /// can be used for \a process
  ///
  /// \param[in] process
  ///     The process for which to try and locate a platform
  ///     plug-in instance.
  ///
  /// \param[in] plugin_name
  ///     An optional name of a specific platform plug-in that
  ///     should be used. If nullptr, pick the best plug-in.
  //        static lldb::PlatformSP
  //        FindPlugin (Process *process, ConstString plugin_name);

  /// 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 Status ResolveExecutable(const ModuleSpec &module_spec,
                                   lldb::ModuleSP &module_sp,
                                   const FileSpecList *module_search_paths_ptr);

  /// Find a symbol file given a symbol file module specification.
  ///
  /// Each platform might have tricks to find symbol files for an executable
  /// given information in a symbol file ModuleSpec. Some platforms might also
  /// support symbol files that are bundles and know how to extract the right
  /// symbol file given a bundle.
  ///
  /// \param[in] target
  ///     The target in which we are trying to resolve the symbol file.
  ///     The target has a list of modules that we might be able to
  ///     use in order to help find the right symbol file. If the
  ///     "m_file" or "m_platform_file" entries in the \a sym_spec
  ///     are filled in, then we might be able to locate a module in
  ///     the target, extract its UUID and locate a symbol file.
  ///     If just the "m_uuid" is specified, then we might be able
  ///     to find the module in the target that matches that UUID
  ///     and pair the symbol file along with it. If just "m_symbol_file"
  ///     is specified, we can use a variety of tricks to locate the
  ///     symbols in an SDK, PDK, or other development kit location.
  ///
  /// \param[in] sym_spec
  ///     A module spec that describes some information about the
  ///     symbol file we are trying to resolve. The ModuleSpec might
  ///     contain the following:
  ///     m_file - A full or partial path to an executable from the
  ///              target (might be empty).
  ///     m_platform_file - Another executable hint that contains
  ///                       the path to the file as known on the
  ///                       local/remote platform.
  ///     m_symbol_file - A full or partial path to a symbol file
  ///                     or symbol bundle that should be used when
  ///                     trying to resolve the symbol file.
  ///     m_arch - The architecture we are looking for when resolving
  ///              the symbol file.
  ///     m_uuid - The UUID of the executable and symbol file. This
  ///              can often be used to match up an executable with
  ///              a symbol file, or resolve an symbol file in a
  ///              symbol file bundle.
  ///
  /// \param[out] sym_file
  ///     The resolved symbol file spec if the returned error
  ///     indicates success.
  ///
  /// \return
  ///     Returns an error that describes success or failure.
  virtual Status ResolveSymbolFile(Target &target, const ModuleSpec &sym_spec,
                                   FileSpec &sym_file);

  /// 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);

  /// Get the OS version from a connected platform.
  ///
  /// Some platforms might not be connected to a remote platform, but can
  /// figure out the OS version for a process. This is common for simulator
  /// platforms that will run native programs on the current host, but the
  /// simulator might be simulating a different OS. The \a process parameter
  /// might be specified to help to determine the OS version.
  virtual llvm::VersionTuple GetOSVersion(Process *process = nullptr);

  bool SetOSVersion(llvm::VersionTuple os_version);

  bool GetOSBuildString(std::string &s);

  bool GetOSKernelDescription(std::string &s);

  // Returns the name of the platform
  ConstString GetName();

  virtual const char *GetHostname();

  virtual ConstString GetFullNameForDylib(ConstString basename);

  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
  // HostInfo::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 FileSpec GetRemoteWorkingDirectory() { return m_working_dir; }

  virtual bool SetRemoteWorkingDirectory(const FileSpec &working_dir);

  virtual UserIDResolver &GetUserIDResolver() = 0;

  /// 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 Status GetFileWithUUID(const FileSpec &platform_file,
                                 const UUID *uuid_ptr, FileSpec &local_file);

  // Locate the scripting resource given a module specification.
  //
  // Locating the file should happen only on the local computer or using the
  // current computers global settings.
  virtual FileSpecList
  LocateExecutableScriptingResources(Target *target, Module &module,
                                     Stream *feedback_stream);

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

  virtual bool GetModuleSpec(const FileSpec &module_file_spec,
                             const ArchSpec &arch, ModuleSpec &module_spec);

  virtual Status ConnectRemote(Args &args);

  virtual Status 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 architecture 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);

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

  /// Perform expansion of the command-line for this launch info This can
  /// potentially involve wildcard expansion
  /// environment variable replacement, and whatever other
  /// argument magic the platform defines as part of its typical
  /// user experience
  virtual Status ShellExpandArguments(ProcessLaunchInfo &launch_info);

  /// Kill process on a platform.
  virtual Status KillProcess(const lldb::pid_t pid);

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

  /// 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 do not need to implement this function as it uses the
  /// Platform::LaunchProcess() followed by Platform::Attach (). Remote
  /// platforms will want to subclass this function in order to be able to
  /// intercept STDIO and possibly launch a separate process that will debug
  /// the debuggee.
  virtual lldb::ProcessSP
  DebugProcess(ProcessLaunchInfo &launch_info, Debugger &debugger,
               Target *target, // Can be nullptr, if nullptr create a new
                               // target, else use existing one
               Status &error);

  virtual lldb::ProcessSP ConnectProcess(llvm::StringRef connect_url,
                                         llvm::StringRef plugin_name,
                                         lldb_private::Debugger &debugger,
                                         lldb_private::Target *target,
                                         lldb_private::Status &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 appropriate
  /// 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
  ///     appropriate error fill into the \a error object.
  virtual lldb::ProcessSP Attach(ProcessAttachInfo &attach_info,
                                 Debugger &debugger,
                                 Target *target, // Can be nullptr, if nullptr
                                                 // create a new target, else
                                                 // use existing one
                                 Status &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,
  //                Status &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);

  // Given a target, find the local SDK directory if one exists on the current
  // host.
  virtual lldb_private::ConstString
  GetSDKDirectory(lldb_private::Target &target) {
    return lldb_private::ConstString();
  }

  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();
  }

  /// If the triple contains not specify the vendor, os, and environment
  /// parts, we "augment" these using information from the platform and return
  /// the resulting ArchSpec object.
  ArchSpec GetAugmentedArchSpec(llvm::StringRef triple);

  // Used for column widths
  size_t GetMaxUserIDNameLength() const { return m_max_uid_name_len; }

  // Used for column widths
  size_t GetMaxGroupIDNameLength() const { return m_max_gid_name_len; }

  ConstString GetSDKRootDirectory() const { return m_sdk_sysroot; }

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

  ConstString GetSDKBuild() const { return m_sdk_build; }

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

  // Override this to return true if your platform supports Clang modules. You
  // may also need to override AddClangModuleCompilationOptions to pass the
  // right Clang flags for your platform.
  virtual bool SupportsModules() { return false; }

  // Appends the platform-specific options required to find the modules for the
  // current platform.
  virtual void
  AddClangModuleCompilationOptions(Target *target,
                                   std::vector<std::string> &options);

  FileSpec GetWorkingDirectory();

  bool SetWorkingDirectory(const FileSpec &working_dir);

  // 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
  ModuleIsExcludedForUnconstrainedSearches(Target &target,
                                           const lldb::ModuleSP &module_sp) {
    return false;
  }

  virtual Status MakeDirectory(const FileSpec &file_spec, uint32_t permissions);

  virtual Status GetFilePermissions(const FileSpec &file_spec,
                                    uint32_t &file_permissions);

  virtual Status SetFilePermissions(const FileSpec &file_spec,
                                    uint32_t file_permissions);

  virtual lldb::user_id_t OpenFile(const FileSpec &file_spec,
                                   File::OpenOptions flags, uint32_t mode,
                                   Status &error) {
    return UINT64_MAX;
  }

  virtual bool CloseFile(lldb::user_id_t fd, Status &error) { return false; }

  virtual lldb::user_id_t GetFileSize(const FileSpec &file_spec) {
    return UINT64_MAX;
  }

  virtual uint64_t ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst,
                            uint64_t dst_len, Status &error) {
    error.SetErrorStringWithFormat(
        "Platform::ReadFile() is not supported in the %s platform",
        GetName().GetCString());
    return -1;
  }

  virtual uint64_t WriteFile(lldb::user_id_t fd, uint64_t offset,
                             const void *src, uint64_t src_len, Status &error) {
    error.SetErrorStringWithFormat(
        "Platform::WriteFile() is not supported in the %s platform",
        GetName().GetCString());
    return -1;
  }

  virtual Status GetFile(const FileSpec &source, const FileSpec &destination);

  virtual Status PutFile(const FileSpec &source, const FileSpec &destination,
                         uint32_t uid = UINT32_MAX, uint32_t gid = UINT32_MAX);

  virtual Status
  CreateSymlink(const FileSpec &src,  // The name of the link is in src
                const FileSpec &dst); // The symlink points to dst

  /// Install a file or directory to the remote system.
  ///
  /// Install is similar to Platform::PutFile(), but it differs in that if an
  /// application/framework/shared library is installed on a remote platform
  /// and the remote platform requires something to be done to register the
  /// application/framework/shared library, then this extra registration can
  /// be done.
  ///
  /// \param[in] src
  ///     The source file/directory to install on the remote system.
  ///
  /// \param[in] dst
  ///     The destination file/directory where \a src will be installed.
  ///     If \a dst has no filename specified, then its filename will
  ///     be set from \a src. It \a dst has no directory specified, it
  ///     will use the platform working directory. If \a dst has a
  ///     directory specified, but the directory path is relative, the
  ///     platform working directory will be prepended to the relative
  ///     directory.
  ///
  /// \return
  ///     An error object that describes anything that went wrong.
  virtual Status Install(const FileSpec &src, const FileSpec &dst);

  virtual Environment GetEnvironment();

  virtual bool GetFileExists(const lldb_private::FileSpec &file_spec);

  virtual Status Unlink(const FileSpec &file_spec);

  virtual MmapArgList GetMmapArgumentList(const ArchSpec &arch,
                                          lldb::addr_t addr,
                                          lldb::addr_t length,
                                          unsigned prot, unsigned flags,
                                          lldb::addr_t fd, lldb::addr_t offset);

  virtual bool GetSupportsRSync() { return m_supports_rsync; }

  virtual void SetSupportsRSync(bool flag) { m_supports_rsync = flag; }

  virtual const char *GetRSyncOpts() { return m_rsync_opts.c_str(); }

  virtual void SetRSyncOpts(const char *opts) { m_rsync_opts.assign(opts); }

  virtual const char *GetRSyncPrefix() { return m_rsync_prefix.c_str(); }

  virtual void SetRSyncPrefix(const char *prefix) {
    m_rsync_prefix.assign(prefix);
  }

  virtual bool GetSupportsSSH() { return m_supports_ssh; }

  virtual void SetSupportsSSH(bool flag) { m_supports_ssh = flag; }

  virtual const char *GetSSHOpts() { return m_ssh_opts.c_str(); }

  virtual void SetSSHOpts(const char *opts) { m_ssh_opts.assign(opts); }

  virtual bool GetIgnoresRemoteHostname() { return m_ignores_remote_hostname; }

  virtual void SetIgnoresRemoteHostname(bool flag) {
    m_ignores_remote_hostname = flag;
  }

  virtual lldb_private::OptionGroupOptions *
  GetConnectionOptions(CommandInterpreter &interpreter) {
    return nullptr;
  }

  virtual lldb_private::Status RunShellCommand(
      const char *command,         // Shouldn't be nullptr
      const FileSpec &working_dir, // Pass empty FileSpec to use the current
                                   // working directory
      int *status_ptr, // Pass nullptr if you don't want the process exit status
      int *signo_ptr,  // Pass nullptr if you don't want the signal that caused
                       // the process to exit
      std::string
          *command_output, // Pass nullptr if you don't want the command output
      const Timeout<std::micro> &timeout);

  virtual void SetLocalCacheDirectory(const char *local);

  virtual const char *GetLocalCacheDirectory();

  virtual std::string GetPlatformSpecificConnectionInformation() { return ""; }

  virtual bool CalculateMD5(const FileSpec &file_spec, uint64_t &low,
                            uint64_t &high);

  virtual int32_t GetResumeCountForLaunchInfo(ProcessLaunchInfo &launch_info) {
    return 1;
  }

  virtual const lldb::UnixSignalsSP &GetRemoteUnixSignals();

  lldb::UnixSignalsSP GetUnixSignals();

  /// Locate a queue name given a thread's qaddr
  ///
  /// On a system using libdispatch ("Grand Central Dispatch") style queues, a
  /// thread may be associated with a GCD queue or not, and a queue may be
  /// associated with multiple threads. The process/thread must provide a way
  /// to find the "dispatch_qaddr" for each thread, and from that
  /// dispatch_qaddr this Platform method will locate the queue name and
  /// provide that.
  ///
  /// \param[in] process
  ///     A process is required for reading memory.
  ///
  /// \param[in] dispatch_qaddr
  ///     The dispatch_qaddr for this thread.
  ///
  /// \return
  ///     The name of the queue, if there is one.  An empty string
  ///     means that this thread is not associated with a dispatch
  ///     queue.
  virtual std::string
  GetQueueNameForThreadQAddress(Process *process, lldb::addr_t dispatch_qaddr) {
    return "";
  }

  /// Locate a queue ID given a thread's qaddr
  ///
  /// On a system using libdispatch ("Grand Central Dispatch") style queues, a
  /// thread may be associated with a GCD queue or not, and a queue may be
  /// associated with multiple threads. The process/thread must provide a way
  /// to find the "dispatch_qaddr" for each thread, and from that
  /// dispatch_qaddr this Platform method will locate the queue ID and provide
  /// that.
  ///
  /// \param[in] process
  ///     A process is required for reading memory.
  ///
  /// \param[in] dispatch_qaddr
  ///     The dispatch_qaddr for this thread.
  ///
  /// \return
  ///     The queue_id for this thread, if this thread is associated
  ///     with a dispatch queue.  Else LLDB_INVALID_QUEUE_ID is returned.
  virtual lldb::queue_id_t
  GetQueueIDForThreadQAddress(Process *process, lldb::addr_t dispatch_qaddr) {
    return LLDB_INVALID_QUEUE_ID;
  }

  /// Provide a list of trap handler function names for this platform
  ///
  /// The unwinder needs to treat trap handlers specially -- the stack frame
  /// may not be aligned correctly for a trap handler (the kernel often won't
  /// perturb the stack pointer, or won't re-align it properly, in the process
  /// of calling the handler) and the frame above the handler needs to be
  /// treated by the unwinder's "frame 0" rules instead of its "middle of the
  /// stack frame" rules.
  ///
  /// In a user process debugging scenario, the list of trap handlers is
  /// typically just "_sigtramp".
  ///
  /// The Platform base class provides the m_trap_handlers ivar but it does
  /// not populate it.  Subclasses should add the names of the asynchronous
  /// signal handler routines as needed.  For most Unix platforms, add
  /// _sigtramp.
  ///
  /// \return
  ///     A list of symbol names.  The list may be empty.
  virtual const std::vector<ConstString> &GetTrapHandlerSymbolNames();

  /// Find a support executable that may not live within in the standard
  /// locations related to LLDB.
  ///
  /// Executable might exist within the Platform SDK directories, or in
  /// standard tool directories within the current IDE that is running LLDB.
  ///
  /// \param[in] basename
  ///     The basename of the executable to locate in the current
  ///     platform.
  ///
  /// \return
  ///     A FileSpec pointing to the executable on disk, or an invalid
  ///     FileSpec if the executable cannot be found.
  virtual FileSpec LocateExecutable(const char *basename) { return FileSpec(); }

  /// Allow the platform to set preferred memory cache line size. If non-zero
  /// (and the user has not set cache line size explicitly), this value will
  /// be used as the cache line size for memory reads.
  virtual uint32_t GetDefaultMemoryCacheLineSize() { return 0; }

  /// Load a shared library into this process.
  ///
  /// Try and load a shared library into the current process. This call might
  /// fail in the dynamic loader plug-in says it isn't safe to try and load
  /// shared libraries at the moment.
  ///
  /// \param[in] process
  ///     The process to load the image.
  ///
  /// \param[in] local_file
  ///     The file spec that points to the shared library that you want
  ///     to load if the library is located on the host. The library will
  ///     be copied over to the location specified by remote_file or into
  ///     the current working directory with the same filename if the
  ///     remote_file isn't specified.
  ///
  /// \param[in] remote_file
  ///     If local_file is specified then the location where the library
  ///     should be copied over from the host. If local_file isn't
  ///     specified, then the path for the shared library on the target
  ///     what you want to load.
  ///
  /// \param[out] error
  ///     An error object that gets filled in with any errors that
  ///     might occur when trying to load the shared library.
  ///
  /// \return
  ///     A token that represents the shared library that can be
  ///     later used to unload the shared library. A value of
  ///     LLDB_INVALID_IMAGE_TOKEN will be returned if the shared
  ///     library can't be opened.
  uint32_t LoadImage(lldb_private::Process *process,
                     const lldb_private::FileSpec &local_file,
                     const lldb_private::FileSpec &remote_file,
                     lldb_private::Status &error);

  /// Load a shared library specified by base name into this process,
  /// looking by hand along a set of paths.
  ///
  /// \param[in] process
  ///     The process to load the image.
  ///
  /// \param[in] library_name
  ///     The name of the library to look for.  If library_name is an
  ///     absolute path, the basename will be extracted and searched for
  ///     along the paths.  This emulates the behavior of the loader when
  ///     given an install name and a set (e.g. DYLD_LIBRARY_PATH provided) of
  ///     alternate paths.
  ///
  /// \param[in] path_list
  ///     The list of paths to use to search for the library.  First
  ///     match wins.
  ///
  /// \param[out] error
  ///     An error object that gets filled in with any errors that
  ///     might occur when trying to load the shared library.
  ///
  /// \param[out] loaded_path
  ///      If non-null, the path to the dylib that was successfully loaded
  ///      is stored in this path.
  /// 
  /// \return
  ///     A token that represents the shared library which can be
  ///     passed to UnloadImage. A value of
  ///     LLDB_INVALID_IMAGE_TOKEN will be returned if the shared
  ///     library can't be opened.
  uint32_t LoadImageUsingPaths(lldb_private::Process *process,
                               const lldb_private::FileSpec &library_name,
                               const std::vector<std::string> &paths,
                               lldb_private::Status &error,
                               lldb_private::FileSpec *loaded_path);

  virtual uint32_t DoLoadImage(lldb_private::Process *process,
                               const lldb_private::FileSpec &remote_file,
                               const std::vector<std::string> *paths,
                               lldb_private::Status &error,
                               lldb_private::FileSpec *loaded_path = nullptr);

  virtual Status UnloadImage(lldb_private::Process *process,
                             uint32_t image_token);

  /// Connect to all processes waiting for a debugger to attach
  ///
  /// If the platform have a list of processes waiting for a debugger to
  /// connect to them then connect to all of these pending processes.
  ///
  /// \param[in] debugger
  ///     The debugger used for the connect.
  ///
  /// \param[out] error
  ///     If an error occurred during the connect then this object will
  ///     contain the error message.
  ///
  /// \return
  ///     The number of processes we are successfully connected to.
  virtual size_t ConnectToWaitingProcesses(lldb_private::Debugger &debugger,
                                           lldb_private::Status &error);

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 HostInfo::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;
  FileSpec m_working_dir; // The working directory which is used when installing
                          // modules that have no install path set
  std::string m_remote_url;
  std::string m_name;
  llvm::VersionTuple m_os_version;
  ArchSpec
      m_system_arch; // The architecture of the kernel or the remote platform
  typedef std::map<uint32_t, ConstString> IDToNameMap;
  // Mutex for modifying Platform data structures that should only be used for
  // non-reentrant code
  std::mutex m_mutex;
  size_t m_max_uid_name_len;
  size_t m_max_gid_name_len;
  bool m_supports_rsync;
  std::string m_rsync_opts;
  std::string m_rsync_prefix;
  bool m_supports_ssh;
  std::string m_ssh_opts;
  bool m_ignores_remote_hostname;
  std::string m_local_cache_directory;
  std::vector<ConstString> m_trap_handlers;
  bool m_calculated_trap_handlers;
  const std::unique_ptr<ModuleCache> m_module_cache;

  /// Ask the Platform subclass to fill in the list of trap handler names
  ///
  /// For most Unix user process environments, this will be a single function
  /// name, _sigtramp.  More specialized environments may have additional
  /// handler names.  The unwinder code needs to know when a trap handler is
  /// on the stack because the unwind rules for the frame that caused the trap
  /// are different.
  ///
  /// The base class Platform ivar m_trap_handlers should be updated by the
  /// Platform subclass when this method is called.  If there are no
  /// predefined trap handlers, this method may be a no-op.
  virtual void CalculateTrapHandlerSymbolNames() = 0;

  Status GetCachedExecutable(ModuleSpec &module_spec, lldb::ModuleSP &module_sp,
                             const FileSpecList *module_search_paths_ptr,
                             Platform &remote_platform);

  virtual Status DownloadModuleSlice(const FileSpec &src_file_spec,
                                     const uint64_t src_offset,
                                     const uint64_t src_size,
                                     const FileSpec &dst_file_spec);

  virtual Status DownloadSymbolFile(const lldb::ModuleSP &module_sp,
                                    const FileSpec &dst_file_spec);

  virtual const char *GetCacheHostname();

private:
  typedef std::function<Status(const ModuleSpec &)> ModuleResolver;

  Status GetRemoteSharedModule(const ModuleSpec &module_spec, Process *process,
                               lldb::ModuleSP &module_sp,
                               const ModuleResolver &module_resolver,
                               bool *did_create_ptr);

  bool GetCachedSharedModule(const ModuleSpec &module_spec,
                             lldb::ModuleSP &module_sp, bool *did_create_ptr);

  Status LoadCachedExecutable(const ModuleSpec &module_spec,
                              lldb::ModuleSP &module_sp,
                              const FileSpecList *module_search_paths_ptr,
                              Platform &remote_platform);

  FileSpec GetModuleCacheRoot();

  DISALLOW_COPY_AND_ASSIGN(Platform);
};

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

  ~PlatformList() = default;

  void Append(const lldb::PlatformSP &platform_sp, bool set_selected) {
    std::lock_guard<std::recursive_mutex> guard(m_mutex);
    m_platforms.push_back(platform_sp);
    if (set_selected)
      m_selected_platform_sp = m_platforms.back();
  }

  size_t GetSize() {
    std::lock_guard<std::recursive_mutex> guard(m_mutex);
    return m_platforms.size();
  }

  lldb::PlatformSP GetAtIndex(uint32_t idx) {
    lldb::PlatformSP platform_sp;
    {
      std::lock_guard<std::recursive_mutex> guard(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() {
    std::lock_guard<std::recursive_mutex> guard(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) {
      std::lock_guard<std::recursive_mutex> guard(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 std::recursive_mutex m_mutex;
  collection m_platforms;
  lldb::PlatformSP m_selected_platform_sp;

private:
  DISALLOW_COPY_AND_ASSIGN(PlatformList);
};

class OptionGroupPlatformRSync : public lldb_private::OptionGroup {
public:
  OptionGroupPlatformRSync() = default;

  ~OptionGroupPlatformRSync() override = default;

  lldb_private::Status
  SetOptionValue(uint32_t option_idx, llvm::StringRef option_value,
                 ExecutionContext *execution_context) override;

  void OptionParsingStarting(ExecutionContext *execution_context) override;

  llvm::ArrayRef<OptionDefinition> GetDefinitions() override;

  // Instance variables to hold the values for command options.

  bool m_rsync;
  std::string m_rsync_opts;
  std::string m_rsync_prefix;
  bool m_ignores_remote_hostname;

private:
  DISALLOW_COPY_AND_ASSIGN(OptionGroupPlatformRSync);
};

class OptionGroupPlatformSSH : public lldb_private::OptionGroup {
public:
  OptionGroupPlatformSSH() = default;

  ~OptionGroupPlatformSSH() override = default;

  lldb_private::Status
  SetOptionValue(uint32_t option_idx, llvm::StringRef option_value,
                 ExecutionContext *execution_context) override;

  void OptionParsingStarting(ExecutionContext *execution_context) override;

  llvm::ArrayRef<OptionDefinition> GetDefinitions() override;

  // Instance variables to hold the values for command options.

  bool m_ssh;
  std::string m_ssh_opts;

private:
  DISALLOW_COPY_AND_ASSIGN(OptionGroupPlatformSSH);
};

class OptionGroupPlatformCaching : public lldb_private::OptionGroup {
public:
  OptionGroupPlatformCaching() = default;

  ~OptionGroupPlatformCaching() override = default;

  lldb_private::Status
  SetOptionValue(uint32_t option_idx, llvm::StringRef option_value,
                 ExecutionContext *execution_context) override;

  void OptionParsingStarting(ExecutionContext *execution_context) override;

  llvm::ArrayRef<OptionDefinition> GetDefinitions() override;

  // Instance variables to hold the values for command options.

  std::string m_cache_dir;

private:
  DISALLOW_COPY_AND_ASSIGN(OptionGroupPlatformCaching);
};

} // namespace lldb_private

#endif // liblldb_Platform_h_