gdb/process-stratum-target.h

   1 /* Abstract base class inherited by all process_stratum targets
   2
   3    Copyright (C) 2018-2021 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef PROCESS_STRATUM_TARGET_H
  21 #define PROCESS_STRATUM_TARGET_H
  22
  23 #include "target.h"
  24 #include <set>
  25
  26 /* Abstract base class inherited by all process_stratum targets.  */
  27
  28 class process_stratum_target : public target_ops
  29 {
  30 public:
  31   ~process_stratum_target () override = 0;
  32
  33   strata stratum () const final override { return process_stratum; }
  34
  35   /* Return a string representation of this target's open connection.
  36      This string is used to distinguish different instances of a given
  37      target type.  For example, when remote debugging, the target is
  38      called "remote", but since we may have more than one remote
  39      target open, connection_string() returns the connection serial
  40      connection name, e.g., "localhost:10001", "192.168.0.1:20000",
  41      etc.  This string is shown in several places, e.g., in "info
  42      connections" and "info inferiors".  */
  43   virtual const char *connection_string () { return nullptr; }
  44
  45   /* We must default these because they must be implemented by any
  46      target that can run.  */
  47   bool can_async_p () override { return false; }
  48   bool supports_non_stop () override { return false; }
  49   bool supports_disable_randomization () override { return false; }
  50
  51   /* This default implementation returns the inferior's address
  52      space.  */
  53   struct address_space *thread_address_space (ptid_t ptid) override;
  54
  55   /* This default implementation always returns target_gdbarch ().  */
  56   struct gdbarch *thread_architecture (ptid_t ptid) override;
  57
  58   /* Default implementations for process_stratum targets.  Return true
  59      if there's a selected inferior, false otherwise.  */
  60   bool has_all_memory () override;
  61   bool has_memory () override;
  62   bool has_stack () override;
  63   bool has_registers () override;
  64   bool has_execution (inferior *inf) override;
  65
  66   /* Default implementation of follow_exec.
  67
  68      If the current inferior and FOLLOW_INF are different (execution continues
  69      in a new inferior), push this process target to FOLLOW_INF's target stack
  70      and add an initial thread to FOLLOW_INF.  */
  71   void follow_exec (inferior *follow_inf, ptid_t ptid,
  72                     const char *execd_pathname) override;
  73
  74   /* True if any thread is, or may be executing.  We need to track
  75      this separately because until we fully sync the thread list, we
  76      won't know whether the target is fully stopped, even if we see
  77      stop events for all known threads, because any of those threads
  78      may have spawned new threads we haven't heard of yet.  */
  79   bool threads_executing = false;
  80
  81   /* The connection number.  Visible in "info connections".  */
  82   int connection_number = 0;
  83
  84   /* Whether resumed threads must be committed to the target.
  85
  86      When true, resumed threads must be committed to the execution
  87      target.
  88
  89      When false, the target may leave resumed threads stopped when
  90      it's convenient or efficient to do so.  When the core requires
  91      resumed threads to be committed again, this is set back to true
  92      and calls the `commit_resumed` method to allow the target to do
  93      so.
  94
  95      To simplify the implementation of targets, the following methods
  96      are guaranteed to be called with COMMIT_RESUMED_STATE set to
  97      false:
  98
  99        - resume
 100        - stop
 101        - wait
 102
 103      Knowing this, the target doesn't need to implement different
 104      behaviors depending on the COMMIT_RESUMED_STATE, and can simply
 105      assume that it is false.
 106
 107      Targets can take advantage of this to batch resumption requests,
 108      for example.  In that case, the target doesn't actually resume in
 109      its `resume` implementation.  Instead, it takes note of the
 110      resumption intent in `resume` and defers the actual resumption to
 111      `commit_resumed`.  For example, the remote target uses this to
 112      coalesce multiple resumption requests in a single vCont
 113      packet.  */
 114   bool commit_resumed_state = false;
 115 };
 116
 117 /* Downcast TARGET to process_stratum_target.  */
 118
 119 static inline process_stratum_target *
 120 as_process_stratum_target (target_ops *target)
 121 {
 122   gdb_assert (target->stratum () == process_stratum);
 123   return static_cast<process_stratum_target *> (target);
 124 }
 125
 126 /* Return a collection of targets that have non-exited inferiors.  */
 127
 128 extern std::set<process_stratum_target *> all_non_exited_process_targets ();
 129
 130 /* Switch to the first inferior (and program space) of TARGET, and
 131    switch to no thread selected.  */
 132
 133 extern void switch_to_target_no_thread (process_stratum_target *target);
 134
 135 #endif /* !defined (PROCESS_STRATUM_TARGET_H) */