gdb/target/target.h

   1 /* Declarations for common target functions.
   2
   3    Copyright (C) 1986-2020 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 TARGET_TARGET_H
  21 #define TARGET_TARGET_H
  22
  23 #include "target/waitstatus.h"
  24 /* This header is a stopgap until more code is shared.  */
  25
  26 /* Read LEN bytes of target memory at address MEMADDR, placing the
  27    results in GDB's memory at MYADDR.  Return zero for success,
  28    nonzero if any error occurs.  This function must be provided by
  29    the client.  Implementations of this function may define and use
  30    their own error codes, but functions in the common, nat and target
  31    directories must treat the return code as opaque.  No guarantee is
  32    made about the contents of the data at MYADDR if any error
  33    occurs.  */
  34
  35 extern int target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr,
  36                                ssize_t len);
  37
  38 /* Read an unsigned 32-bit integer in the target's format from target
  39    memory at address MEMADDR, storing the result in GDB's format in
  40    GDB's memory at RESULT.  Return zero for success, nonzero if any
  41    error occurs.  This function must be provided by the client.
  42    Implementations of this function may define and use their own error
  43    codes, but functions in the common, nat and target directories must
  44    treat the return code as opaque.  No guarantee is made about the
  45    contents of the data at RESULT if any error occurs.  */
  46
  47 extern int target_read_uint32 (CORE_ADDR memaddr, uint32_t *result);
  48
  49 /* Write LEN bytes from MYADDR to target memory at address MEMADDR.
  50    Return zero for success, nonzero if any error occurs.  This
  51    function must be provided by the client.  Implementations of this
  52    function may define and use their own error codes, but functions
  53    in the common, nat and target directories must treat the return
  54    code as opaque.  No guarantee is made about the contents of the
  55    data at MEMADDR if any error occurs.  */
  56
  57 extern int target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr,
  58                                 ssize_t len);
  59
  60 /* Cause the target to stop in a continuable fashion--for instance,
  61    under Unix, this should act like SIGSTOP--and wait for the target
  62    to be stopped before returning.  This function must be provided by
  63    the client.  */
  64
  65 extern void target_stop_and_wait (ptid_t ptid);
  66
  67 /* Restart a target previously stopped.  No signal is delivered to the
  68    target.  This function must be provided by the client.  */
  69
  70 extern void target_continue_no_signal (ptid_t ptid);
  71
  72 /* Restart a target previously stopped.  SIGNAL is delivered to the
  73    target.  This function must be provided by the client.  */
  74
  75 extern void target_continue (ptid_t ptid, enum gdb_signal signal);
  76
  77 /* Wait for process pid to do something.  PTID = -1 to wait for any
  78    pid to do something.  Return pid of child, or -1 in case of error;
  79    store status through argument pointer STATUS.  Note that it is
  80    _NOT_ OK to throw_exception() out of target_wait() without popping
  81    the debugging target from the stack; GDB isn't prepared to get back
  82    to the prompt with a debugging target but without the frame cache,
  83    stop_pc, etc., set up.  OPTIONS is a bitwise OR of TARGET_W*
  84    options.  */
  85
  86 extern ptid_t target_wait (ptid_t ptid, struct target_waitstatus *status,
  87                            int options);
  88
  89 /* The inferior process has died.  Do what is right.  */
  90
  91 extern void target_mourn_inferior (ptid_t ptid);
  92
  93 /* Return 1 if this target can debug multiple processes
  94    simultaneously, zero otherwise.  */
  95
  96 extern int target_supports_multi_process (void);
  97
  98 /* Possible terminal states.  */
  99
 100 enum class target_terminal_state
 101   {
 102     /* The inferior's terminal settings are in effect.  */
 103     is_inferior = 0,
 104
 105     /* Some of our terminal settings are in effect, enough to get
 106        proper output.  */
 107     is_ours_for_output = 1,
 108
 109     /* Our terminal settings are in effect, for output and input.  */
 110     is_ours = 2
 111   };
 112
 113 /* Represents the state of the target terminal.  */
 114 class target_terminal
 115 {
 116 public:
 117
 118   target_terminal () = delete;
 119   ~target_terminal () = delete;
 120   DISABLE_COPY_AND_ASSIGN (target_terminal);
 121
 122   /* Initialize the terminal settings we record for the inferior,
 123      before we actually run the inferior.  */
 124   static void init ();
 125
 126   /* Put the current inferior's terminal settings into effect.  This
 127      is preparation for starting or resuming the inferior.  This is a
 128      no-op unless called with the main UI as current UI.  */
 129   static void inferior ();
 130
 131   /* Put our terminal settings into effect.  First record the inferior's
 132      terminal settings so they can be restored properly later.  This is
 133      a no-op unless called with the main UI as current UI.  */
 134   static void ours ();
 135
 136   /* Put some of our terminal settings into effect, enough to get proper
 137      results from our output, but do not change into or out of RAW mode
 138      so that no input is discarded.  This is a no-op if terminal_ours
 139      was most recently called.  This is a no-op unless called with the main
 140      UI as current UI.  */
 141   static void ours_for_output ();
 142
 143   /* Restore terminal settings of inferiors that are in
 144      is_ours_for_output state back to "inferior".  Used when we need
 145      to temporarily switch to is_ours_for_output state.  */
 146   static void restore_inferior ();
 147
 148   /* Returns true if the terminal settings of the inferior are in
 149      effect.  */
 150   static bool is_inferior ()
 151   {
 152     return m_terminal_state == target_terminal_state::is_inferior;
 153   }
 154
 155   /* Returns true if our terminal settings are in effect.  */
 156   static bool is_ours ()
 157   {
 158     return m_terminal_state == target_terminal_state::is_ours;
 159   }
 160
 161   /* Returns true if our terminal settings are in effect.  */
 162   static bool is_ours_for_output ()
 163   {
 164     return m_terminal_state == target_terminal_state::is_ours_for_output;
 165   }
 166
 167   /* Print useful information about our terminal status, if such a thing
 168      exists.  */
 169   static void info (const char *arg, int from_tty);
 170
 171 public:
 172
 173   /* A class that restores the state of the terminal to the current
 174      state.  */
 175   class scoped_restore_terminal_state
 176   {
 177   public:
 178
 179     scoped_restore_terminal_state ()
 180       : m_state (m_terminal_state)
 181     {
 182     }
 183
 184     ~scoped_restore_terminal_state ()
 185     {
 186       switch (m_state)
 187         {
 188         case target_terminal_state::is_ours:
 189           ours ();
 190           break;
 191         case target_terminal_state::is_ours_for_output:
 192           ours_for_output ();
 193           break;
 194         case target_terminal_state::is_inferior:
 195           restore_inferior ();
 196           break;
 197         }
 198     }
 199
 200     DISABLE_COPY_AND_ASSIGN (scoped_restore_terminal_state);
 201
 202   private:
 203
 204     target_terminal_state m_state;
 205   };
 206
 207 private:
 208
 209   static target_terminal_state m_terminal_state;
 210 };
 211
 212 #endif /* TARGET_TARGET_H */