gdb/target/target.h

   1 /* Declarations for common target functions.
   2
   3    Copyright (C) 1986-2018 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_COMMON_H
  21 #define TARGET_COMMON_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 /* Represents the state of the target terminal.  */
  99 class target_terminal
 100 {
 101 public:
 102
 103   target_terminal () = delete;
 104   ~target_terminal () = delete;
 105   DISABLE_COPY_AND_ASSIGN (target_terminal);
 106
 107   /* Initialize the terminal settings we record for the inferior,
 108      before we actually run the inferior.  */
 109   static void init ();
 110
 111   /* Put the inferior's terminal settings into effect.  This is
 112      preparation for starting or resuming the inferior.  This is a no-op
 113      unless called with the main UI as current UI.  */
 114   static void inferior ();
 115
 116   /* Put our terminal settings into effect.  First record the inferior's
 117      terminal settings so they can be restored properly later.  This is
 118      a no-op unless called with the main UI as current UI.  */
 119   static void ours ();
 120
 121   /* Put some of our terminal settings into effect, enough to get proper
 122      results from our output, but do not change into or out of RAW mode
 123      so that no input is discarded.  This is a no-op if terminal_ours
 124      was most recently called.  This is a no-op unless called with the main
 125      UI as current UI.  */
 126   static void ours_for_output ();
 127
 128   /* Returns true if the terminal settings of the inferior are in
 129      effect.  */
 130   static bool is_inferior ()
 131   {
 132     return terminal_state == terminal_is_inferior;
 133   }
 134
 135   /* Returns true if our terminal settings are in effect.  */
 136   static bool is_ours ()
 137   {
 138     return terminal_state == terminal_is_ours;
 139   }
 140
 141   /* Print useful information about our terminal status, if such a thing
 142      exists.  */
 143   static void info (const char *arg, int from_tty);
 144
 145 private:
 146
 147   /* Possible terminal states.  */
 148
 149   enum terminal_state
 150     {
 151      /* The inferior's terminal settings are in effect.  */
 152      terminal_is_inferior = 0,
 153
 154      /* Some of our terminal settings are in effect, enough to get
 155         proper output.  */
 156      terminal_is_ours_for_output = 1,
 157
 158      /* Our terminal settings are in effect, for output and input.  */
 159      terminal_is_ours = 2
 160     };
 161
 162 public:
 163
 164   /* A class that restores the state of the terminal to the current
 165      state.  */
 166   class scoped_restore_terminal_state
 167   {
 168   public:
 169
 170     scoped_restore_terminal_state ()
 171       : m_state (terminal_state)
 172     {
 173     }
 174
 175     ~scoped_restore_terminal_state ()
 176     {
 177       switch (m_state)
 178         {
 179         case terminal_is_ours:
 180           ours ();
 181           break;
 182         case terminal_is_ours_for_output:
 183           ours_for_output ();
 184           break;
 185         case terminal_is_inferior:
 186           inferior ();
 187           break;
 188         }
 189     }
 190
 191     DISABLE_COPY_AND_ASSIGN (scoped_restore_terminal_state);
 192
 193   private:
 194
 195     target_terminal::terminal_state m_state;
 196   };
 197
 198 private:
 199
 200   static terminal_state terminal_state;
 201 };
 202
 203 #endif /* TARGET_COMMON_H */