libcc1/connection.hh

   1 /* Plugin connection declarations
   2    Copyright (C) 2014-2022 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef CC1_PLUGIN_CONNECTION_HH
  21 #define CC1_PLUGIN_CONNECTION_HH
  22
  23 #include "status.hh"
  24 #include "callbacks.hh"
  25
  26 namespace cc1_plugin
  27 {
  28   // The connection class represents one side of the connection
  29   // between the gdb-side library and the gcc plugin.  It handles the
  30   // low-level details of reading and writing data.
  31   class connection
  32   {
  33   public:
  34
  35     connection (int fd)
  36       : m_fd (fd),
  37         m_aux_fd (-1),
  38         m_callbacks ()
  39     {
  40     }
  41
  42     connection (int fd, int aux_fd)
  43       : m_fd (fd),
  44         m_aux_fd (aux_fd),
  45         m_callbacks ()
  46     {
  47     }
  48
  49     virtual ~connection () = default;
  50
  51     connection (const connection &) = delete;
  52     connection &operator= (const connection &) = delete;
  53
  54     // Send a single character.  This is used to introduce various
  55     // higher-level protocol elements.
  56     status send (char c);
  57
  58     // Send data in bulk.
  59     status send (const void *buf, int len);
  60
  61     // Read a single byte from the connection and verify that it
  62     // matches the argument C.
  63     status require (char c);
  64
  65     // Read data in bulk.
  66     status get (void *buf, int len);
  67
  68     // This is called after a query (remote function call) has been
  69     // sent to the remote.  It waits for a response packet.  The
  70     // response character is read before returning.  Any query packets
  71     // sent from the remote while waiting for a response are handled
  72     // by this function.
  73     status wait_for_result ()
  74     {
  75       return do_wait (true);
  76     }
  77
  78     // Read and respond to query packets sent by the remote.  This
  79     // function returns when the connection is closed.
  80     status wait_for_query ()
  81     {
  82       return do_wait (false);
  83     }
  84
  85     // Register a callback with this connection.  NAME is the name of
  86     // the method being registered.  FUNC is the function.  It must
  87     // know how to decode its own arguments.  When a query packet is
  88     // received by one of the wait_* methods, the corresponding
  89     // callback is invoked.
  90     void add_callback (const char *name, callback_ftype *func)
  91     {
  92       m_callbacks.add_callback (name, func);
  93     }
  94
  95     virtual void print (const char *)
  96     {
  97     }
  98
  99   private:
 100
 101     // Helper function for the wait_* methods.
 102     status do_wait (bool);
 103
 104     // The file descriptor.
 105     int m_fd;
 106
 107     // An auxiliary file descriptor, or -1 if none.
 108     int m_aux_fd;
 109
 110     // Callbacks associated with this connection.
 111     callbacks m_callbacks;
 112   };
 113 }
 114
 115 #endif // CC1_PLUGIN_CONNECTION_HH