1 /* Connect implementation 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 #include <cc1plugin-config.h> 21 #include <string> 22 #include <unistd.h> 23 #include <sys/types.h> 24 #include <string.h> 25 #include <errno.h> 26 #include "marshall.hh" 27 #include "connection.hh" 28 #include "rpc.hh" 29 30 cc1_plugin::status 31 cc1_plugin::connection::send (char c) 32 { 33 if (write (m_fd, &c, 1) != 1) 34 return FAIL; 35 return OK; 36 } 37 38 cc1_plugin::status 39 cc1_plugin::connection::send (const void *buf, int len) 40 { 41 if (write (m_fd, buf, len) != len) 42 return FAIL; 43 return OK; 44 } 45 46 cc1_plugin::status 47 cc1_plugin::connection::require (char c) 48 { 49 char result; 50 51 if (read (m_fd, &result, 1) != 1 52 || result != c) 53 return FAIL; 54 55 return OK; 56 } 57 58 cc1_plugin::status 59 cc1_plugin::connection::get (void *buf, int len) 60 { 61 if (read (m_fd, buf, len) != len) 62 return FAIL; 63 return OK; 64 } 65 66 cc1_plugin::status 67 cc1_plugin::connection::do_wait (bool want_result) 68 { 69 while (true) 70 { 71 char result; 72 fd_set read_set; 73 74 FD_ZERO (&read_set); 75 FD_SET (m_fd, &read_set); 76 if (m_aux_fd != -1) 77 FD_SET (m_aux_fd, &read_set); 78 79 int nfds = select (FD_SETSIZE, &read_set, NULL, NULL, NULL); 80 if (nfds == -1) 81 { 82 if (errno == EINTR) 83 continue; 84 return FAIL; 85 } 86 87 // We have to check the stderr fd first, to avoid a possible 88 // blocking scenario when do_wait is called reentrantly. In 89 // such a call, if we handle the primary fd first, then we may 90 // re-enter this function, read from gcc's stderr, causing the 91 // outer invocation of this function to block when trying to 92 // read. 93 if (m_aux_fd != -1 && FD_ISSET (m_aux_fd, &read_set)) 94 { 95 char buf[1024]; 96 int n = read (m_aux_fd, buf, sizeof (buf) - 1); 97 if (n < 0) 98 return FAIL; 99 if (n > 0) 100 { 101 buf[n] = '\0'; 102 print (buf); 103 } 104 } 105 106 if (FD_ISSET (m_fd, &read_set)) 107 { 108 int n = read (m_fd, &result, 1); 109 if (n == 0) 110 return want_result ? FAIL : OK; 111 if (n != 1) 112 return FAIL; 113 114 switch (result) 115 { 116 case 'R': 117 // The reply is ready; the caller will unmarshall it. 118 return want_result ? OK : FAIL; 119 120 case 'Q': 121 // While waiting for a reply, the other side made a method 122 // call. 123 { 124 // Use an argument_wrapper here to simplify management 125 // of the string's lifetime. 126 argument_wrapper<char *> method_name; 127 128 if (!method_name.unmarshall (this)) 129 return FAIL; 130 131 callback_ftype *callback 132 = m_callbacks.find_callback (method_name.get ()); 133 // The call to CALLBACK is where we may end up in a 134 // reentrant call. 135 if (callback == NULL || !callback (this)) 136 return FAIL; 137 } 138 break; 139 140 default: 141 return FAIL; 142 } 143 } 144 } 145 } 146