1 /* Implementation of the EXECUTE_COMMAND_LINE intrinsic. 2 Copyright (C) 2009-2019 Free Software Foundation, Inc. 3 Contributed by François-Xavier Coudert. 4 5 This file is part of the GNU Fortran runtime library (libgfortran). 6 7 Libgfortran is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 Libgfortran is distributed in the hope that it will be useful, but WITHOUT 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 Under Section 7 of GPL version 3, you are granted additional 18 permissions described in the GCC Runtime Library Exception, version 19 3.1, as published by the Free Software Foundation. 20 21 You should have received a copy of the GNU General Public License and 22 a copy of the GCC Runtime Library Exception along with this program; 23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 <http://www.gnu.org/licenses/>. */ 25 26 #include "libgfortran.h" 27 #include <string.h> 28 29 #ifdef HAVE_UNISTD_H 30 #include <unistd.h> 31 #endif 32 #ifdef HAVE_SYS_WAIT_H 33 #include <sys/wait.h> 34 #endif 35 #ifdef HAVE_POSIX_SPAWN 36 #include <spawn.h> 37 extern char **environ; 38 #endif 39 #if defined(HAVE_POSIX_SPAWN) || defined(HAVE_FORK) 40 #include <signal.h> 41 #endif 42 43 enum { EXEC_SYNCHRONOUS = -2, EXEC_NOERROR = 0, EXEC_SYSTEMFAILED, 44 EXEC_CHILDFAILED, EXEC_INVALIDCOMMAND }; 45 static const char *cmdmsg_values[] = 46 { "", 47 "Termination status of the command-language interpreter cannot be obtained", 48 "Execution of child process impossible", 49 "Invalid command line" }; 50 51 52 53 static void 54 set_cmdstat (int *cmdstat, int value) 55 { 56 if (cmdstat) 57 *cmdstat = value; 58 else if (value > EXEC_NOERROR) 59 { 60 #define MSGLEN 200 61 char msg[MSGLEN] = "EXECUTE_COMMAND_LINE: "; 62 strncat (msg, cmdmsg_values[value], MSGLEN - strlen(msg) - 1); 63 runtime_error ("%s", msg); 64 } 65 } 66 67 68 #if defined(HAVE_WAITPID) && defined(HAVE_SIGACTION) 69 static void 70 sigchld_handler (int signum __attribute__((unused))) 71 { 72 while (waitpid ((pid_t)(-1), NULL, WNOHANG) > 0) {} 73 } 74 #endif 75 76 static void 77 execute_command_line (const char *command, bool wait, int *exitstat, 78 int *cmdstat, char *cmdmsg, 79 gfc_charlen_type command_len, 80 gfc_charlen_type cmdmsg_len) 81 { 82 /* Transform the Fortran string to a C string. */ 83 char *cmd = fc_strdup (command, command_len); 84 85 /* Flush all I/O units before executing the command. */ 86 flush_all_units(); 87 88 #if defined(HAVE_POSIX_SPAWN) || defined(HAVE_FORK) 89 if (!wait) 90 { 91 /* Asynchronous execution. */ 92 pid_t pid; 93 94 set_cmdstat (cmdstat, EXEC_NOERROR); 95 96 #if defined(HAVE_SIGACTION) && defined(HAVE_WAITPID) 97 static bool sig_init_saved; 98 bool sig_init = __atomic_load_n (&sig_init_saved, __ATOMIC_RELAXED); 99 if (!sig_init) 100 { 101 struct sigaction sa; 102 sa.sa_handler = &sigchld_handler; 103 sigemptyset(&sa.sa_mask); 104 sa.sa_flags = SA_RESTART | SA_NOCLDSTOP; 105 sigaction(SIGCHLD, &sa, 0); 106 __atomic_store_n (&sig_init_saved, true, __ATOMIC_RELAXED); 107 } 108 #endif 109 110 #ifdef HAVE_POSIX_SPAWN 111 const char * const argv[] = {"sh", "-c", cmd, NULL}; 112 if (posix_spawn (&pid, "/bin/sh", NULL, NULL, 113 (char * const* restrict) argv, environ)) 114 set_cmdstat (cmdstat, EXEC_CHILDFAILED); 115 #elif defined(HAVE_FORK) 116 if ((pid = fork()) < 0) 117 set_cmdstat (cmdstat, EXEC_CHILDFAILED); 118 else if (pid == 0) 119 { 120 /* Child process. */ 121 int res = system (cmd); 122 _exit (WIFEXITED(res) ? WEXITSTATUS(res) : res); 123 } 124 #endif 125 } 126 else 127 #endif 128 { 129 /* Synchronous execution. */ 130 int res = system (cmd); 131 132 if (res == -1) 133 set_cmdstat (cmdstat, EXEC_SYSTEMFAILED); 134 #if !defined(HAVE_POSIX_SPAWN) && !defined(HAVE_FORK) 135 else if (!wait) 136 set_cmdstat (cmdstat, EXEC_SYNCHRONOUS); 137 #endif 138 else if (res == 127 || res == 126 139 #if defined(WEXITSTATUS) && defined(WIFEXITED) 140 || (WIFEXITED(res) && WEXITSTATUS(res) == 127) 141 || (WIFEXITED(res) && WEXITSTATUS(res) == 126) 142 #endif 143 ) 144 /* Shell return codes 126 and 127 mean that the command line could 145 not be executed for various reasons. */ 146 set_cmdstat (cmdstat, EXEC_INVALIDCOMMAND); 147 else 148 set_cmdstat (cmdstat, EXEC_NOERROR); 149 150 if (res != -1) 151 { 152 #if defined(WEXITSTATUS) && defined(WIFEXITED) 153 *exitstat = WIFEXITED(res) ? WEXITSTATUS(res) : res; 154 #else 155 *exitstat = res; 156 #endif 157 } 158 } 159 160 free (cmd); 161 162 /* Now copy back to the Fortran string if needed. */ 163 if (cmdstat && *cmdstat > EXEC_NOERROR && cmdmsg) 164 fstrcpy (cmdmsg, cmdmsg_len, cmdmsg_values[*cmdstat], 165 strlen (cmdmsg_values[*cmdstat])); 166 } 167 168 169 extern void 170 execute_command_line_i4 (const char *command, GFC_LOGICAL_4 *wait, 171 GFC_INTEGER_4 *exitstat, GFC_INTEGER_4 *cmdstat, 172 char *cmdmsg, gfc_charlen_type command_len, 173 gfc_charlen_type cmdmsg_len); 174 export_proto(execute_command_line_i4); 175 176 void 177 execute_command_line_i4 (const char *command, GFC_LOGICAL_4 *wait, 178 GFC_INTEGER_4 *exitstat, GFC_INTEGER_4 *cmdstat, 179 char *cmdmsg, gfc_charlen_type command_len, 180 gfc_charlen_type cmdmsg_len) 181 { 182 bool w = wait ? *wait : true; 183 int estat, estat_initial, cstat; 184 185 if (exitstat) 186 estat_initial = estat = *exitstat; 187 188 execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL, 189 cmdmsg, command_len, cmdmsg_len); 190 191 if (exitstat && estat != estat_initial) 192 *exitstat = estat; 193 if (cmdstat) 194 *cmdstat = cstat; 195 } 196 197 198 extern void 199 execute_command_line_i8 (const char *command, GFC_LOGICAL_8 *wait, 200 GFC_INTEGER_8 *exitstat, GFC_INTEGER_8 *cmdstat, 201 char *cmdmsg, gfc_charlen_type command_len, 202 gfc_charlen_type cmdmsg_len); 203 export_proto(execute_command_line_i8); 204 205 void 206 execute_command_line_i8 (const char *command, GFC_LOGICAL_8 *wait, 207 GFC_INTEGER_8 *exitstat, GFC_INTEGER_8 *cmdstat, 208 char *cmdmsg, gfc_charlen_type command_len, 209 gfc_charlen_type cmdmsg_len) 210 { 211 bool w = wait ? *wait : true; 212 int estat, estat_initial, cstat; 213 214 if (exitstat) 215 estat_initial = estat = *exitstat; 216 217 execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL, 218 cmdmsg, command_len, cmdmsg_len); 219 220 if (exitstat && estat != estat_initial) 221 *exitstat = estat; 222 if (cmdstat) 223 *cmdstat = cstat; 224 } 225