1 //===- llvm/System/Unix/Program.cpp -----------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Unix specific portion of the Program class.
12 //===----------------------------------------------------------------------===//
14 //===----------------------------------------------------------------------===//
15 //=== WARNING: Implementation here must contain only generic UNIX code that
16 //=== is guaranteed to work on *all* UNIX variants.
17 //===----------------------------------------------------------------------===//
19 #include <llvm/Config/config.h>
24 #if HAVE_SYS_RESOURCE_H
25 #include <sys/resource.h>
33 #ifdef HAVE_POSIX_SPAWN
35 #if !defined(__APPLE__)
36 extern char **environ;
38 #include <crt_externs.h> // _NSGetEnviron
45 Program::Program() : Data_(0) {}
47 Program::~Program() {}
49 unsigned Program::GetPid() const {
50 uint64_t pid = reinterpret_cast<uint64_t>(Data_);
51 return static_cast<unsigned>(pid);
54 // This function just uses the PATH environment variable to find the program.
56 Program::FindProgramByName(const std::string& progName) {
58 // Check some degenerate cases
59 if (progName.length() == 0) // no program
62 if (!temp.set(progName)) // invalid name
64 // Use the given path verbatim if it contains any slashes; this matches
65 // the behavior of sh(1) and friends.
66 if (progName.find('/') != std::string::npos)
69 // At this point, the file name does not contain slashes. Search for it
70 // through the directories specified in the PATH environment variable.
72 // Get the path. If its empty, we can't do anything to find it.
73 const char *PathStr = getenv("PATH");
77 // Now we have a colon separated list of directories to search; try them.
78 size_t PathLen = strlen(PathStr);
80 // Find the first colon...
81 const char *Colon = std::find(PathStr, PathStr+PathLen, ':');
83 // Check to see if this first directory contains the executable...
85 if (FilePath.set(std::string(PathStr,Colon))) {
86 FilePath.appendComponent(progName);
87 if (FilePath.canExecute())
88 return FilePath; // Found the executable!
91 // Nope it wasn't in this directory, check the next path in the list!
92 PathLen -= Colon-PathStr;
95 // Advance past duplicate colons
96 while (*PathStr == ':') {
104 static bool RedirectIO(const Path *Path, int FD, std::string* ErrMsg) {
105 if (Path == 0) // Noop
109 // Redirect empty paths to /dev/null
112 File = Path->c_str();
115 int InFD = open(File, FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666);
117 MakeErrMsg(ErrMsg, "Cannot open file '" + std::string(File) + "' for "
118 + (FD == 0 ? "input" : "output"));
122 // Install it as the requested FD
123 if (dup2(InFD, FD) == -1) {
124 MakeErrMsg(ErrMsg, "Cannot dup2");
128 close(InFD); // Close the original FD
132 #ifdef HAVE_POSIX_SPAWN
133 static bool RedirectIO_PS(const Path *Path, int FD, std::string *ErrMsg,
134 posix_spawn_file_actions_t &FileActions) {
135 if (Path == 0) // Noop
139 // Redirect empty paths to /dev/null
142 File = Path->c_str();
144 if (int Err = posix_spawn_file_actions_addopen(&FileActions, FD,
145 File, FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666))
146 return MakeErrMsg(ErrMsg, "Cannot dup2", Err);
151 static void TimeOutHandler(int Sig) {
154 static void SetMemoryLimits (unsigned size)
156 #if HAVE_SYS_RESOURCE_H && HAVE_GETRLIMIT && HAVE_SETRLIMIT
158 __typeof__ (r.rlim_cur) limit = (__typeof__ (r.rlim_cur)) (size) * 1048576;
161 getrlimit (RLIMIT_DATA, &r);
163 setrlimit (RLIMIT_DATA, &r);
165 // Resident set size.
166 getrlimit (RLIMIT_RSS, &r);
168 setrlimit (RLIMIT_RSS, &r);
170 #ifdef RLIMIT_AS // e.g. NetBSD doesn't have it.
172 getrlimit (RLIMIT_AS, &r);
174 setrlimit (RLIMIT_AS, &r);
180 Program::Execute(const Path &path, const char **args, const char **envp,
181 const Path **redirects, unsigned memoryLimit,
182 std::string *ErrMsg) {
183 // If this OS has posix_spawn and there is no memory limit being implied, use
184 // posix_spawn. It is more efficient than fork/exec.
185 #ifdef HAVE_POSIX_SPAWN
186 if (memoryLimit == 0) {
187 posix_spawn_file_actions_t FileActions;
188 posix_spawn_file_actions_init(&FileActions);
191 // Redirect stdin/stdout.
192 if (RedirectIO_PS(redirects[0], 0, ErrMsg, FileActions) ||
193 RedirectIO_PS(redirects[1], 1, ErrMsg, FileActions))
195 if (redirects[1] == 0 || redirects[2] == 0 ||
196 *redirects[1] != *redirects[2]) {
197 // Just redirect stderr
198 if (RedirectIO_PS(redirects[2], 2, ErrMsg, FileActions)) return false;
200 // If stdout and stderr should go to the same place, redirect stderr
201 // to the FD already open for stdout.
202 if (int Err = posix_spawn_file_actions_adddup2(&FileActions, 1, 2))
203 return !MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout", Err);
208 #if !defined(__APPLE__)
209 envp = (const char**)environ;
211 envp = (const char**)*_NSGetEnviron(); // environ is missing in dylibs.
215 int Err = posix_spawn(&PID, path.c_str(), &FileActions,
216 /*attrp*/0, (char**)args, (char**)envp);
218 posix_spawn_file_actions_destroy(&FileActions);
221 return !MakeErrMsg(ErrMsg, "posix_spawn failed", Err);
223 Data_ = reinterpret_cast<void*>(PID);
228 if (!path.canExecute()) {
230 *ErrMsg = path.str() + " is not executable";
234 // Create a child process.
237 // An error occured: Return to the caller.
239 MakeErrMsg(ErrMsg, "Couldn't fork");
242 // Child process: Execute the program.
244 // Redirect file descriptors...
247 if (RedirectIO(redirects[0], 0, ErrMsg)) { return false; }
249 if (RedirectIO(redirects[1], 1, ErrMsg)) { return false; }
250 if (redirects[1] && redirects[2] &&
251 *(redirects[1]) == *(redirects[2])) {
252 // If stdout and stderr should go to the same place, redirect stderr
253 // to the FD already open for stdout.
254 if (-1 == dup2(1,2)) {
255 MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout");
259 // Just redirect stderr
260 if (RedirectIO(redirects[2], 2, ErrMsg)) { return false; }
265 if (memoryLimit!=0) {
266 SetMemoryLimits(memoryLimit);
271 execve(path.c_str(), (char**)args, (char**)envp);
273 execv(path.c_str(), (char**)args);
274 // If the execve() failed, we should exit. Follow Unix protocol and
275 // return 127 if the executable was not found, and 126 otherwise.
276 // Use _exit rather than exit so that atexit functions and static
277 // object destructors cloned from the parent process aren't
278 // redundantly run, and so that any data buffered in stdio buffers
279 // cloned from the parent aren't redundantly written out.
280 _exit(errno == ENOENT ? 127 : 126);
283 // Parent process: Break out of the switch to do our processing.
288 Data_ = reinterpret_cast<void*>(child);
294 Program::Wait(unsigned secondsToWait,
297 #ifdef HAVE_SYS_WAIT_H
298 struct sigaction Act, Old;
301 MakeErrMsg(ErrMsg, "Process not started!");
305 // Install a timeout handler. The handler itself does nothing, but the simple
306 // fact of having a handler at all causes the wait below to return with EINTR,
307 // unlike if we used SIG_IGN.
310 Act.sa_sigaction = 0;
312 Act.sa_handler = TimeOutHandler;
313 sigemptyset(&Act.sa_mask);
315 sigaction(SIGALRM, &Act, &Old);
316 alarm(secondsToWait);
319 // Parent process: Wait for the child process to terminate.
321 uint64_t pid = reinterpret_cast<uint64_t>(Data_);
322 pid_t child = static_cast<pid_t>(pid);
323 while (waitpid(pid, &status, 0) != child)
324 if (secondsToWait && errno == EINTR) {
326 kill(child, SIGKILL);
328 // Turn off the alarm and restore the signal handler
330 sigaction(SIGALRM, &Old, 0);
332 // Wait for child to die
333 if (wait(&status) != child)
334 MakeErrMsg(ErrMsg, "Child timed out but wouldn't die");
336 MakeErrMsg(ErrMsg, "Child timed out", 0);
338 return -1; // Timeout detected
339 } else if (errno != EINTR) {
340 MakeErrMsg(ErrMsg, "Error waiting for child process");
344 // We exited normally without timeout, so turn off the timer.
347 sigaction(SIGALRM, &Old, 0);
350 // Return the proper exit status. 0=success, >0 is programs' exit status,
351 // <0 means a signal was returned, -9999999 means the program dumped core.
353 if (WIFEXITED(status))
354 result = WEXITSTATUS(status);
355 else if (WIFSIGNALED(status))
356 result = 0 - WTERMSIG(status);
358 else if (WCOREDUMP(status))
359 result |= 0x01000000;
369 Program::Kill(std::string* ErrMsg) {
371 MakeErrMsg(ErrMsg, "Process not started!");
375 uint64_t pid64 = reinterpret_cast<uint64_t>(Data_);
376 pid_t pid = static_cast<pid_t>(pid64);
378 if (kill(pid, SIGKILL) != 0) {
379 MakeErrMsg(ErrMsg, "The process couldn't be killed!");
386 bool Program::ChangeStdinToBinary(){
387 // Do nothing, as Unix doesn't differentiate between text and binary.
391 bool Program::ChangeStdoutToBinary(){
392 // Do nothing, as Unix doesn't differentiate between text and binary.
396 bool Program::ChangeStderrToBinary(){
397 // Do nothing, as Unix doesn't differentiate between text and binary.