1 //===- llvm/Support/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 //===----------------------------------------------------------------------===//
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/FileSystem.h"
22 #include <llvm/Config/config.h>
26 #if HAVE_SYS_RESOURCE_H
27 #include <sys/resource.h>
38 #ifdef HAVE_POSIX_SPAWN
40 #if !defined(__APPLE__)
41 extern char **environ;
43 #include <crt_externs.h> // _NSGetEnviron
50 ProcessInfo::ProcessInfo() : Pid(0), ReturnCode(0) {}
52 // This function just uses the PATH environment variable to find the program.
54 sys::FindProgramByName(const std::string& progName) {
56 // Check some degenerate cases
57 if (progName.length() == 0) // no program
59 std::string temp = progName;
60 // Use the given path verbatim if it contains any slashes; this matches
61 // the behavior of sh(1) and friends.
62 if (progName.find('/') != std::string::npos)
65 // At this point, the file name is valid and does not contain slashes. Search
66 // for it through the directories specified in the PATH environment variable.
68 // Get the path. If its empty, we can't do anything to find it.
69 const char *PathStr = getenv("PATH");
73 // Now we have a colon separated list of directories to search; try them.
74 size_t PathLen = strlen(PathStr);
76 // Find the first colon...
77 const char *Colon = std::find(PathStr, PathStr+PathLen, ':');
79 // Check to see if this first directory contains the executable...
80 SmallString<128> FilePath(PathStr,Colon);
81 sys::path::append(FilePath, progName);
82 if (sys::fs::can_execute(Twine(FilePath)))
83 return FilePath.str(); // Found the executable!
85 // Nope it wasn't in this directory, check the next path in the list!
86 PathLen -= Colon-PathStr;
89 // Advance past duplicate colons
90 while (*PathStr == ':') {
98 static bool RedirectIO(const StringRef *Path, int FD, std::string* ErrMsg) {
99 if (Path == 0) // Noop
103 // Redirect empty paths to /dev/null
109 int InFD = open(File.c_str(), FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666);
111 MakeErrMsg(ErrMsg, "Cannot open file '" + File + "' for "
112 + (FD == 0 ? "input" : "output"));
116 // Install it as the requested FD
117 if (dup2(InFD, FD) == -1) {
118 MakeErrMsg(ErrMsg, "Cannot dup2");
122 close(InFD); // Close the original FD
126 #ifdef HAVE_POSIX_SPAWN
127 static bool RedirectIO_PS(const std::string *Path, int FD, std::string *ErrMsg,
128 posix_spawn_file_actions_t *FileActions) {
129 if (Path == 0) // Noop
133 // Redirect empty paths to /dev/null
136 File = Path->c_str();
138 if (int Err = posix_spawn_file_actions_addopen(
139 FileActions, FD, File,
140 FD == 0 ? O_RDONLY : O_WRONLY | O_CREAT, 0666))
141 return MakeErrMsg(ErrMsg, "Cannot dup2", Err);
146 static void TimeOutHandler(int Sig) {
149 static void SetMemoryLimits (unsigned size)
151 #if HAVE_SYS_RESOURCE_H && HAVE_GETRLIMIT && HAVE_SETRLIMIT
153 __typeof__ (r.rlim_cur) limit = (__typeof__ (r.rlim_cur)) (size) * 1048576;
156 getrlimit (RLIMIT_DATA, &r);
158 setrlimit (RLIMIT_DATA, &r);
160 // Resident set size.
161 getrlimit (RLIMIT_RSS, &r);
163 setrlimit (RLIMIT_RSS, &r);
165 #ifdef RLIMIT_AS // e.g. NetBSD doesn't have it.
166 // Don't set virtual memory limit if built with any Sanitizer. They need 80Tb
167 // of virtual memory for shadow memory mapping.
168 #if !LLVM_MEMORY_SANITIZER_BUILD && !LLVM_ADDRESS_SANITIZER_BUILD
170 getrlimit (RLIMIT_AS, &r);
172 setrlimit (RLIMIT_AS, &r);
180 static bool Execute(ProcessInfo &PI, StringRef Program, const char **args,
181 const char **envp, const StringRef **redirects,
182 unsigned memoryLimit, std::string *ErrMsg) {
183 if (!llvm::sys::fs::exists(Program)) {
185 *ErrMsg = std::string("Executable \"") + Program.str() +
186 std::string("\" doesn't exist!");
190 // If this OS has posix_spawn and there is no memory limit being implied, use
191 // posix_spawn. It is more efficient than fork/exec.
192 #ifdef HAVE_POSIX_SPAWN
193 if (memoryLimit == 0) {
194 posix_spawn_file_actions_t FileActionsStore;
195 posix_spawn_file_actions_t *FileActions = 0;
197 // If we call posix_spawn_file_actions_addopen we have to make sure the
198 // c strings we pass to it stay alive until the call to posix_spawn,
199 // so we copy any StringRefs into this variable.
200 std::string RedirectsStorage[3];
203 std::string *RedirectsStr[3] = {0, 0, 0};
204 for (int I = 0; I < 3; ++I) {
206 RedirectsStorage[I] = *redirects[I];
207 RedirectsStr[I] = &RedirectsStorage[I];
211 FileActions = &FileActionsStore;
212 posix_spawn_file_actions_init(FileActions);
214 // Redirect stdin/stdout.
215 if (RedirectIO_PS(RedirectsStr[0], 0, ErrMsg, FileActions) ||
216 RedirectIO_PS(RedirectsStr[1], 1, ErrMsg, FileActions))
218 if (redirects[1] == 0 || redirects[2] == 0 ||
219 *redirects[1] != *redirects[2]) {
220 // Just redirect stderr
221 if (RedirectIO_PS(RedirectsStr[2], 2, ErrMsg, FileActions))
224 // If stdout and stderr should go to the same place, redirect stderr
225 // to the FD already open for stdout.
226 if (int Err = posix_spawn_file_actions_adddup2(FileActions, 1, 2))
227 return !MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout", Err);
232 #if !defined(__APPLE__)
233 envp = const_cast<const char **>(environ);
235 // environ is missing in dylibs.
236 envp = const_cast<const char **>(*_NSGetEnviron());
239 // Explicitly initialized to prevent what appears to be a valgrind false
242 int Err = posix_spawn(&PID, Program.str().c_str(), FileActions, /*attrp*/0,
243 const_cast<char **>(args), const_cast<char **>(envp));
246 posix_spawn_file_actions_destroy(FileActions);
249 return !MakeErrMsg(ErrMsg, "posix_spawn failed", Err);
257 // Create a child process.
260 // An error occurred: Return to the caller.
262 MakeErrMsg(ErrMsg, "Couldn't fork");
265 // Child process: Execute the program.
267 // Redirect file descriptors...
270 if (RedirectIO(redirects[0], 0, ErrMsg)) { return false; }
272 if (RedirectIO(redirects[1], 1, ErrMsg)) { return false; }
273 if (redirects[1] && redirects[2] &&
274 *(redirects[1]) == *(redirects[2])) {
275 // If stdout and stderr should go to the same place, redirect stderr
276 // to the FD already open for stdout.
277 if (-1 == dup2(1,2)) {
278 MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout");
282 // Just redirect stderr
283 if (RedirectIO(redirects[2], 2, ErrMsg)) { return false; }
288 if (memoryLimit!=0) {
289 SetMemoryLimits(memoryLimit);
293 std::string PathStr = Program;
295 execve(PathStr.c_str(),
296 const_cast<char **>(args),
297 const_cast<char **>(envp));
299 execv(PathStr.c_str(),
300 const_cast<char **>(args));
301 // If the execve() failed, we should exit. Follow Unix protocol and
302 // return 127 if the executable was not found, and 126 otherwise.
303 // Use _exit rather than exit so that atexit functions and static
304 // object destructors cloned from the parent process aren't
305 // redundantly run, and so that any data buffered in stdio buffers
306 // cloned from the parent aren't redundantly written out.
307 _exit(errno == ENOENT ? 127 : 126);
310 // Parent process: Break out of the switch to do our processing.
322 ProcessInfo sys::Wait(const ProcessInfo &PI, unsigned SecondsToWait,
323 bool WaitUntilTerminates, std::string *ErrMsg) {
324 #ifdef HAVE_SYS_WAIT_H
325 struct sigaction Act, Old;
326 assert(PI.Pid && "invalid pid to wait on, process not started?");
328 int WaitPidOptions = 0;
329 pid_t ChildPid = PI.Pid;
330 if (WaitUntilTerminates) {
332 ChildPid = -1; // mimic a wait() using waitpid()
333 } else if (SecondsToWait) {
334 // Install a timeout handler. The handler itself does nothing, but the
335 // simple fact of having a handler at all causes the wait below to return
336 // with EINTR, unlike if we used SIG_IGN.
337 memset(&Act, 0, sizeof(Act));
338 Act.sa_handler = TimeOutHandler;
339 sigemptyset(&Act.sa_mask);
340 sigaction(SIGALRM, &Act, &Old);
341 alarm(SecondsToWait);
342 } else if (SecondsToWait == 0)
343 WaitPidOptions = WNOHANG;
345 // Parent process: Wait for the child process to terminate.
347 ProcessInfo WaitResult;
348 WaitResult.Pid = waitpid(ChildPid, &status, WaitPidOptions);
349 if (WaitResult.Pid != PI.Pid) {
350 if (WaitResult.Pid == 0) {
351 // Non-blocking wait.
354 if (SecondsToWait && errno == EINTR) {
356 kill(PI.Pid, SIGKILL);
358 // Turn off the alarm and restore the signal handler
360 sigaction(SIGALRM, &Old, 0);
362 // Wait for child to die
363 if (wait(&status) != ChildPid)
364 MakeErrMsg(ErrMsg, "Child timed out but wouldn't die");
366 MakeErrMsg(ErrMsg, "Child timed out", 0);
368 WaitResult.ReturnCode = -2; // Timeout detected
370 } else if (errno != EINTR) {
371 MakeErrMsg(ErrMsg, "Error waiting for child process");
372 WaitResult.ReturnCode = -1;
378 // We exited normally without timeout, so turn off the timer.
379 if (SecondsToWait && !WaitUntilTerminates) {
381 sigaction(SIGALRM, &Old, 0);
384 // Return the proper exit status. Detect error conditions
385 // so we can return -1 for them and set ErrMsg informatively.
387 if (WIFEXITED(status)) {
388 result = WEXITSTATUS(status);
389 WaitResult.ReturnCode = result;
393 *ErrMsg = llvm::sys::StrError(ENOENT);
394 WaitResult.ReturnCode = -1;
399 *ErrMsg = "Program could not be executed";
400 WaitResult.ReturnCode = -1;
403 } else if (WIFSIGNALED(status)) {
405 *ErrMsg = strsignal(WTERMSIG(status));
407 if (WCOREDUMP(status))
408 *ErrMsg += " (core dumped)";
411 // Return a special value to indicate that the process received an unhandled
412 // signal during execution as opposed to failing to execute.
413 WaitResult.ReturnCode = -2;
417 *ErrMsg = "Program::Wait is not implemented on this platform yet!";
418 WaitResult.ReturnCode = -2;
423 error_code sys::ChangeStdinToBinary(){
424 // Do nothing, as Unix doesn't differentiate between text and binary.
425 return make_error_code(errc::success);
428 error_code sys::ChangeStdoutToBinary(){
429 // Do nothing, as Unix doesn't differentiate between text and binary.
430 return make_error_code(errc::success);
433 error_code sys::ChangeStderrToBinary(){
434 // Do nothing, as Unix doesn't differentiate between text and binary.
435 return make_error_code(errc::success);
438 bool llvm::sys::argumentsFitWithinSystemLimits(ArrayRef<const char*> Args) {
439 static long ArgMax = sysconf(_SC_ARG_MAX);
441 // System says no practical limit.
445 // Conservatively account for space required by environment variables.
448 size_t ArgLength = 0;
449 for (ArrayRef<const char*>::iterator I = Args.begin(), E = Args.end();
451 ArgLength += strlen(*I) + 1;
452 if (ArgLength > size_t(ArgMax)) {