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 //===----------------------------------------------------------------------===//
19 #include <llvm/Config/config.h>
20 #include "llvm/Support/FileSystem.h"
25 #if HAVE_SYS_RESOURCE_H
26 #include <sys/resource.h>
34 #ifdef HAVE_POSIX_SPAWN
36 #if !defined(__APPLE__)
37 extern char **environ;
39 #include <crt_externs.h> // _NSGetEnviron
46 Program::Program() : Data_(0) {}
48 Program::~Program() {}
50 unsigned Program::GetPid() const {
51 uint64_t pid = reinterpret_cast<uint64_t>(Data_);
52 return static_cast<unsigned>(pid);
55 // This function just uses the PATH environment variable to find the program.
57 Program::FindProgramByName(const std::string& progName) {
59 // Check some degenerate cases
60 if (progName.length() == 0) // no program
63 if (!temp.set(progName)) // invalid name
65 // Use the given path verbatim if it contains any slashes; this matches
66 // the behavior of sh(1) and friends.
67 if (progName.find('/') != std::string::npos)
70 // At this point, the file name is valid and does not contain slashes. Search
71 // for it through the directories specified in the PATH environment variable.
73 // Get the path. If its empty, we can't do anything to find it.
74 const char *PathStr = getenv("PATH");
78 // Now we have a colon separated list of directories to search; try them.
79 size_t PathLen = strlen(PathStr);
81 // Find the first colon...
82 const char *Colon = std::find(PathStr, PathStr+PathLen, ':');
84 // Check to see if this first directory contains the executable...
86 if (FilePath.set(std::string(PathStr,Colon))) {
87 FilePath.appendComponent(progName);
88 if (FilePath.canExecute())
89 return FilePath; // Found the executable!
92 // Nope it wasn't in this directory, check the next path in the list!
93 PathLen -= Colon-PathStr;
96 // Advance past duplicate colons
97 while (*PathStr == ':') {
105 static bool RedirectIO(const Path *Path, int FD, std::string* ErrMsg) {
106 if (Path == 0) // Noop
110 // Redirect empty paths to /dev/null
113 File = Path->c_str();
116 int InFD = open(File, FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666);
118 MakeErrMsg(ErrMsg, "Cannot open file '" + std::string(File) + "' for "
119 + (FD == 0 ? "input" : "output"));
123 // Install it as the requested FD
124 if (dup2(InFD, FD) == -1) {
125 MakeErrMsg(ErrMsg, "Cannot dup2");
129 close(InFD); // Close the original FD
133 #ifdef HAVE_POSIX_SPAWN
134 static bool RedirectIO_PS(const Path *Path, int FD, std::string *ErrMsg,
135 posix_spawn_file_actions_t &FileActions) {
136 if (Path == 0) // Noop
140 // Redirect empty paths to /dev/null
143 File = Path->c_str();
145 if (int Err = posix_spawn_file_actions_addopen(&FileActions, FD,
146 File, FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666))
147 return MakeErrMsg(ErrMsg, "Cannot dup2", Err);
152 static void TimeOutHandler(int Sig) {
155 static void SetMemoryLimits (unsigned size)
157 #if HAVE_SYS_RESOURCE_H && HAVE_GETRLIMIT && HAVE_SETRLIMIT
159 __typeof__ (r.rlim_cur) limit = (__typeof__ (r.rlim_cur)) (size) * 1048576;
162 getrlimit (RLIMIT_DATA, &r);
164 setrlimit (RLIMIT_DATA, &r);
166 // Resident set size.
167 getrlimit (RLIMIT_RSS, &r);
169 setrlimit (RLIMIT_RSS, &r);
171 #ifdef RLIMIT_AS // e.g. NetBSD doesn't have it.
173 getrlimit (RLIMIT_AS, &r);
175 setrlimit (RLIMIT_AS, &r);
181 Program::Execute(const Path &path, const char **args, const char **envp,
182 const Path **redirects, unsigned memoryLimit,
183 std::string *ErrMsg) {
184 // If this OS has posix_spawn and there is no memory limit being implied, use
185 // posix_spawn. It is more efficient than fork/exec.
186 #ifdef HAVE_POSIX_SPAWN
187 if (memoryLimit == 0) {
188 posix_spawn_file_actions_t FileActions;
189 posix_spawn_file_actions_init(&FileActions);
192 // Redirect stdin/stdout.
193 if (RedirectIO_PS(redirects[0], 0, ErrMsg, FileActions) ||
194 RedirectIO_PS(redirects[1], 1, ErrMsg, FileActions))
196 if (redirects[1] == 0 || redirects[2] == 0 ||
197 *redirects[1] != *redirects[2]) {
198 // Just redirect stderr
199 if (RedirectIO_PS(redirects[2], 2, ErrMsg, FileActions)) return false;
201 // If stdout and stderr should go to the same place, redirect stderr
202 // to the FD already open for stdout.
203 if (int Err = posix_spawn_file_actions_adddup2(&FileActions, 1, 2))
204 return !MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout", Err);
209 #if !defined(__APPLE__)
210 envp = const_cast<const char **>(environ);
212 // environ is missing in dylibs.
213 envp = const_cast<const char **>(*_NSGetEnviron());
216 // Explicitly initialized to prevent what appears to be a valgrind false
219 int Err = posix_spawn(&PID, path.c_str(), &FileActions, /*attrp*/0,
220 const_cast<char **>(args), const_cast<char **>(envp));
222 posix_spawn_file_actions_destroy(&FileActions);
225 return !MakeErrMsg(ErrMsg, "posix_spawn failed", Err);
227 Data_ = reinterpret_cast<void*>(PID);
232 // Create a child process.
235 // An error occured: Return to the caller.
237 MakeErrMsg(ErrMsg, "Couldn't fork");
240 // Child process: Execute the program.
242 // Redirect file descriptors...
245 if (RedirectIO(redirects[0], 0, ErrMsg)) { return false; }
247 if (RedirectIO(redirects[1], 1, ErrMsg)) { return false; }
248 if (redirects[1] && redirects[2] &&
249 *(redirects[1]) == *(redirects[2])) {
250 // If stdout and stderr should go to the same place, redirect stderr
251 // to the FD already open for stdout.
252 if (-1 == dup2(1,2)) {
253 MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout");
257 // Just redirect stderr
258 if (RedirectIO(redirects[2], 2, ErrMsg)) { return false; }
263 if (memoryLimit!=0) {
264 SetMemoryLimits(memoryLimit);
270 const_cast<char **>(args),
271 const_cast<char **>(envp));
274 const_cast<char **>(args));
275 // If the execve() failed, we should exit. Follow Unix protocol and
276 // return 127 if the executable was not found, and 126 otherwise.
277 // Use _exit rather than exit so that atexit functions and static
278 // object destructors cloned from the parent process aren't
279 // redundantly run, and so that any data buffered in stdio buffers
280 // cloned from the parent aren't redundantly written out.
281 _exit(errno == ENOENT ? 127 : 126);
284 // Parent process: Break out of the switch to do our processing.
289 Data_ = reinterpret_cast<void*>(child);
295 Program::Wait(const sys::Path &path,
296 unsigned secondsToWait,
299 #ifdef HAVE_SYS_WAIT_H
300 struct sigaction Act, Old;
303 MakeErrMsg(ErrMsg, "Process not started!");
307 // Install a timeout handler. The handler itself does nothing, but the simple
308 // fact of having a handler at all causes the wait below to return with EINTR,
309 // unlike if we used SIG_IGN.
311 memset(&Act, 0, sizeof(Act));
312 Act.sa_handler = TimeOutHandler;
313 sigemptyset(&Act.sa_mask);
314 sigaction(SIGALRM, &Act, &Old);
315 alarm(secondsToWait);
318 // Parent process: Wait for the child process to terminate.
320 uint64_t pid = reinterpret_cast<uint64_t>(Data_);
321 pid_t child = static_cast<pid_t>(pid);
322 while (waitpid(pid, &status, 0) != child)
323 if (secondsToWait && errno == EINTR) {
325 kill(child, SIGKILL);
327 // Turn off the alarm and restore the signal handler
329 sigaction(SIGALRM, &Old, 0);
331 // Wait for child to die
332 if (wait(&status) != child)
333 MakeErrMsg(ErrMsg, "Child timed out but wouldn't die");
335 MakeErrMsg(ErrMsg, "Child timed out", 0);
337 return -1; // Timeout detected
338 } else if (errno != EINTR) {
339 MakeErrMsg(ErrMsg, "Error waiting for child process");
343 // We exited normally without timeout, so turn off the timer.
346 sigaction(SIGALRM, &Old, 0);
349 // Return the proper exit status. Detect error conditions
350 // so we can return -1 for them and set ErrMsg informatively.
352 if (WIFEXITED(status)) {
353 result = WEXITSTATUS(status);
354 #ifdef HAVE_POSIX_SPAWN
355 // The posix_spawn child process returns 127 on any kind of error.
356 // Following the POSIX convention for command-line tools (which posix_spawn
357 // itself apparently does not), check to see if the failure was due to some
358 // reason other than the file not existing, and return 126 in this case.
360 if (result == 127 && !llvm::sys::fs::exists(path.str(), Exists) && Exists)
365 *ErrMsg = llvm::sys::StrError(ENOENT);
370 *ErrMsg = "Program could not be executed";
373 } else if (WIFSIGNALED(status)) {
375 *ErrMsg = strsignal(WTERMSIG(status));
377 if (WCOREDUMP(status))
378 *ErrMsg += " (core dumped)";
386 *ErrMsg = "Program::Wait is not implemented on this platform yet!";
392 Program::Kill(std::string* ErrMsg) {
394 MakeErrMsg(ErrMsg, "Process not started!");
398 uint64_t pid64 = reinterpret_cast<uint64_t>(Data_);
399 pid_t pid = static_cast<pid_t>(pid64);
401 if (kill(pid, SIGKILL) != 0) {
402 MakeErrMsg(ErrMsg, "The process couldn't be killed!");
409 bool Program::ChangeStdinToBinary(){
410 // Do nothing, as Unix doesn't differentiate between text and binary.
414 bool Program::ChangeStdoutToBinary(){
415 // Do nothing, as Unix doesn't differentiate between text and binary.
419 bool Program::ChangeStderrToBinary(){
420 // Do nothing, as Unix doesn't differentiate between text and binary.