1 //===- SystemUtils.cpp - Utilities for low-level system tasks -------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains functions used to do a variety of low-level, often
11 // system-specific, tasks.
13 //===----------------------------------------------------------------------===//
15 #define _POSIX_MAPPED_FILES
16 #include "Support/SystemUtils.h"
17 #include "Config/fcntl.h"
18 #include "Config/pagesize.h"
19 #include "Config/unistd.h"
20 #include "Config/windows.h"
21 #include "Config/sys/mman.h"
22 #include "Config/sys/stat.h"
23 #include "Config/sys/types.h"
24 #include "Config/sys/wait.h"
32 /// isExecutableFile - This function returns true if the filename specified
33 /// exists and is executable.
35 bool llvm::isExecutableFile(const std::string &ExeFileName) {
37 if (stat(ExeFileName.c_str(), &Buf))
38 return false; // Must not be executable!
40 if (!(Buf.st_mode & S_IFREG))
41 return false; // Not a regular file?
43 if (Buf.st_uid == getuid()) // Owner of file?
44 return Buf.st_mode & S_IXUSR;
45 else if (Buf.st_gid == getgid()) // In group of file?
46 return Buf.st_mode & S_IXGRP;
47 else // Unrelated to file?
48 return Buf.st_mode & S_IXOTH;
51 /// isStandardOutAConsole - Return true if we can tell that the standard output
52 /// stream goes to a terminal window or console.
53 bool llvm::isStandardOutAConsole() {
57 // If we don't have isatty, just return false.
62 /// FindExecutable - Find a named executable, giving the argv[0] of program
63 /// being executed. This allows us to find another LLVM tool if it is built
64 /// into the same directory, but that directory is neither the current
65 /// directory, nor in the PATH. If the executable cannot be found, return an
68 #undef FindExecutable // needed on windows :(
69 std::string llvm::FindExecutable(const std::string &ExeName,
70 const std::string &ProgramPath) {
71 // First check the directory that bugpoint is in. We can do this if
72 // BugPointPath contains at least one / character, indicating that it is a
73 // relative path to bugpoint itself.
75 std::string Result = ProgramPath;
76 while (!Result.empty() && Result[Result.size()-1] != '/')
77 Result.erase(Result.size()-1, 1);
79 if (!Result.empty()) {
81 if (isExecutableFile(Result)) return Result; // Found it?
84 // Okay, if the path to the program didn't tell us anything, try using the
85 // PATH environment variable.
86 const char *PathStr = getenv("PATH");
87 if (PathStr == 0) return "";
89 // Now we have a colon separated list of directories to search... try them...
90 unsigned PathLen = strlen(PathStr);
92 // Find the first colon...
93 const char *Colon = std::find(PathStr, PathStr+PathLen, ':');
95 // Check to see if this first directory contains the executable...
96 std::string FilePath = std::string(PathStr, Colon) + '/' + ExeName;
97 if (isExecutableFile(FilePath))
98 return FilePath; // Found the executable!
100 // Nope it wasn't in this directory, check the next range!
101 PathLen -= Colon-PathStr;
103 while (*PathStr == ':') { // Advance past colons
109 // If we fell out, we ran out of directories in PATH to search, return failure
113 static void RedirectFD(const std::string &File, int FD) {
114 if (File.empty()) return; // Noop
117 int InFD = open(File.c_str(), FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666);
119 std::cerr << "Error opening file '" << File << "' for "
120 << (FD == 0 ? "input" : "output") << "!\n";
124 dup2(InFD, FD); // Install it as the requested FD
125 close(InFD); // Close the original FD
128 /// RunProgramWithTimeout - This function executes the specified program, with
129 /// the specified null-terminated argument array, with the stdin/out/err fd's
130 /// redirected, with a timeout specified on the command line. This terminates
131 /// the calling program if there is an error executing the specified program.
132 /// It returns the return value of the program, or -1 if a timeout is detected.
134 int llvm::RunProgramWithTimeout(const std::string &ProgramPath,
136 const std::string &StdInFile,
137 const std::string &StdOutFile,
138 const std::string &StdErrFile) {
139 // FIXME: install sigalarm handler here for timeout...
141 #ifdef HAVE_SYS_WAIT_H
145 std::cerr << "ERROR forking!\n";
148 RedirectFD(StdInFile, 0); // Redirect file descriptors...
149 RedirectFD(StdOutFile, 1);
150 if (StdOutFile != StdErrFile)
151 RedirectFD(StdErrFile, 2);
155 execv(ProgramPath.c_str(), (char *const *)Args);
156 std::cerr << "Error executing program: '" << ProgramPath;
157 for (; *Args; ++Args)
158 std::cerr << " " << *Args;
165 // Make sure all output has been written while waiting
166 std::cout << std::flush;
169 if (wait(&Status) != Child) {
170 if (errno == EINTR) {
171 static bool FirstTimeout = true;
174 "*** Program execution timed out! This mechanism is designed to handle\n"
175 " programs stuck in infinite loops gracefully. The -timeout option\n"
176 " can be used to change the timeout threshold or disable it completely\n"
177 " (with -timeout=0). This message is only displayed once.\n";
178 FirstTimeout = false;
180 return -1; // Timeout detected
183 std::cerr << "Error waiting for child process!\n";
189 std::cerr << "RunProgramWithTimeout not implemented on this platform!\n";
195 // ExecWait - executes a program with the specified arguments and environment.
196 // It then waits for the progarm to termiante and then returns to the caller.
199 // argv - The arguments to the program as an array of C strings. The first
200 // argument should be the name of the program to execute, and the
201 // last argument should be a pointer to NULL.
203 // envp - The environment passes to the program as an array of C strings in
204 // the form of "name=value" pairs. The last element should be a
212 // 1 - The program could not be executed.
213 // 1 - The program returned a non-zero exit status.
214 // 1 - The program terminated abnormally.
217 // The program will inherit the stdin, stdout, and stderr file descriptors
218 // as well as other various configuration settings (umask).
220 // This function should not print anything to stdout/stderr on its own. It is
221 // a generic library function. The caller or executed program should report
222 // errors in the way it sees fit.
224 // This function does not use $PATH to find programs.
226 int llvm::ExecWait(const char * const old_argv[],
227 const char * const old_envp[]) {
228 #ifdef HAVE_SYS_WAIT_H
229 // Create local versions of the parameters that can be passed into execve()
230 // without creating const problems.
231 char ** const argv = (char ** const) old_argv;
232 char ** const envp = (char ** const) old_envp;
234 // Create a child process.
236 // An error occured: Return to the caller.
241 // Child process: Execute the program.
243 execve (argv[0], argv, envp);
244 // If the execve() failed, we should exit and let the parent pick up
245 // our non-zero exit status.
248 // Parent process: Break out of the switch to do our processing.
253 // Parent process: Wait for the child process to terminate.
255 if ((wait (&status)) == -1)
258 // If the program exited normally with a zero exit status, return success!
259 if (WIFEXITED (status) && (WEXITSTATUS(status) == 0))
262 std::cerr << "llvm::ExecWait not implemented on this platform!\n";
265 // Otherwise, return failure.
269 /// AllocateRWXMemory - Allocate a slab of memory with read/write/execute
270 /// permissions. This is typically used for JIT applications where we want
271 /// to emit code to the memory then jump to it. Getting this type of memory
272 /// is very OS specific.
274 void *llvm::AllocateRWXMemory(unsigned NumBytes) {
275 if (NumBytes == 0) return 0;
277 #if defined(HAVE_WINDOWS_H)
278 // On windows we use VirtualAlloc.
279 void *P = VirtualAlloc(0, NumBytes, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
281 std::cerr << "Error allocating executable memory!\n";
286 #elif defined(HAVE_MMAP)
287 static const long pageSize = GetPageSize();
288 unsigned NumPages = (NumBytes+pageSize-1)/pageSize;
290 /* FIXME: This should use the proper autoconf flags */
291 #if defined(i386) || defined(__i386__) || defined(__x86__)
292 /* Linux and *BSD tend to have these flags named differently. */
293 #if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
294 # define MAP_ANONYMOUS MAP_ANON
295 #endif /* defined(MAP_ANON) && !defined(MAP_ANONYMOUS) */
296 #elif defined(sparc) || defined(__sparc__) || defined(__sparcv9)
299 std::cerr << "This architecture has an unknown MMAP implementation!\n";
305 #if defined(__linux__)
309 unsigned mmapFlags = MAP_PRIVATE|MAP_ANONYMOUS;
311 mmapFlags |= MAP_NORESERVE;
314 void *pa = mmap(0, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
316 if (pa == MAP_FAILED) {
322 std::cerr << "Do not know how to allocate mem for the JIT without mmap!\n";