1//===- Unix/Process.cpp - Unix Process Implementation --------- -*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file provides the generic Unix implementation of the Process class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "Unix.h"
15#include "llvm/ADT/Hashing.h"
16#include "llvm/ADT/StringRef.h"
17#include "llvm/Config/config.h"
18#include "llvm/Support/ManagedStatic.h"
19#include "llvm/Support/Mutex.h"
20#include "llvm/Support/MutexGuard.h"
21#if HAVE_FCNTL_H
22#include <fcntl.h>
23#endif
24#ifdef HAVE_SYS_TIME_H
25#include <sys/time.h>
26#endif
27#ifdef HAVE_SYS_RESOURCE_H
28#include <sys/resource.h>
29#endif
30#ifdef HAVE_SYS_STAT_H
31#include <sys/stat.h>
32#endif
33#if HAVE_SIGNAL_H
34#include <signal.h>
35#endif
36// DragonFlyBSD, and OpenBSD have deprecated <malloc.h> for
37// <stdlib.h> instead. Unix.h includes this for us already.
38#if defined(HAVE_MALLOC_H) && !defined(__DragonFly__) && \
39    !defined(__OpenBSD__)
40#include <malloc.h>
41#endif
42#if defined(HAVE_MALLCTL)
43#include <malloc_np.h>
44#endif
45#ifdef HAVE_MALLOC_MALLOC_H
46#include <malloc/malloc.h>
47#endif
48#ifdef HAVE_SYS_IOCTL_H
49#  include <sys/ioctl.h>
50#endif
51#ifdef HAVE_TERMIOS_H
52#  include <termios.h>
53#endif
54
55//===----------------------------------------------------------------------===//
56//=== WARNING: Implementation here must contain only generic UNIX code that
57//===          is guaranteed to work on *all* UNIX variants.
58//===----------------------------------------------------------------------===//
59
60using namespace llvm;
61using namespace sys;
62
63static std::pair<std::chrono::microseconds, std::chrono::microseconds> getRUsageTimes() {
64#if defined(HAVE_GETRUSAGE)
65  struct rusage RU;
66  ::getrusage(RUSAGE_SELF, &RU);
67  return { toDuration(RU.ru_utime), toDuration(RU.ru_stime) };
68#else
69#warning Cannot get usage times on this platform
70  return { std::chrono::microseconds::zero(), std::chrono::microseconds::zero() };
71#endif
72}
73
74// On Cygwin, getpagesize() returns 64k(AllocationGranularity) and
75// offset in mmap(3) should be aligned to the AllocationGranularity.
76unsigned Process::getPageSize() {
77#if defined(HAVE_GETPAGESIZE)
78  static const int page_size = ::getpagesize();
79#elif defined(HAVE_SYSCONF)
80  static long page_size = ::sysconf(_SC_PAGE_SIZE);
81#else
82#warning Cannot get the page size on this machine
83#endif
84  return static_cast<unsigned>(page_size);
85}
86
87size_t Process::GetMallocUsage() {
88#if defined(HAVE_MALLINFO)
89  struct mallinfo mi;
90  mi = ::mallinfo();
91  return mi.uordblks;
92#elif defined(HAVE_MALLOC_ZONE_STATISTICS) && defined(HAVE_MALLOC_MALLOC_H)
93  malloc_statistics_t Stats;
94  malloc_zone_statistics(malloc_default_zone(), &Stats);
95  return Stats.size_in_use;   // darwin
96#elif defined(HAVE_MALLCTL)
97  size_t alloc, sz;
98  sz = sizeof(size_t);
99  if (mallctl("stats.allocated", &alloc, &sz, NULL, 0) == 0)
100    return alloc;
101  return 0;
102#elif defined(HAVE_SBRK)
103  // Note this is only an approximation and more closely resembles
104  // the value returned by mallinfo in the arena field.
105  static char *StartOfMemory = reinterpret_cast<char*>(::sbrk(0));
106  char *EndOfMemory = (char*)sbrk(0);
107  if (EndOfMemory != ((char*)-1) && StartOfMemory != ((char*)-1))
108    return EndOfMemory - StartOfMemory;
109  return 0;
110#else
111#warning Cannot get malloc info on this platform
112  return 0;
113#endif
114}
115
116void Process::GetTimeUsage(TimePoint<> &elapsed, std::chrono::nanoseconds &user_time,
117                           std::chrono::nanoseconds &sys_time) {
118  elapsed = std::chrono::system_clock::now();
119  std::tie(user_time, sys_time) = getRUsageTimes();
120}
121
122#if defined(HAVE_MACH_MACH_H) && !defined(__GNU__)
123#include <mach/mach.h>
124#endif
125
126// Some LLVM programs such as bugpoint produce core files as a normal part of
127// their operation. To prevent the disk from filling up, this function
128// does what's necessary to prevent their generation.
129void Process::PreventCoreFiles() {
130#if HAVE_SETRLIMIT
131  struct rlimit rlim;
132  rlim.rlim_cur = rlim.rlim_max = 0;
133  setrlimit(RLIMIT_CORE, &rlim);
134#endif
135
136#if defined(HAVE_MACH_MACH_H) && !defined(__GNU__)
137  // Disable crash reporting on Mac OS X 10.0-10.4
138
139  // get information about the original set of exception ports for the task
140  mach_msg_type_number_t Count = 0;
141  exception_mask_t OriginalMasks[EXC_TYPES_COUNT];
142  exception_port_t OriginalPorts[EXC_TYPES_COUNT];
143  exception_behavior_t OriginalBehaviors[EXC_TYPES_COUNT];
144  thread_state_flavor_t OriginalFlavors[EXC_TYPES_COUNT];
145  kern_return_t err =
146    task_get_exception_ports(mach_task_self(), EXC_MASK_ALL, OriginalMasks,
147                             &Count, OriginalPorts, OriginalBehaviors,
148                             OriginalFlavors);
149  if (err == KERN_SUCCESS) {
150    // replace each with MACH_PORT_NULL.
151    for (unsigned i = 0; i != Count; ++i)
152      task_set_exception_ports(mach_task_self(), OriginalMasks[i],
153                               MACH_PORT_NULL, OriginalBehaviors[i],
154                               OriginalFlavors[i]);
155  }
156
157  // Disable crash reporting on Mac OS X 10.5
158  signal(SIGABRT, _exit);
159  signal(SIGILL,  _exit);
160  signal(SIGFPE,  _exit);
161  signal(SIGSEGV, _exit);
162  signal(SIGBUS,  _exit);
163#endif
164
165  coreFilesPrevented = true;
166}
167
168Optional<std::string> Process::GetEnv(StringRef Name) {
169  std::string NameStr = Name.str();
170  const char *Val = ::getenv(NameStr.c_str());
171  if (!Val)
172    return None;
173  return std::string(Val);
174}
175
176namespace {
177class FDCloser {
178public:
179  FDCloser(int &FD) : FD(FD), KeepOpen(false) {}
180  void keepOpen() { KeepOpen = true; }
181  ~FDCloser() {
182    if (!KeepOpen && FD >= 0)
183      ::close(FD);
184  }
185
186private:
187  FDCloser(const FDCloser &) = delete;
188  void operator=(const FDCloser &) = delete;
189
190  int &FD;
191  bool KeepOpen;
192};
193}
194
195std::error_code Process::FixupStandardFileDescriptors() {
196  int NullFD = -1;
197  FDCloser FDC(NullFD);
198  const int StandardFDs[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO};
199  for (int StandardFD : StandardFDs) {
200    struct stat st;
201    errno = 0;
202    if (RetryAfterSignal(-1, fstat, StandardFD, &st) < 0) {
203      assert(errno && "expected errno to be set if fstat failed!");
204      // fstat should return EBADF if the file descriptor is closed.
205      if (errno != EBADF)
206        return std::error_code(errno, std::generic_category());
207    }
208    // if fstat succeeds, move on to the next FD.
209    if (!errno)
210      continue;
211    assert(errno == EBADF && "expected errno to have EBADF at this point!");
212
213    if (NullFD < 0) {
214      if ((NullFD = RetryAfterSignal(-1, open, "/dev/null", O_RDWR)) < 0)
215        return std::error_code(errno, std::generic_category());
216    }
217
218    if (NullFD == StandardFD)
219      FDC.keepOpen();
220    else if (dup2(NullFD, StandardFD) < 0)
221      return std::error_code(errno, std::generic_category());
222  }
223  return std::error_code();
224}
225
226std::error_code Process::SafelyCloseFileDescriptor(int FD) {
227  // Create a signal set filled with *all* signals.
228  sigset_t FullSet;
229  if (sigfillset(&FullSet) < 0)
230    return std::error_code(errno, std::generic_category());
231  // Atomically swap our current signal mask with a full mask.
232  sigset_t SavedSet;
233#if LLVM_ENABLE_THREADS
234  if (int EC = pthread_sigmask(SIG_SETMASK, &FullSet, &SavedSet))
235    return std::error_code(EC, std::generic_category());
236#else
237  if (sigprocmask(SIG_SETMASK, &FullSet, &SavedSet) < 0)
238    return std::error_code(errno, std::generic_category());
239#endif
240  // Attempt to close the file descriptor.
241  // We need to save the error, if one occurs, because our subsequent call to
242  // pthread_sigmask might tamper with errno.
243  int ErrnoFromClose = 0;
244  if (::close(FD) < 0)
245    ErrnoFromClose = errno;
246  // Restore the signal mask back to what we saved earlier.
247  int EC = 0;
248#if LLVM_ENABLE_THREADS
249  EC = pthread_sigmask(SIG_SETMASK, &SavedSet, nullptr);
250#else
251  if (sigprocmask(SIG_SETMASK, &SavedSet, nullptr) < 0)
252    EC = errno;
253#endif
254  // The error code from close takes precedence over the one from
255  // pthread_sigmask.
256  if (ErrnoFromClose)
257    return std::error_code(ErrnoFromClose, std::generic_category());
258  return std::error_code(EC, std::generic_category());
259}
260
261bool Process::StandardInIsUserInput() {
262  return FileDescriptorIsDisplayed(STDIN_FILENO);
263}
264
265bool Process::StandardOutIsDisplayed() {
266  return FileDescriptorIsDisplayed(STDOUT_FILENO);
267}
268
269bool Process::StandardErrIsDisplayed() {
270  return FileDescriptorIsDisplayed(STDERR_FILENO);
271}
272
273bool Process::FileDescriptorIsDisplayed(int fd) {
274#if HAVE_ISATTY
275  return isatty(fd);
276#else
277  // If we don't have isatty, just return false.
278  return false;
279#endif
280}
281
282static unsigned getColumns(int FileID) {
283  // If COLUMNS is defined in the environment, wrap to that many columns.
284  if (const char *ColumnsStr = std::getenv("COLUMNS")) {
285    int Columns = std::atoi(ColumnsStr);
286    if (Columns > 0)
287      return Columns;
288  }
289
290  unsigned Columns = 0;
291
292#if defined(HAVE_SYS_IOCTL_H) && defined(HAVE_TERMIOS_H)
293  // Try to determine the width of the terminal.
294  struct winsize ws;
295  if (ioctl(FileID, TIOCGWINSZ, &ws) == 0)
296    Columns = ws.ws_col;
297#endif
298
299  return Columns;
300}
301
302unsigned Process::StandardOutColumns() {
303  if (!StandardOutIsDisplayed())
304    return 0;
305
306  return getColumns(1);
307}
308
309unsigned Process::StandardErrColumns() {
310  if (!StandardErrIsDisplayed())
311    return 0;
312
313  return getColumns(2);
314}
315
316#ifdef HAVE_TERMINFO
317// We manually declare these extern functions because finding the correct
318// headers from various terminfo, curses, or other sources is harder than
319// writing their specs down.
320extern "C" int setupterm(char *term, int filedes, int *errret);
321extern "C" struct term *set_curterm(struct term *termp);
322extern "C" int del_curterm(struct term *termp);
323extern "C" int tigetnum(char *capname);
324#endif
325
326#ifdef HAVE_TERMINFO
327static ManagedStatic<sys::Mutex> TermColorMutex;
328#endif
329
330static bool terminalHasColors(int fd) {
331#ifdef HAVE_TERMINFO
332  // First, acquire a global lock because these C routines are thread hostile.
333  MutexGuard G(*TermColorMutex);
334
335  int errret = 0;
336  if (setupterm(nullptr, fd, &errret) != 0)
337    // Regardless of why, if we can't get terminfo, we shouldn't try to print
338    // colors.
339    return false;
340
341  // Test whether the terminal as set up supports color output. How to do this
342  // isn't entirely obvious. We can use the curses routine 'has_colors' but it
343  // would be nice to avoid a dependency on curses proper when we can make do
344  // with a minimal terminfo parsing library. Also, we don't really care whether
345  // the terminal supports the curses-specific color changing routines, merely
346  // if it will interpret ANSI color escape codes in a reasonable way. Thus, the
347  // strategy here is just to query the baseline colors capability and if it
348  // supports colors at all to assume it will translate the escape codes into
349  // whatever range of colors it does support. We can add more detailed tests
350  // here if users report them as necessary.
351  //
352  // The 'tigetnum' routine returns -2 or -1 on errors, and might return 0 if
353  // the terminfo says that no colors are supported.
354  bool HasColors = tigetnum(const_cast<char *>("colors")) > 0;
355
356  // Now extract the structure allocated by setupterm and free its memory
357  // through a really silly dance.
358  struct term *termp = set_curterm(nullptr);
359  (void)del_curterm(termp); // Drop any errors here.
360
361  // Return true if we found a color capabilities for the current terminal.
362  if (HasColors)
363    return true;
364#else
365  // When the terminfo database is not available, check if the current terminal
366  // is one of terminals that are known to support ANSI color escape codes.
367  if (const char *TermStr = std::getenv("TERM")) {
368    return StringSwitch<bool>(TermStr)
369      .Case("ansi", true)
370      .Case("cygwin", true)
371      .Case("linux", true)
372      .StartsWith("screen", true)
373      .StartsWith("xterm", true)
374      .StartsWith("vt100", true)
375      .StartsWith("rxvt", true)
376      .EndsWith("color", true)
377      .Default(false);
378  }
379#endif
380
381  // Otherwise, be conservative.
382  return false;
383}
384
385bool Process::FileDescriptorHasColors(int fd) {
386  // A file descriptor has colors if it is displayed and the terminal has
387  // colors.
388  return FileDescriptorIsDisplayed(fd) && terminalHasColors(fd);
389}
390
391bool Process::StandardOutHasColors() {
392  return FileDescriptorHasColors(STDOUT_FILENO);
393}
394
395bool Process::StandardErrHasColors() {
396  return FileDescriptorHasColors(STDERR_FILENO);
397}
398
399void Process::UseANSIEscapeCodes(bool /*enable*/) {
400  // No effect.
401}
402
403bool Process::ColorNeedsFlush() {
404  // No, we use ANSI escape sequences.
405  return false;
406}
407
408const char *Process::OutputColor(char code, bool bold, bool bg) {
409  return colorcodes[bg?1:0][bold?1:0][code&7];
410}
411
412const char *Process::OutputBold(bool bg) {
413  return "\033[1m";
414}
415
416const char *Process::OutputReverse() {
417  return "\033[7m";
418}
419
420const char *Process::ResetColor() {
421  return "\033[0m";
422}
423
424#if !HAVE_DECL_ARC4RANDOM
425static unsigned GetRandomNumberSeed() {
426  // Attempt to get the initial seed from /dev/urandom, if possible.
427  int urandomFD = open("/dev/urandom", O_RDONLY);
428
429  if (urandomFD != -1) {
430    unsigned seed;
431    // Don't use a buffered read to avoid reading more data
432    // from /dev/urandom than we need.
433    int count = read(urandomFD, (void *)&seed, sizeof(seed));
434
435    close(urandomFD);
436
437    // Return the seed if the read was successful.
438    if (count == sizeof(seed))
439      return seed;
440  }
441
442  // Otherwise, swizzle the current time and the process ID to form a reasonable
443  // seed.
444  const auto Now = std::chrono::high_resolution_clock::now();
445  return hash_combine(Now.time_since_epoch().count(), ::getpid());
446}
447#endif
448
449unsigned llvm::sys::Process::GetRandomNumber() {
450#if HAVE_DECL_ARC4RANDOM
451  return arc4random();
452#else
453  static int x = (static_cast<void>(::srand(GetRandomNumberSeed())), 0);
454  (void)x;
455  return ::rand();
456#endif
457}
458