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/Support/ManagedStatic.h"
18#include "llvm/Support/Mutex.h"
19#include "llvm/Support/MutexGuard.h"
20#if HAVE_FCNTL_H
21#include <fcntl.h>
22#endif
23#ifdef HAVE_SYS_TIME_H
24#include <sys/time.h>
25#endif
26#ifdef HAVE_SYS_RESOURCE_H
27#include <sys/resource.h>
28#endif
29#ifdef HAVE_SYS_STAT_H
30#include <sys/stat.h>
31#endif
32#if HAVE_SIGNAL_H
33#include <signal.h>
34#endif
35// DragonFlyBSD, and OpenBSD have deprecated <malloc.h> for
36// <stdlib.h> instead. Unix.h includes this for us already.
37#if defined(HAVE_MALLOC_H) && !defined(__DragonFly__) && \
38    !defined(__OpenBSD__)
39#include <malloc.h>
40#endif
41#if defined(HAVE_MALLCTL)
42#include <malloc_np.h>
43#endif
44#ifdef HAVE_MALLOC_MALLOC_H
45#include <malloc/malloc.h>
46#endif
47#ifdef HAVE_SYS_IOCTL_H
48#  include <sys/ioctl.h>
49#endif
50#ifdef HAVE_TERMIOS_H
51#  include <termios.h>
52#endif
53
54//===----------------------------------------------------------------------===//
55//=== WARNING: Implementation here must contain only generic UNIX code that
56//===          is guaranteed to work on *all* UNIX variants.
57//===----------------------------------------------------------------------===//
58
59using namespace llvm;
60using namespace sys;
61
62static std::pair<std::chrono::microseconds, std::chrono::microseconds> getRUsageTimes() {
63#if defined(HAVE_GETRUSAGE)
64  struct rusage RU;
65  ::getrusage(RUSAGE_SELF, &RU);
66  return { toDuration(RU.ru_utime), toDuration(RU.ru_stime) };
67#else
68#warning Cannot get usage times on this platform
69  return { std::chrono::microseconds::zero(), std::chrono::microseconds::zero() };
70#endif
71}
72
73// On Cygwin, getpagesize() returns 64k(AllocationGranularity) and
74// offset in mmap(3) should be aligned to the AllocationGranularity.
75unsigned Process::getPageSize() {
76#if defined(HAVE_GETPAGESIZE)
77  static const int page_size = ::getpagesize();
78#elif defined(HAVE_SYSCONF)
79  static long page_size = ::sysconf(_SC_PAGE_SIZE);
80#else
81#warning Cannot get the page size on this machine
82#endif
83  return static_cast<unsigned>(page_size);
84}
85
86size_t Process::GetMallocUsage() {
87#if defined(HAVE_MALLINFO)
88  struct mallinfo mi;
89  mi = ::mallinfo();
90  return mi.uordblks;
91#elif defined(HAVE_MALLOC_ZONE_STATISTICS) && defined(HAVE_MALLOC_MALLOC_H)
92  malloc_statistics_t Stats;
93  malloc_zone_statistics(malloc_default_zone(), &Stats);
94  return Stats.size_in_use;   // darwin
95#elif defined(HAVE_MALLCTL)
96  size_t alloc, sz;
97  sz = sizeof(size_t);
98  if (mallctl("stats.allocated", &alloc, &sz, NULL, 0) == 0)
99    return alloc;
100  return 0;
101#elif defined(HAVE_SBRK)
102  // Note this is only an approximation and more closely resembles
103  // the value returned by mallinfo in the arena field.
104  static char *StartOfMemory = reinterpret_cast<char*>(::sbrk(0));
105  char *EndOfMemory = (char*)sbrk(0);
106  if (EndOfMemory != ((char*)-1) && StartOfMemory != ((char*)-1))
107    return EndOfMemory - StartOfMemory;
108  return 0;
109#else
110#warning Cannot get malloc info on this platform
111  return 0;
112#endif
113}
114
115void Process::GetTimeUsage(TimePoint<> &elapsed, std::chrono::nanoseconds &user_time,
116                           std::chrono::nanoseconds &sys_time) {
117  elapsed = std::chrono::system_clock::now();
118  std::tie(user_time, sys_time) = getRUsageTimes();
119}
120
121#if defined(HAVE_MACH_MACH_H) && !defined(__GNU__)
122#include <mach/mach.h>
123#endif
124
125// Some LLVM programs such as bugpoint produce core files as a normal part of
126// their operation. To prevent the disk from filling up, this function
127// does what's necessary to prevent their generation.
128void Process::PreventCoreFiles() {
129#if HAVE_SETRLIMIT
130  struct rlimit rlim;
131  rlim.rlim_cur = rlim.rlim_max = 0;
132  setrlimit(RLIMIT_CORE, &rlim);
133#endif
134
135#if defined(HAVE_MACH_MACH_H) && !defined(__GNU__)
136  // Disable crash reporting on Mac OS X 10.0-10.4
137
138  // get information about the original set of exception ports for the task
139  mach_msg_type_number_t Count = 0;
140  exception_mask_t OriginalMasks[EXC_TYPES_COUNT];
141  exception_port_t OriginalPorts[EXC_TYPES_COUNT];
142  exception_behavior_t OriginalBehaviors[EXC_TYPES_COUNT];
143  thread_state_flavor_t OriginalFlavors[EXC_TYPES_COUNT];
144  kern_return_t err =
145    task_get_exception_ports(mach_task_self(), EXC_MASK_ALL, OriginalMasks,
146                             &Count, OriginalPorts, OriginalBehaviors,
147                             OriginalFlavors);
148  if (err == KERN_SUCCESS) {
149    // replace each with MACH_PORT_NULL.
150    for (unsigned i = 0; i != Count; ++i)
151      task_set_exception_ports(mach_task_self(), OriginalMasks[i],
152                               MACH_PORT_NULL, OriginalBehaviors[i],
153                               OriginalFlavors[i]);
154  }
155
156  // Disable crash reporting on Mac OS X 10.5
157  signal(SIGABRT, _exit);
158  signal(SIGILL,  _exit);
159  signal(SIGFPE,  _exit);
160  signal(SIGSEGV, _exit);
161  signal(SIGBUS,  _exit);
162#endif
163
164  coreFilesPrevented = true;
165}
166
167Optional<std::string> Process::GetEnv(StringRef Name) {
168  std::string NameStr = Name.str();
169  const char *Val = ::getenv(NameStr.c_str());
170  if (!Val)
171    return None;
172  return std::string(Val);
173}
174
175std::error_code
176Process::GetArgumentVector(SmallVectorImpl<const char *> &ArgsOut,
177                           ArrayRef<const char *> ArgsIn,
178                           SpecificBumpPtrAllocator<char> &) {
179  ArgsOut.append(ArgsIn.begin(), ArgsIn.end());
180
181  return std::error_code();
182}
183
184namespace {
185class FDCloser {
186public:
187  FDCloser(int &FD) : FD(FD), KeepOpen(false) {}
188  void keepOpen() { KeepOpen = true; }
189  ~FDCloser() {
190    if (!KeepOpen && FD >= 0)
191      ::close(FD);
192  }
193
194private:
195  FDCloser(const FDCloser &) = delete;
196  void operator=(const FDCloser &) = delete;
197
198  int &FD;
199  bool KeepOpen;
200};
201}
202
203std::error_code Process::FixupStandardFileDescriptors() {
204  int NullFD = -1;
205  FDCloser FDC(NullFD);
206  const int StandardFDs[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO};
207  for (int StandardFD : StandardFDs) {
208    struct stat st;
209    errno = 0;
210    if (RetryAfterSignal(-1, fstat, StandardFD, &st) < 0) {
211      assert(errno && "expected errno to be set if fstat failed!");
212      // fstat should return EBADF if the file descriptor is closed.
213      if (errno != EBADF)
214        return std::error_code(errno, std::generic_category());
215    }
216    // if fstat succeeds, move on to the next FD.
217    if (!errno)
218      continue;
219    assert(errno == EBADF && "expected errno to have EBADF at this point!");
220
221    if (NullFD < 0) {
222      if ((NullFD = RetryAfterSignal(-1, open, "/dev/null", O_RDWR)) < 0)
223        return std::error_code(errno, std::generic_category());
224    }
225
226    if (NullFD == StandardFD)
227      FDC.keepOpen();
228    else if (dup2(NullFD, StandardFD) < 0)
229      return std::error_code(errno, std::generic_category());
230  }
231  return std::error_code();
232}
233
234std::error_code Process::SafelyCloseFileDescriptor(int FD) {
235  // Create a signal set filled with *all* signals.
236  sigset_t FullSet;
237  if (sigfillset(&FullSet) < 0)
238    return std::error_code(errno, std::generic_category());
239  // Atomically swap our current signal mask with a full mask.
240  sigset_t SavedSet;
241#if LLVM_ENABLE_THREADS
242  if (int EC = pthread_sigmask(SIG_SETMASK, &FullSet, &SavedSet))
243    return std::error_code(EC, std::generic_category());
244#else
245  if (sigprocmask(SIG_SETMASK, &FullSet, &SavedSet) < 0)
246    return std::error_code(errno, std::generic_category());
247#endif
248  // Attempt to close the file descriptor.
249  // We need to save the error, if one occurs, because our subsequent call to
250  // pthread_sigmask might tamper with errno.
251  int ErrnoFromClose = 0;
252  if (::close(FD) < 0)
253    ErrnoFromClose = errno;
254  // Restore the signal mask back to what we saved earlier.
255  int EC = 0;
256#if LLVM_ENABLE_THREADS
257  EC = pthread_sigmask(SIG_SETMASK, &SavedSet, nullptr);
258#else
259  if (sigprocmask(SIG_SETMASK, &SavedSet, nullptr) < 0)
260    EC = errno;
261#endif
262  // The error code from close takes precedence over the one from
263  // pthread_sigmask.
264  if (ErrnoFromClose)
265    return std::error_code(ErrnoFromClose, std::generic_category());
266  return std::error_code(EC, std::generic_category());
267}
268
269bool Process::StandardInIsUserInput() {
270  return FileDescriptorIsDisplayed(STDIN_FILENO);
271}
272
273bool Process::StandardOutIsDisplayed() {
274  return FileDescriptorIsDisplayed(STDOUT_FILENO);
275}
276
277bool Process::StandardErrIsDisplayed() {
278  return FileDescriptorIsDisplayed(STDERR_FILENO);
279}
280
281bool Process::FileDescriptorIsDisplayed(int fd) {
282#if HAVE_ISATTY
283  return isatty(fd);
284#else
285  // If we don't have isatty, just return false.
286  return false;
287#endif
288}
289
290static unsigned getColumns(int FileID) {
291  // If COLUMNS is defined in the environment, wrap to that many columns.
292  if (const char *ColumnsStr = std::getenv("COLUMNS")) {
293    int Columns = std::atoi(ColumnsStr);
294    if (Columns > 0)
295      return Columns;
296  }
297
298  unsigned Columns = 0;
299
300#if defined(HAVE_SYS_IOCTL_H) && defined(HAVE_TERMIOS_H)
301  // Try to determine the width of the terminal.
302  struct winsize ws;
303  if (ioctl(FileID, TIOCGWINSZ, &ws) == 0)
304    Columns = ws.ws_col;
305#endif
306
307  return Columns;
308}
309
310unsigned Process::StandardOutColumns() {
311  if (!StandardOutIsDisplayed())
312    return 0;
313
314  return getColumns(1);
315}
316
317unsigned Process::StandardErrColumns() {
318  if (!StandardErrIsDisplayed())
319    return 0;
320
321  return getColumns(2);
322}
323
324#ifdef HAVE_TERMINFO
325// We manually declare these extern functions because finding the correct
326// headers from various terminfo, curses, or other sources is harder than
327// writing their specs down.
328extern "C" int setupterm(char *term, int filedes, int *errret);
329extern "C" struct term *set_curterm(struct term *termp);
330extern "C" int del_curterm(struct term *termp);
331extern "C" int tigetnum(char *capname);
332#endif
333
334#ifdef HAVE_TERMINFO
335static ManagedStatic<sys::Mutex> TermColorMutex;
336#endif
337
338static bool terminalHasColors(int fd) {
339#ifdef HAVE_TERMINFO
340  // First, acquire a global lock because these C routines are thread hostile.
341  MutexGuard G(*TermColorMutex);
342
343  int errret = 0;
344  if (setupterm(nullptr, fd, &errret) != 0)
345    // Regardless of why, if we can't get terminfo, we shouldn't try to print
346    // colors.
347    return false;
348
349  // Test whether the terminal as set up supports color output. How to do this
350  // isn't entirely obvious. We can use the curses routine 'has_colors' but it
351  // would be nice to avoid a dependency on curses proper when we can make do
352  // with a minimal terminfo parsing library. Also, we don't really care whether
353  // the terminal supports the curses-specific color changing routines, merely
354  // if it will interpret ANSI color escape codes in a reasonable way. Thus, the
355  // strategy here is just to query the baseline colors capability and if it
356  // supports colors at all to assume it will translate the escape codes into
357  // whatever range of colors it does support. We can add more detailed tests
358  // here if users report them as necessary.
359  //
360  // The 'tigetnum' routine returns -2 or -1 on errors, and might return 0 if
361  // the terminfo says that no colors are supported.
362  bool HasColors = tigetnum(const_cast<char *>("colors")) > 0;
363
364  // Now extract the structure allocated by setupterm and free its memory
365  // through a really silly dance.
366  struct term *termp = set_curterm(nullptr);
367  (void)del_curterm(termp); // Drop any errors here.
368
369  // Return true if we found a color capabilities for the current terminal.
370  if (HasColors)
371    return true;
372#else
373  // When the terminfo database is not available, check if the current terminal
374  // is one of terminals that are known to support ANSI color escape codes.
375  if (const char *TermStr = std::getenv("TERM")) {
376    return StringSwitch<bool>(TermStr)
377      .Case("ansi", true)
378      .Case("cygwin", true)
379      .Case("linux", true)
380      .StartsWith("screen", true)
381      .StartsWith("xterm", true)
382      .StartsWith("vt100", true)
383      .StartsWith("rxvt", true)
384      .EndsWith("color", true)
385      .Default(false);
386  }
387#endif
388
389  // Otherwise, be conservative.
390  return false;
391}
392
393bool Process::FileDescriptorHasColors(int fd) {
394  // A file descriptor has colors if it is displayed and the terminal has
395  // colors.
396  return FileDescriptorIsDisplayed(fd) && terminalHasColors(fd);
397}
398
399bool Process::StandardOutHasColors() {
400  return FileDescriptorHasColors(STDOUT_FILENO);
401}
402
403bool Process::StandardErrHasColors() {
404  return FileDescriptorHasColors(STDERR_FILENO);
405}
406
407void Process::UseANSIEscapeCodes(bool /*enable*/) {
408  // No effect.
409}
410
411bool Process::ColorNeedsFlush() {
412  // No, we use ANSI escape sequences.
413  return false;
414}
415
416const char *Process::OutputColor(char code, bool bold, bool bg) {
417  return colorcodes[bg?1:0][bold?1:0][code&7];
418}
419
420const char *Process::OutputBold(bool bg) {
421  return "\033[1m";
422}
423
424const char *Process::OutputReverse() {
425  return "\033[7m";
426}
427
428const char *Process::ResetColor() {
429  return "\033[0m";
430}
431
432#if !HAVE_DECL_ARC4RANDOM
433static unsigned GetRandomNumberSeed() {
434  // Attempt to get the initial seed from /dev/urandom, if possible.
435  int urandomFD = open("/dev/urandom", O_RDONLY);
436
437  if (urandomFD != -1) {
438    unsigned seed;
439    // Don't use a buffered read to avoid reading more data
440    // from /dev/urandom than we need.
441    int count = read(urandomFD, (void *)&seed, sizeof(seed));
442
443    close(urandomFD);
444
445    // Return the seed if the read was successful.
446    if (count == sizeof(seed))
447      return seed;
448  }
449
450  // Otherwise, swizzle the current time and the process ID to form a reasonable
451  // seed.
452  const auto Now = std::chrono::high_resolution_clock::now();
453  return hash_combine(Now.time_since_epoch().count(), ::getpid());
454}
455#endif
456
457unsigned llvm::sys::Process::GetRandomNumber() {
458#if HAVE_DECL_ARC4RANDOM
459  return arc4random();
460#else
461  static int x = (static_cast<void>(::srand(GetRandomNumberSeed())), 0);
462  (void)x;
463  return ::rand();
464#endif
465}
466