1 files changed, 459 insertions, 0 deletions
diff --git a/llvm/lib/Support/Unix/Process.inc b/llvm/lib/Support/Unix/Process.inc
new file mode 100644
index 000000000000..dfe81d7e2833
--- /dev/null
+++ b/llvm/lib/Support/Unix/Process.inc
@@ -0,0 +1,459 @@
+//===- Unix/Process.cpp - Unix Process Implementation --------- -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides the generic Unix implementation of the Process class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Config/config.h"
+#include "llvm/Support/ManagedStatic.h"
+#include <mutex>
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SIGNAL_H
+#include <signal.h>
+#endif
+#if defined(HAVE_MALLINFO)
+#include <malloc.h>
+#endif
+#if defined(HAVE_MALLCTL)
+#include <malloc_np.h>
+#endif
+#ifdef HAVE_MALLOC_MALLOC_H
+#include <malloc/malloc.h>
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#  include <sys/ioctl.h>
+#endif
+#ifdef HAVE_TERMIOS_H
+#  include <termios.h>
+#endif
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+using namespace llvm;
+using namespace sys;
+
+static std::pair<std::chrono::microseconds, std::chrono::microseconds> getRUsageTimes() {
+#if defined(HAVE_GETRUSAGE)
+  struct rusage RU;
+  ::getrusage(RUSAGE_SELF, &RU);
+  return { toDuration(RU.ru_utime), toDuration(RU.ru_stime) };
+#else
+#warning Cannot get usage times on this platform
+  return { std::chrono::microseconds::zero(), std::chrono::microseconds::zero() };
+#endif
+}
+
+// On Cygwin, getpagesize() returns 64k(AllocationGranularity) and
+// offset in mmap(3) should be aligned to the AllocationGranularity.
+Expected<unsigned> Process::getPageSize() {
+#if defined(HAVE_GETPAGESIZE)
+  static const int page_size = ::getpagesize();
+#elif defined(HAVE_SYSCONF)
+  static long page_size = ::sysconf(_SC_PAGE_SIZE);
+#else
+#error Cannot get the page size on this machine
+#endif
+  if (page_size == -1)
+    return errorCodeToError(std::error_code(errno, std::generic_category()));
+
+  return static_cast<unsigned>(page_size);
+}
+
+size_t Process::GetMallocUsage() {
+#if defined(HAVE_MALLINFO)
+  struct mallinfo mi;
+  mi = ::mallinfo();
+  return mi.uordblks;
+#elif defined(HAVE_MALLOC_ZONE_STATISTICS) && defined(HAVE_MALLOC_MALLOC_H)
+  malloc_statistics_t Stats;
+  malloc_zone_statistics(malloc_default_zone(), &Stats);
+  return Stats.size_in_use;   // darwin
+#elif defined(HAVE_MALLCTL)
+  size_t alloc, sz;
+  sz = sizeof(size_t);
+  if (mallctl("stats.allocated", &alloc, &sz, NULL, 0) == 0)
+    return alloc;
+  return 0;
+#elif defined(HAVE_SBRK)
+  // Note this is only an approximation and more closely resembles
+  // the value returned by mallinfo in the arena field.
+  static char *StartOfMemory = reinterpret_cast<char*>(::sbrk(0));
+  char *EndOfMemory = (char*)sbrk(0);
+  if (EndOfMemory != ((char*)-1) && StartOfMemory != ((char*)-1))
+    return EndOfMemory - StartOfMemory;
+  return 0;
+#else
+#warning Cannot get malloc info on this platform
+  return 0;
+#endif
+}
+
+void Process::GetTimeUsage(TimePoint<> &elapsed, std::chrono::nanoseconds &user_time,
+                           std::chrono::nanoseconds &sys_time) {
+  elapsed = std::chrono::system_clock::now();
+  std::tie(user_time, sys_time) = getRUsageTimes();
+}
+
+#if defined(HAVE_MACH_MACH_H) && !defined(__GNU__)
+#include <mach/mach.h>
+#endif
+
+// Some LLVM programs such as bugpoint produce core files as a normal part of
+// their operation. To prevent the disk from filling up, this function
+// does what's necessary to prevent their generation.
+void Process::PreventCoreFiles() {
+#if HAVE_SETRLIMIT
+  struct rlimit rlim;
+  rlim.rlim_cur = rlim.rlim_max = 0;
+  setrlimit(RLIMIT_CORE, &rlim);
+#endif
+
+#if defined(HAVE_MACH_MACH_H) && !defined(__GNU__)
+  // Disable crash reporting on Mac OS X 10.0-10.4
+
+  // get information about the original set of exception ports for the task
+  mach_msg_type_number_t Count = 0;
+  exception_mask_t OriginalMasks[EXC_TYPES_COUNT];
+  exception_port_t OriginalPorts[EXC_TYPES_COUNT];
+  exception_behavior_t OriginalBehaviors[EXC_TYPES_COUNT];
+  thread_state_flavor_t OriginalFlavors[EXC_TYPES_COUNT];
+  kern_return_t err =
+    task_get_exception_ports(mach_task_self(), EXC_MASK_ALL, OriginalMasks,
+                             &Count, OriginalPorts, OriginalBehaviors,
+                             OriginalFlavors);
+  if (err == KERN_SUCCESS) {
+    // replace each with MACH_PORT_NULL.
+    for (unsigned i = 0; i != Count; ++i)
+      task_set_exception_ports(mach_task_self(), OriginalMasks[i],
+                               MACH_PORT_NULL, OriginalBehaviors[i],
+                               OriginalFlavors[i]);
+  }
+
+  // Disable crash reporting on Mac OS X 10.5
+  signal(SIGABRT, _exit);
+  signal(SIGILL,  _exit);
+  signal(SIGFPE,  _exit);
+  signal(SIGSEGV, _exit);
+  signal(SIGBUS,  _exit);
+#endif
+
+  coreFilesPrevented = true;
+}
+
+Optional<std::string> Process::GetEnv(StringRef Name) {
+  std::string NameStr = Name.str();
+  const char *Val = ::getenv(NameStr.c_str());
+  if (!Val)
+    return None;
+  return std::string(Val);
+}
+
+namespace {
+class FDCloser {
+public:
+  FDCloser(int &FD) : FD(FD), KeepOpen(false) {}
+  void keepOpen() { KeepOpen = true; }
+  ~FDCloser() {
+    if (!KeepOpen && FD >= 0)
+      ::close(FD);
+  }
+
+private:
+  FDCloser(const FDCloser &) = delete;
+  void operator=(const FDCloser &) = delete;
+
+  int &FD;
+  bool KeepOpen;
+};
+}
+
+std::error_code Process::FixupStandardFileDescriptors() {
+  int NullFD = -1;
+  FDCloser FDC(NullFD);
+  const int StandardFDs[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO};
+  for (int StandardFD : StandardFDs) {
+    struct stat st;
+    errno = 0;
+    if (RetryAfterSignal(-1, ::fstat, StandardFD, &st) < 0) {
+      assert(errno && "expected errno to be set if fstat failed!");
+      // fstat should return EBADF if the file descriptor is closed.
+      if (errno != EBADF)
+        return std::error_code(errno, std::generic_category());
+    }
+    // if fstat succeeds, move on to the next FD.
+    if (!errno)
+      continue;
+    assert(errno == EBADF && "expected errno to have EBADF at this point!");
+
+    if (NullFD < 0) {
+      // Call ::open in a lambda to avoid overload resolution in
+      // RetryAfterSignal when open is overloaded, such as in Bionic.
+      auto Open = [&]() { return ::open("/dev/null", O_RDWR); };
+      if ((NullFD = RetryAfterSignal(-1, Open)) < 0)
+        return std::error_code(errno, std::generic_category());
+    }
+
+    if (NullFD == StandardFD)
+      FDC.keepOpen();
+    else if (dup2(NullFD, StandardFD) < 0)
+      return std::error_code(errno, std::generic_category());
+  }
+  return std::error_code();
+}
+
+std::error_code Process::SafelyCloseFileDescriptor(int FD) {
+  // Create a signal set filled with *all* signals.
+  sigset_t FullSet;
+  if (sigfillset(&FullSet) < 0)
+    return std::error_code(errno, std::generic_category());
+  // Atomically swap our current signal mask with a full mask.
+  sigset_t SavedSet;
+#if LLVM_ENABLE_THREADS
+  if (int EC = pthread_sigmask(SIG_SETMASK, &FullSet, &SavedSet))
+    return std::error_code(EC, std::generic_category());
+#else
+  if (sigprocmask(SIG_SETMASK, &FullSet, &SavedSet) < 0)
+    return std::error_code(errno, std::generic_category());
+#endif
+  // Attempt to close the file descriptor.
+  // We need to save the error, if one occurs, because our subsequent call to
+  // pthread_sigmask might tamper with errno.
+  int ErrnoFromClose = 0;
+  if (::close(FD) < 0)
+    ErrnoFromClose = errno;
+  // Restore the signal mask back to what we saved earlier.
+  int EC = 0;
+#if LLVM_ENABLE_THREADS
+  EC = pthread_sigmask(SIG_SETMASK, &SavedSet, nullptr);
+#else
+  if (sigprocmask(SIG_SETMASK, &SavedSet, nullptr) < 0)
+    EC = errno;
+#endif
+  // The error code from close takes precedence over the one from
+  // pthread_sigmask.
+  if (ErrnoFromClose)
+    return std::error_code(ErrnoFromClose, std::generic_category());
+  return std::error_code(EC, std::generic_category());
+}
+
+bool Process::StandardInIsUserInput() {
+  return FileDescriptorIsDisplayed(STDIN_FILENO);
+}
+
+bool Process::StandardOutIsDisplayed() {
+  return FileDescriptorIsDisplayed(STDOUT_FILENO);
+}
+
+bool Process::StandardErrIsDisplayed() {
+  return FileDescriptorIsDisplayed(STDERR_FILENO);
+}
+
+bool Process::FileDescriptorIsDisplayed(int fd) {
+#if HAVE_ISATTY
+  return isatty(fd);
+#else
+  // If we don't have isatty, just return false.
+  return false;
+#endif
+}
+
+static unsigned getColumns(int FileID) {
+  // If COLUMNS is defined in the environment, wrap to that many columns.
+  if (const char *ColumnsStr = std::getenv("COLUMNS")) {
+    int Columns = std::atoi(ColumnsStr);
+    if (Columns > 0)
+      return Columns;
+  }
+
+  unsigned Columns = 0;
+
+#if defined(HAVE_SYS_IOCTL_H) && defined(HAVE_TERMIOS_H) \
+  && !(defined(_XOPEN_SOURCE) || defined(_POSIX_C_SOURCE))
+  // Try to determine the width of the terminal.
+  struct winsize ws;
+  if (ioctl(FileID, TIOCGWINSZ, &ws) == 0)
+    Columns = ws.ws_col;
+#endif
+
+  return Columns;
+}
+
+unsigned Process::StandardOutColumns() {
+  if (!StandardOutIsDisplayed())
+    return 0;
+
+  return getColumns(1);
+}
+
+unsigned Process::StandardErrColumns() {
+  if (!StandardErrIsDisplayed())
+    return 0;
+
+  return getColumns(2);
+}
+
+#ifdef HAVE_TERMINFO
+// We manually declare these extern functions because finding the correct
+// headers from various terminfo, curses, or other sources is harder than
+// writing their specs down.
+extern "C" int setupterm(char *term, int filedes, int *errret);
+extern "C" struct term *set_curterm(struct term *termp);
+extern "C" int del_curterm(struct term *termp);
+extern "C" int tigetnum(char *capname);
+#endif
+
+#ifdef HAVE_TERMINFO
+static ManagedStatic<std::mutex> TermColorMutex;
+#endif
+
+static bool terminalHasColors(int fd) {
+#ifdef HAVE_TERMINFO
+  // First, acquire a global lock because these C routines are thread hostile.
+  std::lock_guard<std::mutex> G(*TermColorMutex);
+
+  int errret = 0;
+  if (setupterm(nullptr, fd, &errret) != 0)
+    // Regardless of why, if we can't get terminfo, we shouldn't try to print
+    // colors.
+    return false;
+
+  // Test whether the terminal as set up supports color output. How to do this
+  // isn't entirely obvious. We can use the curses routine 'has_colors' but it
+  // would be nice to avoid a dependency on curses proper when we can make do
+  // with a minimal terminfo parsing library. Also, we don't really care whether
+  // the terminal supports the curses-specific color changing routines, merely
+  // if it will interpret ANSI color escape codes in a reasonable way. Thus, the
+  // strategy here is just to query the baseline colors capability and if it
+  // supports colors at all to assume it will translate the escape codes into
+  // whatever range of colors it does support. We can add more detailed tests
+  // here if users report them as necessary.
+  //
+  // The 'tigetnum' routine returns -2 or -1 on errors, and might return 0 if
+  // the terminfo says that no colors are supported.
+  bool HasColors = tigetnum(const_cast<char *>("colors")) > 0;
+
+  // Now extract the structure allocated by setupterm and free its memory
+  // through a really silly dance.
+  struct term *termp = set_curterm(nullptr);
+  (void)del_curterm(termp); // Drop any errors here.
+
+  // Return true if we found a color capabilities for the current terminal.
+  if (HasColors)
+    return true;
+#else
+  // When the terminfo database is not available, check if the current terminal
+  // is one of terminals that are known to support ANSI color escape codes.
+  if (const char *TermStr = std::getenv("TERM")) {
+    return StringSwitch<bool>(TermStr)
+      .Case("ansi", true)
+      .Case("cygwin", true)
+      .Case("linux", true)
+      .StartsWith("screen", true)
+      .StartsWith("xterm", true)
+      .StartsWith("vt100", true)
+      .StartsWith("rxvt", true)
+      .EndsWith("color", true)
+      .Default(false);
+  }
+#endif
+
+  // Otherwise, be conservative.
+  return false;
+}
+
+bool Process::FileDescriptorHasColors(int fd) {
+  // A file descriptor has colors if it is displayed and the terminal has
+  // colors.
+  return FileDescriptorIsDisplayed(fd) && terminalHasColors(fd);
+}
+
+bool Process::StandardOutHasColors() {
+  return FileDescriptorHasColors(STDOUT_FILENO);
+}
+
+bool Process::StandardErrHasColors() {
+  return FileDescriptorHasColors(STDERR_FILENO);
+}
+
+void Process::UseANSIEscapeCodes(bool /*enable*/) {
+  // No effect.
+}
+
+bool Process::ColorNeedsFlush() {
+  // No, we use ANSI escape sequences.
+  return false;
+}
+
+const char *Process::OutputColor(char code, bool bold, bool bg) {
+  return colorcodes[bg?1:0][bold?1:0][code&7];
+}
+
+const char *Process::OutputBold(bool bg) {
+  return "\033[1m";
+}
+
+const char *Process::OutputReverse() {
+  return "\033[7m";
+}
+
+const char *Process::ResetColor() {
+  return "\033[0m";
+}
+
+#if !HAVE_DECL_ARC4RANDOM
+static unsigned GetRandomNumberSeed() {
+  // Attempt to get the initial seed from /dev/urandom, if possible.
+  int urandomFD = open("/dev/urandom", O_RDONLY);
+
+  if (urandomFD != -1) {
+    unsigned seed;
+    // Don't use a buffered read to avoid reading more data
+    // from /dev/urandom than we need.
+    int count = read(urandomFD, (void *)&seed, sizeof(seed));
+
+    close(urandomFD);
+
+    // Return the seed if the read was successful.
+    if (count == sizeof(seed))
+      return seed;
+  }
+
+  // Otherwise, swizzle the current time and the process ID to form a reasonable
+  // seed.
+  const auto Now = std::chrono::high_resolution_clock::now();
+  return hash_combine(Now.time_since_epoch().count(), ::getpid());
+}
+#endif
+
+unsigned llvm::sys::Process::GetRandomNumber() {
+#if HAVE_DECL_ARC4RANDOM
+  return arc4random();
+#else
+  static int x = (static_cast<void>(::srand(GetRandomNumberSeed())), 0);
+  (void)x;
+  return ::rand();
+#endif
+}