MFC r309124:

Upgrade our copies of clang, llvm, lldb, compiler-rt and libc++ to 3.9.0
release, and add lld 3.9.0.  Also completely revamp the build system for
clang, llvm, lldb and their related tools.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld are available here:
<http://llvm.org/releases/3.9.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/clang/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Bryan Drewery, Andrew Turner, Antoine Brodin and Jan
Beich for their help.

Relnotes:	yes

MFC r309147:

Pull in r282174 from upstream llvm trunk (by Krzysztof Parzyszek):

  [PPC] Set SP after loading data from stack frame, if no red zone is
  present

  Follow-up to r280705: Make sure that the SP is only restored after
  all data is loaded from the stack frame, if there is no red zone.

  This completes the fix for
  https://llvm.org/bugs/show_bug.cgi?id=26519.

  Differential Revision: https://reviews.llvm.org/D24466

Reported by:    Mark Millard
PR:             214433

MFC r309149:

Pull in r283060 from upstream llvm trunk (by Hal Finkel):

  [PowerPC] Refactor soft-float support, and enable PPC64 soft float

  This change enables soft-float for PowerPC64, and also makes
  soft-float disable all vector instruction sets for both 32-bit and
  64-bit modes. This latter part is necessary because the PPC backend
  canonicalizes many Altivec vector types to floating-point types, and
  so soft-float breaks scalarization support for many operations. Both
  for embedded targets and for operating-system kernels desiring
  soft-float support, it seems reasonable that disabling hardware
  floating-point also disables vector instructions (embedded targets
  without hardware floating point support are unlikely to have Altivec,
  etc. and operating system kernels desiring not to use floating-point
  registers to lower syscall cost are unlikely to want to use vector
  registers either). If someone needs this to work, we'll need to
  change the fact that we promote many Altivec operations to act on
  v4f32. To make it possible to disable Altivec when soft-float is
  enabled, hardware floating-point support needs to be expressed as a
  positive feature, like the others, and not a negative feature,
  because target features cannot have dependencies on the disabling of
  some other feature. So +soft-float has now become -hard-float.

  Fixes PR26970.

Pull in r283061 from upstream clang trunk (by Hal Finkel):

  [PowerPC] Enable soft-float for PPC64, and +soft-float -> -hard-float

  Enable soft-float support on PPC64, as the backend now supports it.
  Also, the backend now uses -hard-float instead of +soft-float, so set
  the target features accordingly.

  Fixes PR26970.

Reported by:	Mark Millard
PR:		214433

MFC r309212:

Add a few missed clang 3.9.0 files to OptionalObsoleteFiles.

MFC r309262:

Fix packaging for clang, lldb and lld 3.9.0

During the upgrade of clang/llvm etc to 3.9.0 in r309124, the PACKAGE
directive in the usr.bin/clang/*.mk files got dropped accidentally.

Restore it, with a few minor changes and additions:
* Correct license in clang.ucl to NCSA
* Add PACKAGE=clang for clang and most of the "ll" tools
* Put lldb in its own package
* Put lld in its own package

Reviewed by:	gjb, jmallett
Differential Revision: https://reviews.freebsd.org/D8666

MFC r309656:

During the bootstrap phase, when building the minimal llvm library on
PowerPC, add lib/Support/Atomic.cpp.  This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.

Reported by:	Mark Millard
PR:		214902

MFC r309835:

Tentatively apply https://reviews.llvm.org/D18730 to work around gcc PR
70528 (bogus error: constructor required before non-static data member).
This should fix buildworld with the external gcc package.

Reported by:	https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc/

MFC r310194:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
3.9.1 release.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/3.9.1/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/lld/docs/ReleaseNotes.html>

Relnotes:	yes

4 files changed, 236 insertions, 57 deletions

diff --git a/contrib/llvm/lib/Support/Unix/Memory.inc b/contrib/llvm/lib/Support/Unix/Memory.inc
index d703191..f3463e5 100644
--- a/contrib/llvm/lib/Support/Unix/Memory.inc
+++ b/contrib/llvm/lib/Support/Unix/Memory.inc
@@ -73,7 +73,7 @@ int getPosixProtectionFlags(unsigned Flags) {
   return PROT_NONE;
 }
 
-} // namespace
+} // anonymous namespace
 
 namespace llvm {
 namespace sys {
@@ -265,7 +265,7 @@ bool Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
 }
 
 bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
-  if (M.Address == 0 || M.Size == 0) return false;
+  if (M.Address == nullptr || M.Size == 0) return false;
   Memory::InvalidateInstructionCache(M.Address, M.Size);
 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
diff --git a/contrib/llvm/lib/Support/Unix/Path.inc b/contrib/llvm/lib/Support/Unix/Path.inc
index d85c37a..84aafcb 100644
--- a/contrib/llvm/lib/Support/Unix/Path.inc
+++ b/contrib/llvm/lib/Support/Unix/Path.inc
@@ -25,6 +25,9 @@
 #if HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_SYS_MMAN_H
 #include <sys/mman.h>
 #endif
@@ -47,6 +50,7 @@
 
 #ifdef __APPLE__
 #include <mach-o/dyld.h>
+#include <sys/attr.h>
 #endif
 
 // Both stdio.h and cstdio are included via different pathes and
@@ -60,6 +64,25 @@
 # define PATH_MAX 4096
 #endif
 
+#include <sys/types.h>
+#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__ANDROID__)
+#include <sys/statvfs.h>
+#define STATVFS statvfs
+#define STATVFS_F_FRSIZE(vfs) vfs.f_frsize
+#else
+#ifdef __OpenBSD__
+#include <sys/param.h>
+#include <sys/mount.h>
+#elif defined(__ANDROID__)
+#include <sys/vfs.h>
+#else
+#include <sys/mount.h>
+#endif
+#define STATVFS statfs
+#define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize)
+#endif
+
+
 using namespace llvm;
 
 namespace llvm {
@@ -70,7 +93,7 @@ namespace fs {
     defined(__linux__) || defined(__CYGWIN__) || defined(__DragonFly__)
 static int
 test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
-{  
+{
   struct stat sb;
   char fullpath[PATH_MAX];
 
@@ -174,6 +197,12 @@ std::string getMainExecutable(const char *argv0, void *MainAddr) {
   return "";
 }
 
+TimeValue file_status::getLastAccessedTime() const {
+  TimeValue Ret;
+  Ret.fromEpochTime(fs_st_atime);
+  return Ret;
+}
+
 TimeValue file_status::getLastModificationTime() const {
   TimeValue Ret;
   Ret.fromEpochTime(fs_st_mtime);
@@ -184,6 +213,18 @@ UniqueID file_status::getUniqueID() const {
   return UniqueID(fs_st_dev, fs_st_ino);
 }
 
+ErrorOr<space_info> disk_space(const Twine &Path) {
+  struct STATVFS Vfs;
+  if (::STATVFS(Path.str().c_str(), &Vfs))
+    return std::error_code(errno, std::generic_category());
+  auto FrSize = STATVFS_F_FRSIZE(Vfs);
+  space_info SpaceInfo;
+  SpaceInfo.capacity = static_cast<uint64_t>(Vfs.f_blocks) * FrSize;
+  SpaceInfo.free = static_cast<uint64_t>(Vfs.f_bfree) * FrSize;
+  SpaceInfo.available = static_cast<uint64_t>(Vfs.f_bavail) * FrSize;
+  return SpaceInfo;
+}
+
 std::error_code current_path(SmallVectorImpl<char> &result) {
   result.clear();
 
@@ -373,8 +414,9 @@ static std::error_code fillStatus(int StatRet, const struct stat &Status,
 
   perms Perms = static_cast<perms>(Status.st_mode);
   Result =
-      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_mtime,
-                  Status.st_uid, Status.st_gid, Status.st_size);
+      file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_atime,
+                  Status.st_mtime, Status.st_uid, Status.st_gid,
+                  Status.st_size);
 
   return std::error_code();
 }
@@ -506,13 +548,47 @@ std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
   return std::error_code();
 }
 
-std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
+#if !defined(F_GETPATH)
+static bool hasProcSelfFD() {
+  // If we have a /proc filesystem mounted, we can quickly establish the
+  // real name of the file with readlink
+  static const bool Result = (::access("/proc/self/fd", R_OK) == 0);
+  return Result;
+}
+#endif
+
+std::error_code openFileForRead(const Twine &Name, int &ResultFD,
+                                SmallVectorImpl<char> *RealPath) {
   SmallString<128> Storage;
   StringRef P = Name.toNullTerminatedStringRef(Storage);
   while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
     if (errno != EINTR)
       return std::error_code(errno, std::generic_category());
   }
+  // Attempt to get the real name of the file, if the user asked
+  if(!RealPath)
+    return std::error_code();
+  RealPath->clear();
+#if defined(F_GETPATH)
+  // When F_GETPATH is availble, it is the quickest way to get
+  // the real path name.
+  char Buffer[MAXPATHLEN];
+  if (::fcntl(ResultFD, F_GETPATH, Buffer) != -1)
+    RealPath->append(Buffer, Buffer + strlen(Buffer));
+#else
+  char Buffer[PATH_MAX];
+  if (hasProcSelfFD()) {
+    char ProcPath[64];
+    snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", ResultFD);
+    ssize_t CharCount = ::readlink(ProcPath, Buffer, sizeof(Buffer));
+    if (CharCount > 0)
+      RealPath->append(Buffer, Buffer + CharCount);
+  } else {
+    // Use ::realpath to get the real path name
+    if (::realpath(P.begin(), Buffer) != nullptr)
+      RealPath->append(Buffer, Buffer + strlen(Buffer));
+  }
+#endif
   return std::error_code();
 }
 
@@ -546,6 +622,53 @@ std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
   return std::error_code();
 }
 
+std::error_code getPathFromOpenFD(int FD, SmallVectorImpl<char> &ResultPath) {
+  if (FD < 0)
+    return make_error_code(errc::bad_file_descriptor);
+
+#if defined(F_GETPATH)
+  // When F_GETPATH is availble, it is the quickest way to get
+  // the path from a file descriptor.
+  ResultPath.reserve(MAXPATHLEN);
+  if (::fcntl(FD, F_GETPATH, ResultPath.begin()) == -1)
+    return std::error_code(errno, std::generic_category());
+
+  ResultPath.set_size(strlen(ResultPath.begin()));
+#else
+  // If we have a /proc filesystem mounted, we can quickly establish the
+  // real name of the file with readlink. Otherwise, we don't know how to
+  // get the filename from a file descriptor. Give up.
+  if (!fs::hasProcSelfFD())
+    return make_error_code(errc::function_not_supported);
+
+  ResultPath.reserve(PATH_MAX);
+  char ProcPath[64];
+  snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", FD);
+  ssize_t CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
+  if (CharCount < 0)
+      return std::error_code(errno, std::generic_category());
+
+  // Was the filename truncated?
+  if (static_cast<size_t>(CharCount) == ResultPath.capacity()) {
+    // Use lstat to get the size of the filename
+    struct stat sb;
+    if (::lstat(ProcPath, &sb) < 0)
+      return std::error_code(errno, std::generic_category());
+
+    ResultPath.reserve(sb.st_size + 1);
+    CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
+    if (CharCount < 0)
+      return std::error_code(errno, std::generic_category());
+
+    // Test for race condition: did the link size change?
+    if (CharCount > sb.st_size)
+      return std::error_code(ENAMETOOLONG, std::generic_category());
+  }
+  ResultPath.set_size(static_cast<size_t>(CharCount));
+#endif
+  return std::error_code();
+}
+
 } // end namespace fs
 
 namespace path {
@@ -586,12 +709,12 @@ static bool getDarwinConfDir(bool TempDir, SmallVectorImpl<char> &Result) {
 }
 
 static bool getUserCacheDir(SmallVectorImpl<char> &Result) {
-  // First try using XDS_CACHE_HOME env variable,
+  // First try using XDG_CACHE_HOME env variable,
   // as specified in XDG Base Directory Specification at
   // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
-  if (const char *XdsCacheDir = std::getenv("XDS_CACHE_HOME")) {
+  if (const char *XdgCacheDir = std::getenv("XDG_CACHE_HOME")) {
     Result.clear();
-    Result.append(XdsCacheDir, XdsCacheDir + strlen(XdsCacheDir));
+    Result.append(XdgCacheDir, XdgCacheDir + strlen(XdgCacheDir));
     return true;
   }
 
diff --git a/contrib/llvm/lib/Support/Unix/Process.inc b/contrib/llvm/lib/Support/Unix/Process.inc
index 27083ee..d81836b 100644
--- a/contrib/llvm/lib/Support/Unix/Process.inc
+++ b/contrib/llvm/lib/Support/Unix/Process.inc
@@ -169,6 +169,8 @@ void Process::PreventCoreFiles() {
   signal(SIGSEGV, _exit);
   signal(SIGBUS,  _exit);
 #endif
+
+  coreFilesPrevented = true;
 }
 
 Optional<std::string> Process::GetEnv(StringRef Name) {
@@ -456,7 +458,7 @@ unsigned llvm::sys::Process::GetRandomNumber() {
 #if defined(HAVE_DECL_ARC4RANDOM) && HAVE_DECL_ARC4RANDOM
   return arc4random();
 #else
-  static int x = (::srand(GetRandomNumberSeed()), 0);
+  static int x = (static_cast<void>(::srand(GetRandomNumberSeed())), 0);
   (void)x;
   return ::rand();
 #endif
diff --git a/contrib/llvm/lib/Support/Unix/Signals.inc b/contrib/llvm/lib/Support/Unix/Signals.inc
index 061cdb3..55fd76d 100644
--- a/contrib/llvm/lib/Support/Unix/Signals.inc
+++ b/contrib/llvm/lib/Support/Unix/Signals.inc
@@ -45,6 +45,17 @@
 #if HAVE_LINK_H
 #include <link.h>
 #endif
+#if HAVE_UNWIND_BACKTRACE
+// FIXME: We should be able to use <unwind.h> for any target that has an
+// _Unwind_Backtrace function, but on FreeBSD the configure test passes
+// despite the function not existing, and on Android, <unwind.h> conflicts
+// with <link.h>.
+#ifdef __GLIBC__
+#include <unwind.h>
+#else
+#undef HAVE_UNWIND_BACKTRACE
+#endif
+#endif
 
 using namespace llvm;
 
@@ -57,6 +68,8 @@ static void (*InterruptFunction)() = nullptr;
 
 static ManagedStatic<std::vector<std::string>> FilesToRemove;
 
+static StringRef Argv0;
+
 // IntSigs - Signals that represent requested termination. There's no bug
 // or failure, or if there is, it's not our direct responsibility. For whatever
 // reason, our continued execution is no longer desirable.
@@ -96,7 +109,7 @@ static void RegisterHandler(int Signal) {
   struct sigaction NewHandler;
 
   NewHandler.sa_handler = SignalHandler;
-  NewHandler.sa_flags = SA_NODEFER|SA_RESETHAND;
+  NewHandler.sa_flags = SA_NODEFER | SA_RESETHAND | SA_ONSTACK;
   sigemptyset(&NewHandler.sa_mask);
 
   // Install the new handler, save the old one in RegisteredSignalInfo.
@@ -106,6 +119,35 @@ static void RegisterHandler(int Signal) {
   ++NumRegisteredSignals;
 }
 
+#if defined(HAVE_SIGALTSTACK)
+// Hold onto the old alternate signal stack so that it's not reported as a leak.
+// We don't make any attempt to remove our alt signal stack if we remove our
+// signal handlers; that can't be done reliably if someone else is also trying
+// to do the same thing.
+static stack_t OldAltStack;
+
+static void CreateSigAltStack() {
+  const size_t AltStackSize = MINSIGSTKSZ + 8192;
+
+  // If we're executing on the alternate stack, or we already have an alternate
+  // signal stack that we're happy with, there's nothing for us to do. Don't
+  // reduce the size, some other part of the process might need a larger stack
+  // than we do.
+  if (sigaltstack(nullptr, &OldAltStack) != 0 ||
+      OldAltStack.ss_flags & SS_ONSTACK ||
+      (OldAltStack.ss_sp && OldAltStack.ss_size >= AltStackSize))
+    return;
+
+  stack_t AltStack = {};
+  AltStack.ss_sp = reinterpret_cast<char *>(malloc(AltStackSize));
+  AltStack.ss_size = AltStackSize;
+  if (sigaltstack(&AltStack, &OldAltStack) != 0)
+    free(AltStack.ss_sp);
+}
+#else
+static void CreateSigAltStack() {}
+#endif
+
 static void RegisterHandlers() {
   // We need to dereference the signals mutex during handler registration so
   // that we force its construction. This is to prevent the first use being
@@ -116,6 +158,10 @@ static void RegisterHandlers() {
   // If the handlers are already registered, we're done.
   if (NumRegisteredSignals != 0) return;
 
+  // Create an alternate stack for signal handling. This is necessary for us to
+  // be able to reliably handle signals due to stack overflow.
+  CreateSigAltStack();
+
   for (auto S : IntSigs) RegisterHandler(S);
   for (auto S : KillSigs) RegisterHandler(S);
 }
@@ -309,20 +355,64 @@ static bool findModulesAndOffsets(void **StackTrace, int Depth,
 }
 #endif // defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES) && ...
 
+#if defined(ENABLE_BACKTRACES) && defined(HAVE_UNWIND_BACKTRACE)
+static int unwindBacktrace(void **StackTrace, int MaxEntries) {
+  if (MaxEntries < 0)
+    return 0;
+
+  // Skip the first frame ('unwindBacktrace' itself).
+  int Entries = -1;
+
+  auto HandleFrame = [&](_Unwind_Context *Context) -> _Unwind_Reason_Code {
+    // Apparently we need to detect reaching the end of the stack ourselves.
+    void *IP = (void *)_Unwind_GetIP(Context);
+    if (!IP)
+      return _URC_END_OF_STACK;
+
+    assert(Entries < MaxEntries && "recursively called after END_OF_STACK?");
+    if (Entries >= 0)
+      StackTrace[Entries] = IP;
+
+    if (++Entries == MaxEntries)
+      return _URC_END_OF_STACK;
+    return _URC_NO_REASON;
+  };
+
+  _Unwind_Backtrace(
+      [](_Unwind_Context *Context, void *Handler) {
+        return (*static_cast<decltype(HandleFrame) *>(Handler))(Context);
+      },
+      static_cast<void *>(&HandleFrame));
+  return std::max(Entries, 0);
+}
+#endif
+
 // PrintStackTrace - In the case of a program crash or fault, print out a stack
 // trace so that the user has an indication of why and where we died.
 //
 // On glibc systems we have the 'backtrace' function, which works nicely, but
 // doesn't demangle symbols.
 void llvm::sys::PrintStackTrace(raw_ostream &OS) {
-#if defined(HAVE_BACKTRACE) && defined(ENABLE_BACKTRACES)
-  static void* StackTrace[256];
+#if defined(ENABLE_BACKTRACES)
+  static void *StackTrace[256];
+  int depth = 0;
+#if defined(HAVE_BACKTRACE)
   // Use backtrace() to output a backtrace on Linux systems with glibc.
-  int depth = backtrace(StackTrace,
+  if (!depth)
+    depth = backtrace(StackTrace, static_cast<int>(array_lengthof(StackTrace)));
+#endif
+#if defined(HAVE_UNWIND_BACKTRACE)
+  // Try _Unwind_Backtrace() if backtrace() failed.
+  if (!depth)
+    depth = unwindBacktrace(StackTrace,
                         static_cast<int>(array_lengthof(StackTrace)));
-  if (printSymbolizedStackTrace(StackTrace, depth, OS))
+#endif
+  if (!depth)
+    return;
+
+  if (printSymbolizedStackTrace(Argv0, StackTrace, depth, OS))
     return;
-#if HAVE_DLFCN_H && __GNUG__
+#if HAVE_DLFCN_H && __GNUG__ && !defined(__CYGWIN__)
   int width = 0;
   for (int i = 0; i < depth; ++i) {
     Dl_info dlinfo;
@@ -369,7 +459,7 @@ void llvm::sys::PrintStackTrace(raw_ostream &OS) {
     }
     OS << '\n';
   }
-#else
+#elif defined(HAVE_BACKTRACE)
   backtrace_symbols_fd(StackTrace, depth, STDERR_FILENO);
 #endif
 #endif
@@ -383,7 +473,10 @@ void llvm::sys::DisableSystemDialogsOnCrash() {}
 
 /// PrintStackTraceOnErrorSignal - When an error signal (such as SIGABRT or
 /// SIGSEGV) is delivered to the process, print a stack trace and then exit.
-void llvm::sys::PrintStackTraceOnErrorSignal(bool DisableCrashReporting) {
+void llvm::sys::PrintStackTraceOnErrorSignal(StringRef Argv0,
+                                             bool DisableCrashReporting) {
+  ::Argv0 = Argv0;
+
   AddSignalHandler(PrintStackTraceSignalHandler, nullptr);
 
 #if defined(__APPLE__) && defined(ENABLE_CRASH_OVERRIDES)
@@ -402,42 +495,3 @@ void llvm::sys::PrintStackTraceOnErrorSignal(bool DisableCrashReporting) {
   }
 #endif
 }
-
-
-/***/
-
-// On Darwin, raise sends a signal to the main thread instead of the current
-// thread. This has the unfortunate effect that assert() and abort() will end up
-// bypassing our crash recovery attempts. We work around this for anything in
-// the same linkage unit by just defining our own versions of the assert handler
-// and abort.
-
-#if defined(__APPLE__) && defined(ENABLE_CRASH_OVERRIDES)
-
-#include <signal.h>
-#include <pthread.h>
-
-int raise(int sig) {
-  return pthread_kill(pthread_self(), sig);
-}
-
-void __assert_rtn(const char *func,
-                  const char *file,
-                  int line,
-                  const char *expr) {
-  if (func)
-    fprintf(stderr, "Assertion failed: (%s), function %s, file %s, line %d.\n",
-            expr, func, file, line);
-  else
-    fprintf(stderr, "Assertion failed: (%s), file %s, line %d.\n",
-            expr, file, line);
-  abort();
-}
-
-void abort() {
-  raise(SIGABRT);
-  usleep(1000);
-  __builtin_trap();
-}
-
-#endif