Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release:

MFC r309142 (by emaste):

Add WITH_LLD_AS_LD build knob

If set it installs LLD as /usr/bin/ld.  LLD (as of version 3.9) is not
capable of linking the world and kernel, but can self-host and link many
substantial applications. GNU ld continues to be used for the world and
kernel build, regardless of how this knob is set.

It is on by default for arm64, and off for all other CPU architectures.

Sponsored by:	The FreeBSD Foundation

MFC r310840:

Reapply 310775, now it also builds correctly if lldb is disabled:

Move llvm-objdump from CLANG_EXTRAS to installed by default

We currently install three tools from binutils 2.17.50: as, ld, and
objdump. Work is underway to migrate to a permissively-licensed
tool-chain, with one goal being the retirement of binutils 2.17.50.

LLVM's llvm-objdump is intended to be compatible with GNU objdump
although it is currently missing some options and may have formatting
differences. Enable it by default for testing and further investigation.
It may later be changed to install as /usr/bin/objdump, it becomes a
fully viable replacement.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D8879

MFC r312855 (by emaste):

Rename LLD_AS_LD to LLD_IS_LD, for consistency with CLANG_IS_CC

Reported by:	Dan McGregor <dan.mcgregor usask.ca>

MFC r313559 | glebius | 2017-02-10 18:34:48 +0100 (Fri, 10 Feb 2017) | 5 lines

Don't check struct rtentry on FreeBSD, it is an internal kernel structure.
On other systems it may be API structure for SIOCADDRT/SIOCDELRT.

Reviewed by:	emaste, dim

MFC r314152 (by jkim):

Remove an assembler flag, which is redundant since r309124.  The upstream
took care of it by introducing a macro NO_EXEC_STACK_DIRECTIVE.

http://llvm.org/viewvc/llvm-project?rev=273500&view=rev

Reviewed by:	dim

MFC r314564:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
4.0.0 (branches/release_40 296509).  The release will follow soon.

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

Also note that as of 4.0.0, lld should be able to link the base system
on amd64 and aarch64.  See the WITH_LLD_IS_LLD setting in src.conf(5).
Though please be aware that this is work in progress.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/4.0.0/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Jan Beich, Antoine Brodin and Eric Fiselier for
their help.

Relnotes:	yes
Exp-run:	antoine
PR:		215969, 216008

MFC r314708:

For now, revert r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.

We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it.  An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142

Reported by:	mjg

MFC r314795:

Reapply r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

Pull in r296992 from upstream llvm trunk (by Sanjoy Das):

  [SCEV] Decrease the recursion threshold for CompareValueComplexity

  Fixes PR32142.

  r287232 accidentally increased the recursion threshold for
  CompareValueComplexity from 2 to 32.  This change reverses that
  change by introducing a separate flag for CompareValueComplexity's
  threshold.

The latter revision fixes the excessive compile times for skein_block.c.

MFC r314907 | mmel | 2017-03-08 12:40:27 +0100 (Wed, 08 Mar 2017) | 7 lines

Unbreak ARMv6 world.

The new compiler_rt library imported with clang 4.0.0 have several fatal
issues (non-functional __udivsi3 for example) with ARM specific instrict
functions. As temporary workaround, until upstream solve these problems,
disable all thumb[1][2] related feature.

MFC r315016:

Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release.
We were already very close to the last release candidate, so this is a
pretty minor update.

Relnotes:	yes

MFC r316005:

Revert r314907, and pull in r298713 from upstream compiler-rt trunk (by
Weiming Zhao):

  builtins: Select correct code fragments when compiling for Thumb1/Thum2/ARM ISA.

  Summary:
  Value of __ARM_ARCH_ISA_THUMB isn't based on the actual compilation
  mode (-mthumb, -marm), it reflect's capability of given CPU.

  Due to this:
   - use  __tbumb__ and __thumb2__ insteand of __ARM_ARCH_ISA_THUMB
   - use '.thumb' directive consistently  in all affected files
   - decorate all thumb functions using
     DEFINE_COMPILERRT_THUMB_FUNCTION()

  ---------
  Note: This patch doesn't fix broken Thumb1 variant of __udivsi3 !

  Reviewers: weimingz, rengolin, compnerd

  Subscribers: aemerson, dim

  Differential Revision: https://reviews.llvm.org/D30938

Discussed with:	mmel

1 files changed, 164 insertions, 20 deletions

diff --git a/contrib/libc++/src/experimental/filesystem/operations.cpp b/contrib/libc++/src/experimental/filesystem/operations.cpp
index 369996f..6c7e4cf 100644
--- a/contrib/libc++/src/experimental/filesystem/operations.cpp
+++ b/contrib/libc++/src/experimental/filesystem/operations.cpp
@@ -51,7 +51,7 @@ void set_or_throw(std::error_code const& m_ec, std::error_code* ec,
     } else {
         string msg_s("std::experimental::filesystem::");
         msg_s += msg;
-        __libcpp_throw(filesystem_error(msg_s, p, p2, m_ec));
+        __throw_filesystem_error(msg_s, p, p2, m_ec);
     }
 }
 
@@ -236,12 +236,11 @@ void __copy(const path& from, const path& to, copy_options options,
         }
         return;
     }
-    else if (is_directory(f)) {
-        if (not bool(copy_options::recursive & options) &&
-            bool(copy_options::__in_recursive_copy & options))
-        {
-            return;
-        }
+    else if (is_directory(f) && bool(copy_options::create_symlinks & options)) {
+        return set_or_throw(make_error_code(errc::is_a_directory), ec, "copy");
+    }
+    else if (is_directory(f) && (bool(copy_options::recursive & options) ||
+             copy_options::none == options)) {
 
         if (!exists(t)) {
             // create directory to with attributes from 'from'.
@@ -283,6 +282,10 @@ bool __copy_file(const path& from, const path& to, copy_options options,
     }
 
     const bool to_exists = exists(to_st);
+    if (to_exists && !is_regular_file(to_st)) {
+        set_or_throw(make_error_code(errc::not_supported), ec, "copy_file", from, to);
+        return false;
+    }
     if (to_exists && bool(copy_options::skip_existing & options)) {
         return false;
     }
@@ -303,6 +306,8 @@ bool __copy_file(const path& from, const path& to, copy_options options,
         set_or_throw(make_error_code(errc::file_exists), ec, "copy", from, to);
         return false;
     }
+
+    _LIBCPP_UNREACHABLE();
 }
 
 void __copy_symlink(const path& existing_symlink, const path& new_symlink,
@@ -476,18 +481,32 @@ bool __fs_is_empty(const path& p, std::error_code *ec)
     std::error_code m_ec;
     struct ::stat pst;
     auto st = detail::posix_stat(p, pst, &m_ec);
-    if (is_directory(st))
-        return directory_iterator(p) == directory_iterator{};
+    if (m_ec) {
+        set_or_throw(m_ec, ec, "is_empty", p);
+        return false;
+    }
+    else if (!is_directory(st) && !is_regular_file(st)) {
+        m_ec = make_error_code(errc::not_supported);
+        set_or_throw(m_ec, ec, "is_empty");
+        return false;
+    }
+    else if (is_directory(st)) {
+        auto it = ec ? directory_iterator(p, *ec) : directory_iterator(p);
+        if (ec && *ec)
+            return false;
+        return it == directory_iterator{};
+    }
     else if (is_regular_file(st))
         return static_cast<std::uintmax_t>(pst.st_size) == 0;
-    // else
-    set_or_throw(m_ec, ec, "is_empty", p);
-    return false;
+
+    _LIBCPP_UNREACHABLE();
 }
 
 
 namespace detail { namespace {
 
+using namespace std::chrono;
+
 template <class CType, class ChronoType>
 bool checked_set(CType* out, ChronoType time) {
     using Lim = numeric_limits<CType>;
@@ -497,8 +516,127 @@ bool checked_set(CType* out, ChronoType time) {
     return true;
 }
 
-constexpr long long min_seconds = file_time_type::duration::min().count()
-    / file_time_type::period::den;
+using TimeSpec = struct ::timespec;
+using StatT = struct ::stat;
+
+#if defined(__APPLE__)
+TimeSpec extract_mtime(StatT const& st) { return st.st_mtimespec; }
+TimeSpec extract_atime(StatT const& st) { return st.st_atimespec; }
+#else
+TimeSpec extract_mtime(StatT const& st) { return st.st_mtim; }
+__attribute__((unused)) // Suppress warning
+TimeSpec extract_atime(StatT const& st) { return st.st_atim; }
+#endif
+
+constexpr auto max_seconds = duration_cast<seconds>(
+    file_time_type::duration::max()).count();
+
+constexpr auto max_nsec = duration_cast<nanoseconds>(
+    file_time_type::duration::max() - seconds(max_seconds)).count();
+
+constexpr auto min_seconds = duration_cast<seconds>(
+    file_time_type::duration::min()).count();
+
+constexpr auto min_nsec_timespec = duration_cast<nanoseconds>(
+    (file_time_type::duration::min() - seconds(min_seconds)) + seconds(1)).count();
+
+// Static assert that these values properly round trip.
+static_assert((seconds(min_seconds) + duration_cast<microseconds>(nanoseconds(min_nsec_timespec)))
+                  - duration_cast<microseconds>(seconds(1))
+                  == file_time_type::duration::min(), "");
+
+constexpr auto max_time_t = numeric_limits<time_t>::max();
+constexpr auto min_time_t = numeric_limits<time_t>::min();
+
+#if !defined(__LP64__) && defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtautological-constant-out-of-range-compare"
+#endif
+
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+bool is_representable(TimeSpec const& tm) {
+  if (tm.tv_sec >= 0) {
+    return (tm.tv_sec < max_seconds) ||
+        (tm.tv_sec == max_seconds && tm.tv_nsec <= max_nsec);
+  } else if (tm.tv_sec == (min_seconds - 1)) {
+     return tm.tv_nsec >= min_nsec_timespec;
+  } else {
+    return (tm.tv_sec >= min_seconds);
+  }
+}
+#ifndef _LIBCPP_HAS_NO_CXX14_CONSTEXPR
+#if defined(__LP64__)
+static_assert(is_representable({max_seconds, max_nsec}), "");
+static_assert(!is_representable({max_seconds + 1, 0}), "");
+static_assert(!is_representable({max_seconds, max_nsec + 1}), "");
+static_assert(!is_representable({max_time_t, 0}), "");
+static_assert(is_representable({min_seconds, 0}), "");
+static_assert(is_representable({min_seconds - 1, min_nsec_timespec}), "");
+static_assert(is_representable({min_seconds - 1, min_nsec_timespec + 1}), "");
+static_assert(!is_representable({min_seconds - 1, min_nsec_timespec - 1}), "");
+static_assert(!is_representable({min_time_t, 999999999}), "");
+#else
+static_assert(is_representable({max_time_t, 999999999}), "");
+static_assert(is_representable({max_time_t, 1000000000}), "");
+static_assert(is_representable({min_time_t, 0}), "");
+#endif
+#endif
+
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+bool is_representable(file_time_type const& tm) {
+  auto secs = duration_cast<seconds>(tm.time_since_epoch());
+  auto nsecs = duration_cast<nanoseconds>(tm.time_since_epoch() - secs);
+  if (nsecs.count() < 0) {
+    secs = secs +  seconds(1);
+    nsecs = nsecs + seconds(1);
+  }
+  using TLim = numeric_limits<time_t>;
+  if (secs.count() >= 0)
+    return secs.count() <= TLim::max();
+  return secs.count() >= TLim::min();
+}
+#ifndef _LIBCPP_HAS_NO_CXX14_CONSTEXPR
+#if defined(__LP64__)
+static_assert(is_representable(file_time_type::max()), "");
+static_assert(is_representable(file_time_type::min()), "");
+#else
+static_assert(!is_representable(file_time_type::max()), "");
+static_assert(!is_representable(file_time_type::min()), "");
+static_assert(is_representable(file_time_type(seconds(max_time_t))), "");
+static_assert(is_representable(file_time_type(seconds(min_time_t))), "");
+#endif
+#endif
+
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+file_time_type convert_timespec(TimeSpec const& tm) {
+  auto adj_msec = duration_cast<microseconds>(nanoseconds(tm.tv_nsec));
+  if (tm.tv_sec >= 0) {
+    auto Dur = seconds(tm.tv_sec) + microseconds(adj_msec);
+    return file_time_type(Dur);
+  } else if (duration_cast<microseconds>(nanoseconds(tm.tv_nsec)).count() == 0) {
+    return file_time_type(seconds(tm.tv_sec));
+  } else { // tm.tv_sec < 0
+    auto adj_subsec = duration_cast<microseconds>(seconds(1) - nanoseconds(tm.tv_nsec));
+    auto Dur = seconds(tm.tv_sec + 1) - adj_subsec;
+    return file_time_type(Dur);
+  }
+}
+#ifndef _LIBCPP_HAS_NO_CXX14_CONSTEXPR
+#if defined(__LP64__)
+static_assert(convert_timespec({max_seconds, max_nsec}) == file_time_type::max(), "");
+static_assert(convert_timespec({max_seconds, max_nsec - 1}) < file_time_type::max(), "");
+static_assert(convert_timespec({max_seconds - 1, 999999999}) < file_time_type::max(), "");
+static_assert(convert_timespec({min_seconds - 1, min_nsec_timespec}) == file_time_type::min(), "");
+static_assert(convert_timespec({min_seconds - 1, min_nsec_timespec + 1}) > file_time_type::min(), "");
+static_assert(convert_timespec({min_seconds , 0}) > file_time_type::min(), "");
+#else
+// FIXME add tests for 32 bit builds
+#endif
+#endif
+
+#if !defined(__LP64__) && defined(__clang__)
+#pragma clang diagnostic pop
+#endif
 
 template <class SubSecDurT, class SubSecT>
 bool set_times_checked(time_t* sec_out, SubSecT* subsec_out, file_time_type tp) {
@@ -509,7 +647,6 @@ bool set_times_checked(time_t* sec_out, SubSecT* subsec_out, file_time_type tp)
     // The tv_nsec and tv_usec fields must not be negative so adjust accordingly
     if (subsec_dur.count() < 0) {
         if (sec_dur.count() > min_seconds) {
-
             sec_dur -= seconds(1);
             subsec_dur += seconds(1);
         } else {
@@ -522,9 +659,9 @@ bool set_times_checked(time_t* sec_out, SubSecT* subsec_out, file_time_type tp)
 
 }} // end namespace detail
 
-
 file_time_type __last_write_time(const path& p, std::error_code *ec)
 {
+    using namespace ::std::chrono;
     std::error_code m_ec;
     struct ::stat st;
     detail::posix_stat(p, st, &m_ec);
@@ -533,7 +670,13 @@ file_time_type __last_write_time(const path& p, std::error_code *ec)
         return file_time_type::min();
     }
     if (ec) ec->clear();
-    return file_time_type::clock::from_time_t(st.st_mtime);
+    auto ts = detail::extract_mtime(st);
+    if (!detail::is_representable(ts)) {
+        set_or_throw(error_code(EOVERFLOW, generic_category()), ec,
+                     "last_write_time", p);
+        return file_time_type::min();
+    }
+    return detail::convert_timespec(ts);
 }
 
 void __last_write_time(const path& p, file_time_type new_time,
@@ -554,9 +697,10 @@ void __last_write_time(const path& p, file_time_type new_time,
         set_or_throw(m_ec, ec, "last_write_time", p);
         return;
     }
+    auto atime = detail::extract_atime(st);
     struct ::timeval tbuf[2];
-    tbuf[0].tv_sec = st.st_atime;
-    tbuf[0].tv_usec = 0;
+    tbuf[0].tv_sec = atime.tv_sec;
+    tbuf[0].tv_usec = duration_cast<microseconds>(nanoseconds(atime.tv_nsec)).count();
     const bool overflowed = !detail::set_times_checked<microseconds>(
         &tbuf[1].tv_sec, &tbuf[1].tv_usec, new_time);
 
@@ -720,7 +864,7 @@ space_info __space(const path& p, std::error_code *ec) {
     // Multiply with overflow checking.
     auto do_mult = [&](std::uintmax_t& out, std::uintmax_t other) {
       out = other * m_svfs.f_frsize;
-      if (out / other != m_svfs.f_frsize || other == 0)
+      if (other == 0 || out / other != m_svfs.f_frsize)
           out = static_cast<std::uintmax_t>(-1);
     };
     do_mult(si.capacity, m_svfs.f_blocks);