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, 189 insertions, 0 deletions

diff --git a/contrib/llvm/lib/Support/TarWriter.cpp b/contrib/llvm/lib/Support/TarWriter.cpp
new file mode 100644
index 0000000..f06abf4
--- /dev/null
+++ b/contrib/llvm/lib/Support/TarWriter.cpp
@@ -0,0 +1,189 @@
+//===-- TarWriter.cpp - Tar archive file creator --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// TarWriter class provides a feature to create a tar archive file.
+//
+// I put emphasis on simplicity over comprehensiveness when implementing this
+// class because we don't need a full-fledged archive file generator in LLVM
+// at the moment.
+//
+// The filename field in the Unix V7 tar header is 100 bytes. Longer filenames
+// are stored using the PAX extension. The PAX header is standardized in
+// POSIX.1-2001.
+//
+// The struct definition of UstarHeader is copied from
+// https://www.freebsd.org/cgi/man.cgi?query=tar&sektion=5
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/TarWriter.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Path.h"
+
+using namespace llvm;
+
+// Each file in an archive must be aligned to this block size.
+static const int BlockSize = 512;
+
+struct UstarHeader {
+  char Name[100];
+  char Mode[8];
+  char Uid[8];
+  char Gid[8];
+  char Size[12];
+  char Mtime[12];
+  char Checksum[8];
+  char TypeFlag;
+  char Linkname[100];
+  char Magic[6];
+  char Version[2];
+  char Uname[32];
+  char Gname[32];
+  char DevMajor[8];
+  char DevMinor[8];
+  char Prefix[155];
+  char Pad[12];
+};
+static_assert(sizeof(UstarHeader) == BlockSize, "invalid Ustar header");
+
+static UstarHeader makeUstarHeader() {
+  UstarHeader Hdr = {};
+  memcpy(Hdr.Magic, "ustar", 5); // Ustar magic
+  memcpy(Hdr.Version, "00", 2);  // Ustar version
+  return Hdr;
+}
+
+// A PAX attribute is in the form of "<length> <key>=<value>\n"
+// where <length> is the length of the entire string including
+// the length field itself. An example string is this.
+//
+//   25 ctime=1084839148.1212\n
+//
+// This function create such string.
+static std::string formatPax(StringRef Key, StringRef Val) {
+  int Len = Key.size() + Val.size() + 3; // +3 for " ", "=" and "\n"
+
+  // We need to compute total size twice because appending
+  // a length field could change total size by one.
+  int Total = Len + Twine(Len).str().size();
+  Total = Len + Twine(Total).str().size();
+  return (Twine(Total) + " " + Key + "=" + Val + "\n").str();
+}
+
+// Headers in tar files must be aligned to 512 byte boundaries.
+// This function forwards the current file position to the next boundary.
+static void pad(raw_fd_ostream &OS) {
+  uint64_t Pos = OS.tell();
+  OS.seek(alignTo(Pos, BlockSize));
+}
+
+// Computes a checksum for a tar header.
+static void computeChecksum(UstarHeader &Hdr) {
+  // Before computing a checksum, checksum field must be
+  // filled with space characters.
+  memset(Hdr.Checksum, ' ', sizeof(Hdr.Checksum));
+
+  // Compute a checksum and set it to the checksum field.
+  unsigned Chksum = 0;
+  for (size_t I = 0; I < sizeof(Hdr); ++I)
+    Chksum += reinterpret_cast<uint8_t *>(&Hdr)[I];
+  snprintf(Hdr.Checksum, sizeof(Hdr.Checksum), "%06o", Chksum);
+}
+
+// Create a tar header and write it to a given output stream.
+static void writePaxHeader(raw_fd_ostream &OS, StringRef Path) {
+  // A PAX header consists of a 512-byte header followed
+  // by key-value strings. First, create key-value strings.
+  std::string PaxAttr = formatPax("path", Path);
+
+  // Create a 512-byte header.
+  UstarHeader Hdr = makeUstarHeader();
+  snprintf(Hdr.Size, sizeof(Hdr.Size), "%011zo", PaxAttr.size());
+  Hdr.TypeFlag = 'x'; // PAX magic
+  computeChecksum(Hdr);
+
+  // Write them down.
+  OS << StringRef(reinterpret_cast<char *>(&Hdr), sizeof(Hdr));
+  OS << PaxAttr;
+  pad(OS);
+}
+
+// In the Ustar header, a path can be split at any '/' to store
+// a path into UstarHeader::Name and UstarHeader::Prefix. This
+// function splits a given path for that purpose.
+static std::pair<StringRef, StringRef> splitPath(StringRef Path) {
+  if (Path.size() <= sizeof(UstarHeader::Name))
+    return {"", Path};
+  size_t Sep = Path.rfind('/', sizeof(UstarHeader::Prefix) + 1);
+  if (Sep == StringRef::npos)
+    return {"", Path};
+  return {Path.substr(0, Sep), Path.substr(Sep + 1)};
+}
+
+// Returns true if a given path can be stored to a Ustar header
+// without the PAX extension.
+static bool fitsInUstar(StringRef Path) {
+  StringRef Prefix;
+  StringRef Name;
+  std::tie(Prefix, Name) = splitPath(Path);
+  return Name.size() <= sizeof(UstarHeader::Name);
+}
+
+// The PAX header is an extended format, so a PAX header needs
+// to be followed by a "real" header.
+static void writeUstarHeader(raw_fd_ostream &OS, StringRef Path, size_t Size) {
+  StringRef Prefix;
+  StringRef Name;
+  std::tie(Prefix, Name) = splitPath(Path);
+
+  UstarHeader Hdr = makeUstarHeader();
+  memcpy(Hdr.Name, Name.data(), Name.size());
+  memcpy(Hdr.Mode, "0000664", 8);
+  snprintf(Hdr.Size, sizeof(Hdr.Size), "%011zo", Size);
+  memcpy(Hdr.Prefix, Prefix.data(), Prefix.size());
+  computeChecksum(Hdr);
+  OS << StringRef(reinterpret_cast<char *>(&Hdr), sizeof(Hdr));
+}
+
+// Creates a TarWriter instance and returns it.
+Expected<std::unique_ptr<TarWriter>> TarWriter::create(StringRef OutputPath,
+                                                       StringRef BaseDir) {
+  int FD;
+  if (std::error_code EC = openFileForWrite(OutputPath, FD, sys::fs::F_None))
+    return make_error<StringError>("cannot open " + OutputPath, EC);
+  return std::unique_ptr<TarWriter>(new TarWriter(FD, BaseDir));
+}
+
+TarWriter::TarWriter(int FD, StringRef BaseDir)
+    : OS(FD, /*shouldClose=*/true, /*unbuffered=*/false), BaseDir(BaseDir) {}
+
+// Append a given file to an archive.
+void TarWriter::append(StringRef Path, StringRef Data) {
+  // Write Path and Data.
+  std::string S = BaseDir + "/" + sys::path::convert_to_slash(Path) + "\0";
+  if (fitsInUstar(S)) {
+    writeUstarHeader(OS, S, Data.size());
+  } else {
+    writePaxHeader(OS, S);
+    writeUstarHeader(OS, "", Data.size());
+  }
+
+  OS << Data;
+  pad(OS);
+
+  // POSIX requires tar archives end with two null blocks.
+  // Here, we write the terminator and then seek back, so that
+  // the file being output is terminated correctly at any moment.
+  uint64_t Pos = OS.tell();
+  OS << std::string(BlockSize * 2, '\0');
+  OS.seek(Pos);
+  OS.flush();
+}