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, 50 insertions, 51 deletions

diff --git a/contrib/llvm/tools/bugpoint/BugDriver.cpp b/contrib/llvm/tools/bugpoint/BugDriver.cpp
index 030749f..78f3529 100644
--- a/contrib/llvm/tools/bugpoint/BugDriver.cpp
+++ b/contrib/llvm/tools/bugpoint/BugDriver.cpp
@@ -29,20 +29,20 @@
 using namespace llvm;
 
 namespace llvm {
-  Triple TargetTriple;
+Triple TargetTriple;
 }
 
 // Anonymous namespace to define command line options for debugging.
 //
 namespace {
-  // Output - The user can specify a file containing the expected output of the
-  // program.  If this filename is set, it is used as the reference diff source,
-  // otherwise the raw input run through an interpreter is used as the reference
-  // source.
-  //
-  cl::opt<std::string>
-  OutputFile("output", cl::desc("Specify a reference program output "
-                                "(for miscompilation detection)"));
+// Output - The user can specify a file containing the expected output of the
+// program.  If this filename is set, it is used as the reference diff source,
+// otherwise the raw input run through an interpreter is used as the reference
+// source.
+//
+cl::opt<std::string> OutputFile("output",
+                                cl::desc("Specify a reference program output "
+                                         "(for miscompilation detection)"));
 }
 
 /// setNewProgram - If we reduce or update the program somehow, call this method
@@ -53,27 +53,26 @@ void BugDriver::setNewProgram(Module *M) {
   Program = M;
 }
 
-
 /// getPassesString - Turn a list of passes into a string which indicates the
 /// command line options that must be passed to add the passes.
 ///
 std::string llvm::getPassesString(const std::vector<std::string> &Passes) {
   std::string Result;
   for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
-    if (i) Result += " ";
+    if (i)
+      Result += " ";
     Result += "-";
     Result += Passes[i];
   }
   return Result;
 }
 
-BugDriver::BugDriver(const char *toolname, bool find_bugs,
-                     unsigned timeout, unsigned memlimit, bool use_valgrind,
-                     LLVMContext& ctxt)
-  : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
-    Program(nullptr), Interpreter(nullptr), SafeInterpreter(nullptr),
-    cc(nullptr), run_find_bugs(find_bugs), Timeout(timeout),
-    MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
+BugDriver::BugDriver(const char *toolname, bool find_bugs, unsigned timeout,
+                     unsigned memlimit, bool use_valgrind, LLVMContext &ctxt)
+    : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
+      Program(nullptr), Interpreter(nullptr), SafeInterpreter(nullptr),
+      cc(nullptr), run_find_bugs(find_bugs), Timeout(timeout),
+      MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
 
 BugDriver::~BugDriver() {
   delete Program;
@@ -123,13 +122,15 @@ bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
 
   // Load the first input file.
   Program = parseInputFile(Filenames[0], Context).release();
-  if (!Program) return true;
+  if (!Program)
+    return true;
 
   outs() << "Read input file      : '" << Filenames[0] << "'\n";
 
   for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
     std::unique_ptr<Module> M = parseInputFile(Filenames[i], Context);
-    if (!M.get()) return true;
+    if (!M.get())
+      return true;
 
     outs() << "Linking in input file: '" << Filenames[i] << "'\n";
     if (Linker::linkModules(*Program, std::move(M)))
@@ -142,16 +143,14 @@ bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
   return false;
 }
 
-
-
 /// run - The top level method that is invoked after all of the instance
 /// variables are set up from command line arguments.
 ///
-bool BugDriver::run(std::string &ErrMsg) {
+Error BugDriver::run() {
   if (run_find_bugs) {
     // Rearrange the passes and apply them to the program. Repeat this process
     // until the user kills the program or we find a bug.
-    return runManyPasses(PassesToRun, ErrMsg);
+    return runManyPasses(PassesToRun);
   }
 
   // If we're not running as a child, the first thing that we must do is
@@ -168,15 +167,14 @@ bool BugDriver::run(std::string &ErrMsg) {
   }
 
   // Set up the execution environment, selecting a method to run LLVM bitcode.
-  if (initializeExecutionEnvironment()) return true;
+  if (Error E = initializeExecutionEnvironment())
+    return E;
 
   // Test to see if we have a code generator crash.
   outs() << "Running the code generator to test for a crash: ";
-  std::string Error;
-  compileProgram(Program, &Error);
-  if (!Error.empty()) {
-    outs() << Error;
-    return debugCodeGeneratorCrash(ErrMsg);
+  if (Error E = compileProgram(Program)) {
+    outs() << toString(std::move(E));
+    return debugCodeGeneratorCrash();
   }
   outs() << '\n';
 
@@ -187,8 +185,9 @@ bool BugDriver::run(std::string &ErrMsg) {
   bool CreatedOutput = false;
   if (ReferenceOutputFile.empty()) {
     outs() << "Generating reference output from raw program: ";
-    if (!createReferenceFile(Program)) {
-      return debugCodeGeneratorCrash(ErrMsg);
+    if (Error E = createReferenceFile(Program)) {
+      errs() << toString(std::move(E));
+      return debugCodeGeneratorCrash();
     }
     CreatedOutput = true;
   }
@@ -202,34 +201,33 @@ bool BugDriver::run(std::string &ErrMsg) {
   // matches, then we assume there is a miscompilation bug and try to
   // diagnose it.
   outs() << "*** Checking the code generator...\n";
-  bool Diff = diffProgram(Program, "", "", false, &Error);
-  if (!Error.empty()) {
-    errs() << Error;
-    return debugCodeGeneratorCrash(ErrMsg);
+  Expected<bool> Diff = diffProgram(Program, "", "", false);
+  if (Error E = Diff.takeError()) {
+    errs() << toString(std::move(E));
+    return debugCodeGeneratorCrash();
   }
-  if (!Diff) {
+  if (!*Diff) {
     outs() << "\n*** Output matches: Debugging miscompilation!\n";
-    debugMiscompilation(&Error);
-    if (!Error.empty()) {
-      errs() << Error;
-      return debugCodeGeneratorCrash(ErrMsg);
+    if (Error E = debugMiscompilation()) {
+      errs() << toString(std::move(E));
+      return debugCodeGeneratorCrash();
     }
-    return false;
+    return Error::success();
   }
 
   outs() << "\n*** Input program does not match reference diff!\n";
   outs() << "Debugging code generator problem!\n";
-  bool Failure = debugCodeGenerator(&Error);
-  if (!Error.empty()) {
-    errs() << Error;
-    return debugCodeGeneratorCrash(ErrMsg);
+  if (Error E = debugCodeGenerator()) {
+    errs() << toString(std::move(E));
+    return debugCodeGeneratorCrash();
   }
-  return Failure;
+  return Error::success();
 }
 
-void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
+void llvm::PrintFunctionList(const std::vector<Function *> &Funcs) {
   unsigned NumPrint = Funcs.size();
-  if (NumPrint > 10) NumPrint = 10;
+  if (NumPrint > 10)
+    NumPrint = 10;
   for (unsigned i = 0; i != NumPrint; ++i)
     outs() << " " << Funcs[i]->getName();
   if (NumPrint < Funcs.size())
@@ -237,9 +235,10 @@ void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
   outs().flush();
 }
 
-void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
+void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable *> &GVs) {
   unsigned NumPrint = GVs.size();
-  if (NumPrint > 10) NumPrint = 10;
+  if (NumPrint > 10)
+    NumPrint = 10;
   for (unsigned i = 0; i != NumPrint; ++i)
     outs() << " " << GVs[i]->getName();
   if (NumPrint < GVs.size())