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, 299 insertions, 0 deletions

diff --git a/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp b/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp
new file mode 100644
index 0000000..f0be41b
--- /dev/null
+++ b/contrib/llvm/tools/clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp
@@ -0,0 +1,299 @@
+//==- GTestChecker.cpp - Model gtest API --*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This checker models the behavior of un-inlined APIs from the gtest
+// unit-testing library to avoid false positives when using assertions from
+// that library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/AST/Expr.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+using namespace ento;
+
+// Modeling of un-inlined AssertionResult constructors
+//
+// The gtest unit testing API provides macros for assertions that expand
+// into an if statement that calls a series of constructors and returns
+// when the "assertion" is false.
+//
+// For example,
+//
+//   ASSERT_TRUE(a == b)
+//
+// expands into:
+//
+//   switch (0)
+//   case 0:
+//   default:
+//     if (const ::testing::AssertionResult gtest_ar_ =
+//             ::testing::AssertionResult((a == b)))
+//       ;
+//     else
+//       return ::testing::internal::AssertHelper(
+//                  ::testing::TestPartResult::kFatalFailure,
+//                  "<path to project>",
+//                  <line number>,
+//                  ::testing::internal::GetBoolAssertionFailureMessage(
+//                      gtest_ar_, "a == b", "false", "true")
+//                      .c_str()) = ::testing::Message();
+//
+// where AssertionResult is defined similarly to
+//
+//   class AssertionResult {
+//   public:
+//     AssertionResult(const AssertionResult& other);
+//     explicit AssertionResult(bool success) : success_(success) {}
+//     operator bool() const { return success_; }
+//     ...
+//     private:
+//     bool success_;
+//   };
+//
+// In order for the analyzer to correctly handle this assertion, it needs to
+// know that the boolean value of the expression "a == b" is stored the
+// 'success_' field of the original AssertionResult temporary and propagated
+// (via the copy constructor) into the 'success_' field of the object stored
+// in 'gtest_ar_'.  That boolean value will then be returned from the bool
+// conversion method in the if statement. This guarantees that the assertion
+// holds when the return path is not taken.
+//
+// If the success value is not properly propagated, then the eager case split
+// on evaluating the expression can cause pernicious false positives
+// on the non-return path:
+//
+//   ASSERT(ptr != NULL)
+//   *ptr = 7; // False positive null pointer dereference here
+//
+// Unfortunately, the bool constructor cannot be inlined (because its
+// implementation is not present in the headers) and the copy constructor is
+// not inlined (because it is constructed into a temporary and the analyzer
+// does not inline these since it does not yet reliably call temporary
+// destructors).
+//
+// This checker compensates for the missing inlining by propagating the
+// _success value across the bool and copy constructors so the assertion behaves
+// as expected.
+
+namespace {
+class GTestChecker : public Checker<check::PostCall> {
+
+  mutable IdentifierInfo *AssertionResultII;
+  mutable IdentifierInfo *SuccessII;
+
+public:
+  GTestChecker();
+
+  void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
+
+private:
+  void modelAssertionResultBoolConstructor(const CXXConstructorCall *Call,
+                                           bool IsRef, CheckerContext &C) const;
+
+  void modelAssertionResultCopyConstructor(const CXXConstructorCall *Call,
+                                           CheckerContext &C) const;
+
+  void initIdentifierInfo(ASTContext &Ctx) const;
+
+  SVal
+  getAssertionResultSuccessFieldValue(const CXXRecordDecl *AssertionResultDecl,
+                                      SVal Instance,
+                                      ProgramStateRef State) const;
+
+  static ProgramStateRef assumeValuesEqual(SVal Val1, SVal Val2,
+                                           ProgramStateRef State,
+                                           CheckerContext &C);
+};
+} // End anonymous namespace.
+
+GTestChecker::GTestChecker() : AssertionResultII(nullptr), SuccessII(nullptr) {}
+
+/// Model a call to an un-inlined AssertionResult(bool) or
+/// AssertionResult(bool &, ...).
+/// To do so, constrain the value of the newly-constructed instance's 'success_'
+/// field to be equal to the passed-in boolean value.
+///
+/// \param IsRef Whether the boolean parameter is a reference or not.
+void GTestChecker::modelAssertionResultBoolConstructor(
+    const CXXConstructorCall *Call, bool IsRef, CheckerContext &C) const {
+  assert(Call->getNumArgs() >= 1 && Call->getNumArgs() <= 2);
+
+  ProgramStateRef State = C.getState();
+  SVal BooleanArgVal = Call->getArgSVal(0);
+  if (IsRef) {
+    // The argument is a reference, so load from it to get the boolean value.
+    if (!BooleanArgVal.getAs<Loc>())
+      return;
+    BooleanArgVal = C.getState()->getSVal(BooleanArgVal.castAs<Loc>());
+  }
+
+  SVal ThisVal = Call->getCXXThisVal();
+
+  SVal ThisSuccess = getAssertionResultSuccessFieldValue(
+      Call->getDecl()->getParent(), ThisVal, State);
+
+  State = assumeValuesEqual(ThisSuccess, BooleanArgVal, State, C);
+  C.addTransition(State);
+}
+
+/// Model a call to an un-inlined AssertionResult copy constructor:
+///
+///   AssertionResult(const &AssertionResult other)
+///
+/// To do so, constrain the value of the newly-constructed instance's
+/// 'success_' field to be equal to the value of the pass-in instance's
+/// 'success_' field.
+void GTestChecker::modelAssertionResultCopyConstructor(
+    const CXXConstructorCall *Call, CheckerContext &C) const {
+  assert(Call->getNumArgs() == 1);
+
+  // The first parameter of the the copy constructor must be the other
+  // instance to initialize this instances fields from.
+  SVal OtherVal = Call->getArgSVal(0);
+  SVal ThisVal = Call->getCXXThisVal();
+
+  const CXXRecordDecl *AssertResultClassDecl = Call->getDecl()->getParent();
+  ProgramStateRef State = C.getState();
+
+  SVal ThisSuccess = getAssertionResultSuccessFieldValue(AssertResultClassDecl,
+                                                         ThisVal, State);
+  SVal OtherSuccess = getAssertionResultSuccessFieldValue(AssertResultClassDecl,
+                                                          OtherVal, State);
+
+  State = assumeValuesEqual(ThisSuccess, OtherSuccess, State, C);
+  C.addTransition(State);
+}
+
+/// Model calls to AssertionResult constructors that are not inlined.
+void GTestChecker::checkPostCall(const CallEvent &Call,
+                                 CheckerContext &C) const {
+  /// If the constructor was inlined, there is no need model it.
+  if (C.wasInlined)
+    return;
+
+  initIdentifierInfo(C.getASTContext());
+
+  auto *CtorCall = dyn_cast<CXXConstructorCall>(&Call);
+  if (!CtorCall)
+    return;
+
+  const CXXConstructorDecl *CtorDecl = CtorCall->getDecl();
+  const CXXRecordDecl *CtorParent = CtorDecl->getParent();
+  if (CtorParent->getIdentifier() != AssertionResultII)
+    return;
+
+  unsigned ParamCount = CtorDecl->getNumParams();
+
+  // Call the appropriate modeling method based the parameters and their
+  // types.
+
+  // We have AssertionResult(const &AssertionResult)
+  if (CtorDecl->isCopyConstructor() && ParamCount == 1) {
+    modelAssertionResultCopyConstructor(CtorCall, C);
+    return;
+  }
+
+  // There are two possible boolean constructors, depending on which
+  // version of gtest is being used:
+  //
+  // v1.7 and earlier:
+  //      AssertionResult(bool success)
+  //
+  // v1.8 and greater:
+  //      template <typename T>
+  //      AssertionResult(const T& success,
+  //                      typename internal::EnableIf<
+  //                          !internal::ImplicitlyConvertible<T,
+  //                              AssertionResult>::value>::type*)
+  //
+  CanQualType BoolTy = C.getASTContext().BoolTy;
+  if (ParamCount == 1 && CtorDecl->getParamDecl(0)->getType() == BoolTy) {
+    // We have AssertionResult(bool)
+    modelAssertionResultBoolConstructor(CtorCall, /*IsRef=*/false, C);
+    return;
+  }
+  if (ParamCount == 2){
+    auto *RefTy = CtorDecl->getParamDecl(0)->getType()->getAs<ReferenceType>();
+    if (RefTy &&
+        RefTy->getPointeeType()->getCanonicalTypeUnqualified() == BoolTy) {
+      // We have AssertionResult(bool &, ...)
+      modelAssertionResultBoolConstructor(CtorCall, /*IsRef=*/true, C);
+      return;
+    }
+  }
+}
+
+void GTestChecker::initIdentifierInfo(ASTContext &Ctx) const {
+  if (AssertionResultII)
+    return;
+
+  AssertionResultII = &Ctx.Idents.get("AssertionResult");
+  SuccessII = &Ctx.Idents.get("success_");
+}
+
+/// Returns the value stored in the 'success_' field of the passed-in
+/// AssertionResult instance.
+SVal GTestChecker::getAssertionResultSuccessFieldValue(
+    const CXXRecordDecl *AssertionResultDecl, SVal Instance,
+    ProgramStateRef State) const {
+
+  DeclContext::lookup_result Result = AssertionResultDecl->lookup(SuccessII);
+  if (Result.empty())
+    return UnknownVal();
+
+  auto *SuccessField = dyn_cast<FieldDecl>(Result.front());
+  if (!SuccessField)
+    return UnknownVal();
+
+  Optional<Loc> FieldLoc =
+      State->getLValue(SuccessField, Instance).getAs<Loc>();
+  if (!FieldLoc.hasValue())
+    return UnknownVal();
+
+  return State->getSVal(*FieldLoc);
+}
+
+/// Constrain the passed-in state to assume two values are equal.
+ProgramStateRef GTestChecker::assumeValuesEqual(SVal Val1, SVal Val2,
+                                                ProgramStateRef State,
+                                                CheckerContext &C) {
+  if (!Val1.getAs<DefinedOrUnknownSVal>() ||
+      !Val2.getAs<DefinedOrUnknownSVal>())
+    return State;
+
+  auto ValuesEqual =
+      C.getSValBuilder().evalEQ(State, Val1.castAs<DefinedOrUnknownSVal>(),
+                                Val2.castAs<DefinedOrUnknownSVal>());
+
+  if (!ValuesEqual.getAs<DefinedSVal>())
+    return State;
+
+  State = C.getConstraintManager().assume(
+      State, ValuesEqual.castAs<DefinedSVal>(), true);
+
+  return State;
+}
+
+void ento::registerGTestChecker(CheckerManager &Mgr) {
+  const LangOptions &LangOpts = Mgr.getLangOpts();
+  // gtest is a C++ API so there is no sense running the checker
+  // if not compiling for C++.
+  if (!LangOpts.CPlusPlus)
+    return;
+
+  Mgr.registerChecker<GTestChecker>();
+}