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, 107 insertions, 90 deletions

diff --git a/contrib/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/contrib/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 13c2b50..ee2c569 100644
--- a/contrib/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/contrib/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -7,14 +7,25 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
-#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
-#include "llvm/Support/Dwarf.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
+#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Path.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
 #include <cstdio>
+#include <vector>
 
 namespace llvm {
+
 using namespace dwarf;
 
 void DWARFUnitSectionBase::parse(DWARFContext &C, const DWARFSection &Section) {
@@ -49,8 +60,7 @@ DWARFUnit::DWARFUnit(DWARFContext &DC, const DWARFSection &Section,
   clear();
 }
 
-DWARFUnit::~DWARFUnit() {
-}
+DWARFUnit::~DWARFUnit() = default;
 
 bool DWARFUnit::getAddrOffsetSectionItem(uint32_t Index,
                                                 uint64_t &Result) const {
@@ -121,7 +131,7 @@ bool DWARFUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) {
 bool DWARFUnit::extractRangeList(uint32_t RangeListOffset,
                                         DWARFDebugRangeList &RangeList) const {
   // Require that compile unit is extracted.
-  assert(DieArray.size() > 0);
+  assert(!DieArray.empty());
   DataExtractor RangesData(RangeSection, isLittleEndian, AddrSize);
   uint32_t ActualRangeListOffset = RangeSectionBase + RangeListOffset;
   return RangeList.extract(RangesData, &ActualRangeListOffset);
@@ -141,53 +151,16 @@ void DWARFUnit::clear() {
 }
 
 const char *DWARFUnit::getCompilationDir() {
-  extractDIEsIfNeeded(true);
-  if (DieArray.empty())
-    return nullptr;
-  return DieArray[0].getAttributeValueAsString(this, DW_AT_comp_dir, nullptr);
+  return getUnitDIE().getAttributeValueAsString(DW_AT_comp_dir, nullptr);
 }
 
-uint64_t DWARFUnit::getDWOId() {
-  extractDIEsIfNeeded(true);
-  const uint64_t FailValue = -1ULL;
-  if (DieArray.empty())
-    return FailValue;
-  return DieArray[0]
-      .getAttributeValueAsUnsignedConstant(this, DW_AT_GNU_dwo_id, FailValue);
-}
-
-void DWARFUnit::setDIERelations() {
-  if (DieArray.size() <= 1)
-    return;
-
-  std::vector<DWARFDebugInfoEntryMinimal *> ParentChain;
-  DWARFDebugInfoEntryMinimal *SiblingChain = nullptr;
-  for (auto &DIE : DieArray) {
-    if (SiblingChain) {
-      SiblingChain->setSibling(&DIE);
-    }
-    if (const DWARFAbbreviationDeclaration *AbbrDecl =
-            DIE.getAbbreviationDeclarationPtr()) {
-      // Normal DIE.
-      if (AbbrDecl->hasChildren()) {
-        ParentChain.push_back(&DIE);
-        SiblingChain = nullptr;
-      } else {
-        SiblingChain = &DIE;
-      }
-    } else {
-      // NULL entry terminates the sibling chain.
-      SiblingChain = ParentChain.back();
-      ParentChain.pop_back();
-    }
-  }
-  assert(SiblingChain == nullptr || SiblingChain == &DieArray[0]);
-  assert(ParentChain.empty());
+Optional<uint64_t> DWARFUnit::getDWOId() {
+  return getUnitDIE().getAttributeValueAsUnsignedConstant(DW_AT_GNU_dwo_id);
 }
 
 void DWARFUnit::extractDIEsToVector(
     bool AppendCUDie, bool AppendNonCUDies,
-    std::vector<DWARFDebugInfoEntryMinimal> &Dies) const {
+    std::vector<DWARFDebugInfoEntry> &Dies) const {
   if (!AppendCUDie && !AppendNonCUDies)
     return;
 
@@ -195,11 +168,13 @@ void DWARFUnit::extractDIEsToVector(
   // next compilation unit header.
   uint32_t DIEOffset = Offset + getHeaderSize();
   uint32_t NextCUOffset = getNextUnitOffset();
-  DWARFDebugInfoEntryMinimal DIE;
+  DWARFDebugInfoEntry DIE;
+  DataExtractor DebugInfoData = getDebugInfoExtractor();
   uint32_t Depth = 0;
   bool IsCUDie = true;
 
-  while (DIEOffset < NextCUOffset && DIE.extractFast(this, &DIEOffset)) {
+  while (DIE.extractFast(*this, &DIEOffset, DebugInfoData, NextCUOffset,
+                         Depth)) {
     if (IsCUDie) {
       if (AppendCUDie)
         Dies.push_back(DIE);
@@ -237,11 +212,11 @@ void DWARFUnit::extractDIEsToVector(
 }
 
 size_t DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) {
-  if ((CUDieOnly && DieArray.size() > 0) ||
+  if ((CUDieOnly && !DieArray.empty()) ||
       DieArray.size() > 1)
     return 0; // Already parsed.
 
-  bool HasCUDie = DieArray.size() > 0;
+  bool HasCUDie = !DieArray.empty();
   extractDIEsToVector(!HasCUDie, !CUDieOnly, DieArray);
 
   if (DieArray.empty())
@@ -249,25 +224,27 @@ size_t DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) {
 
   // If CU DIE was just parsed, copy several attribute values from it.
   if (!HasCUDie) {
-    uint64_t BaseAddr =
-        DieArray[0].getAttributeValueAsAddress(this, DW_AT_low_pc, -1ULL);
-    if (BaseAddr == -1ULL)
-      BaseAddr = DieArray[0].getAttributeValueAsAddress(this, DW_AT_entry_pc, 0);
-    setBaseAddress(BaseAddr);
-    AddrOffsetSectionBase = DieArray[0].getAttributeValueAsSectionOffset(
-        this, DW_AT_GNU_addr_base, 0);
-    RangeSectionBase = DieArray[0].getAttributeValueAsSectionOffset(
-        this, DW_AT_ranges_base, 0);
+    DWARFDie UnitDie = getUnitDIE();
+    auto BaseAddr = UnitDie.getAttributeValueAsAddress(DW_AT_low_pc);
+    if (!BaseAddr)
+      BaseAddr = UnitDie.getAttributeValueAsAddress(DW_AT_entry_pc);
+    if (BaseAddr)
+      setBaseAddress(*BaseAddr);
+    AddrOffsetSectionBase =
+        UnitDie.getAttributeValueAsSectionOffset(DW_AT_GNU_addr_base)
+            .getValueOr(0);
+    RangeSectionBase =
+        UnitDie.getAttributeValueAsSectionOffset(DW_AT_rnglists_base)
+            .getValueOr(0);
     // Don't fall back to DW_AT_GNU_ranges_base: it should be ignored for
     // skeleton CU DIE, so that DWARF users not aware of it are not broken.
   }
 
-  setDIERelations();
   return DieArray.size();
 }
 
 DWARFUnit::DWOHolder::DWOHolder(StringRef DWOPath)
-    : DWOFile(), DWOContext(), DWOU(nullptr) {
+    : DWOU(nullptr) {
   auto Obj = object::ObjectFile::createObjectFile(DWOPath);
   if (!Obj) {
     // TODO: Actually report errors helpfully.
@@ -286,15 +263,15 @@ bool DWARFUnit::parseDWO() {
     return false;
   if (DWO.get())
     return false;
-  extractDIEsIfNeeded(true);
-  if (DieArray.empty())
+  DWARFDie UnitDie = getUnitDIE();
+  if (!UnitDie)
     return false;
   const char *DWOFileName =
-      DieArray[0].getAttributeValueAsString(this, DW_AT_GNU_dwo_name, nullptr);
+      UnitDie.getAttributeValueAsString(DW_AT_GNU_dwo_name, nullptr);
   if (!DWOFileName)
     return false;
   const char *CompilationDir =
-      DieArray[0].getAttributeValueAsString(this, DW_AT_comp_dir, nullptr);
+      UnitDie.getAttributeValueAsString(DW_AT_comp_dir, nullptr);
   SmallString<16> AbsolutePath;
   if (sys::path::is_relative(DWOFileName) && CompilationDir != nullptr) {
     sys::path::append(AbsolutePath, CompilationDir);
@@ -309,8 +286,8 @@ bool DWARFUnit::parseDWO() {
   }
   // Share .debug_addr and .debug_ranges section with compile unit in .dwo
   DWOCU->setAddrOffsetSection(AddrOffsetSection, AddrOffsetSectionBase);
-  uint32_t DWORangesBase = DieArray[0].getRangesBaseAttribute(this, 0);
-  DWOCU->setRangesSection(RangeSection, DWORangesBase);
+  auto DWORangesBase = UnitDie.getRangesBaseAttribute();
+  DWOCU->setRangesSection(RangeSection, DWORangesBase ? *DWORangesBase : 0);
   return true;
 }
 
@@ -323,7 +300,7 @@ void DWARFUnit::clearDIEs(bool KeepCUDie) {
     // contents which will cause just the internal pointers to be swapped
     // so that when temporary vector goes out of scope, it will destroy the
     // contents.
-    std::vector<DWARFDebugInfoEntryMinimal> TmpArray;
+    std::vector<DWARFDebugInfoEntry> TmpArray;
     DieArray.swap(TmpArray);
     // Save at least the compile unit DIE
     if (KeepCUDie)
@@ -332,11 +309,11 @@ void DWARFUnit::clearDIEs(bool KeepCUDie) {
 }
 
 void DWARFUnit::collectAddressRanges(DWARFAddressRangesVector &CURanges) {
-  const auto *U = getUnitDIE();
-  if (U == nullptr)
+  DWARFDie UnitDie = getUnitDIE();
+  if (!UnitDie)
     return;
   // First, check if unit DIE describes address ranges for the whole unit.
-  const auto &CUDIERanges = U->getAddressRanges(this);
+  const auto &CUDIERanges = UnitDie.getAddressRanges();
   if (!CUDIERanges.empty()) {
     CURanges.insert(CURanges.end(), CUDIERanges.begin(), CUDIERanges.end());
     return;
@@ -349,7 +326,7 @@ void DWARFUnit::collectAddressRanges(DWARFAddressRangesVector &CURanges) {
   // up parsing the DWARF and then throwing them all away to keep memory usage
   // down.
   const bool ClearDIEs = extractDIEsIfNeeded(false) > 1;
-  DieArray[0].collectChildrenAddressRanges(this, CURanges);
+  getUnitDIE().collectChildrenAddressRanges(CURanges);
 
   // Collect address ranges from DIEs in .dwo if necessary.
   bool DWOCreated = parseDWO();
@@ -364,36 +341,37 @@ void DWARFUnit::collectAddressRanges(DWARFAddressRangesVector &CURanges) {
     clearDIEs(true);
 }
 
-const DWARFDebugInfoEntryMinimal *
+DWARFDie
 DWARFUnit::getSubprogramForAddress(uint64_t Address) {
   extractDIEsIfNeeded(false);
-  for (const DWARFDebugInfoEntryMinimal &DIE : DieArray) {
+  for (const DWARFDebugInfoEntry &D : DieArray) {
+    DWARFDie DIE(this, &D);
     if (DIE.isSubprogramDIE() &&
-        DIE.addressRangeContainsAddress(this, Address)) {
-      return &DIE;
+        DIE.addressRangeContainsAddress(Address)) {
+      return DIE;
     }
   }
-  return nullptr;
+  return DWARFDie();
 }
 
-DWARFDebugInfoEntryInlinedChain
-DWARFUnit::getInlinedChainForAddress(uint64_t Address) {
+void
+DWARFUnit::getInlinedChainForAddress(uint64_t Address,
+                                     SmallVectorImpl<DWARFDie> &InlinedChain) {
   // First, find a subprogram that contains the given address (the root
   // of inlined chain).
-  const DWARFUnit *ChainCU = nullptr;
-  const DWARFDebugInfoEntryMinimal *SubprogramDIE;
+  DWARFDie SubprogramDIE;
   // Try to look for subprogram DIEs in the DWO file.
   parseDWO();
-  if (DWO) {
-    if ((SubprogramDIE = DWO->getUnit()->getSubprogramForAddress(Address)))
-      ChainCU = DWO->getUnit();
-  } else if ((SubprogramDIE = getSubprogramForAddress(Address)))
-    ChainCU = this;
+  if (DWO)
+    SubprogramDIE = DWO->getUnit()->getSubprogramForAddress(Address);
+  else
+    SubprogramDIE = getSubprogramForAddress(Address);
 
   // Get inlined chain rooted at this subprogram DIE.
-  if (!SubprogramDIE)
-    return DWARFDebugInfoEntryInlinedChain();
-  return SubprogramDIE->getInlinedChainForAddress(ChainCU, Address);
+  if (SubprogramDIE)
+    SubprogramDIE.getInlinedChainForAddress(Address, InlinedChain);
+  else
+    InlinedChain.clear();
 }
 
 const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
@@ -403,4 +381,43 @@ const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
   assert(Kind == DW_SECT_TYPES);
   return Context.getTUIndex();
 }
+
+DWARFDie DWARFUnit::getParent(const DWARFDebugInfoEntry *Die) {
+  if (!Die)
+    return DWARFDie();
+  const uint32_t Depth = Die->getDepth();
+  // Unit DIEs always have a depth of zero and never have parents.
+  if (Depth == 0)
+    return DWARFDie();
+  // Depth of 1 always means parent is the compile/type unit.
+  if (Depth == 1)
+    return getUnitDIE();
+  // Look for previous DIE with a depth that is one less than the Die's depth.
+  const uint32_t ParentDepth = Depth - 1;
+  for (uint32_t I = getDIEIndex(Die) - 1; I > 0; --I) {
+    if (DieArray[I].getDepth() == ParentDepth)
+      return DWARFDie(this, &DieArray[I]);
+  }
+  return DWARFDie();
 }
+
+DWARFDie DWARFUnit::getSibling(const DWARFDebugInfoEntry *Die) {
+  if (!Die)
+    return DWARFDie();
+  uint32_t Depth = Die->getDepth();
+  // Unit DIEs always have a depth of zero and never have siblings.
+  if (Depth == 0)
+    return DWARFDie();
+  // NULL DIEs don't have siblings.
+  if (Die->getAbbreviationDeclarationPtr() == nullptr)
+    return DWARFDie();
+  
+  // Find the next DIE whose depth is the same as the Die's depth.
+  for (size_t I=getDIEIndex(Die)+1, EndIdx = DieArray.size(); I<EndIdx; ++I) {
+    if (DieArray[I].getDepth() == Depth)
+      return DWARFDie(this, &DieArray[I]);
+  }
+  return DWARFDie();
+}
+
+} // end namespace llvm