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, 197 insertions, 23 deletions

diff --git a/contrib/llvm/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp b/contrib/llvm/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
index 4775c75..ddd3259 100644
--- a/contrib/llvm/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
+++ b/contrib/llvm/tools/lld/lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
@@ -22,6 +22,7 @@
 
 #include "MachONormalizedFile.h"
 #include "ArchHandler.h"
+#include "DebugInfo.h"
 #include "MachONormalizedFileBinaryUtils.h"
 #include "lld/Core/Error.h"
 #include "lld/Core/LLVM.h"
@@ -34,6 +35,7 @@
 #include "llvm/Support/MachO.h"
 #include <map>
 #include <system_error>
+#include <unordered_set>
 
 using llvm::StringRef;
 using llvm::isa;
@@ -120,6 +122,7 @@ public:
   void      copySectionInfo(NormalizedFile &file);
   void      updateSectionInfo(NormalizedFile &file);
   void      buildAtomToAddressMap();
+  llvm::Error synthesizeDebugNotes(NormalizedFile &file);
   llvm::Error addSymbols(const lld::File &atomFile, NormalizedFile &file);
   void      addIndirectSymbols(const lld::File &atomFile, NormalizedFile &file);
   void      addRebaseAndBindingInfo(const lld::File &, NormalizedFile &file);
@@ -201,6 +204,7 @@ private:
   bool                          _allSourceFilesHaveMinVersions = true;
   LoadCommandType               _minVersionCommandType = (LoadCommandType)0;
   uint32_t                      _minVersion = 0;
+  std::vector<lld::mach_o::Stab> _stabs;
 };
 
 Util::~Util() {
@@ -785,6 +789,158 @@ void Util::buildAtomToAddressMap() {
   }
 }
 
+llvm::Error Util::synthesizeDebugNotes(NormalizedFile &file) {
+
+  // Bail out early if we don't need to generate a debug map.
+  if (_ctx.debugInfoMode() == MachOLinkingContext::DebugInfoMode::noDebugMap)
+    return llvm::Error::success();
+
+  std::vector<const DefinedAtom*> atomsNeedingDebugNotes;
+  std::set<const mach_o::MachOFile*> filesWithStabs;
+  bool objFileHasDwarf = false;
+  const File *objFile = nullptr;
+
+  for (SectionInfo *sect : _sectionInfos) {
+    for (const AtomInfo &info : sect->atomsAndOffsets) {
+      if (const DefinedAtom *atom = dyn_cast<DefinedAtom>(info.atom)) {
+
+        // FIXME: No stabs/debug-notes for symbols that wouldn't be in the
+        //        symbol table.
+        // FIXME: No stabs/debug-notes for kernel dtrace probes.
+
+        if (atom->contentType() == DefinedAtom::typeCFI ||
+            atom->contentType() == DefinedAtom::typeCString)
+          continue;
+
+        // Whenever we encounter a new file, update the 'objfileHasDwarf' flag.
+        if (&info.atom->file() != objFile) {
+          objFileHasDwarf = false;
+          if (const mach_o::MachOFile *atomFile =
+              dyn_cast<mach_o::MachOFile>(&info.atom->file())) {
+            if (atomFile->debugInfo()) {
+              if (isa<mach_o::DwarfDebugInfo>(atomFile->debugInfo()))
+                objFileHasDwarf = true;
+              else if (isa<mach_o::StabsDebugInfo>(atomFile->debugInfo()))
+                filesWithStabs.insert(atomFile);
+            }
+          }
+        }
+
+        // If this atom is from a file that needs dwarf, add it to the list.
+        if (objFileHasDwarf)
+          atomsNeedingDebugNotes.push_back(info.atom);
+      }
+    }
+  }
+
+  // Sort atoms needing debug notes by file ordinal, then atom ordinal.
+  std::sort(atomsNeedingDebugNotes.begin(), atomsNeedingDebugNotes.end(),
+            [](const DefinedAtom *lhs, const DefinedAtom *rhs) {
+              if (lhs->file().ordinal() != rhs->file().ordinal())
+                return (lhs->file().ordinal() < rhs->file().ordinal());
+              return (lhs->ordinal() < rhs->ordinal());
+            });
+
+  // FIXME: Handle <rdar://problem/17689030>: Add -add_ast_path option to \
+  //        linker which add N_AST stab entry to output
+  // See OutputFile::synthesizeDebugNotes in ObjectFile.cpp in ld64.
+
+  StringRef oldFileName = "";
+  StringRef oldDirPath = "";
+  bool wroteStartSO = false;
+  std::unordered_set<std::string> seenFiles;
+  for (const DefinedAtom *atom : atomsNeedingDebugNotes) {
+    const auto &atomFile = cast<mach_o::MachOFile>(atom->file());
+    assert(dyn_cast_or_null<lld::mach_o::DwarfDebugInfo>(atomFile.debugInfo())
+           && "file for atom needing debug notes does not contain dwarf");
+    auto &dwarf = cast<lld::mach_o::DwarfDebugInfo>(*atomFile.debugInfo());
+
+    auto &tu = dwarf.translationUnitSource();
+    StringRef newFileName = tu.name;
+    StringRef newDirPath = tu.path;
+
+    // Add an SO whenever the TU source file changes.
+    if (newFileName != oldFileName || newDirPath != oldDirPath) {
+      // Translation unit change, emit ending SO
+      if (oldFileName != "")
+        _stabs.push_back(mach_o::Stab(nullptr, N_SO, 1, 0, 0, ""));
+
+      oldFileName = newFileName;
+      oldDirPath = newDirPath;
+
+      // If newDirPath doesn't end with a '/' we need to add one:
+      if (newDirPath.back() != '/') {
+        char *p =
+          file.ownedAllocations.Allocate<char>(newDirPath.size() + 2);
+        memcpy(p, newDirPath.data(), newDirPath.size());
+        p[newDirPath.size()] = '/';
+        p[newDirPath.size() + 1] = '\0';
+        newDirPath = p;
+      }
+
+      // New translation unit, emit start SOs:
+      _stabs.push_back(mach_o::Stab(nullptr, N_SO, 0, 0, 0, newDirPath));
+      _stabs.push_back(mach_o::Stab(nullptr, N_SO, 0, 0, 0, newFileName));
+
+      // Synthesize OSO for start of file.
+      char *fullPath = nullptr;
+      {
+        SmallString<1024> pathBuf(atomFile.path());
+        if (auto EC = llvm::sys::fs::make_absolute(pathBuf))
+          return llvm::errorCodeToError(EC);
+        fullPath = file.ownedAllocations.Allocate<char>(pathBuf.size() + 1);
+        memcpy(fullPath, pathBuf.c_str(), pathBuf.size() + 1);
+      }
+
+      // Get mod time.
+      uint32_t modTime = 0;
+      llvm::sys::fs::file_status stat;
+      if (!llvm::sys::fs::status(fullPath, stat))
+        if (llvm::sys::fs::exists(stat))
+          modTime = llvm::sys::toTimeT(stat.getLastModificationTime());
+
+      _stabs.push_back(mach_o::Stab(nullptr, N_OSO, _ctx.getCPUSubType(), 1,
+                                    modTime, fullPath));
+      // <rdar://problem/6337329> linker should put cpusubtype in n_sect field
+      // of nlist entry for N_OSO debug note entries.
+      wroteStartSO = true;
+    }
+
+    if (atom->contentType() == DefinedAtom::typeCode) {
+      // Synthesize BNSYM and start FUN stabs.
+      _stabs.push_back(mach_o::Stab(atom, N_BNSYM, 1, 0, 0, ""));
+      _stabs.push_back(mach_o::Stab(atom, N_FUN, 1, 0, 0, atom->name()));
+      // Synthesize any SOL stabs needed
+      // FIXME: add SOL stabs.
+      _stabs.push_back(mach_o::Stab(nullptr, N_FUN, 0, 0,
+                                    atom->rawContent().size(), ""));
+      _stabs.push_back(mach_o::Stab(nullptr, N_ENSYM, 1, 0,
+                                    atom->rawContent().size(), ""));
+    } else {
+      if (atom->scope() == Atom::scopeTranslationUnit)
+        _stabs.push_back(mach_o::Stab(atom, N_STSYM, 1, 0, 0, atom->name()));
+      else
+        _stabs.push_back(mach_o::Stab(nullptr, N_GSYM, 1, 0, 0, atom->name()));
+    }
+  }
+
+  // Emit ending SO if necessary.
+  if (wroteStartSO)
+    _stabs.push_back(mach_o::Stab(nullptr, N_SO, 1, 0, 0, ""));
+
+  // Copy any stabs from .o file.
+  for (const auto *objFile : filesWithStabs) {
+    const auto &stabsList =
+      cast<mach_o::StabsDebugInfo>(objFile->debugInfo())->stabs();
+    for (auto &stab : stabsList) {
+      // FIXME: Drop stabs whose atoms have been dead-stripped.
+      _stabs.push_back(stab);
+    }
+  }
+
+  return llvm::Error::success();
+}
+
 uint16_t Util::descBits(const DefinedAtom* atom) {
   uint16_t desc = 0;
   switch (atom->merge()) {
@@ -807,7 +963,8 @@ uint16_t Util::descBits(const DefinedAtom* atom) {
     desc |= REFERENCED_DYNAMICALLY;
   if (_archHandler.isThumbFunction(*atom))
     desc |= N_ARM_THUMB_DEF;
-  if (atom->deadStrip() == DefinedAtom::deadStripNever) {
+  if (atom->deadStrip() == DefinedAtom::deadStripNever &&
+      _ctx.outputMachOType() == llvm::MachO::MH_OBJECT) {
     if ((atom->contentType() != DefinedAtom::typeInitializerPtr)
      && (atom->contentType() != DefinedAtom::typeTerminatorPtr))
     desc |= N_NO_DEAD_STRIP;
@@ -828,7 +985,7 @@ llvm::Error Util::getSymbolTableRegion(const DefinedAtom* atom,
   case Atom::scopeTranslationUnit:
     scope = 0;
     inGlobalsRegion = false;
-    return llvm::Error();
+    return llvm::Error::success();
   case Atom::scopeLinkageUnit:
     if ((_ctx.exportMode() == MachOLinkingContext::ExportMode::whiteList) &&
         _ctx.exportSymbolNamed(atom->name())) {
@@ -840,38 +997,55 @@ llvm::Error Util::getSymbolTableRegion(const DefinedAtom* atom,
         // -keep_private_externs means keep in globals region as N_PEXT.
         scope = N_PEXT | N_EXT;
         inGlobalsRegion = true;
-        return llvm::Error();
+        return llvm::Error::success();
       }
     }
     // scopeLinkageUnit symbols are no longer global once linked.
     scope = N_PEXT;
     inGlobalsRegion = false;
-    return llvm::Error();
+    return llvm::Error::success();
   case Atom::scopeGlobal:
     if (_ctx.exportRestrictMode()) {
       if (_ctx.exportSymbolNamed(atom->name())) {
         scope = N_EXT;
         inGlobalsRegion = true;
-        return llvm::Error();
+        return llvm::Error::success();
       } else {
         scope = N_PEXT;
         inGlobalsRegion = false;
-        return llvm::Error();
+        return llvm::Error::success();
       }
     } else {
       scope = N_EXT;
       inGlobalsRegion = true;
-      return llvm::Error();
+      return llvm::Error::success();
     }
     break;
   }
   llvm_unreachable("atom->scope() unknown enum value");
 }
 
+
+
 llvm::Error Util::addSymbols(const lld::File &atomFile,
                              NormalizedFile &file) {
   bool rMode = (_ctx.outputMachOType() == llvm::MachO::MH_OBJECT);
-  // Mach-O symbol table has three regions: locals, globals, undefs.
+  // Mach-O symbol table has four regions: stabs, locals, globals, undefs.
+
+  // Add all stabs.
+  for (auto &stab : _stabs) {
+    Symbol sym;
+    sym.type = static_cast<NListType>(stab.type);
+    sym.scope = 0;
+    sym.sect = stab.other;
+    sym.desc = stab.desc;
+    if (stab.atom)
+      sym.value = _atomToAddress[stab.atom];
+    else
+      sym.value = stab.value;
+    sym.name = stab.str;
+    file.stabsSymbols.push_back(sym);
+  }
 
   // Add all local (non-global) symbols in address order
   std::vector<AtomAndIndex> globals;
@@ -965,7 +1139,7 @@ llvm::Error Util::addSymbols(const lld::File &atomFile,
     file.undefinedSymbols.push_back(sym);
   }
 
-  return llvm::Error();
+  return llvm::Error::success();
 }
 
 const Atom *Util::targetOfLazyPointer(const DefinedAtom *lpAtom) {
@@ -1040,15 +1214,15 @@ void Util::addIndirectSymbols(const lld::File &atomFile, NormalizedFile &file) {
   }
 }
 
-void Util::addDependentDylibs(const lld::File &atomFile,NormalizedFile &nFile) {
+void Util::addDependentDylibs(const lld::File &atomFile,
+                              NormalizedFile &nFile) {
   // Scan all imported symbols and build up list of dylibs they are from.
   int ordinal = 1;
-  for (const SharedLibraryAtom *slAtom : atomFile.sharedLibrary()) {
-    StringRef loadPath = slAtom->loadName();
-    DylibPathToInfo::iterator pos = _dylibInfo.find(loadPath);
+  for (const auto *dylib : _ctx.allDylibs()) {
+    DylibPathToInfo::iterator pos = _dylibInfo.find(dylib->installName());
     if (pos == _dylibInfo.end()) {
       DylibInfo info;
-      bool flatNamespaceAtom = &slAtom->file() == _ctx.flatNamespaceFile();
+      bool flatNamespaceAtom = dylib == _ctx.flatNamespaceFile();
 
       // If we're in -flat_namespace mode (or this atom came from the flat
       // namespace file under -undefined dynamic_lookup) then use the flat
@@ -1057,24 +1231,22 @@ void Util::addDependentDylibs(const lld::File &atomFile,NormalizedFile &nFile) {
         info.ordinal = BIND_SPECIAL_DYLIB_FLAT_LOOKUP;
       else
         info.ordinal = ordinal++;
-      info.hasWeak = slAtom->canBeNullAtRuntime();
+      info.hasWeak = false;
       info.hasNonWeak = !info.hasWeak;
-      _dylibInfo[loadPath] = info;
+      _dylibInfo[dylib->installName()] = info;
 
       // Unless this was a flat_namespace atom, record the source dylib.
       if (!flatNamespaceAtom) {
         DependentDylib depInfo;
-        depInfo.path = loadPath;
+        depInfo.path = dylib->installName();
         depInfo.kind = llvm::MachO::LC_LOAD_DYLIB;
-        depInfo.currentVersion = _ctx.dylibCurrentVersion(loadPath);
-        depInfo.compatVersion = _ctx.dylibCompatVersion(loadPath);
+        depInfo.currentVersion = _ctx.dylibCurrentVersion(dylib->path());
+        depInfo.compatVersion = _ctx.dylibCompatVersion(dylib->path());
         nFile.dependentDylibs.push_back(depInfo);
       }
     } else {
-      if ( slAtom->canBeNullAtRuntime() )
-        pos->second.hasWeak = true;
-      else
-        pos->second.hasNonWeak = true;
+      pos->second.hasWeak = false;
+      pos->second.hasNonWeak = !pos->second.hasWeak;
     }
   }
   // Automatically weak link dylib in which all symbols are weak (canBeNull).
@@ -1404,6 +1576,8 @@ normalizedFromAtoms(const lld::File &atomFile,
   util.copySectionInfo(normFile);
   util.assignAddressesToSections(normFile);
   util.buildAtomToAddressMap();
+  if (auto err = util.synthesizeDebugNotes(normFile))
+    return std::move(err);
   util.updateSectionInfo(normFile);
   util.copySectionContent(normFile);
   if (auto ec = util.addSymbols(atomFile, normFile)) {