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, 31 deletions

diff --git a/contrib/llvm/lib/Linker/IRMover.cpp b/contrib/llvm/lib/Linker/IRMover.cpp
index 09c67bc..9f3cfc0 100644
--- a/contrib/llvm/lib/Linker/IRMover.cpp
+++ b/contrib/llvm/lib/Linker/IRMover.cpp
@@ -169,11 +169,9 @@ bool TypeMapTy::areTypesIsomorphic(Type *DstTy, Type *SrcTy) {
     if (DSTy->isLiteral() != SSTy->isLiteral() ||
         DSTy->isPacked() != SSTy->isPacked())
       return false;
-  } else if (ArrayType *DATy = dyn_cast<ArrayType>(DstTy)) {
-    if (DATy->getNumElements() != cast<ArrayType>(SrcTy)->getNumElements())
-      return false;
-  } else if (VectorType *DVTy = dyn_cast<VectorType>(DstTy)) {
-    if (DVTy->getNumElements() != cast<VectorType>(SrcTy)->getNumElements())
+  } else if (auto *DSeqTy = dyn_cast<SequentialType>(DstTy)) {
+    if (DSeqTy->getNumElements() !=
+        cast<SequentialType>(SrcTy)->getNumElements())
       return false;
   }
 
@@ -281,7 +279,7 @@ Type *TypeMapTy::get(Type *Ty, SmallPtrSet<StructType *, 8> &Visited) {
   }
 
   // If all of the element types mapped directly over and the type is not
-  // a nomed struct, then the type is usable as-is.
+  // a named struct, then the type is usable as-is.
   if (!AnyChange && IsUniqued)
     return *Entry = Ty;
 
@@ -397,6 +395,12 @@ class IRLinker {
       Worklist.push_back(GV);
   }
 
+  /// Flag whether the ModuleInlineAsm string in Src should be linked with
+  /// (concatenated into) the ModuleInlineAsm string for the destination
+  /// module. It should be true for full LTO, but not when importing for
+  /// ThinLTO, otherwise we can have duplicate symbols.
+  bool LinkModuleInlineAsm;
+
   /// Set to true when all global value body linking is complete (including
   /// lazy linking). Used to prevent metadata linking from creating new
   /// references.
@@ -465,7 +469,7 @@ class IRLinker {
 
   Error linkModuleFlagsMetadata();
 
-  void linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src);
+  void linkGlobalVariable(GlobalVariable &Dst, GlobalVariable &Src);
   Error linkFunctionBody(Function &Dst, Function &Src);
   void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src);
   Error linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src);
@@ -476,16 +480,21 @@ class IRLinker {
   Function *copyFunctionProto(const Function *SF);
   GlobalValue *copyGlobalAliasProto(const GlobalAlias *SGA);
 
+  /// When importing for ThinLTO, prevent importing of types listed on
+  /// the DICompileUnit that we don't need a copy of in the importing
+  /// module.
+  void prepareCompileUnitsForImport();
   void linkNamedMDNodes();
 
 public:
   IRLinker(Module &DstM, MDMapT &SharedMDs,
            IRMover::IdentifiedStructTypeSet &Set, std::unique_ptr<Module> SrcM,
            ArrayRef<GlobalValue *> ValuesToLink,
-           std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor)
+           std::function<void(GlobalValue &, IRMover::ValueAdder)> AddLazyFor,
+           bool LinkModuleInlineAsm, bool IsPerformingImport)
       : DstM(DstM), SrcM(std::move(SrcM)), AddLazyFor(std::move(AddLazyFor)),
         TypeMap(Set), GValMaterializer(*this), LValMaterializer(*this),
-        SharedMDs(SharedMDs),
+        SharedMDs(SharedMDs), LinkModuleInlineAsm(LinkModuleInlineAsm),
         Mapper(ValueMap, RF_MoveDistinctMDs | RF_IgnoreMissingLocals, &TypeMap,
                &GValMaterializer),
         AliasMCID(Mapper.registerAlternateMappingContext(AliasValueMap,
@@ -493,6 +502,8 @@ public:
     ValueMap.getMDMap() = std::move(SharedMDs);
     for (GlobalValue *GV : ValuesToLink)
       maybeAdd(GV);
+    if (IsPerformingImport)
+      prepareCompileUnitsForImport();
   }
   ~IRLinker() { SharedMDs = std::move(*ValueMap.getMDMap()); }
 
@@ -561,7 +572,7 @@ Value *IRLinker::materialize(Value *V, bool ForAlias) {
   }
 
   // When linking a global for an alias, it will always be linked. However we
-  // need to check if it was not already scheduled to satify a reference from a
+  // need to check if it was not already scheduled to satisfy a reference from a
   // regular global value initializer. We know if it has been schedule if the
   // "New" GlobalValue that is mapped here for the alias is the same as the one
   // already mapped. If there is an entry in the ValueMap but the value is
@@ -813,18 +824,17 @@ IRLinker::linkAppendingVarProto(GlobalVariable *DstGV,
   SmallVector<Constant *, 16> SrcElements;
   getArrayElements(SrcGV->getInitializer(), SrcElements);
 
-  if (IsNewStructor)
-    SrcElements.erase(
-        std::remove_if(SrcElements.begin(), SrcElements.end(),
-                       [this](Constant *E) {
-                         auto *Key = dyn_cast<GlobalValue>(
-                             E->getAggregateElement(2)->stripPointerCasts());
-                         if (!Key)
-                           return false;
-                         GlobalValue *DGV = getLinkedToGlobal(Key);
-                         return !shouldLink(DGV, *Key);
-                       }),
-        SrcElements.end());
+  if (IsNewStructor) {
+    auto It = remove_if(SrcElements, [this](Constant *E) {
+      auto *Key =
+          dyn_cast<GlobalValue>(E->getAggregateElement(2)->stripPointerCasts());
+      if (!Key)
+        return false;
+      GlobalValue *DGV = getLinkedToGlobal(Key);
+      return !shouldLink(DGV, *Key);
+    });
+    SrcElements.erase(It, SrcElements.end());
+  }
   uint64_t NewSize = DstNumElements + SrcElements.size();
   ArrayType *NewType = ArrayType::get(EltTy, NewSize);
 
@@ -951,7 +961,7 @@ Expected<Constant *> IRLinker::linkGlobalValueProto(GlobalValue *SGV,
 
 /// Update the initializers in the Dest module now that all globals that may be
 /// referenced are in Dest.
-void IRLinker::linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src) {
+void IRLinker::linkGlobalVariable(GlobalVariable &Dst, GlobalVariable &Src) {
   // Figure out what the initializer looks like in the dest module.
   Mapper.scheduleMapGlobalInitializer(Dst, *Src.getInitializer());
 }
@@ -963,8 +973,8 @@ Error IRLinker::linkFunctionBody(Function &Dst, Function &Src) {
   assert(Dst.isDeclaration() && !Src.isDeclaration());
 
   // Materialize if needed.
-  if (std::error_code EC = Src.materialize())
-    return errorCodeToError(EC);
+  if (Error Err = Src.materialize())
+    return Err;
 
   // Link in the operands without remapping.
   if (Src.hasPrefixData())
@@ -994,13 +1004,77 @@ Error IRLinker::linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src) {
   if (auto *F = dyn_cast<Function>(&Src))
     return linkFunctionBody(cast<Function>(Dst), *F);
   if (auto *GVar = dyn_cast<GlobalVariable>(&Src)) {
-    linkGlobalInit(cast<GlobalVariable>(Dst), *GVar);
+    linkGlobalVariable(cast<GlobalVariable>(Dst), *GVar);
     return Error::success();
   }
   linkAliasBody(cast<GlobalAlias>(Dst), cast<GlobalAlias>(Src));
   return Error::success();
 }
 
+void IRLinker::prepareCompileUnitsForImport() {
+  NamedMDNode *SrcCompileUnits = SrcM->getNamedMetadata("llvm.dbg.cu");
+  if (!SrcCompileUnits)
+    return;
+  // When importing for ThinLTO, prevent importing of types listed on
+  // the DICompileUnit that we don't need a copy of in the importing
+  // module. They will be emitted by the originating module.
+  for (unsigned I = 0, E = SrcCompileUnits->getNumOperands(); I != E; ++I) {
+    auto *CU = cast<DICompileUnit>(SrcCompileUnits->getOperand(I));
+    assert(CU && "Expected valid compile unit");
+    // Enums, macros, and retained types don't need to be listed on the
+    // imported DICompileUnit. This means they will only be imported
+    // if reached from the mapped IR. Do this by setting their value map
+    // entries to nullptr, which will automatically prevent their importing
+    // when reached from the DICompileUnit during metadata mapping.
+    ValueMap.MD()[CU->getRawEnumTypes()].reset(nullptr);
+    ValueMap.MD()[CU->getRawMacros()].reset(nullptr);
+    ValueMap.MD()[CU->getRawRetainedTypes()].reset(nullptr);
+    // If we ever start importing global variable defs, we'll need to
+    // add their DIGlobalVariable to the globals list on the imported
+    // DICompileUnit. Confirm none are imported, and then we can
+    // map the list of global variables to nullptr.
+    assert(none_of(
+               ValuesToLink,
+               [](const GlobalValue *GV) { return isa<GlobalVariable>(GV); }) &&
+           "Unexpected importing of a GlobalVariable definition");
+    ValueMap.MD()[CU->getRawGlobalVariables()].reset(nullptr);
+
+    // Imported entities only need to be mapped in if they have local
+    // scope, as those might correspond to an imported entity inside a
+    // function being imported (any locally scoped imported entities that
+    // don't end up referenced by an imported function will not be emitted
+    // into the object). Imported entities not in a local scope
+    // (e.g. on the namespace) only need to be emitted by the originating
+    // module. Create a list of the locally scoped imported entities, and
+    // replace the source CUs imported entity list with the new list, so
+    // only those are mapped in.
+    // FIXME: Locally-scoped imported entities could be moved to the
+    // functions they are local to instead of listing them on the CU, and
+    // we would naturally only link in those needed by function importing.
+    SmallVector<TrackingMDNodeRef, 4> AllImportedModules;
+    bool ReplaceImportedEntities = false;
+    for (auto *IE : CU->getImportedEntities()) {
+      DIScope *Scope = IE->getScope();
+      assert(Scope && "Invalid Scope encoding!");
+      if (isa<DILocalScope>(Scope))
+        AllImportedModules.emplace_back(IE);
+      else
+        ReplaceImportedEntities = true;
+    }
+    if (ReplaceImportedEntities) {
+      if (!AllImportedModules.empty())
+        CU->replaceImportedEntities(MDTuple::get(
+            CU->getContext(),
+            SmallVector<Metadata *, 16>(AllImportedModules.begin(),
+                                        AllImportedModules.end())));
+      else
+        // If there were no local scope imported entities, we can map
+        // the whole list to nullptr.
+        ValueMap.MD()[CU->getRawImportedEntities()].reset(nullptr);
+    }
+  }
+}
+
 /// Insert all of the named MDNodes in Src into the Dest module.
 void IRLinker::linkNamedMDNodes() {
   const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata();
@@ -1191,8 +1265,8 @@ static std::string mergeTriples(const Triple &SrcTriple,
 Error IRLinker::run() {
   // Ensure metadata materialized before value mapping.
   if (SrcM->getMaterializer())
-    if (std::error_code EC = SrcM->getMaterializer()->materializeMetadata())
-      return errorCodeToError(EC);
+    if (Error Err = SrcM->getMaterializer()->materializeMetadata())
+      return Err;
 
   // Inherit the target data from the source module if the destination module
   // doesn't have one already.
@@ -1223,7 +1297,7 @@ Error IRLinker::run() {
   DstM.setTargetTriple(mergeTriples(SrcTriple, DstTriple));
 
   // Append the module inline asm string.
-  if (!SrcM->getModuleInlineAsm().empty()) {
+  if (LinkModuleInlineAsm && !SrcM->getModuleInlineAsm().empty()) {
     if (DstM.getModuleInlineAsm().empty())
       DstM.setModuleInlineAsm(SrcM->getModuleInlineAsm());
     else
@@ -1361,9 +1435,11 @@ IRMover::IRMover(Module &M) : Composite(M) {
 
 Error IRMover::move(
     std::unique_ptr<Module> Src, ArrayRef<GlobalValue *> ValuesToLink,
-    std::function<void(GlobalValue &, ValueAdder Add)> AddLazyFor) {
+    std::function<void(GlobalValue &, ValueAdder Add)> AddLazyFor,
+    bool LinkModuleInlineAsm, bool IsPerformingImport) {
   IRLinker TheIRLinker(Composite, SharedMDs, IdentifiedStructTypes,
-                       std::move(Src), ValuesToLink, std::move(AddLazyFor));
+                       std::move(Src), ValuesToLink, std::move(AddLazyFor),
+                       LinkModuleInlineAsm, IsPerformingImport);
   Error E = TheIRLinker.run();
   Composite.dropTriviallyDeadConstantArrays();
   return E;