MFC 261991:

Upgrade our copy of llvm/clang to 3.4 release.  This version supports
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.

The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3.  The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.

Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>

MFC 262121 (by emaste):

Update lldb for clang/llvm 3.4 import

This commit largely restores the lldb source to the upstream r196259
snapshot with the addition of threaded inferior support and a few bug
fixes.

Specific upstream lldb revisions restored include:
   SVN      git
  181387  779e6ac
  181703  7bef4e2
  182099  b31044e
  182650  f2dcf35
  182683  0d91b80
  183862  15c1774
  183929  99447a6
  184177  0b2934b
  184948  4dc3761
  184954  007e7bc
  186990  eebd175

Sponsored by:	DARPA, AFRL

MFC 262186 (by emaste):

Fix mismerge in r262121

A break statement was lost in the merge.  The error had no functional
impact, but restore it to reduce the diff against upstream.

MFC 262303:

Pull in r197521 from upstream clang trunk (by rdivacky):

  Use the integrated assembler by default on FreeBSD/ppc and ppc64.

Requested by:	jhibbits

MFC 262611:

Pull in r196874 from upstream llvm trunk:

  Fix a crash that occurs when PWD is invalid.

  MCJIT needs to be able to run in hostile environments, even when PWD
  is invalid. There's no need to crash MCJIT in this case.

  The obvious fix is to simply leave MCContext's CompilationDir empty
  when PWD can't be determined. This way, MCJIT clients,
  and other clients that link with LLVM don't need a valid working directory.

  If we do want to guarantee valid CompilationDir, that should be done
  only for clients of getCompilationDir(). This is as simple as checking
  for an empty string.

  The only current use of getCompilationDir is EmitGenDwarfInfo, which
  won't conceivably run with an invalid working dir. However, in the
  purely hypothetically and untestable case that this happens, the
  AT_comp_dir will be omitted from the compilation_unit DIE.

This should help fix assertions occurring with ports-mgmt/tinderbox,
when it is using jails, and sometimes invalidates clang's current
working directory.

Reported by:	decke

MFC 262809:

Pull in r203007 from upstream clang trunk:

  Don't produce an alias between destructors with different calling conventions.

  Fixes pr19007.

(Please note that is an LLVM PR identifier, not a FreeBSD one.)

This should fix Firefox and/or libxul crashes (due to problems with
regparm/stdcall calling conventions) on i386.

Reported by:	multiple users on freebsd-current
PR:		bin/187103

MFC 263048:

Repair recognition of "CC" as an alias for the C++ compiler, since it
was silently broken by upstream for a Windows-specific use-case.

Apparently some versions of CMake still rely on this archaic feature...

Reported by:	rakuco

MFC 263049:

Garbage collect the old way of adding the libstdc++ include directories
in clang's InitHeaderSearch.cpp.  This has been superseded by David
Chisnall's commit in r255321.

Moreover, if libc++ is used, the libstdc++ include directories should
not be in the search path at all.  These directories are now only used
if you pass -stdlib=libstdc++.

1 files changed, 103 insertions, 128 deletions

diff --git a/contrib/llvm/lib/Transforms/IPO/StripSymbols.cpp b/contrib/llvm/lib/Transforms/IPO/StripSymbols.cpp
index 3396f79..c4f5cfc 100644
--- a/contrib/llvm/lib/Transforms/IPO/StripSymbols.cpp
+++ b/contrib/llvm/lib/Transforms/IPO/StripSymbols.cpp
@@ -9,7 +9,7 @@
 //
 // The StripSymbols transformation implements code stripping. Specifically, it
 // can delete:
-// 
+//
 //   * names for virtual registers
 //   * symbols for internal globals and functions
 //   * debug information
@@ -39,7 +39,7 @@ namespace {
     bool OnlyDebugInfo;
   public:
     static char ID; // Pass identification, replacement for typeid
-    explicit StripSymbols(bool ODI = false) 
+    explicit StripSymbols(bool ODI = false)
       : ModulePass(ID), OnlyDebugInfo(ODI) {
         initializeStripSymbolsPass(*PassRegistry::getPassRegistry());
       }
@@ -144,7 +144,7 @@ static void RemoveDeadConstant(Constant *C) {
   assert(C->use_empty() && "Constant is not dead!");
   SmallPtrSet<Constant*, 4> Operands;
   for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
-    if (OnlyUsedBy(C->getOperand(i), C)) 
+    if (OnlyUsedBy(C->getOperand(i), C))
       Operands.insert(cast<Constant>(C->getOperand(i)));
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
     if (!GV->hasLocalLinkage()) return;   // Don't delete non static globals.
@@ -182,7 +182,7 @@ static void StripTypeNames(Module &M, bool PreserveDbgInfo) {
   for (unsigned i = 0, e = StructTypes.size(); i != e; ++i) {
     StructType *STy = StructTypes[i];
     if (STy->isLiteral() || STy->getName().empty()) continue;
-    
+
     if (PreserveDbgInfo && STy->getName().startswith("llvm.dbg"))
       continue;
 
@@ -199,7 +199,7 @@ static void findUsedValues(GlobalVariable *LLVMUsed,
   ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
 
   for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
-    if (GlobalValue *GV = 
+    if (GlobalValue *GV =
           dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
       UsedValues.insert(GV);
 }
@@ -217,71 +217,20 @@ static bool StripSymbolNames(Module &M, bool PreserveDbgInfo) {
       if (!PreserveDbgInfo || !I->getName().startswith("llvm.dbg"))
         I->setName("");     // Internal symbols can't participate in linkage
   }
-  
+
   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
     if (I->hasLocalLinkage() && llvmUsedValues.count(I) == 0)
       if (!PreserveDbgInfo || !I->getName().startswith("llvm.dbg"))
         I->setName("");     // Internal symbols can't participate in linkage
     StripSymtab(I->getValueSymbolTable(), PreserveDbgInfo);
   }
-  
+
   // Remove all names from types.
   StripTypeNames(M, PreserveDbgInfo);
 
   return true;
 }
 
-// StripDebugInfo - Strip debug info in the module if it exists.  
-// To do this, we remove llvm.dbg.func.start, llvm.dbg.stoppoint, and 
-// llvm.dbg.region.end calls, and any globals they point to if now dead.
-static bool StripDebugInfo(Module &M) {
-
-  bool Changed = false;
-
-  // Remove all of the calls to the debugger intrinsics, and remove them from
-  // the module.
-  if (Function *Declare = M.getFunction("llvm.dbg.declare")) {
-    while (!Declare->use_empty()) {
-      CallInst *CI = cast<CallInst>(Declare->use_back());
-      CI->eraseFromParent();
-    }
-    Declare->eraseFromParent();
-    Changed = true;
-  }
-
-  if (Function *DbgVal = M.getFunction("llvm.dbg.value")) {
-    while (!DbgVal->use_empty()) {
-      CallInst *CI = cast<CallInst>(DbgVal->use_back());
-      CI->eraseFromParent();
-    }
-    DbgVal->eraseFromParent();
-    Changed = true;
-  }
-
-  for (Module::named_metadata_iterator NMI = M.named_metadata_begin(),
-         NME = M.named_metadata_end(); NMI != NME;) {
-    NamedMDNode *NMD = NMI;
-    ++NMI;
-    if (NMD->getName().startswith("llvm.dbg.")) {
-      NMD->eraseFromParent();
-      Changed = true;
-    }
-  }
-
-  for (Module::iterator MI = M.begin(), ME = M.end(); MI != ME; ++MI)
-    for (Function::iterator FI = MI->begin(), FE = MI->end(); FI != FE;
-         ++FI)
-      for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE;
-           ++BI) {
-        if (!BI->getDebugLoc().isUnknown()) {
-          Changed = true;
-          BI->setDebugLoc(DebugLoc());
-        }
-      }
-
-  return Changed;
-}
-
 bool StripSymbols::runOnModule(Module &M) {
   bool Changed = false;
   Changed |= StripDebugInfo(M);
@@ -307,13 +256,13 @@ bool StripDebugDeclare::runOnModule(Module &M) {
       assert(CI->use_empty() && "llvm.dbg intrinsic should have void result");
       CI->eraseFromParent();
       if (Arg1->use_empty()) {
-        if (Constant *C = dyn_cast<Constant>(Arg1)) 
+        if (Constant *C = dyn_cast<Constant>(Arg1))
           DeadConstants.push_back(C);
-        else 
+        else
           RecursivelyDeleteTriviallyDeadInstructions(Arg1);
       }
       if (Arg2->use_empty())
-        if (Constant *C = dyn_cast<Constant>(Arg2)) 
+        if (Constant *C = dyn_cast<Constant>(Arg2))
           DeadConstants.push_back(C);
     }
     Declare->eraseFromParent();
@@ -332,81 +281,107 @@ bool StripDebugDeclare::runOnModule(Module &M) {
   return true;
 }
 
-/// getRealLinkageName - If special LLVM prefix that is used to inform the asm 
-/// printer to not emit usual symbol prefix before the symbol name is used then
-/// return linkage name after skipping this special LLVM prefix.
-static StringRef getRealLinkageName(StringRef LinkageName) {
-  char One = '\1';
-  if (LinkageName.startswith(StringRef(&One, 1)))
-    return LinkageName.substr(1);
-  return LinkageName;
-}
-
+/// Remove any debug info for global variables/functions in the given module for
+/// which said global variable/function no longer exists (i.e. is null).
+///
+/// Debugging information is encoded in llvm IR using metadata. This is designed
+/// such a way that debug info for symbols preserved even if symbols are
+/// optimized away by the optimizer. This special pass removes debug info for
+/// such symbols.
 bool StripDeadDebugInfo::runOnModule(Module &M) {
   bool Changed = false;
 
-  // Debugging infomration is encoded in llvm IR using metadata. This is designed
-  // such a way that debug info for symbols preserved even if symbols are
-  // optimized away by the optimizer. This special pass removes debug info for 
-  // such symbols.
-
-  // llvm.dbg.gv keeps track of debug info for global variables.
-  if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.gv")) {
-    SmallVector<MDNode *, 8> MDs;
-    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
-      if (DIGlobalVariable(NMD->getOperand(i)).Verify())
-        MDs.push_back(NMD->getOperand(i));
-      else
-        Changed = true;
-    NMD->eraseFromParent();
-    NMD = NULL;
-
-    for (SmallVector<MDNode *, 8>::iterator I = MDs.begin(),
-           E = MDs.end(); I != E; ++I) {
-      GlobalVariable *GV = DIGlobalVariable(*I).getGlobal();
-      if (GV && M.getGlobalVariable(GV->getName(), true)) {
-        if (!NMD)
-          NMD = M.getOrInsertNamedMetadata("llvm.dbg.gv");
-        NMD->addOperand(*I);
-      }
+  LLVMContext &C = M.getContext();
+
+  // Find all debug info in F. This is actually overkill in terms of what we
+  // want to do, but we want to try and be as resilient as possible in the face
+  // of potential debug info changes by using the formal interfaces given to us
+  // as much as possible.
+  DebugInfoFinder F;
+  F.processModule(M);
+
+  // For each compile unit, find the live set of global variables/functions and
+  // replace the current list of potentially dead global variables/functions
+  // with the live list.
+  SmallVector<Value *, 64> LiveGlobalVariables;
+  SmallVector<Value *, 64> LiveSubprograms;
+  DenseSet<const MDNode *> VisitedSet;
+
+  for (DebugInfoFinder::iterator CI = F.compile_unit_begin(),
+         CE = F.compile_unit_end(); CI != CE; ++CI) {
+    // Create our compile unit.
+    DICompileUnit DIC(*CI);
+    assert(DIC.Verify() && "DIC must verify as a DICompileUnit.");
+
+    // Create our live subprogram list.
+    DIArray SPs = DIC.getSubprograms();
+    bool SubprogramChange = false;
+    for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
+      DISubprogram DISP(SPs.getElement(i));
+      assert(DISP.Verify() && "DISP must verify as a DISubprogram.");
+
+      // Make sure we visit each subprogram only once.
+      if (!VisitedSet.insert(DISP).second)
+        continue;
+
+      // If the function referenced by DISP is not null, the function is live.
+      if (DISP.getFunction())
+        LiveSubprograms.push_back(DISP);
       else
-        Changed = true;
+        SubprogramChange = true;
     }
-  }
 
-  // llvm.dbg.sp keeps track of debug info for subprograms.
-  if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.sp")) {
-    SmallVector<MDNode *, 8> MDs;
-    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
-      if (DISubprogram(NMD->getOperand(i)).Verify())
-        MDs.push_back(NMD->getOperand(i));
+    // Create our live global variable list.
+    DIArray GVs = DIC.getGlobalVariables();
+    bool GlobalVariableChange = false;
+    for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) {
+      DIGlobalVariable DIG(GVs.getElement(i));
+      assert(DIG.Verify() && "DIG must verify as DIGlobalVariable.");
+
+      // Make sure we only visit each global variable only once.
+      if (!VisitedSet.insert(DIG).second)
+        continue;
+
+      // If the global variable referenced by DIG is not null, the global
+      // variable is live.
+      if (DIG.getGlobal())
+        LiveGlobalVariables.push_back(DIG);
       else
-        Changed = true;
-    NMD->eraseFromParent();
-    NMD = NULL;
-
-    for (SmallVector<MDNode *, 8>::iterator I = MDs.begin(),
-           E = MDs.end(); I != E; ++I) {
-      bool FnIsLive = false;
-      if (Function *F = DISubprogram(*I).getFunction())
-        if (M.getFunction(F->getName()))
-          FnIsLive = true;
-      if (FnIsLive) {
-          if (!NMD)
-            NMD = M.getOrInsertNamedMetadata("llvm.dbg.sp");
-          NMD->addOperand(*I);
-      } else {
-        // Remove llvm.dbg.lv.fnname named mdnode which may have been used
-        // to hold debug info for dead function's local variables.
-        StringRef FName = DISubprogram(*I).getLinkageName();
-        if (FName.empty())
-          FName = DISubprogram(*I).getName();
-        if (NamedMDNode *LVNMD = 
-            M.getNamedMetadata(Twine("llvm.dbg.lv.", 
-                                     getRealLinkageName(FName)))) 
-          LVNMD->eraseFromParent();
-      }
+        GlobalVariableChange = true;
+    }
+
+    // If we found dead subprograms or global variables, replace the current
+    // subprogram list/global variable list with our new live subprogram/global
+    // variable list.
+    if (SubprogramChange) {
+      // Make sure that 9 is still the index of the subprograms. This is to make
+      // sure that an assert is hit if the location of the subprogram array
+      // changes. This is just to make sure that this is updated if such an
+      // event occurs.
+      assert(DIC->getNumOperands() >= 10 &&
+             SPs == DIC->getOperand(9) &&
+             "DICompileUnits is expected to store Subprograms in operand "
+             "9.");
+      DIC->replaceOperandWith(9, MDNode::get(C, LiveSubprograms));
+      Changed = true;
     }
+
+    if (GlobalVariableChange) {
+      // Make sure that 10 is still the index of global variables. This is to
+      // make sure that an assert is hit if the location of the subprogram array
+      // changes. This is just to make sure that this index is updated if such
+      // an event occurs.
+      assert(DIC->getNumOperands() >= 11 &&
+             GVs == DIC->getOperand(10) &&
+             "DICompileUnits is expected to store Global Variables in operand "
+             "10.");
+      DIC->replaceOperandWith(10, MDNode::get(C, LiveGlobalVariables));
+      Changed = true;
+    }
+
+    // Reset lists for the next iteration.
+    LiveSubprograms.clear();
+    LiveGlobalVariables.clear();
   }
 
   return Changed;