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, 85 insertions, 51 deletions

diff --git a/contrib/llvm/lib/Transforms/IPO/Internalize.cpp b/contrib/llvm/lib/Transforms/IPO/Internalize.cpp
index 4bfab5b..64e2ced 100644
--- a/contrib/llvm/lib/Transforms/IPO/Internalize.cpp
+++ b/contrib/llvm/lib/Transforms/IPO/Internalize.cpp
@@ -11,10 +11,17 @@
 // If the function or variable is not in the list of external names given to
 // the pass it is marked as internal.
 //
+// This transformation would not be legal in a regular compilation, but it gets
+// extra information from the linker about what is safe.
+//
+// For example: Internalizing a function with external linkage. Only if we are
+// told it is only used from within this module, it is safe to do it.
+//
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "internalize"
 #include "llvm/Transforms/IPO.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/IR/Module.h"
@@ -22,6 +29,8 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/GlobalStatus.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
 #include <fstream>
 #include <set>
 using namespace llvm;
@@ -48,10 +57,8 @@ namespace {
   public:
     static char ID; // Pass identification, replacement for typeid
     explicit InternalizePass();
-    explicit InternalizePass(ArrayRef<const char *> exportList);
+    explicit InternalizePass(ArrayRef<const char *> ExportList);
     void LoadFile(const char *Filename);
-    void ClearExportList();
-    void AddToExportList(const std::string &val);
     virtual bool runOnModule(Module &M);
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
@@ -70,15 +77,14 @@ InternalizePass::InternalizePass()
   initializeInternalizePassPass(*PassRegistry::getPassRegistry());
   if (!APIFile.empty())           // If a filename is specified, use it.
     LoadFile(APIFile.c_str());
-  if (!APIList.empty())           // If a list is specified, use it as well.
-    ExternalNames.insert(APIList.begin(), APIList.end());
+  ExternalNames.insert(APIList.begin(), APIList.end());
 }
 
-InternalizePass::InternalizePass(ArrayRef<const char *> exportList)
+InternalizePass::InternalizePass(ArrayRef<const char *> ExportList)
   : ModulePass(ID){
   initializeInternalizePassPass(*PassRegistry::getPassRegistry());
-  for(ArrayRef<const char *>::const_iterator itr = exportList.begin();
-        itr != exportList.end(); itr++) {
+  for(ArrayRef<const char *>::const_iterator itr = ExportList.begin();
+        itr != ExportList.end(); itr++) {
     ExternalNames.insert(*itr);
   }
 }
@@ -99,12 +105,25 @@ void InternalizePass::LoadFile(const char *Filename) {
   }
 }
 
-void InternalizePass::ClearExportList() {
-  ExternalNames.clear();
-}
+static bool shouldInternalize(const GlobalValue &GV,
+                              const std::set<std::string> &ExternalNames) {
+  // Function must be defined here
+  if (GV.isDeclaration())
+    return false;
+
+  // Available externally is really just a "declaration with a body".
+  if (GV.hasAvailableExternallyLinkage())
+    return false;
+
+  // Already has internal linkage
+  if (GV.hasLocalLinkage())
+    return false;
+
+  // Marked to keep external?
+  if (ExternalNames.count(GV.getName()))
+    return false;
 
-void InternalizePass::AddToExportList(const std::string &val) {
-  ExternalNames.insert(val);
+  return true;
 }
 
 bool InternalizePass::runOnModule(Module &M) {
@@ -112,26 +131,40 @@ bool InternalizePass::runOnModule(Module &M) {
   CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
   bool Changed = false;
 
-  // Never internalize functions which code-gen might insert.
-  // FIXME: We should probably add this (and the __stack_chk_guard) via some
-  // type of call-back in CodeGen.
-  ExternalNames.insert("__stack_chk_fail");
+  SmallPtrSet<GlobalValue *, 8> Used;
+  collectUsedGlobalVariables(M, Used, false);
+
+  // We must assume that globals in llvm.used have a reference that not even
+  // the linker can see, so we don't internalize them.
+  // For llvm.compiler.used the situation is a bit fuzzy. The assembler and
+  // linker can drop those symbols. If this pass is running as part of LTO,
+  // one might think that it could just drop llvm.compiler.used. The problem
+  // is that even in LTO llvm doesn't see every reference. For example,
+  // we don't see references from function local inline assembly. To be
+  // conservative, we internalize symbols in llvm.compiler.used, but we
+  // keep llvm.compiler.used so that the symbol is not deleted by llvm.
+  for (SmallPtrSet<GlobalValue *, 8>::iterator I = Used.begin(), E = Used.end();
+       I != E; ++I) {
+    GlobalValue *V = *I;
+    ExternalNames.insert(V->getName());
+  }
 
   // Mark all functions not in the api as internal.
   // FIXME: maybe use private linkage?
-  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
-    if (!I->isDeclaration() &&         // Function must be defined here
-        // Available externally is really just a "declaration with a body".
-        !I->hasAvailableExternallyLinkage() &&
-        !I->hasLocalLinkage() &&  // Can't already have internal linkage
-        !ExternalNames.count(I->getName())) {// Not marked to keep external?
-      I->setLinkage(GlobalValue::InternalLinkage);
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
+    if (!shouldInternalize(*I, ExternalNames))
+      continue;
+
+    I->setLinkage(GlobalValue::InternalLinkage);
+
+    if (ExternalNode)
       // Remove a callgraph edge from the external node to this function.
-      if (ExternalNode) ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
-      Changed = true;
-      ++NumFunctions;
-      DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
-    }
+      ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
+
+    Changed = true;
+    ++NumFunctions;
+    DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
+  }
 
   // Never internalize the llvm.used symbol.  It is used to implement
   // attribute((used)).
@@ -146,35 +179,36 @@ bool InternalizePass::runOnModule(Module &M) {
   ExternalNames.insert("llvm.global.annotations");
 
   // Never internalize symbols code-gen inserts.
+  // FIXME: We should probably add this (and the __stack_chk_guard) via some
+  // type of call-back in CodeGen.
+  ExternalNames.insert("__stack_chk_fail");
   ExternalNames.insert("__stack_chk_guard");
 
   // Mark all global variables with initializers that are not in the api as
   // internal as well.
   // FIXME: maybe use private linkage?
   for (Module::global_iterator I = M.global_begin(), E = M.global_end();
-       I != E; ++I)
-    if (!I->isDeclaration() && !I->hasLocalLinkage() &&
-        // Available externally is really just a "declaration with a body".
-        !I->hasAvailableExternallyLinkage() &&
-        !ExternalNames.count(I->getName())) {
-      I->setLinkage(GlobalValue::InternalLinkage);
-      Changed = true;
-      ++NumGlobals;
-      DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
-    }
+       I != E; ++I) {
+    if (!shouldInternalize(*I, ExternalNames))
+      continue;
+
+    I->setLinkage(GlobalValue::InternalLinkage);
+    Changed = true;
+    ++NumGlobals;
+    DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
+  }
 
   // Mark all aliases that are not in the api as internal as well.
   for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
-       I != E; ++I)
-    if (!I->isDeclaration() && !I->hasInternalLinkage() &&
-        // Available externally is really just a "declaration with a body".
-        !I->hasAvailableExternallyLinkage() &&
-        !ExternalNames.count(I->getName())) {
-      I->setLinkage(GlobalValue::InternalLinkage);
-      Changed = true;
-      ++NumAliases;
-      DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
-    }
+       I != E; ++I) {
+    if (!shouldInternalize(*I, ExternalNames))
+      continue;
+
+    I->setLinkage(GlobalValue::InternalLinkage);
+    Changed = true;
+    ++NumAliases;
+    DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
+  }
 
   return Changed;
 }
@@ -183,6 +217,6 @@ ModulePass *llvm::createInternalizePass() {
   return new InternalizePass();
 }
 
-ModulePass *llvm::createInternalizePass(ArrayRef<const char *> el) {
-  return new InternalizePass(el);
+ModulePass *llvm::createInternalizePass(ArrayRef<const char *> ExportList) {
+  return new InternalizePass(ExportList);
 }