MFC r309124:

Upgrade our copies of clang, llvm, lldb, compiler-rt and libc++ to 3.9.0
release, and add lld 3.9.0.  Also completely revamp the build system for
clang, llvm, lldb and their related tools.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld are available here:
<http://llvm.org/releases/3.9.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/clang/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Bryan Drewery, Andrew Turner, Antoine Brodin and Jan
Beich for their help.

Relnotes:	yes

MFC r309147:

Pull in r282174 from upstream llvm trunk (by Krzysztof Parzyszek):

  [PPC] Set SP after loading data from stack frame, if no red zone is
  present

  Follow-up to r280705: Make sure that the SP is only restored after
  all data is loaded from the stack frame, if there is no red zone.

  This completes the fix for
  https://llvm.org/bugs/show_bug.cgi?id=26519.

  Differential Revision: https://reviews.llvm.org/D24466

Reported by:    Mark Millard
PR:             214433

MFC r309149:

Pull in r283060 from upstream llvm trunk (by Hal Finkel):

  [PowerPC] Refactor soft-float support, and enable PPC64 soft float

  This change enables soft-float for PowerPC64, and also makes
  soft-float disable all vector instruction sets for both 32-bit and
  64-bit modes. This latter part is necessary because the PPC backend
  canonicalizes many Altivec vector types to floating-point types, and
  so soft-float breaks scalarization support for many operations. Both
  for embedded targets and for operating-system kernels desiring
  soft-float support, it seems reasonable that disabling hardware
  floating-point also disables vector instructions (embedded targets
  without hardware floating point support are unlikely to have Altivec,
  etc. and operating system kernels desiring not to use floating-point
  registers to lower syscall cost are unlikely to want to use vector
  registers either). If someone needs this to work, we'll need to
  change the fact that we promote many Altivec operations to act on
  v4f32. To make it possible to disable Altivec when soft-float is
  enabled, hardware floating-point support needs to be expressed as a
  positive feature, like the others, and not a negative feature,
  because target features cannot have dependencies on the disabling of
  some other feature. So +soft-float has now become -hard-float.

  Fixes PR26970.

Pull in r283061 from upstream clang trunk (by Hal Finkel):

  [PowerPC] Enable soft-float for PPC64, and +soft-float -> -hard-float

  Enable soft-float support on PPC64, as the backend now supports it.
  Also, the backend now uses -hard-float instead of +soft-float, so set
  the target features accordingly.

  Fixes PR26970.

Reported by:	Mark Millard
PR:		214433

MFC r309212:

Add a few missed clang 3.9.0 files to OptionalObsoleteFiles.

MFC r309262:

Fix packaging for clang, lldb and lld 3.9.0

During the upgrade of clang/llvm etc to 3.9.0 in r309124, the PACKAGE
directive in the usr.bin/clang/*.mk files got dropped accidentally.

Restore it, with a few minor changes and additions:
* Correct license in clang.ucl to NCSA
* Add PACKAGE=clang for clang and most of the "ll" tools
* Put lldb in its own package
* Put lld in its own package

Reviewed by:	gjb, jmallett
Differential Revision: https://reviews.freebsd.org/D8666

MFC r309656:

During the bootstrap phase, when building the minimal llvm library on
PowerPC, add lib/Support/Atomic.cpp.  This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.

Reported by:	Mark Millard
PR:		214902

MFC r309835:

Tentatively apply https://reviews.llvm.org/D18730 to work around gcc PR
70528 (bogus error: constructor required before non-static data member).
This should fix buildworld with the external gcc package.

Reported by:	https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc/

MFC r310194:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
3.9.1 release.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/3.9.1/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/lld/docs/ReleaseNotes.html>

Relnotes:	yes

1 files changed, 158 insertions, 27 deletions

diff --git a/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp b/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp
index 9768a16..ca11f9b 100644
--- a/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp
+++ b/contrib/llvm/tools/clang/lib/Frontend/ModuleDependencyCollector.cpp
@@ -11,9 +11,11 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/Basic/CharInfo.h"
 #include "clang/Frontend/Utils.h"
+#include "clang/Lex/Preprocessor.h"
 #include "clang/Serialization/ASTReader.h"
-#include "llvm/ADT/StringSet.h"
+#include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
@@ -22,73 +24,202 @@
 using namespace clang;
 
 namespace {
-/// Private implementation for ModuleDependencyCollector
+/// Private implementations for ModuleDependencyCollector
 class ModuleDependencyListener : public ASTReaderListener {
   ModuleDependencyCollector &Collector;
-
-  std::error_code copyToRoot(StringRef Src);
 public:
   ModuleDependencyListener(ModuleDependencyCollector &Collector)
       : Collector(Collector) {}
   bool needsInputFileVisitation() override { return true; }
   bool needsSystemInputFileVisitation() override { return true; }
   bool visitInputFile(StringRef Filename, bool IsSystem, bool IsOverridden,
-                      bool IsExplicitModule) override;
+                      bool IsExplicitModule) override {
+    Collector.addFile(Filename);
+    return true;
+  }
+};
+
+struct ModuleDependencyMMCallbacks : public ModuleMapCallbacks {
+  ModuleDependencyCollector &Collector;
+  ModuleDependencyMMCallbacks(ModuleDependencyCollector &Collector)
+      : Collector(Collector) {}
+
+  void moduleMapAddHeader(StringRef HeaderPath) override {
+    if (llvm::sys::path::is_absolute(HeaderPath))
+      Collector.addFile(HeaderPath);
+  }
+  void moduleMapAddUmbrellaHeader(FileManager *FileMgr,
+                                  const FileEntry *Header) override {
+    StringRef HeaderFilename = Header->getName();
+    moduleMapAddHeader(HeaderFilename);
+    // The FileManager can find and cache the symbolic link for a framework
+    // header before its real path, this means a module can have some of its
+    // headers to use other paths. Although this is usually not a problem, it's
+    // inconsistent, and not collecting the original path header leads to
+    // umbrella clashes while rebuilding modules in the crash reproducer. For
+    // example:
+    //    ApplicationServices.framework/Frameworks/ImageIO.framework/ImageIO.h
+    // instead of:
+    //    ImageIO.framework/ImageIO.h
+    //
+    // FIXME: this shouldn't be necessary once we have FileName instances
+    // around instead of FileEntry ones. For now, make sure we collect all
+    // that we need for the reproducer to work correctly.
+    StringRef UmbreallDirFromHeader =
+        llvm::sys::path::parent_path(HeaderFilename);
+    StringRef UmbrellaDir = Header->getDir()->getName();
+    if (!UmbrellaDir.equals(UmbreallDirFromHeader)) {
+      SmallString<128> AltHeaderFilename;
+      llvm::sys::path::append(AltHeaderFilename, UmbrellaDir,
+                              llvm::sys::path::filename(HeaderFilename));
+      if (FileMgr->getFile(AltHeaderFilename))
+        moduleMapAddHeader(AltHeaderFilename);
+    }
+  }
 };
+
+}
+
+// TODO: move this to Support/Path.h and check for HAVE_REALPATH?
+static bool real_path(StringRef SrcPath, SmallVectorImpl<char> &RealPath) {
+#ifdef LLVM_ON_UNIX
+  char CanonicalPath[PATH_MAX];
+
+  // TODO: emit a warning in case this fails...?
+  if (!realpath(SrcPath.str().c_str(), CanonicalPath))
+    return false;
+
+  SmallString<256> RPath(CanonicalPath);
+  RealPath.swap(RPath);
+  return true;
+#else
+  // FIXME: Add support for systems without realpath.
+  return false;
+#endif
 }
 
 void ModuleDependencyCollector::attachToASTReader(ASTReader &R) {
   R.addListener(llvm::make_unique<ModuleDependencyListener>(*this));
 }
 
+void ModuleDependencyCollector::attachToPreprocessor(Preprocessor &PP) {
+  PP.getHeaderSearchInfo().getModuleMap().addModuleMapCallbacks(
+      llvm::make_unique<ModuleDependencyMMCallbacks>(*this));
+}
+
+static bool isCaseSensitivePath(StringRef Path) {
+  SmallString<256> TmpDest = Path, UpperDest, RealDest;
+  // Remove component traversals, links, etc.
+  if (!real_path(Path, TmpDest))
+    return true; // Current default value in vfs.yaml
+  Path = TmpDest;
+
+  // Change path to all upper case and ask for its real path, if the latter
+  // exists and is equal to Path, it's not case sensitive. Default to case
+  // sensitive in the absense of realpath, since this is what the VFSWriter
+  // already expects when sensitivity isn't setup.
+  for (auto &C : Path)
+    UpperDest.push_back(toUppercase(C));
+  if (real_path(UpperDest, RealDest) && Path.equals(RealDest))
+    return false;
+  return true;
+}
+
 void ModuleDependencyCollector::writeFileMap() {
   if (Seen.empty())
     return;
 
-  SmallString<256> Dest = getDest();
-  llvm::sys::path::append(Dest, "vfs.yaml");
+  StringRef VFSDir = getDest();
+
+  // Default to use relative overlay directories in the VFS yaml file. This
+  // allows crash reproducer scripts to work across machines.
+  VFSWriter.setOverlayDir(VFSDir);
+
+  // Explicitly set case sensitivity for the YAML writer. For that, find out
+  // the sensitivity at the path where the headers all collected to.
+  VFSWriter.setCaseSensitivity(isCaseSensitivePath(VFSDir));
+
+  // Do not rely on real path names when executing the crash reproducer scripts
+  // since we only want to actually use the files we have on the VFS cache.
+  VFSWriter.setUseExternalNames(false);
 
   std::error_code EC;
-  llvm::raw_fd_ostream OS(Dest, EC, llvm::sys::fs::F_Text);
+  SmallString<256> YAMLPath = VFSDir;
+  llvm::sys::path::append(YAMLPath, "vfs.yaml");
+  llvm::raw_fd_ostream OS(YAMLPath, EC, llvm::sys::fs::F_Text);
   if (EC) {
-    setHasErrors();
+    HasErrors = true;
     return;
   }
   VFSWriter.write(OS);
 }
 
-std::error_code ModuleDependencyListener::copyToRoot(StringRef Src) {
+bool ModuleDependencyCollector::getRealPath(StringRef SrcPath,
+                                            SmallVectorImpl<char> &Result) {
+  using namespace llvm::sys;
+  SmallString<256> RealPath;
+  StringRef FileName = path::filename(SrcPath);
+  std::string Dir = path::parent_path(SrcPath).str();
+  auto DirWithSymLink = SymLinkMap.find(Dir);
+
+  // Use real_path to fix any symbolic link component present in a path.
+  // Computing the real path is expensive, cache the search through the
+  // parent path directory.
+  if (DirWithSymLink == SymLinkMap.end()) {
+    if (!real_path(Dir, RealPath))
+      return false;
+    SymLinkMap[Dir] = RealPath.str();
+  } else {
+    RealPath = DirWithSymLink->second;
+  }
+
+  path::append(RealPath, FileName);
+  Result.swap(RealPath);
+  return true;
+}
+
+std::error_code ModuleDependencyCollector::copyToRoot(StringRef Src) {
   using namespace llvm::sys;
 
-  // We need an absolute path to append to the root.
+  // We need an absolute src path to append to the root.
   SmallString<256> AbsoluteSrc = Src;
   fs::make_absolute(AbsoluteSrc);
-  // Canonicalize to a native path to avoid mixed separator styles.
+  // Canonicalize src to a native path to avoid mixed separator styles.
   path::native(AbsoluteSrc);
-  // TODO: We probably need to handle .. as well as . in order to have valid
-  // input to the YAMLVFSWriter.
-  path::remove_dots(AbsoluteSrc);
+  // Remove redundant leading "./" pieces and consecutive separators.
+  AbsoluteSrc = path::remove_leading_dotslash(AbsoluteSrc);
 
-  // Build the destination path.
-  SmallString<256> Dest = Collector.getDest();
-  path::append(Dest, path::relative_path(AbsoluteSrc));
+  // Canonicalize the source path by removing "..", "." components.
+  SmallString<256> CanonicalPath = AbsoluteSrc;
+  path::remove_dots(CanonicalPath, /*remove_dot_dot=*/true);
+
+  // If a ".." component is present after a symlink component, remove_dots may
+  // lead to the wrong real destination path. Let the source be canonicalized
+  // like that but make sure we always use the real path for the destination.
+  SmallString<256> RealPath;
+  if (!getRealPath(AbsoluteSrc, RealPath))
+    RealPath = CanonicalPath;
+  SmallString<256> Dest = getDest();
+  path::append(Dest, path::relative_path(RealPath));
 
   // Copy the file into place.
   if (std::error_code EC = fs::create_directories(path::parent_path(Dest),
                                                    /*IgnoreExisting=*/true))
     return EC;
-  if (std::error_code EC = fs::copy_file(AbsoluteSrc, Dest))
+  if (std::error_code EC = fs::copy_file(RealPath, Dest))
     return EC;
-  // Use the absolute path under the root for the file mapping.
-  Collector.addFileMapping(AbsoluteSrc, Dest);
+
+  // Always map a canonical src path to its real path into the YAML, by doing
+  // this we map different virtual src paths to the same entry in the VFS
+  // overlay, which is a way to emulate symlink inside the VFS; this is also
+  // needed for correctness, not doing that can lead to module redifinition
+  // errors.
+  addFileMapping(CanonicalPath, Dest);
   return std::error_code();
 }
 
-bool ModuleDependencyListener::visitInputFile(StringRef Filename, bool IsSystem,
-                                              bool IsOverridden,
-                                              bool IsExplicitModule) {
-  if (Collector.insertSeen(Filename))
+void ModuleDependencyCollector::addFile(StringRef Filename) {
+  if (insertSeen(Filename))
     if (copyToRoot(Filename))
-      Collector.setHasErrors();
-  return true;
+      HasErrors = true;
 }