Merge clang, llvm, lld, lldb, compiler-rt and libc++ 5.0.0 release.

MFC r309126 (by emaste):

  Correct lld llvm-tblgen dependency file name

MFC r309169:

  Get rid of separate Subversion mergeinfo properties for llvm-dwarfdump
  and llvm-lto.  The mergeinfo confuses Subversion enormously, and these
  directories will just use the mergeinfo for llvm itself.

MFC r312765:

  Pull in r276136 from upstream llvm trunk (by Wei Mi):

    Use ValueOffsetPair to enhance value reuse during SCEV expansion.

    In D12090, the ExprValueMap was added to reuse existing value during
    SCEV expansion. However, const folding and sext/zext distribution can
    make the reuse still difficult.

    A simplified case is: suppose we know S1 expands to V1 in
    ExprValueMap, and
      S1 = S2 + C_a
      S3 = S2 + C_b
    where C_a and C_b are different SCEVConstants. Then we'd like to
    expand S3 as V1 - C_a + C_b instead of expanding S2 literally. It is
    helpful when S2 is a complex SCEV expr and S2 has no entry in
    ExprValueMap, which is usually caused by the fact that S3 is
    generated from S1 after const folding.

    In order to do that, we represent ExprValueMap as a mapping from SCEV
    to ValueOffsetPair. We will save both S1->{V1, 0} and S2->{V1, C_a}
    into the ExprValueMap when we create SCEV for V1. When S3 is
    expanded, it will first expand S2 to V1 - C_a because of S2->{V1,
    C_a} in the map, then expand S3 to V1 - C_a + C_b.

    Differential Revision: https://reviews.llvm.org/D21313

  This should fix assertion failures when building OpenCV >= 3.1.

  PR:		215649

MFC r312831:

  Revert r312765 for now, since it causes assertions when building
  lang/spidermonkey24.

  Reported by:	antoine
  PR:		215649

MFC r316511 (by jhb):

  Add an implementation of __ffssi2() derived from __ffsdi2().

  Newer versions of GCC include an __ffssi2() symbol in libgcc and the
  compiler can emit calls to it in generated code.  This is true for at
  least GCC 6.2 when compiling world for mips and mips64.

  Reviewed by:	jmallett, dim
  Sponsored by:	DARPA / AFRL
  Differential Revision:	https://reviews.freebsd.org/D10086

MFC r318601 (by adrian):

  [libcompiler-rt] add bswapdi2/bswapsi2

  This is required for mips gcc 6.3 userland to build/run.

  Reviewed by:	emaste, dim
  Approved by:	emaste
  Differential Revision:	https://reviews.freebsd.org/D10838

MFC r318884 (by emaste):

  lldb: map TRAP_CAP to a trace trap

  In the absense of a more specific handler for TRAP_CAP (generated by
  ENOTCAPABLE or ECAPMODE while in capability mode) treat it as a trace
  trap.

  Example usage (testing the bug in PR219173):

  % proccontrol -m trapcap lldb usr.bin/hexdump/obj/hexdump -- -Cv -s 1 /bin/ls
  ...
  (lldb) run
  Process 12980 launching
  Process 12980 launched: '.../usr.bin/hexdump/obj/hexdump' (x86_64)
  Process 12980 stopped
  * thread #1, stop reason = trace
      frame #0: 0x0000004b80c65f1a libc.so.7`__sys_lseek + 10
  ...

  In the future we should have LLDB control the trapcap procctl itself
  (as it does with ASLR), as well as report a specific stop reason.
  This change eliminates an assertion failure from LLDB for now.

MFC r319796:

  Remove a few unneeded files from libllvm, libclang and liblldb.

MFC r319885 (by emaste):

  lld: ELF: Fix ICF crash on absolute symbol relocations.

  If two sections contained relocations to absolute symbols with the same
  value we would crash when trying to access their sections. Add a check that
  both symbols point to sections before accessing their sections, and treat
  absolute symbols as equal if their values are equal.

  Obtained from:	LLD commit r292578

MFC r319918:

  Revert r319796 for now, it can cause undefined references when linking
  in some circumstances.

  Reported by:	Shawn Webb <shawn.webb@hardenedbsd.org>

MFC r319957 (by emaste):

  lld: Add armelf emulation mode

  Obtained from:	LLD r305375

MFC r321369:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 (trunk r308421).  Upstream has branched for the 5.0.0 release,
  which should be in about a month.  Please report bugs and regressions,
  so we can get them into the release.

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

MFC r321420:

  Add a few more object files to liblldb, which should solve errors when
  linking the lldb executable in some cases.  In particular, when the
  -ffunction-sections -fdata-sections options are turned off, or
  ineffective.

  Reported by:	Shawn Webb, Mark Millard

MFC r321433:

  Cleanup stale Options.inc files from the previous libllvm build for
  clang 4.0.0.  Otherwise, these can get included before the two newly
  generated ones (which are different) for clang 5.0.0.

  Reported by:	Mark Millard

MFC r321439 (by bdrewery):

  Move llvm Options.inc hack from r321433 for NO_CLEAN to lib/clang/libllvm.

  The files are only ever generated to .OBJDIR, not to WORLDTMP (as a
  sysroot) and are only ever included from a compilation.  So using
  a beforebuild target here removes the file before the compilation
  tries to include it.

MFC r321664:

  Pull in r308891 from upstream llvm trunk (by Benjamin Kramer):

    [CodeGenPrepare] Cut off FindAllMemoryUses if there are too many uses.

    This avoids excessive compile time. The case I'm looking at is
    Function.cpp from an old version of LLVM that still had the giant
    memcmp string matcher in it. Before r308322 this compiled in about 2
    minutes, after it, clang takes infinite* time to compile it. With
    this patch we're at 5 min, which is still bad but this is a
    pathological case.

    The cut off at 20 uses was chosen by looking at other cut-offs in LLVM
    for user scanning. It's probably too high, but does the job and is
    very unlikely to regress anything.

    Fixes PR33900.

    * I'm impatient and aborted after 15 minutes, on the bug report it was
      killed after 2h.

  Pull in r308986 from upstream llvm trunk (by Simon Pilgrim):

    [X86][CGP] Reduce memcmp() expansion to 2 load pairs (PR33914)

    D35067/rL308322 attempted to support up to 4 load pairs for memcmp
    inlining which resulted in regressions for some optimized libc memcmp
    implementations (PR33914).

    Until we can match these more optimal cases, this patch reduces the
    memcmp expansion to a maximum of 2 load pairs (which matches what we
    do for -Os).

    This patch should be considered for the 5.0.0 release branch as well

    Differential Revision: https://reviews.llvm.org/D35830

  These fix a hang (or extremely long compile time) when building older
  LLVM ports.

  Reported by:    antoine
  PR:             219139

MFC r321719:

  Pull in r309503 from upstream clang trunk (by Richard Smith):

    PR33902: Invalidate line number cache when adding more text to
    existing buffer.

    This led to crashes as the line number cache would report a bogus
    line number for a line of code, and we'd try to find a nonexistent
    column within the line when printing diagnostics.

  This fixes an assertion when building the graphics/champlain port.

  Reported by:	antoine, kwm
  PR:		219139

MFC r321723:

  Upgrade our copies of clang, llvm, lld and lldb to r309439 from the
  upstream release_50 branch.  This is just after upstream's 5.0.0-rc1.

MFC r322320:

  Upgrade our copies of clang, llvm and libc++ to r310316 from the
  upstream release_50 branch.

MFC r322326 (by emaste):

  lldb: Make i386-*-freebsd expression work on JIT path

  * Enable i386 ABI creation for freebsd
  * Added an extra argument in ABISysV_i386::PrepareTrivialCall for mmap
    syscall
  * Unlike linux, the last argument of mmap is actually 64-bit(off_t).
    This requires us to push an additional word for the higher order bits.
  * Prior to this change, ktrace dump will show mmap failures due to
    invalid argument coming from the 6th mmap argument.

  Submitted by:	Karnajit Wangkhem
  Differential Revision:	https://reviews.llvm.org/D34776

MFC r322360 (by emaste):

  lldb: Report inferior signals as signals, not exceptions, on FreeBSD

  This is the FreeBSD equivalent of LLVM r238549.

  This serves 2 purposes:

  * LLDB should handle inferior process signals SIGSEGV/SIGILL/SIGBUS/
    SIGFPE the way it is suppose to be handled. Prior to this fix these
    signals will neither create a coredump, nor exit from the debugger
    or work for signal handling scenario.
  * eInvalidCrashReason need not report "unknown crash reason" if we have
    a valid si_signo

  llvm.org/pr23699

  Patch by Karnajit Wangkhem

  Differential Revision:  https://reviews.llvm.org/D35223

  Submitted by:	Karnajit Wangkhem
  Obtained from:	LLVM r310591

MFC r322474 (by emaste):

  lld: Add `-z muldefs` option.

  Obtained from:	LLVM r310757

MFC r322740:

  Upgrade our copies of clang, llvm, lld and libc++ to r311219 from the
  upstream release_50 branch.

MFC r322855:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r311606 from
  the upstream release_50 branch.

  As of this version, lib/msun's trig test should also work correctly
  again (see bug 220989 for more information).

  PR:		220989

MFC r323112:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r312293 from
  the upstream release_50 branch.  This corresponds to 5.0.0 rc4.

  As of this version, the cad/stepcode port should now compile in a more
  reasonable time on i386 (see bug 221836 for more information).

  PR:		221836

MFC r323245:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 release (upstream r312559).

  Release notes for llvm, clang and lld will be available here soon:
  <http://releases.llvm.org/5.0.0/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/clang/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/lld/docs/ReleaseNotes.html>

  Relnotes:	yes

(cherry picked from commit 12cd91cf4c6b96a24427c0de5374916f2808d263)

1 files changed, 194 insertions, 136 deletions

diff --git a/contrib/llvm/tools/clang/lib/Frontend/TextDiagnostic.cpp b/contrib/llvm/tools/clang/lib/Frontend/TextDiagnostic.cpp
index a493738..6a72b00 100644
--- a/contrib/llvm/tools/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/contrib/llvm/tools/clang/lib/Frontend/TextDiagnostic.cpp
@@ -672,20 +672,16 @@ TextDiagnostic::TextDiagnostic(raw_ostream &OS,
 
 TextDiagnostic::~TextDiagnostic() {}
 
-void
-TextDiagnostic::emitDiagnosticMessage(SourceLocation Loc,
-                                      PresumedLoc PLoc,
-                                      DiagnosticsEngine::Level Level,
-                                      StringRef Message,
-                                      ArrayRef<clang::CharSourceRange> Ranges,
-                                      const SourceManager *SM,
-                                      DiagOrStoredDiag D) {
+void TextDiagnostic::emitDiagnosticMessage(
+    FullSourceLoc Loc, PresumedLoc PLoc, DiagnosticsEngine::Level Level,
+    StringRef Message, ArrayRef<clang::CharSourceRange> Ranges,
+    DiagOrStoredDiag D) {
   uint64_t StartOfLocationInfo = OS.tell();
 
   // Emit the location of this particular diagnostic.
   if (Loc.isValid())
-    emitDiagnosticLoc(Loc, PLoc, Level, Ranges, *SM);
-  
+    emitDiagnosticLoc(Loc, PLoc, Level, Ranges);
+
   if (DiagOpts->ShowColors)
     OS.resetColor();
   
@@ -787,17 +783,16 @@ void TextDiagnostic::emitFilename(StringRef Filename, const SourceManager &SM) {
 /// This includes extracting as much location information as is present for
 /// the diagnostic and printing it, as well as any include stack or source
 /// ranges necessary.
-void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
+void TextDiagnostic::emitDiagnosticLoc(FullSourceLoc Loc, PresumedLoc PLoc,
                                        DiagnosticsEngine::Level Level,
-                                       ArrayRef<CharSourceRange> Ranges,
-                                       const SourceManager &SM) {
+                                       ArrayRef<CharSourceRange> Ranges) {
   if (PLoc.isInvalid()) {
     // At least print the file name if available:
-    FileID FID = SM.getFileID(Loc);
+    FileID FID = Loc.getFileID();
     if (FID.isValid()) {
-      const FileEntry* FE = SM.getFileEntryForID(FID);
+      const FileEntry *FE = Loc.getFileEntry();
       if (FE && FE->isValid()) {
-        emitFilename(FE->getName(), SM);
+        emitFilename(FE->getName(), Loc.getManager());
         if (FE->isInPCH())
           OS << " (in PCH)";
         OS << ": ";
@@ -813,7 +808,7 @@ void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
   if (DiagOpts->ShowColors)
     OS.changeColor(savedColor, true);
 
-  emitFilename(PLoc.getFilename(), SM);
+  emitFilename(PLoc.getFilename(), Loc.getManager());
   switch (DiagOpts->getFormat()) {
   case DiagnosticOptions::Clang: OS << ':'  << LineNo; break;
   case DiagnosticOptions::MSVC:  OS << '('  << LineNo; break;
@@ -848,8 +843,7 @@ void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
   }
 
   if (DiagOpts->ShowSourceRanges && !Ranges.empty()) {
-    FileID CaretFileID =
-      SM.getFileID(SM.getExpansionLoc(Loc));
+    FileID CaretFileID = Loc.getExpansionLoc().getFileID();
     bool PrintedRange = false;
 
     for (ArrayRef<CharSourceRange>::const_iterator RI = Ranges.begin(),
@@ -858,8 +852,10 @@ void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
       // Ignore invalid ranges.
       if (!RI->isValid()) continue;
 
-      SourceLocation B = SM.getExpansionLoc(RI->getBegin());
-      SourceLocation E = SM.getExpansionLoc(RI->getEnd());
+      FullSourceLoc B =
+          FullSourceLoc(RI->getBegin(), Loc.getManager()).getExpansionLoc();
+      FullSourceLoc E =
+          FullSourceLoc(RI->getEnd(), Loc.getManager()).getExpansionLoc();
 
       // If the End location and the start location are the same and are a
       // macro location, then the range was something that came from a
@@ -867,10 +863,12 @@ void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
       // best we can do is to highlight the range.  If this is a
       // function-like macro, we'd also like to highlight the arguments.
       if (B == E && RI->getEnd().isMacroID())
-        E = SM.getExpansionRange(RI->getEnd()).second;
+        E = FullSourceLoc(RI->getEnd(), Loc.getManager())
+                .getExpansionRange()
+                .second;
 
-      std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(B);
-      std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(E);
+      std::pair<FileID, unsigned> BInfo = B.getDecomposedLoc();
+      std::pair<FileID, unsigned> EInfo = E.getDecomposedLoc();
 
       // If the start or end of the range is in another file, just discard
       // it.
@@ -881,13 +879,10 @@ void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
       // tokens.
       unsigned TokSize = 0;
       if (RI->isTokenRange())
-        TokSize = Lexer::MeasureTokenLength(E, SM, LangOpts);
+        TokSize = Lexer::MeasureTokenLength(E, E.getManager(), LangOpts);
 
-      OS << '{' << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
-        << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
-        << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
-        << (SM.getColumnNumber(EInfo.first, EInfo.second)+TokSize)
-        << '}';
+      OS << '{' << B.getLineNumber() << ':' << B.getColumnNumber() << '-'
+         << E.getLineNumber() << ':' << (E.getColumnNumber() + TokSize) << '}';
       PrintedRange = true;
     }
 
@@ -897,9 +892,7 @@ void TextDiagnostic::emitDiagnosticLoc(SourceLocation Loc, PresumedLoc PLoc,
   OS << ' ';
 }
 
-void TextDiagnostic::emitIncludeLocation(SourceLocation Loc,
-                                         PresumedLoc PLoc,
-                                         const SourceManager &SM) {
+void TextDiagnostic::emitIncludeLocation(FullSourceLoc Loc, PresumedLoc PLoc) {
   if (DiagOpts->ShowLocation && PLoc.isValid())
     OS << "In file included from " << PLoc.getFilename() << ':'
        << PLoc.getLine() << ":\n";
@@ -907,9 +900,8 @@ void TextDiagnostic::emitIncludeLocation(SourceLocation Loc,
     OS << "In included file:\n"; 
 }
 
-void TextDiagnostic::emitImportLocation(SourceLocation Loc, PresumedLoc PLoc,
-                                        StringRef ModuleName,
-                                        const SourceManager &SM) {
+void TextDiagnostic::emitImportLocation(FullSourceLoc Loc, PresumedLoc PLoc,
+                                        StringRef ModuleName) {
   if (DiagOpts->ShowLocation && PLoc.isValid())
     OS << "In module '" << ModuleName << "' imported from "
        << PLoc.getFilename() << ':' << PLoc.getLine() << ":\n";
@@ -917,10 +909,9 @@ void TextDiagnostic::emitImportLocation(SourceLocation Loc, PresumedLoc PLoc,
     OS << "In module '" << ModuleName << "':\n";
 }
 
-void TextDiagnostic::emitBuildingModuleLocation(SourceLocation Loc,
+void TextDiagnostic::emitBuildingModuleLocation(FullSourceLoc Loc,
                                                 PresumedLoc PLoc,
-                                                StringRef ModuleName,
-                                                const SourceManager &SM) {
+                                                StringRef ModuleName) {
   if (DiagOpts->ShowLocation && PLoc.isValid())
     OS << "While building module '" << ModuleName << "' imported from "
       << PLoc.getFilename() << ':' << PLoc.getLine() << ":\n";
@@ -928,6 +919,56 @@ void TextDiagnostic::emitBuildingModuleLocation(SourceLocation Loc,
     OS << "While building module '" << ModuleName << "':\n";
 }
 
+/// \brief Find the suitable set of lines to show to include a set of ranges.
+static llvm::Optional<std::pair<unsigned, unsigned>>
+findLinesForRange(const CharSourceRange &R, FileID FID,
+                  const SourceManager &SM) {
+  if (!R.isValid()) return None;
+
+  SourceLocation Begin = R.getBegin();
+  SourceLocation End = R.getEnd();
+  if (SM.getFileID(Begin) != FID || SM.getFileID(End) != FID)
+    return None;
+
+  return std::make_pair(SM.getExpansionLineNumber(Begin),
+                        SM.getExpansionLineNumber(End));
+}
+
+/// Add as much of range B into range A as possible without exceeding a maximum
+/// size of MaxRange. Ranges are inclusive.
+static std::pair<unsigned, unsigned>
+maybeAddRange(std::pair<unsigned, unsigned> A, std::pair<unsigned, unsigned> B,
+              unsigned MaxRange) {
+  // If A is already the maximum size, we're done.
+  unsigned Slack = MaxRange - (A.second - A.first + 1);
+  if (Slack == 0)
+    return A;
+
+  // Easy case: merge succeeds within MaxRange.
+  unsigned Min = std::min(A.first, B.first);
+  unsigned Max = std::max(A.second, B.second);
+  if (Max - Min + 1 <= MaxRange)
+    return {Min, Max};
+
+  // If we can't reach B from A within MaxRange, there's nothing to do.
+  // Don't add lines to the range that contain nothing interesting.
+  if ((B.first > A.first && B.first - A.first + 1 > MaxRange) ||
+      (B.second < A.second && A.second - B.second + 1 > MaxRange))
+    return A;
+
+  // Otherwise, expand A towards B to produce a range of size MaxRange. We
+  // attempt to expand by the same amount in both directions if B strictly
+  // contains A.
+
+  // Expand downwards by up to half the available amount, then upwards as
+  // much as possible, then downwards as much as possible.
+  A.second = std::min(A.second + (Slack + 1) / 2, Max);
+  Slack = MaxRange - (A.second - A.first + 1);
+  A.first = std::max(Min + Slack, A.first) - Slack;
+  A.second = std::min(A.first + MaxRange - 1, Max);
+  return A;
+}
+
 /// \brief Highlight a SourceRange (with ~'s) for any characters on LineNo.
 static void highlightRange(const CharSourceRange &R,
                            unsigned LineNo, FileID FID,
@@ -990,9 +1031,12 @@ static void highlightRange(const CharSourceRange &R,
       EndColNo = map.startOfPreviousColumn(EndColNo);
 
     // If the start/end passed each other, then we are trying to highlight a
-    // range that just exists in whitespace, which must be some sort of other
-    // bug.
-    assert(StartColNo <= EndColNo && "Trying to highlight whitespace??");
+    // range that just exists in whitespace. That most likely means we have
+    // a multi-line highlighting range that covers a blank line.
+    if (StartColNo > EndColNo) {
+      assert(StartLineNo != EndLineNo && "trying to highlight whitespace");
+      StartColNo = EndColNo;
+    }
   }
 
   assert(StartColNo <= map.getSourceLine().size() && "Invalid range!");
@@ -1008,7 +1052,8 @@ static void highlightRange(const CharSourceRange &R,
   std::fill(CaretLine.begin()+StartColNo,CaretLine.begin()+EndColNo,'~');
 }
 
-static std::string buildFixItInsertionLine(unsigned LineNo,
+static std::string buildFixItInsertionLine(FileID FID,
+                                           unsigned LineNo,
                                            const SourceColumnMap &map,
                                            ArrayRef<FixItHint> Hints,
                                            const SourceManager &SM,
@@ -1025,7 +1070,8 @@ static std::string buildFixItInsertionLine(unsigned LineNo,
       // code contains no newlines and is on the same line as the caret.
       std::pair<FileID, unsigned> HintLocInfo
         = SM.getDecomposedExpansionLoc(I->RemoveRange.getBegin());
-      if (LineNo == SM.getLineNumber(HintLocInfo.first, HintLocInfo.second) &&
+      if (FID == HintLocInfo.first &&
+          LineNo == SM.getLineNumber(HintLocInfo.first, HintLocInfo.second) &&
           StringRef(I->CodeToInsert).find_first_of("\n\r") == StringRef::npos) {
         // Insert the new code into the line just below the code
         // that the user wrote.
@@ -1061,9 +1107,6 @@ static std::string buildFixItInsertionLine(unsigned LineNo,
 
         PrevHintEndCol =
           HintCol + llvm::sys::locale::columnWidth(I->CodeToInsert);
-      } else {
-        FixItInsertionLine.clear();
-        break;
       }
     }
   }
@@ -1081,10 +1124,8 @@ static std::string buildFixItInsertionLine(unsigned LineNo,
 /// \param Ranges The underlined ranges for this code snippet.
 /// \param Hints The FixIt hints active for this diagnostic.
 void TextDiagnostic::emitSnippetAndCaret(
-    SourceLocation Loc, DiagnosticsEngine::Level Level,
-    SmallVectorImpl<CharSourceRange>& Ranges,
-    ArrayRef<FixItHint> Hints,
-    const SourceManager &SM) {
+    FullSourceLoc Loc, DiagnosticsEngine::Level Level,
+    SmallVectorImpl<CharSourceRange> &Ranges, ArrayRef<FixItHint> Hints) {
   assert(Loc.isValid() && "must have a valid source location here");
   assert(Loc.isFileID() && "must have a file location here");
 
@@ -1101,111 +1142,128 @@ void TextDiagnostic::emitSnippetAndCaret(
     return;
 
   // Decompose the location into a FID/Offset pair.
-  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
+  std::pair<FileID, unsigned> LocInfo = Loc.getDecomposedLoc();
   FileID FID = LocInfo.first;
-  unsigned FileOffset = LocInfo.second;
+  const SourceManager &SM = Loc.getManager();
 
   // Get information about the buffer it points into.
   bool Invalid = false;
-  StringRef BufData = SM.getBufferData(FID, &Invalid);
+  StringRef BufData = Loc.getBufferData(&Invalid);
   if (Invalid)
     return;
 
-  const char *BufStart = BufData.data();
-  const char *BufEnd = BufStart + BufData.size();
+  unsigned CaretLineNo = Loc.getLineNumber();
+  unsigned CaretColNo = Loc.getColumnNumber();
 
-  unsigned LineNo = SM.getLineNumber(FID, FileOffset);
-  unsigned ColNo = SM.getColumnNumber(FID, FileOffset);
-  
   // Arbitrarily stop showing snippets when the line is too long.
   static const size_t MaxLineLengthToPrint = 4096;
-  if (ColNo > MaxLineLengthToPrint)
+  if (CaretColNo > MaxLineLengthToPrint)
     return;
 
-  // Rewind from the current position to the start of the line.
-  const char *TokPtr = BufStart+FileOffset;
-  const char *LineStart = TokPtr-ColNo+1; // Column # is 1-based.
-
-  // Compute the line end.  Scan forward from the error position to the end of
-  // the line.
-  const char *LineEnd = TokPtr;
-  while (*LineEnd != '\n' && *LineEnd != '\r' && LineEnd != BufEnd)
-    ++LineEnd;
-
-  // Arbitrarily stop showing snippets when the line is too long.
-  if (size_t(LineEnd - LineStart) > MaxLineLengthToPrint)
-    return;
-
-  // Trim trailing null-bytes.
-  StringRef Line(LineStart, LineEnd - LineStart);
-  while (Line.size() > ColNo && Line.back() == '\0')
-    Line = Line.drop_back();
+  // Find the set of lines to include.
+  const unsigned MaxLines = DiagOpts->SnippetLineLimit;
+  std::pair<unsigned, unsigned> Lines = {CaretLineNo, CaretLineNo};
+  for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
+                                                  E = Ranges.end();
+       I != E; ++I)
+    if (auto OptionalRange = findLinesForRange(*I, FID, SM))
+      Lines = maybeAddRange(Lines, *OptionalRange, MaxLines);
+
+  for (unsigned LineNo = Lines.first; LineNo != Lines.second + 1; ++LineNo) {
+    const char *BufStart = BufData.data();
+    const char *BufEnd = BufStart + BufData.size();
+
+    // Rewind from the current position to the start of the line.
+    const char *LineStart =
+        BufStart +
+        SM.getDecomposedLoc(SM.translateLineCol(FID, LineNo, 1)).second;
+    if (LineStart == BufEnd)
+      break;
 
-  // Copy the line of code into an std::string for ease of manipulation.
-  std::string SourceLine(Line.begin(), Line.end());
+    // Compute the line end.
+    const char *LineEnd = LineStart;
+    while (*LineEnd != '\n' && *LineEnd != '\r' && LineEnd != BufEnd)
+      ++LineEnd;
 
-  // Build the byte to column map.
-  const SourceColumnMap sourceColMap(SourceLine, DiagOpts->TabStop);
+    // Arbitrarily stop showing snippets when the line is too long.
+    // FIXME: Don't print any lines in this case.
+    if (size_t(LineEnd - LineStart) > MaxLineLengthToPrint)
+      return;
 
-  // Create a line for the caret that is filled with spaces that is the same
-  // number of columns as the line of source code.
-  std::string CaretLine(sourceColMap.columns(), ' ');
+    // Trim trailing null-bytes.
+    StringRef Line(LineStart, LineEnd - LineStart);
+    while (!Line.empty() && Line.back() == '\0' &&
+           (LineNo != CaretLineNo || Line.size() > CaretColNo))
+      Line = Line.drop_back();
+
+    // Copy the line of code into an std::string for ease of manipulation.
+    std::string SourceLine(Line.begin(), Line.end());
+
+    // Build the byte to column map.
+    const SourceColumnMap sourceColMap(SourceLine, DiagOpts->TabStop);
+
+    // Create a line for the caret that is filled with spaces that is the same
+    // number of columns as the line of source code.
+    std::string CaretLine(sourceColMap.columns(), ' ');
+
+    // Highlight all of the characters covered by Ranges with ~ characters.
+    for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
+                                                    E = Ranges.end();
+         I != E; ++I)
+      highlightRange(*I, LineNo, FID, sourceColMap, CaretLine, SM, LangOpts);
+
+    // Next, insert the caret itself.
+    if (CaretLineNo == LineNo) {
+      CaretColNo = sourceColMap.byteToContainingColumn(CaretColNo - 1);
+      if (CaretLine.size() < CaretColNo + 1)
+        CaretLine.resize(CaretColNo + 1, ' ');
+      CaretLine[CaretColNo] = '^';
+    }
 
-  // Highlight all of the characters covered by Ranges with ~ characters.
-  for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
-                                                  E = Ranges.end();
-       I != E; ++I)
-    highlightRange(*I, LineNo, FID, sourceColMap, CaretLine, SM, LangOpts);
-
-  // Next, insert the caret itself.
-  ColNo = sourceColMap.byteToContainingColumn(ColNo-1);
-  if (CaretLine.size()<ColNo+1)
-    CaretLine.resize(ColNo+1, ' ');
-  CaretLine[ColNo] = '^';
-
-  std::string FixItInsertionLine = buildFixItInsertionLine(LineNo,
-                                                           sourceColMap,
-                                                           Hints, SM,
-                                                           DiagOpts.get());
-
-  // If the source line is too long for our terminal, select only the
-  // "interesting" source region within that line.
-  unsigned Columns = DiagOpts->MessageLength;
-  if (Columns)
-    selectInterestingSourceRegion(SourceLine, CaretLine, FixItInsertionLine,
-                                  Columns, sourceColMap);
-
-  // If we are in -fdiagnostics-print-source-range-info mode, we are trying
-  // to produce easily machine parsable output.  Add a space before the
-  // source line and the caret to make it trivial to tell the main diagnostic
-  // line from what the user is intended to see.
-  if (DiagOpts->ShowSourceRanges) {
-    SourceLine = ' ' + SourceLine;
-    CaretLine = ' ' + CaretLine;
-  }
+    std::string FixItInsertionLine = buildFixItInsertionLine(
+        FID, LineNo, sourceColMap, Hints, SM, DiagOpts.get());
+
+    // If the source line is too long for our terminal, select only the
+    // "interesting" source region within that line.
+    unsigned Columns = DiagOpts->MessageLength;
+    if (Columns)
+      selectInterestingSourceRegion(SourceLine, CaretLine, FixItInsertionLine,
+                                    Columns, sourceColMap);
+
+    // If we are in -fdiagnostics-print-source-range-info mode, we are trying
+    // to produce easily machine parsable output.  Add a space before the
+    // source line and the caret to make it trivial to tell the main diagnostic
+    // line from what the user is intended to see.
+    if (DiagOpts->ShowSourceRanges) {
+      SourceLine = ' ' + SourceLine;
+      CaretLine = ' ' + CaretLine;
+    }
 
-  // Finally, remove any blank spaces from the end of CaretLine.
-  while (CaretLine[CaretLine.size()-1] == ' ')
-    CaretLine.erase(CaretLine.end()-1);
+    // Finally, remove any blank spaces from the end of CaretLine.
+    while (!CaretLine.empty() && CaretLine[CaretLine.size() - 1] == ' ')
+      CaretLine.erase(CaretLine.end() - 1);
 
-  // Emit what we have computed.
-  emitSnippet(SourceLine);
+    // Emit what we have computed.
+    emitSnippet(SourceLine);
 
-  if (DiagOpts->ShowColors)
-    OS.changeColor(caretColor, true);
-  OS << CaretLine << '\n';
-  if (DiagOpts->ShowColors)
-    OS.resetColor();
+    if (!CaretLine.empty()) {
+      if (DiagOpts->ShowColors)
+        OS.changeColor(caretColor, true);
+      OS << CaretLine << '\n';
+      if (DiagOpts->ShowColors)
+        OS.resetColor();
+    }
 
-  if (!FixItInsertionLine.empty()) {
-    if (DiagOpts->ShowColors)
-      // Print fixit line in color
-      OS.changeColor(fixitColor, false);
-    if (DiagOpts->ShowSourceRanges)
-      OS << ' ';
-    OS << FixItInsertionLine << '\n';
-    if (DiagOpts->ShowColors)
-      OS.resetColor();
+    if (!FixItInsertionLine.empty()) {
+      if (DiagOpts->ShowColors)
+        // Print fixit line in color
+        OS.changeColor(fixitColor, false);
+      if (DiagOpts->ShowSourceRanges)
+        OS << ' ';
+      OS << FixItInsertionLine << '\n';
+      if (DiagOpts->ShowColors)
+        OS.resetColor();
+    }
   }
 
   // Print out any parseable fixit information requested by the options.