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, 661 insertions, 0 deletions

diff --git a/contrib/llvm/tools/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusNameParser.cpp b/contrib/llvm/tools/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusNameParser.cpp
new file mode 100644
index 0000000..88bdd68
--- /dev/null
+++ b/contrib/llvm/tools/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusNameParser.cpp
@@ -0,0 +1,661 @@
+//===-- CPlusPlusNameParser.cpp ---------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CPlusPlusNameParser.h"
+
+#include "clang/Basic/IdentifierTable.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/Threading.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using llvm::Optional;
+using llvm::None;
+using ParsedFunction = lldb_private::CPlusPlusNameParser::ParsedFunction;
+using ParsedName = lldb_private::CPlusPlusNameParser::ParsedName;
+namespace tok = clang::tok;
+
+Optional<ParsedFunction> CPlusPlusNameParser::ParseAsFunctionDefinition() {
+  m_next_token_index = 0;
+  Optional<ParsedFunction> result(None);
+
+  // Try to parse the name as function without a return type specified
+  // e.g. main(int, char*[])
+  {
+    Bookmark start_position = SetBookmark();
+    result = ParseFunctionImpl(false);
+    if (result && !HasMoreTokens())
+      return result;
+  }
+
+  // Try to parse the name as function with function pointer return type
+  // e.g. void (*get_func(const char*))()
+  result = ParseFuncPtr(true);
+  if (result)
+    return result;
+
+  // Finally try to parse the name as a function with non-function return type
+  // e.g. int main(int, char*[])
+  result = ParseFunctionImpl(true);
+  if (HasMoreTokens())
+    return None;
+  return result;
+}
+
+Optional<ParsedName> CPlusPlusNameParser::ParseAsFullName() {
+  m_next_token_index = 0;
+  Optional<ParsedNameRanges> name_ranges = ParseFullNameImpl();
+  if (!name_ranges)
+    return None;
+  if (HasMoreTokens())
+    return None;
+  ParsedName result;
+  result.basename = GetTextForRange(name_ranges.getValue().basename_range);
+  result.context = GetTextForRange(name_ranges.getValue().context_range);
+  return result;
+}
+
+bool CPlusPlusNameParser::HasMoreTokens() {
+  return m_next_token_index < m_tokens.size();
+}
+
+void CPlusPlusNameParser::Advance() { ++m_next_token_index; }
+
+void CPlusPlusNameParser::TakeBack() { --m_next_token_index; }
+
+bool CPlusPlusNameParser::ConsumeToken(tok::TokenKind kind) {
+  if (!HasMoreTokens())
+    return false;
+
+  if (!Peek().is(kind))
+    return false;
+
+  Advance();
+  return true;
+}
+
+template <typename... Ts> bool CPlusPlusNameParser::ConsumeToken(Ts... kinds) {
+  if (!HasMoreTokens())
+    return false;
+
+  if (!Peek().isOneOf(kinds...))
+    return false;
+
+  Advance();
+  return true;
+}
+
+CPlusPlusNameParser::Bookmark CPlusPlusNameParser::SetBookmark() {
+  return Bookmark(m_next_token_index);
+}
+
+size_t CPlusPlusNameParser::GetCurrentPosition() { return m_next_token_index; }
+
+clang::Token &CPlusPlusNameParser::Peek() {
+  assert(HasMoreTokens());
+  return m_tokens[m_next_token_index];
+}
+
+Optional<ParsedFunction>
+CPlusPlusNameParser::ParseFunctionImpl(bool expect_return_type) {
+  Bookmark start_position = SetBookmark();
+  if (expect_return_type) {
+    // Consume return type if it's expected.
+    if (!ConsumeTypename())
+      return None;
+  }
+
+  auto maybe_name = ParseFullNameImpl();
+  if (!maybe_name) {
+    return None;
+  }
+
+  size_t argument_start = GetCurrentPosition();
+  if (!ConsumeArguments()) {
+    return None;
+  }
+
+  size_t qualifiers_start = GetCurrentPosition();
+  SkipFunctionQualifiers();
+  size_t end_position = GetCurrentPosition();
+
+  ParsedFunction result;
+  result.name.basename = GetTextForRange(maybe_name.getValue().basename_range);
+  result.name.context = GetTextForRange(maybe_name.getValue().context_range);
+  result.arguments = GetTextForRange(Range(argument_start, qualifiers_start));
+  result.qualifiers = GetTextForRange(Range(qualifiers_start, end_position));
+  start_position.Remove();
+  return result;
+}
+
+Optional<ParsedFunction>
+CPlusPlusNameParser::ParseFuncPtr(bool expect_return_type) {
+  Bookmark start_position = SetBookmark();
+  if (expect_return_type) {
+    // Consume return type.
+    if (!ConsumeTypename())
+      return None;
+  }
+
+  if (!ConsumeToken(tok::l_paren))
+    return None;
+  if (!ConsumePtrsAndRefs())
+    return None;
+
+  {
+    Bookmark before_inner_function_pos = SetBookmark();
+    auto maybe_inner_function_name = ParseFunctionImpl(false);
+    if (maybe_inner_function_name)
+      if (ConsumeToken(tok::r_paren))
+        if (ConsumeArguments()) {
+          SkipFunctionQualifiers();
+          start_position.Remove();
+          before_inner_function_pos.Remove();
+          return maybe_inner_function_name;
+        }
+  }
+
+  auto maybe_inner_function_ptr_name = ParseFuncPtr(false);
+  if (maybe_inner_function_ptr_name)
+    if (ConsumeToken(tok::r_paren))
+      if (ConsumeArguments()) {
+        SkipFunctionQualifiers();
+        start_position.Remove();
+        return maybe_inner_function_ptr_name;
+      }
+  return None;
+}
+
+bool CPlusPlusNameParser::ConsumeArguments() {
+  return ConsumeBrackets(tok::l_paren, tok::r_paren);
+}
+
+bool CPlusPlusNameParser::ConsumeTemplateArgs() {
+  Bookmark start_position = SetBookmark();
+  if (!HasMoreTokens() || Peek().getKind() != tok::less)
+    return false;
+  Advance();
+
+  // Consuming template arguments is a bit trickier than consuming function
+  // arguments, because '<' '>' brackets are not always trivially balanced.
+  // In some rare cases tokens '<' and '>' can appear inside template arguments
+  // as arithmetic or shift operators not as template brackets.
+  // Examples: std::enable_if<(10u)<(64), bool>
+  //           f<A<operator<(X,Y)::Subclass>>
+  // Good thing that compiler makes sure that really ambiguous cases of
+  // '>' usage should be enclosed within '()' brackets.
+  int template_counter = 1;
+  bool can_open_template = false;
+  while (HasMoreTokens() && template_counter > 0) {
+    tok::TokenKind kind = Peek().getKind();
+    switch (kind) {
+    case tok::greatergreater:
+      template_counter -= 2;
+      can_open_template = false;
+      Advance();
+      break;
+    case tok::greater:
+      --template_counter;
+      can_open_template = false;
+      Advance();
+      break;
+    case tok::less:
+      // '<' is an attempt to open a subteamplte
+      // check if parser is at the point where it's actually possible,
+      // otherwise it's just a part of an expression like 'sizeof(T)<(10)'.
+      // No need to do the same for '>' because compiler actually makes sure
+      // that '>' always surrounded by brackets to avoid ambiguity.
+      if (can_open_template)
+        ++template_counter;
+      can_open_template = false;
+      Advance();
+      break;
+    case tok::kw_operator: // C++ operator overloading.
+      if (!ConsumeOperator())
+        return false;
+      can_open_template = true;
+      break;
+    case tok::raw_identifier:
+      can_open_template = true;
+      Advance();
+      break;
+    case tok::l_square:
+      if (!ConsumeBrackets(tok::l_square, tok::r_square))
+        return false;
+      can_open_template = false;
+      break;
+    case tok::l_paren:
+      if (!ConsumeArguments())
+        return false;
+      can_open_template = false;
+      break;
+    default:
+      can_open_template = false;
+      Advance();
+      break;
+    }
+  }
+
+  assert(template_counter >= 0);
+  if (template_counter > 0) {
+    return false;
+  }
+  start_position.Remove();
+  return true;
+}
+
+bool CPlusPlusNameParser::ConsumeAnonymousNamespace() {
+  Bookmark start_position = SetBookmark();
+  if (!ConsumeToken(tok::l_paren)) {
+    return false;
+  }
+  constexpr llvm::StringLiteral g_anonymous("anonymous");
+  if (HasMoreTokens() && Peek().is(tok::raw_identifier) &&
+      Peek().getRawIdentifier() == g_anonymous) {
+    Advance();
+  } else {
+    return false;
+  }
+
+  if (!ConsumeToken(tok::kw_namespace)) {
+    return false;
+  }
+
+  if (!ConsumeToken(tok::r_paren)) {
+    return false;
+  }
+  start_position.Remove();
+  return true;
+}
+
+bool CPlusPlusNameParser::ConsumeLambda() {
+  Bookmark start_position = SetBookmark();
+  if (!ConsumeToken(tok::l_brace)) {
+    return false;
+  }
+  constexpr llvm::StringLiteral g_lambda("lambda");
+  if (HasMoreTokens() && Peek().is(tok::raw_identifier) &&
+      Peek().getRawIdentifier() == g_lambda) {
+    // Put the matched brace back so we can use ConsumeBrackets
+    TakeBack();
+  } else {
+    return false;
+  }
+
+  if (!ConsumeBrackets(tok::l_brace, tok::r_brace)) {
+    return false;
+  }
+
+  start_position.Remove();
+  return true;
+}
+
+bool CPlusPlusNameParser::ConsumeBrackets(tok::TokenKind left,
+                                          tok::TokenKind right) {
+  Bookmark start_position = SetBookmark();
+  if (!HasMoreTokens() || Peek().getKind() != left)
+    return false;
+  Advance();
+
+  int counter = 1;
+  while (HasMoreTokens() && counter > 0) {
+    tok::TokenKind kind = Peek().getKind();
+    if (kind == right)
+      --counter;
+    else if (kind == left)
+      ++counter;
+    Advance();
+  }
+
+  assert(counter >= 0);
+  if (counter > 0) {
+    return false;
+  }
+  start_position.Remove();
+  return true;
+}
+
+bool CPlusPlusNameParser::ConsumeOperator() {
+  Bookmark start_position = SetBookmark();
+  if (!ConsumeToken(tok::kw_operator))
+    return false;
+
+  if (!HasMoreTokens()) {
+    return false;
+  }
+
+  const auto &token = Peek();
+  switch (token.getKind()) {
+  case tok::kw_new:
+  case tok::kw_delete:
+    // This is 'new' or 'delete' operators.
+    Advance();
+    // Check for array new/delete.
+    if (HasMoreTokens() && Peek().is(tok::l_square)) {
+      // Consume the '[' and ']'.
+      if (!ConsumeBrackets(tok::l_square, tok::r_square))
+        return false;
+    }
+    break;
+
+#define OVERLOADED_OPERATOR(Name, Spelling, Token, Unary, Binary, MemberOnly)  \
+  case tok::Token:                                                             \
+    Advance();                                                                 \
+    break;
+#define OVERLOADED_OPERATOR_MULTI(Name, Spelling, Unary, Binary, MemberOnly)
+#include "clang/Basic/OperatorKinds.def"
+#undef OVERLOADED_OPERATOR
+#undef OVERLOADED_OPERATOR_MULTI
+
+  case tok::l_paren:
+    // Call operator consume '(' ... ')'.
+    if (ConsumeBrackets(tok::l_paren, tok::r_paren))
+      break;
+    return false;
+
+  case tok::l_square:
+    // This is a [] operator.
+    // Consume the '[' and ']'.
+    if (ConsumeBrackets(tok::l_square, tok::r_square))
+      break;
+    return false;
+
+  default:
+    // This might be a cast operator.
+    if (ConsumeTypename())
+      break;
+    return false;
+  }
+  start_position.Remove();
+  return true;
+}
+
+void CPlusPlusNameParser::SkipTypeQualifiers() {
+  while (ConsumeToken(tok::kw_const, tok::kw_volatile))
+    ;
+}
+
+void CPlusPlusNameParser::SkipFunctionQualifiers() {
+  while (ConsumeToken(tok::kw_const, tok::kw_volatile, tok::amp, tok::ampamp))
+    ;
+}
+
+bool CPlusPlusNameParser::ConsumeBuiltinType() {
+  bool result = false;
+  bool continue_parsing = true;
+  // Built-in types can be made of a few keywords
+  // like 'unsigned long long int'. This function
+  // consumes all built-in type keywords without
+  // checking if they make sense like 'unsigned char void'.
+  while (continue_parsing && HasMoreTokens()) {
+    switch (Peek().getKind()) {
+    case tok::kw_short:
+    case tok::kw_long:
+    case tok::kw___int64:
+    case tok::kw___int128:
+    case tok::kw_signed:
+    case tok::kw_unsigned:
+    case tok::kw_void:
+    case tok::kw_char:
+    case tok::kw_int:
+    case tok::kw_half:
+    case tok::kw_float:
+    case tok::kw_double:
+    case tok::kw___float128:
+    case tok::kw_wchar_t:
+    case tok::kw_bool:
+    case tok::kw_char16_t:
+    case tok::kw_char32_t:
+      result = true;
+      Advance();
+      break;
+    default:
+      continue_parsing = false;
+      break;
+    }
+  }
+  return result;
+}
+
+void CPlusPlusNameParser::SkipPtrsAndRefs() {
+  // Ignoring result.
+  ConsumePtrsAndRefs();
+}
+
+bool CPlusPlusNameParser::ConsumePtrsAndRefs() {
+  bool found = false;
+  SkipTypeQualifiers();
+  while (ConsumeToken(tok::star, tok::amp, tok::ampamp, tok::kw_const,
+                      tok::kw_volatile)) {
+    found = true;
+    SkipTypeQualifiers();
+  }
+  return found;
+}
+
+bool CPlusPlusNameParser::ConsumeDecltype() {
+  Bookmark start_position = SetBookmark();
+  if (!ConsumeToken(tok::kw_decltype))
+    return false;
+
+  if (!ConsumeArguments())
+    return false;
+
+  start_position.Remove();
+  return true;
+}
+
+bool CPlusPlusNameParser::ConsumeTypename() {
+  Bookmark start_position = SetBookmark();
+  SkipTypeQualifiers();
+  if (!ConsumeBuiltinType() && !ConsumeDecltype()) {
+    if (!ParseFullNameImpl())
+      return false;
+  }
+  SkipPtrsAndRefs();
+  start_position.Remove();
+  return true;
+}
+
+Optional<CPlusPlusNameParser::ParsedNameRanges>
+CPlusPlusNameParser::ParseFullNameImpl() {
+  // Name parsing state machine.
+  enum class State {
+    Beginning,       // start of the name
+    AfterTwoColons,  // right after ::
+    AfterIdentifier, // right after alphanumerical identifier ([a-z0-9_]+)
+    AfterTemplate,   // right after template brackets (<something>)
+    AfterOperator,   // right after name of C++ operator
+  };
+
+  Bookmark start_position = SetBookmark();
+  State state = State::Beginning;
+  bool continue_parsing = true;
+  Optional<size_t> last_coloncolon_position = None;
+
+  while (continue_parsing && HasMoreTokens()) {
+    const auto &token = Peek();
+    switch (token.getKind()) {
+    case tok::raw_identifier: // Just a name.
+      if (state != State::Beginning && state != State::AfterTwoColons) {
+        continue_parsing = false;
+        break;
+      }
+      Advance();
+      state = State::AfterIdentifier;
+      break;
+    case tok::l_paren: {
+      if (state == State::Beginning || state == State::AfterTwoColons) {
+        // (anonymous namespace)
+        if (ConsumeAnonymousNamespace()) {
+          state = State::AfterIdentifier;
+          break;
+        }
+      }
+
+      // Type declared inside a function 'func()::Type'
+      if (state != State::AfterIdentifier && state != State::AfterTemplate &&
+          state != State::AfterOperator) {
+        continue_parsing = false;
+        break;
+      }
+      Bookmark l_paren_position = SetBookmark();
+      // Consume the '(' ... ') [const]'.
+      if (!ConsumeArguments()) {
+        continue_parsing = false;
+        break;
+      }
+      SkipFunctionQualifiers();
+
+      // Consume '::'
+      size_t coloncolon_position = GetCurrentPosition();
+      if (!ConsumeToken(tok::coloncolon)) {
+        continue_parsing = false;
+        break;
+      }
+      l_paren_position.Remove();
+      last_coloncolon_position = coloncolon_position;
+      state = State::AfterTwoColons;
+      break;
+    }
+    case tok::l_brace:
+      if (state == State::Beginning || state == State::AfterTwoColons) {
+        if (ConsumeLambda()) {
+          state = State::AfterIdentifier;
+          break;
+        }
+      }
+      continue_parsing = false;
+      break;
+    case tok::coloncolon: // Type nesting delimiter.
+      if (state != State::Beginning && state != State::AfterIdentifier &&
+          state != State::AfterTemplate) {
+        continue_parsing = false;
+        break;
+      }
+      last_coloncolon_position = GetCurrentPosition();
+      Advance();
+      state = State::AfterTwoColons;
+      break;
+    case tok::less: // Template brackets.
+      if (state != State::AfterIdentifier && state != State::AfterOperator) {
+        continue_parsing = false;
+        break;
+      }
+      if (!ConsumeTemplateArgs()) {
+        continue_parsing = false;
+        break;
+      }
+      state = State::AfterTemplate;
+      break;
+    case tok::kw_operator: // C++ operator overloading.
+      if (state != State::Beginning && state != State::AfterTwoColons) {
+        continue_parsing = false;
+        break;
+      }
+      if (!ConsumeOperator()) {
+        continue_parsing = false;
+        break;
+      }
+      state = State::AfterOperator;
+      break;
+    case tok::tilde: // Destructor.
+      if (state != State::Beginning && state != State::AfterTwoColons) {
+        continue_parsing = false;
+        break;
+      }
+      Advance();
+      if (ConsumeToken(tok::raw_identifier)) {
+        state = State::AfterIdentifier;
+      } else {
+        TakeBack();
+        continue_parsing = false;
+      }
+      break;
+    default:
+      continue_parsing = false;
+      break;
+    }
+  }
+
+  if (state == State::AfterIdentifier || state == State::AfterOperator ||
+      state == State::AfterTemplate) {
+    ParsedNameRanges result;
+    if (last_coloncolon_position) {
+      result.context_range = Range(start_position.GetSavedPosition(),
+                                   last_coloncolon_position.getValue());
+      result.basename_range =
+          Range(last_coloncolon_position.getValue() + 1, GetCurrentPosition());
+    } else {
+      result.basename_range =
+          Range(start_position.GetSavedPosition(), GetCurrentPosition());
+    }
+    start_position.Remove();
+    return result;
+  } else {
+    return None;
+  }
+}
+
+llvm::StringRef CPlusPlusNameParser::GetTextForRange(const Range &range) {
+  if (range.empty())
+    return llvm::StringRef();
+  assert(range.begin_index < range.end_index);
+  assert(range.begin_index < m_tokens.size());
+  assert(range.end_index <= m_tokens.size());
+  clang::Token &first_token = m_tokens[range.begin_index];
+  clang::Token &last_token = m_tokens[range.end_index - 1];
+  clang::SourceLocation start_loc = first_token.getLocation();
+  clang::SourceLocation end_loc = last_token.getLocation();
+  unsigned start_pos = start_loc.getRawEncoding();
+  unsigned end_pos = end_loc.getRawEncoding() + last_token.getLength();
+  return m_text.take_front(end_pos).drop_front(start_pos);
+}
+
+static const clang::LangOptions &GetLangOptions() {
+  static clang::LangOptions g_options;
+  static llvm::once_flag g_once_flag;
+  llvm::call_once(g_once_flag, []() {
+    g_options.LineComment = true;
+    g_options.C99 = true;
+    g_options.C11 = true;
+    g_options.CPlusPlus = true;
+    g_options.CPlusPlus11 = true;
+    g_options.CPlusPlus14 = true;
+    g_options.CPlusPlus1z = true;
+  });
+  return g_options;
+}
+
+static const llvm::StringMap<tok::TokenKind> &GetKeywordsMap() {
+  static llvm::StringMap<tok::TokenKind> g_map{
+#define KEYWORD(Name, Flags) {llvm::StringRef(#Name), tok::kw_##Name},
+#include "clang/Basic/TokenKinds.def"
+#undef KEYWORD
+  };
+  return g_map;
+}
+
+void CPlusPlusNameParser::ExtractTokens() {
+  clang::Lexer lexer(clang::SourceLocation(), GetLangOptions(), m_text.data(),
+                     m_text.data(), m_text.data() + m_text.size());
+  const auto &kw_map = GetKeywordsMap();
+  clang::Token token;
+  for (lexer.LexFromRawLexer(token); !token.is(clang::tok::eof);
+       lexer.LexFromRawLexer(token)) {
+    if (token.is(clang::tok::raw_identifier)) {
+      auto it = kw_map.find(token.getRawIdentifier());
+      if (it != kw_map.end()) {
+        token.setKind(it->getValue());
+      }
+    }
+
+    m_tokens.push_back(token);
+  }
+}