diff --git a/llvm/lib/Demangle/ItaniumDemangle.cpp b/llvm/lib/Demangle/ItaniumDemangle.cpp
new file mode 100644
index 0000000..ff533f6
--- /dev/null
+++ b/llvm/lib/Demangle/ItaniumDemangle.cpp
@@ -0,0 +1,4431 @@
+//===- ItaniumDemangle.cpp ------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <llvm/Demangle/Demangle.h>
+
+// This file exports a single function: llvm::itanium_demangle.
+// It also has no dependencies on the rest of llvm. It is implemented this way
+// so that it can be easily reused in libcxxabi.
+
+#include <algorithm>
+#include <cctype>
+#include <cstdlib>
+#include <cstring>
+#include <numeric>
+#include <string>
+#include <vector>
+
+#ifdef _MSC_VER
+// snprintf is implemented in VS 2015
+#if _MSC_VER < 1900
+#define snprintf _snprintf_s
+#endif
+#endif
+
+enum {
+  unknown_error = -4,
+  invalid_args = -3,
+  invalid_mangled_name,
+  memory_alloc_failure,
+  success
+};
+
+template <class C>
+static const char *parse_type(const char *first, const char *last, C &db);
+template <class C>
+static const char *parse_encoding(const char *first, const char *last, C &db);
+template <class C>
+static const char *parse_name(const char *first, const char *last, C &db,
+                              bool *ends_with_template_args = 0);
+template <class C>
+static const char *parse_expression(const char *first, const char *last, C &db);
+template <class C>
+static const char *parse_template_args(const char *first, const char *last,
+                                       C &db);
+template <class C>
+static const char *parse_operator_name(const char *first, const char *last,
+                                       C &db);
+template <class C>
+static const char *parse_unqualified_name(const char *first, const char *last,
+                                          C &db);
+template <class C>
+static const char *parse_decltype(const char *first, const char *last, C &db);
+
+// <number> ::= [n] <non-negative decimal integer>
+
+static const char *parse_number(const char *first, const char *last) {
+  if (first != last) {
+    const char *t = first;
+    if (*t == 'n')
+      ++t;
+    if (t != last) {
+      if (*t == '0') {
+        first = t + 1;
+      } else if ('1' <= *t && *t <= '9') {
+        first = t + 1;
+        while (first != last && std::isdigit(*first))
+          ++first;
+      }
+    }
+  }
+  return first;
+}
+
+namespace {
+template <class Float> struct float_data;
+
+template <> struct float_data<float> {
+  static const size_t mangled_size = 8;
+  static const size_t max_demangled_size = 24;
+  static const char *spec;
+};
+const char *float_data<float>::spec = "%af";
+
+template <> struct float_data<double> {
+  static const size_t mangled_size = 16;
+  static const size_t max_demangled_size = 32;
+  static const char *spec;
+};
+
+const char *float_data<double>::spec = "%a";
+
+template <> struct float_data<long double> {
+#if defined(__mips__) && defined(__mips_n64) || defined(__aarch64__) ||        \
+    defined(__wasm__)
+  static const size_t mangled_size = 32;
+#elif defined(__arm__) || defined(__mips__) || defined(__hexagon__)
+  static const size_t mangled_size = 16;
+#else
+  static const size_t mangled_size =
+      20; // May need to be adjusted to 16 or 24 on other platforms
+#endif
+  static const size_t max_demangled_size = 40;
+  static const char *spec;
+};
+
+const char *float_data<long double>::spec = "%LaL";
+}
+
+template <class Float, class C>
+static const char *parse_floating_number(const char *first, const char *last,
+                                         C &db) {
+  const size_t N = float_data<Float>::mangled_size;
+  if (static_cast<std::size_t>(last - first) > N) {
+    last = first + N;
+    union {
+      Float value;
+      char buf[sizeof(Float)];
+    };
+    const char *t = first;
+    char *e = buf;
+    for (; t != last; ++t, ++e) {
+      if (!isxdigit(*t))
+        return first;
+      unsigned d1 = isdigit(*t) ? static_cast<unsigned>(*t - '0')
+                                : static_cast<unsigned>(*t - 'a' + 10);
+      ++t;
+      unsigned d0 = isdigit(*t) ? static_cast<unsigned>(*t - '0')
+                                : static_cast<unsigned>(*t - 'a' + 10);
+      *e = static_cast<char>((d1 << 4) + d0);
+    }
+    if (*t == 'E') {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+      std::reverse(buf, e);
+#endif
+      char num[float_data<Float>::max_demangled_size] = {0};
+      int n = snprintf(num, sizeof(num), float_data<Float>::spec, value);
+      if (static_cast<std::size_t>(n) >= sizeof(num))
+        return first;
+      db.names.push_back(typename C::String(num, static_cast<std::size_t>(n)));
+      first = t + 1;
+    }
+  }
+  return first;
+}
+
+// <source-name> ::= <positive length number> <identifier>
+
+template <class C>
+static const char *parse_source_name(const char *first, const char *last,
+                                     C &db) {
+  if (first != last) {
+    char c = *first;
+    if (isdigit(c) && first + 1 != last) {
+      const char *t = first + 1;
+      size_t n = static_cast<size_t>(c - '0');
+      for (c = *t; isdigit(c); c = *t) {
+        n = n * 10 + static_cast<size_t>(c - '0');
+        if (++t == last)
+          return first;
+      }
+      if (static_cast<size_t>(last - t) >= n) {
+        typename C::String r(t, n);
+        if (r.substr(0, 10) == "_GLOBAL__N")
+          db.names.push_back("(anonymous namespace)");
+        else
+          db.names.push_back(std::move(r));
+        first = t + n;
+      }
+    }
+  }
+  return first;
+}
+
+// <substitution> ::= S <seq-id> _
+//                ::= S_
+// <substitution> ::= Sa # ::std::allocator
+// <substitution> ::= Sb # ::std::basic_string
+// <substitution> ::= Ss # ::std::basic_string < char,
+//                                               ::std::char_traits<char>,
+//                                               ::std::allocator<char> >
+// <substitution> ::= Si # ::std::basic_istream<char,  std::char_traits<char> >
+// <substitution> ::= So # ::std::basic_ostream<char,  std::char_traits<char> >
+// <substitution> ::= Sd # ::std::basic_iostream<char, std::char_traits<char> >
+
+template <class C>
+static const char *parse_substitution(const char *first, const char *last,
+                                      C &db) {
+  if (last - first >= 2) {
+    if (*first == 'S') {
+      switch (first[1]) {
+      case 'a':
+        db.names.push_back("std::allocator");
+        first += 2;
+        break;
+      case 'b':
+        db.names.push_back("std::basic_string");
+        first += 2;
+        break;
+      case 's':
+        db.names.push_back("std::string");
+        first += 2;
+        break;
+      case 'i':
+        db.names.push_back("std::istream");
+        first += 2;
+        break;
+      case 'o':
+        db.names.push_back("std::ostream");
+        first += 2;
+        break;
+      case 'd':
+        db.names.push_back("std::iostream");
+        first += 2;
+        break;
+      case '_':
+        if (!db.subs.empty()) {
+          for (const auto &n : db.subs.front())
+            db.names.push_back(n);
+          first += 2;
+        }
+        break;
+      default:
+        if (std::isdigit(first[1]) || std::isupper(first[1])) {
+          size_t sub = 0;
+          const char *t = first + 1;
+          if (std::isdigit(*t))
+            sub = static_cast<size_t>(*t - '0');
+          else
+            sub = static_cast<size_t>(*t - 'A') + 10;
+          for (++t; t != last && (std::isdigit(*t) || std::isupper(*t)); ++t) {
+            sub *= 36;
+            if (std::isdigit(*t))
+              sub += static_cast<size_t>(*t - '0');
+            else
+              sub += static_cast<size_t>(*t - 'A') + 10;
+          }
+          if (t == last || *t != '_')
+            return first;
+          ++sub;
+          if (sub < db.subs.size()) {
+            for (const auto &n : db.subs[sub])
+              db.names.push_back(n);
+            first = t + 1;
+          }
+        }
+        break;
+      }
+    }
+  }
+  return first;
+}
+
+// <builtin-type> ::= v    # void
+//                ::= w    # wchar_t
+//                ::= b    # bool
+//                ::= c    # char
+//                ::= a    # signed char
+//                ::= h    # unsigned char
+//                ::= s    # short
+//                ::= t    # unsigned short
+//                ::= i    # int
+//                ::= j    # unsigned int
+//                ::= l    # long
+//                ::= m    # unsigned long
+//                ::= x    # long long, __int64
+//                ::= y    # unsigned long long, __int64
+//                ::= n    # __int128
+//                ::= o    # unsigned __int128
+//                ::= f    # float
+//                ::= d    # double
+//                ::= e    # long double, __float80
+//                ::= g    # __float128
+//                ::= z    # ellipsis
+//                ::= Dd   # IEEE 754r decimal floating point (64 bits)
+//                ::= De   # IEEE 754r decimal floating point (128 bits)
+//                ::= Df   # IEEE 754r decimal floating point (32 bits)
+//                ::= Dh   # IEEE 754r half-precision floating point (16 bits)
+//                ::= Di   # char32_t
+//                ::= Ds   # char16_t
+//                ::= Da   # auto (in dependent new-expressions)
+//                ::= Dc   # decltype(auto)
+//                ::= Dn   # std::nullptr_t (i.e., decltype(nullptr))
+//                ::= u <source-name>    # vendor extended type
+
+template <class C>
+static const char *parse_builtin_type(const char *first, const char *last,
+                                      C &db) {
+  if (first != last) {
+    switch (*first) {
+    case 'v':
+      db.names.push_back("void");
+      ++first;
+      break;
+    case 'w':
+      db.names.push_back("wchar_t");
+      ++first;
+      break;
+    case 'b':
+      db.names.push_back("bool");
+      ++first;
+      break;
+    case 'c':
+      db.names.push_back("char");
+      ++first;
+      break;
+    case 'a':
+      db.names.push_back("signed char");
+      ++first;
+      break;
+    case 'h':
+      db.names.push_back("unsigned char");
+      ++first;
+      break;
+    case 's':
+      db.names.push_back("short");
+      ++first;
+      break;
+    case 't':
+      db.names.push_back("unsigned short");
+      ++first;
+      break;
+    case 'i':
+      db.names.push_back("int");
+      ++first;
+      break;
+    case 'j':
+      db.names.push_back("unsigned int");
+      ++first;
+      break;
+    case 'l':
+      db.names.push_back("long");
+      ++first;
+      break;
+    case 'm':
+      db.names.push_back("unsigned long");
+      ++first;
+      break;
+    case 'x':
+      db.names.push_back("long long");
+      ++first;
+      break;
+    case 'y':
+      db.names.push_back("unsigned long long");
+      ++first;
+      break;
+    case 'n':
+      db.names.push_back("__int128");
+      ++first;
+      break;
+    case 'o':
+      db.names.push_back("unsigned __int128");
+      ++first;
+      break;
+    case 'f':
+      db.names.push_back("float");
+      ++first;
+      break;
+    case 'd':
+      db.names.push_back("double");
+      ++first;
+      break;
+    case 'e':
+      db.names.push_back("long double");
+      ++first;
+      break;
+    case 'g':
+      db.names.push_back("__float128");
+      ++first;
+      break;
+    case 'z':
+      db.names.push_back("...");
+      ++first;
+      break;
+    case 'u': {
+      const char *t = parse_source_name(first + 1, last, db);
+      if (t != first + 1)
+        first = t;
+    } break;
+    case 'D':
+      if (first + 1 != last) {
+        switch (first[1]) {
+        case 'd':
+          db.names.push_back("decimal64");
+          first += 2;
+          break;
+        case 'e':
+          db.names.push_back("decimal128");
+          first += 2;
+          break;
+        case 'f':
+          db.names.push_back("decimal32");
+          first += 2;
+          break;
+        case 'h':
+          db.names.push_back("decimal16");
+          first += 2;
+          break;
+        case 'i':
+          db.names.push_back("char32_t");
+          first += 2;
+          break;
+        case 's':
+          db.names.push_back("char16_t");
+          first += 2;
+          break;
+        case 'a':
+          db.names.push_back("auto");
+          first += 2;
+          break;
+        case 'c':
+          db.names.push_back("decltype(auto)");
+          first += 2;
+          break;
+        case 'n':
+          db.names.push_back("std::nullptr_t");
+          first += 2;
+          break;
+        }
+      }
+      break;
+    }
+  }
+  return first;
+}
+
+// <CV-qualifiers> ::= [r] [V] [K]
+
+static const char *parse_cv_qualifiers(const char *first, const char *last,
+                                       unsigned &cv) {
+  cv = 0;
+  if (first != last) {
+    if (*first == 'r') {
+      cv |= 4;
+      ++first;
+    }
+    if (*first == 'V') {
+      cv |= 2;
+      ++first;
+    }
+    if (*first == 'K') {
+      cv |= 1;
+      ++first;
+    }
+  }
+  return first;
+}
+
+// <template-param> ::= T_    # first template parameter
+//                  ::= T <parameter-2 non-negative number> _
+
+template <class C>
+static const char *parse_template_param(const char *first, const char *last,
+                                        C &db) {
+  if (last - first >= 2) {
+    if (*first == 'T') {
+      if (first[1] == '_') {
+        if (db.template_param.empty())
+          return first;
+        if (!db.template_param.back().empty()) {
+          for (auto &t : db.template_param.back().front())
+            db.names.push_back(t);
+          first += 2;
+        } else {
+          db.names.push_back("T_");
+          first += 2;
+          db.fix_forward_references = true;
+        }
+      } else if (isdigit(first[1])) {
+        const char *t = first + 1;
+        size_t sub = static_cast<size_t>(*t - '0');
+        for (++t; t != last && isdigit(*t); ++t) {
+          sub *= 10;
+          sub += static_cast<size_t>(*t - '0');
+        }
+        if (t == last || *t != '_' || db.template_param.empty())
+          return first;
+        ++sub;
+        if (sub < db.template_param.back().size()) {
+          for (auto &temp : db.template_param.back()[sub])
+            db.names.push_back(temp);
+          first = t + 1;
+        } else {
+          db.names.push_back(typename C::String(first, t + 1));
+          first = t + 1;
+          db.fix_forward_references = true;
+        }
+      }
+    }
+  }
+  return first;
+}
+
+// cc <type> <expression>                               # const_cast<type>
+// (expression)
+
+template <class C>
+static const char *parse_const_cast_expr(const char *first, const char *last,
+                                         C &db) {
+  if (last - first >= 3 && first[0] == 'c' && first[1] == 'c') {
+    const char *t = parse_type(first + 2, last, db);
+    if (t != first + 2) {
+      const char *t1 = parse_expression(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto expr = db.names.back().move_full();
+        db.names.pop_back();
+        if (db.names.empty())
+          return first;
+        db.names.back() =
+            "const_cast<" + db.names.back().move_full() + ">(" + expr + ")";
+        first = t1;
+      }
+    }
+  }
+  return first;
+}
+
+// dc <type> <expression>                               # dynamic_cast<type>
+// (expression)
+
+template <class C>
+static const char *parse_dynamic_cast_expr(const char *first, const char *last,
+                                           C &db) {
+  if (last - first >= 3 && first[0] == 'd' && first[1] == 'c') {
+    const char *t = parse_type(first + 2, last, db);
+    if (t != first + 2) {
+      const char *t1 = parse_expression(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto expr = db.names.back().move_full();
+        db.names.pop_back();
+        if (db.names.empty())
+          return first;
+        db.names.back() =
+            "dynamic_cast<" + db.names.back().move_full() + ">(" + expr + ")";
+        first = t1;
+      }
+    }
+  }
+  return first;
+}
+
+// rc <type> <expression>                               # reinterpret_cast<type>
+// (expression)
+
+template <class C>
+static const char *parse_reinterpret_cast_expr(const char *first,
+                                               const char *last, C &db) {
+  if (last - first >= 3 && first[0] == 'r' && first[1] == 'c') {
+    const char *t = parse_type(first + 2, last, db);
+    if (t != first + 2) {
+      const char *t1 = parse_expression(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto expr = db.names.back().move_full();
+        db.names.pop_back();
+        if (db.names.empty())
+          return first;
+        db.names.back() = "reinterpret_cast<" + db.names.back().move_full() +
+                          ">(" + expr + ")";
+        first = t1;
+      }
+    }
+  }
+  return first;
+}
+
+// sc <type> <expression>                               # static_cast<type>
+// (expression)
+
+template <class C>
+static const char *parse_static_cast_expr(const char *first, const char *last,
+                                          C &db) {
+  if (last - first >= 3 && first[0] == 's' && first[1] == 'c') {
+    const char *t = parse_type(first + 2, last, db);
+    if (t != first + 2) {
+      const char *t1 = parse_expression(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto expr = db.names.back().move_full();
+        db.names.pop_back();
+        db.names.back() =
+            "static_cast<" + db.names.back().move_full() + ">(" + expr + ")";
+        first = t1;
+      }
+    }
+  }
+  return first;
+}
+
+// sp <expression>                                  # pack expansion
+
+template <class C>
+static const char *parse_pack_expansion(const char *first, const char *last,
+                                        C &db) {
+  if (last - first >= 3 && first[0] == 's' && first[1] == 'p') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2)
+      first = t;
+  }
+  return first;
+}
+
+// st <type>                                            # sizeof (a type)
+
+template <class C>
+static const char *parse_sizeof_type_expr(const char *first, const char *last,
+                                          C &db) {
+  if (last - first >= 3 && first[0] == 's' && first[1] == 't') {
+    const char *t = parse_type(first + 2, last, db);
+    if (t != first + 2) {
+      if (db.names.empty())
+        return first;
+      db.names.back() = "sizeof (" + db.names.back().move_full() + ")";
+      first = t;
+    }
+  }
+  return first;
+}
+
+// sz <expr>                                            # sizeof (a expression)
+
+template <class C>
+static const char *parse_sizeof_expr_expr(const char *first, const char *last,
+                                          C &db) {
+  if (last - first >= 3 && first[0] == 's' && first[1] == 'z') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2) {
+      if (db.names.empty())
+        return first;
+      db.names.back() = "sizeof (" + db.names.back().move_full() + ")";
+      first = t;
+    }
+  }
+  return first;
+}
+
+// sZ <template-param>                                  # size of a parameter
+// pack
+
+template <class C>
+static const char *parse_sizeof_param_pack_expr(const char *first,
+                                                const char *last, C &db) {
+  if (last - first >= 3 && first[0] == 's' && first[1] == 'Z' &&
+      first[2] == 'T') {
+    size_t k0 = db.names.size();
+    const char *t = parse_template_param(first + 2, last, db);
+    size_t k1 = db.names.size();
+    if (t != first + 2) {
+      typename C::String tmp("sizeof...(");
+      size_t k = k0;
+      if (k != k1) {
+        tmp += db.names[k].move_full();
+        for (++k; k != k1; ++k)
+          tmp += ", " + db.names[k].move_full();
+      }
+      tmp += ")";
+      for (; k1 != k0; --k1)
+        db.names.pop_back();
+      db.names.push_back(std::move(tmp));
+      first = t;
+    }
+  }
+  return first;
+}
+
+// <function-param> ::= fp <top-level CV-qualifiers> _ # L == 0, first parameter
+//                  ::= fp <top-level CV-qualifiers> <parameter-2 non-negative
+//                  number> _   # L == 0, second and later parameters
+//                  ::= fL <L-1 non-negative number> p <top-level CV-qualifiers>
+//                  _         # L > 0, first parameter
+//                  ::= fL <L-1 non-negative number> p <top-level CV-qualifiers>
+//                  <parameter-2 non-negative number> _   # L > 0, second and
+//                  later parameters
+
+template <class C>
+static const char *parse_function_param(const char *first, const char *last,
+                                        C &db) {
+  if (last - first >= 3 && *first == 'f') {
+    if (first[1] == 'p') {
+      unsigned cv;
+      const char *t = parse_cv_qualifiers(first + 2, last, cv);
+      const char *t1 = parse_number(t, last);
+      if (t1 != last && *t1 == '_') {
+        db.names.push_back("fp" + typename C::String(t, t1));
+        first = t1 + 1;
+      }
+    } else if (first[1] == 'L') {
+      unsigned cv;
+      const char *t0 = parse_number(first + 2, last);
+      if (t0 != last && *t0 == 'p') {
+        ++t0;
+        const char *t = parse_cv_qualifiers(t0, last, cv);
+        const char *t1 = parse_number(t, last);
+        if (t1 != last && *t1 == '_') {
+          db.names.push_back("fp" + typename C::String(t, t1));
+          first = t1 + 1;
+        }
+      }
+    }
+  }
+  return first;
+}
+
+// sZ <function-param>                                  # size of a function
+// parameter pack
+
+template <class C>
+static const char *parse_sizeof_function_param_pack_expr(const char *first,
+                                                         const char *last,
+                                                         C &db) {
+  if (last - first >= 3 && first[0] == 's' && first[1] == 'Z' &&
+      first[2] == 'f') {
+    const char *t = parse_function_param(first + 2, last, db);
+    if (t != first + 2) {
+      if (db.names.empty())
+        return first;
+      db.names.back() = "sizeof...(" + db.names.back().move_full() + ")";
+      first = t;
+    }
+  }
+  return first;
+}
+
+// te <expression>                                      # typeid (expression)
+// ti <type>                                            # typeid (type)
+
+template <class C>
+static const char *parse_typeid_expr(const char *first, const char *last,
+                                     C &db) {
+  if (last - first >= 3 && first[0] == 't' &&
+      (first[1] == 'e' || first[1] == 'i')) {
+    const char *t;
+    if (first[1] == 'e')
+      t = parse_expression(first + 2, last, db);
+    else
+      t = parse_type(first + 2, last, db);
+    if (t != first + 2) {
+      if (db.names.empty())
+        return first;
+      db.names.back() = "typeid(" + db.names.back().move_full() + ")";
+      first = t;
+    }
+  }
+  return first;
+}
+
+// tw <expression>                                      # throw expression
+
+template <class C>
+static const char *parse_throw_expr(const char *first, const char *last,
+                                    C &db) {
+  if (last - first >= 3 && first[0] == 't' && first[1] == 'w') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2) {
+      if (db.names.empty())
+        return first;
+      db.names.back() = "throw " + db.names.back().move_full();
+      first = t;
+    }
+  }
+  return first;
+}
+
+// ds <expression> <expression>                         # expr.*expr
+
+template <class C>
+static const char *parse_dot_star_expr(const char *first, const char *last,
+                                       C &db) {
+  if (last - first >= 3 && first[0] == 'd' && first[1] == 's') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2) {
+      const char *t1 = parse_expression(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto expr = db.names.back().move_full();
+        db.names.pop_back();
+        db.names.back().first += ".*" + expr;
+        first = t1;
+      }
+    }
+  }
+  return first;
+}
+
+// <simple-id> ::= <source-name> [ <template-args> ]
+
+template <class C>
+static const char *parse_simple_id(const char *first, const char *last, C &db) {
+  if (first != last) {
+    const char *t = parse_source_name(first, last, db);
+    if (t != first) {
+      const char *t1 = parse_template_args(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto args = db.names.back().move_full();
+        db.names.pop_back();
+        db.names.back().first += std::move(args);
+      }
+      first = t1;
+    } else
+      first = t;
+  }
+  return first;
+}
+
+// <unresolved-type> ::= <template-param>
+//                   ::= <decltype>
+//                   ::= <substitution>
+
+template <class C>
+static const char *parse_unresolved_type(const char *first, const char *last,
+                                         C &db) {
+  if (first != last) {
+    const char *t = first;
+    switch (*first) {
+    case 'T': {
+      size_t k0 = db.names.size();
+      t = parse_template_param(first, last, db);
+      size_t k1 = db.names.size();
+      if (t != first && k1 == k0 + 1) {
+        db.subs.push_back(
+            typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+        first = t;
+      } else {
+        for (; k1 != k0; --k1)
+          db.names.pop_back();
+      }
+      break;
+    }
+    case 'D':
+      t = parse_decltype(first, last, db);
+      if (t != first) {
+        if (db.names.empty())
+          return first;
+        db.subs.push_back(
+            typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+        first = t;
+      }
+      break;
+    case 'S':
+      t = parse_substitution(first, last, db);
+      if (t != first)
+        first = t;
+      else {
+        if (last - first > 2 && first[1] == 't') {
+          t = parse_unqualified_name(first + 2, last, db);
+          if (t != first + 2) {
+            if (db.names.empty())
+              return first;
+            db.names.back().first.insert(0, "std::");
+            db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                   db.names.get_allocator()));
+            first = t;
+          }
+        }
+      }
+      break;
+    }
+  }
+  return first;
+}
+
+// <destructor-name> ::= <unresolved-type>                               # e.g.,
+// ~T or ~decltype(f())
+//                   ::= <simple-id>                                     # e.g.,
+//                   ~A<2*N>
+
+template <class C>
+static const char *parse_destructor_name(const char *first, const char *last,
+                                         C &db) {
+  if (first != last) {
+    const char *t = parse_unresolved_type(first, last, db);
+    if (t == first)
+      t = parse_simple_id(first, last, db);
+    if (t != first) {
+      if (db.names.empty())
+        return first;
+      db.names.back().first.insert(0, "~");
+      first = t;
+    }
+  }
+  return first;
+}
+
+// <base-unresolved-name> ::= <simple-id>                                #
+// unresolved name
+//          extension     ::= <operator-name>                            #
+//          unresolved operator-function-id
+//          extension     ::= <operator-name> <template-args>            #
+//          unresolved operator template-id
+//                        ::= on <operator-name>                         #
+//                        unresolved operator-function-id
+//                        ::= on <operator-name> <template-args>         #
+//                        unresolved operator template-id
+//                        ::= dn <destructor-name>                       #
+//                        destructor or pseudo-destructor;
+//                                                                         #
+//                                                                         e.g.
+//                                                                         ~X or
+//                                                                         ~X<N-1>
+
+template <class C>
+static const char *parse_base_unresolved_name(const char *first,
+                                              const char *last, C &db) {
+  if (last - first >= 2) {
+    if ((first[0] == 'o' || first[0] == 'd') && first[1] == 'n') {
+      if (first[0] == 'o') {
+        const char *t = parse_operator_name(first + 2, last, db);
+        if (t != first + 2) {
+          first = parse_template_args(t, last, db);
+          if (first != t) {
+            if (db.names.size() < 2)
+              return first;
+            auto args = db.names.back().move_full();
+            db.names.pop_back();
+            db.names.back().first += std::move(args);
+          }
+        }
+      } else {
+        const char *t = parse_destructor_name(first + 2, last, db);
+        if (t != first + 2)
+          first = t;
+      }
+    } else {
+      const char *t = parse_simple_id(first, last, db);
+      if (t == first) {
+        t = parse_operator_name(first, last, db);
+        if (t != first) {
+          first = parse_template_args(t, last, db);
+          if (first != t) {
+            if (db.names.size() < 2)
+              return first;
+            auto args = db.names.back().move_full();
+            db.names.pop_back();
+            db.names.back().first += std::move(args);
+          }
+        }
+      } else
+        first = t;
+    }
+  }
+  return first;
+}
+
+// <unresolved-qualifier-level> ::= <simple-id>
+
+template <class C>
+static const char *parse_unresolved_qualifier_level(const char *first,
+                                                    const char *last, C &db) {
+  return parse_simple_id(first, last, db);
+}
+
+// <unresolved-name>
+//  extension        ::= srN <unresolved-type> [<template-args>]
+//  <unresolved-qualifier-level>* E <base-unresolved-name>
+//                   ::= [gs] <base-unresolved-name>                     # x or
+//                   (with "gs") ::x
+//                   ::= [gs] sr <unresolved-qualifier-level>+ E
+//                   <base-unresolved-name>
+//                                                                       # A::x,
+//                                                                       N::y,
+//                                                                       A<T>::z;
+//                                                                       "gs"
+//                                                                       means
+//                                                                       leading
+//                                                                       "::"
+//                   ::= sr <unresolved-type> <base-unresolved-name>     # T::x
+//                   / decltype(p)::x
+//  extension        ::= sr <unresolved-type> <template-args>
+//  <base-unresolved-name>
+//                                                                       #
+//                                                                       T::N::x
+//                                                                       /decltype(p)::N::x
+//  (ignored)        ::= srN <unresolved-type>  <unresolved-qualifier-level>+ E
+//  <base-unresolved-name>
+
+template <class C>
+static const char *parse_unresolved_name(const char *first, const char *last,
+                                         C &db) {
+  if (last - first > 2) {
+    const char *t = first;
+    bool global = false;
+    if (t[0] == 'g' && t[1] == 's') {
+      global = true;
+      t += 2;
+    }
+    const char *t2 = parse_base_unresolved_name(t, last, db);
+    if (t2 != t) {
+      if (global) {
+        if (db.names.empty())
+          return first;
+        db.names.back().first.insert(0, "::");
+      }
+      first = t2;
+    } else if (last - t > 2 && t[0] == 's' && t[1] == 'r') {
+      if (t[2] == 'N') {
+        t += 3;
+        const char *t1 = parse_unresolved_type(t, last, db);
+        if (t1 == t || t1 == last)
+          return first;
+        t = t1;
+        t1 = parse_template_args(t, last, db);
+        if (t1 != t) {
+          if (db.names.size() < 2)
+            return first;
+          auto args = db.names.back().move_full();
+          db.names.pop_back();
+          db.names.back().first += std::move(args);
+          t = t1;
+          if (t == last) {
+            db.names.pop_back();
+            return first;
+          }
+        }
+        while (*t != 'E') {
+          t1 = parse_unresolved_qualifier_level(t, last, db);
+          if (t1 == t || t1 == last || db.names.size() < 2)
+            return first;
+          auto s = db.names.back().move_full();
+          db.names.pop_back();
+          db.names.back().first += "::" + std::move(s);
+          t = t1;
+        }
+        ++t;
+        t1 = parse_base_unresolved_name(t, last, db);
+        if (t1 == t) {
+          if (!db.names.empty())
+            db.names.pop_back();
+          return first;
+        }
+        if (db.names.size() < 2)
+          return first;
+        auto s = db.names.back().move_full();
+        db.names.pop_back();
+        db.names.back().first += "::" + std::move(s);
+        first = t1;
+      } else {
+        t += 2;
+        const char *t1 = parse_unresolved_type(t, last, db);
+        if (t1 != t) {
+          t = t1;
+          t1 = parse_template_args(t, last, db);
+          if (t1 != t) {
+            if (db.names.size() < 2)
+              return first;
+            auto args = db.names.back().move_full();
+            db.names.pop_back();
+            db.names.back().first += std::move(args);
+            t = t1;
+          }
+          t1 = parse_base_unresolved_name(t, last, db);
+          if (t1 == t) {
+            if (!db.names.empty())
+              db.names.pop_back();
+            return first;
+          }
+          if (db.names.size() < 2)
+            return first;
+          auto s = db.names.back().move_full();
+          db.names.pop_back();
+          db.names.back().first += "::" + std::move(s);
+          first = t1;
+        } else {
+          t1 = parse_unresolved_qualifier_level(t, last, db);
+          if (t1 == t || t1 == last)
+            return first;
+          t = t1;
+          if (global) {
+            if (db.names.empty())
+              return first;
+            db.names.back().first.insert(0, "::");
+          }
+          while (*t != 'E') {
+            t1 = parse_unresolved_qualifier_level(t, last, db);
+            if (t1 == t || t1 == last || db.names.size() < 2)
+              return first;
+            auto s = db.names.back().move_full();
+            db.names.pop_back();
+            db.names.back().first += "::" + std::move(s);
+            t = t1;
+          }
+          ++t;
+          t1 = parse_base_unresolved_name(t, last, db);
+          if (t1 == t) {
+            if (!db.names.empty())
+              db.names.pop_back();
+            return first;
+          }
+          if (db.names.size() < 2)
+            return first;
+          auto s = db.names.back().move_full();
+          db.names.pop_back();
+          db.names.back().first += "::" + std::move(s);
+          first = t1;
+        }
+      }
+    }
+  }
+  return first;
+}
+
+// dt <expression> <unresolved-name>                    # expr.name
+
+template <class C>
+static const char *parse_dot_expr(const char *first, const char *last, C &db) {
+  if (last - first >= 3 && first[0] == 'd' && first[1] == 't') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2) {
+      const char *t1 = parse_unresolved_name(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto name = db.names.back().move_full();
+        db.names.pop_back();
+        if (db.names.empty())
+          return first;
+        db.names.back().first += "." + name;
+        first = t1;
+      }
+    }
+  }
+  return first;
+}
+
+// cl <expression>+ E                                   # call
+
+template <class C>
+static const char *parse_call_expr(const char *first, const char *last, C &db) {
+  if (last - first >= 4 && first[0] == 'c' && first[1] == 'l') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2) {
+      if (t == last)
+        return first;
+      if (db.names.empty())
+        return first;
+      db.names.back().first += db.names.back().second;
+      db.names.back().second = typename C::String();
+      db.names.back().first.append("(");
+      bool first_expr = true;
+      while (*t != 'E') {
+        const char *t1 = parse_expression(t, last, db);
+        if (t1 == t || t1 == last)
+          return first;
+        if (db.names.empty())
+          return first;
+        auto tmp = db.names.back().move_full();
+        db.names.pop_back();
+        if (!tmp.empty()) {
+          if (db.names.empty())
+            return first;
+          if (!first_expr) {
+            db.names.back().first.append(", ");
+            first_expr = false;
+          }
+          db.names.back().first.append(tmp);
+        }
+        t = t1;
+      }
+      ++t;
+      if (db.names.empty())
+        return first;
+      db.names.back().first.append(")");
+      first = t;
+    }
+  }
+  return first;
+}
+
+// [gs] nw <expression>* _ <type> E                     # new (expr-list) type
+// [gs] nw <expression>* _ <type> <initializer>         # new (expr-list) type
+// (init)
+// [gs] na <expression>* _ <type> E                     # new[] (expr-list) type
+// [gs] na <expression>* _ <type> <initializer>         # new[] (expr-list) type
+// (init)
+// <initializer> ::= pi <expression>* E                 # parenthesized
+// initialization
+
+template <class C>
+static const char *parse_new_expr(const char *first, const char *last, C &db) {
+  if (last - first >= 4) {
+    const char *t = first;
+    bool parsed_gs = false;
+    if (t[0] == 'g' && t[1] == 's') {
+      t += 2;
+      parsed_gs = true;
+    }
+    if (t[0] == 'n' && (t[1] == 'w' || t[1] == 'a')) {
+      bool is_array = t[1] == 'a';
+      t += 2;
+      if (t == last)
+        return first;
+      bool has_expr_list = false;
+      bool first_expr = true;
+      while (*t != '_') {
+        const char *t1 = parse_expression(t, last, db);
+        if (t1 == t || t1 == last)
+          return first;
+        has_expr_list = true;
+        if (!first_expr) {
+          if (db.names.empty())
+            return first;
+          auto tmp = db.names.back().move_full();
+          db.names.pop_back();
+          if (!tmp.empty()) {
+            if (db.names.empty())
+              return first;
+            db.names.back().first.append(", ");
+            db.names.back().first.append(tmp);
+            first_expr = false;
+          }
+        }
+        t = t1;
+      }
+      ++t;
+      const char *t1 = parse_type(t, last, db);
+      if (t1 == t || t1 == last)
+        return first;
+      t = t1;
+      bool has_init = false;
+      if (last - t >= 3 && t[0] == 'p' && t[1] == 'i') {
+        t += 2;
+        has_init = true;
+        first_expr = true;
+        while (*t != 'E') {
+          t1 = parse_expression(t, last, db);
+          if (t1 == t || t1 == last)
+            return first;
+          if (!first_expr) {
+            if (db.names.empty())
+              return first;
+            auto tmp = db.names.back().move_full();
+            db.names.pop_back();
+            if (!tmp.empty()) {
+              if (db.names.empty())
+                return first;
+              db.names.back().first.append(", ");
+              db.names.back().first.append(tmp);
+              first_expr = false;
+            }
+          }
+          t = t1;
+        }
+      }
+      if (*t != 'E')
+        return first;
+      typename C::String init_list;
+      if (has_init) {
+        if (db.names.empty())
+          return first;
+        init_list = db.names.back().move_full();
+        db.names.pop_back();
+      }
+      if (db.names.empty())
+        return first;
+      auto type = db.names.back().move_full();
+      db.names.pop_back();
+      typename C::String expr_list;
+      if (has_expr_list) {
+        if (db.names.empty())
+          return first;
+        expr_list = db.names.back().move_full();
+        db.names.pop_back();
+      }
+      typename C::String r;
+      if (parsed_gs)
+        r = "::";
+      if (is_array)
+        r += "[] ";
+      else
+        r += " ";
+      if (has_expr_list)
+        r += "(" + expr_list + ") ";
+      r += type;
+      if (has_init)
+        r += " (" + init_list + ")";
+      db.names.push_back(std::move(r));
+      first = t + 1;
+    }
+  }
+  return first;
+}
+
+// cv <type> <expression>                               # conversion with one
+// argument
+// cv <type> _ <expression>* E                          # conversion with a
+// different number of arguments
+
+template <class C>
+static const char *parse_conversion_expr(const char *first, const char *last,
+                                         C &db) {
+  if (last - first >= 3 && first[0] == 'c' && first[1] == 'v') {
+    bool try_to_parse_template_args = db.try_to_parse_template_args;
+    db.try_to_parse_template_args = false;
+    const char *t = parse_type(first + 2, last, db);
+    db.try_to_parse_template_args = try_to_parse_template_args;
+    if (t != first + 2 && t != last) {
+      if (*t != '_') {
+        const char *t1 = parse_expression(t, last, db);
+        if (t1 == t)
+          return first;
+        t = t1;
+      } else {
+        ++t;
+        if (t == last)
+          return first;
+        if (*t == 'E')
+          db.names.emplace_back();
+        else {
+          bool first_expr = true;
+          while (*t != 'E') {
+            const char *t1 = parse_expression(t, last, db);
+            if (t1 == t || t1 == last)
+              return first;
+            if (!first_expr) {
+              if (db.names.empty())
+                return first;
+              auto tmp = db.names.back().move_full();
+              db.names.pop_back();
+              if (!tmp.empty()) {
+                if (db.names.empty())
+                  return first;
+                db.names.back().first.append(", ");
+                db.names.back().first.append(tmp);
+                first_expr = false;
+              }
+            }
+            t = t1;
+          }
+        }
+        ++t;
+      }
+      if (db.names.size() < 2)
+        return first;
+      auto tmp = db.names.back().move_full();
+      db.names.pop_back();
+      db.names.back() = "(" + db.names.back().move_full() + ")(" + tmp + ")";
+      first = t;
+    }
+  }
+  return first;
+}
+
+// pt <expression> <expression>                    # expr->name
+
+template <class C>
+static const char *parse_arrow_expr(const char *first, const char *last,
+                                    C &db) {
+  if (last - first >= 3 && first[0] == 'p' && first[1] == 't') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2) {
+      const char *t1 = parse_expression(t, last, db);
+      if (t1 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto tmp = db.names.back().move_full();
+        db.names.pop_back();
+        db.names.back().first += "->";
+        db.names.back().first += tmp;
+        first = t1;
+      }
+    }
+  }
+  return first;
+}
+
+//  <ref-qualifier> ::= R                   # & ref-qualifier
+//  <ref-qualifier> ::= O                   # && ref-qualifier
+
+// <function-type> ::= F [Y] <bare-function-type> [<ref-qualifier>] E
+
+template <class C>
+static const char *parse_function_type(const char *first, const char *last,
+                                       C &db) {
+  if (first != last && *first == 'F') {
+    const char *t = first + 1;
+    if (t != last) {
+      if (*t == 'Y') {
+        /* extern "C" */
+        if (++t == last)
+          return first;
+      }
+      const char *t1 = parse_type(t, last, db);
+      if (t1 != t) {
+        t = t1;
+        typename C::String sig("(");
+        int ref_qual = 0;
+        while (true) {
+          if (t == last) {
+            db.names.pop_back();
+            return first;
+          }
+          if (*t == 'E') {
+            ++t;
+            break;
+          }
+          if (*t == 'v') {
+            ++t;
+            continue;
+          }
+          if (*t == 'R' && t + 1 != last && t[1] == 'E') {
+            ref_qual = 1;
+            ++t;
+            continue;
+          }
+          if (*t == 'O' && t + 1 != last && t[1] == 'E') {
+            ref_qual = 2;
+            ++t;
+            continue;
+          }
+          size_t k0 = db.names.size();
+          t1 = parse_type(t, last, db);
+          size_t k1 = db.names.size();
+          if (t1 == t || t1 == last)
+            return first;
+          for (size_t k = k0; k < k1; ++k) {
+            if (sig.size() > 1)
+              sig += ", ";
+            sig += db.names[k].move_full();
+          }
+          for (size_t k = k0; k < k1; ++k)
+            db.names.pop_back();
+          t = t1;
+        }
+        sig += ")";
+        switch (ref_qual) {
+        case 1:
+          sig += " &";
+          break;
+        case 2:
+          sig += " &&";
+          break;
+        }
+        if (db.names.empty())
+          return first;
+        db.names.back().first += " ";
+        db.names.back().second.insert(0, sig);
+        first = t;
+      }
+    }
+  }
+  return first;
+}
+
+// <pointer-to-member-type> ::= M <class type> <member type>
+
+template <class C>
+static const char *parse_pointer_to_member_type(const char *first,
+                                                const char *last, C &db) {
+  if (first != last && *first == 'M') {
+    const char *t = parse_type(first + 1, last, db);
+    if (t != first + 1) {
+      const char *t2 = parse_type(t, last, db);
+      if (t2 != t) {
+        if (db.names.size() < 2)
+          return first;
+        auto func = std::move(db.names.back());
+        db.names.pop_back();
+        auto class_type = std::move(db.names.back());
+        if (!func.second.empty() && func.second.front() == '(') {
+          db.names.back().first =
+              std::move(func.first) + "(" + class_type.move_full() + "::*";
+          db.names.back().second = ")" + std::move(func.second);
+        } else {
+          db.names.back().first =
+              std::move(func.first) + " " + class_type.move_full() + "::*";
+          db.names.back().second = std::move(func.second);
+        }
+        first = t2;
+      }
+    }
+  }
+  return first;
+}
+
+// <array-type> ::= A <positive dimension number> _ <element type>
+//              ::= A [<dimension expression>] _ <element type>
+
+template <class C>
+static const char *parse_array_type(const char *first, const char *last,
+                                    C &db) {
+  if (first != last && *first == 'A' && first + 1 != last) {
+    if (first[1] == '_') {
+      const char *t = parse_type(first + 2, last, db);
+      if (t != first + 2) {
+        if (db.names.empty())
+          return first;
+        if (db.names.back().second.substr(0, 2) == " [")
+          db.names.back().second.erase(0, 1);
+        db.names.back().second.insert(0, " []");
+        first = t;
+      }
+    } else if ('1' <= first[1] && first[1] <= '9') {
+      const char *t = parse_number(first + 1, last);
+      if (t != last && *t == '_') {
+        const char *t2 = parse_type(t + 1, last, db);
+        if (t2 != t + 1) {
+          if (db.names.empty())
+            return first;
+          if (db.names.back().second.substr(0, 2) == " [")
+            db.names.back().second.erase(0, 1);
+          db.names.back().second.insert(
+              0, " [" + typename C::String(first + 1, t) + "]");
+          first = t2;
+        }
+      }
+    } else {
+      const char *t = parse_expression(first + 1, last, db);
+      if (t != first + 1 && t != last && *t == '_') {
+        const char *t2 = parse_type(++t, last, db);
+        if (t2 != t) {
+          if (db.names.size() < 2)
+            return first;
+          auto type = std::move(db.names.back());
+          db.names.pop_back();
+          auto expr = std::move(db.names.back());
+          db.names.back().first = std::move(type.first);
+          if (type.second.substr(0, 2) == " [")
+            type.second.erase(0, 1);
+          db.names.back().second =
+              " [" + expr.move_full() + "]" + std::move(type.second);
+          first = t2;
+        }
+      }
+    }
+  }
+  return first;
+}
+
+// <decltype>  ::= Dt <expression> E  # decltype of an id-expression or class
+// member access (C++0x)
+//             ::= DT <expression> E  # decltype of an expression (C++0x)
+
+template <class C>
+static const char *parse_decltype(const char *first, const char *last, C &db) {
+  if (last - first >= 4 && first[0] == 'D') {
+    switch (first[1]) {
+    case 't':
+    case 'T': {
+      const char *t = parse_expression(first + 2, last, db);
+      if (t != first + 2 && t != last && *t == 'E') {
+        if (db.names.empty())
+          return first;
+        db.names.back() = "decltype(" + db.names.back().move_full() + ")";
+        first = t + 1;
+      }
+    } break;
+    }
+  }
+  return first;
+}
+
+// extension:
+// <vector-type>           ::= Dv <positive dimension number> _
+//                                    <extended element type>
+//                         ::= Dv [<dimension expression>] _ <element type>
+// <extended element type> ::= <element type>
+//                         ::= p # AltiVec vector pixel
+
+template <class C>
+static const char *parse_vector_type(const char *first, const char *last,
+                                     C &db) {
+  if (last - first > 3 && first[0] == 'D' && first[1] == 'v') {
+    if ('1' <= first[2] && first[2] <= '9') {
+      const char *t = parse_number(first + 2, last);
+      if (t == last || *t != '_')
+        return first;
+      const char *num = first + 2;
+      size_t sz = static_cast<size_t>(t - num);
+      if (++t != last) {
+        if (*t != 'p') {
+          const char *t1 = parse_type(t, last, db);
+          if (t1 != t) {
+            if (db.names.empty())
+              return first;
+            db.names.back().first +=
+                " vector[" + typename C::String(num, sz) + "]";
+            first = t1;
+          }
+        } else {
+          ++t;
+          db.names.push_back("pixel vector[" + typename C::String(num, sz) +
+                             "]");
+          first = t;
+        }
+      }
+    } else {
+      typename C::String num;
+      const char *t1 = first + 2;
+      if (*t1 != '_') {
+        const char *t = parse_expression(t1, last, db);
+        if (t != t1) {
+          if (db.names.empty())
+            return first;
+          num = db.names.back().move_full();
+          db.names.pop_back();
+          t1 = t;
+        }
+      }
+      if (t1 != last && *t1 == '_' && ++t1 != last) {
+        const char *t = parse_type(t1, last, db);
+        if (t != t1) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first += " vector[" + num + "]";
+          first = t;
+        }
+      }
+    }
+  }
+  return first;
+}
+
+// <type> ::= <builtin-type>
+//        ::= <function-type>
+//        ::= <class-enum-type>
+//        ::= <array-type>
+//        ::= <pointer-to-member-type>
+//        ::= <template-param>
+//        ::= <template-template-param> <template-args>
+//        ::= <decltype>
+//        ::= <substitution>
+//        ::= <CV-qualifiers> <type>
+//        ::= P <type>        # pointer-to
+//        ::= R <type>        # reference-to
+//        ::= O <type>        # rvalue reference-to (C++0x)
+//        ::= C <type>        # complex pair (C 2000)
+//        ::= G <type>        # imaginary (C 2000)
+//        ::= Dp <type>       # pack expansion (C++0x)
+//        ::= U <source-name> <type>  # vendor extended type qualifier
+// extension := U <objc-name> <objc-type>  # objc-type<identifier>
+// extension := <vector-type> # <vector-type> starts with Dv
+
+// <objc-name> ::= <k0 number> objcproto <k1 number> <identifier>  # k0 = 9 +
+// <number of digits in k1> + k1
+// <objc-type> := <source-name>  # PU<11+>objcproto 11objc_object<source-name>
+// 11objc_object -> id<source-name>
+
+template <class C>
+static const char *parse_type(const char *first, const char *last, C &db) {
+  if (first != last) {
+    switch (*first) {
+    case 'r':
+    case 'V':
+    case 'K': {
+      unsigned cv = 0;
+      const char *t = parse_cv_qualifiers(first, last, cv);
+      if (t != first) {
+        bool is_function = *t == 'F';
+        size_t k0 = db.names.size();
+        const char *t1 = parse_type(t, last, db);
+        size_t k1 = db.names.size();
+        if (t1 != t) {
+          if (is_function)
+            db.subs.pop_back();
+          db.subs.emplace_back(db.names.get_allocator());
+          for (size_t k = k0; k < k1; ++k) {
+            if (is_function) {
+              size_t p = db.names[k].second.size();
+              if (db.names[k].second[p - 2] == '&')
+                p -= 3;
+              else if (db.names[k].second.back() == '&')
+                p -= 2;
+              if (cv & 1) {
+                db.names[k].second.insert(p, " const");
+                p += 6;
+              }
+              if (cv & 2) {
+                db.names[k].second.insert(p, " volatile");
+                p += 9;
+              }
+              if (cv & 4)
+                db.names[k].second.insert(p, " restrict");
+            } else {
+              if (cv & 1)
+                db.names[k].first.append(" const");
+              if (cv & 2)
+                db.names[k].first.append(" volatile");
+              if (cv & 4)
+                db.names[k].first.append(" restrict");
+            }
+            db.subs.back().push_back(db.names[k]);
+          }
+          first = t1;
+        }
+      }
+    } break;
+    default: {
+      const char *t = parse_builtin_type(first, last, db);
+      if (t != first) {
+        first = t;
+      } else {
+        switch (*first) {
+        case 'A':
+          t = parse_array_type(first, last, db);
+          if (t != first) {
+            if (db.names.empty())
+              return first;
+            first = t;
+            db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                   db.names.get_allocator()));
+          }
+          break;
+        case 'C':
+          t = parse_type(first + 1, last, db);
+          if (t != first + 1) {
+            if (db.names.empty())
+              return first;
+            db.names.back().first.append(" complex");
+            first = t;
+            db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                   db.names.get_allocator()));
+          }
+          break;
+        case 'F':
+          t = parse_function_type(first, last, db);
+          if (t != first) {
+            if (db.names.empty())
+              return first;
+            first = t;
+            db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                   db.names.get_allocator()));
+          }
+          break;
+        case 'G':
+          t = parse_type(first + 1, last, db);
+          if (t != first + 1) {
+            if (db.names.empty())
+              return first;
+            db.names.back().first.append(" imaginary");
+            first = t;
+            db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                   db.names.get_allocator()));
+          }
+          break;
+        case 'M':
+          t = parse_pointer_to_member_type(first, last, db);
+          if (t != first) {
+            if (db.names.empty())
+              return first;
+            first = t;
+            db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                   db.names.get_allocator()));
+          }
+          break;
+        case 'O': {
+          size_t k0 = db.names.size();
+          t = parse_type(first + 1, last, db);
+          size_t k1 = db.names.size();
+          if (t != first + 1) {
+            db.subs.emplace_back(db.names.get_allocator());
+            for (size_t k = k0; k < k1; ++k) {
+              if (db.names[k].second.substr(0, 2) == " [") {
+                db.names[k].first += " (";
+                db.names[k].second.insert(0, ")");
+              } else if (!db.names[k].second.empty() &&
+                         db.names[k].second.front() == '(') {
+                db.names[k].first += "(";
+                db.names[k].second.insert(0, ")");
+              }
+              db.names[k].first.append("&&");
+              db.subs.back().push_back(db.names[k]);
+            }
+            first = t;
+          }
+          break;
+        }
+        case 'P': {
+          size_t k0 = db.names.size();
+          t = parse_type(first + 1, last, db);
+          size_t k1 = db.names.size();
+          if (t != first + 1) {
+            db.subs.emplace_back(db.names.get_allocator());
+            for (size_t k = k0; k < k1; ++k) {
+              if (db.names[k].second.substr(0, 2) == " [") {
+                db.names[k].first += " (";
+                db.names[k].second.insert(0, ")");
+              } else if (!db.names[k].second.empty() &&
+                         db.names[k].second.front() == '(') {
+                db.names[k].first += "(";
+                db.names[k].second.insert(0, ")");
+              }
+              if (first[1] != 'U' ||
+                  db.names[k].first.substr(0, 12) != "objc_object<") {
+                db.names[k].first.append("*");
+              } else {
+                db.names[k].first.replace(0, 11, "id");
+              }
+              db.subs.back().push_back(db.names[k]);
+            }
+            first = t;
+          }
+          break;
+        }
+        case 'R': {
+          size_t k0 = db.names.size();
+          t = parse_type(first + 1, last, db);
+          size_t k1 = db.names.size();
+          if (t != first + 1) {
+            db.subs.emplace_back(db.names.get_allocator());
+            for (size_t k = k0; k < k1; ++k) {
+              if (db.names[k].second.substr(0, 2) == " [") {
+                db.names[k].first += " (";
+                db.names[k].second.insert(0, ")");
+              } else if (!db.names[k].second.empty() &&
+                         db.names[k].second.front() == '(') {
+                db.names[k].first += "(";
+                db.names[k].second.insert(0, ")");
+              }
+              db.names[k].first.append("&");
+              db.subs.back().push_back(db.names[k]);
+            }
+            first = t;
+          }
+          break;
+        }
+        case 'T': {
+          size_t k0 = db.names.size();
+          t = parse_template_param(first, last, db);
+          size_t k1 = db.names.size();
+          if (t != first) {
+            db.subs.emplace_back(db.names.get_allocator());
+            for (size_t k = k0; k < k1; ++k)
+              db.subs.back().push_back(db.names[k]);
+            if (db.try_to_parse_template_args && k1 == k0 + 1) {
+              const char *t1 = parse_template_args(t, last, db);
+              if (t1 != t) {
+                auto args = db.names.back().move_full();
+                db.names.pop_back();
+                db.names.back().first += std::move(args);
+                db.subs.push_back(typename C::sub_type(
+                    1, db.names.back(), db.names.get_allocator()));
+                t = t1;
+              }
+            }
+            first = t;
+          }
+          break;
+        }
+        case 'U':
+          if (first + 1 != last) {
+            t = parse_source_name(first + 1, last, db);
+            if (t != first + 1) {
+              const char *t2 = parse_type(t, last, db);
+              if (t2 != t) {
+                if (db.names.size() < 2)
+                  return first;
+                auto type = db.names.back().move_full();
+                db.names.pop_back();
+                if (db.names.back().first.substr(0, 9) != "objcproto") {
+                  db.names.back() = type + " " + db.names.back().move_full();
+                } else {
+                  auto proto = db.names.back().move_full();
+                  db.names.pop_back();
+                  t = parse_source_name(proto.data() + 9,
+                                        proto.data() + proto.size(), db);
+                  if (t != proto.data() + 9) {
+                    db.names.back() =
+                        type + "<" + db.names.back().move_full() + ">";
+                  } else {
+                    db.names.push_back(type + " " + proto);
+                  }
+                }
+                db.subs.push_back(typename C::sub_type(
+                    1, db.names.back(), db.names.get_allocator()));
+                first = t2;
+              }
+            }
+          }
+          break;
+        case 'S':
+          if (first + 1 != last && first[1] == 't') {
+            t = parse_name(first, last, db);
+            if (t != first) {
+              if (db.names.empty())
+                return first;
+              db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                     db.names.get_allocator()));
+              first = t;
+            }
+          } else {
+            t = parse_substitution(first, last, db);
+            if (t != first) {
+              first = t;
+              // Parsed a substitution.  If the substitution is a
+              //  <template-param> it might be followed by <template-args>.
+              t = parse_template_args(first, last, db);
+              if (t != first) {
+                if (db.names.size() < 2)
+                  return first;
+                auto template_args = db.names.back().move_full();
+                db.names.pop_back();
+                db.names.back().first += template_args;
+                // Need to create substitution for <template-template-param>
+                // <template-args>
+                db.subs.push_back(typename C::sub_type(
+                    1, db.names.back(), db.names.get_allocator()));
+                first = t;
+              }
+            }
+          }
+          break;
+        case 'D':
+          if (first + 1 != last) {
+            switch (first[1]) {
+            case 'p': {
+              size_t k0 = db.names.size();
+              t = parse_type(first + 2, last, db);
+              size_t k1 = db.names.size();
+              if (t != first + 2) {
+                db.subs.emplace_back(db.names.get_allocator());
+                for (size_t k = k0; k < k1; ++k)
+                  db.subs.back().push_back(db.names[k]);
+                first = t;
+                return first;
+              }
+              break;
+            }
+            case 't':
+            case 'T':
+              t = parse_decltype(first, last, db);
+              if (t != first) {
+                if (db.names.empty())
+                  return first;
+                db.subs.push_back(typename C::sub_type(
+                    1, db.names.back(), db.names.get_allocator()));
+                first = t;
+                return first;
+              }
+              break;
+            case 'v':
+              t = parse_vector_type(first, last, db);
+              if (t != first) {
+                if (db.names.empty())
+                  return first;
+                db.subs.push_back(typename C::sub_type(
+                    1, db.names.back(), db.names.get_allocator()));
+                first = t;
+                return first;
+              }
+              break;
+            }
+          }
+        // drop through
+        default:
+          // must check for builtin-types before class-enum-types to avoid
+          // ambiguities with operator-names
+          t = parse_builtin_type(first, last, db);
+          if (t != first) {
+            first = t;
+          } else {
+            t = parse_name(first, last, db);
+            if (t != first) {
+              if (db.names.empty())
+                return first;
+              db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                     db.names.get_allocator()));
+              first = t;
+            }
+          }
+          break;
+        }
+      }
+      break;
+    }
+    }
+  }
+  return first;
+}
+
+//   <operator-name>
+//                   ::= aa    # &&
+//                   ::= ad    # & (unary)
+//                   ::= an    # &
+//                   ::= aN    # &=
+//                   ::= aS    # =
+//                   ::= cl    # ()
+//                   ::= cm    # ,
+//                   ::= co    # ~
+//                   ::= cv <type>    # (cast)
+//                   ::= da    # delete[]
+//                   ::= de    # * (unary)
+//                   ::= dl    # delete
+//                   ::= dv    # /
+//                   ::= dV    # /=
+//                   ::= eo    # ^
+//                   ::= eO    # ^=
+//                   ::= eq    # ==
+//                   ::= ge    # >=
+//                   ::= gt    # >
+//                   ::= ix    # []
+//                   ::= le    # <=
+//                   ::= li <source-name>  # operator ""
+//                   ::= ls    # <<
+//                   ::= lS    # <<=
+//                   ::= lt    # <
+//                   ::= mi    # -
+//                   ::= mI    # -=
+//                   ::= ml    # *
+//                   ::= mL    # *=
+//                   ::= mm    # -- (postfix in <expression> context)
+//                   ::= na    # new[]
+//                   ::= ne    # !=
+//                   ::= ng    # - (unary)
+//                   ::= nt    # !
+//                   ::= nw    # new
+//                   ::= oo    # ||
+//                   ::= or    # |
+//                   ::= oR    # |=
+//                   ::= pm    # ->*
+//                   ::= pl    # +
+//                   ::= pL    # +=
+//                   ::= pp    # ++ (postfix in <expression> context)
+//                   ::= ps    # + (unary)
+//                   ::= pt    # ->
+//                   ::= qu    # ?
+//                   ::= rm    # %
+//                   ::= rM    # %=
+//                   ::= rs    # >>
+//                   ::= rS    # >>=
+//                   ::= v <digit> <source-name>        # vendor extended
+//                   operator
+
+template <class C>
+static const char *parse_operator_name(const char *first, const char *last,
+                                       C &db) {
+  if (last - first >= 2) {
+    switch (first[0]) {
+    case 'a':
+      switch (first[1]) {
+      case 'a':
+        db.names.push_back("operator&&");
+        first += 2;
+        break;
+      case 'd':
+      case 'n':
+        db.names.push_back("operator&");
+        first += 2;
+        break;
+      case 'N':
+        db.names.push_back("operator&=");
+        first += 2;
+        break;
+      case 'S':
+        db.names.push_back("operator=");
+        first += 2;
+        break;
+      }
+      break;
+    case 'c':
+      switch (first[1]) {
+      case 'l':
+        db.names.push_back("operator()");
+        first += 2;
+        break;
+      case 'm':
+        db.names.push_back("operator,");
+        first += 2;
+        break;
+      case 'o':
+        db.names.push_back("operator~");
+        first += 2;
+        break;
+      case 'v': {
+        bool try_to_parse_template_args = db.try_to_parse_template_args;
+        db.try_to_parse_template_args = false;
+        const char *t = parse_type(first + 2, last, db);
+        db.try_to_parse_template_args = try_to_parse_template_args;
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "operator ");
+          db.parsed_ctor_dtor_cv = true;
+          first = t;
+        }
+      } break;
+      }
+      break;
+    case 'd':
+      switch (first[1]) {
+      case 'a':
+        db.names.push_back("operator delete[]");
+        first += 2;
+        break;
+      case 'e':
+        db.names.push_back("operator*");
+        first += 2;
+        break;
+      case 'l':
+        db.names.push_back("operator delete");
+        first += 2;
+        break;
+      case 'v':
+        db.names.push_back("operator/");
+        first += 2;
+        break;
+      case 'V':
+        db.names.push_back("operator/=");
+        first += 2;
+        break;
+      }
+      break;
+    case 'e':
+      switch (first[1]) {
+      case 'o':
+        db.names.push_back("operator^");
+        first += 2;
+        break;
+      case 'O':
+        db.names.push_back("operator^=");
+        first += 2;
+        break;
+      case 'q':
+        db.names.push_back("operator==");
+        first += 2;
+        break;
+      }
+      break;
+    case 'g':
+      switch (first[1]) {
+      case 'e':
+        db.names.push_back("operator>=");
+        first += 2;
+        break;
+      case 't':
+        db.names.push_back("operator>");
+        first += 2;
+        break;
+      }
+      break;
+    case 'i':
+      if (first[1] == 'x') {
+        db.names.push_back("operator[]");
+        first += 2;
+      }
+      break;
+    case 'l':
+      switch (first[1]) {
+      case 'e':
+        db.names.push_back("operator<=");
+        first += 2;
+        break;
+      case 'i': {
+        const char *t = parse_source_name(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "operator\"\" ");
+          first = t;
+        }
+      } break;
+      case 's':
+        db.names.push_back("operator<<");
+        first += 2;
+        break;
+      case 'S':
+        db.names.push_back("operator<<=");
+        first += 2;
+        break;
+      case 't':
+        db.names.push_back("operator<");
+        first += 2;
+        break;
+      }
+      break;
+    case 'm':
+      switch (first[1]) {
+      case 'i':
+        db.names.push_back("operator-");
+        first += 2;
+        break;
+      case 'I':
+        db.names.push_back("operator-=");
+        first += 2;
+        break;
+      case 'l':
+        db.names.push_back("operator*");
+        first += 2;
+        break;
+      case 'L':
+        db.names.push_back("operator*=");
+        first += 2;
+        break;
+      case 'm':
+        db.names.push_back("operator--");
+        first += 2;
+        break;
+      }
+      break;
+    case 'n':
+      switch (first[1]) {
+      case 'a':
+        db.names.push_back("operator new[]");
+        first += 2;
+        break;
+      case 'e':
+        db.names.push_back("operator!=");
+        first += 2;
+        break;
+      case 'g':
+        db.names.push_back("operator-");
+        first += 2;
+        break;
+      case 't':
+        db.names.push_back("operator!");
+        first += 2;
+        break;
+      case 'w':
+        db.names.push_back("operator new");
+        first += 2;
+        break;
+      }
+      break;
+    case 'o':
+      switch (first[1]) {
+      case 'o':
+        db.names.push_back("operator||");
+        first += 2;
+        break;
+      case 'r':
+        db.names.push_back("operator|");
+        first += 2;
+        break;
+      case 'R':
+        db.names.push_back("operator|=");
+        first += 2;
+        break;
+      }
+      break;
+    case 'p':
+      switch (first[1]) {
+      case 'm':
+        db.names.push_back("operator->*");
+        first += 2;
+        break;
+      case 'l':
+        db.names.push_back("operator+");
+        first += 2;
+        break;
+      case 'L':
+        db.names.push_back("operator+=");
+        first += 2;
+        break;
+      case 'p':
+        db.names.push_back("operator++");
+        first += 2;
+        break;
+      case 's':
+        db.names.push_back("operator+");
+        first += 2;
+        break;
+      case 't':
+        db.names.push_back("operator->");
+        first += 2;
+        break;
+      }
+      break;
+    case 'q':
+      if (first[1] == 'u') {
+        db.names.push_back("operator?");
+        first += 2;
+      }
+      break;
+    case 'r':
+      switch (first[1]) {
+      case 'm':
+        db.names.push_back("operator%");
+        first += 2;
+        break;
+      case 'M':
+        db.names.push_back("operator%=");
+        first += 2;
+        break;
+      case 's':
+        db.names.push_back("operator>>");
+        first += 2;
+        break;
+      case 'S':
+        db.names.push_back("operator>>=");
+        first += 2;
+        break;
+      }
+      break;
+    case 'v':
+      if (std::isdigit(first[1])) {
+        const char *t = parse_source_name(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "operator ");
+          first = t;
+        }
+      }
+      break;
+    }
+  }
+  return first;
+}
+
+template <class C>
+static const char *parse_integer_literal(const char *first, const char *last,
+                                         const typename C::String &lit, C &db) {
+  const char *t = parse_number(first, last);
+  if (t != first && t != last && *t == 'E') {
+    if (lit.size() > 3)
+      db.names.push_back("(" + lit + ")");
+    else
+      db.names.emplace_back();
+    if (*first == 'n') {
+      db.names.back().first += '-';
+      ++first;
+    }
+    db.names.back().first.append(first, t);
+    if (lit.size() <= 3)
+      db.names.back().first += lit;
+    first = t + 1;
+  }
+  return first;
+}
+
+// <expr-primary> ::= L <type> <value number> E                          #
+// integer literal
+//                ::= L <type> <value float> E                           #
+//                floating literal
+//                ::= L <string type> E                                  #
+//                string literal
+//                ::= L <nullptr type> E                                 #
+//                nullptr literal (i.e., "LDnE")
+//                ::= L <type> <real-part float> _ <imag-part float> E   #
+//                complex floating point literal (C 2000)
+//                ::= L <mangled-name> E                                 #
+//                external name
+
+template <class C>
+static const char *parse_expr_primary(const char *first, const char *last,
+                                      C &db) {
+  if (last - first >= 4 && *first == 'L') {
+    switch (first[1]) {
+    case 'w': {
+      const char *t = parse_integer_literal(first + 2, last, "wchar_t", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'b':
+      if (first[3] == 'E') {
+        switch (first[2]) {
+        case '0':
+          db.names.push_back("false");
+          first += 4;
+          break;
+        case '1':
+          db.names.push_back("true");
+          first += 4;
+          break;
+        }
+      }
+      break;
+    case 'c': {
+      const char *t = parse_integer_literal(first + 2, last, "char", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'a': {
+      const char *t = parse_integer_literal(first + 2, last, "signed char", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'h': {
+      const char *t =
+          parse_integer_literal(first + 2, last, "unsigned char", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 's': {
+      const char *t = parse_integer_literal(first + 2, last, "short", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 't': {
+      const char *t =
+          parse_integer_literal(first + 2, last, "unsigned short", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'i': {
+      const char *t = parse_integer_literal(first + 2, last, "", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'j': {
+      const char *t = parse_integer_literal(first + 2, last, "u", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'l': {
+      const char *t = parse_integer_literal(first + 2, last, "l", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'm': {
+      const char *t = parse_integer_literal(first + 2, last, "ul", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'x': {
+      const char *t = parse_integer_literal(first + 2, last, "ll", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'y': {
+      const char *t = parse_integer_literal(first + 2, last, "ull", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'n': {
+      const char *t = parse_integer_literal(first + 2, last, "__int128", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'o': {
+      const char *t =
+          parse_integer_literal(first + 2, last, "unsigned __int128", db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'f': {
+      const char *t = parse_floating_number<float>(first + 2, last, db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'd': {
+      const char *t = parse_floating_number<double>(first + 2, last, db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case 'e': {
+      const char *t = parse_floating_number<long double>(first + 2, last, db);
+      if (t != first + 2)
+        first = t;
+    } break;
+    case '_':
+      if (first[2] == 'Z') {
+        const char *t = parse_encoding(first + 3, last, db);
+        if (t != first + 3 && t != last && *t == 'E')
+          first = t + 1;
+      }
+      break;
+    case 'T':
+      // Invalid mangled name per
+      //   http://sourcerytools.com/pipermail/cxx-abi-dev/2011-August/002422.html
+      break;
+    default: {
+      // might be named type
+      const char *t = parse_type(first + 1, last, db);
+      if (t != first + 1 && t != last) {
+        if (*t != 'E') {
+          const char *n = t;
+          for (; n != last && isdigit(*n); ++n)
+            ;
+          if (n != t && n != last && *n == 'E') {
+            if (db.names.empty())
+              return first;
+            db.names.back() = "(" + db.names.back().move_full() + ")" +
+                              typename C::String(t, n);
+            first = n + 1;
+            break;
+          }
+        } else {
+          first = t + 1;
+          break;
+        }
+      }
+    }
+    }
+  }
+  return first;
+}
+
+template <class String> static String base_name(String &s) {
+  if (s.empty())
+    return s;
+  if (s == "std::string") {
+    s = "std::basic_string<char, std::char_traits<char>, std::allocator<char> "
+        ">";
+    return "basic_string";
+  }
+  if (s == "std::istream") {
+    s = "std::basic_istream<char, std::char_traits<char> >";
+    return "basic_istream";
+  }
+  if (s == "std::ostream") {
+    s = "std::basic_ostream<char, std::char_traits<char> >";
+    return "basic_ostream";
+  }
+  if (s == "std::iostream") {
+    s = "std::basic_iostream<char, std::char_traits<char> >";
+    return "basic_iostream";
+  }
+  const char *const pf = s.data();
+  const char *pe = pf + s.size();
+  if (pe[-1] == '>') {
+    unsigned c = 1;
+    while (true) {
+      if (--pe == pf)
+        return String();
+      if (pe[-1] == '<') {
+        if (--c == 0) {
+          --pe;
+          break;
+        }
+      } else if (pe[-1] == '>')
+        ++c;
+    }
+  }
+  if (pe - pf <= 1)
+    return String();
+  const char *p0 = pe - 1;
+  for (; p0 != pf; --p0) {
+    if (*p0 == ':') {
+      ++p0;
+      break;
+    }
+  }
+  return String(p0, pe);
+}
+
+// <ctor-dtor-name> ::= C1    # complete object constructor
+//                  ::= C2    # base object constructor
+//                  ::= C3    # complete object allocating constructor
+//   extension      ::= C5    # ?
+//                  ::= D0    # deleting destructor
+//                  ::= D1    # complete object destructor
+//                  ::= D2    # base object destructor
+//   extension      ::= D5    # ?
+
+template <class C>
+static const char *parse_ctor_dtor_name(const char *first, const char *last,
+                                        C &db) {
+  if (last - first >= 2 && !db.names.empty()) {
+    switch (first[0]) {
+    case 'C':
+      switch (first[1]) {
+      case '1':
+      case '2':
+      case '3':
+      case '5':
+        if (db.names.empty())
+          return first;
+        db.names.push_back(base_name(db.names.back().first));
+        first += 2;
+        db.parsed_ctor_dtor_cv = true;
+        break;
+      }
+      break;
+    case 'D':
+      switch (first[1]) {
+      case '0':
+      case '1':
+      case '2':
+      case '5':
+        if (db.names.empty())
+          return first;
+        db.names.push_back("~" + base_name(db.names.back().first));
+        first += 2;
+        db.parsed_ctor_dtor_cv = true;
+        break;
+      }
+      break;
+    }
+  }
+  return first;
+}
+
+// <unnamed-type-name> ::= Ut [ <nonnegative number> ] _
+//                     ::= <closure-type-name>
+//
+// <closure-type-name> ::= Ul <lambda-sig> E [ <nonnegative number> ] _
+//
+// <lambda-sig> ::= <parameter type>+  # Parameter types or "v" if the lambda
+// has no parameters
+
+template <class C>
+static const char *parse_unnamed_type_name(const char *first, const char *last,
+                                           C &db) {
+  if (last - first > 2 && first[0] == 'U') {
+    char type = first[1];
+    switch (type) {
+    case 't': {
+      db.names.push_back(typename C::String("'unnamed"));
+      const char *t0 = first + 2;
+      if (t0 == last) {
+        db.names.pop_back();
+        return first;
+      }
+      if (std::isdigit(*t0)) {
+        const char *t1 = t0 + 1;
+        while (t1 != last && std::isdigit(*t1))
+          ++t1;
+        db.names.back().first.append(t0, t1);
+        t0 = t1;
+      }
+      db.names.back().first.push_back('\'');
+      if (t0 == last || *t0 != '_') {
+        db.names.pop_back();
+        return first;
+      }
+      first = t0 + 1;
+    } break;
+    case 'l': {
+      db.names.push_back(typename C::String("'lambda'("));
+      const char *t0 = first + 2;
+      if (first[2] == 'v') {
+        db.names.back().first += ')';
+        ++t0;
+      } else {
+        const char *t1 = parse_type(t0, last, db);
+        if (t1 == t0) {
+          if (!db.names.empty())
+            db.names.pop_back();
+          return first;
+        }
+        if (db.names.size() < 2)
+          return first;
+        auto tmp = db.names.back().move_full();
+        db.names.pop_back();
+        db.names.back().first.append(tmp);
+        t0 = t1;
+        while (true) {
+          t1 = parse_type(t0, last, db);
+          if (t1 == t0)
+            break;
+          if (db.names.size() < 2)
+            return first;
+          tmp = db.names.back().move_full();
+          db.names.pop_back();
+          if (!tmp.empty()) {
+            db.names.back().first.append(", ");
+            db.names.back().first.append(tmp);
+          }
+          t0 = t1;
+        }
+        if (db.names.empty())
+          return first;
+        db.names.back().first.append(")");
+      }
+      if (t0 == last || *t0 != 'E') {
+        if (!db.names.empty())
+          db.names.pop_back();
+        return first;
+      }
+      ++t0;
+      if (t0 == last) {
+        if (!db.names.empty())
+          db.names.pop_back();
+        return first;
+      }
+      if (std::isdigit(*t0)) {
+        const char *t1 = t0 + 1;
+        while (t1 != last && std::isdigit(*t1))
+          ++t1;
+        db.names.back().first.insert(db.names.back().first.begin() + 7, t0, t1);
+        t0 = t1;
+      }
+      if (t0 == last || *t0 != '_') {
+        if (!db.names.empty())
+          db.names.pop_back();
+        return first;
+      }
+      first = t0 + 1;
+    } break;
+    }
+  }
+  return first;
+}
+
+// <unqualified-name> ::= <operator-name>
+//                    ::= <ctor-dtor-name>
+//                    ::= <source-name>
+//                    ::= <unnamed-type-name>
+
+template <class C>
+static const char *parse_unqualified_name(const char *first, const char *last,
+                                          C &db) {
+  if (first != last) {
+    const char *t;
+    switch (*first) {
+    case 'C':
+    case 'D':
+      t = parse_ctor_dtor_name(first, last, db);
+      if (t != first)
+        first = t;
+      break;
+    case 'U':
+      t = parse_unnamed_type_name(first, last, db);
+      if (t != first)
+        first = t;
+      break;
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9':
+      t = parse_source_name(first, last, db);
+      if (t != first)
+        first = t;
+      break;
+    default:
+      t = parse_operator_name(first, last, db);
+      if (t != first)
+        first = t;
+      break;
+    };
+  }
+  return first;
+}
+
+// <unscoped-name> ::= <unqualified-name>
+//                 ::= St <unqualified-name>   # ::std::
+// extension       ::= StL<unqualified-name>
+
+template <class C>
+static const char *parse_unscoped_name(const char *first, const char *last,
+                                       C &db) {
+  if (last - first >= 2) {
+    const char *t0 = first;
+    bool St = false;
+    if (first[0] == 'S' && first[1] == 't') {
+      t0 += 2;
+      St = true;
+      if (t0 != last && *t0 == 'L')
+        ++t0;
+    }
+    const char *t1 = parse_unqualified_name(t0, last, db);
+    if (t1 != t0) {
+      if (St) {
+        if (db.names.empty())
+          return first;
+        db.names.back().first.insert(0, "std::");
+      }
+      first = t1;
+    }
+  }
+  return first;
+}
+
+// at <type>                                            # alignof (a type)
+
+template <class C>
+static const char *parse_alignof_type(const char *first, const char *last,
+                                      C &db) {
+  if (last - first >= 3 && first[0] == 'a' && first[1] == 't') {
+    const char *t = parse_type(first + 2, last, db);
+    if (t != first + 2) {
+      if (db.names.empty())
+        return first;
+      db.names.back().first = "alignof (" + db.names.back().move_full() + ")";
+      first = t;
+    }
+  }
+  return first;
+}
+
+// az <expression>                                            # alignof (a
+// expression)
+
+template <class C>
+static const char *parse_alignof_expr(const char *first, const char *last,
+                                      C &db) {
+  if (last - first >= 3 && first[0] == 'a' && first[1] == 'z') {
+    const char *t = parse_expression(first + 2, last, db);
+    if (t != first + 2) {
+      if (db.names.empty())
+        return first;
+      db.names.back().first = "alignof (" + db.names.back().move_full() + ")";
+      first = t;
+    }
+  }
+  return first;
+}
+
+template <class C>
+static const char *parse_noexcept_expression(const char *first,
+                                             const char *last, C &db) {
+  const char *t1 = parse_expression(first, last, db);
+  if (t1 != first) {
+    if (db.names.empty())
+      return first;
+    db.names.back().first = "noexcept (" + db.names.back().move_full() + ")";
+    first = t1;
+  }
+  return first;
+}
+
+template <class C>
+static const char *parse_prefix_expression(const char *first, const char *last,
+                                           const typename C::String &op,
+                                           C &db) {
+  const char *t1 = parse_expression(first, last, db);
+  if (t1 != first) {
+    if (db.names.empty())
+      return first;
+    db.names.back().first = op + "(" + db.names.back().move_full() + ")";
+    first = t1;
+  }
+  return first;
+}
+
+template <class C>
+static const char *parse_binary_expression(const char *first, const char *last,
+                                           const typename C::String &op,
+                                           C &db) {
+  const char *t1 = parse_expression(first, last, db);
+  if (t1 != first) {
+    const char *t2 = parse_expression(t1, last, db);
+    if (t2 != t1) {
+      if (db.names.size() < 2)
+        return first;
+      auto op2 = db.names.back().move_full();
+      db.names.pop_back();
+      auto op1 = db.names.back().move_full();
+      auto &nm = db.names.back().first;
+      nm.clear();
+      if (op == ">")
+        nm += '(';
+      nm += "(" + op1 + ") " + op + " (" + op2 + ")";
+      if (op == ">")
+        nm += ')';
+      first = t2;
+    } else if (!db.names.empty())
+      db.names.pop_back();
+  }
+  return first;
+}
+
+// <expression> ::= <unary operator-name> <expression>
+//              ::= <binary operator-name> <expression> <expression>
+//              ::= <ternary operator-name> <expression> <expression>
+//              <expression>
+//              ::= cl <expression>+ E                                   # call
+//              ::= cv <type> <expression>                               #
+//              conversion with one argument
+//              ::= cv <type> _ <expression>* E                          #
+//              conversion with a different number of arguments
+//              ::= [gs] nw <expression>* _ <type> E                     # new
+//              (expr-list) type
+//              ::= [gs] nw <expression>* _ <type> <initializer>         # new
+//              (expr-list) type (init)
+//              ::= [gs] na <expression>* _ <type> E                     # new[]
+//              (expr-list) type
+//              ::= [gs] na <expression>* _ <type> <initializer>         # new[]
+//              (expr-list) type (init)
+//              ::= [gs] dl <expression>                                 #
+//              delete expression
+//              ::= [gs] da <expression>                                 #
+//              delete[] expression
+//              ::= pp_ <expression>                                     #
+//              prefix ++
+//              ::= mm_ <expression>                                     #
+//              prefix --
+//              ::= ti <type>                                            #
+//              typeid (type)
+//              ::= te <expression>                                      #
+//              typeid (expression)
+//              ::= dc <type> <expression>                               #
+//              dynamic_cast<type> (expression)
+//              ::= sc <type> <expression>                               #
+//              static_cast<type> (expression)
+//              ::= cc <type> <expression>                               #
+//              const_cast<type> (expression)
+//              ::= rc <type> <expression>                               #
+//              reinterpret_cast<type> (expression)
+//              ::= st <type>                                            #
+//              sizeof (a type)
+//              ::= sz <expression>                                      #
+//              sizeof (an expression)
+//              ::= at <type>                                            #
+//              alignof (a type)
+//              ::= az <expression>                                      #
+//              alignof (an expression)
+//              ::= nx <expression>                                      #
+//              noexcept (expression)
+//              ::= <template-param>
+//              ::= <function-param>
+//              ::= dt <expression> <unresolved-name>                    #
+//              expr.name
+//              ::= pt <expression> <unresolved-name>                    #
+//              expr->name
+//              ::= ds <expression> <expression>                         #
+//              expr.*expr
+//              ::= sZ <template-param>                                  # size
+//              of a parameter pack
+//              ::= sZ <function-param>                                  # size
+//              of a function parameter pack
+//              ::= sp <expression>                                      # pack
+//              expansion
+//              ::= tw <expression>                                      # throw
+//              expression
+//              ::= tr                                                   # throw
+//              with no operand (rethrow)
+//              ::= <unresolved-name>                                    # f(p),
+//              N::f(p), ::f(p),
+//                                                                       #
+//                                                                       freestanding
+//                                                                       dependent
+//                                                                       name
+//                                                                       (e.g.,
+//                                                                       T::x),
+//                                                                       #
+//                                                                       objectless
+//                                                                       nonstatic
+//                                                                       member
+//                                                                       reference
+//              ::= <expr-primary>
+
+template <class C>
+static const char *parse_expression(const char *first, const char *last,
+                                    C &db) {
+  if (last - first >= 2) {
+    const char *t = first;
+    bool parsed_gs = false;
+    if (last - first >= 4 && t[0] == 'g' && t[1] == 's') {
+      t += 2;
+      parsed_gs = true;
+    }
+    switch (*t) {
+    case 'L':
+      first = parse_expr_primary(first, last, db);
+      break;
+    case 'T':
+      first = parse_template_param(first, last, db);
+      break;
+    case 'f':
+      first = parse_function_param(first, last, db);
+      break;
+    case 'a':
+      switch (t[1]) {
+      case 'a':
+        t = parse_binary_expression(first + 2, last, "&&", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'd':
+        t = parse_prefix_expression(first + 2, last, "&", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'n':
+        t = parse_binary_expression(first + 2, last, "&", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'N':
+        t = parse_binary_expression(first + 2, last, "&=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'S':
+        t = parse_binary_expression(first + 2, last, "=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 't':
+        first = parse_alignof_type(first, last, db);
+        break;
+      case 'z':
+        first = parse_alignof_expr(first, last, db);
+        break;
+      }
+      break;
+    case 'c':
+      switch (t[1]) {
+      case 'c':
+        first = parse_const_cast_expr(first, last, db);
+        break;
+      case 'l':
+        first = parse_call_expr(first, last, db);
+        break;
+      case 'm':
+        t = parse_binary_expression(first + 2, last, ",", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'o':
+        t = parse_prefix_expression(first + 2, last, "~", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'v':
+        first = parse_conversion_expr(first, last, db);
+        break;
+      }
+      break;
+    case 'd':
+      switch (t[1]) {
+      case 'a': {
+        const char *t1 = parse_expression(t + 2, last, db);
+        if (t1 != t + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first =
+              (parsed_gs ? typename C::String("::") : typename C::String()) +
+              "delete[] " + db.names.back().move_full();
+          first = t1;
+        }
+      } break;
+      case 'c':
+        first = parse_dynamic_cast_expr(first, last, db);
+        break;
+      case 'e':
+        t = parse_prefix_expression(first + 2, last, "*", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'l': {
+        const char *t1 = parse_expression(t + 2, last, db);
+        if (t1 != t + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first =
+              (parsed_gs ? typename C::String("::") : typename C::String()) +
+              "delete " + db.names.back().move_full();
+          first = t1;
+        }
+      } break;
+      case 'n':
+        return parse_unresolved_name(first, last, db);
+      case 's':
+        first = parse_dot_star_expr(first, last, db);
+        break;
+      case 't':
+        first = parse_dot_expr(first, last, db);
+        break;
+      case 'v':
+        t = parse_binary_expression(first + 2, last, "/", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'V':
+        t = parse_binary_expression(first + 2, last, "/=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      }
+      break;
+    case 'e':
+      switch (t[1]) {
+      case 'o':
+        t = parse_binary_expression(first + 2, last, "^", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'O':
+        t = parse_binary_expression(first + 2, last, "^=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'q':
+        t = parse_binary_expression(first + 2, last, "==", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      }
+      break;
+    case 'g':
+      switch (t[1]) {
+      case 'e':
+        t = parse_binary_expression(first + 2, last, ">=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 't':
+        t = parse_binary_expression(first + 2, last, ">", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      }
+      break;
+    case 'i':
+      if (t[1] == 'x') {
+        const char *t1 = parse_expression(first + 2, last, db);
+        if (t1 != first + 2) {
+          const char *t2 = parse_expression(t1, last, db);
+          if (t2 != t1) {
+            if (db.names.size() < 2)
+              return first;
+            auto op2 = db.names.back().move_full();
+            db.names.pop_back();
+            auto op1 = db.names.back().move_full();
+            db.names.back() = "(" + op1 + ")[" + op2 + "]";
+            first = t2;
+          } else if (!db.names.empty())
+            db.names.pop_back();
+        }
+      }
+      break;
+    case 'l':
+      switch (t[1]) {
+      case 'e':
+        t = parse_binary_expression(first + 2, last, "<=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 's':
+        t = parse_binary_expression(first + 2, last, "<<", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'S':
+        t = parse_binary_expression(first + 2, last, "<<=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 't':
+        t = parse_binary_expression(first + 2, last, "<", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      }
+      break;
+    case 'm':
+      switch (t[1]) {
+      case 'i':
+        t = parse_binary_expression(first + 2, last, "-", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'I':
+        t = parse_binary_expression(first + 2, last, "-=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'l':
+        t = parse_binary_expression(first + 2, last, "*", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'L':
+        t = parse_binary_expression(first + 2, last, "*=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'm':
+        if (first + 2 != last && first[2] == '_') {
+          t = parse_prefix_expression(first + 3, last, "--", db);
+          if (t != first + 3)
+            first = t;
+        } else {
+          const char *t1 = parse_expression(first + 2, last, db);
+          if (t1 != first + 2) {
+            if (db.names.empty())
+              return first;
+            db.names.back() = "(" + db.names.back().move_full() + ")--";
+            first = t1;
+          }
+        }
+        break;
+      }
+      break;
+    case 'n':
+      switch (t[1]) {
+      case 'a':
+      case 'w':
+        first = parse_new_expr(first, last, db);
+        break;
+      case 'e':
+        t = parse_binary_expression(first + 2, last, "!=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'g':
+        t = parse_prefix_expression(first + 2, last, "-", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 't':
+        t = parse_prefix_expression(first + 2, last, "!", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'x':
+        t = parse_noexcept_expression(first + 2, last, db);
+        if (t != first + 2)
+          first = t;
+        break;
+      }
+      break;
+    case 'o':
+      switch (t[1]) {
+      case 'n':
+        return parse_unresolved_name(first, last, db);
+      case 'o':
+        t = parse_binary_expression(first + 2, last, "||", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'r':
+        t = parse_binary_expression(first + 2, last, "|", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'R':
+        t = parse_binary_expression(first + 2, last, "|=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      }
+      break;
+    case 'p':
+      switch (t[1]) {
+      case 'm':
+        t = parse_binary_expression(first + 2, last, "->*", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'l':
+        t = parse_binary_expression(first + 2, last, "+", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'L':
+        t = parse_binary_expression(first + 2, last, "+=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'p':
+        if (first + 2 != last && first[2] == '_') {
+          t = parse_prefix_expression(first + 3, last, "++", db);
+          if (t != first + 3)
+            first = t;
+        } else {
+          const char *t1 = parse_expression(first + 2, last, db);
+          if (t1 != first + 2) {
+            if (db.names.empty())
+              return first;
+            db.names.back() = "(" + db.names.back().move_full() + ")++";
+            first = t1;
+          }
+        }
+        break;
+      case 's':
+        t = parse_prefix_expression(first + 2, last, "+", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 't':
+        first = parse_arrow_expr(first, last, db);
+        break;
+      }
+      break;
+    case 'q':
+      if (t[1] == 'u') {
+        const char *t1 = parse_expression(first + 2, last, db);
+        if (t1 != first + 2) {
+          const char *t2 = parse_expression(t1, last, db);
+          if (t2 != t1) {
+            const char *t3 = parse_expression(t2, last, db);
+            if (t3 != t2) {
+              if (db.names.size() < 3)
+                return first;
+              auto op3 = db.names.back().move_full();
+              db.names.pop_back();
+              auto op2 = db.names.back().move_full();
+              db.names.pop_back();
+              auto op1 = db.names.back().move_full();
+              db.names.back() = "(" + op1 + ") ? (" + op2 + ") : (" + op3 + ")";
+              first = t3;
+            } else {
+              if (db.names.size() < 2)
+                return first;
+              db.names.pop_back();
+              db.names.pop_back();
+            }
+          } else if (!db.names.empty())
+            db.names.pop_back();
+        }
+      }
+      break;
+    case 'r':
+      switch (t[1]) {
+      case 'c':
+        first = parse_reinterpret_cast_expr(first, last, db);
+        break;
+      case 'm':
+        t = parse_binary_expression(first + 2, last, "%", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'M':
+        t = parse_binary_expression(first + 2, last, "%=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 's':
+        t = parse_binary_expression(first + 2, last, ">>", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      case 'S':
+        t = parse_binary_expression(first + 2, last, ">>=", db);
+        if (t != first + 2)
+          first = t;
+        break;
+      }
+      break;
+    case 's':
+      switch (t[1]) {
+      case 'c':
+        first = parse_static_cast_expr(first, last, db);
+        break;
+      case 'p':
+        first = parse_pack_expansion(first, last, db);
+        break;
+      case 'r':
+        return parse_unresolved_name(first, last, db);
+      case 't':
+        first = parse_sizeof_type_expr(first, last, db);
+        break;
+      case 'z':
+        first = parse_sizeof_expr_expr(first, last, db);
+        break;
+      case 'Z':
+        if (last - t >= 3) {
+          switch (t[2]) {
+          case 'T':
+            first = parse_sizeof_param_pack_expr(first, last, db);
+            break;
+          case 'f':
+            first = parse_sizeof_function_param_pack_expr(first, last, db);
+            break;
+          }
+        }
+        break;
+      }
+      break;
+    case 't':
+      switch (t[1]) {
+      case 'e':
+      case 'i':
+        first = parse_typeid_expr(first, last, db);
+        break;
+      case 'r':
+        db.names.push_back("throw");
+        first += 2;
+        break;
+      case 'w':
+        first = parse_throw_expr(first, last, db);
+        break;
+      }
+      break;
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9':
+      return parse_unresolved_name(first, last, db);
+    }
+  }
+  return first;
+}
+
+// <template-arg> ::= <type>                                             # type
+// or template
+//                ::= X <expression> E                                   #
+//                expression
+//                ::= <expr-primary>                                     #
+//                simple expressions
+//                ::= J <template-arg>* E                                #
+//                argument pack
+//                ::= LZ <encoding> E                                    #
+//                extension
+
+template <class C>
+static const char *parse_template_arg(const char *first, const char *last,
+                                      C &db) {
+  if (first != last) {
+    const char *t;
+    switch (*first) {
+    case 'X':
+      t = parse_expression(first + 1, last, db);
+      if (t != first + 1) {
+        if (t != last && *t == 'E')
+          first = t + 1;
+      }
+      break;
+    case 'J':
+      t = first + 1;
+      if (t == last)
+        return first;
+      while (*t != 'E') {
+        const char *t1 = parse_template_arg(t, last, db);
+        if (t1 == t)
+          return first;
+        t = t1;
+      }
+      first = t + 1;
+      break;
+    case 'L':
+      // <expr-primary> or LZ <encoding> E
+      if (first + 1 != last && first[1] == 'Z') {
+        t = parse_encoding(first + 2, last, db);
+        if (t != first + 2 && t != last && *t == 'E')
+          first = t + 1;
+      } else
+        first = parse_expr_primary(first, last, db);
+      break;
+    default:
+      // <type>
+      first = parse_type(first, last, db);
+      break;
+    }
+  }
+  return first;
+}
+
+// <template-args> ::= I <template-arg>* E
+//     extension, the abi says <template-arg>+
+
+template <class C>
+static const char *parse_template_args(const char *first, const char *last,
+                                       C &db) {
+  if (last - first >= 2 && *first == 'I') {
+    if (db.tag_templates)
+      db.template_param.back().clear();
+    const char *t = first + 1;
+    typename C::String args("<");
+    while (*t != 'E') {
+      if (db.tag_templates)
+        db.template_param.emplace_back(db.names.get_allocator());
+      size_t k0 = db.names.size();
+      const char *t1 = parse_template_arg(t, last, db);
+      size_t k1 = db.names.size();
+      if (db.tag_templates)
+        db.template_param.pop_back();
+      if (t1 == t || t1 == last)
+        return first;
+      if (db.tag_templates) {
+        db.template_param.back().emplace_back(db.names.get_allocator());
+        for (size_t k = k0; k < k1; ++k)
+          db.template_param.back().back().push_back(db.names[k]);
+      }
+      for (size_t k = k0; k < k1; ++k) {
+        if (args.size() > 1)
+          args += ", ";
+        args += db.names[k].move_full();
+      }
+      for (; k1 > k0; --k1)
+        if (!db.names.empty())
+          db.names.pop_back();
+      t = t1;
+    }
+    first = t + 1;
+    if (args.back() != '>')
+      args += ">";
+    else
+      args += " >";
+    db.names.push_back(std::move(args));
+  }
+  return first;
+}
+
+// <nested-name> ::= N [<CV-qualifiers>] [<ref-qualifier>] <prefix>
+// <unqualified-name> E
+//               ::= N [<CV-qualifiers>] [<ref-qualifier>] <template-prefix>
+//               <template-args> E
+//
+// <prefix> ::= <prefix> <unqualified-name>
+//          ::= <template-prefix> <template-args>
+//          ::= <template-param>
+//          ::= <decltype>
+//          ::= # empty
+//          ::= <substitution>
+//          ::= <prefix> <data-member-prefix>
+//  extension ::= L
+//
+// <template-prefix> ::= <prefix> <template unqualified-name>
+//                   ::= <template-param>
+//                   ::= <substitution>
+
+template <class C>
+static const char *parse_nested_name(const char *first, const char *last, C &db,
+                                     bool *ends_with_template_args) {
+  if (first != last && *first == 'N') {
+    unsigned cv;
+    const char *t0 = parse_cv_qualifiers(first + 1, last, cv);
+    if (t0 == last)
+      return first;
+    db.ref = 0;
+    if (*t0 == 'R') {
+      db.ref = 1;
+      ++t0;
+    } else if (*t0 == 'O') {
+      db.ref = 2;
+      ++t0;
+    }
+    db.names.emplace_back();
+    if (last - t0 >= 2 && t0[0] == 'S' && t0[1] == 't') {
+      t0 += 2;
+      db.names.back().first = "std";
+    }
+    if (t0 == last) {
+      db.names.pop_back();
+      return first;
+    }
+    bool pop_subs = false;
+    bool component_ends_with_template_args = false;
+    while (*t0 != 'E') {
+      component_ends_with_template_args = false;
+      const char *t1;
+      switch (*t0) {
+      case 'S':
+        if (t0 + 1 != last && t0[1] == 't')
+          goto do_parse_unqualified_name;
+        t1 = parse_substitution(t0, last, db);
+        if (t1 != t0 && t1 != last) {
+          auto name = db.names.back().move_full();
+          db.names.pop_back();
+          if (db.names.empty())
+            return first;
+          if (!db.names.back().first.empty()) {
+            db.names.back().first += "::" + name;
+            db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                   db.names.get_allocator()));
+          } else
+            db.names.back().first = name;
+          pop_subs = true;
+          t0 = t1;
+        } else
+          return first;
+        break;
+      case 'T':
+        t1 = parse_template_param(t0, last, db);
+        if (t1 != t0 && t1 != last) {
+          auto name = db.names.back().move_full();
+          db.names.pop_back();
+          if (db.names.empty())
+            return first;
+          if (!db.names.back().first.empty())
+            db.names.back().first += "::" + name;
+          else
+            db.names.back().first = name;
+          db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                 db.names.get_allocator()));
+          pop_subs = true;
+          t0 = t1;
+        } else
+          return first;
+        break;
+      case 'D':
+        if (t0 + 1 != last && t0[1] != 't' && t0[1] != 'T')
+          goto do_parse_unqualified_name;
+        t1 = parse_decltype(t0, last, db);
+        if (t1 != t0 && t1 != last) {
+          auto name = db.names.back().move_full();
+          db.names.pop_back();
+          if (db.names.empty())
+            return first;
+          if (!db.names.back().first.empty())
+            db.names.back().first += "::" + name;
+          else
+            db.names.back().first = name;
+          db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                 db.names.get_allocator()));
+          pop_subs = true;
+          t0 = t1;
+        } else
+          return first;
+        break;
+      case 'I':
+        t1 = parse_template_args(t0, last, db);
+        if (t1 != t0 && t1 != last) {
+          auto name = db.names.back().move_full();
+          db.names.pop_back();
+          if (db.names.empty())
+            return first;
+          db.names.back().first += name;
+          db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                 db.names.get_allocator()));
+          t0 = t1;
+          component_ends_with_template_args = true;
+        } else
+          return first;
+        break;
+      case 'L':
+        if (++t0 == last)
+          return first;
+        break;
+      default:
+      do_parse_unqualified_name:
+        t1 = parse_unqualified_name(t0, last, db);
+        if (t1 != t0 && t1 != last) {
+          auto name = db.names.back().move_full();
+          db.names.pop_back();
+          if (db.names.empty())
+            return first;
+          if (!db.names.back().first.empty())
+            db.names.back().first += "::" + name;
+          else
+            db.names.back().first = name;
+          db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                 db.names.get_allocator()));
+          pop_subs = true;
+          t0 = t1;
+        } else
+          return first;
+      }
+    }
+    first = t0 + 1;
+    db.cv = cv;
+    if (pop_subs && !db.subs.empty())
+      db.subs.pop_back();
+    if (ends_with_template_args)
+      *ends_with_template_args = component_ends_with_template_args;
+  }
+  return first;
+}
+
+// <discriminator> := _ <non-negative number>      # when number < 10
+//                 := __ <non-negative number> _   # when number >= 10
+//  extension      := decimal-digit+               # at the end of string
+
+static const char *parse_discriminator(const char *first, const char *last) {
+  // parse but ignore discriminator
+  if (first != last) {
+    if (*first == '_') {
+      const char *t1 = first + 1;
+      if (t1 != last) {
+        if (std::isdigit(*t1))
+          first = t1 + 1;
+        else if (*t1 == '_') {
+          for (++t1; t1 != last && std::isdigit(*t1); ++t1)
+            ;
+          if (t1 != last && *t1 == '_')
+            first = t1 + 1;
+        }
+      }
+    } else if (std::isdigit(*first)) {
+      const char *t1 = first + 1;
+      for (; t1 != last && std::isdigit(*t1); ++t1)
+        ;
+      if (t1 == last)
+        first = last;
+    }
+  }
+  return first;
+}
+
+// <local-name> := Z <function encoding> E <entity name> [<discriminator>]
+//              := Z <function encoding> E s [<discriminator>]
+//              := Z <function encoding> Ed [ <parameter number> ] _ <entity
+//              name>
+
+template <class C>
+static const char *parse_local_name(const char *first, const char *last, C &db,
+                                    bool *ends_with_template_args) {
+  if (first != last && *first == 'Z') {
+    const char *t = parse_encoding(first + 1, last, db);
+    if (t != first + 1 && t != last && *t == 'E' && ++t != last) {
+      switch (*t) {
+      case 's':
+        first = parse_discriminator(t + 1, last);
+        if (db.names.empty())
+          return first;
+        db.names.back().first.append("::string literal");
+        break;
+      case 'd':
+        if (++t != last) {
+          const char *t1 = parse_number(t, last);
+          if (t1 != last && *t1 == '_') {
+            t = t1 + 1;
+            t1 = parse_name(t, last, db, ends_with_template_args);
+            if (t1 != t) {
+              if (db.names.size() < 2)
+                return first;
+              auto name = db.names.back().move_full();
+              db.names.pop_back();
+              if (db.names.empty())
+                return first;
+              db.names.back().first.append("::");
+              db.names.back().first.append(name);
+              first = t1;
+            } else if (!db.names.empty())
+              db.names.pop_back();
+          }
+        }
+        break;
+      default: {
+        const char *t1 = parse_name(t, last, db, ends_with_template_args);
+        if (t1 != t) {
+          // parse but ignore discriminator
+          first = parse_discriminator(t1, last);
+          if (db.names.size() < 2)
+            return first;
+          auto name = db.names.back().move_full();
+          db.names.pop_back();
+          if (db.names.empty())
+            return first;
+          db.names.back().first.append("::");
+          db.names.back().first.append(name);
+        } else if (!db.names.empty())
+          db.names.pop_back();
+      } break;
+      }
+    }
+  }
+  return first;
+}
+
+// <name> ::= <nested-name> // N
+//        ::= <local-name> # See Scope Encoding below  // Z
+//        ::= <unscoped-template-name> <template-args>
+//        ::= <unscoped-name>
+
+// <unscoped-template-name> ::= <unscoped-name>
+//                          ::= <substitution>
+
+template <class C>
+static const char *parse_name(const char *first, const char *last, C &db,
+                              bool *ends_with_template_args) {
+  if (last - first >= 2) {
+    const char *t0 = first;
+    // extension: ignore L here
+    if (*t0 == 'L')
+      ++t0;
+    switch (*t0) {
+    case 'N': {
+      const char *t1 = parse_nested_name(t0, last, db, ends_with_template_args);
+      if (t1 != t0)
+        first = t1;
+      break;
+    }
+    case 'Z': {
+      const char *t1 = parse_local_name(t0, last, db, ends_with_template_args);
+      if (t1 != t0)
+        first = t1;
+      break;
+    }
+    default: {
+      const char *t1 = parse_unscoped_name(t0, last, db);
+      if (t1 != t0) {
+        if (t1 != last &&
+            *t1 == 'I') // <unscoped-template-name> <template-args>
+        {
+          if (db.names.empty())
+            return first;
+          db.subs.push_back(typename C::sub_type(1, db.names.back(),
+                                                 db.names.get_allocator()));
+          t0 = t1;
+          t1 = parse_template_args(t0, last, db);
+          if (t1 != t0) {
+            if (db.names.size() < 2)
+              return first;
+            auto tmp = db.names.back().move_full();
+            db.names.pop_back();
+            if (db.names.empty())
+              return first;
+            db.names.back().first += tmp;
+            first = t1;
+            if (ends_with_template_args)
+              *ends_with_template_args = true;
+          }
+        } else // <unscoped-name>
+          first = t1;
+      } else { // try <substitution> <template-args>
+        t1 = parse_substitution(t0, last, db);
+        if (t1 != t0 && t1 != last && *t1 == 'I') {
+          t0 = t1;
+          t1 = parse_template_args(t0, last, db);
+          if (t1 != t0) {
+            if (db.names.size() < 2)
+              return first;
+            auto tmp = db.names.back().move_full();
+            db.names.pop_back();
+            if (db.names.empty())
+              return first;
+            db.names.back().first += tmp;
+            first = t1;
+            if (ends_with_template_args)
+              *ends_with_template_args = true;
+          }
+        }
+      }
+      break;
+    }
+    }
+  }
+  return first;
+}
+
+// <call-offset> ::= h <nv-offset> _
+//               ::= v <v-offset> _
+//
+// <nv-offset> ::= <offset number>
+//               # non-virtual base override
+//
+// <v-offset>  ::= <offset number> _ <virtual offset number>
+//               # virtual base override, with vcall offset
+
+static const char *parse_call_offset(const char *first, const char *last) {
+  if (first != last) {
+    switch (*first) {
+    case 'h': {
+      const char *t = parse_number(first + 1, last);
+      if (t != first + 1 && t != last && *t == '_')
+        first = t + 1;
+    } break;
+    case 'v': {
+      const char *t = parse_number(first + 1, last);
+      if (t != first + 1 && t != last && *t == '_') {
+        const char *t2 = parse_number(++t, last);
+        if (t2 != t && t2 != last && *t2 == '_')
+          first = t2 + 1;
+      }
+    } break;
+    }
+  }
+  return first;
+}
+
+// <special-name> ::= TV <type>    # virtual table
+//                ::= TT <type>    # VTT structure (construction vtable index)
+//                ::= TI <type>    # typeinfo structure
+//                ::= TS <type>    # typeinfo name (null-terminated byte string)
+//                ::= Tc <call-offset> <call-offset> <base encoding>
+//                    # base is the nominal target function of thunk
+//                    # first call-offset is 'this' adjustment
+//                    # second call-offset is result adjustment
+//                ::= T <call-offset> <base encoding>
+//                    # base is the nominal target function of thunk
+//                ::= GV <object name> # Guard variable for one-time
+//                initialization
+//                                     # No <type>
+//      extension ::= TC <first type> <number> _ <second type> # construction
+//      vtable for second-in-first
+//      extension ::= GR <object name> # reference temporary for object
+
+template <class C>
+static const char *parse_special_name(const char *first, const char *last,
+                                      C &db) {
+  if (last - first > 2) {
+    const char *t;
+    switch (*first) {
+    case 'T':
+      switch (first[1]) {
+      case 'V':
+        // TV <type>    # virtual table
+        t = parse_type(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "vtable for ");
+          first = t;
+        }
+        break;
+      case 'T':
+        // TT <type>    # VTT structure (construction vtable index)
+        t = parse_type(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "VTT for ");
+          first = t;
+        }
+        break;
+      case 'I':
+        // TI <type>    # typeinfo structure
+        t = parse_type(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "typeinfo for ");
+          first = t;
+        }
+        break;
+      case 'S':
+        // TS <type>    # typeinfo name (null-terminated byte string)
+        t = parse_type(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "typeinfo name for ");
+          first = t;
+        }
+        break;
+      case 'c':
+        // Tc <call-offset> <call-offset> <base encoding>
+        {
+          const char *t0 = parse_call_offset(first + 2, last);
+          if (t0 == first + 2)
+            break;
+          const char *t1 = parse_call_offset(t0, last);
+          if (t1 == t0)
+            break;
+          t = parse_encoding(t1, last, db);
+          if (t != t1) {
+            if (db.names.empty())
+              return first;
+            db.names.back().first.insert(0, "covariant return thunk to ");
+            first = t;
+          }
+        }
+        break;
+      case 'C':
+        // extension ::= TC <first type> <number> _ <second type> # construction
+        // vtable for second-in-first
+        t = parse_type(first + 2, last, db);
+        if (t != first + 2) {
+          const char *t0 = parse_number(t, last);
+          if (t0 != t && t0 != last && *t0 == '_') {
+            const char *t1 = parse_type(++t0, last, db);
+            if (t1 != t0) {
+              if (db.names.size() < 2)
+                return first;
+              auto left = db.names.back().move_full();
+              db.names.pop_back();
+              if (db.names.empty())
+                return first;
+              db.names.back().first = "construction vtable for " +
+                                      std::move(left) + "-in-" +
+                                      db.names.back().move_full();
+              first = t1;
+            }
+          }
+        }
+        break;
+      default:
+        // T <call-offset> <base encoding>
+        {
+          const char *t0 = parse_call_offset(first + 1, last);
+          if (t0 == first + 1)
+            break;
+          t = parse_encoding(t0, last, db);
+          if (t != t0) {
+            if (db.names.empty())
+              return first;
+            if (first[1] == 'v') {
+              db.names.back().first.insert(0, "virtual thunk to ");
+              first = t;
+            } else {
+              db.names.back().first.insert(0, "non-virtual thunk to ");
+              first = t;
+            }
+          }
+        }
+        break;
+      }
+      break;
+    case 'G':
+      switch (first[1]) {
+      case 'V':
+        // GV <object name> # Guard variable for one-time initialization
+        t = parse_name(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "guard variable for ");
+          first = t;
+        }
+        break;
+      case 'R':
+        // extension ::= GR <object name> # reference temporary for object
+        t = parse_name(first + 2, last, db);
+        if (t != first + 2) {
+          if (db.names.empty())
+            return first;
+          db.names.back().first.insert(0, "reference temporary for ");
+          first = t;
+        }
+        break;
+      }
+      break;
+    }
+  }
+  return first;
+}
+
+namespace {
+template <class T> class save_value {
+  T &restore_;
+  T original_value_;
+
+public:
+  save_value(T &restore) : restore_(restore), original_value_(restore) {}
+
+  ~save_value() { restore_ = std::move(original_value_); }
+
+  save_value(const save_value &) = delete;
+  save_value &operator=(const save_value &) = delete;
+};
+}
+
+// <encoding> ::= <function name> <bare-function-type>
+//            ::= <data name>
+//            ::= <special-name>
+
+template <class C>
+static const char *parse_encoding(const char *first, const char *last, C &db) {
+  if (first != last) {
+    save_value<decltype(db.encoding_depth)> su(db.encoding_depth);
+    ++db.encoding_depth;
+    save_value<decltype(db.tag_templates)> sb(db.tag_templates);
+    if (db.encoding_depth > 1)
+      db.tag_templates = true;
+    switch (*first) {
+    case 'G':
+    case 'T':
+      first = parse_special_name(first, last, db);
+      break;
+    default: {
+      bool ends_with_template_args = false;
+      const char *t = parse_name(first, last, db, &ends_with_template_args);
+      unsigned cv = db.cv;
+      unsigned ref = db.ref;
+      if (t != first) {
+        if (t != last && *t != 'E' && *t != '.') {
+          save_value<bool> sb2(db.tag_templates);
+          db.tag_templates = false;
+          const char *t2;
+          typename C::String ret2;
+          if (db.names.empty())
+            return first;
+          const typename C::String &nm = db.names.back().first;
+          if (nm.empty())
+            return first;
+          if (!db.parsed_ctor_dtor_cv && ends_with_template_args) {
+            t2 = parse_type(t, last, db);
+            if (t2 == t)
+              return first;
+            if (db.names.size() < 2)
+              return first;
+            auto ret1 = std::move(db.names.back().first);
+            ret2 = std::move(db.names.back().second);
+            if (ret2.empty())
+              ret1 += ' ';
+            db.names.pop_back();
+            if (db.names.empty())
+              return first;
+
+            db.names.back().first.insert(0, ret1);
+            t = t2;
+          }
+          db.names.back().first += '(';
+          if (t != last && *t == 'v') {
+            ++t;
+          } else {
+            bool first_arg = true;
+            while (true) {
+              size_t k0 = db.names.size();
+              t2 = parse_type(t, last, db);
+              size_t k1 = db.names.size();
+              if (t2 == t)
+                break;
+              if (k1 > k0) {
+                typename C::String tmp;
+                for (size_t k = k0; k < k1; ++k) {
+                  if (!tmp.empty())
+                    tmp += ", ";
+                  tmp += db.names[k].move_full();
+                }
+                for (size_t k = k0; k < k1; ++k) {
+                  if (db.names.empty())
+                    return first;
+                  db.names.pop_back();
+                }
+                if (!tmp.empty()) {
+                  if (db.names.empty())
+                    return first;
+                  if (!first_arg)
+                    db.names.back().first += ", ";
+                  else
+                    first_arg = false;
+                  db.names.back().first += tmp;
+                }
+              }
+              t = t2;
+            }
+          }
+          if (db.names.empty())
+            return first;
+          db.names.back().first += ')';
+          if (cv & 1)
+            db.names.back().first.append(" const");
+          if (cv & 2)
+            db.names.back().first.append(" volatile");
+          if (cv & 4)
+            db.names.back().first.append(" restrict");
+          if (ref == 1)
+            db.names.back().first.append(" &");
+          else if (ref == 2)
+            db.names.back().first.append(" &&");
+          db.names.back().first += ret2;
+          first = t;
+        } else
+          first = t;
+      }
+      break;
+    }
+    }
+  }
+  return first;
+}
+
+// _block_invoke
+// _block_invoke<decimal-digit>+
+// _block_invoke_<decimal-digit>+
+
+template <class C>
+static const char *parse_block_invoke(const char *first, const char *last,
+                                      C &db) {
+  if (last - first >= 13) {
+    const char test[] = "_block_invoke";
+    const char *t = first;
+    for (int i = 0; i < 13; ++i, ++t) {
+      if (*t != test[i])
+        return first;
+    }
+    if (t != last) {
+      if (*t == '_') {
+        // must have at least 1 decimal digit
+        if (++t == last || !std::isdigit(*t))
+          return first;
+        ++t;
+      }
+      // parse zero or more digits
+      while (t != last && isdigit(*t))
+        ++t;
+    }
+    if (db.names.empty())
+      return first;
+    db.names.back().first.insert(0, "invocation function for block in ");
+    first = t;
+  }
+  return first;
+}
+
+// extension
+// <dot-suffix> := .<anything and everything>
+
+template <class C>
+static const char *parse_dot_suffix(const char *first, const char *last,
+                                    C &db) {
+  if (first != last && *first == '.') {
+    if (db.names.empty())
+      return first;
+    db.names.back().first += " (" + typename C::String(first, last) + ")";
+    first = last;
+  }
+  return first;
+}
+
+// <block-involcaton-function> ___Z<encoding>_block_invoke
+// <block-involcaton-function> ___Z<encoding>_block_invoke<decimal-digit>+
+// <block-involcaton-function> ___Z<encoding>_block_invoke_<decimal-digit>+
+// <mangled-name> ::= _Z<encoding>
+//                ::= <type>
+
+template <class C>
+static void demangle(const char *first, const char *last, C &db, int &status) {
+  if (first >= last) {
+    status = invalid_mangled_name;
+    return;
+  }
+  if (*first == '_') {
+    if (last - first >= 4) {
+      if (first[1] == 'Z') {
+        const char *t = parse_encoding(first + 2, last, db);
+        if (t != first + 2 && t != last && *t == '.')
+          t = parse_dot_suffix(t, last, db);
+        if (t != last)
+          status = invalid_mangled_name;
+      } else if (first[1] == '_' && first[2] == '_' && first[3] == 'Z') {
+        const char *t = parse_encoding(first + 4, last, db);
+        if (t != first + 4 && t != last) {
+          const char *t1 = parse_block_invoke(t, last, db);
+          if (t1 != last)
+            status = invalid_mangled_name;
+        } else
+          status = invalid_mangled_name;
+      } else
+        status = invalid_mangled_name;
+    } else
+      status = invalid_mangled_name;
+  } else {
+    const char *t = parse_type(first, last, db);
+    if (t != last)
+      status = invalid_mangled_name;
+  }
+  if (status == success && db.names.empty())
+    status = invalid_mangled_name;
+}
+
+namespace {
+template <std::size_t N> class arena {
+  static const std::size_t alignment = 16;
+  alignas(alignment) char buf_[N];
+  char *ptr_;
+
+  std::size_t align_up(std::size_t n) noexcept {
+    return (n + (alignment - 1)) & ~(alignment - 1);
+  }
+
+  bool pointer_in_buffer(char *p) noexcept {
+    return buf_ <= p && p <= buf_ + N;
+  }
+
+public:
+  arena() noexcept : ptr_(buf_) {}
+  ~arena() { ptr_ = nullptr; }
+  arena(const arena &) = delete;
+  arena &operator=(const arena &) = delete;
+
+  char *allocate(std::size_t n);
+  void deallocate(char *p, std::size_t n) noexcept;
+
+  static constexpr std::size_t size() { return N; }
+  std::size_t used() const { return static_cast<std::size_t>(ptr_ - buf_); }
+  void reset() { ptr_ = buf_; }
+};
+
+template <std::size_t N> char *arena<N>::allocate(std::size_t n) {
+  n = align_up(n);
+  if (static_cast<std::size_t>(buf_ + N - ptr_) >= n) {
+    char *r = ptr_;
+    ptr_ += n;
+    return r;
+  }
+  return static_cast<char *>(std::malloc(n));
+}
+
+template <std::size_t N>
+void arena<N>::deallocate(char *p, std::size_t n) noexcept {
+  if (pointer_in_buffer(p)) {
+    n = align_up(n);
+    if (p + n == ptr_)
+      ptr_ = p;
+  } else
+    std::free(p);
+}
+
+template <class T, std::size_t N> class short_alloc {
+  arena<N> &a_;
+
+public:
+  typedef T value_type;
+
+public:
+  template <class _Up> struct rebind { typedef short_alloc<_Up, N> other; };
+
+  short_alloc(arena<N> &a) noexcept : a_(a) {}
+  template <class U>
+  short_alloc(const short_alloc<U, N> &a) noexcept : a_(a.a_) {}
+  short_alloc(const short_alloc &) = default;
+  short_alloc &operator=(const short_alloc &) = delete;
+
+  T *allocate(std::size_t n) {
+    return reinterpret_cast<T *>(a_.allocate(n * sizeof(T)));
+  }
+  void deallocate(T *p, std::size_t n) noexcept {
+    a_.deallocate(reinterpret_cast<char *>(p), n * sizeof(T));
+  }
+
+  template <class T1, std::size_t N1, class U, std::size_t M>
+  friend bool operator==(const short_alloc<T1, N1> &x,
+                         const short_alloc<U, M> &y) noexcept;
+
+  template <class U, std::size_t M> friend class short_alloc;
+};
+
+template <class T, std::size_t N, class U, std::size_t M>
+inline bool operator==(const short_alloc<T, N> &x,
+                       const short_alloc<U, M> &y) noexcept {
+  return N == M && &x.a_ == &y.a_;
+}
+
+template <class T, std::size_t N, class U, std::size_t M>
+inline bool operator!=(const short_alloc<T, N> &x,
+                       const short_alloc<U, M> &y) noexcept {
+  return !(x == y);
+}
+
+template <class T> class malloc_alloc {
+public:
+  typedef T value_type;
+  typedef T &reference;
+  typedef const T &const_reference;
+  typedef T *pointer;
+  typedef const T *const_pointer;
+  typedef std::size_t size_type;
+  typedef std::ptrdiff_t difference_type;
+
+  malloc_alloc() = default;
+  template <class U> malloc_alloc(const malloc_alloc<U> &) noexcept {}
+
+  T *allocate(std::size_t n) {
+    return static_cast<T *>(std::malloc(n * sizeof(T)));
+  }
+  void deallocate(T *p, std::size_t) noexcept { std::free(p); }
+
+  template <class U> struct rebind { using other = malloc_alloc<U>; };
+  template <class U, class... Args> void construct(U *p, Args &&... args) {
+    ::new ((void *)p) U(std::forward<Args>(args)...);
+  }
+  void destroy(T *p) { p->~T(); }
+};
+
+template <class T, class U>
+inline bool operator==(const malloc_alloc<T> &,
+                       const malloc_alloc<U> &) noexcept {
+  return true;
+}
+
+template <class T, class U>
+inline bool operator!=(const malloc_alloc<T> &x,
+                       const malloc_alloc<U> &y) noexcept {
+  return !(x == y);
+}
+
+const size_t bs = 4 * 1024;
+template <class T> using Alloc = short_alloc<T, bs>;
+template <class T> using Vector = std::vector<T, Alloc<T>>;
+
+template <class StrT> struct string_pair {
+  StrT first;
+  StrT second;
+
+  string_pair() = default;
+  string_pair(StrT f) : first(std::move(f)) {}
+  string_pair(StrT f, StrT s) : first(std::move(f)), second(std::move(s)) {}
+  template <size_t N> string_pair(const char (&s)[N]) : first(s, N - 1) {}
+
+  size_t size() const { return first.size() + second.size(); }
+  StrT full() const { return first + second; }
+  StrT move_full() { return std::move(first) + std::move(second); }
+};
+
+struct Db {
+  typedef std::basic_string<char, std::char_traits<char>, malloc_alloc<char>>
+      String;
+  typedef Vector<string_pair<String>> sub_type;
+  typedef Vector<sub_type> template_param_type;
+  sub_type names;
+  template_param_type subs;
+  Vector<template_param_type> template_param;
+  unsigned cv;
+  unsigned ref;
+  unsigned encoding_depth;
+  bool parsed_ctor_dtor_cv;
+  bool tag_templates;
+  bool fix_forward_references;
+  bool try_to_parse_template_args;
+
+  template <size_t N>
+  Db(arena<N> &ar)
+      : names(ar), subs(0, names, ar), template_param(0, subs, ar) {}
+};
+}
+
+char *llvm::itaniumDemangle(const char *mangled_name, char *buf, size_t *n,
+                            int *status) {
+  if (mangled_name == nullptr || (buf != nullptr && n == nullptr)) {
+    if (status)
+      *status = invalid_args;
+    return nullptr;
+  }
+  size_t internal_size = buf != nullptr ? *n : 0;
+  arena<bs> a;
+  Db db(a);
+  db.cv = 0;
+  db.ref = 0;
+  db.encoding_depth = 0;
+  db.parsed_ctor_dtor_cv = false;
+  db.tag_templates = true;
+  db.template_param.emplace_back(a);
+  db.fix_forward_references = false;
+  db.try_to_parse_template_args = true;
+  int internal_status = success;
+  size_t len = std::strlen(mangled_name);
+  demangle(mangled_name, mangled_name + len, db, internal_status);
+  if (internal_status == success && db.fix_forward_references &&
+      !db.template_param.empty() && !db.template_param.front().empty()) {
+    db.fix_forward_references = false;
+    db.tag_templates = false;
+    db.names.clear();
+    db.subs.clear();
+    demangle(mangled_name, mangled_name + len, db, internal_status);
+    if (db.fix_forward_references)
+      internal_status = invalid_mangled_name;
+  }
+  if (internal_status == success) {
+    size_t sz = db.names.back().size() + 1;
+    if (sz > internal_size) {
+      char *newbuf = static_cast<char *>(std::realloc(buf, sz));
+      if (newbuf == nullptr) {
+        internal_status = memory_alloc_failure;
+        buf = nullptr;
+      } else {
+        buf = newbuf;
+        if (n != nullptr)
+          *n = sz;
+      }
+    }
+    if (buf != nullptr) {
+      db.names.back().first += db.names.back().second;
+      std::memcpy(buf, db.names.back().first.data(), sz - 1);
+      buf[sz - 1] = char(0);
+    }
+  } else
+    buf = nullptr;
+  if (status)
+    *status = internal_status;
+  return buf;
+}