Renamed lang_ext -> bindings, README updates.

7 files changed, 0 insertions, 2073 deletions

diff --git a/lang_ext/cpp/upb/handlers.hpp b/lang_ext/cpp/upb/handlers.hpp
deleted file mode 100644
index b083f15..0000000
--- a/lang_ext/cpp/upb/handlers.hpp
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
- * upb - a minimalist implementation of protocol buffers.
- *
- * Copyright (c) 2011 Google Inc.  See LICENSE for details.
- * Author: Josh Haberman <jhaberman@gmail.com>
- *
- * Note!  This file is a proof-of-concept for C++ wrappers and does not
- * yet build.
- *
- * upb::Handlers is a generic visitor-like interface for iterating over a
- * stream of protobuf data.  You can register function pointers that will be
- * called for each message and/or field as the data is being parsed or iterated
- * over, without having to know the source format that we are parsing from.
- * This decouples the parsing logic from the processing logic.
- */
-
-#ifndef UPB_HANDLERS_HPP
-#define UPB_HANDLERS_HPP
-
-#include "upb_handlers.h"
-
-namespace upb {
-
-typedef upb_flow_t Flow;
-
-class FieldHandlers : public upb_fhandlers {
- public:
-  typedef upb_value_handler ValueHandler;
-  typedef upb_startfield_handler StartFieldHandler;
-  typedef upb_endfield_handler EndFieldHandler;
-
-  // The FieldHandlers will live at least as long as the upb::Handlers to
-  // which it belongs, but can be Ref'd/Unref'd to make it live longer (which
-  // will prolong the life of the underlying upb::Handlers also).
-  void Ref()   { upb_fhandlers_ref(this); }
-  void Unref() { upb_fhandlers_unref(this); }
-
-  // Functions to set this field's handlers.
-  // These return "this" so they can be conveniently chained, eg.
-  //   message_handlers->NewField(...)
-  //       ->SetStartSequenceHandler(&StartSequence),
-  //       ->SetEndSequenceHandler(&EndSequence),
-  //       ->SetValueHandler(&Value);
-  FieldHandlers* SetValueHandler(ValueHandler* h) {
-    upb_fhandlers_setvalue(this, h); return this;
-  }
-  FieldHandlers* SetStartSequenceHandler(StartFieldHandler* h) {
-    upb_fhandlers_setstartseq(this, h); return this;
-  }
-  FieldHandlers* SetEndSequenceHandler(EndFieldHandler* h) {
-    upb_fhandlers_endseq(this, h); return this;
-  }
-  FieldHandlers* SetStartSubmessageHandler(StartFieldHandler* h) {
-    upb_fhandlers_setstartsubmsg(this, h); return this;
-  }
-  FieldHandlers* SetEndSubmessageHandler(EndFieldHandler* h) {
-    upb_fhandlers_endsubmsg(this, h); return this;
-  }
-
-  // Get/Set the field's bound value, which will be passed to its handlers.
-  Value GetBoundValue() { return upb_fhandlers_getfval(this); }
-  FieldHandlers* SetBoundValue(Value val) {
-    upb_fhandlers_setfval(this, val); return this;
-  }
-
- private:
-  FieldHandlers();  // Only created by upb::Handlers.
-  ~FieldHandlers(); // Only destroyed by refcounting.
-};
-
-
-class MessageHandlers : public upb_mhandlers {
- public:
-  typedef upb_startmsg_handler StartMessageHandler;
-  typedef upb_endmsg_handler EndMessageHandler;
-
-  // The MessageHandlers will live at least as long as the upb::Handlers to
-  // which it belongs, but can be Ref'd/Unref'd to make it live longer (which
-  // will prolong the life of the underlying upb::Handlers also).
-  void Ref()   { upb_mhandlers_ref(this); }
-  void Unref() { upb_mhandlers_unref(this); }
-
-  // Functions to set this message's handlers.
-  // These return "this" so they can be conveniently chained, eg.
-  //   handlers->NewMessage()
-  //       ->SetStartMessageHandler(&StartMessage)
-  //       ->SetEndMessageHandler(&EndMessage);
-  MessageHandlers* SetStartMessageHandler(StartMessageHandler* h) {
-    upb_mhandlers_setstartmsg(this, h); return this;
-  }
-  MessageHandlers* SetEndMessageHandler(EndMessageHandler* h) {
-    upb_mhandlers_setendmsg(this, h); return this;
-  }
-
-  // Functions to create new FieldHandlers for this message.
-  FieldHandlers* NewFieldHandlers(uint32_t fieldnum, upb_fieldtype_t type,
-                                  bool repeated) {
-    return upb_mhandlers_newfhandlers(this, fieldnum, type, repeated);
-  }
-  FieldHandlers* NewFieldHandlers(FieldDef* f) {
-    return upb_mhandlers_newfhandlers_fordef(f);
-  }
-
-  // Like the previous but for MESSAGE or GROUP fields.  For GROUP fields, the
-  // given submessage must not have any fields with this field number.
-  FieldHandlers* NewFieldHandlersForSubmessage(uint32_t n, FieldType type,
-                                               bool repeated,
-                                               MessageHandlers* subm) {
-    return upb_mhandlers_newsubmsgfhandlers(this, n, type, repeated, subm);
-  }
-
-  FieldHandlers* NewFieldHandlersForSubmessage(FieldDef* f,
-                                               MessageHandlers* subm) {
-    return upb_mhandlers_newsubmsgfhandlers_fordef(f);
-  }
-
-
- private:
-  MessageHandlers();  // Only created by upb::Handlers.
-  ~MessageHandlers(); // Only destroyed by refcounting.
-};
-
-class Handlers : public upb_handlers {
- public:
-  // Creates a new Handlers instance.
-  Handlers* New() { return static_cast<Handlers*>(upb_handlers_new()); }
-
-  void Ref()   { upb_handlers_ref(this); }
-  void Unref() { upb_handlers_unref(this); }
-
-  // Returns a new MessageHandlers object.  The first such message that is
-  // obtained will be the top-level message for this Handlers object.
-  MessageHandlers* NewMessageHandlers() { return upb_handlers_newmhandlers(); }
-
- private:
-  FieldHandlers();  // Only created by Handlers::New().
-  ~FieldHandlers(); // Only destroyed by refcounting.
-};
-
-}  // namespace upb
-
-#endif
diff --git a/lang_ext/lua/test.lua b/lang_ext/lua/test.lua
deleted file mode 100644
index 42bce25..0000000
--- a/lang_ext/lua/test.lua
+++ /dev/null
@@ -1,109 +0,0 @@
-
-require "upb"
-
-symtab = upb.SymbolTable{
-  upb.MessageDef{fqname="A", fields={
-    upb.FieldDef{name="a", type=upb.TYPE_INT32, number=1},
-    upb.FieldDef{name="b", type=upb.TYPE_DOUBLE, number=2}}
-  }
-}
-
-symtab = upb.SymbolTable{
-  upb.MessageDef{fqname="A", fields={
-    upb.FieldDef{name="a", type=upb.TYPE_INT32, number=1},
-    upb.FieldDef{name="b", type=upb.TYPE_DOUBLE, number=2}}
-  },
-  upb.MessageDef{fqname="B"}
-}
-A, B, C = symtab:lookup("A", "B")
-print(A)
-print(B)
-print(C)
-
-a = A()
-a2 = upb.Message(A)
-print("YO!  a.a=" .. tostring(a.a) .. ", a2.a=" .. tostring(a2.a))
-a.a = 2
-a2.a = 3
-print("YO!  a.a=" .. tostring(a.a) .. ", a2.a=" .. tostring(a2.a))
-
-A = symtab:lookup("A")
-if not A then
-  error("Could not find A")
-end
-
-f = io.open("../../upb/descriptor.pb")
-if not f then
-  error("Couldn't open descriptor.pb, try running 'make descriptorgen'")
-end
-symtab:parsedesc(f:read("*all"))
-symtab:load_descriptor()
-symtab:load_descriptor_file()
-
-upb.pb.load_descriptor(f:read("*all"))
-
-upb.pb.load_descriptor_file("../../src/descriptor.pb", symtab)
-
-f = io.open("../../benchmarks/google_messages.proto.pb")
-if not f then
-  error("Couldn't open google_messages.proto.pb, try running 'make benchmarks'")
-end
-symtab:parsedesc(f:read("*all"))
-
-for _, def in ipairs(symtab:getdefs(-1)) do
-  print(def:name())
-end
-
-SpeedMessage1 = symtab:lookup("benchmarks.SpeedMessage1")
-SpeedMessage2 = symtab:lookup("benchmarks.SpeedMessage2")
-print(SpeedMessage1:name())
-
-msg = MyType()
-msg:Decode(str)
-
-msg:DecodeJSON(str)
-
-msg = upb.pb.decode(str, MyType)
-str = upb.pb.encode(msg)
-
-msg = upb.pb.decode_text(str, MyType)
-str = upb.pb.encode_text(msg)
-
-upb.clear(msg)
-upb.msgdef(msg)
-upb.has(msg, "foo_bar")
-
-msg = upb.json.decode(str, MyType)
-
-msg = upb.pb.DecodeText(str)
-msg = upb.pb.EncodeText(msg)
-upb.
-
-upb.pb.decode_into(msg, str)
-
-str = upb.json.Encode(msg)
-upb.json.DecodeInto(msg, str)
-f = assert(io.open("../../benchmarks/google_message1.dat"))
-msg:Parse(f:read("*all"))
-print(msg:ToText())
-print(upb.json.encode(msg))
-
-msg = SpeedMessage2()
-f = assert(io.open("../../benchmarks/google_message2.dat"))
-msg:Parse(f:read("*all"))
-print(msg:ToText())
---msg:Serialize()
---msg:FromText(str)
--- print(msg.field129)
--- print(msg.field271)
---print(msg.field15.field15)
---msg.field15.field15 = "my override"
---print(msg.field15.field15)
--- print(msg.field1)
--- print(msg.field1)
--- msg.field1 = "YEAH BABY!"
--- print(msg.field1)
--- print(msg.field129)
--- msg.field129 = 5
--- print(msg.field129)
---]]
diff --git a/lang_ext/lua/upb.c b/lang_ext/lua/upb.c
deleted file mode 100644
index fe523e7..0000000
--- a/lang_ext/lua/upb.c
+++ /dev/null
@@ -1,1012 +0,0 @@
-/*
- * upb - a minimalist implementation of protocol buffers.
- *
- * Copyright (c) 2009 Google Inc.  See LICENSE for details.
- * Author: Josh Haberman <jhaberman@gmail.com>
- *
- * A Lua extension for upb.
- */
-
-#include <stdlib.h>
-#include <math.h>
-#include <float.h>
-#include "lauxlib.h"
-#include "upb/def.h"
-#include "upb/msg.h"
-#include "upb/pb/glue.h"
-
-#if LUA_VERSION_NUM == 501
-#define lua_rawlen lua_objlen
-#endif
-
-static bool streql(const char *a, const char *b) { return strcmp(a, b) == 0; }
-
-static bool lupb_isint(double n) { return (double)(int)n == n; }
-
-static uint8_t lupb_touint8(lua_State *L, int narg, const char *name) {
-  lua_Number n = lua_tonumber(L, narg);
-  if (n > UINT8_MAX || n < 0 || rint(n) != n)
-    luaL_error(L, "Invalid %s", name);
-  return n;
-}
-
-static uint32_t lupb_touint32(lua_State *L, int narg, const char *name) {
-  lua_Number n = lua_tonumber(L, narg);
-  if (n > UINT32_MAX || n < 0 || rint(n) != n)
-    luaL_error(L, "Invalid %s", name);
-  return n;
-}
-
-static void lupb_pushstring(lua_State *L, upb_strref *ref) {
-  if (ref->ptr) {
-    lua_pushlstring(L, ref->ptr, ref->len);
-  } else {
-    // Lua requires a continguous string; must copy+allocate.
-    char *str = upb_strref_dup(ref);
-    lua_pushlstring(L, str, ref->len);
-    free(str);
-  }
-}
-
-static void lupb_pushvalue(lua_State *L, upb_value val, upb_fielddef *f) {
-  switch (f->type) {
-    case UPB_TYPE(INT32):
-    case UPB_TYPE(SINT32):
-    case UPB_TYPE(SFIXED32):
-    case UPB_TYPE(ENUM):
-      lua_pushnumber(L, upb_value_getint32(val)); break;
-    case UPB_TYPE(INT64):
-    case UPB_TYPE(SINT64):
-    case UPB_TYPE(SFIXED64):
-      lua_pushnumber(L, upb_value_getint64(val)); break;
-    case UPB_TYPE(UINT32):
-    case UPB_TYPE(FIXED32):
-      lua_pushnumber(L, upb_value_getuint32(val)); break;
-    case UPB_TYPE(UINT64):
-    case UPB_TYPE(FIXED64):
-      lua_pushnumber(L, upb_value_getuint64(val)); break;
-    case UPB_TYPE(DOUBLE):
-      lua_pushnumber(L, upb_value_getdouble(val)); break;
-    case UPB_TYPE(FLOAT):
-      lua_pushnumber(L, upb_value_getfloat(val)); break;
-    case UPB_TYPE(BOOL):
-      lua_pushboolean(L, upb_value_getbool(val)); break;
-    default: luaL_error(L, "internal error");
-  }
-}
-
-// Returns a scalar value (ie. not a submessage) as a upb_value.
-static upb_value lupb_getvalue(lua_State *L, int narg, upb_fielddef *f,
-                               upb_strref *ref) {
-  assert(!upb_issubmsg(f));
-  upb_value val;
-  if (upb_fielddef_type(f) == UPB_TYPE(BOOL)) {
-    if (!lua_isboolean(L, narg))
-      luaL_error(L, "Must explicitly pass true or false for boolean fields");
-    upb_value_setbool(&val, lua_toboolean(L, narg));
-  } else if (upb_fielddef_type(f) == UPB_TYPE(STRING)) {
-    size_t len;
-    ref->ptr = luaL_checklstring(L, narg, &len);
-    ref->len = len;
-    upb_value_setstrref(&val, ref);
-  } else {
-    // Numeric type.
-    lua_Number num = 0;
-    num = luaL_checknumber(L, narg);
-    switch (upb_fielddef_type(f)) {
-      case UPB_TYPE(INT32):
-      case UPB_TYPE(SINT32):
-      case UPB_TYPE(SFIXED32):
-      case UPB_TYPE(ENUM):
-        if (num > INT32_MAX || num < INT32_MIN || num != rint(num))
-          luaL_error(L, "Cannot convert %f to 32-bit integer", num);
-        upb_value_setint32(&val, num);
-        break;
-      case UPB_TYPE(INT64):
-      case UPB_TYPE(SINT64):
-      case UPB_TYPE(SFIXED64):
-        if (num > INT64_MAX || num < INT64_MIN || num != rint(num))
-          luaL_error(L, "Cannot convert %f to 64-bit integer", num);
-        upb_value_setint64(&val, num);
-        break;
-      case UPB_TYPE(UINT32):
-      case UPB_TYPE(FIXED32):
-        if (num > UINT32_MAX || num < 0 || num != rint(num))
-          luaL_error(L, "Cannot convert %f to unsigned 32-bit integer", num);
-        upb_value_setuint32(&val, num);
-        break;
-      case UPB_TYPE(UINT64):
-      case UPB_TYPE(FIXED64):
-        if (num > UINT64_MAX || num < 0 || num != rint(num))
-          luaL_error(L, "Cannot convert %f to unsigned 64-bit integer", num);
-        upb_value_setuint64(&val, num);
-        break;
-      case UPB_TYPE(DOUBLE):
-        if (num > DBL_MAX || num < -DBL_MAX) {
-          // This could happen if lua_Number was long double.
-          luaL_error(L, "Cannot convert %f to double", num);
-        }
-        upb_value_setdouble(&val, num);
-        break;
-      case UPB_TYPE(FLOAT):
-        if (num > FLT_MAX || num < -FLT_MAX)
-          luaL_error(L, "Cannot convert %f to float", num);
-        upb_value_setfloat(&val, num);
-        break;
-    }
-  }
-  return val;
-}
-
-static void lupb_typecheck(lua_State *L, int narg, upb_fielddef *f) {
-  upb_strref ref;
-  lupb_getvalue(L, narg, f, &ref);
-}
-
-//static void lupb_msg_getorcreate(lua_State *L, upb_msg *msg, upb_msgdef *md);
-static void lupb_fielddef_getorcreate(lua_State *L, upb_fielddef *f);
-static upb_msgdef *lupb_msgdef_check(lua_State *L, int narg);
-static void lupb_msg_pushnew(lua_State *L, void *md);
-
-void lupb_checkstatus(lua_State *L, upb_status *s) {
-  if (!upb_ok(s)) {
-    upb_status_print(s, stderr);
-    // Need to copy the string to the stack, so we can free it and not leak
-    // it (since luaL_error() does not return).
-    char buf[strlen(s->str)+1];
-    strcpy(buf, s->str);
-    upb_status_uninit(s);
-    luaL_error(L, "%s", buf);
-  }
-  upb_status_uninit(s);
-}
-
-
-/* object cache ***************************************************************/
-
-// We cache all the lua objects (userdata) we vend in a weak table, indexed by
-// the C pointer of the object they are caching.
-
-static void *lupb_cache_getorcreate_size(
-    lua_State *L, void *cobj, const char *type, size_t size) {
-  // Lookup our cache in the registry (we don't put our objects in the registry
-  // directly because we need our cache to be a weak table).
-  void **obj = NULL;
-  lua_getfield(L, LUA_REGISTRYINDEX, "upb.objcache");
-  assert(!lua_isnil(L, -1));  // Should have been created by luaopen_upb.
-  lua_pushlightuserdata(L, cobj);
-  lua_rawget(L, -2);
-  // Stack: objcache, cached value.
-  if (lua_isnil(L, -1)) {
-    // Remove bad cached value and push new value.
-    lua_pop(L, 1);
-    // We take advantage of the fact that all of our objects are currently a
-    // single pointer, and thus have the same layout.
-    obj = lua_newuserdata(L, size);
-    *obj = cobj;
-    luaL_getmetatable(L, type);
-    assert(!lua_isnil(L, -1));  // Should have been created by luaopen_upb.
-    lua_setmetatable(L, -2);
-
-    // Set it in the cache.
-    lua_pushlightuserdata(L, cobj);
-    lua_pushvalue(L, -2);
-    lua_rawset(L, -4);
-  }
-  lua_insert(L, -2);
-  lua_pop(L, 1);
-  return obj;
-}
-
-// Most types are just 1 pointer and can use this helper.
-static bool lupb_cache_getorcreate(lua_State *L, void *cobj, const char *type) {
-  return lupb_cache_getorcreate_size(L, cobj, type, sizeof(void*)) != NULL;
-}
-
-static void lupb_cache_create(lua_State *L, void *cobj, const char *type) {
-  bool created =
-      lupb_cache_getorcreate_size(L, cobj, type, sizeof(void*)) != NULL;
-  (void)created;  // For NDEBUG
-  assert(created);
-}
-
-
-/* lupb_def *******************************************************************/
-
-// All the def types share the same C layout, even though they are different Lua
-// types with different metatables.
-typedef struct {
-  upb_def *def;
-} lupb_def;
-
-static lupb_def *lupb_def_check(lua_State *L, int narg) {
-  void *ldef = luaL_checkudata(L, narg, "upb.msgdef");
-  if (!ldef) ldef = luaL_checkudata(L, narg, "upb.enumdef");
-  if (!ldef) luaL_typerror(L, narg, "upb def");
-  return ldef;
-}
-
-static void lupb_def_getorcreate(lua_State *L, upb_def *def, int owned) {
-  bool created = false;
-  switch(def->type) {
-    case UPB_DEF_MSG:
-      created = lupb_cache_getorcreate(L, def, "upb.msgdef");
-      break;
-    case UPB_DEF_ENUM:
-      created = lupb_cache_getorcreate(L, def, "upb.enumdef");
-      break;
-    default:
-      luaL_error(L, "unknown deftype %d", def->type);
-  }
-  if (!owned && created) {
-    upb_def_ref(def);
-  } else if (owned && !created) {
-    upb_def_unref(def);
-  }
-}
-
-
-/* lupb_fielddef **************************************************************/
-
-typedef struct {
-  upb_fielddef *field;
-} lupb_fielddef;
-
-static lupb_fielddef *lupb_fielddef_check(lua_State *L, int narg) {
-  lupb_fielddef *f = luaL_checkudata(L, narg, "upb.fielddef");
-  if (!f) luaL_typerror(L, narg, "upb fielddef");
-  return f;
-}
-
-static int lupb_fielddef_index(lua_State *L) {
-  lupb_fielddef *f = lupb_fielddef_check(L, 1);
-  const char *str = luaL_checkstring(L, 2);
-  if (streql(str, "name")) {
-    lua_pushstring(L, upb_fielddef_name(f->field));
-  } else if (streql(str, "number")) {
-    lua_pushinteger(L, upb_fielddef_number(f->field));
-  } else if (streql(str, "type")) {
-    lua_pushinteger(L, upb_fielddef_type(f->field));
-  } else if (streql(str, "label")) {
-    lua_pushinteger(L, upb_fielddef_label(f->field));
-  } else if (streql(str, "subdef")) {
-    lupb_def_getorcreate(L, upb_fielddef_subdef(f->field), false);
-  } else if (streql(str, "msgdef")) {
-    lupb_def_getorcreate(L, UPB_UPCAST(upb_fielddef_msgdef(f->field)), false);
-  } else {
-    luaL_error(L, "Invalid fielddef member '%s'", str);
-  }
-  return 1;
-}
-
-static void lupb_fielddef_set(lua_State *L, upb_fielddef *f,
-                              const char *field, int narg) {
-  if (!upb_fielddef_ismutable(f)) luaL_error(L, "fielddef is not mutable.");
-  if (streql(field, "name")) {
-    const char *name = lua_tostring(L, narg);
-    if (!name || !upb_fielddef_setname(f, name))
-      luaL_error(L, "Invalid name");
-  } else if (streql(field, "number")) {
-    if (!upb_fielddef_setnumber(f, lupb_touint32(L, narg, "number")))
-      luaL_error(L, "Invalid number");
-  } else if (streql(field, "type")) {
-    if (!upb_fielddef_settype(f, lupb_touint8(L, narg, "type")))
-      luaL_error(L, "Invalid type");
-  } else if (streql(field, "label")) {
-    if (!upb_fielddef_setlabel(f, lupb_touint8(L, narg, "label")))
-      luaL_error(L, "Invalid label");
-  } else if (streql(field, "type_name")) {
-    const char *name = lua_tostring(L, narg);
-    if (!name || !upb_fielddef_settypename(f, name))
-      luaL_error(L, "Invalid type_name");
-  } else if (streql(field, "default_value")) {
-    if (!upb_fielddef_type(f))
-      luaL_error(L, "Must set type before setting default_value");
-    upb_strref ref;
-    upb_fielddef_setdefault(f, lupb_getvalue(L, narg, f, &ref));
-  } else {
-    luaL_error(L, "Cannot set fielddef member '%s'", field);
-  }
-}
-
-static int lupb_fielddef_new(lua_State *L) {
-  upb_fielddef *f = upb_fielddef_new();
-  lupb_cache_create(L, f, "upb.fielddef");
-
-  if (lua_gettop(L) == 0) return 1;
-
-  // User can specify initialization values like so:
-  //   upb.FieldDef{label=upb.LABEL_REQUIRED, name="my_field", number=5,
-  //                type=upb.TYPE_INT32, default_value=12, type_name="Foo"}
-  luaL_checktype(L, 1, LUA_TTABLE);
-  // Iterate over table.
-  lua_pushnil(L);  // first key
-  while (lua_next(L, 1)) {
-    luaL_checktype(L, -2, LUA_TSTRING);
-    const char *key = lua_tostring(L, -2);
-    lupb_fielddef_set(L, f, key, -1);
-    lua_pop(L, 1);
-  }
-  return 1;
-}
-
-static void lupb_fielddef_getorcreate(lua_State *L, upb_fielddef *f) {
-  bool created = lupb_cache_getorcreate(L, f, "upb.fielddef");
-  if (created) upb_fielddef_ref(f);
-}
-
-static int lupb_fielddef_newindex(lua_State *L) {
-  lupb_fielddef *f = lupb_fielddef_check(L, 1);
-  lupb_fielddef_set(L, f->field, luaL_checkstring(L, 2), 3);
-  return 0;
-}
-
-static int lupb_fielddef_gc(lua_State *L) {
-  lupb_fielddef *lfielddef = lupb_fielddef_check(L, 1);
-  upb_fielddef_unref(lfielddef->field);
-  return 0;
-}
-
-static const struct luaL_Reg lupb_fielddef_mm[] = {
-  {"__gc", lupb_fielddef_gc},
-  {"__index", lupb_fielddef_index},
-  {"__newindex", lupb_fielddef_newindex},
-  {NULL, NULL}
-};
-
-
-/* lupb_msgdef ****************************************************************/
-
-static upb_msgdef *lupb_msgdef_check(lua_State *L, int narg) {
-  lupb_def *ldef = luaL_checkudata(L, narg, "upb.msgdef");
-  luaL_argcheck(L, ldef != NULL, narg, "upb msgdef expected");
-  return upb_downcast_msgdef(ldef->def);
-}
-
-static int lupb_msgdef_gc(lua_State *L) {
-  lupb_def *ldef = luaL_checkudata(L, 1, "upb.msgdef");
-  upb_def_unref(ldef->def);
-  return 0;
-}
-
-static int lupb_msgdef_call(lua_State *L) {
-  upb_msgdef *md = lupb_msgdef_check(L, 1);
-  lupb_msg_pushnew(L, md);
-  return 1;
-}
-
-static int lupb_msgdef_new(lua_State *L) {
-  upb_msgdef *md = upb_msgdef_new();
-  lupb_cache_create(L, md, "upb.msgdef");
-
-  if (lua_gettop(L) == 0) return 1;
-
-  // User can specify initialization values like so:
-  //   upb.MessageDef{fqname="MyMessage", extstart=8000, fields={...}}
-  luaL_checktype(L, 1, LUA_TTABLE);
-  // Iterate over table.
-  lua_pushnil(L);  // first key
-  while (lua_next(L, 1)) {
-    luaL_checktype(L, -2, LUA_TSTRING);
-    const char *key = lua_tostring(L, -2);
-
-    if (streql(key, "fqname")) {  // fqname="MyMessage"
-      const char *fqname = lua_tostring(L, -1);
-      if (!fqname || !upb_def_setfqname(UPB_UPCAST(md), fqname))
-        luaL_error(L, "Invalid fqname");
-    } else if (streql(key, "fields")) {  // fields={...}
-      // Iterate over the list of fields.
-      lua_pushnil(L);
-      luaL_checktype(L, -2, LUA_TTABLE);
-      while (lua_next(L, -2)) {
-        lupb_fielddef *f = lupb_fielddef_check(L, -1);
-        if (!upb_msgdef_addfield(md, f->field)) {
-          // TODO: more specific error.
-          luaL_error(L, "Could not add field.");
-        }
-        lua_pop(L, 1);
-      }
-    } else {
-      // TODO: extrange=
-      luaL_error(L, "Unknown initializer key '%s'", key);
-    }
-    lua_pop(L, 1);
-  }
-  return 1;
-}
-
-static int lupb_msgdef_fqname(lua_State *L) {
-  upb_msgdef *m = lupb_msgdef_check(L, 1);
-  lua_pushstring(L, m->base.fqname);
-  return 1;
-}
-
-static int lupb_msgdef_fieldbyname(lua_State *L) {
-  upb_msgdef *m = lupb_msgdef_check(L, 1);
-  upb_fielddef *f = upb_msgdef_ntof(m, luaL_checkstring(L, 2));
-  if (f) {
-    lupb_fielddef_getorcreate(L, f);
-  } else {
-    lua_pushnil(L);
-  }
-  return 1;
-}
-
-static int lupb_msgdef_fieldbynum(lua_State *L) {
-  upb_msgdef *m = lupb_msgdef_check(L, 1);
-  int num = luaL_checkint(L, 2);
-  upb_fielddef *f = upb_msgdef_itof(m, num);
-  if (f) {
-    lupb_fielddef_getorcreate(L, f);
-  } else {
-    lua_pushnil(L);
-  }
-  return 1;
-}
-
-static const struct luaL_Reg lupb_msgdef_mm[] = {
-  {"__call", lupb_msgdef_call},
-  {"__gc", lupb_msgdef_gc},
-  {NULL, NULL}
-};
-
-static const struct luaL_Reg lupb_msgdef_m[] = {
-  {"fieldbyname", lupb_msgdef_fieldbyname},
-  {"fieldbynum", lupb_msgdef_fieldbynum},
-  {"fqname", lupb_msgdef_fqname},
-  {NULL, NULL}
-};
-
-
-/* lupb_enumdef ***************************************************************/
-
-static upb_enumdef *lupb_enumdef_check(lua_State *L, int narg) {
-  lupb_def *ldef = luaL_checkudata(L, narg, "upb.enumdef");
-  return upb_downcast_enumdef(ldef->def);
-}
-
-static int lupb_enumdef_gc(lua_State *L) {
-  upb_enumdef *e = lupb_enumdef_check(L, 1);
-  upb_def_unref(UPB_UPCAST(e));
-  return 0;
-}
-
-static int lupb_enumdef_name(lua_State *L) {
-  upb_enumdef *e = lupb_enumdef_check(L, 1);
-  lua_pushstring(L, e->base.fqname);
-  return 1;
-}
-
-static const struct luaL_Reg lupb_enumdef_mm[] = {
-  {"__gc", lupb_enumdef_gc},
-  {NULL, NULL}
-};
-
-static const struct luaL_Reg lupb_enumdef_m[] = {
-  {"name", lupb_enumdef_name},
-  {NULL, NULL}
-};
-
-
-/* lupb_symtab ****************************************************************/
-
-typedef struct {
-  upb_symtab *symtab;
-} lupb_symtab;
-
-static upb_accessor_vtbl *lupb_accessor(upb_fielddef *f);
-
-// Inherits a ref on the symtab.
-// Checks that narg is a proper lupb_symtab object.  If it is, leaves its
-// metatable on the stack for cache lookups/updates.
-lupb_symtab *lupb_symtab_check(lua_State *L, int narg) {
-  return luaL_checkudata(L, narg, "upb.symtab");
-}
-
-// narg is a lua table containing a list of defs to add.
-void lupb_symtab_doadd(lua_State *L, upb_symtab *s, int narg) {
-  luaL_checktype(L, narg, LUA_TTABLE);
-  // Iterate over table twice.  First iteration to count entries and
-  // check constraints.
-  int n = 0;
-  lua_pushnil(L);  // first key
-  while (lua_next(L, narg)) {
-    lupb_def_check(L, -1);
-    ++n;
-    lua_pop(L, 1);
-  }
-
-  // Second iteration to build deflist and layout.
-  upb_def **defs = malloc(n * sizeof(*defs));
-  n = 0;
-  lua_pushnil(L);  // first key
-  while (lua_next(L, 1)) {
-    upb_def *def = lupb_def_check(L, -1)->def;
-    defs[n++] = def;
-    upb_msgdef *md = upb_dyncast_msgdef(def);
-    if (md) {
-      upb_msg_iter i;
-      for(i = upb_msg_begin(md); !upb_msg_done(i); i = upb_msg_next(md, i)) {
-        upb_fielddef *f = upb_msg_iter_field(i);
-        upb_fielddef_setaccessor(f, lupb_accessor(f));
-      }
-      upb_msgdef_layout(md);
-    }
-    lua_pop(L, 1);
-  }
-
-  upb_status status = UPB_STATUS_INIT;
-  upb_symtab_add(s, defs, n, &status);
-  free(defs);
-  lupb_checkstatus(L, &status);
-}
-
-static int lupb_symtab_new(lua_State *L) {
-  upb_symtab *s = upb_symtab_new();
-  lupb_cache_create(L, s, "upb.symtab");
-  if (lua_gettop(L) == 0) return 1;
-  lupb_symtab_doadd(L, s, 1);
-  return 1;
-}
-
-static int lupb_symtab_add(lua_State *L) {
-  lupb_symtab *s = lupb_symtab_check(L, 1);
-  lupb_symtab_doadd(L, s->symtab, 2);
-  return 0;
-}
-
-static int lupb_symtab_gc(lua_State *L) {
-  lupb_symtab *s = lupb_symtab_check(L, 1);
-  upb_symtab_unref(s->symtab);
-  return 0;
-}
-
-static int lupb_symtab_lookup(lua_State *L) {
-  lupb_symtab *s = lupb_symtab_check(L, 1);
-  for (int i = 2; i <= lua_gettop(L); i++) {
-    upb_def *def = upb_symtab_lookup(s->symtab, luaL_checkstring(L, i));
-    if (def) {
-      lupb_def_getorcreate(L, def, true);
-    } else {
-      lua_pushnil(L);
-    }
-    lua_replace(L, i);
-  }
-  return lua_gettop(L) - 1;
-}
-
-static int lupb_symtab_getdefs(lua_State *L) {
-  lupb_symtab *s = lupb_symtab_check(L, 1);
-  upb_deftype_t type = luaL_checkint(L, 2);
-  int count;
-  upb_def **defs = upb_symtab_getdefs(s->symtab, &count, type);
-
-  // Create the table in which we will return the defs.
-  lua_createtable(L, count, 0);
-  for (int i = 0; i < count; i++) {
-    upb_def *def = defs[i];
-    lupb_def_getorcreate(L, def, true);
-    lua_rawseti(L, -2, i + 1);
-  }
-  free(defs);
-  return 1;
-}
-
-static const struct luaL_Reg lupb_symtab_m[] = {
-  {"add", lupb_symtab_add},
-  {"getdefs", lupb_symtab_getdefs},
-  {"lookup", lupb_symtab_lookup},
-  {NULL, NULL}
-};
-
-static const struct luaL_Reg lupb_symtab_mm[] = {
-  {"__gc", lupb_symtab_gc},
-  {NULL, NULL}
-};
-
-
-/* lupb_msg********************************************************************/
-
-// Messages are userdata.  Primitive values (numbers and bools, and their
-// hasbits) are stored right in the userdata.  Other values are stored using
-// integer entries in the environment table and no hasbits are used (since
-// "nil" in the environment table can indicate "not present").
-//
-// The environment table looks like:
-//   {msgdef, <string, submessage, and array fields>}
-
-// Must pass a upb_fielddef as the pointer.
-static void lupb_array_pushnew(lua_State *L, void *f);
-
-static void *lupb_msg_check(lua_State *L, int narg, upb_msgdef **md) {
-  void *msg = luaL_checkudata(L, narg, "upb.msg");
-  luaL_argcheck(L, msg != NULL, narg, "msg expected");
-  // If going all the way to the environment table for the msgdef is an
-  // efficiency issue, we could put the pointer right in the userdata.
-  lua_getfenv(L, narg);
-  lua_rawgeti(L, -1, 1);
-  // Shouldn't have to check msgdef userdata validity, environment table can't
-  // be accessed from Lua.
-  lupb_def *lmd = lua_touserdata(L, -1);
-  *md = upb_downcast_msgdef(lmd->def);
-  return msg;
-}
-
-static void lupb_msg_pushnew(lua_State *L, void *md) {
-  void *msg = lua_newuserdata(L, upb_msgdef_size(md));
-  luaL_getmetatable(L, "upb.msg");
-  assert(!lua_isnil(L, -1));  // Should have been created by luaopen_upb.
-  lua_setmetatable(L, -2);
-  upb_msg_clear(msg, md);
-  lua_getfenv(L, -1);
-  lupb_cache_getorcreate(L, md, "upb.msgdef");
-  lua_rawseti(L, -2, 1);
-  lua_pop(L, 1);  // Pop the fenv.
-}
-
-static int lupb_msg_new(lua_State *L) {
-  upb_msgdef *md = lupb_msgdef_check(L, 1);
-  lupb_msg_pushnew(L, md);
-  return 1;
-}
-
-static int lupb_msg_index(lua_State *L) {
-  upb_msgdef *md;
-  void *m = lupb_msg_check(L, 1, &md);
-  upb_fielddef *f = upb_msgdef_ntof(md, luaL_checkstring(L, 2));
-  if (!f) luaL_argerror(L, 2, "not a field name");
-  if (upb_isprimitivetype(upb_fielddef_type(f))) {
-    upb_value v = upb_msg_has(m, f) ? upb_msg_get(m, f) : upb_fielddef_default(f);
-    lupb_pushvalue(L, v, f);
-  } else {
-    lua_getfenv(L, 1);
-    lua_rawgeti(L, -1, f->offset);
-    if (lua_isnil(L, -1)) {
-      // Need to lazily create array, string, or submessage.
-      if (upb_isseq(f)) {
-        lupb_array_pushnew(L, f);
-      } else if (upb_isstring(f)) {
-        // TODO: (need to figure out default string ownership).
-      } else if (upb_issubmsg(f)) {
-        lupb_msg_pushnew(L, upb_downcast_msgdef(upb_fielddef_subdef(f)));
-      } else {
-        luaL_error(L, "internal error");
-      }
-      lua_rawseti(L, -2, f->offset);
-    }
-  }
-  return 1;
-}
-
-static int lupb_msg_newindex(lua_State *L) {
-  upb_msgdef *md;
-  void *m = lupb_msg_check(L, 1, &md);
-  upb_fielddef *f = upb_msgdef_ntof(md, luaL_checkstring(L, 2));
-  if (!f) luaL_error(L, "not a field name");
-  if (upb_isprimitivetype(upb_fielddef_type(f))) {
-    if (lua_isnil(L, 3))
-      upb_msg_clearbit(m, f);
-    else
-      upb_msg_set(m, f, lupb_getvalue(L, 3, f, NULL));
-  } else {
-    if (!lua_isnil(L, 3)) lupb_typecheck(L, 3, f);
-    lua_getfenv(L, 1);
-    lua_pushvalue(L, 3);
-    lua_rawseti(L, -1, f->offset);
-  }
-  return 0;
-}
-
-static const struct luaL_Reg lupb_msg_mm[] = {
-  {"__index", lupb_msg_index},
-  {"__newindex", lupb_msg_newindex},
-  {NULL, NULL}
-};
-
-// Functions that operate on msgdefs but do not live in the msgdef namespace.
-static int lupb_clear(lua_State *L) {
-  upb_msgdef *md;
-  void *m = lupb_msg_check(L, 1, &md);
-  upb_msg_clear(m, md);
-  return 0;
-}
-
-static int lupb_has(lua_State *L) {
-  upb_msgdef *md;
-  void *m = lupb_msg_check(L, 1, &md);
-  upb_fielddef *f = upb_msgdef_ntof(md, luaL_checkstring(L, 2));
-  if (!f) luaL_argerror(L, 2, "not a field name");
-  lua_pushboolean(L, upb_msg_has(m, f));
-  return 1;
-}
-
-static int lupb_msgdef(lua_State *L) {
-  upb_msgdef *md;
-  lupb_msg_check(L, 1, &md);
-  lupb_def_getorcreate(L, UPB_UPCAST(md), false);
-  return 1;
-}
-
-// Accessors for arrays, strings, and submessages need access to the current
-// userdata's environment table, which can only be stored in Lua space.
-// Options for storing it are:
-//
-// - put the env tables for all messages and arrays in the registry, keyed by
-//   userdata pointer (light userdata), or by a reference using luaL_ref().
-//   Then we can just let upb's parse stack track the stack of env tables.
-//   Easy but requires all messages and arrays to be in the registry, which
-//   seems too heavyweight.
-//
-// - store the stack of env tables in the Lua stack.  Convenient, but requires
-//   special code to handle resumable decoders.
-//
-// There is also the question of how to obtain the lua_State* pointer.
-// The main options for this are:
-//
-// - make our closure point to a struct:
-//     struct { void *msg; lua_State *L; }
-//   But then we can't use standard accessors, which expect the closure
-//   to point to the data itself.  Using the standard accessors for
-//   primitive values is both a simplicity and a performance win.
-//
-// - store a lua_State* pointer inside each userdata.  Convenient and
-//   efficient, but makes every message sizeof(void*) larger.
-//   Currently we take this route.
-//
-// - use thread-local storage.  Convenient and efficient, but not portable.
-
-typedef void createfunc_t(lua_State *L, void *param);
-
-static upb_sflow_t lupb_msg_start(void *m, upb_fielddef *f, bool array,
-                                  createfunc_t *pushnew, void *param) {
-  lua_State *L = *(lua_State**)m;
-  int offset = array ? lua_rawlen(L, -1) : f->offset;
-  if (!lua_checkstack(L, 3)) luaL_error(L, "stack full");
-  lua_rawgeti(L, -1, offset);
-  if (lua_isnil(L, -1)) {
-    lua_pop(L, 1);
-    pushnew(L, param);
-    lua_pushvalue(L, -1);
-    lua_rawseti(L, -3, offset);
-  }
-  void *subval = lua_touserdata(L, -1);
-  lua_getfenv(L, -1);
-  lua_replace(L, -2);  // Replace subval userdata with fenv.
-  return UPB_CONTINUE_WITH(subval);
-}
-
-static upb_flow_t lupb_msg_string(void *m, upb_value fval, upb_value val,
-                                  bool array) {
-  // Could add lazy materialization of strings here.
-  upb_fielddef *f = upb_value_getfielddef(fval);
-  lua_State *L = *(lua_State**)m;
-  int offset = array ? lua_rawlen(L, -1) : f->offset;
-  if (!lua_checkstack(L, 1)) luaL_error(L, "stack full");
-  lupb_pushstring(L, upb_value_getstrref(val));
-  lua_rawseti(L, -2, offset);
-  return UPB_CONTINUE;
-}
-
-static upb_sflow_t lupb_msg_startseq(void *m, upb_value fval) {
-  upb_fielddef *f = upb_value_getfielddef(fval);
-  return lupb_msg_start(m, f, false, lupb_array_pushnew, f);
-}
-
-static upb_sflow_t lupb_msg_startsubmsg(void *m, upb_value fval) {
-  upb_fielddef *f = upb_value_getfielddef(fval);
-  return lupb_msg_start(m, f, false, lupb_msg_pushnew, upb_fielddef_subdef(f));
-}
-
-static upb_sflow_t lupb_msg_startsubmsg_r(void *a, upb_value fval) {
-  upb_fielddef *f = upb_value_getfielddef(fval);
-  return lupb_msg_start(a, f, true, lupb_msg_pushnew, upb_fielddef_subdef(f));
-}
-
-static upb_flow_t lupb_msg_stringval(void *m, upb_value fval, upb_value val) {
-  return lupb_msg_string(m, fval, val, false);
-}
-
-static upb_flow_t lupb_msg_stringval_r(void *a, upb_value fval, upb_value val) {
-  return lupb_msg_string(a, fval, val, true);
-}
-
-#define STDMSG(type, size) static upb_accessor_vtbl vtbl = { \
-    &lupb_msg_startsubmsg, \
-    &upb_stdmsg_set ## type, \
-    &lupb_msg_startseq, \
-    &lupb_msg_startsubmsg_r, \
-    &upb_stdmsg_set ## type ## _r, \
-    &upb_stdmsg_has, \
-    &upb_stdmsg_getptr, \
-    &upb_stdmsg_get ## type, \
-    &upb_stdmsg_seqbegin, \
-    &upb_stdmsg_ ## size ## byte_seqnext, \
-    &upb_stdmsg_seqget ## type};
-
-#define RETURN_STDMSG(type, size) { STDMSG(type, size); return &vtbl; }
-
-static upb_accessor_vtbl *lupb_accessor(upb_fielddef *f) {
-  switch (f->type) {
-    case UPB_TYPE(DOUBLE): RETURN_STDMSG(double, 8)
-    case UPB_TYPE(FLOAT): RETURN_STDMSG(float, 4)
-    case UPB_TYPE(UINT64):
-    case UPB_TYPE(FIXED64): RETURN_STDMSG(uint64, 8)
-    case UPB_TYPE(INT64):
-    case UPB_TYPE(SFIXED64):
-    case UPB_TYPE(SINT64): RETURN_STDMSG(int64, 8)
-    case UPB_TYPE(INT32):
-    case UPB_TYPE(SINT32):
-    case UPB_TYPE(ENUM):
-    case UPB_TYPE(SFIXED32): RETURN_STDMSG(int32, 4)
-    case UPB_TYPE(UINT32):
-    case UPB_TYPE(FIXED32): RETURN_STDMSG(uint32, 4)
-    case UPB_TYPE(BOOL): { STDMSG(bool, 1); return &vtbl; }
-    case UPB_TYPE(GROUP):
-    case UPB_TYPE(MESSAGE): RETURN_STDMSG(ptr, 8)  // TODO: 32-bit
-    case UPB_TYPE(STRING):
-    case UPB_TYPE(BYTES): {
-      STDMSG(ptr, 8);
-      vtbl.set = &lupb_msg_stringval;
-      vtbl.append = &lupb_msg_stringval_r;
-      return &vtbl;
-    }
-  }
-  return NULL;
-}
-
-
-/* lupb_array ****************************************************************/
-
-// Array: we store all elements in the environment table.  Could optimize by
-// storing primitive arrays in our own memory; this would be significantly more
-// space efficient.  Lua array elements are 16 bytes each; our own array would
-// be 1/4 the space for 32-bit integers, or 1/16 the space for booleans.
-//
-// The first element of the environment table stores our type (which will be
-// either an integer from upb.TYPE_* or a upb.msgdef), the remaining elements
-// store the elements.  We always keep all elements contiguous so we can use
-// lua_objlen()/lua_rawlen() (for Lua 5.1/5.2 respectively) to report its len).
-
-// narg is offset of environment table.
-static size_t lupb_array_getlen(lua_State *L, int narg) {
-  return lua_rawlen(L, narg) - 1;
-}
-
-static void lupb_array_check(lua_State *L, int narg) {
-  if (!luaL_checkudata(L, narg, "upb.array"))
-    luaL_typerror(L, narg, "upb array");
-}
-
-static void lupb_array_pushnew(lua_State *L, void *f) {
-  (void)L;
-  (void)f;
-}
-
-static int lupb_array_new(lua_State *L) {
-  (void)L;
-  return 0;
-}
-
-static int lupb_array_len(lua_State *L) {
-  lupb_array_check(L, 1);
-  lua_getfenv(L, 1);
-  lua_pushnumber(L, lupb_array_getlen(L, -1));
-  return 1;
-}
-
-static int lupb_array_index(lua_State *L) {
-  assert(lua_gettop(L) == 2);  // __index should always be called with 2 args.
-  lupb_array_check(L, 1);
-  lua_Number num = luaL_checknumber(L, 2);
-  if (!lupb_isint(num)) luaL_typerror(L, 2, "integer");
-
-  lua_getfenv(L, 1);
-  size_t len = lupb_array_getlen(L, -1);
-  if (num < 1 || num > len) luaL_error(L, "array bounds check failed");
-  lua_rawgeti(L, -1, num + 1);
-  return 1;
-}
-
-static int lupb_array_newindex(lua_State *L) {
-  assert(lua_gettop(L) == 3);  // __newindex should always be called with 3 args.
-  lupb_array_check(L, 1);
-  lua_Number num = luaL_checknumber(L, 2);
-  if (rint(num) != num) luaL_typerror(L, 2, "integer");
-
-  lua_getfenv(L, 1);
-  size_t len = lupb_array_getlen(L, -1);
-  // We only allow extending the index one beyond the end.
-  if (num < 1 || num > len + 1) luaL_error(L, "array bounds check failed");
-  lua_pushvalue(L, 3);
-  lua_rawseti(L, -2, num);
-  return 0;
-}
-
-static const struct luaL_Reg lupb_array_mm[] = {
-  {"__len", lupb_array_len},
-  {"__index", lupb_array_index},
-  {"__newindex", lupb_array_newindex},
-  {NULL, NULL}
-};
-
-/* lupb toplevel **************************************************************/
-
-static const struct luaL_Reg lupb_toplevel_m[] = {
-  {"SymbolTable", lupb_symtab_new},
-  {"MessageDef", lupb_msgdef_new},
-  {"FieldDef", lupb_fielddef_new},
-
-  {"Message", lupb_msg_new},
-  {"Array", lupb_array_new},
-
-  {"clear", lupb_clear},
-  {"msgdef", lupb_msgdef},
-  {"has", lupb_has},
-
-  {NULL, NULL}
-};
-
-// Register the given type with the given methods and metamethods.
-static void lupb_register_type(lua_State *L, const char *name,
-                               const luaL_Reg *m, const luaL_Reg *mm) {
-  luaL_newmetatable(L, name);
-  luaL_register(L, NULL, mm);  // Register all mm in the metatable.
-  lua_createtable(L, 0, 0);
-  if (m) {
-    // Methods go in the mt's __index method.  This implies that you can't
-    // implement __index and also set methods yourself.
-    luaL_register(L, NULL, m);
-    lua_setfield(L, -2, "__index");
-  }
-  lua_pop(L, 1);  // The mt.
-}
-
-static void lupb_setfieldi(lua_State *L, const char *field, int i) {
-  lua_pushnumber(L, i);
-  lua_setfield(L, -2, field);
-}
-
-int luaopen_upb(lua_State *L) {
-  lupb_register_type(L, "upb.msgdef", lupb_msgdef_m, lupb_msgdef_mm);
-  lupb_register_type(L, "upb.enumdef", lupb_enumdef_m, lupb_enumdef_mm);
-  lupb_register_type(L, "upb.fielddef", NULL, lupb_fielddef_mm);
-  lupb_register_type(L, "upb.symtab", lupb_symtab_m, lupb_symtab_mm);
-
-  lupb_register_type(L, "upb.msg", NULL, lupb_msg_mm);
-  lupb_register_type(L, "upb.array", NULL, lupb_msg_mm);
-
-  // Create our object cache.
-  lua_createtable(L, 0, 0);
-  lua_createtable(L, 0, 1);  // Cache metatable.
-  lua_pushstring(L, "v");    // Values are weak.
-  lua_setfield(L, -2, "__mode");
-  lua_setfield(L, LUA_REGISTRYINDEX, "upb.objcache");
-
-  luaL_register(L, "upb", lupb_toplevel_m);
-
-  // Register constants.
-  lupb_setfieldi(L, "LABEL_OPTIONAL", UPB_LABEL(OPTIONAL));
-  lupb_setfieldi(L, "LABEL_REQUIRED", UPB_LABEL(REQUIRED));
-  lupb_setfieldi(L, "LABEL_REPEATED", UPB_LABEL(REPEATED));
-
-  lupb_setfieldi(L, "TYPE_DOUBLE", UPB_TYPE(DOUBLE));
-  lupb_setfieldi(L, "TYPE_FLOAT", UPB_TYPE(FLOAT));
-  lupb_setfieldi(L, "TYPE_INT64", UPB_TYPE(INT64));
-  lupb_setfieldi(L, "TYPE_UINT64", UPB_TYPE(UINT64));
-  lupb_setfieldi(L, "TYPE_INT32", UPB_TYPE(INT32));
-  lupb_setfieldi(L, "TYPE_FIXED64", UPB_TYPE(FIXED64));
-  lupb_setfieldi(L, "TYPE_FIXED32", UPB_TYPE(FIXED32));
-  lupb_setfieldi(L, "TYPE_BOOL", UPB_TYPE(BOOL));
-  lupb_setfieldi(L, "TYPE_STRING", UPB_TYPE(STRING));
-  lupb_setfieldi(L, "TYPE_GROUP", UPB_TYPE(GROUP));
-  lupb_setfieldi(L, "TYPE_MESSAGE", UPB_TYPE(MESSAGE));
-  lupb_setfieldi(L, "TYPE_BYTES", UPB_TYPE(BYTES));
-  lupb_setfieldi(L, "TYPE_UINT32", UPB_TYPE(UINT32));
-  lupb_setfieldi(L, "TYPE_ENUM", UPB_TYPE(ENUM));
-  lupb_setfieldi(L, "TYPE_SFIXED32", UPB_TYPE(SFIXED32));
-  lupb_setfieldi(L, "TYPE_SFIXED64", UPB_TYPE(SFIXED64));
-  lupb_setfieldi(L, "TYPE_SINT32", UPB_TYPE(SINT32));
-  lupb_setfieldi(L, "TYPE_SINT64", UPB_TYPE(SINT64));
-
-  return 1;  // Return package table.
-}
diff --git a/lang_ext/python/setup.py b/lang_ext/python/setup.py
deleted file mode 100644
index 8abaff8..0000000
--- a/lang_ext/python/setup.py
+++ /dev/null
@@ -1,14 +0,0 @@
-from distutils.core import setup, Extension
-
-setup(name='upb',
-      version='0.1',
-      ext_modules=[
-          Extension('upb.__init__', ['upb.c'],
-              include_dirs=['../../'],
-              define_macros=[("UPB_UNALIGNED_READS_OK", 1)],
-              library_dirs=['../../upb'],
-              libraries=['upb_pic'],
-          ),
-      ],
-      packages=['upb']
-      )
diff --git a/lang_ext/python/test.py b/lang_ext/python/test.py
deleted file mode 100644
index 29a6c45..0000000
--- a/lang_ext/python/test.py
+++ /dev/null
@@ -1,72 +0,0 @@
-
-import upb
-import unittest
-
-class TestFieldDef(unittest.TestCase):
-  def test_construction(self):
-    fielddef1 = upb.FieldDef()
-    self.assertTrue(fielddef1.number is None)
-    self.assertTrue(fielddef1.name is None)
-    self.assertTrue(fielddef1.type is None)
-    self.assertEqual(fielddef1.label, upb.LABEL_OPTIONAL)
-
-    fielddef2 = upb.FieldDef(number=5, name="field2",
-                             label=upb.LABEL_REQUIRED, type=upb.TYPE_INT32,
-                             type_name="MyType")
-
-    self.assertTrue(id(fielddef1) != id(fielddef2))
-    self.assertEqual(fielddef2.number, 5)
-    self.assertEqual(fielddef2.name, "field2")
-    self.assertEqual(fielddef2.label, upb.LABEL_REQUIRED)
-    self.assertEqual(fielddef2.type, upb.TYPE_INT32)
-    self.assertEqual(fielddef2.type_name, "MyType")
-
-    fielddef2.number = 8
-    self.assertEqual(fielddef2.number, 8)
-
-    fielddef2.name = "xxx"
-    self.assertEqual(fielddef2.name, "xxx")
-
-    fielddef2.label = upb.LABEL_REPEATED
-    self.assertEqual(fielddef2.label, upb.LABEL_REPEATED)
-
-    fielddef2.type = upb.TYPE_FLOAT
-    self.assertEqual(fielddef2.type, upb.TYPE_FLOAT)
-
-  def test_nosubclasses(self):
-    def create_subclass():
-      class MyClass(upb.FieldDef):
-        pass
-
-    self.assertRaises(TypeError, create_subclass)
-
-  # TODO: test that assigning invalid values is properly prevented.
-
-class TestMessageDef(unittest.TestCase):
-  def test_construction(self):
-    msgdef1 = upb.MessageDef()
-    self.assertTrue(msgdef1.fqname is None)
-    self.assertEqual(msgdef1.fields(), [])
-
-    fields = [upb.FieldDef(number=1, name="field1", type=upb.TYPE_INT32)]
-    msgdef2 = upb.MessageDef(fqname="Message2", fields=fields)
-
-    self.assertEqual(set(msgdef2.fields()), set(fields))
-
-    f2 = upb.FieldDef(number=2, name="field2", type=upb.TYPE_INT64)
-    msgdef2.add_field(f2)
-
-    fields.append(f2)
-    self.assertEqual(set(msgdef2.fields()), set(fields))
-
-class TestSymbolTable(unittest.TestCase):
-  def test_construction(self):
-    s = upb.SymbolTable()
-    self.assertEqual(s.defs(), []);
-
-    s.add_def(upb.MessageDef(fqname="A"))
-    self.assertTrue(s.lookup("A") is not None)
-    self.assertTrue(s.lookup("A") is s.lookup("A"))
-
-if __name__ == '__main__':
-  unittest.main()
diff --git a/lang_ext/python/upb.c b/lang_ext/python/upb.c
deleted file mode 100644
index ffb3d52..0000000
--- a/lang_ext/python/upb.c
+++ /dev/null
@@ -1,724 +0,0 @@
-/*
- * upb - a minimalist implementation of protocol buffers.
- *
- * Copyright (c) 2009 Google Inc.  See LICENSE for details.
- * Author: Josh Haberman <jhaberman@gmail.com>
- *
- * Python extension exposing the core of upb: definitions, handlers,
- * and a message type.
- */
-
-#include <stddef.h>
-#include <Python.h>
-#include "upb/def.h"
-#include "upb/msg.h"
-
-static bool streql(const char *a, const char *b) { return strcmp(a, b) == 0; }
-
-PyObject *PyUpb_Error(const char *str) {
-  PyErr_SetString(PyExc_TypeError, str);
-  return NULL;
-}
-
-int PyUpb_ErrorInt(const char *str) {
-  PyErr_SetString(PyExc_TypeError, str);
-  return -1;
-}
-
-#define PyUpb_CheckStatus(status) \
-  if (!upb_ok(status)) return PyUpb_Error((status)->str);
-
-static upb_accessor_vtbl *PyUpb_AccessorForField(upb_fielddef *f);
-
-
-/* Object cache ***************************************************************/
-
-// For objects that are just wrappers around a C object pointer, we keep a
-// cache mapping C pointer -> wrapper object.  This allows us to consistently
-// vend the same Python object given the same C object.  This prevents us from
-// creating too many Python objects unnecessarily.  More importantly, it provides
-// the expected semantics:
-//
-//   if field.subdef is field.subdef:
-//     print "Sanity prevails."
-//
-// If we conjured up a new wrapper object every time, the above would not be
-// true.
-//
-// The cost is having to put all such objects in a table, but since this only
-// applies to schema-level objects (defs, handlers, etc) this seems acceptable.
-// We do *not* have to put all message objects in this table.
-//
-// We use weak refs so that the cache does not prevent the wrapper objects from
-// being collected.  The table is stored as a static variable; to use
-// sub-interpreters this would need to change, but I believe that using
-// sub-interpreters is exceedingly rare in practice.
-
-typedef struct {
-  PyObject_HEAD;
-  void *obj;
-  PyObject *weakreflist;
-} PyUpb_ObjWrapper;
-
-static PyObject *obj_cache = NULL;
-static PyObject *reverse_cache = NULL;
-static PyObject *weakref_callback = NULL;
-
-// Utility functions for manipulating Python dictionaries keyed by pointer.
-
-static PyObject *PyUpb_StringForPointer(void *ptr) {
-  PyObject *o = PyString_FromStringAndSize((const char *)&ptr, sizeof(void*));
-  assert(o);
-  return o;
-}
-
-static PyObject *PyUpb_ObjCacheDeleteCallback(PyObject *self, PyObject *ref) {
-  // Python very unfortunately clears the weakref before running our callback.
-  // This prevents us from using the weakref to find the C pointer we need to
-  // remove from the cache.  As a result we are forced to keep a second map
-  // mapping weakref->C pointer.
-  PyObject *ptr_str = PyDict_GetItem(reverse_cache, ref);
-  assert(ptr_str);
-  int err = PyDict_DelItem(obj_cache, ptr_str);
-  assert(!err);
-  err = PyDict_DelItem(reverse_cache, ref);
-  assert(!err);
-  return Py_None;
-}
-
-static PyObject *PyUpb_ObjCacheGet(void *obj, PyTypeObject *type) {
-  PyObject *kv = PyUpb_StringForPointer(obj);
-  PyObject *ref = PyDict_GetItem(obj_cache, kv);
-  PyObject *ret;
-  if (ref) {
-    ret = PyWeakref_GetObject(ref);
-    assert(ret != Py_None);
-    Py_INCREF(ret);
-  } else {
-    PyUpb_ObjWrapper *wrapper = (PyUpb_ObjWrapper*)type->tp_alloc(type, 0);
-    wrapper->obj = obj;
-    wrapper->weakreflist = NULL;
-    ret = (PyObject*)wrapper;
-    ref = PyWeakref_NewRef(ret, weakref_callback);
-    assert(PyWeakref_GetObject(ref) == ret);
-    assert(ref);
-    PyDict_SetItem(obj_cache, kv, ref);
-    PyDict_SetItem(reverse_cache, ref, kv);
-  }
-  assert(ret);
-  Py_DECREF(kv);
-  return ret;
-}
-
-
-/* PyUpb_Def ******************************************************************/
-
-static PyTypeObject *PyUpb_TypeForDef(upb_def *def);
-
-static void PyUpb_Def_dealloc(PyObject *obj) {
-  PyUpb_ObjWrapper *wrapper = (void*)obj;
-  upb_def_unref((upb_def*)wrapper->obj);
-  obj->ob_type->tp_free(obj);
-}
-
-PyObject *PyUpb_Def_GetOrCreate(upb_def *def) {
-  return def ? PyUpb_ObjCacheGet(def, PyUpb_TypeForDef(def)) : Py_None;
-}
-
-// Will need to expand once other kinds of defs are supported.
-#define Check_Def(o, badret) Check_MessageDef(o, badret)
-
-
-/* PyUpb_FieldDef *************************************************************/
-
-static PyTypeObject PyUpb_FieldDefType;
-static int PyUpb_FieldDef_setattro(PyObject *o, PyObject *key, PyObject *val);
-
-#define Check_FieldDef(o, badret) \
-  (void*)(((PyUpb_ObjWrapper*)o)->obj); do { \
-    if(!PyObject_TypeCheck(o, &PyUpb_FieldDefType)) { \
-      PyErr_SetString(PyExc_TypeError, "must be a upb.FieldDef"); \
-      return badret; \
-    } \
-  } while(0)
-
-static PyObject *PyUpb_FieldDef_GetOrCreate(upb_fielddef *f) {
-  return PyUpb_ObjCacheGet(f, &PyUpb_FieldDefType);
-}
-
-static PyObject *PyUpb_FieldDef_new(PyTypeObject *subtype,
-                                    PyObject *args, PyObject *kwds) {
-  return PyUpb_ObjCacheGet(upb_fielddef_new(), subtype);
-}
-
-static int PyUpb_FieldDef_init(PyObject *self, PyObject *args, PyObject *kwds) {
-  if (!kwds) return 0;
-  PyObject *key, *value;
-  Py_ssize_t pos = 0;
-  while (PyDict_Next(kwds, &pos, &key, &value))
-    PyUpb_FieldDef_setattro(self, key, value);
-  return 0;
-}
-
-static void PyUpb_FieldDef_dealloc(PyObject *obj) {
-  PyUpb_ObjWrapper *wrapper = (void*)obj;
-  if (wrapper->weakreflist) PyObject_ClearWeakRefs(obj);
-  upb_fielddef_unref((upb_fielddef*)wrapper->obj);
-  obj->ob_type->tp_free(obj);
-}
-
-static PyObject *PyUpb_FieldDef_getattro(PyObject *obj, PyObject *attr_name) {
-  upb_fielddef *f = Check_FieldDef(obj, NULL);
-  if (!upb_fielddef_ismutable(f)) {
-    PyErr_SetString(PyExc_TypeError, "fielddef is not mutable.");
-    return NULL;
-  }
-  const char *name = PyString_AsString(attr_name);
-  if (streql(name, "name")) {
-    const char *name = upb_fielddef_name(f);
-    return name == NULL ? Py_None : PyString_FromString(name);
-  } else if (streql(name, "number")) {
-    uint32_t num = upb_fielddef_number(f);
-    return num == 0 ? Py_None : PyInt_FromLong(num);
-  } else if (streql(name, "type")) {
-    uint8_t type = upb_fielddef_type(f);
-    return type == 0 ? Py_None : PyInt_FromLong(type);
-  } else if (streql(name, "label")) {
-    return PyInt_FromLong(upb_fielddef_label(f));
-  } else if (streql(name, "type_name")) {
-    const char *name = upb_fielddef_typename(f);
-    return name == NULL ? Py_None : PyString_FromString(name);
-  } else if (streql(name, "subdef")) {
-    // NYI;
-    return NULL;
-  } else if (streql(name, "msgdef")) {
-    // NYI;
-    return NULL;
-  } else {
-    return PyUpb_Error("Invalid fielddef member.");
-  }
-}
-
-static int PyUpb_FieldDef_setattro(PyObject *o, PyObject *key, PyObject *val) {
-  upb_fielddef *f = Check_FieldDef(o, -1);
-  const char *field = PyString_AsString(key);
-  if (!upb_fielddef_ismutable(f))
-    return PyUpb_ErrorInt("fielddef is not mutable.");
-  if (streql(field, "name")) {
-    const char *name = PyString_AsString(val);
-    if (!name || !upb_fielddef_setname(f, name))
-      return PyUpb_ErrorInt("Invalid name");
-  } else if (streql(field, "number")) {
-    // TODO: should check truncation.  Non-security issue.
-    // Non-int will return -1, which is already invalid as a field number.
-    if (!upb_fielddef_setnumber(f, PyInt_AsLong(val)))
-      return PyUpb_ErrorInt("Invalid number");
-  } else if (streql(field, "type")) {
-    // TODO: should check truncation.  Non-security issue.
-    if (!upb_fielddef_settype(f, PyInt_AsLong(val)))
-      return PyUpb_ErrorInt("Invalid type");
-  } else if (streql(field, "label")) {
-    // TODO: should check truncation.  Non-security issue.
-    if (!upb_fielddef_setlabel(f, PyInt_AsLong(val)))
-      return PyUpb_ErrorInt("Invalid label");
-  } else if (streql(field, "type_name")) {
-    const char *name = PyString_AsString(val);
-    if (!name || !upb_fielddef_settypename(f, name))
-      return PyUpb_ErrorInt("Invalid type_name");
-  } else if (streql(field, "default_value")) {
-    // NYI
-    return -1;
-  } else {
-    return PyUpb_ErrorInt("Invalid fielddef member.");
-  }
-  return 0;
-}
-
-static PyTypeObject PyUpb_FieldDefType = {
-  PyObject_HEAD_INIT(NULL)
-  0,                                      /* ob_size */
-  "upb.FieldDef",                         /* tp_name */
-  sizeof(PyUpb_ObjWrapper),               /* tp_basicsize */
-  0,                                      /* tp_itemsize */
-  &PyUpb_FieldDef_dealloc,                /* tp_dealloc */
-  0,                                      /* tp_print */
-  0,                                      /* tp_getattr */
-  0,                                      /* tp_setattr */
-  0,                                      /* tp_compare */
-  0, /* TODO */                           /* tp_repr */
-  0,                                      /* tp_as_number */
-  0,                                      /* tp_as_sequence */
-  0,                                      /* tp_as_mapping */
-  0,                                      /* tp_hash */
-  0,                                      /* tp_call */
-  0,                                      /* tp_str */
-  &PyUpb_FieldDef_getattro,               /* tp_getattro */
-  &PyUpb_FieldDef_setattro,               /* tp_setattro */
-  0,                                      /* tp_as_buffer */
-  Py_TPFLAGS_DEFAULT,                     /* tp_flags */
-  0,                                      /* tp_doc */
-  0,                                      /* tp_traverse */
-  0,                                      /* tp_clear */
-  0,                                      /* tp_richcompare */
-  offsetof(PyUpb_ObjWrapper, weakreflist),/* tp_weaklistoffset */
-  0,                                      /* tp_iter */
-  0,                                      /* tp_iternext */
-  0,                                      /* tp_methods */
-  0,                                      /* tp_members */
-  0,                                      /* tp_getset */
-  0,                                      /* tp_base */
-  0,                                      /* tp_dict */
-  0,                                      /* tp_descr_get */
-  0,                                      /* tp_descr_set */
-  0,                                      /* tp_dictoffset */
-  &PyUpb_FieldDef_init,                   /* tp_init */
-  0,                                      /* tp_alloc */
-  &PyUpb_FieldDef_new,                    /* tp_new */
-  0,                                      /* tp_free */
-};
-
-
-/* PyUpb_MessageDef ***********************************************************/
-
-static PyTypeObject PyUpb_MessageDefType;
-static int PyUpb_MessageDef_setattro(PyObject *o, PyObject *key, PyObject *val);
-
-#define Check_MessageDef(o, badret) \
-  (void*)(((PyUpb_ObjWrapper*)o)->obj); do { \
-    if(!PyObject_TypeCheck(o, &PyUpb_MessageDefType)) { \
-      PyErr_SetString(PyExc_TypeError, "must be a upb.MessageDef"); \
-      return badret; \
-    } \
-  } while(0)
-
-static PyObject *PyUpb_MessageDef_new(PyTypeObject *subtype,
-                                      PyObject *args, PyObject *kwds) {
-  return PyUpb_ObjCacheGet(upb_msgdef_new(), subtype);
-}
-
-static PyObject *PyUpb_MessageDef_add_fields(PyObject *o, PyObject *args);
-
-static int PyUpb_MessageDef_init(PyObject *self, PyObject *args, PyObject *kwds) {
-  if (!kwds) return 0;
-  PyObject *key, *value;
-  Py_ssize_t pos = 0;
-  while (PyDict_Next(kwds, &pos, &key, &value)) {
-    const char *field = PyString_AsString(key);
-    if (streql(field, "fields")) {
-      PyUpb_MessageDef_add_fields(self, value);
-    } else {
-      PyUpb_MessageDef_setattro(self, key, value);
-    }
-  }
-  return 0;
-}
-
-static PyObject *PyUpb_MessageDef_getattro(PyObject *obj, PyObject *attr_name) {
-  upb_msgdef *m = Check_MessageDef(obj, NULL);
-  const char *name = PyString_AsString(attr_name);
-  if (streql(name, "fqname")) {
-    const char *fqname = upb_def_fqname(UPB_UPCAST(m));
-    return fqname == NULL ? Py_None : PyString_FromString(fqname);
-  }
-  return PyObject_GenericGetAttr(obj, attr_name);
-}
-
-static int PyUpb_MessageDef_setattro(PyObject *o, PyObject *key, PyObject *val) {
-  upb_msgdef *m = Check_MessageDef(o, -1);
-  if (!upb_def_ismutable(UPB_UPCAST(m))) {
-    PyErr_SetString(PyExc_TypeError, "MessageDef is not mutable.");
-    return -1;
-  }
-  const char *name = PyString_AsString(key);
-  if (streql(name, "fqname")) {
-    const char *fqname = PyString_AsString(val);
-    if (!fqname || !upb_def_setfqname(UPB_UPCAST(m), fqname))
-      return PyUpb_ErrorInt("Invalid fqname");
-  } else {
-    return PyUpb_ErrorInt("Invalid MessageDef member.");
-  }
-  return 0;
-}
-
-static PyObject *PyUpb_MessageDef_fields(PyObject *obj, PyObject *args) {
-  upb_msgdef *m = Check_MessageDef(obj, NULL);
-  PyObject *ret = PyList_New(0);
-  upb_msg_iter i;
-  for(i = upb_msg_begin(m); !upb_msg_done(i); i = upb_msg_next(m, i)) {
-    upb_fielddef *f = upb_msg_iter_field(i);
-    PyList_Append(ret, PyUpb_FieldDef_GetOrCreate(f));
-  }
-  return ret;
-}
-
-static PyObject *PyUpb_MessageDef_add_fields(PyObject *o, PyObject *fields) {
-  upb_msgdef *m = Check_MessageDef(o, NULL);
-  if (!PySequence_Check(fields)) return PyUpb_Error("Must be a sequence");
-  Py_ssize_t len = PySequence_Length(fields);
-  if (len > UPB_MAX_FIELDS) return PyUpb_Error("Too many fields.");
-  upb_fielddef *f[len];
-  int i;
-  for (i = 0; i < len; i++) {
-    PyObject *field = PySequence_GetItem(fields, i);
-    f[i] = Check_FieldDef(field, NULL);
-  }
-  upb_msgdef_addfields(m, f, len);
-  return Py_None;
-}
-
-static PyObject *PyUpb_MessageDef_add_field(PyObject *o, PyObject *field) {
-  upb_msgdef *m = Check_MessageDef(o, NULL);
-  upb_fielddef *f = Check_FieldDef(field, NULL);
-  upb_msgdef_addfield(m, f);
-  return Py_None;
-}
-
-static PyMethodDef PyUpb_MessageDef_methods[] = {
-  {"add_field", &PyUpb_MessageDef_add_field, METH_O, "Adds a list of fields."},
-  {"add_fields", &PyUpb_MessageDef_add_fields, METH_O, "Adds a list of fields."},
-  {"fields", &PyUpb_MessageDef_fields, METH_NOARGS, "Returns list of fields."},
-  {NULL, NULL}
-};
-
-static PyTypeObject PyUpb_MessageDefType = {
-  PyObject_HEAD_INIT(NULL)
-  0,                                      /* ob_size */
-  "upb.MessageDef",                       /* tp_name */
-  sizeof(PyUpb_ObjWrapper),               /* tp_basicsize */
-  0,                                      /* tp_itemsize */
-  &PyUpb_Def_dealloc,                     /* tp_dealloc */
-  0,                                      /* tp_print */
-  0,                                      /* tp_getattr */
-  0,                                      /* tp_setattr */
-  0,                                      /* tp_compare */
-  0, /* TODO */                           /* tp_repr */
-  0,                                      /* tp_as_number */
-  0,                                      /* tp_as_sequence */
-  0,                                      /* tp_as_mapping */
-  0,                                      /* tp_hash */
-  0,                                      /* tp_call */
-  0,                                      /* tp_str */
-  &PyUpb_MessageDef_getattro,             /* tp_getattro */
-  &PyUpb_MessageDef_setattro,             /* tp_setattro */
-  0,                                      /* tp_as_buffer */
-  Py_TPFLAGS_DEFAULT,                     /* tp_flags */
-  0,                                      /* tp_doc */
-  0,                                      /* tp_traverse */
-  0,                                      /* tp_clear */
-  0,                                      /* tp_richcompare */
-  offsetof(PyUpb_ObjWrapper, weakreflist),/* tp_weaklistoffset */
-  0,                                      /* tp_iter */
-  0,                                      /* tp_iternext */
-  PyUpb_MessageDef_methods,               /* tp_methods */
-  0,                                      /* tp_members */
-  0,                                      /* tp_getset */
-  0,                                      /* tp_base */
-  0,                                      /* tp_dict */
-  0,                                      /* tp_descr_get */
-  0,                                      /* tp_descr_set */
-  0,                                      /* tp_dictoffset */
-  &PyUpb_MessageDef_init,                 /* tp_init */
-  0,                                      /* tp_alloc */
-  &PyUpb_MessageDef_new,                  /* tp_new */
-  0,                                      /* tp_free */
-};
-
-
-static PyTypeObject *PyUpb_TypeForDef(upb_def *def) {
-  switch(def->type) {
-    case UPB_DEF_MSG: return &PyUpb_MessageDefType;
-    default: return NULL;
-  }
-}
-
-/* PyUpb_SymbolTable **********************************************************/
-
-static PyTypeObject PyUpb_SymbolTableType;
-
-#define Check_SymbolTable(o, badret) \
-  (void*)(((PyUpb_ObjWrapper*)o)->obj); do { \
-    if(!PyObject_TypeCheck(o, &PyUpb_SymbolTableType)) { \
-      PyErr_SetString(PyExc_TypeError, "must be a upb.MessageDef"); \
-      return badret; \
-    } \
-  } while(0)
-
-static PyObject *PyUpb_SymbolTable_new(PyTypeObject *subtype,
-                                       PyObject *args, PyObject *kwds) {
-  return PyUpb_ObjCacheGet(upb_symtab_new(), subtype);
-}
-
-static int PyUpb_SymbolTable_init(PyObject *self, PyObject *args, PyObject *kwds) {
-  return 0;
-}
-
-static void PyUpb_SymbolTable_dealloc(PyObject *obj) {
-  PyUpb_ObjWrapper *wrapper = (void*)obj;
-  upb_symtab_unref((upb_symtab*)wrapper->obj);
-  obj->ob_type->tp_free(obj);
-}
-
-// narg is a lua table containing a list of defs to add.
-static PyObject *PyUpb_SymbolTable_add_defs(PyObject *o, PyObject *defs) {
-  upb_symtab *s = Check_SymbolTable(o, NULL);
-  if (!PySequence_Check(defs)) return PyUpb_Error("Must be a sequence");
-  Py_ssize_t n = PySequence_Length(defs);
-
-  // Prevent stack overflow.
-  if (n > 2048) return PyUpb_Error("Too many defs");
-  upb_def *cdefs[n];
-
-  int i = 0;
-  for (i = 0; i < n; i++) {
-    PyObject *pydef = PySequence_GetItem(defs, i);
-    upb_def *def = Check_MessageDef(pydef, NULL);
-    cdefs[i++] = def;
-    upb_msgdef *md = upb_dyncast_msgdef(def);
-    if (!md) continue;
-    upb_msg_iter j;
-    for(j = upb_msg_begin(md); !upb_msg_done(j); j = upb_msg_next(md, j)) {
-      upb_fielddef *f = upb_msg_iter_field(j);
-      upb_fielddef_setaccessor(f, PyUpb_AccessorForField(f));
-    }
-    upb_msgdef_layout(md);
-  }
-
-  upb_status status = UPB_STATUS_INIT;
-  upb_symtab_add(s, cdefs, n, &status);
-  PyUpb_CheckStatus(&status);
-  return Py_None;
-}
-
-static PyObject *PyUpb_SymbolTable_add_def(PyObject *o, PyObject *def) {
-  PyObject *defs = PyList_New(1);
-  PyList_SetItem(defs, 0, def);
-  return PyUpb_SymbolTable_add_defs(o, defs);
-}
-
-// TODO: update to allow user to choose type of defs.
-static PyObject *PyUpb_SymbolTable_defs(PyObject *o, PyObject *none) {
-  upb_symtab *s = Check_SymbolTable(o, NULL);
-  int count;
-  upb_def **defs = upb_symtab_getdefs(s, &count, UPB_DEF_ANY);
-  PyObject *ret = PyList_New(count);
-  int i;
-  for(i = 0; i < count; i++)
-    PyList_SetItem(ret, i, PyUpb_Def_GetOrCreate(defs[i]));
-  return ret;
-}
-
-static PyObject *PyUpb_SymbolTable_lookup(PyObject *o, PyObject *arg) {
-  upb_symtab *s = Check_SymbolTable(o, NULL);
-  const char *name = PyString_AsString(arg);
-  upb_def *def = upb_symtab_lookup(s, name);
-  return PyUpb_Def_GetOrCreate(def);
-}
-
-static PyMethodDef PyUpb_SymbolTable_methods[] = {
-  {"add_def", &PyUpb_SymbolTable_add_def, METH_O, NULL},
-  {"add_defs", &PyUpb_SymbolTable_add_defs, METH_O, NULL},
-  {"defs", &PyUpb_SymbolTable_defs, METH_NOARGS, NULL},
-  {"lookup", &PyUpb_SymbolTable_lookup, METH_O, NULL},
-  {NULL, NULL}
-};
-
-static PyTypeObject PyUpb_SymbolTableType = {
-  PyObject_HEAD_INIT(NULL)
-  0,                                      /* ob_size */
-  "upb.SymbolTable",                      /* tp_name */
-  sizeof(PyUpb_ObjWrapper),               /* tp_basicsize */
-  0,                                      /* tp_itemsize */
-  &PyUpb_SymbolTable_dealloc,             /* tp_dealloc */
-  0,                                      /* tp_print */
-  0,                                      /* tp_getattr */
-  0,                                      /* tp_setattr */
-  0,                                      /* tp_compare */
-  0, /* TODO */                           /* tp_repr */
-  0,                                      /* tp_as_number */
-  0,                                      /* tp_as_sequence */
-  0,                                      /* tp_as_mapping */
-  0,                                      /* tp_hash */
-  0,                                      /* tp_call */
-  0,                                      /* tp_str */
-  0,                                      /* tp_getattro */
-  0,                                      /* tp_setattro */
-  0,                                      /* tp_as_buffer */
-  Py_TPFLAGS_DEFAULT,                     /* tp_flags */
-  0,                                      /* tp_doc */
-  0,                                      /* tp_traverse */
-  0,                                      /* tp_clear */
-  0,                                      /* tp_richcompare */
-  offsetof(PyUpb_ObjWrapper, weakreflist),/* tp_weaklistoffset */
-  0,                                      /* tp_iter */
-  0,                                      /* tp_iternext */
-  PyUpb_SymbolTable_methods,              /* tp_methods */
-  0,                                      /* tp_members */
-  0,                                      /* tp_getset */
-  0,                                      /* tp_base */
-  0,                                      /* tp_dict */
-  0,                                      /* tp_descr_get */
-  0,                                      /* tp_descr_set */
-  0,                                      /* tp_dictoffset */
-  &PyUpb_SymbolTable_init,                /* tp_init */
-  0,                                      /* tp_alloc */
-  &PyUpb_SymbolTable_new,                 /* tp_new */
-  0,                                      /* tp_free */
-};
-
-
-/* Accessor and PyUpb_Message *************************************************/
-
-typedef struct {
-  PyTypeObject type;
-  PyTypeObject *alt_type;
-} PyUpb_MessageType;
-
-typedef struct {
-  PyObject_HEAD;
-  PyObject *msgdef;
-  char data[1];
-} PyUpb_Message;
-
-PyObject **PyUpb_Accessor_GetPtr(PyObject *_m, upb_value fval) {
-  PyUpb_Message *m = (PyUpb_Message*)_m;
-  upb_fielddef *f = upb_value_getfielddef(fval);
-  return (PyObject**)&m->data[f->offset];
-}
-
-static upb_sflow_t PyUpb_Message_StartSequence(void *m, upb_value fval) {
-  PyObject **seq = PyUpb_Accessor_GetPtr(m, fval);
-  PyTypeObject *type = ((PyUpb_MessageType*)Py_TYPE(m))->alt_type;
-  if (!*seq) *seq = type->tp_alloc(type, 0);
-  upb_stdmsg_sethas(m, fval);
-  return UPB_CONTINUE_WITH(*seq);
-}
-
-static upb_sflow_t PyUpb_Message_StartSubmessage(void *m, upb_value fval) {
-  PyObject **submsg = PyUpb_Accessor_GetPtr(m, fval);
-  PyTypeObject *type = Py_TYPE(m);
-  if (!*submsg) *submsg = type->tp_alloc(type, 0);
-  upb_stdmsg_sethas(m, fval);
-  return UPB_CONTINUE_WITH(*submsg);
-}
-
-static upb_sflow_t PyUpb_Message_StartRepeatedSubmessage(void *a, upb_value fval) {
-  (void)fval;
-  PyObject **elem = upb_stdarray_append(a, sizeof(void*));
-  PyTypeObject *type = ((PyUpb_MessageType*)Py_TYPE(a))->alt_type;
-  if (!*elem) *elem = type->tp_alloc(type, 0);
-  return UPB_CONTINUE_WITH(*elem);
-}
-
-static upb_flow_t PyUpb_Message_StringValue(void *m, upb_value fval, upb_value val) {
-  PyObject **str = PyUpb_Accessor_GetPtr(m, fval);
-  if (*str) Py_DECREF(*str);
-  *str = PyString_FromStringAndSize(NULL, upb_value_getstrref(val)->len);
-  upb_strref_read(upb_value_getstrref(val), PyString_AsString(*str));
-  upb_stdmsg_sethas(m, fval);
-  return UPB_CONTINUE;
-}
-
-static upb_flow_t PyUpb_Message_AppendStringValue(void *a, upb_value fval, upb_value val) {
-  (void)fval;
-  PyObject **elem = upb_stdarray_append(a, sizeof(void*));
-  *elem = PyString_FromStringAndSize(NULL, upb_value_getstrref(val)->len);
-  upb_strref_read(upb_value_getstrref(val), PyString_AsString(*elem));
-  return UPB_CONTINUE;
-}
-
-#define STDMSG(type, size) static upb_accessor_vtbl vtbl = { \
-    &PyUpb_Message_StartSubmessage, \
-    &upb_stdmsg_set ## type, \
-    &PyUpb_Message_StartSequence, \
-    &PyUpb_Message_StartRepeatedSubmessage, \
-    &upb_stdmsg_set ## type ## _r, \
-    &upb_stdmsg_has, \
-    &upb_stdmsg_getptr, \
-    &upb_stdmsg_get ## type, \
-    &upb_stdmsg_seqbegin, \
-    &upb_stdmsg_ ## size ## byte_seqnext, \
-    &upb_stdmsg_seqget ## type};
-
-#define RETURN_STDMSG(type, size) { STDMSG(type, size); return &vtbl; }
-
-static upb_accessor_vtbl *PyUpb_AccessorForField(upb_fielddef *f) {
-  switch (f->type) {
-    case UPB_TYPE(DOUBLE): RETURN_STDMSG(double, 8)
-    case UPB_TYPE(FLOAT): RETURN_STDMSG(float, 4)
-    case UPB_TYPE(UINT64):
-    case UPB_TYPE(FIXED64): RETURN_STDMSG(uint64, 8)
-    case UPB_TYPE(INT64):
-    case UPB_TYPE(SFIXED64):
-    case UPB_TYPE(SINT64): RETURN_STDMSG(int64, 8)
-    case UPB_TYPE(INT32):
-    case UPB_TYPE(SINT32):
-    case UPB_TYPE(ENUM):
-    case UPB_TYPE(SFIXED32): RETURN_STDMSG(int32, 4)
-    case UPB_TYPE(UINT32):
-    case UPB_TYPE(FIXED32): RETURN_STDMSG(uint32, 4)
-    case UPB_TYPE(BOOL): { STDMSG(bool, 1); return &vtbl; }
-    case UPB_TYPE(GROUP):
-    case UPB_TYPE(MESSAGE): RETURN_STDMSG(ptr, 8)  // TODO: 32-bit
-    case UPB_TYPE(STRING):
-    case UPB_TYPE(BYTES): {
-      STDMSG(ptr, 8);
-      vtbl.set = &PyUpb_Message_StringValue;
-      vtbl.append = &PyUpb_Message_AppendStringValue;
-      return &vtbl;
-    }
-  }
-  return NULL;
-}
-
-
-/* Toplevel *******************************************************************/
-
-static PyMethodDef methods[] = {
-  {NULL, NULL}
-};
-
-// PyModule_AddObject steals a ref, but our object is statically allocated
-// and must not be deleted.
-#define PyUpb_AddType(mod, name, type) \
-  if (PyType_Ready(type) < 0) return; \
-  Py_INCREF(type); \
-  PyModule_AddObject(mod, name, (PyObject*)type);
-
-PyMODINIT_FUNC initupb(void) {
-  PyObject *mod = Py_InitModule("upb", methods);
-
-  PyUpb_AddType(mod, "FieldDef", &PyUpb_FieldDefType);
-  PyUpb_AddType(mod, "MessageDef", &PyUpb_MessageDefType);
-  PyUpb_AddType(mod, "SymbolTable", &PyUpb_SymbolTableType);
-
-  PyModule_AddIntConstant(mod, "LABEL_OPTIONAL", UPB_LABEL(OPTIONAL));
-  PyModule_AddIntConstant(mod, "LABEL_REQUIRED", UPB_LABEL(REQUIRED));
-  PyModule_AddIntConstant(mod, "LABEL_REPEATED", UPB_LABEL(REPEATED));
-
-  PyModule_AddIntConstant(mod, "TYPE_DOUBLE", UPB_TYPE(DOUBLE));
-  PyModule_AddIntConstant(mod, "TYPE_FLOAT", UPB_TYPE(FLOAT));
-  PyModule_AddIntConstant(mod, "TYPE_INT64", UPB_TYPE(INT64));
-  PyModule_AddIntConstant(mod, "TYPE_UINT64", UPB_TYPE(UINT64));
-  PyModule_AddIntConstant(mod, "TYPE_INT32", UPB_TYPE(INT32));
-  PyModule_AddIntConstant(mod, "TYPE_FIXED64", UPB_TYPE(FIXED64));
-  PyModule_AddIntConstant(mod, "TYPE_FIXED32", UPB_TYPE(FIXED32));
-  PyModule_AddIntConstant(mod, "TYPE_BOOL", UPB_TYPE(BOOL));
-  PyModule_AddIntConstant(mod, "TYPE_STRING", UPB_TYPE(STRING));
-  PyModule_AddIntConstant(mod, "TYPE_GROUP", UPB_TYPE(GROUP));
-  PyModule_AddIntConstant(mod, "TYPE_MESSAGE", UPB_TYPE(MESSAGE));
-  PyModule_AddIntConstant(mod, "TYPE_BYTES", UPB_TYPE(BYTES));
-  PyModule_AddIntConstant(mod, "TYPE_UINT32", UPB_TYPE(UINT32));
-  PyModule_AddIntConstant(mod, "TYPE_ENUM", UPB_TYPE(ENUM));
-  PyModule_AddIntConstant(mod, "TYPE_SFIXED32", UPB_TYPE(SFIXED32));
-  PyModule_AddIntConstant(mod, "TYPE_SFIXED64", UPB_TYPE(SFIXED64));
-  PyModule_AddIntConstant(mod, "TYPE_SINT32", UPB_TYPE(SINT32));
-  PyModule_AddIntConstant(mod, "TYPE_SINT64", UPB_TYPE(SINT64));
-
-  obj_cache = PyDict_New();
-  reverse_cache = PyDict_New();
-  static PyMethodDef method = {
-        "WeakRefCallback", &PyUpb_ObjCacheDeleteCallback, METH_O, NULL};
-  PyObject *pyname = PyString_FromString(method.ml_name);
-  weakref_callback = PyCFunction_NewEx(&method, NULL, pyname);
-  Py_DECREF(pyname);
-}
diff --git a/lang_ext/python/upb/__init__.py b/lang_ext/python/upb/__init__.py
deleted file mode 100644
index e69de29..0000000
--- a/lang_ext/python/upb/__init__.py
+++ /dev/null