// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC.  All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#include "python/descriptor.h"

// clang-format off
#include "Python.h"
// clang-format on
#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#include "google/protobuf/descriptor.upb_minitable.h"
#include "google/protobuf/breaking_changes.h"
#include "python/convert.h"
#include "python/descriptor_containers.h"
#include "python/descriptor_pool.h"
#include "python/free_threading/lazy_ptr.h"
#include "python/free_threading/weak_map.h"
#include "python/message.h"
#include "python/protobuf.h"
#include "upb/base/descriptor_constants.h"
#include "upb/base/upcast.h"
#include "upb/mem/arena.h"
#include "upb/message/message.h"
#include "upb/mini_table/message.h"
#include "upb/port/atomic.h"
#include "upb/reflection/def.h"
#include "upb/reflection/message.h"
#include "upb/util/def_to_proto.h"

// Must be last.
#include "upb/port/def.inc"
#include "upb/wire/decode.h"
#include "upb/wire/encode.h"

// -----------------------------------------------------------------------------
// DescriptorBase
// -----------------------------------------------------------------------------

// This representation is used by all concrete descriptors.

typedef struct {
  // clang-format off
  PyObject_HEAD
  PyObject* pool;          // We own a ref.
  // clang-format on
  const void* def;  // Type depends on the class. Kept alive by "pool".
  PYUPB_LAZYPTR(PyObject) options;   // NULL if not present or not cached.
  PYUPB_LAZYPTR(PyObject) features;  // NULL if not present or not cached.
  PyObject* message_meta;            // We own a ref.
} PyUpb_DescriptorBase;

PyObject* PyUpb_AnyDescriptor_GetPool(PyObject* desc) {
  PyUpb_DescriptorBase* base = (void*)desc;
  return base->pool;
}

const void* PyUpb_AnyDescriptor_GetDef(PyObject* desc) {
  PyUpb_DescriptorBase* base = (void*)desc;
  return base->def;
}

static PyUpb_DescriptorBase* PyUpb_DescriptorBase_DoCreate(
    PyUpb_DescriptorType type, const void* def, PyObject* pool) {
  PyUpb_ModuleState* state = PyUpb_ModuleState_Get();
  PyTypeObject* type_obj = state->descriptor_types[type];
  assert(def);
  assert(pool);
  assert(type_obj);

  PyUpb_DescriptorBase* base = (void*)PyType_GenericAlloc(type_obj, 0);
  if (!base) return NULL;
  base->pool = pool;
  Py_INCREF(base->pool);
  base->def = def;
  base->options = NULL;
  base->features = NULL;
  base->message_meta = NULL;

  return base;
}

// Returns a Python object wrapping |def|, of descriptor type |type|.  If a
// wrapper was previously created for this def, returns it, otherwise creates a
// new wrapper.
static PyObject* PyUpb_DescriptorBase_Get(PyUpb_DescriptorType type,
                                          const void* def, PyObject* pool) {
  assert(pool);
  PyObject* ret = PyUpb_DescriptorPool_CacheGet(pool, def);
  if (ret) return ret;

  PyUpb_DescriptorBase* base = PyUpb_DescriptorBase_DoCreate(type, def, pool);
  if (!base) return NULL;

  PyObject* py_base = &base->ob_base;
  if (!PyUpb_DescriptorPool_CacheAdd(pool, def, &py_base)) {
    Py_DECREF(&base->ob_base);
    return NULL;
  }
  return py_base;
}

static PyUpb_DescriptorBase* PyUpb_DescriptorBase_Check(
    PyObject* obj, PyUpb_DescriptorType type) {
  PyUpb_ModuleState* state = PyUpb_ModuleState_MaybeGet();
  if (!state) {
    return (PyUpb_DescriptorBase*)obj;
  }
  PyTypeObject* type_obj = state->descriptor_types[type];
  if (!PyObject_TypeCheck(obj, type_obj)) {
    PyErr_Format(PyExc_TypeError, "Expected object of type %S, but got %R",
                 type_obj, obj);
    return NULL;
  }
  return (PyUpb_DescriptorBase*)obj;
}

typedef struct {
  const upb_Message* opts;
  const upb_MiniTable* layout;
  const char* msg_name;
  const char* strip_field;
} PyUpb_GetCachedArgs;

static PyObject* PyUpb_DescriptorBase_CreateCachedOptions(void* _args) {
  PyUpb_GetCachedArgs* args = _args;
  PyObject* py_arena = NULL;

  // Load descriptors protos if they are not loaded already. We have to do
  // this lazily, otherwise, it would lead to circular imports.
  PyObject* mod =
      PyImport_ImportModuleLevel(PYUPB_DESCRIPTOR_MODULE, NULL, NULL, NULL, 0);
  if (mod == NULL) return NULL;
  Py_DECREF(mod);

  // Find the correct options message.
  PyObject* default_pool = PyUpb_DescriptorPool_GetDefaultPool();
  const upb_DefPool* symtab = PyUpb_DescriptorPool_GetSymtab(default_pool);
  const upb_MessageDef* m =
      upb_DefPool_FindMessageByName(symtab, args->msg_name);
  assert(m);

  // Copy the options message from C to Python using serialize+parse.
  // We don't wrap the C object directly because there is no guarantee that
  // the descriptor_pb2 that was loaded at runtime has the same members or
  // layout as the C types that were compiled in.
  size_t size;
  py_arena = PyUpb_Arena_New(default_pool);
  if (!py_arena) goto err;
  upb_Arena* arena = PyUpb_Arena_Get(py_arena);
  char* pb;
  upb_EncodeStatus es =
      upb_Encode(args->opts, args->layout, 0, arena, &pb, &size);
  if (es != kUpb_EncodeStatus_Ok) {
    if (es == kUpb_EncodeStatus_OutOfMemory) {
      PyErr_SetNone(PyExc_MemoryError);
    } else {
      PyErr_Format(PyUpb_ModuleState_Get()->decode_error_class,
                   "Error parsing descriptor: %s", upb_EncodeStatus_String(es));
    }
    goto err;
  }
  const upb_MiniTable* opts2_layout = upb_MessageDef_MiniTable(m);
  upb_Message* opts2 = upb_Message_New(opts2_layout, arena);
  if (!opts2) {
    PyErr_SetNone(PyExc_MemoryError);
    goto err;
  }
  upb_DecodeStatus ds =
      upb_Decode(pb, size, opts2, opts2_layout,
                 upb_DefPool_ExtensionRegistry(symtab), 0, arena);
  if (ds != kUpb_DecodeStatus_Ok) {
    if (ds == kUpb_DecodeStatus_OutOfMemory) {
      PyErr_SetNone(PyExc_MemoryError);
    } else {
      PyErr_Format(PyUpb_ModuleState_Get()->decode_error_class,
                   "Error parsing descriptor: %s", upb_DecodeStatus_String(ds));
    }
    goto err;
  }

  if (args->strip_field) {
    const upb_FieldDef* field =
        upb_MessageDef_FindFieldByName(m, args->strip_field);
    assert(field);
    upb_Message_ClearFieldByDef(opts2, field);
  }

#if PROTOBUF_PY_FUTURE_FREEZE_OPTIONS
  upb_Message_Freeze(opts2, opts2_layout);
#else
  PyUpb_Arena_SetFrozen(py_arena, true);
#endif
  PyObject* val = PyUpb_Message_Get(default_pool, opts2, m, py_arena);
  Py_DECREF(py_arena);
  return val;

err:
  Py_XDECREF(py_arena);
  return NULL;
}

static PyObject* PyUpb_DescriptorBase_GetCached(void* cached,
                                                const upb_Message* opts,
                                                const upb_MiniTable* layout,
                                                const char* msg_name,
                                                const char* strip_field) {
  PyUpb_GetCachedArgs args = {opts, layout, msg_name, strip_field};
  return PyUpb_LazyPtr_LazyInitPyObj(
      cached, PyUpb_DescriptorBase_CreateCachedOptions, &args);
}

static PyObject* PyUpb_DescriptorBase_GetOptions(void* cached,
                                                 const upb_Message* opts,
                                                 const upb_MiniTable* layout,
                                                 const char* msg_name) {
  return PyUpb_DescriptorBase_GetCached(cached, opts, layout, msg_name,
                                        "features");
}

static PyObject* PyUpb_DescriptorBase_GetFeatures(void* cached,
                                                  const upb_Message* opts) {
  return PyUpb_DescriptorBase_GetCached(
      cached, opts, &google__protobuf__FeatureSet_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".FeatureSet", NULL);
}

typedef void* PyUpb_ToProto_Func(const void* def, upb_Arena* arena);

static PyObject* PyUpb_DescriptorBase_GetSerializedProto(
    PyObject* _self, PyUpb_ToProto_Func* func, const upb_MiniTable* layout) {
  PyUpb_DescriptorBase* self = (void*)_self;
  upb_Arena* arena = upb_Arena_New();
  if (!arena) PYUPB_RETURN_OOM;
  upb_Message* proto = func(self->def, arena);
  if (!proto) goto oom;
  size_t size;
  char* pb;
  upb_EncodeStatus status = upb_Encode(proto, layout, 0, arena, &pb, &size);
  if (status) goto oom;  // TODO non-oom errors are possible here
  PyObject* str = PyBytes_FromStringAndSize(pb, size);
  upb_Arena_Free(arena);
  return str;

oom:
  upb_Arena_Free(arena);
  PyErr_SetNone(PyExc_MemoryError);
  return NULL;
}

static PyObject* PyUpb_DescriptorBase_CopyToProto(PyObject* _self,
                                                  PyUpb_ToProto_Func* func,
                                                  const upb_MiniTable* layout,
                                                  const char* expected_type,
                                                  PyObject* py_proto) {
  if (!PyUpb_Message_Verify(py_proto)) return NULL;
  const upb_MessageDef* m = PyUpb_Message_GetMsgdef(py_proto);
  const char* type = upb_MessageDef_FullName(m);
  if (strcmp(type, expected_type) != 0) {
    PyErr_Format(
        PyExc_TypeError,
        "CopyToProto: message is of incorrect type '%s' (expected '%s'", type,
        expected_type);
    return NULL;
  }
  PyObject* serialized =
      PyUpb_DescriptorBase_GetSerializedProto(_self, func, layout);
  if (!serialized) return NULL;
  PyObject* ret = PyUpb_Message_MergeFromString(py_proto, serialized);
  Py_DECREF(serialized);
  return ret;
}

static void PyUpb_DescriptorBase_Dealloc(PyUpb_DescriptorBase* base) {
  // This deallocator can be called on different types (which, despite
  // 'Base' in the name of one of them, do not inherit from each other).
  // Some of these types are GC types (they have Py_TPFLAGS_HAVE_GC set),
  // which means Python's GC can visit them (via tp_visit and/or tp_clear
  // methods) at any time. This also means we *must* stop GC from tracking
  // instances of them before we start destructing the object. In Python
  // 3.11, failing to do so would raise a runtime warning.
  if (PyType_HasFeature(Py_TYPE(base), Py_TPFLAGS_HAVE_GC)) {
    PyObject_GC_UnTrack(base);
  }
  PyUpb_DescriptorPool_CacheEraseIfEqual(base->pool, base->def,
                                         (PyObject*)base);
  // In addition to being visited by GC, instances can also (potentially) be
  // accessed whenever arbitrary code is executed. Destructors can execute
  // arbitrary code, so any struct members we DECREF should be set to NULL
  // or a new value *before* calling Py_DECREF on them. The Py_CLEAR macro
  // (and Py_SETREF in Python 3.8+) takes care to do this safely.
  Py_CLEAR(base->message_meta);
  Py_CLEAR(base->pool);
  PyUpb_LazyPtr_Clear(&base->options);
  PyUpb_LazyPtr_Clear(&base->features);
  PyUpb_Dealloc(base);
}

static int PyUpb_Descriptor_Traverse(PyUpb_DescriptorBase* base,
                                     visitproc visit, void* arg) {
  Py_VISIT(base->message_meta);
  return 0;
}

static int PyUpb_Descriptor_Clear(PyUpb_DescriptorBase* base) {
  Py_CLEAR(base->message_meta);
  return 0;
}

#define DESCRIPTOR_BASE_SLOTS                           \
  {Py_tp_new, (void*)&PyUpb_Forbidden_New}, {           \
    Py_tp_dealloc, (void*)&PyUpb_DescriptorBase_Dealloc \
  }

// -----------------------------------------------------------------------------
// Descriptor
// -----------------------------------------------------------------------------

PyObject* PyUpb_Descriptor_Get(PyObject* pool, const upb_MessageDef* m) {
  assert(m);
  assert(pool);
  return PyUpb_DescriptorBase_Get(kPyUpb_Descriptor, m, pool);
}

PyObject* PyUpb_Descriptor_GetClass(PyObject* pool, const upb_MessageDef* m) {
  assert(pool != NULL);
  PyObject* ret =
      PyUpb_DescriptorPool_CacheGet(pool, upb_MessageDef_MiniTable(m));
  if (ret) return ret;

  PyUpb_ModuleState* state = PyUpb_ModuleState_MaybeGet();
  if (!state) {
    PyErr_SetString(PyExc_RuntimeError, "Interpreter is finalizing");
    return NULL;
  }

  // On demand create the class if it does not exist. However, if users
  // repeatedly create and destroy a class, it could trigger a loop. This is not
  // an issue now, but if we see CPU waste for repeatedly create and destroy
  // in the future, we could make PyUpb_Descriptor_Get() append the descriptor
  // to an internal list in DescriptorPool, let the pool keep descriptors alive.
  PyObject* py_descriptor = PyUpb_Descriptor_Get(pool, m);
  if (py_descriptor == NULL) return NULL;
  const char* name = upb_MessageDef_Name(m);
  PyObject* dict = PyDict_New();
  if (dict == NULL) goto err;
  int status = PyDict_SetItemString(dict, "DESCRIPTOR", py_descriptor);
  if (status < 0) goto err;
  ret = PyUpb_MessageMeta_DoCreateClass(py_descriptor, name, dict);

err:
  Py_XDECREF(py_descriptor);
  Py_XDECREF(dict);
  return ret;
}

void PyUpb_Descriptor_SetClass(PyObject* py_descriptor, PyObject* meta) {
  PyUpb_DescriptorBase* base = (PyUpb_DescriptorBase*)py_descriptor;
  Py_XINCREF(meta);
  PyObject* tmp = base->message_meta;
  base->message_meta = meta;
  Py_XDECREF(tmp);
}

// The LookupNested*() functions provide name lookup for entities nested inside
// a message.  This uses the symtab's table, which requires that the symtab is
// not being mutated concurrently.  We can guarantee this for Python-owned
// symtabs, but upb cannot guarantee it in general for an arbitrary
// `const upb_MessageDef*`.

static const void* PyUpb_Descriptor_LookupNestedMessage(const upb_MessageDef* m,
                                                        const char* name) {
  const upb_FileDef* filedef = upb_MessageDef_File(m);
  const upb_DefPool* symtab = upb_FileDef_Pool(filedef);
  PyObject* qname =
      PyUnicode_FromFormat("%s.%s", upb_MessageDef_FullName(m), name);
  const upb_MessageDef* ret = upb_DefPool_FindMessageByName(
      symtab, PyUnicode_AsUTF8AndSize(qname, NULL));
  Py_DECREF(qname);
  return ret;
}

static const void* PyUpb_Descriptor_LookupNestedEnum(const upb_MessageDef* m,
                                                     const char* name) {
  const upb_FileDef* filedef = upb_MessageDef_File(m);
  const upb_DefPool* symtab = upb_FileDef_Pool(filedef);
  PyObject* qname =
      PyUnicode_FromFormat("%s.%s", upb_MessageDef_FullName(m), name);
  const upb_EnumDef* ret =
      upb_DefPool_FindEnumByName(symtab, PyUnicode_AsUTF8AndSize(qname, NULL));
  Py_DECREF(qname);
  return ret;
}

static const void* PyUpb_Descriptor_LookupNestedExtension(
    const upb_MessageDef* m, const char* name) {
  const upb_FileDef* filedef = upb_MessageDef_File(m);
  const upb_DefPool* symtab = upb_FileDef_Pool(filedef);
  PyObject* qname =
      PyUnicode_FromFormat("%s.%s", upb_MessageDef_FullName(m), name);
  const upb_FieldDef* ret = upb_DefPool_FindExtensionByName(
      symtab, PyUnicode_AsUTF8AndSize(qname, NULL));
  Py_DECREF(qname);
  return ret;
}

static PyObject* PyUpb_Descriptor_GetExtensionRanges(PyObject* _self,
                                                     void* closure) {
  PyUpb_DescriptorBase* self = (PyUpb_DescriptorBase*)_self;
  int n = upb_MessageDef_ExtensionRangeCount(self->def);
  PyObject* range_list = PyList_New(n);

  for (int i = 0; i < n; i++) {
    const upb_ExtensionRange* range =
        upb_MessageDef_ExtensionRange(self->def, i);
    PyObject* start = PyLong_FromLong(upb_ExtensionRange_Start(range));
    PyObject* end = PyLong_FromLong(upb_ExtensionRange_End(range));
    PyObject* tuple = PyTuple_Pack(2, start, end);
    Py_DECREF(start);
    Py_DECREF(end);
    PyList_SetItem(range_list, i, tuple);
  }

  return range_list;
}

static PyObject* PyUpb_Descriptor_GetExtensions(PyObject* _self,
                                                void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_MessageDef_NestedExtensionCount,
      (void*)&upb_MessageDef_NestedExtension,
      (void*)&PyUpb_FieldDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetExtensionsByName(PyObject* _self,
                                                      void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_MessageDef_NestedExtensionCount,
          (void*)&upb_MessageDef_NestedExtension,
          (void*)&PyUpb_FieldDescriptor_Get,
      },
      (void*)&PyUpb_Descriptor_LookupNestedExtension,
      (void*)&upb_FieldDef_Name,
  };
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetEnumTypes(PyObject* _self, void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_MessageDef_NestedEnumCount,
      (void*)&upb_MessageDef_NestedEnum,
      (void*)&PyUpb_EnumDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetOneofs(PyObject* _self, void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_MessageDef_OneofCount,
      (void*)&upb_MessageDef_Oneof,
      (void*)&PyUpb_OneofDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetOptions(PyObject* _self, PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_MessageDef_Options(self->def)),
      &google__protobuf__MessageOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".MessageOptions");
}

static PyObject* PyUpb_Descriptor_GetFeatures(PyObject* _self, PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features, UPB_UPCAST(upb_MessageDef_ResolvedFeatures(self->def)));
}

static PyObject* PyUpb_Descriptor_CopyToProto(PyObject* _self,
                                              PyObject* py_proto) {
  return PyUpb_DescriptorBase_CopyToProto(
      _self, (PyUpb_ToProto_Func*)&upb_MessageDef_ToProto,
      &google__protobuf__DescriptorProto_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".DescriptorProto", py_proto);
}

static PyObject* PyUpb_Descriptor_EnumValueName(PyObject* _self,
                                                PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const char* enum_name;
  int number;
  if (!PyArg_ParseTuple(args, "si", &enum_name, &number)) return NULL;
  const upb_EnumDef* e =
      PyUpb_Descriptor_LookupNestedEnum(self->def, enum_name);
  if (!e) {
    PyErr_SetString(PyExc_KeyError, enum_name);
    return NULL;
  }
  const upb_EnumValueDef* ev = upb_EnumDef_FindValueByNumber(e, number);
  if (!ev) {
    PyErr_Format(PyExc_KeyError, "%d", number);
    return NULL;
  }
  return PyUnicode_FromString(upb_EnumValueDef_Name(ev));
}

static PyObject* PyUpb_Descriptor_GetFieldsByName(PyObject* _self,
                                                  void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_MessageDef_FieldCount,
          (void*)&upb_MessageDef_Field,
          (void*)&PyUpb_FieldDescriptor_Get,
      },
      (void*)&upb_MessageDef_FindFieldByName,
      (void*)&upb_FieldDef_Name,
  };
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetFieldsByCamelCaseName(PyObject* _self,
                                                           void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_MessageDef_FieldCount,
          (void*)&upb_MessageDef_Field,
          (void*)&PyUpb_FieldDescriptor_Get,
      },
      (void*)&upb_MessageDef_FindByJsonName,
      (void*)&upb_FieldDef_JsonName,
  };
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetFieldsByNumber(PyObject* _self,
                                                    void* closure) {
  static PyUpb_ByNumberMap_Funcs funcs = {
      {
          (void*)&upb_MessageDef_FieldCount,
          (void*)&upb_MessageDef_Field,
          (void*)&PyUpb_FieldDescriptor_Get,
      },
      (void*)&upb_MessageDef_FindFieldByNumber,
      (void*)&upb_FieldDef_Number,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNumberMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetNestedTypes(PyObject* _self,
                                                 void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_MessageDef_NestedMessageCount,
      (void*)&upb_MessageDef_NestedMessage,
      (void*)&PyUpb_Descriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetNestedTypesByName(PyObject* _self,
                                                       void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_MessageDef_NestedMessageCount,
          (void*)&upb_MessageDef_NestedMessage,
          (void*)&PyUpb_Descriptor_Get,
      },
      (void*)&PyUpb_Descriptor_LookupNestedMessage,
      (void*)&upb_MessageDef_Name,
  };
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetContainingType(PyObject* _self,
                                                    void* closure) {
  // upb does not natively store the lexical parent of a message type, but we
  // can derive it with some string manipulation and a lookup.
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_MessageDef* m = self->def;
  const upb_FileDef* file = upb_MessageDef_File(m);
  const upb_DefPool* symtab = upb_FileDef_Pool(file);
  const char* full_name = upb_MessageDef_FullName(m);
  const char* last_dot = strrchr(full_name, '.');
  if (!last_dot) Py_RETURN_NONE;
  const upb_MessageDef* parent = upb_DefPool_FindMessageByNameWithSize(
      symtab, full_name, last_dot - full_name);
  if (!parent) Py_RETURN_NONE;
  return PyUpb_Descriptor_Get(self->pool, parent);
}

static PyObject* PyUpb_Descriptor_GetEnumTypesByName(PyObject* _self,
                                                     void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_MessageDef_NestedEnumCount,
          (void*)&upb_MessageDef_NestedEnum,
          (void*)&PyUpb_EnumDescriptor_Get,
      },
      (void*)&PyUpb_Descriptor_LookupNestedEnum,
      (void*)&upb_EnumDef_Name,
  };
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetIsExtendable(PyObject* _self,
                                                  void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  if (upb_MessageDef_ExtensionRangeCount(self->def) > 0) {
    Py_RETURN_TRUE;
  } else {
    Py_RETURN_FALSE;
  }
}

static PyObject* PyUpb_Descriptor_GetFullName(PyObject* self, void* closure) {
  const upb_MessageDef* msgdef = PyUpb_Descriptor_GetDef(self);
  return PyUnicode_FromString(upb_MessageDef_FullName(msgdef));
}

static PyObject* PyUpb_Descriptor_GetConcreteClass(PyObject* self,
                                                   void* closure) {
  PyUpb_DescriptorBase* base = (void*)self;
  const upb_MessageDef* msgdef = PyUpb_Descriptor_GetDef(self);
  return PyUpb_DescriptorPool_CacheGet(base->pool,
                                       upb_MessageDef_MiniTable(msgdef));
}

static PyObject* PyUpb_Descriptor_GetFile(PyObject* _self, void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_MessageDef* msgdef = PyUpb_Descriptor_GetDef(_self);
  return PyUpb_FileDescriptor_Get(self->pool, upb_MessageDef_File(msgdef));
}

static PyObject* PyUpb_Descriptor_GetFields(PyObject* _self, void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_MessageDef_FieldCount,
      (void*)&upb_MessageDef_Field,
      (void*)&PyUpb_FieldDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_Descriptor_GetHasOptions(PyObject* _self,
                                                void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_MessageDef_HasOptions(self->def));
}

static PyObject* PyUpb_Descriptor_GetName(PyObject* self, void* closure) {
  const upb_MessageDef* msgdef = PyUpb_Descriptor_GetDef(self);
  return PyUnicode_FromString(upb_MessageDef_Name(msgdef));
}

static PyObject* PyUpb_Descriptor_GetEnumValuesByName(PyObject* _self,
                                                      void* closure) {
  // upb does not natively store any table containing all nested values.
  // Consider:
  //     message M {
  //       enum E1 {
  //         A = 0;
  //         B = 1;
  //       }
  //       enum E2 {
  //         C = 0;
  //         D = 1;
  //       }
  //     }
  //
  // In this case, upb stores tables for E1 and E2, but it does not store a
  // table for M that combines them (it is rarely needed and costs precious
  // space and time to build).
  //
  // To work around this, we build an actual Python dict whenever a user
  // actually asks for this.
  PyUpb_DescriptorBase* self = (void*)_self;
  PyObject* ret = PyDict_New();
  if (!ret) return NULL;
  int enum_count = upb_MessageDef_NestedEnumCount(self->def);
  for (int i = 0; i < enum_count; i++) {
    const upb_EnumDef* e = upb_MessageDef_NestedEnum(self->def, i);
    int value_count = upb_EnumDef_ValueCount(e);
    for (int j = 0; j < value_count; j++) {
      // Collisions should be impossible here, as uniqueness is checked by
      // protoc (this is an invariant of the protobuf language).  However this
      // uniqueness constraint is not currently checked by upb/def.c at load
      // time, so if the user supplies a manually-constructed descriptor that
      // does not respect this constraint, a collision could be possible and the
      // last-defined enumerator would win.  This could be seen as an argument
      // for having upb actually build the table at load time, thus checking the
      // constraint proactively, but upb is always checking a subset of the full
      // validation performed by C++, and we have to pick and choose the biggest
      // bang for the buck.
      const upb_EnumValueDef* ev = upb_EnumDef_Value(e, j);
      const char* name = upb_EnumValueDef_Name(ev);
      PyObject* val = PyUpb_EnumValueDescriptor_Get(self->pool, ev);
      if (!val || PyDict_SetItemString(ret, name, val) < 0) {
        Py_XDECREF(val);
        Py_DECREF(ret);
        return NULL;
      }
      Py_DECREF(val);
    }
  }
  return ret;
}

static PyObject* PyUpb_Descriptor_GetOneofsByName(PyObject* _self,
                                                  void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_MessageDef_OneofCount,
          (void*)&upb_MessageDef_Oneof,
          (void*)&PyUpb_OneofDescriptor_Get,
      },
      (void*)&upb_MessageDef_FindOneofByName,
      (void*)&upb_OneofDef_Name,
  };
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyGetSetDef PyUpb_Descriptor_Getters[] = {
    {"name", PyUpb_Descriptor_GetName, NULL, "Last name"},
    {"full_name", PyUpb_Descriptor_GetFullName, NULL, "Full name"},
    {"_concrete_class", PyUpb_Descriptor_GetConcreteClass, NULL,
     "concrete class"},
    {"file", PyUpb_Descriptor_GetFile, NULL, "File descriptor"},
    {"fields", PyUpb_Descriptor_GetFields, NULL, "Fields sequence"},
    {"fields_by_name", PyUpb_Descriptor_GetFieldsByName, NULL,
     "Fields by name"},
    {"fields_by_camelcase_name", PyUpb_Descriptor_GetFieldsByCamelCaseName,
     NULL, "Fields by camelCase name"},
    {"fields_by_number", PyUpb_Descriptor_GetFieldsByNumber, NULL,
     "Fields by number"},
    {"nested_types", PyUpb_Descriptor_GetNestedTypes, NULL,
     "Nested types sequence"},
    {"nested_types_by_name", PyUpb_Descriptor_GetNestedTypesByName, NULL,
     "Nested types by name"},
    {"extensions", PyUpb_Descriptor_GetExtensions, NULL, "Extensions Sequence"},
    {"extensions_by_name", PyUpb_Descriptor_GetExtensionsByName, NULL,
     "Extensions by name"},
    {"extension_ranges", PyUpb_Descriptor_GetExtensionRanges, NULL,
     "Extension ranges"},
    {"enum_types", PyUpb_Descriptor_GetEnumTypes, NULL, "Enum sequence"},
    {"enum_types_by_name", PyUpb_Descriptor_GetEnumTypesByName, NULL,
     "Enum types by name"},
    {"enum_values_by_name", PyUpb_Descriptor_GetEnumValuesByName, NULL,
     "Enum values by name"},
    {"oneofs_by_name", PyUpb_Descriptor_GetOneofsByName, NULL,
     "Oneofs by name"},
    {"oneofs", PyUpb_Descriptor_GetOneofs, NULL, "Oneofs Sequence"},
    {"containing_type", PyUpb_Descriptor_GetContainingType, NULL,
     "Containing type"},
    {"is_extendable", PyUpb_Descriptor_GetIsExtendable, NULL},
    {"has_options", PyUpb_Descriptor_GetHasOptions, NULL, "Has Options"},
    {NULL}};

static PyMethodDef PyUpb_Descriptor_Methods[] = {
    {"GetOptions", PyUpb_Descriptor_GetOptions, METH_NOARGS},
    {"_GetFeatures", PyUpb_Descriptor_GetFeatures, METH_NOARGS},
    {"CopyToProto", PyUpb_Descriptor_CopyToProto, METH_O},
    {"EnumValueName", PyUpb_Descriptor_EnumValueName, METH_VARARGS},
    {NULL}};

static PyType_Slot PyUpb_Descriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_Descriptor_Methods},
    {Py_tp_getset, PyUpb_Descriptor_Getters},
    {Py_tp_traverse, PyUpb_Descriptor_Traverse},
    {Py_tp_clear, PyUpb_Descriptor_Clear},
    {0, NULL}};

static PyType_Spec PyUpb_Descriptor_Spec = {
    PYUPB_MODULE_NAME ".Descriptor",          // tp_name
    sizeof(PyUpb_DescriptorBase),             // tp_basicsize
    0,                                        // tp_itemsize
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,  // tp_flags
    PyUpb_Descriptor_Slots,
};

const upb_MessageDef* PyUpb_Descriptor_GetDef(PyObject* _self) {
  PyUpb_DescriptorBase* self =
      PyUpb_DescriptorBase_Check(_self, kPyUpb_Descriptor);
  return self ? self->def : NULL;
}

// -----------------------------------------------------------------------------
// EnumDescriptor
// -----------------------------------------------------------------------------

PyObject* PyUpb_EnumDescriptor_Get(PyObject* pool, const upb_EnumDef* enumdef) {
  assert(enumdef);
  assert(pool);
  return PyUpb_DescriptorBase_Get(kPyUpb_EnumDescriptor, enumdef, pool);
}

const upb_EnumDef* PyUpb_EnumDescriptor_GetDef(PyObject* _self) {
  PyUpb_DescriptorBase* self =
      PyUpb_DescriptorBase_Check(_self, kPyUpb_EnumDescriptor);
  return self ? self->def : NULL;
}

static PyObject* PyUpb_EnumDescriptor_GetFullName(PyObject* self,
                                                  void* closure) {
  const upb_EnumDef* enumdef = PyUpb_EnumDescriptor_GetDef(self);
  return PyUnicode_FromString(upb_EnumDef_FullName(enumdef));
}

static PyObject* PyUpb_EnumDescriptor_GetName(PyObject* self, void* closure) {
  const upb_EnumDef* enumdef = PyUpb_EnumDescriptor_GetDef(self);
  return PyUnicode_FromString(upb_EnumDef_Name(enumdef));
}

static PyObject* PyUpb_EnumDescriptor_GetFile(PyObject* _self, void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_EnumDef* enumdef = PyUpb_EnumDescriptor_GetDef(_self);
  return PyUpb_FileDescriptor_Get(self->pool, upb_EnumDef_File(enumdef));
}

static PyObject* PyUpb_EnumDescriptor_GetValues(PyObject* _self,
                                                void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_EnumDef_ValueCount,
      (void*)&upb_EnumDef_Value,
      (void*)&PyUpb_EnumValueDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_EnumDescriptor_GetValuesByName(PyObject* _self,
                                                      void* closure) {
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_EnumDef_ValueCount,
          (void*)&upb_EnumDef_Value,
          (void*)&PyUpb_EnumValueDescriptor_Get,
      },
      (void*)&upb_EnumDef_FindValueByName,
      (void*)&upb_EnumValueDef_Name,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_EnumDescriptor_GetValuesByNumber(PyObject* _self,
                                                        void* closure) {
  static PyUpb_ByNumberMap_Funcs funcs = {
      {
          (void*)&upb_EnumDef_ValueCount,
          (void*)&upb_EnumDef_Value,
          (void*)&PyUpb_EnumValueDescriptor_Get,
      },
      (void*)&upb_EnumDef_FindValueByNumber,
      (void*)&upb_EnumValueDef_Number,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNumberMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_EnumDescriptor_GetContainingType(PyObject* _self,
                                                        void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_MessageDef* m = upb_EnumDef_ContainingType(self->def);
  if (!m) Py_RETURN_NONE;
  return PyUpb_Descriptor_Get(self->pool, m);
}

static PyObject* PyUpb_EnumDescriptor_GetHasOptions(PyObject* _self,
                                                    void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_EnumDef_HasOptions(self->def));
}

static PyObject* PyUpb_EnumDescriptor_GetIsClosed(PyObject* _self,
                                                  void* closure) {
  const upb_EnumDef* enumdef = PyUpb_EnumDescriptor_GetDef(_self);
  return PyBool_FromLong(upb_EnumDef_IsClosed(enumdef));
}

static PyObject* PyUpb_EnumDescriptor_GetOptions(PyObject* _self,
                                                 PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_EnumDef_Options(self->def)),
      &google__protobuf__EnumOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".EnumOptions");
}

static PyObject* PyUpb_EnumDescriptor_GetFeatures(PyObject* _self,
                                                  PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features, UPB_UPCAST(upb_EnumDef_ResolvedFeatures(self->def)));
}

static PyObject* PyUpb_EnumDescriptor_CopyToProto(PyObject* _self,
                                                  PyObject* py_proto) {
  return PyUpb_DescriptorBase_CopyToProto(
      _self, (PyUpb_ToProto_Func*)&upb_EnumDef_ToProto,
      &google__protobuf__EnumDescriptorProto_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".EnumDescriptorProto", py_proto);
}

static PyGetSetDef PyUpb_EnumDescriptor_Getters[] = {
    {"full_name", PyUpb_EnumDescriptor_GetFullName, NULL, "Full name"},
    {"name", PyUpb_EnumDescriptor_GetName, NULL, "last name"},
    {"file", PyUpb_EnumDescriptor_GetFile, NULL, "File descriptor"},
    {"values", PyUpb_EnumDescriptor_GetValues, NULL, "values"},
    {"values_by_name", PyUpb_EnumDescriptor_GetValuesByName, NULL,
     "Enum values by name"},
    {"values_by_number", PyUpb_EnumDescriptor_GetValuesByNumber, NULL,
     "Enum values by number"},
    {"containing_type", PyUpb_EnumDescriptor_GetContainingType, NULL,
     "Containing type"},
    {"has_options", PyUpb_EnumDescriptor_GetHasOptions, NULL, "Has Options"},
    {"is_closed", PyUpb_EnumDescriptor_GetIsClosed, NULL,
     "Checks if the enum is closed"},
    {NULL}};

static PyMethodDef PyUpb_EnumDescriptor_Methods[] = {
    {"GetOptions", PyUpb_EnumDescriptor_GetOptions, METH_NOARGS},
    {"_GetFeatures", PyUpb_EnumDescriptor_GetFeatures, METH_NOARGS},
    {"CopyToProto", PyUpb_EnumDescriptor_CopyToProto, METH_O},
    {NULL}};

static PyType_Slot PyUpb_EnumDescriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_EnumDescriptor_Methods},
    {Py_tp_getset, PyUpb_EnumDescriptor_Getters},
    {0, NULL}};

static PyType_Spec PyUpb_EnumDescriptor_Spec = {
    PYUPB_MODULE_NAME ".EnumDescriptor",  // tp_name
    sizeof(PyUpb_DescriptorBase),         // tp_basicsize
    0,                                    // tp_itemsize
    Py_TPFLAGS_DEFAULT,                   // tp_flags
    PyUpb_EnumDescriptor_Slots,
};

// -----------------------------------------------------------------------------
// EnumValueDescriptor
// -----------------------------------------------------------------------------

PyObject* PyUpb_EnumValueDescriptor_Get(PyObject* pool,
                                        const upb_EnumValueDef* ev) {
  return PyUpb_DescriptorBase_Get(kPyUpb_EnumValueDescriptor, ev, pool);
}

static PyObject* PyUpb_EnumValueDescriptor_GetName(PyObject* self,
                                                   void* closure) {
  PyUpb_DescriptorBase* base = (PyUpb_DescriptorBase*)self;
  return PyUnicode_FromString(upb_EnumValueDef_Name(base->def));
}

static PyObject* PyUpb_EnumValueDescriptor_GetNumber(PyObject* self,
                                                     void* closure) {
  PyUpb_DescriptorBase* base = (PyUpb_DescriptorBase*)self;
  return PyLong_FromLong(upb_EnumValueDef_Number(base->def));
}

static PyObject* PyUpb_EnumValueDescriptor_GetIndex(PyObject* self,
                                                    void* closure) {
  PyUpb_DescriptorBase* base = (PyUpb_DescriptorBase*)self;
  return PyLong_FromLong(upb_EnumValueDef_Index(base->def));
}

static PyObject* PyUpb_EnumValueDescriptor_GetType(PyObject* self,
                                                   void* closure) {
  PyUpb_DescriptorBase* base = (PyUpb_DescriptorBase*)self;
  return PyUpb_EnumDescriptor_Get(base->pool, upb_EnumValueDef_Enum(base->def));
}

static PyObject* PyUpb_EnumValueDescriptor_GetHasOptions(PyObject* _self,
                                                         void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_EnumValueDef_HasOptions(self->def));
}

static PyObject* PyUpb_EnumValueDescriptor_GetOptions(PyObject* _self,
                                                      PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_EnumValueDef_Options(self->def)),
      &google__protobuf__EnumValueOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".EnumValueOptions");
}

static PyObject* PyUpb_EnumValueDescriptor_GetFeatures(PyObject* _self,
                                                       PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features,
      UPB_UPCAST(upb_EnumValueDef_ResolvedFeatures(self->def)));
}

static PyGetSetDef PyUpb_EnumValueDescriptor_Getters[] = {
    {"name", PyUpb_EnumValueDescriptor_GetName, NULL, "name"},
    {"number", PyUpb_EnumValueDescriptor_GetNumber, NULL, "number"},
    {"index", PyUpb_EnumValueDescriptor_GetIndex, NULL, "index"},
    {"type", PyUpb_EnumValueDescriptor_GetType, NULL, "index"},
    {"has_options", PyUpb_EnumValueDescriptor_GetHasOptions, NULL,
     "Has Options"},
    {NULL}};

static PyMethodDef PyUpb_EnumValueDescriptor_Methods[] = {
    {
        "GetOptions",
        PyUpb_EnumValueDescriptor_GetOptions,
        METH_NOARGS,
    },
    {
        "_GetFeatures",
        PyUpb_EnumValueDescriptor_GetFeatures,
        METH_NOARGS,
    },
    {NULL}};

static PyType_Slot PyUpb_EnumValueDescriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_EnumValueDescriptor_Methods},
    {Py_tp_getset, PyUpb_EnumValueDescriptor_Getters},
    {0, NULL}};

static PyType_Spec PyUpb_EnumValueDescriptor_Spec = {
    PYUPB_MODULE_NAME ".EnumValueDescriptor",  // tp_name
    sizeof(PyUpb_DescriptorBase),              // tp_basicsize
    0,                                         // tp_itemsize
    Py_TPFLAGS_DEFAULT,                        // tp_flags
    PyUpb_EnumValueDescriptor_Slots,
};

// -----------------------------------------------------------------------------
// FieldDescriptor
// -----------------------------------------------------------------------------

const upb_FieldDef* PyUpb_FieldDescriptor_GetDef(PyObject* _self) {
  assert(_self);
  PyUpb_DescriptorBase* self =
      PyUpb_DescriptorBase_Check(_self, kPyUpb_FieldDescriptor);
  return self ? self->def : NULL;
}

PyObject* PyUpb_FieldDescriptor_Get(PyObject* pool, const upb_FieldDef* field) {
  assert(field);
  assert(pool);
  return PyUpb_DescriptorBase_Get(kPyUpb_FieldDescriptor, field, pool);
}

static PyObject* PyUpb_FieldDescriptor_GetFullName(PyUpb_DescriptorBase* self,
                                                   void* closure) {
  return PyUnicode_FromString(upb_FieldDef_FullName(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetName(PyUpb_DescriptorBase* self,
                                               void* closure) {
  return PyUnicode_FromString(upb_FieldDef_Name(self->def));
}

static char PyUpb_AsciiIsUpper(char ch) { return ch >= 'A' && ch <= 'Z'; }

static char PyUpb_AsciiToLower(char ch) {
  assert(PyUpb_AsciiIsUpper(ch));
  return ch + ('a' - 'A');
}

static PyObject* PyUpb_FieldDescriptor_GetCamelCaseName(
    PyUpb_DescriptorBase* self, void* closure) {
  // Camelcase is equivalent to JSON name except for potentially the first
  // character.
  const char* name = upb_FieldDef_JsonName(self->def);
  size_t size = strlen(name);
  return size > 0 && PyUpb_AsciiIsUpper(name[0])
             ? PyUnicode_FromFormat("%c%s", PyUpb_AsciiToLower(name[0]),
                                    name + 1)
             : PyUnicode_FromStringAndSize(name, size);
}

static PyObject* PyUpb_FieldDescriptor_GetJsonName(PyUpb_DescriptorBase* self,
                                                   void* closure) {
  return PyUnicode_FromString(upb_FieldDef_JsonName(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetFile(PyUpb_DescriptorBase* self,
                                               void* closure) {
  const upb_FileDef* file = upb_FieldDef_File(self->def);
  if (!file) Py_RETURN_NONE;
  return PyUpb_FileDescriptor_Get(self->pool, file);
}

static PyObject* PyUpb_FieldDescriptor_GetType(PyUpb_DescriptorBase* self,
                                               void* closure) {
  return PyLong_FromLong(upb_FieldDef_Type(self->def));
}

// Enum values copied from descriptor.h in C++.
enum CppType {
  CPPTYPE_INT32 = 1,     // TYPE_INT32, TYPE_SINT32, TYPE_SFIXED32
  CPPTYPE_INT64 = 2,     // TYPE_INT64, TYPE_SINT64, TYPE_SFIXED64
  CPPTYPE_UINT32 = 3,    // TYPE_UINT32, TYPE_FIXED32
  CPPTYPE_UINT64 = 4,    // TYPE_UINT64, TYPE_FIXED64
  CPPTYPE_DOUBLE = 5,    // TYPE_DOUBLE
  CPPTYPE_FLOAT = 6,     // TYPE_FLOAT
  CPPTYPE_BOOL = 7,      // TYPE_BOOL
  CPPTYPE_ENUM = 8,      // TYPE_ENUM
  CPPTYPE_STRING = 9,    // TYPE_STRING, TYPE_BYTES
  CPPTYPE_MESSAGE = 10,  // TYPE_MESSAGE, TYPE_GROUP
};

static PyObject* PyUpb_FieldDescriptor_GetCppType(PyUpb_DescriptorBase* self,
                                                  void* closure) {
  static const uint8_t cpp_types[] = {
      -1,
      [kUpb_CType_Int32] = CPPTYPE_INT32,
      [kUpb_CType_Int64] = CPPTYPE_INT64,
      [kUpb_CType_UInt32] = CPPTYPE_UINT32,
      [kUpb_CType_UInt64] = CPPTYPE_UINT64,
      [kUpb_CType_Double] = CPPTYPE_DOUBLE,
      [kUpb_CType_Float] = CPPTYPE_FLOAT,
      [kUpb_CType_Bool] = CPPTYPE_BOOL,
      [kUpb_CType_Enum] = CPPTYPE_ENUM,
      [kUpb_CType_String] = CPPTYPE_STRING,
      [kUpb_CType_Bytes] = CPPTYPE_STRING,
      [kUpb_CType_Message] = CPPTYPE_MESSAGE,
  };
  return PyLong_FromLong(cpp_types[upb_FieldDef_CType(self->def)]);
}

static PyObject* PyUpb_FieldDescriptor_IsRequired(PyUpb_DescriptorBase* self,
                                                  void* closure) {
  return PyBool_FromLong(upb_FieldDef_IsRequired(self->def));
}

static PyObject* PyUpb_FieldDescriptor_IsRepeated(PyUpb_DescriptorBase* self,
                                                  void* closure) {
  return PyBool_FromLong(upb_FieldDef_IsRepeated(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetIsExtension(
    PyUpb_DescriptorBase* self, void* closure) {
  return PyBool_FromLong(upb_FieldDef_IsExtension(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetIsPacked(PyUpb_DescriptorBase* self,
                                                   void* closure) {
  return PyBool_FromLong(upb_FieldDef_IsPacked(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetNumber(PyUpb_DescriptorBase* self,
                                                 void* closure) {
  return PyLong_FromLong(upb_FieldDef_Number(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetIndex(PyUpb_DescriptorBase* self,
                                                void* closure) {
  return PyLong_FromLong(upb_FieldDef_Index(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetMessageType(
    PyUpb_DescriptorBase* self, void* closure) {
  const upb_MessageDef* subdef = upb_FieldDef_MessageSubDef(self->def);
  if (!subdef) Py_RETURN_NONE;
  return PyUpb_Descriptor_Get(self->pool, subdef);
}

static PyObject* PyUpb_FieldDescriptor_GetEnumType(PyUpb_DescriptorBase* self,
                                                   void* closure) {
  const upb_EnumDef* enumdef = upb_FieldDef_EnumSubDef(self->def);
  if (!enumdef) Py_RETURN_NONE;
  return PyUpb_EnumDescriptor_Get(self->pool, enumdef);
}

static PyObject* PyUpb_FieldDescriptor_GetContainingType(
    PyUpb_DescriptorBase* self, void* closure) {
  const upb_MessageDef* m = upb_FieldDef_ContainingType(self->def);
  if (!m) Py_RETURN_NONE;
  return PyUpb_Descriptor_Get(self->pool, m);
}

static PyObject* PyUpb_FieldDescriptor_GetExtensionScope(
    PyUpb_DescriptorBase* self, void* closure) {
  const upb_MessageDef* m = upb_FieldDef_ExtensionScope(self->def);
  if (!m) Py_RETURN_NONE;
  return PyUpb_Descriptor_Get(self->pool, m);
}

static PyObject* PyUpb_FieldDescriptor_HasDefaultValue(
    PyUpb_DescriptorBase* self, void* closure) {
  return PyBool_FromLong(upb_FieldDef_HasDefault(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetDefaultValue(
    PyUpb_DescriptorBase* self, void* closure) {
  const upb_FieldDef* f = self->def;
  if (upb_FieldDef_IsRepeated(f)) return PyList_New(0);
  if (upb_FieldDef_IsSubMessage(f)) Py_RETURN_NONE;
  return PyUpb_UpbToPy(upb_FieldDef_Default(self->def), self->def, NULL);
}

static PyObject* PyUpb_FieldDescriptor_GetContainingOneof(
    PyUpb_DescriptorBase* self, void* closure) {
  const upb_OneofDef* oneof = upb_FieldDef_ContainingOneof(self->def);
  if (!oneof) Py_RETURN_NONE;
  return PyUpb_OneofDescriptor_Get(self->pool, oneof);
}

static PyObject* PyUpb_FieldDescriptor_GetHasOptions(
    PyUpb_DescriptorBase* _self, void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_FieldDef_HasOptions(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetHasPresence(
    PyUpb_DescriptorBase* _self, void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_FieldDef_HasPresence(self->def));
}

static PyObject* PyUpb_FieldDescriptor_GetOptions(PyObject* _self,
                                                  PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_FieldDef_Options(self->def)),
      &google__protobuf__FieldOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".FieldOptions");
}

static PyObject* PyUpb_FieldDescriptor_GetFeatures(PyObject* _self,
                                                   PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features, UPB_UPCAST(upb_FieldDef_ResolvedFeatures(self->def)));
}

static PyGetSetDef PyUpb_FieldDescriptor_Getters[] = {
    {"full_name", (getter)PyUpb_FieldDescriptor_GetFullName, NULL, "Full name"},
    {"name", (getter)PyUpb_FieldDescriptor_GetName, NULL, "Unqualified name"},
    {"camelcase_name", (getter)PyUpb_FieldDescriptor_GetCamelCaseName, NULL,
     "CamelCase name"},
    {"json_name", (getter)PyUpb_FieldDescriptor_GetJsonName, NULL, "Json name"},
    {"file", (getter)PyUpb_FieldDescriptor_GetFile, NULL, "File Descriptor"},
    {"type", (getter)PyUpb_FieldDescriptor_GetType, NULL, "Type"},
    {"cpp_type", (getter)PyUpb_FieldDescriptor_GetCppType, NULL, "C++ Type"},
    {"is_required", (getter)PyUpb_FieldDescriptor_IsRequired, NULL,
     "Is Required"},
    {"is_repeated", (getter)PyUpb_FieldDescriptor_IsRepeated, NULL,
     "Is Repeated"},
    {"number", (getter)PyUpb_FieldDescriptor_GetNumber, NULL, "Number"},
    {"index", (getter)PyUpb_FieldDescriptor_GetIndex, NULL, "Index"},
    {"default_value", (getter)PyUpb_FieldDescriptor_GetDefaultValue, NULL,
     "Default Value"},
    {"has_default_value", (getter)PyUpb_FieldDescriptor_HasDefaultValue},
    {"is_extension", (getter)PyUpb_FieldDescriptor_GetIsExtension, NULL, "ID"},
    {"is_packed", (getter)PyUpb_FieldDescriptor_GetIsPacked, NULL, "Is Packed"},
    // TODO
    //{ "id", (getter)GetID, NULL, "ID"},
    {"message_type", (getter)PyUpb_FieldDescriptor_GetMessageType, NULL,
     "Message type"},
    {"enum_type", (getter)PyUpb_FieldDescriptor_GetEnumType, NULL, "Enum type"},
    {"containing_type", (getter)PyUpb_FieldDescriptor_GetContainingType, NULL,
     "Containing type"},
    {"extension_scope", (getter)PyUpb_FieldDescriptor_GetExtensionScope, NULL,
     "Extension scope"},
    {"containing_oneof", (getter)PyUpb_FieldDescriptor_GetContainingOneof, NULL,
     "Containing oneof"},
    {"has_options", (getter)PyUpb_FieldDescriptor_GetHasOptions, NULL,
     "Has Options"},
    {"has_presence", (getter)PyUpb_FieldDescriptor_GetHasPresence, NULL,
     "Has Presence"},
    // TODO
    //{ "_options",
    //(getter)NULL, (setter)SetOptions, "Options"}, { "_serialized_options",
    //(getter)NULL, (setter)SetSerializedOptions, "Serialized Options"},
    {NULL}};

static PyMethodDef PyUpb_FieldDescriptor_Methods[] = {
    {
        "GetOptions",
        PyUpb_FieldDescriptor_GetOptions,
        METH_NOARGS,
    },
    {
        "_GetFeatures",
        PyUpb_FieldDescriptor_GetFeatures,
        METH_NOARGS,
    },
    {NULL}};

static PyType_Slot PyUpb_FieldDescriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_FieldDescriptor_Methods},
    {Py_tp_getset, PyUpb_FieldDescriptor_Getters},
    {0, NULL}};

static PyType_Spec PyUpb_FieldDescriptor_Spec = {
    PYUPB_MODULE_NAME ".FieldDescriptor",
    sizeof(PyUpb_DescriptorBase),
    0,  // tp_itemsize
    Py_TPFLAGS_DEFAULT,
    PyUpb_FieldDescriptor_Slots,
};

// -----------------------------------------------------------------------------
// FileDescriptor
// -----------------------------------------------------------------------------

PyObject* PyUpb_FileDescriptor_Get(PyObject* pool, const upb_FileDef* file) {
  return PyUpb_DescriptorBase_Get(kPyUpb_FileDescriptor, file, pool);
}

// These are not provided on upb_FileDef because they use the underlying
// symtab's hash table. This works for Python because everything happens under
// the GIL, but in general the caller has to guarantee that the symtab is not
// being mutated concurrently.
typedef const void* PyUpb_FileDescriptor_LookupFunc(const upb_DefPool*,
                                                    const char*);

static const void* PyUpb_FileDescriptor_NestedLookup(
    const upb_FileDef* filedef, const char* name,
    PyUpb_FileDescriptor_LookupFunc* func) {
  const upb_DefPool* symtab = upb_FileDef_Pool(filedef);
  const char* package = upb_FileDef_Package(filedef);
  if (strlen(package)) {
    PyObject* qname = PyUnicode_FromFormat("%s.%s", package, name);
    const void* ret = func(symtab, PyUnicode_AsUTF8AndSize(qname, NULL));
    Py_DECREF(qname);
    return ret;
  } else {
    return func(symtab, name);
  }
}

static const void* PyUpb_FileDescriptor_LookupMessage(
    const upb_FileDef* filedef, const char* name) {
  const upb_MessageDef* m = PyUpb_FileDescriptor_NestedLookup(
      filedef, name, (void*)&upb_DefPool_FindMessageByName);
  if (!m) return NULL;
  return upb_MessageDef_File(m) == filedef ? m : NULL;
}

static const void* PyUpb_FileDescriptor_LookupEnum(const upb_FileDef* filedef,
                                                   const char* name) {
  const upb_EnumDef* e = PyUpb_FileDescriptor_NestedLookup(
      filedef, name, (void*)&upb_DefPool_FindEnumByName);
  if (!e) return NULL;
  return upb_EnumDef_File(e) == filedef ? e : NULL;
}

static const void* PyUpb_FileDescriptor_LookupExtension(
    const upb_FileDef* filedef, const char* name) {
  const upb_FieldDef* f = PyUpb_FileDescriptor_NestedLookup(
      filedef, name, (void*)&upb_DefPool_FindExtensionByName);
  if (!f) return NULL;
  return upb_FieldDef_File(f) == filedef ? f : NULL;
}

static const void* PyUpb_FileDescriptor_LookupService(
    const upb_FileDef* filedef, const char* name) {
  const upb_ServiceDef* s = PyUpb_FileDescriptor_NestedLookup(
      filedef, name, (void*)&upb_DefPool_FindServiceByName);
  if (!s) return NULL;
  return upb_ServiceDef_File(s) == filedef ? s : NULL;
}

static PyObject* PyUpb_FileDescriptor_GetName(PyUpb_DescriptorBase* self,
                                              void* closure) {
  return PyUnicode_FromString(upb_FileDef_Name(self->def));
}

static PyObject* PyUpb_FileDescriptor_GetPool(PyObject* _self, void* closure) {
  PyUpb_DescriptorBase* self = (PyUpb_DescriptorBase*)_self;
  Py_INCREF(self->pool);
  return self->pool;
}

static PyObject* PyUpb_FileDescriptor_GetPackage(PyObject* _self,
                                                 void* closure) {
  PyUpb_DescriptorBase* self = (PyUpb_DescriptorBase*)_self;
  return PyUnicode_FromString(upb_FileDef_Package(self->def));
}

static PyObject* PyUpb_FileDescriptor_GetSerializedPb(PyObject* self,
                                                      void* closure) {
  return PyUpb_DescriptorBase_GetSerializedProto(
      self, (PyUpb_ToProto_Func*)&upb_FileDef_ToProto,
      &google__protobuf__FileDescriptorProto_msg_init);
}

static PyObject* PyUpb_FileDescriptor_GetMessageTypesByName(PyObject* _self,
                                                            void* closure) {
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_FileDef_TopLevelMessageCount,
          (void*)&upb_FileDef_TopLevelMessage,
          (void*)&PyUpb_Descriptor_Get,
      },
      (void*)&PyUpb_FileDescriptor_LookupMessage,
      (void*)&upb_MessageDef_Name,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_FileDescriptor_GetEnumTypesByName(PyObject* _self,
                                                         void* closure) {
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_FileDef_TopLevelEnumCount,
          (void*)&upb_FileDef_TopLevelEnum,
          (void*)&PyUpb_EnumDescriptor_Get,
      },
      (void*)&PyUpb_FileDescriptor_LookupEnum,
      (void*)&upb_EnumDef_Name,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_FileDescriptor_GetExtensionsByName(PyObject* _self,
                                                          void* closure) {
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_FileDef_TopLevelExtensionCount,
          (void*)&upb_FileDef_TopLevelExtension,
          (void*)&PyUpb_FieldDescriptor_Get,
      },
      (void*)&PyUpb_FileDescriptor_LookupExtension,
      (void*)&upb_FieldDef_Name,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_FileDescriptor_GetServicesByName(PyObject* _self,
                                                        void* closure) {
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_FileDef_ServiceCount,
          (void*)&upb_FileDef_Service,
          (void*)&PyUpb_ServiceDescriptor_Get,
      },
      (void*)&PyUpb_FileDescriptor_LookupService,
      (void*)&upb_ServiceDef_Name,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_FileDescriptor_GetDependencies(PyObject* _self,
                                                      void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_FileDef_DependencyCount,
      (void*)&upb_FileDef_Dependency,
      (void*)&PyUpb_FileDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_FileDescriptor_GetPublicDependencies(PyObject* _self,
                                                            void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_FileDef_PublicDependencyCount,
      (void*)&upb_FileDef_PublicDependency,
      (void*)&PyUpb_FileDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_FileDescriptor_GetHasOptions(PyObject* _self,
                                                    void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_FileDef_HasOptions(self->def));
}

static PyObject* PyUpb_FileDescriptor_GetOptions(PyObject* _self,
                                                 PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_FileDef_Options(self->def)),
      &google__protobuf__FileOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".FileOptions");
}

static PyObject* PyUpb_FileDescriptor_GetFeatures(PyObject* _self,
                                                  PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features, UPB_UPCAST(upb_FileDef_ResolvedFeatures(self->def)));
}

static PyObject* PyUpb_FileDescriptor_CopyToProto(PyObject* _self,
                                                  PyObject* py_proto) {
  return PyUpb_DescriptorBase_CopyToProto(
      _self, (PyUpb_ToProto_Func*)&upb_FileDef_ToProto,
      &google__protobuf__FileDescriptorProto_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".FileDescriptorProto", py_proto);
}

static PyGetSetDef PyUpb_FileDescriptor_Getters[] = {
    {"pool", PyUpb_FileDescriptor_GetPool, NULL, "pool"},
    {"name", (getter)PyUpb_FileDescriptor_GetName, NULL, "name"},
    {"package", PyUpb_FileDescriptor_GetPackage, NULL, "package"},
    {"serialized_pb", PyUpb_FileDescriptor_GetSerializedPb},
    {"message_types_by_name", PyUpb_FileDescriptor_GetMessageTypesByName, NULL,
     "Messages by name"},
    {"enum_types_by_name", PyUpb_FileDescriptor_GetEnumTypesByName, NULL,
     "Enums by name"},
    {"extensions_by_name", PyUpb_FileDescriptor_GetExtensionsByName, NULL,
     "Extensions by name"},
    {"services_by_name", PyUpb_FileDescriptor_GetServicesByName, NULL,
     "Services by name"},
    {"dependencies", PyUpb_FileDescriptor_GetDependencies, NULL,
     "Dependencies"},
    {"public_dependencies", PyUpb_FileDescriptor_GetPublicDependencies, NULL,
     "Dependencies"},
    {"has_options", PyUpb_FileDescriptor_GetHasOptions, NULL, "Has Options"},
    {NULL},
};

static PyMethodDef PyUpb_FileDescriptor_Methods[] = {
    {"GetOptions", PyUpb_FileDescriptor_GetOptions, METH_NOARGS},
    {"_GetFeatures", PyUpb_FileDescriptor_GetFeatures, METH_NOARGS},
    {"CopyToProto", PyUpb_FileDescriptor_CopyToProto, METH_O},
    {NULL}};

static PyType_Slot PyUpb_FileDescriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_FileDescriptor_Methods},
    {Py_tp_getset, PyUpb_FileDescriptor_Getters},
    {0, NULL}};

static PyType_Spec PyUpb_FileDescriptor_Spec = {
    PYUPB_MODULE_NAME ".FileDescriptor",  // tp_name
    sizeof(PyUpb_DescriptorBase),         // tp_basicsize
    0,                                    // tp_itemsize
    Py_TPFLAGS_DEFAULT,                   // tp_flags
    PyUpb_FileDescriptor_Slots,
};

const upb_FileDef* PyUpb_FileDescriptor_GetDef(PyObject* _self) {
  PyUpb_DescriptorBase* self =
      PyUpb_DescriptorBase_Check(_self, kPyUpb_FileDescriptor);
  return self ? self->def : NULL;
}

// -----------------------------------------------------------------------------
// MethodDescriptor
// -----------------------------------------------------------------------------

const upb_MethodDef* PyUpb_MethodDescriptor_GetDef(PyObject* _self) {
  PyUpb_DescriptorBase* self =
      PyUpb_DescriptorBase_Check(_self, kPyUpb_MethodDescriptor);
  return self ? self->def : NULL;
}

PyObject* PyUpb_MethodDescriptor_Get(PyObject* pool, const upb_MethodDef* m) {
  return PyUpb_DescriptorBase_Get(kPyUpb_MethodDescriptor, m, pool);
}

static PyObject* PyUpb_MethodDescriptor_GetName(PyObject* self, void* closure) {
  const upb_MethodDef* m = PyUpb_MethodDescriptor_GetDef(self);
  return PyUnicode_FromString(upb_MethodDef_Name(m));
}

static PyObject* PyUpb_MethodDescriptor_GetFullName(PyObject* self,
                                                    void* closure) {
  const upb_MethodDef* m = PyUpb_MethodDescriptor_GetDef(self);
  return PyUnicode_FromString(upb_MethodDef_FullName(m));
}

static PyObject* PyUpb_MethodDescriptor_GetIndex(PyObject* self,
                                                 void* closure) {
  const upb_MethodDef* oneof = PyUpb_MethodDescriptor_GetDef(self);
  return PyLong_FromLong(upb_MethodDef_Index(oneof));
}

static PyObject* PyUpb_MethodDescriptor_GetContainingService(PyObject* _self,
                                                             void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_MethodDef* m = PyUpb_MethodDescriptor_GetDef(_self);
  return PyUpb_ServiceDescriptor_Get(self->pool, upb_MethodDef_Service(m));
}

static PyObject* PyUpb_MethodDescriptor_GetInputType(PyObject* _self,
                                                     void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_MethodDef* m = PyUpb_MethodDescriptor_GetDef(_self);
  return PyUpb_Descriptor_Get(self->pool, upb_MethodDef_InputType(m));
}

static PyObject* PyUpb_MethodDescriptor_GetOutputType(PyObject* _self,
                                                      void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_MethodDef* m = PyUpb_MethodDescriptor_GetDef(_self);
  return PyUpb_Descriptor_Get(self->pool, upb_MethodDef_OutputType(m));
}

static PyObject* PyUpb_MethodDescriptor_GetClientStreaming(PyObject* self,
                                                           void* closure) {
  const upb_MethodDef* m = PyUpb_MethodDescriptor_GetDef(self);
  return PyBool_FromLong(upb_MethodDef_ClientStreaming(m) ? 1 : 0);
}

static PyObject* PyUpb_MethodDescriptor_GetServerStreaming(PyObject* self,
                                                           void* closure) {
  const upb_MethodDef* m = PyUpb_MethodDescriptor_GetDef(self);
  return PyBool_FromLong(upb_MethodDef_ServerStreaming(m) ? 1 : 0);
}

static PyObject* PyUpb_MethodDescriptor_GetHasOptions(PyObject* _self,
                                                      void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_MethodDef_HasOptions(self->def));
}

static PyObject* PyUpb_MethodDescriptor_GetOptions(PyObject* _self,
                                                   PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_MethodDef_Options(self->def)),
      &google__protobuf__MethodOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".MethodOptions");
}

static PyObject* PyUpb_MethodDescriptor_GetFeatures(PyObject* _self,
                                                    PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features, UPB_UPCAST(upb_MethodDef_ResolvedFeatures(self->def)));
}

static PyObject* PyUpb_MethodDescriptor_CopyToProto(PyObject* _self,
                                                    PyObject* py_proto) {
  return PyUpb_DescriptorBase_CopyToProto(
      _self, (PyUpb_ToProto_Func*)&upb_MethodDef_ToProto,
      &google__protobuf__MethodDescriptorProto_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".MethodDescriptorProto", py_proto);
}

static PyGetSetDef PyUpb_MethodDescriptor_Getters[] = {
    {"name", PyUpb_MethodDescriptor_GetName, NULL, "Name", NULL},
    {"full_name", PyUpb_MethodDescriptor_GetFullName, NULL, "Full name", NULL},
    {"index", PyUpb_MethodDescriptor_GetIndex, NULL, "Index", NULL},
    {"containing_service", PyUpb_MethodDescriptor_GetContainingService, NULL,
     "Containing service", NULL},
    {"input_type", PyUpb_MethodDescriptor_GetInputType, NULL, "Input type",
     NULL},
    {"output_type", PyUpb_MethodDescriptor_GetOutputType, NULL, "Output type",
     NULL},
    {"client_streaming", PyUpb_MethodDescriptor_GetClientStreaming, NULL,
     "Client streaming", NULL},
    {"server_streaming", PyUpb_MethodDescriptor_GetServerStreaming, NULL,
     "Server streaming", NULL},
    {"has_options", PyUpb_MethodDescriptor_GetHasOptions, NULL, "Has Options"},

    {NULL}};

static PyMethodDef PyUpb_MethodDescriptor_Methods[] = {
    {"GetOptions", PyUpb_MethodDescriptor_GetOptions, METH_NOARGS},
    {"_GetFeatures", PyUpb_MethodDescriptor_GetFeatures, METH_NOARGS},
    {"CopyToProto", PyUpb_MethodDescriptor_CopyToProto, METH_O},
    {NULL}};

static PyType_Slot PyUpb_MethodDescriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_MethodDescriptor_Methods},
    {Py_tp_getset, PyUpb_MethodDescriptor_Getters},
    {0, NULL}};

static PyType_Spec PyUpb_MethodDescriptor_Spec = {
    PYUPB_MODULE_NAME ".MethodDescriptor",  // tp_name
    sizeof(PyUpb_DescriptorBase),           // tp_basicsize
    0,                                      // tp_itemsize
    Py_TPFLAGS_DEFAULT,                     // tp_flags
    PyUpb_MethodDescriptor_Slots,
};

// -----------------------------------------------------------------------------
// OneofDescriptor
// -----------------------------------------------------------------------------

const upb_OneofDef* PyUpb_OneofDescriptor_GetDef(PyObject* _self) {
  PyUpb_DescriptorBase* self =
      PyUpb_DescriptorBase_Check(_self, kPyUpb_OneofDescriptor);
  return self ? self->def : NULL;
}

PyObject* PyUpb_OneofDescriptor_Get(PyObject* pool, const upb_OneofDef* oneof) {
  return PyUpb_DescriptorBase_Get(kPyUpb_OneofDescriptor, oneof, pool);
}

static PyObject* PyUpb_OneofDescriptor_GetName(PyObject* self, void* closure) {
  const upb_OneofDef* oneof = PyUpb_OneofDescriptor_GetDef(self);
  return PyUnicode_FromString(upb_OneofDef_Name(oneof));
}

static PyObject* PyUpb_OneofDescriptor_GetFullName(PyObject* self,
                                                   void* closure) {
  const upb_OneofDef* oneof = PyUpb_OneofDescriptor_GetDef(self);
  return PyUnicode_FromFormat(
      "%s.%s", upb_MessageDef_FullName(upb_OneofDef_ContainingType(oneof)),
      upb_OneofDef_Name(oneof));
}

static PyObject* PyUpb_OneofDescriptor_GetIndex(PyObject* self, void* closure) {
  const upb_OneofDef* oneof = PyUpb_OneofDescriptor_GetDef(self);
  return PyLong_FromLong(upb_OneofDef_Index(oneof));
}

static PyObject* PyUpb_OneofDescriptor_GetContainingType(PyObject* _self,
                                                         void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_OneofDef* oneof = PyUpb_OneofDescriptor_GetDef(_self);
  return PyUpb_Descriptor_Get(self->pool, upb_OneofDef_ContainingType(oneof));
}

static PyObject* PyUpb_OneofDescriptor_GetHasOptions(PyObject* _self,
                                                     void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_OneofDef_HasOptions(self->def));
}

static PyObject* PyUpb_OneofDescriptor_GetFields(PyObject* _self,
                                                 void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_OneofDef_FieldCount,
      (void*)&upb_OneofDef_Field,
      (void*)&PyUpb_FieldDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_OneofDescriptor_GetOptions(PyObject* _self,
                                                  PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_OneofDef_Options(self->def)),
      &google__protobuf__OneofOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".OneofOptions");
}

static PyObject* PyUpb_OneofDescriptor_GetFeatures(PyObject* _self,
                                                   PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features, UPB_UPCAST(upb_OneofDef_ResolvedFeatures(self->def)));
}

static PyGetSetDef PyUpb_OneofDescriptor_Getters[] = {
    {"name", PyUpb_OneofDescriptor_GetName, NULL, "Name"},
    {"full_name", PyUpb_OneofDescriptor_GetFullName, NULL, "Full name"},
    {"index", PyUpb_OneofDescriptor_GetIndex, NULL, "Index"},
    {"containing_type", PyUpb_OneofDescriptor_GetContainingType, NULL,
     "Containing type"},
    {"has_options", PyUpb_OneofDescriptor_GetHasOptions, NULL, "Has Options"},
    {"fields", PyUpb_OneofDescriptor_GetFields, NULL, "Fields"},
    {NULL}};

static PyMethodDef PyUpb_OneofDescriptor_Methods[] = {
    {"GetOptions", PyUpb_OneofDescriptor_GetOptions, METH_NOARGS},
    {"_GetFeatures", PyUpb_OneofDescriptor_GetFeatures, METH_NOARGS},
    {NULL}};

static PyType_Slot PyUpb_OneofDescriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_OneofDescriptor_Methods},
    {Py_tp_getset, PyUpb_OneofDescriptor_Getters},
    {0, NULL}};

static PyType_Spec PyUpb_OneofDescriptor_Spec = {
    PYUPB_MODULE_NAME ".OneofDescriptor",  // tp_name
    sizeof(PyUpb_DescriptorBase),          // tp_basicsize
    0,                                     // tp_itemsize
    Py_TPFLAGS_DEFAULT,                    // tp_flags
    PyUpb_OneofDescriptor_Slots,
};

// -----------------------------------------------------------------------------
// ServiceDescriptor
// -----------------------------------------------------------------------------

const upb_ServiceDef* PyUpb_ServiceDescriptor_GetDef(PyObject* _self) {
  PyUpb_DescriptorBase* self =
      PyUpb_DescriptorBase_Check(_self, kPyUpb_ServiceDescriptor);
  return self ? self->def : NULL;
}

PyObject* PyUpb_ServiceDescriptor_Get(PyObject* pool, const upb_ServiceDef* s) {
  return PyUpb_DescriptorBase_Get(kPyUpb_ServiceDescriptor, s, pool);
}

static PyObject* PyUpb_ServiceDescriptor_GetFullName(PyObject* self,
                                                     void* closure) {
  const upb_ServiceDef* s = PyUpb_ServiceDescriptor_GetDef(self);
  return PyUnicode_FromString(upb_ServiceDef_FullName(s));
}

static PyObject* PyUpb_ServiceDescriptor_GetName(PyObject* self,
                                                 void* closure) {
  const upb_ServiceDef* s = PyUpb_ServiceDescriptor_GetDef(self);
  return PyUnicode_FromString(upb_ServiceDef_Name(s));
}

static PyObject* PyUpb_ServiceDescriptor_GetFile(PyObject* _self,
                                                 void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const upb_ServiceDef* s = PyUpb_ServiceDescriptor_GetDef(_self);
  return PyUpb_FileDescriptor_Get(self->pool, upb_ServiceDef_File(s));
}

static PyObject* PyUpb_ServiceDescriptor_GetIndex(PyObject* self,
                                                  void* closure) {
  const upb_ServiceDef* s = PyUpb_ServiceDescriptor_GetDef(self);
  return PyLong_FromLong(upb_ServiceDef_Index(s));
}

static PyObject* PyUpb_ServiceDescriptor_GetMethods(PyObject* _self,
                                                    void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  static PyUpb_GenericSequence_Funcs funcs = {
      (void*)&upb_ServiceDef_MethodCount,
      (void*)&upb_ServiceDef_Method,
      (void*)&PyUpb_MethodDescriptor_Get,
  };
  return PyUpb_GenericSequence_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_ServiceDescriptor_GetMethodsByName(PyObject* _self,
                                                          void* closure) {
  static PyUpb_ByNameMap_Funcs funcs = {
      {
          (void*)&upb_ServiceDef_MethodCount,
          (void*)&upb_ServiceDef_Method,
          (void*)&PyUpb_MethodDescriptor_Get,
      },
      (void*)&upb_ServiceDef_FindMethodByName,
      (void*)&upb_MethodDef_Name,
  };
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_ByNameMap_New(&funcs, self->def, self->pool);
}

static PyObject* PyUpb_ServiceDescriptor_GetHasOptions(PyObject* _self,
                                                       void* closure) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyBool_FromLong(upb_ServiceDef_HasOptions(self->def));
}

static PyObject* PyUpb_ServiceDescriptor_GetOptions(PyObject* _self,
                                                    PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetOptions(
      &self->options, UPB_UPCAST(upb_ServiceDef_Options(self->def)),
      &google__protobuf__ServiceOptions_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".ServiceOptions");
}

static PyObject* PyUpb_ServiceDescriptor_GetFeatures(PyObject* _self,
                                                     PyObject* args) {
  PyUpb_DescriptorBase* self = (void*)_self;
  return PyUpb_DescriptorBase_GetFeatures(
      &self->features, UPB_UPCAST(upb_ServiceDef_ResolvedFeatures(self->def)));
}

static PyObject* PyUpb_ServiceDescriptor_CopyToProto(PyObject* _self,
                                                     PyObject* py_proto) {
  return PyUpb_DescriptorBase_CopyToProto(
      _self, (PyUpb_ToProto_Func*)&upb_ServiceDef_ToProto,
      &google__protobuf__ServiceDescriptorProto_msg_init,
      PYUPB_DESCRIPTOR_PROTO_PACKAGE ".ServiceDescriptorProto", py_proto);
}

static PyObject* PyUpb_ServiceDescriptor_FindMethodByName(PyObject* _self,
                                                          PyObject* py_name) {
  PyUpb_DescriptorBase* self = (void*)_self;
  const char* name = PyUnicode_AsUTF8AndSize(py_name, NULL);
  if (!name) return NULL;
  const upb_MethodDef* method =
      upb_ServiceDef_FindMethodByName(self->def, name);
  if (method == NULL) {
    return PyErr_Format(PyExc_KeyError, "Couldn't find method %.200s", name);
  }
  return PyUpb_MethodDescriptor_Get(self->pool, method);
}

static PyGetSetDef PyUpb_ServiceDescriptor_Getters[] = {
    {"name", PyUpb_ServiceDescriptor_GetName, NULL, "Name", NULL},
    {"full_name", PyUpb_ServiceDescriptor_GetFullName, NULL, "Full name", NULL},
    {"file", PyUpb_ServiceDescriptor_GetFile, NULL, "File descriptor"},
    {"index", PyUpb_ServiceDescriptor_GetIndex, NULL, "Index", NULL},
    {"methods", PyUpb_ServiceDescriptor_GetMethods, NULL, "Methods", NULL},
    {"methods_by_name", PyUpb_ServiceDescriptor_GetMethodsByName, NULL,
     "Methods by name", NULL},
    {"has_options", PyUpb_ServiceDescriptor_GetHasOptions, NULL, "Has Options"},
    {NULL}};

static PyMethodDef PyUpb_ServiceDescriptor_Methods[] = {
    {"GetOptions", PyUpb_ServiceDescriptor_GetOptions, METH_NOARGS},
    {"_GetFeatures", PyUpb_ServiceDescriptor_GetFeatures, METH_NOARGS},
    {"CopyToProto", PyUpb_ServiceDescriptor_CopyToProto, METH_O},
    {"FindMethodByName", PyUpb_ServiceDescriptor_FindMethodByName, METH_O},
    {NULL}};

static PyType_Slot PyUpb_ServiceDescriptor_Slots[] = {
    DESCRIPTOR_BASE_SLOTS,
    {Py_tp_methods, PyUpb_ServiceDescriptor_Methods},
    {Py_tp_getset, PyUpb_ServiceDescriptor_Getters},
    {0, NULL}};

static PyType_Spec PyUpb_ServiceDescriptor_Spec = {
    PYUPB_MODULE_NAME ".ServiceDescriptor",  // tp_name
    sizeof(PyUpb_DescriptorBase),            // tp_basicsize
    0,                                       // tp_itemsize
    Py_TPFLAGS_DEFAULT,                      // tp_flags
    PyUpb_ServiceDescriptor_Slots,
};

// -----------------------------------------------------------------------------
// Top Level
// -----------------------------------------------------------------------------

static bool PyUpb_SetIntAttr(PyObject* obj, const char* name, int val) {
  PyObject* num = PyLong_FromLong(val);
  if (!num) return false;
  int status = PyObject_SetAttrString(obj, name, num);
  Py_DECREF(num);
  return status >= 0;
}

// These must be in the same order as PyUpb_DescriptorType in the header.
static PyType_Spec* desc_specs[] = {
    &PyUpb_Descriptor_Spec,          &PyUpb_EnumDescriptor_Spec,
    &PyUpb_EnumValueDescriptor_Spec, &PyUpb_FieldDescriptor_Spec,
    &PyUpb_FileDescriptor_Spec,      &PyUpb_MethodDescriptor_Spec,
    &PyUpb_OneofDescriptor_Spec,     &PyUpb_ServiceDescriptor_Spec,
};

bool PyUpb_InitDescriptor(PyObject* m) {
  PyUpb_ModuleState* s = PyUpb_ModuleState_GetFromModule(m);

  for (size_t i = 0; i < kPyUpb_Descriptor_Count; i++) {
    s->descriptor_types[i] = PyUpb_AddClass(m, desc_specs[i]);
    if (!s->descriptor_types[i]) {
      return false;
    }
  }

  PyObject* fd = (PyObject*)s->descriptor_types[kPyUpb_FieldDescriptor];
  return PyUpb_SetIntAttr(fd, "LABEL_OPTIONAL", kUpb_Label_Optional) &&
         PyUpb_SetIntAttr(fd, "LABEL_REPEATED", kUpb_Label_Repeated) &&
         PyUpb_SetIntAttr(fd, "LABEL_REQUIRED", kUpb_Label_Required) &&
         PyUpb_SetIntAttr(fd, "TYPE_BOOL", kUpb_FieldType_Bool) &&
         PyUpb_SetIntAttr(fd, "TYPE_BYTES", kUpb_FieldType_Bytes) &&
         PyUpb_SetIntAttr(fd, "TYPE_DOUBLE", kUpb_FieldType_Double) &&
         PyUpb_SetIntAttr(fd, "TYPE_ENUM", kUpb_FieldType_Enum) &&
         PyUpb_SetIntAttr(fd, "TYPE_FIXED32", kUpb_FieldType_Fixed32) &&
         PyUpb_SetIntAttr(fd, "TYPE_FIXED64", kUpb_FieldType_Fixed64) &&
         PyUpb_SetIntAttr(fd, "TYPE_FLOAT", kUpb_FieldType_Float) &&
         PyUpb_SetIntAttr(fd, "TYPE_GROUP", kUpb_FieldType_Group) &&
         PyUpb_SetIntAttr(fd, "TYPE_INT32", kUpb_FieldType_Int32) &&
         PyUpb_SetIntAttr(fd, "TYPE_INT64", kUpb_FieldType_Int64) &&
         PyUpb_SetIntAttr(fd, "TYPE_MESSAGE", kUpb_FieldType_Message) &&
         PyUpb_SetIntAttr(fd, "TYPE_SFIXED32", kUpb_FieldType_SFixed32) &&
         PyUpb_SetIntAttr(fd, "TYPE_SFIXED64", kUpb_FieldType_SFixed64) &&
         PyUpb_SetIntAttr(fd, "TYPE_SINT32", kUpb_FieldType_SInt32) &&
         PyUpb_SetIntAttr(fd, "TYPE_SINT64", kUpb_FieldType_SInt64) &&
         PyUpb_SetIntAttr(fd, "TYPE_STRING", kUpb_FieldType_String) &&
         PyUpb_SetIntAttr(fd, "TYPE_UINT32", kUpb_FieldType_UInt32) &&
         PyUpb_SetIntAttr(fd, "TYPE_UINT64", kUpb_FieldType_UInt64) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_INT32", CPPTYPE_INT32) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_INT64", CPPTYPE_INT64) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_UINT32", CPPTYPE_UINT32) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_UINT64", CPPTYPE_UINT64) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_DOUBLE", CPPTYPE_DOUBLE) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_FLOAT", CPPTYPE_FLOAT) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_BOOL", CPPTYPE_BOOL) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_ENUM", CPPTYPE_ENUM) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_STRING", CPPTYPE_STRING) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_BYTES", CPPTYPE_STRING) &&
         PyUpb_SetIntAttr(fd, "CPPTYPE_MESSAGE", CPPTYPE_MESSAGE);
}

#include "upb/port/undef.inc"