objectivec/GPBDescriptor_PackagePrivate.h - third_party/protobuf - Git at Google

 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 // This header is private to the ProtobolBuffers library and must NOT be
 // included by any sources outside this library. The contents of this file are
 // subject to change at any time without notice.

 #import "GPBDescriptor.h"
 #import "GPBWireFormat.h"

 // Describes attributes of the field.
 typedef NS_OPTIONS(uint16_t, GPBFieldFlags) {
   GPBFieldNone = 0,
   // These map to standard protobuf concepts.
   GPBFieldRequired = 1 << 0,
   GPBFieldRepeated = 1 << 1,
   GPBFieldPacked = 1 << 2,
   GPBFieldOptional = 1 << 3,
   GPBFieldHasDefaultValue = 1 << 4,

   // Indicate that the field should "clear" when set to zero value. This is the
   // proto3 non optional behavior for singular data (ints, data, string, enum)
   // fields.
   GPBFieldClearHasIvarOnZero = 1 << 5,
   // Indicates the field needs custom handling for the TextFormat name, if not
   // set, the name can be derived from the ObjC name.
   GPBFieldTextFormatNameCustom = 1 << 6,
   // This flag has never had any meaning, it was set on all enum fields.
   GPBFieldHasEnumDescriptor = 1 << 7,

   // These are not standard protobuf concepts, they are specific to the
   // Objective C runtime.

   // These bits are used to mark the field as a map and what the key
   // type is.
   GPBFieldMapKeyMask = 0xF << 8,
   GPBFieldMapKeyInt32 = 1 << 8,
   GPBFieldMapKeyInt64 = 2 << 8,
   GPBFieldMapKeyUInt32 = 3 << 8,
   GPBFieldMapKeyUInt64 = 4 << 8,
   GPBFieldMapKeySInt32 = 5 << 8,
   GPBFieldMapKeySInt64 = 6 << 8,
   GPBFieldMapKeyFixed32 = 7 << 8,
   GPBFieldMapKeyFixed64 = 8 << 8,
   GPBFieldMapKeySFixed32 = 9 << 8,
   GPBFieldMapKeySFixed64 = 10 << 8,
   GPBFieldMapKeyBool = 11 << 8,
   GPBFieldMapKeyString = 12 << 8,

   // If the enum for this field is "closed", meaning that it:
   // - Has a fixed set of named values.
   // - Encountering values not in this set causes them to be treated as unknown
   //   fields.
   // - The first value (i.e., the default) may be nonzero.
   // NOTE: This could be tracked just on the GPBEnumDescriptor, but to support
   // previously generated code, there would be not data to get the behavior
   // correct, so instead it is tracked on the field. If old source compatibility
   // is removed, this could be removed and the GPBEnumDescription fetched from
   // the GPBFieldDescriptor instead.
   GPBFieldClosedEnum = 1 << 12,
 };

 // NOTE: The structures defined here have their members ordered to minimize
 // their size. This directly impacts the size of apps since these exist per
 // field/extension.

 typedef struct GPBFileDescription {
   // The proto package for the file.
   const char *package;
   // The objc_class_prefix option if present.
   const char *prefix;
   // The file's proto syntax.
   GPBFileSyntax syntax;
 } GPBFileDescription;

 // Describes a single field in a protobuf as it is represented as an ivar.
 typedef struct GPBMessageFieldDescription {
   // Name of ivar.
   const char *name;
   union {
     // className is deprecated and will be removed in favor of clazz.
     // kept around right now for backwards compatibility.
     // clazz is used iff GPBDescriptorInitializationFlag_UsesClassRefs is set.
     char *className;  // Name of the class of the message.
     Class clazz;      // Class of the message.
     // For enums only.
     GPBEnumDescriptorFunc enumDescFunc;
   } dataTypeSpecific;
   // The field number for the ivar.
   uint32_t number;
   // The index (in bits) into _has_storage_.
   //   >= 0: the bit to use for a value being set.
   //   = GPBNoHasBit(INT32_MAX): no storage used.
   //   < 0: in a oneOf, use a full int32 to record the field active.
   int32_t hasIndex;
   // Offset of the variable into it's structure struct.
   uint32_t offset;
   // Field flags. Use accessor functions below.
   GPBFieldFlags flags;
   // Data type of the ivar.
   GPBDataType dataType;
 } GPBMessageFieldDescription;

 // Fields in messages defined in a 'proto2' syntax file can provide a default
 // value. This struct provides the default along with the field info.
 typedef struct GPBMessageFieldDescriptionWithDefault {
   // Default value for the ivar.
   GPBGenericValue defaultValue;

   GPBMessageFieldDescription core;
 } GPBMessageFieldDescriptionWithDefault;

 // Describes attributes of the extension.
 typedef NS_OPTIONS(uint8_t, GPBExtensionOptions) {
   GPBExtensionNone = 0,
   // These map to standard protobuf concepts.
   GPBExtensionRepeated = 1 << 0,
   GPBExtensionPacked = 1 << 1,
   GPBExtensionSetWireFormat = 1 << 2,
 };

 // An extension
 typedef struct GPBExtensionDescription {
   GPBGenericValue defaultValue;
   const char *singletonName;
   // Before 3.12, `extendedClass` was just a `const char *`. Thanks to nested
   // initialization
   // (https://en.cppreference.com/w/c/language/struct_initialization#Nested_initialization) old
   // generated code with `.extendedClass = GPBStringifySymbol(Something)` still works; and the
   // current generator can use `extendedClass.clazz`, to pass a Class reference.
   union {
     const char *name;
     Class clazz;
   } extendedClass;
   // Before 3.12, this was `const char *messageOrGroupClassName`. In the
   // initial 3.12 release, we moved the `union messageOrGroupClass`, and failed
   // to realize that would break existing source code for extensions. So to
   // keep existing source code working, we added an unnamed union (C11) to
   // provide both the old field name and the new union. This keeps both older
   // and newer code working.
   // Background: https://github.com/protocolbuffers/protobuf/issues/7555
   union {
     const char *messageOrGroupClassName;
     union {
       const char *name;
       Class clazz;
     } messageOrGroupClass;
   };
   GPBEnumDescriptorFunc enumDescriptorFunc;
   int32_t fieldNumber;
   GPBDataType dataType;
   GPBExtensionOptions options;
 } GPBExtensionDescription;

 typedef NS_OPTIONS(uint32_t, GPBDescriptorInitializationFlags) {
   GPBDescriptorInitializationFlag_None = 0,
   GPBDescriptorInitializationFlag_FieldsWithDefault = 1 << 0,
   GPBDescriptorInitializationFlag_WireFormat = 1 << 1,

   // This is used as a stopgap as we move from using class names to class
   // references. The runtime needs to support both until we allow a
   // breaking change in the runtime.
   GPBDescriptorInitializationFlag_UsesClassRefs = 1 << 2,

   // This flag is used to indicate that the generated sources already contain
   // the `GPBFieldClearHasIvarOnZero` flag and it doesn't have to be computed
   // at startup. This allows older generated code to still work with the
   // current runtime library.
   GPBDescriptorInitializationFlag_Proto3OptionalKnown = 1 << 3,

   // This flag is used to indicate that the generated sources already contain
   // the `GPBFieldCloseEnum` flag and it doesn't have to be computed at startup.
   // This allows the older generated code to still work with the current runtime
   // library.
   GPBDescriptorInitializationFlag_ClosedEnumSupportKnown = 1 << 4,
 };

 @interface GPBDescriptor () {
  @package
   NSArray *fields_;
   NSArray *oneofs_;
   uint32_t storageSize_;
 }

 // fieldDescriptions and fileDescription have to be long lived, they are held as raw pointers.
 + (instancetype)allocDescriptorForClass:(Class)messageClass
                             messageName:(NSString *)messageName
                         fileDescription:(GPBFileDescription *)fileDescription
                                  fields:(void *)fieldDescriptions
                              fieldCount:(uint32_t)fieldCount
                             storageSize:(uint32_t)storageSize
                                   flags:(GPBDescriptorInitializationFlags)flags;

 // Called right after init to provide extra information to avoid init having
 // an explosion of args. These pointers are recorded, so they are expected
 // to live for the lifetime of the app.
 - (void)setupOneofs:(const char **)oneofNames
               count:(uint32_t)count
       firstHasIndex:(int32_t)firstHasIndex;
 - (void)setupExtraTextInfo:(const char *)extraTextFormatInfo;
 - (void)setupExtensionRanges:(const GPBExtensionRange *)ranges count:(int32_t)count;
 - (void)setupContainingMessageClass:(Class)msgClass;

 // Deprecated, these remain to support older versions of source generation.
 + (instancetype)allocDescriptorForClass:(Class)messageClass
                                    file:(GPBFileDescriptor *)file
                                  fields:(void *)fieldDescriptions
                              fieldCount:(uint32_t)fieldCount
                             storageSize:(uint32_t)storageSize
                                   flags:(GPBDescriptorInitializationFlags)flags;
 + (instancetype)allocDescriptorForClass:(Class)messageClass
                               rootClass:(Class)rootClass
                                    file:(GPBFileDescriptor *)file
                                  fields:(void *)fieldDescriptions
                              fieldCount:(uint32_t)fieldCount
                             storageSize:(uint32_t)storageSize
                                   flags:(GPBDescriptorInitializationFlags)flags;
 - (void)setupContainingMessageClassName:(const char *)msgClassName;
 - (void)setupMessageClassNameSuffix:(NSString *)suffix;

 @end

 @interface GPBFileDescriptor ()
 - (instancetype)initWithPackage:(NSString *)package
                      objcPrefix:(NSString *)objcPrefix
                          syntax:(GPBFileSyntax)syntax;
 - (instancetype)initWithPackage:(NSString *)package syntax:(GPBFileSyntax)syntax;
 @end

 @interface GPBOneofDescriptor () {
  @package
   const char *name_;
   NSArray *fields_;
   SEL caseSel_;
 }
 // name must be long lived.
 - (instancetype)initWithName:(const char *)name fields:(NSArray *)fields;
 @end

 @interface GPBFieldDescriptor () {
  @package
   GPBMessageFieldDescription *description_;
   GPB_UNSAFE_UNRETAINED GPBOneofDescriptor *containingOneof_;

   SEL getSel_;
   SEL setSel_;
   SEL hasOrCountSel_;  // *Count for map<>/repeated fields, has* otherwise.
   SEL setHasSel_;
 }
 @end

 typedef NS_OPTIONS(uint32_t, GPBEnumDescriptorInitializationFlags) {
   GPBEnumDescriptorInitializationFlag_None = 0,

   // Available: 1 << 0

   // Marks this enum as a closed enum.
   GPBEnumDescriptorInitializationFlag_IsClosed = 1 << 1,
 };

 @interface GPBEnumDescriptor ()
 // valueNames, values and extraTextFormatInfo have to be long lived, they are
 // held as raw pointers.
 + (instancetype)allocDescriptorForName:(NSString *)name
                             valueNames:(const char *)valueNames
                                 values:(const int32_t *)values
                                  count:(uint32_t)valueCount
                           enumVerifier:(GPBEnumValidationFunc)enumVerifier
                                  flags:(GPBEnumDescriptorInitializationFlags)flags;
 + (instancetype)allocDescriptorForName:(NSString *)name
                             valueNames:(const char *)valueNames
                                 values:(const int32_t *)values
                                  count:(uint32_t)valueCount
                           enumVerifier:(GPBEnumValidationFunc)enumVerifier
                                  flags:(GPBEnumDescriptorInitializationFlags)flags
                    extraTextFormatInfo:(const char *)extraTextFormatInfo;

 // Deprecated, these remain to support older versions of source generation.
 + (instancetype)allocDescriptorForName:(NSString *)name
                             valueNames:(const char *)valueNames
                                 values:(const int32_t *)values
                                  count:(uint32_t)valueCount
                           enumVerifier:(GPBEnumValidationFunc)enumVerifier;
 + (instancetype)allocDescriptorForName:(NSString *)name
                             valueNames:(const char *)valueNames
                                 values:(const int32_t *)values
                                  count:(uint32_t)valueCount
                           enumVerifier:(GPBEnumValidationFunc)enumVerifier
                    extraTextFormatInfo:(const char *)extraTextFormatInfo;
 @end

 @interface GPBExtensionDescriptor () {
  @package
   GPBExtensionDescription *description_;
 }
 @property(nonatomic, readonly) GPBWireFormat wireType;

 // For repeated extensions, alternateWireType is the wireType with the opposite
 // value for the packable property.  i.e. - if the extension was marked packed
 // it would be the wire type for unpacked; if the extension was marked unpacked,
 // it would be the wire type for packed.
 @property(nonatomic, readonly) GPBWireFormat alternateWireType;

 // description has to be long lived, it is held as a raw pointer.
 - (instancetype)initWithExtensionDescription:(GPBExtensionDescription *)desc
                                usesClassRefs:(BOOL)usesClassRefs;
 // Deprecated. Calls above with `usesClassRefs = NO`
 - (instancetype)initWithExtensionDescription:(GPBExtensionDescription *)desc;

 - (NSComparisonResult)compareByFieldNumber:(GPBExtensionDescriptor *)other;
 @end

 CF_EXTERN_C_BEGIN

 // Direct access is use for speed, to avoid even internally declaring things
 // read/write, etc. The warning is enabled in the project to ensure code calling
 // protos can turn on -Wdirect-ivar-access without issues.
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdirect-ivar-access"

 GPB_INLINE BOOL GPBFieldIsMapOrArray(GPBFieldDescriptor *field) {
   return (field->description_->flags & (GPBFieldRepeated | GPBFieldMapKeyMask)) != 0;
 }

 GPB_INLINE GPBDataType GPBGetFieldDataType(GPBFieldDescriptor *field) {
   return field->description_->dataType;
 }

 GPB_INLINE int32_t GPBFieldHasIndex(GPBFieldDescriptor *field) {
   return field->description_->hasIndex;
 }

 GPB_INLINE uint32_t GPBFieldNumber(GPBFieldDescriptor *field) {
   return field->description_->number;
 }

 GPB_INLINE BOOL GPBFieldIsClosedEnum(GPBFieldDescriptor *field) {
   return (field->description_->flags & GPBFieldClosedEnum) != 0;
 }

 #pragma clang diagnostic pop

 uint32_t GPBFieldTag(GPBFieldDescriptor *self);

 // For repeated fields, alternateWireType is the wireType with the opposite
 // value for the packable property.  i.e. - if the field was marked packed it
 // would be the wire type for unpacked; if the field was marked unpacked, it
 // would be the wire type for packed.
 uint32_t GPBFieldAlternateTag(GPBFieldDescriptor *self);

 GPB_INLINE BOOL GPBExtensionIsRepeated(GPBExtensionDescription *description) {
   return (description->options & GPBExtensionRepeated) != 0;
 }

 GPB_INLINE BOOL GPBExtensionIsPacked(GPBExtensionDescription *description) {
   return (description->options & GPBExtensionPacked) != 0;
 }

 GPB_INLINE BOOL GPBExtensionIsWireFormat(GPBExtensionDescription *description) {
   return (description->options & GPBExtensionSetWireFormat) != 0;
 }

 // Helper for compile time assets.
 #ifndef GPBInternalCompileAssert
 #define GPBInternalCompileAssert(test, msg) _Static_assert((test), #msg)
 #endif  // GPBInternalCompileAssert

 // Sanity check that there isn't padding between the field description
 // structures with and without a default.
 GPBInternalCompileAssert(sizeof(GPBMessageFieldDescriptionWithDefault) ==
                              (sizeof(GPBGenericValue) + sizeof(GPBMessageFieldDescription)),
                          DescriptionsWithDefault_different_size_than_expected);

 CF_EXTERN_C_END
	// Protocol Buffers - Google's data interchange format
	// Copyright 2008 Google Inc. All rights reserved.
	// https://developers.google.com/protocol-buffers/
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	// This header is private to the ProtobolBuffers library and must NOT be
	// included by any sources outside this library. The contents of this file are
	// subject to change at any time without notice.

	#import "GPBDescriptor.h"
	#import "GPBWireFormat.h"

	// Describes attributes of the field.
	typedef NS_OPTIONS(uint16_t, GPBFieldFlags) {
	GPBFieldNone = 0,
	// These map to standard protobuf concepts.
	GPBFieldRequired = 1 << 0,
	GPBFieldRepeated = 1 << 1,
	GPBFieldPacked = 1 << 2,
	GPBFieldOptional = 1 << 3,
	GPBFieldHasDefaultValue = 1 << 4,

	// Indicate that the field should "clear" when set to zero value. This is the
	// proto3 non optional behavior for singular data (ints, data, string, enum)
	// fields.
	GPBFieldClearHasIvarOnZero = 1 << 5,
	// Indicates the field needs custom handling for the TextFormat name, if not
	// set, the name can be derived from the ObjC name.
	GPBFieldTextFormatNameCustom = 1 << 6,
	// This flag has never had any meaning, it was set on all enum fields.
	GPBFieldHasEnumDescriptor = 1 << 7,

	// These are not standard protobuf concepts, they are specific to the
	// Objective C runtime.

	// These bits are used to mark the field as a map and what the key
	// type is.
	GPBFieldMapKeyMask = 0xF << 8,
	GPBFieldMapKeyInt32 = 1 << 8,
	GPBFieldMapKeyInt64 = 2 << 8,
	GPBFieldMapKeyUInt32 = 3 << 8,
	GPBFieldMapKeyUInt64 = 4 << 8,
	GPBFieldMapKeySInt32 = 5 << 8,
	GPBFieldMapKeySInt64 = 6 << 8,
	GPBFieldMapKeyFixed32 = 7 << 8,
	GPBFieldMapKeyFixed64 = 8 << 8,
	GPBFieldMapKeySFixed32 = 9 << 8,
	GPBFieldMapKeySFixed64 = 10 << 8,
	GPBFieldMapKeyBool = 11 << 8,
	GPBFieldMapKeyString = 12 << 8,

	// If the enum for this field is "closed", meaning that it:
	// - Has a fixed set of named values.
	// - Encountering values not in this set causes them to be treated as unknown
	// fields.
	// - The first value (i.e., the default) may be nonzero.
	// NOTE: This could be tracked just on the GPBEnumDescriptor, but to support
	// previously generated code, there would be not data to get the behavior
	// correct, so instead it is tracked on the field. If old source compatibility
	// is removed, this could be removed and the GPBEnumDescription fetched from
	// the GPBFieldDescriptor instead.
	GPBFieldClosedEnum = 1 << 12,
	};

	// NOTE: The structures defined here have their members ordered to minimize
	// their size. This directly impacts the size of apps since these exist per
	// field/extension.

	typedef struct GPBFileDescription {
	// The proto package for the file.
	const char *package;
	// The objc_class_prefix option if present.
	const char *prefix;
	// The file's proto syntax.
	GPBFileSyntax syntax;
	} GPBFileDescription;

	// Describes a single field in a protobuf as it is represented as an ivar.
	typedef struct GPBMessageFieldDescription {
	// Name of ivar.
	const char *name;
	union {
	// className is deprecated and will be removed in favor of clazz.
	// kept around right now for backwards compatibility.
	// clazz is used iff GPBDescriptorInitializationFlag_UsesClassRefs is set.
	char *className; // Name of the class of the message.
	Class clazz; // Class of the message.
	// For enums only.
	GPBEnumDescriptorFunc enumDescFunc;
	} dataTypeSpecific;
	// The field number for the ivar.
	uint32_t number;
	// The index (in bits) into _has_storage_.
	// >= 0: the bit to use for a value being set.
	// = GPBNoHasBit(INT32_MAX): no storage used.
	// < 0: in a oneOf, use a full int32 to record the field active.
	int32_t hasIndex;
	// Offset of the variable into it's structure struct.
	uint32_t offset;
	// Field flags. Use accessor functions below.
	GPBFieldFlags flags;
	// Data type of the ivar.
	GPBDataType dataType;
	} GPBMessageFieldDescription;

	// Fields in messages defined in a 'proto2' syntax file can provide a default
	// value. This struct provides the default along with the field info.
	typedef struct GPBMessageFieldDescriptionWithDefault {
	// Default value for the ivar.
	GPBGenericValue defaultValue;

	GPBMessageFieldDescription core;
	} GPBMessageFieldDescriptionWithDefault;

	// Describes attributes of the extension.
	typedef NS_OPTIONS(uint8_t, GPBExtensionOptions) {
	GPBExtensionNone = 0,
	// These map to standard protobuf concepts.
	GPBExtensionRepeated = 1 << 0,
	GPBExtensionPacked = 1 << 1,
	GPBExtensionSetWireFormat = 1 << 2,
	};

	// An extension
	typedef struct GPBExtensionDescription {
	GPBGenericValue defaultValue;
	const char *singletonName;
	// Before 3.12, `extendedClass` was just a `const char *`. Thanks to nested
	// initialization
	// (https://en.cppreference.com/w/c/language/struct_initialization#Nested_initialization) old
	// generated code with `.extendedClass = GPBStringifySymbol(Something)` still works; and the
	// current generator can use `extendedClass.clazz`, to pass a Class reference.
	union {
	const char *name;
	Class clazz;
	} extendedClass;
	// Before 3.12, this was `const char *messageOrGroupClassName`. In the
	// initial 3.12 release, we moved the `union messageOrGroupClass`, and failed
	// to realize that would break existing source code for extensions. So to
	// keep existing source code working, we added an unnamed union (C11) to
	// provide both the old field name and the new union. This keeps both older
	// and newer code working.
	// Background: https://github.com/protocolbuffers/protobuf/issues/7555
	union {
	const char *messageOrGroupClassName;
	union {
	const char *name;
	Class clazz;
	} messageOrGroupClass;
	};
	GPBEnumDescriptorFunc enumDescriptorFunc;
	int32_t fieldNumber;
	GPBDataType dataType;
	GPBExtensionOptions options;
	} GPBExtensionDescription;

	typedef NS_OPTIONS(uint32_t, GPBDescriptorInitializationFlags) {
	GPBDescriptorInitializationFlag_None = 0,
	GPBDescriptorInitializationFlag_FieldsWithDefault = 1 << 0,
	GPBDescriptorInitializationFlag_WireFormat = 1 << 1,

	// This is used as a stopgap as we move from using class names to class
	// references. The runtime needs to support both until we allow a
	// breaking change in the runtime.
	GPBDescriptorInitializationFlag_UsesClassRefs = 1 << 2,

	// This flag is used to indicate that the generated sources already contain
	// the `GPBFieldClearHasIvarOnZero` flag and it doesn't have to be computed
	// at startup. This allows older generated code to still work with the
	// current runtime library.
	GPBDescriptorInitializationFlag_Proto3OptionalKnown = 1 << 3,

	// This flag is used to indicate that the generated sources already contain
	// the `GPBFieldCloseEnum` flag and it doesn't have to be computed at startup.
	// This allows the older generated code to still work with the current runtime
	// library.
	GPBDescriptorInitializationFlag_ClosedEnumSupportKnown = 1 << 4,
	};

	@interface GPBDescriptor () {
	@package
	NSArray *fields_;
	NSArray *oneofs_;
	uint32_t storageSize_;
	}

	// fieldDescriptions and fileDescription have to be long lived, they are held as raw pointers.
	+ (instancetype)allocDescriptorForClass:(Class)messageClass
	messageName:(NSString *)messageName
	fileDescription:(GPBFileDescription *)fileDescription
	fields:(void *)fieldDescriptions
	fieldCount:(uint32_t)fieldCount
	storageSize:(uint32_t)storageSize
	flags:(GPBDescriptorInitializationFlags)flags;

	// Called right after init to provide extra information to avoid init having
	// an explosion of args. These pointers are recorded, so they are expected
	// to live for the lifetime of the app.
	- (void)setupOneofs:(const char **)oneofNames
	count:(uint32_t)count
	firstHasIndex:(int32_t)firstHasIndex;
	- (void)setupExtraTextInfo:(const char *)extraTextFormatInfo;
	- (void)setupExtensionRanges:(const GPBExtensionRange *)ranges count:(int32_t)count;
	- (void)setupContainingMessageClass:(Class)msgClass;

	// Deprecated, these remain to support older versions of source generation.
	+ (instancetype)allocDescriptorForClass:(Class)messageClass
	file:(GPBFileDescriptor *)file
	fields:(void *)fieldDescriptions
	fieldCount:(uint32_t)fieldCount
	storageSize:(uint32_t)storageSize
	flags:(GPBDescriptorInitializationFlags)flags;
	+ (instancetype)allocDescriptorForClass:(Class)messageClass
	rootClass:(Class)rootClass
	file:(GPBFileDescriptor *)file
	fields:(void *)fieldDescriptions
	fieldCount:(uint32_t)fieldCount
	storageSize:(uint32_t)storageSize
	flags:(GPBDescriptorInitializationFlags)flags;
	- (void)setupContainingMessageClassName:(const char *)msgClassName;
	- (void)setupMessageClassNameSuffix:(NSString *)suffix;

	@end

	@interface GPBFileDescriptor ()
	- (instancetype)initWithPackage:(NSString *)package
	objcPrefix:(NSString *)objcPrefix
	syntax:(GPBFileSyntax)syntax;
	- (instancetype)initWithPackage:(NSString *)package syntax:(GPBFileSyntax)syntax;
	@end

	@interface GPBOneofDescriptor () {
	@package
	const char *name_;
	NSArray *fields_;
	SEL caseSel_;
	}
	// name must be long lived.
	- (instancetype)initWithName:(const char )name fields:(NSArray )fields;
	@end

	@interface GPBFieldDescriptor () {
	@package
	GPBMessageFieldDescription *description_;
	GPB_UNSAFE_UNRETAINED GPBOneofDescriptor *containingOneof_;

	SEL getSel_;
	SEL setSel_;
	SEL hasOrCountSel_; // Count for map<>/repeated fields, has otherwise.
	SEL setHasSel_;
	}
	@end

	typedef NS_OPTIONS(uint32_t, GPBEnumDescriptorInitializationFlags) {
	GPBEnumDescriptorInitializationFlag_None = 0,

	// Available: 1 << 0

	// Marks this enum as a closed enum.
	GPBEnumDescriptorInitializationFlag_IsClosed = 1 << 1,
	};

	@interface GPBEnumDescriptor ()
	// valueNames, values and extraTextFormatInfo have to be long lived, they are
	// held as raw pointers.
	+ (instancetype)allocDescriptorForName:(NSString *)name
	valueNames:(const char *)valueNames
	values:(const int32_t *)values
	count:(uint32_t)valueCount
	enumVerifier:(GPBEnumValidationFunc)enumVerifier
	flags:(GPBEnumDescriptorInitializationFlags)flags;
	+ (instancetype)allocDescriptorForName:(NSString *)name
	valueNames:(const char *)valueNames
	values:(const int32_t *)values
	count:(uint32_t)valueCount
	enumVerifier:(GPBEnumValidationFunc)enumVerifier
	flags:(GPBEnumDescriptorInitializationFlags)flags
	extraTextFormatInfo:(const char *)extraTextFormatInfo;

	// Deprecated, these remain to support older versions of source generation.
	+ (instancetype)allocDescriptorForName:(NSString *)name
	valueNames:(const char *)valueNames
	values:(const int32_t *)values
	count:(uint32_t)valueCount
	enumVerifier:(GPBEnumValidationFunc)enumVerifier;
	+ (instancetype)allocDescriptorForName:(NSString *)name
	valueNames:(const char *)valueNames
	values:(const int32_t *)values
	count:(uint32_t)valueCount
	enumVerifier:(GPBEnumValidationFunc)enumVerifier
	extraTextFormatInfo:(const char *)extraTextFormatInfo;
	@end

	@interface GPBExtensionDescriptor () {
	@package
	GPBExtensionDescription *description_;
	}
	@property(nonatomic, readonly) GPBWireFormat wireType;

	// For repeated extensions, alternateWireType is the wireType with the opposite
	// value for the packable property. i.e. - if the extension was marked packed
	// it would be the wire type for unpacked; if the extension was marked unpacked,
	// it would be the wire type for packed.
	@property(nonatomic, readonly) GPBWireFormat alternateWireType;

	// description has to be long lived, it is held as a raw pointer.
	- (instancetype)initWithExtensionDescription:(GPBExtensionDescription *)desc
	usesClassRefs:(BOOL)usesClassRefs;
	// Deprecated. Calls above with `usesClassRefs = NO`
	- (instancetype)initWithExtensionDescription:(GPBExtensionDescription *)desc;

	- (NSComparisonResult)compareByFieldNumber:(GPBExtensionDescriptor *)other;
	@end

	CF_EXTERN_C_BEGIN

	// Direct access is use for speed, to avoid even internally declaring things
	// read/write, etc. The warning is enabled in the project to ensure code calling
	// protos can turn on -Wdirect-ivar-access without issues.
	#pragma clang diagnostic push
	#pragma clang diagnostic ignored "-Wdirect-ivar-access"

	GPB_INLINE BOOL GPBFieldIsMapOrArray(GPBFieldDescriptor *field) {
	return (field->description_->flags & (GPBFieldRepeated \| GPBFieldMapKeyMask)) != 0;
	}

	GPB_INLINE GPBDataType GPBGetFieldDataType(GPBFieldDescriptor *field) {
	return field->description_->dataType;
	}

	GPB_INLINE int32_t GPBFieldHasIndex(GPBFieldDescriptor *field) {
	return field->description_->hasIndex;
	}

	GPB_INLINE uint32_t GPBFieldNumber(GPBFieldDescriptor *field) {
	return field->description_->number;
	}

	GPB_INLINE BOOL GPBFieldIsClosedEnum(GPBFieldDescriptor *field) {
	return (field->description_->flags & GPBFieldClosedEnum) != 0;
	}

	#pragma clang diagnostic pop

	uint32_t GPBFieldTag(GPBFieldDescriptor *self);

	// For repeated fields, alternateWireType is the wireType with the opposite
	// value for the packable property. i.e. - if the field was marked packed it
	// would be the wire type for unpacked; if the field was marked unpacked, it
	// would be the wire type for packed.
	uint32_t GPBFieldAlternateTag(GPBFieldDescriptor *self);

	GPB_INLINE BOOL GPBExtensionIsRepeated(GPBExtensionDescription *description) {
	return (description->options & GPBExtensionRepeated) != 0;
	}

	GPB_INLINE BOOL GPBExtensionIsPacked(GPBExtensionDescription *description) {
	return (description->options & GPBExtensionPacked) != 0;
	}

	GPB_INLINE BOOL GPBExtensionIsWireFormat(GPBExtensionDescription *description) {
	return (description->options & GPBExtensionSetWireFormat) != 0;
	}

	// Helper for compile time assets.
	#ifndef GPBInternalCompileAssert
	#define GPBInternalCompileAssert(test, msg) _Static_assert((test), #msg)
	#endif // GPBInternalCompileAssert

	// Sanity check that there isn't padding between the field description
	// structures with and without a default.
	GPBInternalCompileAssert(sizeof(GPBMessageFieldDescriptionWithDefault) ==
	(sizeof(GPBGenericValue) + sizeof(GPBMessageFieldDescription)),
	DescriptionsWithDefault_different_size_than_expected);

	CF_EXTERN_C_END