• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 //     * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 //     * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 //     * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31 // Author: kenton@google.com (Kenton Varda)
32 //  Based on original Protocol Buffers design by
33 //  Sanjay Ghemawat, Jeff Dean, and others.
34 //
35 // This file contains classes which describe a type of protocol message.
36 // You can use a message's descriptor to learn at runtime what fields
37 // it contains and what the types of those fields are.  The Message
38 // interface also allows you to dynamically access and modify individual
39 // fields by passing the FieldDescriptor of the field you are interested
40 // in.
41 //
42 // Most users will not care about descriptors, because they will write
43 // code specific to certain protocol types and will simply use the classes
44 // generated by the protocol compiler directly.  Advanced users who want
45 // to operate on arbitrary types (not known at compile time) may want to
46 // read descriptors in order to learn about the contents of a message.
47 // A very small number of users will want to construct their own
48 // Descriptors, either because they are implementing Message manually or
49 // because they are writing something like the protocol compiler.
50 //
51 // For an example of how you might use descriptors, see the code example
52 // at the top of message.h.
53 
54 #ifndef GOOGLE_PROTOBUF_DESCRIPTOR_H__
55 #define GOOGLE_PROTOBUF_DESCRIPTOR_H__
56 
57 #include <memory>
58 #include <set>
59 #include <string>
60 #include <vector>
61 #include <google/protobuf/stubs/common.h>
62 #include <google/protobuf/stubs/mutex.h>
63 #include <google/protobuf/stubs/once.h>
64 
65 #include <google/protobuf/port_def.inc>
66 
67 // TYPE_BOOL is defined in the MacOS's ConditionalMacros.h.
68 #ifdef TYPE_BOOL
69 #undef TYPE_BOOL
70 #endif  // TYPE_BOOL
71 
72 #ifdef SWIG
73 #define PROTOBUF_EXPORT
74 #endif
75 
76 
77 namespace google {
78 namespace protobuf {
79 
80 // Defined in this file.
81 class Descriptor;
82 class FieldDescriptor;
83 class OneofDescriptor;
84 class EnumDescriptor;
85 class EnumValueDescriptor;
86 class ServiceDescriptor;
87 class MethodDescriptor;
88 class FileDescriptor;
89 class DescriptorDatabase;
90 class DescriptorPool;
91 
92 // Defined in descriptor.proto
93 class DescriptorProto;
94 class DescriptorProto_ExtensionRange;
95 class FieldDescriptorProto;
96 class OneofDescriptorProto;
97 class EnumDescriptorProto;
98 class EnumValueDescriptorProto;
99 class ServiceDescriptorProto;
100 class MethodDescriptorProto;
101 class FileDescriptorProto;
102 class MessageOptions;
103 class FieldOptions;
104 class OneofOptions;
105 class EnumOptions;
106 class EnumValueOptions;
107 class ExtensionRangeOptions;
108 class ServiceOptions;
109 class MethodOptions;
110 class FileOptions;
111 class UninterpretedOption;
112 class SourceCodeInfo;
113 
114 // Defined in message.h
115 class Message;
116 class Reflection;
117 
118 // Defined in descriptor.cc
119 class DescriptorBuilder;
120 class FileDescriptorTables;
121 struct Symbol;
122 
123 // Defined in unknown_field_set.h.
124 class UnknownField;
125 
126 // Defined in command_line_interface.cc
127 namespace compiler {
128 class CommandLineInterface;
129 namespace cpp {
130 // Defined in helpers.h
131 class Formatter;
132 }  // namespace cpp
133 }  // namespace compiler
134 
135 namespace descriptor_unittest {
136 class DescriptorTest;
137 }  // namespace descriptor_unittest
138 
139 // Defined in printer.h
140 namespace io {
141 class Printer;
142 }  // namespace io
143 
144 // NB, all indices are zero-based.
145 struct SourceLocation {
146   int start_line;
147   int end_line;
148   int start_column;
149   int end_column;
150 
151   // Doc comments found at the source location.
152   // See the comments in SourceCodeInfo.Location (descriptor.proto) for details.
153   std::string leading_comments;
154   std::string trailing_comments;
155   std::vector<std::string> leading_detached_comments;
156 };
157 
158 // Options when generating machine-parsable output from a descriptor with
159 // DebugString().
160 struct DebugStringOptions {
161   // include original user comments as recorded in SourceLocation entries. N.B.
162   // that this must be |false| by default: several other pieces of code (for
163   // example, the C++ code generation for fields in the proto compiler) rely on
164   // DebugString() output being unobstructed by user comments.
165   bool include_comments;
166   // If true, elide the braced body in the debug string.
167   bool elide_group_body;
168   bool elide_oneof_body;
169 
DebugStringOptionsDebugStringOptions170   DebugStringOptions()
171       : include_comments(false),
172         elide_group_body(false),
173         elide_oneof_body(false) {
174   }
175 };
176 
177 // A class to handle the simplest cases of a lazily linked descriptor
178 // for a message type that isn't built at the time of cross linking,
179 // which is needed when a pool has lazily_build_dependencies_ set.
180 // Must be instantiated as mutable in a descriptor.
181 namespace internal {
182 class PROTOBUF_EXPORT LazyDescriptor {
183  public:
184   // Init function to be called at init time of a descriptor containing
185   // a LazyDescriptor.
Init()186   void Init() {
187     descriptor_ = nullptr;
188     name_ = nullptr;
189     once_ = nullptr;
190     file_ = nullptr;
191   }
192 
193   // Sets the value of the descriptor if it is known during the descriptor
194   // building process. Not thread safe, should only be called during the
195   // descriptor build process. Should not be called after SetLazy has been
196   // called.
197   void Set(const Descriptor* descriptor);
198 
199   // Sets the information needed to lazily cross link the descriptor at a later
200   // time, SetLazy is not thread safe, should be called only once at descriptor
201   // build time if the symbol wasn't found and building of the file containing
202   // that type is delayed because lazily_build_dependencies_ is set on the pool.
203   // Should not be called after Set() has been called.
204   void SetLazy(const std::string& name, const FileDescriptor* file);
205 
206   // Returns the current value of the descriptor, thread-safe. If SetLazy(...)
207   // has been called, will do a one-time cross link of the type specified,
208   // building the descriptor file that contains the type if necessary.
Get()209   inline const Descriptor* Get() {
210     Once();
211     return descriptor_;
212   }
213 
214  private:
215   static void OnceStatic(LazyDescriptor* lazy);
216   void OnceInternal();
217   void Once();
218 
219   const Descriptor* descriptor_;
220   const std::string* name_;
221   internal::once_flag* once_;
222   const FileDescriptor* file_;
223 };
224 }  // namespace internal
225 
226 // Describes a type of protocol message, or a particular group within a
227 // message.  To obtain the Descriptor for a given message object, call
228 // Message::GetDescriptor().  Generated message classes also have a
229 // static method called descriptor() which returns the type's descriptor.
230 // Use DescriptorPool to construct your own descriptors.
231 class PROTOBUF_EXPORT Descriptor {
232  public:
233   typedef DescriptorProto Proto;
234 
235   // The name of the message type, not including its scope.
236   const std::string& name() const;
237 
238   // The fully-qualified name of the message type, scope delimited by
239   // periods.  For example, message type "Foo" which is declared in package
240   // "bar" has full name "bar.Foo".  If a type "Baz" is nested within
241   // Foo, Baz's full_name is "bar.Foo.Baz".  To get only the part that
242   // comes after the last '.', use name().
243   const std::string& full_name() const;
244 
245   // Index of this descriptor within the file or containing type's message
246   // type array.
247   int index() const;
248 
249   // The .proto file in which this message type was defined.  Never nullptr.
250   const FileDescriptor* file() const;
251 
252   // If this Descriptor describes a nested type, this returns the type
253   // in which it is nested.  Otherwise, returns nullptr.
254   const Descriptor* containing_type() const;
255 
256   // Get options for this message type.  These are specified in the .proto file
257   // by placing lines like "option foo = 1234;" in the message definition.
258   // Allowed options are defined by MessageOptions in descriptor.proto, and any
259   // available extensions of that message.
260   const MessageOptions& options() const;
261 
262   // Write the contents of this Descriptor into the given DescriptorProto.
263   // The target DescriptorProto must be clear before calling this; if it
264   // isn't, the result may be garbage.
265   void CopyTo(DescriptorProto* proto) const;
266 
267   // Write the contents of this decriptor in a human-readable form. Output
268   // will be suitable for re-parsing.
269   std::string DebugString() const;
270 
271   // Similar to DebugString(), but additionally takes options (e.g.,
272   // include original user comments in output).
273   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
274 
275   // Returns true if this is a placeholder for an unknown type. This will
276   // only be the case if this descriptor comes from a DescriptorPool
277   // with AllowUnknownDependencies() set.
278   bool is_placeholder() const;
279 
280   // Field stuff -----------------------------------------------------
281 
282   // The number of fields in this message type.
283   int field_count() const;
284   // Gets a field by index, where 0 <= index < field_count().
285   // These are returned in the order they were defined in the .proto file.
286   const FieldDescriptor* field(int index) const;
287 
288   // Looks up a field by declared tag number.  Returns nullptr if no such field
289   // exists.
290   const FieldDescriptor* FindFieldByNumber(int number) const;
291   // Looks up a field by name.  Returns nullptr if no such field exists.
292   const FieldDescriptor* FindFieldByName(const std::string& name) const;
293 
294   // Looks up a field by lowercased name (as returned by lowercase_name()).
295   // This lookup may be ambiguous if multiple field names differ only by case,
296   // in which case the field returned is chosen arbitrarily from the matches.
297   const FieldDescriptor* FindFieldByLowercaseName(
298       const std::string& lowercase_name) const;
299 
300   // Looks up a field by camel-case name (as returned by camelcase_name()).
301   // This lookup may be ambiguous if multiple field names differ in a way that
302   // leads them to have identical camel-case names, in which case the field
303   // returned is chosen arbitrarily from the matches.
304   const FieldDescriptor* FindFieldByCamelcaseName(
305       const std::string& camelcase_name) const;
306 
307   // The number of oneofs in this message type.
308   int oneof_decl_count() const;
309   // Get a oneof by index, where 0 <= index < oneof_decl_count().
310   // These are returned in the order they were defined in the .proto file.
311   const OneofDescriptor* oneof_decl(int index) const;
312 
313   // Looks up a oneof by name.  Returns nullptr if no such oneof exists.
314   const OneofDescriptor* FindOneofByName(const std::string& name) const;
315 
316   // Nested type stuff -----------------------------------------------
317 
318   // The number of nested types in this message type.
319   int nested_type_count() const;
320   // Gets a nested type by index, where 0 <= index < nested_type_count().
321   // These are returned in the order they were defined in the .proto file.
322   const Descriptor* nested_type(int index) const;
323 
324   // Looks up a nested type by name.  Returns nullptr if no such nested type
325   // exists.
326   const Descriptor* FindNestedTypeByName(const std::string& name) const;
327 
328   // Enum stuff ------------------------------------------------------
329 
330   // The number of enum types in this message type.
331   int enum_type_count() const;
332   // Gets an enum type by index, where 0 <= index < enum_type_count().
333   // These are returned in the order they were defined in the .proto file.
334   const EnumDescriptor* enum_type(int index) const;
335 
336   // Looks up an enum type by name.  Returns nullptr if no such enum type
337   // exists.
338   const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
339 
340   // Looks up an enum value by name, among all enum types in this message.
341   // Returns nullptr if no such value exists.
342   const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
343 
344   // Extensions ------------------------------------------------------
345 
346   // A range of field numbers which are designated for third-party
347   // extensions.
348   struct ExtensionRange {
349     typedef DescriptorProto_ExtensionRange Proto;
350 
351     typedef ExtensionRangeOptions OptionsType;
352 
353     // See Descriptor::CopyTo().
354     void CopyTo(DescriptorProto_ExtensionRange* proto) const;
355 
356     int start;  // inclusive
357     int end;    // exclusive
358 
359     const ExtensionRangeOptions* options_;
360   };
361 
362   // The number of extension ranges in this message type.
363   int extension_range_count() const;
364   // Gets an extension range by index, where 0 <= index <
365   // extension_range_count(). These are returned in the order they were defined
366   // in the .proto file.
367   const ExtensionRange* extension_range(int index) const;
368 
369   // Returns true if the number is in one of the extension ranges.
370   bool IsExtensionNumber(int number) const;
371 
372   // Returns nullptr if no extension range contains the given number.
373   const ExtensionRange* FindExtensionRangeContainingNumber(int number) const;
374 
375   // The number of extensions -- extending *other* messages -- that were
376   // defined nested within this message type's scope.
377   int extension_count() const;
378   // Get an extension by index, where 0 <= index < extension_count().
379   // These are returned in the order they were defined in the .proto file.
380   const FieldDescriptor* extension(int index) const;
381 
382   // Looks up a named extension (which extends some *other* message type)
383   // defined within this message type's scope.
384   const FieldDescriptor* FindExtensionByName(const std::string& name) const;
385 
386   // Similar to FindFieldByLowercaseName(), but finds extensions defined within
387   // this message type's scope.
388   const FieldDescriptor* FindExtensionByLowercaseName(
389       const std::string& name) const;
390 
391   // Similar to FindFieldByCamelcaseName(), but finds extensions defined within
392   // this message type's scope.
393   const FieldDescriptor* FindExtensionByCamelcaseName(
394       const std::string& name) const;
395 
396   // Reserved fields -------------------------------------------------
397 
398   // A range of reserved field numbers.
399   struct ReservedRange {
400     int start;  // inclusive
401     int end;    // exclusive
402   };
403 
404   // The number of reserved ranges in this message type.
405   int reserved_range_count() const;
406   // Gets an reserved range by index, where 0 <= index <
407   // reserved_range_count(). These are returned in the order they were defined
408   // in the .proto file.
409   const ReservedRange* reserved_range(int index) const;
410 
411   // Returns true if the number is in one of the reserved ranges.
412   bool IsReservedNumber(int number) const;
413 
414   // Returns nullptr if no reserved range contains the given number.
415   const ReservedRange* FindReservedRangeContainingNumber(int number) const;
416 
417   // The number of reserved field names in this message type.
418   int reserved_name_count() const;
419 
420   // Gets a reserved name by index, where 0 <= index < reserved_name_count().
421   const std::string& reserved_name(int index) const;
422 
423   // Returns true if the field name is reserved.
424   bool IsReservedName(const std::string& name) const;
425 
426   // Source Location ---------------------------------------------------
427 
428   // Updates |*out_location| to the source location of the complete
429   // extent of this message declaration.  Returns false and leaves
430   // |*out_location| unchanged iff location information was not available.
431   bool GetSourceLocation(SourceLocation* out_location) const;
432 
433  private:
434   typedef MessageOptions OptionsType;
435 
436   // Allows tests to test CopyTo(proto, true).
437   friend class descriptor_unittest::DescriptorTest;
438 
439   // Allows access to GetLocationPath for annotations.
440   friend class io::Printer;
441   friend class compiler::cpp::Formatter;
442 
443   // Fill the json_name field of FieldDescriptorProto.
444   void CopyJsonNameTo(DescriptorProto* proto) const;
445 
446   // Internal version of DebugString; controls the level of indenting for
447   // correct depth. Takes |options| to control debug-string options, and
448   // |include_opening_clause| to indicate whether the "message ... " part of the
449   // clause has already been generated (this varies depending on context).
450   void DebugString(int depth, std::string* contents,
451                    const DebugStringOptions& options,
452                    bool include_opening_clause) const;
453 
454   // Walks up the descriptor tree to generate the source location path
455   // to this descriptor from the file root.
456   void GetLocationPath(std::vector<int>* output) const;
457 
458   const std::string* name_;
459   const std::string* full_name_;
460   const FileDescriptor* file_;
461   const Descriptor* containing_type_;
462   const MessageOptions* options_;
463 
464   // These arrays are separated from their sizes to minimize padding on 64-bit.
465   FieldDescriptor* fields_;
466   OneofDescriptor* oneof_decls_;
467   Descriptor* nested_types_;
468   EnumDescriptor* enum_types_;
469   ExtensionRange* extension_ranges_;
470   FieldDescriptor* extensions_;
471   ReservedRange* reserved_ranges_;
472   const std::string** reserved_names_;
473 
474   int field_count_;
475   int oneof_decl_count_;
476   int nested_type_count_;
477   int enum_type_count_;
478   int extension_range_count_;
479   int extension_count_;
480   int reserved_range_count_;
481   int reserved_name_count_;
482 
483   // True if this is a placeholder for an unknown type.
484   bool is_placeholder_;
485   // True if this is a placeholder and the type name wasn't fully-qualified.
486   bool is_unqualified_placeholder_;
487 
488   // IMPORTANT:  If you add a new field, make sure to search for all instances
489   // of Allocate<Descriptor>() and AllocateArray<Descriptor>() in descriptor.cc
490   // and update them to initialize the field.
491 
492   // Must be constructed using DescriptorPool.
Descriptor()493   Descriptor() {}
494   friend class DescriptorBuilder;
495   friend class DescriptorPool;
496   friend class EnumDescriptor;
497   friend class FieldDescriptor;
498   friend class OneofDescriptor;
499   friend class MethodDescriptor;
500   friend class FileDescriptor;
501   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Descriptor);
502 };
503 
504 
505 // Describes a single field of a message.  To get the descriptor for a given
506 // field, first get the Descriptor for the message in which it is defined,
507 // then call Descriptor::FindFieldByName().  To get a FieldDescriptor for
508 // an extension, do one of the following:
509 // - Get the Descriptor or FileDescriptor for its containing scope, then
510 //   call Descriptor::FindExtensionByName() or
511 //   FileDescriptor::FindExtensionByName().
512 // - Given a DescriptorPool, call DescriptorPool::FindExtensionByNumber() or
513 //   DescriptorPool::FindExtensionByPrintableName().
514 // Use DescriptorPool to construct your own descriptors.
515 class PROTOBUF_EXPORT FieldDescriptor {
516  public:
517   typedef FieldDescriptorProto Proto;
518 
519   // Identifies a field type.  0 is reserved for errors.  The order is weird
520   // for historical reasons.  Types 12 and up are new in proto2.
521   enum Type {
522     TYPE_DOUBLE = 1,    // double, exactly eight bytes on the wire.
523     TYPE_FLOAT = 2,     // float, exactly four bytes on the wire.
524     TYPE_INT64 = 3,     // int64, varint on the wire.  Negative numbers
525                         // take 10 bytes.  Use TYPE_SINT64 if negative
526                         // values are likely.
527     TYPE_UINT64 = 4,    // uint64, varint on the wire.
528     TYPE_INT32 = 5,     // int32, varint on the wire.  Negative numbers
529                         // take 10 bytes.  Use TYPE_SINT32 if negative
530                         // values are likely.
531     TYPE_FIXED64 = 6,   // uint64, exactly eight bytes on the wire.
532     TYPE_FIXED32 = 7,   // uint32, exactly four bytes on the wire.
533     TYPE_BOOL = 8,      // bool, varint on the wire.
534     TYPE_STRING = 9,    // UTF-8 text.
535     TYPE_GROUP = 10,    // Tag-delimited message.  Deprecated.
536     TYPE_MESSAGE = 11,  // Length-delimited message.
537 
538     TYPE_BYTES = 12,     // Arbitrary byte array.
539     TYPE_UINT32 = 13,    // uint32, varint on the wire
540     TYPE_ENUM = 14,      // Enum, varint on the wire
541     TYPE_SFIXED32 = 15,  // int32, exactly four bytes on the wire
542     TYPE_SFIXED64 = 16,  // int64, exactly eight bytes on the wire
543     TYPE_SINT32 = 17,    // int32, ZigZag-encoded varint on the wire
544     TYPE_SINT64 = 18,    // int64, ZigZag-encoded varint on the wire
545 
546     MAX_TYPE = 18,  // Constant useful for defining lookup tables
547                     // indexed by Type.
548   };
549 
550   // Specifies the C++ data type used to represent the field.  There is a
551   // fixed mapping from Type to CppType where each Type maps to exactly one
552   // CppType.  0 is reserved for errors.
553   enum CppType {
554     CPPTYPE_INT32 = 1,     // TYPE_INT32, TYPE_SINT32, TYPE_SFIXED32
555     CPPTYPE_INT64 = 2,     // TYPE_INT64, TYPE_SINT64, TYPE_SFIXED64
556     CPPTYPE_UINT32 = 3,    // TYPE_UINT32, TYPE_FIXED32
557     CPPTYPE_UINT64 = 4,    // TYPE_UINT64, TYPE_FIXED64
558     CPPTYPE_DOUBLE = 5,    // TYPE_DOUBLE
559     CPPTYPE_FLOAT = 6,     // TYPE_FLOAT
560     CPPTYPE_BOOL = 7,      // TYPE_BOOL
561     CPPTYPE_ENUM = 8,      // TYPE_ENUM
562     CPPTYPE_STRING = 9,    // TYPE_STRING, TYPE_BYTES
563     CPPTYPE_MESSAGE = 10,  // TYPE_MESSAGE, TYPE_GROUP
564 
565     MAX_CPPTYPE = 10,  // Constant useful for defining lookup tables
566                        // indexed by CppType.
567   };
568 
569   // Identifies whether the field is optional, required, or repeated.  0 is
570   // reserved for errors.
571   enum Label {
572     LABEL_OPTIONAL = 1,  // optional
573     LABEL_REQUIRED = 2,  // required
574     LABEL_REPEATED = 3,  // repeated
575 
576     MAX_LABEL = 3,  // Constant useful for defining lookup tables
577                     // indexed by Label.
578   };
579 
580   // Valid field numbers are positive integers up to kMaxNumber.
581   static const int kMaxNumber = (1 << 29) - 1;
582 
583   // First field number reserved for the protocol buffer library implementation.
584   // Users may not declare fields that use reserved numbers.
585   static const int kFirstReservedNumber = 19000;
586   // Last field number reserved for the protocol buffer library implementation.
587   // Users may not declare fields that use reserved numbers.
588   static const int kLastReservedNumber = 19999;
589 
590   const std::string& name() const;  // Name of this field within the message.
591   const std::string& full_name() const;  // Fully-qualified name of the field.
592   const std::string& json_name() const;  // JSON name of this field.
593   const FileDescriptor* file() const;  // File in which this field was defined.
594   bool is_extension() const;           // Is this an extension field?
595   int number() const;                  // Declared tag number.
596 
597   // Same as name() except converted to lower-case.  This (and especially the
598   // FindFieldByLowercaseName() method) can be useful when parsing formats
599   // which prefer to use lowercase naming style.  (Although, technically
600   // field names should be lowercased anyway according to the protobuf style
601   // guide, so this only makes a difference when dealing with old .proto files
602   // which do not follow the guide.)
603   const std::string& lowercase_name() const;
604 
605   // Same as name() except converted to camel-case.  In this conversion, any
606   // time an underscore appears in the name, it is removed and the next
607   // letter is capitalized.  Furthermore, the first letter of the name is
608   // lower-cased.  Examples:
609   //   FooBar -> fooBar
610   //   foo_bar -> fooBar
611   //   fooBar -> fooBar
612   // This (and especially the FindFieldByCamelcaseName() method) can be useful
613   // when parsing formats which prefer to use camel-case naming style.
614   const std::string& camelcase_name() const;
615 
616   Type type() const;                  // Declared type of this field.
617   const char* type_name() const;      // Name of the declared type.
618   CppType cpp_type() const;           // C++ type of this field.
619   const char* cpp_type_name() const;  // Name of the C++ type.
620   Label label() const;                // optional/required/repeated
621 
622   bool is_required() const;  // shorthand for label() == LABEL_REQUIRED
623   bool is_optional() const;  // shorthand for label() == LABEL_OPTIONAL
624   bool is_repeated() const;  // shorthand for label() == LABEL_REPEATED
625   bool is_packable() const;  // shorthand for is_repeated() &&
626                              //               IsTypePackable(type())
627   bool is_packed() const;    // shorthand for is_packable() &&
628                              //               options().packed()
629   bool is_map() const;       // shorthand for type() == TYPE_MESSAGE &&
630                              // message_type()->options().map_entry()
631 
632   // Index of this field within the message's field array, or the file or
633   // extension scope's extensions array.
634   int index() const;
635 
636   // Does this field have an explicitly-declared default value?
637   bool has_default_value() const;
638 
639   // Whether the user has specified the json_name field option in the .proto
640   // file.
641   bool has_json_name() const;
642 
643   // Get the field default value if cpp_type() == CPPTYPE_INT32.  If no
644   // explicit default was defined, the default is 0.
645   int32 default_value_int32() const;
646   // Get the field default value if cpp_type() == CPPTYPE_INT64.  If no
647   // explicit default was defined, the default is 0.
648   int64 default_value_int64() const;
649   // Get the field default value if cpp_type() == CPPTYPE_UINT32.  If no
650   // explicit default was defined, the default is 0.
651   uint32 default_value_uint32() const;
652   // Get the field default value if cpp_type() == CPPTYPE_UINT64.  If no
653   // explicit default was defined, the default is 0.
654   uint64 default_value_uint64() const;
655   // Get the field default value if cpp_type() == CPPTYPE_FLOAT.  If no
656   // explicit default was defined, the default is 0.0.
657   float default_value_float() const;
658   // Get the field default value if cpp_type() == CPPTYPE_DOUBLE.  If no
659   // explicit default was defined, the default is 0.0.
660   double default_value_double() const;
661   // Get the field default value if cpp_type() == CPPTYPE_BOOL.  If no
662   // explicit default was defined, the default is false.
663   bool default_value_bool() const;
664   // Get the field default value if cpp_type() == CPPTYPE_ENUM.  If no
665   // explicit default was defined, the default is the first value defined
666   // in the enum type (all enum types are required to have at least one value).
667   // This never returns nullptr.
668   const EnumValueDescriptor* default_value_enum() const;
669   // Get the field default value if cpp_type() == CPPTYPE_STRING.  If no
670   // explicit default was defined, the default is the empty string.
671   const std::string& default_value_string() const;
672 
673   // The Descriptor for the message of which this is a field.  For extensions,
674   // this is the extended type.  Never nullptr.
675   const Descriptor* containing_type() const;
676 
677   // If the field is a member of a oneof, this is the one, otherwise this is
678   // nullptr.
679   const OneofDescriptor* containing_oneof() const;
680 
681   // If the field is a member of a oneof, returns the index in that oneof.
682   int index_in_oneof() const;
683 
684   // An extension may be declared within the scope of another message.  If this
685   // field is an extension (is_extension() is true), then extension_scope()
686   // returns that message, or nullptr if the extension was declared at global
687   // scope.  If this is not an extension, extension_scope() is undefined (may
688   // assert-fail).
689   const Descriptor* extension_scope() const;
690 
691   // If type is TYPE_MESSAGE or TYPE_GROUP, returns a descriptor for the
692   // message or the group type.  Otherwise, returns null.
693   const Descriptor* message_type() const;
694   // If type is TYPE_ENUM, returns a descriptor for the enum.  Otherwise,
695   // returns null.
696   const EnumDescriptor* enum_type() const;
697 
698   // Get the FieldOptions for this field.  This includes things listed in
699   // square brackets after the field definition.  E.g., the field:
700   //   optional string text = 1 [ctype=CORD];
701   // has the "ctype" option set.  Allowed options are defined by FieldOptions in
702   // descriptor.proto, and any available extensions of that message.
703   const FieldOptions& options() const;
704 
705   // See Descriptor::CopyTo().
706   void CopyTo(FieldDescriptorProto* proto) const;
707 
708   // See Descriptor::DebugString().
709   std::string DebugString() const;
710 
711   // See Descriptor::DebugStringWithOptions().
712   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
713 
714   // Helper method to get the CppType for a particular Type.
715   static CppType TypeToCppType(Type type);
716 
717   // Helper method to get the name of a Type.
718   static const char* TypeName(Type type);
719 
720   // Helper method to get the name of a CppType.
721   static const char* CppTypeName(CppType cpp_type);
722 
723   // Return true iff [packed = true] is valid for fields of this type.
724   static inline bool IsTypePackable(Type field_type);
725 
726   // Returns full_name() except if the field is a MessageSet extension,
727   // in which case it returns the full_name() of the containing message type
728   // for backwards compatibility with proto1.
729   //
730   // A MessageSet extension is defined as an optional message extension
731   // whose containing type has the message_set_wire_format option set.
732   // This should be true of extensions of google.protobuf.bridge.MessageSet;
733   // by convention, such extensions are named "message_set_extension".
734   //
735   // The opposite operation (looking up an extension's FieldDescriptor given
736   // its printable name) can be accomplished with
737   //     message->file()->pool()->FindExtensionByPrintableName(message, name)
738   // where the extension extends "message".
739   const std::string& PrintableNameForExtension() const;
740 
741   // Source Location ---------------------------------------------------
742 
743   // Updates |*out_location| to the source location of the complete
744   // extent of this field declaration.  Returns false and leaves
745   // |*out_location| unchanged iff location information was not available.
746   bool GetSourceLocation(SourceLocation* out_location) const;
747 
748  private:
749   typedef FieldOptions OptionsType;
750 
751   // Allows access to GetLocationPath for annotations.
752   friend class io::Printer;
753   friend class compiler::cpp::Formatter;
754 
755   // Fill the json_name field of FieldDescriptorProto.
756   void CopyJsonNameTo(FieldDescriptorProto* proto) const;
757 
758   // See Descriptor::DebugString().
759   enum PrintLabelFlag { PRINT_LABEL, OMIT_LABEL };
760   void DebugString(int depth, PrintLabelFlag print_label_flag,
761                    std::string* contents,
762                    const DebugStringOptions& options) const;
763 
764   // formats the default value appropriately and returns it as a string.
765   // Must have a default value to call this. If quote_string_type is true, then
766   // types of CPPTYPE_STRING whill be surrounded by quotes and CEscaped.
767   std::string DefaultValueAsString(bool quote_string_type) const;
768 
769   // Helper function that returns the field type name for DebugString.
770   std::string FieldTypeNameDebugString() const;
771 
772   // Walks up the descriptor tree to generate the source location path
773   // to this descriptor from the file root.
774   void GetLocationPath(std::vector<int>* output) const;
775 
776   // Returns true if this is a map message type.
777   bool is_map_message_type() const;
778 
779   const std::string* name_;
780   const std::string* full_name_;
781   const std::string* lowercase_name_;
782   const std::string* camelcase_name_;
783   // If has_json_name_ is true, it's the value specified by the user.
784   // Otherwise, it has the same value as camelcase_name_.
785   const std::string* json_name_;
786   const FileDescriptor* file_;
787   internal::once_flag* type_once_;
788   static void TypeOnceInit(const FieldDescriptor* to_init);
789   void InternalTypeOnceInit() const;
790   mutable Type type_;
791   Label label_;
792   bool has_default_value_;
793   // Whether the user has specified the json_name field option in the .proto
794   // file.
795   bool has_json_name_;
796   bool is_extension_;
797   int number_;
798   int index_in_oneof_;
799   const Descriptor* containing_type_;
800   const OneofDescriptor* containing_oneof_;
801   const Descriptor* extension_scope_;
802   mutable const Descriptor* message_type_;
803   mutable const EnumDescriptor* enum_type_;
804   const FieldOptions* options_;
805   const std::string* type_name_;
806   const std::string* default_value_enum_name_;
807   // IMPORTANT:  If you add a new field, make sure to search for all instances
808   // of Allocate<FieldDescriptor>() and AllocateArray<FieldDescriptor>() in
809   // descriptor.cc and update them to initialize the field.
810 
811   union {
812     int32 default_value_int32_;
813     int64 default_value_int64_;
814     uint32 default_value_uint32_;
815     uint64 default_value_uint64_;
816     float default_value_float_;
817     double default_value_double_;
818     bool default_value_bool_;
819 
820     mutable const EnumValueDescriptor* default_value_enum_;
821     const std::string* default_value_string_;
822   };
823 
824   static const CppType kTypeToCppTypeMap[MAX_TYPE + 1];
825 
826   static const char* const kTypeToName[MAX_TYPE + 1];
827 
828   static const char* const kCppTypeToName[MAX_CPPTYPE + 1];
829 
830   static const char* const kLabelToName[MAX_LABEL + 1];
831 
832   // Must be constructed using DescriptorPool.
FieldDescriptor()833   FieldDescriptor() {}
834   friend class DescriptorBuilder;
835   friend class FileDescriptor;
836   friend class Descriptor;
837   friend class OneofDescriptor;
838   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldDescriptor);
839 };
840 
841 
842 // Describes a oneof defined in a message type.
843 class PROTOBUF_EXPORT OneofDescriptor {
844  public:
845   typedef OneofDescriptorProto Proto;
846 
847   const std::string& name() const;       // Name of this oneof.
848   const std::string& full_name() const;  // Fully-qualified name of the oneof.
849 
850   // Index of this oneof within the message's oneof array.
851   int index() const;
852 
853   // The .proto file in which this oneof was defined.  Never nullptr.
854   const FileDescriptor* file() const;
855   // The Descriptor for the message containing this oneof.
856   const Descriptor* containing_type() const;
857 
858   // The number of (non-extension) fields which are members of this oneof.
859   int field_count() const;
860   // Get a member of this oneof, in the order in which they were declared in the
861   // .proto file.  Does not include extensions.
862   const FieldDescriptor* field(int index) const;
863 
864   const OneofOptions& options() const;
865 
866   // See Descriptor::CopyTo().
867   void CopyTo(OneofDescriptorProto* proto) const;
868 
869   // See Descriptor::DebugString().
870   std::string DebugString() const;
871 
872   // See Descriptor::DebugStringWithOptions().
873   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
874 
875   // Source Location ---------------------------------------------------
876 
877   // Updates |*out_location| to the source location of the complete
878   // extent of this oneof declaration.  Returns false and leaves
879   // |*out_location| unchanged iff location information was not available.
880   bool GetSourceLocation(SourceLocation* out_location) const;
881 
882  private:
883   typedef OneofOptions OptionsType;
884 
885   // Allows access to GetLocationPath for annotations.
886   friend class io::Printer;
887   friend class compiler::cpp::Formatter;
888 
889   // See Descriptor::DebugString().
890   void DebugString(int depth, std::string* contents,
891                    const DebugStringOptions& options) const;
892 
893   // Walks up the descriptor tree to generate the source location path
894   // to this descriptor from the file root.
895   void GetLocationPath(std::vector<int>* output) const;
896 
897   const std::string* name_;
898   const std::string* full_name_;
899   const Descriptor* containing_type_;
900   int field_count_;
901   const FieldDescriptor** fields_;
902   const OneofOptions* options_;
903 
904   // IMPORTANT:  If you add a new field, make sure to search for all instances
905   // of Allocate<OneofDescriptor>() and AllocateArray<OneofDescriptor>()
906   // in descriptor.cc and update them to initialize the field.
907 
908   // Must be constructed using DescriptorPool.
OneofDescriptor()909   OneofDescriptor() {}
910   friend class DescriptorBuilder;
911   friend class Descriptor;
912   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(OneofDescriptor);
913 };
914 
915 // Describes an enum type defined in a .proto file.  To get the EnumDescriptor
916 // for a generated enum type, call TypeName_descriptor().  Use DescriptorPool
917 // to construct your own descriptors.
918 class PROTOBUF_EXPORT EnumDescriptor {
919  public:
920   typedef EnumDescriptorProto Proto;
921 
922   // The name of this enum type in the containing scope.
923   const std::string& name() const;
924 
925   // The fully-qualified name of the enum type, scope delimited by periods.
926   const std::string& full_name() const;
927 
928   // Index of this enum within the file or containing message's enum array.
929   int index() const;
930 
931   // The .proto file in which this enum type was defined.  Never nullptr.
932   const FileDescriptor* file() const;
933 
934   // The number of values for this EnumDescriptor.  Guaranteed to be greater
935   // than zero.
936   int value_count() const;
937   // Gets a value by index, where 0 <= index < value_count().
938   // These are returned in the order they were defined in the .proto file.
939   const EnumValueDescriptor* value(int index) const;
940 
941   // Looks up a value by name.  Returns nullptr if no such value exists.
942   const EnumValueDescriptor* FindValueByName(const std::string& name) const;
943   // Looks up a value by number.  Returns nullptr if no such value exists.  If
944   // multiple values have this number, the first one defined is returned.
945   const EnumValueDescriptor* FindValueByNumber(int number) const;
946 
947   // If this enum type is nested in a message type, this is that message type.
948   // Otherwise, nullptr.
949   const Descriptor* containing_type() const;
950 
951   // Get options for this enum type.  These are specified in the .proto file by
952   // placing lines like "option foo = 1234;" in the enum definition.  Allowed
953   // options are defined by EnumOptions in descriptor.proto, and any available
954   // extensions of that message.
955   const EnumOptions& options() const;
956 
957   // See Descriptor::CopyTo().
958   void CopyTo(EnumDescriptorProto* proto) const;
959 
960   // See Descriptor::DebugString().
961   std::string DebugString() const;
962 
963   // See Descriptor::DebugStringWithOptions().
964   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
965 
966   // Returns true if this is a placeholder for an unknown enum. This will
967   // only be the case if this descriptor comes from a DescriptorPool
968   // with AllowUnknownDependencies() set.
969   bool is_placeholder() const;
970 
971   // Reserved fields -------------------------------------------------
972 
973   // A range of reserved field numbers.
974   struct ReservedRange {
975     int start;  // inclusive
976     int end;    // inclusive
977   };
978 
979   // The number of reserved ranges in this message type.
980   int reserved_range_count() const;
981   // Gets an reserved range by index, where 0 <= index <
982   // reserved_range_count(). These are returned in the order they were defined
983   // in the .proto file.
984   const EnumDescriptor::ReservedRange* reserved_range(int index) const;
985 
986   // Returns true if the number is in one of the reserved ranges.
987   bool IsReservedNumber(int number) const;
988 
989   // Returns nullptr if no reserved range contains the given number.
990   const EnumDescriptor::ReservedRange* FindReservedRangeContainingNumber(
991       int number) const;
992 
993   // The number of reserved field names in this message type.
994   int reserved_name_count() const;
995 
996   // Gets a reserved name by index, where 0 <= index < reserved_name_count().
997   const std::string& reserved_name(int index) const;
998 
999   // Returns true if the field name is reserved.
1000   bool IsReservedName(const std::string& name) const;
1001 
1002   // Source Location ---------------------------------------------------
1003 
1004   // Updates |*out_location| to the source location of the complete
1005   // extent of this enum declaration.  Returns false and leaves
1006   // |*out_location| unchanged iff location information was not available.
1007   bool GetSourceLocation(SourceLocation* out_location) const;
1008 
1009  private:
1010   typedef EnumOptions OptionsType;
1011 
1012   // Allows access to GetLocationPath for annotations.
1013   friend class io::Printer;
1014   friend class compiler::cpp::Formatter;
1015 
1016   // Looks up a value by number.  If the value does not exist, dynamically
1017   // creates a new EnumValueDescriptor for that value, assuming that it was
1018   // unknown. If a new descriptor is created, this is done in a thread-safe way,
1019   // and future calls will return the same value descriptor pointer.
1020   //
1021   // This is private but is used by Reflection (which is friended below) to
1022   // return a valid EnumValueDescriptor from GetEnum() when this feature is
1023   // enabled.
1024   const EnumValueDescriptor* FindValueByNumberCreatingIfUnknown(
1025       int number) const;
1026 
1027   // See Descriptor::DebugString().
1028   void DebugString(int depth, std::string* contents,
1029                    const DebugStringOptions& options) const;
1030 
1031   // Walks up the descriptor tree to generate the source location path
1032   // to this descriptor from the file root.
1033   void GetLocationPath(std::vector<int>* output) const;
1034 
1035   const std::string* name_;
1036   const std::string* full_name_;
1037   const FileDescriptor* file_;
1038   const Descriptor* containing_type_;
1039   const EnumOptions* options_;
1040 
1041   // True if this is a placeholder for an unknown type.
1042   bool is_placeholder_;
1043   // True if this is a placeholder and the type name wasn't fully-qualified.
1044   bool is_unqualified_placeholder_;
1045 
1046   int value_count_;
1047   EnumValueDescriptor* values_;
1048 
1049   int reserved_range_count_;
1050   int reserved_name_count_;
1051   EnumDescriptor::ReservedRange* reserved_ranges_;
1052   const std::string** reserved_names_;
1053 
1054   // IMPORTANT:  If you add a new field, make sure to search for all instances
1055   // of Allocate<EnumDescriptor>() and AllocateArray<EnumDescriptor>() in
1056   // descriptor.cc and update them to initialize the field.
1057 
1058   // Must be constructed using DescriptorPool.
EnumDescriptor()1059   EnumDescriptor() {}
1060   friend class DescriptorBuilder;
1061   friend class Descriptor;
1062   friend class FieldDescriptor;
1063   friend class EnumValueDescriptor;
1064   friend class FileDescriptor;
1065   friend class DescriptorPool;
1066   friend class Reflection;
1067   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumDescriptor);
1068 };
1069 
1070 // Describes an individual enum constant of a particular type.  To get the
1071 // EnumValueDescriptor for a given enum value, first get the EnumDescriptor
1072 // for its type, then use EnumDescriptor::FindValueByName() or
1073 // EnumDescriptor::FindValueByNumber().  Use DescriptorPool to construct
1074 // your own descriptors.
1075 class PROTOBUF_EXPORT EnumValueDescriptor {
1076  public:
1077   typedef EnumValueDescriptorProto Proto;
1078 
1079   const std::string& name() const;  // Name of this enum constant.
1080   int index() const;                // Index within the enums's Descriptor.
1081   int number() const;               // Numeric value of this enum constant.
1082 
1083   // The full_name of an enum value is a sibling symbol of the enum type.
1084   // e.g. the full name of FieldDescriptorProto::TYPE_INT32 is actually
1085   // "google.protobuf.FieldDescriptorProto.TYPE_INT32", NOT
1086   // "google.protobuf.FieldDescriptorProto.Type.TYPE_INT32".  This is to conform
1087   // with C++ scoping rules for enums.
1088   const std::string& full_name() const;
1089 
1090   // The .proto file in which this value was defined.  Never nullptr.
1091   const FileDescriptor* file() const;
1092   // The type of this value.  Never nullptr.
1093   const EnumDescriptor* type() const;
1094 
1095   // Get options for this enum value.  These are specified in the .proto file by
1096   // adding text like "[foo = 1234]" after an enum value definition.  Allowed
1097   // options are defined by EnumValueOptions in descriptor.proto, and any
1098   // available extensions of that message.
1099   const EnumValueOptions& options() const;
1100 
1101   // See Descriptor::CopyTo().
1102   void CopyTo(EnumValueDescriptorProto* proto) const;
1103 
1104   // See Descriptor::DebugString().
1105   std::string DebugString() const;
1106 
1107   // See Descriptor::DebugStringWithOptions().
1108   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
1109 
1110   // Source Location ---------------------------------------------------
1111 
1112   // Updates |*out_location| to the source location of the complete
1113   // extent of this enum value declaration.  Returns false and leaves
1114   // |*out_location| unchanged iff location information was not available.
1115   bool GetSourceLocation(SourceLocation* out_location) const;
1116 
1117  private:
1118   typedef EnumValueOptions OptionsType;
1119 
1120   // Allows access to GetLocationPath for annotations.
1121   friend class io::Printer;
1122   friend class compiler::cpp::Formatter;
1123 
1124   // See Descriptor::DebugString().
1125   void DebugString(int depth, std::string* contents,
1126                    const DebugStringOptions& options) const;
1127 
1128   // Walks up the descriptor tree to generate the source location path
1129   // to this descriptor from the file root.
1130   void GetLocationPath(std::vector<int>* output) const;
1131 
1132   const std::string* name_;
1133   const std::string* full_name_;
1134   int number_;
1135   const EnumDescriptor* type_;
1136   const EnumValueOptions* options_;
1137   // IMPORTANT:  If you add a new field, make sure to search for all instances
1138   // of Allocate<EnumValueDescriptor>() and AllocateArray<EnumValueDescriptor>()
1139   // in descriptor.cc and update them to initialize the field.
1140 
1141   // Must be constructed using DescriptorPool.
EnumValueDescriptor()1142   EnumValueDescriptor() {}
1143   friend class DescriptorBuilder;
1144   friend class EnumDescriptor;
1145   friend class DescriptorPool;
1146   friend class FileDescriptorTables;
1147   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumValueDescriptor);
1148 };
1149 
1150 // Describes an RPC service. Use DescriptorPool to construct your own
1151 // descriptors.
1152 class PROTOBUF_EXPORT ServiceDescriptor {
1153  public:
1154   typedef ServiceDescriptorProto Proto;
1155 
1156   // The name of the service, not including its containing scope.
1157   const std::string& name() const;
1158   // The fully-qualified name of the service, scope delimited by periods.
1159   const std::string& full_name() const;
1160   // Index of this service within the file's services array.
1161   int index() const;
1162 
1163   // The .proto file in which this service was defined.  Never nullptr.
1164   const FileDescriptor* file() const;
1165 
1166   // Get options for this service type.  These are specified in the .proto file
1167   // by placing lines like "option foo = 1234;" in the service definition.
1168   // Allowed options are defined by ServiceOptions in descriptor.proto, and any
1169   // available extensions of that message.
1170   const ServiceOptions& options() const;
1171 
1172   // The number of methods this service defines.
1173   int method_count() const;
1174   // Gets a MethodDescriptor by index, where 0 <= index < method_count().
1175   // These are returned in the order they were defined in the .proto file.
1176   const MethodDescriptor* method(int index) const;
1177 
1178   // Look up a MethodDescriptor by name.
1179   const MethodDescriptor* FindMethodByName(const std::string& name) const;
1180   // See Descriptor::CopyTo().
1181   void CopyTo(ServiceDescriptorProto* proto) const;
1182 
1183   // See Descriptor::DebugString().
1184   std::string DebugString() const;
1185 
1186   // See Descriptor::DebugStringWithOptions().
1187   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
1188 
1189   // Source Location ---------------------------------------------------
1190 
1191   // Updates |*out_location| to the source location of the complete
1192   // extent of this service declaration.  Returns false and leaves
1193   // |*out_location| unchanged iff location information was not available.
1194   bool GetSourceLocation(SourceLocation* out_location) const;
1195 
1196  private:
1197   typedef ServiceOptions OptionsType;
1198 
1199   // Allows access to GetLocationPath for annotations.
1200   friend class io::Printer;
1201   friend class compiler::cpp::Formatter;
1202 
1203   // See Descriptor::DebugString().
1204   void DebugString(std::string* contents,
1205                    const DebugStringOptions& options) const;
1206 
1207   // Walks up the descriptor tree to generate the source location path
1208   // to this descriptor from the file root.
1209   void GetLocationPath(std::vector<int>* output) const;
1210 
1211   const std::string* name_;
1212   const std::string* full_name_;
1213   const FileDescriptor* file_;
1214   const ServiceOptions* options_;
1215   MethodDescriptor* methods_;
1216   int method_count_;
1217   // IMPORTANT:  If you add a new field, make sure to search for all instances
1218   // of Allocate<ServiceDescriptor>() and AllocateArray<ServiceDescriptor>() in
1219   // descriptor.cc and update them to initialize the field.
1220 
1221   // Must be constructed using DescriptorPool.
ServiceDescriptor()1222   ServiceDescriptor() {}
1223   friend class DescriptorBuilder;
1224   friend class FileDescriptor;
1225   friend class MethodDescriptor;
1226   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ServiceDescriptor);
1227 };
1228 
1229 
1230 // Describes an individual service method.  To obtain a MethodDescriptor given
1231 // a service, first get its ServiceDescriptor, then call
1232 // ServiceDescriptor::FindMethodByName().  Use DescriptorPool to construct your
1233 // own descriptors.
1234 class PROTOBUF_EXPORT MethodDescriptor {
1235  public:
1236   typedef MethodDescriptorProto Proto;
1237 
1238   // Name of this method, not including containing scope.
1239   const std::string& name() const;
1240   // The fully-qualified name of the method, scope delimited by periods.
1241   const std::string& full_name() const;
1242   // Index within the service's Descriptor.
1243   int index() const;
1244 
1245   // The .proto file in which this method was defined.  Never nullptr.
1246   const FileDescriptor* file() const;
1247   // Gets the service to which this method belongs.  Never nullptr.
1248   const ServiceDescriptor* service() const;
1249 
1250   // Gets the type of protocol message which this method accepts as input.
1251   const Descriptor* input_type() const;
1252   // Gets the type of protocol message which this message produces as output.
1253   const Descriptor* output_type() const;
1254 
1255   // Gets whether the client streams multiple requests.
1256   bool client_streaming() const;
1257   // Gets whether the server streams multiple responses.
1258   bool server_streaming() const;
1259 
1260   // Get options for this method.  These are specified in the .proto file by
1261   // placing lines like "option foo = 1234;" in curly-braces after a method
1262   // declaration.  Allowed options are defined by MethodOptions in
1263   // descriptor.proto, and any available extensions of that message.
1264   const MethodOptions& options() const;
1265 
1266   // See Descriptor::CopyTo().
1267   void CopyTo(MethodDescriptorProto* proto) const;
1268 
1269   // See Descriptor::DebugString().
1270   std::string DebugString() const;
1271 
1272   // See Descriptor::DebugStringWithOptions().
1273   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
1274 
1275   // Source Location ---------------------------------------------------
1276 
1277   // Updates |*out_location| to the source location of the complete
1278   // extent of this method declaration.  Returns false and leaves
1279   // |*out_location| unchanged iff location information was not available.
1280   bool GetSourceLocation(SourceLocation* out_location) const;
1281 
1282  private:
1283   typedef MethodOptions OptionsType;
1284 
1285   // Allows access to GetLocationPath for annotations.
1286   friend class io::Printer;
1287   friend class compiler::cpp::Formatter;
1288 
1289   // See Descriptor::DebugString().
1290   void DebugString(int depth, std::string* contents,
1291                    const DebugStringOptions& options) const;
1292 
1293   // Walks up the descriptor tree to generate the source location path
1294   // to this descriptor from the file root.
1295   void GetLocationPath(std::vector<int>* output) const;
1296 
1297   const std::string* name_;
1298   const std::string* full_name_;
1299   const ServiceDescriptor* service_;
1300   mutable internal::LazyDescriptor input_type_;
1301   mutable internal::LazyDescriptor output_type_;
1302   const MethodOptions* options_;
1303   bool client_streaming_;
1304   bool server_streaming_;
1305   // IMPORTANT:  If you add a new field, make sure to search for all instances
1306   // of Allocate<MethodDescriptor>() and AllocateArray<MethodDescriptor>() in
1307   // descriptor.cc and update them to initialize the field.
1308 
1309   // Must be constructed using DescriptorPool.
MethodDescriptor()1310   MethodDescriptor() {}
1311   friend class DescriptorBuilder;
1312   friend class ServiceDescriptor;
1313   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MethodDescriptor);
1314 };
1315 
1316 
1317 // Describes a whole .proto file.  To get the FileDescriptor for a compiled-in
1318 // file, get the descriptor for something defined in that file and call
1319 // descriptor->file().  Use DescriptorPool to construct your own descriptors.
1320 class PROTOBUF_EXPORT FileDescriptor {
1321  public:
1322   typedef FileDescriptorProto Proto;
1323 
1324   // The filename, relative to the source tree.
1325   // e.g. "foo/bar/baz.proto"
1326   const std::string& name() const;
1327 
1328   // The package, e.g. "google.protobuf.compiler".
1329   const std::string& package() const;
1330 
1331   // The DescriptorPool in which this FileDescriptor and all its contents were
1332   // allocated.  Never nullptr.
1333   const DescriptorPool* pool() const;
1334 
1335   // The number of files imported by this one.
1336   int dependency_count() const;
1337   // Gets an imported file by index, where 0 <= index < dependency_count().
1338   // These are returned in the order they were defined in the .proto file.
1339   const FileDescriptor* dependency(int index) const;
1340 
1341   // The number of files public imported by this one.
1342   // The public dependency list is a subset of the dependency list.
1343   int public_dependency_count() const;
1344   // Gets a public imported file by index, where 0 <= index <
1345   // public_dependency_count().
1346   // These are returned in the order they were defined in the .proto file.
1347   const FileDescriptor* public_dependency(int index) const;
1348 
1349   // The number of files that are imported for weak fields.
1350   // The weak dependency list is a subset of the dependency list.
1351   int weak_dependency_count() const;
1352   // Gets a weak imported file by index, where 0 <= index <
1353   // weak_dependency_count().
1354   // These are returned in the order they were defined in the .proto file.
1355   const FileDescriptor* weak_dependency(int index) const;
1356 
1357   // Number of top-level message types defined in this file.  (This does not
1358   // include nested types.)
1359   int message_type_count() const;
1360   // Gets a top-level message type, where 0 <= index < message_type_count().
1361   // These are returned in the order they were defined in the .proto file.
1362   const Descriptor* message_type(int index) const;
1363 
1364   // Number of top-level enum types defined in this file.  (This does not
1365   // include nested types.)
1366   int enum_type_count() const;
1367   // Gets a top-level enum type, where 0 <= index < enum_type_count().
1368   // These are returned in the order they were defined in the .proto file.
1369   const EnumDescriptor* enum_type(int index) const;
1370 
1371   // Number of services defined in this file.
1372   int service_count() const;
1373   // Gets a service, where 0 <= index < service_count().
1374   // These are returned in the order they were defined in the .proto file.
1375   const ServiceDescriptor* service(int index) const;
1376 
1377   // Number of extensions defined at file scope.  (This does not include
1378   // extensions nested within message types.)
1379   int extension_count() const;
1380   // Gets an extension's descriptor, where 0 <= index < extension_count().
1381   // These are returned in the order they were defined in the .proto file.
1382   const FieldDescriptor* extension(int index) const;
1383 
1384   // Get options for this file.  These are specified in the .proto file by
1385   // placing lines like "option foo = 1234;" at the top level, outside of any
1386   // other definitions.  Allowed options are defined by FileOptions in
1387   // descriptor.proto, and any available extensions of that message.
1388   const FileOptions& options() const;
1389 
1390   // Syntax of this file.
1391   enum Syntax {
1392     SYNTAX_UNKNOWN = 0,
1393     SYNTAX_PROTO2 = 2,
1394     SYNTAX_PROTO3 = 3,
1395   };
1396   Syntax syntax() const;
1397   static const char* SyntaxName(Syntax syntax);
1398 
1399   // Find a top-level message type by name.  Returns nullptr if not found.
1400   const Descriptor* FindMessageTypeByName(const std::string& name) const;
1401   // Find a top-level enum type by name.  Returns nullptr if not found.
1402   const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
1403   // Find an enum value defined in any top-level enum by name.  Returns nullptr
1404   // if not found.
1405   const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
1406   // Find a service definition by name.  Returns nullptr if not found.
1407   const ServiceDescriptor* FindServiceByName(const std::string& name) const;
1408   // Find a top-level extension definition by name.  Returns nullptr if not
1409   // found.
1410   const FieldDescriptor* FindExtensionByName(const std::string& name) const;
1411   // Similar to FindExtensionByName(), but searches by lowercased-name.  See
1412   // Descriptor::FindFieldByLowercaseName().
1413   const FieldDescriptor* FindExtensionByLowercaseName(
1414       const std::string& name) const;
1415   // Similar to FindExtensionByName(), but searches by camelcased-name.  See
1416   // Descriptor::FindFieldByCamelcaseName().
1417   const FieldDescriptor* FindExtensionByCamelcaseName(
1418       const std::string& name) const;
1419 
1420   // See Descriptor::CopyTo().
1421   // Notes:
1422   // - This method does NOT copy source code information since it is relatively
1423   //   large and rarely needed.  See CopySourceCodeInfoTo() below.
1424   void CopyTo(FileDescriptorProto* proto) const;
1425   // Write the source code information of this FileDescriptor into the given
1426   // FileDescriptorProto.  See CopyTo() above.
1427   void CopySourceCodeInfoTo(FileDescriptorProto* proto) const;
1428   // Fill the json_name field of FieldDescriptorProto for all fields. Can only
1429   // be called after CopyTo().
1430   void CopyJsonNameTo(FileDescriptorProto* proto) const;
1431 
1432   // See Descriptor::DebugString().
1433   std::string DebugString() const;
1434 
1435   // See Descriptor::DebugStringWithOptions().
1436   std::string DebugStringWithOptions(const DebugStringOptions& options) const;
1437 
1438   // Returns true if this is a placeholder for an unknown file. This will
1439   // only be the case if this descriptor comes from a DescriptorPool
1440   // with AllowUnknownDependencies() set.
1441   bool is_placeholder() const;
1442 
1443   // Updates |*out_location| to the source location of the complete extent of
1444   // this file declaration (namely, the empty path).
1445   bool GetSourceLocation(SourceLocation* out_location) const;
1446 
1447   // Updates |*out_location| to the source location of the complete
1448   // extent of the declaration or declaration-part denoted by |path|.
1449   // Returns false and leaves |*out_location| unchanged iff location
1450   // information was not available.  (See SourceCodeInfo for
1451   // description of path encoding.)
1452   bool GetSourceLocation(const std::vector<int>& path,
1453                          SourceLocation* out_location) const;
1454 
1455  private:
1456   typedef FileOptions OptionsType;
1457 
1458   const std::string* name_;
1459   const std::string* package_;
1460   const DescriptorPool* pool_;
1461   internal::once_flag* dependencies_once_;
1462   static void DependenciesOnceInit(const FileDescriptor* to_init);
1463   void InternalDependenciesOnceInit() const;
1464 
1465   // These are arranged to minimze padding on 64-bit.
1466   int dependency_count_;
1467   int public_dependency_count_;
1468   int weak_dependency_count_;
1469   int message_type_count_;
1470   int enum_type_count_;
1471   int service_count_;
1472   int extension_count_;
1473   Syntax syntax_;
1474   bool is_placeholder_;
1475 
1476   // Indicates the FileDescriptor is completed building. Used to verify
1477   // that type accessor functions that can possibly build a dependent file
1478   // aren't called during the process of building the file.
1479   bool finished_building_;
1480 
1481   mutable const FileDescriptor** dependencies_;
1482   const std::string** dependencies_names_;
1483   int* public_dependencies_;
1484   int* weak_dependencies_;
1485   Descriptor* message_types_;
1486   EnumDescriptor* enum_types_;
1487   ServiceDescriptor* services_;
1488   FieldDescriptor* extensions_;
1489   const FileOptions* options_;
1490 
1491   const FileDescriptorTables* tables_;
1492   const SourceCodeInfo* source_code_info_;
1493 
1494   // IMPORTANT:  If you add a new field, make sure to search for all instances
1495   // of Allocate<FileDescriptor>() and AllocateArray<FileDescriptor>() in
1496   // descriptor.cc and update them to initialize the field.
1497 
FileDescriptor()1498   FileDescriptor() {}
1499   friend class DescriptorBuilder;
1500   friend class DescriptorPool;
1501   friend class Descriptor;
1502   friend class FieldDescriptor;
1503   friend class internal::LazyDescriptor;
1504   friend class OneofDescriptor;
1505   friend class EnumDescriptor;
1506   friend class EnumValueDescriptor;
1507   friend class MethodDescriptor;
1508   friend class ServiceDescriptor;
1509   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FileDescriptor);
1510 };
1511 
1512 
1513 // ===================================================================
1514 
1515 // Used to construct descriptors.
1516 //
1517 // Normally you won't want to build your own descriptors.  Message classes
1518 // constructed by the protocol compiler will provide them for you.  However,
1519 // if you are implementing Message on your own, or if you are writing a
1520 // program which can operate on totally arbitrary types and needs to load
1521 // them from some sort of database, you might need to.
1522 //
1523 // Since Descriptors are composed of a whole lot of cross-linked bits of
1524 // data that would be a pain to put together manually, the
1525 // DescriptorPool class is provided to make the process easier.  It can
1526 // take a FileDescriptorProto (defined in descriptor.proto), validate it,
1527 // and convert it to a set of nicely cross-linked Descriptors.
1528 //
1529 // DescriptorPool also helps with memory management.  Descriptors are
1530 // composed of many objects containing static data and pointers to each
1531 // other.  In all likelihood, when it comes time to delete this data,
1532 // you'll want to delete it all at once.  In fact, it is not uncommon to
1533 // have a whole pool of descriptors all cross-linked with each other which
1534 // you wish to delete all at once.  This class represents such a pool, and
1535 // handles the memory management for you.
1536 //
1537 // You can also search for descriptors within a DescriptorPool by name, and
1538 // extensions by number.
1539 class PROTOBUF_EXPORT DescriptorPool {
1540  public:
1541   // Create a normal, empty DescriptorPool.
1542   DescriptorPool();
1543 
1544   // Constructs a DescriptorPool that, when it can't find something among the
1545   // descriptors already in the pool, looks for it in the given
1546   // DescriptorDatabase.
1547   // Notes:
1548   // - If a DescriptorPool is constructed this way, its BuildFile*() methods
1549   //   must not be called (they will assert-fail).  The only way to populate
1550   //   the pool with descriptors is to call the Find*By*() methods.
1551   // - The Find*By*() methods may block the calling thread if the
1552   //   DescriptorDatabase blocks.  This in turn means that parsing messages
1553   //   may block if they need to look up extensions.
1554   // - The Find*By*() methods will use mutexes for thread-safety, thus making
1555   //   them slower even when they don't have to fall back to the database.
1556   //   In fact, even the Find*By*() methods of descriptor objects owned by
1557   //   this pool will be slower, since they will have to obtain locks too.
1558   // - An ErrorCollector may optionally be given to collect validation errors
1559   //   in files loaded from the database.  If not given, errors will be printed
1560   //   to GOOGLE_LOG(ERROR).  Remember that files are built on-demand, so this
1561   //   ErrorCollector may be called from any thread that calls one of the
1562   //   Find*By*() methods.
1563   // - The DescriptorDatabase must not be mutated during the lifetime of
1564   //   the DescriptorPool. Even if the client takes care to avoid data races,
1565   //   changes to the content of the DescriptorDatabase may not be reflected
1566   //   in subsequent lookups in the DescriptorPool.
1567   class ErrorCollector;
1568   explicit DescriptorPool(DescriptorDatabase* fallback_database,
1569                           ErrorCollector* error_collector = nullptr);
1570 
1571   ~DescriptorPool();
1572 
1573   // Get a pointer to the generated pool.  Generated protocol message classes
1574   // which are compiled into the binary will allocate their descriptors in
1575   // this pool.  Do not add your own descriptors to this pool.
1576   static const DescriptorPool* generated_pool();
1577 
1578 
1579   // Find a FileDescriptor in the pool by file name.  Returns nullptr if not
1580   // found.
1581   const FileDescriptor* FindFileByName(const std::string& name) const;
1582 
1583   // Find the FileDescriptor in the pool which defines the given symbol.
1584   // If any of the Find*ByName() methods below would succeed, then this is
1585   // equivalent to calling that method and calling the result's file() method.
1586   // Otherwise this returns nullptr.
1587   const FileDescriptor* FindFileContainingSymbol(
1588       const std::string& symbol_name) const;
1589 
1590   // Looking up descriptors ------------------------------------------
1591   // These find descriptors by fully-qualified name.  These will find both
1592   // top-level descriptors and nested descriptors.  They return nullptr if not
1593   // found.
1594 
1595   const Descriptor* FindMessageTypeByName(const std::string& name) const;
1596   const FieldDescriptor* FindFieldByName(const std::string& name) const;
1597   const FieldDescriptor* FindExtensionByName(const std::string& name) const;
1598   const OneofDescriptor* FindOneofByName(const std::string& name) const;
1599   const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
1600   const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
1601   const ServiceDescriptor* FindServiceByName(const std::string& name) const;
1602   const MethodDescriptor* FindMethodByName(const std::string& name) const;
1603 
1604   // Finds an extension of the given type by number.  The extendee must be
1605   // a member of this DescriptorPool or one of its underlays.
1606   const FieldDescriptor* FindExtensionByNumber(const Descriptor* extendee,
1607                                                int number) const;
1608 
1609   // Finds an extension of the given type by its printable name.
1610   // See comments above PrintableNameForExtension() for the definition of
1611   // "printable name".  The extendee must be a member of this DescriptorPool
1612   // or one of its underlays.  Returns nullptr if there is no known message
1613   // extension with the given printable name.
1614   const FieldDescriptor* FindExtensionByPrintableName(
1615       const Descriptor* extendee, const std::string& printable_name) const;
1616 
1617   // Finds extensions of extendee. The extensions will be appended to
1618   // out in an undefined order. Only extensions defined directly in
1619   // this DescriptorPool or one of its underlays are guaranteed to be
1620   // found: extensions defined in the fallback database might not be found
1621   // depending on the database implementation.
1622   void FindAllExtensions(const Descriptor* extendee,
1623                          std::vector<const FieldDescriptor*>* out) const;
1624 
1625   // Building descriptors --------------------------------------------
1626 
1627   // When converting a FileDescriptorProto to a FileDescriptor, various
1628   // errors might be detected in the input.  The caller may handle these
1629   // programmatically by implementing an ErrorCollector.
1630   class PROTOBUF_EXPORT ErrorCollector {
1631    public:
ErrorCollector()1632     inline ErrorCollector() {}
1633     virtual ~ErrorCollector();
1634 
1635     // These constants specify what exact part of the construct is broken.
1636     // This is useful e.g. for mapping the error back to an exact location
1637     // in a .proto file.
1638     enum ErrorLocation {
1639       NAME,           // the symbol name, or the package name for files
1640       NUMBER,         // field or extension range number
1641       TYPE,           // field type
1642       EXTENDEE,       // field extendee
1643       DEFAULT_VALUE,  // field default value
1644       INPUT_TYPE,     // method input type
1645       OUTPUT_TYPE,    // method output type
1646       OPTION_NAME,    // name in assignment
1647       OPTION_VALUE,   // value in option assignment
1648       IMPORT,         // import error
1649       OTHER           // some other problem
1650     };
1651 
1652     // Reports an error in the FileDescriptorProto. Use this function if the
1653     // problem occurred should interrupt building the FileDescriptorProto.
1654     virtual void AddError(
1655         const std::string& filename,  // File name in which the error occurred.
1656         const std::string& element_name,  // Full name of the erroneous element.
1657         const Message* descriptor,  // Descriptor of the erroneous element.
1658         ErrorLocation location,     // One of the location constants, above.
1659         const std::string& message  // Human-readable error message.
1660         ) = 0;
1661 
1662     // Reports a warning in the FileDescriptorProto. Use this function if the
1663     // problem occurred should NOT interrupt building the FileDescriptorProto.
AddWarning(const std::string &,const std::string &,const Message *,ErrorLocation,const std::string &)1664     virtual void AddWarning(
1665         const std::string& /*filename*/,      // File name in which the error
1666                                               // occurred.
1667         const std::string& /*element_name*/,  // Full name of the erroneous
1668                                               // element.
1669         const Message* /*descriptor*/,  // Descriptor of the erroneous element.
1670         ErrorLocation /*location*/,     // One of the location constants, above.
1671         const std::string& /*message*/  // Human-readable error message.
1672     ) {}
1673 
1674    private:
1675     GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ErrorCollector);
1676   };
1677 
1678   // Convert the FileDescriptorProto to real descriptors and place them in
1679   // this DescriptorPool.  All dependencies of the file must already be in
1680   // the pool.  Returns the resulting FileDescriptor, or nullptr if there were
1681   // problems with the input (e.g. the message was invalid, or dependencies
1682   // were missing).  Details about the errors are written to GOOGLE_LOG(ERROR).
1683   const FileDescriptor* BuildFile(const FileDescriptorProto& proto);
1684 
1685   // Same as BuildFile() except errors are sent to the given ErrorCollector.
1686   const FileDescriptor* BuildFileCollectingErrors(
1687       const FileDescriptorProto& proto, ErrorCollector* error_collector);
1688 
1689   // By default, it is an error if a FileDescriptorProto contains references
1690   // to types or other files that are not found in the DescriptorPool (or its
1691   // backing DescriptorDatabase, if any).  If you call
1692   // AllowUnknownDependencies(), however, then unknown types and files
1693   // will be replaced by placeholder descriptors (which can be identified by
1694   // the is_placeholder() method).  This can allow you to
1695   // perform some useful operations with a .proto file even if you do not
1696   // have access to other .proto files on which it depends.  However, some
1697   // heuristics must be used to fill in the gaps in information, and these
1698   // can lead to descriptors which are inaccurate.  For example, the
1699   // DescriptorPool may be forced to guess whether an unknown type is a message
1700   // or an enum, as well as what package it resides in.  Furthermore,
1701   // placeholder types will not be discoverable via FindMessageTypeByName()
1702   // and similar methods, which could confuse some descriptor-based algorithms.
1703   // Generally, the results of this option should be handled with extreme care.
AllowUnknownDependencies()1704   void AllowUnknownDependencies() { allow_unknown_ = true; }
1705 
1706   // By default, weak imports are allowed to be missing, in which case we will
1707   // use a placeholder for the dependency and convert the field to be an Empty
1708   // message field. If you call EnforceWeakDependencies(true), however, the
1709   // DescriptorPool will report a import not found error.
EnforceWeakDependencies(bool enforce)1710   void EnforceWeakDependencies(bool enforce) { enforce_weak_ = enforce; }
1711 
1712   // Internal stuff --------------------------------------------------
1713   // These methods MUST NOT be called from outside the proto2 library.
1714   // These methods may contain hidden pitfalls and may be removed in a
1715   // future library version.
1716 
1717   // Create a DescriptorPool which is overlaid on top of some other pool.
1718   // If you search for a descriptor in the overlay and it is not found, the
1719   // underlay will be searched as a backup.  If the underlay has its own
1720   // underlay, that will be searched next, and so on.  This also means that
1721   // files built in the overlay will be cross-linked with the underlay's
1722   // descriptors if necessary.  The underlay remains property of the caller;
1723   // it must remain valid for the lifetime of the newly-constructed pool.
1724   //
1725   // Example:  Say you want to parse a .proto file at runtime in order to use
1726   // its type with a DynamicMessage.  Say this .proto file has dependencies,
1727   // but you know that all the dependencies will be things that are already
1728   // compiled into the binary.  For ease of use, you'd like to load the types
1729   // right out of generated_pool() rather than have to parse redundant copies
1730   // of all these .protos and runtime.  But, you don't want to add the parsed
1731   // types directly into generated_pool(): this is not allowed, and would be
1732   // bad design anyway.  So, instead, you could use generated_pool() as an
1733   // underlay for a new DescriptorPool in which you add only the new file.
1734   //
1735   // WARNING:  Use of underlays can lead to many subtle gotchas.  Instead,
1736   //   try to formulate what you want to do in terms of DescriptorDatabases.
1737   explicit DescriptorPool(const DescriptorPool* underlay);
1738 
1739   // Called by generated classes at init time to add their descriptors to
1740   // generated_pool.  Do NOT call this in your own code!  filename must be a
1741   // permanent string (e.g. a string literal).
1742   static void InternalAddGeneratedFile(const void* encoded_file_descriptor,
1743                                        int size);
1744 
1745   // Disallow [enforce_utf8 = false] in .proto files.
DisallowEnforceUtf8()1746   void DisallowEnforceUtf8() { disallow_enforce_utf8_ = true; }
1747 
1748 
1749   // For internal use only:  Gets a non-const pointer to the generated pool.
1750   // This is called at static-initialization time only, so thread-safety is
1751   // not a concern.  If both an underlay and a fallback database are present,
1752   // the underlay takes precedence.
1753   static DescriptorPool* internal_generated_pool();
1754 
1755   // For internal use only:  Changes the behavior of BuildFile() such that it
1756   // allows the file to make reference to message types declared in other files
1757   // which it did not officially declare as dependencies.
1758   void InternalDontEnforceDependencies();
1759 
1760   // For internal use only: Enables lazy building of dependencies of a file.
1761   // Delay the building of dependencies of a file descriptor until absolutely
1762   // necessary, like when message_type() is called on a field that is defined
1763   // in that dependency's file. This will cause functional issues if a proto
1764   // or one of it's dependencies has errors. Should only be enabled for the
1765   // generated_pool_ (because no descriptor build errors are guaranteed by
1766   // the compilation generation process), testing, or if a lack of descriptor
1767   // build errors can be guaranteed for a pool.
InternalSetLazilyBuildDependencies()1768   void InternalSetLazilyBuildDependencies() {
1769     lazily_build_dependencies_ = true;
1770     // This needs to be set when lazily building dependencies, as it breaks
1771     // dependency checking.
1772     InternalDontEnforceDependencies();
1773   }
1774 
1775   // For internal use only.
internal_set_underlay(const DescriptorPool * underlay)1776   void internal_set_underlay(const DescriptorPool* underlay) {
1777     underlay_ = underlay;
1778   }
1779 
1780   // For internal (unit test) use only:  Returns true if a FileDescriptor has
1781   // been constructed for the given file, false otherwise.  Useful for testing
1782   // lazy descriptor initialization behavior.
1783   bool InternalIsFileLoaded(const std::string& filename) const;
1784 
1785   // Add a file to unused_import_track_files_. DescriptorBuilder will log
1786   // warnings for those files if there is any unused import.
1787   void AddUnusedImportTrackFile(const std::string& file_name);
1788   void ClearUnusedImportTrackFiles();
1789 
1790  private:
1791   friend class Descriptor;
1792   friend class internal::LazyDescriptor;
1793   friend class FieldDescriptor;
1794   friend class EnumDescriptor;
1795   friend class ServiceDescriptor;
1796   friend class MethodDescriptor;
1797   friend class FileDescriptor;
1798   friend class StreamDescriptor;
1799   friend class DescriptorBuilder;
1800   friend class FileDescriptorTables;
1801 
1802   // Return true if the given name is a sub-symbol of any non-package
1803   // descriptor that already exists in the descriptor pool.  (The full
1804   // definition of such types is already known.)
1805   bool IsSubSymbolOfBuiltType(const std::string& name) const;
1806 
1807   // Tries to find something in the fallback database and link in the
1808   // corresponding proto file.  Returns true if successful, in which case
1809   // the caller should search for the thing again.  These are declared
1810   // const because they are called by (semantically) const methods.
1811   bool TryFindFileInFallbackDatabase(const std::string& name) const;
1812   bool TryFindSymbolInFallbackDatabase(const std::string& name) const;
1813   bool TryFindExtensionInFallbackDatabase(const Descriptor* containing_type,
1814                                           int field_number) const;
1815 
1816   // Like BuildFile() but called internally when the file has been loaded from
1817   // fallback_database_.  Declared const because it is called by (semantically)
1818   // const methods.
1819   const FileDescriptor* BuildFileFromDatabase(
1820       const FileDescriptorProto& proto) const;
1821 
1822   // Helper for when lazily_build_dependencies_ is set, can look up a symbol
1823   // after the file's descriptor is built, and can build the file where that
1824   // symbol is defined if necessary. Will create a placeholder if the type
1825   // doesn't exist in the fallback database, or the file doesn't build
1826   // successfully.
1827   Symbol CrossLinkOnDemandHelper(const std::string& name,
1828                                  bool expecting_enum) const;
1829 
1830   // Create a placeholder FileDescriptor of the specified name
1831   FileDescriptor* NewPlaceholderFile(const std::string& name) const;
1832   FileDescriptor* NewPlaceholderFileWithMutexHeld(
1833       const std::string& name) const;
1834 
1835   enum PlaceholderType {
1836     PLACEHOLDER_MESSAGE,
1837     PLACEHOLDER_ENUM,
1838     PLACEHOLDER_EXTENDABLE_MESSAGE
1839   };
1840   // Create a placeholder Descriptor of the specified name
1841   Symbol NewPlaceholder(const std::string& name,
1842                         PlaceholderType placeholder_type) const;
1843   Symbol NewPlaceholderWithMutexHeld(const std::string& name,
1844                                      PlaceholderType placeholder_type) const;
1845 
1846   // If fallback_database_ is nullptr, this is nullptr.  Otherwise, this is a
1847   // mutex which must be locked while accessing tables_.
1848   internal::WrappedMutex* mutex_;
1849 
1850   // See constructor.
1851   DescriptorDatabase* fallback_database_;
1852   ErrorCollector* default_error_collector_;
1853   const DescriptorPool* underlay_;
1854 
1855   // This class contains a lot of hash maps with complicated types that
1856   // we'd like to keep out of the header.
1857   class Tables;
1858   std::unique_ptr<Tables> tables_;
1859 
1860   bool enforce_dependencies_;
1861   bool lazily_build_dependencies_;
1862   bool allow_unknown_;
1863   bool enforce_weak_;
1864   bool disallow_enforce_utf8_;
1865   std::set<std::string> unused_import_track_files_;
1866 
1867   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DescriptorPool);
1868 };
1869 
1870 
1871 // inline methods ====================================================
1872 
1873 // These macros makes this repetitive code more readable.
1874 #define PROTOBUF_DEFINE_ACCESSOR(CLASS, FIELD, TYPE) \
1875   inline TYPE CLASS::FIELD() const { return FIELD##_; }
1876 
1877 // Strings fields are stored as pointers but returned as const references.
1878 #define PROTOBUF_DEFINE_STRING_ACCESSOR(CLASS, FIELD) \
1879   inline const std::string& CLASS::FIELD() const { return *FIELD##_; }
1880 
1881 // Arrays take an index parameter, obviously.
1882 #define PROTOBUF_DEFINE_ARRAY_ACCESSOR(CLASS, FIELD, TYPE) \
1883   inline TYPE CLASS::FIELD(int index) const { return FIELD##s_ + index; }
1884 
1885 #define PROTOBUF_DEFINE_OPTIONS_ACCESSOR(CLASS, TYPE) \
1886   inline const TYPE& CLASS::options() const { return *options_; }
1887 
PROTOBUF_DEFINE_STRING_ACCESSOR(Descriptor,name)1888 PROTOBUF_DEFINE_STRING_ACCESSOR(Descriptor, name)
1889 PROTOBUF_DEFINE_STRING_ACCESSOR(Descriptor, full_name)
1890 PROTOBUF_DEFINE_ACCESSOR(Descriptor, file, const FileDescriptor*)
1891 PROTOBUF_DEFINE_ACCESSOR(Descriptor, containing_type, const Descriptor*)
1892 
1893 PROTOBUF_DEFINE_ACCESSOR(Descriptor, field_count, int)
1894 PROTOBUF_DEFINE_ACCESSOR(Descriptor, oneof_decl_count, int)
1895 PROTOBUF_DEFINE_ACCESSOR(Descriptor, nested_type_count, int)
1896 PROTOBUF_DEFINE_ACCESSOR(Descriptor, enum_type_count, int)
1897 
1898 PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, field, const FieldDescriptor*)
1899 PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, oneof_decl, const OneofDescriptor*)
1900 PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, nested_type, const Descriptor*)
1901 PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, enum_type, const EnumDescriptor*)
1902 
1903 PROTOBUF_DEFINE_ACCESSOR(Descriptor, extension_range_count, int)
1904 PROTOBUF_DEFINE_ACCESSOR(Descriptor, extension_count, int)
1905 PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, extension_range,
1906                                const Descriptor::ExtensionRange*)
1907 PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, extension, const FieldDescriptor*)
1908 
1909 PROTOBUF_DEFINE_ACCESSOR(Descriptor, reserved_range_count, int)
1910 PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, reserved_range,
1911                                const Descriptor::ReservedRange*)
1912 PROTOBUF_DEFINE_ACCESSOR(Descriptor, reserved_name_count, int)
1913 
1914 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(Descriptor, MessageOptions)
1915 PROTOBUF_DEFINE_ACCESSOR(Descriptor, is_placeholder, bool)
1916 
1917 PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, name)
1918 PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, full_name)
1919 PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, json_name)
1920 PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, lowercase_name)
1921 PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, camelcase_name)
1922 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, file, const FileDescriptor*)
1923 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, number, int)
1924 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, is_extension, bool)
1925 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, label, FieldDescriptor::Label)
1926 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, containing_type, const Descriptor*)
1927 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, containing_oneof,
1928                          const OneofDescriptor*)
1929 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, index_in_oneof, int)
1930 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, extension_scope, const Descriptor*)
1931 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(FieldDescriptor, FieldOptions)
1932 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, has_default_value, bool)
1933 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, has_json_name, bool)
1934 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_int32, int32)
1935 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_int64, int64)
1936 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_uint32, uint32)
1937 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_uint64, uint64)
1938 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_float, float)
1939 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_double, double)
1940 PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_bool, bool)
1941 PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, default_value_string)
1942 
1943 PROTOBUF_DEFINE_STRING_ACCESSOR(OneofDescriptor, name)
1944 PROTOBUF_DEFINE_STRING_ACCESSOR(OneofDescriptor, full_name)
1945 PROTOBUF_DEFINE_ACCESSOR(OneofDescriptor, containing_type, const Descriptor*)
1946 PROTOBUF_DEFINE_ACCESSOR(OneofDescriptor, field_count, int)
1947 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(OneofDescriptor, OneofOptions)
1948 
1949 PROTOBUF_DEFINE_STRING_ACCESSOR(EnumDescriptor, name)
1950 PROTOBUF_DEFINE_STRING_ACCESSOR(EnumDescriptor, full_name)
1951 PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, file, const FileDescriptor*)
1952 PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, containing_type, const Descriptor*)
1953 PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, value_count, int)
1954 PROTOBUF_DEFINE_ARRAY_ACCESSOR(EnumDescriptor, value,
1955                                const EnumValueDescriptor*)
1956 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(EnumDescriptor, EnumOptions)
1957 PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, is_placeholder, bool)
1958 PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, reserved_range_count, int)
1959 PROTOBUF_DEFINE_ARRAY_ACCESSOR(EnumDescriptor, reserved_range,
1960                                const EnumDescriptor::ReservedRange*)
1961 PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, reserved_name_count, int)
1962 
1963 PROTOBUF_DEFINE_STRING_ACCESSOR(EnumValueDescriptor, name)
1964 PROTOBUF_DEFINE_STRING_ACCESSOR(EnumValueDescriptor, full_name)
1965 PROTOBUF_DEFINE_ACCESSOR(EnumValueDescriptor, number, int)
1966 PROTOBUF_DEFINE_ACCESSOR(EnumValueDescriptor, type, const EnumDescriptor*)
1967 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(EnumValueDescriptor, EnumValueOptions)
1968 
1969 PROTOBUF_DEFINE_STRING_ACCESSOR(ServiceDescriptor, name)
1970 PROTOBUF_DEFINE_STRING_ACCESSOR(ServiceDescriptor, full_name)
1971 PROTOBUF_DEFINE_ACCESSOR(ServiceDescriptor, file, const FileDescriptor*)
1972 PROTOBUF_DEFINE_ACCESSOR(ServiceDescriptor, method_count, int)
1973 PROTOBUF_DEFINE_ARRAY_ACCESSOR(ServiceDescriptor, method,
1974                                const MethodDescriptor*)
1975 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(ServiceDescriptor, ServiceOptions)
1976 
1977 PROTOBUF_DEFINE_STRING_ACCESSOR(MethodDescriptor, name)
1978 PROTOBUF_DEFINE_STRING_ACCESSOR(MethodDescriptor, full_name)
1979 PROTOBUF_DEFINE_ACCESSOR(MethodDescriptor, service, const ServiceDescriptor*)
1980 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(MethodDescriptor, MethodOptions)
1981 PROTOBUF_DEFINE_ACCESSOR(MethodDescriptor, client_streaming, bool)
1982 PROTOBUF_DEFINE_ACCESSOR(MethodDescriptor, server_streaming, bool)
1983 
1984 PROTOBUF_DEFINE_STRING_ACCESSOR(FileDescriptor, name)
1985 PROTOBUF_DEFINE_STRING_ACCESSOR(FileDescriptor, package)
1986 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, pool, const DescriptorPool*)
1987 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, dependency_count, int)
1988 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, public_dependency_count, int)
1989 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, weak_dependency_count, int)
1990 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, message_type_count, int)
1991 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, enum_type_count, int)
1992 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, service_count, int)
1993 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, extension_count, int)
1994 PROTOBUF_DEFINE_OPTIONS_ACCESSOR(FileDescriptor, FileOptions)
1995 PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, is_placeholder, bool)
1996 
1997 PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, message_type, const Descriptor*)
1998 PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, enum_type, const EnumDescriptor*)
1999 PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, service,
2000                                const ServiceDescriptor*)
2001 PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, extension,
2002                                const FieldDescriptor*)
2003 
2004 #undef PROTOBUF_DEFINE_ACCESSOR
2005 #undef PROTOBUF_DEFINE_STRING_ACCESSOR
2006 #undef PROTOBUF_DEFINE_ARRAY_ACCESSOR
2007 
2008 // A few accessors differ from the macros...
2009 
2010 inline bool Descriptor::IsExtensionNumber(int number) const {
2011   return FindExtensionRangeContainingNumber(number) != nullptr;
2012 }
2013 
IsReservedNumber(int number)2014 inline bool Descriptor::IsReservedNumber(int number) const {
2015   return FindReservedRangeContainingNumber(number) != nullptr;
2016 }
2017 
IsReservedName(const std::string & name)2018 inline bool Descriptor::IsReservedName(const std::string& name) const {
2019   for (int i = 0; i < reserved_name_count(); i++) {
2020     if (name == reserved_name(i)) {
2021       return true;
2022     }
2023   }
2024   return false;
2025 }
2026 
2027 // Can't use PROTOBUF_DEFINE_ARRAY_ACCESSOR because reserved_names_ is actually
2028 // an array of pointers rather than the usual array of objects.
reserved_name(int index)2029 inline const std::string& Descriptor::reserved_name(int index) const {
2030   return *reserved_names_[index];
2031 }
2032 
IsReservedNumber(int number)2033 inline bool EnumDescriptor::IsReservedNumber(int number) const {
2034   return FindReservedRangeContainingNumber(number) != nullptr;
2035 }
2036 
IsReservedName(const std::string & name)2037 inline bool EnumDescriptor::IsReservedName(const std::string& name) const {
2038   for (int i = 0; i < reserved_name_count(); i++) {
2039     if (name == reserved_name(i)) {
2040       return true;
2041     }
2042   }
2043   return false;
2044 }
2045 
2046 // Can't use PROTOBUF_DEFINE_ARRAY_ACCESSOR because reserved_names_ is actually
2047 // an array of pointers rather than the usual array of objects.
reserved_name(int index)2048 inline const std::string& EnumDescriptor::reserved_name(int index) const {
2049   return *reserved_names_[index];
2050 }
2051 
type()2052 inline FieldDescriptor::Type FieldDescriptor::type() const {
2053   if (type_once_) {
2054     internal::call_once(*type_once_, &FieldDescriptor::TypeOnceInit, this);
2055   }
2056   return type_;
2057 }
2058 
is_required()2059 inline bool FieldDescriptor::is_required() const {
2060   return label() == LABEL_REQUIRED;
2061 }
2062 
is_optional()2063 inline bool FieldDescriptor::is_optional() const {
2064   return label() == LABEL_OPTIONAL;
2065 }
2066 
is_repeated()2067 inline bool FieldDescriptor::is_repeated() const {
2068   return label() == LABEL_REPEATED;
2069 }
2070 
is_packable()2071 inline bool FieldDescriptor::is_packable() const {
2072   return is_repeated() && IsTypePackable(type());
2073 }
2074 
is_map()2075 inline bool FieldDescriptor::is_map() const {
2076   return type() == TYPE_MESSAGE && is_map_message_type();
2077 }
2078 
2079 // To save space, index() is computed by looking at the descriptor's position
2080 // in the parent's array of children.
index()2081 inline int FieldDescriptor::index() const {
2082   if (!is_extension_) {
2083     return static_cast<int>(this - containing_type()->fields_);
2084   } else if (extension_scope_ != nullptr) {
2085     return static_cast<int>(this - extension_scope_->extensions_);
2086   } else {
2087     return static_cast<int>(this - file_->extensions_);
2088   }
2089 }
2090 
index()2091 inline int Descriptor::index() const {
2092   if (containing_type_ == nullptr) {
2093     return static_cast<int>(this - file_->message_types_);
2094   } else {
2095     return static_cast<int>(this - containing_type_->nested_types_);
2096   }
2097 }
2098 
file()2099 inline const FileDescriptor* OneofDescriptor::file() const {
2100   return containing_type()->file();
2101 }
2102 
index()2103 inline int OneofDescriptor::index() const {
2104   return static_cast<int>(this - containing_type_->oneof_decls_);
2105 }
2106 
index()2107 inline int EnumDescriptor::index() const {
2108   if (containing_type_ == nullptr) {
2109     return static_cast<int>(this - file_->enum_types_);
2110   } else {
2111     return static_cast<int>(this - containing_type_->enum_types_);
2112   }
2113 }
2114 
file()2115 inline const FileDescriptor* EnumValueDescriptor::file() const {
2116   return type()->file();
2117 }
2118 
index()2119 inline int EnumValueDescriptor::index() const {
2120   return static_cast<int>(this - type_->values_);
2121 }
2122 
index()2123 inline int ServiceDescriptor::index() const {
2124   return static_cast<int>(this - file_->services_);
2125 }
2126 
file()2127 inline const FileDescriptor* MethodDescriptor::file() const {
2128   return service()->file();
2129 }
2130 
index()2131 inline int MethodDescriptor::index() const {
2132   return static_cast<int>(this - service_->methods_);
2133 }
2134 
type_name()2135 inline const char* FieldDescriptor::type_name() const {
2136   return kTypeToName[type()];
2137 }
2138 
cpp_type()2139 inline FieldDescriptor::CppType FieldDescriptor::cpp_type() const {
2140   return kTypeToCppTypeMap[type()];
2141 }
2142 
cpp_type_name()2143 inline const char* FieldDescriptor::cpp_type_name() const {
2144   return kCppTypeToName[kTypeToCppTypeMap[type()]];
2145 }
2146 
TypeToCppType(Type type)2147 inline FieldDescriptor::CppType FieldDescriptor::TypeToCppType(Type type) {
2148   return kTypeToCppTypeMap[type];
2149 }
2150 
TypeName(Type type)2151 inline const char* FieldDescriptor::TypeName(Type type) {
2152   return kTypeToName[type];
2153 }
2154 
CppTypeName(CppType cpp_type)2155 inline const char* FieldDescriptor::CppTypeName(CppType cpp_type) {
2156   return kCppTypeToName[cpp_type];
2157 }
2158 
IsTypePackable(Type field_type)2159 inline bool FieldDescriptor::IsTypePackable(Type field_type) {
2160   return (field_type != FieldDescriptor::TYPE_STRING &&
2161           field_type != FieldDescriptor::TYPE_GROUP &&
2162           field_type != FieldDescriptor::TYPE_MESSAGE &&
2163           field_type != FieldDescriptor::TYPE_BYTES);
2164 }
2165 
public_dependency(int index)2166 inline const FileDescriptor* FileDescriptor::public_dependency(
2167     int index) const {
2168   return dependency(public_dependencies_[index]);
2169 }
2170 
weak_dependency(int index)2171 inline const FileDescriptor* FileDescriptor::weak_dependency(int index) const {
2172   return dependency(weak_dependencies_[index]);
2173 }
2174 
syntax()2175 inline FileDescriptor::Syntax FileDescriptor::syntax() const { return syntax_; }
2176 
2177 // Can't use PROTOBUF_DEFINE_ARRAY_ACCESSOR because fields_ is actually an array
2178 // of pointers rather than the usual array of objects.
field(int index)2179 inline const FieldDescriptor* OneofDescriptor::field(int index) const {
2180   return fields_[index];
2181 }
2182 
2183 }  // namespace protobuf
2184 }  // namespace google
2185 
2186 #include <google/protobuf/port_undef.inc>
2187 
2188 #endif  // GOOGLE_PROTOBUF_DESCRIPTOR_H__
2189