xref: /aosp_15_r20/external/nanopb-c/generator/proto/nanopb.proto (revision c8d645cafcee3f91213d30caa0fe303887010b9b)

// Custom options for defining:
// - Maximum size of string/bytes
// - Maximum number of elements in array
//
// These are used by nanopb to generate statically allocable structures
// for memory-limited environments.

syntax = "proto2";
import "google/protobuf/descriptor.proto";

option java_package = "fi.kapsi.koti.jpa.nanopb";

enum FieldType {
    FT_DEFAULT = 0; // Automatically decide field type, generate static field if possible.
    FT_CALLBACK = 1; // Always generate a callback field.
    FT_POINTER = 4; // Always generate a dynamically allocated field.
    FT_STATIC = 2; // Generate a static field or raise an exception if not possible.
    FT_IGNORE = 3; // Ignore the field completely.
    FT_INLINE = 5; // Legacy option, use the separate 'fixed_length' option instead
}

enum IntSize {
    IS_DEFAULT = 0; // Default, 32/64bit based on type in .proto
    IS_8 = 8;
    IS_16 = 16;
    IS_32 = 32;
    IS_64 = 64;
}

enum TypenameMangling {
    M_NONE = 0; // Default, no typename mangling
    M_STRIP_PACKAGE = 1; // Strip current package name
    M_FLATTEN = 2; // Only use last path component
}

// This is the inner options message, which basically defines options for
// a field. When it is used in message or file scope, it applies to all
// fields.
message NanoPBOptions {
  // Allocated size for 'bytes' and 'string' fields.
  // For string fields, this should include the space for null terminator.
  optional int32 max_size = 1;

  // Maximum length for 'string' fields. Setting this is equivalent
  // to setting max_size to a value of length+1.
  optional int32 max_length = 14;

  // Allocated number of entries in arrays ('repeated' fields)
  optional int32 max_count = 2;

  // Size of integer fields. Can save some memory if you don't need
  // full 32 bits for the value.
  optional IntSize int_size = 7 [default = IS_DEFAULT];

  // Force type of field (callback or static allocation)
  optional FieldType type = 3 [default = FT_DEFAULT];

  // Use long names for enums, i.e. EnumName_EnumValue.
  optional bool long_names = 4 [default = true];

  // Add 'packed' attribute to generated structs.
  // Note: this cannot be used on CPUs that break on unaligned
  // accesses to variables.
  optional bool packed_struct = 5 [default = false];

  // Add 'packed' attribute to generated enums.
  optional bool packed_enum = 10 [default = false];

  // Skip this message
  optional bool skip_message = 6 [default = false];

  // Generate oneof fields as normal optional fields instead of union.
  optional bool no_unions = 8 [default = false];

  // integer type tag for a message
  optional uint32 msgid = 9;

  // decode oneof as anonymous union
  optional bool anonymous_oneof = 11 [default = false];

  // Proto3 singular field does not generate a "has_" flag
  optional bool proto3 = 12 [default = false];

  // Generate an enum->string mapping function (can take up lots of space).
  optional bool enum_to_string = 13 [default = false];

  // Generate bytes arrays with fixed length
  optional bool fixed_length = 15 [default = false];

  // Generate repeated field with fixed count
  optional bool fixed_count = 16 [default = false];

  // Mangle long names
  optional TypenameMangling mangle_names = 17 [default = M_NONE];
}

// Extensions to protoc 'Descriptor' type in order to define options
// inside a .proto file.
//
// Protocol Buffers extension number registry
// --------------------------------
// Project:  Nanopb
// Contact:  Petteri Aimonen <[email protected]>
// Web site: http://kapsi.fi/~jpa/nanopb
// Extensions: 1010 (all types)
// --------------------------------

extend google.protobuf.FileOptions {
    optional NanoPBOptions nanopb_fileopt = 1010;
}

extend google.protobuf.MessageOptions {
    optional NanoPBOptions nanopb_msgopt = 1010;
}

extend google.protobuf.EnumOptions {
    optional NanoPBOptions nanopb_enumopt = 1010;
}

extend google.protobuf.FieldOptions {
    optional NanoPBOptions nanopb = 1010;
}