1 Using the schema compiler {#flatbuffers_guide_using_schema_compiler} 2 ========================= 3 4 Usage: 5 6 flatc [ GENERATOR OPTIONS ] [ -o PATH ] [ -I PATH ] [ -S ] FILES... 7 [ -- FILES...] 8 9 The files are read and parsed in order, and can contain either schemas 10 or data (see below). Data files are processed according to the definitions of 11 the most recent schema specified. 12 13 `--` indicates that the following files are binary files in 14 FlatBuffer format conforming to the schema indicated before it. 15 16 Depending on the flags passed, additional files may 17 be generated for each file processed: 18 19 For any schema input files, one or more generators can be specified: 20 21 - `--cpp`, `-c` : Generate a C++ header for all definitions in this file (as 22 `filename_generated.h`). 23 24 - `--java`, `-j` : Generate Java code. 25 26 - `--csharp`, `-n` : Generate C# code. 27 28 - `--go`, `-g` : Generate Go code. 29 30 - `--python`, `-p`: Generate Python code. 31 32 - `--js`, `-s`: Generate JavaScript code. 33 34 - `--ts`: Generate TypeScript code. 35 36 - `--php`: Generate PHP code. 37 38 - `--grpc`: Generate RPC stub code for GRPC. 39 40 - `--dart`: Generate Dart code. 41 42 - `--lua`: Generate Lua code. 43 44 - `--lobster`: Generate Lobster code. 45 46 - `--rust`, `-r` : Generate Rust code. 47 48 For any data input files: 49 50 - `--binary`, `-b` : If data is contained in this file, generate a 51 `filename.bin` containing the binary flatbuffer (or a different extension 52 if one is specified in the schema). 53 54 - `--json`, `-t` : If data is contained in this file, generate a 55 `filename.json` representing the data in the flatbuffer. 56 57 Additional options: 58 59 - `-o PATH` : Output all generated files to PATH (either absolute, or 60 relative to the current directory). If omitted, PATH will be the 61 current directory. PATH should end in your systems path separator, 62 e.g. `/` or `\`. 63 64 - `-I PATH` : when encountering `include` statements, attempt to load the 65 files from this path. Paths will be tried in the order given, and if all 66 fail (or none are specified) it will try to load relative to the path of 67 the schema file being parsed. 68 69 - `-M` : Print make rules for generated files. 70 71 - `--strict-json` : Require & generate strict JSON (field names are enclosed 72 in quotes, no trailing commas in tables/vectors). By default, no quotes are 73 required/generated, and trailing commas are allowed. 74 75 - `--allow-non-utf8` : Pass non-UTF-8 input through parser and emit nonstandard 76 \x escapes in JSON. (Default is to raise parse error on non-UTF-8 input.) 77 78 - `--natural-utf8` : Output strings with UTF-8 as human-readable strings. 79 By default, UTF-8 characters are printed as \uXXXX escapes." 80 81 - `--defaults-json` : Output fields whose value is equal to the default value 82 when writing JSON text. 83 84 - `--no-prefix` : Don't prefix enum values in generated C++ by their enum 85 type. 86 87 - `--scoped-enums` : Use C++11 style scoped and strongly typed enums in 88 generated C++. This also implies `--no-prefix`. 89 90 - `--gen-includes` : (deprecated), this is the default behavior. 91 If the original behavior is required (no include 92 statements) use `--no-includes.` 93 94 - `--no-includes` : Don't generate include statements for included schemas the 95 generated file depends on (C++). 96 97 - `--gen-mutable` : Generate additional non-const accessors for mutating 98 FlatBuffers in-place. 99 100 - `--gen-onefile` : Generate single output file for C# and Go. 101 102 - `--gen-name-strings` : Generate type name functions for C++. 103 104 - `--gen-object-api` : Generate an additional object-based API. This API is 105 more convenient for object construction and mutation than the base API, 106 at the cost of efficiency (object allocation). Recommended only to be used 107 if other options are insufficient. 108 109 - `--gen-compare` : Generate operator== for object-based API types. 110 111 - `--gen-nullable` : Add Clang _Nullable for C++ pointer. or @Nullable for Java. 112 113 - `--gen-generated` : Add @Generated annotation for Java. 114 115 - `--gen-all` : Generate not just code for the current schema files, but 116 for all files it includes as well. If the language uses a single file for 117 output (by default the case for C++ and JS), all code will end up in 118 this one file. 119 120 - `--cpp-ptr-type T` : Set object API pointer type (default std::unique_ptr) 121 122 - `--cpp-str-type T` : Set object API string type (default std::string) 123 - T::c_str() and T::length() must be supported. 124 125 - `--object-prefix` : Customise class prefix for C++ object-based API. 126 127 - `--object-suffix` : Customise class suffix for C++ object-based API. 128 129 - `--no-js-exports` : Removes Node.js style export lines (useful for JS) 130 131 - `--goog-js-export` : Uses goog.exportsSymbol and goog.exportsProperty 132 instead of Node.js style exporting. Needed for compatibility with the 133 Google closure compiler (useful for JS). 134 135 - `--es6-js-export` : Generates ECMAScript v6 style export definitions 136 instead of Node.js style exporting. Useful when integrating flatbuffers 137 with modern Javascript projects. 138 139 - `--go-namespace` : Generate the overrided namespace in Golang. 140 141 - `--go-import` : Generate the overrided import for flatbuffers in Golang. 142 (default is "github.com/google/flatbuffers/go"). 143 144 - `--raw-binary` : Allow binaries without a file_indentifier to be read. 145 This may crash flatc given a mismatched schema. 146 147 - `--size-prefixed` : Input binaries are size prefixed buffers. 148 149 - `--proto`: Expect input files to be .proto files (protocol buffers). 150 Output the corresponding .fbs file. 151 Currently supports: `package`, `message`, `enum`, nested declarations, 152 `import` (use `-I` for paths), `extend`, `oneof`, `group`. 153 Does not support, but will skip without error: `option`, `service`, 154 `extensions`, and most everything else. 155 156 - `--oneof-union` : Translate .proto oneofs to flatbuffer unions. 157 158 - `--grpc` : Generate GRPC interfaces for the specified languages. 159 160 - `--schema`: Serialize schemas instead of JSON (use with -b). This will 161 output a binary version of the specified schema that itself corresponds 162 to the reflection/reflection.fbs schema. Loading this binary file is the 163 basis for reflection functionality. 164 165 - `--bfbs-comments`: Add doc comments to the binary schema files. 166 167 - `--conform FILE` : Specify a schema the following schemas should be 168 an evolution of. Gives errors if not. Useful to check if schema 169 modifications don't break schema evolution rules. 170 171 - `--conform-includes PATH` : Include path for the schema given with 172 `--conform PATH`. 173 174 - `--include-prefix PATH` : Prefix this path to any generated include 175 statements. 176 177 - `--keep-prefix` : Keep original prefix of schema include statement. 178 179 - `--no-fb-impor` : Don't include flatbuffers import statement for TypeScript. 180 181 - `--no-ts-reexpor` : Don't re-export imported dependencies for TypeScript. 182 183 - `--short-name` : Use short function names for JS and TypeScript. 184 185 - `--reflect-types` : Add minimal type reflection to code generation. 186 187 - `--reflect-names` : Add minimal type/name reflection. 188 189 - `--root-type T` : Select or override the default root_type. 190 191 - `--force-defaults` : Emit default values in binary output from JSON. 192 193 - `--force-empty` : When serializing from object API representation, force 194 strings and vectors to empty rather than null. 195 196 NOTE: short-form options for generators are deprecated, use the long form 197 whenever possible. 198
