Refactor usage message

include/flatbuffers/flatc.h

@@ -114,7 +114,7 @@ class FlatCompiler {
 
   explicit FlatCompiler(const InitParams &params) : params_(params) {}
 
-  bool RegisterCodeGenerator(const std::string& flag,
+  bool RegisterCodeGenerator(const FlatCOption &option,
                              std::shared_ptr<CodeGenerator> code_generator);
 
   int Compile(const FlatCOptions &options);

src/flatc.cpp

@@ -241,6 +241,9 @@ const static FlatCOption flatc_options[] = {
     "Currently this is required to generate private types in Rust" },
 };
 
+auto cmp = [](FlatCOption a, FlatCOption b) { return a.long_opt < b.long_opt; };
+static std::set<FlatCOption, decltype(cmp)> language_options(cmp);
+
 static void AppendTextWrappedString(std::stringstream &ss, std::string &text,
                                     size_t max_col, size_t start_col) {
   size_t max_line_length = max_col - start_col;
@@ -312,12 +315,19 @@ std::string FlatCompiler::GetShortUsageString(
     const std::string &program_name) const {
   std::stringstream ss;
   ss << "Usage: " << program_name << " [";
+
+  for (const FlatCOption &option : language_options) {
+    AppendShortOption(ss, option);
+    ss << ", ";
+  }
+
   // TODO(derekbailey): These should be generated from this.generators
   for (size_t i = 0; i < params_.num_generators; ++i) {
     const Generator &g = params_.generators[i];
     AppendShortOption(ss, g.option);
     ss << ", ";
   }
+
   for (const FlatCOption &option : flatc_options) {
     AppendShortOption(ss, option);
     ss << ", ";
@@ -335,6 +345,11 @@ std::string FlatCompiler::GetUsageString(
   std::stringstream ss;
   ss << "Usage: " << program_name
      << " [OPTION]... FILE... [-- BINARY_FILE...]\n";
+
+  for (const FlatCOption &option : language_options) {
+    AppendOption(ss, option, 80, 25);
+  }
+
   // TODO(derekbailey): These should be generated from this.generators
   for (size_t i = 0; i < params_.num_generators; ++i) {
     const Generator &g = params_.generators[i];
@@ -1018,12 +1033,31 @@ int FlatCompiler::Compile(const FlatCOptions &options) {
 }
 
 bool FlatCompiler::RegisterCodeGenerator(
-    const std::string &flag, std::shared_ptr<CodeGenerator> code_generator) {
-  if (code_generators_.find(flag) != code_generators_.end()) {
-    Error("multiple generators registered under: " + flag, false, false);
+    const FlatCOption &option, std::shared_ptr<CodeGenerator> code_generator) {
+  if (!option.short_opt.empty() &&
+      code_generators_.find("-" + option.short_opt) != code_generators_.end()) {
+    Error("multiple generators registered under: -" + option.short_opt, false,
+          false);
     return false;
   }
-  code_generators_[flag] = std::move(code_generator);
+
+  if (!option.short_opt.empty()) {
+    code_generators_["-" + option.short_opt] = code_generator;
+  }
+
+  if (!option.long_opt.empty() &&
+      code_generators_.find("--" + option.long_opt) != code_generators_.end()) {
+    Error("multiple generators registered under: --" + option.long_opt, false,
+          false);
+    return false;
+  }
+
+  if (!option.long_opt.empty()) {
+    code_generators_["--" + option.long_opt] = code_generator;
+  }
+
+  language_options.insert(option);
+
   return true;
 }
 

src/flatc_main.cpp

@@ -78,88 +78,17 @@ int main(int argc, const char *argv[]) {
   g_program_name = argv[0];
 
   const flatbuffers::FlatCompiler::Generator generators[] = {
-    { flatbuffers::GenerateBinary, "binary", false, nullptr,
-      flatbuffers::IDLOptions::kBinary,
-      flatbuffers::FlatCOption{
-          "b", "binary", "",
-          "Generate wire format binaries for any data definitions" },
-      flatbuffers::BinaryMakeRule, nullptr, nullptr },
     { flatbuffers::GenerateTextFile, "text", false, nullptr,
       flatbuffers::IDLOptions::kJson,
       flatbuffers::FlatCOption{
           "t", "json", "", "Generate text output for any data definitions" },
 
       flatbuffers::TextMakeRule, nullptr, nullptr },
-    { flatbuffers::GenerateCPP, "C++", true, flatbuffers::GenerateCppGRPC,
-      flatbuffers::IDLOptions::kCpp,
-      flatbuffers::FlatCOption{ "c", "cpp", "",
-                                "Generate C++ headers for tables/structs" },
-      flatbuffers::CPPMakeRule, nullptr, nullptr },
-    { flatbuffers::GenerateGo, "Go", true, flatbuffers::GenerateGoGRPC,
-      flatbuffers::IDLOptions::kGo,
-      flatbuffers::FlatCOption{ "g", "go", "",
-                                "Generate Go files for tables/structs" },
-      nullptr, nullptr, nullptr },
-    { flatbuffers::GenerateJava, "Java", true, flatbuffers::GenerateJavaGRPC,
-      flatbuffers::IDLOptions::kJava,
-      flatbuffers::FlatCOption{ "j", "java", "",
-                                "Generate Java classes for tables/structs" },
-      flatbuffers::JavaMakeRule, nullptr, nullptr },
-    { flatbuffers::GenerateDart, "Dart", true, nullptr,
-      flatbuffers::IDLOptions::kDart,
-      flatbuffers::FlatCOption{ "d", "dart", "",
-                                "Generate Dart classes for tables/structs" },
-      flatbuffers::DartMakeRule, nullptr, nullptr },
-    { flatbuffers::GenerateTS, "TypeScript", true, flatbuffers::GenerateTSGRPC,
-      flatbuffers::IDLOptions::kTs,
-      flatbuffers::FlatCOption{ "T", "ts", "",
-                                "Generate TypeScript code for tables/structs" },
-      flatbuffers::TSMakeRule, nullptr, nullptr },
-    { flatbuffers::GenerateCSharp, "C#", true, nullptr,
-      flatbuffers::IDLOptions::kCSharp,
-      flatbuffers::FlatCOption{ "n", "csharp", "",
-                                "Generate C# classes for tables/structs" },
-      flatbuffers::CSharpMakeRule, nullptr, nullptr },
-    { flatbuffers::GeneratePython, "Python", true,
-      flatbuffers::GeneratePythonGRPC, flatbuffers::IDLOptions::kPython,
-      flatbuffers::FlatCOption{ "p", "python", "",
-                                "Generate Python files for tables/structs" },
-      nullptr, nullptr, nullptr },
-    { flatbuffers::GenerateLobster, "Lobster", true, nullptr,
-      flatbuffers::IDLOptions::kLobster,
-      flatbuffers::FlatCOption{ "", "lobster", "",
-                                "Generate Lobster files for tables/structs" },
-      nullptr, nullptr, nullptr },
     { flatbuffers::GenerateLua, "Lua", true, nullptr,
       flatbuffers::IDLOptions::kLua,
       flatbuffers::FlatCOption{ "l", "lua", "",
                                 "Generate Lua files for tables/structs" },
       nullptr, bfbs_gen_lua.get(), nullptr },
-    { flatbuffers::GenerateRust, "Rust", true, nullptr,
-      flatbuffers::IDLOptions::kRust,
-      flatbuffers::FlatCOption{ "r", "rust", "",
-                                "Generate Rust files for tables/structs" },
-      flatbuffers::RustMakeRule, nullptr,
-      flatbuffers::GenerateRustModuleRootFile },
-    { flatbuffers::GeneratePhp, "PHP", true, nullptr,
-      flatbuffers::IDLOptions::kPhp,
-      flatbuffers::FlatCOption{ "", "php", "",
-                                "Generate PHP files for tables/structs" },
-      nullptr, nullptr, nullptr },
-    { flatbuffers::GenerateKotlin, "Kotlin", true, nullptr,
-      flatbuffers::IDLOptions::kKotlin,
-      flatbuffers::FlatCOption{ "", "kotlin", "",
-                                "Generate Kotlin classes for tables/structs" },
-      nullptr, nullptr, nullptr },
-    { flatbuffers::GenerateJsonSchema, "JsonSchema", true, nullptr,
-      flatbuffers::IDLOptions::kJsonSchema,
-      flatbuffers::FlatCOption{ "", "jsonschema", "", "Generate Json schema" },
-      nullptr, nullptr, nullptr },
-    { flatbuffers::GenerateSwift, "swift", true, flatbuffers::GenerateSwiftGRPC,
-      flatbuffers::IDLOptions::kSwift,
-      flatbuffers::FlatCOption{ "", "swift", "",
-                                "Generate Swift files for tables/structs" },
-      nullptr, nullptr, nullptr },
     { nullptr, "Nim", true, nullptr, flatbuffers::IDLOptions::kNim,
       flatbuffers::FlatCOption{ "", "nim", "",
                                 "Generate Nim files for tables/structs" },
@@ -174,84 +103,75 @@ int main(int argc, const char *argv[]) {
 
   flatbuffers::FlatCompiler flatc(params);
 
-  std::shared_ptr<flatbuffers::CodeGenerator> binary_generator =
-      flatbuffers::NewBinaryCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> cpp_generator =
-      flatbuffers::NewCppCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> csharp_generator =
-      flatbuffers::NewCSharpCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> dart_generator =
-      flatbuffers::NewDartCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> go_generator =
-      flatbuffers::NewGoCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> java_generator =
-      flatbuffers::NewJavaCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> json_schema_generator =
-      flatbuffers::NewJsonSchemaCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> kotlin_generator =
-      flatbuffers::NewKotlinCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> lobster_generator =
-      flatbuffers::NewLobsterCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> php_generator =
-      flatbuffers::NewPhpCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> python_generator =
-      flatbuffers::NewPythonCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> rust_generator =
-      flatbuffers::NewRustCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> swift_generator =
-      flatbuffers::NewSwiftCodeGenerator();
-
-  std::shared_ptr<flatbuffers::CodeGenerator> ts_generator =
-      flatbuffers::NewTsCodeGenerator();
-
-  flatc.RegisterCodeGenerator("--binary", binary_generator);
-  flatc.RegisterCodeGenerator("-b", binary_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{
+          "b", "binary", "",
+          "Generate wire format binaries for any data definitions" },
+      flatbuffers::NewBinaryCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--cpp", cpp_generator);
-  flatc.RegisterCodeGenerator("-c", cpp_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "c", "cpp", "",
+                                "Generate C++ headers for tables/structs" },
+      flatbuffers::NewCppCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--csharp", csharp_generator);
-  flatc.RegisterCodeGenerator("-n", csharp_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "n", "csharp", "",
+                                "Generate C# classes for tables/structs" },
+      flatbuffers::NewCSharpCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--dart", dart_generator);
-  flatc.RegisterCodeGenerator("-d", dart_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "d", "dart", "",
+                                "Generate Dart classes for tables/structs" },
+      flatbuffers::NewDartCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--go", go_generator);
-  flatc.RegisterCodeGenerator("-g", go_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "g", "go", "",
+                                "Generate Go files for tables/structs" },
+      flatbuffers::NewGoCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--java", java_generator);
-  flatc.RegisterCodeGenerator("-j", java_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "j", "java", "",
+                                "Generate Java classes for tables/structs" },
+      flatbuffers::NewJavaCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--jsonschema", json_schema_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "", "jsonschema", "", "Generate Json schema" },
+      flatbuffers::NewJsonSchemaCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--kotlin", kotlin_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "", "kotlin", "",
+                                "Generate Kotlin classes for tables/structs" },
+      flatbuffers::NewKotlinCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--lobster", lobster_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "", "lobster", "",
+                                "Generate Lobster files for tables/structs" },
+      flatbuffers::NewLobsterCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--php", php_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "", "php", "",
+                                "Generate PHP files for tables/structs" },
+      flatbuffers::NewPhpCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--python", python_generator);
-  flatc.RegisterCodeGenerator("-p", python_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "p", "python", "",
+                                "Generate Python files for tables/structs" },
+      flatbuffers::NewPythonCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--rust", rust_generator);
-  flatc.RegisterCodeGenerator("-r", rust_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "r", "rust", "",
+                                "Generate Rust files for tables/structs" },
+      flatbuffers::NewRustCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--swift", swift_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "", "swift", "",
+                                "Generate Swift files for tables/structs" },
+      flatbuffers::NewSwiftCodeGenerator());
 
-  flatc.RegisterCodeGenerator("--ts", ts_generator);
-  flatc.RegisterCodeGenerator("-T", ts_generator);
+  flatc.RegisterCodeGenerator(
+      flatbuffers::FlatCOption{ "T", "ts", "",
+                                "Generate TypeScript code for tables/structs" },
+      flatbuffers::NewTsCodeGenerator());
 
   // Create the FlatC options by parsing the command line arguments.
   const flatbuffers::FlatCOptions &options =