Codechange: internally use a span of arguments for GetOptData

src/misc/getoptdata.cpp

@@ -21,15 +21,14 @@
  */
 int GetOptData::GetOpt()
 {
-	char *s = this->cont;
+	const char *s = this->cont;
 	if (s == nullptr) {
-		if (this->numleft == 0) return -1; // No arguments left -> finished.
+		if (this->arguments.empty()) return -1; // No arguments left -> finished.
 
-		s = this->argv[0];
+		s = this->arguments[0];
 		if (*s != '-') return -1; // No leading '-' -> not an option -> finished.
 
-		this->argv++;
-		this->numleft--;
+		this->arguments = this->arguments.subspan(1);
 
 		/* Is it a long option? */
 		for (auto &option : this->options) {
@@ -68,14 +67,13 @@ int GetOptData::GetOpt(const OptionData &option)
 				return option.id;
 			}
 			/* No more arguments, either return an error or a value-less option. */
-			if (this->numleft == 0) return (option.type == ODF_HAS_VALUE) ? -2 : option.id;
+			if (this->arguments.empty()) return (option.type == ODF_HAS_VALUE) ? -2 : option.id;
 
 			/* Next argument looks like another option, let's not return it as option value. */
-			if (option.type == ODF_OPTIONAL_VALUE && this->argv[0][0] == '-') return option.id;
+			if (option.type == ODF_OPTIONAL_VALUE && this->arguments[0][0] == '-') return option.id;
 
-			this->opt = this->argv[0]; // Next argument is the option value.
-			this->argv++;
-			this->numleft--;
+			this->opt = this->arguments[0]; // Next argument is the option value.
+			this->arguments = this->arguments.subspan(1);
 			return option.id;
 
 		default: NOT_REACHED();

src/misc/getoptdata.h

@@ -28,26 +28,19 @@ struct OptionData {
 /** Data storage for parsing command line options. */
 struct GetOptData {
 	using OptionSpan = std::span<const OptionData>;
-	char *opt;                 ///< Option value, if available (else \c nullptr).
-	int numleft;               ///< Number of arguments left in #argv.
-	char **argv;               ///< Remaining command line arguments.
-	OptionSpan options; ///< Command line option descriptions.
-	char *cont;                ///< Next call to #GetOpt should start here (in the middle of an argument).
+	using ArgumentSpan = std::span<char * const>;
+
+	ArgumentSpan arguments; ///< Remaining command line arguments.
+	const OptionSpan options; ///< Command line option descriptions.
+	const char *opt = nullptr; ///< Option value, if available (else \c nullptr).
+	const char *cont = nullptr; ///< Next call to #GetOpt should start here (in the middle of an argument).
 
 	/**
 	 * Constructor of the data store.
-	 * @param argc Number of command line arguments, excluding the program name.
-	 * @param argv Command line arguments, excluding the program name.
+	 * @param argument The command line arguments, excluding the program name.
 	 * @param options Command line option descriptions.
 	 */
-	GetOptData(int argc, char **argv, OptionSpan options) :
-			opt(nullptr),
-			numleft(argc),
-			argv(argv),
-			options(options),
-			cont(nullptr)
-	{
-	}
+	GetOptData(ArgumentSpan arguments, OptionSpan options) : arguments(arguments), options(options) {}
 
 	int GetOpt();
 	int GetOpt(const OptionData &option);

src/openttd.cpp

@@ -530,7 +530,7 @@ int openttd_main(int argc, char *argv[])
 	_switch_mode = SM_MENU;
 
 	auto options = CreateOptions();
-	GetOptData mgo(argc - 1, argv + 1, options);
+	GetOptData mgo(std::span(argv + 1, argc - 1), options);
 	int ret = 0;
 
 	int i;
@@ -654,7 +654,7 @@ int openttd_main(int argc, char *argv[])
 		if (i == -2) break;
 	}
 
-	if (i == -2 || mgo.numleft > 0) {
+	if (i == -2 || !mgo.arguments.empty()) {
 		/* Either the user typed '-h', they made an error, or they added unrecognized command line arguments.
 		 * In all cases, print the help, and exit.
 		 *

src/settingsgen/settingsgen.cpp

@@ -435,7 +435,7 @@ int CDECL main(int argc, char *argv[])
 	const char *before_file = nullptr;
 	const char *after_file = nullptr;
 
-	GetOptData mgo(argc - 1, argv + 1, _opts);
+	GetOptData mgo(std::span(argv + 1, argc - 1), _opts);
 	for (;;) {
 		int i = mgo.GetOpt();
 		if (i == -1) break;
@@ -472,7 +472,7 @@ int CDECL main(int argc, char *argv[])
 	_stored_output.Clear();
 	_post_amble_output.Clear();
 
-	for (int i = 0; i < mgo.numleft; i++) ProcessIniFile(mgo.argv[i]);
+	for (auto &argument : mgo.arguments) ProcessIniFile(argument);
 
 	/* Write output. */
 	if (output_file == nullptr) {

src/strgen/strgen.cpp

@@ -328,7 +328,7 @@ int CDECL main(int argc, char *argv[])
 	std::filesystem::path src_dir(".");
 	std::filesystem::path dest_dir;
 
-	GetOptData mgo(argc - 1, argv + 1, _opts);
+	GetOptData mgo(std::span(argv + 1, argc - 1), _opts);
 	for (;;) {
 		int i = mgo.GetOpt();
 		if (i == -1) break;
@@ -412,7 +412,7 @@ int CDECL main(int argc, char *argv[])
 		 * strgen generates strings.h to the destination directory. If it is supplied
 		 * with a (free) parameter the program will translate that language to destination
 		 * directory. As input english.txt is parsed from the source directory */
-		if (mgo.numleft == 0) {
+		if (mgo.arguments.empty()) {
 			std::filesystem::path input_path = src_dir;
 			input_path /= "english.txt";
 
@@ -431,7 +431,7 @@ int CDECL main(int argc, char *argv[])
 			writer.WriteHeader(data);
 			writer.Finalise(data);
 			if (_errors != 0) return 1;
-		} else if (mgo.numleft >= 1) {
+		} else {
 			std::filesystem::path input_path = src_dir;
 			input_path /= "english.txt";
 
@@ -440,10 +440,10 @@ int CDECL main(int argc, char *argv[])
 			FileStringReader master_reader(data, input_path, true, false);
 			master_reader.ParseFile();
 
-			for (int i = 0; i < mgo.numleft; i++) {
+			for (auto &argument: mgo.arguments) {
 				data.FreeTranslation();
 
-				std::filesystem::path lang_file = mgo.argv[i];
+				std::filesystem::path lang_file = argument;
 				FileStringReader translation_reader(data, lang_file, false, lang_file.filename() != "english.txt");
 				translation_reader.ParseFile(); // target file
 				if (_errors != 0) return 1;