Codechange: Add const versions of GetItem/GetGroup, and sprinkle liberally.

Non-const version of GetItem is not needed.

src/base_media_base.h

@@ -95,7 +95,7 @@ struct BaseSet {
 		return Tnum_files - this->valid_files;
 	}
 
-	bool FillSetDetails(IniFile &ini, const std::string &path, const std::string &full_filename, bool allow_empty_filename = true);
+	bool FillSetDetails(const IniFile &ini, const std::string &path, const std::string &full_filename, bool allow_empty_filename = true);
 
 	/**
 	 * Get the description for the given ISO code.
@@ -244,7 +244,7 @@ struct GraphicsSet : BaseSet<GraphicsSet, MAX_GFT, true> {
 	PaletteType palette;       ///< Palette of this graphics set
 	BlitterType blitter;       ///< Blitter of this graphics set
 
-	bool FillSetDetails(IniFile &ini, const std::string &path, const std::string &full_filename);
+	bool FillSetDetails(const IniFile &ini, const std::string &path, const std::string &full_filename);
 
 	static MD5File::ChecksumResult CheckMD5(const MD5File *file, Subdirectory subdir);
 };
@@ -301,7 +301,7 @@ struct MusicSet : BaseSet<MusicSet, NUM_SONGS_AVAILABLE, false> {
 	/** Number of valid songs in set. */
 	byte num_available;
 
-	bool FillSetDetails(IniFile &ini, const std::string &path, const std::string &full_filename);
+	bool FillSetDetails(const IniFile &ini, const std::string &path, const std::string &full_filename);
 };
 
 /** All data/functions related with replacing the base music */

src/base_media_func.h

@@ -39,15 +39,15 @@ extern void CheckExternalFiles();
  * @return true if loading was successful.
  */
 template <class T, size_t Tnum_files, bool Tsearch_in_tars>
-bool BaseSet<T, Tnum_files, Tsearch_in_tars>::FillSetDetails(IniFile &ini, const std::string &path, const std::string &full_filename, bool allow_empty_filename)
+bool BaseSet<T, Tnum_files, Tsearch_in_tars>::FillSetDetails(const IniFile &ini, const std::string &path, const std::string &full_filename, bool allow_empty_filename)
 {
-	IniGroup *metadata = ini.GetGroup("metadata");
+	const IniGroup *metadata = ini.GetGroup("metadata");
 	if (metadata == nullptr) {
 		Debug(grf, 0, "Base " SET_TYPE "set detail loading: metadata missing.");
 		Debug(grf, 0, "  Is {} readable for the user running OpenTTD?", full_filename);
 		return false;
 	}
-	IniItem *item;
+	const IniItem *item;
 
 	fetch_metadata("name");
 	this->name = *item->value;
@@ -74,9 +74,9 @@ bool BaseSet<T, Tnum_files, Tsearch_in_tars>::FillSetDetails(IniFile &ini, const
 	this->fallback = (item != nullptr && item->value && *item->value != "0" && *item->value != "false");
 
 	/* For each of the file types we want to find the file, MD5 checksums and warning messages. */
-	IniGroup *files  = ini.GetGroup("files");
+	const IniGroup *files  = ini.GetGroup("files");
-	IniGroup *md5s   = ini.GetGroup("md5s");
+	const IniGroup *md5s   = ini.GetGroup("md5s");
-	IniGroup *origin = ini.GetGroup("origin");
+	const IniGroup *origin = ini.GetGroup("origin");
 	for (uint i = 0; i < Tnum_files; i++) {
 		MD5File *file = &this->files[i];
 		/* Find the filename first. */

src/gfxinit.cpp

@@ -347,13 +347,13 @@ void GfxLoadSprites()
 	UpdateCursorSize();
 }
 
-bool GraphicsSet::FillSetDetails(IniFile &ini, const std::string &path, const std::string &full_filename)
+bool GraphicsSet::FillSetDetails(const IniFile &ini, const std::string &path, const std::string &full_filename)
 {
 	bool ret = this->BaseSet<GraphicsSet, MAX_GFT, true>::FillSetDetails(ini, path, full_filename, false);
 	if (ret) {
-		IniGroup *metadata = ini.GetGroup("metadata");
+		const IniGroup *metadata = ini.GetGroup("metadata");
 		assert(metadata != nullptr); /* ret can't be true if metadata isn't present. */
-		IniItem *item;
+		const IniItem *item;
 
 		fetch_metadata("palette");
 		this->palette = ((*item->value)[0] == 'D' || (*item->value)[0] == 'd') ? PAL_DOS : PAL_WINDOWS;

src/hotkeys.cpp

@@ -274,12 +274,12 @@ HotkeyList::~HotkeyList()
  * Load HotkeyList from IniFile.
  * @param ini IniFile to load from.
  */
-void HotkeyList::Load(IniFile &ini)
+void HotkeyList::Load(const IniFile &ini)
 {
-	IniGroup *group = ini.GetGroup(this->ini_group);
+	const IniGroup *group = ini.GetGroup(this->ini_group);
 	if (group == nullptr) return;
 	for (Hotkey &hotkey : this->items) {
-		IniItem *item = group->GetItem(hotkey.name);
+		const IniItem *item = group->GetItem(hotkey.name);
 		if (item != nullptr) {
 			hotkey.keycodes.clear();
 			if (item->value.has_value()) ParseHotkeys(hotkey, item->value->c_str());

src/hotkeys.h

@@ -40,7 +40,7 @@ struct HotkeyList {
 	HotkeyList(const std::string &ini_group, const std::vector<Hotkey> &items, GlobalHotkeyHandlerFunc global_hotkey_handler = nullptr);
 	~HotkeyList();
 
-	void Load(IniFile &ini);
+	void Load(const IniFile &ini);
 	void Save(IniFile &ini) const;
 
 	int CheckMatch(uint16_t keycode, bool global_only = false) const;

src/ini_load.cpp

@@ -49,9 +49,9 @@ IniGroup::IniGroup(const std::string &name, IniGroupType type) : type(type)
  * @param name   name of the item to find.
  * @return the requested item or nullptr if not found.
  */
-IniItem *IniGroup::GetItem(const std::string &name)
+const IniItem *IniGroup::GetItem(const std::string &name) const
 {
-	for (IniItem &item : this->items) {
+	for (const IniItem &item : this->items) {
 		if (item.name == name) return &item;
 	}
 
@@ -111,6 +111,20 @@ IniLoadFile::IniLoadFile(const IniGroupNameList &list_group_names, const IniGrou
 {
 }
 
+/**
+ * Get the group with the given name.
+ * @param name name of the group to find.
+ * @return The requested group or \c nullptr if not found.
+ */
+const IniGroup *IniLoadFile::GetGroup(const std::string &name) const
+{
+	for (const IniGroup &group : this->groups) {
+		if (group.name == name) return &group;
+	}
+
+	return nullptr;
+}
+
 /**
  * Get the group with the given name.
  * @param name name of the group to find.

src/ini_type.h

@@ -39,7 +39,7 @@ struct IniGroup {
 
 	IniGroup(const std::string &name, IniGroupType type);
 
-	IniItem *GetItem(const std::string &name);
+	const IniItem *GetItem(const std::string &name) const;
 	IniItem &GetOrCreateItem(const std::string &name);
 	IniItem &CreateItem(const std::string &name);
 	void RemoveItem(const std::string &name);
@@ -58,6 +58,7 @@ struct IniLoadFile {
 	IniLoadFile(const IniGroupNameList &list_group_names = {}, const IniGroupNameList &seq_group_names = {});
 	virtual ~IniLoadFile() { }
 
+	const IniGroup *GetGroup(const std::string &name) const;
 	IniGroup *GetGroup(const std::string &name);
 	IniGroup &GetOrCreateGroup(const std::string &name);
 	IniGroup &CreateGroup(const std::string &name);

src/music.cpp

@@ -116,14 +116,14 @@ template <class Tbase_set>
 	return BaseMedia<Tbase_set>::used_set != nullptr;
 }
 
-bool MusicSet::FillSetDetails(IniFile &ini, const std::string &path, const std::string &full_filename)
+bool MusicSet::FillSetDetails(const IniFile &ini, const std::string &path, const std::string &full_filename)
 {
 	bool ret = this->BaseSet<MusicSet, NUM_SONGS_AVAILABLE, false>::FillSetDetails(ini, path, full_filename);
 	if (ret) {
 		this->num_available = 0;
-		IniGroup *names = ini.GetGroup("names");
+		const IniGroup *names = ini.GetGroup("names");
-		IniGroup *catindex = ini.GetGroup("catindex");
+		const IniGroup *catindex = ini.GetGroup("catindex");
-		IniGroup *timingtrim = ini.GetGroup("timingtrim");
+		const IniGroup *timingtrim = ini.GetGroup("timingtrim");
 		uint tracknr = 1;
 		for (uint i = 0; i < lengthof(this->songinfo); i++) {
 			const std::string &filename = this->files[i].filename;
@@ -133,7 +133,7 @@ bool MusicSet::FillSetDetails(IniFile &ini, const std::string &path, const std::
 
 			this->songinfo[i].filename = filename; // non-owned pointer
 
-			IniItem *item = catindex != nullptr ? catindex->GetItem(_music_file_names[i]) : nullptr;
+			const IniItem *item = catindex != nullptr ? catindex->GetItem(_music_file_names[i]) : nullptr;
 			if (item != nullptr && item->value.has_value() && !item->value->empty()) {
 				/* Song has a CAT file index, assume it's MPS MIDI format */
 				this->songinfo[i].filetype = MTT_MPSMIDI;

src/settings.cpp

@@ -586,8 +586,8 @@ const std::string &StringSettingDesc::Read(const void *object) const
  */
 static void IniLoadSettings(IniFile &ini, const SettingTable &settings_table, const char *grpname, void *object, bool only_startup)
 {
-	IniGroup *group;
+	const IniGroup *group;
-	IniGroup *group_def = ini.GetGroup(grpname);
+	const IniGroup *group_def = ini.GetGroup(grpname);
 
 	for (auto &desc : settings_table) {
 		const SettingDesc *sd = GetSettingDesc(desc);
@@ -605,7 +605,7 @@ static void IniLoadSettings(IniFile &ini, const SettingTable &settings_table, co
 			group = group_def;
 		}
 
-		IniItem *item = nullptr;
+		const IniItem *item = nullptr;
 		if (group != nullptr) item = group->GetItem(s);
 		if (item == nullptr && group != group_def && group_def != nullptr) {
 			/* For settings.xx.yy load the settings from [settings] yy = ? in case the previous
@@ -780,7 +780,7 @@ bool ListSettingDesc::IsDefaultValue(void *) const
  */
 static void IniLoadSettingList(IniFile &ini, const char *grpname, StringList &list)
 {
-	IniGroup *group = ini.GetGroup(grpname);
+	const IniGroup *group = ini.GetGroup(grpname);
 
 	if (group == nullptr) return;
 
@@ -894,9 +894,9 @@ static void ValidateSettings()
 	}
 }
 
-static void AILoadConfig(IniFile &ini, const char *grpname)
+static void AILoadConfig(const IniFile &ini, const char *grpname)
 {
-	IniGroup *group = ini.GetGroup(grpname);
+	const IniGroup *group = ini.GetGroup(grpname);
 
 	/* Clean any configured AI */
 	for (CompanyID c = COMPANY_FIRST; c < MAX_COMPANIES; c++) {
@@ -923,9 +923,9 @@ static void AILoadConfig(IniFile &ini, const char *grpname)
 	}
 }
 
-static void GameLoadConfig(IniFile &ini, const char *grpname)
+static void GameLoadConfig(const IniFile &ini, const char *grpname)
 {
-	IniGroup *group = ini.GetGroup(grpname);
+	const IniGroup *group = ini.GetGroup(grpname);
 
 	/* Clean any configured GameScript */
 	GameConfig::GetConfig(GameConfig::SSS_FORCE_NEWGAME)->Change(std::nullopt);
@@ -933,7 +933,7 @@ static void GameLoadConfig(IniFile &ini, const char *grpname)
 	/* If no group exists, return */
 	if (group == nullptr || group->items.empty()) return;
 
-	IniItem &item = group->items.front();
+	const IniItem &item = group->items.front();
 
 	GameConfig *config = GameConfig::GetConfig(AIConfig::SSS_FORCE_NEWGAME);
 
@@ -987,9 +987,9 @@ static bool DecodeHexText(const char *pos, uint8_t *dest, size_t dest_size)
  * @param grpname   Group name containing the configuration of the GRF.
  * @param is_static GRF is static.
  */
-static GRFConfig *GRFLoadConfig(IniFile &ini, const char *grpname, bool is_static)
+static GRFConfig *GRFLoadConfig(const IniFile &ini, const char *grpname, bool is_static)
 {
-	IniGroup *group = ini.GetGroup(grpname);
+	const IniGroup *group = ini.GetGroup(grpname);
 	GRFConfig *first = nullptr;
 	GRFConfig **curr = &first;
 
@@ -1088,9 +1088,9 @@ static GRFConfig *GRFLoadConfig(IniFile &ini, const char *grpname, bool is_stati
 	return first;
 }
 
-static IniFileVersion LoadVersionFromConfig(IniFile &ini)
+static IniFileVersion LoadVersionFromConfig(const IniFile &ini)
 {
-	IniGroup *group = ini.GetGroup("version");
+	const IniGroup *group = ini.GetGroup("version");
 	if (group == nullptr) return IFV_0;
 
 	auto version_number = group->GetItem("ini_version");
@@ -1247,16 +1247,16 @@ static void RemoveEntriesFromIni(IniFile &ini, const SettingTable &table)
  * @param[out] old_item The old item to base upgrading on.
  * @return Whether upgrading should happen; if false, old_item is a nullptr.
  */
-bool IsConversionNeeded(ConfigIniFile &ini, std::string group, std::string old_var, std::string new_var, IniItem **old_item)
+bool IsConversionNeeded(const ConfigIniFile &ini, const std::string &group, const std::string &old_var, const std::string &new_var, const IniItem **old_item)
 {
 	*old_item = nullptr;
 
-	IniGroup *igroup = ini.GetGroup(group);
+	const IniGroup *igroup = ini.GetGroup(group);
 	/* If the group doesn't exist, there is nothing to convert. */
 	if (igroup == nullptr) return false;
 
-	IniItem *tmp_old_item = igroup->GetItem(old_var);
+	const IniItem *tmp_old_item = igroup->GetItem(old_var);
-	IniItem *new_item = igroup->GetItem(new_var);
+	const IniItem *new_item = igroup->GetItem(new_var);
 
 	/* If the old item doesn't exist, there is nothing to convert. */
 	if (tmp_old_item == nullptr) return false;
@@ -1301,9 +1301,9 @@ void LoadFromConfig(bool startup)
 
 		/* Move no_http_content_downloads and use_relay_service from generic_ini to private_ini. */
 		if (generic_version < IFV_NETWORK_PRIVATE_SETTINGS) {
-			IniGroup *network = generic_ini.GetGroup("network");
+			const IniGroup *network = generic_ini.GetGroup("network");
 			if (network != nullptr) {
-				IniItem *no_http_content_downloads = network->GetItem("no_http_content_downloads");
+				const IniItem *no_http_content_downloads = network->GetItem("no_http_content_downloads");
 				if (no_http_content_downloads != nullptr) {
 					if (no_http_content_downloads->value == "true") {
 						_settings_client.network.no_http_content_downloads = true;
@@ -1312,7 +1312,7 @@ void LoadFromConfig(bool startup)
 					}
 				}
 
-				IniItem *use_relay_service = network->GetItem("use_relay_service");
+				const IniItem *use_relay_service = network->GetItem("use_relay_service");
 				if (use_relay_service != nullptr) {
 					if (use_relay_service->value == "never") {
 						_settings_client.network.use_relay_service = UseRelayService::URS_NEVER;
@@ -1325,7 +1325,7 @@ void LoadFromConfig(bool startup)
 			}
 		}
 
-		IniItem *old_item;
+		const IniItem *old_item;
 
 		if (generic_version < IFV_GAME_TYPE && IsConversionNeeded(generic_ini, "network", "server_advertise", "server_game_type", &old_item)) {
 			auto old_value = BoolSettingDesc::ParseSingleValue(old_item->value->c_str());

src/settingsgen/settingsgen.cpp

@@ -193,11 +193,11 @@ static const char *DEFAULTS_GROUP_NAME  = "defaults"; ///< Name of the group con
  * @param ifile      Loaded INI data.
  * @param group_name Name of the group to copy.
  */
-static void DumpGroup(IniLoadFile &ifile, const char * const group_name)
+static void DumpGroup(const IniLoadFile &ifile, const char * const group_name)
 {
-	IniGroup *grp = ifile.GetGroup(group_name);
+	const IniGroup *grp = ifile.GetGroup(group_name);
 	if (grp != nullptr && grp->type == IGT_SEQUENCE) {
-		for (IniItem &item : grp->items) {
+		for (const IniItem &item : grp->items) {
 			if (!item.name.empty()) {
 				_stored_output.Add(item.name.c_str());
 				_stored_output.Add("\n", 1);
@@ -213,9 +213,9 @@ static void DumpGroup(IniLoadFile &ifile, const char * const group_name)
  * @param defaults Fallback group to search, \c nullptr skips the search.
  * @return Text of the item if found, else \c nullptr.
  */
-static const char *FindItemValue(const char *name, IniGroup *grp, IniGroup *defaults)
+static const char *FindItemValue(const char *name, const IniGroup *grp, const IniGroup *defaults)
 {
-	IniItem *item = grp->GetItem(name);
+	const IniItem *item = grp->GetItem(name);
 	if (item == nullptr && defaults != nullptr) item = defaults->GetItem(name);
 	if (item == nullptr || !item->value.has_value()) return nullptr;
 	return item->value->c_str();
@@ -228,7 +228,7 @@ static const char *FindItemValue(const char *name, IniGroup *grp, IniGroup *defa
  * @param default_grp Default values for items not set in @grp.
  * @param output Output to use for result.
  */
-static void DumpLine(IniItem *item, IniGroup *grp, IniGroup *default_grp, OutputStore &output)
+static void DumpLine(const IniItem *item, const IniGroup *grp, const IniGroup *default_grp, OutputStore &output)
 {
 	static const int MAX_VAR_LENGTH = 64;
 
@@ -292,28 +292,28 @@ static void DumpLine(IniItem *item, IniGroup *grp, IniGroup *default_grp, Output
  * Output all non-special sections through the template / template variable expansion system.
  * @param ifile Loaded INI data.
  */
-static void DumpSections(IniLoadFile &ifile)
+static void DumpSections(const IniLoadFile &ifile)
 {
 	static const auto special_group_names = {PREAMBLE_GROUP_NAME, POSTAMBLE_GROUP_NAME, DEFAULTS_GROUP_NAME, TEMPLATES_GROUP_NAME, VALIDATION_GROUP_NAME};
 
-	IniGroup *default_grp = ifile.GetGroup(DEFAULTS_GROUP_NAME);
+	const IniGroup *default_grp = ifile.GetGroup(DEFAULTS_GROUP_NAME);
-	IniGroup *templates_grp = ifile.GetGroup(TEMPLATES_GROUP_NAME);
+	const IniGroup *templates_grp = ifile.GetGroup(TEMPLATES_GROUP_NAME);
-	IniGroup *validation_grp = ifile.GetGroup(VALIDATION_GROUP_NAME);
+	const IniGroup *validation_grp = ifile.GetGroup(VALIDATION_GROUP_NAME);
 	if (templates_grp == nullptr) return;
 
 	/* Output every group, using its name as template name. */
-	for (IniGroup &grp : ifile.groups) {
+	for (const IniGroup &grp : ifile.groups) {
 		/* Exclude special group names. */
 		if (std::find(std::begin(special_group_names), std::end(special_group_names), grp.name) != std::end(special_group_names)) continue;
 
-		IniItem *template_item = templates_grp->GetItem(grp.name); // Find template value.
+		const IniItem *template_item = templates_grp->GetItem(grp.name); // Find template value.
 		if (template_item == nullptr || !template_item->value.has_value()) {
 			FatalError("Cannot find template {}", grp.name);
 		}
 		DumpLine(template_item, &grp, default_grp, _stored_output);
 
 		if (validation_grp != nullptr) {
-			IniItem *validation_item = validation_grp->GetItem(grp.name); // Find template value.
+			const IniItem *validation_item = validation_grp->GetItem(grp.name); // Find template value.
 			if (validation_item != nullptr && validation_item->value.has_value()) {
 				DumpLine(validation_item, &grp, default_grp, _post_amble_output);
 			}