Catch all exceptions (where possible) as const references

A few catch blocks modify something in their exceptions, so those are kept non-const.

src/actions/attack.cpp

@@ -1202,14 +1202,14 @@ bool attack::perform_hit(bool attacker_turn, statistics::attack_context& stats)
 	if(hits) {
 		try {
 			fire_event(attacker_turn ? "attacker_hits" : "defender_hits");
-		} catch(attack_end_exception) {
+		} catch(const attack_end_exception&) {
 			refresh_bc();
 			return false;
 		}
 	} else {
 		try {
 			fire_event(attacker_turn ? "attacker_misses" : "defender_misses");
-		} catch(attack_end_exception) {
+		} catch(const attack_end_exception&) {
 			refresh_bc();
 			return false;
 		}
@@ -1434,7 +1434,7 @@ void attack::perform()
 
 	try {
 		fire_event("attack");
-	} catch(attack_end_exception) {
+	} catch(const attack_end_exception&) {
 		return;
 	}
 

src/actions/undo.cpp

@@ -298,11 +298,11 @@ void undo_list::read(const config & cfg)
 			if ( action ) {
 				undos_.push_back(action);
 			}
-		} catch (bad_lexical_cast &) {
+		} catch (const bad_lexical_cast &) {
 			ERR_NG << "Error when parsing undo list from config: bad lexical cast." << std::endl;
 			ERR_NG << "config was: " << child.debug() << std::endl;
 			ERR_NG << "Skipping this undo action..." << std::endl;
-		} catch (config::error& e) {
+		} catch (const config::error& e) {
 			ERR_NG << "Error when parsing undo list from config: " << e.what() << std::endl;
 			ERR_NG << "config was: " << child.debug() << std::endl;
 			ERR_NG << "Skipping this undo action..." << std::endl;
@@ -313,11 +313,11 @@ void undo_list::read(const config & cfg)
 	for (const config & child : cfg.child_range("redo")) {
 		try {
 			redos_.push_back(new config(child));
-		} catch (bad_lexical_cast &) {
+		} catch (const bad_lexical_cast &) {
 			ERR_NG << "Error when parsing redo list from config: bad lexical cast." << std::endl;
 			ERR_NG << "config was: " << child.debug() << std::endl;
 			ERR_NG << "Skipping this redo action..." << std::endl;
-		} catch (config::error& e) {
+		} catch (const config::error& e) {
 			ERR_NG << "Error when parsing redo list from config: " << e.what() << std::endl;
 			ERR_NG << "config was: " << child.debug() << std::endl;
 			ERR_NG << "Skipping this redo action..." << std::endl;

src/addon/client.cpp

@@ -148,7 +148,7 @@ bool addons_client::upload_addon(const std::string& id, std::string& response_me
 	config addon_data;
 	try {
 		archive_addon(id, addon_data);
-	} catch(utf8::invalid_utf8_exception&){
+	} catch(const utf8::invalid_utf8_exception&){
 		this->last_error_ =
 			VGETTEXT("The add-on <i>$addon_title</i> has a file or directory "
 				"containing invalid characters and cannot be published.", i18n_symbols);

src/addon/manager_ui.cpp

@@ -95,7 +95,7 @@ bool addons_manager_ui(const std::string& remote_address)
 
 		gui2::show_error_message(
 			VGETTEXT("A local file with add-on publishing information could not be read.\n\nFile: $path\nError message: $msg", symbols));
-	} catch(wml_exception& e) {
+	} catch(const wml_exception& e) {
 		e.show();
 	} catch(const addons_client::user_exit&) {
 		LOG_AC << "initial connection canceled by user\n";
@@ -306,7 +306,7 @@ bool ad_hoc_addon_fetch_session(const std::vector<std::string>& addon_ids)
 
 		gui2::show_error_message(
 			VGETTEXT("A local file with add-on publishing information could not be read.\n\nFile: $path\nError message: $msg", symbols));
-	} catch(wml_exception& e) {
+	} catch(const wml_exception& e) {
 		e.show();
 	} catch(const addons_client::user_exit&) {
 		LOG_AC << "initial connection canceled by user\n";

src/ai/actions.cpp

@@ -96,7 +96,7 @@ void action_result::execute()
 	if (is_success()){
 		try {
 			do_execute();
-		} catch (return_to_play_side_exception&) {
+		} catch (const return_to_play_side_exception&) {
 			if (!is_ok()) { DBG_AI_ACTIONS << "Return value of AI ACTION was not checked." << std::endl; } //Demotes to DBG "unchecked result" warning
 			throw;
 		}

src/ai/composite/component.cpp

@@ -160,7 +160,7 @@ static component *find_component(component *root, const std::string &path, path_
 		} else {
 			try {
 				pe.position = std::stoi(position);
-			} catch (std::invalid_argument&) {
+			} catch (const std::invalid_argument&) {
 				pe.position = -2;
 			}
 		}

src/ai/composite/goal.cpp

@@ -334,7 +334,7 @@ void lua_goal::add_targets(std::back_insert_iterator< std::vector< target >> tar
 		{
 			*target_list = tg;
 		}
-	} catch(bad_enum_cast& e) {
+	} catch(const bad_enum_cast& e) {
 		ERR_AI_GOAL << "A Lua goal returned a target of an unknown type (\"" << e.value() << "\"; unfortunately, the engine cannot recover from this error. As a result, all targets returned by the goal have been lost.\n";
 	}
 

src/ai/configuration.cpp

@@ -172,7 +172,7 @@ bool configuration::get_side_config_from_file(const std::string& file, config& c
 		filesystem::scoped_istream stream = preprocess_file(filesystem::get_wml_location(file));
 		read(cfg, *stream);
 		LOG_AI_CONFIGURATION << "Reading AI configuration from file '" << file  << "'" << std::endl;
-	} catch(config::error &) {
+	} catch(const config::error &) {
 		ERR_AI_CONFIGURATION << "Error while reading AI configuration from file '" << file  << "'" << std::endl;
 		return false;
 	}

src/ai/formula/ai.cpp

@@ -86,7 +86,7 @@ ca_ptr formula_ai::load_candidate_action_from_config(const config& rc_action)
 		} else {
 			ERR_AI << "Unknown candidate action type: " << type << std::endl;
 		}
-	} catch(formula_error& e) {
+	} catch(const formula_error& e) {
 		handle_exception(e, "Error while registering candidate action '" + name + "'");
 	}
 	return new_ca;
@@ -144,7 +144,7 @@ formula_ptr formula_ai::create_optional_formula(const std::string& formula_strin
 	try{
 		return formula::create_optional_formula(formula_string, &function_table_);
 	}
-	catch(formula_error& e) {
+	catch(const formula_error& e) {
 		handle_exception(e);
 		return wfl::formula_ptr();
 	}
@@ -656,7 +656,7 @@ void formula_ai::on_create(){
 					     create_optional_formula(func["precondition"]),
 					     args);
 		}
-		catch(formula_error& e) {
+		catch(const formula_error& e) {
 			handle_exception(e, "Error while registering function '" + name + "'");
 		}
 	}
@@ -752,7 +752,7 @@ config formula_ai::to_config() const
 		{
 			try {
 				str = i->second.serialize_to_string();
-			} catch (type_error&) {
+			} catch(const type_error&) {
 				WRN_AI << "variable ["<< i->first <<"] is not serializable - it will not be persisted across savegames"<<std::endl;
 				continue;
 			}

src/ai/formula/candidates.cpp

@@ -46,10 +46,10 @@ int base_candidate_action::execute_formula(const const_formula_ptr& formula,
 	int res = 0;
 	try {
 		res = (formula::evaluate(formula, callable)).as_int();
-	} catch(formula_error& e) {
+	} catch(const formula_error& e) {
 		ai->handle_exception(e);
 		res = 0;
-	} catch(type_error& e) {
+	} catch(const type_error& e) {
 		res = 0;
 		ERR_AI << "formula type error while evaluating candidate action: " << e.message << std::endl;
 	}
@@ -116,7 +116,7 @@ void move_candidate_action::evaluate(ai::formula_ai* ai, unit_map& units)
 		else
 			filtered_units=my_units;
 	}
-	catch(formula_error& e) {
+	catch(const formula_error& e) {
 		ai->handle_exception(e, "Error while executing filter formula for '" + get_name() + "' Candidate Action");
 		return;
 	}
@@ -186,7 +186,7 @@ void attack_candidate_action::evaluate(ai::formula_ai* ai, unit_map& units)
 		else
 			filtered_enemy_units = enemy_units;
 	}
-	catch(formula_error& e) {
+	catch(const formula_error& e) {
 		ai->handle_exception(e, "Error while executing filter formula for '" + get_name() + "' Candidate Action");
 		return;
 	}
@@ -195,7 +195,7 @@ void attack_candidate_action::evaluate(ai::formula_ai* ai, unit_map& units)
 		if( !(filtered_enemy_units.num_elements() && filtered_my_units.num_elements() ) )
 			return;
 	}
-	catch(type_error& e) {
+	catch(const type_error& e) {
 		ERR_AI << "Error while executing filter formulas for '" + get_name() + "' Candidate Action: " << e.message << std::endl;
 		return;
 	}

src/ai/formula/stage_unit_formulas.cpp

@@ -78,7 +78,7 @@ bool stage_unit_formulas::do_play_stage()
 						fai_.handle_exception( e, "Unit priority formula error for unit: '" + i->type_id() + "' standing at (" + std::to_string(i->get_location().wml_x()) + "," + std::to_string(i->get_location().wml_y()) + ")");
 
 						priority = 0;
-					} catch(wfl::type_error& e) {
+					} catch(const wfl::type_error& e) {
 						priority = 0;
 						ERR_AI << "formula type error while evaluating unit priority formula  " << e.message << std::endl;
 					}

src/campaign_server/campaign_server.cpp

@@ -589,14 +589,14 @@ void server::handle_request_campaign_list(const server::request& req)
 	try {
 		before = before + lexical_cast<time_t>(req.cfg["before"]);
 		before_flag = true;
-	} catch(bad_lexical_cast) {}
+	} catch(const bad_lexical_cast&) {}
 
 	bool after_flag = false;
 	time_t after = epoch;
 	try {
 		after = after + lexical_cast<time_t>(req.cfg["after"]);
 		after_flag = true;
-	} catch(bad_lexical_cast) {}
+	} catch(const bad_lexical_cast&) {}
 
 	const std::string& name = req.cfg["name"];
 	const std::string& lang = req.cfg["language"];
@@ -1009,13 +1009,13 @@ int main()
 		const std::string cfg_path = filesystem::normalize_path("server.cfg");
 
 		campaignd::server(cfg_path).run();
-	} catch(config::error& /*e*/) {
+	} catch(const config::error& /*e*/) {
 		std::cerr << "Could not parse config file\n";
 		return 1;
-	} catch(filesystem::io_exception& e) {
+	} catch(const filesystem::io_exception& e) {
 		std::cerr << "File I/O error: " << e.what() << "\n";
 		return 2;
-	} catch(std::bad_function_call& /*e*/) {
+	} catch(const std::bad_function_call& /*e*/) {
 		std::cerr << "Bad request handler function call\n";
 		return 4;
 	}

src/commandline_options.cpp

@@ -518,7 +518,7 @@ void commandline_options::parse_resolution_ ( const std::string& resolution_stri
 	try {
 		xres = std::stoi(tokens[0]);
 		yres = std::stoi(tokens[1]);
-	} catch(std::invalid_argument &) {
+	} catch(const std::invalid_argument &) {
 		throw bad_commandline_resolution(resolution_string);
 	}
 
@@ -541,7 +541,7 @@ std::vector<std::pair<unsigned int,std::string>> commandline_options::parse_to_u
 		unsigned int temp;
 		try {
 			temp = lexical_cast<unsigned int>(tokens[0]);
-		} catch (bad_lexical_cast &) {
+		} catch (const bad_lexical_cast &) {
 			throw bad_commandline_tuple(s, expected_format);
 		}
 
@@ -566,7 +566,7 @@ std::vector<std::tuple<unsigned int,std::string,std::string>> commandline_option
 		unsigned int temp;
 		try {
 			temp = lexical_cast<unsigned int>(tokens[0]);
-		} catch (bad_lexical_cast &) {
+		} catch (const bad_lexical_cast &) {
 			throw bad_commandline_tuple(s, expected_format);
 		}
 

src/config_cache.cpp

@@ -175,9 +175,9 @@ void config_cache::read_cache(const std::string& file_path, config& cfg)
 
 					dir_checksum = filesystem::file_tree_checksum(checksum_cfg);
 				}
-			} catch(config::error&) {
+			} catch(const config::error&) {
 				ERR_CACHE << "cache checksum is corrupt" << std::endl;
-			} catch(filesystem::io_exception&) {
+			} catch(const filesystem::io_exception&) {
 				ERR_CACHE << "error reading cache checksum" << std::endl;
 			}
 		}
@@ -199,11 +199,11 @@ void config_cache::read_cache(const std::string& file_path, config& cfg)
 				}
 
 				return;
-			} catch(config::error& e) {
+			} catch(const config::error& e) {
 				ERR_CACHE << "cache " << fname << extension << " is corrupt. Loading from files: "<< e.message << std::endl;
-			} catch(filesystem::io_exception&) {
+			} catch(const filesystem::io_exception&) {
 				ERR_CACHE << "error reading cache " << fname << extension << ". Loading from files" << std::endl;
-			} catch (boost::iostreams::gzip_error& e) {
+			} catch (const boost::iostreams::gzip_error& e) {
 				//read_file -> ... -> read_gz can throw this exception.
 				ERR_CACHE << "cache " << fname << extension << " is corrupt. Error code: " << e.error() << std::endl;
 			}
@@ -227,7 +227,7 @@ void config_cache::read_cache(const std::string& file_path, config& cfg)
 
 			filesystem::data_tree_checksum().write(checksum_cfg);
 			write_file(fname_checksum, checksum_cfg);
-		} catch(filesystem::io_exception&) {
+		} catch(const filesystem::io_exception&) {
 			ERR_CACHE << "could not write to cache '" << fname << "'" << std::endl;
 		}
 

src/display.cpp

@@ -341,7 +341,7 @@ void display::init_flags_for_side_internal(size_t n, const std::string& side_col
 			str = sub_items.front();
 			try {
 				time = std::max<int>(1, std::stoi(sub_items.back()));
-			} catch(std::invalid_argument&) {
+			} catch(const std::invalid_argument&) {
 				ERR_DP << "Invalid time value found when constructing flag for side " << n << ": " << sub_items.back() << "\n";
 			}
 		}

src/editor/controller/editor_controller.cpp

@@ -174,10 +174,10 @@ EXIT_STATUS editor_controller::main_loop()
 		while (!do_quit_) {
 			play_slice();
 		}
-	} catch (editor_exception& e) {
+	} catch (const editor_exception& e) {
 		gui2::show_transient_message(_("Fatal error"), e.what());
 		return EXIT_ERROR;
-	} catch (wml_exception& e) {
+	} catch (const wml_exception& e) {
 		e.show();
 	}
 	return quit_mode_;
@@ -193,7 +193,7 @@ void editor_controller::do_screenshot(const std::string& screenshot_filename /*
 		if(screenshot.null() || image::save_image(screenshot, screenshot_filename) != image::save_result::success) {
 			ERR_ED << "Screenshot creation failed!\n";
 		}
-	} catch (wml_exception& e) {
+	} catch (const wml_exception& e) {
 		e.show();
 	}
 }

src/editor/editor_main.cpp

@@ -62,7 +62,7 @@ EXIT_STATUS start(const config& game_conf, const std::string& filename /* = "" *
 		if (!take_screenshot)
 			e = editor.main_loop();
 
-	} catch (editor_exception& e) {
+	} catch(const editor_exception& e) {
 		ERR_ED << "Editor exception in editor::start: " << e.what() << std::endl;
 		throw;
 	}