Codechange: Remove unnecessary 'return_cmd_error` macro. (OpenTTD#13160)

This macro is a leftover from when errors used to be packed into a single int32_t.

`return CommandCost` is clearer, and doesn't need a macro.

src/command_func.h

@@ -27,16 +27,6 @@
  */
 static const CommandCost CMD_ERROR = CommandCost(INVALID_STRING_ID);
 
-/**
- * Returns from a function with a specific StringID as error.
- *
- * This macro is used to return from a function. The parameter contains the
- * StringID which will be returned.
- *
- * @param errcode The StringID to return
- */
-#define return_cmd_error(errcode) return CommandCost(errcode);
-
 void NetworkSendCommand(Commands cmd, StringID err_message, CommandCallback *callback, CompanyID company, const CommandDataBuffer &cmd_data);
 
 bool IsValidCommand(Commands cmd);

src/company_cmd.cpp

@@ -368,7 +368,7 @@ CommandCost CheckOwnership(Owner owner, TileIndex tile)
 	if (owner == _current_company) return CommandCost();
 
 	SetDParamsForOwnedBy(owner, tile);
-	return_cmd_error(STR_ERROR_OWNED_BY);
+	return CommandCost(STR_ERROR_OWNED_BY);
 }
 
 /**
@@ -388,7 +388,7 @@ CommandCost CheckTileOwnership(TileIndex tile)
 
 	/* no need to get the name of the owner unless we're the local company (saves some time) */
 	if (IsLocalCompany()) SetDParamsForOwnedBy(owner, tile);
-	return_cmd_error(STR_ERROR_OWNED_BY);
+	return CommandCost(STR_ERROR_OWNED_BY);
 }
 
 /**
@@ -1172,7 +1172,7 @@ CommandCost CmdRenameCompany(DoCommandFlag flags, const std::string &text)
 
 	if (!reset) {
 		if (Utf8StringLength(text) >= MAX_LENGTH_COMPANY_NAME_CHARS) return CMD_ERROR;
-		if (!IsUniqueCompanyName(text)) return_cmd_error(STR_ERROR_NAME_MUST_BE_UNIQUE);
+		if (!IsUniqueCompanyName(text)) return CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE);
 	}
 
 	if (flags & DC_EXEC) {
@@ -1215,7 +1215,7 @@ CommandCost CmdRenamePresident(DoCommandFlag flags, const std::string &text)
 
 	if (!reset) {
 		if (Utf8StringLength(text) >= MAX_LENGTH_PRESIDENT_NAME_CHARS) return CMD_ERROR;
-		if (!IsUniquePresidentName(text)) return_cmd_error(STR_ERROR_NAME_MUST_BE_UNIQUE);
+		if (!IsUniquePresidentName(text)) return CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE);
 	}
 
 	if (flags & DC_EXEC) {
@@ -1301,7 +1301,7 @@ CommandCost CmdGiveMoney(DoCommandFlag flags, Money money, CompanyID dest_compan
 	CommandCost amount(EXPENSES_OTHER, std::min<Money>(money, 20000000LL));
 
 	/* You can only transfer funds that is in excess of your loan */
-	if (c->money - c->current_loan < amount.GetCost() || amount.GetCost() < 0) return_cmd_error(STR_ERROR_INSUFFICIENT_FUNDS);
+	if (c->money - c->current_loan < amount.GetCost() || amount.GetCost() < 0) return CommandCost(STR_ERROR_INSUFFICIENT_FUNDS);
 	if (!Company::IsValidID(dest_company)) return CMD_ERROR;
 
 	if (flags & DC_EXEC) {

src/depot_cmd.cpp

@@ -55,7 +55,7 @@ CommandCost CmdRenameDepot(DoCommandFlag flags, DepotID depot_id, const std::str
 
 	if (!reset) {
 		if (Utf8StringLength(text) >= MAX_LENGTH_DEPOT_NAME_CHARS) return CMD_ERROR;
-		if (!IsUniqueDepotName(text)) return_cmd_error(STR_ERROR_NAME_MUST_BE_UNIQUE);
+		if (!IsUniqueDepotName(text)) return CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE);
 	}
 
 	if (flags & DC_EXEC) {

src/economy.cpp

@@ -2064,7 +2064,7 @@ CommandCost CmdBuyCompany(DoCommandFlag flags, CompanyID target_company, bool ho
 	if (target_company == _current_company) return CMD_ERROR;
 
 	/* Do not allow takeover if the resulting company would have too many vehicles. */
-	if (!CheckTakeoverVehicleLimit(_current_company, target_company)) return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
+	if (!CheckTakeoverVehicleLimit(_current_company, target_company)) return CommandCost(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
 
 	/* Get the cost here as the company is deleted in DoAcquireCompany.
 	 * For bankruptcy this amount is calculated when the offer was made;

src/engine.cpp

@@ -1226,7 +1226,7 @@ CommandCost CmdRenameEngine(DoCommandFlag flags, EngineID engine_id, const std::
 
 	if (!reset) {
 		if (Utf8StringLength(text) >= MAX_LENGTH_ENGINE_NAME_CHARS) return CMD_ERROR;
-		if (!IsUniqueEngineName(text)) return_cmd_error(STR_ERROR_NAME_MUST_BE_UNIQUE);
+		if (!IsUniqueEngineName(text)) return CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE);
 	}
 
 	if (flags & DC_EXEC) {

src/group_cmd.cpp

@@ -462,7 +462,7 @@ CommandCost CmdAlterGroup(DoCommandFlag flags, AlterGroupMode mode, GroupID grou
 
 			/* Ensure request parent isn't child of group.
 			 * This is the only place that infinite loops are prevented. */
-			if (GroupIsInGroup(pg->index, g->index)) return_cmd_error(STR_ERROR_GROUP_CAN_T_SET_PARENT_RECURSION);
+			if (GroupIsInGroup(pg->index, g->index)) return CommandCost(STR_ERROR_GROUP_CAN_T_SET_PARENT_RECURSION);
 		}
 
 		if (flags & DC_EXEC) {

src/industry_cmd.cpp

@@ -505,7 +505,7 @@ static CommandCost ClearTile_Industry(TileIndex tile, DoCommandFlag flags)
 				((indspec->behaviour & INDUSTRYBEH_BUILT_ONWATER) ||
 				HasBit(GetIndustryTileSpec(GetIndustryGfx(tile))->slopes_refused, 5)))) {
 		SetDParam(1, indspec->name);
-		return_cmd_error(flags & DC_AUTO ? STR_ERROR_GENERIC_OBJECT_IN_THE_WAY : INVALID_STRING_ID);
+		return CommandCost(flags & DC_AUTO ? STR_ERROR_GENERIC_OBJECT_IN_THE_WAY : INVALID_STRING_ID);
 	}
 
 	if (flags & DC_EXEC) {
@@ -1273,7 +1273,7 @@ static CommandCost CheckNewIndustry_Forest(TileIndex tile)
 {
 	if (_settings_game.game_creation.landscape == LT_ARCTIC) {
 		if (GetTileZ(tile) < HighestSnowLine() + 2) {
-			return_cmd_error(STR_ERROR_FOREST_CAN_ONLY_BE_PLANTED);
+			return CommandCost(STR_ERROR_FOREST_CAN_ONLY_BE_PLANTED);
 		}
 	}
 	return CommandCost();
@@ -1313,7 +1313,7 @@ static CommandCost CheckNewIndustry_OilRefinery(TileIndex tile)
 
 	if (CheckScaledDistanceFromEdge(TileAddXY(tile, 1, 1), _settings_game.game_creation.oil_refinery_limit)) return CommandCost();
 
-	return_cmd_error(STR_ERROR_CAN_ONLY_BE_POSITIONED);
+	return CommandCost(STR_ERROR_CAN_ONLY_BE_POSITIONED);
 }
 
 extern bool _ignore_restrictions;
@@ -1330,7 +1330,7 @@ static CommandCost CheckNewIndustry_OilRig(TileIndex tile)
 	if (TileHeight(tile) == 0 &&
 			CheckScaledDistanceFromEdge(TileAddXY(tile, 1, 1), _settings_game.game_creation.oil_refinery_limit)) return CommandCost();
 
-	return_cmd_error(STR_ERROR_CAN_ONLY_BE_POSITIONED);
+	return CommandCost(STR_ERROR_CAN_ONLY_BE_POSITIONED);
 }
 
 /**
@@ -1342,7 +1342,7 @@ static CommandCost CheckNewIndustry_Farm(TileIndex tile)
 {
 	if (_settings_game.game_creation.landscape == LT_ARCTIC) {
 		if (GetTileZ(tile) + 2 >= HighestSnowLine()) {
-			return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+			return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 		}
 	}
 	return CommandCost();
@@ -1356,7 +1356,7 @@ static CommandCost CheckNewIndustry_Farm(TileIndex tile)
 static CommandCost CheckNewIndustry_Plantation(TileIndex tile)
 {
 	if (GetTropicZone(tile) == TROPICZONE_DESERT) {
-		return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+		return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 	}
 	return CommandCost();
 }
@@ -1369,7 +1369,7 @@ static CommandCost CheckNewIndustry_Plantation(TileIndex tile)
 static CommandCost CheckNewIndustry_Water(TileIndex tile)
 {
 	if (GetTropicZone(tile) != TROPICZONE_DESERT) {
-		return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_IN_DESERT);
+		return CommandCost(STR_ERROR_CAN_ONLY_BE_BUILT_IN_DESERT);
 	}
 	return CommandCost();
 }
@@ -1382,7 +1382,7 @@ static CommandCost CheckNewIndustry_Water(TileIndex tile)
 static CommandCost CheckNewIndustry_Lumbermill(TileIndex tile)
 {
 	if (GetTropicZone(tile) != TROPICZONE_RAINFOREST) {
-		return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_IN_RAINFOREST);
+		return CommandCost(STR_ERROR_CAN_ONLY_BE_BUILT_IN_RAINFOREST);
 	}
 	return CommandCost();
 }
@@ -1395,7 +1395,7 @@ static CommandCost CheckNewIndustry_Lumbermill(TileIndex tile)
 static CommandCost CheckNewIndustry_BubbleGen(TileIndex tile)
 {
 	if (GetTileZ(tile) > 4) {
-		return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_IN_LOW_AREAS);
+		return CommandCost(STR_ERROR_CAN_ONLY_BE_BUILT_IN_LOW_AREAS);
 	}
 	return CommandCost();
 }
@@ -1439,7 +1439,7 @@ static CommandCost FindTownForIndustry(TileIndex tile, IndustryType type, Town *
 	for (const IndustryID &industry : Industry::industries[type]) {
 		if (Industry::Get(industry)->town == *t) {
 			*t = nullptr;
-			return_cmd_error(STR_ERROR_ONLY_ONE_ALLOWED_PER_TOWN);
+			return CommandCost(STR_ERROR_ONLY_ONE_ALLOWED_PER_TOWN);
 		}
 	}
 
@@ -1479,28 +1479,28 @@ static CommandCost CheckIfIndustryTilesAreFree(TileIndex tile, const IndustryTil
 		TileIndex cur_tile = TileAddWrap(tile, it.ti.x, it.ti.y);
 
 		if (!IsValidTile(cur_tile)) {
-			return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+			return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 		}
 
 		if (gfx == GFX_WATERTILE_SPECIALCHECK) {
 			if (!IsWaterTile(cur_tile) ||
 					!IsTileFlat(cur_tile)) {
-				return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+				return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 			}
 		} else {
 			CommandCost ret = EnsureNoVehicleOnGround(cur_tile);
 			if (ret.Failed()) return ret;
-			if (IsBridgeAbove(cur_tile)) return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+			if (IsBridgeAbove(cur_tile)) return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 
 			const IndustryTileSpec *its = GetIndustryTileSpec(gfx);
 
 			/* Perform land/water check if not disabled */
-			if (!HasBit(its->slopes_refused, 5) && ((HasTileWaterClass(cur_tile) && IsTileOnWater(cur_tile)) == !(ind_behav & INDUSTRYBEH_BUILT_ONWATER))) return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+			if (!HasBit(its->slopes_refused, 5) && ((HasTileWaterClass(cur_tile) && IsTileOnWater(cur_tile)) == !(ind_behav & INDUSTRYBEH_BUILT_ONWATER))) return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 
 			if ((ind_behav & (INDUSTRYBEH_ONLY_INTOWN | INDUSTRYBEH_TOWN1200_MORE)) || // Tile must be a house
 					((ind_behav & INDUSTRYBEH_ONLY_NEARTOWN) && IsTileType(cur_tile, MP_HOUSE))) { // Tile is allowed to be a house (and it is a house)
 				if (!IsTileType(cur_tile, MP_HOUSE)) {
-					return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_IN_TOWNS);
+					return CommandCost(STR_ERROR_CAN_ONLY_BE_BUILT_IN_TOWNS);
 				}
 
 				/* Clear the tiles as OWNER_TOWN to not affect town rating, and to not clear protected buildings */
@@ -1564,7 +1564,7 @@ static CommandCost CheckIfIndustryTileSlopes(TileIndex tile, const IndustryTileL
 	if (!refused_slope || (_settings_game.game_creation.land_generator == LG_TERRAGENESIS && _generating_world && !custom_shape && !_ignore_restrictions)) {
 		return CommandCost();
 	}
-	return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+	return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 }
 
 /**
@@ -1577,11 +1577,11 @@ static CommandCost CheckIfIndustryTileSlopes(TileIndex tile, const IndustryTileL
 static CommandCost CheckIfIndustryIsAllowed(TileIndex tile, IndustryType type, const Town *t)
 {
 	if ((GetIndustrySpec(type)->behaviour & INDUSTRYBEH_TOWN1200_MORE) && t->cache.population < 1200) {
-		return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_IN_TOWNS_WITH_POPULATION_OF_1200);
+		return CommandCost(STR_ERROR_CAN_ONLY_BE_BUILT_IN_TOWNS_WITH_POPULATION_OF_1200);
 	}
 
 	if ((GetIndustrySpec(type)->behaviour & INDUSTRYBEH_ONLY_NEARTOWN) && DistanceMax(t->xy, tile) > 9) {
-		return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_NEAR_TOWN_CENTER);
+		return CommandCost(STR_ERROR_CAN_ONLY_BE_BUILT_NEAR_TOWN_CENTER);
 	}
 
 	return CommandCost();
@@ -1702,7 +1702,7 @@ static CommandCost CheckIfFarEnoughFromConflictingIndustry(TileIndex tile, Indus
 			/* Within 14 tiles from another industry is considered close */
 			if (DistanceMax(tile, Industry::Get(industry)->location.tile) > 14) continue;
 
-			return_cmd_error(STR_ERROR_INDUSTRY_TOO_CLOSE);
+			return CommandCost(STR_ERROR_INDUSTRY_TOO_CLOSE);
 		}
 	}
 	return CommandCost();
@@ -2021,10 +2021,10 @@ static CommandCost CreateNewIndustryHelper(TileIndex tile, IndustryType type, Do
 
 	if (!custom_shape_check && _settings_game.game_creation.land_generator == LG_TERRAGENESIS && _generating_world &&
 			!_ignore_restrictions && !CheckIfCanLevelIndustryPlatform(tile, DC_NO_WATER, layout)) {
-		return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+		return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 	}
 
-	if (!Industry::CanAllocateItem()) return_cmd_error(STR_ERROR_TOO_MANY_INDUSTRIES);
+	if (!Industry::CanAllocateItem()) return CommandCost(STR_ERROR_TOO_MANY_INDUSTRIES);
 
 	if (flags & DC_EXEC) {
 		*ip = new Industry(tile);

src/landscape.cpp

@@ -656,14 +656,14 @@ CommandCost CmdLandscapeClear(DoCommandFlag flags, TileIndex tile)
 	bool do_clear = false;
 	/* Test for stuff which results in water when cleared. Then add the cost to also clear the water. */
 	if ((flags & DC_FORCE_CLEAR_TILE) && HasTileWaterClass(tile) && IsTileOnWater(tile) && !IsWaterTile(tile) && !IsCoastTile(tile)) {
-		if ((flags & DC_AUTO) && GetWaterClass(tile) == WATER_CLASS_CANAL) return_cmd_error(STR_ERROR_MUST_DEMOLISH_CANAL_FIRST);
+		if ((flags & DC_AUTO) && GetWaterClass(tile) == WATER_CLASS_CANAL) return CommandCost(STR_ERROR_MUST_DEMOLISH_CANAL_FIRST);
 		do_clear = true;
 		cost.AddCost(GetWaterClass(tile) == WATER_CLASS_CANAL ? _price[PR_CLEAR_CANAL] : _price[PR_CLEAR_WATER]);
 	}
 
 	Company *c = (flags & (DC_AUTO | DC_BANKRUPT)) ? nullptr : Company::GetIfValid(_current_company);
 	if (c != nullptr && (int)GB(c->clear_limit, 16, 16) < 1) {
-		return_cmd_error(STR_ERROR_CLEARING_LIMIT_REACHED);
+		return CommandCost(STR_ERROR_CLEARING_LIMIT_REACHED);
 	}
 
 	const ClearedObjectArea *coa = FindClearedObject(tile);
@@ -677,7 +677,7 @@ CommandCost CmdLandscapeClear(DoCommandFlag flags, TileIndex tile)
 
 		/* If a object is removed, it leaves either bare land or water. */
 		if ((flags & DC_NO_WATER) && HasTileWaterClass(tile) && IsTileOnWater(tile)) {
-			return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
+			return CommandCost(STR_ERROR_CAN_T_BUILD_ON_WATER);
 		}
 	} else {
 		cost.AddCost(_tile_type_procs[GetTileType(tile)]->clear_tile_proc(tile, flags));

src/misc_cmd.cpp

@@ -42,7 +42,7 @@ CommandCost CmdIncreaseLoan(DoCommandFlag flags, LoanCommand cmd, Money amount)
 	Money max_loan = c->GetMaxLoan();
 	if (c->current_loan >= max_loan) {
 		SetDParam(0, max_loan);
-		return_cmd_error(STR_ERROR_MAXIMUM_PERMITTED_LOAN);
+		return CommandCost(STR_ERROR_MAXIMUM_PERMITTED_LOAN);
 	}
 
 	Money loan;
@@ -87,7 +87,7 @@ CommandCost CmdDecreaseLoan(DoCommandFlag flags, LoanCommand cmd, Money amount)
 {
 	Company *c = Company::Get(_current_company);
 
-	if (c->current_loan == 0) return_cmd_error(STR_ERROR_LOAN_ALREADY_REPAYED);
+	if (c->current_loan == 0) return CommandCost(STR_ERROR_LOAN_ALREADY_REPAYED);
 
 	Money loan;
 	switch (cmd) {
@@ -107,7 +107,7 @@ CommandCost CmdDecreaseLoan(DoCommandFlag flags, LoanCommand cmd, Money amount)
 
 	if (GetAvailableMoneyForCommand() < loan) {
 		SetDParam(0, loan);
-		return_cmd_error(STR_ERROR_CURRENCY_REQUIRED);
+		return CommandCost(STR_ERROR_CURRENCY_REQUIRED);
 	}
 
 	if (flags & DC_EXEC) {

src/newgrf_industrytiles.cpp

@@ -240,11 +240,11 @@ CommandCost PerformIndustryTileSlopeCheck(TileIndex ind_base_tile, TileIndex ind
 	uint16_t callback_res = GetIndustryTileCallback(CBID_INDTILE_SHAPE_CHECK, 0, creation_type << 8 | (uint32_t)layout_index, gfx, &ind, ind_tile);
 	if (callback_res == CALLBACK_FAILED) {
 		if (!IsSlopeRefused(GetTileSlope(ind_tile), its->slopes_refused)) return CommandCost();
-		return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+		return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 	}
 	if (its->grf_prop.grffile->grf_version < 7) {
 		if (callback_res != 0) return CommandCost();
-		return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+		return CommandCost(STR_ERROR_SITE_UNSUITABLE);
 	}
 
 	return GetErrorMessageFromLocationCallbackResult(callback_res, its->grf_prop.grffile, STR_ERROR_SITE_UNSUITABLE);