Fix: do not hide parameter by local variable with the same name

14 files changed, 130 insertions, 130 deletions

diff --git a/src/blitter/common.hpp b/src/blitter/common.hpp
index aaf63cd6a..cd3b6276a 100644
--- a/src/blitter/common.hpp
+++ b/src/blitter/common.hpp
@@ -16,14 +16,14 @@
 #include <utility>
 
 template <typename SetPixelT>
-void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, int screen_height, int width, int dash, SetPixelT set_pixel)
+void Blitter::DrawLineGeneric(int x1, int y1, int x2, int y2, int screen_width, int screen_height, int width, int dash, SetPixelT set_pixel)
 {
 	int dy;
 	int dx;
 	int stepx;
 	int stepy;
 
-	dy = (y2 - y) * 2;
+	dy = (y2 - y1) * 2;
 	if (dy < 0) {
 		dy = -dy;
 		stepy = -1;
@@ -31,7 +31,7 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 		stepy = 1;
 	}
 
-	dx = (x2 - x) * 2;
+	dx = (x2 - x1) * 2;
 	if (dx < 0) {
 		dx = -dx;
 		stepx = -1;
@@ -41,7 +41,7 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 
 	if (dx == 0 && dy == 0) {
 		/* The algorithm below cannot handle this special case; make it work at least for line width 1 */
-		if (x >= 0 && x < screen_width && y >= 0 && y < screen_height) set_pixel(x, y);
+		if (x1 >= 0 && x1 < screen_width && y1 >= 0 && y1 < screen_height) set_pixel(x1, y1);
 		return;
 	}
 
@@ -67,14 +67,14 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 	int dash_count = 0;
 	if (dx > dy) {
 		if (stepx < 0) {
-			std::swap(x, x2);
-			std::swap(y, y2);
+			std::swap(x1, x2);
+			std::swap(y1, y2);
 			stepy = -stepy;
 		}
-		if (x2 < 0 || x >= screen_width) return;
+		if (x2 < 0 || x1 >= screen_width) return;
 
-		int y_low     = y;
-		int y_high    = y;
+		int y_low     = y1;
+		int y_high    = y1;
 		int frac_low  = dy - frac_diff / 2;
 		int frac_high = dy + frac_diff / 2;
 
@@ -87,10 +87,10 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 			y_high += stepy;
 		}
 
-		if (x < 0) {
-			dash_count = (-x) % (dash + gap);
+		if (x1 < 0) {
+			dash_count = (-x1) % (dash + gap);
 			auto adjust_frac = [&](int64 frac, int &y_bound) -> int {
-				frac -= ((int64) dy) * ((int64) x);
+				frac -= ((int64) dy) * ((int64) x1);
 				if (frac >= 0) {
 					int quotient = frac / dx;
 					int remainder = frac % dx;
@@ -101,17 +101,17 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 			};
 			frac_low = adjust_frac(frac_low, y_low);
 			frac_high = adjust_frac(frac_high, y_high);
-			x = 0;
+			x1 = 0;
 		}
 		x2++;
 		if (x2 > screen_width) {
 			x2 = screen_width;
 		}
 
-		while (x != x2) {
+		while (x1 != x2) {
 			if (dash_count < dash) {
 				for (int y = y_low; y != y_high; y += stepy) {
-					if (y >= 0 && y < screen_height) set_pixel(x, y);
+					if (y >= 0 && y < screen_height) set_pixel(x1, y);
 				}
 			}
 			if (frac_low >= 0) {
@@ -122,21 +122,21 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 				y_high += stepy;
 				frac_high -= dx;
 			}
-			x++;
+			x1++;
 			frac_low += dy;
 			frac_high += dy;
 			if (++dash_count >= dash + gap) dash_count = 0;
 		}
 	} else {
 		if (stepy < 0) {
-			std::swap(x, x2);
-			std::swap(y, y2);
+			std::swap(x1, x2);
+			std::swap(y1, y2);
 			stepx = -stepx;
 		}
-		if (y2 < 0 || y >= screen_height) return;
+		if (y2 < 0 || y1 >= screen_height) return;
 
-		int x_low     = x;
-		int x_high    = x;
+		int x_low     = x1;
+		int x_high    = x1;
 		int frac_low  = dx - frac_diff / 2;
 		int frac_high = dx + frac_diff / 2;
 
@@ -149,10 +149,10 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 			x_high += stepx;
 		}
 
-		if (y < 0) {
-			dash_count = (-y) % (dash + gap);
+		if (y1 < 0) {
+			dash_count = (-y1) % (dash + gap);
 			auto adjust_frac = [&](int64 frac, int &x_bound) -> int {
-				frac -= ((int64) dx) * ((int64) y);
+				frac -= ((int64) dx) * ((int64) y1);
 				if (frac >= 0) {
 					int quotient = frac / dy;
 					int remainder = frac % dy;
@@ -163,17 +163,17 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 			};
 			frac_low = adjust_frac(frac_low, x_low);
 			frac_high = adjust_frac(frac_high, x_high);
-			y = 0;
+			y1 = 0;
 		}
 		y2++;
 		if (y2 > screen_height) {
 			y2 = screen_height;
 		}
 
-		while (y != y2) {
+		while (y1 != y2) {
 			if (dash_count < dash) {
 				for (int x = x_low; x != x_high; x += stepx) {
-					if (x >= 0 && x < screen_width) set_pixel(x, y);
+					if (x >= 0 && x < screen_width) set_pixel(x, y1);
 				}
 			}
 			if (frac_low >= 0) {
@@ -184,7 +184,7 @@ void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, in
 				x_high += stepx;
 				frac_high -= dy;
 			}
-			y++;
+			y1++;
 			frac_low += dx;
 			frac_high += dx;
 			if (++dash_count >= dash + gap) dash_count = 0;
diff --git a/src/company_gui.cpp b/src/company_gui.cpp
index f9eceba17..a23bda7bd 100644
--- a/src/company_gui.cpp
+++ b/src/company_gui.cpp
@@ -776,11 +776,11 @@ public:
 
 			case WID_SCL_PRI_COL_DROPDOWN: {
 				this->square = GetSpriteSize(SPR_SQUARE);
-				int padding = this->square.width + NWidgetScrollbar::GetVerticalDimension().width + 10;
+				int string_padding = this->square.width + NWidgetScrollbar::GetVerticalDimension().width + 10;
 				for (const StringID *id = _colour_dropdown; id != endof(_colour_dropdown); id++) {
-					size->width = std::max(size->width, GetStringBoundingBox(*id).width + padding);
+					size->width = std::max(size->width, GetStringBoundingBox(*id).width + string_padding);
 				}
-				size->width = std::max(size->width, GetStringBoundingBox(STR_COLOUR_DEFAULT).width + padding);
+				size->width = std::max(size->width, GetStringBoundingBox(STR_COLOUR_DEFAULT).width + string_padding);
 				break;
 			}
 		}
diff --git a/src/industry_gui.cpp b/src/industry_gui.cpp
index b1768af1f..fd5f5d487 100644
--- a/src/industry_gui.cpp
+++ b/src/industry_gui.cpp
@@ -2700,14 +2700,14 @@ struct IndustryCargoesWindow : public Window {
 
 	/**
 	 * Compute what and where to display for industry type \a it.
-	 * @param it Industry type to display.
+	 * @param displayed_it Industry type to display.
 	 */
-	void ComputeIndustryDisplay(IndustryType it)
+	void ComputeIndustryDisplay(IndustryType displayed_it)
 	{
 		this->GetWidget<NWidgetCore>(WID_IC_CAPTION)->widget_data = STR_INDUSTRY_CARGOES_INDUSTRY_CAPTION;
-		this->ind_cargo = it;
+		this->ind_cargo = displayed_it;
 		_displayed_industries.reset();
-		_displayed_industries.set(it);
+		_displayed_industries.set(displayed_it);
 
 		this->fields.clear();
 		CargoesRow &row = this->fields.emplace_back();
@@ -2717,7 +2717,7 @@ struct IndustryCargoesWindow : public Window {
 		row.columns[3].MakeEmpty(CFT_SMALL_EMPTY);
 		row.columns[4].MakeHeader(STR_INDUSTRY_CARGOES_CUSTOMERS);
 
-		const IndustrySpec *central_sp = GetIndustrySpec(it);
+		const IndustrySpec *central_sp = GetIndustrySpec(displayed_it);
 		bool houses_supply = HousesCanSupply(central_sp->accepts_cargo, lengthof(central_sp->accepts_cargo));
 		bool houses_accept = HousesCanAccept(central_sp->produced_cargo, lengthof(central_sp->produced_cargo));
 		/* Make a field consisting of two cargo columns. */
@@ -2734,7 +2734,7 @@ struct IndustryCargoesWindow : public Window {
 		}
 		/* Add central industry. */
 		int central_row = 1 + num_indrows / 2;
-		this->fields[central_row].columns[2].MakeIndustry(it);
+		this->fields[central_row].columns[2].MakeIndustry(displayed_it);
 		this->fields[central_row].ConnectIndustryProduced(2);
 		this->fields[central_row].ConnectIndustryAccepted(2);
 
diff --git a/src/network/network_content.cpp b/src/network/network_content.cpp
index 2b90cf415..e09b05ec7 100644
--- a/src/network/network_content.cpp
+++ b/src/network/network_content.cpp
@@ -1010,9 +1010,9 @@ void ClientNetworkContentSocketHandler::CheckDependencyState(ContentInfo *ci)
 		/* First check whether anything depends on us */
 		int sel_count = 0;
 		bool force_selection = false;
-		for (const ContentInfo *ci : parents) {
-			if (ci->IsSelected()) sel_count++;
-			if (ci->state == ContentInfo::SELECTED) force_selection = true;
+		for (const ContentInfo *parent_ci : parents) {
+			if (parent_ci->IsSelected()) sel_count++;
+			if (parent_ci->state == ContentInfo::SELECTED) force_selection = true;
 		}
 		if (sel_count == 0) {
 			/* Nothing depends on us */
@@ -1027,8 +1027,8 @@ void ClientNetworkContentSocketHandler::CheckDependencyState(ContentInfo *ci)
 		this->ReverseLookupTreeDependency(parents, c);
 
 		/* Is there anything that is "force" selected?, if so... we're done. */
-		for (const ContentInfo *ci : parents) {
-			if (ci->state != ContentInfo::SELECTED) continue;
+		for (const ContentInfo *parent_ci : parents) {
+			if (parent_ci->state != ContentInfo::SELECTED) continue;
 
 			force_selection = true;
 			break;
diff --git a/src/newgrf_station.cpp b/src/newgrf_station.cpp
index fbc6f5c60..c66b53d3f 100644
--- a/src/newgrf_station.cpp
+++ b/src/newgrf_station.cpp
@@ -550,16 +550,16 @@ uint32 StationResolverObject::GetDebugID() const
 /**
  * Resolver for stations.
  * @param statspec Station (type) specification.
- * @param st Instance of the station.
+ * @param base_station Instance of the station.
  * @param tile %Tile of the station.
  * @param callback Callback ID.
  * @param callback_param1 First parameter (var 10) of the callback.
  * @param callback_param2 Second parameter (var 18) of the callback.
  */
-StationResolverObject::StationResolverObject(const StationSpec *statspec, BaseStation *st, TileIndex tile,
+StationResolverObject::StationResolverObject(const StationSpec *statspec, BaseStation *base_station, TileIndex tile,
 		CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 	: ResolverObject(statspec->grf_prop.grffile, callback, callback_param1, callback_param2),
-	station_scope(*this, statspec, st, tile), town_scope(nullptr)
+	station_scope(*this, statspec, base_station, tile), town_scope(nullptr)
 {
 	/* Invalidate all cached vars */
 	_svc.valid = 0;
@@ -921,7 +921,7 @@ void AnimateStationTile(TileIndex tile)
 	StationAnimationBase::AnimateTile(ss, BaseStation::GetByTile(tile), tile, HasBit(ss->flags, SSF_CB141_RANDOM_BITS));
 }
 
-void TriggerStationAnimation(BaseStation *st, TileIndex tile, StationAnimationTrigger trigger, CargoID cargo_type)
+void TriggerStationAnimation(BaseStation *st, TileIndex trigger_tile, StationAnimationTrigger trigger, CargoID cargo_type)
 {
 	/* List of coverage areas for each animation trigger */
 	static const TriggerArea tas[] = {
@@ -929,14 +929,14 @@ void TriggerStationAnimation(BaseStation *st, TileIndex tile, StationAnimationTr
 	};
 
 	/* Get Station if it wasn't supplied */
-	if (st == nullptr) st = BaseStation::GetByTile(tile);
+	if (st == nullptr) st = BaseStation::GetByTile(trigger_tile);
 
 	/* Check the cached animation trigger bitmask to see if we need
 	 * to bother with any further processing. */
 	if (!HasBit(st->cached_anim_triggers, trigger)) return;
 
 	uint16 random_bits = Random();
-	ETileArea area = ETileArea(st, tile, tas[trigger]);
+	ETileArea area = ETileArea(st, trigger_tile, tas[trigger]);
 
 	/* Check all tiles over the station to check if the specindex is still in use */
 	for (TileIndex tile : area) {
@@ -958,11 +958,11 @@ void TriggerStationAnimation(BaseStation *st, TileIndex tile, StationAnimationTr
 /**
  * Trigger station randomisation
  * @param st station being triggered
- * @param tile specific tile of platform to trigger
+ * @param trigger_tile specific tile of platform to trigger
  * @param trigger trigger type
  * @param cargo_type cargo type causing trigger
  */
-void TriggerStationRandomisation(Station *st, TileIndex tile, StationRandomTrigger trigger, CargoID cargo_type)
+void TriggerStationRandomisation(Station *st, TileIndex trigger_tile, StationRandomTrigger trigger, CargoID cargo_type)
 {
 	/* List of coverage areas for each animation trigger */
 	static const TriggerArea tas[] = {
@@ -970,7 +970,7 @@ void TriggerStationRandomisation(Station *st, TileIndex tile, StationRandomTrigg
 	};
 
 	/* Get Station if it wasn't supplied */
-	if (st == nullptr) st = Station::GetByTile(tile);
+	if (st == nullptr) st = Station::GetByTile(trigger_tile);
 
 	/* Check the cached cargo trigger bitmask to see if we need
 	 * to bother with any further processing. */
@@ -978,7 +978,7 @@ void TriggerStationRandomisation(Station *st, TileIndex tile, StationRandomTrigg
 	if (cargo_type != CT_INVALID && !HasBit(st->cached_cargo_triggers, cargo_type)) return;
 
 	uint32 whole_reseed = 0;
-	ETileArea area = ETileArea(st, tile, tas[trigger]);
+	ETileArea area = ETileArea(st, trigger_tile, tas[trigger]);
 
 	CargoTypes empty_mask = 0;
 	if (trigger == SRT_CARGO_TAKEN) {
diff --git a/src/rail_cmd.cpp b/src/rail_cmd.cpp
index 888b98e94..72ae0724c 100644
--- a/src/rail_cmd.cpp
+++ b/src/rail_cmd.cpp
@@ -1359,11 +1359,11 @@ static CommandCost CmdSignalTrackHelper(TileIndex tile, DoCommandFlag flags, uin
 	for (;;) {
 		/* only build/remove signals with the specified density */
 		if (remove || minimise_gaps || signal_ctr % signal_density == 0) {
-			uint32 p1 = GB(TrackdirToTrack(trackdir), 0, 3);
-			SB(p1, 3, 1, mode);
-			SB(p1, 4, 1, semaphores);
-			SB(p1, 5, 3, sigtype);
-			if (!remove && signal_ctr == 0) SetBit(p1, 17);
+			uint32 param1 = GB(TrackdirToTrack(trackdir), 0, 3);
+			SB(param1, 3, 1, mode);
+			SB(param1, 4, 1, semaphores);
+			SB(param1, 5, 3, sigtype);
+			if (!remove && signal_ctr == 0) SetBit(param1, 17);
 
 			/* Pick the correct orientation for the track direction */
 			signals = 0;
@@ -1372,7 +1372,7 @@ static CommandCost CmdSignalTrackHelper(TileIndex tile, DoCommandFlag flags, uin
 
 			/* Test tiles in between for suitability as well if minimising gaps. */
 			bool test_only = !remove && minimise_gaps && signal_ctr < (last_used_ctr + signal_density);
-			CommandCost ret = DoCommand(tile, p1, signals, test_only ? flags & ~DC_EXEC : flags, remove ? CMD_REMOVE_SIGNALS : CMD_BUILD_SIGNALS);
+			CommandCost ret = DoCommand(tile, param1, signals, test_only ? flags & ~DC_EXEC : flags, remove ? CMD_REMOVE_SIGNALS : CMD_BUILD_SIGNALS);
 
 			if (ret.Succeeded()) {
 				/* Remember last track piece where we can place a signal. */
diff --git a/src/smallmap_gui.cpp b/src/smallmap_gui.cpp
index 17d1d25cb..bc0a7b447 100644
--- a/src/smallmap_gui.cpp
+++ b/src/smallmap_gui.cpp
@@ -1436,8 +1436,8 @@ int SmallMapWindow::GetPositionOnLegend(Point pt)
 		case WID_SM_ZOOM_IN:
 		case WID_SM_ZOOM_OUT: {
 			const NWidgetBase *wid = this->GetWidget<NWidgetBase>(WID_SM_MAP);
-			Point pt = { (int)wid->current_x / 2, (int)wid->current_y / 2};
-			this->SetZoomLevel((widget == WID_SM_ZOOM_IN) ? ZLC_ZOOM_IN : ZLC_ZOOM_OUT, &pt);
+			Point zoom_pt = { (int)wid->current_x / 2, (int)wid->current_y / 2};
+			this->SetZoomLevel((widget == WID_SM_ZOOM_IN) ? ZLC_ZOOM_IN : ZLC_ZOOM_OUT, &zoom_pt);
 			if (_settings_client.sound.click_beep) SndPlayFx(SND_15_BEEP);
 			break;
 		}
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index d1e12604c..d9529da11 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -498,16 +498,16 @@ static void ShowRejectOrAcceptNews(const Station *st, uint num_items, CargoID *c
 
 /**
  * Get the cargo types being produced around the tile (in a rectangle).
- * @param tile Northtile of area
+ * @param north_tile Northern most tile of area
  * @param w X extent of the area
  * @param h Y extent of the area
  * @param rad Search radius in addition to the given area
  */
-CargoArray GetProductionAroundTiles(TileIndex tile, int w, int h, int rad)
+CargoArray GetProductionAroundTiles(TileIndex north_tile, int w, int h, int rad)
 {
 	CargoArray produced;
 	std::set<IndustryID> industries;
-	TileArea ta = TileArea(tile, w, h).Expand(rad);
+	TileArea ta = TileArea(north_tile, w, h).Expand(rad);
 
 	/* Loop over all tiles to get the produced cargo of
 	 * everything except industries */
@@ -535,19 +535,19 @@ CargoArray GetProductionAroundTiles(TileIndex tile, int w, int h, int rad)
 
 /**
  * Get the acceptance of cargoes around the tile in 1/8.
- * @param tile Center of the search area
+ * @param center_tile Center of the search area
  * @param w X extent of area
  * @param h Y extent of area
  * @param rad Search radius in addition to given area
  * @param always_accepted bitmask of cargo accepted by houses and headquarters; can be nullptr
  * @param ind Industry associated with neutral station (e.g. oil rig) or nullptr
  */
-CargoArray GetAcceptanceAroundTiles(TileIndex tile, int w, int h, int rad, CargoTypes *always_accepted)
+CargoArray GetAcceptanceAroundTiles(TileIndex center_tile, int w, int h, int rad, CargoTypes *always_accepted)
 {
 	CargoArray acceptance;
 	if (always_accepted != nullptr) *always_accepted = 0;
 
-	TileArea ta = TileArea(tile, w, h).Expand(rad);
+	TileArea ta = TileArea(center_tile, w, h).Expand(rad);
 
 	for (TileIndex tile : ta) {
 		/* Ignore industry if it has a neutral station. */
diff --git a/src/terraform_cmd.cpp b/src/terraform_cmd.cpp
index bc4df173d..a23e02ab9 100644
--- a/src/terraform_cmd.cpp
+++ b/src/terraform_cmd.cpp
@@ -226,18 +226,18 @@ CommandCost CmdTerraformLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 	 * Pass == 1: Collect the actual cost. */
 	for (int pass = 0; pass < 2; pass++) {
 		for (TileIndexSet::const_iterator it = ts.dirty_tiles.begin(); it != ts.dirty_tiles.end(); it++) {
-			TileIndex tile = *it;
+			TileIndex t = *it;
 
-			assert(tile < MapSize());
+			assert(t < MapSize());
 			/* MP_VOID tiles can be terraformed but as tunnels and bridges
 			 * cannot go under / over these tiles they don't need checking. */
-			if (IsTileType(tile, MP_VOID)) continue;
+			if (IsTileType(t, MP_VOID)) continue;
 
 			/* Find new heights of tile corners */
-			int z_N = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
-			int z_W = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
-			int z_S = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
-			int z_E = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
+			int z_N = TerraformGetHeightOfTile(&ts, t + TileDiffXY(0, 0));
+			int z_W = TerraformGetHeightOfTile(&ts, t + TileDiffXY(1, 0));
+			int z_S = TerraformGetHeightOfTile(&ts, t + TileDiffXY(1, 1));
+			int z_E = TerraformGetHeightOfTile(&ts, t + TileDiffXY(0, 1));
 
 			/* Find min and max height of tile */
 			int z_min = std::min({z_N, z_W, z_S, z_E});
@@ -252,31 +252,31 @@ CommandCost CmdTerraformLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 
 			if (pass == 0) {
 				/* Check if bridge would take damage */
-				if (IsBridgeAbove(tile)) {
-					int bridge_height = GetBridgeHeight(GetSouthernBridgeEnd(tile));
+				if (IsBridgeAbove(t)) {
+					int bridge_height = GetBridgeHeight(GetSouthernBridgeEnd(t));
 
 					/* Check if bridge would take damage. */
 					if (direction == 1 && bridge_height <= z_max) {
-						_terraform_err_tile = tile; // highlight the tile under the bridge
+						_terraform_err_tile = t; // highlight the tile under the bridge
 						return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
 					}
 
 					/* Is the bridge above not too high afterwards? */
 					if (direction == -1 && bridge_height > (z_min + _settings_game.construction.max_bridge_height)) {
-						_terraform_err_tile = tile;
+						_terraform_err_tile = t;
 						return_cmd_error(STR_ERROR_BRIDGE_TOO_HIGH_AFTER_LOWER_LAND);
 					}
 				}
 				/* Check if tunnel would take damage */
-				if (direction == -1 && IsTunnelInWay(tile, z_min)) {
-					_terraform_err_tile = tile; // highlight the tile above the tunnel
+				if (direction == -1 && IsTunnelInWay(t, z_min)) {
+					_terraform_err_tile = t; // highlight the tile above the tunnel
 					return_cmd_error(STR_ERROR_EXCAVATION_WOULD_DAMAGE);
 				}
 			}
 
 			/* Is the tile already cleared? */
-			const ClearedObjectArea *coa = FindClearedObject(tile);
-			bool indirectly_cleared = coa != nullptr && coa->first_tile != tile;
+			const ClearedObjectArea *coa = FindClearedObject(t);
+			bool indirectly_cleared = coa != nullptr && coa->first_tile != t;
 
 			/* Check tiletype-specific things, and add extra-cost */
 			const bool curr_gen = _generating_world;
@@ -288,13 +288,13 @@ CommandCost CmdTerraformLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 			}
 			CommandCost cost;
 			if (indirectly_cleared) {
-				cost = DoCommand(tile, 0, 0, tile_flags, CMD_LANDSCAPE_CLEAR);
+				cost = DoCommand(t, 0, 0, tile_flags, CMD_LANDSCAPE_CLEAR);
 			} else {
-				cost = _tile_type_procs[GetTileType(tile)]->terraform_tile_proc(tile, tile_flags, z_min, tileh);
+				cost = _tile_type_procs[GetTileType(t)]->terraform_tile_proc(t, tile_flags, z_min, tileh);
 			}
 			_generating_world = curr_gen;
 			if (cost.Failed()) {
-				_terraform_err_tile = tile;
+				_terraform_err_tile = t;
 				return cost;
 			}
 			if (pass == 1) total_cost.AddCost(cost);
@@ -318,10 +318,10 @@ CommandCost CmdTerraformLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 		/* change the height */
 		for (TileIndexToHeightMap::const_iterator it = ts.tile_to_new_height.begin();
 				it != ts.tile_to_new_height.end(); it++) {
-			TileIndex tile = it->first;
+			TileIndex t = it->first;
 			int height = it->second;
 
-			SetTileHeight(tile, (uint)height);
+			SetTileHeight(t, (uint)height);
 		}
 
 		if (c != nullptr) c->terraform_limit -= (uint32)ts.tile_to_new_height.size() << 16;
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 033d04248..177b507e4 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -2988,27 +2988,27 @@ CommandCost CmdDeleteTown(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	 * these do not directly have an owner so we need to check adjacent
 	 * tiles. This won't work correctly in the same loop if the adjacent
 	 * tile was already deleted earlier in the loop. */
-	for (TileIndex tile = 0; tile < MapSize(); ++tile) {
-		if (IsTileType(tile, MP_TUNNELBRIDGE) && TestTownOwnsBridge(tile, t)) {
-			CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+	for (TileIndex current_tile = 0; current_tile < MapSize(); ++current_tile) {
+		if (IsTileType(current_tile, MP_TUNNELBRIDGE) && TestTownOwnsBridge(current_tile, t)) {
+			CommandCost ret = DoCommand(current_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 			if (ret.Failed()) return ret;
 		}
 	}
 
 	/* Check all remaining tiles for town ownership. */
-	for (TileIndex tile = 0; tile < MapSize(); ++tile) {
+	for (TileIndex current_tile = 0; current_tile < MapSize(); ++current_tile) {
 		bool try_clear = false;
-		switch (GetTileType(tile)) {
+		switch (GetTileType(current_tile)) {
 			case MP_ROAD:
-				try_clear = HasTownOwnedRoad(tile) && GetTownIndex(tile) == t->index;
+				try_clear = HasTownOwnedRoad(current_tile) && GetTownIndex(current_tile) == t->index;
 				break;
 
 			case MP_HOUSE:
-				try_clear = GetTownIndex(tile) == t->index;
+				try_clear = GetTownIndex(current_tile) == t->index;
 				break;
 
 			case MP_INDUSTRY:
-				try_clear = Industry::GetByTile(tile)->town == t;
+				try_clear = Industry::GetByTile(current_tile)->town == t;
 				break;
 
 			case MP_OBJECT:
@@ -3016,7 +3016,7 @@ CommandCost CmdDeleteTown(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 					/* No towns will be left, remove it! */
 					try_clear = true;
 				} else {
-					Object *o = Object::GetByTile(tile);
+					Object *o = Object::GetByTile(current_tile);
 					if (o->town == t) {
 						if (o->type == OBJECT_STATUE) {
 							/* Statue... always remove. */
@@ -3033,7 +3033,7 @@ CommandCost CmdDeleteTown(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 				break;
 		}
 		if (try_clear) {
-			CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+			CommandCost ret = DoCommand(current_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 			if (ret.Failed()) return ret;
 		}
 	}
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 3b1667094..0a3a5db9e 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -1391,7 +1391,7 @@ CommandCost CmdSellRailWagon(DoCommandFlag flags, Vehicle *t, uint16 data, uint3
 	}
 
 	CommandCost cost(EXPENSES_NEW_VEHICLES);
-	for (Train *t = sell_head; t != nullptr; t = t->Next()) cost.AddCost(-t->value);
+	for (Train *part = sell_head; part != nullptr; part = part->Next()) cost.AddCost(-part->value);
 
 	/* do it? */
 	if (flags & DC_EXEC) {
diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
index 9798c2bb5..baf149f5f 100644
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -392,11 +392,11 @@ CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	int limit = (c == nullptr ? INT32_MAX : GB(c->tree_limit, 16, 16));
 
 	TileArea ta(tile, p2);
-	for (TileIndex tile : ta) {
-		switch (GetTileType(tile)) {
+	for (TileIndex current_tile : ta) {
+		switch (GetTileType(current_tile)) {
 			case MP_TREES:
 				/* no more space for trees? */
-				if (GetTreeCount(tile) == 4) {
+				if (GetTreeCount(current_tile) == 4) {
 					msg = STR_ERROR_TREE_ALREADY_HERE;
 					continue;
 				}
@@ -408,8 +408,8 @@ CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 				}
 
 				if (flags & DC_EXEC) {
-					AddTreeCount(tile, 1);
-					MarkTileDirtyByTile(tile);
+					AddTreeCount(current_tile, 1);
+					MarkTileDirtyByTile(current_tile);
 					if (c != nullptr) c->tree_limit -= 1 << 16;
 				}
 				/* 2x as expensive to add more trees to an existing tile */
@@ -417,14 +417,14 @@ CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 				break;
 
 			case MP_WATER:
-				if (!IsCoast(tile) || IsSlopeWithOneCornerRaised(GetTileSlope(tile))) {
+				if (!IsCoast(current_tile) || IsSlopeWithOneCornerRaised(GetTileSlope(current_tile))) {
 					msg = STR_ERROR_CAN_T_BUILD_ON_WATER;
 					continue;
 				}
 				FALLTHROUGH;
 
 			case MP_CLEAR: {
-				if (IsBridgeAbove(tile)) {
+				if (IsBridgeAbove(current_tile)) {
 					msg = STR_ERROR_SITE_UNSUITABLE;
 					continue;
 				}
@@ -433,11 +433,11 @@ CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 				/* Be a bit picky about which trees go where. */
 				if (_settings_game.game_creation.landscape == LT_TROPIC && treetype != TREE_INVALID && (
 						/* No cacti outside the desert */
-						(treetype == TREE_CACTUS && GetTropicZone(tile) != TROPICZONE_DESERT) ||
+						(treetype == TREE_CACTUS && GetTropicZone(current_tile) != TROPICZONE_DESERT) ||
 						/* No rain forest trees outside the rain forest, except in the editor mode where it makes those tiles rain forest tile */
-						(IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS) && GetTropicZone(tile) != TROPICZONE_RAINFOREST && _game_mode != GM_EDITOR) ||
+						(IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS) && GetTropicZone(current_tile) != TROPICZONE_RAINFOREST && _game_mode != GM_EDITOR) ||
 						/* And no subtropical trees in the desert/rain forest */
-						(IsInsideMM(treetype, TREE_SUB_TROPICAL, TREE_TOYLAND) && GetTropicZone(tile) != TROPICZONE_NORMAL))) {
+						(IsInsideMM(treetype, TREE_SUB_TROPICAL, TREE_TOYLAND) && GetTropicZone(current_tile) != TROPICZONE_NORMAL))) {
 					msg = STR_ERROR_TREE_WRONG_TERRAIN_FOR_TREE_TYPE;
 					continue;
 				}
@@ -453,7 +453,7 @@ CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 					switch (GetRawClearGround(tile)) {
 						case CLEAR_FIELDS:
 						case CLEAR_ROCKS: {
-							CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+							CommandCost ret = DoCommand(current_tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 							if (ret.Failed()) return ret;
 							cost.AddCost(ret);
 							break;
@@ -464,24 +464,24 @@ CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 				}
 
 				if (_game_mode != GM_EDITOR && Company::IsValidID(_current_company)) {
-					Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
+					Town *t = ClosestTownFromTile(current_tile, _settings_game.economy.dist_local_authority);
 					if (t != nullptr) ChangeTownRating(t, RATING_TREE_UP_STEP, RATING_TREE_MAXIMUM, flags);
 				}
 
 				if (flags & DC_EXEC) {
 					if (treetype == TREE_INVALID) {
-						treetype = GetRandomTreeType(tile, GB(Random(), 24, 8));
+						treetype = GetRandomTreeType(current_tile, GB(Random(), 24, 8));
 						if (treetype == TREE_INVALID) treetype = TREE_CACTUS;
 					}
 
 					/* Plant full grown trees in scenario editor */
-					PlantTreesOnTile(tile, treetype, 0, _game_mode == GM_EDITOR ? 3 : 0);
-					MarkTileDirtyByTile(tile);
+					PlantTreesOnTile(current_tile, treetype, 0, _game_mode == GM_EDITOR ? 3 : 0);
+					MarkTileDirtyByTile(current_tile);
 					if (c != nullptr) c->tree_limit -= 1 << 16;
 
 					/* When planting rainforest-trees, set tropiczone to rainforest in editor. */
 					if (_game_mode == GM_EDITOR && IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS)) {
-						SetTropicZone(tile, TROPICZONE_RAINFOREST);
+						SetTropicZone(current_tile, TROPICZONE_RAINFOREST);
 					}
 				}
 				cost.AddCost(_price[PR_BUILD_TREES]);
diff --git a/src/viewport.cpp b/src/viewport.cpp
index 4344eac2a..7217cbc45 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -245,8 +245,8 @@ void InitializeWindowViewport(Window *w, int x, int y,
 		veh = Vehicle::Get(vp->follow_vehicle);
 		pt = MapXYZToViewport(vp, veh->x_pos, veh->y_pos, veh->z_pos);
 	} else {
-		uint x = TileX(follow_flags) * TILE_SIZE;
-		uint y = TileY(follow_flags) * TILE_SIZE;
+		x = TileX(follow_flags) * TILE_SIZE;
+		y = TileY(follow_flags) * TILE_SIZE;
 
 		vp->follow_vehicle = INVALID_VEHICLE;
 		pt = MapXYZToViewport(vp, x, y, GetSlopePixelZ(x, y));
diff --git a/src/water_cmd.cpp b/src/water_cmd.cpp
index 8c8a438a5..dfbed6012 100644
--- a/src/water_cmd.cpp
+++ b/src/water_cmd.cpp
@@ -467,19 +467,19 @@ CommandCost CmdBuildCanal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	}
 
 	for (; *iter != INVALID_TILE; ++(*iter)) {
-		TileIndex tile = *iter;
+		TileIndex current_tile = *iter;
 		CommandCost ret;
 
-		Slope slope = GetTileSlope(tile);
+		Slope slope = GetTileSlope(current_tile);
 		if (slope != SLOPE_FLAT && (wc != WATER_CLASS_RIVER || !IsInclinedSlope(slope))) {
 			return_cmd_error(STR_ERROR_FLAT_LAND_REQUIRED);
 		}
 
 		/* can't make water of water! */
-		if (IsTileType(tile, MP_WATER) && (!IsTileOwner(tile, OWNER_WATER) || wc == WATER_CLASS_SEA)) continue;
+		if (IsTileType(current_tile, MP_WATER) && (!IsTileOwner(current_tile, OWNER_WATER) || wc == WATER_CLASS_SEA)) continue;
 
-		bool water = IsWaterTile(tile);
-		ret = DoCommand(tile, 0, 0, flags | DC_FORCE_CLEAR_TILE, CMD_LANDSCAPE_CLEAR);
+		bool water = IsWaterTile(current_tile);
+		ret = DoCommand(current_tile, 0, 0, flags | DC_FORCE_CLEAR_TILE, CMD_LANDSCAPE_CLEAR);
 		if (ret.Failed()) return ret;
 
 		if (!water) cost.AddCost(ret);
@@ -487,31 +487,31 @@ CommandCost CmdBuildCanal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 		if (flags & DC_EXEC) {
 			switch (wc) {
 				case WATER_CLASS_RIVER:
-					MakeRiver(tile, Random());
+					MakeRiver(current_tile, Random());
 					if (_game_mode == GM_EDITOR) {
-						TileIndex tile2 = tile;
+						TileIndex tile2 = current_tile;
 						CircularTileSearch(&tile2, RIVER_OFFSET_DESERT_DISTANCE, RiverModifyDesertZone, nullptr);
 					}
 					break;
 
 				case WATER_CLASS_SEA:
-					if (TileHeight(tile) == 0) {
-						MakeSea(tile);
+					if (TileHeight(current_tile) == 0) {
+						MakeSea(current_tile);
 						break;
 					}
 					FALLTHROUGH;
 
 				default:
-					MakeCanal(tile, _current_company, Random());
+					MakeCanal(current_tile, _current_company, Random());
 					if (Company::IsValidID(_current_company)) {
 						Company::Get(_current_company)->infrastructure.water++;
 						DirtyCompanyInfrastructureWindows(_current_company);
 					}
 					break;
 			}
-			MarkTileDirtyByTile(tile);
-			MarkCanalsAndRiversAroundDirty(tile);
-			CheckForDockingTile(tile);
+			MarkTileDirtyByTile(current_tile);
+			MarkCanalsAndRiversAroundDirty(current_tile);
+			CheckForDockingTile(current_tile);
 		}
 
 		cost.AddCost(_price[PR_BUILD_CANAL]);
@@ -1044,8 +1044,8 @@ static void FloodVehicles(TileIndex tile)
 
 	if (IsAirportTile(tile)) {
 		const Station *st = Station::GetByTile(tile);
-		for (TileIndex tile : st->airport) {
-			if (st->TileBelongsToAirport(tile)) FindVehicleOnPos(tile, &z, &FloodVehicleProc);
+		for (TileIndex airport_tile : st->airport) {
+			if (st->TileBelongsToAirport(airport_tile)) FindVehicleOnPos(airport_tile, &z, &FloodVehicleProc);
 		}
 
 		/* No vehicle could be flooded on this airport anymore */