Run codebase through IWYU and add a CI check. ~7-10% improvements to build times.

.github/workflows/iwyu.yml

@@ -0,0 +1,69 @@
+name: IWYU (include-what-you-use)
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+    types: [opened, reopened, synchronize, ready_for_review]
+    paths:
+      - 'src/**'
+      - 'tests/**'
+      - 'tools/iwyu/**'
+      - '**/CMakeLists.txt'
+      - '.github/workflows/iwyu.yml'
+
+# We only care about the latest revision of a PR, so cancel all previous instances.
+concurrency:
+  group: iwyu-${{ github.event.pull_request.number || github.ref_name }}
+  cancel-in-progress: true
+jobs:
+  run:
+    runs-on: ubuntu-24.04
+    env:
+        COMPILER: clang++-19
+    steps:
+    - name: install LLVM 19
+      if: ${{ needs.skip-duplicates.outputs.should_skip != 'true' && github.event_name != 'pull_request' || github.event.pull_request.draft == false }}
+      run: |
+          sudo apt install llvm-19 llvm-19-dev llvm-19-tools clang-19 clang-tidy-19 clang-tools-19 libclang-19-dev
+          sudo apt install python3-pip ninja-build cmake
+    - name: checkout IWYU repository
+      uses: actions/checkout@v4
+      with:
+        repository: include-what-you-use/include-what-you-use
+        path: include-what-you-use-src
+        ref: clang_19
+    - name: checkout own repository
+      uses: actions/checkout@v4
+      with:
+        path: Cataclysm-DDA
+    - name: build IWYU
+      id: build-iwyu
+      run: |
+        cmake -B iwyu-build -DCMAKE_PREFIX_PATH=/usr/lib/llvm-19 include-what-you-use-src
+        cmake --build iwyu-build --parallel 4
+        echo "IWYU_SRC_DIR=${PWD}/include-what-you-use-src">> "$GITHUB_OUTPUT"
+        echo "IWYU_BIN_DIR=${PWD}/iwyu-build/bin">> "$GITHUB_OUTPUT"
+    - uses: ammaraskar/gcc-problem-matcher@master
+    - name: create CDDA compilation database
+      run: |
+        cmake -B Cataclysm-DDA/build \
+            -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
+            -DCMAKE_CXX_COMPILER=$COMPILER \
+            -DCMAKE_BUILD_TYPE="Release" \
+            -DTILES=${TILES:-0} \
+            -DSOUND=${SOUND:-0} \
+            -DLOCALIZE=${LOCALIZE:-0} \
+            Cataclysm-DDA
+    - name: run the thing
+      env:
+        IWYU_SRC_DIR: ${{ steps.build-iwyu.outputs.IWYU_SRC_DIR }}
+        IWYU_BIN_DIR: ${{ steps.build-iwyu.outputs.IWYU_BIN_DIR }}
+      run: |
+        PATH="${PATH}:${IWYU_BIN_DIR}"
+
+        cd Cataclysm-DDA
+        FILES_LIST=$( find src/ tests/ -maxdepth 1 -name '*.cpp' | grep -v -f tools/iwyu/bad_files.txt | sort )
+        python ${IWYU_SRC_DIR}/iwyu_tool.py ${FILES_LIST} -p build --output-format clang --jobs 4  -- -Xiwyu "--mapping_file=${PWD}/tools/iwyu/cata.imp" -Xiwyu --cxx17ns -Xiwyu --comment_style=long -Xiwyu --max_line_length=1000 

src/achievement.cpp

@@ -1,7 +1,6 @@
 #include "achievement.h"
 
 #include <cstdlib>
-#include <set>
 #include <string>
 #include <tuple>
 #include <utility>
@@ -14,12 +13,9 @@
 #include "enums.h"
 #include "event.h"
 #include "event_statistics.h"
-#include "flexbuffer_json-inl.h"
 #include "flexbuffer_json.h"
 #include "generic_factory.h"
-#include "init.h"
 #include "json.h"
-#include "json_error.h"
 #include "past_achievements_info.h"
 #include "stats_tracker.h"
 #include "string_formatter.h"

src/achievement.h

@@ -23,15 +23,10 @@
 class JsonObject;
 class JsonOut;
 class achievements_tracker;
-struct achievement_requirement;
-template <typename E> struct enum_traits;
-
-namespace cata
-{
-class event;
-}  // namespace cata
 class requirement_watcher;
 class stats_tracker;
+struct achievement_requirement;
+template <typename E> struct enum_traits;
 
 enum class achievement_comparison : int {
     equal,

src/active_item_cache.cpp

@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <numeric>
+#include <string>
 #include <utility>
 
 #include "item.h"

src/active_item_cache.h

@@ -8,10 +8,11 @@
 #include <vector>
 
 #include "coordinates.h"
+#include "item_pocket.h"
+#include "point.h"
 #include "safe_reference.h"
 
 class item;
-class item_pocket;
 
 // A struct used to uniquely identify an item within a submap or vehicle.
 struct item_reference {

src/activity_actor.cpp

@@ -12,10 +12,7 @@
 #include <map>
 #include <optional>
 #include <set>
-#include <sstream>
 #include <string>
-#include <string_view>
-#include <type_traits>
 #include <unordered_set>
 #include <utility>
 #include <vector>
@@ -27,31 +24,29 @@
 #include "avatar.h"
 #include "avatar_action.h"
 #include "bodypart.h"
+#include "cached_options.h"
 #include "calendar.h"
-#include "cata_assert.h"
 #include "cata_utility.h"
 #include "character.h"
 #include "character_id.h"
 #include "clzones.h"
 #include "contents_change_handler.h"
 #include "coordinates.h"
 #include "craft_command.h"
-#include "crafting_gui.h"
 #include "creature.h"
 #include "creature_tracker.h"
 #include "debug.h"
+#include "enum_conversions.h"
 #include "enums.h"
 #include "event.h"
 #include "event_bus.h"
 #include "faction.h"
-#include "field_type.h"
 #include "fault.h"
+#include "field_type.h"
 #include "flag.h"
-#include "flexbuffer_json-inl.h"
 #include "flexbuffer_json.h"
 #include "game.h"
 #include "game_constants.h"
-#include "game_inventory.h"
 #include "gates.h"
 #include "gun_mode.h"
 #include "handle_liquid.h"
@@ -66,41 +61,39 @@
 #include "iuse.h"
 #include "iuse_actor.h"
 #include "json.h"
-#include "json_error.h"
-#include "line.h"
 #include "magic_enchantment.h"
 #include "map.h"
 #include "map_iterator.h"
+#include "map_scale_constants.h"
 #include "map_selector.h"
 #include "mapdata.h"
 #include "martialarts.h"
+#include "memory_fast.h"
 #include "messages.h"
 #include "monster.h"
-#include "morale_types.h"
 #include "mtype.h"
 #include "npc.h"
 #include "options.h"
 #include "output.h"
+#include "overmap_ui.h"
 #include "pickup.h"
 #include "pimpl.h"
 #include "player_activity.h"
 #include "pocket_type.h"
 #include "point.h"
 #include "ranged.h"
 #include "recipe.h"
-#include "recipe_dictionary.h"
 #include "requirements.h"
 #include "ret_val.h"
 #include "rng.h"
+#include "safe_reference.h"
 #include "shearing.h"
 #include "skill.h"
 #include "sounds.h"
 #include "string_formatter.h"
 #include "translation.h"
 #include "translations.h"
-#include "trap.h"
 #include "type_id.h"
-#include "try_parse_integer.h"
 #include "ui.h"
 #include "uistate.h"
 #include "units.h"

src/activity_handlers.cpp

@@ -40,6 +40,7 @@
 #include "creature_tracker.h"
 #include "cuboid_rectangle.h"
 #include "debug.h"
+#include "effect_on_condition.h"
 #include "enums.h"
 #include "event.h"
 #include "event_bus.h"

src/activity_handlers.h

@@ -8,7 +8,6 @@
 #include <map>
 #include <optional>
 #include <string>
-#include <unordered_set>
 #include <vector>
 
 #include "coords_fwd.h"

src/activity_item_handling.cpp

@@ -10,18 +10,18 @@
 #include <string>
 #include <tuple>
 #include <unordered_map>
+#include <unordered_set>
 #include <utility>
 #include <vector>
 
 #include "activity_actor_definitions.h"
-#include "activity_type.h"
 #include "avatar.h"
 #include "calendar.h"
 #include "cata_utility.h"
 #include "character.h"
 #include "clzones.h"
-#include "colony.h"
 #include "construction.h"
+#include "coordinates.h"
 #include "craft_command.h"
 #include "creature.h"
 #include "creature_tracker.h"
@@ -45,6 +45,7 @@
 #include "itype.h"
 #include "map.h"
 #include "map_iterator.h"
+#include "map_scale_constants.h"
 #include "map_selector.h"
 #include "mapdata.h"
 #include "messages.h"
@@ -183,9 +184,6 @@ struct act_item {
 };
 
 // TODO: Deliberately unified with multidrop. Unify further.
-using drop_location = std::pair<item_location, int>;
-using drop_locations = std::list<std::pair<item_location, int>>;
-
 static bool same_type( const std::list<item> &items )
 {
     return std::all_of( items.begin(), items.end(), [&items]( const item & it ) {

src/activity_type.cpp

@@ -10,10 +10,9 @@
 #include "activity_handlers.h"
 #include "assign.h"
 #include "debug.h"
-#include "flexbuffer_json-inl.h"
+#include "enums.h"
 #include "flexbuffer_json.h"
 #include "generic_factory.h"
-#include "json_error.h"
 #include "sounds.h"
 #include "string_formatter.h"
 #include "translations.h"

src/activity_type.h

@@ -5,7 +5,6 @@
 #include <set>
 #include <string>
 
-#include "enums.h"
 #include "game_constants.h"
 #include "translation.h"
 #include "type_id.h"
@@ -14,6 +13,7 @@ class Character;
 class JsonObject;
 class activity_type;
 class player_activity;
+enum class distraction_type : int;
 template <typename T> struct enum_traits;
 
 /** @relates string_id */

src/addiction.cpp

@@ -5,7 +5,6 @@
 #include <map>
 #include <memory>
 #include <optional>
-#include <set>
 #include <string>
 #include <utility>
 
@@ -16,11 +15,7 @@
 #include "dialogue.h"
 #include "effect_on_condition.h"
 #include "enums.h"
-#include "flexbuffer_json-inl.h"
-#include "flexbuffer_json.h"
 #include "generic_factory.h"
-#include "init.h"
-#include "json_error.h"
 #include "rng.h"
 #include "talker.h"
 #include "text_snippets.h"

src/advanced_inv_area.h

@@ -6,6 +6,7 @@
 #include <string>
 #include <vector>
 
+#include "coordinates.h"
 #include "item_location.h"
 #include "point.h"
 #include "units.h"

src/advanced_inv_pagination.cpp

@@ -1,8 +1,8 @@
 #include "advanced_inv_pagination.h"
 
-#include <memory>
 #include <vector>
 
+#include "advanced_inv_listitem.h"
 #include "advanced_inv_pane.h"
 
 class item_category;

src/ammo.cpp

@@ -5,10 +5,8 @@
 #include <utility>
 
 #include "debug.h"
-#include "flexbuffer_json-inl.h"
 #include "flexbuffer_json.h"
 #include "item.h"
-#include "json_error.h"
 #include "type_id.h"
 
 namespace

src/ammo_effect.cpp

@@ -1,12 +1,8 @@
 #include "ammo_effect.h"
 
-#include <set>
-
 #include "debug.h"
-#include "flexbuffer_json-inl.h"
 #include "flexbuffer_json.h"
 #include "generic_factory.h"
-#include "init.h"
 
 generic_factory<ammo_effect> &get_all_ammo_effects()
 {

src/anatomy.cpp

@@ -2,8 +2,6 @@
 
 #include <algorithm>
 #include <cmath>
-#include <map>
-#include <set>
 #include <string>
 #include <unordered_set>
 
@@ -12,11 +10,7 @@
 #include "creature.h"
 #include "debug.h"
 #include "flag.h"
-#include "flexbuffer_json-inl.h"
-#include "flexbuffer_json.h"
 #include "generic_factory.h"
-#include "init.h"
-#include "json_error.h"
 #include "messages.h"
 #include "output.h"
 #include "rng.h"

src/anatomy.h

@@ -12,7 +12,6 @@
 
 class Creature;
 class JsonObject;
-class anatomy;
 
 /**
  * A structure that contains body parts.