Merge pull request #592 from Phlosioneer/extern-cleanup

Extern cleanup

66 files changed, 159 insertions, 315 deletions

diff --git a/src/battle_anim_effects_2.c b/src/battle_anim_effects_2.c
index ee6676e64..80b3258b4 100755
--- a/src/battle_anim_effects_2.c
+++ b/src/battle_anim_effects_2.c
@@ -16,9 +16,6 @@
 #include "constants/rgb.h"
 #include "constants/songs.h"
 
-extern void sub_8108C94(struct Sprite *);
-extern void sub_810310C(u8, struct Sprite *);
-
 void sub_8103448(struct Sprite *);
 void sub_8103498(struct Sprite *);
 void sub_810358C(struct Sprite *);
diff --git a/src/battle_anim_effects_3.c b/src/battle_anim_effects_3.c
index 49fb69342..efa2620fd 100755
--- a/src/battle_anim_effects_3.c
+++ b/src/battle_anim_effects_3.c
@@ -24,9 +24,6 @@
 #include "constants/species.h"
 #include "constants/weather.h"
 
-extern u8 sub_807521C(s16 x, s16 y, u8 a3);
-extern void sub_810E2C8(struct Sprite *);
-
 extern const struct SpriteTemplate gUnknown_08593114;
 extern const union AffineAnimCmd *const gUnknown_082FF6C0[];
 extern const union AffineAnimCmd *const gUnknown_082FF694[];
diff --git a/src/battle_controller_link_opponent.c b/src/battle_controller_link_opponent.c
index 28ab4c279..23d469c27 100644
--- a/src/battle_controller_link_opponent.c
+++ b/src/battle_controller_link_opponent.c
@@ -27,13 +27,12 @@
 #include "constants/battle_anim.h"
 #include "constants/songs.h"
 #include "constants/trainers.h"
+#include "recorded_battle.h"
 
 extern struct MusicPlayerInfo gMPlayInfo_BGM;
 
 extern const struct CompressedSpritePalette gTrainerFrontPicPaletteTable[];
 
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-
 // this file's functions
 static void LinkOpponentHandleGetMonData(void);
 static void LinkOpponentHandleGetRawMonData(void);
diff --git a/src/battle_controller_link_partner.c b/src/battle_controller_link_partner.c
index 06a8d4a6a..22633c5bc 100644
--- a/src/battle_controller_link_partner.c
+++ b/src/battle_controller_link_partner.c
@@ -27,12 +27,11 @@
 #include "constants/battle_anim.h"
 #include "constants/songs.h"
 #include "constants/trainers.h"
+#include "recorded_battle.h"
 
 extern const struct CompressedSpritePalette gTrainerFrontPicPaletteTable[];
 extern const struct CompressedSpritePalette gTrainerBackPicPaletteTable[];
 
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-
 // this file's functions
 static void LinkPartnerHandleGetMonData(void);
 static void LinkPartnerHandleGetRawMonData(void);
diff --git a/src/battle_controller_opponent.c b/src/battle_controller_opponent.c
index cdb886e5d..7d940cb89 100644
--- a/src/battle_controller_opponent.c
+++ b/src/battle_controller_opponent.c
@@ -32,14 +32,12 @@
 #include "constants/moves.h"
 #include "constants/songs.h"
 #include "constants/trainers.h"
+#include "trainer_hill.h"
 
 extern struct MusicPlayerInfo gMPlayInfo_BGM;
 
 extern const struct CompressedSpritePalette gTrainerFrontPicPaletteTable[];
 
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-extern u8 GetTrainerHillTrainerFrontSpriteId(u16 trainerId);
-
 // this file's functions
 static void OpponentHandleGetMonData(void);
 static void OpponentHandleGetRawMonData(void);
diff --git a/src/battle_controller_player.c b/src/battle_controller_player.c
index a0d92f23a..b377ecf64 100644
--- a/src/battle_controller_player.c
+++ b/src/battle_controller_player.c
@@ -39,10 +39,6 @@ extern struct MusicPlayerInfo gMPlayInfo_BGM;
 extern const struct CompressedSpritePalette gTrainerFrontPicPaletteTable[];
 extern const struct CompressedSpritePalette gTrainerBackPicPaletteTable[];
 
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-extern void sub_81AABB0(void);
-extern void sub_81851A8(u8 *);
-
 // this file's functions
 static void PlayerHandleGetMonData(void);
 static void PlayerHandleSetMonData(void);
diff --git a/src/battle_controller_player_partner.c b/src/battle_controller_player_partner.c
index 787a4f77c..2c53938c1 100644
--- a/src/battle_controller_player_partner.c
+++ b/src/battle_controller_player_partner.c
@@ -30,9 +30,6 @@
 extern const struct CompressedSpritePalette gTrainerFrontPicPaletteTable[];
 extern const struct CompressedSpritePalette gTrainerBackPicPaletteTable[];
 
-extern void sub_81358F4(void);
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-
 // this file's functions
 static void PlayerPartnerHandleGetMonData(void);
 static void PlayerPartnerHandleGetRawMonData(void);
diff --git a/src/battle_controller_recorded_opponent.c b/src/battle_controller_recorded_opponent.c
index 79065c2e2..e43c5f8ae 100644
--- a/src/battle_controller_recorded_opponent.c
+++ b/src/battle_controller_recorded_opponent.c
@@ -33,8 +33,6 @@ extern struct MusicPlayerInfo gMPlayInfo_BGM;
 
 extern const struct CompressedSpritePalette gTrainerFrontPicPaletteTable[];
 
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-
 // this file's functions
 static void RecordedOpponentHandleGetMonData(void);
 static void RecordedOpponentHandleGetRawMonData(void);
diff --git a/src/battle_controller_recorded_player.c b/src/battle_controller_recorded_player.c
index e5e934761..412c49f17 100644
--- a/src/battle_controller_recorded_player.c
+++ b/src/battle_controller_recorded_player.c
@@ -30,8 +30,6 @@ extern struct MusicPlayerInfo gMPlayInfo_BGM;
 extern const struct CompressedSpritePalette gTrainerFrontPicPaletteTable[];
 extern const struct CompressedSpritePalette gTrainerBackPicPaletteTable[];
 
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-
 // this file's functions
 static void RecordedPlayerHandleGetMonData(void);
 static void RecordedPlayerHandleGetRawMonData(void);
diff --git a/src/battle_controller_safari.c b/src/battle_controller_safari.c
index 247f00627..e9da16252 100644
--- a/src/battle_controller_safari.c
+++ b/src/battle_controller_safari.c
@@ -25,8 +25,6 @@
 
 extern const struct CompressedSpritePalette gTrainerBackPicPaletteTable[];
 
-extern void sub_81358F4(void);
-
 // this file's functions
 static void SafariHandleGetMonData(void);
 static void SafariHandleGetRawMonData(void);
diff --git a/src/battle_controller_wally.c b/src/battle_controller_wally.c
index 7f4fe4761..f1b783b21 100644
--- a/src/battle_controller_wally.c
+++ b/src/battle_controller_wally.c
@@ -33,8 +33,6 @@
 
 extern const struct CompressedSpritePalette gTrainerBackPicPaletteTable[];
 
-extern void sub_8172EF0(u8 battlerId, struct Pokemon *mon);
-
 // this file's functions
 static void WallyHandleGetMonData(void);
 static void WallyHandleGetRawMonData(void);
diff --git a/src/battle_main.c b/src/battle_main.c
index 853dafe01..2b0c5980e 100644
--- a/src/battle_main.c
+++ b/src/battle_main.c
@@ -57,6 +57,7 @@
 #include "constants/songs.h"
 #include "constants/species.h"
 #include "constants/trainers.h"
+#include "cable_club.h"
 
 extern struct MusicPlayerInfo gMPlayInfo_SE1;
 extern struct MusicPlayerInfo gMPlayInfo_SE2;
@@ -69,9 +70,6 @@ extern const u8 *const gBattlescriptsForRunningByItem[];
 extern const u8 *const gBattlescriptsForUsingItem[];
 extern const u8 *const gBattlescriptsForSafariActions[];
 
-// functions
-extern void sub_80B3AF8(u8 taskId); // cable club
-
 // this file's functions
 static void CB2_InitBattleInternal(void);
 static void CB2_PreInitMultiBattle(void);
diff --git a/src/battle_records.c b/src/battle_records.c
index 6997e40dd..fdd915d07 100644
--- a/src/battle_records.c
+++ b/src/battle_records.c
@@ -21,8 +21,7 @@
 #include "alloc.h"
 #include "gpu_regs.h"
 #include "constants/game_stat.h"
-
-extern void PrintOnTrainerHillRecordsWindow(void); // pokenav.s
+#include "trainer_hill.h"
 
 // this file's functions
 static void Task_CloseTrainerHillRecordsOnButton(u8 taskId);
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index 620366b52..ac9fb3073 100644
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -48,6 +48,7 @@
 #include "battle_pyramid.h"
 #include "field_specials.h"
 #include "pokemon_summary_screen.h"
+#include "pokenav.h"
 
 extern struct MusicPlayerInfo gMPlayInfo_BGM;
 
@@ -55,9 +56,6 @@ extern const u8* const gBattleScriptsForMoveEffects[];
 
 // functions
 extern void sub_81D388C(struct Pokemon* mon, void* statStoreLocation); // pokenav.s
-extern void sub_81D3640(u16 arg0, void* statStoreLocation1, void* statStoreLocation2, u8 arg3, u8 arg4, u8 arg5); // pokenav.s
-extern void sub_81D3784(u16 arg0, void* statStoreLocation1, u8 arg2, u8 arg3, u8 arg4); // pokenav.s
-extern u8 sub_813B21C(void);
 
 #define DEFENDER_IS_PROTECTED ((gProtectStructs[gBattlerTarget].protected) && (gBattleMoves[gCurrentMove].flags & FLAG_PROTECT_AFFECTED))
 
diff --git a/src/battle_setup.c b/src/battle_setup.c
index 40423697e..347486a0b 100644
--- a/src/battle_setup.c
+++ b/src/battle_setup.c
@@ -44,6 +44,7 @@
 #include "mirage_tower.h"
 #include "constants/map_types.h"
 #include "constants/battle_frontier.h"
+#include "field_screen_effect.h"
 
 enum
 {
@@ -62,10 +63,6 @@ struct TrainerBattleParameter
     u8 ptrType;
 };
 
-extern void ClearPoisonStepCounter(void);
-extern void sub_808BCF4(void);
-extern void sub_80AF6F0(void);
-
 // this file's functions
 static void DoBattlePikeWildBattle(void);
 static void DoSafariBattle(void);
diff --git a/src/berry.c b/src/berry.c
index bd596db7f..cbac06a3d 100644
--- a/src/berry.c
+++ b/src/berry.c
@@ -11,11 +11,9 @@
 #include "text.h"
 #include "constants/event_object_movement_constants.h"
 #include "constants/items.h"
+#include "event_object_movement.h"
+
 
-extern u8 EventObjectGetBerryTreeId(u8 eventObjectId);
-extern void sub_8092EF0(u8 mapId, u8 mapNumber, u8 mapGroup);
-extern void CB2_ChooseBerry(void);
-extern bool8 IsBerryTreeSparkling(u8, u8, u8);
 
 extern const u8 BerryTreeScript[];
 
diff --git a/src/berry_blender.c b/src/berry_blender.c
index 8d852819b..450bcae42 100644
--- a/src/berry_blender.c
+++ b/src/berry_blender.c
@@ -142,9 +142,6 @@ extern const u8 gText_Space[];
 extern const u8 gText_BlenderMaxSpeedRecord[];
 extern const u8 gText_234Players[];
 
-extern void sub_81AABF0(void (*callback)(void));
-extern void sub_800B4C0(void);
-
 // this file's functions
 static void BerryBlender_SetBackgroundsPos(void);
 static void sub_8080EA4(u8 taskId);
diff --git a/src/bike.c b/src/bike.c
index 1e91baab0..530742bdf 100644
--- a/src/bike.c
+++ b/src/bike.c
@@ -14,12 +14,6 @@
 extern bool8 gBikeCyclingChallenge;
 extern u8 gBikeCollisions;
 
-extern u8 sub_808B980(u8 direction);
-extern u8 sub_808B9BC(u8 direction);
-extern u8 sub_808B9A4(u8 direction);
-extern u8 sub_808C1B4(u8 direction);
-extern u8 sub_808B9D4(u8 direction);
-
 // this file's functions
 static void MovePlayerOnMachBike(u8, u16, u16);
 static u8 GetMachBikeTransition(u8 *);
diff --git a/src/contest.c b/src/contest.c
index e9353596b..114a1fb69 100644
--- a/src/contest.c
+++ b/src/contest.c
@@ -45,8 +45,6 @@
 #include "constants/rgb.h"
 #include "contest_ai.h"
 
-extern void sub_80FC9F8(u8); // contest_link_80FC4F4.c
-
 // This file's functions.
 static void sub_80D782C(void);
 static void sub_80D7C7C(u8 taskId);
diff --git a/src/contest_link_80F57C4.c b/src/contest_link_80F57C4.c
index b2ce52757..a4b88c074 100644
--- a/src/contest_link_80F57C4.c
+++ b/src/contest_link_80F57C4.c
@@ -39,6 +39,7 @@
 #include "constants/rgb.h"
 #include "constants/songs.h"
 #include "constants/vars.h"
+#include "contest.h"
 
 struct ContestLinkUnk0
 {
@@ -99,8 +100,6 @@ extern const struct SpriteSheet gUnknown_0858D810[];
 extern const struct SpritePalette gUnknown_0858D850;
 extern const struct SpriteTemplate gSpriteTemplate_858D860;
 
-extern void sub_81D9DE4(u8);
-
 static void sub_80F6A9C(void);
 static void sub_80F71C8(void);
 u8 sub_80F7310(u8, u8);
diff --git a/src/dewford_trend.c b/src/dewford_trend.c
index cad5ef9c2..ee310af04 100644
--- a/src/dewford_trend.c
+++ b/src/dewford_trend.c
@@ -159,7 +159,7 @@ static void sub_8122804(struct EasyChatPair *s, u16 b, u8 c)
     }
 }
 
-void ReceiveEasyChatPairsData(void *a, u32 b, u8 unused)
+void ReceiveEasyChatPairsData(struct EasyChatPair *a, size_t size, u8 unused)
 {
     u16 i, j, r3, players;
     struct EasyChatPair *buffer1, *buffer2, *src, *dst, *foo_of_buffer2;
@@ -176,7 +176,7 @@ void ReceiveEasyChatPairsData(void *a, u32 b, u8 unused)
         {
             players = GetLinkPlayerCount();
             for (i = 0; i < players; i++)
-                memcpy(&(buffer1[i * 5]), (u8 *)a + i * b, 40);
+                memcpy(&(buffer1[i * 5]), (u8 *)a + i * size, 40);
             src = buffer1;
             dst = buffer2;
             r3 = 0;
diff --git a/src/diploma.c b/src/diploma.c
index 716495034..2113b09ed 100644
--- a/src/diploma.c
+++ b/src/diploma.c
@@ -13,8 +13,7 @@
 #include "text.h"
 #include "overworld.h"
 #include "menu.h"
-
-extern bool16 sub_80C0944(void);
+#include "pokedex.h"
 
 extern const u8 gText_DexNational[];
 extern const u8 gText_DexHoenn[];
diff --git a/src/electric.c b/src/electric.c
index 142a9ca09..5e7729842 100644
--- a/src/electric.c
+++ b/src/electric.c
@@ -5,9 +5,6 @@
 #include "constants/songs.h"
 #include "sound.h"
 
-extern void sub_810E2C8(struct Sprite *);
-extern void TranslateAnimSpriteToTargetMonLocation(struct Sprite *);
-
 static void sub_810A1A8(struct Sprite *);
 static void sub_810A1F8(struct Sprite *);
 static void sub_810A214(struct Sprite *);
diff --git a/src/field_control_avatar.c b/src/field_control_avatar.c
index 8a7076591..680191bb3 100644
--- a/src/field_control_avatar.c
+++ b/src/field_control_avatar.c
@@ -32,8 +32,7 @@
 #include "constants/map_types.h"
 #include "constants/maps.h"
 #include "constants/songs.h"
-
-extern bool32 TryStartMatchCall(void);
+#include "match_call.h"
 
 static EWRAM_DATA u8 sWildEncounterImmunitySteps = 0;
 static EWRAM_DATA u16 sPreviousPlayerMetatileBehavior = 0;
diff --git a/src/field_effect.c b/src/field_effect.c
index 158d4dead..ee9dcb987 100644
--- a/src/field_effect.c
+++ b/src/field_effect.c
@@ -240,12 +240,6 @@ static IWRAM_DATA u8 sActiveList[32];
 
 extern u8 *gFieldEffectScriptPointers[];
 extern const struct SpriteTemplate *const gFieldEffectObjectTemplatePointers[];
-extern void sub_81555D8(u8, u8);
-extern void pal_fill_for_maplights(void);
-extern void sub_80E1558(u8);
-extern void sub_80E1570(void);
-extern bool8 sub_80E1584(void);
-extern void WarpFadeScreen(void);
 
 // .rodata
 const u32 gNewGameBirchPic[] = INCBIN_U32("graphics/birch_speech/birch.4bpp");
diff --git a/src/field_message_box.c b/src/field_message_box.c
index ac5e7a4bb..1c554b6c6 100755
--- a/src/field_message_box.c
+++ b/src/field_message_box.c
@@ -4,9 +4,7 @@
 #include "string_util.h"
 #include "task.h"
 #include "text.h"
-
-extern bool32 IsMatchCallTaskActive(void);
-extern void StartMatchCallFromScript(u8*);
+#include "match_call.h"
 
 static EWRAM_DATA u8 sFieldMessageBoxMode = 0;
 
diff --git a/src/field_player_avatar.c b/src/field_player_avatar.c
index 96e679dd7..a070fe0e1 100644
--- a/src/field_player_avatar.c
+++ b/src/field_player_avatar.c
@@ -2125,7 +2125,7 @@ void sub_808D194(void)
     sub_808D1FC(CreateTask(sub_808D1FC, 0));
 }
 
-bool8 sub_808D1B4(void)
+bool32 sub_808D1B4(void)
 {
     return FuncIsActiveTask(sub_808D1FC);
 }
@@ -2135,7 +2135,7 @@ void sub_808D1C8(void)
     sub_808D094(CreateTask(sub_808D094, 0));
 }
 
-bool8 sub_808D1E8(void)
+bool32 sub_808D1E8(void)
 {
     return FuncIsActiveTask(sub_808D094);
 }
diff --git a/src/field_screen_effect.c b/src/field_screen_effect.c
index e7476dea3..b6dcf212c 100644
--- a/src/field_screen_effect.c
+++ b/src/field_screen_effect.c
@@ -10,7 +10,6 @@
 #include "field_screen_effect.h"
 #include "field_special_scene.h"
 #include "field_weather.h"
-// #include "fldeff_flash.h"
 #include "gpu_regs.h"
 #include "link.h"
 #include "link_rfu.h"
@@ -31,22 +30,9 @@
 #include "constants/event_object_movement_constants.h"
 #include "constants/songs.h"
 #include "constants/rgb.h"
-
-extern bool32 sub_81D6534(void);
-extern bool8 walkrun_is_standing_still(void);
-extern void ScriptUnfreezeEventObjects(void);
-extern void sub_80FB768(void);
-extern void sub_808D194(void);
-extern void sub_808D1C8(void);
-extern bool32 sub_808D1B4(void);
-extern bool32 sub_808D1E8(void);
-extern void sub_80B6B68(void);
-extern void sub_80B6E4C(u8, u8);
-extern void sub_80B75D8(u8);
-extern void sub_80B7A74(u8);
-extern void sub_808C0A8(u8);
-extern u8 GetMapPairFadeToType(u8, u8);
-extern u8 GetMapPairFadeFromType(u8, u8);
+#include "trainer_hill.h"
+#include "event_obj_lock.h"
+#include "fldeff.h"
 
 extern const u16 gUnknown_82EC7CC[];
 
diff --git a/src/field_specials.c b/src/field_specials.c
index a6e0ef746..436b06f53 100644
--- a/src/field_specials.c
+++ b/src/field_specials.c
@@ -55,6 +55,7 @@
 #include "constants/vars.h"
 #include "constants/battle_frontier.h"
 #include "constants/weather.h"
+#include "palette.h"
 
 EWRAM_DATA bool8 gBikeCyclingChallenge = FALSE;
 EWRAM_DATA u8 gBikeCollisions = 0;
@@ -80,9 +81,6 @@ extern const u16 gEventObjectPalette17[];
 extern const u16 gEventObjectPalette33[];
 extern const u16 gEventObjectPalette34[];
 
-extern void LoadPalette(const void *src, u32 offset, u16 size); // incorrect signature, needed to match
-extern void BlendPalettes(u32, u8, u16);
-extern void FieldInitRegionMap(MainCallback callback);
 
 void UpdateMovedLilycoveFanClubMembers(void);
 void sub_813BF60(void);
@@ -591,7 +589,9 @@ void SpawnLinkPartnerEventObject(void)
 
 static void LoadLinkPartnerEventObjectSpritePalette(u8 graphicsId, u8 localEventId, u8 paletteNum)
 {
-    paletteNum += 6;
+    u8 adjustedPaletteNum;
+    // Note: This temp var is necessary; paletteNum += 6 doesn't match.
+    adjustedPaletteNum = paletteNum + 6;
     if (graphicsId == EVENT_OBJ_GFX_LINK_RS_BRENDAN ||
         graphicsId == EVENT_OBJ_GFX_LINK_RS_MAY ||
         graphicsId == EVENT_OBJ_GFX_RIVAL_BRENDAN_NORMAL ||
@@ -602,21 +602,21 @@ static void LoadLinkPartnerEventObjectSpritePalette(u8 graphicsId, u8 localEvent
         {
             u8 spriteId = gEventObjects[obj].spriteId;
             struct Sprite *sprite = &gSprites[spriteId];
-            sprite->oam.paletteNum = paletteNum;
+            sprite->oam.paletteNum = adjustedPaletteNum;
 
             switch (graphicsId)
             {
                 case EVENT_OBJ_GFX_LINK_RS_BRENDAN:
-                    LoadPalette(gEventObjectPalette33, 0x100 + paletteNum * 16, 0x20);
+                    LoadPalette(gEventObjectPalette33, 0x100 + (adjustedPaletteNum << 4), 0x20);
                     break;
                 case EVENT_OBJ_GFX_LINK_RS_MAY:
-                    LoadPalette(gEventObjectPalette34, 0x100 + paletteNum * 16, 0x20);
+                    LoadPalette(gEventObjectPalette34, 0x100 + (adjustedPaletteNum << 4), 0x20);
                     break;
                 case EVENT_OBJ_GFX_RIVAL_BRENDAN_NORMAL:
-                    LoadPalette(gEventObjectPalette8, 0x100 + paletteNum * 16, 0x20);
+                    LoadPalette(gEventObjectPalette8, 0x100 + (adjustedPaletteNum << 4), 0x20);
                     break;
                 case EVENT_OBJ_GFX_RIVAL_MAY_NORMAL:
-                    LoadPalette(gEventObjectPalette17, 0x100 + paletteNum * 16, 0x20);
+                    LoadPalette(gEventObjectPalette17, 0x100 + (adjustedPaletteNum << 4), 0x20);
                     break;
             }
         }
@@ -3379,7 +3379,7 @@ u16 get_unknown_box_id(void)
     return gUnknown_0203AB6F;
 }
 
-bool32 sub_813B21C(void)
+bool8 sub_813B21C(void)
 {
     if (FlagGet(FLAG_SYS_STORAGE_UNKNOWN_FLAG) == FALSE)
     {
diff --git a/src/fldeff_cut.c b/src/fldeff_cut.c
index 348a1f46c..a715608c5 100644
--- a/src/fldeff_cut.c
+++ b/src/fldeff_cut.c
@@ -20,7 +20,6 @@
 #include "constants/field_effects.h"
 #include "constants/songs.h"
 
-extern void ScriptUnfreezeEventObjects(void);
 extern bool8 IsMewPlayingHideAndSeek(void);
 
 extern struct MapPosition gPlayerFacingPosition;
diff --git a/src/frontier_util.c b/src/frontier_util.c
index 0c68bf119..bce7b926f 100644
--- a/src/frontier_util.c
+++ b/src/frontier_util.c
@@ -35,8 +35,7 @@
 #include "constants/moves.h"
 #include "constants/items.h"
 #include "constants/event_objects.h"
-
-extern u8 gSelectedOrderFromParty[];
+#include "party_menu.h"
 
 struct FrontierBrainMon
 {
@@ -48,8 +47,6 @@ struct FrontierBrainMon
     u16 moves[4];
 };
 
-extern void sub_81B8558(void);
-
 // This file's functions.
 static void sub_81A17A0(void);
 static void sub_81A1830(void);
diff --git a/src/hall_of_fame.c b/src/hall_of_fame.c
index 53577e166..2c31dba01 100644
--- a/src/hall_of_fame.c
+++ b/src/hall_of_fame.c
@@ -66,8 +66,6 @@ extern struct MusicPlayerInfo gMPlayInfo_BGM;
 
 #define HALL_OF_FAME_MAX_TEAMS 50
 
-extern void ReturnFromHallOfFamePC(void);
-
 // this file's functions
 static void ClearVramOamPltt_LoadHofPal(void);
 static void sub_8174F70(void);
diff --git a/src/hof_pc.c b/src/hof_pc.c
index 2cea5540a..d76f04372 100644
--- a/src/hof_pc.c
+++ b/src/hof_pc.c
@@ -7,10 +7,6 @@
 #include "script_menu.h"
 #include "task.h"
 
-extern void Overworld_PlaySpecialMapMusic(void);
-extern bool16 ScrSpecial_CreatePCMenu(void);
-extern void ScriptMenu_DisplayPCStartupPrompt(void);
-
 static void ReshowPCMenuAfterHallOfFamePC(void);
 static void Task_WaitForPaletteFade(u8);
 
diff --git a/src/ice.c b/src/ice.c
index 34ad572e8..fa1913b96 100644
--- a/src/ice.c
+++ b/src/ice.c
@@ -21,30 +21,29 @@ struct HailStruct {
 };
 
 static void sub_810B6C4(struct Sprite *);
-extern void sub_810B848(struct Sprite *);
-extern void AnimIcePunchSwirlingParticle(struct Sprite *);
-extern void AnimIceBeamParticle(struct Sprite *);
-extern void AnimIceEffectParticle(struct Sprite *);
-extern void AnimFlickerIceEffectParticle(struct Sprite *);
-extern void AnimSwirlingSnowball_Step1(struct Sprite *);
-extern void AnimSwirlingSnowball_Step2(struct Sprite *);
-extern void AnimSwirlingSnowball_Step3(struct Sprite *);
-extern void AnimSwirlingSnowball_End(struct Sprite *);
-extern void AnimMoveParticleBeyondTarget(struct Sprite *);
-extern void AnimWiggleParticleTowardsTarget(struct Sprite *);
-extern void AnimWaveFromCenterOfTarget(struct Sprite *);
-extern void InitSwirlingFogAnim(struct Sprite *);
-extern void AnimSwirlingFogAnim(struct Sprite *);
-extern void AnimThrowMistBall(struct Sprite *);
-extern void InitPoisonGasCloudAnim(struct Sprite *);
-extern void MovePoisonGasCloud(struct Sprite *);
-extern void AnimHailBegin(struct Sprite *);
-extern void AnimHailContinue(struct Sprite *);
-extern void sub_80A8EE4(struct Sprite *);
-extern void InitIceBallAnim(struct Sprite *);
-extern void AnimThrowIceBall(struct Sprite *);
-extern void InitIceBallParticle(struct Sprite *);
-extern void AnimIceBallParticle(struct Sprite *);
+void sub_810B848(struct Sprite *);
+void AnimIcePunchSwirlingParticle(struct Sprite *);
+void AnimIceBeamParticle(struct Sprite *);
+void AnimIceEffectParticle(struct Sprite *);
+void AnimFlickerIceEffectParticle(struct Sprite *);
+void AnimSwirlingSnowball_Step1(struct Sprite *);
+void AnimSwirlingSnowball_Step2(struct Sprite *);
+void AnimSwirlingSnowball_Step3(struct Sprite *);
+void AnimSwirlingSnowball_End(struct Sprite *);
+void AnimMoveParticleBeyondTarget(struct Sprite *);
+void AnimWiggleParticleTowardsTarget(struct Sprite *);
+void AnimWaveFromCenterOfTarget(struct Sprite *);
+void InitSwirlingFogAnim(struct Sprite *);
+void AnimSwirlingFogAnim(struct Sprite *);
+void AnimThrowMistBall(struct Sprite *);
+void InitPoisonGasCloudAnim(struct Sprite *);
+void MovePoisonGasCloud(struct Sprite *);
+void AnimHailBegin(struct Sprite *);
+void AnimHailContinue(struct Sprite *);
+void InitIceBallAnim(struct Sprite *);
+void AnimThrowIceBall(struct Sprite *);
+void InitIceBallParticle(struct Sprite *);
+void AnimIceBallParticle(struct Sprite *);
 void AnimTask_Haze2(u8);
 void AnimTask_OverlayFogTiles(u8);
 void AnimTask_Hail2(u8);
diff --git a/src/item_menu.c b/src/item_menu.c
index 5b9946e62..5738757bd 100755
--- a/src/item_menu.c
+++ b/src/item_menu.c
@@ -141,7 +141,6 @@ void unknown_ItemMenu_Confirm2(u8 taskId);
 void unknown_item_menu_type(u8 taskId);
 void item_menu_type_2(u8 taskId);
 void display_sell_item_ask_str(u8 taskId);
-void unknown_ItemMenu_Confirm(u8 taskId);
 void display_deposit_item_ask_str(u8 taskId);
 void item_menu_type_b(u8 taskId);
 void BagMenuActuallyToss(u8 taskId);
@@ -476,7 +475,7 @@ void CB2_ChooseBerry(void)
     GoToBagMenu(RETURN_LOCATION_FIELD_2, BERRIES_POCKET, CB2_ReturnToFieldContinueScript);
 }
 
-void sub_81AABF0(void(*callback)(void))
+void sub_81AABF0(void (*callback)(void))
 {
     GoToBagMenu(RETURN_LOCATION_FIELD_3, BERRIES_POCKET, callback);
 }
diff --git a/src/item_use.c b/src/item_use.c
index 2281cc198..e646a18ee 100755
--- a/src/item_use.c
+++ b/src/item_use.c
@@ -8,13 +8,15 @@
 #include "coins.h"
 #include "data2.h"
 #include "event_data.h"
-#include "fieldmap.h"
 #include "event_object_movement.h"
+#include "fieldmap.h"
+#include "field_effect.h"
 #include "field_player_avatar.h"
 #include "field_screen_effect.h"
 #include "field_weather.h"
 #include "item.h"
 #include "item_menu.h"
+#include "item_use.h"
 #include "mail.h"
 #include "main.h"
 #include "menu.h"
@@ -37,31 +39,15 @@
 #include "constants/items.h"
 #include "constants/songs.h"
 #include "constants/vars.h"
+#include "event_obj_lock.h"
 
-extern void unknown_ItemMenu_Confirm(u8 taskId);
-extern void sub_81C5B14(u8 taskId);
-extern void ScriptUnfreezeEventObjects(void);
-extern void ItemUseOutOfBattle_TMHM(u8 a);
-extern void ItemUseOutOfBattle_EvolutionStone(u8 b);
-extern bool8 IsPlayerFacingSurfableFishableWater(void);
-extern bool8 sub_81221AC(void);
 extern u8 Route102_EventScript_274482[];
 extern u8 Route102_EventScript_2744C0[];
 extern u8 BattleFrontier_OutsideEast_EventScript_242CFC[];
-extern int sub_80247BC(void);
-extern struct MapHeader* mapconnection_get_mapheader(struct MapConnection *connection);
-extern void SetUpItemUseCallback(u8 taskId);
-extern void ItemUseCB_Medicine(u8, TaskFunc);
-extern void bag_menu_yes_no(u8, u8, const struct YesNoFuncTable*);
-extern void sub_81C5924(void);
-extern void sub_81C59BC(void);
-extern void sub_81AB9A8(u8);
-extern void StartEscapeRopeFieldEffect(void);
-extern u8* sub_806CF78(u16);
-extern void sub_81B89F0(void);
-extern u8 GetItemEffectType(u16);
-extern struct MapConnection *sub_8088A8C(s16, s16);
 
+extern s32 sub_80247BC(void);
+
+void SetUpItemUseCallback(u8 taskId);
 void MapPostLoadHook_UseItem(void);
 void sub_80AF6D4(void);
 void Task_CallItemUseOnFieldCallback(u8 taskId);
@@ -404,12 +390,12 @@ bool8 sub_80FD6D4(const struct MapEvents *events, s16 x, s16 y)
 
 bool8 sub_80FD730(struct MapConnection *connection, int x, int y)
 {
-    struct MapHeader *mapHeader;
+    
     u16 localX, localY;
     u32 localOffset;
     s32 localLength;
 
-    mapHeader = mapconnection_get_mapheader(connection);
+    struct MapHeader const *const mapHeader = mapconnection_get_mapheader(connection);
 
     switch (connection->direction)
     {
diff --git a/src/link.c b/src/link.c
index a49ffaca8..525d50d7c 100644
--- a/src/link.c
+++ b/src/link.c
@@ -1893,7 +1893,7 @@ u32 GetLinkRecvQueueLength(void)
     return gLink.recvQueue.count;
 }
 
-bool8 sub_800B504(void)
+bool32 sub_800B504(void)
 {
     if (GetLinkRecvQueueLength() > 2)
     {
diff --git a/src/link_rfu.c b/src/link_rfu.c
index 8da6b166a..d80ff2ae9 100644
--- a/src/link_rfu.c
+++ b/src/link_rfu.c
@@ -17,9 +17,9 @@
 #include "text.h"
 #include "constants/species.h"
 #include "save.h"
+#include "rom_8011DC0.h"
 
 extern u16 gHeldKeyCodeToSend;
-extern void nullsub_89(u8 taskId);
 
 struct UnkRfuStruct_1 gUnknown_03004140;
 struct UnkRfuStruct_2 gUnknown_03005000;
diff --git a/src/load_save.c b/src/load_save.c
index 7d307ec1b..d6785254f 100644
--- a/src/load_save.c
+++ b/src/load_save.c
@@ -11,10 +11,10 @@
 #include "trainer_hill.h"
 #include "gba/flash_internal.h"
 #include "decoration_inventory.h"
+#include "agb_flash.h"
 
 static void ApplyNewEncryptionKeyToAllEncryptedData(u32 encryptionKey);
 
-extern bool16 IdentifyFlash(void);
 extern void ApplyNewEncryptionKeyToBerryPowder(u32 key);
 
 #define SAVEBLOCK_MOVE_RANGE    128
diff --git a/src/main.c b/src/main.c
index 3049f4f90..40381bb68 100644
--- a/src/main.c
+++ b/src/main.c
@@ -24,9 +24,6 @@
 #include "main.h"
 #include "trainer_hill.h"
 
-extern void sub_800B9B8(void);
-extern u8 gUnknown_03002748;
-
 static void VBlankIntr(void);
 static void HBlankIntr(void);
 static void VCountIntr(void);
@@ -313,8 +310,6 @@ void SetSerialCallback(IntrCallback callback)
     gMain.serialCallback = callback;
 }
 
-extern void CopyBufferedValuesToGpuRegs(void);
-
 static void VBlankIntr(void)
 {
     if (gWirelessCommType != 0)
diff --git a/src/match_call.c b/src/match_call.c
index cca55fcb6..641079ba9 100644
--- a/src/match_call.c
+++ b/src/match_call.c
@@ -111,8 +111,6 @@ static void PopulateSpeciesFromTrainerParty(int, u8 *);
 static void PopulateBattleFrontierFacilityName(int, u8 *);
 static void PopulateBattleFrontierStreak(int, u8 *);
 
-extern void sub_81973A4(void);
-
 #define TEXT_ID(topic, id) (((topic) << 8) | ((id) & 0xFF))
 
 static const struct MatchCallTrainerTextInfo sMatchCallTrainers[] =
diff --git a/src/menu.c b/src/menu.c
index 8cb7ac0b2..b04572b81 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -122,20 +122,18 @@ const struct MoveMenuInfoIcon gMoveMenuInfoIcons[] =
     {  8,  8, 0xAF },       // Unused (Small dark pokeball)
 };
 
+
 // Forward declarations
-extern void sub_81973A4(void);
-extern void WindowFunc_DrawStandardFrame(u8, u8, u8, u8, u8, u8);
-extern void WindowFunc_DrawDialogueFrame(u8, u8, u8, u8, u8, u8);
-extern void WindowFunc_ClearStdWindowAndFrame(u8, u8, u8, u8, u8, u8);
-extern void WindowFunc_ClearDialogWindowAndFrame(u8, u8, u8, u8, u8, u8);
-extern void WindowFunc_DrawDialogFrameWithCustomTileAndPalette(u8, u8, u8, u8, u8, u8);
-extern void WindowFunc_ClearDialogWindowAndFrameNullPalette(u8, u8, u8, u8, u8, u8);
-extern void WindowFunc_DrawStdFrameWithCustomTileAndPalette(u8, u8, u8, u8, u8, u8);
-extern void WindowFunc_ClearStdWindowAndFrameToTransparent(u8, u8, u8, u8, u8, u8);
-extern u8 Menu_MoveCursor(s8);
-extern u8 sub_8199134(s8, s8);
-extern void sub_8198C78(void);
-extern void task_free_buf_after_copying_tile_data_to_vram(u8 taskId);
+void WindowFunc_DrawStandardFrame(u8, u8, u8, u8, u8, u8);
+void WindowFunc_DrawDialogueFrame(u8, u8, u8, u8, u8, u8);
+void WindowFunc_ClearStdWindowAndFrame(u8, u8, u8, u8, u8, u8);
+void WindowFunc_ClearDialogWindowAndFrame(u8, u8, u8, u8, u8, u8);
+void WindowFunc_DrawDialogFrameWithCustomTileAndPalette(u8, u8, u8, u8, u8, u8);
+void WindowFunc_ClearDialogWindowAndFrameNullPalette(u8, u8, u8, u8, u8, u8);
+void WindowFunc_DrawStdFrameWithCustomTileAndPalette(u8, u8, u8, u8, u8, u8);
+void WindowFunc_ClearStdWindowAndFrameToTransparent(u8, u8, u8, u8, u8, u8);
+void sub_8198C78(void);
+void task_free_buf_after_copying_tile_data_to_vram(u8 taskId);
 
 void InitStandardTextBoxWindows(void)
 {
diff --git a/src/menu_helpers.c b/src/menu_helpers.c
index 25058abf9..3fb5ca40d 100644
--- a/src/menu_helpers.c
+++ b/src/menu_helpers.c
@@ -18,8 +18,6 @@
 #include "constants/items.h"
 #include "constants/maps.h"
 
-extern bool32 sub_800B504(void);
-
 // this file's functions
 static void Task_ContinueTaskAfterMessagePrints(u8 taskId);
 static void Task_CallYesOrNoCallback(u8 taskId);
diff --git a/src/mystery_event_script.c b/src/mystery_event_script.c
index 4196bb34c..dba914b51 100644
--- a/src/mystery_event_script.c
+++ b/src/mystery_event_script.c
@@ -17,8 +17,6 @@
 #include "mystery_event_msg.h"
 #include "pokemon_storage_system.h"
 
-extern void sub_811EFC0(u8);
-
 extern ScrCmdFunc gMysteryEventScriptCmdTable[];
 extern ScrCmdFunc gMysteryEventScriptCmdTableEnd[];
 
diff --git a/src/normal.c b/src/normal.c
index 87c8792f1..2b592e199 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -36,8 +36,6 @@ static void sub_81162F8(u8);
 static void sub_81163D0(struct Sprite *);
 static void sub_81165E4(struct Sprite *);
 
-extern void sub_810E2C8(struct Sprite *);
-
 const union AnimCmd gUnknown_0859722C[] =
 {
     ANIMCMD_FRAME(0, 8),
diff --git a/src/option_menu.c b/src/option_menu.c
index 1766f0bdb..2fc0d6f3e 100644
--- a/src/option_menu.c
+++ b/src/option_menu.c
@@ -13,8 +13,7 @@
 #include "text_window.h"
 #include "international_string_util.h"
 #include "strings.h"
-
-extern void SetPokemonCryStereo(u32 val);
+#include "gba/m4a_internal.h"
 
 // Task data
 enum
diff --git a/src/poison.c b/src/poison.c
index c86ec2cd8..9af981694 100644
--- a/src/poison.c
+++ b/src/poison.c
@@ -3,8 +3,6 @@
 #include "trig.h"
 #include "constants/rgb.h"
 
-extern void sub_80A77C8(struct Sprite *);
-
 void sub_810DBAC(struct Sprite *);
 void sub_810DC2C(struct Sprite *);
 void sub_810DCD0(struct Sprite *);
diff --git a/src/pokeblock_feed.c b/src/pokeblock_feed.c
index d72a9ffbe..da803f454 100644
--- a/src/pokeblock_feed.c
+++ b/src/pokeblock_feed.c
@@ -55,8 +55,6 @@ extern struct MusicPlayerInfo gMPlayInfo_BGM;
 extern const struct CompressedSpriteSheet gMonFrontPicTable[];
 extern const u16 gUnknown_0860F074[];
 
-extern bool8 sub_81221EC(void);
-
 // this file's functions
 static void HandleInitBackgrounds(void);
 static void HandleInitWindows(void);
diff --git a/src/pokemon.c b/src/pokemon.c
index a35033d49..a984abbb9 100644
--- a/src/pokemon.c
+++ b/src/pokemon.c
@@ -10,6 +10,7 @@
 #include "battle_tower.h"
 #include "event_data.h"
 #include "evolution_scene.h"
+#include "field_specials.h"
 #include "item.h"
 #include "link.h"
 #include "main.h"
@@ -72,10 +73,6 @@ extern const struct CompressedSpritePalette gMonPaletteTable[];
 extern const struct CompressedSpritePalette gMonShinyPaletteTable[];
 extern const u8 gTrainerClassNames[][13];
 
-extern u16 get_unknown_box_id(void);
-extern void set_unknown_box_id(u8);
-extern bool8 sub_806F104(void);
-
 // this file's functions
 static u16 CalculateBoxMonChecksum(struct BoxPokemon *boxMon);
 static union PokemonSubstruct *GetSubstruct(struct BoxPokemon *boxMon, u32 personality, u8 substructType);
diff --git a/src/pokemon_size_record.c b/src/pokemon_size_record.c
index b0e14d2b1..98d83d8ce 100644
--- a/src/pokemon_size_record.c
+++ b/src/pokemon_size_record.c
@@ -1,5 +1,6 @@
 #include "global.h"
 #include "event_data.h"
+#include "pokedex.h"
 #include "pokemon.h"
 #include "pokemon_size_record.h"
 #include "string_util.h"
@@ -15,9 +16,6 @@ struct UnknownStruct
     u16 unk4;
 };
 
-extern u16 GetPokedexHeightWeight(u16 dexNo, bool8 height);
-extern u16 SpeciesToNationalPokedexNum(u16 species);
-
 static const struct UnknownStruct sBigMonSizeTable[] =
 {
     {  290,   1,      0 },
diff --git a/src/pokenav.c b/src/pokenav.c
index 8eb82ffa5..42114a4b2 100644
--- a/src/pokenav.c
+++ b/src/pokenav.c
@@ -141,7 +141,7 @@ void sub_81C7710(void);
 static void InitKeys_(void);
 static void FreeVars(void);
 static void VblankCb_Pokenav(void);
-static void Cb2_Pokenav(void);
+static void CB2_Pokenav(void);
 void sub_81C7C28(void);
 void sub_81C72BC(void);
 void sub_81C7B74(void);
@@ -485,7 +485,7 @@ void sub_81C71E4(u8 taskId)
     }
 }
 
-void CB2_PokeNav(void)
+void CB2_InitPokeNav(void)
 {
     gUnknown_0203CF40 = Alloc(sizeof(*gUnknown_0203CF40));
     if (gUnknown_0203CF40 == NULL)
@@ -498,7 +498,7 @@ void CB2_PokeNav(void)
         ResetTasks();
         SetVBlankCallback(NULL);
         CreateTask(sub_81C742C, 0);
-        SetMainCallback2(Cb2_Pokenav);
+        SetMainCallback2(CB2_Pokenav);
         SetVBlankCallback(VblankCb_Pokenav);
     }
 }
@@ -529,7 +529,7 @@ void sub_81C72BC(void)
         FreeAllSpritePalettes();
         SetVBlankCallback(NULL);
         CreateTask(sub_81C742C, 0);
-        SetMainCallback2(Cb2_Pokenav);
+        SetMainCallback2(CB2_Pokenav);
         SetVBlankCallback(VblankCb_Pokenav);
     }
 }
@@ -588,7 +588,7 @@ static bool32 AnyMonHasRibbon(void)
     return FALSE;
 }
 
-static void Cb2_Pokenav(void)
+static void CB2_Pokenav(void)
 {
     RunTasks();
     AnimateSprites();
diff --git a/src/pokenav_match_call.c b/src/pokenav_match_call.c
index 53f9f0548..b775ed10e 100644
--- a/src/pokenav_match_call.c
+++ b/src/pokenav_match_call.c
@@ -1,13 +1,11 @@
-
-// Includes
 #include "global.h"
 #include "battle_setup.h"
 #include "event_data.h"
 #include "string_util.h"
 #include "battle.h"
 #include "gym_leader_rematch.h"
+#include "match_call.h"
 
-extern void sub_8197080(u8 *dest);
 extern const u8 gTrainerClassNames[][13];
 
 // Static type declarations
diff --git a/src/record_mixing.c b/src/record_mixing.c
index ad34bc432..3a16f817e 100644
--- a/src/record_mixing.c
+++ b/src/record_mixing.c
@@ -34,9 +34,8 @@
 #include "daycare.h"
 #include "international_string_util.h"
 #include "constants/battle_frontier.h"
+#include "dewford_trend.h"
 
-extern void ReceiveSecretBasesData(struct SecretBaseRecord *, size_t, u8);
-extern void ReceiveEasyChatPairsData(struct EasyChatPair *, size_t, u8);
 
 // Static type declarations
 
diff --git a/src/reshow_battle_screen.c b/src/reshow_battle_screen.c
index 0926d4569..dd177f884 100644
--- a/src/reshow_battle_screen.c
+++ b/src/reshow_battle_screen.c
@@ -2,6 +2,7 @@
 #include "reshow_battle_screen.h"
 #include "battle.h"
 #include "palette.h"
+#include "pokemon.h"
 #include "main.h"
 #include "scanline_effect.h"
 #include "text.h"
@@ -18,8 +19,6 @@
 
 extern const union AnimCmd * const * const gMonAnimationsSpriteAnimsPtrTable[];
 
-extern void SetMultiuseSpriteTemplateToTrainerBack(u16 backPicId, u8 battlerPosition);
-
 // this file's functions
 static void CB2_ReshowBattleScreenAfterMenu(void);
 static bool8 LoadBattlerSpriteGfx(u8 battlerId);
diff --git a/src/rock.c b/src/rock.c
index 14ffc63e0..814b1d88b 100644
--- a/src/rock.c
+++ b/src/rock.c
@@ -12,8 +12,6 @@
 extern const union AnimCmd *const gUnknown_085950E0[];
 extern const union AnimCmd *const gUnknown_085954D0[];
 
-extern void AnimMoveTwisterParticle(struct Sprite *);
-
 void sub_81109F0(struct Sprite *);
 void sub_8110AB4(struct Sprite *);
 void AnimDirtParticleAcrossScreen(struct Sprite *);
diff --git a/src/rom_8011DC0.c b/src/rom_8011DC0.c
index 64850d2e3..3d9eab8d7 100644
--- a/src/rom_8011DC0.c
+++ b/src/rom_8011DC0.c
@@ -33,8 +33,7 @@
 #include "start_menu.h"
 #include "data2.h"
 #include "field_screen_effect.h"
-
-extern void HealPlayerParty(void);
+#include "script_pokemon_util_80F87D8.h"
 
 struct UnkStruct_Shared
 {
diff --git a/src/safari_zone.c b/src/safari_zone.c
index accf94981..703c3d0cd 100644
--- a/src/safari_zone.c
+++ b/src/safari_zone.c
@@ -10,6 +10,7 @@
 #include "string_util.h"
 #include "tv.h"
 #include "constants/game_stat.h"
+#include "field_screen_effect.h"
 
 struct PokeblockFeeder
 {
@@ -27,8 +28,6 @@ extern const u8 EventScript_2A4B6F[];
 extern const u8 EventScript_2A4B4C[];
 extern const u8 EventScript_2A4B9B[];
 
-extern void sub_80AF6F0(void);
-
 EWRAM_DATA u8 gNumSafariBalls = 0;
 EWRAM_DATA static u16 sSafariZoneStepCounter = 0;
 EWRAM_DATA static u8 sSafariZoneCaughtMons = 0;
diff --git a/src/save.c b/src/save.c
index 4444e122c..361a88e1e 100644
--- a/src/save.c
+++ b/src/save.c
@@ -1,5 +1,7 @@
 #include "global.h"
+#include "agb_flash.h"
 #include "gba/flash_internal.h"
+#include "fieldmap.h"
 #include "save.h"
 #include "task.h"
 #include "decompress.h"
@@ -8,6 +10,7 @@
 #include "pokemon_storage_system.h"
 #include "main.h"
 #include "trainer_hill.h"
+#include "link.h"
 #include "constants/game_stat.h"
 
 static u16 CalculateChecksum(void *data, u16 size);
@@ -70,12 +73,6 @@ const struct SaveSectionOffsets gSaveSectionOffsets[] =
     SAVEBLOCK_CHUNK(gPokemonStorage, 8),
 };
 
-extern void DoSaveFailedScreen(u8); // save_failed_screen
-extern bool32 ProgramFlashSectorAndVerify(u8 sector, u8 *data);
-extern void save_serialize_map(void);
-extern void sub_800ADF8(void);
-extern bool8 IsLinkTaskFinished(void);
-
 // iwram common
 u16 gLastWrittenSector;
 u32 gLastSaveCounter;
diff --git a/src/script_menu.c b/src/script_menu.c
index afb1ef312..c7523a370 100644
--- a/src/script_menu.c
+++ b/src/script_menu.c
@@ -1312,7 +1312,7 @@ static void Task_HandleMultichoiceGridInput(u8 taskId)
 
 #undef tWindowId
 
-bool8 ScrSpecial_CreatePCMenu(void)
+bool16 ScrSpecial_CreatePCMenu(void)
 {
     if (FuncIsActiveTask(Task_HandleMultichoiceInput) == TRUE)
     {
diff --git a/src/secret_base.c b/src/secret_base.c
index 9147c19f9..4b270e424 100644
--- a/src/secret_base.c
+++ b/src/secret_base.c
@@ -43,8 +43,6 @@
 #include "constants/species.h"
 #include "constants/trainers.h"
 
-extern void mapldr_default(void);
-
 // Static type declarations
 
 struct SecretBaseListMenuBuffer {
diff --git a/src/start_menu.c b/src/start_menu.c
index f56e5e861..4822c12e6 100644
--- a/src/start_menu.c
+++ b/src/start_menu.c
@@ -1,44 +1,49 @@
 #include "global.h"
-#include "start_menu.h"
-#include "menu.h"
-#include "safari_zone.h"
-#include "event_data.h"
-#include "window.h"
-#include "string_util.h"
-#include "text.h"
-#include "strings.h"
+#include "battle_pike.h"
+#include "battle_pyramid.h"
+#include "battle_pyramid_bag.h"
 #include "bg.h"
+#include "event_data.h"
+#include "event_object_movement.h"
+#include "event_obj_lock.h"
+#include "event_scripts.h"
+#include "fieldmap.h"
 #include "field_effect.h"
-#include "party_menu.h"
-#include "frontier_pass.h"
-#include "task.h"
-#include "overworld.h"
-#include "link.h"
-#include "frontier_util.h"
+#include "field_player_avatar.h"
 #include "field_specials.h"
-#include "event_object_movement.h"
-#include "script.h"
-#include "main.h"
-#include "sound.h"
-#include "pokedex.h"
 #include "field_weather.h"
-#include "palette.h"
+#include "field_screen_effect.h"
+#include "frontier_pass.h"
+#include "frontier_util.h"
+#include "gpu_regs.h"
+#include "international_string_util.h"
 #include "item_menu.h"
+#include "link.h"
+#include "load_save.h"
+#include "main.h"
+#include "menu.h"
+#include "new_game.h"
 #include "option_menu.h"
-#include "event_scripts.h"
+#include "overworld.h"
+#include "palette.h"
+#include "party_menu.h"
+#include "pokedex.h"
+#include "pokenav.h"
+#include "safari_zone.h"
 #include "save.h"
-#include "gpu_regs.h"
 #include "scanline_effect.h"
+#include "script.h"
+#include "sound.h"
+#include "start_menu.h"
+#include "strings.h"
+#include "string_util.h"
+#include "task.h"
+#include "text.h"
 #include "text_window.h"
-#include "load_save.h"
 #include "trainer_card.h"
-#include "international_string_util.h"
+#include "window.h"
 #include "constants/songs.h"
-#include "field_player_avatar.h"
-#include "battle_pyramid.h"
-#include "battle_pyramid_bag.h"
-#include "battle_pike.h"
-#include "new_game.h"
+#include "rom_8011DC0.h"
 
 // Menu actions
 enum
@@ -83,19 +88,6 @@ EWRAM_DATA static u8 sSaveDialogTimer = 0;
 EWRAM_DATA static bool8 sSavingComplete = FALSE;
 EWRAM_DATA static u8 sSaveInfoWindowId = 0;
 
-// Extern variables.
-extern u8 gLocalLinkPlayerId;
-
-// Extern functions in not decompiled files.
-extern void sub_80AF688(void);
-extern void var_800D_set_xB(void);
-extern void sub_808B864(void);
-extern void CB2_Pokedex(void);
-extern void PlayRainStoppingSoundEffect(void);
-extern void CB2_PokeNav(void);
-extern void ScriptUnfreezeEventObjects(void);
-extern void save_serialize_map(void);
-
 // Menu action callbacks
 static bool8 StartMenuPokedexCallback(void);
 static bool8 StartMenuPokemonCallback(void);
@@ -656,7 +648,7 @@ static bool8 StartMenuPokeNavCallback(void)
         PlayRainStoppingSoundEffect();
         RemoveExtraStartMenuWindows();
         CleanupOverworldWindowsAndTilemaps();
-        SetMainCallback2(CB2_PokeNav);  // Display PokeNav
+        SetMainCallback2(CB2_InitPokeNav);  // Display PokeNav
 
         return TRUE;
     }
diff --git a/src/text.c b/src/text.c
index 2d286992d..be4bf2697 100644
--- a/src/text.c
+++ b/src/text.c
@@ -12,10 +12,6 @@
 #include "menu.h"
 #include "dynamic_placeholder_text_util.h"
 
-extern u8 GetKeypadIconWidth(u8 keypadIconId);
-extern u16 Font6Func(struct TextPrinter *textPrinter);
-extern u32 GetGlyphWidthFont6(u16 glyphId, bool32 isJapanese);
-
 EWRAM_DATA struct TextPrinter gTempTextPrinter = {0};
 EWRAM_DATA struct TextPrinter gTextPrinters[NUM_TEXT_PRINTERS] = {0};
 
diff --git a/src/trainer_card.c b/src/trainer_card.c
index cd8b34865..01839d598 100755
--- a/src/trainer_card.c
+++ b/src/trainer_card.c
@@ -21,6 +21,7 @@
 #include "gpu_regs.h"
 #include "international_string_util.h"
 #include "pokedex.h"
+#include "pokemon_icon.h"
 #include "graphics.h"
 #include "pokemon_icon.h"
 #include "trainer_pokemon_sprites.h"
@@ -89,9 +90,6 @@ struct TrainerCardData
     u8 language;
 };
 
-//external functions
-extern u8 sub_80D30A0(u16);
-
 // EWRAM
 EWRAM_DATA struct TrainerCard gTrainerCards[4] = {0};
 EWRAM_DATA static struct TrainerCardData *sData = NULL;
diff --git a/src/trainer_see.c b/src/trainer_see.c
index bc5d9cbc3..16ea88a45 100644
--- a/src/trainer_see.c
+++ b/src/trainer_see.c
@@ -17,8 +17,6 @@
 #include "constants/event_object_movement_constants.h"
 #include "constants/field_effects.h"
 
-extern void sub_809BE48(u16 npcId);
-
 // this file's functions
 static u8 CheckTrainer(u8 eventObjectId);
 static u8 GetTrainerApproachDistance(struct EventObject *trainerObj);
diff --git a/src/unk_text_util_2.c b/src/unk_text_util_2.c
index 03e049d72..02648bf93 100644
--- a/src/unk_text_util_2.c
+++ b/src/unk_text_util_2.c
@@ -214,7 +214,7 @@ static void DecompressGlyphFont6(u16 glyph)
     gUnknown_03002F90.unk81 = 0x10;
 }
 
-u8 GetGlyphWidthFont6(void)
+u32 GetGlyphWidthFont6(u16 glyphId, bool32 isJapanese)
 {
     return 0x10;
 }
diff --git a/src/water.c b/src/water.c
index d13b1378e..20bf2542d 100644
--- a/src/water.c
+++ b/src/water.c
@@ -13,35 +13,33 @@
 #include "constants/battle.h"
 #include "constants/rgb.h"
 
-extern void sub_810721C(struct Sprite *);
-extern void sub_8107228(struct Sprite *);
-extern void sub_8107260(struct Sprite *);
-extern void sub_8107380(struct Sprite *);
-extern void sub_8107408(struct Sprite *);
-extern void sub_8107430(struct Sprite *);
-extern void sub_810744C(struct Sprite *);
-extern void sub_81074E4(struct Sprite *);
-extern void sub_81075EC(struct Sprite *);
-extern void sub_8107674(struct Sprite *);
-extern void sub_8107730(struct Sprite *);
-extern void sub_81077A4(struct Sprite *);
-extern void sub_81077C0(struct Sprite *);
-extern void sub_80A78AC(struct Sprite *);
-extern void sub_8107894(struct Sprite *);
-extern void sub_81078D0(struct Sprite *);
-extern void sub_810790C(struct Sprite *);
-extern void sub_8108034(struct Sprite *);
-extern void sub_8108098(struct Sprite *);
-extern void sub_810851C(struct Sprite *);
-extern void sub_81087C0(struct Sprite *);
-extern void sub_810886C(struct Sprite *);
-extern void sub_8108B2C(struct Sprite *);
-extern void sub_8108B94(struct Sprite *);
-extern void sub_8108BE0(struct Sprite *);
-extern void sub_8108C08(struct Sprite *);
-extern void sub_8108C54(struct Sprite *);
-extern void sub_8108CDC(struct Sprite *);
-extern void sub_80A8EE4(struct Sprite *);
+void sub_810721C(struct Sprite *);
+void sub_8107228(struct Sprite *);
+void sub_8107260(struct Sprite *);
+void sub_8107380(struct Sprite *);
+void sub_8107408(struct Sprite *);
+void sub_8107430(struct Sprite *);
+void sub_810744C(struct Sprite *);
+void sub_81074E4(struct Sprite *);
+void sub_81075EC(struct Sprite *);
+void sub_8107674(struct Sprite *);
+void sub_8107730(struct Sprite *);
+void sub_81077A4(struct Sprite *);
+void sub_81077C0(struct Sprite *);
+void sub_8107894(struct Sprite *);
+void sub_81078D0(struct Sprite *);
+void sub_810790C(struct Sprite *);
+void sub_8108034(struct Sprite *);
+void sub_8108098(struct Sprite *);
+void sub_810851C(struct Sprite *);
+void sub_81087C0(struct Sprite *);
+void sub_810886C(struct Sprite *);
+void sub_8108B2C(struct Sprite *);
+void sub_8108B94(struct Sprite *);
+void sub_8108BE0(struct Sprite *);
+void sub_8108C08(struct Sprite *);
+void sub_8108C54(struct Sprite *);
+void sub_8108CDC(struct Sprite *);
 void sub_810756C(u8);
 void sub_81076F4(u8);
 void sub_8107B84(u8);