Merge branch 'dl/no-extern-in-func-decl'

Mechanically and systematically drop "extern" from function
declarlation.

* dl/no-extern-in-func-decl:
  *.[ch]: manually align parameter lists
  *.[ch]: remove extern from function declarations using sed
  *.[ch]: remove extern from function declarations using spatch

70 files changed, 1082 insertions, 1082 deletions

diff --git a/advice.h b/advice.h
index cb5d361614..e50f02cdfe 100644
--- a/advice.h
+++ b/advice.h
@@ -32,7 +32,7 @@ int git_default_advice_config(const char *var, const char *value);
 __attribute__((format (printf, 1, 2)))
 void advise(const char *advice, ...);
 int error_resolve_conflict(const char *me);
-extern void NORETURN die_resolve_conflict(const char *me);
+void NORETURN die_resolve_conflict(const char *me);
 void NORETURN die_conclude_merge(void);
 void detach_advice(const char *new_name);
 
diff --git a/archive.h b/archive.h
index dd022a6b46..e60e3dd31c 100644
--- a/archive.h
+++ b/archive.h
@@ -23,9 +23,9 @@ struct archiver_args {
 
 /* main api */
 
-extern int write_archive(int argc, const char **argv, const char *prefix,
-			 struct repository *repo,
-			 const char *name_hint, int remote);
+int write_archive(int argc, const char **argv, const char *prefix,
+		  struct repository *repo,
+		  const char *name_hint, int remote);
 
 const char *archive_format_from_filename(const char *filename);
 
@@ -39,21 +39,21 @@ struct archiver {
 	unsigned flags;
 	void *data;
 };
-extern void register_archiver(struct archiver *);
+void register_archiver(struct archiver *);
 
-extern void init_tar_archiver(void);
-extern void init_zip_archiver(void);
-extern void init_archivers(void);
+void init_tar_archiver(void);
+void init_zip_archiver(void);
+void init_archivers(void);
 
 typedef int (*write_archive_entry_fn_t)(struct archiver_args *args,
 					const struct object_id *oid,
 					const char *path, size_t pathlen,
 					unsigned int mode);
 
-extern int write_archive_entries(struct archiver_args *args, write_archive_entry_fn_t write_entry);
-extern void *object_file_to_archive(const struct archiver_args *args,
-				    const char *path, const struct object_id *oid,
-				    unsigned int mode, enum object_type *type,
-				    unsigned long *sizep);
+int write_archive_entries(struct archiver_args *args, write_archive_entry_fn_t write_entry);
+void *object_file_to_archive(const struct archiver_args *args,
+			     const char *path, const struct object_id *oid,
+			     unsigned int mode, enum object_type *type,
+			     unsigned long *sizep);
 
 #endif	/* ARCHIVE_H */
diff --git a/bisect.h b/bisect.h
index 821d16e4dd..4e69a11ea8 100644
--- a/bisect.h
+++ b/bisect.h
@@ -11,14 +11,14 @@ struct repository;
  * Otherwise, it will be either all non-SAMETREE commits or the single
  * best commit, as chosen by `find_all`.
  */
-extern void find_bisection(struct commit_list **list, int *reaches, int *all,
-			   int find_all);
+void find_bisection(struct commit_list **list, int *reaches, int *all,
+		    int find_all);
 
-extern struct commit_list *filter_skipped(struct commit_list *list,
-					  struct commit_list **tried,
-					  int show_all,
-					  int *count,
-					  int *skipped_first);
+struct commit_list *filter_skipped(struct commit_list *list,
+				   struct commit_list **tried,
+				   int show_all,
+				   int *count,
+				   int *skipped_first);
 
 #define BISECT_SHOW_ALL		(1<<0)
 #define REV_LIST_QUIET		(1<<1)
@@ -31,14 +31,14 @@ struct rev_list_info {
 	const char *header_prefix;
 };
 
-extern int bisect_next_all(struct repository *r,
-			   const char *prefix,
-			   int no_checkout);
+int bisect_next_all(struct repository *r,
+		    const char *prefix,
+		    int no_checkout);
 
-extern int estimate_bisect_steps(int all);
+int estimate_bisect_steps(int all);
 
-extern void read_bisect_terms(const char **bad, const char **good);
+void read_bisect_terms(const char **bad, const char **good);
 
-extern int bisect_clean_state(void);
+int bisect_clean_state(void);
 
 #endif
diff --git a/blame.h b/blame.h
index 2a285eb027..d62f80fa74 100644
--- a/blame.h
+++ b/blame.h
@@ -177,6 +177,6 @@ struct blame_entry *blame_entry_prepend(struct blame_entry *head,
 					long start, long end,
 					struct blame_origin *o);
 
-extern struct blame_origin *get_blame_suspects(struct commit *commit);
+struct blame_origin *get_blame_suspects(struct commit *commit);
 
 #endif /* BLAME_H */
diff --git a/branch.h b/branch.h
index 29c1afa4d0..6f38db14e9 100644
--- a/branch.h
+++ b/branch.h
@@ -50,7 +50,7 @@ void create_branch(struct repository *r,
  * Return 1 if the named branch already exists; return 0 otherwise.
  * Fill ref with the full refname for the branch.
  */
-extern int validate_branchname(const char *name, struct strbuf *ref);
+int validate_branchname(const char *name, struct strbuf *ref);
 
 /*
  * Check if a branch 'name' can be created as a new branch; die otherwise.
@@ -58,7 +58,7 @@ extern int validate_branchname(const char *name, struct strbuf *ref);
  * Return 1 if the named branch already exists; return 0 otherwise.
  * Fill ref with the full refname for the branch.
  */
-extern int validate_new_branchname(const char *name, struct strbuf *ref, int force);
+int validate_new_branchname(const char *name, struct strbuf *ref, int force);
 
 /*
  * Remove information about the state of working on the current
@@ -72,26 +72,26 @@ void remove_branch_state(struct repository *r);
  * Returns 0 on success.
  */
 #define BRANCH_CONFIG_VERBOSE 01
-extern int install_branch_config(int flag, const char *local, const char *origin, const char *remote);
+int install_branch_config(int flag, const char *local, const char *origin, const char *remote);
 
 /*
  * Read branch description
  */
-extern int read_branch_desc(struct strbuf *, const char *branch_name);
+int read_branch_desc(struct strbuf *, const char *branch_name);
 
 /*
  * Check if a branch is checked out in the main worktree or any linked
  * worktree and die (with a message describing its checkout location) if
  * it is.
  */
-extern void die_if_checked_out(const char *branch, int ignore_current_worktree);
+void die_if_checked_out(const char *branch, int ignore_current_worktree);
 
 /*
  * Update all per-worktree HEADs pointing at the old ref to point the new ref.
  * This will be used when renaming a branch. Returns 0 if successful, non-zero
  * otherwise.
  */
-extern int replace_each_worktree_head_symref(const char *oldref, const char *newref,
-					     const char *logmsg);
+int replace_each_worktree_head_symref(const char *oldref, const char *newref,
+				      const char *logmsg);
 
 #endif
diff --git a/builtin.h b/builtin.h
index ac552ff0d2..ec7e0954c4 100644
--- a/builtin.h
+++ b/builtin.h
@@ -102,7 +102,7 @@ extern const char git_more_info_string[];
 #define PRUNE_PACKED_DRY_RUN 01
 #define PRUNE_PACKED_VERBOSE 02
 
-extern void prune_packed_objects(int);
+void prune_packed_objects(int);
 
 struct fmt_merge_msg_opts {
 	unsigned add_title:1,
@@ -110,8 +110,8 @@ struct fmt_merge_msg_opts {
 	int shortlog_len;
 };
 
-extern int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
-			 struct fmt_merge_msg_opts *);
+int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
+		  struct fmt_merge_msg_opts *);
 
 /**
  * If a built-in has DELAY_PAGER_CONFIG set, the built-in should call this early
@@ -123,131 +123,131 @@ extern int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
  * You should most likely use a default of 0 or 1. "Punt" (-1) could be useful
  * to be able to fall back to some historical compatibility name.
  */
-extern void setup_auto_pager(const char *cmd, int def);
+void setup_auto_pager(const char *cmd, int def);
 
-extern int is_builtin(const char *s);
+int is_builtin(const char *s);
 
-extern int cmd_add(int argc, const char **argv, const char *prefix);
-extern int cmd_am(int argc, const char **argv, const char *prefix);
-extern int cmd_annotate(int argc, const char **argv, const char *prefix);
-extern int cmd_apply(int argc, const char **argv, const char *prefix);
-extern int cmd_archive(int argc, const char **argv, const char *prefix);
-extern int cmd_bisect__helper(int argc, const char **argv, const char *prefix);
-extern int cmd_blame(int argc, const char **argv, const char *prefix);
-extern int cmd_branch(int argc, const char **argv, const char *prefix);
-extern int cmd_bundle(int argc, const char **argv, const char *prefix);
-extern int cmd_cat_file(int argc, const char **argv, const char *prefix);
-extern int cmd_checkout(int argc, const char **argv, const char *prefix);
-extern int cmd_checkout_index(int argc, const char **argv, const char *prefix);
-extern int cmd_check_attr(int argc, const char **argv, const char *prefix);
-extern int cmd_check_ignore(int argc, const char **argv, const char *prefix);
-extern int cmd_check_mailmap(int argc, const char **argv, const char *prefix);
-extern int cmd_check_ref_format(int argc, const char **argv, const char *prefix);
-extern int cmd_cherry(int argc, const char **argv, const char *prefix);
-extern int cmd_cherry_pick(int argc, const char **argv, const char *prefix);
-extern int cmd_clone(int argc, const char **argv, const char *prefix);
-extern int cmd_clean(int argc, const char **argv, const char *prefix);
-extern int cmd_column(int argc, const char **argv, const char *prefix);
-extern int cmd_commit(int argc, const char **argv, const char *prefix);
-extern int cmd_commit_graph(int argc, const char **argv, const char *prefix);
-extern int cmd_commit_tree(int argc, const char **argv, const char *prefix);
-extern int cmd_config(int argc, const char **argv, const char *prefix);
-extern int cmd_count_objects(int argc, const char **argv, const char *prefix);
-extern int cmd_credential(int argc, const char **argv, const char *prefix);
-extern int cmd_describe(int argc, const char **argv, const char *prefix);
-extern int cmd_diff_files(int argc, const char **argv, const char *prefix);
-extern int cmd_diff_index(int argc, const char **argv, const char *prefix);
-extern int cmd_diff(int argc, const char **argv, const char *prefix);
-extern int cmd_diff_tree(int argc, const char **argv, const char *prefix);
-extern int cmd_difftool(int argc, const char **argv, const char *prefix);
-extern int cmd_fast_export(int argc, const char **argv, const char *prefix);
-extern int cmd_fetch(int argc, const char **argv, const char *prefix);
-extern int cmd_fetch_pack(int argc, const char **argv, const char *prefix);
-extern int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix);
-extern int cmd_for_each_ref(int argc, const char **argv, const char *prefix);
-extern int cmd_format_patch(int argc, const char **argv, const char *prefix);
-extern int cmd_fsck(int argc, const char **argv, const char *prefix);
-extern int cmd_gc(int argc, const char **argv, const char *prefix);
-extern int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix);
-extern int cmd_grep(int argc, const char **argv, const char *prefix);
-extern int cmd_hash_object(int argc, const char **argv, const char *prefix);
-extern int cmd_help(int argc, const char **argv, const char *prefix);
-extern int cmd_index_pack(int argc, const char **argv, const char *prefix);
-extern int cmd_init_db(int argc, const char **argv, const char *prefix);
-extern int cmd_interpret_trailers(int argc, const char **argv, const char *prefix);
-extern int cmd_log(int argc, const char **argv, const char *prefix);
-extern int cmd_log_reflog(int argc, const char **argv, const char *prefix);
-extern int cmd_ls_files(int argc, const char **argv, const char *prefix);
-extern int cmd_ls_tree(int argc, const char **argv, const char *prefix);
-extern int cmd_ls_remote(int argc, const char **argv, const char *prefix);
-extern int cmd_mailinfo(int argc, const char **argv, const char *prefix);
-extern int cmd_mailsplit(int argc, const char **argv, const char *prefix);
-extern int cmd_merge(int argc, const char **argv, const char *prefix);
-extern int cmd_merge_base(int argc, const char **argv, const char *prefix);
-extern int cmd_merge_index(int argc, const char **argv, const char *prefix);
-extern int cmd_merge_ours(int argc, const char **argv, const char *prefix);
-extern int cmd_merge_file(int argc, const char **argv, const char *prefix);
-extern int cmd_merge_recursive(int argc, const char **argv, const char *prefix);
-extern int cmd_merge_tree(int argc, const char **argv, const char *prefix);
-extern int cmd_mktag(int argc, const char **argv, const char *prefix);
-extern int cmd_mktree(int argc, const char **argv, const char *prefix);
-extern int cmd_multi_pack_index(int argc, const char **argv, const char *prefix);
-extern int cmd_mv(int argc, const char **argv, const char *prefix);
-extern int cmd_name_rev(int argc, const char **argv, const char *prefix);
-extern int cmd_notes(int argc, const char **argv, const char *prefix);
-extern int cmd_pack_objects(int argc, const char **argv, const char *prefix);
-extern int cmd_pack_redundant(int argc, const char **argv, const char *prefix);
-extern int cmd_patch_id(int argc, const char **argv, const char *prefix);
-extern int cmd_prune(int argc, const char **argv, const char *prefix);
-extern int cmd_prune_packed(int argc, const char **argv, const char *prefix);
-extern int cmd_pull(int argc, const char **argv, const char *prefix);
-extern int cmd_push(int argc, const char **argv, const char *prefix);
-extern int cmd_range_diff(int argc, const char **argv, const char *prefix);
-extern int cmd_read_tree(int argc, const char **argv, const char *prefix);
-extern int cmd_rebase(int argc, const char **argv, const char *prefix);
-extern int cmd_rebase__interactive(int argc, const char **argv, const char *prefix);
-extern int cmd_receive_pack(int argc, const char **argv, const char *prefix);
-extern int cmd_reflog(int argc, const char **argv, const char *prefix);
-extern int cmd_remote(int argc, const char **argv, const char *prefix);
-extern int cmd_remote_ext(int argc, const char **argv, const char *prefix);
-extern int cmd_remote_fd(int argc, const char **argv, const char *prefix);
-extern int cmd_repack(int argc, const char **argv, const char *prefix);
-extern int cmd_rerere(int argc, const char **argv, const char *prefix);
-extern int cmd_reset(int argc, const char **argv, const char *prefix);
-extern int cmd_rev_list(int argc, const char **argv, const char *prefix);
-extern int cmd_rev_parse(int argc, const char **argv, const char *prefix);
-extern int cmd_revert(int argc, const char **argv, const char *prefix);
-extern int cmd_rm(int argc, const char **argv, const char *prefix);
-extern int cmd_send_pack(int argc, const char **argv, const char *prefix);
-extern int cmd_shortlog(int argc, const char **argv, const char *prefix);
-extern int cmd_show(int argc, const char **argv, const char *prefix);
-extern int cmd_show_branch(int argc, const char **argv, const char *prefix);
-extern int cmd_show_index(int argc, const char **argv, const char *prefix);
-extern int cmd_status(int argc, const char **argv, const char *prefix);
-extern int cmd_stash(int argc, const char **argv, const char *prefix);
-extern int cmd_stripspace(int argc, const char **argv, const char *prefix);
-extern int cmd_submodule__helper(int argc, const char **argv, const char *prefix);
-extern int cmd_symbolic_ref(int argc, const char **argv, const char *prefix);
-extern int cmd_tag(int argc, const char **argv, const char *prefix);
-extern int cmd_tar_tree(int argc, const char **argv, const char *prefix);
-extern int cmd_unpack_file(int argc, const char **argv, const char *prefix);
-extern int cmd_unpack_objects(int argc, const char **argv, const char *prefix);
-extern int cmd_update_index(int argc, const char **argv, const char *prefix);
-extern int cmd_update_ref(int argc, const char **argv, const char *prefix);
-extern int cmd_update_server_info(int argc, const char **argv, const char *prefix);
-extern int cmd_upload_archive(int argc, const char **argv, const char *prefix);
-extern int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix);
-extern int cmd_upload_pack(int argc, const char **argv, const char *prefix);
-extern int cmd_var(int argc, const char **argv, const char *prefix);
-extern int cmd_verify_commit(int argc, const char **argv, const char *prefix);
-extern int cmd_verify_tag(int argc, const char **argv, const char *prefix);
-extern int cmd_version(int argc, const char **argv, const char *prefix);
-extern int cmd_whatchanged(int argc, const char **argv, const char *prefix);
-extern int cmd_worktree(int argc, const char **argv, const char *prefix);
-extern int cmd_write_tree(int argc, const char **argv, const char *prefix);
-extern int cmd_verify_pack(int argc, const char **argv, const char *prefix);
-extern int cmd_show_ref(int argc, const char **argv, const char *prefix);
-extern int cmd_pack_refs(int argc, const char **argv, const char *prefix);
-extern int cmd_replace(int argc, const char **argv, const char *prefix);
+int cmd_add(int argc, const char **argv, const char *prefix);
+int cmd_am(int argc, const char **argv, const char *prefix);
+int cmd_annotate(int argc, const char **argv, const char *prefix);
+int cmd_apply(int argc, const char **argv, const char *prefix);
+int cmd_archive(int argc, const char **argv, const char *prefix);
+int cmd_bisect__helper(int argc, const char **argv, const char *prefix);
+int cmd_blame(int argc, const char **argv, const char *prefix);
+int cmd_branch(int argc, const char **argv, const char *prefix);
+int cmd_bundle(int argc, const char **argv, const char *prefix);
+int cmd_cat_file(int argc, const char **argv, const char *prefix);
+int cmd_checkout(int argc, const char **argv, const char *prefix);
+int cmd_checkout_index(int argc, const char **argv, const char *prefix);
+int cmd_check_attr(int argc, const char **argv, const char *prefix);
+int cmd_check_ignore(int argc, const char **argv, const char *prefix);
+int cmd_check_mailmap(int argc, const char **argv, const char *prefix);
+int cmd_check_ref_format(int argc, const char **argv, const char *prefix);
+int cmd_cherry(int argc, const char **argv, const char *prefix);
+int cmd_cherry_pick(int argc, const char **argv, const char *prefix);
+int cmd_clone(int argc, const char **argv, const char *prefix);
+int cmd_clean(int argc, const char **argv, const char *prefix);
+int cmd_column(int argc, const char **argv, const char *prefix);
+int cmd_commit(int argc, const char **argv, const char *prefix);
+int cmd_commit_graph(int argc, const char **argv, const char *prefix);
+int cmd_commit_tree(int argc, const char **argv, const char *prefix);
+int cmd_config(int argc, const char **argv, const char *prefix);
+int cmd_count_objects(int argc, const char **argv, const char *prefix);
+int cmd_credential(int argc, const char **argv, const char *prefix);
+int cmd_describe(int argc, const char **argv, const char *prefix);
+int cmd_diff_files(int argc, const char **argv, const char *prefix);
+int cmd_diff_index(int argc, const char **argv, const char *prefix);
+int cmd_diff(int argc, const char **argv, const char *prefix);
+int cmd_diff_tree(int argc, const char **argv, const char *prefix);
+int cmd_difftool(int argc, const char **argv, const char *prefix);
+int cmd_fast_export(int argc, const char **argv, const char *prefix);
+int cmd_fetch(int argc, const char **argv, const char *prefix);
+int cmd_fetch_pack(int argc, const char **argv, const char *prefix);
+int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix);
+int cmd_for_each_ref(int argc, const char **argv, const char *prefix);
+int cmd_format_patch(int argc, const char **argv, const char *prefix);
+int cmd_fsck(int argc, const char **argv, const char *prefix);
+int cmd_gc(int argc, const char **argv, const char *prefix);
+int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix);
+int cmd_grep(int argc, const char **argv, const char *prefix);
+int cmd_hash_object(int argc, const char **argv, const char *prefix);
+int cmd_help(int argc, const char **argv, const char *prefix);
+int cmd_index_pack(int argc, const char **argv, const char *prefix);
+int cmd_init_db(int argc, const char **argv, const char *prefix);
+int cmd_interpret_trailers(int argc, const char **argv, const char *prefix);
+int cmd_log(int argc, const char **argv, const char *prefix);
+int cmd_log_reflog(int argc, const char **argv, const char *prefix);
+int cmd_ls_files(int argc, const char **argv, const char *prefix);
+int cmd_ls_tree(int argc, const char **argv, const char *prefix);
+int cmd_ls_remote(int argc, const char **argv, const char *prefix);
+int cmd_mailinfo(int argc, const char **argv, const char *prefix);
+int cmd_mailsplit(int argc, const char **argv, const char *prefix);
+int cmd_merge(int argc, const char **argv, const char *prefix);
+int cmd_merge_base(int argc, const char **argv, const char *prefix);
+int cmd_merge_index(int argc, const char **argv, const char *prefix);
+int cmd_merge_ours(int argc, const char **argv, const char *prefix);
+int cmd_merge_file(int argc, const char **argv, const char *prefix);
+int cmd_merge_recursive(int argc, const char **argv, const char *prefix);
+int cmd_merge_tree(int argc, const char **argv, const char *prefix);
+int cmd_mktag(int argc, const char **argv, const char *prefix);
+int cmd_mktree(int argc, const char **argv, const char *prefix);
+int cmd_multi_pack_index(int argc, const char **argv, const char *prefix);
+int cmd_mv(int argc, const char **argv, const char *prefix);
+int cmd_name_rev(int argc, const char **argv, const char *prefix);
+int cmd_notes(int argc, const char **argv, const char *prefix);
+int cmd_pack_objects(int argc, const char **argv, const char *prefix);
+int cmd_pack_redundant(int argc, const char **argv, const char *prefix);
+int cmd_patch_id(int argc, const char **argv, const char *prefix);
+int cmd_prune(int argc, const char **argv, const char *prefix);
+int cmd_prune_packed(int argc, const char **argv, const char *prefix);
+int cmd_pull(int argc, const char **argv, const char *prefix);
+int cmd_push(int argc, const char **argv, const char *prefix);
+int cmd_range_diff(int argc, const char **argv, const char *prefix);
+int cmd_read_tree(int argc, const char **argv, const char *prefix);
+int cmd_rebase(int argc, const char **argv, const char *prefix);
+int cmd_rebase__interactive(int argc, const char **argv, const char *prefix);
+int cmd_receive_pack(int argc, const char **argv, const char *prefix);
+int cmd_reflog(int argc, const char **argv, const char *prefix);
+int cmd_remote(int argc, const char **argv, const char *prefix);
+int cmd_remote_ext(int argc, const char **argv, const char *prefix);
+int cmd_remote_fd(int argc, const char **argv, const char *prefix);
+int cmd_repack(int argc, const char **argv, const char *prefix);
+int cmd_rerere(int argc, const char **argv, const char *prefix);
+int cmd_reset(int argc, const char **argv, const char *prefix);
+int cmd_rev_list(int argc, const char **argv, const char *prefix);
+int cmd_rev_parse(int argc, const char **argv, const char *prefix);
+int cmd_revert(int argc, const char **argv, const char *prefix);
+int cmd_rm(int argc, const char **argv, const char *prefix);
+int cmd_send_pack(int argc, const char **argv, const char *prefix);
+int cmd_shortlog(int argc, const char **argv, const char *prefix);
+int cmd_show(int argc, const char **argv, const char *prefix);
+int cmd_show_branch(int argc, const char **argv, const char *prefix);
+int cmd_show_index(int argc, const char **argv, const char *prefix);
+int cmd_status(int argc, const char **argv, const char *prefix);
+int cmd_stash(int argc, const char **argv, const char *prefix);
+int cmd_stripspace(int argc, const char **argv, const char *prefix);
+int cmd_submodule__helper(int argc, const char **argv, const char *prefix);
+int cmd_symbolic_ref(int argc, const char **argv, const char *prefix);
+int cmd_tag(int argc, const char **argv, const char *prefix);
+int cmd_tar_tree(int argc, const char **argv, const char *prefix);
+int cmd_unpack_file(int argc, const char **argv, const char *prefix);
+int cmd_unpack_objects(int argc, const char **argv, const char *prefix);
+int cmd_update_index(int argc, const char **argv, const char *prefix);
+int cmd_update_ref(int argc, const char **argv, const char *prefix);
+int cmd_update_server_info(int argc, const char **argv, const char *prefix);
+int cmd_upload_archive(int argc, const char **argv, const char *prefix);
+int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix);
+int cmd_upload_pack(int argc, const char **argv, const char *prefix);
+int cmd_var(int argc, const char **argv, const char *prefix);
+int cmd_verify_commit(int argc, const char **argv, const char *prefix);
+int cmd_verify_tag(int argc, const char **argv, const char *prefix);
+int cmd_version(int argc, const char **argv, const char *prefix);
+int cmd_whatchanged(int argc, const char **argv, const char *prefix);
+int cmd_worktree(int argc, const char **argv, const char *prefix);
+int cmd_write_tree(int argc, const char **argv, const char *prefix);
+int cmd_verify_pack(int argc, const char **argv, const char *prefix);
+int cmd_show_ref(int argc, const char **argv, const char *prefix);
+int cmd_pack_refs(int argc, const char **argv, const char *prefix);
+int cmd_replace(int argc, const char **argv, const char *prefix);
 
 #endif
diff --git a/bulk-checkin.h b/bulk-checkin.h
index f438f93811..b26f3dc3b7 100644
--- a/bulk-checkin.h
+++ b/bulk-checkin.h
@@ -6,11 +6,11 @@
 
 #include "cache.h"
 
-extern int index_bulk_checkin(struct object_id *oid,
-			      int fd, size_t size, enum object_type type,
-			      const char *path, unsigned flags);
+int index_bulk_checkin(struct object_id *oid,
+		       int fd, size_t size, enum object_type type,
+		       const char *path, unsigned flags);
 
-extern void plug_bulk_checkin(void);
-extern void unplug_bulk_checkin(void);
+void plug_bulk_checkin(void);
+void unplug_bulk_checkin(void);
 
 #endif
diff --git a/cache.h b/cache.h
index 67cc2e1806..fa8ede9a2d 100644
--- a/cache.h
+++ b/cache.h
@@ -352,10 +352,10 @@ struct index_state {
 };
 
 /* Name hashing */
-extern int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
-extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
-extern void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
-extern void free_name_hash(struct index_state *istate);
+int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
+void add_name_hash(struct index_state *istate, struct cache_entry *ce);
+void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
+void free_name_hash(struct index_state *istate);
 
 
 /* Cache entry creation and cleanup */
@@ -545,7 +545,7 @@ static inline enum object_type object_type(unsigned int mode)
  */
 extern const char * const local_repo_env[];
 
-extern void setup_git_env(const char *git_dir);
+void setup_git_env(const char *git_dir);
 
 /*
  * Returns true iff we have a configured git repository (either via
@@ -554,29 +554,29 @@ extern void setup_git_env(const char *git_dir);
 int have_git_dir(void);
 
 extern int is_bare_repository_cfg;
-extern int is_bare_repository(void);
-extern int is_inside_git_dir(void);
+int is_bare_repository(void);
+int is_inside_git_dir(void);
 extern char *git_work_tree_cfg;
-extern int is_inside_work_tree(void);
-extern const char *get_git_dir(void);
-extern const char *get_git_common_dir(void);
-extern char *get_object_directory(void);
-extern char *get_index_file(void);
-extern char *get_graft_file(struct repository *r);
-extern void set_git_dir(const char *path);
-extern int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
-extern int get_common_dir(struct strbuf *sb, const char *gitdir);
-extern const char *get_git_namespace(void);
-extern const char *strip_namespace(const char *namespaced_ref);
-extern const char *get_super_prefix(void);
-extern const char *get_git_work_tree(void);
+int is_inside_work_tree(void);
+const char *get_git_dir(void);
+const char *get_git_common_dir(void);
+char *get_object_directory(void);
+char *get_index_file(void);
+char *get_graft_file(struct repository *r);
+void set_git_dir(const char *path);
+int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
+int get_common_dir(struct strbuf *sb, const char *gitdir);
+const char *get_git_namespace(void);
+const char *strip_namespace(const char *namespaced_ref);
+const char *get_super_prefix(void);
+const char *get_git_work_tree(void);
 
 /*
  * Return true if the given path is a git directory; note that this _just_
  * looks at the directory itself. If you want to know whether "foo/.git"
  * is a repository, you must feed that path, not just "foo".
  */
-extern int is_git_directory(const char *path);
+int is_git_directory(const char *path);
 
 /*
  * Return 1 if the given path is the root of a git repository or
@@ -588,7 +588,7 @@ extern int is_git_directory(const char *path);
  * as we usually consider sub-repos precious, and would prefer to err on the
  * side of not disrupting or deleting them.
  */
-extern int is_nonbare_repository_dir(struct strbuf *path);
+int is_nonbare_repository_dir(struct strbuf *path);
 
 #define READ_GITFILE_ERR_STAT_FAILED 1
 #define READ_GITFILE_ERR_NOT_A_FILE 2
@@ -598,17 +598,17 @@ extern int is_nonbare_repository_dir(struct strbuf *path);
 #define READ_GITFILE_ERR_NO_PATH 6
 #define READ_GITFILE_ERR_NOT_A_REPO 7
 #define READ_GITFILE_ERR_TOO_LARGE 8
-extern void read_gitfile_error_die(int error_code, const char *path, const char *dir);
-extern const char *read_gitfile_gently(const char *path, int *return_error_code);
+void read_gitfile_error_die(int error_code, const char *path, const char *dir);
+const char *read_gitfile_gently(const char *path, int *return_error_code);
 #define read_gitfile(path) read_gitfile_gently((path), NULL)
-extern const char *resolve_gitdir_gently(const char *suspect, int *return_error_code);
+const char *resolve_gitdir_gently(const char *suspect, int *return_error_code);
 #define resolve_gitdir(path) resolve_gitdir_gently((path), NULL)
 
-extern void set_git_work_tree(const char *tree);
+void set_git_work_tree(const char *tree);
 
 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 
-extern void setup_work_tree(void);
+void setup_work_tree(void);
 /*
  * Find the commondir and gitdir of the repository that contains the current
  * working directory, without changing the working directory or other global
@@ -617,12 +617,12 @@ extern void setup_work_tree(void);
  * both have the same result appended to the buffer.  The return value is
  * either 0 upon success and non-zero if no repository was found.
  */
-extern int discover_git_directory(struct strbuf *commondir,
-				  struct strbuf *gitdir);
-extern const char *setup_git_directory_gently(int *);
-extern const char *setup_git_directory(void);
-extern char *prefix_path(const char *prefix, int len, const char *path);
-extern char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);
+int discover_git_directory(struct strbuf *commondir,
+			   struct strbuf *gitdir);
+const char *setup_git_directory_gently(int *);
+const char *setup_git_directory(void);
+char *prefix_path(const char *prefix, int len, const char *path);
+char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);
 
 /*
  * Concatenate "prefix" (if len is non-zero) and "path", with no
@@ -634,23 +634,23 @@ extern char *prefix_path_gently(const char *prefix, int len, int *remaining, con
  * The return value is always a newly allocated string (even if the
  * prefix was empty).
  */
-extern char *prefix_filename(const char *prefix, const char *path);
+char *prefix_filename(const char *prefix, const char *path);
 
-extern int check_filename(const char *prefix, const char *name);
-extern void verify_filename(const char *prefix,
-			    const char *name,
-			    int diagnose_misspelt_rev);
-extern void verify_non_filename(const char *prefix, const char *name);
-extern int path_inside_repo(const char *prefix, const char *path);
+int check_filename(const char *prefix, const char *name);
+void verify_filename(const char *prefix,
+		     const char *name,
+		     int diagnose_misspelt_rev);
+void verify_non_filename(const char *prefix, const char *name);
+int path_inside_repo(const char *prefix, const char *path);
 
 #define INIT_DB_QUIET 0x0001
 #define INIT_DB_EXIST_OK 0x0002
 
-extern int init_db(const char *git_dir, const char *real_git_dir,
-		   const char *template_dir, unsigned int flags);
+int init_db(const char *git_dir, const char *real_git_dir,
+	    const char *template_dir, unsigned int flags);
 
-extern void sanitize_stdfds(void);
-extern int daemonize(void);
+void sanitize_stdfds(void);
+int daemonize(void);
 
 #define alloc_nr(x) (((x)+16)*3/2)
 
@@ -674,14 +674,14 @@ extern int daemonize(void);
 
 /* Initialize and use the cache information */
 struct lock_file;
-extern void preload_index(struct index_state *index,
-			  const struct pathspec *pathspec,
-			  unsigned int refresh_flags);
-extern int do_read_index(struct index_state *istate, const char *path,
-			 int must_exist); /* for testting only! */
-extern int read_index_from(struct index_state *, const char *path,
-			   const char *gitdir);
-extern int is_index_unborn(struct index_state *);
+void preload_index(struct index_state *index,
+		   const struct pathspec *pathspec,
+		   unsigned int refresh_flags);
+int do_read_index(struct index_state *istate, const char *path,
+		  int must_exist); /* for testting only! */
+int read_index_from(struct index_state *, const char *path,
+		    const char *gitdir);
+int is_index_unborn(struct index_state *);
 
 /* For use with `write_locked_index()`. */
 #define COMMIT_LOCK		(1 << 0)
@@ -706,11 +706,11 @@ extern int is_index_unborn(struct index_state *);
  * If `SKIP_IF_UNCHANGED` is given and the index is unchanged, nothing
  * is written (and the lock is rolled back if `COMMIT_LOCK` is given).
  */
-extern int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
+int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
 
-extern int discard_index(struct index_state *);
-extern void move_index_extensions(struct index_state *dst, struct index_state *src);
-extern int unmerged_index(const struct index_state *);
+int discard_index(struct index_state *);
+void move_index_extensions(struct index_state *dst, struct index_state *src);
+int unmerged_index(const struct index_state *);
 
 /**
  * Returns 1 if istate differs from tree, 0 otherwise.  If tree is NULL,
@@ -719,15 +719,15 @@ extern int unmerged_index(const struct index_state *);
  * provided, the space-separated list of files that differ will be appended
  * to it.
  */
-extern int repo_index_has_changes(struct repository *repo,
-				  struct tree *tree,
-				  struct strbuf *sb);
+int repo_index_has_changes(struct repository *repo,
+			   struct tree *tree,
+			   struct strbuf *sb);
 
-extern int verify_path(const char *path, unsigned mode);
-extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
-extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);
-extern void adjust_dirname_case(struct index_state *istate, char *name);
-extern struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);
+int verify_path(const char *path, unsigned mode);
+int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
+int index_dir_exists(struct index_state *istate, const char *name, int namelen);
+void adjust_dirname_case(struct index_state *istate, char *name);
+struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);
 
 /*
  * Searches for an entry defined by name and namelen in the given index.
@@ -746,7 +746,7 @@ extern struct cache_entry *index_file_exists(struct index_state *istate, const c
  * index_name_pos(&index, "f", 1) -> -3
  * index_name_pos(&index, "g", 1) -> -5
  */
-extern int index_name_pos(const struct index_state *, const char *name, int namelen);
+int index_name_pos(const struct index_state *, const char *name, int namelen);
 
 #define ADD_CACHE_OK_TO_ADD 1		/* Ok to add */
 #define ADD_CACHE_OK_TO_REPLACE 2	/* Ok to replace file/directory */
@@ -755,14 +755,14 @@ extern int index_name_pos(const struct index_state *, const char *name, int name
 #define ADD_CACHE_NEW_ONLY 16		/* Do not replace existing ones */
 #define ADD_CACHE_KEEP_CACHE_TREE 32	/* Do not invalidate cache-tree */
 #define ADD_CACHE_RENORMALIZE 64        /* Pass along HASH_RENORMALIZE */
-extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
-extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
+int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
+void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
 
 /* Remove entry, return true if there are more entries to go. */
-extern int remove_index_entry_at(struct index_state *, int pos);
+int remove_index_entry_at(struct index_state *, int pos);
 
-extern void remove_marked_cache_entries(struct index_state *istate, int invalidate);
-extern int remove_file_from_index(struct index_state *, const char *path);
+void remove_marked_cache_entries(struct index_state *istate, int invalidate);
+int remove_file_from_index(struct index_state *, const char *path);
 #define ADD_CACHE_VERBOSE 1
 #define ADD_CACHE_PRETEND 2
 #define ADD_CACHE_IGNORE_ERRORS	4
@@ -777,14 +777,14 @@ extern int remove_file_from_index(struct index_state *, const char *path);
  * the latter will do necessary lstat(2) internally before
  * calling the former.
  */
-extern int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
-extern int add_file_to_index(struct index_state *, const char *path, int flags);
+int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
+int add_file_to_index(struct index_state *, const char *path, int flags);
 
-extern int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
-extern int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
-extern void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
-extern int index_name_is_other(const struct index_state *, const char *, int);
-extern void *read_blob_data_from_index(const struct index_state *, const char *, unsigned long *);
+int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
+int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
+void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
+int index_name_is_other(const struct index_state *, const char *, int);
+void *read_blob_data_from_index(const struct index_state *, const char *, unsigned long *);
 
 /* do stat comparison even if CE_VALID is true */
 #define CE_MATCH_IGNORE_VALID		01
@@ -798,22 +798,22 @@ extern void *read_blob_data_from_index(const struct index_state *, const char *,
 #define CE_MATCH_REFRESH		0x10
 /* don't refresh_fsmonitor state or do stat comparison even if CE_FSMONITOR_VALID is true */
 #define CE_MATCH_IGNORE_FSMONITOR 0X20
-extern int is_racy_timestamp(const struct index_state *istate,
-			     const struct cache_entry *ce);
-extern int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
-extern int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
+int is_racy_timestamp(const struct index_state *istate,
+		      const struct cache_entry *ce);
+int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
+int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 
 #define HASH_WRITE_OBJECT 1
 #define HASH_FORMAT_CHECK 2
 #define HASH_RENORMALIZE  4
-extern int index_fd(struct index_state *istate, struct object_id *oid, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
-extern int index_path(struct index_state *istate, struct object_id *oid, const char *path, struct stat *st, unsigned flags);
+int index_fd(struct index_state *istate, struct object_id *oid, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
+int index_path(struct index_state *istate, struct object_id *oid, const char *path, struct stat *st, unsigned flags);
 
 /*
  * Record to sd the data from st that we use to check whether a file
  * might have changed.
  */
-extern void fill_stat_data(struct stat_data *sd, struct stat *st);
+void fill_stat_data(struct stat_data *sd, struct stat *st);
 
 /*
  * Return 0 if st is consistent with a file not having been changed
@@ -821,11 +821,11 @@ extern void fill_stat_data(struct stat_data *sd, struct stat *st);
  * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
  * INODE_CHANGED, and DATA_CHANGED.
  */
-extern int match_stat_data(const struct stat_data *sd, struct stat *st);
-extern int match_stat_data_racy(const struct index_state *istate,
-				const struct stat_data *sd, struct stat *st);
+int match_stat_data(const struct stat_data *sd, struct stat *st);
+int match_stat_data_racy(const struct index_state *istate,
+			 const struct stat_data *sd, struct stat *st);
 
-extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
+void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 
 #define REFRESH_REALLY		0x0001	/* ignore_valid */
 #define REFRESH_UNMERGED	0x0002	/* allow unmerged */
@@ -834,10 +834,10 @@ extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);
 #define REFRESH_IGNORE_SUBMODULES	0x0010	/* ignore submodules */
 #define REFRESH_IN_PORCELAIN	0x0020	/* user friendly output, not "needs update" */
 #define REFRESH_PROGRESS	0x0040  /* show progress bar if stderr is tty */
-extern int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
-extern struct cache_entry *refresh_cache_entry(struct index_state *, struct cache_entry *, unsigned int);
+int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
+struct cache_entry *refresh_cache_entry(struct index_state *, struct cache_entry *, unsigned int);
 
-extern void set_alternate_index_output(const char *);
+void set_alternate_index_output(const char *);
 
 extern int verify_index_checksum;
 extern int verify_ce_order;
@@ -1022,7 +1022,7 @@ int verify_repository_format(const struct repository_format *format,
  * set_git_dir() before calling this, and use it only for "are we in a valid
  * repo?".
  */
-extern void check_repository_format(void);
+void check_repository_format(void);
 
 #define MTIME_CHANGED	0x0001
 #define CTIME_CHANGED	0x0002
@@ -1246,7 +1246,7 @@ typedef int create_file_fn(const char *path, void *cb);
 int raceproof_create_file(const char *path, create_file_fn fn, void *cb);
 
 int mkdir_in_gitdir(const char *path);
-extern char *expand_user_path(const char *path, int real_home);
+char *expand_user_path(const char *path, int real_home);
 const char *enter_repo(const char *path, int strict);
 static inline int is_absolute_path(const char *path)
 {
@@ -1290,26 +1290,26 @@ int looks_like_command_line_option(const char *str);
  * "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
  * "$HOME/.config/git/$filename". Return NULL upon error.
  */
-extern char *xdg_config_home(const char *filename);
+char *xdg_config_home(const char *filename);
 
 /**
  * Return a newly allocated string with the evaluation of
  * "$XDG_CACHE_HOME/git/$filename" if $XDG_CACHE_HOME is non-empty, otherwise
  * "$HOME/.cache/git/$filename". Return NULL upon error.
  */
-extern char *xdg_cache_home(const char *filename);
+char *xdg_cache_home(const char *filename);
 
-extern int git_open_cloexec(const char *name, int flags);
+int git_open_cloexec(const char *name, int flags);
 #define git_open(name) git_open_cloexec(name, O_RDONLY)
-extern int unpack_loose_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
-extern int parse_loose_header(const char *hdr, unsigned long *sizep);
+int unpack_loose_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
+int parse_loose_header(const char *hdr, unsigned long *sizep);
 
-extern int check_object_signature(const struct object_id *oid, void *buf, unsigned long size, const char *type);
+int check_object_signature(const struct object_id *oid, void *buf, unsigned long size, const char *type);
 
-extern int finalize_object_file(const char *tmpfile, const char *filename);
+int finalize_object_file(const char *tmpfile, const char *filename);
 
 /* Helper to check and "touch" a file */
-extern int check_and_freshen_file(const char *fn, int freshen);
+int check_and_freshen_file(const char *fn, int freshen);
 
 extern const signed char hexval_table[256];
 static inline unsigned int hexval(unsigned char c)
@@ -1393,9 +1393,9 @@ int repo_get_oid_mb(struct repository *r, const char *str, struct object_id *oid
 void maybe_die_on_misspelt_object_name(struct repository *repo,
 				       const char *name,
 				       const char *prefix);
-extern enum get_oid_result get_oid_with_context(struct repository *repo, const char *str,
-				unsigned flags, struct object_id *oid,
-				struct object_context *oc);
+enum get_oid_result get_oid_with_context(struct repository *repo, const char *str,
+					 unsigned flags, struct object_id *oid,
+					 struct object_context *oc);
 
 #define get_oid(str, oid)		repo_get_oid(the_repository, str, oid)
 #define get_oid_commit(str, oid)	repo_get_oid_commit(the_repository, str, oid)
@@ -1409,7 +1409,7 @@ typedef int each_abbrev_fn(const struct object_id *oid, void *);
 int repo_for_each_abbrev(struct repository *r, const char *prefix, each_abbrev_fn, void *);
 #define for_each_abbrev(prefix, fn, data) repo_for_each_abbrev(the_repository, prefix, fn, data)
 
-extern int set_disambiguate_hint_config(const char *var, const char *value);
+int set_disambiguate_hint_config(const char *var, const char *value);
 
 /*
  * Try to read a SHA1 in hexadecimal format from the 40 characters
@@ -1418,15 +1418,15 @@ extern int set_disambiguate_hint_config(const char *var, const char *value);
  * input, so it is safe to pass this function an arbitrary
  * null-terminated string.
  */
-extern int get_sha1_hex(const char *hex, unsigned char *sha1);
-extern int get_oid_hex(const char *hex, struct object_id *sha1);
+int get_sha1_hex(const char *hex, unsigned char *sha1);
+int get_oid_hex(const char *hex, struct object_id *sha1);
 
 /*
  * Read `len` pairs of hexadecimal digits from `hex` and write the
  * values to `binary` as `len` bytes. Return 0 on success, or -1 if
  * the input does not consist of hex digits).
  */
-extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
+int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
 
 /*
  * Convert a binary hash to its hex equivalent. The `_r` variant is reentrant,
@@ -1454,7 +1454,7 @@ char *oid_to_hex(const struct object_id *oid);						/* same static buffer */
  * other invalid character.  end is only updated on success; otherwise, it is
  * unmodified.
  */
-extern int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
+int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
 
 /*
  * This reads short-hand syntax that not only evaluates to a commit
@@ -1492,17 +1492,17 @@ int repo_interpret_branch_name(struct repository *r,
 #define interpret_branch_name(str, len, buf, allowed) \
 	repo_interpret_branch_name(the_repository, str, len, buf, allowed)
 
-extern int validate_headref(const char *ref);
+int validate_headref(const char *ref);
 
-extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
-extern int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
-extern int name_compare(const char *name1, size_t len1, const char *name2, size_t len2);
-extern int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2);
+int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
+int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
+int name_compare(const char *name1, size_t len1, const char *name2, size_t len2);
+int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2);
 
-extern void *read_object_with_reference(const struct object_id *oid,
-					const char *required_type,
-					unsigned long *size,
-					struct object_id *oid_ret);
+void *read_object_with_reference(const struct object_id *oid,
+				 const char *required_type,
+				 unsigned long *size,
+				 struct object_id *oid_ret);
 
 struct object *repo_peel_to_type(struct repository *r,
 				 const char *name, int namelen,
@@ -1562,24 +1562,24 @@ enum want_ident {
 	WANT_COMMITTER_IDENT
 };
 
-extern const char *git_author_info(int);
-extern const char *git_committer_info(int);
-extern const char *fmt_ident(const char *name, const char *email,
-		enum want_ident whose_ident,
-		const char *date_str, int);
-extern const char *fmt_name(enum want_ident);
-extern const char *ident_default_name(void);
-extern const char *ident_default_email(void);
-extern const char *git_editor(void);
-extern const char *git_sequence_editor(void);
-extern const char *git_pager(int stdout_is_tty);
-extern int is_terminal_dumb(void);
-extern int git_ident_config(const char *, const char *, void *);
+const char *git_author_info(int);
+const char *git_committer_info(int);
+const char *fmt_ident(const char *name, const char *email,
+		      enum want_ident whose_ident,
+		      const char *date_str, int);
+const char *fmt_name(enum want_ident);
+const char *ident_default_name(void);
+const char *ident_default_email(void);
+const char *git_editor(void);
+const char *git_sequence_editor(void);
+const char *git_pager(int stdout_is_tty);
+int is_terminal_dumb(void);
+int git_ident_config(const char *, const char *, void *);
 /*
  * Prepare an ident to fall back on if the user didn't configure it.
  */
 void prepare_fallback_ident(const char *name, const char *email);
-extern void reset_ident_date(void);
+void reset_ident_date(void);
 
 struct ident_split {
 	const char *name_begin;
@@ -1595,7 +1595,7 @@ struct ident_split {
  * Signals an success with 0, but time part of the result may be NULL
  * if the input lacks timestamp and zone
  */
-extern int split_ident_line(struct ident_split *, const char *, int);
+int split_ident_line(struct ident_split *, const char *, int);
 
 /*
  * Like show_date, but pull the timestamp and tz parameters from
@@ -1612,7 +1612,7 @@ const char *show_ident_date(const struct ident_split *id,
  * Because there are two fields, we must choose one as the primary key; we
  * currently arbitrarily pick the email.
  */
-extern int ident_cmp(const struct ident_split *, const struct ident_split *);
+int ident_cmp(const struct ident_split *, const struct ident_split *);
 
 struct checkout {
 	struct index_state *istate;
@@ -1628,14 +1628,14 @@ struct checkout {
 #define CHECKOUT_INIT { NULL, "" }
 
 #define TEMPORARY_FILENAME_LENGTH 25
-extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath, int *nr_checkouts);
-extern void enable_delayed_checkout(struct checkout *state);
-extern int finish_delayed_checkout(struct checkout *state, int *nr_checkouts);
+int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath, int *nr_checkouts);
+void enable_delayed_checkout(struct checkout *state);
+int finish_delayed_checkout(struct checkout *state, int *nr_checkouts);
 /*
  * Unlink the last component and schedule the leading directories for
  * removal, such that empty directories get removed.
  */
-extern void unlink_entry(const struct cache_entry *ce);
+void unlink_entry(const struct cache_entry *ce);
 
 struct cache_def {
 	struct strbuf path;
@@ -1649,12 +1649,12 @@ static inline void cache_def_clear(struct cache_def *cache)
 	strbuf_release(&cache->path);
 }
 
-extern int has_symlink_leading_path(const char *name, int len);
-extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
-extern int check_leading_path(const char *name, int len);
-extern int has_dirs_only_path(const char *name, int len, int prefix_len);
-extern void schedule_dir_for_removal(const char *name, int len);
-extern void remove_scheduled_dirs(void);
+int has_symlink_leading_path(const char *name, int len);
+int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
+int check_leading_path(const char *name, int len);
+int has_dirs_only_path(const char *name, int len, int prefix_len);
+void schedule_dir_for_removal(const char *name, int len);
+void remove_scheduled_dirs(void);
 
 struct pack_window {
 	struct pack_window *next;
@@ -1676,14 +1676,14 @@ struct pack_entry {
  * usual "XXXXXX" trailer, and the resulting filename is written into the
  * "template" buffer. Returns the open descriptor.
  */
-extern int odb_mkstemp(struct strbuf *temp_filename, const char *pattern);
+int odb_mkstemp(struct strbuf *temp_filename, const char *pattern);
 
 /*
  * Create a pack .keep file named "name" (which should generally be the output
  * of odb_pack_name). Returns a file descriptor opened for writing, or -1 on
  * error.
  */
-extern int odb_pack_keep(const char *name);
+int odb_pack_keep(const char *name);
 
 /*
  * Set this to 0 to prevent oid_object_info_extended() from fetching missing
@@ -1694,10 +1694,10 @@ extern int odb_pack_keep(const char *name);
 extern int fetch_if_missing;
 
 /* Dumb servers support */
-extern int update_server_info(int);
+int update_server_info(int);
 
-extern const char *get_log_output_encoding(void);
-extern const char *get_commit_output_encoding(void);
+const char *get_log_output_encoding(void);
+const char *get_commit_output_encoding(void);
 
 /*
  * This is a hack for test programs like test-dump-untracked-cache to
@@ -1706,8 +1706,8 @@ extern const char *get_commit_output_encoding(void);
  */
 extern int ignore_untracked_cache_config;
 
-extern int committer_ident_sufficiently_given(void);
-extern int author_ident_sufficiently_given(void);
+int committer_ident_sufficiently_given(void);
+int author_ident_sufficiently_given(void);
 
 extern const char *git_commit_encoding;
 extern const char *git_log_output_encoding;
@@ -1715,22 +1715,22 @@ extern const char *git_mailmap_file;
 extern const char *git_mailmap_blob;
 
 /* IO helper functions */
-extern void maybe_flush_or_die(FILE *, const char *);
+void maybe_flush_or_die(FILE *, const char *);
 __attribute__((format (printf, 2, 3)))
-extern void fprintf_or_die(FILE *, const char *fmt, ...);
+void fprintf_or_die(FILE *, const char *fmt, ...);
 
 #define COPY_READ_ERROR (-2)
 #define COPY_WRITE_ERROR (-3)
-extern int copy_fd(int ifd, int ofd);
-extern int copy_file(const char *dst, const char *src, int mode);
-extern int copy_file_with_time(const char *dst, const char *src, int mode);
+int copy_fd(int ifd, int ofd);
+int copy_file(const char *dst, const char *src, int mode);
+int copy_file_with_time(const char *dst, const char *src, int mode);
 
-extern void write_or_die(int fd, const void *buf, size_t count);
-extern void fsync_or_die(int fd, const char *);
+void write_or_die(int fd, const void *buf, size_t count);
+void fsync_or_die(int fd, const char *);
 
-extern ssize_t read_in_full(int fd, void *buf, size_t count);
-extern ssize_t write_in_full(int fd, const void *buf, size_t count);
-extern ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset);
+ssize_t read_in_full(int fd, void *buf, size_t count);
+ssize_t write_in_full(int fd, const void *buf, size_t count);
+ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset);
 
 static inline ssize_t write_str_in_full(int fd, const char *str)
 {
@@ -1741,7 +1741,7 @@ static inline ssize_t write_str_in_full(int fd, const char *str)
  * Open (and truncate) the file at path, write the contents of buf to it,
  * and close it. Dies if any errors are encountered.
  */
-extern void write_file_buf(const char *path, const char *buf, size_t len);
+void write_file_buf(const char *path, const char *buf, size_t len);
 
 /**
  * Like write_file_buf(), but format the contents into a buffer first.
@@ -1751,16 +1751,16 @@ extern void write_file_buf(const char *path, const char *buf, size_t len);
  *   write_file(path, "counter: %d", ctr);
  */
 __attribute__((format (printf, 2, 3)))
-extern void write_file(const char *path, const char *fmt, ...);
+void write_file(const char *path, const char *fmt, ...);
 
 /* pager.c */
-extern void setup_pager(void);
-extern int pager_in_use(void);
+void setup_pager(void);
+int pager_in_use(void);
 extern int pager_use_color;
-extern int term_columns(void);
-extern int decimal_width(uintmax_t);
-extern int check_pager_config(const char *cmd);
-extern void prepare_pager_args(struct child_process *, const char *pager);
+int term_columns(void);
+int decimal_width(uintmax_t);
+int check_pager_config(const char *cmd);
+void prepare_pager_args(struct child_process *, const char *pager);
 
 extern const char *editor_program;
 extern const char *askpass_program;
@@ -1804,13 +1804,13 @@ void shift_tree_by(const struct object_id *, const struct object_id *, struct ob
 /* All WS_* -- when extended, adapt diff.c emit_symbol */
 #define WS_RULE_MASK           07777
 extern unsigned whitespace_rule_cfg;
-extern unsigned whitespace_rule(struct index_state *, const char *);
-extern unsigned parse_whitespace_rule(const char *);
-extern unsigned ws_check(const char *line, int len, unsigned ws_rule);
-extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
-extern char *whitespace_error_string(unsigned ws);
-extern void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
-extern int ws_blank_line(const char *line, int len, unsigned ws_rule);
+unsigned whitespace_rule(struct index_state *, const char *);
+unsigned parse_whitespace_rule(const char *);
+unsigned ws_check(const char *line, int len, unsigned ws_rule);
+void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
+char *whitespace_error_string(unsigned ws);
+void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
+int ws_blank_line(const char *line, int len, unsigned ws_rule);
 #define ws_tab_width(rule)     ((rule) & WS_TAB_WIDTH_MASK)
 
 /* ls-files */
@@ -1880,9 +1880,9 @@ void safe_create_dir(const char *dir, int share);
  * Should we print an ellipsis after an abbreviated SHA-1 value
  * when doing diff-raw output or indicating a detached HEAD?
  */
-extern int print_sha1_ellipsis(void);
+int print_sha1_ellipsis(void);
 
 /* Return 1 if the file is empty or does not exists, 0 otherwise. */
-extern int is_empty_or_missing_file(const char *filename);
+int is_empty_or_missing_file(const char *filename);
 
 #endif /* CACHE_H */
diff --git a/checkout.h b/checkout.h
index 6b2073310c..1152133bd7 100644
--- a/checkout.h
+++ b/checkout.h
@@ -8,8 +8,8 @@
  * tracking branch.  Return the name of the remote if such a branch
  * exists, NULL otherwise.
  */
-extern const char *unique_tracking_name(const char *name,
-					struct object_id *oid,
-					int *dwim_remotes_matched);
+const char *unique_tracking_name(const char *name,
+				 struct object_id *oid,
+				 int *dwim_remotes_matched);
 
 #endif /* CHECKOUT_H */
diff --git a/column.h b/column.h
index 2567a5cf4d..448c7440b3 100644
--- a/column.h
+++ b/column.h
@@ -27,20 +27,20 @@ struct column_options {
 };
 
 struct option;
-extern int parseopt_column_callback(const struct option *, const char *, int);
-extern int git_column_config(const char *var, const char *value,
-			     const char *command, unsigned int *colopts);
-extern int finalize_colopts(unsigned int *colopts, int stdout_is_tty);
+int parseopt_column_callback(const struct option *, const char *, int);
+int git_column_config(const char *var, const char *value,
+		      const char *command, unsigned int *colopts);
+int finalize_colopts(unsigned int *colopts, int stdout_is_tty);
 static inline int column_active(unsigned int colopts)
 {
 	return (colopts & COL_ENABLE_MASK) == COL_ENABLED;
 }
 
 struct string_list;
-extern void print_columns(const struct string_list *list, unsigned int colopts,
-			  const struct column_options *opts);
+void print_columns(const struct string_list *list, unsigned int colopts,
+		   const struct column_options *opts);
 
-extern int run_column_filter(int colopts, const struct column_options *);
-extern int stop_column_filter(void);
+int run_column_filter(int colopts, const struct column_options *);
+int stop_column_filter(void);
 
 #endif
diff --git a/commit.h b/commit.h
index cc19cb5314..f5295ca7f3 100644
--- a/commit.h
+++ b/commit.h
@@ -184,10 +184,10 @@ void free_commit_list(struct commit_list *list);
 
 struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
 
-extern int has_non_ascii(const char *text);
-extern const char *logmsg_reencode(const struct commit *commit,
-				   char **commit_encoding,
-				   const char *output_encoding);
+int has_non_ascii(const char *text);
+const char *logmsg_reencode(const struct commit *commit,
+			    char **commit_encoding,
+			    const char *output_encoding);
 const char *repo_logmsg_reencode(struct repository *r,
 				 const struct commit *commit,
 				 char **commit_encoding,
@@ -196,7 +196,7 @@ const char *repo_logmsg_reencode(struct repository *r,
 #define logmsg_reencode(c, enc, out) repo_logmsg_reencode(the_repository, c, enc, out)
 #endif
 
-extern const char *skip_blank_lines(const char *msg);
+const char *skip_blank_lines(const char *msg);
 
 /** Removes the first commit from a list sorted by date, and adds all
  * of its parents.
@@ -247,22 +247,22 @@ struct commit *get_fork_point(const char *refname, struct commit *commit);
 
 struct oid_array;
 struct ref;
-extern int register_shallow(struct repository *r, const struct object_id *oid);
-extern int unregister_shallow(const struct object_id *oid);
-extern int for_each_commit_graft(each_commit_graft_fn, void *);
-extern int is_repository_shallow(struct repository *r);
-extern struct commit_list *get_shallow_commits(struct object_array *heads,
-		int depth, int shallow_flag, int not_shallow_flag);
-extern struct commit_list *get_shallow_commits_by_rev_list(
+int register_shallow(struct repository *r, const struct object_id *oid);
+int unregister_shallow(const struct object_id *oid);
+int for_each_commit_graft(each_commit_graft_fn, void *);
+int is_repository_shallow(struct repository *r);
+struct commit_list *get_shallow_commits(struct object_array *heads,
+					int depth, int shallow_flag, int not_shallow_flag);
+struct commit_list *get_shallow_commits_by_rev_list(
 		int ac, const char **av, int shallow_flag, int not_shallow_flag);
-extern void set_alternate_shallow_file(struct repository *r, const char *path, int override);
-extern int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
-				 const struct oid_array *extra);
-extern void setup_alternate_shallow(struct lock_file *shallow_lock,
-				    const char **alternate_shallow_file,
-				    const struct oid_array *extra);
-extern const char *setup_temporary_shallow(const struct oid_array *extra);
-extern void advertise_shallow_grafts(int);
+void set_alternate_shallow_file(struct repository *r, const char *path, int override);
+int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
+			  const struct oid_array *extra);
+void setup_alternate_shallow(struct lock_file *shallow_lock,
+			     const char **alternate_shallow_file,
+			     const struct oid_array *extra);
+const char *setup_temporary_shallow(const struct oid_array *extra);
+void advertise_shallow_grafts(int);
 
 /*
  * Initialize with prepare_shallow_info() or zero-initialize (equivalent to
@@ -283,21 +283,21 @@ struct shallow_info {
 	int nr_commits;
 };
 
-extern void prepare_shallow_info(struct shallow_info *, struct oid_array *);
-extern void clear_shallow_info(struct shallow_info *);
-extern void remove_nonexistent_theirs_shallow(struct shallow_info *);
-extern void assign_shallow_commits_to_refs(struct shallow_info *info,
-					   uint32_t **used,
-					   int *ref_status);
-extern int delayed_reachability_test(struct shallow_info *si, int c);
+void prepare_shallow_info(struct shallow_info *, struct oid_array *);
+void clear_shallow_info(struct shallow_info *);
+void remove_nonexistent_theirs_shallow(struct shallow_info *);
+void assign_shallow_commits_to_refs(struct shallow_info *info,
+				    uint32_t **used,
+				    int *ref_status);
+int delayed_reachability_test(struct shallow_info *si, int c);
 #define PRUNE_SHOW_ONLY 1
 #define PRUNE_QUICK 2
-extern void prune_shallow(unsigned options);
+void prune_shallow(unsigned options);
 extern struct trace_key trace_shallow;
 
-extern int interactive_add(int argc, const char **argv, const char *prefix, int patch);
-extern int run_add_interactive(const char *revision, const char *patch_mode,
-			       const struct pathspec *pathspec);
+int interactive_add(int argc, const char **argv, const char *prefix, int patch);
+int run_add_interactive(const char *revision, const char *patch_mode,
+			const struct pathspec *pathspec);
 
 struct commit_extra_header {
 	struct commit_extra_header *next;
@@ -306,24 +306,24 @@ struct commit_extra_header {
 	size_t len;
 };
 
-extern void append_merge_tag_headers(struct commit_list *parents,
-				     struct commit_extra_header ***tail);
+void append_merge_tag_headers(struct commit_list *parents,
+			      struct commit_extra_header ***tail);
 
-extern int commit_tree(const char *msg, size_t msg_len,
-		       const struct object_id *tree,
-		       struct commit_list *parents, struct object_id *ret,
-		       const char *author, const char *sign_commit);
+int commit_tree(const char *msg, size_t msg_len,
+		const struct object_id *tree,
+		struct commit_list *parents, struct object_id *ret,
+		const char *author, const char *sign_commit);
 
-extern int commit_tree_extended(const char *msg, size_t msg_len,
-				const struct object_id *tree,
-				struct commit_list *parents,
-				struct object_id *ret, const char *author,
-				const char *sign_commit,
-				struct commit_extra_header *);
+int commit_tree_extended(const char *msg, size_t msg_len,
+			 const struct object_id *tree,
+			 struct commit_list *parents,
+			 struct object_id *ret, const char *author,
+			 const char *sign_commit,
+			 struct commit_extra_header *);
 
-extern struct commit_extra_header *read_commit_extra_headers(struct commit *, const char **);
+struct commit_extra_header *read_commit_extra_headers(struct commit *, const char **);
 
-extern void free_commit_extra_headers(struct commit_extra_header *extra);
+void free_commit_extra_headers(struct commit_extra_header *extra);
 
 /*
  * Search the commit object contents given by "msg" for the header "key".
@@ -333,24 +333,24 @@ extern void free_commit_extra_headers(struct commit_extra_header *extra);
  * Note that some headers (like mergetag) may be multi-line. It is the caller's
  * responsibility to parse further in this case!
  */
-extern const char *find_commit_header(const char *msg, const char *key,
-				      size_t *out_len);
+const char *find_commit_header(const char *msg, const char *key,
+			       size_t *out_len);
 
 /* Find the end of the log message, the right place for a new trailer. */
-extern size_t ignore_non_trailer(const char *buf, size_t len);
+size_t ignore_non_trailer(const char *buf, size_t len);
 
 typedef int (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
-				 void *cb_data);
+				void *cb_data);
 
-extern int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
+int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
 
 struct merge_remote_desc {
 	struct object *obj; /* the named object, could be a tag */
 	char name[FLEX_ARRAY];
 };
-extern struct merge_remote_desc *merge_remote_util(struct commit *);
-extern void set_merge_remote_desc(struct commit *commit,
-				  const char *name, struct object *obj);
+struct merge_remote_desc *merge_remote_util(struct commit *);
+void set_merge_remote_desc(struct commit *commit,
+			   const char *name, struct object *obj);
 
 /*
  * Given "name" from the command line to merge, find the commit object
@@ -359,9 +359,9 @@ extern void set_merge_remote_desc(struct commit *commit,
  */
 struct commit *get_merge_parent(const char *name);
 
-extern int parse_signed_commit(const struct commit *commit,
-			       struct strbuf *message, struct strbuf *signature);
-extern int remove_signature(struct strbuf *buf);
+int parse_signed_commit(const struct commit *commit,
+			struct strbuf *message, struct strbuf *signature);
+int remove_signature(struct strbuf *buf);
 
 /*
  * Check the signature of the given commit. The result of the check is stored
@@ -370,7 +370,7 @@ extern int remove_signature(struct strbuf *buf);
  * at all.  This may allocate memory for sig->gpg_output, sig->gpg_status,
  * sig->signer and sig->key.
  */
-extern int check_commit_signature(const struct commit *commit, struct signature_check *sigc);
+int check_commit_signature(const struct commit *commit, struct signature_check *sigc);
 
 /* record author-date for each commit object */
 struct author_date_slab;
@@ -390,6 +390,6 @@ int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused);
 
 LAST_ARG_MUST_BE_NULL
-extern int run_commit_hook(int editor_is_used, const char *index_file, const char *name, ...);
+int run_commit_hook(int editor_is_used, const char *index_file, const char *name, ...);
 
 #endif /* COMMIT_H */
diff --git a/config.h b/config.h
index 36bb23a9d9..f0ed464004 100644
--- a/config.h
+++ b/config.h
@@ -72,63 +72,63 @@ struct config_options {
 };
 
 typedef int (*config_fn_t)(const char *, const char *, void *);
-extern int git_default_config(const char *, const char *, void *);
-extern int git_config_from_file(config_fn_t fn, const char *, void *);
-extern int git_config_from_file_with_options(config_fn_t fn, const char *,
-					     void *,
-					     const struct config_options *);
-extern int git_config_from_mem(config_fn_t fn,
-			       const enum config_origin_type,
-			       const char *name,
-			       const char *buf, size_t len,
-			       void *data, const struct config_options *opts);
-extern int git_config_from_blob_oid(config_fn_t fn, const char *name,
-				    const struct object_id *oid, void *data);
-extern void git_config_push_parameter(const char *text);
-extern int git_config_from_parameters(config_fn_t fn, void *data);
-extern void read_early_config(config_fn_t cb, void *data);
-extern void read_very_early_config(config_fn_t cb, void *data);
-extern void git_config(config_fn_t fn, void *);
-extern int config_with_options(config_fn_t fn, void *,
-			       struct git_config_source *config_source,
-			       const struct config_options *opts);
-extern int git_parse_ssize_t(const char *, ssize_t *);
-extern int git_parse_ulong(const char *, unsigned long *);
-extern int git_parse_maybe_bool(const char *);
-extern int git_config_int(const char *, const char *);
-extern int64_t git_config_int64(const char *, const char *);
-extern unsigned long git_config_ulong(const char *, const char *);
-extern ssize_t git_config_ssize_t(const char *, const char *);
-extern int git_config_bool_or_int(const char *, const char *, int *);
-extern int git_config_bool(const char *, const char *);
-extern int git_config_string(const char **, const char *, const char *);
-extern int git_config_pathname(const char **, const char *, const char *);
-extern int git_config_expiry_date(timestamp_t *, const char *, const char *);
-extern int git_config_color(char *, const char *, const char *);
-extern int git_config_set_in_file_gently(const char *, const char *, const char *);
-extern void git_config_set_in_file(const char *, const char *, const char *);
-extern int git_config_set_gently(const char *, const char *);
-extern void git_config_set(const char *, const char *);
-extern int git_config_parse_key(const char *, char **, int *);
-extern int git_config_key_is_valid(const char *key);
-extern int git_config_set_multivar_gently(const char *, const char *, const char *, int);
-extern void git_config_set_multivar(const char *, const char *, const char *, int);
-extern int git_config_set_multivar_in_file_gently(const char *, const char *, const char *, const char *, int);
-extern void git_config_set_multivar_in_file(const char *, const char *, const char *, const char *, int);
-extern int git_config_rename_section(const char *, const char *);
-extern int git_config_rename_section_in_file(const char *, const char *, const char *);
-extern int git_config_copy_section(const char *, const char *);
-extern int git_config_copy_section_in_file(const char *, const char *, const char *);
-extern const char *git_etc_gitconfig(void);
-extern int git_env_bool(const char *, int);
-extern unsigned long git_env_ulong(const char *, unsigned long);
-extern int git_config_system(void);
-extern int config_error_nonbool(const char *);
+int git_default_config(const char *, const char *, void *);
+int git_config_from_file(config_fn_t fn, const char *, void *);
+int git_config_from_file_with_options(config_fn_t fn, const char *,
+				      void *,
+				      const struct config_options *);
+int git_config_from_mem(config_fn_t fn,
+			const enum config_origin_type,
+			const char *name,
+			const char *buf, size_t len,
+			void *data, const struct config_options *opts);
+int git_config_from_blob_oid(config_fn_t fn, const char *name,
+			     const struct object_id *oid, void *data);
+void git_config_push_parameter(const char *text);
+int git_config_from_parameters(config_fn_t fn, void *data);
+void read_early_config(config_fn_t cb, void *data);
+void read_very_early_config(config_fn_t cb, void *data);
+void git_config(config_fn_t fn, void *);
+int config_with_options(config_fn_t fn, void *,
+			struct git_config_source *config_source,
+			const struct config_options *opts);
+int git_parse_ssize_t(const char *, ssize_t *);
+int git_parse_ulong(const char *, unsigned long *);
+int git_parse_maybe_bool(const char *);
+int git_config_int(const char *, const char *);
+int64_t git_config_int64(const char *, const char *);
+unsigned long git_config_ulong(const char *, const char *);
+ssize_t git_config_ssize_t(const char *, const char *);
+int git_config_bool_or_int(const char *, const char *, int *);
+int git_config_bool(const char *, const char *);
+int git_config_string(const char **, const char *, const char *);
+int git_config_pathname(const char **, const char *, const char *);
+int git_config_expiry_date(timestamp_t *, const char *, const char *);
+int git_config_color(char *, const char *, const char *);
+int git_config_set_in_file_gently(const char *, const char *, const char *);
+void git_config_set_in_file(const char *, const char *, const char *);
+int git_config_set_gently(const char *, const char *);
+void git_config_set(const char *, const char *);
+int git_config_parse_key(const char *, char **, int *);
+int git_config_key_is_valid(const char *key);
+int git_config_set_multivar_gently(const char *, const char *, const char *, int);
+void git_config_set_multivar(const char *, const char *, const char *, int);
+int git_config_set_multivar_in_file_gently(const char *, const char *, const char *, const char *, int);
+void git_config_set_multivar_in_file(const char *, const char *, const char *, const char *, int);
+int git_config_rename_section(const char *, const char *);
+int git_config_rename_section_in_file(const char *, const char *, const char *);
+int git_config_copy_section(const char *, const char *);
+int git_config_copy_section_in_file(const char *, const char *, const char *);
+const char *git_etc_gitconfig(void);
+int git_env_bool(const char *, int);
+unsigned long git_env_ulong(const char *, unsigned long);
+int git_config_system(void);
+int config_error_nonbool(const char *);
 #if defined(__GNUC__)
 #define config_error_nonbool(s) (config_error_nonbool(s), const_error())
 #endif
 
-extern int git_config_parse_parameter(const char *, config_fn_t fn, void *data);
+int git_config_parse_parameter(const char *, config_fn_t fn, void *data);
 
 enum config_scope {
 	CONFIG_SCOPE_UNKNOWN = 0,
@@ -138,9 +138,9 @@ enum config_scope {
 	CONFIG_SCOPE_CMDLINE,
 };
 
-extern enum config_scope current_config_scope(void);
-extern const char *current_config_origin_type(void);
-extern const char *current_config_name(void);
+enum config_scope current_config_scope(void);
+const char *current_config_origin_type(void);
+const char *current_config_name(void);
 
 struct config_include_data {
 	int depth;
@@ -149,7 +149,7 @@ struct config_include_data {
 	const struct config_options *opts;
 };
 #define CONFIG_INCLUDE_INIT { 0 }
-extern int git_config_include(const char *name, const char *value, void *data);
+int git_config_include(const char *name, const char *value, void *data);
 
 /*
  * Match and parse a config key of the form:
@@ -164,10 +164,10 @@ extern int git_config_include(const char *name, const char *value, void *data);
  * If the subsection pointer-to-pointer passed in is NULL, returns 0 only if
  * there is no subsection at all.
  */
-extern int parse_config_key(const char *var,
-			    const char *section,
-			    const char **subsection, int *subsection_len,
-			    const char **key);
+int parse_config_key(const char *var,
+		     const char *section,
+		     const char **subsection, int *subsection_len,
+		     const char **key);
 
 struct config_set_element {
 	struct hashmap_entry ent;
@@ -197,71 +197,71 @@ struct config_set {
 	struct configset_list list;
 };
 
-extern void git_configset_init(struct config_set *cs);
-extern int git_configset_add_file(struct config_set *cs, const char *filename);
-extern const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key);
-extern void git_configset_clear(struct config_set *cs);
+void git_configset_init(struct config_set *cs);
+int git_configset_add_file(struct config_set *cs, const char *filename);
+const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key);
+void git_configset_clear(struct config_set *cs);
 
 /*
  * These functions return 1 if not found, and 0 if found, leaving the found
  * value in the 'dest' pointer.
  */
-extern int git_configset_get_value(struct config_set *cs, const char *key, const char **dest);
-extern int git_configset_get_string_const(struct config_set *cs, const char *key, const char **dest);
-extern int git_configset_get_string(struct config_set *cs, const char *key, char **dest);
-extern int git_configset_get_int(struct config_set *cs, const char *key, int *dest);
-extern int git_configset_get_ulong(struct config_set *cs, const char *key, unsigned long *dest);
-extern int git_configset_get_bool(struct config_set *cs, const char *key, int *dest);
-extern int git_configset_get_bool_or_int(struct config_set *cs, const char *key, int *is_bool, int *dest);
-extern int git_configset_get_maybe_bool(struct config_set *cs, const char *key, int *dest);
-extern int git_configset_get_pathname(struct config_set *cs, const char *key, const char **dest);
+int git_configset_get_value(struct config_set *cs, const char *key, const char **dest);
+int git_configset_get_string_const(struct config_set *cs, const char *key, const char **dest);
+int git_configset_get_string(struct config_set *cs, const char *key, char **dest);
+int git_configset_get_int(struct config_set *cs, const char *key, int *dest);
+int git_configset_get_ulong(struct config_set *cs, const char *key, unsigned long *dest);
+int git_configset_get_bool(struct config_set *cs, const char *key, int *dest);
+int git_configset_get_bool_or_int(struct config_set *cs, const char *key, int *is_bool, int *dest);
+int git_configset_get_maybe_bool(struct config_set *cs, const char *key, int *dest);
+int git_configset_get_pathname(struct config_set *cs, const char *key, const char **dest);
 
 /* Functions for reading a repository's config */
 struct repository;
-extern void repo_config(struct repository *repo, config_fn_t fn, void *data);
-extern int repo_config_get_value(struct repository *repo,
-				 const char *key, const char **value);
-extern const struct string_list *repo_config_get_value_multi(struct repository *repo,
-							     const char *key);
-extern int repo_config_get_string_const(struct repository *repo,
-					const char *key, const char **dest);
-extern int repo_config_get_string(struct repository *repo,
-				  const char *key, char **dest);
-extern int repo_config_get_int(struct repository *repo,
+void repo_config(struct repository *repo, config_fn_t fn, void *data);
+int repo_config_get_value(struct repository *repo,
+			  const char *key, const char **value);
+const struct string_list *repo_config_get_value_multi(struct repository *repo,
+						      const char *key);
+int repo_config_get_string_const(struct repository *repo,
+				 const char *key, const char **dest);
+int repo_config_get_string(struct repository *repo,
+			   const char *key, char **dest);
+int repo_config_get_int(struct repository *repo,
+			const char *key, int *dest);
+int repo_config_get_ulong(struct repository *repo,
+			  const char *key, unsigned long *dest);
+int repo_config_get_bool(struct repository *repo,
+			 const char *key, int *dest);
+int repo_config_get_bool_or_int(struct repository *repo,
+				const char *key, int *is_bool, int *dest);
+int repo_config_get_maybe_bool(struct repository *repo,
 			       const char *key, int *dest);
-extern int repo_config_get_ulong(struct repository *repo,
-				 const char *key, unsigned long *dest);
-extern int repo_config_get_bool(struct repository *repo,
-				const char *key, int *dest);
-extern int repo_config_get_bool_or_int(struct repository *repo,
-				       const char *key, int *is_bool, int *dest);
-extern int repo_config_get_maybe_bool(struct repository *repo,
-				      const char *key, int *dest);
-extern int repo_config_get_pathname(struct repository *repo,
-				    const char *key, const char **dest);
+int repo_config_get_pathname(struct repository *repo,
+			     const char *key, const char **dest);
 
-extern int git_config_get_value(const char *key, const char **value);
-extern const struct string_list *git_config_get_value_multi(const char *key);
-extern void git_config_clear(void);
-extern int git_config_get_string_const(const char *key, const char **dest);
-extern int git_config_get_string(const char *key, char **dest);
-extern int git_config_get_int(const char *key, int *dest);
-extern int git_config_get_ulong(const char *key, unsigned long *dest);
-extern int git_config_get_bool(const char *key, int *dest);
-extern int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
-extern int git_config_get_maybe_bool(const char *key, int *dest);
-extern int git_config_get_pathname(const char *key, const char **dest);
-extern int git_config_get_index_threads(int *dest);
-extern int git_config_get_untracked_cache(void);
-extern int git_config_get_split_index(void);
-extern int git_config_get_max_percent_split_change(void);
-extern int git_config_get_fsmonitor(void);
+int git_config_get_value(const char *key, const char **value);
+const struct string_list *git_config_get_value_multi(const char *key);
+void git_config_clear(void);
+int git_config_get_string_const(const char *key, const char **dest);
+int git_config_get_string(const char *key, char **dest);
+int git_config_get_int(const char *key, int *dest);
+int git_config_get_ulong(const char *key, unsigned long *dest);
+int git_config_get_bool(const char *key, int *dest);
+int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
+int git_config_get_maybe_bool(const char *key, int *dest);
+int git_config_get_pathname(const char *key, const char **dest);
+int git_config_get_index_threads(int *dest);
+int git_config_get_untracked_cache(void);
+int git_config_get_split_index(void);
+int git_config_get_max_percent_split_change(void);
+int git_config_get_fsmonitor(void);
 
 /* This dies if the configured or default date is in the future */
-extern int git_config_get_expiry(const char *key, const char **output);
+int git_config_get_expiry(const char *key, const char **output);
 
 /* parse either "this many days" integer, or "5.days.ago" approxidate */
-extern int git_config_get_expiry_in_days(const char *key, timestamp_t *, timestamp_t now);
+int git_config_get_expiry_in_days(const char *key, timestamp_t *, timestamp_t now);
 
 struct key_value_info {
 	const char *filename;
@@ -270,8 +270,8 @@ struct key_value_info {
 	enum config_scope scope;
 };
 
-extern NORETURN void git_die_config(const char *key, const char *err, ...) __attribute__((format(printf, 2, 3)));
-extern NORETURN void git_die_config_linenr(const char *key, const char *filename, int linenr);
+NORETURN void git_die_config(const char *key, const char *err, ...) __attribute__((format(printf, 2, 3)));
+NORETURN void git_die_config_linenr(const char *key, const char *filename, int linenr);
 
 #define LOOKUP_CONFIG(mapping, var) \
 	lookup_config(mapping, ARRAY_SIZE(mapping), var)
diff --git a/connect.h b/connect.h
index 32aff60979..5f2382e018 100644
--- a/connect.h
+++ b/connect.h
@@ -7,19 +7,19 @@
 #define CONNECT_DIAG_URL      (1u << 1)
 #define CONNECT_IPV4          (1u << 2)
 #define CONNECT_IPV6          (1u << 3)
-extern struct child_process *git_connect(int fd[2], const char *url, const char *prog, int flags);
-extern int finish_connect(struct child_process *conn);
-extern int git_connection_is_socket(struct child_process *conn);
-extern int server_supports(const char *feature);
-extern int parse_feature_request(const char *features, const char *feature);
-extern const char *server_feature_value(const char *feature, int *len_ret);
-extern int url_is_local_not_ssh(const char *url);
+struct child_process *git_connect(int fd[2], const char *url, const char *prog, int flags);
+int finish_connect(struct child_process *conn);
+int git_connection_is_socket(struct child_process *conn);
+int server_supports(const char *feature);
+int parse_feature_request(const char *features, const char *feature);
+const char *server_feature_value(const char *feature, int *len_ret);
+int url_is_local_not_ssh(const char *url);
 
 struct packet_reader;
-extern enum protocol_version discover_version(struct packet_reader *reader);
+enum protocol_version discover_version(struct packet_reader *reader);
 
-extern int server_supports_v2(const char *c, int die_on_error);
-extern int server_supports_feature(const char *c, const char *feature,
-				   int die_on_error);
+int server_supports_v2(const char *c, int die_on_error);
+int server_supports_feature(const char *c, const char *feature,
+			    int die_on_error);
 
 #endif
diff --git a/csum-file.h b/csum-file.h
index 3bf7184736..a98b1eee53 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -25,22 +25,22 @@ struct hashfile_checkpoint {
 	git_hash_ctx ctx;
 };
 
-extern void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
-extern int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
+void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
+int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
 
 /* finalize_hashfile flags */
 #define CSUM_CLOSE		1
 #define CSUM_FSYNC		2
 #define CSUM_HASH_IN_STREAM	4
 
-extern struct hashfile *hashfd(int fd, const char *name);
-extern struct hashfile *hashfd_check(const char *name);
-extern struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp);
-extern int finalize_hashfile(struct hashfile *, unsigned char *, unsigned int);
-extern void hashwrite(struct hashfile *, const void *, unsigned int);
-extern void hashflush(struct hashfile *f);
-extern void crc32_begin(struct hashfile *);
-extern uint32_t crc32_end(struct hashfile *);
+struct hashfile *hashfd(int fd, const char *name);
+struct hashfile *hashfd_check(const char *name);
+struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp);
+int finalize_hashfile(struct hashfile *, unsigned char *, unsigned int);
+void hashwrite(struct hashfile *, const void *, unsigned int);
+void hashflush(struct hashfile *f);
+void crc32_begin(struct hashfile *);
+uint32_t crc32_end(struct hashfile *);
 
 static inline void hashwrite_u8(struct hashfile *f, uint8_t data)
 {
diff --git a/decorate.h b/decorate.h
index 9014c1e996..ee43dee1f0 100644
--- a/decorate.h
+++ b/decorate.h
@@ -50,12 +50,12 @@ struct decoration {
  * NULL), returning the previously associated pointer. If there is no previous
  * association, this function returns NULL.
  */
-extern void *add_decoration(struct decoration *n, const struct object *obj, void *decoration);
+void *add_decoration(struct decoration *n, const struct object *obj, void *decoration);
 
 /*
  * Return the pointer associated to the given object. If there is no
  * association, this function returns NULL.
  */
-extern void *lookup_decoration(struct decoration *n, const struct object *obj);
+void *lookup_decoration(struct decoration *n, const struct object *obj);
 
 #endif
diff --git a/delta.h b/delta.h
index 9b67531dfa..2df5fe13d9 100644
--- a/delta.h
+++ b/delta.h
@@ -13,7 +13,7 @@ struct delta_index;
  * before free_delta_index() is called.  The returned pointer must be freed
  * using free_delta_index().
  */
-extern struct delta_index *
+struct delta_index *
 create_delta_index(const void *buf, unsigned long bufsize);
 
 /*
@@ -21,14 +21,14 @@ create_delta_index(const void *buf, unsigned long bufsize);
  *
  * Given pointer must be what create_delta_index() returned, or NULL.
  */
-extern void free_delta_index(struct delta_index *index);
+void free_delta_index(struct delta_index *index);
 
 /*
  * sizeof_delta_index: returns memory usage of delta index
  *
  * Given pointer must be what create_delta_index() returned, or NULL.
  */
-extern unsigned long sizeof_delta_index(struct delta_index *index);
+unsigned long sizeof_delta_index(struct delta_index *index);
 
 /*
  * create_delta: create a delta from given index for the given buffer
@@ -40,7 +40,7 @@ extern unsigned long sizeof_delta_index(struct delta_index *index);
  * returned and *delta_size is updated with its size.  The returned buffer
  * must be freed by the caller.
  */
-extern void *
+void *
 create_delta(const struct delta_index *index,
 	     const void *buf, unsigned long bufsize,
 	     unsigned long *delta_size, unsigned long max_delta_size);
@@ -75,9 +75,9 @@ diff_delta(const void *src_buf, unsigned long src_bufsize,
  * *trg_bufsize is updated with its size.  On failure a NULL pointer is
  * returned.  The returned buffer must be freed by the caller.
  */
-extern void *patch_delta(const void *src_buf, unsigned long src_size,
-			 const void *delta_buf, unsigned long delta_size,
-			 unsigned long *dst_size);
+void *patch_delta(const void *src_buf, unsigned long src_size,
+		  const void *delta_buf, unsigned long delta_size,
+		  unsigned long *dst_size);
 
 /* the smallest possible delta size is 4 bytes */
 #define DELTA_SIZE_MIN	4
diff --git a/dir.h b/dir.h
index c23313b021..680079bbe3 100644
--- a/dir.h
+++ b/dir.h
@@ -202,7 +202,7 @@ struct dir_struct {
 };
 
 /*Count the number of slashes for string s*/
-extern int count_slashes(const char *s);
+int count_slashes(const char *s);
 
 /*
  * The ordering of these constants is significant, with
@@ -213,27 +213,27 @@ extern int count_slashes(const char *s);
 #define MATCHED_RECURSIVELY 1
 #define MATCHED_FNMATCH 2
 #define MATCHED_EXACTLY 3
-extern int simple_length(const char *match);
-extern int no_wildcard(const char *string);
-extern char *common_prefix(const struct pathspec *pathspec);
-extern int match_pathspec(const struct index_state *istate,
-			  const struct pathspec *pathspec,
-			  const char *name, int namelen,
-			  int prefix, char *seen, int is_dir);
-extern int report_path_error(const char *ps_matched, const struct pathspec *pathspec);
-extern int within_depth(const char *name, int namelen, int depth, int max_depth);
-
-extern int fill_directory(struct dir_struct *dir,
-			  struct index_state *istate,
-			  const struct pathspec *pathspec);
-extern int read_directory(struct dir_struct *, struct index_state *istate,
-			  const char *path, int len,
-			  const struct pathspec *pathspec);
-
-extern int is_excluded_from_list(const char *pathname, int pathlen,
-				 const char *basename, int *dtype,
-				 struct exclude_list *el,
-				 struct index_state *istate);
+int simple_length(const char *match);
+int no_wildcard(const char *string);
+char *common_prefix(const struct pathspec *pathspec);
+int match_pathspec(const struct index_state *istate,
+		   const struct pathspec *pathspec,
+		   const char *name, int namelen,
+		   int prefix, char *seen, int is_dir);
+int report_path_error(const char *ps_matched, const struct pathspec *pathspec);
+int within_depth(const char *name, int namelen, int depth, int max_depth);
+
+int fill_directory(struct dir_struct *dir,
+		   struct index_state *istate,
+		   const struct pathspec *pathspec);
+int read_directory(struct dir_struct *, struct index_state *istate,
+		   const char *path, int len,
+		   const struct pathspec *pathspec);
+
+int is_excluded_from_list(const char *pathname, int pathlen,
+			  const char *basename, int *dtype,
+			  struct exclude_list *el,
+			  struct index_state *istate);
 struct dir_entry *dir_add_ignored(struct dir_struct *dir,
 				  struct index_state *istate,
 				  const char *pathname, int len);
@@ -242,39 +242,39 @@ struct dir_entry *dir_add_ignored(struct dir_struct *dir,
  * these implement the matching logic for dir.c:excluded_from_list and
  * attr.c:path_matches()
  */
-extern int match_basename(const char *, int,
-			  const char *, int, int, unsigned);
-extern int match_pathname(const char *, int,
-			  const char *, int,
-			  const char *, int, int, unsigned);
-
-extern struct exclude *last_exclude_matching(struct dir_struct *dir,
-					     struct index_state *istate,
-					     const char *name, int *dtype);
-
-extern int is_excluded(struct dir_struct *dir,
-		       struct index_state *istate,
-		       const char *name, int *dtype);
-
-extern struct exclude_list *add_exclude_list(struct dir_struct *dir,
-					     int group_type, const char *src);
-extern int add_excludes_from_file_to_list(const char *fname, const char *base, int baselen,
-					  struct exclude_list *el, struct  index_state *istate);
-extern void add_excludes_from_file(struct dir_struct *, const char *fname);
-extern int add_excludes_from_blob_to_list(struct object_id *oid,
-					  const char *base, int baselen,
-					  struct exclude_list *el);
-extern void parse_exclude_pattern(const char **string, int *patternlen, unsigned *flags, int *nowildcardlen);
-extern void add_exclude(const char *string, const char *base,
-			int baselen, struct exclude_list *el, int srcpos);
-extern void clear_exclude_list(struct exclude_list *el);
-extern void clear_directory(struct dir_struct *dir);
+int match_basename(const char *, int,
+		   const char *, int, int, unsigned);
+int match_pathname(const char *, int,
+		   const char *, int,
+		   const char *, int, int, unsigned);
+
+struct exclude *last_exclude_matching(struct dir_struct *dir,
+				      struct index_state *istate,
+				      const char *name, int *dtype);
+
+int is_excluded(struct dir_struct *dir,
+		struct index_state *istate,
+		const char *name, int *dtype);
+
+struct exclude_list *add_exclude_list(struct dir_struct *dir,
+				      int group_type, const char *src);
+int add_excludes_from_file_to_list(const char *fname, const char *base, int baselen,
+				   struct exclude_list *el, struct  index_state *istate);
+void add_excludes_from_file(struct dir_struct *, const char *fname);
+int add_excludes_from_blob_to_list(struct object_id *oid,
+				   const char *base, int baselen,
+				   struct exclude_list *el);
+void parse_exclude_pattern(const char **string, int *patternlen, unsigned *flags, int *nowildcardlen);
+void add_exclude(const char *string, const char *base,
+		 int baselen, struct exclude_list *el, int srcpos);
+void clear_exclude_list(struct exclude_list *el);
+void clear_directory(struct dir_struct *dir);
 
 int repo_file_exists(struct repository *repo, const char *path);
 int file_exists(const char *);
 
-extern int is_inside_dir(const char *dir);
-extern int dir_inside_of(const char *subdir, const char *dir);
+int is_inside_dir(const char *dir);
+int dir_inside_of(const char *subdir, const char *dir);
 
 static inline int is_dot_or_dotdot(const char *name)
 {
@@ -283,9 +283,9 @@ static inline int is_dot_or_dotdot(const char *name)
 		 (name[1] == '.' && name[2] == '\0')));
 }
 
-extern int is_empty_dir(const char *dir);
+int is_empty_dir(const char *dir);
 
-extern void setup_standard_excludes(struct dir_struct *dir);
+void setup_standard_excludes(struct dir_struct *dir);
 
 
 /* Constants for remove_dir_recursively: */
@@ -313,26 +313,26 @@ extern void setup_standard_excludes(struct dir_struct *dir);
  * This function uses path as temporary scratch space, but restores it
  * before returning.
  */
-extern int remove_dir_recursively(struct strbuf *path, int flag);
+int remove_dir_recursively(struct strbuf *path, int flag);
 
 /* tries to remove the path with empty directories along it, ignores ENOENT */
-extern int remove_path(const char *path);
+int remove_path(const char *path);
 
-extern int fspathcmp(const char *a, const char *b);
-extern int fspathncmp(const char *a, const char *b, size_t count);
+int fspathcmp(const char *a, const char *b);
+int fspathncmp(const char *a, const char *b, size_t count);
 
 /*
  * The prefix part of pattern must not contains wildcards.
  */
 struct pathspec_item;
-extern int git_fnmatch(const struct pathspec_item *item,
-		       const char *pattern, const char *string,
-		       int prefix);
+int git_fnmatch(const struct pathspec_item *item,
+		const char *pattern, const char *string,
+		int prefix);
 
-extern int submodule_path_match(const struct index_state *istate,
-				const struct pathspec *ps,
-				const char *submodule_name,
-				char *seen);
+int submodule_path_match(const struct index_state *istate,
+			 const struct pathspec *ps,
+			 const char *submodule_name,
+			 char *seen);
 
 static inline int ce_path_match(const struct index_state *istate,
 				const struct cache_entry *ce,
@@ -374,10 +374,10 @@ void remove_untracked_cache(struct index_state *istate);
  * When `recurse_into_nested` is set, recurse into any nested submodules,
  * connecting them as well.
  */
-extern void connect_work_tree_and_git_dir(const char *work_tree,
-					  const char *git_dir,
-					  int recurse_into_nested);
-extern void relocate_gitdir(const char *path,
-			    const char *old_git_dir,
-			    const char *new_git_dir);
+void connect_work_tree_and_git_dir(const char *work_tree,
+				   const char *git_dir,
+				   int recurse_into_nested);
+void relocate_gitdir(const char *path,
+		     const char *old_git_dir,
+		     const char *new_git_dir);
 #endif
diff --git a/exec-cmd.h b/exec-cmd.h
index 2522453cda..8cd1df28d3 100644
--- a/exec-cmd.h
+++ b/exec-cmd.h
@@ -3,14 +3,14 @@
 
 struct argv_array;
 
-extern void git_set_exec_path(const char *exec_path);
-extern void git_resolve_executable_dir(const char *path);
-extern const char *git_exec_path(void);
-extern void setup_path(void);
-extern const char **prepare_git_cmd(struct argv_array *out, const char **argv);
-extern int execv_git_cmd(const char **argv); /* NULL terminated */
+void git_set_exec_path(const char *exec_path);
+void git_resolve_executable_dir(const char *path);
+const char *git_exec_path(void);
+void setup_path(void);
+const char **prepare_git_cmd(struct argv_array *out, const char **argv);
+int execv_git_cmd(const char **argv); /* NULL terminated */
 LAST_ARG_MUST_BE_NULL
-extern int execl_git_cmd(const char *cmd, ...);
-extern char *system_path(const char *path);
+int execl_git_cmd(const char *cmd, ...);
+char *system_path(const char *path);
 
 #endif /* GIT_EXEC_CMD_H */
diff --git a/fmt-merge-msg.h b/fmt-merge-msg.h
index b28d3a6113..01e3aa88c5 100644
--- a/fmt-merge-msg.h
+++ b/fmt-merge-msg.h
@@ -2,6 +2,6 @@
 #define FMT_MERGE_MSG_H
 
 extern int merge_log_config;
-extern int fmt_merge_msg_config(const char *key, const char *value, void *cb);
+int fmt_merge_msg_config(const char *key, const char *value, void *cb);
 
 #endif /* FMT_MERGE_MSG_H */
diff --git a/fsmonitor.h b/fsmonitor.h
index 01017c43aa..8489fa3244 100644
--- a/fsmonitor.h
+++ b/fsmonitor.h
@@ -10,31 +10,31 @@ extern struct trace_key trace_fsmonitor;
  * Read the fsmonitor index extension and (if configured) restore the
  * CE_FSMONITOR_VALID state.
  */
-extern int read_fsmonitor_extension(struct index_state *istate, const void *data, unsigned long sz);
+int read_fsmonitor_extension(struct index_state *istate, const void *data, unsigned long sz);
 
 /*
  * Fill the fsmonitor_dirty ewah bits with their state from the index,
  * before it is split during writing.
  */
-extern void fill_fsmonitor_bitmap(struct index_state *istate);
+void fill_fsmonitor_bitmap(struct index_state *istate);
 
 /*
  * Write the CE_FSMONITOR_VALID state into the fsmonitor index
  * extension.  Reads from the fsmonitor_dirty ewah in the index.
  */
-extern void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate);
+void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate);
 
 /*
  * Add/remove the fsmonitor index extension
  */
-extern void add_fsmonitor(struct index_state *istate);
-extern void remove_fsmonitor(struct index_state *istate);
+void add_fsmonitor(struct index_state *istate);
+void remove_fsmonitor(struct index_state *istate);
 
 /*
  * Add/remove the fsmonitor index extension as necessary based on the current
  * core.fsmonitor setting.
  */
-extern void tweak_fsmonitor(struct index_state *istate);
+void tweak_fsmonitor(struct index_state *istate);
 
 /*
  * Run the configured fsmonitor integration script and clear the
@@ -42,7 +42,7 @@ extern void tweak_fsmonitor(struct index_state *istate);
  * any corresponding untracked cache directory structures. Optimized to only
  * run the first time it is called.
  */
-extern void refresh_fsmonitor(struct index_state *istate);
+void refresh_fsmonitor(struct index_state *istate);
 
 /*
  * Set the given cache entries CE_FSMONITOR_VALID bit. This should be
diff --git a/gettext.h b/gettext.h
index 71255e503e..bee52eb113 100644
--- a/gettext.h
+++ b/gettext.h
@@ -28,11 +28,11 @@
 
 #define FORMAT_PRESERVING(n) __attribute__((format_arg(n)))
 
-extern int use_gettext_poison(void);
+int use_gettext_poison(void);
 
 #ifndef NO_GETTEXT
-extern void git_setup_gettext(void);
-extern int gettext_width(const char *s);
+void git_setup_gettext(void);
+int gettext_width(const char *s);
 #else
 static inline void git_setup_gettext(void)
 {
@@ -87,6 +87,6 @@ const char *Q_(const char *msgid, const char *plu, unsigned long n)
 #endif
 
 const char *get_preferred_languages(void);
-extern int is_utf8_locale(void);
+int is_utf8_locale(void);
 
 #endif
diff --git a/git-compat-util.h b/git-compat-util.h
index 4386b3e1c8..fd3460108b 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -250,7 +250,7 @@ typedef unsigned long uintptr_t;
 
 #ifdef MKDIR_WO_TRAILING_SLASH
 #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b))
-extern int compat_mkdir_wo_trailing_slash(const char*, mode_t);
+int compat_mkdir_wo_trailing_slash(const char*, mode_t);
 #endif
 
 #ifdef NO_STRUCT_ITIMERVAL
@@ -268,9 +268,9 @@ struct itimerval {
 #include <libgen.h>
 #else
 #define basename gitbasename
-extern char *gitbasename(char *);
+char *gitbasename(char *);
 #define dirname gitdirname
-extern char *gitdirname(char *);
+char *gitdirname(char *);
 #endif
 
 #ifndef NO_ICONV
@@ -447,15 +447,15 @@ static inline char *git_find_last_dir_sep(const char *path)
 struct strbuf;
 
 /* General helper functions */
-extern void vreportf(const char *prefix, const char *err, va_list params);
-extern NORETURN void usage(const char *err);
-extern NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
-extern NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
-extern NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
-extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
-extern int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
-extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
-extern void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
+void vreportf(const char *prefix, const char *err, va_list params);
+NORETURN void usage(const char *err);
+NORETURN void usagef(const char *err, ...) __attribute__((format (printf, 1, 2)));
+NORETURN void die(const char *err, ...) __attribute__((format (printf, 1, 2)));
+NORETURN void die_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
+int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
+int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
+void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
+void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
 #ifndef NO_OPENSSL
 #ifdef APPLE_COMMON_CRYPTO
@@ -483,15 +483,15 @@ static inline int const_error(void)
 #define error_errno(...) (error_errno(__VA_ARGS__), const_error())
 #endif
 
-extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
-extern void set_error_routine(void (*routine)(const char *err, va_list params));
+void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
+void set_error_routine(void (*routine)(const char *err, va_list params));
 extern void (*get_error_routine(void))(const char *err, va_list params);
-extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
+void set_warn_routine(void (*routine)(const char *warn, va_list params));
 extern void (*get_warn_routine(void))(const char *warn, va_list params);
-extern void set_die_is_recursing_routine(int (*routine)(void));
+void set_die_is_recursing_routine(int (*routine)(void));
 
-extern int starts_with(const char *str, const char *prefix);
-extern int istarts_with(const char *str, const char *prefix);
+int starts_with(const char *str, const char *prefix);
+int istarts_with(const char *str, const char *prefix);
 
 /*
  * If the string "str" begins with the string found in "prefix", return 1.
@@ -614,8 +614,8 @@ static inline int ends_with(const char *str, const char *suffix)
 
 #define mmap git_mmap
 #define munmap git_munmap
-extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
-extern int git_munmap(void *start, size_t length);
+void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
+int git_munmap(void *start, size_t length);
 
 #else /* NO_MMAP || USE_WIN32_MMAP */
 
@@ -669,17 +669,17 @@ extern int git_munmap(void *start, size_t length);
 #undef stat
 #endif
 #define stat(path, buf) git_stat(path, buf)
-extern int git_stat(const char *, struct stat *);
+int git_stat(const char *, struct stat *);
 #ifdef fstat
 #undef fstat
 #endif
 #define fstat(fd, buf) git_fstat(fd, buf)
-extern int git_fstat(int, struct stat *);
+int git_fstat(int, struct stat *);
 #ifdef lstat
 #undef lstat
 #endif
 #define lstat(path, buf) git_lstat(path, buf)
-extern int git_lstat(const char *, struct stat *);
+int git_lstat(const char *, struct stat *);
 #endif
 
 #define DEFAULT_PACKED_GIT_LIMIT \
@@ -687,50 +687,50 @@ extern int git_lstat(const char *, struct stat *);
 
 #ifdef NO_PREAD
 #define pread git_pread
-extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
+ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
 #endif
 /*
  * Forward decl that will remind us if its twin in cache.h changes.
  * This function is used in compat/pread.c.  But we can't include
  * cache.h there.
  */
-extern ssize_t read_in_full(int fd, void *buf, size_t count);
+ssize_t read_in_full(int fd, void *buf, size_t count);
 
 #ifdef NO_SETENV
 #define setenv gitsetenv
-extern int gitsetenv(const char *, const char *, int);
+int gitsetenv(const char *, const char *, int);
 #endif
 
 #ifdef NO_MKDTEMP
 #define mkdtemp gitmkdtemp
-extern char *gitmkdtemp(char *);
+char *gitmkdtemp(char *);
 #endif
 
 #ifdef NO_UNSETENV
 #define unsetenv gitunsetenv
-extern void gitunsetenv(const char *);
+void gitunsetenv(const char *);
 #endif
 
 #ifdef NO_STRCASESTR
 #define strcasestr gitstrcasestr
-extern char *gitstrcasestr(const char *haystack, const char *needle);
+char *gitstrcasestr(const char *haystack, const char *needle);
 #endif
 
 #ifdef NO_STRLCPY
 #define strlcpy gitstrlcpy
-extern size_t gitstrlcpy(char *, const char *, size_t);
+size_t gitstrlcpy(char *, const char *, size_t);
 #endif
 
 #ifdef NO_STRTOUMAX
 #define strtoumax gitstrtoumax
-extern uintmax_t gitstrtoumax(const char *, char **, int);
+uintmax_t gitstrtoumax(const char *, char **, int);
 #define strtoimax gitstrtoimax
-extern intmax_t gitstrtoimax(const char *, char **, int);
+intmax_t gitstrtoimax(const char *, char **, int);
 #endif
 
 #ifdef NO_HSTRERROR
 #define hstrerror githstrerror
-extern const char *githstrerror(int herror);
+const char *githstrerror(int herror);
 #endif
 
 #ifdef NO_MEMMEM
@@ -762,7 +762,7 @@ char *gitstrdup(const char *s);
 #  endif
 #  define fopen(a,b) git_fopen(a,b)
 # endif
-extern FILE *git_fopen(const char*, const char*);
+FILE *git_fopen(const char*, const char*);
 #endif
 
 #ifdef SNPRINTF_RETURNS_BOGUS
@@ -770,14 +770,14 @@ extern FILE *git_fopen(const char*, const char*);
 #undef snprintf
 #endif
 #define snprintf git_snprintf
-extern int git_snprintf(char *str, size_t maxsize,
-			const char *format, ...);
+int git_snprintf(char *str, size_t maxsize,
+		 const char *format, ...);
 #ifdef vsnprintf
 #undef vsnprintf
 #endif
 #define vsnprintf git_vsnprintf
-extern int git_vsnprintf(char *str, size_t maxsize,
-			 const char *format, va_list ap);
+int git_vsnprintf(char *str, size_t maxsize,
+		  const char *format, va_list ap);
 #endif
 
 #ifdef __GLIBC_PREREQ
@@ -806,11 +806,11 @@ const char *inet_ntop(int af, const void *src, char *dst, size_t size);
 
 #ifdef NO_PTHREADS
 #define atexit git_atexit
-extern int git_atexit(void (*handler)(void));
+int git_atexit(void (*handler)(void));
 #endif
 
 typedef void (*try_to_free_t)(size_t);
-extern try_to_free_t set_try_to_free_routine(try_to_free_t);
+try_to_free_t set_try_to_free_routine(try_to_free_t);
 
 static inline size_t st_add(size_t a, size_t b)
 {
@@ -846,28 +846,28 @@ static inline size_t st_sub(size_t a, size_t b)
 # define xalloca(size)      (xmalloc(size))
 # define xalloca_free(p)    (free(p))
 #endif
-extern char *xstrdup(const char *str);
-extern void *xmalloc(size_t size);
-extern void *xmallocz(size_t size);
-extern void *xmallocz_gently(size_t size);
-extern void *xmemdupz(const void *data, size_t len);
-extern char *xstrndup(const char *str, size_t len);
-extern void *xrealloc(void *ptr, size_t size);
-extern void *xcalloc(size_t nmemb, size_t size);
-extern void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
-extern void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
-extern int xopen(const char *path, int flags, ...);
-extern ssize_t xread(int fd, void *buf, size_t len);
-extern ssize_t xwrite(int fd, const void *buf, size_t len);
-extern ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
-extern int xdup(int fd);
-extern FILE *xfopen(const char *path, const char *mode);
-extern FILE *xfdopen(int fd, const char *mode);
-extern int xmkstemp(char *temp_filename);
-extern int xmkstemp_mode(char *temp_filename, int mode);
-extern char *xgetcwd(void);
-extern FILE *fopen_for_writing(const char *path);
-extern FILE *fopen_or_warn(const char *path, const char *mode);
+char *xstrdup(const char *str);
+void *xmalloc(size_t size);
+void *xmallocz(size_t size);
+void *xmallocz_gently(size_t size);
+void *xmemdupz(const void *data, size_t len);
+char *xstrndup(const char *str, size_t len);
+void *xrealloc(void *ptr, size_t size);
+void *xcalloc(size_t nmemb, size_t size);
+void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
+void *xmmap_gently(void *start, size_t length, int prot, int flags, int fd, off_t offset);
+int xopen(const char *path, int flags, ...);
+ssize_t xread(int fd, void *buf, size_t len);
+ssize_t xwrite(int fd, const void *buf, size_t len);
+ssize_t xpread(int fd, void *buf, size_t len, off_t offset);
+int xdup(int fd);
+FILE *xfopen(const char *path, const char *mode);
+FILE *xfdopen(int fd, const char *mode);
+int xmkstemp(char *temp_filename);
+int xmkstemp_mode(char *temp_filename, int mode);
+char *xgetcwd(void);
+FILE *fopen_for_writing(const char *path);
+FILE *fopen_or_warn(const char *path, const char *mode);
 
 /*
  * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
@@ -967,13 +967,13 @@ static inline size_t xsize_t(off_t len)
 }
 
 __attribute__((format (printf, 3, 4)))
-extern int xsnprintf(char *dst, size_t max, const char *fmt, ...);
+int xsnprintf(char *dst, size_t max, const char *fmt, ...);
 
 #ifndef HOST_NAME_MAX
 #define HOST_NAME_MAX 256
 #endif
 
-extern int xgethostname(char *buf, size_t len);
+int xgethostname(char *buf, size_t len);
 
 /* in ctype.c, for kwset users */
 extern const unsigned char tolower_trans_tbl[256];
@@ -1258,7 +1258,7 @@ static inline int is_missing_file_error(int errno_)
 	return (errno_ == ENOENT || errno_ == ENOTDIR);
 }
 
-extern int cmd_main(int, const char **);
+int cmd_main(int, const char **);
 
 /*
  * Intercept all calls to exit() and route them to trace2 to
@@ -1281,7 +1281,7 @@ int trace2_cmd_exit_fl(const char *file, int line, int code);
  * an annotation, and does nothing in non-leak-checking builds.
  */
 #ifdef SUPPRESS_ANNOTATED_LEAKS
-extern void unleak_memory(const void *ptr, size_t len);
+void unleak_memory(const void *ptr, size_t len);
 #define UNLEAK(var) unleak_memory(&(var), sizeof(var))
 #else
 #define UNLEAK(var) do {} while (0)
diff --git a/grep.h b/grep.h
index fb04893721..1875880f37 100644
--- a/grep.h
+++ b/grep.h
@@ -186,17 +186,17 @@ struct grep_opt {
 	void *output_priv;
 };
 
-extern void init_grep_defaults(struct repository *);
-extern int grep_config(const char *var, const char *value, void *);
-extern void grep_init(struct grep_opt *, struct repository *repo, const char *prefix);
+void init_grep_defaults(struct repository *);
+int grep_config(const char *var, const char *value, void *);
+void grep_init(struct grep_opt *, struct repository *repo, const char *prefix);
 void grep_commit_pattern_type(enum grep_pattern_type, struct grep_opt *opt);
 
-extern void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen, const char *origin, int no, enum grep_pat_token t);
-extern void append_grep_pattern(struct grep_opt *opt, const char *pat, const char *origin, int no, enum grep_pat_token t);
-extern void append_header_grep_pattern(struct grep_opt *, enum grep_header_field, const char *);
-extern void compile_grep_patterns(struct grep_opt *opt);
-extern void free_grep_patterns(struct grep_opt *opt);
-extern int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size);
+void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen, const char *origin, int no, enum grep_pat_token t);
+void append_grep_pattern(struct grep_opt *opt, const char *pat, const char *origin, int no, enum grep_pat_token t);
+void append_header_grep_pattern(struct grep_opt *, enum grep_header_field, const char *);
+void compile_grep_patterns(struct grep_opt *opt);
+void free_grep_patterns(struct grep_opt *opt);
+int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size);
 
 struct grep_source {
 	char *name;
@@ -226,8 +226,8 @@ void grep_source_load_driver(struct grep_source *gs,
 
 int grep_source(struct grep_opt *opt, struct grep_source *gs);
 
-extern struct grep_opt *grep_opt_dup(const struct grep_opt *opt);
-extern int grep_threads_ok(const struct grep_opt *opt);
+struct grep_opt *grep_opt_dup(const struct grep_opt *opt);
+int grep_threads_ok(const struct grep_opt *opt);
 
 /*
  * Mutex used around access to the attributes machinery if
diff --git a/hashmap.h b/hashmap.h
index d375d9cce7..f95593b6cf 100644
--- a/hashmap.h
+++ b/hashmap.h
@@ -104,11 +104,11 @@
  * `memihash_cont` is a variant of `memihash` that allows a computation to be
  * continued with another chunk of data.
  */
-extern unsigned int strhash(const char *buf);
-extern unsigned int strihash(const char *buf);
-extern unsigned int memhash(const void *buf, size_t len);
-extern unsigned int memihash(const void *buf, size_t len);
-extern unsigned int memihash_cont(unsigned int hash_seed, const void *buf, size_t len);
+unsigned int strhash(const char *buf);
+unsigned int strihash(const char *buf);
+unsigned int memhash(const void *buf, size_t len);
+unsigned int memihash(const void *buf, size_t len);
+unsigned int memihash_cont(unsigned int hash_seed, const void *buf, size_t len);
 
 /*
  * Converts a cryptographic hash (e.g. SHA-1) into an int-sized hash code
@@ -216,7 +216,7 @@ struct hashmap {
  * parameter may be used to preallocate a sufficiently large table and thus
  * prevent expensive resizing. If 0, the table is dynamically resized.
  */
-extern void hashmap_init(struct hashmap *map,
+void hashmap_init(struct hashmap *map,
 			 hashmap_cmp_fn equals_function,
 			 const void *equals_function_data,
 			 size_t initial_size);
@@ -227,7 +227,7 @@ extern void hashmap_init(struct hashmap *map,
  * If `free_entries` is true, each hashmap_entry in the map is freed as well
  * using stdlibs free().
  */
-extern void hashmap_free(struct hashmap *map, int free_entries);
+void hashmap_free(struct hashmap *map, int free_entries);
 
 /* hashmap_entry functions */
 
@@ -284,7 +284,7 @@ static inline unsigned int hashmap_get_size(struct hashmap *map)
  * If an entry with matching hash code is found, `key` and `keydata` are passed
  * to `hashmap_cmp_fn` to decide whether the entry matches the key.
  */
-extern void *hashmap_get(const struct hashmap *map, const void *key,
+void *hashmap_get(const struct hashmap *map, const void *key,
 			 const void *keydata);
 
 /*
@@ -316,7 +316,7 @@ static inline void *hashmap_get_from_hash(const struct hashmap *map,
  * `entry` is the hashmap_entry to start the search from, obtained via a previous
  * call to `hashmap_get` or `hashmap_get_next`.
  */
-extern void *hashmap_get_next(const struct hashmap *map, const void *entry);
+void *hashmap_get_next(const struct hashmap *map, const void *entry);
 
 /*
  * Adds a hashmap entry. This allows to add duplicate entries (i.e.
@@ -325,7 +325,7 @@ extern void *hashmap_get_next(const struct hashmap *map, const void *entry);
  * `map` is the hashmap structure.
  * `entry` is the entry to add.
  */
-extern void hashmap_add(struct hashmap *map, void *entry);
+void hashmap_add(struct hashmap *map, void *entry);
 
 /*
  * Adds or replaces a hashmap entry. If the hashmap contains duplicate
@@ -335,7 +335,7 @@ extern void hashmap_add(struct hashmap *map, void *entry);
  * `entry` is the entry to add or replace.
  * Returns the replaced entry, or NULL if not found (i.e. the entry was added).
  */
-extern void *hashmap_put(struct hashmap *map, void *entry);
+void *hashmap_put(struct hashmap *map, void *entry);
 
 /*
  * Removes a hashmap entry matching the specified key. If the hashmap contains
@@ -344,7 +344,7 @@ extern void *hashmap_put(struct hashmap *map, void *entry);
  *
  * Argument explanation is the same as in `hashmap_get`.
  */
-extern void *hashmap_remove(struct hashmap *map, const void *key,
+void *hashmap_remove(struct hashmap *map, const void *key,
 		const void *keydata);
 
 /*
@@ -365,10 +365,10 @@ struct hashmap_iter {
 };
 
 /* Initializes a `hashmap_iter` structure. */
-extern void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter);
+void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter);
 
 /* Returns the next hashmap_entry, or NULL if there are no more entries. */
-extern void *hashmap_iter_next(struct hashmap_iter *iter);
+void *hashmap_iter_next(struct hashmap_iter *iter);
 
 /* Initializes the iterator and returns the first entry, if any. */
 static inline void *hashmap_iter_first(struct hashmap *map,
@@ -429,7 +429,7 @@ static inline void hashmap_enable_item_counting(struct hashmap *map)
  *
  * Uses a hashmap to store the pool of interned strings.
  */
-extern const void *memintern(const void *data, size_t len);
+const void *memintern(const void *data, size_t len);
 static inline const char *strintern(const char *string)
 {
 	return memintern(string, strlen(string));
diff --git a/help.h b/help.h
index a141e209ae..b8780fbd0f 100644
--- a/help.h
+++ b/help.h
@@ -19,31 +19,31 @@ static inline void mput_char(char c, unsigned int num)
 		putchar(c);
 }
 
-extern void list_common_cmds_help(void);
-extern void list_all_cmds_help(void);
-extern void list_common_guides_help(void);
-extern void list_config_help(int for_human);
+void list_common_cmds_help(void);
+void list_all_cmds_help(void);
+void list_common_guides_help(void);
+void list_config_help(int for_human);
 
-extern void list_all_main_cmds(struct string_list *list);
-extern void list_all_other_cmds(struct string_list *list);
-extern void list_cmds_by_category(struct string_list *list,
-				  const char *category);
-extern void list_cmds_by_config(struct string_list *list);
-extern const char *help_unknown_cmd(const char *cmd);
-extern void load_command_list(const char *prefix,
-			      struct cmdnames *main_cmds,
-			      struct cmdnames *other_cmds);
-extern void add_cmdname(struct cmdnames *cmds, const char *name, int len);
+void list_all_main_cmds(struct string_list *list);
+void list_all_other_cmds(struct string_list *list);
+void list_cmds_by_category(struct string_list *list,
+			   const char *category);
+void list_cmds_by_config(struct string_list *list);
+const char *help_unknown_cmd(const char *cmd);
+void load_command_list(const char *prefix,
+		       struct cmdnames *main_cmds,
+		       struct cmdnames *other_cmds);
+void add_cmdname(struct cmdnames *cmds, const char *name, int len);
 /* Here we require that excludes is a sorted list. */
-extern void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes);
-extern int is_in_cmdlist(struct cmdnames *cmds, const char *name);
-extern void list_commands(unsigned int colopts, struct cmdnames *main_cmds, struct cmdnames *other_cmds);
+void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes);
+int is_in_cmdlist(struct cmdnames *cmds, const char *name);
+void list_commands(unsigned int colopts, struct cmdnames *main_cmds, struct cmdnames *other_cmds);
 
 /*
  * call this to die(), when it is suspected that the user mistyped a
  * ref to the command, to give suggested "correct" refs.
  */
-extern void help_unknown_ref(const char *ref, const char *cmd, const char *error);
+void help_unknown_ref(const char *ref, const char *cmd, const char *error);
 
 static inline void list_config_item(struct string_list *list,
 				    const char *prefix,
diff --git a/http.h b/http.h
index ddfe52f023..b429f1cf04 100644
--- a/http.h
+++ b/http.h
@@ -75,18 +75,18 @@ struct buffer {
 };
 
 /* Curl request read/write callbacks */
-extern size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
-extern size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
-extern size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
+size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
+size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
+size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
 #ifndef NO_CURL_IOCTL
-extern curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);
+curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);
 #endif
 
 /* Slot lifecycle functions */
-extern struct active_request_slot *get_active_slot(void);
-extern int start_active_slot(struct active_request_slot *slot);
-extern void run_active_slot(struct active_request_slot *slot);
-extern void finish_all_active_slots(void);
+struct active_request_slot *get_active_slot(void);
+int start_active_slot(struct active_request_slot *slot);
+void run_active_slot(struct active_request_slot *slot);
+void finish_all_active_slots(void);
 
 /*
  * This will run one slot to completion in a blocking manner, similar to how
@@ -98,15 +98,15 @@ int run_one_slot(struct active_request_slot *slot,
 		 struct slot_results *results);
 
 #ifdef USE_CURL_MULTI
-extern void fill_active_slots(void);
-extern void add_fill_function(void *data, int (*fill)(void *));
-extern void step_active_slots(void);
+void fill_active_slots(void);
+void add_fill_function(void *data, int (*fill)(void *));
+void step_active_slots(void);
 #endif
 
-extern void http_init(struct remote *remote, const char *url,
-		      int proactive_auth);
-extern void http_cleanup(void);
-extern struct curl_slist *http_copy_default_headers(void);
+void http_init(struct remote *remote, const char *url,
+	       int proactive_auth);
+void http_cleanup(void);
+struct curl_slist *http_copy_default_headers(void);
 
 extern long int git_curl_ipresolve;
 extern int active_requests;
@@ -146,11 +146,11 @@ void normalize_curl_result(CURLcode *result, long http_code, char *errorstr,
 			   size_t errorlen);
 
 /* Helpers for modifying and creating URLs */
-extern void append_remote_object_url(struct strbuf *buf, const char *url,
-				     const char *hex,
-				     int only_two_digit_prefix);
-extern char *get_remote_object_url(const char *url, const char *hex,
-				   int only_two_digit_prefix);
+void append_remote_object_url(struct strbuf *buf, const char *url,
+			      const char *hex,
+			      int only_two_digit_prefix);
+char *get_remote_object_url(const char *url, const char *hex,
+			    int only_two_digit_prefix);
 
 /* Options for http_get_*() */
 struct http_get_options {
@@ -204,11 +204,11 @@ struct http_get_options {
  */
 int http_get_strbuf(const char *url, struct strbuf *result, struct http_get_options *options);
 
-extern int http_fetch_ref(const char *base, struct ref *ref);
+int http_fetch_ref(const char *base, struct ref *ref);
 
 /* Helpers for fetching packs */
-extern int http_get_info_packs(const char *base_url,
-	struct packed_git **packs_head);
+int http_get_info_packs(const char *base_url,
+			struct packed_git **packs_head);
 
 struct http_pack_request {
 	char *url;
@@ -219,10 +219,10 @@ struct http_pack_request {
 	struct active_request_slot *slot;
 };
 
-extern struct http_pack_request *new_http_pack_request(
+struct http_pack_request *new_http_pack_request(
 	struct packed_git *target, const char *base_url);
-extern int finish_http_pack_request(struct http_pack_request *preq);
-extern void release_http_pack_request(struct http_pack_request *preq);
+int finish_http_pack_request(struct http_pack_request *preq);
+void release_http_pack_request(struct http_pack_request *preq);
 
 /* Helpers for fetching object */
 struct http_object_request {
@@ -241,12 +241,12 @@ struct http_object_request {
 	struct active_request_slot *slot;
 };
 
-extern struct http_object_request *new_http_object_request(
+struct http_object_request *new_http_object_request(
 	const char *base_url, const struct object_id *oid);
-extern void process_http_object_request(struct http_object_request *freq);
-extern int finish_http_object_request(struct http_object_request *freq);
-extern void abort_http_object_request(struct http_object_request *freq);
-extern void release_http_object_request(struct http_object_request *freq);
+void process_http_object_request(struct http_object_request *freq);
+int finish_http_object_request(struct http_object_request *freq);
+void abort_http_object_request(struct http_object_request *freq);
+void release_http_object_request(struct http_object_request *freq);
 
 /* setup routine for curl_easy_setopt CURLOPT_DEBUGFUNCTION */
 void setup_curl_trace(CURL *handle);
diff --git a/khash.h b/khash.h
index a09163b3e3..af747a683f 100644
--- a/khash.h
+++ b/khash.h
@@ -69,14 +69,14 @@ static const double __ac_HASH_UPPER = 0.77;
 		khval_t *vals; \
 	} kh_##name##_t;
 
-#define __KHASH_PROTOTYPES(name, khkey_t, khval_t)	 					\
-	extern kh_##name##_t *kh_init_##name(void);							\
-	extern void kh_destroy_##name(kh_##name##_t *h);					\
-	extern void kh_clear_##name(kh_##name##_t *h);						\
-	extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); 	\
-	extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \
-	extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \
-	extern void kh_del_##name(kh_##name##_t *h, khint_t x);
+#define __KHASH_PROTOTYPES(name, khkey_t, khval_t)	 			\
+	kh_##name##_t *kh_init_##name(void);						\
+	void kh_destroy_##name(kh_##name##_t *h);					\
+	void kh_clear_##name(kh_##name##_t *h);						\
+	khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); \
+	int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \
+	khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \
+	void kh_del_##name(kh_##name##_t *h, khint_t x);
 
 #define __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
 	SCOPE kh_##name##_t *kh_init_##name(void) {							\
diff --git a/kwset.h b/kwset.h
index 583f6268ef..df99a92178 100644
--- a/kwset.h
+++ b/kwset.h
@@ -37,16 +37,16 @@ typedef struct kwset_t* kwset_t;
    if enough memory cannot be obtained.  The argument if non-NULL
    specifies a table of character translations to be applied to all
    pattern and search text. */
-extern kwset_t kwsalloc(unsigned char const *);
+kwset_t kwsalloc(unsigned char const *);
 
 /* Incrementally extend the keyword set to include the given string.
    Return NULL for success, or an error message.  Remember an index
    number for each keyword included in the set. */
-extern const char *kwsincr(kwset_t, char const *, size_t);
+const char *kwsincr(kwset_t, char const *, size_t);
 
 /* When the keyword set has been completely built, prepare it for
    use.  Return NULL for success, or an error message. */
-extern const char *kwsprep(kwset_t);
+const char *kwsprep(kwset_t);
 
 /* Search through the given buffer for a member of the keyword set.
    Return a pointer to the leftmost longest match found, or NULL if
@@ -54,8 +54,8 @@ extern const char *kwsprep(kwset_t);
    the matching substring in the integer it points to.  Similarly,
    if foundindex is non-NULL, store the index of the particular
    keyword found therein. */
-extern size_t kwsexec(kwset_t, char const *, size_t, struct kwsmatch *);
+size_t kwsexec(kwset_t, char const *, size_t, struct kwsmatch *);
 
 /* Deallocate the given keyword set and all its associated storage. */
-extern void kwsfree(kwset_t);
+void kwsfree(kwset_t);
 
diff --git a/line-log.h b/line-log.h
index e2a5ee7c6d..8ee7a2bd4a 100644
--- a/line-log.h
+++ b/line-log.h
@@ -25,17 +25,17 @@ struct diff_ranges {
 	struct range_set target;
 };
 
-extern void range_set_init(struct range_set *, size_t prealloc);
-extern void range_set_release(struct range_set *);
+void range_set_init(struct range_set *, size_t prealloc);
+void range_set_release(struct range_set *);
 /* Range includes start; excludes end */
-extern void range_set_append_unsafe(struct range_set *, long start, long end);
+void range_set_append_unsafe(struct range_set *, long start, long end);
 /* New range must begin at or after end of last added range */
-extern void range_set_append(struct range_set *, long start, long end);
+void range_set_append(struct range_set *, long start, long end);
 /*
  * In-place pass of sorting and merging the ranges in the range set,
  * to sort and make the ranges disjoint.
  */
-extern void sort_and_merge_range_set(struct range_set *);
+void sort_and_merge_range_set(struct range_set *);
 
 /* Linked list of interesting files and their associated ranges.  The
  * list must be kept sorted by path.
@@ -54,10 +54,10 @@ struct line_log_data {
 	struct diff_ranges diff;
 };
 
-extern void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args);
+void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args);
 
-extern int line_log_filter(struct rev_info *rev);
+int line_log_filter(struct rev_info *rev);
 
-extern int line_log_print(struct rev_info *rev, struct commit *commit);
+int line_log_print(struct rev_info *rev, struct commit *commit);
 
 #endif /* LINE_LOG_H */
diff --git a/lockfile.h b/lockfile.h
index 35403ccc0d..9843053ce8 100644
--- a/lockfile.h
+++ b/lockfile.h
@@ -159,7 +159,7 @@ struct lock_file {
  * timeout_ms is -1, retry indefinitely. The flags argument and error
  * handling are described above.
  */
-extern int hold_lock_file_for_update_timeout(
+int hold_lock_file_for_update_timeout(
 		struct lock_file *lk, const char *path,
 		int flags, long timeout_ms);
 
@@ -188,8 +188,8 @@ static inline int is_lock_file_locked(struct lock_file *lk)
  * of `hold_lock_file_for_update()` to lock `path`. `err` should be the
  * `errno` set by the failing call.
  */
-extern void unable_to_lock_message(const char *path, int err,
-				   struct strbuf *buf);
+void unable_to_lock_message(const char *path, int err,
+			    struct strbuf *buf);
 
 /*
  * Emit an appropriate error message and `die()` following the failure
@@ -197,7 +197,7 @@ extern void unable_to_lock_message(const char *path, int err,
  * `errno` set by the failing
  * call.
  */
-extern NORETURN void unable_to_lock_die(const char *path, int err);
+NORETURN void unable_to_lock_die(const char *path, int err);
 
 /*
  * Associate a stdio stream with the lockfile (which must still be
@@ -234,7 +234,7 @@ static inline FILE *get_lock_file_fp(struct lock_file *lk)
  * Return the path of the file that is locked by the specified
  * lock_file object. The caller must free the memory.
  */
-extern char *get_locked_file_path(struct lock_file *lk);
+char *get_locked_file_path(struct lock_file *lk);
 
 /*
  * If the lockfile is still open, close it (and the file pointer if it
@@ -282,7 +282,7 @@ static inline int reopen_lock_file(struct lock_file *lk)
  * call `commit_lock_file()` for a `lock_file` object that is not
  * currently locked.
  */
-extern int commit_lock_file(struct lock_file *lk);
+int commit_lock_file(struct lock_file *lk);
 
 /*
  * Like `commit_lock_file()`, but rename the lockfile to the provided
diff --git a/ls-refs.h b/ls-refs.h
index b62877e8da..7e5646f5f6 100644
--- a/ls-refs.h
+++ b/ls-refs.h
@@ -4,7 +4,7 @@
 struct repository;
 struct argv_array;
 struct packet_reader;
-extern int ls_refs(struct repository *r, struct argv_array *keys,
-		   struct packet_reader *request);
+int ls_refs(struct repository *r, struct argv_array *keys,
+	    struct packet_reader *request);
 
 #endif /* LS_REFS_H */
diff --git a/mailinfo.h b/mailinfo.h
index 6830e1e625..79b1d6774e 100644
--- a/mailinfo.h
+++ b/mailinfo.h
@@ -39,8 +39,8 @@ struct mailinfo {
 	int input_error;
 };
 
-extern void setup_mailinfo(struct mailinfo *);
-extern int mailinfo(struct mailinfo *, const char *msg, const char *patch);
-extern void clear_mailinfo(struct mailinfo *);
+void setup_mailinfo(struct mailinfo *);
+int mailinfo(struct mailinfo *, const char *msg, const char *patch);
+void clear_mailinfo(struct mailinfo *);
 
 #endif /* MAILINFO_H */
diff --git a/merge-blobs.h b/merge-blobs.h
index cc31038b80..13cf9669e5 100644
--- a/merge-blobs.h
+++ b/merge-blobs.h
@@ -4,8 +4,8 @@
 struct blob;
 struct index_state;
 
-extern void *merge_blobs(struct index_state *, const char *,
-			 struct blob *, struct blob *,
-			 struct blob *, unsigned long *);
+void *merge_blobs(struct index_state *, const char *,
+		  struct blob *, struct blob *,
+		  struct blob *, unsigned long *);
 
 #endif /* MERGE_BLOBS_H */
diff --git a/object-store.h b/object-store.h
index b086f5ecdb..46a1da79cc 100644
--- a/object-store.h
+++ b/object-store.h
@@ -162,10 +162,10 @@ const char *loose_object_path(struct repository *r, struct strbuf *buf,
 void *map_loose_object(struct repository *r, const struct object_id *oid,
 		       unsigned long *size);
 
-extern void *read_object_file_extended(struct repository *r,
-				       const struct object_id *oid,
-				       enum object_type *type,
-				       unsigned long *size, int lookup_replace);
+void *read_object_file_extended(struct repository *r,
+				const struct object_id *oid,
+				enum object_type *type,
+				unsigned long *size, int lookup_replace);
 static inline void *repo_read_object_file(struct repository *r,
 					  const struct object_id *oid,
 					  enum object_type *type,
@@ -180,20 +180,20 @@ static inline void *repo_read_object_file(struct repository *r,
 /* Read and unpack an object file into memory, write memory to an object file */
 int oid_object_info(struct repository *r, const struct object_id *, unsigned long *);
 
-extern int hash_object_file(const void *buf, unsigned long len,
-			    const char *type, struct object_id *oid);
+int hash_object_file(const void *buf, unsigned long len,
+		     const char *type, struct object_id *oid);
 
-extern int write_object_file(const void *buf, unsigned long len,
-			     const char *type, struct object_id *oid);
+int write_object_file(const void *buf, unsigned long len,
+		      const char *type, struct object_id *oid);
 
-extern int hash_object_file_literally(const void *buf, unsigned long len,
-				      const char *type, struct object_id *oid,
-				      unsigned flags);
+int hash_object_file_literally(const void *buf, unsigned long len,
+			       const char *type, struct object_id *oid,
+			       unsigned flags);
 
-extern int pretend_object_file(void *, unsigned long, enum object_type,
-			       struct object_id *oid);
+int pretend_object_file(void *, unsigned long, enum object_type,
+			struct object_id *oid);
 
-extern int force_object_loose(const struct object_id *oid, time_t mtime);
+int force_object_loose(const struct object_id *oid, time_t mtime);
 
 /*
  * Open the loose object at path, check its hash, and return the contents,
@@ -227,9 +227,9 @@ int repo_has_object_file_with_flags(struct repository *r,
  * with the specified name.  This function does not respect replace
  * references.
  */
-extern int has_loose_object_nonlocal(const struct object_id *);
+int has_loose_object_nonlocal(const struct object_id *);
 
-extern void assert_oid_type(const struct object_id *oid, enum object_type expect);
+void assert_oid_type(const struct object_id *oid, enum object_type expect);
 
 struct object_info {
 	/* Request */
diff --git a/object.h b/object.h
index 796792cb32..4526979ccf 100644
--- a/object.h
+++ b/object.h
@@ -90,19 +90,19 @@ struct object {
 	struct object_id oid;
 };
 
-extern const char *type_name(unsigned int type);
-extern int type_from_string_gently(const char *str, ssize_t, int gentle);
+const char *type_name(unsigned int type);
+int type_from_string_gently(const char *str, ssize_t, int gentle);
 #define type_from_string(str) type_from_string_gently(str, -1, 0)
 
 /*
  * Return the current number of buckets in the object hashmap.
  */
-extern unsigned int get_max_object_index(void);
+unsigned int get_max_object_index(void);
 
 /*
  * Return the object from the specified bucket in the object hashmap.
  */
-extern struct object *get_indexed_object(unsigned int);
+struct object *get_indexed_object(unsigned int);
 
 /*
  * This can be used to see if we have heard of the object before, but
@@ -118,7 +118,7 @@ extern struct object *get_indexed_object(unsigned int);
  */
 struct object *lookup_object(struct repository *r, const unsigned char *sha1);
 
-extern void *create_object(struct repository *r, const unsigned char *sha1, void *obj);
+void *create_object(struct repository *r, const unsigned char *sha1, void *obj);
 
 void *object_as_type(struct repository *r, struct object *obj, enum object_type type, int quiet);
 
@@ -189,6 +189,6 @@ void clear_object_flags(unsigned flags);
 /*
  * Clear the specified object flags from all in-core commit objects.
  */
-extern void clear_commit_marks_all(unsigned int flags);
+void clear_commit_marks_all(unsigned int flags);
 
 #endif /* OBJECT_H */
diff --git a/oidmap.h b/oidmap.h
index 72430b611e..7a939461ff 100644
--- a/oidmap.h
+++ b/oidmap.h
@@ -33,7 +33,7 @@ struct oidmap {
  * parameter may be used to preallocate a sufficiently large table and thus
  * prevent expensive resizing. If 0, the table is dynamically resized.
  */
-extern void oidmap_init(struct oidmap *map, size_t initial_size);
+void oidmap_init(struct oidmap *map, size_t initial_size);
 
 /*
  * Frees an oidmap structure and allocated memory.
@@ -41,13 +41,13 @@ extern void oidmap_init(struct oidmap *map, size_t initial_size);
  * If `free_entries` is true, each oidmap_entry in the map is freed as well
  * using stdlibs free().
  */
-extern void oidmap_free(struct oidmap *map, int free_entries);
+void oidmap_free(struct oidmap *map, int free_entries);
 
 /*
  * Returns the oidmap entry for the specified oid, or NULL if not found.
  */
-extern void *oidmap_get(const struct oidmap *map,
-			const struct object_id *key);
+void *oidmap_get(const struct oidmap *map,
+		 const struct object_id *key);
 
 /*
  * Adds or replaces an oidmap entry.
@@ -57,14 +57,14 @@ extern void *oidmap_get(const struct oidmap *map,
  *
  * Returns the replaced entry, or NULL if not found (i.e. the entry was added).
  */
-extern void *oidmap_put(struct oidmap *map, void *entry);
+void *oidmap_put(struct oidmap *map, void *entry);
 
 /*
  * Removes an oidmap entry matching the specified oid.
  *
  * Returns the removed entry, or NULL if not found.
  */
-extern void *oidmap_remove(struct oidmap *map, const struct object_id *key);
+void *oidmap_remove(struct oidmap *map, const struct object_id *key);
 
 
 struct oidmap_iter {
diff --git a/pack.h b/pack.h
index da99fdd1d2..9fc0945ac9 100644
--- a/pack.h
+++ b/pack.h
@@ -55,7 +55,7 @@ struct pack_idx_option {
 	uint32_t *anomaly;
 };
 
-extern void reset_pack_idx_option(struct pack_idx_option *);
+void reset_pack_idx_option(struct pack_idx_option *);
 
 /*
  * Packed object index header
@@ -79,28 +79,28 @@ struct progress;
 /* Note, the data argument could be NULL if object type is blob */
 typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*);
 
-extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
-extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
-extern int verify_pack_index(struct packed_git *);
-extern int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t);
-extern off_t write_pack_header(struct hashfile *f, uint32_t);
-extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
-extern char *index_pack_lockfile(int fd);
+const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
+int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
+int verify_pack_index(struct packed_git *);
+int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t);
+off_t write_pack_header(struct hashfile *f, uint32_t);
+void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
+char *index_pack_lockfile(int fd);
 
 /*
  * The "hdr" output buffer should be at least this big, which will handle sizes
  * up to 2^67.
  */
 #define MAX_PACK_OBJECT_HEADER 10
-extern int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
-					enum object_type, uintmax_t);
+int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
+				 enum object_type, uintmax_t);
 
 #define PH_ERROR_EOF		(-1)
 #define PH_ERROR_PACK_SIGNATURE	(-2)
 #define PH_ERROR_PROTOCOL	(-3)
-extern int read_pack_header(int fd, struct pack_header *);
+int read_pack_header(int fd, struct pack_header *);
 
-extern struct hashfile *create_tmp_packfile(char **pack_tmp_name);
-extern void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);
+struct hashfile *create_tmp_packfile(char **pack_tmp_name);
+void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);
 
 #endif
diff --git a/path.h b/path.h
index 651e6157fc..2ba6ca58c8 100644
--- a/path.h
+++ b/path.h
@@ -13,19 +13,19 @@ struct strbuf;
 /*
  * Return a statically allocated path.
  */
-extern const char *mkpath(const char *fmt, ...)
+const char *mkpath(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 /*
  * Return a path.
  */
-extern char *mkpathdup(const char *fmt, ...)
+char *mkpathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 /*
  * Construct a path and place the result in the provided buffer `buf`.
  */
-extern char *mksnpath(char *buf, size_t n, const char *fmt, ...)
+char *mksnpath(char *buf, size_t n, const char *fmt, ...)
 	__attribute__((format (printf, 3, 4)));
 
 /*
@@ -37,16 +37,16 @@ extern char *mksnpath(char *buf, size_t n, const char *fmt, ...)
  * Constructs a path into the common git directory of repository `repo` and
  * append it in the provided buffer `sb`.
  */
-extern void strbuf_git_common_path(struct strbuf *sb,
-				   const struct repository *repo,
-				   const char *fmt, ...)
+void strbuf_git_common_path(struct strbuf *sb,
+			    const struct repository *repo,
+			    const char *fmt, ...)
 	__attribute__((format (printf, 3, 4)));
 
 /*
  * Return a statically allocated path into the main repository's
  * (the_repository) common git directory.
  */
-extern const char *git_common_path(const char *fmt, ...)
+const char *git_common_path(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 
@@ -66,30 +66,30 @@ extern const char *git_common_path(const char *fmt, ...)
 /*
  * Return a path into the git directory of repository `repo`.
  */
-extern char *repo_git_path(const struct repository *repo,
-			   const char *fmt, ...)
+char *repo_git_path(const struct repository *repo,
+		    const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
 /*
  * Construct a path into the git directory of repository `repo` and append it
  * to the provided buffer `sb`.
  */
-extern void strbuf_repo_git_path(struct strbuf *sb,
-				 const struct repository *repo,
-				 const char *fmt, ...)
+void strbuf_repo_git_path(struct strbuf *sb,
+			  const struct repository *repo,
+			  const char *fmt, ...)
 	__attribute__((format (printf, 3, 4)));
 
 /*
  * Return a statically allocated path into the main repository's
  * (the_repository) git directory.
  */
-extern const char *git_path(const char *fmt, ...)
+const char *git_path(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 /*
  * Return a path into the main repository's (the_repository) git directory.
  */
-extern char *git_pathdup(const char *fmt, ...)
+char *git_pathdup(const char *fmt, ...)
 	__attribute__((format (printf, 1, 2)));
 
 /*
@@ -97,14 +97,14 @@ extern char *git_pathdup(const char *fmt, ...)
  * and place it in the provided buffer `buf`, the contents of the buffer will
  * be overridden.
  */
-extern char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
+char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
 /*
  * Construct a path into the main repository's (the_repository) git directory
  * and append it to the provided buffer `sb`.
  */
-extern void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
+void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
 /*
@@ -112,7 +112,7 @@ extern void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
  *
  * If the repository doesn't have a worktree NULL is returned.
  */
-extern char *repo_worktree_path(const struct repository *repo,
+char *repo_worktree_path(const struct repository *repo,
 				const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
@@ -122,7 +122,7 @@ extern char *repo_worktree_path(const struct repository *repo,
  *
  * If the repository doesn't have a worktree nothing will be appended to `sb`.
  */
-extern void strbuf_repo_worktree_path(struct strbuf *sb,
+void strbuf_repo_worktree_path(struct strbuf *sb,
 				      const struct repository *repo,
 				      const char *fmt, ...)
 	__attribute__((format (printf, 3, 4)));
@@ -131,7 +131,7 @@ extern void strbuf_repo_worktree_path(struct strbuf *sb,
  * Return a path into a submodule's git directory located at `path`.  `path`
  * must only reference a submodule of the main repository (the_repository).
  */
-extern char *git_pathdup_submodule(const char *path, const char *fmt, ...)
+char *git_pathdup_submodule(const char *path, const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
 /*
@@ -139,11 +139,11 @@ extern char *git_pathdup_submodule(const char *path, const char *fmt, ...)
  * append it to the provided buffer `sb`.  `path` must only reference a
  * submodule of the main repository (the_repository).
  */
-extern int strbuf_git_path_submodule(struct strbuf *sb, const char *path,
+int strbuf_git_path_submodule(struct strbuf *sb, const char *path,
 				     const char *fmt, ...)
 	__attribute__((format (printf, 3, 4)));
 
-extern void report_linked_checkout_garbage(void);
+void report_linked_checkout_garbage(void);
 
 /*
  * You can define a static memoized git path like:
diff --git a/pkt-line.h b/pkt-line.h
index c36cb788ed..5c62015db4 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -172,9 +172,9 @@ struct packet_reader {
  * Initialize a 'struct packet_reader' object which is an
  * abstraction around the 'packet_read_with_status()' function.
  */
-extern void packet_reader_init(struct packet_reader *reader, int fd,
-			       char *src_buffer, size_t src_len,
-			       int options);
+void packet_reader_init(struct packet_reader *reader, int fd,
+			char *src_buffer, size_t src_len,
+			int options);
 
 /*
  * Perform a packet read and return the status of the read.
@@ -186,7 +186,7 @@ extern void packet_reader_init(struct packet_reader *reader, int fd,
  *		       'line' is set to point at the read line
  * PACKET_READ_FLUSH: 'pktlen' is set to '0' and 'line' is set to NULL
  */
-extern enum packet_read_status packet_reader_read(struct packet_reader *reader);
+enum packet_read_status packet_reader_read(struct packet_reader *reader);
 
 /*
  * Peek the next packet line without consuming it and return the status.
@@ -196,7 +196,7 @@ extern enum packet_read_status packet_reader_read(struct packet_reader *reader);
  * Peeking multiple times without calling 'packet_reader_read()' will return
  * the same result.
  */
-extern enum packet_read_status packet_reader_peek(struct packet_reader *reader);
+enum packet_read_status packet_reader_peek(struct packet_reader *reader);
 
 #define DEFAULT_PACKET_MAX 1000
 #define LARGE_PACKET_MAX 65520
diff --git a/ppc/sha1.c b/ppc/sha1.c
index ec6a1926d4..1b705cee1f 100644
--- a/ppc/sha1.c
+++ b/ppc/sha1.c
@@ -10,8 +10,8 @@
 #include <string.h>
 #include "sha1.h"
 
-extern void ppc_sha1_core(uint32_t *hash, const unsigned char *p,
-			  unsigned int nblocks);
+void ppc_sha1_core(uint32_t *hash, const unsigned char *p,
+		   unsigned int nblocks);
 
 int ppc_SHA1_Init(ppc_SHA_CTX *c)
 {
diff --git a/prio-queue.h b/prio-queue.h
index 682e51867a..4f9a37e6be 100644
--- a/prio-queue.h
+++ b/prio-queue.h
@@ -37,24 +37,24 @@ struct prio_queue {
 /*
  * Add the "thing" to the queue.
  */
-extern void prio_queue_put(struct prio_queue *, void *thing);
+void prio_queue_put(struct prio_queue *, void *thing);
 
 /*
  * Extract the "thing" that compares the smallest out of the queue,
  * or NULL.  If compare function is NULL, the queue acts as a LIFO
  * stack.
  */
-extern void *prio_queue_get(struct prio_queue *);
+void *prio_queue_get(struct prio_queue *);
 
 /*
  * Gain access to the "thing" that would be returned by
  * prio_queue_get, but do not remove it from the queue.
  */
-extern void *prio_queue_peek(struct prio_queue *);
+void *prio_queue_peek(struct prio_queue *);
 
-extern void clear_prio_queue(struct prio_queue *);
+void clear_prio_queue(struct prio_queue *);
 
 /* Reverse the LIFO elements */
-extern void prio_queue_reverse(struct prio_queue *);
+void prio_queue_reverse(struct prio_queue *);
 
 #endif /* PRIO_QUEUE_H */
diff --git a/protocol.h b/protocol.h
index 2ad35e433c..cef1a4a01c 100644
--- a/protocol.h
+++ b/protocol.h
@@ -14,7 +14,7 @@ enum protocol_version {
  * 'protocol.version' config.  If unconfigured, a value of 'protocol_v0' is
  * returned.
  */
-extern enum protocol_version get_protocol_version_config(void);
+enum protocol_version get_protocol_version_config(void);
 
 /*
  * Used by a server to determine which protocol version should be used based on
@@ -23,12 +23,12 @@ extern enum protocol_version get_protocol_version_config(void);
  * request a particular protocol version, a default of 'protocol_v0' will be
  * used.
  */
-extern enum protocol_version determine_protocol_version_server(void);
+enum protocol_version determine_protocol_version_server(void);
 
 /*
  * Used by a client to determine which protocol version the server is speaking
  * based on the server's initial response.
  */
-extern enum protocol_version determine_protocol_version_client(const char *server_response);
+enum protocol_version determine_protocol_version_client(const char *server_response);
 
 #endif /* PROTOCOL_H */
diff --git a/quote.h b/quote.h
index ea992dcc91..fb08dc085c 100644
--- a/quote.h
+++ b/quote.h
@@ -29,9 +29,9 @@ struct strbuf;
  * sq_quotef() quotes the entire formatted string as a single result.
  */
 
-extern void sq_quote_buf(struct strbuf *, const char *src);
-extern void sq_quote_argv(struct strbuf *, const char **argv);
-extern void sq_quotef(struct strbuf *, const char *fmt, ...);
+void sq_quote_buf(struct strbuf *, const char *src);
+void sq_quote_argv(struct strbuf *, const char **argv);
+void sq_quotef(struct strbuf *, const char *fmt, ...);
 
 /*
  * These match their non-pretty variants, except that they avoid
@@ -45,14 +45,14 @@ void sq_quote_argv_pretty(struct strbuf *, const char **argv);
  * NULL if the input does not look like what sq_quote would have
  * produced.
  */
-extern char *sq_dequote(char *);
+char *sq_dequote(char *);
 
 /*
  * Same as the above, but can be used to unwrap many arguments in the
  * same string separated by space. Like sq_quote, it works in place,
  * modifying arg and appending pointers into it to argv.
  */
-extern int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc);
+int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc);
 
 /*
  * Same as above, but store the unquoted strings in an argv_array. We will
@@ -60,24 +60,24 @@ extern int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc
  * will duplicate and take ownership of the strings.
  */
 struct argv_array;
-extern int sq_dequote_to_argv_array(char *arg, struct argv_array *);
+int sq_dequote_to_argv_array(char *arg, struct argv_array *);
 
-extern int unquote_c_style(struct strbuf *, const char *quoted, const char **endp);
-extern size_t quote_c_style(const char *name, struct strbuf *, FILE *, int no_dq);
-extern void quote_two_c_style(struct strbuf *, const char *, const char *, int);
+int unquote_c_style(struct strbuf *, const char *quoted, const char **endp);
+size_t quote_c_style(const char *name, struct strbuf *, FILE *, int no_dq);
+void quote_two_c_style(struct strbuf *, const char *, const char *, int);
 
-extern void write_name_quoted(const char *name, FILE *, int terminator);
-extern void write_name_quoted_relative(const char *name, const char *prefix,
-		FILE *fp, int terminator);
+void write_name_quoted(const char *name, FILE *, int terminator);
+void write_name_quoted_relative(const char *name, const char *prefix,
+				FILE *fp, int terminator);
 
 /* quote path as relative to the given prefix */
-extern char *quote_path_relative(const char *in, const char *prefix,
+char *quote_path_relative(const char *in, const char *prefix,
 			  struct strbuf *out);
 
 /* quoting as a string literal for other languages */
-extern void perl_quote_buf(struct strbuf *sb, const char *src);
-extern void python_quote_buf(struct strbuf *sb, const char *src);
-extern void tcl_quote_buf(struct strbuf *sb, const char *src);
-extern void basic_regex_quote_buf(struct strbuf *sb, const char *src);
+void perl_quote_buf(struct strbuf *sb, const char *src);
+void python_quote_buf(struct strbuf *sb, const char *src);
+void tcl_quote_buf(struct strbuf *sb, const char *src);
+void basic_regex_quote_buf(struct strbuf *sb, const char *src);
 
 #endif
diff --git a/reachable.h b/reachable.h
index 18b0f9f2f0..5df932ad8f 100644
--- a/reachable.h
+++ b/reachable.h
@@ -4,9 +4,9 @@
 struct progress;
 struct rev_info;
 
-extern int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
-						  timestamp_t timestamp);
-extern void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
-				   timestamp_t mark_recent, struct progress *);
+int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
+					   timestamp_t timestamp);
+void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
+			    timestamp_t mark_recent, struct progress *);
 
 #endif
diff --git a/reflog-walk.h b/reflog-walk.h
index cb3e73755d..f26408f6cc 100644
--- a/reflog-walk.h
+++ b/reflog-walk.h
@@ -6,21 +6,21 @@
 struct commit;
 struct reflog_walk_info;
 
-extern void init_reflog_walk(struct reflog_walk_info **info);
-extern int add_reflog_for_walk(struct reflog_walk_info *info,
-		struct commit *commit, const char *name);
-extern void show_reflog_message(struct reflog_walk_info *info, int,
-				const struct date_mode *, int force_date);
-extern void get_reflog_message(struct strbuf *sb,
-		struct reflog_walk_info *reflog_info);
-extern const char *get_reflog_ident(struct reflog_walk_info *reflog_info);
-extern timestamp_t get_reflog_timestamp(struct reflog_walk_info *reflog_info);
-extern void get_reflog_selector(struct strbuf *sb,
-		struct reflog_walk_info *reflog_info,
-		const struct date_mode *dmode, int force_date,
-		int shorten);
+void init_reflog_walk(struct reflog_walk_info **info);
+int add_reflog_for_walk(struct reflog_walk_info *info,
+			struct commit *commit, const char *name);
+void show_reflog_message(struct reflog_walk_info *info, int,
+			 const struct date_mode *, int force_date);
+void get_reflog_message(struct strbuf *sb,
+			struct reflog_walk_info *reflog_info);
+const char *get_reflog_ident(struct reflog_walk_info *reflog_info);
+timestamp_t get_reflog_timestamp(struct reflog_walk_info *reflog_info);
+void get_reflog_selector(struct strbuf *sb,
+			 struct reflog_walk_info *reflog_info,
+			 const struct date_mode *dmode, int force_date,
+			 int shorten);
 
-extern int reflog_walk_empty(struct reflog_walk_info *walk);
+int reflog_walk_empty(struct reflog_walk_info *walk);
 
 struct commit *next_reflog_entry(struct reflog_walk_info *reflog_info);
 
diff --git a/refs.h b/refs.h
index 8f9cbf8a93..2727405b61 100644
--- a/refs.h
+++ b/refs.h
@@ -111,7 +111,7 @@ int should_autocreate_reflog(const char *refname);
 
 int is_branch(const char *refname);
 
-extern int refs_init_db(struct strbuf *err);
+int refs_init_db(struct strbuf *err);
 
 /*
  * If refname is a non-symbolic reference that refers to a tag object,
diff --git a/remote.h b/remote.h
index 6a1795947e..83e885672b 100644
--- a/remote.h
+++ b/remote.h
@@ -119,13 +119,13 @@ struct ref {
 #define REF_HEADS	(1u << 1)
 #define REF_TAGS	(1u << 2)
 
-extern struct ref *find_ref_by_name(const struct ref *list, const char *name);
+struct ref *find_ref_by_name(const struct ref *list, const char *name);
 
 struct ref *alloc_ref(const char *name);
 struct ref *copy_ref(const struct ref *ref);
 struct ref *copy_ref_list(const struct ref *ref);
 void sort_ref_list(struct ref **, int (*cmp)(const void *, const void *));
-extern int count_refspec_match(const char *, struct ref *refs, struct ref **matched_ref);
+int count_refspec_match(const char *, struct ref *refs, struct ref **matched_ref);
 int ref_compare_name(const void *, const void *);
 
 int check_ref_type(const struct ref *ref, int flags);
@@ -141,16 +141,16 @@ struct oid_array;
 struct packet_reader;
 struct argv_array;
 struct string_list;
-extern struct ref **get_remote_heads(struct packet_reader *reader,
-				     struct ref **list, unsigned int flags,
-				     struct oid_array *extra_have,
-				     struct oid_array *shallow_points);
+struct ref **get_remote_heads(struct packet_reader *reader,
+			      struct ref **list, unsigned int flags,
+			      struct oid_array *extra_have,
+			      struct oid_array *shallow_points);
 
 /* Used for protocol v2 in order to retrieve refs from a remote */
-extern struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
-				    struct ref **list, int for_push,
-				    const struct argv_array *ref_prefixes,
-				    const struct string_list *server_options);
+struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
+			     struct ref **list, int for_push,
+			     const struct argv_array *ref_prefixes,
+			     const struct string_list *server_options);
 
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 
@@ -290,9 +290,9 @@ struct push_cas_option {
 	int alloc;
 };
 
-extern int parseopt_push_cas_option(const struct option *, const char *arg, int unset);
+int parseopt_push_cas_option(const struct option *, const char *arg, int unset);
 
-extern int is_empty_cas(const struct push_cas_option *);
+int is_empty_cas(const struct push_cas_option *);
 void apply_push_cas(struct push_cas_option *, struct remote *, struct ref *);
 
 #endif
diff --git a/replace-object.h b/replace-object.h
index 16528df942..04ed7a85a2 100644
--- a/replace-object.h
+++ b/replace-object.h
@@ -16,8 +16,8 @@ void prepare_replace_object(struct repository *r);
  * This internal function is only declared here for the benefit of
  * lookup_replace_object().  Please do not call it directly.
  */
-extern const struct object_id *do_lookup_replace_object(struct repository *r,
-							const struct object_id *oid);
+const struct object_id *do_lookup_replace_object(struct repository *r,
+						 const struct object_id *oid);
 
 /*
  * If object sha1 should be replaced, return the replacement object's
diff --git a/resolve-undo.h b/resolve-undo.h
index fbe348efac..2b3f0f901e 100644
--- a/resolve-undo.h
+++ b/resolve-undo.h
@@ -8,12 +8,12 @@ struct resolve_undo_info {
 	struct object_id oid[3];
 };
 
-extern void record_resolve_undo(struct index_state *, struct cache_entry *);
-extern void resolve_undo_write(struct strbuf *, struct string_list *);
-extern struct string_list *resolve_undo_read(const char *, unsigned long);
-extern void resolve_undo_clear_index(struct index_state *);
-extern int unmerge_index_entry_at(struct index_state *, int);
-extern void unmerge_index(struct index_state *, const struct pathspec *);
-extern void unmerge_marked_index(struct index_state *);
+void record_resolve_undo(struct index_state *, struct cache_entry *);
+void resolve_undo_write(struct strbuf *, struct string_list *);
+struct string_list *resolve_undo_read(const char *, unsigned long);
+void resolve_undo_clear_index(struct index_state *);
+int unmerge_index_entry_at(struct index_state *, int);
+void unmerge_index(struct index_state *, const struct pathspec *);
+void unmerge_marked_index(struct index_state *);
 
 #endif
diff --git a/run-command.h b/run-command.h
index a6950691c0..f769e03f01 100644
--- a/run-command.h
+++ b/run-command.h
@@ -55,7 +55,7 @@ struct child_process {
 #define CHILD_PROCESS_INIT { NULL, ARGV_ARRAY_INIT, ARGV_ARRAY_INIT }
 void child_process_init(struct child_process *);
 void child_process_clear(struct child_process *);
-extern int is_executable(const char *name);
+int is_executable(const char *name);
 
 int start_command(struct child_process *);
 int finish_command(struct child_process *);
@@ -67,10 +67,10 @@ int run_command(struct child_process *);
  * or disabled. Note that this points to static storage that will be
  * overwritten by further calls to find_hook and run_hook_*.
  */
-extern const char *find_hook(const char *name);
+const char *find_hook(const char *name);
 LAST_ARG_MUST_BE_NULL
-extern int run_hook_le(const char *const *env, const char *name, ...);
-extern int run_hook_ve(const char *const *env, const char *name, va_list args);
+int run_hook_le(const char *const *env, const char *name, ...);
+int run_hook_ve(const char *const *env, const char *name, va_list args);
 
 #define RUN_COMMAND_NO_STDIN 1
 #define RUN_GIT_CMD	     2	/*If this is to be git sub-command */
diff --git a/serve.h b/serve.h
index fe65ba9f46..42ddca7f8b 100644
--- a/serve.h
+++ b/serve.h
@@ -2,14 +2,14 @@
 #define SERVE_H
 
 struct argv_array;
-extern int has_capability(const struct argv_array *keys, const char *capability,
-			  const char **value);
+int has_capability(const struct argv_array *keys, const char *capability,
+		   const char **value);
 
 struct serve_options {
 	unsigned advertise_capabilities;
 	unsigned stateless_rpc;
 };
 #define SERVE_OPTIONS_INIT { 0 }
-extern void serve(struct serve_options *options);
+void serve(struct serve_options *options);
 
 #endif /* SERVE_H */
diff --git a/sha1-lookup.h b/sha1-lookup.h
index 7678b23b36..5afcd011c6 100644
--- a/sha1-lookup.h
+++ b/sha1-lookup.h
@@ -3,10 +3,10 @@
 
 typedef const unsigned char *sha1_access_fn(size_t index, void *table);
 
-extern int sha1_pos(const unsigned char *sha1,
-		    void *table,
-		    size_t nr,
-		    sha1_access_fn fn);
+int sha1_pos(const unsigned char *sha1,
+	     void *table,
+	     size_t nr,
+	     sha1_access_fn fn);
 
 /*
  * Searches for sha1 in table, using the given fanout table to determine the
diff --git a/streaming.h b/streaming.h
index 32f4626771..f465a3cd31 100644
--- a/streaming.h
+++ b/streaming.h
@@ -8,10 +8,10 @@
 /* opaque */
 struct git_istream;
 
-extern struct git_istream *open_istream(const struct object_id *, enum object_type *, unsigned long *, struct stream_filter *);
-extern int close_istream(struct git_istream *);
-extern ssize_t read_istream(struct git_istream *, void *, size_t);
+struct git_istream *open_istream(const struct object_id *, enum object_type *, unsigned long *, struct stream_filter *);
+int close_istream(struct git_istream *);
+ssize_t read_istream(struct git_istream *, void *, size_t);
 
-extern int stream_blob_to_fd(int fd, const struct object_id *, struct stream_filter *, int can_seek);
+int stream_blob_to_fd(int fd, const struct object_id *, struct stream_filter *, int can_seek);
 
 #endif /* STREAMING_H */
diff --git a/string-list.h b/string-list.h
index 18c718c12c..f964399949 100644
--- a/string-list.h
+++ b/string-list.h
@@ -174,8 +174,8 @@ struct string_list_item *string_list_insert(struct string_list *list, const char
  * Remove the given string from the sorted list.  If the string
  * doesn't exist, the list is not altered.
  */
-extern void string_list_remove(struct string_list *list, const char *string,
-			       int free_util);
+void string_list_remove(struct string_list *list, const char *string,
+			int free_util);
 
 /**
  * Check if the given string is part of a sorted list. If it is part of the list,
diff --git a/sub-process.h b/sub-process.h
index 71b18ad5af..5c182fad98 100644
--- a/sub-process.h
+++ b/sub-process.h
@@ -42,10 +42,10 @@ struct subprocess_capability {
 /* subprocess functions */
 
 /* Function to test two subprocess hashmap entries for equality. */
-extern int cmd2process_cmp(const void *unused_cmp_data,
-			   const void *e1,
-			   const void *e2,
-			   const void *unused_keydata);
+int cmd2process_cmp(const void *unused_cmp_data,
+		    const void *e1,
+		    const void *e2,
+		    const void *unused_keydata);
 
 /*
  * User-supplied function to initialize the sub-process.  This is
diff --git a/submodule-config.h b/submodule-config.h
index 4dc9b0771c..1b4e2da658 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -30,17 +30,17 @@ struct submodule {
 struct submodule_cache;
 struct repository;
 
-extern void submodule_cache_free(struct submodule_cache *cache);
+void submodule_cache_free(struct submodule_cache *cache);
 
-extern int parse_submodule_fetchjobs(const char *var, const char *value);
-extern int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
+int parse_submodule_fetchjobs(const char *var, const char *value);
+int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
 struct option;
-extern int option_fetch_parse_recurse_submodules(const struct option *opt,
-						 const char *arg, int unset);
-extern int parse_update_recurse_submodules_arg(const char *opt, const char *arg);
-extern int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
-extern void repo_read_gitmodules(struct repository *repo);
-extern void gitmodules_config_oid(const struct object_id *commit_oid);
+int option_fetch_parse_recurse_submodules(const struct option *opt,
+					  const char *arg, int unset);
+int parse_update_recurse_submodules_arg(const char *opt, const char *arg);
+int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
+void repo_read_gitmodules(struct repository *repo);
+void gitmodules_config_oid(const struct object_id *commit_oid);
 const struct submodule *submodule_from_name(struct repository *r,
 					    const struct object_id *commit_or_tree,
 					    const char *name);
@@ -66,7 +66,7 @@ int check_submodule_name(const char *name);
  * New helpers to retrieve arbitrary configuration from the '.gitmodules' file
  * should NOT be added.
  */
-extern void fetch_config_from_gitmodules(int *max_children, int *recurse_submodules);
-extern void update_clone_config_from_gitmodules(int *max_jobs);
+void fetch_config_from_gitmodules(int *max_children, int *recurse_submodules);
+void update_clone_config_from_gitmodules(int *max_jobs);
 
 #endif /* SUBMODULE_CONFIG_H */
diff --git a/tag.h b/tag.h
index e669c3e497..03265fbfe2 100644
--- a/tag.h
+++ b/tag.h
@@ -11,13 +11,13 @@ struct tag {
 	char *tag;
 	timestamp_t date;
 };
-extern struct tag *lookup_tag(struct repository *r, const struct object_id *oid);
-extern int parse_tag_buffer(struct repository *r, struct tag *item, const void *data, unsigned long size);
-extern int parse_tag(struct tag *item);
-extern void release_tag_memory(struct tag *t);
-extern struct object *deref_tag(struct repository *r, struct object *, const char *, int);
-extern struct object *deref_tag_noverify(struct object *);
-extern int gpg_verify_tag(const struct object_id *oid,
-		const char *name_to_report, unsigned flags);
+struct tag *lookup_tag(struct repository *r, const struct object_id *oid);
+int parse_tag_buffer(struct repository *r, struct tag *item, const void *data, unsigned long size);
+int parse_tag(struct tag *item);
+void release_tag_memory(struct tag *t);
+struct object *deref_tag(struct repository *r, struct object *, const char *, int);
+struct object *deref_tag_noverify(struct object *);
+int gpg_verify_tag(const struct object_id *oid,
+		   const char *name_to_report, unsigned flags);
 
 #endif /* TAG_H */
diff --git a/tempfile.h b/tempfile.h
index 61d8dc4d1b..cddda0a33c 100644
--- a/tempfile.h
+++ b/tempfile.h
@@ -89,7 +89,7 @@ struct tempfile {
  * a tempfile (whose "fd" member can be used for writing to it), or
  * NULL on error. It is an error if a file already exists at that path.
  */
-extern struct tempfile *create_tempfile(const char *path);
+struct tempfile *create_tempfile(const char *path);
 
 /*
  * Register an existing file as a tempfile, meaning that it will be
@@ -97,7 +97,7 @@ extern struct tempfile *create_tempfile(const char *path);
  * but it can be worked with like any other closed tempfile (for
  * example, it can be opened using reopen_tempfile()).
  */
-extern struct tempfile *register_tempfile(const char *path);
+struct tempfile *register_tempfile(const char *path);
 
 
 /*
@@ -136,8 +136,8 @@ extern struct tempfile *register_tempfile(const char *path);
  */
 
 /* See "mks_tempfile functions" above. */
-extern struct tempfile *mks_tempfile_sm(const char *filename_template,
-					int suffixlen, int mode);
+struct tempfile *mks_tempfile_sm(const char *filename_template,
+				 int suffixlen, int mode);
 
 /* See "mks_tempfile functions" above. */
 static inline struct tempfile *mks_tempfile_s(const char *filename_template,
@@ -159,8 +159,8 @@ static inline struct tempfile *mks_tempfile(const char *filename_template)
 }
 
 /* See "mks_tempfile functions" above. */
-extern struct tempfile *mks_tempfile_tsm(const char *filename_template,
-					 int suffixlen, int mode);
+struct tempfile *mks_tempfile_tsm(const char *filename_template,
+				  int suffixlen, int mode);
 
 /* See "mks_tempfile functions" above. */
 static inline struct tempfile *mks_tempfile_ts(const char *filename_template,
@@ -182,7 +182,7 @@ static inline struct tempfile *mks_tempfile_t(const char *filename_template)
 }
 
 /* See "mks_tempfile functions" above. */
-extern struct tempfile *xmks_tempfile_m(const char *filename_template, int mode);
+struct tempfile *xmks_tempfile_m(const char *filename_template, int mode);
 
 /* See "mks_tempfile functions" above. */
 static inline struct tempfile *xmks_tempfile(const char *filename_template)
@@ -196,7 +196,7 @@ static inline struct tempfile *xmks_tempfile(const char *filename_template)
  * stream is closed automatically when `close_tempfile_gently()` is called or
  * when the file is deleted or renamed.
  */
-extern FILE *fdopen_tempfile(struct tempfile *tempfile, const char *mode);
+FILE *fdopen_tempfile(struct tempfile *tempfile, const char *mode);
 
 static inline int is_tempfile_active(struct tempfile *tempfile)
 {
@@ -207,10 +207,10 @@ static inline int is_tempfile_active(struct tempfile *tempfile)
  * Return the path of the lockfile. The return value is a pointer to a
  * field within the lock_file object and should not be freed.
  */
-extern const char *get_tempfile_path(struct tempfile *tempfile);
+const char *get_tempfile_path(struct tempfile *tempfile);
 
-extern int get_tempfile_fd(struct tempfile *tempfile);
-extern FILE *get_tempfile_fp(struct tempfile *tempfile);
+int get_tempfile_fd(struct tempfile *tempfile);
+FILE *get_tempfile_fp(struct tempfile *tempfile);
 
 /*
  * If the temporary file is still open, close it (and the file pointer
@@ -220,7 +220,7 @@ extern FILE *get_tempfile_fp(struct tempfile *tempfile);
  * should eventually be called regardless of whether `close_tempfile_gently()`
  * succeeds.
  */
-extern int close_tempfile_gently(struct tempfile *tempfile);
+int close_tempfile_gently(struct tempfile *tempfile);
 
 /*
  * Re-open a temporary file that has been closed using
@@ -241,7 +241,7 @@ extern int close_tempfile_gently(struct tempfile *tempfile);
  *
  * * `rename_tempfile()` to move the file to its permanent location.
  */
-extern int reopen_tempfile(struct tempfile *tempfile);
+int reopen_tempfile(struct tempfile *tempfile);
 
 /*
  * Close the file descriptor and/or file pointer and remove the
@@ -249,7 +249,7 @@ extern int reopen_tempfile(struct tempfile *tempfile);
  * `delete_tempfile()` for a `tempfile` object that has already been
  * deleted or renamed.
  */
-extern void delete_tempfile(struct tempfile **tempfile_p);
+void delete_tempfile(struct tempfile **tempfile_p);
 
 /*
  * Close the file descriptor and/or file pointer if they are still
@@ -260,6 +260,6 @@ extern void delete_tempfile(struct tempfile **tempfile_p);
  * `rename(2)`. It is a bug to call `rename_tempfile()` for a
  * `tempfile` object that is not currently active.
  */
-extern int rename_tempfile(struct tempfile **tempfile_p, const char *path);
+int rename_tempfile(struct tempfile **tempfile_p, const char *path);
 
 #endif /* TEMPFILE_H */
diff --git a/trace.h b/trace.h
index 171b256d26..9fa3e7a594 100644
--- a/trace.h
+++ b/trace.h
@@ -17,34 +17,34 @@ extern struct trace_key trace_default_key;
 extern struct trace_key trace_perf_key;
 extern struct trace_key trace_setup_key;
 
-extern void trace_repo_setup(const char *prefix);
-extern int trace_want(struct trace_key *key);
-extern void trace_disable(struct trace_key *key);
-extern uint64_t getnanotime(void);
-extern void trace_command_performance(const char **argv);
-extern void trace_verbatim(struct trace_key *key, const void *buf, unsigned len);
+void trace_repo_setup(const char *prefix);
+int trace_want(struct trace_key *key);
+void trace_disable(struct trace_key *key);
+uint64_t getnanotime(void);
+void trace_command_performance(const char **argv);
+void trace_verbatim(struct trace_key *key, const void *buf, unsigned len);
 uint64_t trace_performance_enter(void);
 
 #ifndef HAVE_VARIADIC_MACROS
 
 __attribute__((format (printf, 1, 2)))
-extern void trace_printf(const char *format, ...);
+void trace_printf(const char *format, ...);
 
 __attribute__((format (printf, 2, 3)))
-extern void trace_printf_key(struct trace_key *key, const char *format, ...);
+void trace_printf_key(struct trace_key *key, const char *format, ...);
 
 __attribute__((format (printf, 2, 3)))
-extern void trace_argv_printf(const char **argv, const char *format, ...);
+void trace_argv_printf(const char **argv, const char *format, ...);
 
-extern void trace_strbuf(struct trace_key *key, const struct strbuf *data);
+void trace_strbuf(struct trace_key *key, const struct strbuf *data);
 
 /* Prints elapsed time (in nanoseconds) if GIT_TRACE_PERFORMANCE is enabled. */
 __attribute__((format (printf, 2, 3)))
-extern void trace_performance(uint64_t nanos, const char *format, ...);
+void trace_performance(uint64_t nanos, const char *format, ...);
 
 /* Prints elapsed time since 'start' if GIT_TRACE_PERFORMANCE is enabled. */
 __attribute__((format (printf, 2, 3)))
-extern void trace_performance_since(uint64_t start, const char *format, ...);
+void trace_performance_since(uint64_t start, const char *format, ...);
 
 __attribute__((format (printf, 1, 2)))
 void trace_performance_leave(const char *format, ...);
@@ -132,19 +132,19 @@ void trace_performance_leave(const char *format, ...);
 
 /* backend functions, use non-*fl macros instead */
 __attribute__((format (printf, 4, 5)))
-extern void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
-				const char *format, ...);
+void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
+			 const char *format, ...);
 __attribute__((format (printf, 4, 5)))
-extern void trace_argv_printf_fl(const char *file, int line, const char **argv,
-				 const char *format, ...);
-extern void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
-			    const struct strbuf *data);
+void trace_argv_printf_fl(const char *file, int line, const char **argv,
+			  const char *format, ...);
+void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
+		     const struct strbuf *data);
 __attribute__((format (printf, 4, 5)))
-extern void trace_performance_fl(const char *file, int line,
-				 uint64_t nanos, const char *fmt, ...);
+void trace_performance_fl(const char *file, int line,
+			  uint64_t nanos, const char *fmt, ...);
 __attribute__((format (printf, 4, 5)))
-extern void trace_performance_leave_fl(const char *file, int line,
-				       uint64_t nanos, const char *fmt, ...);
+void trace_performance_leave_fl(const char *file, int line,
+				uint64_t nanos, const char *fmt, ...);
 static inline int trace_pass_fl(struct trace_key *key)
 {
 	return key->fd || !key->initialized;
diff --git a/transport.h b/transport.h
index f2ee7c4f49..06e06d3d89 100644
--- a/transport.h
+++ b/transport.h
@@ -134,7 +134,7 @@ struct transport {
 #define TRANSPORT_PUSH_OPTIONS			(1<<14)
 #define TRANSPORT_RECURSE_SUBMODULES_ONLY	(1<<15)
 
-extern int transport_summary_width(const struct ref *refs);
+int transport_summary_width(const struct ref *refs);
 
 /* Returns a transport suitable for the url */
 struct transport *transport_get(struct remote *, const char *);
@@ -263,5 +263,5 @@ void transport_print_push_status(const char *dest, struct ref *refs,
 		  int verbose, int porcelain, unsigned int *reject_reasons);
 
 typedef void alternate_ref_fn(const struct object_id *oid, void *);
-extern void for_each_alternate_ref(alternate_ref_fn, void *);
+void for_each_alternate_ref(alternate_ref_fn, void *);
 #endif
diff --git a/tree-walk.h b/tree-walk.h
index 3aa381b6a3..161e2400f4 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -67,8 +67,8 @@ struct traverse_info {
 };
 
 int get_tree_entry(const struct object_id *, const char *, struct object_id *, unsigned short *);
-extern char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n);
-extern void setup_traverse_info(struct traverse_info *info, const char *base);
+char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n);
+void setup_traverse_info(struct traverse_info *info, const char *base);
 
 static inline int traverse_path_len(const struct traverse_info *info, const struct name_entry *n)
 {
diff --git a/upload-pack.h b/upload-pack.h
index cab2178796..4bafe16a22 100644
--- a/upload-pack.h
+++ b/upload-pack.h
@@ -13,11 +13,11 @@ void upload_pack(struct upload_pack_options *options);
 struct repository;
 struct argv_array;
 struct packet_reader;
-extern int upload_pack_v2(struct repository *r, struct argv_array *keys,
-			  struct packet_reader *request);
+int upload_pack_v2(struct repository *r, struct argv_array *keys,
+		   struct packet_reader *request);
 
 struct strbuf;
-extern int upload_pack_advertise(struct repository *r,
-				 struct strbuf *value);
+int upload_pack_advertise(struct repository *r,
+			  struct strbuf *value);
 
 #endif /* UPLOAD_PACK_H */
diff --git a/url.h b/url.h
index f311c40a46..00b7d58c33 100644
--- a/url.h
+++ b/url.h
@@ -3,14 +3,14 @@
 
 struct strbuf;
 
-extern int is_url(const char *url);
-extern int is_urlschemechar(int first_flag, int ch);
-extern char *url_decode(const char *url);
-extern char *url_decode_mem(const char *url, int len);
-extern char *url_decode_parameter_name(const char **query);
-extern char *url_decode_parameter_value(const char **query);
+int is_url(const char *url);
+int is_urlschemechar(int first_flag, int ch);
+char *url_decode(const char *url);
+char *url_decode_mem(const char *url, int len);
+char *url_decode_parameter_name(const char **query);
+char *url_decode_parameter_value(const char **query);
 
-extern void end_url_with_slash(struct strbuf *buf, const char *url);
-extern void str_end_url_with_slash(const char *url, char **dest);
+void end_url_with_slash(struct strbuf *buf, const char *url);
+void str_end_url_with_slash(const char *url, char **dest);
 
 #endif /* URL_H */
diff --git a/urlmatch.h b/urlmatch.h
index e482148248..eed5f29235 100644
--- a/urlmatch.h
+++ b/urlmatch.h
@@ -33,7 +33,7 @@ struct url_info {
 				 * '?...' and '#...' portion; will always be >= 1 */
 };
 
-extern char *url_normalize(const char *, struct url_info *);
+char *url_normalize(const char *, struct url_info *);
 
 struct urlmatch_item {
 	size_t hostmatch_len;
@@ -52,6 +52,6 @@ struct urlmatch_config {
 	int (*cascade_fn)(const char *var, const char *value, void *cb);
 };
 
-extern int urlmatch_config_entry(const char *var, const char *value, void *cb);
+int urlmatch_config_entry(const char *var, const char *value, void *cb);
 
 #endif /* URL_MATCH_H */
diff --git a/utf8.h b/utf8.h
index 84efbfcb1f..fcd5167baf 100644
--- a/utf8.h
+++ b/utf8.h
@@ -16,7 +16,7 @@ __attribute__((format (printf, 2, 3)))
 int utf8_fprintf(FILE *, const char *, ...);
 
 extern const char utf8_bom[];
-extern int skip_utf8_bom(char **, size_t);
+int skip_utf8_bom(char **, size_t);
 
 void strbuf_add_wrapped_text(struct strbuf *buf,
 		const char *text, int indent, int indent2, int width);
diff --git a/varint.h b/varint.h
index c1c44d9a6b..f78bb0ca52 100644
--- a/varint.h
+++ b/varint.h
@@ -1,7 +1,7 @@
 #ifndef VARINT_H
 #define VARINT_H
 
-extern int encode_varint(uintmax_t, unsigned char *);
-extern uintmax_t decode_varint(const unsigned char **);
+int encode_varint(uintmax_t, unsigned char *);
+uintmax_t decode_varint(const unsigned char **);
 
 #endif /* VARINT_H */
diff --git a/vcs-svn/sliding_window.h b/vcs-svn/sliding_window.h
index 189c32d84c..a7fc0999cb 100644
--- a/vcs-svn/sliding_window.h
+++ b/vcs-svn/sliding_window.h
@@ -13,6 +13,6 @@ struct sliding_view {
 
 #define SLIDING_VIEW_INIT(input, len)	{ (input), 0, 0, (len), STRBUF_INIT }
 
-extern int move_window(struct sliding_view *view, off_t off, size_t width);
+int move_window(struct sliding_view *view, off_t off, size_t width);
 
 #endif
diff --git a/vcs-svn/svndiff.h b/vcs-svn/svndiff.h
index 10a2cbc40e..625d950bb8 100644
--- a/vcs-svn/svndiff.h
+++ b/vcs-svn/svndiff.h
@@ -4,7 +4,7 @@
 struct line_buffer;
 struct sliding_view;
 
-extern int svndiff0_apply(struct line_buffer *delta, off_t delta_len,
-		struct sliding_view *preimage, FILE *postimage);
+int svndiff0_apply(struct line_buffer *delta, off_t delta_len,
+		   struct sliding_view *preimage, FILE *postimage);
 
 #endif
diff --git a/worktree.h b/worktree.h
index 9e3b0b7b6f..caecc7a281 100644
--- a/worktree.h
+++ b/worktree.h
@@ -30,37 +30,37 @@ struct worktree {
  * The caller is responsible for freeing the memory from the returned
  * worktree(s).
  */
-extern struct worktree **get_worktrees(unsigned flags);
+struct worktree **get_worktrees(unsigned flags);
 
 /*
  * Returns 1 if linked worktrees exist, 0 otherwise.
  */
-extern int submodule_uses_worktrees(const char *path);
+int submodule_uses_worktrees(const char *path);
 
 /*
  * Return git dir of the worktree. Note that the path may be relative.
  * If wt is NULL, git dir of current worktree is returned.
  */
-extern const char *get_worktree_git_dir(const struct worktree *wt);
+const char *get_worktree_git_dir(const struct worktree *wt);
 
 /*
  * Search a worktree that can be unambiguously identified by
  * "arg". "prefix" must not be NULL.
  */
-extern struct worktree *find_worktree(struct worktree **list,
-				      const char *prefix,
-				      const char *arg);
+struct worktree *find_worktree(struct worktree **list,
+			       const char *prefix,
+			       const char *arg);
 
 /*
  * Return true if the given worktree is the main one.
  */
-extern int is_main_worktree(const struct worktree *wt);
+int is_main_worktree(const struct worktree *wt);
 
 /*
  * Return the reason string if the given worktree is locked or NULL
  * otherwise.
  */
-extern const char *worktree_lock_reason(struct worktree *wt);
+const char *worktree_lock_reason(struct worktree *wt);
 
 #define WT_VALIDATE_WORKTREE_MISSING_OK (1 << 0)
 
@@ -68,28 +68,28 @@ extern const char *worktree_lock_reason(struct worktree *wt);
  * Return zero if the worktree is in good condition. Error message is
  * returned if "errmsg" is not NULL.
  */
-extern int validate_worktree(const struct worktree *wt,
-			     struct strbuf *errmsg,
-			     unsigned flags);
+int validate_worktree(const struct worktree *wt,
+		      struct strbuf *errmsg,
+		      unsigned flags);
 
 /*
  * Update worktrees/xxx/gitdir with the new path.
  */
-extern void update_worktree_location(struct worktree *wt,
-				     const char *path_);
+void update_worktree_location(struct worktree *wt,
+			      const char *path_);
 
 /*
  * Free up the memory for worktree(s)
  */
-extern void free_worktrees(struct worktree **);
+void free_worktrees(struct worktree **);
 
 /*
  * Check if a per-worktree symref points to a ref in the main worktree
  * or any linked worktree, and return the worktree that holds the ref,
  * or NULL otherwise. The result may be destroyed by the next call.
  */
-extern const struct worktree *find_shared_symref(const char *symref,
-						 const char *target);
+const struct worktree *find_shared_symref(const char *symref,
+					  const char *target);
 
 /*
  * Similar to head_ref() for all HEADs _except_ one from the current
@@ -104,8 +104,8 @@ int is_worktree_being_bisected(const struct worktree *wt, const char *target);
  * Similar to git_path() but can produce paths for a specified
  * worktree instead of current one
  */
-extern const char *worktree_git_path(const struct worktree *wt,
-				     const char *fmt, ...)
+const char *worktree_git_path(const struct worktree *wt,
+			      const char *fmt, ...)
 	__attribute__((format (printf, 2, 3)));
 
 /*
diff --git a/xdiff-interface.h b/xdiff-interface.h
index 2d41fffd4c..ede4246bbd 100644
--- a/xdiff-interface.h
+++ b/xdiff-interface.h
@@ -27,9 +27,9 @@ int read_mmfile(mmfile_t *ptr, const char *filename);
 void read_mmblob(mmfile_t *ptr, const struct object_id *oid);
 int buffer_is_binary(const char *ptr, unsigned long size);
 
-extern void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line, int cflags);
-extern void xdiff_clear_find_func(xdemitconf_t *xecfg);
-extern int git_xmerge_config(const char *var, const char *value, void *cb);
+void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line, int cflags);
+void xdiff_clear_find_func(xdemitconf_t *xecfg);
+int git_xmerge_config(const char *var, const char *value, void *cb);
 extern int git_xmerge_style;
 
 /*
@@ -46,14 +46,14 @@ void discard_hunk_line(void *priv,
  * The `flags` given as XDF_WHITESPACE_FLAGS determine how white spaces
  * are treated for the comparision.
  */
-extern int xdiff_compare_lines(const char *l1, long s1,
-			       const char *l2, long s2, long flags);
+int xdiff_compare_lines(const char *l1, long s1,
+			const char *l2, long s2, long flags);
 
 /*
  * Returns a hash of the string s of length len.
  * The `flags` given as XDF_WHITESPACE_FLAGS determine how white spaces
  * are treated for the hash.
  */
-extern unsigned long xdiff_hash_string(const char *s, size_t len, long flags);
+unsigned long xdiff_hash_string(const char *s, size_t len, long flags);
 
 #endif