*.[ch]: remove extern from function declarations using spatch

There has been a push to remove extern from function declarations.
Remove some instances of "extern" for function declarations which are
caught by Coccinelle. Note that Coccinelle has some difficulty with
processing functions with `__attribute__` or varargs so some `extern`
declarations are left behind to be dealt with in a future patch.

This was the Coccinelle patch used:

	@@
	type T;
	identifier f;
	@@
	- extern
	  T f(...);

and it was run with:

	$ git ls-files \*.{c,h} |
		grep -v ^compat/ |
		xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place

Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.

Signed-off-by: Denton Liu <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

advice.h

@@ -31,7 +31,7 @@ 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);
 

archive.h

@@ -23,7 +23,7 @@ struct archiver_args {
 
 /* main api */
 
-extern int write_archive(int argc, const char **argv, const char *prefix,
+int write_archive(int argc, const char **argv, const char *prefix,
 			 struct repository *repo,
 			 const char *name_hint, int remote);
 
@@ -39,19 +39,19 @@ 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,
+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);

bisect.h

@@ -11,10 +11,10 @@ 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,
+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 *filter_skipped(struct commit_list *list,
 					  struct commit_list **tried,
 					  int show_all,
 					  int *count,
@@ -31,14 +31,14 @@ struct rev_list_info {
 	const char *header_prefix;
 };
 
-extern int bisect_next_all(struct repository *r,
+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

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 */

branch.h

@@ -50,15 +50,15 @@ 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.
  * 'force' can be used when it is OK for the named branch already exists.
  * 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,
+int replace_each_worktree_head_symref(const char *oldref, const char *newref,
 					     const char *logmsg);
 
 #endif