sparse cleanup

Fix various things that sparse complains about:
 - use NULL instead of 0
 - make sure we declare everything properly, or mark it static
 - use proper function declarations ("fn(void)" instead of "fn()")

Sparse is always right.

date.c

@@ -10,6 +10,8 @@
 #include <ctype.h>
 #include <time.h>
 
+#include "cache.h"
+
 static time_t my_mktime(struct tm *tm)
 {
 	static const int mdays[] = {

diff-cache.c

@@ -204,11 +204,11 @@ int main(int argc, char **argv)
 
 	diff_setup(detect_rename, diff_score_opt, reverse_diff,
 		   (generate_patch ? -1 : line_termination),
-		   0, 0);
+		   NULL, 0);
 
 	mark_merge_entries();
 
-	tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
+	tree = read_object_with_reference(tree_sha1, "tree", &size, NULL);
 	if (!tree)
 		die("bad tree object %s", argv[1]);
 	if (read_tree(tree, size, 1))

diff-files.c

@@ -86,7 +86,7 @@ int main(int argc, char **argv)
 
 	diff_setup(detect_rename, diff_score_opt, reverse_diff,
 		   (generate_patch ? -1 : line_termination),
-		   0, 0);
+		   NULL, 0);
 
 	for (i = 0; i < entries; i++) {
 		struct stat st;

diff-helper.c

@@ -79,7 +79,7 @@ static int parse_diff_raw_output(const char *buf)
 		if ((*cp != '\t') && *cp != ' ')
 			return -1;
 		strcpy(path, ++cp);
-		diff_change(old_mode, new_mode, old_sha1, new_sha1, path, 0);
+		diff_change(old_mode, new_mode, old_sha1, new_sha1, path, NULL);
 		break;
 	default:
 		return -1;

diff-tree.c

@@ -254,10 +254,10 @@ static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, co
 	unsigned long size1, size2;
 	int retval;
 
-	tree1 = read_object_with_reference(old, "tree", &size1, 0);
+	tree1 = read_object_with_reference(old, "tree", &size1, NULL);
 	if (!tree1)
 		die("unable to read source tree (%s)", sha1_to_hex(old));
-	tree2 = read_object_with_reference(new, "tree", &size2, 0);
+	tree2 = read_object_with_reference(new, "tree", &size2, NULL);
 	if (!tree2)
 		die("unable to read destination tree (%s)", sha1_to_hex(new));
 	retval = diff_tree(tree1, size1, tree2, size2, base);
@@ -273,7 +273,7 @@ static int diff_tree_sha1_top(const unsigned char *old,
 
 	diff_setup(detect_rename, diff_score_opt, reverse_diff,
 		   (generate_patch ? -1 : line_termination),
-		   0, 0);
+		   NULL, 0);
 	ret = diff_tree_sha1(old, new, base);
 	diff_flush();
 	return ret;
@@ -287,8 +287,8 @@ static int diff_root_tree(const unsigned char *new, const char *base)
 
 	diff_setup(detect_rename, diff_score_opt, reverse_diff,
 		   (generate_patch ? -1 : line_termination),
-		   0, 0);
-	tree = read_object_with_reference(new, "tree", &size, 0);
+		   NULL, 0);
+	tree = read_object_with_reference(new, "tree", &size, NULL);
 	if (!tree)
 		die("unable to read root tree (%s)", sha1_to_hex(new));
 	retval = diff_tree("", 0, tree, size, base);

diff.c

@@ -385,7 +385,7 @@ static void run_external_diff(const char *name,
 				*arg++ = temp[1].mode;
 				if (other)
 					*arg++ = other;
-				*arg = 0;
+				*arg = NULL;
 				execvp(pgm, (char *const*) exec_arg);
 			}
 			else
@@ -504,7 +504,7 @@ static void free_data(struct diff_spec_hold *s)
 	else if (s->flags & SHOULD_MUNMAP)
 		munmap(s->data, s->size);
 	s->flags &= ~(SHOULD_FREE|SHOULD_MUNMAP);
-	s->data = 0;
+	s->data = NULL;
 }
 
 static void flush_remaining_diff(struct diff_spec_hold *elem,
@@ -541,7 +541,7 @@ static int is_exact_match(struct diff_spec_hold *src,
 	return 0;
 }
 
-int estimate_similarity(struct diff_spec_hold *src, struct diff_spec_hold *dst)
+static int estimate_similarity(struct diff_spec_hold *src, struct diff_spec_hold *dst)
 {
 	/* src points at a deleted file and dst points at a created
 	 * file.  They may be quite similar, in which case we want to

export.c

@@ -4,7 +4,7 @@
 /*
  * Show one commit
  */
-void show_commit(struct commit *commit)
+static void show_commit(struct commit *commit)
 {
 	char cmdline[400];
 	char hex[100];
@@ -27,7 +27,7 @@ void show_commit(struct commit *commit)
 /*
  * Show all unseen commits, depth-first
  */
-void show_unseen(struct commit *top)
+static void show_unseen(struct commit *top)
 {
 	struct commit_list *parents;
 
@@ -42,15 +42,15 @@ void show_unseen(struct commit *top)
 	show_commit(top);
 }
 
-void export(struct commit *top, struct commit *base)
+static void export(struct commit *top, struct commit *base)
 {
 	mark_reachable(&top->object, 1);
 	if (base)
 		mark_reachable(&base->object, 2);
 	show_unseen(top);
 }
 
-struct commit *get_commit(unsigned char *sha1)
+static struct commit *get_commit(unsigned char *sha1)
 {
 	struct commit *commit = lookup_commit(sha1);
 	if (!commit->object.parsed) {

init-db.c

@@ -5,7 +5,7 @@
  */
 #include "cache.h"
 
-void safe_create_dir(const char *dir)
+static void safe_create_dir(const char *dir)
 {
 	if (mkdir(dir, 0755) < 0) {
 		if (errno != EEXIST) {

ls-files.c

@@ -179,7 +179,7 @@ static int cmp_name(const void *p1, const void *p2)
 				  e2->name, e2->len);
 }
 
-static void show_killed_files()
+static void show_killed_files(void)
 {
 	int i;
 	for (i = 0; i < nr_dir; i++) {

ls-tree.c

@@ -5,8 +5,8 @@
  */
 #include "cache.h"
 
-int line_termination = '\n';
-int recursive = 0;
+static int line_termination = '\n';
+static int recursive = 0;
 
 struct path_prefix {
 	struct path_prefix *prev;
@@ -73,7 +73,7 @@ static int list(unsigned char *sha1)
 	void *buffer;
 	unsigned long size;
 
-	buffer = read_object_with_reference(sha1, "tree", &size, 0);
+	buffer = read_object_with_reference(sha1, "tree", &size, NULL);
 	if (!buffer)
 		die("unable to read sha1 file");
 	list_recursive(buffer, "tree", size, NULL);

merge-base.c

@@ -15,7 +15,7 @@ static struct commit *process_list(struct commit_list **list_p, int this_mark,
 	return NULL;
 }
 
-struct commit *common_ancestor(struct commit *rev1, struct commit *rev2)
+static struct commit *common_ancestor(struct commit *rev1, struct commit *rev2)
 {
 	struct commit_list *rev1list = NULL;
 	struct commit_list *rev2list = NULL;

read-tree.c

@@ -13,7 +13,7 @@ static int unpack_tree(unsigned char *sha1)
 	unsigned long size;
 	int ret;
 
-	buffer = read_object_with_reference(sha1, "tree", &size, 0);
+	buffer = read_object_with_reference(sha1, "tree", &size, NULL);
 	if (!buffer)
 		return -1;
 	ret = read_tree(buffer, size, stage);

rev-tree.c

@@ -46,7 +46,7 @@ static int interesting(struct commit *rev)
 	return 1;
 }
 
-void process_commit(unsigned char *sha1)
+static void process_commit(unsigned char *sha1)
 {
 	struct commit_list *parents;
 	struct commit *obj = lookup_commit(sha1);

rpush.c

@@ -3,7 +3,7 @@
 #include <sys/socket.h>
 #include <errno.h>
 
-void service(int fd_in, int fd_out) {
+static void service(int fd_in, int fd_out) {
 	ssize_t size;
 	int posn;
 	char unsigned sha1[20];

sha1_file.c

@@ -44,7 +44,7 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 	return 0;
 }
 
-int get_sha1_file(const char *path, unsigned char *result)
+static int get_sha1_file(const char *path, unsigned char *result)
 {
 	char buffer[60];
 	int fd = open(path, O_RDONLY);
@@ -199,7 +199,7 @@ static void prepare_alt_odb(void)
 {
 	int pass, totlen, i;
 	const char *cp, *last;
-	char *op = 0;
+	char *op = NULL;
 	const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
 
 	/* The first pass counts how large an area to allocate to
@@ -236,7 +236,7 @@ static void prepare_alt_odb(void)
 		if (pass)
 			break;
 		alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
-		alt_odb[i].base = alt_odb[i].name = 0;
+		alt_odb[i].base = alt_odb[i].name = NULL;
 		op = (char*)(&alt_odb[i+1]);
 	}
 }

strbuf.c

@@ -4,7 +4,7 @@
 #include "cache.h"
 
 void strbuf_init(struct strbuf *sb) {
-	sb->buf = 0;
+	sb->buf = NULL;
 	sb->eof = sb->alloc = sb->len = 0;
 }
 

tar-tree.c

@@ -375,7 +375,7 @@ static void traverse_tree(void *buffer, unsigned long size,
 }
 
 /* get commit time from committer line of commit object */
-time_t commit_time(void * buffer, unsigned long size)
+static time_t commit_time(void * buffer, unsigned long size)
 {
 	time_t result = 0;
 	char *p = buffer;

update-cache.c

@@ -292,7 +292,7 @@ static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
 	return add_cache_entry(ce, option);
 }
 
-struct cache_file cache_file;
+static struct cache_file cache_file;
 
 int main(int argc, char **argv)
 {