Use "-Wall -O2" for the compiler to get more warnings.

And fix up the warnings that it pointed out. Let's keep the tree
clean from early on.

Not that the code is very beautiful anyway ;)

Makefile

@@ -1,4 +1,4 @@
-CFLAGS=-g
+CFLAGS=-g -O3 -Wall
 CC=gcc
 
 PROG=update-cache show-diff init-db write-tree read-tree commit-tree cat-file

cat-file.c

@@ -11,7 +11,6 @@ int main(int argc, char **argv)
 	char type[20];
 	void *buf;
 	unsigned long size;
-	int fd;
 
 	if (argc != 3 || get_sha1_hex(argv[2], sha1))
 		usage("cat-file: cat-file [-t | tagname] <sha1>");

init-db.c

@@ -8,7 +8,7 @@
 int main(int argc, char **argv)
 {
 	char *sha1_dir = getenv(DB_ENVIRONMENT), *path;
-	int len, i, fd;
+	int len, i;
 
 	if (mkdir(".dircache", 0700) < 0) {
 		perror("unable to create .dircache");
@@ -25,7 +25,7 @@ int main(int argc, char **argv)
 	if (sha1_dir) {
 		struct stat st;
 		if (!stat(sha1_dir, &st) < 0 && S_ISDIR(st.st_mode))
-			return;
+			return 0;
 		fprintf(stderr, "DB_ENVIRONMENT set to bad directory %s: ", sha1_dir);
 	}
 

read-cache.c

@@ -89,7 +89,7 @@ void * read_sha1_file(unsigned char *sha1, char *type, unsigned long *size)
 	z_stream stream;
 	char buffer[8192];
 	struct stat st;
-	int i, fd, ret, bytes;
+	int fd, ret, bytes;
 	void *map, *buf;
 	char *filename = sha1_file_name(sha1);
 
@@ -173,7 +173,7 @@ int write_sha1_file(char *buf, unsigned len)
 int write_sha1_buffer(unsigned char *sha1, void *buf, unsigned int size)
 {
 	char *filename = sha1_file_name(sha1);
-	int i, fd;
+	int fd;
 
 	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
 	if (fd < 0)
@@ -228,6 +228,7 @@ int read_cache(void)
 	if (fd < 0)
 		return (errno == ENOENT) ? 0 : error("open failed");
 
+	size = 0; // avoid gcc warning
 	map = (void *)-1;
 	if (!fstat(fd, &st)) {
 		map = NULL;

read-tree.c

@@ -72,7 +72,6 @@ static int unpack(unsigned char *sha1)
 
 int main(int argc, char **argv)
 {
-	int fd;
 	unsigned char sha1[20];
 
 	if (argc != 2)

show-diff.c

@@ -60,7 +60,6 @@ int main(int argc, char **argv)
 		struct stat st;
 		struct cache_entry *ce = active_cache[i];
 		int n, changed;
-		unsigned int mode;
 		unsigned long size;
 		char type[20];
 		void *new;

update-cache.c

@@ -50,6 +50,7 @@ static int remove_file_from_cache(char *path)
 		if (pos < active_nr)
 			memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos - 1) * sizeof(struct cache_entry *));
 	}
+	return 0;
 }
 
 static int add_cache_entry(struct cache_entry *ce)
@@ -250,4 +251,5 @@ int main(int argc, char **argv)
 		return 0;
 out:
 	unlink(".dircache/index.lock");
+	return 0;
 }

write-tree.c

@@ -31,7 +31,7 @@ static int prepend_integer(char *buffer, unsigned val, int i)
 
 int main(int argc, char **argv)
 {
-	unsigned long size, offset, val;
+	unsigned long size, offset;
 	int i, entries = read_cache();
 	char *buffer;