Initialize tree descriptors with a helper function rather than by hand.

This removes slightly more lines than it adds, but the real reason for
doing this is that future optimizations will require more setup of the
tree descriptor, and so we want to do it in one place.

Also renamed the "desc.buf" field to "desc.buffer" just to trigger
compiler errors for old-style manual initializations, making sure I
didn't miss anything.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

15 files changed, 60 insertions, 62 deletions

diff --git a/builtin-fsck.c b/builtin-fsck.c
index b8e71b640b..21f1f9e91d 100644
--- a/builtin-fsck.c
+++ b/builtin-fsck.c
@@ -227,8 +227,7 @@ static int fsck_tree(struct tree *item)
 	const char *o_name;
 	const unsigned char *o_sha1;
 
-	desc.buf = item->buffer;
-	desc.size = item->size;
+	init_tree_desc(&desc, item->buffer, item->size);
 
 	o_mode = 0;
 	o_name = NULL;
@@ -242,7 +241,7 @@ static int fsck_tree(struct tree *item)
 
 		if (strchr(name, '/'))
 			has_full_path = 1;
-		has_zero_pad |= *(char *)desc.buf == '0';
+		has_zero_pad |= *(char *)desc.buffer == '0';
 		update_tree_entry(&desc);
 
 		switch (mode) {
diff --git a/builtin-grep.c b/builtin-grep.c
index 1348cc92ef..981f3d4d8e 100644
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -388,11 +388,13 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
 			enum object_type type;
 			struct tree_desc sub;
 			void *data;
-			data = read_sha1_file(entry.sha1, &type, &sub.size);
+			unsigned long size;
+
+			data = read_sha1_file(entry.sha1, &type, &size);
 			if (!data)
 				die("unable to read tree (%s)",
 				    sha1_to_hex(entry.sha1));
-			sub.buf = data;
+			init_tree_desc(&sub, data, size);
 			hit |= grep_tree(opt, paths, &sub, tree_name, down);
 			free(data);
 		}
@@ -408,12 +410,13 @@ static int grep_object(struct grep_opt *opt, const char **paths,
 	if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 		struct tree_desc tree;
 		void *data;
+		unsigned long size;
 		int hit;
 		data = read_object_with_reference(obj->sha1, tree_type,
-						  &tree.size, NULL);
+						  &size, NULL);
 		if (!data)
 			die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
-		tree.buf = data;
+		init_tree_desc(&tree, data, size);
 		hit = grep_tree(opt, paths, &tree, name, "");
 		free(data);
 		return hit;
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 9231b6564f..b5f9648e80 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -873,8 +873,7 @@ static void add_pbase_object(struct tree_desc *tree,
 			tree = pbase_tree_get(entry.sha1);
 			if (!tree)
 				return;
-			sub.buf = tree->tree_data;
-			sub.size = tree->tree_size;
+			init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 
 			add_pbase_object(&sub, down, downlen, fullname);
 			pbase_tree_put(tree);
@@ -937,8 +936,7 @@ static void add_preferred_base_object(const char *name, unsigned hash)
 		}
 		else {
 			struct tree_desc tree;
-			tree.buf = it->pcache.tree_data;
-			tree.size = it->pcache.tree_size;
+			init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 			add_pbase_object(&tree, name, cmplen, name);
 		}
 	}
diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index e47715538b..82df94101a 100644
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -55,8 +55,7 @@ static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 	int cnt;
 
 	hashcpy(it->sha1, tree->object.sha1);
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 	cnt = 0;
 	while (tree_entry(&desc, &entry)) {
 		if (!S_ISDIR(entry.mode))
diff --git a/builtin-reflog.c b/builtin-reflog.c
index 186aabce04..4c39f1da98 100644
--- a/builtin-reflog.c
+++ b/builtin-reflog.c
@@ -52,18 +52,18 @@ static int tree_is_complete(const unsigned char *sha1)
 	if (tree->object.flags & INCOMPLETE)
 		return 0;
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
-	if (!desc.buf) {
+	if (!tree->buffer) {
 		enum object_type type;
-		void *data = read_sha1_file(sha1, &type, &desc.size);
+		unsigned long size;
+		void *data = read_sha1_file(sha1, &type, &size);
 		if (!data) {
 			tree->object.flags |= INCOMPLETE;
 			return 0;
 		}
-		desc.buf = data;
 		tree->buffer = data;
+		tree->size = size;
 	}
+	init_tree_desc(&desc, tree->buffer, tree->size);
 	complete = 1;
 	while (tree_entry(&desc, &entry)) {
 		if (!has_sha1_file(entry.sha1) ||
diff --git a/fetch.c b/fetch.c
index f69be82f10..8e29d313f8 100644
--- a/fetch.c
+++ b/fetch.c
@@ -42,8 +42,7 @@ static int process_tree(struct tree *tree)
 	if (parse_tree(tree))
 		return -1;
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 	while (tree_entry(&desc, &entry)) {
 		struct object *obj = NULL;
 
diff --git a/http-push.c b/http-push.c
index cbb02d3bc1..724720c562 100644
--- a/http-push.c
+++ b/http-push.c
@@ -1750,8 +1750,7 @@ static struct object_list **process_tree(struct tree *tree,
 	me.elem = name;
 	me.elem_len = strlen(name);
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 
 	while (tree_entry(&desc, &entry)) {
 		if (S_ISDIR(entry.mode))
diff --git a/list-objects.c b/list-objects.c
index f1fa21c397..2ba2c958e0 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -49,8 +49,7 @@ static void process_tree(struct rev_info *revs,
 	me.elem = name;
 	me.elem_len = strlen(name);
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 
 	while (tree_entry(&desc, &entry)) {
 		if (S_ISDIR(entry.mode))
diff --git a/reachable.c b/reachable.c
index 01760d7046..ff3dd34962 100644
--- a/reachable.c
+++ b/reachable.c
@@ -42,8 +42,7 @@ static void process_tree(struct tree *tree,
 	me.elem = name;
 	me.elem_len = strlen(name);
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 
 	while (tree_entry(&desc, &entry)) {
 		if (S_ISDIR(entry.mode))
diff --git a/revision.c b/revision.c
index c680dcb8ba..adc381c268 100644
--- a/revision.c
+++ b/revision.c
@@ -62,8 +62,7 @@ void mark_tree_uninteresting(struct tree *tree)
 	if (parse_tree(tree) < 0)
 		die("bad tree %s", sha1_to_hex(obj->sha1));
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 	while (tree_entry(&desc, &entry)) {
 		if (S_ISDIR(entry.mode))
 			mark_tree_uninteresting(lookup_tree(entry.sha1));
@@ -275,18 +274,17 @@ int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 {
 	int retval;
 	void *tree;
+	unsigned long size;
 	struct tree_desc empty, real;
 
 	if (!t1)
 		return 0;
 
-	tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
+	tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 	if (!tree)
 		return 0;
-	real.buf = tree;
-
-	empty.buf = "";
-	empty.size = 0;
+	init_tree_desc(&real, tree, size);
+	init_tree_desc(&empty, "", 0);
 
 	tree_difference = REV_TREE_SAME;
 	revs->pruning.has_changes = 0;
diff --git a/tree-diff.c b/tree-diff.c
index b2f35dc3d8..36788058ae 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -154,12 +154,13 @@ static void show_entry(struct diff_options *opt, const char *prefix, struct tree
 		char *newbase = malloc_base(base, baselen, path, pathlen);
 		struct tree_desc inner;
 		void *tree;
+		unsigned long size;
 
-		tree = read_sha1_file(sha1, &type, &inner.size);
+		tree = read_sha1_file(sha1, &type, &size);
 		if (!tree || type != OBJ_TREE)
 			die("corrupt tree sha %s", sha1_to_hex(sha1));
 
-		inner.buf = tree;
+		init_tree_desc(&inner, tree, size);
 		show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
 
 		free(tree);
@@ -227,16 +228,17 @@ int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const cha
 {
 	void *tree1, *tree2;
 	struct tree_desc t1, t2;
+	unsigned long size1, size2;
 	int retval;
 
-	tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL);
+	tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
 	if (!tree1)
 		die("unable to read source tree (%s)", sha1_to_hex(old));
-	tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL);
+	tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
 	if (!tree2)
 		die("unable to read destination tree (%s)", sha1_to_hex(new));
-	t1.buf = tree1;
-	t2.buf = tree2;
+	init_tree_desc(&t1, tree1, size1);
+	init_tree_desc(&t2, tree2, size2);
 	retval = diff_tree(&t1, &t2, base, opt);
 	free(tree1);
 	free(tree2);
@@ -247,15 +249,15 @@ int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_
 {
 	int retval;
 	void *tree;
+	unsigned long size;
 	struct tree_desc empty, real;
 
-	tree = read_object_with_reference(new, tree_type, &real.size, NULL);
+	tree = read_object_with_reference(new, tree_type, &size, NULL);
 	if (!tree)
 		die("unable to read root tree (%s)", sha1_to_hex(new));
-	real.buf = tree;
+	init_tree_desc(&real, tree, size);
 
-	empty.size = 0;
-	empty.buf = "";
+	init_tree_desc(&empty, "", 0);
 	retval = diff_tree(&empty, &real, base, opt);
 	free(tree);
 	return retval;
diff --git a/tree-walk.c b/tree-walk.c
index 1869baede5..c65492c02d 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -2,6 +2,12 @@
 #include "tree-walk.h"
 #include "tree.h"
 
+void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
+{
+	desc->buffer = buffer;
+	desc->size = size;
+}
+
 void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
 {
 	unsigned long size = 0;
@@ -12,8 +18,7 @@ void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
 		if (!buf)
 			die("unable to read tree %s", sha1_to_hex(sha1));
 	}
-	desc->size = size;
-	desc->buf = buf;
+	init_tree_desc(desc, buf, size);
 	return buf;
 }
 
@@ -36,13 +41,13 @@ static void entry_extract(struct tree_desc *t, struct name_entry *a)
 
 void update_tree_entry(struct tree_desc *desc)
 {
-	const void *buf = desc->buf;
+	const void *buf = desc->buffer;
 	unsigned long size = desc->size;
 	int len = strlen(buf) + 1 + 20;
 
 	if (size < len)
 		die("corrupt tree file");
-	desc->buf = (char *) buf + len;
+	desc->buffer = (char *) buf + len;
 	desc->size = size - len;
 }
 
@@ -62,7 +67,7 @@ static const char *get_mode(const char *str, unsigned int *modep)
 
 const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
 {
-	const void *tree = desc->buf;
+	const void *tree = desc->buffer;
 	unsigned long size = desc->size;
 	int len = strlen(tree)+1;
 	const unsigned char *sha1 = (unsigned char *) tree + len;
@@ -79,7 +84,7 @@ const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pat
 
 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
 {
-	const void *tree = desc->buf;
+	const void *tree = desc->buffer;
 	const char *path;
 	unsigned long len, size = desc->size;
 
@@ -101,7 +106,7 @@ int tree_entry(struct tree_desc *desc, struct name_entry *entry)
 	if (len > size)
 		die("corrupt tree file");
 
-	desc->buf = path;
+	desc->buffer = path;
 	desc->size = size - len;
 	return 1;
 }
@@ -196,10 +201,11 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
 {
 	int retval;
 	void *tree;
+	unsigned long size;
 	struct tree_desc t;
 	unsigned char root[20];
 
-	tree = read_object_with_reference(tree_sha1, tree_type, &t.size, root);
+	tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
 	if (!tree)
 		return -1;
 
@@ -208,7 +214,7 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
 		return 0;
 	}
 
-	t.buf = tree;
+	init_tree_desc(&t, tree, size);
 	retval = find_tree_entry(&t, name, sha1, mode);
 	free(tree);
 	return retval;
diff --git a/tree-walk.h b/tree-walk.h
index 149393aaa4..ca0c29fb1a 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -2,8 +2,8 @@
 #define TREE_WALK_H
 
 struct tree_desc {
-	const void *buf;
-	unsigned long size;
+	const void *buffer;
+	unsigned int size;
 };
 
 struct name_entry {
@@ -18,6 +18,7 @@ static inline int tree_entry_len(const char *name, const unsigned char *sha1)
 }
 
 void update_tree_entry(struct tree_desc *);
+void init_tree_desc(struct tree_desc *desc, const void *buf, unsigned long size);
 const unsigned char *tree_entry_extract(struct tree_desc *, const char **, unsigned int *);
 
 /* Helper function that does both of the above and returns true for success */
diff --git a/tree.c b/tree.c
index 705a481255..d188c0fbae 100644
--- a/tree.c
+++ b/tree.c
@@ -83,8 +83,7 @@ int read_tree_recursive(struct tree *tree,
 	if (parse_tree(tree))
 		return -1;
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 
 	while (tree_entry(&desc, &entry)) {
 		if (!match_tree_entry(base, baselen, entry.path, entry.mode, match))
@@ -152,16 +151,14 @@ static void track_tree_refs(struct tree *item)
 	struct name_entry entry;
 
 	/* Count how many entries there are.. */
-	desc.buf = item->buffer;
-	desc.size = item->size;
+	init_tree_desc(&desc, item->buffer, item->size);
 	while (tree_entry(&desc, &entry))
 		n_refs++;
 
 	/* Allocate object refs and walk it again.. */
 	i = 0;
 	refs = alloc_object_refs(n_refs);
-	desc.buf = item->buffer;
-	desc.size = item->size;
+	init_tree_desc(&desc, item->buffer, item->size);
 	while (tree_entry(&desc, &entry)) {
 		struct object *obj;
 
diff --git a/unpack-trees.c b/unpack-trees.c
index 2e2232cbb0..ee10eea24c 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -27,8 +27,7 @@ static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
 	if (!tree->object.parsed)
 		parse_tree(tree);
 
-	desc.buf = tree->buffer;
-	desc.size = tree->size;
+	init_tree_desc(&desc, tree->buffer, tree->size);
 
 	while (tree_entry(&desc, &one)) {
 		struct tree_entry_list *entry;