tree-diff: consolidate code for emitting diffs and recursion in one place
[gitweb.git] / tree-diff.c
index ba01563a0241041cb401cfb03495e6067847248e..1af82190339b058549cb2197b92edb1369c0ba42 100644 (file)
@@ -6,8 +6,8 @@
 #include "diffcore.h"
 #include "tree.h"
 
-static void show_entry(struct diff_options *opt, const char *prefix,
-                      struct tree_desc *desc, struct strbuf *base);
+static void show_path(struct strbuf *base, struct diff_options *opt,
+                     struct tree_desc *t1, struct tree_desc *t2);
 
 static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
                              struct strbuf *base, struct diff_options *opt)
@@ -16,111 +16,130 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
        const char *path1, *path2;
        const unsigned char *sha1, *sha2;
        int cmp, pathlen1, pathlen2;
-       int old_baselen = base->len;
 
        sha1 = tree_entry_extract(t1, &path1, &mode1);
        sha2 = tree_entry_extract(t2, &path2, &mode2);
 
        pathlen1 = tree_entry_len(&t1->entry);
        pathlen2 = tree_entry_len(&t2->entry);
+
+       /*
+        * NOTE files and directories *always* compare differently,
+        * even when having the same name.
+        */
        cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
        if (cmp < 0) {
-               show_entry(opt, "-", t1, base);
+               show_path(base, opt, t1, /*t2=*/NULL);
                return -1;
        }
        if (cmp > 0) {
-               show_entry(opt, "+", t2, base);
+               show_path(base, opt, /*t1=*/NULL, t2);
                return 1;
        }
        if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
                return 0;
 
-       /*
-        * If the filemode has changed to/from a directory from/to a regular
-        * file, we need to consider it a remove and an add.
-        */
-       if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
-               show_entry(opt, "-", t1, base);
-               show_entry(opt, "+", t2, base);
-               return 0;
-       }
-
-       strbuf_add(base, path1, pathlen1);
-       if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
-               if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
-                       opt->change(opt, mode1, mode2,
-                                   sha1, sha2, 1, 1, base->buf, 0, 0);
-               }
-               strbuf_addch(base, '/');
-               diff_tree_sha1(sha1, sha2, base->buf, opt);
-       } else {
-               opt->change(opt, mode1, mode2, sha1, sha2, 1, 1, base->buf, 0, 0);
-       }
-       strbuf_setlen(base, old_baselen);
+       show_path(base, opt, t1, t2);
        return 0;
 }
 
-/* A whole sub-tree went away or appeared */
-static void show_tree(struct diff_options *opt, const char *prefix,
-                     struct tree_desc *desc, struct strbuf *base)
+
+/* convert path, t1/t2 -> opt->diff_*() callbacks */
+static void emit_diff(struct diff_options *opt, struct strbuf *path,
+                     struct tree_desc *t1, struct tree_desc *t2)
 {
-       enum interesting match = entry_not_interesting;
-       for (; desc->size; update_tree_entry(desc)) {
-               if (match != all_entries_interesting) {
-                       match = tree_entry_interesting(&desc->entry, base, 0,
-                                                      &opt->pathspec);
-                       if (match == all_entries_not_interesting)
-                               break;
-                       if (match == entry_not_interesting)
-                               continue;
+       unsigned int mode1 = t1 ? t1->entry.mode : 0;
+       unsigned int mode2 = t2 ? t2->entry.mode : 0;
+
+       if (mode1 && mode2) {
+               opt->change(opt, mode1, mode2, t1->entry.sha1, t2->entry.sha1,
+                       1, 1, path->buf, 0, 0);
+       }
+       else {
+               const unsigned char *sha1;
+               unsigned int mode;
+               int addremove;
+
+               if (mode2) {
+                       addremove = '+';
+                       sha1 = t2->entry.sha1;
+                       mode = mode2;
+               } else {
+                       addremove = '-';
+                       sha1 = t1->entry.sha1;
+                       mode = mode1;
                }
-               show_entry(opt, prefix, desc, base);
+
+               opt->add_remove(opt, addremove, mode, sha1, 1, path->buf, 0);
        }
 }
 
-/* A file entry went away or appeared */
-static void show_entry(struct diff_options *opt, const char *prefix,
-                      struct tree_desc *desc, struct strbuf *base)
+
+/* new path should be added to diff
+ *
+ * 3 cases on how/when it should be called and behaves:
+ *
+ *     !t1,  t2        -> path added, parent lacks it
+ *      t1, !t2        -> path removed from parent
+ *      t1,  t2        -> path modified
+ */
+static void show_path(struct strbuf *base, struct diff_options *opt,
+                     struct tree_desc *t1, struct tree_desc *t2)
 {
        unsigned mode;
        const char *path;
-       const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
-       int pathlen = tree_entry_len(&desc->entry);
+       int pathlen;
        int old_baselen = base->len;
+       int isdir, recurse = 0, emitthis = 1;
 
-       strbuf_add(base, path, pathlen);
-       if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
-               enum object_type type;
-               struct tree_desc inner;
-               void *tree;
-               unsigned long size;
+       /* at least something has to be valid */
+       assert(t1 || t2);
+
+       if (t2) {
+               /* path present in resulting tree */
+               tree_entry_extract(t2, &path, &mode);
+               pathlen = tree_entry_len(&t2->entry);
+               isdir = S_ISDIR(mode);
+       } else {
+               /*
+                * a path was removed - take path from parent. Also take
+                * mode from parent, to decide on recursion.
+                */
+               tree_entry_extract(t1, &path, &mode);
+               pathlen = tree_entry_len(&t1->entry);
 
-               tree = read_sha1_file(sha1, &type, &size);
-               if (!tree || type != OBJ_TREE)
-                       die("corrupt tree sha %s", sha1_to_hex(sha1));
+               isdir = S_ISDIR(mode);
+               mode = 0;
+       }
 
-               if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
-                       opt->add_remove(opt, *prefix, mode, sha1, 1, base->buf, 0);
+       if (DIFF_OPT_TST(opt, RECURSIVE) && isdir) {
+               recurse = 1;
+               emitthis = DIFF_OPT_TST(opt, TREE_IN_RECURSIVE);
+       }
 
-               strbuf_addch(base, '/');
+       strbuf_add(base, path, pathlen);
 
-               init_tree_desc(&inner, tree, size);
-               show_tree(opt, prefix, &inner, base);
-               free(tree);
-       } else
-               opt->add_remove(opt, prefix[0], mode, sha1, 1, base->buf, 0);
+       if (emitthis)
+               emit_diff(opt, base, t1, t2);
+
+       if (recurse) {
+               strbuf_addch(base, '/');
+               diff_tree_sha1(t1 ? t1->entry.sha1 : NULL,
+                              t2 ? t2->entry.sha1 : NULL, base->buf, opt);
+       }
 
        strbuf_setlen(base, old_baselen);
 }
 
 static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
-                              struct diff_options *opt,
-                              enum interesting *match)
+                              struct diff_options *opt)
 {
+       enum interesting match;
+
        while (t->size) {
-               *match = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
-               if (*match) {
-                       if (*match == all_entries_not_interesting)
+               match = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
+               if (match) {
+                       if (match == all_entries_not_interesting)
                                t->size = 0;
                        break;
                }
@@ -133,12 +152,9 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
 {
        struct strbuf base;
        int baselen = strlen(base_str);
-       enum interesting t1_match = entry_not_interesting;
-       enum interesting t2_match = entry_not_interesting;
 
        /* Enable recursion indefinitely */
        opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
-       opt->pathspec.max_depth = -1;
 
        strbuf_init(&base, PATH_MAX);
        strbuf_add(&base, base_str, baselen);
@@ -147,18 +163,18 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
                if (diff_can_quit_early(opt))
                        break;
                if (opt->pathspec.nr) {
-                       skip_uninteresting(t1, &base, opt, &t1_match);
-                       skip_uninteresting(t2, &base, opt, &t2_match);
+                       skip_uninteresting(t1, &base, opt);
+                       skip_uninteresting(t2, &base, opt);
                }
                if (!t1->size) {
                        if (!t2->size)
                                break;
-                       show_entry(opt, "+", t2, &base);
+                       show_path(&base, opt, /*t1=*/NULL, t2);
                        update_tree_entry(t2);
                        continue;
                }
                if (!t2->size) {
-                       show_entry(opt, "-", t1, &base);
+                       show_path(&base, opt, t1, /*t2=*/NULL);
                        update_tree_entry(t1);
                        continue;
                }
@@ -196,9 +212,27 @@ static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, co
        struct diff_options diff_opts;
        struct diff_queue_struct *q = &diff_queued_diff;
        struct diff_filepair *choice;
-       const char *paths[1];
        int i;
 
+       /*
+        * follow-rename code is very specific, we need exactly one
+        * path. Magic that matches more than one path is not
+        * supported.
+        */
+       GUARD_PATHSPEC(&opt->pathspec, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
+#if 0
+       /*
+        * We should reject wildcards as well. Unfortunately we
+        * haven't got a reliable way to detect that 'foo\*bar' in
+        * fact has no wildcards. nowildcard_len is merely a hint for
+        * optimization. Let it slip for now until wildmatch is taught
+        * about dry-run mode and returns wildcard info.
+        */
+       if (opt->pathspec.has_wildcard)
+               die("BUG:%s:%d: wildcards are not supported",
+                   __FILE__, __LINE__);
+#endif
+
        /* Remove the file creation entry from the diff queue, and remember it */
        choice = q->queue[0];
        q->nr = 0;
@@ -207,15 +241,13 @@ static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, co
        DIFF_OPT_SET(&diff_opts, RECURSIVE);
        DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
-       diff_opts.single_follow = opt->pathspec.raw[0];
+       diff_opts.single_follow = opt->pathspec.items[0].match;
        diff_opts.break_opt = opt->break_opt;
        diff_opts.rename_score = opt->rename_score;
-       paths[0] = NULL;
-       diff_tree_setup_paths(paths, &diff_opts);
        diff_setup_done(&diff_opts);
        diff_tree(t1, t2, base, &diff_opts);
        diffcore_std(&diff_opts);
-       diff_tree_release_paths(&diff_opts);
+       free_pathspec(&diff_opts.pathspec);
 
        /* Go through the new set of filepairing, and see if we find a more interesting one */
        opt->found_follow = 0;
@@ -228,15 +260,20 @@ static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, co
                 * the future!
                 */
                if ((p->status == 'R' || p->status == 'C') &&
-                   !strcmp(p->two->path, opt->pathspec.raw[0])) {
+                   !strcmp(p->two->path, opt->pathspec.items[0].match)) {
+                       const char *path[2];
+
                        /* Switch the file-pairs around */
                        q->queue[i] = choice;
                        choice = p;
 
                        /* Update the path we use from now on.. */
-                       diff_tree_release_paths(opt);
-                       opt->pathspec.raw[0] = xstrdup(p->one->path);
-                       diff_tree_setup_paths(opt->pathspec.raw, opt);
+                       path[0] = p->one->path;
+                       path[1] = NULL;
+                       free_pathspec(&opt->pathspec);
+                       parse_pathspec(&opt->pathspec,
+                                      PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
+                                      PATHSPEC_LITERAL_PATH, "", path);
 
                        /*
                         * The caller expects us to return a set of vanilla
@@ -274,14 +311,10 @@ int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const cha
        unsigned long size1, size2;
        int retval;
 
-       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, &size2, NULL);
-       if (!tree2)
-               die("unable to read destination tree (%s)", sha1_to_hex(new));
-       init_tree_desc(&t1, tree1, size1);
-       init_tree_desc(&t2, tree2, size2);
+       tree1 = fill_tree_descriptor(&t1, old);
+       tree2 = fill_tree_descriptor(&t2, new);
+       size1 = t1.size;
+       size2 = t2.size;
        retval = diff_tree(&t1, &t2, base, opt);
        if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
                init_tree_desc(&t1, tree1, size1);
@@ -295,28 +328,5 @@ int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const cha
 
 int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
 {
-       int retval;
-       void *tree;
-       unsigned long size;
-       struct tree_desc empty, real;
-
-       tree = read_object_with_reference(new, tree_type, &size, NULL);
-       if (!tree)
-               die("unable to read root tree (%s)", sha1_to_hex(new));
-       init_tree_desc(&real, tree, size);
-
-       init_tree_desc(&empty, "", 0);
-       retval = diff_tree(&empty, &real, base, opt);
-       free(tree);
-       return retval;
-}
-
-void diff_tree_release_paths(struct diff_options *opt)
-{
-       free_pathspec(&opt->pathspec);
-}
-
-void diff_tree_setup_paths(const char **p, struct diff_options *opt)
-{
-       init_pathspec(&opt->pathspec, p);
+       return diff_tree_sha1(NULL, new, base, opt);
 }