unpack-trees: allow Porcelain to give different error messages
[gitweb.git] / diff-lib.c
index ec1b5e3d446c4e5a56fb5f3e4420499c4e8918eb..fe2ccec7e6b3230715cbdf04591d1c0efb6a6389 100644 (file)
@@ -9,6 +9,8 @@
 #include "revision.h"
 #include "cache-tree.h"
 #include "path-list.h"
+#include "unpack-trees.h"
+#include "refs.h"
 
 /*
  * diff-files
@@ -37,7 +39,7 @@ static int get_mode(const char *path, int *mode)
        if (!path || !strcmp(path, "/dev/null"))
                *mode = 0;
        else if (!strcmp(path, "-"))
-               *mode = ntohl(create_ce_mode(0666));
+               *mode = create_ce_mode(0666);
        else if (stat(path, &st))
                return error("Could not access '%s'", path);
        else
@@ -121,7 +123,7 @@ static int queue_diff(struct diff_options *o,
        } else {
                struct diff_filespec *d1, *d2;
 
-               if (o->reverse_diff) {
+               if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
                        unsigned tmp;
                        const char *tmp_c;
                        tmp = mode1; mode1 = mode2; mode2 = tmp;
@@ -189,8 +191,8 @@ static int handle_diff_files_args(struct rev_info *revs,
                else if (!strcmp(argv[1], "-n") ||
                                !strcmp(argv[1], "--no-index")) {
                        revs->max_count = -2;
-                       revs->diffopt.exit_with_status = 1;
-                       revs->diffopt.no_index = 1;
+                       DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
+                       DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
                }
                else if (!strcmp(argv[1], "-q"))
                        *options |= DIFF_SILENT_ON_REMOVED;
@@ -208,7 +210,7 @@ static int handle_diff_files_args(struct rev_info *revs,
                if (!is_in_index(revs->diffopt.paths[0]) ||
                                        !is_in_index(revs->diffopt.paths[1])) {
                        revs->max_count = -2;
-                       revs->diffopt.no_index = 1;
+                       DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
                }
        }
 
@@ -231,7 +233,7 @@ static int handle_diff_files_args(struct rev_info *revs,
 static int is_outside_repo(const char *path, int nongit, const char *prefix)
 {
        int i;
-       if (nongit || !strcmp(path, "-") || path[0] == '/')
+       if (nongit || !strcmp(path, "-") || is_absolute_path(path))
                return 1;
        if (prefixcmp(path, "../"))
                return 0;
@@ -259,9 +261,12 @@ int setup_diff_no_index(struct rev_info *revs,
                        break;
                } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
                        i = argc - 3;
-                       revs->diffopt.exit_with_status = 1;
+                       DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
                        break;
                }
+       if (nongit && argc != i + 2)
+               die("git diff [--no-index] takes two paths");
+
        if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
                                !is_outside_repo(argv[i], nongit, prefix)))
                return -1;
@@ -297,7 +302,7 @@ int setup_diff_no_index(struct rev_info *revs,
        else
                revs->diffopt.paths = argv + argc - 2;
        revs->diffopt.nr_paths = 2;
-       revs->diffopt.no_index = 1;
+       DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
        revs->max_count = -2;
        if (diff_setup_done(&revs->diffopt) < 0)
                die("diff_setup_done failed");
@@ -311,7 +316,7 @@ int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
        if (handle_diff_files_args(revs, argc, argv, &options))
                return -1;
 
-       if (revs->diffopt.no_index) {
+       if (DIFF_OPT_TST(&revs->diffopt, NO_INDEX)) {
                if (revs->diffopt.nr_paths != 2)
                        return error("need two files/directories with --no-index");
                if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
@@ -333,6 +338,45 @@ int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
        return run_diff_files(revs, options);
 }
 
+/*
+ * Has the work tree entity been removed?
+ *
+ * Return 1 if it was removed from the work tree, 0 if an entity to be
+ * compared with the cache entry ce still exists (the latter includes
+ * the case where a directory that is not a submodule repository
+ * exists for ce that is a submodule -- it is a submodule that is not
+ * checked out).  Return negative for an error.
+ */
+static int check_removed(const struct cache_entry *ce, struct stat *st)
+{
+       if (lstat(ce->name, st) < 0) {
+               if (errno != ENOENT && errno != ENOTDIR)
+                       return -1;
+               return 1;
+       }
+       if (has_symlink_leading_path(ce_namelen(ce), ce->name))
+               return 1;
+       if (S_ISDIR(st->st_mode)) {
+               unsigned char sub[20];
+
+               /*
+                * If ce is already a gitlink, we can have a plain
+                * directory (i.e. the submodule is not checked out),
+                * or a checked out submodule.  Either case this is not
+                * a case where something was removed from the work tree,
+                * so we will return 0.
+                *
+                * Otherwise, if the directory is not a submodule
+                * repository, that means ce which was a blob turned into
+                * a directory --- the blob was removed!
+                */
+               if (!S_ISGITLINK(ce->ce_mode) &&
+                   resolve_gitlink_ref(ce->name, "HEAD", sub))
+                       return 1;
+       }
+       return 0;
+}
+
 int run_diff_files(struct rev_info *revs, unsigned int option)
 {
        int entries, i;
@@ -340,17 +384,20 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
        int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
        unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
                              ? CE_MATCH_RACY_IS_DIRTY : 0);
+       char symcache[PATH_MAX];
 
        if (diff_unmerged_stage < 0)
                diff_unmerged_stage = 2;
        entries = active_nr;
+       symcache[0] = '\0';
        for (i = 0; i < entries; i++) {
                struct stat st;
                unsigned int oldmode, newmode;
                struct cache_entry *ce = active_cache[i];
                int changed;
 
-               if (revs->diffopt.quiet && revs->diffopt.has_changes)
+               if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
+                       DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
                        break;
 
                if (!ce_path_match(ce, revs->prune_data))
@@ -374,16 +421,17 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                        memset(&(dpath->parent[0]), 0,
                               sizeof(struct combine_diff_parent)*5);
 
-                       if (lstat(ce->name, &st) < 0) {
-                               if (errno != ENOENT && errno != ENOTDIR) {
+                       changed = check_removed(ce, &st);
+                       if (!changed)
+                               dpath->mode = ce_mode_from_stat(ce, st.st_mode);
+                       else {
+                               if (changed < 0) {
                                        perror(ce->name);
                                        continue;
                                }
                                if (silent_on_removed)
                                        continue;
                        }
-                       else
-                               dpath->mode = ntohl(ce_mode_from_stat(ce, st.st_mode));
 
                        while (i < entries) {
                                struct cache_entry *nce = active_cache[i];
@@ -397,10 +445,10 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                                 */
                                stage = ce_stage(nce);
                                if (2 <= stage) {
-                                       int mode = ntohl(nce->ce_mode);
+                                       int mode = nce->ce_mode;
                                        num_compare_stages++;
                                        hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
-                                       dpath->parent[stage-2].mode = ntohl(ce_mode_from_stat(nce, mode));
+                                       dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
                                        dpath->parent[stage-2].status =
                                                DIFF_STATUS_MODIFIED;
                                }
@@ -434,22 +482,29 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
                                continue;
                }
 
-               if (lstat(ce->name, &st) < 0) {
-                       if (errno != ENOENT && errno != ENOTDIR) {
+               if (ce_uptodate(ce))
+                       continue;
+
+               changed = check_removed(ce, &st);
+               if (changed) {
+                       if (changed < 0) {
                                perror(ce->name);
                                continue;
                        }
                        if (silent_on_removed)
                                continue;
-                       diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
+                       diff_addremove(&revs->diffopt, '-', ce->ce_mode,
                                       ce->sha1, ce->name, NULL);
                        continue;
                }
                changed = ce_match_stat(ce, &st, ce_option);
-               if (!changed && !revs->diffopt.find_copies_harder)
-                       continue;
-               oldmode = ntohl(ce->ce_mode);
-               newmode = ntohl(ce_mode_from_stat(ce, st.st_mode));
+               if (!changed) {
+                       ce_mark_uptodate(ce);
+                       if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
+                               continue;
+               }
+               oldmode = ce->ce_mode;
+               newmode = ce_mode_from_stat(ce, st.st_mode);
                diff_change(&revs->diffopt, oldmode, newmode,
                            ce->sha1, (changed ? null_sha1 : ce->sha1),
                            ce->name, NULL);
@@ -464,30 +519,38 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
  * diff-index
  */
 
+struct oneway_unpack_data {
+       struct rev_info *revs;
+       char symcache[PATH_MAX];
+};
+
 /* A file entry went away or appeared */
 static void diff_index_show_file(struct rev_info *revs,
                                 const char *prefix,
                                 struct cache_entry *ce,
-                                unsigned char *sha1, unsigned int mode)
+                                const unsigned char *sha1, unsigned int mode)
 {
-       diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
+       diff_addremove(&revs->diffopt, prefix[0], mode,
                       sha1, ce->name, NULL);
 }
 
 static int get_stat_data(struct cache_entry *ce,
-                        unsigned char **sha1p,
+                        const unsigned char **sha1p,
                         unsigned int *modep,
-                        int cached, int match_missing)
+                        int cached, int match_missing,
+                        struct oneway_unpack_data *cbdata)
 {
-       unsigned char *sha1 = ce->sha1;
+       const unsigned char *sha1 = ce->sha1;
        unsigned int mode = ce->ce_mode;
 
        if (!cached) {
-               static unsigned char no_sha1[20];
                int changed;
                struct stat st;
-               if (lstat(ce->name, &st) < 0) {
-                       if (errno == ENOENT && match_missing) {
+               changed = check_removed(ce, &st);
+               if (changed < 0)
+                       return -1;
+               else if (changed) {
+                       if (match_missing) {
                                *sha1p = sha1;
                                *modep = mode;
                                return 0;
@@ -497,7 +560,7 @@ static int get_stat_data(struct cache_entry *ce,
                changed = ce_match_stat(ce, &st, 0);
                if (changed) {
                        mode = ce_mode_from_stat(ce, st.st_mode);
-                       sha1 = no_sha1;
+                       sha1 = null_sha1;
                }
        }
 
@@ -506,32 +569,35 @@ static int get_stat_data(struct cache_entry *ce,
        return 0;
 }
 
-static void show_new_file(struct rev_info *revs,
+static void show_new_file(struct oneway_unpack_data *cbdata,
                          struct cache_entry *new,
                          int cached, int match_missing)
 {
-       unsigned char *sha1;
+       const unsigned char *sha1;
        unsigned int mode;
+       struct rev_info *revs = cbdata->revs;
 
-       /* New file in the index: it might actually be different in
+       /*
+        * New file in the index: it might actually be different in
         * the working copy.
         */
-       if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
+       if (get_stat_data(new, &sha1, &mode, cached, match_missing, cbdata) < 0)
                return;
 
        diff_index_show_file(revs, "+", new, sha1, mode);
 }
 
-static int show_modified(struct rev_info *revs,
+static int show_modified(struct oneway_unpack_data *cbdata,
                         struct cache_entry *old,
                         struct cache_entry *new,
                         int report_missing,
                         int cached, int match_missing)
 {
        unsigned int mode, oldmode;
-       unsigned char *sha1;
+       const unsigned char *sha1;
+       struct rev_info *revs = cbdata->revs;
 
-       if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
+       if (get_stat_data(new, &sha1, &mode, cached, match_missing, cbdata) < 0) {
                if (report_missing)
                        diff_index_show_file(revs, "-", old,
                                             old->sha1, old->ce_mode);
@@ -549,14 +615,14 @@ static int show_modified(struct rev_info *revs,
                p->len = pathlen;
                memcpy(p->path, new->name, pathlen);
                p->path[pathlen] = 0;
-               p->mode = ntohl(mode);
+               p->mode = mode;
                hashclr(p->sha1);
                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
                p->parent[0].status = DIFF_STATUS_MODIFIED;
-               p->parent[0].mode = ntohl(new->ce_mode);
+               p->parent[0].mode = new->ce_mode;
                hashcpy(p->parent[0].sha1, new->sha1);
                p->parent[1].status = DIFF_STATUS_MODIFIED;
-               p->parent[1].mode = ntohl(old->ce_mode);
+               p->parent[1].mode = old->ce_mode;
                hashcpy(p->parent[1].sha1, old->sha1);
                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
                free(p);
@@ -565,91 +631,14 @@ static int show_modified(struct rev_info *revs,
 
        oldmode = old->ce_mode;
        if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
-           !revs->diffopt.find_copies_harder)
+           !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
                return 0;
 
-       mode = ntohl(mode);
-       oldmode = ntohl(oldmode);
-
        diff_change(&revs->diffopt, oldmode, mode,
                    old->sha1, sha1, old->name, NULL);
        return 0;
 }
 
-static int diff_cache(struct rev_info *revs,
-                     struct cache_entry **ac, int entries,
-                     const char **pathspec,
-                     int cached, int match_missing)
-{
-       while (entries) {
-               struct cache_entry *ce = *ac;
-               int same = (entries > 1) && ce_same_name(ce, ac[1]);
-
-               if (revs->diffopt.quiet && revs->diffopt.has_changes)
-                       break;
-
-               if (!ce_path_match(ce, pathspec))
-                       goto skip_entry;
-
-               switch (ce_stage(ce)) {
-               case 0:
-                       /* No stage 1 entry? That means it's a new file */
-                       if (!same) {
-                               show_new_file(revs, ce, cached, match_missing);
-                               break;
-                       }
-                       /* Show difference between old and new */
-                       show_modified(revs, ac[1], ce, 1,
-                                     cached, match_missing);
-                       break;
-               case 1:
-                       /* No stage 3 (merge) entry?
-                        * That means it's been deleted.
-                        */
-                       if (!same) {
-                               diff_index_show_file(revs, "-", ce,
-                                                    ce->sha1, ce->ce_mode);
-                               break;
-                       }
-                       /* We come here with ce pointing at stage 1
-                        * (original tree) and ac[1] pointing at stage
-                        * 3 (unmerged).  show-modified with
-                        * report-missing set to false does not say the
-                        * file is deleted but reports true if work
-                        * tree does not have it, in which case we
-                        * fall through to report the unmerged state.
-                        * Otherwise, we show the differences between
-                        * the original tree and the work tree.
-                        */
-                       if (!cached &&
-                           !show_modified(revs, ce, ac[1], 0,
-                                          cached, match_missing))
-                               break;
-                       diff_unmerge(&revs->diffopt, ce->name,
-                                    ntohl(ce->ce_mode), ce->sha1);
-                       break;
-               case 3:
-                       diff_unmerge(&revs->diffopt, ce->name,
-                                    0, null_sha1);
-                       break;
-
-               default:
-                       die("impossible cache entry stage");
-               }
-
-skip_entry:
-               /*
-                * Ignore all the different stages for this file,
-                * we've handled the relevant cases now.
-                */
-               do {
-                       ac++;
-                       entries--;
-               } while (entries && ce_same_name(ce, ac[0]));
-       }
-       return 0;
-}
-
 /*
  * This turns all merge entries into "stage 3". That guarantees that
  * when we read in the new tree (into "stage 1"), we won't lose sight
@@ -662,24 +651,123 @@ static void mark_merge_entries(void)
                struct cache_entry *ce = active_cache[i];
                if (!ce_stage(ce))
                        continue;
-               ce->ce_flags |= htons(CE_STAGEMASK);
+               ce->ce_flags |= CE_STAGEMASK;
        }
 }
 
-int run_diff_index(struct rev_info *revs, int cached)
+/*
+ * This gets a mix of an existing index and a tree, one pathname entry
+ * at a time. The index entry may be a single stage-0 one, but it could
+ * also be multiple unmerged entries (in which case idx_pos/idx_nr will
+ * give you the position and number of entries in the index).
+ */
+static void do_oneway_diff(struct unpack_trees_options *o,
+       struct cache_entry *idx,
+       struct cache_entry *tree)
 {
-       int ret;
-       struct object *ent;
-       struct tree *tree;
-       const char *tree_name;
-       int match_missing = 0;
+       struct oneway_unpack_data *cbdata = o->unpack_data;
+       struct rev_info *revs = cbdata->revs;
+       int match_missing, cached;
 
        /*
         * Backward compatibility wart - "diff-index -m" does
-        * not mean "do not ignore merges", but totally different.
+        * not mean "do not ignore merges", but "match_missing".
+        *
+        * But with the revision flag parsing, that's found in
+        * "!revs->ignore_merges".
+        */
+       cached = o->index_only;
+       match_missing = !revs->ignore_merges;
+
+       if (cached && idx && ce_stage(idx)) {
+               if (tree)
+                       diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode, idx->sha1);
+               return;
+       }
+
+       /*
+        * Something added to the tree?
+        */
+       if (!tree) {
+               show_new_file(cbdata, idx, cached, match_missing);
+               return;
+       }
+
+       /*
+        * Something removed from the tree?
+        */
+       if (!idx) {
+               diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode);
+               return;
+       }
+
+       /* Show difference between old and new */
+       show_modified(cbdata, tree, idx, 1, cached, match_missing);
+}
+
+static inline void skip_same_name(struct cache_entry *ce, struct unpack_trees_options *o)
+{
+       int len = ce_namelen(ce);
+       const struct index_state *index = o->src_index;
+
+       while (o->pos < index->cache_nr) {
+               struct cache_entry *next = index->cache[o->pos];
+               if (len != ce_namelen(next))
+                       break;
+               if (memcmp(ce->name, next->name, len))
+                       break;
+               o->pos++;
+       }
+}
+
+/*
+ * The unpack_trees() interface is designed for merging, so
+ * the different source entries are designed primarily for
+ * the source trees, with the old index being really mainly
+ * used for being replaced by the result.
+ *
+ * For diffing, the index is more important, and we only have a
+ * single tree.
+ *
+ * We're supposed to return how many index entries we want to skip.
+ *
+ * This wrapper makes it all more readable, and takes care of all
+ * the fairly complex unpack_trees() semantic requirements, including
+ * the skipping, the path matching, the type conflict cases etc.
+ */
+static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
+{
+       struct cache_entry *idx = src[0];
+       struct cache_entry *tree = src[1];
+       struct oneway_unpack_data *cbdata = o->unpack_data;
+       struct rev_info *revs = cbdata->revs;
+
+       if (idx && ce_stage(idx))
+               skip_same_name(idx, o);
+
+       /*
+        * Unpack-trees generates a DF/conflict entry if
+        * there was a directory in the index and a tree
+        * in the tree. From a diff standpoint, that's a
+        * delete of the tree and a create of the file.
         */
-       if (!revs->ignore_merges)
-               match_missing = 1;
+       if (tree == o->df_conflict_entry)
+               tree = NULL;
+
+       if (ce_path_match(idx ? idx : tree, revs->prune_data))
+               do_oneway_diff(o, idx, tree);
+
+       return 0;
+}
+
+int run_diff_index(struct rev_info *revs, int cached)
+{
+       struct object *ent;
+       struct tree *tree;
+       const char *tree_name;
+       struct unpack_trees_options opts;
+       struct tree_desc t;
+       struct oneway_unpack_data unpack_cb;
 
        mark_merge_entries();
 
@@ -688,13 +776,25 @@ int run_diff_index(struct rev_info *revs, int cached)
        tree = parse_tree_indirect(ent->sha1);
        if (!tree)
                return error("bad tree object %s", tree_name);
-       if (read_tree(tree, 1, revs->prune_data))
-               return error("unable to read tree object %s", tree_name);
-       ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
-                        cached, match_missing);
+
+       unpack_cb.revs = revs;
+       unpack_cb.symcache[0] = '\0';
+       memset(&opts, 0, sizeof(opts));
+       opts.head_idx = 1;
+       opts.index_only = cached;
+       opts.merge = 1;
+       opts.fn = oneway_diff;
+       opts.unpack_data = &unpack_cb;
+       opts.src_index = &the_index;
+       opts.dst_index = NULL;
+
+       init_tree_desc(&t, tree->buffer, tree->size);
+       if (unpack_trees(1, &t, &opts))
+               exit(128);
+
        diffcore_std(&revs->diffopt);
        diff_flush(&revs->diffopt);
-       return ret;
+       return 0;
 }
 
 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
@@ -704,6 +804,9 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
        int i;
        struct cache_entry **dst;
        struct cache_entry *last = NULL;
+       struct unpack_trees_options opts;
+       struct tree_desc t;
+       struct oneway_unpack_data unpack_cb;
 
        /*
         * This is used by git-blame to run diff-cache internally;
@@ -720,8 +823,7 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
                        cache_tree_invalidate_path(active_cache_tree,
                                                   ce->name);
                        last = ce;
-                       ce->ce_mode = 0;
-                       ce->ce_flags &= ~htons(CE_STAGEMASK);
+                       ce->ce_flags |= CE_REMOVE;
                }
                *dst++ = ce;
        }
@@ -732,8 +834,20 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
        tree = parse_tree_indirect(tree_sha1);
        if (!tree)
                die("bad tree object %s", sha1_to_hex(tree_sha1));
-       if (read_tree(tree, 1, opt->paths))
-               return error("unable to read tree %s", sha1_to_hex(tree_sha1));
-       return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
-                         1, 0);
+
+       unpack_cb.revs = &revs;
+       unpack_cb.symcache[0] = '\0';
+       memset(&opts, 0, sizeof(opts));
+       opts.head_idx = 1;
+       opts.index_only = 1;
+       opts.merge = 1;
+       opts.fn = oneway_diff;
+       opts.unpack_data = &unpack_cb;
+       opts.src_index = &the_index;
+       opts.dst_index = &the_index;
+
+       init_tree_desc(&t, tree->buffer, tree->size);
+       if (unpack_trees(1, &t, &opts))
+               exit(128);
+       return 0;
 }