diff-lib: define diff_get_merge_base()
In a future commit, we will be using this function to implement --merge-base functionality in various diff commands. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Denton Liu committed
Sep 20, 2020 at 04:22 UTC
177a8302683da62a62b5b03e8192fcfa897db750
2 files changed
+47
diff-lib.c
+45
@@ -13,6 +13,7 @@
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#include "submodule.h"
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#include "dir.h"
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#include "fsmonitor.h"
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+#include "commit-reach.h"
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/*
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* diff-files
@@ -512,6 +513,50 @@ static int diff_cache(struct rev_info *revs,
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return unpack_trees(1, &t, &opts);
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}
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+void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
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+{
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+ int i;
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+ struct commit *mb_child[2] = {0};
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+ struct commit_list *merge_bases;
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+
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+ for (i = 0; i < revs->pending.nr; i++) {
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+ struct object *obj = revs->pending.objects[i].item;
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+ if (obj->flags)
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+ die(_("--merge-base does not work with ranges"));
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+ if (obj->type != OBJ_COMMIT)
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+ die(_("--merge-base only works with commits"));
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+ }
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+
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+ /*
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+ * This check must go after the for loop above because A...B
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+ * ranges produce three pending commits, resulting in a
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+ * misleading error message.
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+ */
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+ if (revs->pending.nr < 1 || revs->pending.nr > 2)
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+ BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
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+
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+ for (i = 0; i < revs->pending.nr; i++)
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+ mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
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+ if (revs->pending.nr == 1) {
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+ struct object_id oid;
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+
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+ if (get_oid("HEAD", &oid))
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+ die(_("unable to get HEAD"));
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+
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+ mb_child[1] = lookup_commit_reference(the_repository, &oid);
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+ }
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+
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+ merge_bases = repo_get_merge_bases(the_repository, mb_child[0], mb_child[1]);
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+ if (!merge_bases)
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+ die(_("no merge base found"));
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+ if (merge_bases->next)
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+ die(_("multiple merge bases found"));
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+
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+ oidcpy(mb, &merge_bases->item->object.oid);
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+
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+ free_commit_list(merge_bases);
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+}
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+
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int run_diff_index(struct rev_info *revs, unsigned int option)
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{
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struct object_array_entry *ent;
diff.h
+2
@@ -580,6 +580,8 @@ void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc);
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*/
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const char *diff_aligned_abbrev(const struct object_id *sha1, int);
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+void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb);
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+
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/* do not report anything on removed paths */
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#define DIFF_SILENT_ON_REMOVED 01
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/* report racily-clean paths as modified */