git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH 2/7] merge-ort: add ability to record conflict messages in a file

From
Elijah Newren via GitGitGadget <gitgitgadget@gmail.com>
Date
Aug 31, 2021, 02:26 UTC
Message-ID
<ed71913886e19ccc276b382de707b4bab7834d12.1630376800.git.gitgitgadget@gmail.com>
In-Reply-To
<pull.1080.git.git.1630376800.gitgitgadget@gmail.com>
From: Elijah Newren <newren@gmail.com>
We want to add an ability for users to run
    git show --remerge-diff $MERGE_COMMIT
or even
    git log -p --remerge-diff ...
and have git show the differences between where the merge machinery
would stop and what is recorded in merge commits.  However, in such
cases, stdout is not an appropriate location to dump conflict messages.
Write those messages to a file in the merge result (not to the working
tree or index, but just to a blob recorded in the relevant tree object).
There are several considerations here:
  * We have to pick file(s) where we write these conflict messages too
  * We want to make it as clear as possible that it's not a real file
    but a set of messages about another file
  * We want conflict messages about a file to appear near the file in
    question in a diff, preferably immediately preceding the file in
    question
  * Related to the above, per-file conflict messages are preferred
    over lumping all conflict messages into one big file
To achive the above:
  * We put the conflict messages for $filename in
      $filename[0:-1] + " " + $filename[-1] + ".conflict_msg"
    or, in words, we insert a space before the final character of
    the filename and then also add ".conflict_msg" at the end.
  * We start the file with a "== Conflict notices for $filename =="
    banner
Signed-off-by: Elijah Newren <newren@gmail.com>
---
 merge-ort.c       | 79 ++++++++++++++++++++++++++++++++++++++++++++++-
 merge-recursive.c |  3 ++
 merge-recursive.h |  1 +
 3 files changed, 82 insertions(+), 1 deletion(-)
diff --git a/merge-ort.c b/merge-ort.c
index 4dbf0a477af..a9e69d9cbb0 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -632,7 +632,11 @@ static void path_msg(struct merge_options *opt,
 		     const char *fmt, ...)
 {
 	va_list ap;
-	struct strbuf *sb = strmap_get(&opt->priv->output, path);
+	struct strbuf *sb;
+
+	if (opt->record_conflict_msgs_in_tree && omittable_hint)
+		return; /* Do not record mere hints in tree */
+	sb = strmap_get(&opt->priv->output, path);
 	if (!sb) {
 		sb = xmalloc(sizeof(*sb));
 		strbuf_init(sb, 0);
@@ -3531,6 +3535,74 @@ static void write_completed_directory(struct merge_options *opt,
 	info->last_directory_len = strlen(info->last_directory);
 }
 
+static void put_path_msgs_in_file(struct merge_options *opt,
+				  const char *path,
+				  struct merged_info *mi,
+				  struct directory_versions *dir_metadata)
+{
+	struct strbuf tmp = STRBUF_INIT, new_path_contents = STRBUF_INIT;
+	char *new_path;
+	int new_path_basic_len, unique_counter;
+	struct merged_info *new_mi;
+	char final;
+	struct strbuf *sb = strmap_get(&opt->priv->output, path);
+
+	assert(opt->record_conflict_msgs_in_tree);
+	if (!sb)
+		return;
+
+	/*
+	 * Determine a pathname for recording conflict messages.  We'd like it
+	 * to sort just before path, but have a name very similar to what path
+	 * has.
+	 */
+	strbuf_addstr(&tmp, path);
+	final = tmp.buf[tmp.len-1];
+	strbuf_setlen(&tmp, tmp.len-1);
+	strbuf_addf(&tmp, " %c.conflict_msg", final);
+
+	/*
+	 * In extremely unlikely event this filename is not unique, modify it
+	 * with ".<integer>" suffixes until it is.
+	 */
+	new_path_basic_len = tmp.len;
+	unique_counter = 0;
+	while (strmap_contains(&opt->priv->paths, tmp.buf)) {
+		strbuf_setlen(&tmp, new_path_basic_len);
+		strbuf_addf(&tmp, ".%d", ++unique_counter);
+	}
+
+	/* Now that we have a unique string, move it to our pool */
+	new_path = mem_pool_strdup(&opt->priv->pool, tmp.buf);
+	strbuf_release(&tmp);
+
+	/* Set up contents we want to place in the file. */
+	strbuf_addf(&new_path_contents, "== Conflict notices for %s ==\n",
+		    path);
+	strbuf_addbuf(&new_path_contents, sb);
+
+	/* Set up new_mi */
+	new_mi = mem_pool_calloc(&opt->priv->pool, 1, sizeof(*new_mi));
+	new_mi->result.mode = 0100644;
+	new_mi->is_null = 0;
+	new_mi->clean = 1;
+	new_mi->basename_offset = mi->basename_offset;
+	new_mi->directory_name = mi->directory_name;
+	if (write_object_file(new_path_contents.buf, new_path_contents.len,
+			      blob_type, &new_mi->result.oid))
+		die(_("Unable to add %s to database"), new_path);
+
+	/*
+	 * Save new_mi in opt->priv->path (so that something will deallocate
+	 * it later), and record the entry for it.
+	 */
+	strmap_put(&opt->priv->paths, new_path, new_mi);
+	record_entry_for_tree(dir_metadata, new_path, new_mi);
+
+	/* Cleanup */
+	strbuf_release(&new_path_contents);
+}
+
 /* Per entry merge function */
 static void process_entry(struct merge_options *opt,
 			  const char *path,
@@ -3991,6 +4063,8 @@ static void process_entries(struct merge_options *opt,
 			struct conflict_info *ci = (struct conflict_info *)mi;
 			process_entry(opt, path, ci, &dir_metadata);
 		}
+		if (!opt->priv->call_depth && opt->record_conflict_msgs_in_tree)
+			put_path_msgs_in_file(opt, path, mi, &dir_metadata);
 	}
 	trace2_region_leave("merge", "processing", opt->repo);
 
@@ -4226,6 +4300,9 @@ void merge_switch_to_result(struct merge_options *opt,
 		struct string_list olist = STRING_LIST_INIT_NODUP;
 		int i;
 
+		if (opt->record_conflict_msgs_in_tree)
+			BUG("Either display conflict messages or record them in tree, not both");
+
 		trace2_region_enter("merge", "display messages", opt->repo);
 
 		/* Hack to pre-allocate olist to the desired size */
diff --git a/merge-recursive.c b/merge-recursive.c
index 3355d50e8ad..b14fa15be91 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -3697,6 +3697,9 @@ static int merge_start(struct merge_options *opt, struct tree *head)
 
 	assert(opt->priv == NULL);
 
+	/* Not supported; option specific to merge-ort */
+	assert(!opt->record_conflict_msgs_in_tree);
+
 	/* Sanity check on repo state; index must match head */
 	if (repo_index_has_changes(opt->repo, head, &sb)) {
 		err(opt, _("Your local changes to the following files would be overwritten by merge:\n  %s"),
diff --git a/merge-recursive.h b/merge-recursive.h
index 0795a1d3ec1..2e2fab37f46 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -46,6 +46,7 @@ struct merge_options {
 	/* miscellaneous control options */
 	const char *subtree_shift;
 	unsigned renormalize : 1;
+	unsigned record_conflict_msgs_in_tree : 1;
 
 	/* internal fields used by the implementation */
 	struct merge_options_internal *priv;
-- 
gitgitgadget
Previous: Junio C HamanoNext: Jeff King
Message 6 of 64 in “Add a new --remerge-diff capability to show & log”
  1. 0/7 Add a new --remerge-diff capability to show & logElijah Newren via GitGitGadget, Aug 31, 2021
  2. 1/7 merge-ort: mark a few more conflict messages as omittableElijah Newren via GitGitGadget, Aug 31, 2021
  3. Junio C HamanoAug 31, 2021
  4. Elijah NewrenSep 1, 2021
  5. Junio C HamanoSep 1, 2021
  6. 2/7 merge-ort: add ability to record conflict messages in a fileElijah Newren via GitGitGadget, Aug 31, 2021
  7. Jeff KingSep 28, 2021
  8. Elijah NewrenSep 29, 2021
  9. Junio C HamanoSep 29, 2021
  10. Elijah NewrenSep 29, 2021
  11. Jeff KingSep 30, 2021
  12. Ævar Arnfjörð BjarmasonSep 30, 2021
  13. Elijah NewrenOct 1, 2021
  14. Jeff KingOct 1, 2021
  15. 3/7 ll-merge: add API for capturing warnings in a strbuf instead of stderrElijah Newren via GitGitGadget, Aug 31, 2021
  16. Jeff KingSep 28, 2021
  17. Junio C HamanoSep 28, 2021
  18. Elijah NewrenSep 29, 2021
  19. 4/7 merge-ort: capture and print ll-merge warnings in our preferred fashionElijah Newren via GitGitGadget, Aug 31, 2021
  20. Jeff KingSep 28, 2021
  21. Ævar Arnfjörð BjarmasonSep 30, 2021
  22. Elijah NewrenOct 1, 2021
  23. Ævar Arnfjörð BjarmasonOct 1, 2021
  24. 5/7 tmp-objdir: new API for creating and removing primary object dirsElijah Newren via GitGitGadget, Aug 31, 2021
  25. Ævar Arnfjörð BjarmasonSep 28, 2021
  26. Elijah NewrenSep 29, 2021
  27. Jeff KingSep 30, 2021
  28. Ævar Arnfjörð BjarmasonSep 30, 2021
  29. Elijah NewrenOct 1, 2021
  30. Jeff KingSep 28, 2021
  31. Junio C HamanoSep 29, 2021
  32. Jeff KingSep 30, 2021
  33. Ævar Arnfjörð BjarmasonSep 30, 2021
  34. Jeff KingSep 30, 2021
  35. Elijah NewrenOct 1, 2021
  36. Ævar Arnfjörð BjarmasonOct 1, 2021
  37. Elijah NewrenOct 1, 2021
  38. Elijah NewrenOct 1, 2021
  39. Jeff KingOct 1, 2021
  40. Ævar Arnfjörð BjarmasonOct 1, 2021
  41. Elijah NewrenSep 29, 2021
  42. Jeff KingSep 30, 2021
  43. Jeff KingSep 30, 2021
  44. Junio C HamanoSep 30, 2021
  45. Elijah NewrenOct 1, 2021
  46. Junio C HamanoOct 1, 2021
  47. Elijah NewrenOct 1, 2021
  48. Jeff KingOct 1, 2021
  49. Neeraj SinghSep 30, 2021
  50. Junio C HamanoSep 30, 2021
  51. Junio C HamanoSep 30, 2021
  52. Elijah NewrenOct 1, 2021
  53. 7/7 doc/diff-options: explain the new --remerge-diff optionElijah Newren via GitGitGadget, Aug 31, 2021
  54. 6/7 show, log: provide a --remerge-diff capabilityElijah Newren via GitGitGadget, Aug 31, 2021
  55. Sergey OrganovAug 31, 2021
  56. Ævar Arnfjörð BjarmasonSep 28, 2021
  57. Elijah NewrenSep 29, 2021
  58. Bagas SanjayaAug 31, 2021
  59. Elijah NewrenAug 31, 2021
  60. Junio C HamanoAug 31, 2021
  61. Elijah NewrenAug 31, 2021
  62. Junio C HamanoSep 1, 2021
  63. Elijah NewrenSep 1, 2021
  64. Junio C HamanoSep 1, 2021

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.