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[PATCH 3/8] merge-tree: add option parsing and initial shell for real merge function

From
Elijah Newren via GitGitGadget <gitgitgadget@gmail.com>
Date
Dec 31, 2021, 05:03 UTC
Message-ID
<9d03d3f56ab9ab01281b63cc2ecff195ab8089ae.1640927044.git.gitgitgadget@gmail.com>
In-Reply-To
<pull.1114.git.git.1640927044.gitgitgadget@gmail.com>
From: Elijah Newren <newren@gmail.com>
Let merge-tree accept a `--real` parameter for choosing real merges
instead of trivial merges.  Note that real merges differ from trivial
merges in that they handle:
  - three way content merges
  - recursive ancestor consolidation
  - renames
  - proper directory/file conflict handling
  - etc.
Basically all the stuff you'd expect from `git merge`, just without
updating the index and working tree.  The initial shell added here does
nothing more than die with "real merges are not yet implemented", but
that will be fixed in subsequent commits.
Signed-off-by: Elijah Newren <newren@gmail.com>
---
 builtin/merge-tree.c | 56 +++++++++++++++++++++++++++++++++++++-------
 git.c                |  2 +-
 2 files changed, 48 insertions(+), 10 deletions(-)
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 9fe5b99f623..f04b1eaad0a 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -3,13 +3,12 @@
 #include "tree-walk.h"
 #include "xdiff-interface.h"
 #include "object-store.h"
+#include "parse-options.h"
 #include "repository.h"
 #include "blob.h"
 #include "exec-cmd.h"
 #include "merge-blobs.h"
 
-static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>";
-
 struct merge_list {
 	struct merge_list *next;
 	struct merge_list *link;	/* other stages for this object */
@@ -366,14 +365,16 @@ static void *get_tree_descriptor(struct repository *r,
 	return buf;
 }
 
-static int trivial_merge(int argc, const char **argv) {
+static int trivial_merge(const char *base,
+			 const char *branch1,
+			 const char *branch2) {
 	struct repository *r = the_repository;
 	struct tree_desc t[3];
 	void *buf1, *buf2, *buf3;
 
-	buf1 = get_tree_descriptor(r, t+0, argv[1]);
-	buf2 = get_tree_descriptor(r, t+1, argv[2]);
-	buf3 = get_tree_descriptor(r, t+2, argv[3]);
+	buf1 = get_tree_descriptor(r, t+0, base);
+	buf2 = get_tree_descriptor(r, t+1, branch1);
+	buf3 = get_tree_descriptor(r, t+2, branch2);
 	trivial_merge_trees(t, "");
 	free(buf1);
 	free(buf2);
@@ -383,9 +384,46 @@ static int trivial_merge(int argc, const char **argv) {
 	return 0;
 }
 
+struct merge_tree_options {
+	int real;
+};
+
+static int real_merge(struct merge_tree_options *o,
+		      const char *branch1, const char *branch2)
+{
+	die(_("real merges are not yet implemented"));
+}
+
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
-	if (argc != 4)
-		usage(merge_tree_usage);
-	return trivial_merge(argc, argv);
+	struct merge_tree_options o = { 0 };
+	int expected_remaining_argc;
+
+	const char * const merge_tree_usage[] = {
+		N_("git merge-tree --real <branch1> <branch2>"),
+		N_("git merge-tree <base-tree> <branch1> <branch2>"),
+		NULL
+	};
+	struct option mt_options[] = {
+		OPT_BOOL(0, "real", &o.real,
+			 N_("do a real merge instead of a trivial merge")),
+		OPT_END()
+	};
+
+	/* Check for a request for basic help */
+	if (argc == 2 && !strcmp(argv[1], "-h"))
+		usage_with_options(merge_tree_usage, mt_options);
+
+	/* Parse arguments */
+	argc = parse_options(argc, argv, prefix, mt_options,
+			     merge_tree_usage, 0);
+	expected_remaining_argc = (o.real ? 2 : 3);
+	if (argc != expected_remaining_argc)
+		usage_with_options(merge_tree_usage, mt_options);
+
+	/* Do the relevant type of merge */
+	if (o.real)
+		return real_merge(&o, argv[0], argv[1]);
+	else
+		return trivial_merge(argv[0], argv[1], argv[2]);
 }
diff --git a/git.c b/git.c
index 7edafd8ecff..0124c053878 100644
--- a/git.c
+++ b/git.c
@@ -561,7 +561,7 @@ static struct cmd_struct commands[] = {
 	{ "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 	{ "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 	{ "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
-	{ "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
+	{ "merge-tree", cmd_merge_tree, RUN_SETUP },
 	{ "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 	{ "mktree", cmd_mktree, RUN_SETUP },
 	{ "multi-pack-index", cmd_multi_pack_index, RUN_SETUP },
-- 
gitgitgadget
Previous: Elijah NewrenNext: Elijah Newren via GitGitGadget
Message 6 of 57 in “RFC: Server side merges (no ref updating, no commit creating, no touching worktree or index)”
  1. 0/8 RFC: Server side merges (no ref updating, no commit creating, no touching worktree or index)Elijah Newren via GitGitGadget, Dec 31, 2021
  2. 1/8 merge-tree: rename merge_trees() to trivial_merge_trees()Elijah Newren via GitGitGadget, Dec 31, 2021
  3. 2/8 merge-tree: move logic for existing merge into new functionElijah Newren via GitGitGadget, Dec 31, 2021
  4. Johannes AltmanningerJan 1, 2022
  5. Elijah NewrenJan 1, 2022
  6. 3/8 merge-tree: add option parsing and initial shell for real merge functionElijah Newren via GitGitGadget, Dec 31, 2021
  7. 4/8 merge-tree: implement real mergesElijah Newren via GitGitGadget, Dec 31, 2021
  8. Johannes AltmanningerJan 1, 2022
  9. Elijah NewrenJan 1, 2022
  10. Fabian StelzerJan 3, 2022
  11. Elijah NewrenJan 3, 2022
  12. 5/8 merge-ort: split out a separate display_update_messages() functionElijah Newren via GitGitGadget, Dec 31, 2021
  13. Fabian StelzerJan 3, 2022
  14. Fabian StelzerJan 3, 2022
  15. 8/8 merge-tree: provide an easy way to access which files have conflictsElijah Newren via GitGitGadget, Dec 31, 2021
  16. 7/8 merge-tree: support saving merge messages to a separate fileElijah Newren via GitGitGadget, Dec 31, 2021
  17. Fabian StelzerJan 3, 2022
  18. Elijah NewrenJan 3, 2022
  19. Fabian StelzerJan 3, 2022
  20. Elijah NewrenJan 3, 2022
  21. Fabian StelzerJan 4, 2022
  22. Fabian StelzerJan 3, 2022
  23. Elijah NewrenJan 3, 2022
  24. 6/8 merge-ort: allow update messages to be written to different file streamElijah Newren via GitGitGadget, Dec 31, 2021
  25. Johannes AltmanningerJan 1, 2022
  26. Elijah NewrenJan 1, 2022
  27. 0/8 RFC: Server side merges (no ref updating, no commit creating, no touching worktree or index)Elijah Newren via GitGitGadget, Jan 5, 2022
  28. 1/8 merge-tree: rename merge_trees() to trivial_merge_trees()Elijah Newren via GitGitGadget, Jan 5, 2022
  29. 2/8 merge-tree: move logic for existing merge into new functionElijah Newren via GitGitGadget, Jan 5, 2022
  30. 3/8 merge-tree: add option parsing and initial shell for real merge functionElijah Newren via GitGitGadget, Jan 5, 2022
  31. 5/8 merge-ort: split out a separate display_update_messages() functionElijah Newren via GitGitGadget, Jan 5, 2022
  32. 4/8 merge-tree: implement real mergesElijah Newren via GitGitGadget, Jan 5, 2022
  33. Johannes SchindelinJan 7, 2022
  34. Elijah NewrenJan 7, 2022
  35. Johannes SchindelinJan 7, 2022
  36. Elijah NewrenJan 7, 2022
  37. Junio C HamanoJan 7, 2022
  38. Johannes SchindelinJan 11, 2022
  39. Christian CouderJan 7, 2022
  40. Elijah NewrenJan 7, 2022
  41. 6/8 merge-ort: allow update messages to be written to different file streamElijah Newren via GitGitGadget, Jan 5, 2022
  42. 7/8 merge-tree: support saving merge messages to a separate fileElijah Newren via GitGitGadget, Jan 5, 2022
  43. Johannes SchindelinJan 7, 2022
  44. Elijah NewrenJan 8, 2022
  45. 8/8 merge-tree: provide an easy way to access which files have conflictsElijah Newren via GitGitGadget, Jan 5, 2022
  46. Ramsay JonesJan 5, 2022
  47. Elijah NewrenJan 5, 2022
  48. Johannes SchindelinJan 7, 2022
  49. Elijah NewrenJan 7, 2022
  50. Johannes SchindelinFeb 22, 2022
  51. Elijah NewrenJan 8, 2022
  52. Johannes SchindelinFeb 22, 2022
  53. Junio C HamanoJan 5, 2022
  54. Elijah NewrenJan 5, 2022
  55. Christian CouderJan 7, 2022
  56. Elijah NewrenJan 7, 2022
  57. René ScharfeJan 7, 2022

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