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[PATCH v2 11/14] reset_head(): take struct rebase_head_opts

From
PGPhillip Wood via GitGitGadget <gitgitgadget@gmail.com>
Date
Dec 8, 2021, 14:57 UTC
Message-ID
<24b0566aba5d8800d209261a14aca4d872af8027.1638975482.git.gitgitgadget@gmail.com>
In-Reply-To
<pull.1049.v2.git.1638975481.gitgitgadget@gmail.com>
From: Phillip Wood <phillip.wood@dunelm.org.uk>

This function takes a confusingly large number of parameters which makes it difficult to remember which order to pass them in. The following commits will add a couple more parameters which makes the problem worse. To address this change the function to take a struct of options. Using a struct means that it is no longer necessary to remember which order to pass the parameters in and anyone reading the code can easily see which value is passed to each parameter.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---
 builtin/rebase.c | 57 ++++++++++++++++++++++++++++++------------------
 reset.c          | 38 +++++++++++++++-----------------
 reset.h          | 40 +++++++++++++++++++++++++++++----
 sequencer.c      |  5 ++---
 4 files changed, 92 insertions(+), 48 deletions(-)
diff --git a/builtin/rebase.c b/builtin/rebase.c
index fdd822c470f..ecc368dd4f4 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -571,6 +571,7 @@ static int finish_rebase(struct rebase_options *opts)
 static int move_to_original_branch(struct rebase_options *opts)
 {
 	struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
+	struct reset_head_opts ropts = { 0 };
 	int ret;
 
 	if (!opts->head_name)
@@ -583,9 +584,11 @@ static int move_to_original_branch(struct rebase_options *opts)
 		    opts->head_name, oid_to_hex(&opts->onto->object.oid));
 	strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 		    opts->head_name);
-	ret = reset_head(the_repository, NULL, opts->head_name,
-			 RESET_HEAD_REFS_ONLY,
-			 orig_head_reflog.buf, head_reflog.buf, NULL);
+	ropts.branch = opts->head_name;
+	ropts.flags = RESET_HEAD_REFS_ONLY;
+	ropts.orig_head_msg = orig_head_reflog.buf;
+	ropts.head_msg = head_reflog.buf;
+	ret = reset_head(the_repository, &ropts);
 
 	strbuf_release(&orig_head_reflog);
 	strbuf_release(&head_reflog);
@@ -669,13 +672,15 @@ static int run_am(struct rebase_options *opts)
 
 	status = run_command(&format_patch);
 	if (status) {
+		struct reset_head_opts ropts = { 0 };
 		unlink(rebased_patches);
 		free(rebased_patches);
 		strvec_clear(&am.args);
 
-		reset_head(the_repository, &opts->orig_head,
-			   opts->head_name, 0,
-			   NULL, NULL, DEFAULT_REFLOG_ACTION);
+		ropts.oid = &opts->orig_head;
+		ropts.branch = opts->head_name;
+		ropts.default_reflog_action = DEFAULT_REFLOG_ACTION;
+		reset_head(the_repository, &ropts);
 		error(_("\ngit encountered an error while preparing the "
 			"patches to replay\n"
 			"these revisions:\n"
@@ -814,14 +819,17 @@ static int rebase_config(const char *var, const char *value, void *data)
 static int checkout_up_to_date(struct rebase_options *options)
 {
 	struct strbuf buf = STRBUF_INIT;
+	struct reset_head_opts ropts = { 0 };
 	int ret = 0;
 
 	strbuf_addf(&buf, "%s: checkout %s",
 		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
 		    options->switch_to);
-	if (reset_head(the_repository, &options->orig_head,
-		       options->head_name, RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
-		       NULL, buf.buf, NULL) < 0)
+	ropts.oid = &options->orig_head;
+	ropts.branch = options->head_name;
+	ropts.flags = RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	ropts.head_msg = buf.buf;
+	if (reset_head(the_repository, &ropts) < 0)
 		ret = error(_("could not switch to %s"), options->switch_to);
 	strbuf_release(&buf);
 
@@ -1033,6 +1041,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	int reschedule_failed_exec = -1;
 	int allow_preemptive_ff = 1;
 	int preserve_merges_selected = 0;
+	struct reset_head_opts ropts = { 0 };
 	struct option builtin_rebase_options[] = {
 		OPT_STRING(0, "onto", &options.onto_name,
 			   N_("revision"),
@@ -1270,9 +1279,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 		rerere_clear(the_repository, &merge_rr);
 		string_list_clear(&merge_rr, 1);
-
-		if (reset_head(the_repository, NULL, NULL, RESET_HEAD_HARD,
-			       NULL, NULL, NULL) < 0)
+		ropts.flags = RESET_HEAD_HARD;
+		if (reset_head(the_repository, &ropts) < 0)
 			die(_("could not discard worktree changes"));
 		remove_branch_state(the_repository, 0);
 		if (read_basic_state(&options))
@@ -1289,9 +1297,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 		if (read_basic_state(&options))
 			exit(1);
-		if (reset_head(the_repository, &options.orig_head,
-			       options.head_name, RESET_HEAD_HARD,
-			       NULL, NULL, DEFAULT_REFLOG_ACTION) < 0)
+		ropts.oid = &options.orig_head;
+		ropts.branch = options.head_name;
+		ropts.flags = RESET_HEAD_HARD;
+		ropts.default_reflog_action = DEFAULT_REFLOG_ACTION;
+		if (reset_head(the_repository, &ropts) < 0)
 			die(_("could not move back to %s"),
 			    oid_to_hex(&options.orig_head));
 		remove_branch_state(the_repository, 0);
@@ -1758,10 +1768,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 	strbuf_addf(&msg, "%s: checkout %s",
 		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
-	if (reset_head(the_repository, &options.onto->object.oid, NULL,
-		       RESET_HEAD_DETACH | RESET_ORIG_HEAD |
-		       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
-		       NULL, msg.buf, DEFAULT_REFLOG_ACTION))
+	ropts.oid = &options.onto->object.oid;
+	ropts.flags = RESET_HEAD_DETACH | RESET_ORIG_HEAD |
+			RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	ropts.head_msg = msg.buf;
+	ropts.default_reflog_action = DEFAULT_REFLOG_ACTION;
+	if (reset_head(the_repository, &ropts))
 		die(_("Could not detach HEAD"));
 	strbuf_release(&msg);
 
@@ -1776,8 +1788,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		strbuf_addf(&msg, "rebase finished: %s onto %s",
 			options.head_name ? options.head_name : "detached HEAD",
 			oid_to_hex(&options.onto->object.oid));
-		reset_head(the_repository, NULL, options.head_name,
-			   RESET_HEAD_REFS_ONLY, NULL, msg.buf, NULL);
+		memset(&ropts, 0, sizeof(ropts));
+		ropts.branch = options.head_name;
+		ropts.flags = RESET_HEAD_REFS_ONLY;
+		ropts.head_msg = msg.buf;
+		reset_head(the_repository, &ropts);
 		strbuf_release(&msg);
 		ret = finish_rebase(&options);
 		goto cleanup;
diff --git a/reset.c b/reset.c
index 4a92e4bc30b..78145d5c456 100644
--- a/reset.c
+++ b/reset.c
@@ -8,14 +8,17 @@
 #include "tree.h"
 #include "unpack-trees.h"
 
-static int update_refs(const struct object_id *oid, const char *switch_to_branch,
-		       const struct object_id *head, const char *reflog_head,
-		       const char *reflog_orig_head,
-		       const char *default_reflog_action, unsigned flags)
+static int update_refs(const struct reset_head_opts *opts,
+		       const struct object_id *oid,
+		       const struct object_id *head)
 {
-	unsigned detach_head = flags & RESET_HEAD_DETACH;
-	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
-	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
+	unsigned detach_head = opts->flags & RESET_HEAD_DETACH;
+	unsigned run_hook = opts->flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
+	const char *switch_to_branch = opts->branch;
+	const char *reflog_head = opts->head_msg;
+	const char *reflog_orig_head = opts->orig_head_msg;
+	const char *default_reflog_action = opts->default_reflog_action;
 	struct object_id *old_orig = NULL, oid_old_orig;
 	struct strbuf msg = STRBUF_INIT;
 	const char *reflog_action;
@@ -69,14 +72,13 @@ static int update_refs(const struct object_id *oid, const char *switch_to_branch
 	return ret;
 }
 
-int reset_head(struct repository *r, struct object_id *oid,
-	       const char *switch_to_branch, unsigned flags,
-	       const char *reflog_orig_head, const char *reflog_head,
-	       const char *default_reflog_action)
+int reset_head(struct repository *r, const struct reset_head_opts *opts)
 {
-	unsigned reset_hard = flags & RESET_HEAD_HARD;
-	unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
-	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
+	const struct object_id *oid = opts->oid;
+	const char *switch_to_branch = opts->branch;
+	unsigned reset_hard = opts->flags & RESET_HEAD_HARD;
+	unsigned refs_only = opts->flags & RESET_HEAD_REFS_ONLY;
+	unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
 	struct object_id *head = NULL, head_oid;
 	struct tree_desc desc[2] = { { NULL }, { NULL } };
 	struct lock_file lock = LOCK_INIT;
@@ -104,9 +106,7 @@ int reset_head(struct repository *r, struct object_id *oid,
 		oid = &head_oid;
 
 	if (refs_only)
-		return update_refs(oid, switch_to_branch, head, reflog_head,
-				   reflog_orig_head, default_reflog_action,
-				   flags);
+		return update_refs(opts, oid, head);
 
 	action = reset_hard ? "reset" : "checkout";
 	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
@@ -151,9 +151,7 @@ int reset_head(struct repository *r, struct object_id *oid,
 	}
 
 	if (oid != &head_oid || update_orig_head || switch_to_branch)
-		ret = update_refs(oid, switch_to_branch, head, reflog_head,
-				  reflog_orig_head, default_reflog_action,
-				  flags);
+		ret = update_refs(opts, oid, head);
 
 leave_reset_head:
 	rollback_lock_file(&lock);
diff --git a/reset.h b/reset.h
index 2daec804259..a205be2fb85 100644
--- a/reset.h
+++ b/reset.h
@@ -6,15 +6,47 @@
 
 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 
+/* Request a detached checkout */
 #define RESET_HEAD_DETACH (1<<0)
+/* Request a reset rather than a checkout */
 #define RESET_HEAD_HARD (1<<1)
+/* Run the post-checkout hook */
 #define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
+/* Only update refs, do not touch the worktree */
 #define RESET_HEAD_REFS_ONLY (1<<3)
+/* Update ORIG_HEAD as well as HEAD */
 #define RESET_ORIG_HEAD (1<<4)
 
-int reset_head(struct repository *r, struct object_id *oid,
-	       const char *switch_to_branch, unsigned flags,
-	       const char *reflog_orig_head, const char *reflog_head,
-	       const char *default_reflog_action);
+struct reset_head_opts {
+	/*
+	 * The commit to checkout/reset to. Defaults to HEAD.
+	 */
+	const struct object_id *oid;
+	/*
+	 * Optional branch to switch to.
+	 */
+	const char *branch;
+	/*
+	 * Flags defined above.
+	 */
+	unsigned flags;
+	/*
+	 * Optional reflog message for HEAD, if this omitted but oid or branch
+	 * are given then default_reflog_action must be given.
+	 */
+	const char *head_msg;
+	/*
+	 * Optional reflog message for ORIG_HEAD, if this omitted and flags
+	 * contains RESET_ORIG_HEAD then default_reflog_action must be given.
+	 */
+	const char *orig_head_msg;
+	/*
+	 * Action to use in default reflog messages, only required if a ref is
+	 * being updated and the reflog messages above are omitted.
+	 */
+	const char *default_reflog_action;
+};
+
+int reset_head(struct repository *r, const struct reset_head_opts *opts);
 
 #endif
diff --git a/sequencer.c b/sequencer.c
index 78d203dec47..a62ea9d0e05 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -4109,6 +4109,7 @@ void create_autostash(struct repository *r, const char *path)
 	if (has_unstaged_changes(r, 1) ||
 	    has_uncommitted_changes(r, 1)) {
 		struct child_process stash = CHILD_PROCESS_INIT;
+		struct reset_head_opts ropts = { .flags = RESET_HEAD_HARD };
 		struct object_id oid;
 
 		strvec_pushl(&stash.args,
@@ -4130,10 +4131,8 @@ void create_autostash(struct repository *r, const char *path)
 			    path);
 		write_file(path, "%s", oid_to_hex(&oid));
 		printf(_("Created autostash: %s\n"), buf.buf);
-		if (reset_head(r, NULL, NULL, RESET_HEAD_HARD, NULL, NULL,
-			       NULL) < 0)
+		if (reset_head(r, &ropts) < 0)
 			die(_("could not reset --hard"));
-
 		if (discard_index(r->index) < 0 ||
 			repo_read_index(r) < 0)
 			die(_("could not read index"));
-- 
gitgitgadget
Previous: Phillip WoodNext: Junio C Hamano
Message 57 of 85 in “rebase: reset_head() related fixes and improvements”
  1. 00/11 rebase: reset_head() related fixes and improvementsPhillip Wood via GitGitGadget, Oct 1, 2021
  2. 01/11 rebase: factor out checkout for up to date branchPhillip Wood via GitGitGadget, Oct 1, 2021
  3. 03/11 reset_head(): don't run checkout hook if there is an errorPhillip Wood via GitGitGadget, Oct 1, 2021
  4. Junio C HamanoOct 1, 2021
  5. Phillip WoodOct 4, 2021
  6. Ævar Arnfjörð BjarmasonOct 12, 2021
  7. 04/11 reset_head(): remove action parameterPhillip Wood via GitGitGadget, Oct 1, 2021
  8. Junio C HamanoOct 1, 2021
  9. Phillip WoodOct 4, 2021
  10. 05/11 reset_head(): factor out ref updatesPhillip Wood via GitGitGadget, Oct 1, 2021
  11. Junio C HamanoOct 1, 2021
  12. Phillip WoodOct 4, 2021
  13. 06/11 reset_head(): make default_reflog_action optionalPhillip Wood via GitGitGadget, Oct 1, 2021
  14. Junio C HamanoOct 1, 2021
  15. Junio C HamanoOct 1, 2021
  16. Phillip WoodOct 4, 2021
  17. 09/11 rebase --apply: fix reflogPhillip Wood via GitGitGadget, Oct 1, 2021
  18. Junio C HamanoOct 1, 2021
  19. 08/11 reset_head(): take struct rebase_head_optsPhillip Wood via GitGitGadget, Oct 1, 2021
  20. Junio C HamanoOct 1, 2021
  21. Phillip WoodOct 4, 2021
  22. 10/11 rebase --apply: set ORIG_HEAD correctlyPhillip Wood via GitGitGadget, Oct 1, 2021
  23. Junio C HamanoOct 1, 2021
  24. 02/11 reset_head(): fix checkoutPhillip Wood via GitGitGadget, Oct 1, 2021
  25. Junio C HamanoOct 1, 2021
  26. Phillip WoodOct 4, 2021
  27. Junio C HamanoOct 4, 2021
  28. Eric SunshineOct 1, 2021
  29. 11/11 rebase -m: don't fork git checkoutPhillip Wood via GitGitGadget, Oct 1, 2021
  30. 07/11 rebase: cleanup reset_head() callsPhillip Wood via GitGitGadget, Oct 1, 2021
  31. Junio C HamanoOct 2, 2021
  32. Junio C HamanoOct 2, 2021
  33. Phillip WoodOct 2, 2021
  34. Phillip WoodOct 2, 2021
  35. René ScharfeOct 2, 2021
  36. Phillip WoodOct 6, 2021
  37. 00/14 rebase: reset_head() related fixes and improvementsPhillip Wood via GitGitGadget, Dec 8, 2021
  38. 01/14 rebase: factor out checkout for up to date branchPhillip Wood via GitGitGadget, Dec 8, 2021
  39. Junio C HamanoDec 9, 2021
  40. 02/14 t5403: refactor rebase post-checkout hook testsPhillip Wood via GitGitGadget, Dec 8, 2021
  41. Junio C HamanoDec 9, 2021
  42. 03/14 rebase: pass correct arguments to post-checkout hookPhillip Wood via GitGitGadget, Dec 8, 2021
  43. Junio C HamanoDec 9, 2021
  44. 04/14 rebase: do not remove untracked files on checkoutPhillip Wood via GitGitGadget, Dec 8, 2021
  45. Junio C HamanoDec 9, 2021
  46. 05/14 rebase --apply: don't run post-checkout hook if there is an errorPhillip Wood via GitGitGadget, Dec 8, 2021
  47. 06/14 reset_head(): remove action parameterPhillip Wood via GitGitGadget, Dec 8, 2021
  48. 07/14 create_autostash(): remove unneeded parameterPhillip Wood via GitGitGadget, Dec 8, 2021
  49. Junio C HamanoDec 9, 2021
  50. Phillip WoodJan 25, 2022
  51. 08/14 reset_head(): factor out ref updatesPhillip Wood via GitGitGadget, Dec 8, 2021
  52. 09/14 reset_head(): make default_reflog_action optionalPhillip Wood via GitGitGadget, Dec 8, 2021
  53. Junio C HamanoDec 9, 2021
  54. 10/14 rebase: cleanup reset_head() callsPhillip Wood via GitGitGadget, Dec 8, 2021
  55. Junio C HamanoDec 9, 2021
  56. Phillip WoodJan 25, 2022
  57. 11/14 reset_head(): take struct rebase_head_optsPhillip Wood via GitGitGadget, Dec 8, 2021
  58. Junio C HamanoDec 9, 2021
  59. 12/14 rebase --apply: fix reflogPhillip Wood via GitGitGadget, Dec 8, 2021
  60. Junio C HamanoDec 9, 2021
  61. 13/14 rebase --apply: set ORIG_HEAD correctlyPhillip Wood via GitGitGadget, Dec 8, 2021
  62. Elijah NewrenDec 11, 2021
  63. 14/14 rebase -m: don't fork git checkoutPhillip Wood via GitGitGadget, Dec 8, 2021
  64. Junio C HamanoDec 9, 2021
  65. Phillip WoodJan 26, 2022
  66. Junio C HamanoJan 27, 2022
  67. Elijah NewrenDec 11, 2021
  68. 00/14 rebase: reset_head() related fixes and improvementsPhillip Wood via GitGitGadget, Jan 26, 2022
  69. 01/14 rebase: factor out checkout for up to date branchPhillip Wood via GitGitGadget, Jan 26, 2022
  70. 02/14 t5403: refactor rebase post-checkout hook testsPhillip Wood via GitGitGadget, Jan 26, 2022
  71. 03/14 rebase: pass correct arguments to post-checkout hookPhillip Wood via GitGitGadget, Jan 26, 2022
  72. 04/14 rebase: do not remove untracked files on checkoutPhillip Wood via GitGitGadget, Jan 26, 2022
  73. 05/14 rebase --apply: don't run post-checkout hook if there is an errorPhillip Wood via GitGitGadget, Jan 26, 2022
  74. 06/14 reset_head(): remove action parameterPhillip Wood via GitGitGadget, Jan 26, 2022
  75. 07/14 reset_head(): factor out ref updatesPhillip Wood via GitGitGadget, Jan 26, 2022
  76. 08/14 reset_head(): make default_reflog_action optionalPhillip Wood via GitGitGadget, Jan 26, 2022
  77. 09/14 create_autostash(): remove unneeded parameterPhillip Wood via GitGitGadget, Jan 26, 2022
  78. 10/14 rebase: cleanup reset_head() callsPhillip Wood via GitGitGadget, Jan 26, 2022
  79. 11/14 reset_head(): take struct rebase_head_optsPhillip Wood via GitGitGadget, Jan 26, 2022
  80. Ævar Arnfjörð BjarmasonJan 26, 2022
  81. Phillip WoodJan 26, 2022
  82. 12/14 rebase --apply: fix reflogPhillip Wood via GitGitGadget, Jan 26, 2022
  83. 13/14 rebase --apply: set ORIG_HEAD correctlyPhillip Wood via GitGitGadget, Jan 26, 2022
  84. 14/14 rebase -m: don't fork git checkoutPhillip Wood via GitGitGadget, Jan 26, 2022
  85. Elijah NewrenFeb 1, 2022

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