Re: [PATCH v7 07/16] sequencer: refactor sequencer_add_exec_commands() to work on a todo_list

Hi Phillip,

Le 12/02/2019 à 11:52, Phillip Wood a écrit :

Hi Alban

I think this is almost there, I've got a couple of small comments below.

On 10/02/2019 13:26, Alban Gruin wrote:

quoted

-%<-

diff --git a/builtin/rebase--interactive.c b/builtin/rebase--interactive.c
index df19ccaeb9..c131fd4a27 100644
--- a/builtin/rebase--interactive.c
+++ b/builtin/rebase--interactive.c
-%<-

@@ -221,6 +222,11 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 		warning(_("--[no-]rebase-cousins has no effect without "
 			  "--rebase-merges"));
 
+	if (cmd && *cmd) {
+		string_list_split(&commands, cmd, '\n', -1);

I'd suggest a comment along the lines of
/* As cmd always ends with a newline the last item is empty */

quoted

+		--commands.nr;

Style: commands.nr--

quoted

+	}
+
 	switch (command) {
 	case NONE:
 		if (!onto && !upstream)

@@ -228,7 +234,7 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 
 		ret = do_interactive_rebase(&opts, flags, switch_to, upstream, onto,
 					    onto_name, squash_onto, head_name, restrict_revision,
-					    raw_strategies, cmd, autosquash);
+					    raw_strategies, &commands, autosquash);
 		break;
 	case SKIP: {
 		struct string_list merge_rr = STRING_LIST_INIT_DUP;

@@ -262,11 +268,12 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 		ret = rearrange_squash(the_repository);
 		break;
 	case ADD_EXEC:
-		ret = sequencer_add_exec_commands(the_repository, cmd);
+		ret = sequencer_add_exec_commands(the_repository, &commands);
 		break;
 	default:
 		BUG("invalid command '%d'", command);
 	}

Before freeing the string list it would be good to reset the number of
items with commands.nr++ (with a comment explaining why) so the NUL in
the last item gets freed.

quoted

+	string_list_clear(&commands, 1);

As we don't use item.util I think the second argument would be better as 0.

quoted

 	return !!ret;
 }

FWIW I just stumbled across string_list_remove_empty_items(), which
seems to do exactly the same thing, but that way we don’t have to do
this kind of hacks.

quoted

diff --git a/sequencer.c b/sequencer.c
index 99e12c751e..82ca3432cd 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -4505,21 +4505,27 @@ int sequencer_make_script(struct repository *r, FILE *out,
  * Add commands after pick and (series of) squash/fixup commands
  * in the todo list.
  */
-int sequencer_add_exec_commands(struct repository *r,
-				const char *commands)
+static void todo_list_add_exec_commands(struct todo_list *todo_list,
+					struct string_list *commands)
 {
-	const char *todo_file = rebase_path_todo();
-	struct todo_list todo_list = TODO_LIST_INIT;
-	struct strbuf *buf = &todo_list.buf;
-	size_t offset = 0, commands_len = strlen(commands);
-	int i, insert;
+	struct strbuf *buf = &todo_list->buf;
+	size_t base_offset = buf->len;
+	int i, insert, nr = 0, alloc = 0;
+	struct todo_item *items = NULL, *base_items = NULL;
 
-	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
-		return error(_("could not read '%s'."), todo_file);
+	base_items = xcalloc(commands->nr, sizeof(struct todo_item));
+	for (i = 0; i < commands->nr; i++) {
+		size_t command_len = strlen(commands->items[i].string);
 
-	if (todo_list_parse_insn_buffer(r, todo_list.buf.buf, &todo_list)) {
-		todo_list_release(&todo_list);
-		return error(_("unusable todo list: '%s'"), todo_file);
+		strbuf_addstr(buf, commands->items[i].string);
+		strbuf_addch(buf, '\n');
+
+		base_items[i].command = TODO_EXEC;
+		base_items[i].offset_in_buf = base_offset;
+		base_items[i].arg_offset = base_offset + strlen("exec ");
+		base_items[i].arg_len = command_len - strlen("exec ");
+
+		base_offset += command_len + 1;
 	}
 
 	/*

@@ -4527,39 +4533,60 @@ int sequencer_add_exec_commands(struct repository *r,
 	 * are considered part of the pick, so we insert the commands *after*
 	 * those chains if there are any.
 	 */
-	insert = -1;
-	for (i = 0; i < todo_list.nr; i++) {
-		enum todo_command command = todo_list.items[i].command;
-
-		if (insert >= 0) {
-			/* skip fixup/squash chains */
-			if (command == TODO_COMMENT)
-				continue;
-			else if (is_fixup(command)) {
-				insert = i + 1;
-				continue;
-			}
-			strbuf_insert(buf,
-				      todo_list.items[insert].offset_in_buf +
-				      offset, commands, commands_len);
-			offset += commands_len;
-			insert = -1;

I like the simplification of using insert as a flag. Perhaps we should
document the assumptions. Maybe something like

We insert the exec commands immediately after rearranging any fixups and
before the user edits the list. This means that a fixup chain can never
contain comments (any comments are empty picks that have been commented
out the the user did not specify --keep-empty) and so it is safe to
insert the exec command without looking at the command following the
comment.

I slightly reworded this and added it to the existing comment just
before the for loop:

	/*
	 * Insert <commands> after every pick. Here, fixup/squash chains
	 * are considered part of the pick, so we insert the commands *after*
	 * those chains if there are any.
	 *
	 * As we insert the exec commands immediatly after rearranging
	 * any fixups and before the user edits the list, a fixup chain
	 * can never contain comments (any comments are empty picks that
	 * have been commented out because the user did not specify
	 * --keep-empty).  So, it is safe to insert an exec command
	 * without looking at the command following a comment.
	 */

quoted

+	insert = 0;
+	for (i = 0; i < todo_list->nr; i++) {
+		enum todo_command command = todo_list->items[i].command;
+		if (insert && !is_fixup(command)) {
+			ALLOC_GROW(items, nr + commands->nr, alloc);
+			COPY_ARRAY(items + nr, base_items, commands->nr);
+			nr += commands->nr;
+
+			insert = 0;
 		}
 
-		if (command == TODO_PICK || command == TODO_MERGE)
-			insert = i + 1;
+		ALLOC_GROW(items, nr + 1, alloc);
+		items[nr++] = todo_list->items[i];
+
+		if (command == TODO_PICK || command == TODO_MERGE || is_fixup(command))

I'm not sure what the is_fixup() is for, if the command is a fixup then
it will have been preceded by a pick or merge so insert will already be 1

I feel a bit mean suggesting a reroll when we're on v7 already but I
think these clean-ups would improve the maintainability of the code.
I'll take a look at the rest of the changes to this series sometime this
week.

Best Wishes

Phillip

Cheers,
Alban