[vim/vim] Fix Vim9 read-only register assignment compilation (PR #18806)

dkearns

unread,

Nov 25, 2025, 6:15:04 AM (5 days ago) Nov 25

to vim/vim, Subscribed

Problem: Assignment to read-only registers @: and @% is allowed during
compilation.
Solution: Abort compilation and emit an E354 error when assigning to
these registers.

Fix the E354 error emitted when attempting to declare @: with :var so
that it references the correct register, @:, rather than the garbage
string "^@".

You can view, comment on, or merge this pull request online at:

https://github.com/vim/vim/pull/18806

Commit Summary

8e87667 Fix Vim9 read-only register assignment compilation

File Changes

(3 files)

Patch Links:

—
Reply to this email directly, view it on GitHub.
You are receiving this because you are subscribed to this thread.

Yegappan Lakshmanan

unread,

Nov 28, 2025, 11:03:08 AM (yesterday) Nov 28

to vim/vim, Subscribed

@yegappan approved this pull request.

—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.

Yegappan Lakshmanan

unread,

Nov 28, 2025, 11:05:00 AM (yesterday) Nov 28

to vim/vim, Subscribed

@yegappan commented on this pull request.

In src/testdir/test_vim9_assign.vim:

> @@ -1592,12 +1592,21 @@ def Test_assignment_failure()
   v9.CheckDefFailure(['var $VAR = 5'], 'E1016: Cannot declare an environment variable:')
   v9.CheckScriptFailure(['vim9script', 'var $ENV = "xxx"'], 'E1016:')
 
+  # read-only registers
+  v9.CheckDefFailure(['var @. = 5'], 'E354:', 1)
+  v9.CheckDefFailure(['var @% = 5'], 'E354:', 1)
+  v9.CheckDefFailure(['var @: = 5'], 'E354:', 1)
+  v9.CheckScriptFailure(['vim9script', 'var @. = 5'], 'E1066:', 2)
+  v9.CheckScriptFailure(['vim9script', 'var @% = 5'], 'E1066:', 2)
+  v9.CheckScriptFailure(['vim9script', 'var @: = 5'], 'E1066:', 2)

Instead of using CheckDefFailure() and then CheckScriptFailure() for the same test, can you use the CheckDefAndScriptFailure() function instead?

—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.

dkearns

unread,

Nov 28, 2025, 10:55:28 PM (23 hours ago) Nov 28

to vim/vim, Push

@dkearns pushed 1 commit.

df462a2 Fix Vim9 read-only register assignment compilation

—
View it on GitHub or unsubscribe.
You are receiving this because you are subscribed to this thread.

dkearns

unread,

Nov 28, 2025, 10:58:42 PM (23 hours ago) Nov 28

to vim/vim, Subscribed

@dkearns commented on this pull request.

In src/testdir/test_vim9_assign.vim:

> @@ -1592,12 +1592,21 @@ def Test_assignment_failure()
   v9.CheckDefFailure(['var $VAR = 5'], 'E1016: Cannot declare an environment variable:')
   v9.CheckScriptFailure(['vim9script', 'var $ENV = "xxx"'], 'E1016:')
 
+  # read-only registers
+  v9.CheckDefFailure(['var @. = 5'], 'E354:', 1)
+  v9.CheckDefFailure(['var @% = 5'], 'E354:', 1)
+  v9.CheckDefFailure(['var @: = 5'], 'E354:', 1)
+  v9.CheckScriptFailure(['vim9script', 'var @. = 5'], 'E1066:', 2)
+  v9.CheckScriptFailure(['vim9script', 'var @% = 5'], 'E1066:', 2)
+  v9.CheckScriptFailure(['vim9script', 'var @: = 5'], 'E1066:', 2)

Done.

I was just matching the local use of the Check* functions there. I'll also do a separate pass to update that file and others to use v9.CheckDefAndScriptFailure as I prefer to keep these bug fix commits as tight as possible.

Thanks for looking it over.

—
Reply to this email directly, view it on GitHub, or unsubscribe.
You are receiving this because you are subscribed to this thread.

Reply all

Reply to author

Forward