Re: Better c-ts-mode indentation when there are macros in the way

> On Jul 18, 2026, at 1:24 AM, Eli Zaretskii <[email protected]> wrote:
> 
>> Date: Sat, 04 Jul 2026 08:45:36 +0300
>> From: Eli Zaretskii <[email protected]>
>> Cc: [email protected]
>> 
>>> From: Björn Lindqvist <[email protected]>
>>> Date: Fri, 3 Jul 2026 18:26:27 +0200
>>> 
>>> Hello Emacs developers!
>>> 
>>> Two years ago I posted about my woes getting c-ts-mode to indent
>>> C code the way I wanted in the presence of preprocessor macros:
>>> 
>>> https://lists.gnu.org/archive/html/emacs-devel/2024-11/msg00806.html
>>> 
>>> To summarize, there are two problems related to how tree-sitter parses
>>> preprocessor macros. The first is that #if and #else becomes part of
>>> the parse tree. So tree-sitter indentation rules like (parent-is
>>> "something") fails. The second problem is that preprocessor macros
>>> cause incorrect parse trees of unbraced block statements:
>>> 
>>>    if (true)
>>>    #define M
>>>    printf("ooo");
>>> 
>>> Neither the macro nor the printf becomes the child of the if
>>> statement.
>>> 
>>> I solved these problems by creating two functions that walks the parse
>>> tree upwards to find the "real"/semantic parent of a node that I use like this:
>>> 
>>>    (my/c-parent-is "translation_unit") column-0 0)
>>>    (my/real-c-parent-is-container my/real-c-parent-bol ,ofs)
>>> 
>>> Implementation here:
>>> 
>>>    https://gist.github.com/bjourne/63ffea0c420bf84104c3f98ca1623ea6
>>> 
>>> My elisp is admittedly pretty bad, but it works, and is not as brittle
>>> as I thought it would be. Could something like this be added to
>>> cs-ts-mode or tree-sitter?
>> 
>> Thanks.
>> 
>> Theo and Yuan, any comments on that?
> 
> Ping!

As sorry, I meant to look at it. Let me wrap my head around the code first. But it sounds promising!

Yuan