bug#61558: 29.0.60; Indentation with c-ts-mode doesn't work in code guarded by #ifdef..#endif

[Eli Zaretskii]

> From: Theodor Thornhill <theo@thornhill.no>
> Cc: 61558@debbugs.gnu.org
> Date: Fri, 17 Feb 2023 20:23:33 +0100
> 
> #if defined GLYPH_DEBUG && defined ENABLE_CHECKING
>   /* Increment number of allocated matrices.  This count is used
>      to detect memory leaks.  */
>   ++glyph_matrix_count;
> #endif
> 
> 
> Is it a correct assuption to think that whatever is inside one of these
> if-blocks should indent according to their grand-parents rule?

Yes.  Basically, a cpp macro definition is like a comment: it
disappears when cpp processes it.  So, from the language POV, it
doesn't exist.

> In this case:
> 
> 
> static struct glyph_matrix *
> new_glyph_matrix (struct glyph_pool *pool)
> {
>   struct glyph_matrix *result = xzalloc (sizeof *result);
> 
> #if defined GLYPH_DEBUG && defined ENABLE_CHECKING
>   /* Increment number of allocated matrices.  This count is used
>      to detect memory leaks.  */
>   ++glyph_matrix_count;
> #endif
> 
>   /* Set pool and return.  */
>   result->pool = pool;
>   return result;
> }
> 
>   ++glyph_matrix_count;
> 
> is indented one step from the compound_statement node, right?

Sorry: what is the compound_statement node in this case?

> > Strangely, in other places indentation does work: lines 1069, 3119.
> >
> 
> Yeah, in these cases we have something other than the preproc directive
> itself to indent from.

Preprocessor directives should have no effect whatsoever on code
indentation.