Re: Call for volunteers: add tree-sitter support to major modes

[Jostein Kjønigsen]

> Could someone please tell me how well tree-sitter supports pre-standard
> C with liberal (and sometimes non-standard) use of the C language?  I'm
> talking about code that looks like this:
>
> MACRO_USED_TO_DEFINE_SPECIAL_FUNCTIONS (function_name, cells, transform)
>       some_kind_of_ptr cells;
>       another_kind_of_ptr *transform;
> {
>    extern maybe_tls (int) errno;
>    extern caddr_t bar (_P (another_kind_of_ptr, ...));
>    int rc;
>
>    BEGIN_A_KIND_OF_SECTION ({
>        ENTRY (dx, dy, shx, shy)
>         float dx, dy, shx, shy;
>
>        if (!bar (other_function (dx, dy, shx, shy),
>                 etc, etc, etc))
>         die ("bar", sys_errlist[errno]);
>      }, register float, section_name);
>
>    rc = more_code_here (&section_name_desc, etc);
>    return rc;
> }
>
> I don't doubt that tree-sitter is good at parsing newer languages like
> Typescript, but does it support C all that well?
If you want to get an idea of the syntaxes which are supported by 
tree-sitter, all language grammar-specifications have test-cases 
associated with them.

Some of the test-cases for "vanilla" C can be found here:

https://github.com/tree-sitter/tree-sitter-c/tree/master/test/corpus

You may find the amibiguities file in particular interesting: 
https://github.com/tree-sitter/tree-sitter-c/blob/master/test/corpus/ambiguities.txt

For C++ there is a separate grammar all together:

https://github.com/tree-sitter/tree-sitter-cpp/tree/master/test/corpus

It similarly has defined test-cases for how ambiguous statements should 
be parsed:

https://github.com/tree-sitter/tree-sitter-cpp/blob/master/test/corpus/ambiguities.txt

--

Jostein