Filtering out builtins from --emit-clang-ast only half-works

[fitzgen]

#566 only fixed half the situation it seems. When I run with --emit-clang-ast, the builtin types are only half-filtered:

(

 type.kind = Invalid
)
(

 type.kind = Invalid
)
(

 type.kind = Invalid
)
(

 type.kind = Invalid
)
(

 type.kind = Invalid
)
(

 type.kind = Invalid
)
(

 type.kind = Invalid
)

Etc...

We should finish the job and not even print those shells out. @tsliang, want to finish this?

[fitzgen]

I think the check needs to be earlier.

[tsliang]

@fitzgen can do! It seems that the easiest thing to do would be to simply move the short-circuit in print_type (line 1559:1561) above the call to print_indent (line 1558). Alternatively, could we move both of these checks to ast_dump itself? There's no way that a builtin would have children that would need to be dumped, right?

[fitzgen]

Alternatively, could we move both of these checks to ast_dump itself?

This sounds pretty good to me. The only concern is that if someone explicitly calls ast_dump(some_builtin, 0) then they should get the dump for it.

One sorta hacky way to do this would be to check the indent level and whether it is zero or not. The other way would be to make ast_dump always dump the builtins and filter the builtins before we call ast_dump in the parse function in src/lib.rs:

    if context.options().emit_ast {
        cursor.visit(|cur| clang::ast_dump(&cur, 0)); // <---- add filtering here
    }

I like the latter idea.

There's no way that a builtin would have children that would need to be dumped, right?

Not AFAIK