witx-codegen 0.11.4

WITX code generator for WebAssembly guest modules.
Documentation 
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use super::*;
use std::io::Write;

impl CppGenerator {
    fn define_union_member<T: Write>(
        w: &mut PrettyWriter<T>,
        // union_name: &str,
        i: usize,
        member: &ASUnionMember,
    ) -> Result<(), Error> {
        let member_type = member.type_.as_ref();
        match member_type {
            ASType::Void => {
                w.write_line(format!(
                    "// {}: (no associated content) if tag={}",
                    member.name.as_var(),
                    i
                ))?;
            }
            _ => {
                w.write_line(format!(
                    "{} {}; // if tag={}",
                    member_type.as_lang(),
                    member.name.as_var(),
                    i
                ))?;
            }
        }
        // Self::define_union_member_accessors(w, union_name, i, member)?;
        Ok(())
    }

    pub fn define_as_union<T: Write>(
        w: &mut PrettyWriter<T>,
        name: &str,
        union_: &ASUnion,
    ) -> Result<(), Error> {
        let tag_repr = union_.tag_repr.as_ref();
        let inner_name = format!("{}_member", name);
        w.write_line(format!("union {} {{", inner_name.as_type()))?;
        for (i, member) in union_.members.iter().enumerate() {
            // w.eob()?;
            Self::define_union_member(&mut w.new_block(), /* name, */ i, member)?;
        }
        w.write_line("};")?.eob()?;

        w.write_line(format!(
            "struct __attribute__((packed)) {} {{",
            name.as_type()
        ))?;
        {
            let mut w = w.new_block();
            w.write_line(format!("{} tag;", tag_repr.as_lang()))?;
            let pad_len = union_.padding_after_tag;
            for i in 0..(pad_len & 1) {
                w.write_line(format!("uint8_t __pad8_{};", i))?;
            }
            for i in 0..(pad_len & 3) / 2 {
                w.write_line(format!("uint16_t __pad16_{};", i))?;
            }
            for i in 0..(pad_len & 7) / 4 {
                w.write_line(format!("uint32_t __pad32_{};", i))?;
            }
            for i in 0..pad_len / 8 {
                w.write_line(format!("uint64_t __pad64_{};", i))?;
            }

            w.write_line(format!("{} member;", inner_name.as_type()))?;
        }

        w.write_line("};")?.eob()?;
        Ok(())
    }
}