rucc-lower 0.2.13

//! The typed AST to IR walk: SSA construction and ABI-directed lowering.
//!
//! Design: `spec/08-ir.md`. Layer rank 9, see `spec/18-package-layout.md`.
//!
//! # What is here so far
//!
//! [`lower`], the walk from the typed tree to the IR, and [`Ssa`], the SSA construction by
//! Braun's algorithm that it drives: the thing that lets a local variable become a value
//! without ever having been a stack slot.
//!
//! The walk is in three files, one per level of the thing it walks. `unit` is the
//! translation unit: objects with static storage, their images, and the functions. `body` is
//! one function: the statements, the control flow, and the expressions. `repr` is the answer
//! to what a C type is once the IR is the one asking.
//!
//! What it does not build yet is reported rather than mislowered. A `switch`, a `goto`, an
//! aggregate passed or returned by value, a bit-field, a statement expression, `va_arg`, a
//! variable length array and inline asm each become a diagnostic, so a program that uses one
//! fails to compile rather than compiling into something that is not what it says.
//!
//! Every crate in the workspace is published, and publishing implies a promise. This one is
//! tier 3: its Rust API is explicitly unstable and will change without a major version bump.
//! Depend on the `rucc` binary's behaviour, not on this.

#![doc(html_root_url = "https://docs.rs/rucc-lower/0.2.13")]

mod body;
mod repr;
mod ssa;
mod unit;

pub use ssa::{Ssa, Var};
pub use unit::{Context, Lowered, lower};

/// The milestone in `spec/17-milestones.md` that fills this crate in.
pub const MILESTONE: &str = "M2";

#[cfg(test)]
mod tests {
    #[test]
    fn milestone_is_recorded() {
        assert!(super::MILESTONE.starts_with('M'));
    }
}