Macro declare_passes

macro_rules! declare_passes {
    (
        $(
            $vis:vis mod $mod_name:ident : $($pass_name:ident $( { $($ident:ident),* } )?),+ $(,)?;
        )*
    ) => { ... };
}

We import passes via this macro so that we can have a static list of pass names (used to verify CLI arguments). It takes a list of modules, followed by the passes declared within them.

declare_passes! {
    // Declare a single pass from the module `abort_unwinding_calls`
    mod abort_unwinding_calls : AbortUnwindingCalls;
    // When passes are grouped together as an enum, declare the two constituent passes
    mod add_call_guards : AddCallGuards {
        AllCallEdges,
        CriticalCallEdges
    };
    // Declares multiple pass groups, each containing their own constituent passes
    mod simplify : SimplifyCfg {
        Initial,
        /* omitted */
    }, SimplifyLocals {
        BeforeConstProp,
        /* omitted */
    };
}