The pio_asm macro returns ProgramWithDefines struct instead of Program struct

[adoble]

The PIO examples in rp-rs/rp-hal/rp2040-hal tend to use the following "pattern" to install the PIO program:

// Define some simple PIO program.
let mut a = pio::Assembler::<32>::new();
// ...
let program = a.assemble_with_wrap(wrap_source, wrap_target);

// ...

let (mut pio, sm0, _, _, _) = pac.PIO0.split(&mut pac.RESETS);
let installed = pio.install(&program).unwrap(); 

Based on my understanding of the README file, I tried to repeat this pattern, but instead used the pio_asm! macro, i.e.:

let program = pio_proc::pio_asm!(
        "set pindirs, 1",
        ".wrap_target",
        "set pins, 0 [31]", //31
        "set pins, 1 [15]", //31
        ".wrap",
        options(max_program_size = 32) // Optional, defaults to 32
    );

// ...

let (mut pio, sm0, _, _, _) = pac.PIO0.split(&mut pac.RESETS);
let installed = pio.install(&program).unwrap();

However, I got the following error:

error[E0308]: mismatched types
  --> src\main.rs:77:33
   |
77 |     let installed = pio.install(&program).unwrap(); 
   |                                 ^^^^^^^^ expected struct `Program`, found struct `ProgramWithDefines`
   |
   = note: expected reference `&Program<32_usize>`
              found reference `&ProgramWithDefines<ExpandedDefines, 32_usize>`

For more information about this error, try `rustc --explain E0308`.

I managed to get it to compile (and load on the RP2040), by changing the installation line to:

let installed = pio.install(&program.program).unwrap(); 

I'm not sure if this just requires a change to the README or the code needs to be changed to return the Program struct instead of ProgramWithDefines (or maybe I've missed something).

[devsnek]

It is intended to return a ProgramWithDefines. The examples which use pio_asm! use program.program. I'm not sure there is really any issue here, you changed the API you were calling so you had to change your code to match it.

[adoble]

Thanks for the quick answer.

I guess I was assuming from the README that the pio_asm! macro was a drop in substitute for the assemble* function. Maybe it just is really a case for making the docs clearer here. If you want me to do this, just let me know.