Compiler panic when using the data bus feature

[ggiraldez]

Aim

When compiling multiple functions and using the data bus feature, the compiler fails with this error:

The application panicked (crashed).
Message:  index out of bounds: the len is 3 but the index is 3
Location: compiler/noirc_evaluator/src/ssa/opt/inlining.rs:211

Expected Behavior

The compiler should not crash.

Bug

This happens because the code that saves the data bus configuration during SSA gen phase is incorrectly placed after processing all other functions. As such, it saves the configuration to the last compiled function instead of the main function.

To Reproduce

Given this program:

use dep::std;

fn main(mut x: u32, y: call_data u32, z: call_data [u32;4]) -> return_data u32 {
  let a = z[x];
  a+foo(y)
}

// Use an unconstrained function to to avoid the compiler inlining it
unconstrained fn foo(x: u32) -> u32 {
  x+1
}

Compile the program with nargo compile. The compiler will panic with the error mentioned above.

Installation Method

Binary

Nargo Version

nargo version = 0.22.0 noirc version = 0.22.0+420a5c74a14dcfeede04337a42282093a7b5e63e (git version hash: 420a5c7, is dirty: false)

Additional Context

No response

Would you like to submit a PR for this Issue?

Yes

Support Needs

No response