rust/tests/mir-opt/building/custom/aggregate_exprs.rs
Nicholas Nethercote ac24299636 Reformat mir! macro invocations to use braces.
The `mir!` macro has multiple parts:
- An optional return type annotation.
- A sequence of zero or more local declarations.
- A mandatory starting anonymous basic block, which is brace-delimited.
- A sequence of zero of more additional named basic blocks.

Some `mir!` invocations use braces with a "block" style, like so:
```
mir! {
    let _unit: ();
    {
	let non_copy = S(42);
	let ptr = std::ptr::addr_of_mut!(non_copy);
	// Inside `callee`, the first argument and `*ptr` are basically
	// aliasing places!
	Call(_unit = callee(Move(*ptr), ptr), ReturnTo(after_call), UnwindContinue())
    }
    after_call = {
	Return()
    }
}
```
Some invocations use parens with a "block" style, like so:
```
mir!(
    let x: [i32; 2];
    let one: i32;
    {
	x = [42, 43];
	one = 1;
	x = [one, 2];
	RET = Move(x);
	Return()
    }
)
```
And some invocations uses parens with a "tighter" style, like so:
```
mir!({
    SetDiscriminant(*b, 0);
    Return()
})
```
This last style is generally used for cases where just the mandatory
starting basic block is present. Its braces are placed next to the
parens.

This commit changes all `mir!` invocations to use braces with a "block"
style. Why?

- Consistency is good.

- The contents of the invocation is a block of code, so it's odd to use
  parens. They are more normally used for function-like macros.

- Most importantly, the next commit will enable rustfmt for
  `tests/mir-opt/`. rustfmt is more aggressive about formatting macros
  that use parens than macros that use braces. Without this commit's
  changes, rustfmt would break a couple of `mir!` macro invocations that
  use braces within `tests/mir-opt` by inserting an extraneous comma.
  E.g.:
  ```
  mir!(type RET = (i32, bool);, { // extraneous comma after ';'
      RET.0 = 1;
      RET.1 = true;
      Return()
  })
  ```
  Switching those `mir!` invocations to use braces avoids that problem,
  resulting in this, which is nicer to read as well as being valid
  syntax:
  ```
  mir! {
      type RET = (i32, bool);
      {
	  RET.0 = 1;
	  RET.1 = true;
	  Return()
      }
  }
  ```
2024-06-03 13:24:44 +10:00

73 lines
1.3 KiB
Rust

// skip-filecheck
#![feature(custom_mir, core_intrinsics)]
extern crate core;
use core::intrinsics::mir::*;
// EMIT_MIR aggregate_exprs.tuple.built.after.mir
#[custom_mir(dialect = "built")]
fn tuple() -> (i32, bool) {
mir! {
{
RET = (1, true);
Return()
}
}
}
// EMIT_MIR aggregate_exprs.array.built.after.mir
#[custom_mir(dialect = "built")]
fn array() -> [i32; 2] {
mir! {
let x: [i32; 2];
let one: i32;
{
x = [42, 43];
one = 1;
x = [one, 2];
RET = Move(x);
Return()
}
}
}
struct Foo {
a: i32,
b: i32,
}
enum Bar {
Foo(Foo, i32),
}
union Onion {
neon: i32,
noun: f32,
}
// EMIT_MIR aggregate_exprs.adt.built.after.mir
#[custom_mir(dialect = "built")]
fn adt() -> Onion {
mir! {
let one: i32;
let x: Foo;
let y: Bar;
{
one = 1;
x = Foo {
a: 1,
b: 2,
};
y = Bar::Foo(Move(x), one);
RET = Onion { neon: Field(Variant(y, 0), 1) };
Return()
}
}
}
fn main() {
assert_eq!(tuple(), (1, true));
assert_eq!(array(), [1, 2]);
assert_eq!(unsafe { adt().neon }, 1);
}