ac24299636
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()
}
}
```
70 lines
1.6 KiB
Rust
70 lines
1.6 KiB
Rust
// skip-filecheck
|
|
#![feature(custom_mir, core_intrinsics)]
|
|
|
|
extern crate core;
|
|
use core::intrinsics::mir::*;
|
|
use core::ptr::{addr_of, addr_of_mut};
|
|
|
|
// EMIT_MIR references.mut_ref.built.after.mir
|
|
#[custom_mir(dialect = "runtime", phase = "optimized")]
|
|
pub fn mut_ref(x: &mut i32) -> &mut i32 {
|
|
mir! {
|
|
let t: *mut i32;
|
|
{
|
|
t = addr_of_mut!(*x);
|
|
RET = &mut *t;
|
|
Retag(RET);
|
|
Return()
|
|
}
|
|
}
|
|
}
|
|
|
|
// EMIT_MIR references.immut_ref.built.after.mir
|
|
#[custom_mir(dialect = "runtime", phase = "optimized")]
|
|
pub fn immut_ref(x: &i32) -> &i32 {
|
|
mir! {
|
|
let t: *const i32;
|
|
{
|
|
t = addr_of!(*x);
|
|
RET = & *t;
|
|
Retag(RET);
|
|
Return()
|
|
}
|
|
}
|
|
}
|
|
|
|
// EMIT_MIR references.raw_pointer.built.after.mir
|
|
#[custom_mir(dialect = "built")]
|
|
pub fn raw_pointer(x: *const i32) -> *const i32 {
|
|
// Regression test for a bug in which unsafetyck was not correctly turned off for
|
|
// `dialect = "built"`
|
|
mir! {
|
|
{
|
|
RET = addr_of!(*x);
|
|
Return()
|
|
}
|
|
}
|
|
}
|
|
|
|
// EMIT_MIR references.raw_pointer_offset.built.after.mir
|
|
#[custom_mir(dialect = "built")]
|
|
pub fn raw_pointer_offset(x: *const i32) -> *const i32 {
|
|
mir! {
|
|
{
|
|
RET = Offset(x, 1_isize);
|
|
Return()
|
|
}
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let mut x = 5;
|
|
let arr = [1, 2];
|
|
assert_eq!(*mut_ref(&mut x), 5);
|
|
assert_eq!(*immut_ref(&x), 5);
|
|
unsafe {
|
|
assert_eq!(*raw_pointer(addr_of!(x)), 5);
|
|
assert_eq!(*raw_pointer_offset(addr_of!(arr[0])), 2);
|
|
}
|
|
}
|