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Auto merge of #3148 - RalfJung:underscore-patterns, r=RalfJung
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Underscore pattern tests
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bors committed Oct 28, 2023
2 parents 111a410 + 507fc23 commit 98ce6d1
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Showing 7 changed files with 121 additions and 17 deletions.
Original file line number Diff line number Diff line change
Expand Up @@ -8,10 +8,8 @@ fn main() {
unsafe {
let x: Uninit<Void> = Uninit { uninit: () };
match x.value {
// rustc warns about un unreachable pattern,
// but is wrong in unsafe code.
#[allow(unreachable_patterns)]
_ => println!("hi from the void!"),
_x => println!("hi from the void!"), //~ERROR: invalid value
}
}
}
15 changes: 15 additions & 0 deletions tests/fail/validity/match_binder_checks_validity1.stderr
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@@ -0,0 +1,15 @@
error: Undefined Behavior: constructing invalid value: encountered a value of uninhabited type `main::Void`
--> $DIR/match_binder_checks_validity1.rs:LL:CC
|
LL | _x => println!("hi from the void!"),
| ^^ constructing invalid value: encountered a value of uninhabited type `main::Void`
|
= help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
= help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
= note: BACKTRACE:
= note: inside `main` at $DIR/match_binder_checks_validity1.rs:LL:CC

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error

14 changes: 14 additions & 0 deletions tests/fail/validity/match_binder_checks_validity2.rs
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@@ -0,0 +1,14 @@
fn main() {
#[derive(Copy, Clone)]
union Uninit<T: Copy> {
value: T,
uninit: u8,
}
unsafe {
let x: Uninit<bool> = Uninit { uninit: 3 };
match x.value {
#[allow(unreachable_patterns)]
_x => println!("hi from the void!"), //~ERROR: invalid value
}
}
}
15 changes: 15 additions & 0 deletions tests/fail/validity/match_binder_checks_validity2.stderr
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@@ -0,0 +1,15 @@
error: Undefined Behavior: constructing invalid value: encountered 0x03, but expected a boolean
--> $DIR/match_binder_checks_validity2.rs:LL:CC
|
LL | _x => println!("hi from the void!"),
| ^^ constructing invalid value: encountered 0x03, but expected a boolean
|
= help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
= help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
= note: BACKTRACE:
= note: inside `main` at $DIR/match_binder_checks_validity2.rs:LL:CC

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error

14 changes: 0 additions & 14 deletions tests/pass/dangling_pointer_deref_match_underscore.rs

This file was deleted.

76 changes: 76 additions & 0 deletions tests/pass/underscore_pattern.rs
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// Various tests ensuring that underscore patterns really just construct the place, but don't check its contents.
#![feature(strict_provenance)]
use std::ptr;

fn main() {
dangling_deref_match();
union_uninhabited_match();
dangling_let();
invalid_let();
dangling_let_type_annotation();
invalid_let_type_annotation();
}

fn dangling_deref_match() {
let p = {
let b = Box::new(42);
&*b as *const i32
};
unsafe {
match *p {
_ => {}
}
}
}

fn union_uninhabited_match() {
#[derive(Copy, Clone)]
enum Void {}
union Uninit<T: Copy> {
value: T,
uninit: (),
}
unsafe {
let x: Uninit<Void> = Uninit { uninit: () };
match x.value {
// rustc warns about un unreachable pattern,
// but is wrong in unsafe code.
#[allow(unreachable_patterns)]
_ => println!("hi from the void!"),
}
}
}

fn dangling_let() {
unsafe {
let ptr = ptr::invalid::<bool>(0x40);
let _ = *ptr;
}
}

fn invalid_let() {
unsafe {
let val = 3u8;
let ptr = ptr::addr_of!(val).cast::<bool>();
let _ = *ptr;
}
}

// Adding a type annotation used to change how MIR is generated, make sure we cover both cases.
fn dangling_let_type_annotation() {
unsafe {
let ptr = ptr::invalid::<bool>(0x40);
let _: bool = *ptr;
}
}

fn invalid_let_type_annotation() {
unsafe {
let val = 3u8;
let ptr = ptr::addr_of!(val).cast::<bool>();
let _: bool = *ptr;
}
}

// FIXME: we should also test `!`, not just `bool` -- but that s currently buggy:
// https://github.com/rust-lang/rust/issues/117288
File renamed without changes.

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