dnrops
/
rust-clippy
mirror of https://github.com/rust-lang/rust-clippy.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Auto merge of #10879 - Centri3:ptr_cast_constness, r=blyxyas,xFrednet 

[`ptr_cast_constness`]: Only lint on casts which don't change type

fixes #10874

changelog: [`ptr_cast_constness`]: Only lint on casts which don't change type
This commit is contained in:
bors 2023-06-03 13:19:59 +00:00
parent a97a94ab17 cd1d7a3c6f
commit 52c235351a
4 changed files with 67 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
clippy_lints/src/casts/ptr_cast_constness.rs
View File

@ -9,20 +9,21 @@ use rustc_middle::ty::{self, Ty, TypeAndMut};
use super::PTR_CAST_CONSTNESS;
pub(super) fn check(
pub(super) fn check<'tcx>(
cx: &LateContext<'_>,
expr: &Expr<'_>,
cast_expr: &Expr<'_>,
cast_from: Ty<'_>,
cast_to: Ty<'_>,
cast_from: Ty<'tcx>,
cast_to: Ty<'tcx>,
msrv: &Msrv,
) {
if_chain! {
if msrv.meets(POINTER_CAST_CONSTNESS);
if let ty::RawPtr(TypeAndMut { mutbl: from_mutbl, .. }) = cast_from.kind();
if let ty::RawPtr(TypeAndMut { mutbl: to_mutbl, .. }) = cast_to.kind();
if let ty::RawPtr(TypeAndMut { mutbl: from_mutbl, ty: from_ty }) = cast_from.kind();
if let ty::RawPtr(TypeAndMut { mutbl: to_mutbl, ty: to_ty }) = cast_to.kind();
if matches!((from_mutbl, to_mutbl),
(Mutability::Not, Mutability::Mut) | (Mutability::Mut, Mutability::Not));
if from_ty == to_ty;
then {
let sugg = Sugg::hir(cx, cast_expr, "_");
let constness = match *to_mutbl {
@ -34,7 +35,7 @@ pub(super) fn check(
cx,
PTR_CAST_CONSTNESS,
expr.span,
"`as` casting between raw pointers while changing its constness",
"`as` casting between raw pointers while changing only its constness",
&format!("try `pointer::cast_{constness}`, a safer alternative"),
format!("{}.cast_{constness}()", sugg.maybe_par()),
Applicability::MachineApplicable,

19
tests/ui/ptr_cast_constness.fixed
View File

@ -2,17 +2,24 @@
//@aux-build:proc_macros.rs
#![warn(clippy::ptr_cast_constness)]
#![allow(clippy::transmute_ptr_to_ref, clippy::unnecessary_cast, unused)]
extern crate proc_macros;
use proc_macros::{external, inline_macros};
unsafe fn ptr_to_ref<T, U>(p: *const T, om: *mut U) {
let _: &mut T = std::mem::transmute(p.cast_mut());
let _ = &mut *p.cast_mut();
let _: &T = &*(om as *const T);
}
#[inline_macros]
fn main() {
let ptr: *const u32 = &42_u32;
let mut_ptr: *mut u32 = &mut 42_u32;
let _ = ptr as *const i32;
let _ = mut_ptr as *mut i32;
let _ = ptr as *const u32;
let _ = mut_ptr as *mut u32;
// Make sure the lint can handle the difference in their operator precedences.
unsafe {
@ -29,10 +36,10 @@ fn main() {
let _ = ptr_of_array as *const dyn std::fmt::Debug;
// Make sure the lint is triggered inside a macro
let _ = inline!($ptr as *const i32);
let _ = inline!($ptr as *const u32);
// Do not lint inside macros from external crates
let _ = external!($ptr as *const i32);
let _ = external!($ptr as *const u32);
}
#[clippy::msrv = "1.64"]
@ -41,8 +48,8 @@ fn _msrv_1_64() {
let mut_ptr: *mut u32 = &mut 42_u32;
// `pointer::cast_const` and `pointer::cast_mut` were stabilized in 1.65. Do not lint this
let _ = ptr as *mut i32;
let _ = mut_ptr as *const i32;
let _ = ptr as *mut u32;
let _ = mut_ptr as *const u32;
}
#[clippy::msrv = "1.65"]

29
tests/ui/ptr_cast_constness.rs
View File

@ -2,26 +2,33 @@
//@aux-build:proc_macros.rs
#![warn(clippy::ptr_cast_constness)]
#![allow(clippy::transmute_ptr_to_ref, clippy::unnecessary_cast, unused)]
extern crate proc_macros;
use proc_macros::{external, inline_macros};
unsafe fn ptr_to_ref<T, U>(p: *const T, om: *mut U) {
let _: &mut T = std::mem::transmute(p as *mut T);
let _ = &mut *(p as *mut T);
let _: &T = &*(om as *const T);
}
#[inline_macros]
fn main() {
let ptr: *const u32 = &42_u32;
let mut_ptr: *mut u32 = &mut 42_u32;
let _ = ptr as *const i32;
let _ = mut_ptr as *mut i32;
let _ = ptr as *const u32;
let _ = mut_ptr as *mut u32;
// Make sure the lint can handle the difference in their operator precedences.
unsafe {
let ptr_ptr: *const *const u32 = &ptr;
let _ = *ptr_ptr as *mut i32;
let _ = *ptr_ptr as *mut u32;
}
let _ = ptr as *mut i32;
let _ = mut_ptr as *const i32;
let _ = ptr as *mut u32;
let _ = mut_ptr as *const u32;
// Lint this, since pointer::cast_mut and pointer::cast_const have ?Sized
let ptr_of_array: *const [u32; 4] = &[1, 2, 3, 4];
@ -29,10 +36,10 @@ fn main() {
let _ = ptr_of_array as *const dyn std::fmt::Debug;
// Make sure the lint is triggered inside a macro
let _ = inline!($ptr as *const i32);
let _ = inline!($ptr as *const u32);
// Do not lint inside macros from external crates
let _ = external!($ptr as *const i32);
let _ = external!($ptr as *const u32);
}
#[clippy::msrv = "1.64"]
@ -41,8 +48,8 @@ fn _msrv_1_64() {
let mut_ptr: *mut u32 = &mut 42_u32;
// `pointer::cast_const` and `pointer::cast_mut` were stabilized in 1.65. Do not lint this
let _ = ptr as *mut i32;
let _ = mut_ptr as *const i32;
let _ = ptr as *mut u32;
let _ = mut_ptr as *const u32;
}
#[clippy::msrv = "1.65"]
@ -50,6 +57,6 @@ fn _msrv_1_65() {
let ptr: *const u32 = &42_u32;
let mut_ptr: *mut u32 = &mut 42_u32;
let _ = ptr as *mut i32;
let _ = mut_ptr as *const i32;
let _ = ptr as *mut u32;
let _ = mut_ptr as *const u32;
}

46
tests/ui/ptr_cast_constness.stderr
View File

@ -1,34 +1,46 @@
error: `as` casting between raw pointers while changing its constness
--> $DIR/ptr_cast_constness.rs:20:17
error: `as` casting between raw pointers while changing only its constness
--> $DIR/ptr_cast_constness.rs:11:41
|
LL | let _ = *ptr_ptr as *mut i32;
| ^^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast_mut`, a safer alternative: `(*ptr_ptr).cast_mut()`
LL | let _: &mut T = std::mem::transmute(p as *mut T);
| ^^^^^^^^^^^ help: try `pointer::cast_mut`, a safer alternative: `p.cast_mut()`
|
= note: `-D clippy::ptr-cast-constness` implied by `-D warnings`
error: `as` casting between raw pointers while changing its constness
--> $DIR/ptr_cast_constness.rs:23:13
error: `as` casting between raw pointers while changing only its constness
--> $DIR/ptr_cast_constness.rs:12:19
|
LL | let _ = ptr as *mut i32;
LL | let _ = &mut *(p as *mut T);
| ^^^^^^^^^^^^^ help: try `pointer::cast_mut`, a safer alternative: `p.cast_mut()`
error: `as` casting between raw pointers while changing only its constness
--> $DIR/ptr_cast_constness.rs:27:17
|
LL | let _ = *ptr_ptr as *mut u32;
| ^^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast_mut`, a safer alternative: `(*ptr_ptr).cast_mut()`
error: `as` casting between raw pointers while changing only its constness
--> $DIR/ptr_cast_constness.rs:30:13
|
LL | let _ = ptr as *mut u32;
| ^^^^^^^^^^^^^^^ help: try `pointer::cast_mut`, a safer alternative: `ptr.cast_mut()`
error: `as` casting between raw pointers while changing its constness
--> $DIR/ptr_cast_constness.rs:24:13
error: `as` casting between raw pointers while changing only its constness
--> $DIR/ptr_cast_constness.rs:31:13
|
LL | let _ = mut_ptr as *const i32;
LL | let _ = mut_ptr as *const u32;
| ^^^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast_const`, a safer alternative: `mut_ptr.cast_const()`
error: `as` casting between raw pointers while changing its constness
--> $DIR/ptr_cast_constness.rs:53:13
error: `as` casting between raw pointers while changing only its constness
--> $DIR/ptr_cast_constness.rs:60:13
|
LL | let _ = ptr as *mut i32;
LL | let _ = ptr as *mut u32;
| ^^^^^^^^^^^^^^^ help: try `pointer::cast_mut`, a safer alternative: `ptr.cast_mut()`
error: `as` casting between raw pointers while changing its constness
--> $DIR/ptr_cast_constness.rs:54:13
error: `as` casting between raw pointers while changing only its constness
--> $DIR/ptr_cast_constness.rs:61:13
|
LL | let _ = mut_ptr as *const i32;
LL | let _ = mut_ptr as *const u32;
| ^^^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast_const`, a safer alternative: `mut_ptr.cast_const()`
error: aborting due to 5 previous errors
error: aborting due to 7 previous errors