From 4839cca9aaa7452c07c4ead76eeea8879e41b0cf Mon Sep 17 00:00:00 2001 From: Urgau Date: Tue, 12 Dec 2023 20:06:28 +0100 Subject: [PATCH] Recurse into let bindings if possible in ref casting lint --- compiler/rustc_lint/src/reference_casting.rs | 7 +++- tests/ui/lint/reference_casting.rs | 7 ++++ tests/ui/lint/reference_casting.stderr | 36 +++++++++++++++----- 3 files changed, 41 insertions(+), 9 deletions(-) diff --git a/compiler/rustc_lint/src/reference_casting.rs b/compiler/rustc_lint/src/reference_casting.rs index cba47315548..96290288f07 100644 --- a/compiler/rustc_lint/src/reference_casting.rs +++ b/compiler/rustc_lint/src/reference_casting.rs @@ -182,7 +182,12 @@ fn peel_casts<'tcx>(cx: &LateContext<'tcx>, mut e: &'tcx Expr<'tcx>) -> (&'tcx E } arg } else { - break; + let init = cx.expr_or_init(e); + if init.hir_id != e.hir_id { + init + } else { + break; + } }; } diff --git a/tests/ui/lint/reference_casting.rs b/tests/ui/lint/reference_casting.rs index 25e0c75f70d..fe8c6e3ff23 100644 --- a/tests/ui/lint/reference_casting.rs +++ b/tests/ui/lint/reference_casting.rs @@ -113,6 +113,13 @@ unsafe fn assign_to_ref() { *((&std::cell::UnsafeCell::new(0)) as *const _ as *mut i32) = 5; //~^ ERROR assigning to `&T` is undefined behavior + let value = num as *const i32 as *mut i32; + *value = 1; + //~^ ERROR assigning to `&T` is undefined behavior + let value = num as *const i32; + let value = value as *mut i32; + *value = 1; + //~^ ERROR assigning to `&T` is undefined behavior let value = num as *const i32 as *mut i32; *value = 1; //~^ ERROR assigning to `&T` is undefined behavior diff --git a/tests/ui/lint/reference_casting.stderr b/tests/ui/lint/reference_casting.stderr index 8d5f8da6852..2820696508a 100644 --- a/tests/ui/lint/reference_casting.stderr +++ b/tests/ui/lint/reference_casting.stderr @@ -286,7 +286,27 @@ LL | *value = 1; = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:120:5 + --> $DIR/reference_casting.rs:121:5 + | +LL | let value = value as *mut i32; + | ----------------- casting happend here +LL | *value = 1; + | ^^^^^^^^^^ + | + = note: for more information, visit + +error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` + --> $DIR/reference_casting.rs:124:5 + | +LL | let value = num as *const i32 as *mut i32; + | ----------------------------- casting happend here +LL | *value = 1; + | ^^^^^^^^^^ + | + = note: for more information, visit + +error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` + --> $DIR/reference_casting.rs:127:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -297,7 +317,7 @@ LL | *value_rebind = 1; = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:122:5 + --> $DIR/reference_casting.rs:129:5 | LL | *(num as *const i32).cast::().cast_mut() = 2; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -305,7 +325,7 @@ LL | *(num as *const i32).cast::().cast_mut() = 2; = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:124:5 + --> $DIR/reference_casting.rs:131:5 | LL | *(num as *const _ as usize as *mut i32) = 2; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -313,7 +333,7 @@ LL | *(num as *const _ as usize as *mut i32) = 2; = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:126:5 + --> $DIR/reference_casting.rs:133:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -324,7 +344,7 @@ LL | std::ptr::write(value, 2); = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:128:5 + --> $DIR/reference_casting.rs:135:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -335,7 +355,7 @@ LL | std::ptr::write_unaligned(value, 2); = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:130:5 + --> $DIR/reference_casting.rs:137:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -346,12 +366,12 @@ LL | std::ptr::write_volatile(value, 2); = note: for more information, visit error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:134:9 + --> $DIR/reference_casting.rs:141:9 | LL | *(this as *const _ as *mut _) = a; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: for more information, visit -error: aborting due to 40 previous errors +error: aborting due to 42 previous errors