From 8f3e876e522f9ecc8f855485bb4857163c0f86e4 Mon Sep 17 00:00:00 2001 From: Wim Looman Date: Sat, 27 May 2023 22:20:14 +0200 Subject: [PATCH] Add note about unsafe functions body not being unsafe --- compiler/rustc_mir_transform/messages.ftl | 1 + .../rustc_mir_transform/src/check_unsafety.rs | 7 ++- compiler/rustc_mir_transform/src/errors.rs | 10 +++- ...rfc-2585-unsafe_op_in_unsafe_fn.mir.stderr | 10 ++++ .../unsafe/wrapping-unsafe-block-sugg.fixed | 17 ++++++- tests/ui/unsafe/wrapping-unsafe-block-sugg.rs | 17 ++++++- .../unsafe/wrapping-unsafe-block-sugg.stderr | 49 ++++++++++++------- 7 files changed, 89 insertions(+), 22 deletions(-) diff --git a/compiler/rustc_mir_transform/messages.ftl b/compiler/rustc_mir_transform/messages.ftl index 300e592a6b4..2598eb2ed09 100644 --- a/compiler/rustc_mir_transform/messages.ftl +++ b/compiler/rustc_mir_transform/messages.ftl @@ -56,6 +56,7 @@ mir_transform_union_access_label = access to union field mir_transform_union_access_note = the field may not be properly initialized: using uninitialized data will cause undefined behavior mir_transform_unsafe_op_in_unsafe_fn = {$details} is unsafe and requires unsafe block (error E0133) .suggestion = consider wrapping the function body in an unsafe block + .note = an unsafe function restricts its caller, but its body is safe by default mir_transform_unused_unsafe = unnecessary `unsafe` block .label = because it's nested under this `unsafe` block diff --git a/compiler/rustc_mir_transform/src/check_unsafety.rs b/compiler/rustc_mir_transform/src/check_unsafety.rs index fd8e02ebeab..41e31df77cb 100644 --- a/compiler/rustc_mir_transform/src/check_unsafety.rs +++ b/compiler/rustc_mir_transform/src/check_unsafety.rs @@ -571,11 +571,16 @@ pub fn check_unsafety(tcx: TyCtxt<'_>, def_id: LocalDefId) { errors::UnsafeOpInUnsafeFn { details, suggest_unsafe_block: suggest_unsafe_block.then(|| { + let hir_id = tcx.hir().local_def_id_to_hir_id(def_id); + let fn_sig = tcx + .hir() + .fn_sig_by_hir_id(hir_id) + .expect("this violation only occurs in fn"); let body = tcx.hir().body_owned_by(def_id); let body_span = tcx.hir().body(body).value.span; let start = tcx.sess.source_map().start_point(body_span).shrink_to_hi(); let end = tcx.sess.source_map().end_point(body_span).shrink_to_lo(); - (start, end) + (start, end, fn_sig.span) }), }, ); diff --git a/compiler/rustc_mir_transform/src/errors.rs b/compiler/rustc_mir_transform/src/errors.rs index 6570da51bcc..05a27f853b8 100644 --- a/compiler/rustc_mir_transform/src/errors.rs +++ b/compiler/rustc_mir_transform/src/errors.rs @@ -131,7 +131,12 @@ fn label(self) -> DiagnosticMessage { pub(crate) struct UnsafeOpInUnsafeFn { pub details: RequiresUnsafeDetail, - pub suggest_unsafe_block: Option<(Span, Span)>, + + /// These spans point to: + /// 1. the start of the function body + /// 2. the end of the function body + /// 3. the function signature + pub suggest_unsafe_block: Option<(Span, Span, Span)>, } impl<'a> DecorateLint<'a, ()> for UnsafeOpInUnsafeFn { @@ -146,7 +151,8 @@ fn decorate_lint<'b>( diag.span_label(self.details.span, self.details.label()); diag.note(self.details.note()); - if let Some((start, end)) = self.suggest_unsafe_block { + if let Some((start, end, fn_sig)) = self.suggest_unsafe_block { + diag.span_note(fn_sig, crate::fluent_generated::mir_transform_note); diag.tool_only_multipart_suggestion( crate::fluent_generated::mir_transform_suggestion, vec![(start, " unsafe {".into()), (end, "}".into())], diff --git a/tests/ui/unsafe/rfc-2585-unsafe_op_in_unsafe_fn.mir.stderr b/tests/ui/unsafe/rfc-2585-unsafe_op_in_unsafe_fn.mir.stderr index 6f005fe8958..0c0826c1cfb 100644 --- a/tests/ui/unsafe/rfc-2585-unsafe_op_in_unsafe_fn.mir.stderr +++ b/tests/ui/unsafe/rfc-2585-unsafe_op_in_unsafe_fn.mir.stderr @@ -5,6 +5,11 @@ LL | unsf(); | ^^^^^^ call to unsafe function | = note: consult the function's documentation for information on how to avoid undefined behavior +note: an unsafe function restricts its caller, but its body is safe by default + --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:11:1 + | +LL | unsafe fn deny_level() { + | ^^^^^^^^^^^^^^^^^^^^^^ note: the lint level is defined here --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:4:9 | @@ -46,6 +51,11 @@ LL | unsf(); | ^^^^^^ call to unsafe function | = note: consult the function's documentation for information on how to avoid undefined behavior +note: an unsafe function restricts its caller, but its body is safe by default + --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:27:1 + | +LL | unsafe fn warning_level() { + | ^^^^^^^^^^^^^^^^^^^^^^^^^ note: the lint level is defined here --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:26:8 | diff --git a/tests/ui/unsafe/wrapping-unsafe-block-sugg.fixed b/tests/ui/unsafe/wrapping-unsafe-block-sugg.fixed index c36aabb7c92..8fdc21ee109 100644 --- a/tests/ui/unsafe/wrapping-unsafe-block-sugg.fixed +++ b/tests/ui/unsafe/wrapping-unsafe-block-sugg.fixed @@ -1,23 +1,38 @@ // run-rustfix -#![deny(unsafe_op_in_unsafe_fn)] +#![deny(unsafe_op_in_unsafe_fn)] //~ NOTE unsafe fn unsf() {} pub unsafe fn foo() { unsafe { + //~^ NOTE an unsafe function restricts its caller, but its body is safe by default unsf(); //~ ERROR call to unsafe function is unsafe + //~^ NOTE + //~| NOTE unsf(); //~ ERROR call to unsafe function is unsafe + //~^ NOTE + //~| NOTE }} pub unsafe fn bar(x: *const i32) -> i32 { unsafe { + //~^ NOTE an unsafe function restricts its caller, but its body is safe by default let y = *x; //~ ERROR dereference of raw pointer is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE y + *x //~ ERROR dereference of raw pointer is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE }} static mut BAZ: i32 = 0; pub unsafe fn baz() -> i32 { unsafe { + //~^ NOTE an unsafe function restricts its caller, but its body is safe by default let y = BAZ; //~ ERROR use of mutable static is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE y + BAZ //~ ERROR use of mutable static is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE }} fn main() {} diff --git a/tests/ui/unsafe/wrapping-unsafe-block-sugg.rs b/tests/ui/unsafe/wrapping-unsafe-block-sugg.rs index 95e22d1bc4d..0c6feee4ff2 100644 --- a/tests/ui/unsafe/wrapping-unsafe-block-sugg.rs +++ b/tests/ui/unsafe/wrapping-unsafe-block-sugg.rs @@ -1,23 +1,38 @@ // run-rustfix -#![deny(unsafe_op_in_unsafe_fn)] +#![deny(unsafe_op_in_unsafe_fn)] //~ NOTE unsafe fn unsf() {} pub unsafe fn foo() { + //~^ NOTE an unsafe function restricts its caller, but its body is safe by default unsf(); //~ ERROR call to unsafe function is unsafe + //~^ NOTE + //~| NOTE unsf(); //~ ERROR call to unsafe function is unsafe + //~^ NOTE + //~| NOTE } pub unsafe fn bar(x: *const i32) -> i32 { + //~^ NOTE an unsafe function restricts its caller, but its body is safe by default let y = *x; //~ ERROR dereference of raw pointer is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE y + *x //~ ERROR dereference of raw pointer is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE } static mut BAZ: i32 = 0; pub unsafe fn baz() -> i32 { + //~^ NOTE an unsafe function restricts its caller, but its body is safe by default let y = BAZ; //~ ERROR use of mutable static is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE y + BAZ //~ ERROR use of mutable static is unsafe and requires unsafe block + //~^ NOTE + //~| NOTE } fn main() {} diff --git a/tests/ui/unsafe/wrapping-unsafe-block-sugg.stderr b/tests/ui/unsafe/wrapping-unsafe-block-sugg.stderr index b22c5b74b56..76f86b09d68 100644 --- a/tests/ui/unsafe/wrapping-unsafe-block-sugg.stderr +++ b/tests/ui/unsafe/wrapping-unsafe-block-sugg.stderr @@ -1,16 +1,3 @@ -error: call to unsafe function is unsafe and requires unsafe block (error E0133) - --> $DIR/wrapping-unsafe-block-sugg.rs:8:5 - | -LL | unsf(); - | ^^^^^^ call to unsafe function - | - = note: consult the function's documentation for information on how to avoid undefined behavior -note: the lint level is defined here - --> $DIR/wrapping-unsafe-block-sugg.rs:3:9 - | -LL | #![deny(unsafe_op_in_unsafe_fn)] - | ^^^^^^^^^^^^^^^^^^^^^^ - error: call to unsafe function is unsafe and requires unsafe block (error E0133) --> $DIR/wrapping-unsafe-block-sugg.rs:9:5 | @@ -18,17 +5,40 @@ LL | unsf(); | ^^^^^^ call to unsafe function | = note: consult the function's documentation for information on how to avoid undefined behavior +note: an unsafe function restricts its caller, but its body is safe by default + --> $DIR/wrapping-unsafe-block-sugg.rs:7:1 + | +LL | pub unsafe fn foo() { + | ^^^^^^^^^^^^^^^^^^^ +note: the lint level is defined here + --> $DIR/wrapping-unsafe-block-sugg.rs:3:9 + | +LL | #![deny(unsafe_op_in_unsafe_fn)] + | ^^^^^^^^^^^^^^^^^^^^^^ + +error: call to unsafe function is unsafe and requires unsafe block (error E0133) + --> $DIR/wrapping-unsafe-block-sugg.rs:12:5 + | +LL | unsf(); + | ^^^^^^ call to unsafe function + | + = note: consult the function's documentation for information on how to avoid undefined behavior error: dereference of raw pointer is unsafe and requires unsafe block (error E0133) - --> $DIR/wrapping-unsafe-block-sugg.rs:13:13 + --> $DIR/wrapping-unsafe-block-sugg.rs:19:13 | LL | let y = *x; | ^^ dereference of raw pointer | = note: raw pointers may be null, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior +note: an unsafe function restricts its caller, but its body is safe by default + --> $DIR/wrapping-unsafe-block-sugg.rs:17:1 + | +LL | pub unsafe fn bar(x: *const i32) -> i32 { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: dereference of raw pointer is unsafe and requires unsafe block (error E0133) - --> $DIR/wrapping-unsafe-block-sugg.rs:14:9 + --> $DIR/wrapping-unsafe-block-sugg.rs:22:9 | LL | y + *x | ^^ dereference of raw pointer @@ -36,15 +46,20 @@ LL | y + *x = note: raw pointers may be null, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior error: use of mutable static is unsafe and requires unsafe block (error E0133) - --> $DIR/wrapping-unsafe-block-sugg.rs:19:13 + --> $DIR/wrapping-unsafe-block-sugg.rs:30:13 | LL | let y = BAZ; | ^^^ use of mutable static | = note: mutable statics can be mutated by multiple threads: aliasing violations or data races will cause undefined behavior +note: an unsafe function restricts its caller, but its body is safe by default + --> $DIR/wrapping-unsafe-block-sugg.rs:28:1 + | +LL | pub unsafe fn baz() -> i32 { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ error: use of mutable static is unsafe and requires unsafe block (error E0133) - --> $DIR/wrapping-unsafe-block-sugg.rs:20:9 + --> $DIR/wrapping-unsafe-block-sugg.rs:33:9 | LL | y + BAZ | ^^^ use of mutable static