From 12f2bcde63285bf2b2f9f9ac615d4edf139a3f0e Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Wed, 18 Sep 2024 16:45:27 -0400 Subject: [PATCH] Check params for unsafety in THIR --- .../rustc_mir_build/src/check_unsafety.rs | 14 ++++++++++++++ tests/ui/unsafe/union-pat-in-param.rs | 19 +++++++++++++++++++ tests/ui/unsafe/union-pat-in-param.stderr | 19 +++++++++++++++++++ 3 files changed, 52 insertions(+) create mode 100644 tests/ui/unsafe/union-pat-in-param.rs create mode 100644 tests/ui/unsafe/union-pat-in-param.stderr diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs index c7fcfe3ce2aa0..57390dd58f4d9 100644 --- a/compiler/rustc_mir_build/src/check_unsafety.rs +++ b/compiler/rustc_mir_build/src/check_unsafety.rs @@ -218,6 +218,13 @@ impl<'tcx> UnsafetyVisitor<'_, 'tcx> { warnings: self.warnings, suggest_unsafe_block: self.suggest_unsafe_block, }; + // params in THIR may be unsafe, e.g. a union pattern. + for param in &inner_thir.params { + if let Some(param_pat) = param.pat.as_deref() { + inner_visitor.visit_pat(param_pat); + } + } + // Visit the body. inner_visitor.visit_expr(&inner_thir[expr]); // Unsafe blocks can be used in the inner body, make sure to take it into account self.safety_context = inner_visitor.safety_context; @@ -1032,6 +1039,13 @@ pub(crate) fn check_unsafety(tcx: TyCtxt<'_>, def: LocalDefId) { warnings: &mut warnings, suggest_unsafe_block: true, }; + // params in THIR may be unsafe, e.g. a union pattern. + for param in &thir.params { + if let Some(param_pat) = param.pat.as_deref() { + visitor.visit_pat(param_pat); + } + } + // Visit the body. visitor.visit_expr(&thir[expr]); warnings.sort_by_key(|w| w.block_span); diff --git a/tests/ui/unsafe/union-pat-in-param.rs b/tests/ui/unsafe/union-pat-in-param.rs new file mode 100644 index 0000000000000..8454bfb20dcb8 --- /dev/null +++ b/tests/ui/unsafe/union-pat-in-param.rs @@ -0,0 +1,19 @@ +union U { + a: &'static i32, + b: usize, +} + +fn fun(U { a }: U) { + //~^ ERROR access to union field is unsafe + dbg!(*a); +} + +fn main() { + fun(U { b: 0 }); + + let closure = |U { a }| { + //~^ ERROR access to union field is unsafe + dbg!(*a); + }; + closure(U { b: 0 }); +} diff --git a/tests/ui/unsafe/union-pat-in-param.stderr b/tests/ui/unsafe/union-pat-in-param.stderr new file mode 100644 index 0000000000000..b9709b7cc9bf1 --- /dev/null +++ b/tests/ui/unsafe/union-pat-in-param.stderr @@ -0,0 +1,19 @@ +error[E0133]: access to union field is unsafe and requires unsafe function or block + --> $DIR/union-pat-in-param.rs:6:12 + | +LL | fn fun(U { a }: U) { + | ^ access to union field + | + = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior + +error[E0133]: access to union field is unsafe and requires unsafe function or block + --> $DIR/union-pat-in-param.rs:14:24 + | +LL | let closure = |U { a }| { + | ^ access to union field + | + = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0133`.