diff options
| -rw-r--r-- | compiler/rustc_hir_typeck/src/cast.rs | 5 | ||||
| -rw-r--r-- | compiler/rustc_hir_typeck/src/expr.rs | 10 | ||||
| -rw-r--r-- | compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs | 15 | ||||
| -rw-r--r-- | src/test/ui/rfc-2632-const-trait-impl/issue-103677.rs | 5 | ||||
| -rw-r--r-- | src/tools/clippy/clippy_lints/src/transmute/utils.rs | 3 |
5 files changed, 33 insertions, 5 deletions
diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs index 0e7576ecf8b..60157c3b9ab 100644 --- a/compiler/rustc_hir_typeck/src/cast.rs +++ b/compiler/rustc_hir_typeck/src/cast.rs @@ -60,6 +60,8 @@ pub struct CastCheck<'tcx> { cast_ty: Ty<'tcx>, cast_span: Span, span: Span, + /// whether the cast is made in a const context or not. + pub constness: hir::Constness, } /// The kind of pointer and associated metadata (thin, length or vtable) - we @@ -210,9 +212,10 @@ impl<'a, 'tcx> CastCheck<'tcx> { cast_ty: Ty<'tcx>, cast_span: Span, span: Span, + constness: hir::Constness, ) -> Result<CastCheck<'tcx>, ErrorGuaranteed> { let expr_span = expr.span.find_ancestor_inside(span).unwrap_or(expr.span); - let check = CastCheck { expr, expr_ty, expr_span, cast_ty, cast_span, span }; + let check = CastCheck { expr, expr_ty, expr_span, cast_ty, cast_span, span, constness }; // For better error messages, check for some obviously unsized // cases now. We do a more thorough check at the end, once diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs index 41b00fda03e..9fde62a81a1 100644 --- a/compiler/rustc_hir_typeck/src/expr.rs +++ b/compiler/rustc_hir_typeck/src/expr.rs @@ -1272,7 +1272,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } else { // Defer other checks until we're done type checking. let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut(); - match cast::CastCheck::new(self, e, t_expr, t_cast, t.span, expr.span) { + match cast::CastCheck::new( + self, + e, + t_expr, + t_cast, + t.span, + expr.span, + self.param_env.constness(), + ) { Ok(cast_check) => { debug!( "check_expr_cast: deferring cast from {:?} to {:?}: {:?}", diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs index 08a3cbccfb0..8e0fcb56c7f 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs @@ -33,16 +33,27 @@ use rustc_span::{self, sym, Span}; use rustc_trait_selection::traits::{self, ObligationCauseCode, SelectionContext}; use std::iter; +use std::mem; use std::ops::ControlFlow; use std::slice; impl<'a, 'tcx> FnCtxt<'a, 'tcx> { - pub(in super::super) fn check_casts(&self) { - let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut(); + pub(in super::super) fn check_casts(&mut self) { + // don't hold the borrow to deferred_cast_checks while checking to avoid borrow checker errors + // when writing to `self.param_env`. + let mut deferred_cast_checks = mem::take(&mut *self.deferred_cast_checks.borrow_mut()); + debug!("FnCtxt::check_casts: {} deferred checks", deferred_cast_checks.len()); for cast in deferred_cast_checks.drain(..) { + let prev_env = self.param_env; + self.param_env = self.param_env.with_constness(cast.constness); + cast.check(self); + + self.param_env = prev_env; } + + *self.deferred_cast_checks.borrow_mut() = deferred_cast_checks; } pub(in super::super) fn check_transmutes(&self) { diff --git a/src/test/ui/rfc-2632-const-trait-impl/issue-103677.rs b/src/test/ui/rfc-2632-const-trait-impl/issue-103677.rs new file mode 100644 index 00000000000..d81724a3685 --- /dev/null +++ b/src/test/ui/rfc-2632-const-trait-impl/issue-103677.rs @@ -0,0 +1,5 @@ +// check-pass + +const _: fn(&String) = |s| { &*s as &str; }; + +fn main() {} diff --git a/src/tools/clippy/clippy_lints/src/transmute/utils.rs b/src/tools/clippy/clippy_lints/src/transmute/utils.rs index 2f190e594a8..641cdf5d330 100644 --- a/src/tools/clippy/clippy_lints/src/transmute/utils.rs +++ b/src/tools/clippy/clippy_lints/src/transmute/utils.rs @@ -3,6 +3,7 @@ use rustc_hir_typeck::{cast, FnCtxt, Inherited}; use rustc_lint::LateContext; use rustc_middle::ty::{cast::CastKind, Ty}; use rustc_span::DUMMY_SP; +use rustc_hir as hir; // check if the component types of the transmuted collection and the result have different ABI, // size or alignment @@ -56,7 +57,7 @@ fn check_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx> if let Ok(check) = cast::CastCheck::new( &fn_ctxt, e, from_ty, to_ty, // We won't show any error to the user, so we don't care what the span is here. - DUMMY_SP, DUMMY_SP, + DUMMY_SP, DUMMY_SP, hir::Constness::NotConst, ) { let res = check.do_check(&fn_ctxt); |