diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index a960b96b91c20..8db2904cfd7b7 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -1895,7 +1895,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { if !output_ty .is_privately_uninhabited(self.tcx(), self.infcx.typing_env(self.infcx.param_env)) { - span_mirbug!(self, term, "call to converging function {:?} w/o dest", sig); + span_mirbug!(self, term, "call to non-diverging function {:?} w/o dest", sig); } } else { let dest_ty = destination.ty(self.body, tcx).ty; diff --git a/compiler/rustc_mir_build/src/check_tail_calls.rs b/compiler/rustc_mir_build/src/check_tail_calls.rs index d4b6da2c14b76..e0cbe8519edd5 100644 --- a/compiler/rustc_mir_build/src/check_tail_calls.rs +++ b/compiler/rustc_mir_build/src/check_tail_calls.rs @@ -135,30 +135,23 @@ impl<'tcx> TailCallCkVisitor<'_, 'tcx> { self.report_abi_mismatch(expr.span, caller_sig.abi, callee_sig.abi); } + // FIXME(explicit_tail_calls): this currently fails for cases where opaques are used. + // e.g. + // ``` + // fn a() -> impl Sized { become b() } // ICE + // fn b() -> u8 { 0 } + // ``` + // we should think what is the expected behavior here. + // (we should probably just accept this by revealing opaques?) if caller_sig.inputs_and_output != callee_sig.inputs_and_output { - if caller_sig.inputs() != callee_sig.inputs() { - self.report_arguments_mismatch( - expr.span, - self.tcx.liberate_late_bound_regions( - CRATE_DEF_ID.to_def_id(), - self.caller_ty.fn_sig(self.tcx), - ), - self.tcx - .liberate_late_bound_regions(CRATE_DEF_ID.to_def_id(), ty.fn_sig(self.tcx)), - ); - } - - // FIXME(explicit_tail_calls): this currently fails for cases where opaques are used. - // e.g. - // ``` - // fn a() -> impl Sized { become b() } // ICE - // fn b() -> u8 { 0 } - // ``` - // we should think what is the expected behavior here. - // (we should probably just accept this by revealing opaques?) - if caller_sig.output() != callee_sig.output() { - span_bug!(expr.span, "hir typeck should have checked the return type already"); - } + self.report_signature_mismatch( + expr.span, + self.tcx.liberate_late_bound_regions( + CRATE_DEF_ID.to_def_id(), + self.caller_ty.fn_sig(self.tcx), + ), + self.tcx.liberate_late_bound_regions(CRATE_DEF_ID.to_def_id(), ty.fn_sig(self.tcx)), + ); } { @@ -365,7 +358,7 @@ impl<'tcx> TailCallCkVisitor<'_, 'tcx> { self.found_errors = Err(err); } - fn report_arguments_mismatch( + fn report_signature_mismatch( &mut self, sp: Span, caller_sig: ty::FnSig<'_>, diff --git a/tests/ui/explicit-tail-calls/ret-ty-hr-mismatch.rs b/tests/ui/explicit-tail-calls/ret-ty-hr-mismatch.rs new file mode 100644 index 0000000000000..8ad244568a3ee --- /dev/null +++ b/tests/ui/explicit-tail-calls/ret-ty-hr-mismatch.rs @@ -0,0 +1,15 @@ +#![feature(explicit_tail_calls)] +#![expect(incomplete_features)] + +fn foo() -> for<'a> fn(&'a i32) { + become bar(); + //~^ ERROR mismatched signatures +} + +fn bar() -> fn(&'static i32) { + dummy +} + +fn dummy(_: &i32) {} + +fn main() {} diff --git a/tests/ui/explicit-tail-calls/ret-ty-hr-mismatch.stderr b/tests/ui/explicit-tail-calls/ret-ty-hr-mismatch.stderr new file mode 100644 index 0000000000000..f6594580ba52d --- /dev/null +++ b/tests/ui/explicit-tail-calls/ret-ty-hr-mismatch.stderr @@ -0,0 +1,12 @@ +error: mismatched signatures + --> $DIR/ret-ty-hr-mismatch.rs:5:5 + | +LL | become bar(); + | ^^^^^^^^^^^^ + | + = note: `become` requires caller and callee to have matching signatures + = note: caller signature: `fn() -> for<'a> fn(&'a i32)` + = note: callee signature: `fn() -> fn(&'static i32)` + +error: aborting due to 1 previous error + diff --git a/tests/ui/explicit-tail-calls/ret-ty-modulo-anonymization.rs b/tests/ui/explicit-tail-calls/ret-ty-modulo-anonymization.rs new file mode 100644 index 0000000000000..0cd4e204278ac --- /dev/null +++ b/tests/ui/explicit-tail-calls/ret-ty-modulo-anonymization.rs @@ -0,0 +1,16 @@ +// Ensure that we anonymize the output of a function for tail call signature compatibility. + +//@ check-pass + +#![feature(explicit_tail_calls)] +#![expect(incomplete_features)] + +fn foo() -> for<'a> fn(&'a ()) { + become bar(); +} + +fn bar() -> for<'b> fn(&'b ()) { + todo!() +} + +fn main() {}