diff --git a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs index 945953edd5aec..cd7e991720454 100644 --- a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs +++ b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs @@ -44,20 +44,7 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> { false } - fn check_asm_operand_type( - &self, - idx: usize, - reg: InlineAsmRegOrRegClass, - expr: &'tcx hir::Expr<'tcx>, - template: &[InlineAsmTemplatePiece], - is_input: bool, - tied_input: Option<(&'tcx hir::Expr<'tcx>, Option)>, - target_features: &FxIndexSet, - ) -> Option { - let ty = (self.get_operand_ty)(expr); - if ty.has_non_region_infer() { - bug!("inference variable in asm operand ty: {:?} {:?}", expr, ty); - } + fn get_asm_ty(&self, ty: Ty<'tcx>) -> Option { let asm_ty_isize = match self.tcx.sess.target.pointer_width { 16 => InlineAsmType::I16, 32 => InlineAsmType::I32, @@ -65,10 +52,7 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> { _ => unreachable!(), }; - let asm_ty = match *ty.kind() { - // `!` is allowed for input but not for output (issue #87802) - ty::Never if is_input => return None, - _ if ty.references_error() => return None, + match *ty.kind() { ty::Int(IntTy::I8) | ty::Uint(UintTy::U8) => Some(InlineAsmType::I8), ty::Int(IntTy::I16) | ty::Uint(UintTy::U16) => Some(InlineAsmType::I16), ty::Int(IntTy::I32) | ty::Uint(UintTy::U32) => Some(InlineAsmType::I32), @@ -99,7 +83,6 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> { }; match ty.kind() { - ty::Never | ty::Error(_) => return None, ty::Int(IntTy::I8) | ty::Uint(UintTy::U8) => Some(InlineAsmType::VecI8(size)), ty::Int(IntTy::I16) | ty::Uint(UintTy::U16) => { Some(InlineAsmType::VecI16(size)) @@ -128,6 +111,38 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> { } ty::Infer(_) => unreachable!(), _ => None, + } + } + + fn check_asm_operand_type( + &self, + idx: usize, + reg: InlineAsmRegOrRegClass, + expr: &'tcx hir::Expr<'tcx>, + template: &[InlineAsmTemplatePiece], + is_input: bool, + tied_input: Option<(&'tcx hir::Expr<'tcx>, Option)>, + target_features: &FxIndexSet, + ) -> Option { + let ty = (self.get_operand_ty)(expr); + if ty.has_non_region_infer() { + bug!("inference variable in asm operand ty: {:?} {:?}", expr, ty); + } + + let asm_ty = match *ty.kind() { + // `!` is allowed for input but not for output (issue #87802) + ty::Never if is_input => return None, + _ if ty.references_error() => return None, + ty::Adt(adt, args) if Some(adt.did()) == self.tcx.lang_items().maybe_uninit() => { + let fields = &adt.non_enum_variant().fields; + let ty = fields[FieldIdx::from_u32(1)].ty(self.tcx, args); + let ty::Adt(ty, args) = ty.kind() else { unreachable!() }; + assert!(ty.is_manually_drop()); + let fields = &ty.non_enum_variant().fields; + let ty = fields[FieldIdx::from_u32(0)].ty(self.tcx, args); + self.get_asm_ty(ty) + } + _ => self.get_asm_ty(ty), }; let Some(asm_ty) = asm_ty else { let msg = format!("cannot use value of type `{ty}` for inline assembly"); diff --git a/tests/codegen/asm-maybe-uninit.rs b/tests/codegen/asm-maybe-uninit.rs new file mode 100644 index 0000000000000..d7e4a9489546a --- /dev/null +++ b/tests/codegen/asm-maybe-uninit.rs @@ -0,0 +1,27 @@ +// compile-flags: -O +// only-x86_64 + +#![crate_type = "rlib"] +#![allow(asm_sub_register)] + +use std::mem::MaybeUninit; +use std::arch::asm; + +// CHECK-LABEL: @int +#[no_mangle] +pub unsafe fn int(x: MaybeUninit) -> MaybeUninit { + let y: MaybeUninit; + asm!("/*{}{}*/", in(reg) x, out(reg) y); + y +} + +// CHECK-LABEL: @inout +#[no_mangle] +pub unsafe fn inout(mut x: i32) -> MaybeUninit { + let mut y: MaybeUninit; + asm!("/*{}*/", inout(reg) x => y); + asm!("/*{}*/", inout(reg) y => x); + asm!("/*{}*/", inlateout(reg) x => y); + asm!("/*{}*/", inlateout(reg) y => x); + y +}