diff options
| -rw-r--r-- | src/constant.rs | 58 |
1 files changed, 23 insertions, 35 deletions
diff --git a/src/constant.rs b/src/constant.rs index 5478caee57d..077f33bb99c 100644 --- a/src/constant.rs +++ b/src/constant.rs @@ -38,22 +38,8 @@ impl ConstantCx { pub(crate) fn check_constants(fx: &mut FunctionCx<'_, '_, '_>) -> bool { let mut all_constants_ok = true; for constant in &fx.mir.required_consts { - let unevaluated = match fx.monomorphize(constant.literal) { - ConstantKind::Ty(_) => unreachable!(), - ConstantKind::Unevaluated(uv, _) => uv, - ConstantKind::Val(..) => continue, - }; - - if let Err(err) = fx.tcx.const_eval_resolve(ParamEnv::reveal_all(), unevaluated, None) { + if eval_mir_constant(fx, constant).is_none() { all_constants_ok = false; - match err { - ErrorHandled::Reported(_) => { - fx.tcx.sess.span_err(constant.span, "erroneous constant encountered"); - } - ErrorHandled::TooGeneric => { - span_bug!(constant.span, "codegen encountered polymorphic constant: {:?}", err); - } - } } } all_constants_ok @@ -80,15 +66,15 @@ pub(crate) fn codegen_tls_ref<'tcx>( } pub(crate) fn eval_mir_constant<'tcx>( - fx: &mut FunctionCx<'_, '_, 'tcx>, + fx: &FunctionCx<'_, '_, 'tcx>, constant: &Constant<'tcx>, -) -> (ConstValue<'tcx>, Ty<'tcx>) { +) -> Option<(ConstValue<'tcx>, Ty<'tcx>)> { let constant_kind = fx.monomorphize(constant.literal); let uv = match constant_kind { ConstantKind::Ty(const_) => match const_.kind() { ty::ConstKind::Unevaluated(uv) => uv.expand(), ty::ConstKind::Value(val) => { - return (fx.tcx.valtree_to_const_val((const_.ty(), val)), const_.ty()); + return Some((fx.tcx.valtree_to_const_val((const_.ty(), val)), const_.ty())); } err => span_bug!( constant.span, @@ -102,22 +88,31 @@ pub(crate) fn eval_mir_constant<'tcx>( span_bug!(constant.span, "MIR constant refers to static"); } ConstantKind::Unevaluated(uv, _) => uv, - ConstantKind::Val(val, _) => return (val, constant_kind.ty()), + ConstantKind::Val(val, _) => return Some((val, constant_kind.ty())), }; - ( - fx.tcx.const_eval_resolve(ty::ParamEnv::reveal_all(), uv, None).unwrap_or_else(|_err| { - span_bug!(constant.span, "erroneous constant not captured by required_consts"); - }), - constant_kind.ty(), - ) + let val = fx + .tcx + .const_eval_resolve(ty::ParamEnv::reveal_all(), uv, None) + .map_err(|err| match err { + ErrorHandled::Reported(_) => { + fx.tcx.sess.span_err(constant.span, "erroneous constant encountered"); + } + ErrorHandled::TooGeneric => { + span_bug!(constant.span, "codegen encountered polymorphic constant: {:?}", err); + } + }) + .ok(); + val.map(|val| (val, constant_kind.ty())) } pub(crate) fn codegen_constant_operand<'tcx>( fx: &mut FunctionCx<'_, '_, 'tcx>, constant: &Constant<'tcx>, ) -> CValue<'tcx> { - let (const_val, ty) = eval_mir_constant(fx, constant); + let (const_val, ty) = eval_mir_constant(fx, constant).unwrap_or_else(|| { + span_bug!(constant.span, "erroneous constant not captured by required_consts") + }); codegen_const_value(fx, const_val, ty) } @@ -453,20 +448,13 @@ fn define_all_allocs(tcx: TyCtxt<'_>, module: &mut dyn Module, cx: &mut Constant assert!(cx.todo.is_empty(), "{:?}", cx.todo); } +/// Used only for intrinsic implementations that need a compile-time constant pub(crate) fn mir_operand_get_const_val<'tcx>( fx: &FunctionCx<'_, '_, 'tcx>, operand: &Operand<'tcx>, ) -> Option<ConstValue<'tcx>> { match operand { - Operand::Constant(const_) => match fx.monomorphize(const_.literal) { - ConstantKind::Ty(const_) => Some( - const_.eval_for_mir(fx.tcx, ParamEnv::reveal_all()).try_to_value(fx.tcx).unwrap(), - ), - ConstantKind::Val(val, _) => Some(val), - ConstantKind::Unevaluated(uv, _) => { - Some(fx.tcx.const_eval_resolve(ParamEnv::reveal_all(), uv, None).unwrap()) - } - }, + Operand::Constant(const_) => Some(eval_mir_constant(fx, const_).unwrap().0), // FIXME(rust-lang/rust#85105): Casts like `IMM8 as u32` result in the const being stored // inside a temporary before being passed to the intrinsic requiring the const argument. // This code tries to find a single constant defining definition of the referenced local. |