diff options
Diffstat (limited to 'compiler/rustc_codegen_cranelift/src/constant.rs')
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/constant.rs | 97 |
1 files changed, 26 insertions, 71 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/constant.rs b/compiler/rustc_codegen_cranelift/src/constant.rs index c31535742..14b10ed8b 100644 --- a/compiler/rustc_codegen_cranelift/src/constant.rs +++ b/compiler/rustc_codegen_cranelift/src/constant.rs @@ -2,9 +2,8 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags; -use rustc_middle::mir::interpret::{ - read_target_uint, AllocId, ConstAllocation, ConstValue, ErrorHandled, GlobalAlloc, Scalar, -}; +use rustc_middle::mir::interpret::{read_target_uint, AllocId, GlobalAlloc, Scalar}; +use rustc_middle::mir::ConstValue; use cranelift_module::*; @@ -33,16 +32,6 @@ impl ConstantCx { } } -pub(crate) fn check_constants(fx: &mut FunctionCx<'_, '_, '_>) -> bool { - let mut all_constants_ok = true; - for constant in &fx.mir.required_consts { - if eval_mir_constant(fx, constant).is_none() { - all_constants_ok = false; - } - } - all_constants_ok -} - pub(crate) fn codegen_static(tcx: TyCtxt<'_>, module: &mut dyn Module, def_id: DefId) { let mut constants_cx = ConstantCx::new(); constants_cx.todo.push(TodoItem::Static(def_id)); @@ -75,53 +64,21 @@ pub(crate) fn codegen_tls_ref<'tcx>( pub(crate) fn eval_mir_constant<'tcx>( fx: &FunctionCx<'_, '_, 'tcx>, - constant: &Constant<'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 Some((fx.tcx.valtree_to_const_val((const_.ty(), val)), const_.ty())); - } - err => span_bug!( - constant.span, - "encountered bad ConstKind after monomorphizing: {:?}", - err - ), - }, - ConstantKind::Unevaluated(mir::UnevaluatedConst { def, .. }, _) - if fx.tcx.is_static(def) => - { - span_bug!(constant.span, "MIR constant refers to static"); - } - ConstantKind::Unevaluated(uv, _) => uv, - ConstantKind::Val(val, _) => return Some((val, 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())) + constant: &ConstOperand<'tcx>, +) -> (ConstValue<'tcx>, Ty<'tcx>) { + let cv = fx.monomorphize(constant.const_); + // This cannot fail because we checked all required_consts in advance. + let val = cv + .eval(fx.tcx, ty::ParamEnv::reveal_all(), Some(constant.span)) + .expect("erroneous constant not captured by required_consts"); + (val, cv.ty()) } pub(crate) fn codegen_constant_operand<'tcx>( fx: &mut FunctionCx<'_, '_, 'tcx>, - constant: &Constant<'tcx>, + constant: &ConstOperand<'tcx>, ) -> CValue<'tcx> { - let (const_val, ty) = eval_mir_constant(fx, constant).unwrap_or_else(|| { - span_bug!(constant.span, "erroneous constant not captured by required_consts") - }); - + let (const_val, ty) = eval_mir_constant(fx, constant); codegen_const_value(fx, const_val, ty) } @@ -138,7 +95,7 @@ pub(crate) fn codegen_const_value<'tcx>( } match const_val { - ConstValue::ZeroSized => unreachable!(), // we already handles ZST above + ConstValue::ZeroSized => unreachable!(), // we already handled ZST above ConstValue::Scalar(x) => match x { Scalar::Int(int) => { if fx.clif_type(layout.ty).is_some() { @@ -222,19 +179,16 @@ pub(crate) fn codegen_const_value<'tcx>( CValue::by_val(val, layout) } }, - ConstValue::ByRef { alloc, offset } => CValue::by_ref( - pointer_for_allocation(fx, alloc) + ConstValue::Indirect { alloc_id, offset } => CValue::by_ref( + pointer_for_allocation(fx, alloc_id) .offset_i64(fx, i64::try_from(offset.bytes()).unwrap()), layout, ), - ConstValue::Slice { data, start, end } => { - let ptr = pointer_for_allocation(fx, data) - .offset_i64(fx, i64::try_from(start).unwrap()) - .get_addr(fx); - let len = fx - .bcx - .ins() - .iconst(fx.pointer_type, i64::try_from(end.checked_sub(start).unwrap()).unwrap()); + ConstValue::Slice { data, meta } => { + let alloc_id = fx.tcx.reserve_and_set_memory_alloc(data); + let ptr = pointer_for_allocation(fx, alloc_id).get_addr(fx); + // FIXME: the `try_from` here can actually fail, e.g. for very long ZST slices. + let len = fx.bcx.ins().iconst(fx.pointer_type, i64::try_from(meta).unwrap()); CValue::by_val_pair(ptr, len, layout) } } @@ -242,9 +196,9 @@ pub(crate) fn codegen_const_value<'tcx>( fn pointer_for_allocation<'tcx>( fx: &mut FunctionCx<'_, '_, 'tcx>, - alloc: ConstAllocation<'tcx>, + alloc_id: AllocId, ) -> crate::pointer::Pointer { - let alloc_id = fx.tcx.create_memory_alloc(alloc); + let alloc = fx.tcx.global_alloc(alloc_id).unwrap_memory(); let data_id = data_id_for_alloc_id( &mut fx.constants_cx, &mut *fx.module, @@ -375,6 +329,7 @@ fn define_all_allocs(tcx: TyCtxt<'_>, module: &mut dyn Module, cx: &mut Constant unreachable!() } }; + // FIXME: should we have a cache so we don't do this multiple times for the same `ConstAllocation`? let data_id = *cx.anon_allocs.entry(alloc_id).or_insert_with(|| { module.declare_anonymous_data(alloc.inner().mutability.is_mut(), false).unwrap() }); @@ -479,7 +434,7 @@ pub(crate) fn mir_operand_get_const_val<'tcx>( operand: &Operand<'tcx>, ) -> Option<ConstValue<'tcx>> { match operand { - Operand::Constant(const_) => Some(eval_mir_constant(fx, const_).unwrap().0), + Operand::Constant(const_) => Some(eval_mir_constant(fx, const_).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. @@ -550,8 +505,8 @@ pub(crate) fn mir_operand_get_const_val<'tcx>( match &bb_data.terminator().kind { TerminatorKind::Goto { .. } | TerminatorKind::SwitchInt { .. } - | TerminatorKind::Resume - | TerminatorKind::Terminate + | TerminatorKind::UnwindResume + | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } |