diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/mir/block.rs')
-rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/block.rs | 221 |
1 files changed, 149 insertions, 72 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 3eee58d9d..a6b226ef7 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -13,15 +13,14 @@ use rustc_ast as ast; use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece}; use rustc_hir::lang_items::LangItem; use rustc_index::vec::Idx; -use rustc_middle::mir::AssertKind; -use rustc_middle::mir::{self, SwitchTargets}; +use rustc_middle::mir::{self, AssertKind, SwitchTargets}; use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf}; use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; use rustc_middle::ty::{self, Instance, Ty, TypeVisitable}; use rustc_span::source_map::Span; use rustc_span::{sym, Symbol}; use rustc_symbol_mangling::typeid::typeid_for_fnabi; -use rustc_target::abi::call::{ArgAbi, FnAbi, PassMode}; +use rustc_target::abi::call::{ArgAbi, FnAbi, PassMode, Reg}; use rustc_target::abi::{self, HasDataLayout, WrappingRange}; use rustc_target::spec::abi::Abi; @@ -324,7 +323,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { bx.unreachable(); return; } - let llval = match self.fn_abi.ret.mode { + let llval = match &self.fn_abi.ret.mode { PassMode::Ignore | PassMode::Indirect { .. } => { bx.ret_void(); return; @@ -339,7 +338,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } } - PassMode::Cast(cast_ty) => { + PassMode::Cast(cast_ty, _) => { let op = match self.locals[mir::RETURN_PLACE] { LocalRef::Operand(Some(op)) => op, LocalRef::Operand(None) => bug!("use of return before def"), @@ -360,7 +359,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { llval } }; - let ty = bx.cast_backend_type(&cast_ty); + let ty = bx.cast_backend_type(cast_ty); let addr = bx.pointercast(llslot, bx.type_ptr_to(ty)); bx.load(ty, addr, self.fn_abi.ret.layout.align.abi) } @@ -368,6 +367,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { bx.ret(llval); } + #[tracing::instrument(level = "trace", skip(self, helper, bx))] fn codegen_drop_terminator( &mut self, helper: TerminatorCodegenHelper<'tcx>, @@ -398,13 +398,29 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let (drop_fn, fn_abi) = match ty.kind() { // FIXME(eddyb) perhaps move some of this logic into // `Instance::resolve_drop_in_place`? - ty::Dynamic(..) => { + ty::Dynamic(_, _, ty::Dyn) => { + // IN THIS ARM, WE HAVE: + // ty = *mut (dyn Trait) + // which is: exists<T> ( *mut T, Vtable<T: Trait> ) + // args[0] args[1] + // + // args = ( Data, Vtable ) + // | + // v + // /-------\ + // | ... | + // \-------/ + // let virtual_drop = Instance { def: ty::InstanceDef::Virtual(drop_fn.def_id(), 0), substs: drop_fn.substs, }; + debug!("ty = {:?}", ty); + debug!("drop_fn = {:?}", drop_fn); + debug!("args = {:?}", args); let fn_abi = bx.fn_abi_of_instance(virtual_drop, ty::List::empty()); let vtable = args[1]; + // Truncate vtable off of args list args = &args[..1]; ( meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE) @@ -412,6 +428,51 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { fn_abi, ) } + ty::Dynamic(_, _, ty::DynStar) => { + // IN THIS ARM, WE HAVE: + // ty = *mut (dyn* Trait) + // which is: *mut exists<T: sizeof(T) == sizeof(usize)> (T, Vtable<T: Trait>) + // + // args = [ * ] + // | + // v + // ( Data, Vtable ) + // | + // v + // /-------\ + // | ... | + // \-------/ + // + // + // WE CAN CONVERT THIS INTO THE ABOVE LOGIC BY DOING + // + // data = &(*args[0]).0 // gives a pointer to Data above (really the same pointer) + // vtable = (*args[0]).1 // loads the vtable out + // (data, vtable) // an equivalent Rust `*mut dyn Trait` + // + // SO THEN WE CAN USE THE ABOVE CODE. + let virtual_drop = Instance { + def: ty::InstanceDef::Virtual(drop_fn.def_id(), 0), + substs: drop_fn.substs, + }; + debug!("ty = {:?}", ty); + debug!("drop_fn = {:?}", drop_fn); + debug!("args = {:?}", args); + let fn_abi = bx.fn_abi_of_instance(virtual_drop, ty::List::empty()); + let data = args[0]; + let data_ty = bx.cx().backend_type(place.layout); + let vtable_ptr = + bx.gep(data_ty, data, &[bx.cx().const_i32(0), bx.cx().const_i32(1)]); + let vtable = bx.load(bx.type_i8p(), vtable_ptr, abi::Align::ONE); + // Truncate vtable off of args list + args = &args[..1]; + debug!("args' = {:?}", args); + ( + meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE) + .get_fn(&mut bx, vtable, ty, &fn_abi), + fn_abi, + ) + } _ => (bx.get_fn_addr(drop_fn), bx.fn_abi_of_instance(drop_fn, ty::List::empty())), }; helper.do_call( @@ -798,58 +859,78 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let mut op = self.codegen_operand(&mut bx, arg); if let (0, Some(ty::InstanceDef::Virtual(_, idx))) = (i, def) { - if let Pair(..) = op.val { - // In the case of Rc<Self>, we need to explicitly pass a - // *mut RcBox<Self> with a Scalar (not ScalarPair) ABI. This is a hack - // that is understood elsewhere in the compiler as a method on - // `dyn Trait`. - // To get a `*mut RcBox<Self>`, we just keep unwrapping newtypes until - // we get a value of a built-in pointer type - 'descend_newtypes: while !op.layout.ty.is_unsafe_ptr() - && !op.layout.ty.is_region_ptr() - { - for i in 0..op.layout.fields.count() { - let field = op.extract_field(&mut bx, i); - if !field.layout.is_zst() { - // we found the one non-zero-sized field that is allowed - // now find *its* non-zero-sized field, or stop if it's a - // pointer - op = field; - continue 'descend_newtypes; + match op.val { + Pair(data_ptr, meta) => { + // In the case of Rc<Self>, we need to explicitly pass a + // *mut RcBox<Self> with a Scalar (not ScalarPair) ABI. This is a hack + // that is understood elsewhere in the compiler as a method on + // `dyn Trait`. + // To get a `*mut RcBox<Self>`, we just keep unwrapping newtypes until + // we get a value of a built-in pointer type + 'descend_newtypes: while !op.layout.ty.is_unsafe_ptr() + && !op.layout.ty.is_region_ptr() + { + for i in 0..op.layout.fields.count() { + let field = op.extract_field(&mut bx, i); + if !field.layout.is_zst() { + // we found the one non-zero-sized field that is allowed + // now find *its* non-zero-sized field, or stop if it's a + // pointer + op = field; + continue 'descend_newtypes; + } } + + span_bug!(span, "receiver has no non-zero-sized fields {:?}", op); } - span_bug!(span, "receiver has no non-zero-sized fields {:?}", op); + // now that we have `*dyn Trait` or `&dyn Trait`, split it up into its + // data pointer and vtable. Look up the method in the vtable, and pass + // the data pointer as the first argument + llfn = Some(meth::VirtualIndex::from_index(idx).get_fn( + &mut bx, + meta, + op.layout.ty, + &fn_abi, + )); + llargs.push(data_ptr); + continue 'make_args; } - - // now that we have `*dyn Trait` or `&dyn Trait`, split it up into its - // data pointer and vtable. Look up the method in the vtable, and pass - // the data pointer as the first argument - match op.val { - Pair(data_ptr, meta) => { - llfn = Some(meth::VirtualIndex::from_index(idx).get_fn( - &mut bx, - meta, - op.layout.ty, - &fn_abi, - )); - llargs.push(data_ptr); - continue 'make_args; + Ref(data_ptr, Some(meta), _) => { + // by-value dynamic dispatch + llfn = Some(meth::VirtualIndex::from_index(idx).get_fn( + &mut bx, + meta, + op.layout.ty, + &fn_abi, + )); + llargs.push(data_ptr); + continue; + } + Immediate(_) => { + let ty::Ref(_, ty, _) = op.layout.ty.kind() else { + span_bug!(span, "can't codegen a virtual call on {:#?}", op); + }; + if !ty.is_dyn_star() { + span_bug!(span, "can't codegen a virtual call on {:#?}", op); } - other => bug!("expected a Pair, got {:?}", other), + // FIXME(dyn-star): Make sure this is done on a &dyn* receiver + let place = op.deref(bx.cx()); + let data_ptr = place.project_field(&mut bx, 0); + let meta_ptr = place.project_field(&mut bx, 1); + let meta = bx.load_operand(meta_ptr); + llfn = Some(meth::VirtualIndex::from_index(idx).get_fn( + &mut bx, + meta.immediate(), + op.layout.ty, + &fn_abi, + )); + llargs.push(data_ptr.llval); + continue; + } + _ => { + span_bug!(span, "can't codegen a virtual call on {:#?}", op); } - } else if let Ref(data_ptr, Some(meta), _) = op.val { - // by-value dynamic dispatch - llfn = Some(meth::VirtualIndex::from_index(idx).get_fn( - &mut bx, - meta, - op.layout.ty, - &fn_abi, - )); - llargs.push(data_ptr); - continue; - } else { - span_bug!(span, "can't codegen a virtual call on {:?}", op); } } @@ -1161,39 +1242,35 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { llargs: &mut Vec<Bx::Value>, arg: &ArgAbi<'tcx, Ty<'tcx>>, ) { - // Fill padding with undef value, where applicable. - if let Some(ty) = arg.pad { - llargs.push(bx.const_undef(bx.reg_backend_type(&ty))) - } - - if arg.is_ignore() { - return; - } - - if let PassMode::Pair(..) = arg.mode { - match op.val { + match arg.mode { + PassMode::Ignore => return, + PassMode::Cast(_, true) => { + // Fill padding with undef value, where applicable. + llargs.push(bx.const_undef(bx.reg_backend_type(&Reg::i32()))); + } + PassMode::Pair(..) => match op.val { Pair(a, b) => { llargs.push(a); llargs.push(b); return; } _ => bug!("codegen_argument: {:?} invalid for pair argument", op), - } - } else if arg.is_unsized_indirect() { - match op.val { + }, + PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => match op.val { Ref(a, Some(b), _) => { llargs.push(a); llargs.push(b); return; } _ => bug!("codegen_argument: {:?} invalid for unsized indirect argument", op), - } + }, + _ => {} } // Force by-ref if we have to load through a cast pointer. let (mut llval, align, by_ref) = match op.val { Immediate(_) | Pair(..) => match arg.mode { - PassMode::Indirect { .. } | PassMode::Cast(_) => { + PassMode::Indirect { .. } | PassMode::Cast(..) => { let scratch = PlaceRef::alloca(bx, arg.layout); op.val.store(bx, scratch); (scratch.llval, scratch.align, true) @@ -1225,8 +1302,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { if by_ref && !arg.is_indirect() { // Have to load the argument, maybe while casting it. - if let PassMode::Cast(ty) = arg.mode { - let llty = bx.cast_backend_type(&ty); + if let PassMode::Cast(ty, _) = &arg.mode { + let llty = bx.cast_backend_type(ty); let addr = bx.pointercast(llval, bx.type_ptr_to(llty)); llval = bx.load(llty, addr, align.min(arg.layout.align.abi)); } else { @@ -1625,7 +1702,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } DirectOperand(index) => { // If there is a cast, we have to store and reload. - let op = if let PassMode::Cast(_) = ret_abi.mode { + let op = if let PassMode::Cast(..) = ret_abi.mode { let tmp = PlaceRef::alloca(bx, ret_abi.layout); tmp.storage_live(bx); bx.store_arg(&ret_abi, llval, tmp); |