From 7740476a43a7dc67c2b27eb2d981368a6c88832e Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Thu, 7 Sep 2023 22:06:37 +0200 Subject: [PATCH 1/4] explain PassMode::Cast --- compiler/rustc_codegen_llvm/src/abi.rs | 18 +++++++------ compiler/rustc_codegen_llvm/src/intrinsic.rs | 4 +-- compiler/rustc_codegen_ssa/src/mir/block.rs | 10 ++++---- .../rustc_codegen_ssa/src/mir/intrinsic.rs | 2 +- compiler/rustc_codegen_ssa/src/mir/mod.rs | 4 +-- compiler/rustc_target/src/abi/call/mod.rs | 25 +++++++++++++------ compiler/rustc_target/src/abi/call/x86.rs | 2 +- 7 files changed, 38 insertions(+), 27 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs index 64587f98b8a..883c5f5fe54 100644 --- a/compiler/rustc_codegen_llvm/src/abi.rs +++ b/compiler/rustc_codegen_llvm/src/abi.rs @@ -211,7 +211,7 @@ fn store( OperandValue::Ref(val, None, self.layout.align.abi).store(bx, dst) } else if self.is_unsized_indirect() { bug!("unsized `ArgAbi` must be handled through `store_fn_arg`"); - } else if let PassMode::Cast(cast, _) = &self.mode { + } else if let PassMode::Cast { cast, pad_i32: _ } = &self.mode { // FIXME(eddyb): Figure out when the simpler Store is safe, clang // uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}. let can_store_through_cast_ptr = false; @@ -279,7 +279,7 @@ fn store_fn_arg( } PassMode::Direct(_) | PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } - | PassMode::Cast(..) => { + | PassMode::Cast { .. } => { let next_arg = next(); self.store(bx, next_arg, dst); } @@ -332,7 +332,7 @@ fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type { let llreturn_ty = match &self.ret.mode { PassMode::Ignore => cx.type_void(), PassMode::Direct(_) | PassMode::Pair(..) => self.ret.layout.immediate_llvm_type(cx), - PassMode::Cast(cast, _) => cast.llvm_type(cx), + PassMode::Cast { cast, pad_i32: _ } => cast.llvm_type(cx), PassMode::Indirect { .. } => { llargument_tys.push(cx.type_ptr()); cx.type_void() @@ -390,7 +390,9 @@ fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type { llargument_tys.push(ptr_layout.scalar_pair_element_llvm_type(cx, 1, true)); continue; } - PassMode::Cast(cast, pad_i32) => { + PassMode::Cast { cast, pad_i32 } => { + // `Cast` means "transmute to `CastType`"; that only makes sense for sized types. + assert!(arg.layout.is_sized()); // add padding if *pad_i32 { llargument_tys.push(Reg::i32().llvm_type(cx)); @@ -448,7 +450,7 @@ fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) { let sret = llvm::CreateStructRetAttr(cx.llcx, self.ret.layout.llvm_type(cx)); attributes::apply_to_llfn(llfn, llvm::AttributePlace::Argument(i), &[sret]); } - PassMode::Cast(cast, _) => { + PassMode::Cast { cast, pad_i32: _ } => { cast.attrs.apply_attrs_to_llfn(llvm::AttributePlace::ReturnValue, cx, llfn); } _ => {} @@ -474,7 +476,7 @@ fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) { apply(a); apply(b); } - PassMode::Cast(cast, pad_i32) => { + PassMode::Cast { cast, pad_i32 } => { if *pad_i32 { apply(&ArgAttributes::new()); } @@ -510,7 +512,7 @@ fn apply_attrs_callsite(&self, bx: &mut Builder<'_, 'll, 'tcx>, callsite: &'ll V let sret = llvm::CreateStructRetAttr(bx.cx.llcx, self.ret.layout.llvm_type(bx)); attributes::apply_to_callsite(callsite, llvm::AttributePlace::Argument(i), &[sret]); } - PassMode::Cast(cast, _) => { + PassMode::Cast { cast, pad_i32: _ } => { cast.attrs.apply_attrs_to_callsite( llvm::AttributePlace::ReturnValue, &bx.cx, @@ -553,7 +555,7 @@ fn apply_attrs_callsite(&self, bx: &mut Builder<'_, 'll, 'tcx>, callsite: &'ll V apply(bx.cx, a); apply(bx.cx, b); } - PassMode::Cast(cast, pad_i32) => { + PassMode::Cast { cast, pad_i32 } => { if *pad_i32 { apply(bx.cx, &ArgAttributes::new()); } diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs index a9b06030e70..9289c37d763 100644 --- a/compiler/rustc_codegen_llvm/src/intrinsic.rs +++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs @@ -165,7 +165,7 @@ fn codegen_intrinsic_call( sym::volatile_load | sym::unaligned_volatile_load => { let tp_ty = fn_args.type_at(0); let ptr = args[0].immediate(); - let load = if let PassMode::Cast(ty, _) = &fn_abi.ret.mode { + let load = if let PassMode::Cast { cast: ty, pad_i32: _ } = &fn_abi.ret.mode { let llty = ty.llvm_type(self); self.volatile_load(llty, ptr) } else { @@ -386,7 +386,7 @@ fn codegen_intrinsic_call( }; if !fn_abi.ret.is_ignore() { - if let PassMode::Cast(_, _) = &fn_abi.ret.mode { + if let PassMode::Cast { .. } = &fn_abi.ret.mode { self.store(llval, result.llval, result.align); } else { OperandRef::from_immediate_or_packed_pair(self, llval, result.layout) diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index d8f6b4ed836..6138fda7a8d 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -416,7 +416,7 @@ fn codegen_return_terminator(&mut self, bx: &mut Bx) { } } - PassMode::Cast(cast_ty, _) => { + PassMode::Cast { cast: cast_ty, pad_i32: _ } => { let op = match self.locals[mir::RETURN_PLACE] { LocalRef::Operand(op) => op, LocalRef::PendingOperand => bug!("use of return before def"), @@ -1310,7 +1310,7 @@ fn codegen_argument( ) { match arg.mode { PassMode::Ignore => return, - PassMode::Cast(_, true) => { + PassMode::Cast { pad_i32: true, .. } => { // Fill padding with undef value, where applicable. llargs.push(bx.const_undef(bx.reg_backend_type(&Reg::i32()))); } @@ -1347,7 +1347,7 @@ fn codegen_argument( op.val.store(bx, scratch); (scratch.llval, scratch.align, true) } - PassMode::Cast(..) => { + PassMode::Cast { .. } => { let scratch = PlaceRef::alloca(bx, arg.layout); op.val.store(bx, scratch); (scratch.llval, scratch.align, true) @@ -1400,7 +1400,7 @@ fn codegen_argument( if by_ref && !arg.is_indirect() { // Have to load the argument, maybe while casting it. - if let PassMode::Cast(ty, _) = &arg.mode { + if let PassMode::Cast { cast: ty, .. } = &arg.mode { let llty = bx.cast_backend_type(ty); llval = bx.load(llty, llval, align.min(arg.layout.align.abi)); } else { @@ -1744,7 +1744,7 @@ fn store_return( } 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); diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs index 8821fb21fd0..8efef440522 100644 --- a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs +++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs @@ -462,7 +462,7 @@ pub fn codegen_intrinsic_call( }; if !fn_abi.ret.is_ignore() { - if let PassMode::Cast(..) = &fn_abi.ret.mode { + if let PassMode::Cast { .. } = &fn_abi.ret.mode { bx.store(llval, result.llval, result.align); } else { OperandRef::from_immediate_or_packed_pair(bx, llval, result.layout) diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs index c4408f2db4c..8445de6c678 100644 --- a/compiler/rustc_codegen_ssa/src/mir/mod.rs +++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs @@ -327,7 +327,7 @@ fn arg_local_refs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( for i in 0..tupled_arg_tys.len() { let arg = &fx.fn_abi.args[idx]; idx += 1; - if let PassMode::Cast(_, true) = arg.mode { + if let PassMode::Cast { pad_i32: true, .. } = arg.mode { llarg_idx += 1; } let pr_field = place.project_field(bx, i); @@ -351,7 +351,7 @@ fn arg_local_refs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( let arg = &fx.fn_abi.args[idx]; idx += 1; - if let PassMode::Cast(_, true) = arg.mode { + if let PassMode::Cast { pad_i32: true, .. } = arg.mode { llarg_idx += 1; } diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs index 1a4a46ceb40..c528e7b363f 100644 --- a/compiler/rustc_target/src/abi/call/mod.rs +++ b/compiler/rustc_target/src/abi/call/mod.rs @@ -45,10 +45,9 @@ pub enum PassMode { /// /// The argument has a layout abi of `ScalarPair`. Pair(ArgAttributes, ArgAttributes), - /// Pass the argument after casting it, to either a single uniform or a - /// pair of registers. The bool indicates if a `Reg::i32()` dummy argument - /// is emitted before the real argument. - Cast(Box, bool), + /// Pass the argument after casting it. See the `CastTarget` docs for details. The bool + /// indicates if a `Reg::i32()` dummy argument is emitted before the real argument. + Cast { pad_i32: bool, cast: Box }, /// Pass the argument indirectly via a hidden pointer. /// The `extra_attrs` value, if any, is for the extra data (vtable or length) /// which indicates that it refers to an unsized rvalue. @@ -64,10 +63,13 @@ impl PassMode { /// so that needs to be compared as well! pub fn eq_abi(&self, other: &Self) -> bool { match (self, other) { - (PassMode::Ignore, PassMode::Ignore) => true, // can still be reached for the return type + (PassMode::Ignore, PassMode::Ignore) => true, (PassMode::Direct(a1), PassMode::Direct(a2)) => a1.eq_abi(a2), (PassMode::Pair(a1, b1), PassMode::Pair(a2, b2)) => a1.eq_abi(a2) && b1.eq_abi(b2), - (PassMode::Cast(c1, pad1), PassMode::Cast(c2, pad2)) => c1.eq_abi(c2) && pad1 == pad2, + ( + PassMode::Cast { cast: c1, pad_i32: pad1 }, + PassMode::Cast { cast: c2, pad_i32: pad2 }, + ) => c1.eq_abi(c2) && pad1 == pad2, ( PassMode::Indirect { attrs: a1, extra_attrs: None, on_stack: s1 }, PassMode::Indirect { attrs: a2, extra_attrs: None, on_stack: s2 }, @@ -255,6 +257,13 @@ pub fn align(&self, cx: &C) -> Align { } } +/// Describes the type used for `PassMode::Cast`. +/// +/// Passing arguments in this mode works as follows: the registers in the `prefix` (the ones that +/// are `Some`) get laid out one after the other (using `repr(C)` layout rules). Then the +/// `rest.unit` register type gets repeated often enough to cover `rest.size`. This describes the +/// actual type used for the call; the Rust type of the argument is then transmuted to this ABI type +/// (and all data in the padding between the registers is dropped). #[derive(Clone, PartialEq, Eq, Hash, Debug, HashStable_Generic)] pub struct CastTarget { pub prefix: [Option; 8], @@ -607,11 +616,11 @@ pub fn extend_integer_width_to(&mut self, bits: u64) { } pub fn cast_to>(&mut self, target: T) { - self.mode = PassMode::Cast(Box::new(target.into()), false); + self.mode = PassMode::Cast { cast: Box::new(target.into()), pad_i32: false }; } pub fn cast_to_and_pad_i32>(&mut self, target: T, pad_i32: bool) { - self.mode = PassMode::Cast(Box::new(target.into()), pad_i32); + self.mode = PassMode::Cast { cast: Box::new(target.into()), pad_i32 }; } pub fn is_indirect(&self) -> bool { diff --git a/compiler/rustc_target/src/abi/call/x86.rs b/compiler/rustc_target/src/abi/call/x86.rs index b738c3133d9..42a914296c3 100644 --- a/compiler/rustc_target/src/abi/call/x86.rs +++ b/compiler/rustc_target/src/abi/call/x86.rs @@ -148,7 +148,7 @@ fn contains_vector<'a, Ty, C>(cx: &C, layout: TyAndLayout<'a, Ty>) -> bool PassMode::Direct(ref mut attrs) => attrs, PassMode::Pair(..) | PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } - | PassMode::Cast(..) => { + | PassMode::Cast { .. } => { unreachable!("x86 shouldn't be passing arguments by {:?}", arg.mode) } }; From 89139d4c4646456a91eadf141b9f58b2d96d5b2b Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Fri, 8 Sep 2023 08:48:41 +0200 Subject: [PATCH 2/4] clarify PassMode::Indirect as well --- .../src/abi/pass_mode.rs | 14 ++++---- .../src/abi/returning.rs | 16 ++++----- compiler/rustc_codegen_gcc/src/abi.rs | 6 ++-- .../rustc_codegen_gcc/src/intrinsic/mod.rs | 4 +-- compiler/rustc_codegen_llvm/src/abi.rs | 35 +++++++++++-------- compiler/rustc_codegen_ssa/src/mir/block.rs | 2 +- compiler/rustc_target/src/abi/call/mod.rs | 33 ++++++++--------- compiler/rustc_target/src/abi/call/x86.rs | 4 +-- tests/ui/abi/debug.stderr | 4 +-- 9 files changed, 62 insertions(+), 56 deletions(-) diff --git a/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs b/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs index d847e524f8c..270059c061d 100644 --- a/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs +++ b/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs @@ -104,7 +104,7 @@ impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> { assert!(!pad_i32, "padding support not yet implemented"); cast_target_to_abi_params(cast) } - PassMode::Indirect { attrs, extra_attrs: None, on_stack } => { + PassMode::Indirect { attrs, meta_attrs: None, on_stack } => { if on_stack { // Abi requires aligning struct size to pointer size let size = self.layout.size.align_to(tcx.data_layout.pointer_align.abi); @@ -117,11 +117,11 @@ impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> { smallvec![apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), attrs)] } } - PassMode::Indirect { attrs, extra_attrs: Some(extra_attrs), on_stack } => { + PassMode::Indirect { attrs, meta_attrs: Some(meta_attrs), on_stack } => { assert!(!on_stack); smallvec![ apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), attrs), - apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), extra_attrs), + apply_arg_attrs_to_abi_param(AbiParam::new(pointer_ty(tcx)), meta_attrs), ] } } @@ -151,11 +151,11 @@ fn get_abi_return(&self, tcx: TyCtxt<'tcx>) -> (Option, Vec) PassMode::Cast(ref cast, _) => { (None, cast_target_to_abi_params(cast).into_iter().collect()) } - PassMode::Indirect { attrs: _, extra_attrs: None, on_stack } => { + PassMode::Indirect { attrs: _, meta_attrs: None, on_stack } => { assert!(!on_stack); (Some(AbiParam::special(pointer_ty(tcx), ArgumentPurpose::StructReturn)), vec![]) } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { unreachable!("unsized return value") } } @@ -290,11 +290,11 @@ pub(super) fn cvalue_for_param<'tcx>( PassMode::Cast(ref cast, _) => { Some(from_casted_value(fx, &block_params, arg_abi.layout, cast)) } - PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { assert_eq!(block_params.len(), 1, "{:?}", block_params); Some(CValue::by_ref(Pointer::new(block_params[0]), arg_abi.layout)) } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { assert_eq!(block_params.len(), 2, "{:?}", block_params); Some(CValue::by_ref_unsized( Pointer::new(block_params[0]), diff --git a/compiler/rustc_codegen_cranelift/src/abi/returning.rs b/compiler/rustc_codegen_cranelift/src/abi/returning.rs index 14e54d5ee38..dc76e4f0b5a 100644 --- a/compiler/rustc_codegen_cranelift/src/abi/returning.rs +++ b/compiler/rustc_codegen_cranelift/src/abi/returning.rs @@ -26,7 +26,7 @@ pub(super) fn codegen_return_param<'tcx>( smallvec![], ) } - PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { let ret_param = block_params_iter.next().unwrap(); assert_eq!(fx.bcx.func.dfg.value_type(ret_param), fx.pointer_type); ( @@ -34,7 +34,7 @@ pub(super) fn codegen_return_param<'tcx>( smallvec![ret_param], ) } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { unreachable!("unsized return value") } }; @@ -62,7 +62,7 @@ pub(super) fn codegen_with_call_return_arg<'tcx>( ) { let (ret_temp_place, return_ptr) = match ret_arg_abi.mode { PassMode::Ignore => (None, None), - PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { if let Some(ret_ptr) = ret_place.try_to_ptr() { // This is an optimization to prevent unnecessary copies of the return value when // the return place is already a memory place as opposed to a register. @@ -73,7 +73,7 @@ pub(super) fn codegen_with_call_return_arg<'tcx>( (Some(place), Some(place.to_ptr().get_addr(fx))) } } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { unreachable!("unsized return value") } PassMode::Direct(_) | PassMode::Pair(_, _) | PassMode::Cast(..) => (None, None), @@ -100,14 +100,14 @@ pub(super) fn codegen_with_call_return_arg<'tcx>( super::pass_mode::from_casted_value(fx, &results, ret_place.layout(), cast); ret_place.write_cvalue(fx, result); } - PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { if let Some(ret_temp_place) = ret_temp_place { // If ret_temp_place is None, it is not necessary to copy the return value. let ret_temp_value = ret_temp_place.to_cvalue(fx); ret_place.write_cvalue(fx, ret_temp_value); } } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { unreachable!("unsized return value") } } @@ -116,10 +116,10 @@ pub(super) fn codegen_with_call_return_arg<'tcx>( /// Codegen a return instruction with the right return value(s) if any. pub(crate) fn codegen_return(fx: &mut FunctionCx<'_, '_, '_>) { match fx.fn_abi.as_ref().unwrap().ret.mode { - PassMode::Ignore | PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => { + PassMode::Ignore | PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { fx.bcx.ins().return_(&[]); } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { unreachable!("unsized return value") } PassMode::Direct(_) => { diff --git a/compiler/rustc_codegen_gcc/src/abi.rs b/compiler/rustc_codegen_gcc/src/abi.rs index 377dc753f68..9c93a1b52fa 100644 --- a/compiler/rustc_codegen_gcc/src/abi.rs +++ b/compiler/rustc_codegen_gcc/src/abi.rs @@ -129,7 +129,7 @@ fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec>, argument_tys.push(arg.layout.scalar_pair_element_gcc_type(cx, 1)); continue; } - PassMode::Indirect { extra_attrs: Some(_), .. } => { + PassMode::Indirect { meta_attrs: Some(_), .. } => { unimplemented!(); } PassMode::Cast(ref cast, pad_i32) => { @@ -139,11 +139,11 @@ fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec>, } cast.gcc_type(cx) } - PassMode::Indirect { extra_attrs: None, on_stack: true, .. } => { + PassMode::Indirect { meta_attrs: None, on_stack: true, .. } => { on_stack_param_indices.insert(argument_tys.len()); arg.memory_ty(cx) }, - PassMode::Indirect { extra_attrs: None, on_stack: false, .. } => cx.type_ptr_to(arg.memory_ty(cx)), + PassMode::Indirect { meta_attrs: None, on_stack: false, .. } => cx.type_ptr_to(arg.memory_ty(cx)), }; argument_tys.push(arg_ty); } diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs index f8c32c6dbbb..b59a17b5cad 100644 --- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs +++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs @@ -511,10 +511,10 @@ fn store_fn_arg<'a>(&self, bx: &mut Builder<'a, 'gcc, 'tcx>, idx: &mut usize, ds PassMode::Pair(..) => { OperandValue::Pair(next(), next()).store(bx, dst); }, - PassMode::Indirect { extra_attrs: Some(_), .. } => { + PassMode::Indirect { meta_attrs: Some(_), .. } => { OperandValue::Ref(next(), Some(next()), self.layout.align.abi).store(bx, dst); }, - PassMode::Direct(_) | PassMode::Indirect { extra_attrs: None, .. } | PassMode::Cast(..) => { + PassMode::Direct(_) | PassMode::Indirect { meta_attrs: None, .. } | PassMode::Cast(..) => { let next_arg = next(); self.store(bx, next_arg, dst); }, diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs index 883c5f5fe54..65d4d5120d0 100644 --- a/compiler/rustc_codegen_llvm/src/abi.rs +++ b/compiler/rustc_codegen_llvm/src/abi.rs @@ -274,11 +274,11 @@ fn store_fn_arg( PassMode::Pair(..) => { OperandValue::Pair(next(), next()).store(bx, dst); } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { OperandValue::Ref(next(), Some(next()), self.layout.align.abi).store(bx, dst); } PassMode::Direct(_) - | PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } + | PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } | PassMode::Cast { .. } => { let next_arg = next(); self.store(bx, next_arg, dst); @@ -378,8 +378,10 @@ fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type { llargument_tys.push(arg.layout.scalar_pair_element_llvm_type(cx, 1, true)); continue; } - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => { - assert!(arg.layout.is_unsized()); + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack } => { + // `Indirect` with metadata is only for unsized types, and doesn't work with + // on-stack passing. + assert!(arg.layout.is_unsized() && !on_stack); // Construct the type of a (wide) pointer to `ty`, and pass its two fields. // Any two ABI-compatible unsized types have the same metadata type and // moreover the same metadata value leads to the same dynamic size and @@ -390,6 +392,10 @@ fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type { llargument_tys.push(ptr_layout.scalar_pair_element_llvm_type(cx, 1, true)); continue; } + PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { + assert!(arg.layout.is_sized()); + cx.type_ptr() + } PassMode::Cast { cast, pad_i32 } => { // `Cast` means "transmute to `CastType`"; that only makes sense for sized types. assert!(arg.layout.is_sized()); @@ -401,7 +407,6 @@ fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type { // We assume here that ABI-compatible Rust types have the same cast type. cast.llvm_type(cx) } - PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => cx.type_ptr(), }; llargument_tys.push(llarg_ty); } @@ -444,7 +449,7 @@ fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) { PassMode::Direct(attrs) => { attrs.apply_attrs_to_llfn(llvm::AttributePlace::ReturnValue, cx, llfn); } - PassMode::Indirect { attrs, extra_attrs: _, on_stack } => { + PassMode::Indirect { attrs, meta_attrs: _, on_stack } => { assert!(!on_stack); let i = apply(attrs); let sret = llvm::CreateStructRetAttr(cx.llcx, self.ret.layout.llvm_type(cx)); @@ -458,19 +463,19 @@ fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) { for arg in self.args.iter() { match &arg.mode { PassMode::Ignore => {} - PassMode::Indirect { attrs, extra_attrs: None, on_stack: true } => { + PassMode::Indirect { attrs, meta_attrs: None, on_stack: true } => { let i = apply(attrs); let byval = llvm::CreateByValAttr(cx.llcx, arg.layout.llvm_type(cx)); attributes::apply_to_llfn(llfn, llvm::AttributePlace::Argument(i), &[byval]); } PassMode::Direct(attrs) - | PassMode::Indirect { attrs, extra_attrs: None, on_stack: false } => { + | PassMode::Indirect { attrs, meta_attrs: None, on_stack: false } => { apply(attrs); } - PassMode::Indirect { attrs, extra_attrs: Some(extra_attrs), on_stack } => { + PassMode::Indirect { attrs, meta_attrs: Some(meta_attrs), on_stack } => { assert!(!on_stack); apply(attrs); - apply(extra_attrs); + apply(meta_attrs); } PassMode::Pair(a, b) => { apply(a); @@ -506,7 +511,7 @@ fn apply_attrs_callsite(&self, bx: &mut Builder<'_, 'll, 'tcx>, callsite: &'ll V PassMode::Direct(attrs) => { attrs.apply_attrs_to_callsite(llvm::AttributePlace::ReturnValue, bx.cx, callsite); } - PassMode::Indirect { attrs, extra_attrs: _, on_stack } => { + PassMode::Indirect { attrs, meta_attrs: _, on_stack } => { assert!(!on_stack); let i = apply(bx.cx, attrs); let sret = llvm::CreateStructRetAttr(bx.cx.llcx, self.ret.layout.llvm_type(bx)); @@ -534,7 +539,7 @@ fn apply_attrs_callsite(&self, bx: &mut Builder<'_, 'll, 'tcx>, callsite: &'ll V for arg in self.args.iter() { match &arg.mode { PassMode::Ignore => {} - PassMode::Indirect { attrs, extra_attrs: None, on_stack: true } => { + PassMode::Indirect { attrs, meta_attrs: None, on_stack: true } => { let i = apply(bx.cx, attrs); let byval = llvm::CreateByValAttr(bx.cx.llcx, arg.layout.llvm_type(bx)); attributes::apply_to_callsite( @@ -544,12 +549,12 @@ fn apply_attrs_callsite(&self, bx: &mut Builder<'_, 'll, 'tcx>, callsite: &'ll V ); } PassMode::Direct(attrs) - | PassMode::Indirect { attrs, extra_attrs: None, on_stack: false } => { + | PassMode::Indirect { attrs, meta_attrs: None, on_stack: false } => { apply(bx.cx, attrs); } - PassMode::Indirect { attrs, extra_attrs: Some(extra_attrs), on_stack: _ } => { + PassMode::Indirect { attrs, meta_attrs: Some(meta_attrs), on_stack: _ } => { apply(bx.cx, attrs); - apply(bx.cx, extra_attrs); + apply(bx.cx, meta_attrs); } PassMode::Pair(a, b) => { apply(bx.cx, a); diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 6138fda7a8d..464278f9c5e 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -1322,7 +1322,7 @@ fn codegen_argument( } _ => bug!("codegen_argument: {:?} invalid for pair argument", op), }, - PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => match op.val { + PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => match op.val { Ref(a, Some(b), _) => { llargs.push(a); llargs.push(b); diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs index c528e7b363f..7fda6d6d910 100644 --- a/compiler/rustc_target/src/abi/call/mod.rs +++ b/compiler/rustc_target/src/abi/call/mod.rs @@ -49,12 +49,13 @@ pub enum PassMode { /// indicates if a `Reg::i32()` dummy argument is emitted before the real argument. Cast { pad_i32: bool, cast: Box }, /// Pass the argument indirectly via a hidden pointer. - /// The `extra_attrs` value, if any, is for the extra data (vtable or length) - /// which indicates that it refers to an unsized rvalue. - /// `on_stack` defines that the value should be passed at a fixed - /// stack offset in accordance to the ABI rather than passed using a - /// pointer. This corresponds to the `byval` LLVM argument attribute. - Indirect { attrs: ArgAttributes, extra_attrs: Option, on_stack: bool }, + /// The `meta_attrs` value, if any, is for the metadata (vtable or length) of an unsized + /// argument. (This is the only mode that supports unsized arguments.) + /// `on_stack` defines that the value should be passed at a fixed stack offset in accordance to + /// the ABI rather than passed using a pointer. This corresponds to the `byval` LLVM argument + /// attribute (using the Rust type of this argument). `on_stack` cannot be true for unsized + /// arguments, i.e., when `meta_attrs` is `Some`. + Indirect { attrs: ArgAttributes, meta_attrs: Option, on_stack: bool }, } impl PassMode { @@ -71,12 +72,12 @@ pub fn eq_abi(&self, other: &Self) -> bool { PassMode::Cast { cast: c2, pad_i32: pad2 }, ) => c1.eq_abi(c2) && pad1 == pad2, ( - PassMode::Indirect { attrs: a1, extra_attrs: None, on_stack: s1 }, - PassMode::Indirect { attrs: a2, extra_attrs: None, on_stack: s2 }, + PassMode::Indirect { attrs: a1, meta_attrs: None, on_stack: s1 }, + PassMode::Indirect { attrs: a2, meta_attrs: None, on_stack: s2 }, ) => a1.eq_abi(a2) && s1 == s2, ( - PassMode::Indirect { attrs: a1, extra_attrs: Some(e1), on_stack: s1 }, - PassMode::Indirect { attrs: a2, extra_attrs: Some(e2), on_stack: s2 }, + PassMode::Indirect { attrs: a1, meta_attrs: Some(e1), on_stack: s1 }, + PassMode::Indirect { attrs: a2, meta_attrs: Some(e2), on_stack: s2 }, ) => a1.eq_abi(a2) && e1.eq_abi(e2) && s1 == s2, _ => false, } @@ -565,15 +566,15 @@ fn indirect_pass_mode(layout: &TyAndLayout<'a, Ty>) -> PassMode { attrs.pointee_size = layout.size; attrs.pointee_align = Some(layout.align.abi); - let extra_attrs = layout.is_unsized().then_some(ArgAttributes::new()); + let meta_attrs = layout.is_unsized().then_some(ArgAttributes::new()); - PassMode::Indirect { attrs, extra_attrs, on_stack: false } + PassMode::Indirect { attrs, meta_attrs, on_stack: false } } pub fn make_indirect(&mut self) { match self.mode { PassMode::Direct(_) | PassMode::Pair(_, _) => {} - PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: false } => return, + PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: false } => return, _ => panic!("Tried to make {:?} indirect", self.mode), } @@ -583,7 +584,7 @@ pub fn make_indirect(&mut self) { pub fn make_indirect_byval(&mut self, byval_align: Option) { self.make_indirect(); match self.mode { - PassMode::Indirect { ref mut attrs, extra_attrs: _, ref mut on_stack } => { + PassMode::Indirect { ref mut attrs, meta_attrs: _, ref mut on_stack } => { *on_stack = true; // Some platforms, like 32-bit x86, change the alignment of the type when passing @@ -628,11 +629,11 @@ pub fn is_indirect(&self) -> bool { } pub fn is_sized_indirect(&self) -> bool { - matches!(self.mode, PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ }) + matches!(self.mode, PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ }) } pub fn is_unsized_indirect(&self) -> bool { - matches!(self.mode, PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ }) + matches!(self.mode, PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ }) } pub fn is_ignore(&self) -> bool { diff --git a/compiler/rustc_target/src/abi/call/x86.rs b/compiler/rustc_target/src/abi/call/x86.rs index 42a914296c3..afa1b70efc2 100644 --- a/compiler/rustc_target/src/abi/call/x86.rs +++ b/compiler/rustc_target/src/abi/call/x86.rs @@ -142,12 +142,12 @@ fn contains_vector<'a, Ty, C>(cx: &C, layout: TyAndLayout<'a, Ty>) -> bool for arg in fn_abi.args.iter_mut() { let attrs = match arg.mode { PassMode::Ignore - | PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => { + | PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { continue; } PassMode::Direct(ref mut attrs) => attrs, PassMode::Pair(..) - | PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } + | PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } | PassMode::Cast { .. } => { unreachable!("x86 shouldn't be passing arguments by {:?}", arg.mode) } diff --git a/tests/ui/abi/debug.stderr b/tests/ui/abi/debug.stderr index f56f5c525ab..84e96da336e 100644 --- a/tests/ui/abi/debug.stderr +++ b/tests/ui/abi/debug.stderr @@ -450,7 +450,7 @@ error: ABIs are not compatible Align(1 bytes), ), }, - extra_attrs: None, + meta_attrs: None, on_stack: false, }, }, @@ -521,7 +521,7 @@ error: ABIs are not compatible Align(4 bytes), ), }, - extra_attrs: None, + meta_attrs: None, on_stack: false, }, }, From 29a4b7b9710a8abc587bbbf6ee1aba4a37af4f17 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Sat, 9 Sep 2023 09:23:56 +0200 Subject: [PATCH 3/4] fix gcc, cranelift build --- compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs | 8 ++++---- compiler/rustc_codegen_cranelift/src/abi/returning.rs | 8 ++++---- compiler/rustc_codegen_gcc/src/abi.rs | 4 ++-- compiler/rustc_codegen_gcc/src/intrinsic/mod.rs | 8 ++++---- 4 files changed, 14 insertions(+), 14 deletions(-) diff --git a/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs b/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs index 270059c061d..0d16da48067 100644 --- a/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs +++ b/compiler/rustc_codegen_cranelift/src/abi/pass_mode.rs @@ -100,7 +100,7 @@ impl<'tcx> ArgAbiExt<'tcx> for ArgAbi<'tcx, Ty<'tcx>> { } _ => unreachable!("{:?}", self.layout.abi), }, - PassMode::Cast(ref cast, pad_i32) => { + PassMode::Cast { ref cast, pad_i32 } => { assert!(!pad_i32, "padding support not yet implemented"); cast_target_to_abi_params(cast) } @@ -148,7 +148,7 @@ fn get_abi_return(&self, tcx: TyCtxt<'tcx>) -> (Option, Vec) } _ => unreachable!("{:?}", self.layout.abi), }, - PassMode::Cast(ref cast, _) => { + PassMode::Cast { ref cast, .. } => { (None, cast_target_to_abi_params(cast).into_iter().collect()) } PassMode::Indirect { attrs: _, meta_attrs: None, on_stack } => { @@ -229,7 +229,7 @@ pub(super) fn adjust_arg_for_abi<'tcx>( let (a, b) = arg.load_scalar_pair(fx); smallvec![a, b] } - PassMode::Cast(ref cast, _) => to_casted_value(fx, arg, cast), + PassMode::Cast { ref cast, .. } => to_casted_value(fx, arg, cast), PassMode::Indirect { .. } => { if is_owned { match arg.force_stack(fx) { @@ -287,7 +287,7 @@ pub(super) fn cvalue_for_param<'tcx>( assert_eq!(block_params.len(), 2, "{:?}", block_params); Some(CValue::by_val_pair(block_params[0], block_params[1], arg_abi.layout)) } - PassMode::Cast(ref cast, _) => { + PassMode::Cast { ref cast, .. } => { Some(from_casted_value(fx, &block_params, arg_abi.layout, cast)) } PassMode::Indirect { attrs: _, meta_attrs: None, on_stack: _ } => { diff --git a/compiler/rustc_codegen_cranelift/src/abi/returning.rs b/compiler/rustc_codegen_cranelift/src/abi/returning.rs index dc76e4f0b5a..646fb4a3cdc 100644 --- a/compiler/rustc_codegen_cranelift/src/abi/returning.rs +++ b/compiler/rustc_codegen_cranelift/src/abi/returning.rs @@ -13,7 +13,7 @@ pub(super) fn codegen_return_param<'tcx>( block_params_iter: &mut impl Iterator, ) -> CPlace<'tcx> { let (ret_place, ret_param): (_, SmallVec<[_; 2]>) = match fx.fn_abi.as_ref().unwrap().ret.mode { - PassMode::Ignore | PassMode::Direct(_) | PassMode::Pair(_, _) | PassMode::Cast(..) => { + PassMode::Ignore | PassMode::Direct(_) | PassMode::Pair(_, _) | PassMode::Cast { .. } => { let is_ssa = ssa_analyzed[RETURN_PLACE].is_ssa(fx, fx.fn_abi.as_ref().unwrap().ret.layout.ty); ( @@ -76,7 +76,7 @@ pub(super) fn codegen_with_call_return_arg<'tcx>( PassMode::Indirect { attrs: _, meta_attrs: Some(_), on_stack: _ } => { unreachable!("unsized return value") } - PassMode::Direct(_) | PassMode::Pair(_, _) | PassMode::Cast(..) => (None, None), + PassMode::Direct(_) | PassMode::Pair(_, _) | PassMode::Cast { .. } => (None, None), }; let call_inst = f(fx, return_ptr); @@ -93,7 +93,7 @@ pub(super) fn codegen_with_call_return_arg<'tcx>( ret_place .write_cvalue(fx, CValue::by_val_pair(ret_val_a, ret_val_b, ret_arg_abi.layout)); } - PassMode::Cast(ref cast, _) => { + PassMode::Cast { ref cast, .. } => { let results = fx.bcx.inst_results(call_inst).iter().copied().collect::>(); let result = @@ -132,7 +132,7 @@ pub(crate) fn codegen_return(fx: &mut FunctionCx<'_, '_, '_>) { let (ret_val_a, ret_val_b) = place.to_cvalue(fx).load_scalar_pair(fx); fx.bcx.ins().return_(&[ret_val_a, ret_val_b]); } - PassMode::Cast(ref cast, _) => { + PassMode::Cast { ref cast, .. } => { let place = fx.get_local_place(RETURN_PLACE); let ret_val = place.to_cvalue(fx); let ret_vals = super::pass_mode::to_casted_value(fx, ret_val, cast); diff --git a/compiler/rustc_codegen_gcc/src/abi.rs b/compiler/rustc_codegen_gcc/src/abi.rs index 9c93a1b52fa..a49530ebb4c 100644 --- a/compiler/rustc_codegen_gcc/src/abi.rs +++ b/compiler/rustc_codegen_gcc/src/abi.rs @@ -113,7 +113,7 @@ fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec>, match self.ret.mode { PassMode::Ignore => cx.type_void(), PassMode::Direct(_) | PassMode::Pair(..) => self.ret.layout.immediate_gcc_type(cx), - PassMode::Cast(ref cast, _) => cast.gcc_type(cx), + PassMode::Cast { ref cast, .. } => cast.gcc_type(cx), PassMode::Indirect { .. } => { argument_tys.push(cx.type_ptr_to(self.ret.memory_ty(cx))); cx.type_void() @@ -132,7 +132,7 @@ fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec>, PassMode::Indirect { meta_attrs: Some(_), .. } => { unimplemented!(); } - PassMode::Cast(ref cast, pad_i32) => { + PassMode::Cast { ref cast, pad_i32 } => { // add padding if pad_i32 { argument_tys.push(Reg::i32().gcc_type(cx)); diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs index b59a17b5cad..68a087a1d7f 100644 --- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs +++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs @@ -144,7 +144,7 @@ fn codegen_intrinsic_call(&mut self, instance: Instance<'tcx>, fn_abi: &FnAbi<'t sym::volatile_load | sym::unaligned_volatile_load => { let tp_ty = fn_args.type_at(0); let mut ptr = args[0].immediate(); - if let PassMode::Cast(ty, _) = &fn_abi.ret.mode { + if let PassMode::Cast { cast: ty, .. } = &fn_abi.ret.mode { ptr = self.pointercast(ptr, self.type_ptr_to(ty.gcc_type(self))); } let load = self.volatile_load(ptr.get_type(), ptr); @@ -353,7 +353,7 @@ fn codegen_intrinsic_call(&mut self, instance: Instance<'tcx>, fn_abi: &FnAbi<'t }; if !fn_abi.ret.is_ignore() { - if let PassMode::Cast(ty, _) = &fn_abi.ret.mode { + if let PassMode::Cast { cast: ty, .. } = &fn_abi.ret.mode { let ptr_llty = self.type_ptr_to(ty.gcc_type(self)); let ptr = self.pointercast(result.llval, ptr_llty); self.store(llval, ptr, result.align); @@ -449,7 +449,7 @@ fn store(&self, bx: &mut Builder<'_, 'gcc, 'tcx>, val: RValue<'gcc>, dst: PlaceR else if self.is_unsized_indirect() { bug!("unsized `ArgAbi` must be handled through `store_fn_arg`"); } - else if let PassMode::Cast(ref cast, _) = self.mode { + else if let PassMode::Cast { ref cast, .. } = self.mode { // FIXME(eddyb): Figure out when the simpler Store is safe, clang // uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}. let can_store_through_cast_ptr = false; @@ -514,7 +514,7 @@ fn store_fn_arg<'a>(&self, bx: &mut Builder<'a, 'gcc, 'tcx>, idx: &mut usize, ds PassMode::Indirect { meta_attrs: Some(_), .. } => { OperandValue::Ref(next(), Some(next()), self.layout.align.abi).store(bx, dst); }, - PassMode::Direct(_) | PassMode::Indirect { meta_attrs: None, .. } | PassMode::Cast(..) => { + PassMode::Direct(_) | PassMode::Indirect { meta_attrs: None, .. } | PassMode::Cast { .. } => { let next_arg = next(); self.store(bx, next_arg, dst); }, From 3ee65c28e92c678bfd99c76f4090a36974093974 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Fri, 15 Sep 2023 10:45:32 +0200 Subject: [PATCH 4/4] cannot have Direct for unsized types --- compiler/rustc_codegen_llvm/src/abi.rs | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs index 65d4d5120d0..9e834b83df4 100644 --- a/compiler/rustc_codegen_llvm/src/abi.rs +++ b/compiler/rustc_codegen_llvm/src/abi.rs @@ -351,6 +351,11 @@ fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type { // guarnateeing that we generate ABI-compatible LLVM IR. Things get tricky for // aggregates... if matches!(arg.layout.abi, abi::Abi::Aggregate { .. }) { + assert!( + arg.layout.is_sized(), + "`PassMode::Direct` for unsized type: {}", + arg.layout.ty + ); // This really shouldn't happen, since `immediate_llvm_type` will use // `layout.fields` to turn this Rust type into an LLVM type. This means all // sorts of Rust type details leak into the ABI. However wasm sadly *does*