diff options
Diffstat (limited to 'compiler/rustc_codegen_gcc/src/type_of.rs')
| -rw-r--r-- | compiler/rustc_codegen_gcc/src/type_of.rs | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_gcc/src/type_of.rs b/compiler/rustc_codegen_gcc/src/type_of.rs new file mode 100644 index 000000000..524d10fb5 --- /dev/null +++ b/compiler/rustc_codegen_gcc/src/type_of.rs @@ -0,0 +1,385 @@ +use std::fmt::Write; + +use gccjit::{Struct, Type}; +use crate::rustc_codegen_ssa::traits::{BaseTypeMethods, DerivedTypeMethods, LayoutTypeMethods}; +use rustc_middle::bug; +use rustc_middle::ty::{self, Ty, TypeVisitable}; +use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout}; +use rustc_middle::ty::print::with_no_trimmed_paths; +use rustc_target::abi::{self, Abi, F32, F64, FieldsShape, Int, Integer, Pointer, PointeeInfo, Size, TyAbiInterface, Variants}; +use rustc_target::abi::call::{CastTarget, FnAbi, Reg}; + +use crate::abi::{FnAbiGccExt, GccType}; +use crate::context::CodegenCx; +use crate::type_::struct_fields; + +impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> { + fn type_from_unsigned_integer(&self, i: Integer) -> Type<'gcc> { + use Integer::*; + match i { + I8 => self.type_u8(), + I16 => self.type_u16(), + I32 => self.type_u32(), + I64 => self.type_u64(), + I128 => self.type_u128(), + } + } + + #[cfg(feature="master")] + pub fn type_int_from_ty(&self, t: ty::IntTy) -> Type<'gcc> { + match t { + ty::IntTy::Isize => self.type_isize(), + ty::IntTy::I8 => self.type_i8(), + ty::IntTy::I16 => self.type_i16(), + ty::IntTy::I32 => self.type_i32(), + ty::IntTy::I64 => self.type_i64(), + ty::IntTy::I128 => self.type_i128(), + } + } + + #[cfg(feature="master")] + pub fn type_uint_from_ty(&self, t: ty::UintTy) -> Type<'gcc> { + match t { + ty::UintTy::Usize => self.type_isize(), + ty::UintTy::U8 => self.type_i8(), + ty::UintTy::U16 => self.type_i16(), + ty::UintTy::U32 => self.type_i32(), + ty::UintTy::U64 => self.type_i64(), + ty::UintTy::U128 => self.type_i128(), + } + } +} + +pub fn uncached_gcc_type<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, layout: TyAndLayout<'tcx>, defer: &mut Option<(Struct<'gcc>, TyAndLayout<'tcx>)>) -> Type<'gcc> { + match layout.abi { + Abi::Scalar(_) => bug!("handled elsewhere"), + Abi::Vector { ref element, count } => { + let element = layout.scalar_gcc_type_at(cx, element, Size::ZERO); + return cx.context.new_vector_type(element, count); + }, + Abi::ScalarPair(..) => { + return cx.type_struct( + &[ + layout.scalar_pair_element_gcc_type(cx, 0, false), + layout.scalar_pair_element_gcc_type(cx, 1, false), + ], + false, + ); + } + Abi::Uninhabited | Abi::Aggregate { .. } => {} + } + + let name = match layout.ty.kind() { + // FIXME(eddyb) producing readable type names for trait objects can result + // in problematically distinct types due to HRTB and subtyping (see #47638). + // ty::Dynamic(..) | + ty::Adt(..) | ty::Closure(..) | ty::Foreign(..) | ty::Generator(..) | ty::Str + if !cx.sess().fewer_names() => + { + let mut name = with_no_trimmed_paths!(layout.ty.to_string()); + if let (&ty::Adt(def, _), &Variants::Single { index }) = + (layout.ty.kind(), &layout.variants) + { + if def.is_enum() && !def.variants().is_empty() { + write!(&mut name, "::{}", def.variant(index).name).unwrap(); + } + } + if let (&ty::Generator(_, _, _), &Variants::Single { index }) = + (layout.ty.kind(), &layout.variants) + { + write!(&mut name, "::{}", ty::GeneratorSubsts::variant_name(index)).unwrap(); + } + Some(name) + } + ty::Adt(..) => { + // If `Some` is returned then a named struct is created in LLVM. Name collisions are + // avoided by LLVM (with increasing suffixes). If rustc doesn't generate names then that + // can improve perf. + // FIXME(antoyo): I don't think that's true for libgccjit. + Some(String::new()) + } + _ => None, + }; + + match layout.fields { + FieldsShape::Primitive | FieldsShape::Union(_) => { + let fill = cx.type_padding_filler(layout.size, layout.align.abi); + let packed = false; + match name { + None => cx.type_struct(&[fill], packed), + Some(ref name) => { + let gcc_type = cx.type_named_struct(name); + cx.set_struct_body(gcc_type, &[fill], packed); + gcc_type.as_type() + }, + } + } + FieldsShape::Array { count, .. } => cx.type_array(layout.field(cx, 0).gcc_type(cx, true), count), + FieldsShape::Arbitrary { .. } => + match name { + None => { + let (gcc_fields, packed) = struct_fields(cx, layout); + cx.type_struct(&gcc_fields, packed) + }, + Some(ref name) => { + let gcc_type = cx.type_named_struct(name); + *defer = Some((gcc_type, layout)); + gcc_type.as_type() + }, + }, + } +} + +pub trait LayoutGccExt<'tcx> { + fn is_gcc_immediate(&self) -> bool; + fn is_gcc_scalar_pair(&self) -> bool; + fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, set_fields: bool) -> Type<'gcc>; + fn immediate_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc>; + fn scalar_gcc_type_at<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, scalar: &abi::Scalar, offset: Size) -> Type<'gcc>; + fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize, immediate: bool) -> Type<'gcc>; + fn gcc_field_index(&self, index: usize) -> u64; + fn pointee_info_at<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, offset: Size) -> Option<PointeeInfo>; +} + +impl<'tcx> LayoutGccExt<'tcx> for TyAndLayout<'tcx> { + fn is_gcc_immediate(&self) -> bool { + match self.abi { + Abi::Scalar(_) | Abi::Vector { .. } => true, + Abi::ScalarPair(..) => false, + Abi::Uninhabited | Abi::Aggregate { .. } => self.is_zst(), + } + } + + fn is_gcc_scalar_pair(&self) -> bool { + match self.abi { + Abi::ScalarPair(..) => true, + Abi::Uninhabited | Abi::Scalar(_) | Abi::Vector { .. } | Abi::Aggregate { .. } => false, + } + } + + /// Gets the GCC type corresponding to a Rust type, i.e., `rustc_middle::ty::Ty`. + /// The pointee type of the pointer in `PlaceRef` is always this type. + /// For sized types, it is also the right LLVM type for an `alloca` + /// containing a value of that type, and most immediates (except `bool`). + /// Unsized types, however, are represented by a "minimal unit", e.g. + /// `[T]` becomes `T`, while `str` and `Trait` turn into `i8` - this + /// is useful for indexing slices, as `&[T]`'s data pointer is `T*`. + /// If the type is an unsized struct, the regular layout is generated, + /// with the inner-most trailing unsized field using the "minimal unit" + /// of that field's type - this is useful for taking the address of + /// that field and ensuring the struct has the right alignment. + //TODO(antoyo): do we still need the set_fields parameter? + fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, set_fields: bool) -> Type<'gcc> { + if let Abi::Scalar(ref scalar) = self.abi { + // Use a different cache for scalars because pointers to DSTs + // can be either fat or thin (data pointers of fat pointers). + if let Some(&ty) = cx.scalar_types.borrow().get(&self.ty) { + return ty; + } + let ty = + match *self.ty.kind() { + ty::Ref(_, ty, _) | ty::RawPtr(ty::TypeAndMut { ty, .. }) => { + cx.type_ptr_to(cx.layout_of(ty).gcc_type(cx, set_fields)) + } + ty::Adt(def, _) if def.is_box() => { + cx.type_ptr_to(cx.layout_of(self.ty.boxed_ty()).gcc_type(cx, true)) + } + ty::FnPtr(sig) => cx.fn_ptr_backend_type(&cx.fn_abi_of_fn_ptr(sig, ty::List::empty())), + _ => self.scalar_gcc_type_at(cx, scalar, Size::ZERO), + }; + cx.scalar_types.borrow_mut().insert(self.ty, ty); + return ty; + } + + // Check the cache. + let variant_index = + match self.variants { + Variants::Single { index } => Some(index), + _ => None, + }; + let cached_type = cx.types.borrow().get(&(self.ty, variant_index)).cloned(); + if let Some(ty) = cached_type { + let type_to_set_fields = cx.types_with_fields_to_set.borrow_mut().remove(&ty); + if let Some((struct_type, layout)) = type_to_set_fields { + // Since we might be trying to generate a type containing another type which is not + // completely generated yet, we deferred setting the fields until now. + let (fields, packed) = struct_fields(cx, layout); + cx.set_struct_body(struct_type, &fields, packed); + } + return ty; + } + + assert!(!self.ty.has_escaping_bound_vars(), "{:?} has escaping bound vars", self.ty); + + // Make sure lifetimes are erased, to avoid generating distinct LLVM + // types for Rust types that only differ in the choice of lifetimes. + let normal_ty = cx.tcx.erase_regions(self.ty); + + let mut defer = None; + let ty = + if self.ty != normal_ty { + let mut layout = cx.layout_of(normal_ty); + if let Some(v) = variant_index { + layout = layout.for_variant(cx, v); + } + layout.gcc_type(cx, true) + } + else { + uncached_gcc_type(cx, *self, &mut defer) + }; + + cx.types.borrow_mut().insert((self.ty, variant_index), ty); + + if let Some((ty, layout)) = defer { + let (fields, packed) = struct_fields(cx, layout); + cx.set_struct_body(ty, &fields, packed); + } + + ty + } + + fn immediate_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc> { + if let Abi::Scalar(ref scalar) = self.abi { + if scalar.is_bool() { + return cx.type_i1(); + } + } + self.gcc_type(cx, true) + } + + fn scalar_gcc_type_at<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, scalar: &abi::Scalar, offset: Size) -> Type<'gcc> { + match scalar.primitive() { + Int(i, true) => cx.type_from_integer(i), + Int(i, false) => cx.type_from_unsigned_integer(i), + F32 => cx.type_f32(), + F64 => cx.type_f64(), + Pointer => { + // If we know the alignment, pick something better than i8. + let pointee = + if let Some(pointee) = self.pointee_info_at(cx, offset) { + cx.type_pointee_for_align(pointee.align) + } + else { + cx.type_i8() + }; + cx.type_ptr_to(pointee) + } + } + } + + fn scalar_pair_element_gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, 'tcx>, index: usize, immediate: bool) -> Type<'gcc> { + // TODO(antoyo): remove llvm hack: + // HACK(eddyb) special-case fat pointers until LLVM removes + // pointee types, to avoid bitcasting every `OperandRef::deref`. + match self.ty.kind() { + ty::Ref(..) | ty::RawPtr(_) => { + return self.field(cx, index).gcc_type(cx, true); + } + // only wide pointer boxes are handled as pointers + // thin pointer boxes with scalar allocators are handled by the general logic below + ty::Adt(def, substs) if def.is_box() && cx.layout_of(substs.type_at(1)).is_zst() => { + let ptr_ty = cx.tcx.mk_mut_ptr(self.ty.boxed_ty()); + return cx.layout_of(ptr_ty).scalar_pair_element_gcc_type(cx, index, immediate); + } + _ => {} + } + + let (a, b) = match self.abi { + Abi::ScalarPair(ref a, ref b) => (a, b), + _ => bug!("TyAndLayout::scalar_pair_element_llty({:?}): not applicable", self), + }; + let scalar = [a, b][index]; + + // Make sure to return the same type `immediate_gcc_type` would when + // dealing with an immediate pair. This means that `(bool, bool)` is + // effectively represented as `{i8, i8}` in memory and two `i1`s as an + // immediate, just like `bool` is typically `i8` in memory and only `i1` + // when immediate. We need to load/store `bool` as `i8` to avoid + // crippling LLVM optimizations or triggering other LLVM bugs with `i1`. + // TODO(antoyo): this bugs certainly don't happen in this case since the bool type is used instead of i1. + if scalar.is_bool() { + return cx.type_i1(); + } + + let offset = + if index == 0 { + Size::ZERO + } + else { + a.size(cx).align_to(b.align(cx).abi) + }; + self.scalar_gcc_type_at(cx, scalar, offset) + } + + fn gcc_field_index(&self, index: usize) -> u64 { + match self.abi { + Abi::Scalar(_) | Abi::ScalarPair(..) => { + bug!("TyAndLayout::gcc_field_index({:?}): not applicable", self) + } + _ => {} + } + match self.fields { + FieldsShape::Primitive | FieldsShape::Union(_) => { + bug!("TyAndLayout::gcc_field_index({:?}): not applicable", self) + } + + FieldsShape::Array { .. } => index as u64, + + FieldsShape::Arbitrary { .. } => 1 + (self.fields.memory_index(index) as u64) * 2, + } + } + + fn pointee_info_at<'a>(&self, cx: &CodegenCx<'a, 'tcx>, offset: Size) -> Option<PointeeInfo> { + if let Some(&pointee) = cx.pointee_infos.borrow().get(&(self.ty, offset)) { + return pointee; + } + + let result = Ty::ty_and_layout_pointee_info_at(*self, cx, offset); + + cx.pointee_infos.borrow_mut().insert((self.ty, offset), result); + result + } +} + +impl<'gcc, 'tcx> LayoutTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> { + fn backend_type(&self, layout: TyAndLayout<'tcx>) -> Type<'gcc> { + layout.gcc_type(self, true) + } + + fn immediate_backend_type(&self, layout: TyAndLayout<'tcx>) -> Type<'gcc> { + layout.immediate_gcc_type(self) + } + + fn is_backend_immediate(&self, layout: TyAndLayout<'tcx>) -> bool { + layout.is_gcc_immediate() + } + + fn is_backend_scalar_pair(&self, layout: TyAndLayout<'tcx>) -> bool { + layout.is_gcc_scalar_pair() + } + + fn backend_field_index(&self, layout: TyAndLayout<'tcx>, index: usize) -> u64 { + layout.gcc_field_index(index) + } + + fn scalar_pair_element_backend_type(&self, layout: TyAndLayout<'tcx>, index: usize, immediate: bool) -> Type<'gcc> { + layout.scalar_pair_element_gcc_type(self, index, immediate) + } + + fn cast_backend_type(&self, ty: &CastTarget) -> Type<'gcc> { + ty.gcc_type(self) + } + + fn fn_ptr_backend_type(&self, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Type<'gcc> { + fn_abi.ptr_to_gcc_type(self) + } + + fn reg_backend_type(&self, _ty: &Reg) -> Type<'gcc> { + unimplemented!(); + } + + fn fn_decl_backend_type(&self, _fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Type<'gcc> { + // FIXME(antoyo): return correct type. + self.type_void() + } +} |