| // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| #![allow(non_camel_case_types)] |
| |
| use rustc::hir::def_id::DefId; |
| use rustc::ty::subst; |
| use abi::FnType; |
| use adt; |
| use common::*; |
| use machine; |
| use rustc::traits::ProjectionMode; |
| use rustc::ty::{self, Ty, TypeFoldable}; |
| |
| use type_::Type; |
| |
| use syntax::ast; |
| |
| // LLVM doesn't like objects that are too big. Issue #17913 |
| fn ensure_array_fits_in_address_space<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, |
| llet: Type, |
| size: machine::llsize, |
| scapegoat: Ty<'tcx>) { |
| let esz = machine::llsize_of_alloc(ccx, llet); |
| match esz.checked_mul(size) { |
| Some(n) if n < ccx.obj_size_bound() => {} |
| _ => { ccx.report_overbig_object(scapegoat) } |
| } |
| } |
| |
| // A "sizing type" is an LLVM type, the size and alignment of which are |
| // guaranteed to be equivalent to what you would get out of `type_of()`. It's |
| // useful because: |
| // |
| // (1) It may be cheaper to compute the sizing type than the full type if all |
| // you're interested in is the size and/or alignment; |
| // |
| // (2) It won't make any recursive calls to determine the structure of the |
| // type behind pointers. This can help prevent infinite loops for |
| // recursive types. For example, enum types rely on this behavior. |
| |
| pub fn sizing_type_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>) -> Type { |
| if let Some(t) = cx.llsizingtypes().borrow().get(&t).cloned() { |
| return t; |
| } |
| |
| debug!("sizing_type_of {:?}", t); |
| let _recursion_lock = cx.enter_type_of(t); |
| |
| let llsizingty = match t.sty { |
| _ if !type_is_sized(cx.tcx(), t) => { |
| Type::struct_(cx, &[Type::i8p(cx), unsized_info_ty(cx, t)], false) |
| } |
| |
| ty::TyBool => Type::bool(cx), |
| ty::TyChar => Type::char(cx), |
| ty::TyInt(t) => Type::int_from_ty(cx, t), |
| ty::TyUint(t) => Type::uint_from_ty(cx, t), |
| ty::TyFloat(t) => Type::float_from_ty(cx, t), |
| |
| ty::TyBox(ty) | |
| ty::TyRef(_, ty::TypeAndMut{ty, ..}) | |
| ty::TyRawPtr(ty::TypeAndMut{ty, ..}) => { |
| if type_is_sized(cx.tcx(), ty) { |
| Type::i8p(cx) |
| } else { |
| Type::struct_(cx, &[Type::i8p(cx), unsized_info_ty(cx, ty)], false) |
| } |
| } |
| |
| ty::TyFnDef(..) => Type::nil(cx), |
| ty::TyFnPtr(_) => Type::i8p(cx), |
| |
| ty::TyArray(ty, size) => { |
| let llty = sizing_type_of(cx, ty); |
| let size = size as u64; |
| ensure_array_fits_in_address_space(cx, llty, size, t); |
| Type::array(&llty, size) |
| } |
| |
| ty::TyTuple(ref tys) if tys.is_empty() => { |
| Type::nil(cx) |
| } |
| |
| ty::TyTuple(..) | ty::TyEnum(..) | ty::TyClosure(..) => { |
| let repr = adt::represent_type(cx, t); |
| adt::sizing_type_of(cx, &repr, false) |
| } |
| |
| ty::TyStruct(..) => { |
| if t.is_simd() { |
| let e = t.simd_type(cx.tcx()); |
| if !e.is_machine() { |
| cx.sess().fatal(&format!("monomorphising SIMD type `{}` with \ |
| a non-machine element type `{}`", |
| t, e)) |
| } |
| let llet = type_of(cx, e); |
| let n = t.simd_size(cx.tcx()) as u64; |
| ensure_array_fits_in_address_space(cx, llet, n, t); |
| Type::vector(&llet, n) |
| } else { |
| let repr = adt::represent_type(cx, t); |
| adt::sizing_type_of(cx, &repr, false) |
| } |
| } |
| |
| ty::TyProjection(..) | ty::TyInfer(..) | ty::TyParam(..) | ty::TyError => { |
| bug!("fictitious type {:?} in sizing_type_of()", t) |
| } |
| ty::TySlice(_) | ty::TyTrait(..) | ty::TyStr => bug!() |
| }; |
| |
| debug!("--> mapped t={:?} to llsizingty={:?}", t, llsizingty); |
| |
| cx.llsizingtypes().borrow_mut().insert(t, llsizingty); |
| |
| // FIXME(eddyb) Temporary sanity check for ty::layout. |
| let layout = cx.tcx().normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| { |
| t.layout(&infcx) |
| }); |
| match layout { |
| Ok(layout) => { |
| if !type_is_sized(cx.tcx(), t) { |
| if !layout.is_unsized() { |
| bug!("layout should be unsized for type `{}` / {:#?}", |
| t, layout); |
| } |
| |
| // Unsized types get turned into a fat pointer for LLVM. |
| return llsizingty; |
| } |
| let r = layout.size(&cx.tcx().data_layout).bytes(); |
| let l = machine::llsize_of_alloc(cx, llsizingty); |
| if r != l { |
| bug!("size differs (rustc: {}, llvm: {}) for type `{}` / {:#?}", |
| r, l, t, layout); |
| } |
| let r = layout.align(&cx.tcx().data_layout).abi(); |
| let l = machine::llalign_of_min(cx, llsizingty) as u64; |
| if r != l { |
| bug!("align differs (rustc: {}, llvm: {}) for type `{}` / {:#?}", |
| r, l, t, layout); |
| } |
| } |
| Err(e) => { |
| bug!("failed to get layout for `{}`: {}", t, e); |
| } |
| } |
| llsizingty |
| } |
| |
| pub fn fat_ptr_base_ty<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> Type { |
| match ty.sty { |
| ty::TyBox(t) | |
| ty::TyRef(_, ty::TypeAndMut { ty: t, .. }) | |
| ty::TyRawPtr(ty::TypeAndMut { ty: t, .. }) if !type_is_sized(ccx.tcx(), t) => { |
| in_memory_type_of(ccx, t).ptr_to() |
| } |
| _ => bug!("expected fat ptr ty but got {:?}", ty) |
| } |
| } |
| |
| fn unsized_info_ty<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> Type { |
| let unsized_part = ccx.tcx().struct_tail(ty); |
| match unsized_part.sty { |
| ty::TyStr | ty::TyArray(..) | ty::TySlice(_) => { |
| Type::uint_from_ty(ccx, ast::UintTy::Us) |
| } |
| ty::TyTrait(_) => Type::vtable_ptr(ccx), |
| _ => bug!("Unexpected tail in unsized_info_ty: {:?} for ty={:?}", |
| unsized_part, ty) |
| } |
| } |
| |
| pub fn immediate_type_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>) -> Type { |
| if t.is_bool() { |
| Type::i1(cx) |
| } else { |
| type_of(cx, t) |
| } |
| } |
| |
| /// Get the LLVM type corresponding to a Rust type, i.e. `rustc::ty::Ty`. |
| /// This is the right LLVM type for an alloca containing a value of that type, |
| /// and the pointee of an Lvalue Datum (which is always a LLVM pointer). |
| /// For unsized types, the returned type is a fat pointer, thus the resulting |
| /// LLVM type for a `Trait` Lvalue is `{ i8*, void(i8*)** }*`, which is a double |
| /// indirection to the actual data, unlike a `i8` Lvalue, which is just `i8*`. |
| /// This is needed due to the treatment of immediate values, as a fat pointer |
| /// is too large for it to be placed in SSA value (by our rules). |
| /// For the raw type without far pointer indirection, see `in_memory_type_of`. |
| pub fn type_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, ty: Ty<'tcx>) -> Type { |
| let ty = if !type_is_sized(cx.tcx(), ty) { |
| cx.tcx().mk_imm_ptr(ty) |
| } else { |
| ty |
| }; |
| in_memory_type_of(cx, ty) |
| } |
| |
| /// Get the LLVM type corresponding to a Rust type, i.e. `rustc::ty::Ty`. |
| /// This is the right LLVM type for a field/array element of that type, |
| /// and is the same as `type_of` for all Sized types. |
| /// 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. |
| /// For the LLVM type of a value as a whole, see `type_of`. |
| /// NB: If you update this, be sure to update `sizing_type_of()` as well. |
| pub fn in_memory_type_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>) -> Type { |
| // Check the cache. |
| if let Some(&llty) = cx.lltypes().borrow().get(&t) { |
| return llty; |
| } |
| |
| debug!("type_of {:?}", t); |
| |
| assert!(!t.has_escaping_regions(), "{:?} has escaping regions", t); |
| |
| // Replace any typedef'd types with their equivalent non-typedef |
| // type. This ensures that all LLVM nominal types that contain |
| // Rust types are defined as the same LLVM types. If we don't do |
| // this then, e.g. `Option<{myfield: bool}>` would be a different |
| // type than `Option<myrec>`. |
| let t_norm = cx.tcx().erase_regions(&t); |
| |
| if t != t_norm { |
| let llty = in_memory_type_of(cx, t_norm); |
| debug!("--> normalized {:?} to {:?} llty={:?}", t, t_norm, llty); |
| cx.lltypes().borrow_mut().insert(t, llty); |
| return llty; |
| } |
| |
| let mut llty = match t.sty { |
| ty::TyBool => Type::bool(cx), |
| ty::TyChar => Type::char(cx), |
| ty::TyInt(t) => Type::int_from_ty(cx, t), |
| ty::TyUint(t) => Type::uint_from_ty(cx, t), |
| ty::TyFloat(t) => Type::float_from_ty(cx, t), |
| ty::TyEnum(def, ref substs) => { |
| // Only create the named struct, but don't fill it in. We |
| // fill it in *after* placing it into the type cache. This |
| // avoids creating more than one copy of the enum when one |
| // of the enum's variants refers to the enum itself. |
| let repr = adt::represent_type(cx, t); |
| let tps = substs.types.get_slice(subst::TypeSpace); |
| let name = llvm_type_name(cx, def.did, tps); |
| adt::incomplete_type_of(cx, &repr, &name[..]) |
| } |
| ty::TyClosure(..) => { |
| // Only create the named struct, but don't fill it in. We |
| // fill it in *after* placing it into the type cache. |
| let repr = adt::represent_type(cx, t); |
| // Unboxed closures can have substitutions in all spaces |
| // inherited from their environment, so we use entire |
| // contents of the VecPerParamSpace to construct the llvm |
| // name |
| adt::incomplete_type_of(cx, &repr, "closure") |
| } |
| |
| ty::TyBox(ty) | |
| ty::TyRef(_, ty::TypeAndMut{ty, ..}) | |
| ty::TyRawPtr(ty::TypeAndMut{ty, ..}) => { |
| if !type_is_sized(cx.tcx(), ty) { |
| if let ty::TyStr = ty.sty { |
| // This means we get a nicer name in the output (str is always |
| // unsized). |
| cx.tn().find_type("str_slice").unwrap() |
| } else { |
| let ptr_ty = in_memory_type_of(cx, ty).ptr_to(); |
| let info_ty = unsized_info_ty(cx, ty); |
| Type::struct_(cx, &[ptr_ty, info_ty], false) |
| } |
| } else { |
| in_memory_type_of(cx, ty).ptr_to() |
| } |
| } |
| |
| ty::TyArray(ty, size) => { |
| let size = size as u64; |
| // we must use `sizing_type_of` here as the type may |
| // not be fully initialized. |
| let szty = sizing_type_of(cx, ty); |
| ensure_array_fits_in_address_space(cx, szty, size, t); |
| |
| let llty = in_memory_type_of(cx, ty); |
| Type::array(&llty, size) |
| } |
| |
| // Unsized slice types (and str) have the type of their element, and |
| // traits have the type of u8. This is so that the data pointer inside |
| // fat pointers is of the right type (e.g. for array accesses), even |
| // when taking the address of an unsized field in a struct. |
| ty::TySlice(ty) => in_memory_type_of(cx, ty), |
| ty::TyStr | ty::TyTrait(..) => Type::i8(cx), |
| |
| ty::TyFnDef(..) => Type::nil(cx), |
| ty::TyFnPtr(f) => { |
| let sig = cx.tcx().erase_late_bound_regions(&f.sig); |
| let sig = cx.tcx().normalize_associated_type(&sig); |
| FnType::new(cx, f.abi, &sig, &[]).llvm_type(cx).ptr_to() |
| } |
| ty::TyTuple(ref tys) if tys.is_empty() => Type::nil(cx), |
| ty::TyTuple(..) => { |
| let repr = adt::represent_type(cx, t); |
| adt::type_of(cx, &repr) |
| } |
| ty::TyStruct(def, ref substs) => { |
| if t.is_simd() { |
| let e = t.simd_type(cx.tcx()); |
| if !e.is_machine() { |
| cx.sess().fatal(&format!("monomorphising SIMD type `{}` with \ |
| a non-machine element type `{}`", |
| t, e)) |
| } |
| let llet = in_memory_type_of(cx, e); |
| let n = t.simd_size(cx.tcx()) as u64; |
| ensure_array_fits_in_address_space(cx, llet, n, t); |
| Type::vector(&llet, n) |
| } else { |
| // Only create the named struct, but don't fill it in. We fill it |
| // in *after* placing it into the type cache. This prevents |
| // infinite recursion with recursive struct types. |
| let repr = adt::represent_type(cx, t); |
| let tps = substs.types.get_slice(subst::TypeSpace); |
| let name = llvm_type_name(cx, def.did, tps); |
| adt::incomplete_type_of(cx, &repr, &name[..]) |
| } |
| } |
| |
| ty::TyInfer(..) => bug!("type_of with TyInfer"), |
| ty::TyProjection(..) => bug!("type_of with TyProjection"), |
| ty::TyParam(..) => bug!("type_of with ty_param"), |
| ty::TyError => bug!("type_of with TyError"), |
| }; |
| |
| debug!("--> mapped t={:?} to llty={:?}", t, llty); |
| |
| cx.lltypes().borrow_mut().insert(t, llty); |
| |
| // If this was an enum or struct, fill in the type now. |
| match t.sty { |
| ty::TyEnum(..) | ty::TyStruct(..) | ty::TyClosure(..) |
| if !t.is_simd() => { |
| let repr = adt::represent_type(cx, t); |
| adt::finish_type_of(cx, &repr, &mut llty); |
| } |
| _ => () |
| } |
| |
| llty |
| } |
| |
| pub fn align_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, t: Ty<'tcx>) |
| -> machine::llalign { |
| let llty = sizing_type_of(cx, t); |
| machine::llalign_of_min(cx, llty) |
| } |
| |
| fn llvm_type_name<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, |
| did: DefId, |
| tps: &[Ty<'tcx>]) |
| -> String { |
| let base = cx.tcx().item_path_str(did); |
| let strings: Vec<String> = tps.iter().map(|t| t.to_string()).collect(); |
| let tstr = if strings.is_empty() { |
| base |
| } else { |
| format!("{}<{}>", base, strings.join(", ")) |
| }; |
| |
| if did.krate == 0 { |
| tstr |
| } else { |
| format!("{}.{}", did.krate, tstr) |
| } |
| } |
