use crate::common::*;
use crate::type_::Type;
use rustc::hir;
+use abi::{FnType, FnTypeExt};
+use common::*;
use rustc::ty::{self, Ty, TypeFoldable};
-use rustc::ty::layout::{self, Align, LayoutOf, Size, TyLayout};
-use rustc_target::abi::FloatTy;
+use rustc::ty::layout::{self, Align, LayoutOf, PointeeInfo, Size, TyLayout};
+use rustc_target::abi::{FloatTy, TyLayoutMethods};
use rustc_mir::monomorphize::item::DefPathBasedNames;
use rustc_codegen_ssa::traits::*;
}
}
-#[derive(Copy, Clone, PartialEq, Eq)]
-pub enum PointerKind {
- /// Most general case, we know no restrictions to tell LLVM.
- Shared,
-
- /// `&T` where `T` contains no `UnsafeCell`, is `noalias` and `readonly`.
- Frozen,
-
- /// `&mut T`, when we know `noalias` is safe for LLVM.
- UniqueBorrowed,
-
- /// `Box<T>`, unlike `UniqueBorrowed`, it also has `noalias` on returns.
- UniqueOwned
-}
-
-#[derive(Copy, Clone)]
-pub struct PointeeInfo {
- pub size: Size,
- pub align: Align,
- pub safe: Option<PointerKind>,
-}
-
pub trait LayoutLlvmExt<'tcx> {
fn is_llvm_immediate(&self) -> bool;
fn is_llvm_scalar_pair<'a>(&self) -> bool;
return pointee;
}
- let mut result = None;
- match self.ty.sty {
- ty::RawPtr(mt) if offset.bytes() == 0 => {
- let (size, align) = cx.size_and_align_of(mt.ty);
- result = Some(PointeeInfo {
- size,
- align,
- safe: None
- });
- }
-
- ty::Ref(_, ty, mt) if offset.bytes() == 0 => {
- let (size, align) = cx.size_and_align_of(ty);
-
- let kind = match mt {
- hir::MutImmutable => if cx.type_is_freeze(ty) {
- PointerKind::Frozen
- } else {
- PointerKind::Shared
- },
- hir::MutMutable => {
- // Previously we would only emit noalias annotations for LLVM >= 6 or in
- // panic=abort mode. That was deemed right, as prior versions had many bugs
- // in conjunction with unwinding, but later versions didn’t seem to have
- // said issues. See issue #31681.
- //
- // Alas, later on we encountered a case where noalias would generate wrong
- // code altogether even with recent versions of LLVM in *safe* code with no
- // unwinding involved. See #54462.
- //
- // For now, do not enable mutable_noalias by default at all, while the
- // issue is being figured out.
- let mutable_noalias = cx.tcx.sess.opts.debugging_opts.mutable_noalias
- .unwrap_or(false);
- if mutable_noalias {
- PointerKind::UniqueBorrowed
- } else {
- PointerKind::Shared
- }
- }
- };
-
- result = Some(PointeeInfo {
- size,
- align,
- safe: Some(kind)
- });
- }
-
- _ => {
- let mut data_variant = match self.variants {
- // Within the discriminant field, only the niche itself is
- // always initialized, so we only check for a pointer at its
- // offset.
- //
- // If the niche is a pointer, it's either valid (according
- // to its type), or null (which the niche field's scalar
- // validity range encodes). This allows using
- // `dereferenceable_or_null` for e.g., `Option<&T>`, and
- // this will continue to work as long as we don't start
- // using more niches than just null (e.g., the first page of
- // the address space, or unaligned pointers).
- layout::Variants::Multiple {
- discr_kind: layout::DiscriminantKind::Niche {
- dataful_variant,
- ..
- },
- discr_index,
- ..
- } if self.fields.offset(discr_index) == offset =>
- Some(self.for_variant(cx, dataful_variant)),
- _ => Some(*self),
- };
-
- if let Some(variant) = data_variant {
- // We're not interested in any unions.
- if let layout::FieldPlacement::Union(_) = variant.fields {
- data_variant = None;
- }
- }
-
- if let Some(variant) = data_variant {
- let ptr_end = offset + layout::Pointer.size(cx);
- for i in 0..variant.fields.count() {
- let field_start = variant.fields.offset(i);
- if field_start <= offset {
- let field = variant.field(cx, i);
- if ptr_end <= field_start + field.size {
- // We found the right field, look inside it.
- result = field.pointee_info_at(cx, offset - field_start);
- break;
- }
- }
- }
- }
-
- // FIXME(eddyb) This should be for `ptr::Unique<T>`, not `Box<T>`.
- if let Some(ref mut pointee) = result {
- if let ty::Adt(def, _) = self.ty.sty {
- if def.is_box() && offset.bytes() == 0 {
- pointee.safe = Some(PointerKind::UniqueOwned);
- }
- }
- }
- }
- }
+ let result = Ty::pointee_info_at(*self, cx, offset);
cx.pointee_infos.borrow_mut().insert((self.ty, offset), result);
result