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Generalized base::coerce_unsized_into

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This commit is contained in:
Denis Merigoux 2018-09-14 17:48:57 +02:00 • committed by Eduard-Mihai Burtescu
parent 78dd95f4c7
commit cbe31a4229
15 changed files with 184 additions and 145 deletions
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26
src/librustc_codegen_llvm/base.rs
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@ -65,7 +65,7 @@ use monomorphize::partitioning::{CodegenUnit, CodegenUnitExt};
use rustc_codegen_utils::symbol_names_test;
use time_graph;
use mono_item::{MonoItem, MonoItemExt};
use type_of::LayoutLlvmExt;
use rustc::util::nodemap::FxHashMap;
use CrateInfo;
use rustc_data_structures::small_c_str::SmallCStr;
@ -208,7 +208,7 @@ pub fn unsized_info<'tcx, Cx: CodegenMethods<'tcx>>(
let vtable_ptr = cx.layout_of(cx.tcx().mk_mut_ptr(target))
.field(cx, abi::FAT_PTR_EXTRA);
cx.static_ptrcast(meth::get_vtable(cx, source, data.principal()),
cx.backend_type(&vtable_ptr))
cx.backend_type(vtable_ptr))
}
_ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
source,
@ -232,13 +232,13 @@ pub fn unsize_thin_ptr<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
(&ty::RawPtr(ty::TypeAndMut { ty: a, .. }),
&ty::RawPtr(ty::TypeAndMut { ty: b, .. })) => {
assert!(bx.cx().type_is_sized(a));
let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(&bx.cx().layout_of(b)));
let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
(bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
}
(&ty::Adt(def_a, _), &ty::Adt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
let (a, b) = (src_ty.boxed_ty(), dst_ty.boxed_ty());
assert!(bx.cx().type_is_sized(a));
let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(&bx.cx().layout_of(b)));
let ptr_ty = bx.cx().type_ptr_to(bx.cx().backend_type(bx.cx().layout_of(b)));
(bx.pointercast(src, ptr_ty), unsized_info(bx.cx(), a, b, None))
}
(&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
@ -263,8 +263,8 @@ pub fn unsize_thin_ptr<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
}
let (lldata, llextra) = result.unwrap();
// HACK(eddyb) have to bitcast pointers until LLVM removes pointee types.
(bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(&dst_layout, 0, true)),
bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(&dst_layout, 1, true)))
(bx.bitcast(lldata, bx.cx().scalar_pair_element_backend_type(dst_layout, 0, true)),
bx.bitcast(llextra, bx.cx().scalar_pair_element_backend_type(dst_layout, 1, true)))
}
_ => bug!("unsize_thin_ptr: called on bad types"),
}
@ -272,22 +272,22 @@ pub fn unsize_thin_ptr<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
/// Coerce `src`, which is a reference to a value of type `src_ty`,
/// to a value of type `dst_ty` and store the result in `dst`
pub fn coerce_unsized_into(
bx: &Builder<'a, 'll, 'tcx>,
src: PlaceRef<'tcx, &'ll Value>,
dst: PlaceRef<'tcx, &'ll Value>
) {
pub fn coerce_unsized_into<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
bx: &Bx,
src: PlaceRef<'tcx, Bx::Value>,
dst: PlaceRef<'tcx, Bx::Value>
) {
let src_ty = src.layout.ty;
let dst_ty = dst.layout.ty;
let coerce_ptr = || {
let (base, info) = match src.load(bx).val {
let (base, info) = match bx.load_operand(src).val {
OperandValue::Pair(base, info) => {
// fat-ptr to fat-ptr unsize preserves the vtable
// i.e. &'a fmt::Debug+Send => &'a fmt::Debug
// So we need to pointercast the base to ensure
// the types match up.
let thin_ptr = dst.layout.field(bx.cx(), abi::FAT_PTR_ADDR);
(bx.pointercast(base, thin_ptr.llvm_type(bx.cx())), info)
(bx.pointercast(base, bx.cx().backend_type(thin_ptr)), info)
}
OperandValue::Immediate(base) => {
unsize_thin_ptr(bx, base, src_ty, dst_ty)