bjoernager/rust
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Refactor to make interpreter and codegen backend neutral to vtable internal representation.

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This commit is contained in:
Charles Lew 2021-06-14 18:02:53 +08:00
parent 14831568d5
commit a86d3a7e45
10 changed files with 246 additions and 177 deletions
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7
compiler/rustc_codegen_ssa/src/glue.rs
View file

@ -23,7 +23,12 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
ty::Dynamic(..) => {
// load size/align from vtable
let vtable = info.unwrap();
(meth::SIZE.get_usize(bx, vtable), meth::ALIGN.get_usize(bx, vtable))
(
meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_SIZE)
.get_usize(bx, vtable),
meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_ALIGN)
.get_usize(bx, vtable),
)
}
ty::Slice(_) | ty::Str => {
let unit = layout.field(bx, 0);

61
compiler/rustc_codegen_ssa/src/meth.rs
View file

@ -1,18 +1,14 @@
use crate::traits::*;
use rustc_middle::ty::{self, Instance, Ty};
use rustc_middle::ty::{self, Instance, Ty, VtblEntry, COMMON_VTABLE_ENTRIES};
use rustc_target::abi::call::FnAbi;
#[derive(Copy, Clone, Debug)]
pub struct VirtualIndex(u64);
pub const DESTRUCTOR: VirtualIndex = VirtualIndex(0);
pub const SIZE: VirtualIndex = VirtualIndex(1);
pub const ALIGN: VirtualIndex = VirtualIndex(2);
impl<'a, 'tcx> VirtualIndex {
pub fn from_index(index: usize) -> Self {
VirtualIndex(index as u64 + 3)
VirtualIndex(index as u64)
}
pub fn get_fn<Bx: BuilderMethods<'a, 'tcx>>(
@ -77,43 +73,38 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
// Not in the cache; build it.
let nullptr = cx.const_null(cx.type_i8p_ext(cx.data_layout().instruction_address_space));
let methods_root;
let methods = if let Some(trait_ref) = trait_ref {
methods_root = tcx.vtable_methods(trait_ref.with_self_ty(tcx, ty));
methods_root.iter()
let vtable_entries = if let Some(trait_ref) = trait_ref {
tcx.vtable_entries(trait_ref.with_self_ty(tcx, ty))
} else {
(&[]).iter()
COMMON_VTABLE_ENTRIES
};
let methods = methods.cloned().map(|opt_mth| {
opt_mth.map_or(nullptr, |(def_id, substs)| {
cx.get_fn_addr(
ty::Instance::resolve_for_vtable(
cx.tcx(),
ty::ParamEnv::reveal_all(),
def_id,
substs,
)
.unwrap()
.polymorphize(cx.tcx()),
)
})
});
let layout = cx.layout_of(ty);
// /////////////////////////////////////////////////////////////////////////////////////////////
// If you touch this code, be sure to also make the corresponding changes to
// `get_vtable` in `rust_mir/interpret/traits.rs`.
// /////////////////////////////////////////////////////////////////////////////////////////////
let components: Vec<_> = [
cx.get_fn_addr(Instance::resolve_drop_in_place(cx.tcx(), ty)),
cx.const_usize(layout.size.bytes()),
cx.const_usize(layout.align.abi.bytes()),
]
.iter()
.cloned()
.chain(methods)
.collect();
let components: Vec<_> = vtable_entries
.iter()
.map(|entry| match entry {
VtblEntry::MetadataDropInPlace => {
cx.get_fn_addr(Instance::resolve_drop_in_place(cx.tcx(), ty))
}
VtblEntry::MetadataSize => cx.const_usize(layout.size.bytes()),
VtblEntry::MetadataAlign => cx.const_usize(layout.align.abi.bytes()),
VtblEntry::Vacant => nullptr,
VtblEntry::Method(def_id, substs) => cx.get_fn_addr(
ty::Instance::resolve_for_vtable(
cx.tcx(),
ty::ParamEnv::reveal_all(),
*def_id,
substs,
)
.unwrap()
.polymorphize(cx.tcx()),
),
})
.collect();
let vtable_const = cx.const_struct(&components, false);
let align = cx.data_layout().pointer_align.abi;

6
compiler/rustc_codegen_ssa/src/mir/block.rs
View file

@ -332,7 +332,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let fn_abi = FnAbi::of_instance(&bx, virtual_drop, &[]);
let vtable = args[1];
args = &args[..1];
(meth::DESTRUCTOR.get_fn(&mut bx, vtable, &fn_abi), fn_abi)
(
meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE)
.get_fn(&mut bx, vtable, &fn_abi),
fn_abi,
)
}
_ => (bx.get_fn_addr(drop_fn), FnAbi::of_instance(&bx, drop_fn, &[])),
};