bjoernager/rust
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Update other codegens to use tcx managed vtable allocations.

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This commit is contained in:
Charles Lew 2021-06-20 17:43:25 +08:00
parent 654e3345e5
commit d3ff497bec
12 changed files with 144 additions and 250 deletions
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43
compiler/rustc_codegen_ssa/src/meth.rs
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@ -1,6 +1,6 @@
use crate::traits::*;
use rustc_middle::ty::{self, Instance, Ty, VtblEntry, COMMON_VTABLE_ENTRIES};
use rustc_middle::ty::{self, Ty};
use rustc_target::abi::call::FnAbi;
#[derive(Copy, Clone, Debug)]
@ -70,48 +70,13 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
return val;
}
// Not in the cache; build it.
let nullptr = cx.const_null(cx.type_i8p_ext(cx.data_layout().instruction_address_space));
let vtable_entries = if let Some(trait_ref) = trait_ref {
tcx.vtable_entries(trait_ref.with_self_ty(tcx, ty))
} else {
COMMON_VTABLE_ENTRIES
};
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<_> = 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 vtable_alloc_id = tcx.vtable_allocation(ty, trait_ref);
let vtable_allocation = tcx.global_alloc(vtable_alloc_id).unwrap_memory();
let vtable_const = cx.const_data_from_alloc(vtable_allocation);
let align = cx.data_layout().pointer_align.abi;
let vtable = cx.static_addr_of(vtable_const, align, Some("vtable"));
cx.create_vtable_metadata(ty, vtable);
cx.vtables().borrow_mut().insert((ty, trait_ref), vtable);
vtable
}