//! Codegen vtables and vtable accesses.
//!
//! See `rustc_codegen_ssa/src/meth.rs` for reference.
-// FIXME dedup this logic between miri, cg_llvm and cg_clif
+use crate::constant::data_id_for_alloc_id;
use crate::prelude::*;
-use ty::VtblEntry;
-fn vtable_memflags() -> MemFlags {
+pub(crate) fn vtable_memflags() -> MemFlags {
let mut flags = MemFlags::trusted(); // A vtable access is always aligned and will never trap.
flags.set_readonly(); // A vtable is always read-only.
flags
pub(crate) fn drop_fn_of_obj(fx: &mut FunctionCx<'_, '_, '_>, vtable: Value) -> Value {
let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
fx.bcx.ins().load(
- pointer_ty(fx.tcx),
+ fx.pointer_type,
vtable_memflags(),
vtable,
(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE * usize_size) as i32,
pub(crate) fn size_of_obj(fx: &mut FunctionCx<'_, '_, '_>, vtable: Value) -> Value {
let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
fx.bcx.ins().load(
- pointer_ty(fx.tcx),
+ fx.pointer_type,
vtable_memflags(),
vtable,
(ty::COMMON_VTABLE_ENTRIES_SIZE * usize_size) as i32,
pub(crate) fn min_align_of_obj(fx: &mut FunctionCx<'_, '_, '_>, vtable: Value) -> Value {
let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
fx.bcx.ins().load(
- pointer_ty(fx.tcx),
+ fx.pointer_type,
vtable_memflags(),
vtable,
- (ty::COMMON_VTABLE_ENTRIES_SIZE * usize_size) as i32,
+ (ty::COMMON_VTABLE_ENTRIES_ALIGN * usize_size) as i32,
)
}
let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes();
let func_ref = fx.bcx.ins().load(
- pointer_ty(fx.tcx),
+ fx.pointer_type,
vtable_memflags(),
vtable,
(idx * usize_size as usize) as i32,
pub(crate) fn get_vtable<'tcx>(
fx: &mut FunctionCx<'_, '_, 'tcx>,
- layout: TyAndLayout<'tcx>,
+ ty: Ty<'tcx>,
trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
) -> Value {
- let data_id = if let Some(data_id) = fx.vtables.get(&(layout.ty, trait_ref)) {
- *data_id
- } else {
- let data_id = build_vtable(fx, layout, trait_ref);
- fx.vtables.insert((layout.ty, trait_ref), data_id);
- data_id
- };
-
+ let alloc_id = fx.tcx.vtable_allocation((ty, trait_ref));
+ let data_id =
+ data_id_for_alloc_id(&mut fx.constants_cx, &mut *fx.module, alloc_id, Mutability::Not);
let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
- fx.bcx.ins().global_value(fx.pointer_type, local_data_id)
-}
-
-fn build_vtable<'tcx>(
- fx: &mut FunctionCx<'_, '_, 'tcx>,
- layout: TyAndLayout<'tcx>,
- trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
-) -> DataId {
- let tcx = fx.tcx;
- let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
-
- let drop_in_place_fn = import_function(
- tcx,
- fx.module,
- Instance::resolve_drop_in_place(tcx, layout.ty).polymorphize(fx.tcx),
- );
-
- let vtable_entries = if let Some(trait_ref) = trait_ref {
- tcx.vtable_entries(trait_ref.with_self_ty(tcx, layout.ty))
- } else {
- ty::COMMON_VTABLE_ENTRIES
- };
-
- let mut data_ctx = DataContext::new();
- let mut data = ::std::iter::repeat(0u8)
- .take(vtable_entries.len() * usize_size)
- .collect::<Vec<u8>>()
- .into_boxed_slice();
-
- for (idx, entry) in vtable_entries.iter().enumerate() {
- match entry {
- VtblEntry::MetadataSize => {
- write_usize(fx.tcx, &mut data, idx, layout.size.bytes());
- }
- VtblEntry::MetadataAlign => {
- write_usize(fx.tcx, &mut data, idx, layout.align.abi.bytes());
- }
- VtblEntry::MetadataDropInPlace | VtblEntry::Vacant | VtblEntry::Method(_, _) => {}
- }
- }
- data_ctx.define(data);
-
- for (idx, entry) in vtable_entries.iter().enumerate() {
- match entry {
- VtblEntry::MetadataDropInPlace => {
- let func_ref = fx.module.declare_func_in_data(drop_in_place_fn, &mut data_ctx);
- data_ctx.write_function_addr((idx * usize_size) as u32, func_ref);
- }
- VtblEntry::Method(def_id, substs) => {
- let func_id = import_function(
- tcx,
- fx.module,
- Instance::resolve_for_vtable(tcx, ParamEnv::reveal_all(), *def_id, substs)
- .unwrap()
- .polymorphize(fx.tcx),
- );
- let func_ref = fx.module.declare_func_in_data(func_id, &mut data_ctx);
- data_ctx.write_function_addr((idx * usize_size) as u32, func_ref);
- }
- VtblEntry::MetadataSize | VtblEntry::MetadataAlign | VtblEntry::Vacant => {}
- }
- }
-
- data_ctx.set_align(fx.tcx.data_layout.pointer_align.pref.bytes());
-
- let data_id = fx.module.declare_anonymous_data(false, false).unwrap();
-
- fx.module.define_data(data_id, &data_ctx).unwrap();
-
- data_id
-}
-
-fn write_usize(tcx: TyCtxt<'_>, buf: &mut [u8], idx: usize, num: u64) {
- let pointer_size =
- tcx.layout_of(ParamEnv::reveal_all().and(tcx.types.usize)).unwrap().size.bytes() as usize;
- let target = &mut buf[idx * pointer_size..(idx + 1) * pointer_size];
-
- match tcx.data_layout.endian {
- rustc_target::abi::Endian::Little => match pointer_size {
- 4 => target.copy_from_slice(&(num as u32).to_le_bytes()),
- 8 => target.copy_from_slice(&(num as u64).to_le_bytes()),
- _ => todo!("pointer size {} is not yet supported", pointer_size),
- },
- rustc_target::abi::Endian::Big => match pointer_size {
- 4 => target.copy_from_slice(&(num as u32).to_be_bytes()),
- 8 => target.copy_from_slice(&(num as u64).to_be_bytes()),
- _ => todo!("pointer size {} is not yet supported", pointer_size),
- },
+ if fx.clif_comments.enabled() {
+ fx.add_comment(local_data_id, format!("vtable: {:?}", alloc_id));
}
+ fx.bcx.ins().global_value(fx.pointer_type, local_data_id)
}
projects / rust.git / blobdiff