+//! Codegen vtables and vtable accesses.
+//!
//! See librustc_codegen_llvm/meth.rs for reference
+// FIXME dedup this logic between miri, cg_llvm and cg_clif
use crate::prelude::*;
const SIZE_INDEX: usize = 1;
const ALIGN_INDEX: usize = 2;
-pub fn drop_fn_of_obj(
- fx: &mut FunctionCx<'_, '_, impl Backend>,
- vtable: Value,
-) -> Value {
+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<'_, '_, impl Backend>, 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),
- MemFlags::new(),
+ vtable_memflags(),
vtable,
(DROP_FN_INDEX * usize_size) as i32,
)
}
-pub fn size_of_obj(
- fx: &mut FunctionCx<'_, '_, impl Backend>,
- vtable: Value,
-) -> Value {
+pub(crate) fn size_of_obj(fx: &mut FunctionCx<'_, '_, impl Backend>, 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),
- MemFlags::new(),
+ vtable_memflags(),
vtable,
(SIZE_INDEX * usize_size) as i32,
)
}
-pub fn min_align_of_obj(
- fx: &mut FunctionCx<'_, '_, impl Backend>,
- vtable: Value,
-) -> Value {
+pub(crate) fn min_align_of_obj(fx: &mut FunctionCx<'_, '_, impl Backend>, 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),
- MemFlags::new(),
+ vtable_memflags(),
vtable,
(ALIGN_INDEX * usize_size) as i32,
)
}
-pub fn get_ptr_and_method_ref<'tcx>(
+pub(crate) fn get_ptr_and_method_ref<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
arg: CValue<'tcx>,
idx: usize,
) -> (Value, Value) {
- let (ptr, vtable) = arg.load_scalar_pair(fx);
+ let (ptr, vtable) = if let Abi::ScalarPair(_, _) = arg.layout().abi {
+ arg.load_scalar_pair(fx)
+ } else {
+ let (ptr, vtable) = arg.try_to_ptr().unwrap();
+ (ptr.get_addr(fx), vtable.unwrap())
+ };
+
let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes();
let func_ref = fx.bcx.ins().load(
pointer_ty(fx.tcx),
- MemFlags::new(),
+ vtable_memflags(),
vtable,
((idx + 3) * usize_size as usize) as i32,
);
(ptr, func_ref)
}
-pub fn get_vtable<'tcx>(
+pub(crate) fn get_vtable<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
- ty: Ty<'tcx>,
+ layout: TyAndLayout<'tcx>,
trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
) -> Value {
- let data_id = if let Some(data_id) = fx.caches.vtables.get(&(ty, trait_ref)) {
+ let data_id = if let Some(data_id) = fx.cx.vtables.get(&(layout.ty, trait_ref)) {
*data_id
} else {
- let data_id = build_vtable(fx, ty, trait_ref);
- fx.caches.vtables.insert((ty, trait_ref), data_id);
+ let data_id = build_vtable(fx, layout, trait_ref);
+ fx.cx.vtables.insert((layout.ty, trait_ref), data_id);
data_id
};
- let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
+ let local_data_id = fx.cx.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, impl Backend>,
- ty: Ty<'tcx>,
+ layout: TyAndLayout<'tcx>,
trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
) -> DataId {
let tcx = fx.tcx;
let drop_in_place_fn = import_function(
tcx,
- fx.module,
- Instance::resolve_drop_in_place(tcx, ty),
+ &mut fx.cx.module,
+ Instance::resolve_drop_in_place(tcx, layout.ty).polymorphize(fx.tcx),
);
let mut components: Vec<_> = vec![Some(drop_in_place_fn), None, None];
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 = tcx.vtable_methods(trait_ref.with_self_ty(tcx, layout.ty));
methods_root.iter()
} else {
(&[]).iter()
opt_mth.map_or(None, |(def_id, substs)| {
Some(import_function(
tcx,
- fx.module,
- Instance::resolve_for_vtable(tcx, ParamEnv::reveal_all(), def_id, substs).unwrap(),
+ &mut fx.cx.module,
+ Instance::resolve_for_vtable(tcx, ParamEnv::reveal_all(), def_id, substs)
+ .unwrap()
+ .polymorphize(fx.tcx),
))
})
});
.collect::<Vec<u8>>()
.into_boxed_slice();
- let layout = tcx.layout_of(ParamEnv::reveal_all().and(ty)).unwrap();
write_usize(fx.tcx, &mut data, SIZE_INDEX, layout.size.bytes());
write_usize(fx.tcx, &mut data, ALIGN_INDEX, layout.align.abi.bytes());
data_ctx.define(data);
for (i, component) in components.into_iter().enumerate() {
if let Some(func_id) = component {
- let func_ref = fx.module.declare_func_in_data(func_id, &mut data_ctx);
+ let func_ref = fx.cx.module.declare_func_in_data(func_id, &mut data_ctx);
data_ctx.write_function_addr((i * usize_size) as u32, func_ref);
}
}
let data_id = fx
+ .cx
.module
.declare_data(
- &format!("vtable.{:?}.for.{:?}", trait_ref, ty),
+ &format!(
+ "__vtable.{}.for.{:?}.{}",
+ trait_ref
+ .as_ref()
+ .map(|trait_ref| format!("{:?}", trait_ref.skip_binder()).into())
+ .unwrap_or(std::borrow::Cow::Borrowed("???")),
+ layout.ty,
+ fx.cx.vtables.len(),
+ ),
Linkage::Local,
false,
- Some(fx.tcx.data_layout.pointer_align.pref.bytes().try_into().unwrap())
+ false,
+ Some(
+ fx.tcx
+ .data_layout
+ .pointer_align
+ .pref
+ .bytes()
+ .try_into()
+ .unwrap(),
+ ),
)
.unwrap();
- match fx.module.define_data(data_id, &data_ctx) {
- Ok(()) | Err(cranelift_module::ModuleError::DuplicateDefinition(_)) => {}
- err => err.unwrap(),
- }
+ fx.cx.module.define_data(data_id, &data_ctx).unwrap();
data_id
}
-fn write_usize(tcx: TyCtxt, buf: &mut [u8], idx: usize, num: u64) {
- use byteorder::{BigEndian, LittleEndian, WriteBytesExt};
-
- let usize_size = tcx
+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 mut target = &mut buf[idx * usize_size..(idx + 1) * usize_size];
+ let target = &mut buf[idx * pointer_size..(idx + 1) * pointer_size];
match tcx.data_layout.endian {
- layout::Endian::Little => target.write_uint::<LittleEndian>(num, usize_size),
- layout::Endian::Big => target.write_uint::<BigEndian>(num, usize_size),
+ 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),
+ },
}
- .unwrap()
}
projects / rust.git / blobdiff