1 //! See librustc_codegen_llvm/meth.rs for reference
5 const DROP_FN_INDEX: usize = 0;
6 const SIZE_INDEX: usize = 1;
7 const ALIGN_INDEX: usize = 2;
9 pub fn size_of_obj<'a, 'tcx: 'a>(
10 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
13 let (_ptr, vtable) = val.load_value_pair(fx);
14 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
19 (SIZE_INDEX * usize_size) as i32,
23 pub fn min_align_of_obj<'a, 'tcx: 'a>(
24 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
27 let (_ptr, vtable) = val.load_value_pair(fx);
28 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
33 (ALIGN_INDEX * usize_size) as i32,
37 pub fn get_ptr_and_method_ref<'a, 'tcx: 'a>(
38 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
42 let (ptr, vtable) = arg.load_value_pair(fx);
43 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes();
44 let func_ref = fx.bcx.ins().load(
48 ((idx + 3) * usize_size as usize) as i32,
53 pub fn get_vtable<'a, 'tcx: 'a>(
54 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
56 trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
58 let data_id = if let Some(data_id) = fx.caches.vtables.get(&(ty, trait_ref)) {
61 let data_id = build_vtable(fx, ty, trait_ref);
62 fx.caches.vtables.insert((ty, trait_ref), data_id);
66 let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
69 .global_value(fx.module.pointer_type(), local_data_id)
72 fn build_vtable<'a, 'tcx: 'a>(
73 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
75 trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
78 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
80 let (size, align) = tcx
81 .layout_of(ParamEnv::reveal_all().and(ty))
84 let drop_in_place_fn =
85 fx.get_function_id(crate::rustc_mir::monomorphize::resolve_drop_in_place(tcx, ty));
87 let mut components: Vec<_> = vec![Some(drop_in_place_fn), None, None];
89 if let Some(trait_ref) = trait_ref {
90 let trait_ref = trait_ref.with_self_ty(tcx, ty);
91 let methods = tcx.vtable_methods(trait_ref);
92 let methods = methods.iter().cloned().map(|opt_mth| {
93 opt_mth.map_or(None, |(def_id, substs)| {
94 Some(fx.get_function_id(
95 Instance::resolve(tcx, ParamEnv::reveal_all(), def_id, substs).unwrap(),
99 components.extend(methods);
102 let mut data_ctx = DataContext::new();
103 let mut data = ::std::iter::repeat(0u8)
104 .take(components.len() * usize_size)
105 .collect::<Vec<u8>>()
107 write_usize(fx.tcx, &mut data, SIZE_INDEX, size.bytes());
108 write_usize(fx.tcx, &mut data, ALIGN_INDEX, align.abi());
109 data_ctx.define(data);
111 for (i, component) in components.into_iter().enumerate() {
112 if let Some(func_id) = component {
113 let func_ref = fx.module.declare_func_in_data(func_id, &mut data_ctx);
114 data_ctx.write_function_addr((i * usize_size) as u32, func_ref);
121 &format!("vtable.{:?}.for.{:?}", trait_ref, ty),
125 fx.module.define_data(data_id, &data_ctx).unwrap();
129 fn write_usize(tcx: TyCtxt, buf: &mut [u8], idx: usize, num: u64) {
130 use byteorder::{BigEndian, LittleEndian, WriteBytesExt};
133 .layout_of(ParamEnv::reveal_all().and(tcx.types.usize))
137 let mut target = &mut buf[idx * usize_size..(idx + 1) * usize_size];
139 match tcx.data_layout.endian {
140 layout::Endian::Little => target.write_uint::<LittleEndian>(num, usize_size),
141 layout::Endian::Big => target.write_uint::<BigEndian>(num, usize_size),