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 drop_fn_of_obj<'a, 'tcx: 'a>(
10 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
13 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
18 (DROP_FN_INDEX * usize_size) as i32,
22 pub fn size_of_obj<'a, 'tcx: 'a>(
23 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
26 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
31 (SIZE_INDEX * usize_size) as i32,
35 pub fn min_align_of_obj<'a, 'tcx: 'a>(
36 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
39 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
44 (ALIGN_INDEX * usize_size) as i32,
48 pub fn get_ptr_and_method_ref<'a, 'tcx: 'a>(
49 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
53 let (ptr, vtable) = arg.load_scalar_pair(fx);
54 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes();
55 let func_ref = fx.bcx.ins().load(
59 ((idx + 3) * usize_size as usize) as i32,
64 pub fn get_vtable<'a, 'tcx: 'a>(
65 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
67 trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
69 let data_id = if let Some(data_id) = fx.caches.vtables.get(&(ty, trait_ref)) {
72 let data_id = build_vtable(fx, ty, trait_ref);
73 fx.caches.vtables.insert((ty, trait_ref), data_id);
77 let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
78 fx.bcx.ins().global_value(fx.pointer_type, local_data_id)
81 fn build_vtable<'a, 'tcx: 'a>(
82 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
84 trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
87 let usize_size = fx.layout_of(fx.tcx.types.usize).size.bytes() as usize;
89 let drop_in_place_fn = import_function(
92 Instance::resolve_drop_in_place(tcx, ty),
95 let mut components: Vec<_> = vec![Some(drop_in_place_fn), None, None];
98 let methods = if let Some(trait_ref) = trait_ref {
99 methods_root = tcx.vtable_methods(trait_ref.with_self_ty(tcx, ty));
104 let methods = methods.cloned().map(|opt_mth| {
105 opt_mth.map_or(None, |(def_id, substs)| {
106 Some(import_function(
109 Instance::resolve_for_vtable(tcx, ParamEnv::reveal_all(), def_id, substs).unwrap(),
113 components.extend(methods);
115 let mut data_ctx = DataContext::new();
116 let mut data = ::std::iter::repeat(0u8)
117 .take(components.len() * usize_size)
118 .collect::<Vec<u8>>()
121 let layout = tcx.layout_of(ParamEnv::reveal_all().and(ty)).unwrap();
122 write_usize(fx.tcx, &mut data, SIZE_INDEX, layout.size.bytes());
123 write_usize(fx.tcx, &mut data, ALIGN_INDEX, layout.align.abi.bytes());
124 data_ctx.define(data);
126 for (i, component) in components.into_iter().enumerate() {
127 if let Some(func_id) = component {
128 let func_ref = fx.module.declare_func_in_data(func_id, &mut data_ctx);
129 data_ctx.write_function_addr((i * usize_size) as u32, func_ref);
136 &format!("vtable.{:?}.for.{:?}", trait_ref, ty),
139 Some(fx.tcx.data_layout.pointer_align.pref.bytes().try_into().unwrap())
143 match fx.module.define_data(data_id, &data_ctx) {
144 Ok(()) | Err(cranelift_module::ModuleError::DuplicateDefinition(_)) => {}
151 fn write_usize(tcx: TyCtxt, buf: &mut [u8], idx: usize, num: u64) {
152 use byteorder::{BigEndian, LittleEndian, WriteBytesExt};
155 .layout_of(ParamEnv::reveal_all().and(tcx.types.usize))
159 let mut target = &mut buf[idx * usize_size..(idx + 1) * usize_size];
161 match tcx.data_layout.endian {
162 layout::Endian::Little => target.write_uint::<LittleEndian>(num, usize_size),
163 layout::Endian::Big => target.write_uint::<BigEndian>(num, usize_size),