1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
use abi::{FnType, FnTypeExt};
use callee;
use common::*;
use builder::Builder;
use consts;
use monomorphize;
use type_::Type;
use value::Value;
use rustc::ty::{self, Ty};
use rustc::ty::layout::HasDataLayout;
use debuginfo;
#[derive(Copy, Clone, Debug)]
pub struct VirtualIndex(u64);
pub const DESTRUCTOR: VirtualIndex = VirtualIndex(0);
pub const SIZE: VirtualIndex = VirtualIndex(1);
pub const ALIGN: VirtualIndex = VirtualIndex(2);
impl<'a, 'tcx> VirtualIndex {
pub fn from_index(index: usize) -> Self {
VirtualIndex(index as u64 + 3)
}
pub fn get_fn(self, bx: &Builder<'a, 'll, 'tcx>,
llvtable: &'ll Value,
fn_ty: &FnType<'tcx, Ty<'tcx>>) -> &'ll Value {
debug!("get_fn({:?}, {:?})", llvtable, self);
let llvtable = bx.pointercast(llvtable, fn_ty.llvm_type(bx.cx).ptr_to().ptr_to());
let ptr_align = bx.tcx().data_layout.pointer_align;
let ptr = bx.load(bx.inbounds_gep(llvtable, &[C_usize(bx.cx, self.0)]), ptr_align);
bx.nonnull_metadata(ptr);
bx.set_invariant_load(ptr);
ptr
}
pub fn get_usize(self, bx: &Builder<'a, 'll, 'tcx>, llvtable: &'ll Value) -> &'ll Value {
debug!("get_int({:?}, {:?})", llvtable, self);
let llvtable = bx.pointercast(llvtable, Type::isize(bx.cx).ptr_to());
let usize_align = bx.tcx().data_layout.pointer_align;
let ptr = bx.load(bx.inbounds_gep(llvtable, &[C_usize(bx.cx, self.0)]), usize_align);
bx.set_invariant_load(ptr);
ptr
}
}
pub fn get_vtable(
cx: &CodegenCx<'ll, 'tcx>,
ty: Ty<'tcx>,
trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
) -> &'ll Value {
let tcx = cx.tcx;
debug!("get_vtable(ty={:?}, trait_ref={:?})", ty, trait_ref);
if let Some(&val) = cx.vtables.borrow().get(&(ty, trait_ref)) {
return val;
}
let nullptr = C_null(Type::i8p(cx));
let (size, align) = cx.size_and_align_of(ty);
let mut components: Vec<_> = [
callee::get_fn(cx, monomorphize::resolve_drop_in_place(cx.tcx, ty)),
C_usize(cx, size.bytes()),
C_usize(cx, align.abi())
].iter().cloned().collect();
if let Some(trait_ref) = trait_ref {
let trait_ref = trait_ref.with_self_ty(tcx, ty);
let methods = tcx.vtable_methods(trait_ref);
let methods = methods.iter().cloned().map(|opt_mth| {
opt_mth.map_or(nullptr, |(def_id, substs)| {
callee::resolve_and_get_fn(cx, def_id, substs)
})
});
components.extend(methods);
}
let vtable_const = C_struct(cx, &components, false);
let align = cx.data_layout().pointer_align;
let vtable = consts::addr_of(cx, vtable_const, align, Some("vtable"));
debuginfo::create_vtable_metadata(cx, ty, vtable);
cx.vtables.borrow_mut().insert((ty, trait_ref), vtable);
vtable
}