Refactor to make interpreter and codegen backend neutral to vtable internal representation.

3 files changed, 34 insertions, 34 deletions

diff --git a/compiler/rustc_codegen_ssa/src/glue.rs b/compiler/rustc_codegen_ssa/src/glue.rs
index b88de0b2411..cf217b52c86 100644
--- a/compiler/rustc_codegen_ssa/src/glue.rs
+++ b/compiler/rustc_codegen_ssa/src/glue.rs
@@ -23,7 +23,12 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         ty::Dynamic(..) => {
             // load size/align from vtable
             let vtable = info.unwrap();
-            (meth::SIZE.get_usize(bx, vtable), meth::ALIGN.get_usize(bx, vtable))
+            (
+                meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_SIZE)
+                    .get_usize(bx, vtable),
+                meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_ALIGN)
+                    .get_usize(bx, vtable),
+            )
         }
         ty::Slice(_) | ty::Str => {
             let unit = layout.field(bx, 0);
diff --git a/compiler/rustc_codegen_ssa/src/meth.rs b/compiler/rustc_codegen_ssa/src/meth.rs
index bcc19c6a44b..4f0de729704 100644
--- a/compiler/rustc_codegen_ssa/src/meth.rs
+++ b/compiler/rustc_codegen_ssa/src/meth.rs
@@ -1,18 +1,14 @@
 use crate::traits::*;
 
-use rustc_middle::ty::{self, Instance, Ty};
+use rustc_middle::ty::{self, Instance, Ty, VtblEntry, COMMON_VTABLE_ENTRIES};
 use rustc_target::abi::call::FnAbi;
 
 #[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)
+        VirtualIndex(index as u64)
     }
 
     pub fn get_fn<Bx: BuilderMethods<'a, 'tcx>>(
@@ -77,43 +73,38 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
     // Not in the cache; build it.
     let nullptr = cx.const_null(cx.type_i8p_ext(cx.data_layout().instruction_address_space));
 
-    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.iter()
+    let vtable_entries = if let Some(trait_ref) = trait_ref {
+        tcx.vtable_entries(trait_ref.with_self_ty(tcx, ty))
     } else {
-        (&[]).iter()
+        COMMON_VTABLE_ENTRIES
     };
 
-    let methods = methods.cloned().map(|opt_mth| {
-        opt_mth.map_or(nullptr, |(def_id, substs)| {
-            cx.get_fn_addr(
+    let layout = cx.layout_of(ty);
+    // /////////////////////////////////////////////////////////////////////////////////////////////
+    // If you touch this code, be sure to also make the corresponding changes to
+    // `get_vtable` in `rust_mir/interpret/traits.rs`.
+    // /////////////////////////////////////////////////////////////////////////////////////////////
+    let components: Vec<_> = vtable_entries
+        .iter()
+        .map(|entry| match entry {
+            VtblEntry::MetadataDropInPlace => {
+                cx.get_fn_addr(Instance::resolve_drop_in_place(cx.tcx(), ty))
+            }
+            VtblEntry::MetadataSize => cx.const_usize(layout.size.bytes()),
+            VtblEntry::MetadataAlign => cx.const_usize(layout.align.abi.bytes()),
+            VtblEntry::Vacant => nullptr,
+            VtblEntry::Method(def_id, substs) => cx.get_fn_addr(
                 ty::Instance::resolve_for_vtable(
                     cx.tcx(),
                     ty::ParamEnv::reveal_all(),
-                    def_id,
+                    *def_id,
                     substs,
                 )
                 .unwrap()
                 .polymorphize(cx.tcx()),
-            )
+            ),
         })
-    });
-
-    let layout = cx.layout_of(ty);
-    // /////////////////////////////////////////////////////////////////////////////////////////////
-    // If you touch this code, be sure to also make the corresponding changes to
-    // `get_vtable` in `rust_mir/interpret/traits.rs`.
-    // /////////////////////////////////////////////////////////////////////////////////////////////
-    let components: Vec<_> = [
-        cx.get_fn_addr(Instance::resolve_drop_in_place(cx.tcx(), ty)),
-        cx.const_usize(layout.size.bytes()),
-        cx.const_usize(layout.align.abi.bytes()),
-    ]
-    .iter()
-    .cloned()
-    .chain(methods)
-    .collect();
+        .collect();
 
     let vtable_const = cx.const_struct(&components, false);
     let align = cx.data_layout().pointer_align.abi;
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 93200bd1f26..2cb28d7361c 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -332,7 +332,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 let fn_abi = FnAbi::of_instance(&bx, virtual_drop, &[]);
                 let vtable = args[1];
                 args = &args[..1];
-                (meth::DESTRUCTOR.get_fn(&mut bx, vtable, &fn_abi), fn_abi)
+                (
+                    meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE)
+                        .get_fn(&mut bx, vtable, &fn_abi),
+                    fn_abi,
+                )
             }
             _ => (bx.get_fn_addr(drop_fn), FnAbi::of_instance(&bx, drop_fn, &[])),
         };