Don't deduplicate vtables between functions

Author: bjorn3

src/base.rs

@@ -18,9 +18,9 @@ pub(crate) fn codegen_fn<'tcx>(cx: &mut crate::CodegenCx<'_, 'tcx>, instance: In
     let mir = tcx.instance_mir(instance.def);
 
     // Declare function
-    let name = tcx.symbol_name(instance).name.to_string();
+    let symbol_name = tcx.symbol_name(instance);
     let sig = get_function_sig(tcx, cx.module.isa().triple(), instance);
-    let func_id = cx.module.declare_function(&name, Linkage::Local, &sig).unwrap();
+    let func_id = cx.module.declare_function(symbol_name.name, Linkage::Local, &sig).unwrap();
 
     cx.cached_context.clear();
 
@@ -46,8 +46,10 @@ pub(crate) fn codegen_fn<'tcx>(cx: &mut crate::CodegenCx<'_, 'tcx>, instance: In
         cx,
         tcx,
         pointer_type,
+        vtables: FxHashMap::default(),
 
         instance,
+        symbol_name,
         mir,
         fn_abi: Some(FnAbi::of_instance(&RevealAllLayoutCx(tcx), instance, &[])),
 
@@ -151,7 +153,7 @@ pub(crate) fn codegen_fn<'tcx>(cx: &mut crate::CodegenCx<'_, 'tcx>, instance: In
             debug_context.define_function(
                 instance,
                 func_id,
-                &name,
+                symbol_name.name,
                 isa,
                 context,
                 &source_info_set,

src/common.rs

@@ -1,4 +1,5 @@
 use rustc_index::vec::IndexVec;
+use rustc_middle::ty::SymbolName;
 use rustc_target::abi::call::FnAbi;
 use rustc_target::abi::{Integer, Primitive};
 use rustc_target::spec::{HasTargetSpec, Target};
@@ -230,8 +231,10 @@ pub(crate) struct FunctionCx<'m, 'clif, 'tcx> {
     pub(crate) cx: &'clif mut crate::CodegenCx<'m, 'tcx>,
     pub(crate) tcx: TyCtxt<'tcx>,
     pub(crate) pointer_type: Type, // Cached from module
+    pub(crate) vtables: FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), DataId>,
 
     pub(crate) instance: Instance<'tcx>,
+    pub(crate) symbol_name: SymbolName<'tcx>,
     pub(crate) mir: &'tcx Body<'tcx>,
     pub(crate) fn_abi: Option<FnAbi<'tcx, Ty<'tcx>>>,
 

src/inline_asm.rs

@@ -92,8 +92,7 @@ pub(crate) fn codegen_inline_asm<'tcx>(
 
     let inline_asm_index = fx.inline_asm_index;
     fx.inline_asm_index += 1;
-    let asm_name =
-        format!("{}__inline_asm_{}", fx.tcx.symbol_name(fx.instance).name, inline_asm_index);
+    let asm_name = format!("{}__inline_asm_{}", fx.symbol_name, inline_asm_index);
 
     let generated_asm = generate_asm_wrapper(
         &asm_name,

src/lib.rs

@@ -125,7 +125,6 @@ struct CodegenCx<'m, 'tcx: 'm> {
     global_asm: String,
     constants_cx: ConstantCx,
     cached_context: Context,
-    vtables: FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), DataId>,
     debug_context: Option<DebugContext<'tcx>>,
     unwind_context: UnwindContext<'tcx>,
 }
@@ -150,7 +149,6 @@ impl<'m, 'tcx> CodegenCx<'m, 'tcx> {
             global_asm: String::new(),
             constants_cx: ConstantCx::default(),
             cached_context: Context::new(),
-            vtables: FxHashMap::default(),
             debug_context,
             unwind_context,
         }

src/trap.rs

@@ -21,8 +21,7 @@ fn codegen_print(fx: &mut FunctionCx<'_, '_, '_>, msg: &str) {
         fx.add_comment(puts, "puts");
     }
 
-    let symbol_name = fx.tcx.symbol_name(fx.instance);
-    let real_msg = format!("trap at {:?} ({}): {}\0", fx.instance, symbol_name, msg);
+    let real_msg = format!("trap at {:?} ({}): {}\0", fx.instance, fx.symbol_name, msg);
     let msg_ptr = fx.anonymous_str("trap", &real_msg);
     fx.bcx.ins().call(puts, &[msg_ptr]);
 }

src/vtable.rs

@@ -72,11 +72,11 @@ pub(crate) fn get_vtable<'tcx>(
     layout: TyAndLayout<'tcx>,
     trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
 ) -> Value {
-    let data_id = if let Some(data_id) = fx.cx.vtables.get(&(layout.ty, trait_ref)) {
+    let data_id = if let Some(data_id) = fx.vtables.get(&(layout.ty, trait_ref)) {
         *data_id
     } else {
         let data_id = build_vtable(fx, layout, trait_ref);
-        fx.cx.vtables.insert((layout.ty, trait_ref), data_id);
+        fx.vtables.insert((layout.ty, trait_ref), data_id);
         data_id
     };
 
@@ -139,27 +139,9 @@ fn build_vtable<'tcx>(
 
     data_ctx.set_align(fx.tcx.data_layout.pointer_align.pref.bytes());
 
-    let data_id = fx
-        .cx
-        .module
-        .declare_data(
-            &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,
-            false,
-        )
-        .unwrap();
-
-    // FIXME don't duplicate definitions in lazy jit mode
-    let _ = fx.cx.module.define_data(data_id, &data_ctx);
+    let data_id = fx.cx.module.declare_anonymous_data(false, false).unwrap();
+
+    fx.cx.module.define_data(data_id, &data_ctx).unwrap();
 
     data_id
 }