From 496f4dbcf41c12cde6980f2e8f305163eabeba75 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Tue, 19 Jul 2022 20:19:15 -0400 Subject: [PATCH] slightly cleaner, if more verbose, vtable handling in codegen backends --- .../rustc_codegen_cranelift/src/constant.rs | 20 +++++++++++++------ compiler/rustc_codegen_gcc/src/common.rs | 13 +++++------- compiler/rustc_codegen_llvm/src/common.rs | 17 ++++++++-------- 3 files changed, 28 insertions(+), 22 deletions(-) diff --git a/compiler/rustc_codegen_cranelift/src/constant.rs b/compiler/rustc_codegen_cranelift/src/constant.rs index 2380f3e1df022..b5a143485893f 100644 --- a/compiler/rustc_codegen_cranelift/src/constant.rs +++ b/compiler/rustc_codegen_cranelift/src/constant.rs @@ -195,11 +195,6 @@ pub(crate) fn codegen_const_value<'tcx>( } Scalar::Ptr(ptr, _size) => { let (alloc_id, offset) = ptr.into_parts(); // we know the `offset` is relative - // For vtables, get the underlying data allocation. - let alloc_id = match fx.tcx.global_alloc(alloc_id) { - GlobalAlloc::VTable(ty, trait_ref) => fx.tcx.vtable_allocation((ty, trait_ref)), - _ => alloc_id, - }; let base_addr = match fx.tcx.global_alloc(alloc_id) { GlobalAlloc::Memory(alloc) => { let data_id = data_id_for_alloc_id( @@ -221,7 +216,20 @@ pub(crate) fn codegen_const_value<'tcx>( fx.module.declare_func_in_func(func_id, &mut fx.bcx.func); fx.bcx.ins().func_addr(fx.pointer_type, local_func_id) } - GlobalAlloc::VTable(..) => bug!("vtables are already handled"), + GlobalAlloc::VTable(ty, trait_ref) => { + let alloc_id = fx.tcx.vtable_allocation((ty, trait_ref)); + let alloc = fx.tcx.global_alloc(alloc_id).unwrap_memory(); + // FIXME: factor this common code with the `Memory` arm into a function? + let data_id = data_id_for_alloc_id( + &mut fx.constants_cx, + fx.module, + alloc_id, + alloc.inner().mutability, + ); + let local_data_id = + fx.module.declare_data_in_func(data_id, &mut fx.bcx.func); + fx.bcx.ins().global_value(fx.pointer_type, local_data_id) + } GlobalAlloc::Static(def_id) => { assert!(fx.tcx.is_static(def_id)); let data_id = data_id_for_static(fx.tcx, fx.module, def_id, false); diff --git a/compiler/rustc_codegen_gcc/src/common.rs b/compiler/rustc_codegen_gcc/src/common.rs index d1afca18427d6..ccb6cbbc2c8a7 100644 --- a/compiler/rustc_codegen_gcc/src/common.rs +++ b/compiler/rustc_codegen_gcc/src/common.rs @@ -183,13 +183,6 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> { } Scalar::Ptr(ptr, _size) => { let (alloc_id, offset) = ptr.into_parts(); - // For vtables, get the underlying data allocation. - let alloc_id = match self.tcx.global_alloc(alloc_id) { - GlobalAlloc::VTable(ty, trait_ref) => { - self.tcx.vtable_allocation((ty, trait_ref)) - } - _ => alloc_id, - }; let base_addr = match self.tcx.global_alloc(alloc_id) { GlobalAlloc::Memory(alloc) => { @@ -208,7 +201,11 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> { GlobalAlloc::Function(fn_instance) => { self.get_fn_addr(fn_instance) }, - GlobalAlloc::VTable(..) => panic!("vtables are already handled"), + GlobalAlloc::VTable(ty, trait_ref) => { + let alloc = self.tcx.global_alloc(self.tcx.vtable_allocation((ty, trait_ref))).unwrap_memory(); + let init = const_alloc_to_gcc(self, alloc); + self.static_addr_of(init, alloc.inner().align, None) + } GlobalAlloc::Static(def_id) => { assert!(self.tcx.is_static(def_id)); self.get_static(def_id).get_address(None) diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs index f83b359743802..fb4da9a5f3370 100644 --- a/compiler/rustc_codegen_llvm/src/common.rs +++ b/compiler/rustc_codegen_llvm/src/common.rs @@ -240,13 +240,6 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> { } Scalar::Ptr(ptr, _size) => { let (alloc_id, offset) = ptr.into_parts(); - // For vtables, get the underlying data allocation. - let alloc_id = match self.tcx.global_alloc(alloc_id) { - GlobalAlloc::VTable(ty, trait_ref) => { - self.tcx.vtable_allocation((ty, trait_ref)) - } - _ => alloc_id, - }; let (base_addr, base_addr_space) = match self.tcx.global_alloc(alloc_id) { GlobalAlloc::Memory(alloc) => { let init = const_alloc_to_llvm(self, alloc); @@ -264,7 +257,15 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> { self.get_fn_addr(fn_instance.polymorphize(self.tcx)), self.data_layout().instruction_address_space, ), - GlobalAlloc::VTable(..) => bug!("vtables are already handled"), + GlobalAlloc::VTable(ty, trait_ref) => { + let alloc = self + .tcx + .global_alloc(self.tcx.vtable_allocation((ty, trait_ref))) + .unwrap_memory(); + let init = const_alloc_to_llvm(self, alloc); + let value = self.static_addr_of(init, alloc.inner().align, None); + (value, AddressSpace::DATA) + } GlobalAlloc::Static(def_id) => { assert!(self.tcx.is_static(def_id)); assert!(!self.tcx.is_thread_local_static(def_id));