Auto merge of #133883 - saethlin:remove-polymorphization, r=compiler-…

…errors Remove polymorphization This PR removes the flag `-Zpolymorphize` and all the infrastructure in the compiler that exists only to support it, per rust-lang/compiler-team#810.
rust-lang · Dec 7, 2024 · ca13e91 · ca13e91
2 parents 75716b4 + 711c8cc
commit ca13e91
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Showing 92 changed files with 59 additions and 2,643 deletions.
diff --git a/compiler/rustc_codegen_cranelift/build_system/tests.rs b/compiler/rustc_codegen_cranelift/build_system/tests.rs
@@ -92,10 +92,6 @@ const BASE_SYSROOT_SUITE: &[TestCase] = &[
     TestCase::build_bin_and_run("aot.mod_bench", "example/mod_bench.rs", &[]),
     TestCase::build_bin_and_run("aot.issue-72793", "example/issue-72793.rs", &[]),
     TestCase::build_bin("aot.issue-59326", "example/issue-59326.rs"),
-    TestCase::custom("aot.polymorphize_coroutine", &|runner| {
-        runner.run_rustc(&["example/polymorphize_coroutine.rs", "-Zpolymorphize"]);
-        runner.run_out_command("polymorphize_coroutine", &[]);
-    }),
     TestCase::build_bin_and_run("aot.neon", "example/neon.rs", &[]),
     TestCase::custom("aot.gen_block_iterate", &|runner| {
         runner.run_rustc([

diff --git a/compiler/rustc_codegen_cranelift/config.txt b/compiler/rustc_codegen_cranelift/config.txt
@@ -42,7 +42,6 @@ aot.float-minmax-pass
 aot.mod_bench
 aot.issue-72793
 aot.issue-59326
-aot.polymorphize_coroutine
 aot.neon
 aot.gen_block_iterate
 aot.raw-dylib

diff --git a/compiler/rustc_codegen_cranelift/example/polymorphize_coroutine.rs b/compiler/rustc_codegen_cranelift/example/polymorphize_coroutine.rs
diff --git a/compiler/rustc_codegen_cranelift/src/abi/mod.rs b/compiler/rustc_codegen_cranelift/src/abi/mod.rs
@@ -394,8 +394,7 @@ pub(crate) fn codegen_terminator_call<'tcx>(
             def_id,
             fn_args,
             source_info.span,
-        )
-        .polymorphize(fx.tcx);
+        );
 
         if is_call_from_compiler_builtins_to_upstream_monomorphization(fx.tcx, instance) {
             if target.is_some() {
@@ -698,7 +697,7 @@ pub(crate) fn codegen_drop<'tcx>(
     target: BasicBlock,
 ) {
     let ty = drop_place.layout().ty;
-    let drop_instance = Instance::resolve_drop_in_place(fx.tcx, ty).polymorphize(fx.tcx);
+    let drop_instance = Instance::resolve_drop_in_place(fx.tcx, ty);
 
     if let ty::InstanceKind::DropGlue(_, None) | ty::InstanceKind::AsyncDropGlueCtorShim(_, None) =
         drop_instance.def

diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs
@@ -673,8 +673,7 @@ fn codegen_stmt<'tcx>(
                                     def_id,
                                     args,
                                 )
-                                .unwrap()
-                                .polymorphize(fx.tcx),
+                                .unwrap(),
                             );
                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
                             lval.write_cvalue(fx, CValue::by_val(func_addr, to_layout));
@@ -760,8 +759,7 @@ fn codegen_stmt<'tcx>(
                                 def_id,
                                 args,
                                 ty::ClosureKind::FnOnce,
-                            )
-                            .polymorphize(fx.tcx);
+                            );
                             let func_ref = fx.get_function_ref(instance);
                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
                             lval.write_cvalue(fx, CValue::by_val(func_addr, lval.layout()));
@@ -1087,7 +1085,7 @@ fn codegen_panic_inner<'tcx>(
 
     let def_id = fx.tcx.require_lang_item(lang_item, span);
 
-    let instance = Instance::mono(fx.tcx, def_id).polymorphize(fx.tcx);
+    let instance = Instance::mono(fx.tcx, def_id);
 
     if is_call_from_compiler_builtins_to_upstream_monomorphization(fx.tcx, instance) {
         fx.bcx.ins().trap(TrapCode::user(2).unwrap());

diff --git a/compiler/rustc_codegen_cranelift/src/constant.rs b/compiler/rustc_codegen_cranelift/src/constant.rs
@@ -452,8 +452,7 @@ fn define_all_allocs(tcx: TyCtxt<'_>, module: &mut dyn Module, cx: &mut Constant
             let data_id = match reloc_target_alloc {
                 GlobalAlloc::Function { instance, .. } => {
                     assert_eq!(addend, 0);
-                    let func_id =
-                        crate::abi::import_function(tcx, module, instance.polymorphize(tcx));
+                    let func_id = crate::abi::import_function(tcx, module, instance);
                     let local_func_id = module.declare_func_in_data(func_id, &mut data);
                     data.write_function_addr(offset.bytes() as u32, local_func_id);
                     continue;

diff --git a/compiler/rustc_codegen_cranelift/src/main_shim.rs b/compiler/rustc_codegen_cranelift/src/main_shim.rs
@@ -24,7 +24,7 @@ pub(crate) fn maybe_create_entry_wrapper(
     };
 
     if main_def_id.is_local() {
-        let instance = Instance::mono(tcx, main_def_id).polymorphize(tcx);
+        let instance = Instance::mono(tcx, main_def_id);
         if module.get_name(tcx.symbol_name(instance).name).is_none() {
             return;
         }
@@ -75,7 +75,7 @@ pub(crate) fn maybe_create_entry_wrapper(
             }
         };
 
-        let instance = Instance::mono(tcx, rust_main_def_id).polymorphize(tcx);
+        let instance = Instance::mono(tcx, rust_main_def_id);
 
         let main_name = tcx.symbol_name(instance).name;
         let main_sig = get_function_sig(tcx, m.target_config().default_call_conv, instance);
@@ -117,8 +117,7 @@ pub(crate) fn maybe_create_entry_wrapper(
                     report.def_id,
                     tcx.mk_args(&[GenericArg::from(main_ret_ty)]),
                     DUMMY_SP,
-                )
-                .polymorphize(tcx);
+                );
 
                 let report_name = tcx.symbol_name(report).name;
                 let report_sig = get_function_sig(tcx, m.target_config().default_call_conv, report);
@@ -143,8 +142,7 @@ pub(crate) fn maybe_create_entry_wrapper(
                     start_def_id,
                     tcx.mk_args(&[main_ret_ty.into()]),
                     DUMMY_SP,
-                )
-                .polymorphize(tcx);
+                );
                 let start_func_id = import_function(tcx, m, start_instance);
 
                 let main_val = bcx.ins().func_addr(m.target_config().pointer_type(), main_func_ref);

diff --git a/compiler/rustc_codegen_cranelift/src/value_and_place.rs b/compiler/rustc_codegen_cranelift/src/value_and_place.rs
@@ -1005,9 +1005,6 @@ pub(crate) fn assert_assignable<'tcx>(
                 }
             }
         }
-        (ty::Param(_), _) | (_, ty::Param(_)) if fx.tcx.sess.opts.unstable_opts.polymorphize => {
-            // No way to check if it is correct or not with polymorphization enabled
-        }
         _ => {
             assert_eq!(
                 from_ty,

diff --git a/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt b/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt
@@ -6,7 +6,6 @@ tests/ui/functions-closures/parallel-codegen-closures.rs
 tests/ui/linkage-attr/linkage1.rs
 tests/ui/lto/dylib-works.rs
 tests/ui/numbers-arithmetic/saturating-float-casts.rs
-tests/ui/polymorphization/promoted-function.rs
 tests/ui/sepcomp/sepcomp-cci.rs
 tests/ui/sepcomp/sepcomp-extern.rs
 tests/ui/sepcomp/sepcomp-fns-backwards.rs

diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
@@ -302,10 +302,9 @@ impl<'ll, 'tcx> ConstCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                             (value, AddressSpace::DATA)
                         }
                     }
-                    GlobalAlloc::Function { instance, .. } => (
-                        self.get_fn_addr(instance.polymorphize(self.tcx)),
-                        self.data_layout().instruction_address_space,
-                    ),
+                    GlobalAlloc::Function { instance, .. } => {
+                        (self.get_fn_addr(instance), self.data_layout().instruction_address_space)
+                    }
                     GlobalAlloc::VTable(ty, dyn_ty) => {
                         let alloc = self
                             .tcx

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -471,8 +471,6 @@ pub(crate) fn type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) ->
             AdtKind::Enum => enums::build_enum_type_di_node(cx, unique_type_id),
         },
         ty::Tuple(_) => build_tuple_type_di_node(cx, unique_type_id),
-        // Type parameters from polymorphized functions.
-        ty::Param(_) => build_param_type_di_node(cx, t),
         _ => bug!("debuginfo: unexpected type in type_di_node(): {:?}", t),
     };
 
@@ -871,26 +869,6 @@ fn build_foreign_type_di_node<'ll, 'tcx>(
     )
 }
 
-fn build_param_type_di_node<'ll, 'tcx>(
-    cx: &CodegenCx<'ll, 'tcx>,
-    t: Ty<'tcx>,
-) -> DINodeCreationResult<'ll> {
-    debug!("build_param_type_di_node: {:?}", t);
-    let name = format!("{t:?}");
-    DINodeCreationResult {
-        di_node: unsafe {
-            llvm::LLVMRustDIBuilderCreateBasicType(
-                DIB(cx),
-                name.as_c_char_ptr(),
-                name.len(),
-                Size::ZERO.bits(),
-                DW_ATE_unsigned,
-            )
-        },
-        already_stored_in_typemap: false,
-    }
-}
-
 pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>(
     tcx: TyCtxt<'tcx>,
     codegen_unit_name: &str,

diff --git a/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs b/compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
@@ -432,11 +432,8 @@ fn push_debuginfo_type_name<'tcx>(
                 push_closure_or_coroutine_name(tcx, def_id, args, qualified, output, visited);
             }
         }
-        // Type parameters from polymorphized functions.
-        ty::Param(_) => {
-            write!(output, "{t:?}").unwrap();
-        }
-        ty::Error(_)
+        ty::Param(_)
+        | ty::Error(_)
         | ty::Infer(_)
         | ty::Placeholder(..)
         | ty::Alias(..)

diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -847,10 +847,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         let (instance, mut llfn) = match *callee.layout.ty.kind() {
             ty::FnDef(def_id, args) => (
-                Some(
-                    ty::Instance::expect_resolve(bx.tcx(), bx.typing_env(), def_id, args, fn_span)
-                        .polymorphize(bx.tcx()),
-                ),
+                Some(ty::Instance::expect_resolve(
+                    bx.tcx(),
+                    bx.typing_env(),
+                    def_id,
+                    args,
+                    fn_span,
+                )),
                 None,
             ),
             ty::FnPtr(..) => (None, Some(callee.immediate())),

diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -478,8 +478,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                                     def_id,
                                     args,
                                 )
-                                .unwrap()
-                                .polymorphize(bx.cx().tcx());
+                                .unwrap();
                                 OperandValue::Immediate(bx.get_fn_addr(instance))
                             }
                             _ => bug!("{} cannot be reified to a fn ptr", operand.layout.ty),
@@ -493,8 +492,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                                     def_id,
                                     args,
                                     ty::ClosureKind::FnOnce,
-                                )
-                                .polymorphize(bx.cx().tcx());
+                                );
                                 OperandValue::Immediate(bx.cx().get_fn_addr(instance))
                             }
                             _ => bug!("{} cannot be cast to a fn ptr", operand.layout.ty),

diff --git a/compiler/rustc_const_eval/src/interpret/util.rs b/compiler/rustc_const_eval/src/interpret/util.rs
@@ -14,10 +14,8 @@ use crate::const_eval::{CompileTimeInterpCx, CompileTimeMachine, InterpretationR
 
 /// Checks whether a type contains generic parameters which must be instantiated.
 ///
-/// In case it does, returns a `TooGeneric` const eval error. Note that due to polymorphization
-/// types may be "concrete enough" even though they still contain generic parameters in
-/// case these parameters are unused.
-pub(crate) fn ensure_monomorphic_enough<'tcx, T>(tcx: TyCtxt<'tcx>, ty: T) -> InterpResult<'tcx>
+/// In case it does, returns a `TooGeneric` const eval error.
+pub(crate) fn ensure_monomorphic_enough<'tcx, T>(_tcx: TyCtxt<'tcx>, ty: T) -> InterpResult<'tcx>
 where
     T: TypeVisitable<TyCtxt<'tcx>>,
 {
@@ -27,11 +25,9 @@ where
     }
 
     struct FoundParam;
-    struct UsedParamsNeedInstantiationVisitor<'tcx> {
-        tcx: TyCtxt<'tcx>,
-    }
+    struct UsedParamsNeedInstantiationVisitor {}
 
-    impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for UsedParamsNeedInstantiationVisitor<'tcx> {
+    impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for UsedParamsNeedInstantiationVisitor {
         type Result = ControlFlow<FoundParam>;
 
         fn visit_ty(&mut self, ty: Ty<'tcx>) -> Self::Result {
@@ -41,25 +37,7 @@ where
 
             match *ty.kind() {
                 ty::Param(_) => ControlFlow::Break(FoundParam),
-                ty::Closure(def_id, args)
-                | ty::CoroutineClosure(def_id, args, ..)
-                | ty::Coroutine(def_id, args, ..)
-                | ty::FnDef(def_id, args) => {
-                    let instance = ty::InstanceKind::Item(def_id);
-                    let unused_params = self.tcx.unused_generic_params(instance);
-                    for (index, arg) in args.into_iter().enumerate() {
-                        let index = index
-                            .try_into()
-                            .expect("more generic parameters than can fit into a `u32`");
-                        // Only recurse when generic parameters in fns, closures and coroutines
-                        // are used and have to be instantiated.
-                        //
-                        // Just in case there are closures or coroutines within this arg,
-                        // recurse.
-                        if unused_params.is_used(index) && arg.has_param() {
-                            return arg.visit_with(self);
-                        }
-                    }
+                ty::Closure(..) | ty::CoroutineClosure(..) | ty::Coroutine(..) | ty::FnDef(..) => {
                     ControlFlow::Continue(())
                 }
                 _ => ty.super_visit_with(self),
@@ -74,7 +52,7 @@ where
         }
     }
 
-    let mut vis = UsedParamsNeedInstantiationVisitor { tcx };
+    let mut vis = UsedParamsNeedInstantiationVisitor {};
     if matches!(ty.visit_with(&mut vis), ControlFlow::Break(FoundParam)) {
         throw_inval!(TooGeneric);
     } else {

diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -1103,10 +1103,6 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         TEST, rustc_symbol_name, Normal, template!(Word),
         WarnFollowing, EncodeCrossCrate::No
     ),
-    rustc_attr!(
-        TEST, rustc_polymorphize_error, Normal, template!(Word),
-        WarnFollowing, EncodeCrossCrate::Yes
-    ),
     rustc_attr!(
         TEST, rustc_def_path, Normal, template!(Word),
         WarnFollowing, EncodeCrossCrate::No

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
@@ -876,7 +876,6 @@ fn run_required_analyses(tcx: TyCtxt<'_>) {
                 || tcx.hir().body_const_context(def_id).is_some()
             {
                 tcx.ensure().mir_drops_elaborated_and_const_checked(def_id);
-                tcx.ensure().unused_generic_params(ty::InstanceKind::Item(def_id.to_def_id()));
             }
         }
     });
@@ -895,8 +894,7 @@ fn run_required_analyses(tcx: TyCtxt<'_>) {
     // If `-Zvalidate-mir` is set, we also want to compute the final MIR for each item
     // (either its `mir_for_ctfe` or `optimized_mir`) since that helps uncover any bugs
     // in MIR optimizations that may only be reachable through codegen, or other codepaths
-    // that requires the optimized/ctfe MIR, such as polymorphization, coroutine bodies,
-    // or evaluating consts.
+    // that requires the optimized/ctfe MIR, coroutine bodies, or evaluating consts.
     if tcx.sess.opts.unstable_opts.validate_mir {
         sess.time("ensuring_final_MIR_is_computable", || {
             tcx.hir().par_body_owners(|def_id| {

diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -269,7 +269,6 @@ provide! { tcx, def_id, other, cdata,
     lookup_default_body_stability => { table }
     lookup_deprecation_entry => { table }
     params_in_repr => { table }
-    unused_generic_params => { table_direct }
     def_kind => { cdata.def_kind(def_id.index) }
     impl_parent => { table }
     defaultness => { table_direct }

diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1767,10 +1767,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             {
                 record!(self.tables.mir_coroutine_witnesses[def_id.to_def_id()] <- witnesses);
             }
-
-            let instance = ty::InstanceKind::Item(def_id.to_def_id());
-            let unused = tcx.unused_generic_params(instance);
-            self.tables.unused_generic_params.set(def_id.local_def_index, unused);
         }
 
         // Encode all the deduced parameter attributes for everything that has MIR, even for items

diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -395,7 +395,6 @@ define_tables! {
     inherent_impls: Table<DefIndex, LazyArray<DefIndex>>,
     associated_types_for_impl_traits_in_associated_fn: Table<DefIndex, LazyArray<DefId>>,
     opt_rpitit_info: Table<DefIndex, Option<LazyValue<ty::ImplTraitInTraitData>>>,
-    unused_generic_params: Table<DefIndex, UnusedGenericParams>,
     // Reexported names are not associated with individual `DefId`s,
     // e.g. a glob import can introduce a lot of names, all with the same `DefId`.
     // That's why the encoded list needs to contain `ModChild` structures describing all the names

diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
@@ -82,7 +82,7 @@ use crate::ty::print::{PrintTraitRefExt, describe_as_module};
 use crate::ty::util::AlwaysRequiresDrop;
 use crate::ty::{
     self, CrateInherentImpls, GenericArg, GenericArgsRef, PseudoCanonicalInput, Ty, TyCtxt,
-    TyCtxtFeed, UnusedGenericParams,
+    TyCtxtFeed,
 };
 use crate::{dep_graph, mir, thir};
 
@@ -2048,15 +2048,6 @@ rustc_queries! {
         desc { "getting codegen unit `{sym}`" }
     }
 
-    query unused_generic_params(key: ty::InstanceKind<'tcx>) -> UnusedGenericParams {
-        cache_on_disk_if { key.def_id().is_local() }
-        desc {
-            |tcx| "determining which generic parameters are unused by `{}`",
-                tcx.def_path_str(key.def_id())
-        }
-        separate_provide_extern
-    }
-
     query backend_optimization_level(_: ()) -> OptLevel {
         desc { "optimization level used by backend" }
     }