Auto merge of #125456 - fmease:rollup-n8608gc, r=fmease

Rollup of 7 pull requests

Successful merges:

 - #122382 (Detect unused structs which implement private traits)
 - #124389 (Add a warning to proc_macro::Delimiter::None that rustc currently does not respect it.)
 - #125224 (Migrate `run-make/issue-53964` to `rmake`)
 - #125227 (Migrate `run-make/issue-30063` to `rmake`)
 - #125336 (Add dedicated definition for intrinsics)
 - #125401 (Migrate `run-make/rustdoc-scrape-examples-macros` to `rmake.rs`)
 - #125454 (Improve the doc of query associated_item)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: compiler/rustc_middle/src/query/mod.rs

@@ -780,7 +780,7 @@ rustc_queries! {
         separate_provide_extern
     }
 
-    /// Maps from a trait item to the trait item "descriptor".
+    /// Maps from a trait/impl item to the trait/impl item "descriptor".
     query associated_item(key: DefId) -> ty::AssocItem {
         desc { |tcx| "computing associated item data for `{}`", tcx.def_path_str(key) }
         cache_on_disk_if { key.is_local() }

Diff for: compiler/rustc_passes/src/dead.rs

@@ -425,10 +425,11 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                             && let ItemKind::Impl(impl_ref) =
                                 self.tcx.hir().expect_item(local_impl_id).kind
                         {
-                            if self.tcx.visibility(trait_id).is_public()
-                                && matches!(trait_item.kind, hir::TraitItemKind::Fn(..))
+                            if matches!(trait_item.kind, hir::TraitItemKind::Fn(..))
                                 && !ty_ref_to_pub_struct(self.tcx, impl_ref.self_ty)
                             {
+                                // skip methods of private ty,
+                                // they would be solved in `solve_rest_impl_items`
                                 continue;
                             }
 
@@ -485,32 +486,46 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
 
     fn solve_rest_impl_items(&mut self, mut unsolved_impl_items: Vec<(hir::ItemId, LocalDefId)>) {
         let mut ready;
-        (ready, unsolved_impl_items) = unsolved_impl_items
-            .into_iter()
-            .partition(|&(impl_id, _)| self.impl_item_with_used_self(impl_id));
+        (ready, unsolved_impl_items) =
+            unsolved_impl_items.into_iter().partition(|&(impl_id, impl_item_id)| {
+                self.impl_item_with_used_self(impl_id, impl_item_id)
+            });
 
         while !ready.is_empty() {
             self.worklist =
                 ready.into_iter().map(|(_, id)| (id, ComesFromAllowExpect::No)).collect();
             self.mark_live_symbols();
 
-            (ready, unsolved_impl_items) = unsolved_impl_items
-                .into_iter()
-                .partition(|&(impl_id, _)| self.impl_item_with_used_self(impl_id));
+            (ready, unsolved_impl_items) =
+                unsolved_impl_items.into_iter().partition(|&(impl_id, impl_item_id)| {
+                    self.impl_item_with_used_self(impl_id, impl_item_id)
+                });
         }
     }
 
-    fn impl_item_with_used_self(&mut self, impl_id: hir::ItemId) -> bool {
+    fn impl_item_with_used_self(&mut self, impl_id: hir::ItemId, impl_item_id: LocalDefId) -> bool {
         if let TyKind::Path(hir::QPath::Resolved(_, path)) =
             self.tcx.hir().item(impl_id).expect_impl().self_ty.kind
             && let Res::Def(def_kind, def_id) = path.res
             && let Some(local_def_id) = def_id.as_local()
             && matches!(def_kind, DefKind::Struct | DefKind::Enum | DefKind::Union)
         {
-            self.live_symbols.contains(&local_def_id)
-        } else {
-            false
+            if self.tcx.visibility(impl_item_id).is_public() {
+                // for the public method, we don't know the trait item is used or not,
+                // so we mark the method live if the self is used
+                return self.live_symbols.contains(&local_def_id);
+            }
+
+            if let Some(trait_item_id) = self.tcx.associated_item(impl_item_id).trait_item_def_id
+                && let Some(local_id) = trait_item_id.as_local()
+            {
+                // for the private method, we can know the trait item is used or not,
+                // so we mark the method live if the self is used and the trait item is used
+                return self.live_symbols.contains(&local_id)
+                    && self.live_symbols.contains(&local_def_id);
+            }
         }
+        false
     }
 }
 
@@ -745,20 +760,22 @@ fn check_item<'tcx>(
                         matches!(fn_sig.decl.implicit_self, hir::ImplicitSelfKind::None);
                 }
 
-                // for impl trait blocks, mark associate functions live if the trait is public
+                // for trait impl blocks,
+                // mark the method live if the self_ty is public,
+                // or the method is public and may construct self
                 if of_trait
                     && (!matches!(tcx.def_kind(local_def_id), DefKind::AssocFn)
                         || tcx.visibility(local_def_id).is_public()
                             && (ty_is_pub || may_construct_self))
                 {
                     worklist.push((local_def_id, ComesFromAllowExpect::No));
-                } else if of_trait && tcx.visibility(local_def_id).is_public() {
-                    // pub method && private ty & methods not construct self
-                    unsolved_impl_items.push((id, local_def_id));
                 } else if let Some(comes_from_allow) =
                     has_allow_dead_code_or_lang_attr(tcx, local_def_id)
                 {
                     worklist.push((local_def_id, comes_from_allow));
+                } else if of_trait {
+                    // private method || public method not constructs self
+                    unsolved_impl_items.push((id, local_def_id));
                 }
             }
         }

Diff for: compiler/rustc_smir/src/rustc_smir/context.rs

@@ -23,8 +23,8 @@ use stable_mir::mir::{BinOp, Body, Place};
 use stable_mir::target::{MachineInfo, MachineSize};
 use stable_mir::ty::{
     AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, Const, FieldDef, FnDef, ForeignDef,
-    ForeignItemKind, GenericArgs, LineInfo, PolyFnSig, RigidTy, Span, Ty, TyKind, UintTy,
-    VariantDef,
+    ForeignItemKind, GenericArgs, IntrinsicDef, LineInfo, PolyFnSig, RigidTy, Span, Ty, TyKind,
+    UintTy, VariantDef,
 };
 use stable_mir::{Crate, CrateDef, CrateItem, CrateNum, DefId, Error, Filename, ItemKind, Symbol};
 use std::cell::RefCell;
@@ -312,6 +312,28 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         sig.stable(&mut *tables)
     }
 
+    fn intrinsic(&self, def: DefId) -> Option<IntrinsicDef> {
+        let mut tables = self.0.borrow_mut();
+        let tcx = tables.tcx;
+        let def_id = def.internal(&mut *tables, tcx);
+        let intrinsic = tcx.intrinsic_raw(def_id);
+        intrinsic.map(|_| IntrinsicDef(def))
+    }
+
+    fn intrinsic_name(&self, def: IntrinsicDef) -> Symbol {
+        let mut tables = self.0.borrow_mut();
+        let tcx = tables.tcx;
+        let def_id = def.0.internal(&mut *tables, tcx);
+        tcx.intrinsic(def_id).unwrap().name.to_string()
+    }
+
+    fn intrinsic_must_be_overridden(&self, def: IntrinsicDef) -> bool {
+        let mut tables = self.0.borrow_mut();
+        let tcx = tables.tcx;
+        let def_id = def.0.internal(&mut *tables, tcx);
+        tcx.intrinsic_raw(def_id).unwrap().must_be_overridden
+    }
+
     fn closure_sig(&self, args: &GenericArgs) -> PolyFnSig {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
@@ -650,16 +672,6 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    /// Retrieve the plain intrinsic name of an instance.
-    ///
-    /// This assumes that the instance is an intrinsic.
-    fn intrinsic_name(&self, def: InstanceDef) -> Symbol {
-        let tables = self.0.borrow_mut();
-        let instance = tables.instances[def];
-        let intrinsic = tables.tcx.intrinsic(instance.def_id()).unwrap();
-        intrinsic.name.to_string()
-    }
-
     fn ty_layout(&self, ty: Ty) -> Result<Layout, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;

Diff for: compiler/stable_mir/src/compiler_interface.rs

@@ -13,8 +13,8 @@ use crate::target::MachineInfo;
 use crate::ty::{
     AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, Const, FieldDef, FnDef, ForeignDef,
     ForeignItemKind, ForeignModule, ForeignModuleDef, GenericArgs, GenericPredicates, Generics,
-    ImplDef, ImplTrait, LineInfo, PolyFnSig, RigidTy, Span, TraitDecl, TraitDef, Ty, TyKind,
-    UintTy, VariantDef,
+    ImplDef, ImplTrait, IntrinsicDef, LineInfo, PolyFnSig, RigidTy, Span, TraitDecl, TraitDef, Ty,
+    TyKind, UintTy, VariantDef,
 };
 use crate::{
     mir, Crate, CrateItem, CrateItems, CrateNum, DefId, Error, Filename, ImplTraitDecls, ItemKind,
@@ -88,6 +88,16 @@ pub trait Context {
     /// Retrieve the function signature for the given generic arguments.
     fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig;
 
+    /// Retrieve the intrinsic definition if the item corresponds one.
+    fn intrinsic(&self, item: DefId) -> Option<IntrinsicDef>;
+
+    /// Retrieve the plain function name of an intrinsic.
+    fn intrinsic_name(&self, def: IntrinsicDef) -> Symbol;
+
+    /// Returns whether the intrinsic has no meaningful body and all backends
+    /// need to shim all calls to it.
+    fn intrinsic_must_be_overridden(&self, def: IntrinsicDef) -> bool;
+
     /// Retrieve the closure signature for the given generic arguments.
     fn closure_sig(&self, args: &GenericArgs) -> PolyFnSig;
 
@@ -198,7 +208,6 @@ pub trait Context {
     fn vtable_allocation(&self, global_alloc: &GlobalAlloc) -> Option<AllocId>;
     fn krate(&self, def_id: DefId) -> Crate;
     fn instance_name(&self, def: InstanceDef, trimmed: bool) -> Symbol;
-    fn intrinsic_name(&self, def: InstanceDef) -> Symbol;
 
     /// Return information about the target machine.
     fn target_info(&self) -> MachineInfo;

Diff for: compiler/stable_mir/src/mir/mono.rs

@@ -106,7 +106,9 @@ impl Instance {
     /// which is more convenient to match with intrinsic symbols.
     pub fn intrinsic_name(&self) -> Option<Symbol> {
         match self.kind {
-            InstanceKind::Intrinsic => Some(with(|context| context.intrinsic_name(self.def))),
+            InstanceKind::Intrinsic => {
+                Some(with(|context| context.intrinsic(self.def.def_id()).unwrap().fn_name()))
+            }
             InstanceKind::Item | InstanceKind::Virtual { .. } | InstanceKind::Shim => None,
         }
     }

Diff for: compiler/stable_mir/src/ty.rs

@@ -621,6 +621,41 @@ impl FnDef {
     pub fn body(&self) -> Option<Body> {
         with(|ctx| ctx.has_body(self.0).then(|| ctx.mir_body(self.0)))
     }
+
+    /// Get the information of the intrinsic if this function is a definition of one.
+    pub fn as_intrinsic(&self) -> Option<IntrinsicDef> {
+        with(|cx| cx.intrinsic(self.def_id()))
+    }
+
+    /// Check if the function is an intrinsic.
+    #[inline]
+    pub fn is_intrinsic(&self) -> bool {
+        self.as_intrinsic().is_some()
+    }
+}
+
+crate_def! {
+    pub IntrinsicDef;
+}
+
+impl IntrinsicDef {
+    /// Returns the plain name of the intrinsic.
+    /// e.g., `transmute` for `core::intrinsics::transmute`.
+    pub fn fn_name(&self) -> Symbol {
+        with(|cx| cx.intrinsic_name(*self))
+    }
+
+    /// Returns whether the intrinsic has no meaningful body and all backends
+    /// need to shim all calls to it.
+    pub fn must_be_overridden(&self) -> bool {
+        with(|cx| cx.intrinsic_must_be_overridden(*self))
+    }
+}
+
+impl From<IntrinsicDef> for FnDef {
+    fn from(def: IntrinsicDef) -> Self {
+        FnDef(def.0)
+    }
 }
 
 crate_def! {

Diff for: library/proc_macro/src/lib.rs

@@ -815,6 +815,18 @@ pub enum Delimiter {
     /// "macro variable" `$var`. It is important to preserve operator priorities in cases like
     /// `$var * 3` where `$var` is `1 + 2`.
     /// Invisible delimiters might not survive roundtrip of a token stream through a string.
+    ///
+    /// <div class="warning">
+    ///
+    /// Note: rustc currently can ignore the grouping of tokens delimited by `None` in the output
+    /// of a proc_macro. Only `None`-delimited groups created by a macro_rules macro in the input
+    /// of a proc_macro macro are preserved, and only in very specific circumstances.
+    /// Any `None`-delimited groups (re)created by a proc_macro will therefore not preserve
+    /// operator priorities as indicated above. The other `Delimiter` variants should be used
+    /// instead in this context. This is a rustc bug. For details, see
+    /// [rust-lang/rust#67062](https://github.com/rust-lang/rust/issues/67062).
+    ///
+    /// </div>
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     None,
 }

Diff for: src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -101,7 +101,6 @@ run-make/issue-25581/Makefile
 run-make/issue-26006/Makefile
 run-make/issue-26092/Makefile
 run-make/issue-28595/Makefile
-run-make/issue-30063/Makefile
 run-make/issue-33329/Makefile
 run-make/issue-35164/Makefile
 run-make/issue-36710/Makefile
@@ -111,7 +110,6 @@ run-make/issue-40535/Makefile
 run-make/issue-47384/Makefile
 run-make/issue-47551/Makefile
 run-make/issue-51671/Makefile
-run-make/issue-53964/Makefile
 run-make/issue-64153/Makefile
 run-make/issue-68794-textrel-on-minimal-lib/Makefile
 run-make/issue-69368/Makefile
@@ -229,7 +227,6 @@ run-make/rlib-format-packed-bundled-libs/Makefile
 run-make/rmeta-preferred/Makefile
 run-make/rustc-macro-dep-files/Makefile
 run-make/rustdoc-io-error/Makefile
-run-make/rustdoc-scrape-examples-macros/Makefile
 run-make/rustdoc-verify-output-files/Makefile
 run-make/rustdoc-with-output-option/Makefile
 run-make/rustdoc-with-short-out-dir-option/Makefile

Diff for: tests/run-make/issue-53964/app.rs renamed to tests/run-make/external-crate-panic-handle-no-lint/app.rs

@@ -0,0 +1,12 @@
+// Defining a crate that provides panic handling as an external crate
+// could uselessly trigger the "unused external crate" lint. In this test,
+// if the lint is triggered, it will trip #![deny(unused_extern_crates)],
+// and cause the test to fail.
+// See https://github.com/rust-lang/rust/issues/53964
+
+use run_make_support::{rustc, tmp_dir};
+
+fn main() {
+    rustc().input("panic.rs").run();
+    rustc().input("app.rs").panic("abort").emit("obj").library_search_path(tmp_dir()).run();
+}

Diff for: tests/run-make/issue-53964/panic.rs renamed to tests/run-make/external-crate-panic-handle-no-lint/panic.rs

@@ -0,0 +1,38 @@
+// When rustc received 4 codegen-units, an output path and an emit flag all simultaneously,
+// this could cause an annoying recompilation issue, uselessly lengthening the build process.
+// A fix was delivered, which resets codegen-units to 1 when necessary,
+// but as it directly affected the way codegen-units are manipulated,
+// this test was created to check that this fix did not cause compilation failures.
+// See https://github.com/rust-lang/rust/issues/30063
+
+//@ ignore-cross-compile
+
+use run_make_support::{rustc, tmp_dir};
+use std::fs;
+
+fn compile(output_file: &str, emit: Option<&str>) {
+    let mut rustc = rustc();
+    let rustc = rustc.codegen_units(4).output(tmp_dir().join(output_file)).input("foo.rs");
+    if let Some(emit) = emit {
+        rustc.emit(emit);
+    }
+    rustc.run();
+}
+
+fn main() {
+    let flags = [
+        ("foo-output", None),
+        ("asm-output", Some("asm")),
+        ("bc-output", Some("llvm-bc")),
+        ("ir-output", Some("llvm-ir")),
+        ("link-output", Some("link")),
+        ("obj-output", Some("obj")),
+        ("dep-output", Some("dep-info")),
+        ("multi-output", Some("asm,obj")),
+    ];
+    for (output_file, emit) in flags {
+        fs::remove_file(output_file).unwrap_or_default();
+        compile(output_file, emit);
+        fs::remove_file(output_file);
+    }
+}