Auto merge of #156263 - jhpratt:rollup-aEyNvml, r=jhpratt

Rollup of 14 pull requests

Successful merges:

 - #146273 (lint ImproperCTypes: refactor linting architecture (part 2))
 - #149509 (Lint unused pub items in binary crates)
 - #156173 (Fewer global node_id_to_def_id lookups)
 - #156177 (windows/time: avoid being too close to 0)
 - #155961 (Deny warnings in the test for crates that are available on stable)
 - #155981 (Use special DefIds for aliases)
 - #156109 (Migrate libraries from ptr::slice_from_raw_parts to .cast_slice)
 - #156130 (Fold/visit tweaks)
 - #156131 (Metadata macro/query cleanups)
 - #156202 (llvm: Use correct type for splat mask)
 - #156227 (Add Trusty OS to the generic error implementation.)
 - #156237 (compiletest: prevent directives from having multiple revisions)
 - #156241 (Move tests coercion)
 - #156258 (Document wasi-sdk minimum versions for WASI targets)

Author: bors

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -2086,7 +2086,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
     }
 
     if name == sym::simd_splat {
-        let (_out_len, out_ty) = require_simd!(ret_ty, SimdReturn);
+        let (out_len, out_ty) = require_simd!(ret_ty, SimdReturn);
 
         require!(
             args[0].layout.ty == out_ty,
@@ -2105,7 +2105,8 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
 
         // `shufflevector <N x elem> v0, <N x elem> poison, <N x i32> zeroinitializer`
         // The masks is all zeros, so this splats lane 0 (which has our element in it).
-        let splat = bx.shuffle_vector(v0, poison_vec, bx.const_null(llret_ty));
+        let mask_ty = bx.type_vector(bx.type_i32(), out_len);
+        let splat = bx.shuffle_vector(v0, poison_vec, bx.const_null(mask_ty));
 
         return Ok(splat);
     }

compiler/rustc_lint/src/types/improper_ctypes.rs

@@ -34,6 +34,7 @@ declare_lint_pass! {
         CONST_EVALUATABLE_UNCHECKED,
         CONST_ITEM_MUTATION,
         DEAD_CODE,
+        DEAD_CODE_PUB_IN_BINARY,
         DEPENDENCY_ON_UNIT_NEVER_TYPE_FALLBACK,
         DEPRECATED,
         DEPRECATED_IN_FUTURE,
@@ -789,6 +790,37 @@ declare_lint! {
     "detect unused, unexported items"
 }
 
+declare_lint! {
+    /// The `dead_code_pub_in_binary` lint detects unused `pub` items in
+    /// executable crates.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// #![deny(dead_code_pub_in_binary)]
+    ///
+    /// pub fn unused_pub_fn() {}
+    ///
+    /// fn main() {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// In executable crates, `pub` items are often implementation details
+    /// rather than part of an external API. This lint helps find those items
+    /// when they are never used.
+    ///
+    /// This lint only applies to executable crates. In library crates, public
+    /// items are considered part of the crate's API and are not reported by
+    /// this lint.
+    pub DEAD_CODE_PUB_IN_BINARY,
+    Allow,
+    "detect public items in executable crates that are never used",
+    crate_level_only
+}
+
 declare_lint! {
     /// The `unused_attributes` lint detects attributes that were not used by
     /// the compiler.

compiler/rustc_lint_defs/src/builtin.rs

@@ -261,7 +261,8 @@ provide! { tcx, def_id, other, cdata,
             .coerce_unsized_info
             .get(cdata, def_id.index)
             .map(|lazy| lazy.decode((cdata, tcx)))
-            .process_decoded(tcx, || panic!("{def_id:?} does not have coerce_unsized_info"))) }
+            .process_decoded(tcx, || panic!("{def_id:?} does not have coerce_unsized_info")))
+    }
     mir_const_qualif => { table }
     rendered_const => { table }
     rendered_precise_capturing_args => { table }
@@ -300,10 +301,10 @@ provide! { tcx, def_id, other, cdata,
         Ok(cdata
             .root
             .tables
-            .trait_impl_trait_tys
+            .collect_return_position_impl_trait_in_trait_tys
             .get(cdata, def_id.index)
             .map(|lazy| lazy.decode((cdata, tcx)))
-            .process_decoded(tcx, || panic!("{def_id:?} does not have trait_impl_trait_tys")))
+            .process_decoded(tcx, || panic!("{def_id:?} does not have collect_return_position_impl_trait_in_trait_tys")))
     }
 
     associated_types_for_impl_traits_in_trait_or_impl => { table }
@@ -695,6 +696,7 @@ impl CrateStore for CStore {
     fn as_any(&self) -> &dyn Any {
         self
     }
+
     fn untracked_as_any(&mut self) -> &mut dyn Any {
         self
     }

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -1628,7 +1628,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             if tcx.impl_method_has_trait_impl_trait_tys(def_id)
                 && let Ok(table) = self.tcx.collect_return_position_impl_trait_in_trait_tys(def_id)
             {
-                record!(self.tables.trait_impl_trait_tys[def_id] <- table);
+                record!(self.tables.collect_return_position_impl_trait_in_trait_tys[def_id] <- table);
             }
             if let DefKind::Impl { .. } | DefKind::Trait = def_kind {
                 let table = tcx.associated_types_for_impl_traits_in_trait_or_impl(def_id);

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -466,7 +466,7 @@ define_tables! {
     macro_definition: Table<DefIndex, LazyValue<ast::DelimArgs>>,
     proc_macro: Table<DefIndex, MacroKind>,
     deduced_param_attrs: Table<DefIndex, LazyArray<DeducedParamAttrs>>,
-    trait_impl_trait_tys: Table<DefIndex, LazyValue<DefIdMap<ty::EarlyBinder<'static, Ty<'static>>>>>,
+    collect_return_position_impl_trait_in_trait_tys: Table<DefIndex, LazyValue<DefIdMap<ty::EarlyBinder<'static, Ty<'static>>>>>,
     doc_link_resolutions: Table<DefIndex, LazyValue<DocLinkResMap>>,
     doc_link_traits_in_scope: Table<DefIndex, LazyArray<DefId>>,
     assumed_wf_types_for_rpitit: Table<DefIndex, LazyArray<(Ty<'static>, Span)>>,

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -1,16 +1,15 @@
 /// This higher-order macro declares a list of types which can be allocated by `Arena`.
 ///
 /// Specifying the `decode` modifier will add decode impls for `&T` and `&[T]` where `T` is the type
-/// listed. These impls will appear in the implement_ty_decoder! macro.
+/// listed. See the `impl_arena_allocatable_decoder!` macro for more.
 #[macro_export]
 macro_rules! arena_types {
     ($macro:path) => (
         $macro!([
             [] layout: rustc_abi::LayoutData<rustc_abi::FieldIdx, rustc_abi::VariantIdx>,
             [] proxy_coroutine_layout: rustc_middle::mir::CoroutineLayout<'tcx>,
             [] fn_abi: rustc_target::callconv::FnAbi<'tcx, rustc_middle::ty::Ty<'tcx>>,
-            // AdtDef are interned and compared by address
-            [decode] adt_def: rustc_middle::ty::AdtDefData,
+            [] adt_def: rustc_middle::ty::AdtDefData,
             [] steal_thir: rustc_data_structures::steal::Steal<rustc_middle::thir::Thir<'tcx>>,
             [] steal_mir: rustc_data_structures::steal::Steal<rustc_middle::mir::Body<'tcx>>,
             [decode] mir: rustc_middle::mir::Body<'tcx>,
@@ -27,7 +26,7 @@ macro_rules! arena_types {
                     rustc_middle::mir::Body<'tcx>
                 >,
             [decode] typeck_results: rustc_middle::ty::TypeckResults<'tcx>,
-            [decode] borrowck_result: rustc_data_structures::fx::FxIndexMap<
+            [] borrowck_result: rustc_data_structures::fx::FxIndexMap<
                 rustc_hir::def_id::LocalDefId,
                 rustc_middle::ty::DefinitionSiteHiddenType<'tcx>,
             >,
@@ -100,7 +99,7 @@ macro_rules! arena_types {
             // (during lowering) and the `rustc_middle` arena (for decoding MIR)
             [decode] asm_template: rustc_ast::InlineAsmTemplatePiece,
             [decode] used_trait_imports: rustc_data_structures::unord::UnordSet<rustc_hir::def_id::LocalDefId>,
-            [decode] is_late_bound_map: rustc_data_structures::fx::FxIndexSet<rustc_hir::ItemLocalId>,
+            [] is_late_bound_map: rustc_data_structures::fx::FxIndexSet<rustc_hir::ItemLocalId>,
             [decode] impl_source: rustc_middle::traits::ImplSource<'tcx, ()>,
 
             [] dep_kind_vtable: rustc_middle::dep_graph::DepKindVTable<'tcx>,
@@ -111,7 +110,7 @@ macro_rules! arena_types {
                     rustc_middle::ty::EarlyBinder<'tcx, rustc_middle::ty::Ty<'tcx>>
                 >,
             [] external_constraints: rustc_middle::traits::solve::ExternalConstraintsData<rustc_middle::ty::TyCtxt<'tcx>>,
-            [decode] doc_link_resolutions: rustc_hir::def::DocLinkResMap,
+            [] doc_link_resolutions: rustc_hir::def::DocLinkResMap,
             [] stripped_cfg_items: rustc_hir::attrs::StrippedCfgItem,
             [] mod_child: rustc_middle::metadata::ModChild,
             [] features: rustc_feature::Features,

compiler/rustc_middle/src/arena.rs

@@ -0,0 +1,23 @@
+use rustc_data_structures::fx::FxIndexSet;
+use rustc_hir::def_id::{DefId, LocalDefIdMap, LocalDefIdSet};
+use rustc_macros::StableHash;
+
+/// A single snapshot of dead-code liveness analysis state.
+#[derive(Clone, Debug, StableHash)]
+pub struct DeadCodeLivenessSnapshot {
+    pub live_symbols: LocalDefIdSet,
+    /// Maps each ADT to derived traits (for example `Debug` and `Clone`) that should be ignored
+    /// when checking for dead code diagnostics.
+    pub ignored_derived_traits: LocalDefIdMap<FxIndexSet<DefId>>,
+}
+
+/// Dead-code liveness data for both analysis phases.
+///
+/// `pre_deferred_seeding` is computed before reachable-public and `#[allow(dead_code)]` seeding,
+/// and is used for lint `dead_code_pub_in_binary`.
+/// `final_result` is the final liveness snapshot used for lint `dead_code`.
+#[derive(Clone, Debug, StableHash)]
+pub struct DeadCodeLivenessSummary {
+    pub pre_deferred_seeding: DeadCodeLivenessSnapshot,
+    pub final_result: DeadCodeLivenessSnapshot,
+}

compiler/rustc_middle/src/middle/dead_code.rs

@@ -1,4 +1,5 @@
 pub mod codegen_fn_attrs;
+pub mod dead_code;
 pub mod debugger_visualizer;
 pub mod deduced_param_attrs;
 pub mod dependency_format;

compiler/rustc_middle/src/middle/mod.rs

@@ -64,9 +64,7 @@ use rustc_errors::{ErrorGuaranteed, catch_fatal_errors};
 use rustc_hir as hir;
 use rustc_hir::attrs::{EiiDecl, EiiImpl, StrippedCfgItem};
 use rustc_hir::def::{DefKind, DocLinkResMap};
-use rustc_hir::def_id::{
-    CrateNum, DefId, DefIdMap, LocalDefId, LocalDefIdMap, LocalDefIdSet, LocalModDefId,
-};
+use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, LocalDefIdSet, LocalModDefId};
 use rustc_hir::lang_items::{LangItem, LanguageItems};
 use rustc_hir::{ItemLocalId, ItemLocalMap, PreciseCapturingArgKind, TraitCandidate};
 use rustc_index::IndexVec;
@@ -87,6 +85,7 @@ use crate::infer::canonical::{self, Canonical};
 use crate::lint::LintExpectation;
 use crate::metadata::ModChild;
 use crate::middle::codegen_fn_attrs::{CodegenFnAttrs, SanitizerFnAttrs};
+use crate::middle::dead_code::DeadCodeLivenessSummary;
 use crate::middle::debugger_visualizer::DebuggerVisualizerFile;
 use crate::middle::deduced_param_attrs::DeducedParamAttrs;
 use crate::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo};
@@ -1203,13 +1202,8 @@ rustc_queries! {
         desc { "checking liveness of variables in `{}`", tcx.def_path_str(key.to_def_id()) }
     }
 
-    /// Return the live symbols in the crate for dead code check.
-    ///
-    /// The second return value maps from ADTs to ignored derived traits (e.g. Debug and Clone).
-    query live_symbols_and_ignored_derived_traits(_: ()) -> Result<&'tcx (
-        LocalDefIdSet,
-        LocalDefIdMap<FxIndexSet<DefId>>,
-    ), ErrorGuaranteed> {
+    /// Return dead-code liveness summary for the crate.
+    query live_symbols_and_ignored_derived_traits(_: ()) -> Result<&'tcx DeadCodeLivenessSummary, ErrorGuaranteed> {
         arena_cache
         desc { "finding live symbols in crate" }
     }