Auto merge of #145063 - tgross35:rollup-mkyt3zj, r=tgross35

Rollup of 8 pull requests

Successful merges:

 - #144705 (compiler-builtins: plumb LSE support for aarch64 on linux/gnu when optimized-compiler-builtins not enabled)
 - #144857 (Port `#[allow_internal_unsafe]` to the new attribute system)
 - #144900 (Stabilize `unsigned_signed_diff` feature)
 - #144903 (Rename `begin_panic_handler` to `panic_handler`)
 - #144974 (compiler-builtins subtree update)
 - #145004 (Couple of minor cleanups)
 - #145007 (Fix build/doc/test of error index generator)
 - #145018 (Derive `Hash` for rustc_public types)

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

Author: bors

compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs

@@ -113,3 +113,11 @@ impl<S: Stage> AttributeParser<S> for MacroUseParser {
         Some(AttributeKind::MacroUse { span: self.first_span?, arguments: self.state })
     }
 }
+
+pub(crate) struct AllowInternalUnsafeParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for AllowInternalUnsafeParser {
+    const PATH: &[Symbol] = &[sym::allow_internal_unsafe];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Ignore;
+    const CREATE: fn(Span) -> AttributeKind = |span| AttributeKind::AllowInternalUnsafe(span);
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -33,7 +33,9 @@ use crate::attributes::lint_helpers::{
     AsPtrParser, AutomaticallyDerivedParser, PassByValueParser, PubTransparentParser,
 };
 use crate::attributes::loop_match::{ConstContinueParser, LoopMatchParser};
-use crate::attributes::macro_attrs::{MacroEscapeParser, MacroUseParser};
+use crate::attributes::macro_attrs::{
+    AllowInternalUnsafeParser, MacroEscapeParser, MacroUseParser,
+};
 use crate::attributes::must_use::MustUseParser;
 use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser;
 use crate::attributes::non_exhaustive::NonExhaustiveParser;
@@ -178,6 +180,7 @@ attribute_parsers!(
         Single<SkipDuringMethodDispatchParser>,
         Single<TransparencyParser>,
         Single<WithoutArgs<AllowIncoherentImplParser>>,
+        Single<WithoutArgs<AllowInternalUnsafeParser>>,
         Single<WithoutArgs<AsPtrParser>>,
         Single<WithoutArgs<AutomaticallyDerivedParser>>,
         Single<WithoutArgs<CoherenceIsCoreParser>>,

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -862,7 +862,7 @@ pub(crate) fn codegen(
                     .generic_activity_with_arg("LLVM_module_codegen_embed_bitcode", &*module.name);
                 let thin_bc =
                     module.thin_lto_buffer.as_deref().expect("cannot find embedded bitcode");
-                embed_bitcode(cgcx, llcx, llmod, &config.bc_cmdline, &thin_bc);
+                embed_bitcode(cgcx, llcx, llmod, &thin_bc);
             }
         }
 
@@ -1058,40 +1058,38 @@ fn embed_bitcode(
     cgcx: &CodegenContext<LlvmCodegenBackend>,
     llcx: &llvm::Context,
     llmod: &llvm::Module,
-    cmdline: &str,
     bitcode: &[u8],
 ) {
     // We're adding custom sections to the output object file, but we definitely
     // do not want these custom sections to make their way into the final linked
-    // executable. The purpose of these custom sections is for tooling
-    // surrounding object files to work with the LLVM IR, if necessary. For
-    // example rustc's own LTO will look for LLVM IR inside of the object file
-    // in these sections by default.
+    // executable. The purpose of this custom section is for tooling surrounding
+    // object files to work with the LLVM IR, if necessary. For example rustc's
+    // own LTO will look for LLVM IR inside of the object file in this section
+    // by default.
     //
     // To handle this is a bit different depending on the object file format
     // used by the backend, broken down into a few different categories:
     //
     // * Mach-O - this is for macOS. Inspecting the source code for the native
-    //   linker here shows that the `.llvmbc` and `.llvmcmd` sections are
-    //   automatically skipped by the linker. In that case there's nothing extra
-    //   that we need to do here.
+    //   linker here shows that the `.llvmbc` section is automatically skipped
+    //   by the linker. In that case there's nothing extra that we need to do
+    //   here.
     //
-    // * Wasm - the native LLD linker is hard-coded to skip `.llvmbc` and
-    //   `.llvmcmd` sections, so there's nothing extra we need to do.
+    // * Wasm - the native LLD linker is hard-coded to skip `.llvmbc` section,
+    //   so there's nothing extra we need to do.
     //
-    // * COFF - if we don't do anything the linker will by default copy all
-    //   these sections to the output artifact, not what we want! To subvert
-    //   this we want to flag the sections we inserted here as
-    //   `IMAGE_SCN_LNK_REMOVE`.
+    // * COFF - if we don't do anything the linker will by default copy this
+    //   section to the output artifact, not what we want! To subvert this we
+    //   want to flag the section we inserted here as `IMAGE_SCN_LNK_REMOVE`.
     //
-    // * ELF - this is very similar to COFF above. One difference is that these
-    //   sections are removed from the output linked artifact when
-    //   `--gc-sections` is passed, which we pass by default. If that flag isn't
-    //   passed though then these sections will show up in the final output.
-    //   Additionally the flag that we need to set here is `SHF_EXCLUDE`.
+    // * ELF - this is very similar to COFF above. One difference is that this
+    //   section is removed from the output linked artifact when `--gc-sections`
+    //   is passed, which we pass by default. If that flag isn't passed through
+    //   then this section will show up in the final output. Additionally the
+    //   flag that we need to set here is `SHF_EXCLUDE`.
     //
-    // * XCOFF - AIX linker ignores content in .ipa and .info if no auxiliary
-    //   symbol associated with these sections.
+    // * XCOFF - AIX linker ignores content in .ipa if no auxiliary symbol
+    //   associated with this section.
     //
     // Unfortunately, LLVM provides no way to set custom section flags. For ELF
     // and COFF we emit the sections using module level inline assembly for that
@@ -1110,26 +1108,11 @@ fn embed_bitcode(
         llvm::set_section(llglobal, bitcode_section_name(cgcx));
         llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
         llvm::LLVMSetGlobalConstant(llglobal, llvm::True);
-
-        let llconst = common::bytes_in_context(llcx, cmdline.as_bytes());
-        let llglobal = llvm::add_global(llmod, common::val_ty(llconst), c"rustc.embedded.cmdline");
-        llvm::set_initializer(llglobal, llconst);
-        let section = if cgcx.target_is_like_darwin {
-            c"__LLVM,__cmdline"
-        } else if cgcx.target_is_like_aix {
-            c".info"
-        } else {
-            c".llvmcmd"
-        };
-        llvm::set_section(llglobal, section);
-        llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
     } else {
         // We need custom section flags, so emit module-level inline assembly.
         let section_flags = if cgcx.is_pe_coff { "n" } else { "e" };
         let asm = create_section_with_flags_asm(".llvmbc", section_flags, bitcode);
         llvm::append_module_inline_asm(llmod, &asm);
-        let asm = create_section_with_flags_asm(".llvmcmd", section_flags, cmdline.as_bytes());
-        llvm::append_module_inline_asm(llmod, &asm);
     }
 }
 

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -76,12 +76,9 @@ pub struct ModuleConfig {
     /// Names of additional optimization passes to run.
     pub passes: Vec<String>,
     /// Some(level) to optimize at a certain level, or None to run
-    /// absolutely no optimizations (used for the metadata module).
+    /// absolutely no optimizations (used for the allocator module).
     pub opt_level: Option<config::OptLevel>,
 
-    /// Some(level) to optimize binary size, or None to not affect program size.
-    pub opt_size: Option<config::OptLevel>,
-
     pub pgo_gen: SwitchWithOptPath,
     pub pgo_use: Option<PathBuf>,
     pub pgo_sample_use: Option<PathBuf>,
@@ -102,15 +99,13 @@ pub struct ModuleConfig {
     pub emit_obj: EmitObj,
     pub emit_thin_lto: bool,
     pub emit_thin_lto_summary: bool,
-    pub bc_cmdline: String,
 
     // Miscellaneous flags. These are mostly copied from command-line
     // options.
     pub verify_llvm_ir: bool,
     pub lint_llvm_ir: bool,
     pub no_prepopulate_passes: bool,
     pub no_builtins: bool,
-    pub time_module: bool,
     pub vectorize_loop: bool,
     pub vectorize_slp: bool,
     pub merge_functions: bool,
@@ -171,7 +166,6 @@ impl ModuleConfig {
             passes: if_regular!(sess.opts.cg.passes.clone(), vec![]),
 
             opt_level: opt_level_and_size,
-            opt_size: opt_level_and_size,
 
             pgo_gen: if_regular!(
                 sess.opts.cg.profile_generate.clone(),
@@ -221,17 +215,12 @@ impl ModuleConfig {
                 sess.opts.output_types.contains_key(&OutputType::ThinLinkBitcode),
                 false
             ),
-            bc_cmdline: sess.target.bitcode_llvm_cmdline.to_string(),
 
             verify_llvm_ir: sess.verify_llvm_ir(),
             lint_llvm_ir: sess.opts.unstable_opts.lint_llvm_ir,
             no_prepopulate_passes: sess.opts.cg.no_prepopulate_passes,
             no_builtins: no_builtins || sess.target.no_builtins,
 
-            // Exclude metadata and allocator modules from time_passes output,
-            // since they throw off the "LLVM passes" measurement.
-            time_module: if_regular!(true, false),
-
             // Copy what clang does by turning on loop vectorization at O2 and
             // slp vectorization at O3.
             vectorize_loop: !sess.opts.cg.no_vectorize_loops
@@ -1740,7 +1729,7 @@ fn spawn_work<'a, B: ExtraBackendMethods>(
     llvm_start_time: &mut Option<VerboseTimingGuard<'a>>,
     work: WorkItem<B>,
 ) {
-    if cgcx.config(work.module_kind()).time_module && llvm_start_time.is_none() {
+    if llvm_start_time.is_none() {
         *llvm_start_time = Some(cgcx.prof.verbose_generic_activity("LLVM_passes"));
     }
 

compiler/rustc_codegen_ssa/src/base.rs

@@ -681,33 +681,6 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
 
     let ongoing_codegen = start_async_codegen(backend.clone(), tcx, target_cpu, autodiff_items);
 
-    // Codegen an allocator shim, if necessary.
-    if let Some(kind) = allocator_kind_for_codegen(tcx) {
-        let llmod_id =
-            cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("allocator")).to_string();
-        let module_llvm = tcx.sess.time("write_allocator_module", || {
-            backend.codegen_allocator(
-                tcx,
-                &llmod_id,
-                kind,
-                // If allocator_kind is Some then alloc_error_handler_kind must
-                // also be Some.
-                tcx.alloc_error_handler_kind(()).unwrap(),
-            )
-        });
-
-        ongoing_codegen.wait_for_signal_to_codegen_item();
-        ongoing_codegen.check_for_errors(tcx.sess);
-
-        // These modules are generally cheap and won't throw off scheduling.
-        let cost = 0;
-        submit_codegened_module_to_llvm(
-            &ongoing_codegen.coordinator,
-            ModuleCodegen::new_allocator(llmod_id, module_llvm),
-            cost,
-        );
-    }
-
     // For better throughput during parallel processing by LLVM, we used to sort
     // CGUs largest to smallest. This would lead to better thread utilization
     // by, for example, preventing a large CGU from being processed last and
@@ -823,6 +796,35 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
         }
     }
 
+    // Codegen an allocator shim, if necessary.
+    // Do this last to ensure the LLVM_passes timer doesn't start while no CGUs have been codegened
+    // yet for the backend to optimize.
+    if let Some(kind) = allocator_kind_for_codegen(tcx) {
+        let llmod_id =
+            cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("allocator")).to_string();
+        let module_llvm = tcx.sess.time("write_allocator_module", || {
+            backend.codegen_allocator(
+                tcx,
+                &llmod_id,
+                kind,
+                // If allocator_kind is Some then alloc_error_handler_kind must
+                // also be Some.
+                tcx.alloc_error_handler_kind(()).unwrap(),
+            )
+        });
+
+        ongoing_codegen.wait_for_signal_to_codegen_item();
+        ongoing_codegen.check_for_errors(tcx.sess);
+
+        // These modules are generally cheap and won't throw off scheduling.
+        let cost = 0;
+        submit_codegened_module_to_llvm(
+            &ongoing_codegen.coordinator,
+            ModuleCodegen::new_allocator(llmod_id, module_llvm),
+            cost,
+        );
+    }
+
     ongoing_codegen.codegen_finished(tcx);
 
     // Since the main thread is sometimes blocked during codegen, we keep track

compiler/rustc_expand/src/base.rs

@@ -905,10 +905,7 @@ impl SyntaxExtension {
             find_attr!(attrs, AttributeKind::AllowInternalUnstable(i, _) => i)
                 .map(|i| i.as_slice())
                 .unwrap_or_default();
-        // FIXME(jdonszelman): allow_internal_unsafe isn't yet new-style
-        // let allow_internal_unsafe = find_attr!(attrs, AttributeKind::AllowInternalUnsafe);
-        let allow_internal_unsafe =
-            ast::attr::find_by_name(attrs, sym::allow_internal_unsafe).is_some();
+        let allow_internal_unsafe = find_attr!(attrs, AttributeKind::AllowInternalUnsafe(_));
 
         let local_inner_macros = ast::attr::find_by_name(attrs, sym::macro_export)
             .and_then(|macro_export| macro_export.meta_item_list())

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -249,6 +249,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_allow_incoherent_impl]`.
     AllowIncoherentImpl(Span),
 
+    /// Represents `#[allow_internal_unsafe]`.
+    AllowInternalUnsafe(Span),
+
     /// Represents `#[allow_internal_unstable]`.
     AllowInternalUnstable(ThinVec<(Symbol, Span)>, Span),
 

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -16,6 +16,7 @@ impl AttributeKind {
             Align { .. } => No,
             AllowConstFnUnstable(..) => No,
             AllowIncoherentImpl(..) => No,
+            AllowInternalUnsafe(..) => Yes,
             AllowInternalUnstable(..) => Yes,
             AsPtr(..) => Yes,
             AutomaticallyDerived(..) => Yes,

compiler/rustc_lint/src/builtin.rs

@@ -14,13 +14,15 @@
 //! [`crate::late_lint_methods!`] invocation in `lib.rs`.
 
 use std::fmt::Write;
+use std::slice;
 
 use ast::token::TokenKind;
 use rustc_abi::BackendRepr;
 use rustc_ast::tokenstream::{TokenStream, TokenTree};
 use rustc_ast::visit::{FnCtxt, FnKind};
 use rustc_ast::{self as ast, *};
 use rustc_ast_pretty::pprust::expr_to_string;
+use rustc_attr_parsing::AttributeParser;
 use rustc_errors::{Applicability, LintDiagnostic};
 use rustc_feature::GateIssue;
 use rustc_hir as hir;
@@ -249,7 +251,16 @@ impl UnsafeCode {
 
 impl EarlyLintPass for UnsafeCode {
     fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &ast::Attribute) {
-        if attr.has_name(sym::allow_internal_unsafe) {
+        if AttributeParser::parse_limited(
+            cx.builder.sess(),
+            slice::from_ref(attr),
+            sym::allow_internal_unsafe,
+            attr.span,
+            DUMMY_NODE_ID,
+            Some(cx.builder.features()),
+        )
+        .is_some()
+        {
             self.report_unsafe(cx, attr.span, BuiltinUnsafe::AllowInternalUnsafe);
         }
     }

compiler/rustc_passes/messages.ftl

@@ -29,7 +29,7 @@ passes_allow_incoherent_impl =
     `rustc_allow_incoherent_impl` attribute should be applied to impl items
     .label = the only currently supported targets are inherent methods
 
-passes_allow_internal_unstable =
+passes_macro_only_attribute =
     attribute should be applied to a macro
     .label = not a macro