Rollup merge of #150072 - Bryntet:parse_no_link, r=JonathanBrouwer

Port #[no_link] to use attribute parser

Adds `#[no_link]` to the attribute parser, as well as adds tests making sure to FCW warn on `field`, `arm`, and `macrodef `

Author: jhpratt

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -47,6 +47,7 @@ pub(crate) mod loop_match;
 pub(crate) mod macro_attrs;
 pub(crate) mod must_use;
 pub(crate) mod no_implicit_prelude;
+pub(crate) mod no_link;
 pub(crate) mod non_exhaustive;
 pub(crate) mod path;
 pub(crate) mod pin_v2;

compiler/rustc_attr_parsing/src/attributes/no_link.rs

@@ -0,0 +1,14 @@
+use super::prelude::*;
+
+pub(crate) struct NoLinkParser;
+impl<S: Stage> NoArgsAttributeParser<S> for NoLinkParser {
+    const PATH: &[Symbol] = &[sym::no_link];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
+        Allow(Target::ExternCrate),
+        Warn(Target::Field),
+        Warn(Target::Arm),
+        Warn(Target::MacroDef),
+    ]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::NoLink;
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -50,6 +50,7 @@ use crate::attributes::macro_attrs::{
 };
 use crate::attributes::must_use::MustUseParser;
 use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser;
+use crate::attributes::no_link::NoLinkParser;
 use crate::attributes::non_exhaustive::NonExhaustiveParser;
 use crate::attributes::path::PathParser as PathAttributeParser;
 use crate::attributes::pin_v2::PinV2Parser;
@@ -241,6 +242,7 @@ attribute_parsers!(
         Single<WithoutArgs<MayDangleParser>>,
         Single<WithoutArgs<NoCoreParser>>,
         Single<WithoutArgs<NoImplicitPreludeParser>>,
+        Single<WithoutArgs<NoLinkParser>>,
         Single<WithoutArgs<NoMangleParser>>,
         Single<WithoutArgs<NoStdParser>>,
         Single<WithoutArgs<NonExhaustiveParser>>,

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -803,6 +803,9 @@ pub enum AttributeKind {
     /// Represents `#[no_implicit_prelude]`
     NoImplicitPrelude(Span),
 
+    /// Represents `#[no_link]`
+    NoLink,
+
     /// Represents `#[no_mangle]`
     NoMangle(Span),
 

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -70,6 +70,7 @@ impl AttributeKind {
             Naked(..) => No,
             NoCore(..) => No,
             NoImplicitPrelude(..) => No,
+            NoLink => No,
             NoMangle(..) => Yes, // Needed for rustdoc
             NoStd(..) => No,
             NonExhaustive(..) => Yes, // Needed for rustdoc

compiler/rustc_passes/messages.ftl

@@ -240,11 +240,6 @@ passes_has_incoherent_inherent_impl =
     `rustc_has_incoherent_inherent_impls` attribute should be applied to types or traits
     .label = only adts, extern types and traits are supported
 
-passes_ignored_attr_with_macro =
-    `#[{$sym}]` is ignored on struct fields, match arms and macro defs
-    .warn = {-passes_previously_accepted}
-    .note = {-passes_see_issue(issue: "80564")}
-
 passes_ignored_derived_impls =
     `{$name}` has {$trait_list_len ->
       [one] a derived impl
@@ -379,10 +374,6 @@ passes_must_not_suspend =
     `must_not_suspend` attribute should be applied to a struct, enum, union, or trait
     .label = is not a struct, enum, union, or trait
 
-passes_no_link =
-    attribute should be applied to an `extern crate` item
-    .label = not an `extern crate` item
-
 passes_no_main_function =
     `main` function not found in crate `{$crate_name}`
     .here_is_main = here is a function named `main`

compiler/rustc_passes/src/check_attr.rs

@@ -254,6 +254,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::LinkSection { .. }
                     | AttributeKind::MacroUse { .. }
                     | AttributeKind::MacroEscape( .. )
+                    | AttributeKind::NoLink
                     | AttributeKind::RustcLayoutScalarValidRangeStart(..)
                     | AttributeKind::RustcLayoutScalarValidRangeEnd(..)
                     | AttributeKind::RustcScalableVector { .. }
@@ -303,7 +304,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             self.check_diagnostic_on_const(attr.span(), hir_id, target, item)
                         }
                         [sym::thread_local, ..] => self.check_thread_local(attr, span, target),
-                        [sym::no_link, ..] => self.check_no_link(hir_id, attr, span, target),
                         [sym::rustc_no_implicit_autorefs, ..] => {
                             self.check_applied_to_fn_or_method(hir_id, attr.span(), span, target)
                         }
@@ -457,15 +457,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         self.check_mix_no_mangle_export(hir_id, attrs);
     }
 
-    fn inline_attr_str_error_with_macro_def(&self, hir_id: HirId, attr_span: Span, sym: &str) {
-        self.tcx.emit_node_span_lint(
-            UNUSED_ATTRIBUTES,
-            hir_id,
-            attr_span,
-            errors::IgnoredAttrWithMacro { sym },
-        );
-    }
-
     fn check_eii_impl(&self, impls: &[EiiImpl], target: Target) {
         for EiiImpl { span, inner_span, eii_macro, impl_marked_unsafe, is_default: _ } in impls {
             match target {
@@ -1199,23 +1190,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         );
     }
 
-    /// Checks if `#[no_link]` is applied to an `extern crate`.
-    fn check_no_link(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) {
-        match target {
-            Target::ExternCrate => {}
-            // FIXME(#80564): We permit struct fields, match arms and macro defs to have an
-            // `#[no_link]` attribute with just a lint, because we previously
-            // erroneously allowed it and some crates used it accidentally, to be compatible
-            // with crates depending on them, we can't throw an error here.
-            Target::Field | Target::Arm | Target::MacroDef => {
-                self.inline_attr_str_error_with_macro_def(hir_id, attr.span(), "no_link");
-            }
-            _ => {
-                self.dcx().emit_err(errors::NoLink { attr_span: attr.span(), span });
-            }
-        }
-    }
-
     /// Checks if `#[rustc_legacy_const_generics]` is applied to a function and has a valid argument.
     fn check_rustc_legacy_const_generics(
         &self,

compiler/rustc_passes/src/errors.rs

@@ -80,12 +80,6 @@ pub(crate) struct OuterCrateLevelAttrSuggestion {
 #[diag(passes_inner_crate_level_attr)]
 pub(crate) struct InnerCrateLevelAttr;
 
-#[derive(LintDiagnostic)]
-#[diag(passes_ignored_attr_with_macro)]
-pub(crate) struct IgnoredAttrWithMacro<'a> {
-    pub sym: &'a str,
-}
-
 #[derive(Diagnostic)]
 #[diag(passes_should_be_applied_to_fn)]
 pub(crate) struct AttrShouldBeAppliedToFn {
@@ -254,15 +248,6 @@ pub(crate) struct Link {
     pub span: Option<Span>,
 }
 
-#[derive(Diagnostic)]
-#[diag(passes_no_link)]
-pub(crate) struct NoLink {
-    #[primary_span]
-    pub attr_span: Span,
-    #[label]
-    pub span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(passes_rustc_legacy_const_generics_only)]
 pub(crate) struct RustcLegacyConstGenericsOnly {

tests/ui/attributes/malformed-attrs.stderr

@@ -147,14 +147,6 @@ error: malformed `thread_local` attribute input
 LL | #[thread_local()]
    | ^^^^^^^^^^^^^^^^^ help: must be of the form: `#[thread_local]`
 
-error: malformed `no_link` attribute input
-  --> $DIR/malformed-attrs.rs:214:1
-   |
-LL | #[no_link()]
-   | ^^^^^^^^^^^^ help: must be of the form: `#[no_link]`
-   |
-   = note: for more information, visit <https://doc.rust-lang.org/reference/items/extern-crates.html#the-no_link-attribute>
-
 error: the `#[proc_macro]` attribute is only usable with crates of the `proc-macro` crate type
   --> $DIR/malformed-attrs.rs:105:1
    |
@@ -626,6 +618,15 @@ LL | #[non_exhaustive = 1]
    | |                didn't expect any arguments here
    | help: must be of the form: `#[non_exhaustive]`
 
+error[E0565]: malformed `no_link` attribute input
+  --> $DIR/malformed-attrs.rs:214:1
+   |
+LL | #[no_link()]
+   | ^^^^^^^^^--^
+   | |        |
+   | |        didn't expect any arguments here
+   | help: must be of the form: `#[no_link]`
+
 error[E0539]: malformed `macro_use` attribute input
   --> $DIR/malformed-attrs.rs:216:1
    |

tests/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.rs

@@ -1,4 +1,3 @@
-//~ NOTE: not an `extern crate` item
 // This is testing whether various builtin attributes signals an
 // error or warning when put in "weird" places.
 //
@@ -29,7 +28,7 @@
 //~| WARN cannot be used on crates
 //~| WARN previously accepted
 #![no_link]
-//~^ ERROR: attribute should be applied to an `extern crate` item
+//~^ ERROR: `#[no_link]` attribute cannot be used on crates
 #![export_name = "2200"]
 //~^ ERROR: attribute cannot be used on
 //~| NOTE takes precedence
@@ -60,29 +59,40 @@ mod inline {
 }
 
 #[no_link]
-//~^ ERROR attribute should be applied to an `extern crate` item
+//~^ ERROR `#[no_link]` attribute cannot be used on modules
 mod no_link {
-    //~^ NOTE not an `extern crate` item
-
     mod inner { #![no_link] }
-    //~^ ERROR attribute should be applied to an `extern crate` item
-    //~| NOTE not an `extern crate` item
-
-    #[no_link] fn f() { }
-    //~^ ERROR attribute should be applied to an `extern crate` item
-    //~| NOTE not an `extern crate` item
+    //~^ ERROR `#[no_link]` attribute cannot be used on modules
+
+    #[no_link] fn f() {
+        //~^ ERROR `#[no_link]` attribute cannot be used on functions
+        match () {
+            #[no_link]
+            //~^ WARN `#[no_link]` attribute cannot be used on match arms [unused_attributes]
+            //~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+            _ => ()
+        }
+    }
 
-    #[no_link] struct S;
-    //~^ ERROR attribute should be applied to an `extern crate` item
-    //~| NOTE not an `extern crate` item
+    #[no_link]
+    //~^ ERROR `#[no_link]` attribute cannot be used on structs
+    struct S {
+        #[no_link]
+        //~^ WARN `#[no_link]` attribute cannot be used on struct fields [unused_attributes]
+        //~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+        field: ()
+    }
 
     #[no_link]type T = S;
-    //~^ ERROR attribute should be applied to an `extern crate` item
-    //~| NOTE not an `extern crate` item
+    //~^ ERROR `#[no_link]` attribute cannot be used on type aliases
 
     #[no_link] impl S { }
-    //~^ ERROR attribute should be applied to an `extern crate` item
-    //~| NOTE not an `extern crate` item
+    //~^ ERROR `#[no_link]` attribute cannot be used on inherent impl blocks
+
+    #[no_link]
+    //~^ WARN `#[no_link]` attribute cannot be used on macro defs
+    //~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+    macro_rules! m{() => {}}
 }
 
 #[export_name = "2200"]