Tweak suggestion span for outer attr and point at item following invalid inner attr

compiler/rustc_passes/messages.ftl

@@ -393,6 +393,9 @@ passes_invalid_attr_at_crate_level =
     `{$name}` attribute cannot be used at crate level
     .suggestion = perhaps you meant to use an outer attribute
 
+passes_invalid_attr_at_crate_level_item =
+    the inner attribute doesn't annotate this {$kind}
+
 passes_invalid_deprecation_version =
     invalid deprecation version found
     .label = invalid deprecation version

compiler/rustc_passes/src/check_attr.rs

@@ -2534,10 +2534,30 @@ fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
         if attr.style == AttrStyle::Inner {
             for attr_to_check in ATTRS_TO_CHECK {
                 if attr.has_name(*attr_to_check) {
+                    let item = tcx
+                        .hir()
+                        .items()
+                        .map(|id| tcx.hir().item(id))
+                        .find(|item| !item.span.is_dummy()) // Skip prelude `use`s
+                        .map(|item| errors::ItemFollowingInnerAttr {
+                            span: item.ident.span,
+                            kind: item.kind.descr(),
+                        });
                     tcx.sess.emit_err(errors::InvalidAttrAtCrateLevel {
                         span: attr.span,
-                        snippet: tcx.sess.source_map().span_to_snippet(attr.span).ok(),
+                        sugg_span: tcx
+                            .sess
+                            .source_map()
+                            .span_to_snippet(attr.span)
+                            .ok()
+                            .filter(|src| src.starts_with("#!["))
+                            .map(|_| {
+                                attr.span
+                                    .with_lo(attr.span.lo() + BytePos(1))
+                                    .with_hi(attr.span.lo() + BytePos(2))
+                            }),
                         name: *attr_to_check,
+                        item,
                     });
                 }
             }

compiler/rustc_passes/src/errors.rs

@@ -856,8 +856,15 @@ pub struct UnknownLangItem {
 
 pub struct InvalidAttrAtCrateLevel {
     pub span: Span,
-    pub snippet: Option<String>,
+    pub sugg_span: Option<Span>,
     pub name: Symbol,
+    pub item: Option<ItemFollowingInnerAttr>,
+}
+
+#[derive(Clone, Copy)]
+pub struct ItemFollowingInnerAttr {
+    pub span: Span,
+    pub kind: &'static str,
 }
 
 impl IntoDiagnostic<'_> for InvalidAttrAtCrateLevel {
@@ -871,15 +878,18 @@ impl IntoDiagnostic<'_> for InvalidAttrAtCrateLevel {
         diag.set_arg("name", self.name);
         // Only emit an error with a suggestion if we can create a string out
         // of the attribute span
-        if let Some(src) = self.snippet {
-            let replacement = src.replace("#!", "#");
+        if let Some(span) = self.sugg_span {
             diag.span_suggestion_verbose(
-                self.span,
+                span,
                 fluent::passes_suggestion,
-                replacement,
+                String::new(),
                 rustc_errors::Applicability::MachineApplicable,
             );
         }
+        if let Some(item) = self.item {
+            diag.set_arg("kind", item.kind);
+            diag.span_label(item.span, fluent::passes_invalid_attr_at_crate_level_item);
+        }
         diag
     }
 }

tests/ui/attributes/unix_sigpipe/unix_sigpipe-crate.stderr

@@ -3,11 +3,15 @@ error: `unix_sigpipe` attribute cannot be used at crate level
    |
 LL | #![unix_sigpipe = "inherit"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
    |
 help: perhaps you meant to use an outer attribute
    |
-LL | #[unix_sigpipe = "inherit"]
-   | ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+LL - #![unix_sigpipe = "inherit"]
+LL + #[unix_sigpipe = "inherit"]
+   |
 
 error: aborting due to previous error
 

tests/ui/derives/issue-36617.stderr

@@ -43,55 +43,75 @@ error: `derive` attribute cannot be used at crate level
    |
 LL | #![derive(Copy)]
    | ^^^^^^^^^^^^^^^^
+...
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
    |
 help: perhaps you meant to use an outer attribute
    |
-LL | #[derive(Copy)]
-   | ~~~~~~~~~~~~~~~
+LL - #![derive(Copy)]
+LL + #[derive(Copy)]
+   |
 
 error: `test` attribute cannot be used at crate level
   --> $DIR/issue-36617.rs:4:1
    |
 LL | #![test]
    | ^^^^^^^^
+...
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
    |
 help: perhaps you meant to use an outer attribute
    |
-LL | #[test]
-   | ~~~~~~~
+LL - #![test]
+LL + #[test]
+   |
 
 error: `test_case` attribute cannot be used at crate level
   --> $DIR/issue-36617.rs:7:1
    |
 LL | #![test_case]
    | ^^^^^^^^^^^^^
+...
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
    |
 help: perhaps you meant to use an outer attribute
    |
-LL | #[test_case]
-   | ~~~~~~~~~~~~
+LL - #![test_case]
+LL + #[test_case]
+   |
 
 error: `bench` attribute cannot be used at crate level
   --> $DIR/issue-36617.rs:10:1
    |
 LL | #![bench]
    | ^^^^^^^^^
+...
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
    |
 help: perhaps you meant to use an outer attribute
    |
-LL | #[bench]
-   | ~~~~~~~~
+LL - #![bench]
+LL + #[bench]
+   |
 
 error: `global_allocator` attribute cannot be used at crate level
   --> $DIR/issue-36617.rs:13:1
    |
 LL | #![global_allocator]
    | ^^^^^^^^^^^^^^^^^^^^
+...
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
    |
 help: perhaps you meant to use an outer attribute
    |
-LL | #[global_allocator]
-   | ~~~~~~~~~~~~~~~~~~~
+LL - #![global_allocator]
+LL + #[global_allocator]
+   |
 
 error: aborting due to 10 previous errors
 

tests/ui/feature-gates/issue-43106-gating-of-bench.stderr

@@ -11,10 +11,14 @@ error: `bench` attribute cannot be used at crate level
    |
 LL | #![bench                   = "4100"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
    |
 help: perhaps you meant to use an outer attribute
    |
-LL | #[bench                   = "4100"]
+LL - #![bench                   = "4100"]
+LL + #[bench                   = "4100"]
    |
 
 error: aborting due to 2 previous errors

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

@@ -32,6 +32,12 @@
 //~^ ERROR attribute should be applied to function or closure
 mod inline {
     //~^ NOTE not a function or closure
+    //~| NOTE the inner attribute doesn't annotate this module
+    //~| NOTE the inner attribute doesn't annotate this module
+    //~| NOTE the inner attribute doesn't annotate this module
+    //~| NOTE the inner attribute doesn't annotate this module
+    //~| NOTE the inner attribute doesn't annotate this module
+    //~| NOTE the inner attribute doesn't annotate this module
 
     mod inner { #![inline] }
     //~^ ERROR attribute should be applied to function or closure