Print all labels, even if they have no span. Fall back to main item's span.

Author: oli-obk

compiler/rustc_error_messages/locales/en-US/passes.ftl

@@ -47,7 +47,10 @@ passes_no_coverage_not_coverable =
 
 passes_should_be_applied_to_fn =
     attribute should be applied to a function definition
-    .label = not a function definition
+    .label = {$on_crate ->
+        [true] cannot be applied to crates
+        *[false] not a function definition
+    }
 
 passes_naked_tracked_caller =
     cannot use `#[track_caller]` with `#[naked]`

compiler/rustc_errors/src/emitter.rs

@@ -2210,22 +2210,45 @@ impl FileWithAnnotatedLines {
 
         if let Some(ref sm) = emitter.source_map() {
             for span_label in msp.span_labels() {
+                let fixup_lo_hi = |span: Span| {
+                    let lo = sm.lookup_char_pos(span.lo());
+                    let mut hi = sm.lookup_char_pos(span.hi());
+
+                    // Watch out for "empty spans". If we get a span like 6..6, we
+                    // want to just display a `^` at 6, so convert that to
+                    // 6..7. This is degenerate input, but it's best to degrade
+                    // gracefully -- and the parser likes to supply a span like
+                    // that for EOF, in particular.
+
+                    if lo.col_display == hi.col_display && lo.line == hi.line {
+                        hi.col_display += 1;
+                    }
+                    (lo, hi)
+                };
+
                 if span_label.span.is_dummy() {
+                    if let Some(span) = msp.primary_span() {
+                        // if we don't know where to render the annotation, emit it as a note
+                        // on the primary span.
+
+                        let (lo, hi) = fixup_lo_hi(span);
+
+                        let ann = Annotation {
+                            start_col: lo.col_display,
+                            end_col: hi.col_display,
+                            is_primary: span_label.is_primary,
+                            label: span_label
+                                .label
+                                .as_ref()
+                                .map(|m| emitter.translate_message(m, args).to_string()),
+                            annotation_type: AnnotationType::Singleline,
+                        };
+                        add_annotation_to_file(&mut output, lo.file, lo.line, ann);
+                    }
                     continue;
                 }
 
-                let lo = sm.lookup_char_pos(span_label.span.lo());
-                let mut hi = sm.lookup_char_pos(span_label.span.hi());
-
-                // Watch out for "empty spans". If we get a span like 6..6, we
-                // want to just display a `^` at 6, so convert that to
-                // 6..7. This is degenerate input, but it's best to degrade
-                // gracefully -- and the parser likes to supply a span like
-                // that for EOF, in particular.
-
-                if lo.col_display == hi.col_display && lo.line == hi.line {
-                    hi.col_display += 1;
-                }
+                let (lo, hi) = fixup_lo_hi(span_label.span);
 
                 if lo.line != hi.line {
                     let ml = MultilineAnnotation {

compiler/rustc_passes/src/check_attr.rs

@@ -119,13 +119,13 @@ impl CheckAttrVisitor<'_> {
                 }
                 sym::naked => self.check_naked(hir_id, attr, span, target),
                 sym::rustc_legacy_const_generics => {
-                    self.check_rustc_legacy_const_generics(&attr, span, target, item)
+                    self.check_rustc_legacy_const_generics(hir_id, &attr, span, target, item)
                 }
                 sym::rustc_lint_query_instability => {
-                    self.check_rustc_lint_query_instability(&attr, span, target)
+                    self.check_rustc_lint_query_instability(hir_id, &attr, span, target)
                 }
                 sym::rustc_lint_diagnostics => {
-                    self.check_rustc_lint_diagnostics(&attr, span, target)
+                    self.check_rustc_lint_diagnostics(hir_id, &attr, span, target)
                 }
                 sym::rustc_lint_opt_ty => self.check_rustc_lint_opt_ty(&attr, span, target),
                 sym::rustc_lint_opt_deny_field_access => {
@@ -135,7 +135,9 @@ impl CheckAttrVisitor<'_> {
                 | sym::rustc_dirty
                 | sym::rustc_if_this_changed
                 | sym::rustc_then_this_would_need => self.check_rustc_dirty_clean(&attr),
-                sym::cmse_nonsecure_entry => self.check_cmse_nonsecure_entry(attr, span, target),
+                sym::cmse_nonsecure_entry => {
+                    self.check_cmse_nonsecure_entry(hir_id, attr, span, target)
+                }
                 sym::collapse_debuginfo => self.check_collapse_debuginfo(attr, span, target),
                 sym::const_trait => self.check_const_trait(attr, span, target),
                 sym::must_not_suspend => self.check_must_not_suspend(&attr, span, target),
@@ -386,21 +388,29 @@ impl CheckAttrVisitor<'_> {
                 self.tcx.sess.emit_err(errors::AttrShouldBeAppliedToFn {
                     attr_span: attr.span,
                     defn_span: span,
+                    on_crate: hir_id == CRATE_HIR_ID,
                 });
                 false
             }
         }
     }
 
     /// Checks if `#[cmse_nonsecure_entry]` is applied to a function definition.
-    fn check_cmse_nonsecure_entry(&self, attr: &Attribute, span: Span, target: Target) -> bool {
+    fn check_cmse_nonsecure_entry(
+        &self,
+        hir_id: HirId,
+        attr: &Attribute,
+        span: Span,
+        target: Target,
+    ) -> bool {
         match target {
             Target::Fn
             | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true,
             _ => {
                 self.tcx.sess.emit_err(errors::AttrShouldBeAppliedToFn {
                     attr_span: attr.span,
                     defn_span: span,
+                    on_crate: hir_id == CRATE_HIR_ID,
                 });
                 false
             }
@@ -465,9 +475,11 @@ impl CheckAttrVisitor<'_> {
                 true
             }
             _ => {
-                self.tcx
-                    .sess
-                    .emit_err(errors::TrackedCallerWrongLocation { attr_span, defn_span: span });
+                self.tcx.sess.emit_err(errors::TrackedCallerWrongLocation {
+                    attr_span,
+                    defn_span: span,
+                    on_crate: hir_id == CRATE_HIR_ID,
+                });
                 false
             }
         }
@@ -576,6 +588,7 @@ impl CheckAttrVisitor<'_> {
                 self.tcx.sess.emit_err(errors::AttrShouldBeAppliedToFn {
                     attr_span: attr.span,
                     defn_span: span,
+                    on_crate: hir_id == CRATE_HIR_ID,
                 });
                 false
             }
@@ -1240,7 +1253,7 @@ impl CheckAttrVisitor<'_> {
                     UNUSED_ATTRIBUTES,
                     hir_id,
                     attr.span,
-                    errors::Cold { span },
+                    errors::Cold { span, on_crate: hir_id == CRATE_HIR_ID },
                 );
             }
         }
@@ -1376,6 +1389,7 @@ impl CheckAttrVisitor<'_> {
     /// Checks if `#[rustc_legacy_const_generics]` is applied to a function and has a valid argument.
     fn check_rustc_legacy_const_generics(
         &self,
+        hir_id: HirId,
         attr: &Attribute,
         span: Span,
         target: Target,
@@ -1386,6 +1400,7 @@ impl CheckAttrVisitor<'_> {
             self.tcx.sess.emit_err(errors::AttrShouldBeAppliedToFn {
                 attr_span: attr.span,
                 defn_span: span,
+                on_crate: hir_id == CRATE_HIR_ID,
             });
             return false;
         }
@@ -1450,12 +1465,19 @@ impl CheckAttrVisitor<'_> {
 
     /// Helper function for checking that the provided attribute is only applied to a function or
     /// method.
-    fn check_applied_to_fn_or_method(&self, attr: &Attribute, span: Span, target: Target) -> bool {
+    fn check_applied_to_fn_or_method(
+        &self,
+        hir_id: HirId,
+        attr: &Attribute,
+        span: Span,
+        target: Target,
+    ) -> bool {
         let is_function = matches!(target, Target::Fn | Target::Method(..));
         if !is_function {
             self.tcx.sess.emit_err(errors::AttrShouldBeAppliedToFn {
                 attr_span: attr.span,
                 defn_span: span,
+                on_crate: hir_id == CRATE_HIR_ID,
             });
             false
         } else {
@@ -1467,17 +1489,24 @@ impl CheckAttrVisitor<'_> {
     /// or method.
     fn check_rustc_lint_query_instability(
         &self,
+        hir_id: HirId,
         attr: &Attribute,
         span: Span,
         target: Target,
     ) -> bool {
-        self.check_applied_to_fn_or_method(attr, span, target)
+        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
     }
 
     /// Checks that the `#[rustc_lint_diagnostics]` attribute is only applied to a function or
     /// method.
-    fn check_rustc_lint_diagnostics(&self, attr: &Attribute, span: Span, target: Target) -> bool {
-        self.check_applied_to_fn_or_method(attr, span, target)
+    fn check_rustc_lint_diagnostics(
+        &self,
+        hir_id: HirId,
+        attr: &Attribute,
+        span: Span,
+        target: Target,
+    ) -> bool {
+        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
     }
 
     /// Checks that the `#[rustc_lint_opt_ty]` attribute is only applied to a struct.

compiler/rustc_passes/src/errors.rs

@@ -81,6 +81,7 @@ pub struct AttrShouldBeAppliedToFn {
     pub attr_span: Span,
     #[label]
     pub defn_span: Span,
+    pub on_crate: bool,
 }
 
 #[derive(Diagnostic)]
@@ -97,6 +98,7 @@ pub struct TrackedCallerWrongLocation {
     pub attr_span: Span,
     #[label]
     pub defn_span: Span,
+    pub on_crate: bool,
 }
 
 #[derive(Diagnostic)]
@@ -367,6 +369,7 @@ pub struct MustNotSuspend {
 pub struct Cold {
     #[label]
     pub span: Span,
+    pub on_crate: bool,
 }
 
 #[derive(LintDiagnostic)]

compiler/rustc_resolve/src/diagnostics.rs

@@ -241,10 +241,12 @@ impl<'a> Resolver<'a> {
         ));
 
         err.span_label(span, format!("`{}` re{} here", name, new_participle));
-        err.span_label(
-            self.session.source_map().guess_head_span(old_binding.span),
-            format!("previous {} of the {} `{}` here", old_noun, old_kind, name),
-        );
+        if !old_binding.span.is_dummy() && old_binding.span != span {
+            err.span_label(
+                self.session.source_map().guess_head_span(old_binding.span),
+                format!("previous {} of the {} `{}` here", old_noun, old_kind, name),
+            );
+        }
 
         // See https://github.com/rust-lang/rust/issues/32354
         use NameBindingKind::Import;

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -806,14 +806,16 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
         err.code(rustc_errors::error_code!(E0411));
         err.span_label(span, "`Self` is only available in impls, traits, and type definitions");
         if let Some(item_kind) = self.diagnostic_metadata.current_item {
-            err.span_label(
-                item_kind.ident.span,
-                format!(
-                    "`Self` not allowed in {} {}",
-                    item_kind.kind.article(),
-                    item_kind.kind.descr()
-                ),
-            );
+            if !item_kind.ident.span.is_dummy() {
+                err.span_label(
+                    item_kind.ident.span,
+                    format!(
+                        "`Self` not allowed in {} {}",
+                        item_kind.kind.article(),
+                        item_kind.kind.descr()
+                    ),
+                );
+            }
         }
         true
     }

src/test/ui/asm/naked-invalid-attr.stderr

@@ -36,7 +36,7 @@ error: attribute should be applied to a function definition
   --> $DIR/naked-invalid-attr.rs:5:1
    |
 LL | #![naked]
-   | ^^^^^^^^^
+   | ^^^^^^^^^ cannot be applied to crates
 
 error: aborting due to 5 previous errors
 

src/test/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr

@@ -110,19 +110,19 @@ error: attribute should be applied to an `extern crate` item
   --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:25:1
    |
 LL | #![no_link]
-   | ^^^^^^^^^^^
+   | ^^^^^^^^^^^ not an `extern crate` item
 
 error: attribute should be applied to a free function, impl method or static
   --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:27:1
    |
 LL | #![export_name = "2200"]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^ not a free function, impl method or static
 
 error[E0518]: attribute should be applied to function or closure
   --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:29:1
    |
 LL | #![inline]
-   | ^^^^^^^^^^
+   | ^^^^^^^^^^ not a function or closure
 
 error: `macro_export` attribute cannot be used at crate level
   --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:12:1

src/test/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs

@@ -1,6 +1,6 @@
 //~ NOTE not a function
 //~| NOTE not a foreign function or static
-//~| NOTE not a function or static
+//~| NOTE cannot be applied to crates
 //~| NOTE not an `extern` block
 // This test enumerates as many compiler-builtin ungated attributes as
 // possible (that is, all the mutually compatible ones), and checks

src/test/ui/feature-gates/issue-43106-gating-of-builtin-attrs.stderr

@@ -403,31 +403,31 @@ warning: attribute should be applied to a function definition
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:62:1
    |
 LL | #![cold]
-   | ^^^^^^^^
+   | ^^^^^^^^ cannot be applied to crates
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to an `extern` block with non-Rust ABI
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:64:1
    |
 LL | #![link()]
-   | ^^^^^^^^^^
+   | ^^^^^^^^^^ not an `extern` block
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a foreign function or static
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:66:1
    |
 LL | #![link_name = "1900"]
-   | ^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^ not a foreign function or static
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function or static
   --> $DIR/issue-43106-gating-of-builtin-attrs.rs:69:1
    |
 LL | #![link_section = "1800"]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^ not a function or static
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!