Rollup merge of #124875 - compiler-errors:more-diagnostics-ices, r=estebank

Fix more ICEs in `diagnostic::on_unimplemented`

There were 8 other calls to `expect_local` left in `on_unimplemented.rs` -- all of which (afaict) could be turned into ICEs.

I would really like to see validation of `on_unimplemented` separated from parsing, so we only emit errors here:
https://github.com/rust-lang/rust/blob/a60f077c38fe66d05449919842d3d73e3299bbab/compiler/rustc_hir_analysis/src/check/check.rs#L836-L839
...And gracefully fail instead when emitting trait predicate failures, not *ever* even trying to emit an error or a lint. But that's left for a separate PR.

r? `@estebank`

6 files changed, 259 insertions, 86 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
index f1eb5b7e826..4b49e014c0f 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
@@ -350,12 +350,14 @@ impl IgnoredDiagnosticOption {
         option_name: &'static str,
     ) {
         if let (Some(new_item), Some(old_item)) = (new, old) {
-            tcx.emit_node_span_lint(
-                UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                new_item,
-                IgnoredDiagnosticOption { span: new_item, prev_span: old_item, option_name },
-            );
+            if let Some(item_def_id) = item_def_id.as_local() {
+                tcx.emit_node_span_lint(
+                    UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                    tcx.local_def_id_to_hir_id(item_def_id),
+                    new_item,
+                    IgnoredDiagnosticOption { span: new_item, prev_span: old_item, option_name },
+                );
+            }
         }
     }
 }
@@ -639,30 +641,38 @@ impl<'tcx> OnUnimplementedDirective {
                     AttrArgs::Eq(span, AttrArgsEq::Hir(expr)) => span.to(expr.span),
                 };
 
-                tcx.emit_node_span_lint(
-                    UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                    tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                    report_span,
-                    MalformedOnUnimplementedAttrLint::new(report_span),
-                );
+                if let Some(item_def_id) = item_def_id.as_local() {
+                    tcx.emit_node_span_lint(
+                        UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                        tcx.local_def_id_to_hir_id(item_def_id),
+                        report_span,
+                        MalformedOnUnimplementedAttrLint::new(report_span),
+                    );
+                }
                 Ok(None)
             }
         } else if is_diagnostic_namespace_variant {
             match &attr.kind {
                 AttrKind::Normal(p) if !matches!(p.item.args, AttrArgs::Empty) => {
-                    tcx.emit_node_span_lint(
-                        UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                        tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                        attr.span,
-                        MalformedOnUnimplementedAttrLint::new(attr.span),
-                    );
+                    if let Some(item_def_id) = item_def_id.as_local() {
+                        tcx.emit_node_span_lint(
+                            UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                            tcx.local_def_id_to_hir_id(item_def_id),
+                            attr.span,
+                            MalformedOnUnimplementedAttrLint::new(attr.span),
+                        );
+                    }
+                }
+                _ => {
+                    if let Some(item_def_id) = item_def_id.as_local() {
+                        tcx.emit_node_span_lint(
+                            UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                            tcx.local_def_id_to_hir_id(item_def_id),
+                            attr.span,
+                            MissingOptionsForOnUnimplementedAttr,
+                        )
+                    }
                 }
-                _ => tcx.emit_node_span_lint(
-                    UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                    tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                    attr.span,
-                    MissingOptionsForOnUnimplementedAttr,
-                ),
             };
 
             Ok(None)
@@ -791,12 +801,14 @@ impl<'tcx> OnUnimplementedFormatString {
                             || format_spec.precision_span.is_some()
                             || format_spec.fill_span.is_some())
                     {
-                        tcx.emit_node_span_lint(
-                            UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                            tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                            self.span,
-                            InvalidFormatSpecifier,
-                        );
+                        if let Some(item_def_id) = item_def_id.as_local() {
+                            tcx.emit_node_span_lint(
+                                UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                                tcx.local_def_id_to_hir_id(item_def_id),
+                                self.span,
+                                InvalidFormatSpecifier,
+                            );
+                        }
                     }
                     match a.position {
                         Position::ArgumentNamed(s) => {
@@ -812,15 +824,17 @@ impl<'tcx> OnUnimplementedFormatString {
                                 s if generics.params.iter().any(|param| param.name == s) => (),
                                 s => {
                                     if self.is_diagnostic_namespace_variant {
-                                        tcx.emit_node_span_lint(
-                                            UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                                            tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                                            self.span,
-                                            UnknownFormatParameterForOnUnimplementedAttr {
-                                                argument_name: s,
-                                                trait_name,
-                                            },
-                                        );
+                                        if let Some(item_def_id) = item_def_id.as_local() {
+                                            tcx.emit_node_span_lint(
+                                                UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                                                tcx.local_def_id_to_hir_id(item_def_id),
+                                                self.span,
+                                                UnknownFormatParameterForOnUnimplementedAttr {
+                                                    argument_name: s,
+                                                    trait_name,
+                                                },
+                                            );
+                                        }
                                     } else {
                                         result = Err(struct_span_code_err!(
                                             tcx.dcx(),
@@ -842,12 +856,14 @@ impl<'tcx> OnUnimplementedFormatString {
                         // `{:1}` and `{}` are not to be used
                         Position::ArgumentIs(..) | Position::ArgumentImplicitlyIs(_) => {
                             if self.is_diagnostic_namespace_variant {
-                                tcx.emit_node_span_lint(
-                                    UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                                    tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                                    self.span,
-                                    DisallowedPositionalArgument,
-                                );
+                                if let Some(item_def_id) = item_def_id.as_local() {
+                                    tcx.emit_node_span_lint(
+                                        UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                                        tcx.local_def_id_to_hir_id(item_def_id),
+                                        self.span,
+                                        DisallowedPositionalArgument,
+                                    );
+                                }
                             } else {
                                 let reported = struct_span_code_err!(
                                     tcx.dcx(),
@@ -870,12 +886,14 @@ impl<'tcx> OnUnimplementedFormatString {
         // so that users are aware that something is not correct
         for e in parser.errors {
             if self.is_diagnostic_namespace_variant {
-                tcx.emit_node_span_lint(
-                    UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
-                    tcx.local_def_id_to_hir_id(item_def_id.expect_local()),
-                    self.span,
-                    WrappedParserError { description: e.description, label: e.label },
-                );
+                if let Some(item_def_id) = item_def_id.as_local() {
+                    tcx.emit_node_span_lint(
+                        UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                        tcx.local_def_id_to_hir_id(item_def_id),
+                        self.span,
+                        WrappedParserError { description: e.description, label: e.label },
+                    );
+                }
             } else {
                 let reported =
                     struct_span_code_err!(tcx.dcx(), self.span, E0231, "{}", e.description,).emit();
diff --git a/tests/ui/diagnostic_namespace/auxiliary/bad_on_unimplemented.rs b/tests/ui/diagnostic_namespace/auxiliary/bad_on_unimplemented.rs
index 4a5fca43e36..e44c7e4e850 100644
--- a/tests/ui/diagnostic_namespace/auxiliary/bad_on_unimplemented.rs
+++ b/tests/ui/diagnostic_namespace/auxiliary/bad_on_unimplemented.rs
@@ -1,2 +1,26 @@
 #[diagnostic::on_unimplemented(aa = "broken")]
-pub trait Test {}
+pub trait MissingAttr {}
+
+#[diagnostic::on_unimplemented(label = "a", label = "b")]
+pub trait DuplicateAttr {}
+
+#[diagnostic::on_unimplemented = "broken"]
+pub trait NotMetaList {}
+
+#[diagnostic::on_unimplemented]
+pub trait Empty {}
+
+#[diagnostic::on_unimplemented {}]
+pub trait WrongDelim {}
+
+#[diagnostic::on_unimplemented(label = "{A:.3}")]
+pub trait BadFormatter<A> {}
+
+#[diagnostic::on_unimplemented(label = "test {}")]
+pub trait NoImplicitArgs {}
+
+#[diagnostic::on_unimplemented(label = "{missing}")]
+pub trait MissingArg {}
+
+#[diagnostic::on_unimplemented(label = "{_}")]
+pub trait BadArg {}
diff --git a/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.rs b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.rs
new file mode 100644
index 00000000000..8b7467a17d0
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.rs
@@ -0,0 +1,31 @@
+//@ edition:2021
+//@ aux-build:bad_on_unimplemented.rs
+
+// Do not ICE when encountering a malformed `#[diagnostic::on_unimplemented]` annotation in a
+// dependency when incorrectly used (#124651).
+
+extern crate bad_on_unimplemented;
+
+use bad_on_unimplemented::*;
+
+fn missing_attr<T: MissingAttr>(_: T) {}
+fn duplicate_attr<T: DuplicateAttr>(_: T) {}
+fn not_meta_list<T: NotMetaList>(_: T) {}
+fn empty<T: Empty>(_: T) {}
+fn wrong_delim<T: WrongDelim>(_: T) {}
+fn bad_formatter<T: BadFormatter<()>>(_: T) {}
+fn no_implicit_args<T: NoImplicitArgs>(_: T) {}
+fn missing_arg<T: MissingArg>(_: T) {}
+fn bad_arg<T: BadArg>(_: T) {}
+
+fn main() {
+    missing_attr(()); //~ ERROR E0277
+    duplicate_attr(()); //~ ERROR E0277
+    not_meta_list(()); //~ ERROR E0277
+    empty(()); //~ ERROR E0277
+    wrong_delim(()); //~ ERROR E0277
+    bad_formatter(()); //~ ERROR E0277
+    no_implicit_args(()); //~ ERROR E0277
+    missing_arg(()); //~ ERROR E0277
+    bad_arg(()); //~ ERROR E0277
+}
diff --git a/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.stderr b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.stderr
new file mode 100644
index 00000000000..c3e56550b70
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/malformed_foreign_on_unimplemented.stderr
@@ -0,0 +1,134 @@
+error[E0277]: the trait bound `(): bad_on_unimplemented::MissingAttr` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:22:18
+   |
+LL |     missing_attr(());
+   |     ------------ ^^ the trait `bad_on_unimplemented::MissingAttr` is not implemented for `()`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `missing_attr`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:11:20
+   |
+LL | fn missing_attr<T: MissingAttr>(_: T) {}
+   |                    ^^^^^^^^^^^ required by this bound in `missing_attr`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::DuplicateAttr` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:23:20
+   |
+LL |     duplicate_attr(());
+   |     -------------- ^^ a
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `bad_on_unimplemented::DuplicateAttr` is not implemented for `()`
+note: required by a bound in `duplicate_attr`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:12:22
+   |
+LL | fn duplicate_attr<T: DuplicateAttr>(_: T) {}
+   |                      ^^^^^^^^^^^^^ required by this bound in `duplicate_attr`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::NotMetaList` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:24:19
+   |
+LL |     not_meta_list(());
+   |     ------------- ^^ the trait `bad_on_unimplemented::NotMetaList` is not implemented for `()`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `not_meta_list`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:13:21
+   |
+LL | fn not_meta_list<T: NotMetaList>(_: T) {}
+   |                     ^^^^^^^^^^^ required by this bound in `not_meta_list`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::Empty` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:25:11
+   |
+LL |     empty(());
+   |     ----- ^^ the trait `bad_on_unimplemented::Empty` is not implemented for `()`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `empty`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:14:13
+   |
+LL | fn empty<T: Empty>(_: T) {}
+   |             ^^^^^ required by this bound in `empty`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::WrongDelim` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:26:17
+   |
+LL |     wrong_delim(());
+   |     ----------- ^^ the trait `bad_on_unimplemented::WrongDelim` is not implemented for `()`
+   |     |
+   |     required by a bound introduced by this call
+   |
+note: required by a bound in `wrong_delim`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:15:19
+   |
+LL | fn wrong_delim<T: WrongDelim>(_: T) {}
+   |                   ^^^^^^^^^^ required by this bound in `wrong_delim`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::BadFormatter<()>` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:27:19
+   |
+LL |     bad_formatter(());
+   |     ------------- ^^ ()
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `bad_on_unimplemented::BadFormatter<()>` is not implemented for `()`
+note: required by a bound in `bad_formatter`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:16:21
+   |
+LL | fn bad_formatter<T: BadFormatter<()>>(_: T) {}
+   |                     ^^^^^^^^^^^^^^^^ required by this bound in `bad_formatter`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::NoImplicitArgs` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:28:22
+   |
+LL |     no_implicit_args(());
+   |     ---------------- ^^ test {}
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `bad_on_unimplemented::NoImplicitArgs` is not implemented for `()`
+note: required by a bound in `no_implicit_args`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:17:24
+   |
+LL | fn no_implicit_args<T: NoImplicitArgs>(_: T) {}
+   |                        ^^^^^^^^^^^^^^ required by this bound in `no_implicit_args`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::MissingArg` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:29:17
+   |
+LL |     missing_arg(());
+   |     ----------- ^^ {missing}
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `bad_on_unimplemented::MissingArg` is not implemented for `()`
+note: required by a bound in `missing_arg`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:18:19
+   |
+LL | fn missing_arg<T: MissingArg>(_: T) {}
+   |                   ^^^^^^^^^^ required by this bound in `missing_arg`
+
+error[E0277]: the trait bound `(): bad_on_unimplemented::BadArg` is not satisfied
+  --> $DIR/malformed_foreign_on_unimplemented.rs:30:13
+   |
+LL |     bad_arg(());
+   |     ------- ^^ {_}
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `bad_on_unimplemented::BadArg` is not implemented for `()`
+note: required by a bound in `bad_arg`
+  --> $DIR/malformed_foreign_on_unimplemented.rs:19:15
+   |
+LL | fn bad_arg<T: BadArg>(_: T) {}
+   |               ^^^^^^ required by this bound in `bad_arg`
+
+error: aborting due to 9 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented_ice.rs b/tests/ui/diagnostic_namespace/on_unimplemented_ice.rs
deleted file mode 100644
index 8969f5030e2..00000000000
--- a/tests/ui/diagnostic_namespace/on_unimplemented_ice.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-//@ edition:2021
-//@ compile-flags:--test
-//@ aux-build:bad_on_unimplemented.rs
-
-// Do not ICE when encountering a malformed `#[diagnostic::on_unimplemented]` annotation in a
-// dependency when incorrectly used (#124651).
-
-extern crate bad_on_unimplemented;
-
-use bad_on_unimplemented::Test;
-
-fn breakage<T: Test>(_: T) {}
-
-#[test]
-fn test() {
-    breakage(1); //~ ERROR E0277
-}
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented_ice.stderr b/tests/ui/diagnostic_namespace/on_unimplemented_ice.stderr
deleted file mode 100644
index 1c0da96abd9..00000000000
--- a/tests/ui/diagnostic_namespace/on_unimplemented_ice.stderr
+++ /dev/null
@@ -1,17 +0,0 @@
-error[E0277]: the trait bound `{integer}: Test` is not satisfied
-  --> $DIR/on_unimplemented_ice.rs:16:14
-   |
-LL |     breakage(1);
-   |     -------- ^ the trait `Test` is not implemented for `{integer}`
-   |     |
-   |     required by a bound introduced by this call
-   |
-note: required by a bound in `breakage`
-  --> $DIR/on_unimplemented_ice.rs:12:16
-   |
-LL | fn breakage<T: Test>(_: T) {}
-   |                ^^^^ required by this bound in `breakage`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0277`.