Rollup merge of #143808 - JonathanBrouwer:should_panic_parser, r=jdonszelmann

Port `#[should_panic]` to the new attribute parsing infrastructure

Ports `#[should_panic]` to the new attribute parsing infrastructure for https://github.com/rust-lang/rust/issues/131229#issuecomment-2971351163

r? ```@jdonszelmann```

1 files changed, 52 insertions, 0 deletions

diff --git a/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs
index a90ed830cd1..77b494328c7 100644
--- a/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/test_attrs.rs
@@ -44,3 +44,55 @@ impl<S: Stage> SingleAttributeParser<S> for IgnoreParser {
         })
     }
 }
+
+pub(crate) struct ShouldPanicParser;
+
+impl<S: Stage> SingleAttributeParser<S> for ShouldPanicParser {
+    const PATH: &[Symbol] = &[sym::should_panic];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
+    const TEMPLATE: AttributeTemplate =
+        template!(Word, List: r#"expected = "reason""#, NameValueStr: "reason");
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        Some(AttributeKind::ShouldPanic {
+            span: cx.attr_span,
+            reason: match args {
+                ArgParser::NoArgs => None,
+                ArgParser::NameValue(name_value) => {
+                    let Some(str_value) = name_value.value_as_str() else {
+                        cx.expected_string_literal(
+                            name_value.value_span,
+                            Some(name_value.value_as_lit()),
+                        );
+                        return None;
+                    };
+                    Some(str_value)
+                }
+                ArgParser::List(list) => {
+                    let Some(single) = list.single() else {
+                        cx.expected_single_argument(list.span);
+                        return None;
+                    };
+                    let Some(single) = single.meta_item() else {
+                        cx.expected_name_value(single.span(), Some(sym::expected));
+                        return None;
+                    };
+                    if !single.path().word_is(sym::expected) {
+                        cx.expected_specific_argument_strings(list.span, vec!["expected"]);
+                        return None;
+                    }
+                    let Some(nv) = single.args().name_value() else {
+                        cx.expected_name_value(single.span(), Some(sym::expected));
+                        return None;
+                    };
+                    let Some(expected) = nv.value_as_str() else {
+                        cx.expected_string_literal(nv.value_span, Some(nv.value_as_lit()));
+                        return None;
+                    };
+                    Some(expected)
+                }
+            },
+        })
+    }
+}