Merge pull request #1889 from rust-lang/rustc-pull

Rustc pull update

1 files changed, 115 insertions, 0 deletions

diff --git a/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs
new file mode 100644
index 00000000000..eade49180ac
--- /dev/null
+++ b/compiler/rustc_attr_parsing/src/attributes/macro_attrs.rs
@@ -0,0 +1,115 @@
+use rustc_attr_data_structures::{AttributeKind, MacroUseArgs};
+use rustc_errors::DiagArgValue;
+use rustc_feature::{AttributeTemplate, template};
+use rustc_span::{Span, Symbol, sym};
+use thin_vec::ThinVec;
+
+use crate::attributes::{AcceptMapping, AttributeParser, NoArgsAttributeParser, OnDuplicate};
+use crate::context::{AcceptContext, FinalizeContext, Stage};
+use crate::parser::ArgParser;
+use crate::session_diagnostics;
+
+pub(crate) struct MacroEscapeParser;
+impl<S: Stage> NoArgsAttributeParser<S> for MacroEscapeParser {
+    const PATH: &[Symbol] = &[sym::macro_escape];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const CREATE: fn(Span) -> AttributeKind = AttributeKind::MacroEscape;
+}
+
+/// `#[macro_use]` attributes can either:
+/// - Use all macros from a crate, if provided without arguments
+/// - Use specific macros from a crate, if provided with arguments `#[macro_use(macro1, macro2)]`
+/// A warning should be provided if an use all is combined with specific uses, or if multiple use-alls are used.
+#[derive(Default)]
+pub(crate) struct MacroUseParser {
+    state: MacroUseArgs,
+
+    /// Spans of all `#[macro_use]` arguments with arguments, used for linting
+    uses_attr_spans: ThinVec<Span>,
+    /// If `state` is `UseSpecific`, stores the span of the first `#[macro_use]` argument, used as the span for this attribute
+    /// If `state` is `UseAll`, stores the span of the first `#[macro_use]` arguments without arguments
+    first_span: Option<Span>,
+}
+
+const MACRO_USE_TEMPLATE: AttributeTemplate = template!(Word, List: "name1, name2, ...");
+
+impl<S: Stage> AttributeParser<S> for MacroUseParser {
+    const ATTRIBUTES: AcceptMapping<Self, S> = &[(
+        &[sym::macro_use],
+        MACRO_USE_TEMPLATE,
+        |group: &mut Self, cx: &mut AcceptContext<'_, '_, S>, args| {
+            let span = cx.attr_span;
+            group.first_span.get_or_insert(span);
+            match args {
+                ArgParser::NoArgs => {
+                    match group.state {
+                        MacroUseArgs::UseAll => {
+                            let first_span = group.first_span.expect(
+                                "State is UseAll is some so this is not the first attribute",
+                            );
+                            // Since there is a `#[macro_use]` import already, give a warning
+                            cx.warn_unused_duplicate(first_span, span);
+                        }
+                        MacroUseArgs::UseSpecific(_) => {
+                            group.state = MacroUseArgs::UseAll;
+                            group.first_span = Some(span);
+                            // If there is a `#[macro_use]` attribute, warn on all `#[macro_use(...)]` attributes since everything is already imported
+                            for specific_use in group.uses_attr_spans.drain(..) {
+                                cx.warn_unused_duplicate(span, specific_use);
+                            }
+                        }
+                    }
+                }
+                ArgParser::List(list) => {
+                    if list.is_empty() {
+                        cx.warn_empty_attribute(list.span);
+                        return;
+                    }
+
+                    match &mut group.state {
+                        MacroUseArgs::UseAll => {
+                            let first_span = group.first_span.expect(
+                                "State is UseAll is some so this is not the first attribute",
+                            );
+                            cx.warn_unused_duplicate(first_span, span);
+                        }
+                        MacroUseArgs::UseSpecific(arguments) => {
+                            // Store here so if we encounter a `UseAll` later we can still lint this attribute
+                            group.uses_attr_spans.push(cx.attr_span);
+
+                            for item in list.mixed() {
+                                let Some(item) = item.meta_item() else {
+                                    cx.expected_identifier(item.span());
+                                    continue;
+                                };
+                                if let Err(err_span) = item.args().no_args() {
+                                    cx.expected_no_args(err_span);
+                                    continue;
+                                }
+                                let Some(item) = item.path().word() else {
+                                    cx.expected_identifier(item.span());
+                                    continue;
+                                };
+                                arguments.push(item);
+                            }
+                        }
+                    }
+                }
+                ArgParser::NameValue(_) => {
+                    let suggestions = MACRO_USE_TEMPLATE.suggestions(false, sym::macro_use);
+                    cx.emit_err(session_diagnostics::IllFormedAttributeInputLint {
+                        num_suggestions: suggestions.len(),
+                        suggestions: DiagArgValue::StrListSepByAnd(
+                            suggestions.into_iter().map(|s| format!("`{s}`").into()).collect(),
+                        ),
+                        span,
+                    });
+                }
+            }
+        },
+    )];
+
+    fn finalize(self, _cx: &FinalizeContext<'_, '_, S>) -> Option<AttributeKind> {
+        Some(AttributeKind::MacroUse { span: self.first_span?, arguments: self.state })
+    }
+}