implement inline parser

Author: jdonszelmann

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -8,7 +8,7 @@ use thin_vec::ThinVec;
 
 use crate::{DefaultBodyStability, PartialConstStability, PrintAttribute, RustcVersion, Stability};
 
-#[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
+#[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic, PrintAttribute)]
 pub enum InlineAttr {
     None,
     Hint,
@@ -189,6 +189,7 @@ pub enum AttributeKind {
         span: Span,
         comment: Symbol,
     },
+    Inline(InlineAttr, Span),
     MacroTransparency(Transparency),
     Repr(ThinVec<(ReprAttr, Span)>),
     Stability {

compiler/rustc_attr_parsing/src/attributes/inline.rs

@@ -0,0 +1,49 @@
+use rustc_attr_data_structures::{AttributeKind, InlineAttr};
+use rustc_errors::{E0534, E0535, struct_span_code_err};
+use rustc_span::sym;
+
+use super::{AcceptContext, AttributeOrder, OnDuplicate};
+use crate::attributes::SingleAttributeParser;
+use crate::context::Stage;
+use crate::parser::ArgParser;
+
+pub(crate) struct InlineParser;
+
+impl<S: Stage> SingleAttributeParser<S> for InlineParser {
+    const PATH: &'static [rustc_span::Symbol] = &[sym::inline];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError;
+
+    fn convert(cx: &AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        match args {
+            ArgParser::NoArgs => Some(AttributeKind::Inline(InlineAttr::Hint, cx.attr_span)),
+            ArgParser::List(list) => {
+                let Some(l) = list.single() else {
+                    struct_span_code_err!(cx.dcx(), cx.attr_span, E0534, "expected one argument")
+                        .emit();
+                    return None;
+                };
+
+                match l.meta_item().and_then(|i| i.word_without_args().map(|i| i.name)) {
+                    Some(sym::always) => {
+                        Some(AttributeKind::Inline(InlineAttr::Always, cx.attr_span))
+                    }
+                    Some(sym::never) => {
+                        Some(AttributeKind::Inline(InlineAttr::Never, cx.attr_span))
+                    }
+                    _ => {
+                        struct_span_code_err!(cx.dcx(), l.span(), E0535, "invalid argument")
+                            .with_help("valid inline arguments are `always` and `never`")
+                            .emit();
+                        return None;
+                    }
+                }
+            }
+            ArgParser::NameValue(_) => {
+                // silently ignored, we warn somewhere else.
+                // FIXME(jdonszelmann): that warning *should* go here.
+                None
+            }
+        }
+    }
+}

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -29,6 +29,7 @@ pub(crate) mod allow_unstable;
 pub(crate) mod cfg;
 pub(crate) mod confusables;
 pub(crate) mod deprecation;
+pub(crate) mod inline;
 pub(crate) mod repr;
 pub(crate) mod stability;
 pub(crate) mod transparency;

compiler/rustc_attr_parsing/src/context.rs

@@ -19,6 +19,7 @@ use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
 use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::deprecation::DeprecationParser;
+use crate::attributes::inline::InlineParser;
 use crate::attributes::repr::ReprParser;
 use crate::attributes::stability::{
     BodyStabilityParser, ConstStabilityIndirectParser, ConstStabilityParser, StabilityParser,
@@ -104,6 +105,7 @@ attribute_groups!(
         // tidy-alphabetical-start
         Single<ConstStabilityIndirectParser>,
         Single<DeprecationParser>,
+        Single<InlineParser>,
         Single<TransparencyParser>,
         // tidy-alphabetical-end
     ];