From 2f50c7807cab4e0b2c8fd2811733fdc58edd35b1 Mon Sep 17 00:00:00 2001 From: Jonathan Brouwer Date: Mon, 7 Jul 2025 17:03:53 +0200 Subject: [PATCH] Parsers for the attributes Signed-off-by: Jonathan Brouwer --- .../rustc_attr_parsing/src/attributes/mod.rs | 1 + .../src/attributes/proc_macro_attrs.rs | 139 ++++++++++++++++++ compiler/rustc_attr_parsing/src/context.rs | 7 + 3 files changed, 147 insertions(+) create mode 100644 compiler/rustc_attr_parsing/src/attributes/proc_macro_attrs.rs diff --git a/compiler/rustc_attr_parsing/src/attributes/mod.rs b/compiler/rustc_attr_parsing/src/attributes/mod.rs index 15b90bd2ed72..0c10517d0440 100644 --- a/compiler/rustc_attr_parsing/src/attributes/mod.rs +++ b/compiler/rustc_attr_parsing/src/attributes/mod.rs @@ -41,6 +41,7 @@ pub(crate) mod must_use; pub(crate) mod no_implicit_prelude; pub(crate) mod non_exhaustive; pub(crate) mod path; +pub(crate) mod proc_macro_attrs; pub(crate) mod repr; pub(crate) mod rustc_internal; pub(crate) mod semantics; diff --git a/compiler/rustc_attr_parsing/src/attributes/proc_macro_attrs.rs b/compiler/rustc_attr_parsing/src/attributes/proc_macro_attrs.rs new file mode 100644 index 000000000000..c8d591fa056f --- /dev/null +++ b/compiler/rustc_attr_parsing/src/attributes/proc_macro_attrs.rs @@ -0,0 +1,139 @@ +use rustc_attr_data_structures::AttributeKind; +use rustc_feature::{AttributeTemplate, template}; +use rustc_span::{Span, Symbol, sym}; +use thin_vec::ThinVec; + +use crate::attributes::{ + AttributeOrder, NoArgsAttributeParser, OnDuplicate, SingleAttributeParser, +}; +use crate::context::{AcceptContext, Stage}; +use crate::parser::ArgParser; + +pub(crate) struct ProcMacroParser; +impl NoArgsAttributeParser for ProcMacroParser { + const PATH: &[Symbol] = &[sym::proc_macro]; + const ON_DUPLICATE: OnDuplicate = OnDuplicate::Error; + const CREATE: fn(Span) -> AttributeKind = AttributeKind::ProcMacro; +} + +pub(crate) struct ProcMacroAttributeParser; +impl NoArgsAttributeParser for ProcMacroAttributeParser { + const PATH: &[Symbol] = &[sym::proc_macro_attribute]; + const ON_DUPLICATE: OnDuplicate = OnDuplicate::Error; + const CREATE: fn(Span) -> AttributeKind = AttributeKind::ProcMacroAttribute; +} + +pub(crate) struct ProcMacroDeriveParser; +impl SingleAttributeParser for ProcMacroDeriveParser { + const PATH: &[Symbol] = &[sym::proc_macro_derive]; + const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost; + const ON_DUPLICATE: OnDuplicate = OnDuplicate::Error; + const TEMPLATE: AttributeTemplate = + template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)"); + + fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option { + let (trait_name, helper_attrs) = parse_derive_like(cx, args, true)?; + Some(AttributeKind::ProcMacroDerive { + trait_name: trait_name.expect("Trait name is mandatory, so it is present"), + helper_attrs, + span: cx.attr_span, + }) + } +} + +pub(crate) struct RustcBuiltinMacroParser; +impl SingleAttributeParser for RustcBuiltinMacroParser { + const PATH: &[Symbol] = &[sym::rustc_builtin_macro]; + const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepOutermost; + const ON_DUPLICATE: OnDuplicate = OnDuplicate::Error; + const TEMPLATE: AttributeTemplate = + template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)"); + + fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option { + let (builtin_name, helper_attrs) = parse_derive_like(cx, args, false)?; + Some(AttributeKind::RustcBuiltinMacro { builtin_name, helper_attrs, span: cx.attr_span }) + } +} + +fn parse_derive_like( + cx: &mut AcceptContext<'_, '_, S>, + args: &ArgParser<'_>, + trait_name_mandatory: bool, +) -> Option<(Option, ThinVec)> { + let Some(list) = args.list() else { + cx.expected_list(cx.attr_span); + return None; + }; + let mut items = list.mixed(); + + // Parse the name of the trait that is derived. + let Some(trait_attr) = items.next() else { + // For #[rustc_builtin_macro], it is permitted to leave out the trait name + if !trait_name_mandatory { + return None; + } + cx.expected_at_least_one_argument(list.span); + return None; + }; + let Some(trait_attr) = trait_attr.meta_item() else { + cx.unexpected_literal(trait_attr.span()); + return None; + }; + let Some(trait_ident) = trait_attr.path().word() else { + cx.expected_identifier(trait_attr.path().span()); + return None; + }; + if !trait_ident.name.can_be_raw() { + cx.expected_identifier(trait_ident.span); + return None; + } + if let Err(e) = trait_attr.args().no_args() { + cx.expected_no_args(e); + return None; + }; + + // Parse optional attributes + let mut attributes = ThinVec::new(); + if let Some(attrs) = items.next() { + let Some(attr_list) = attrs.meta_item() else { + cx.expected_list(attrs.span()); + return None; + }; + if !attr_list.path().word_is(sym::attributes) { + cx.expected_specific_argument(attrs.span(), vec!["attributes"]); + return None; + } + let Some(attr_list) = attr_list.args().list() else { + cx.expected_list(attrs.span()); + return None; + }; + + // Parse item in `attributes(...)` argument + for attr in attr_list.mixed() { + let Some(attr) = attr.meta_item() else { + cx.expected_identifier(attr.span()); + return None; + }; + if let Err(e) = attr.args().no_args() { + cx.expected_no_args(e); + return None; + }; + let Some(ident) = attr.path().word() else { + cx.expected_identifier(attr.path().span()); + return None; + }; + if !ident.name.can_be_raw() { + cx.expected_identifier(ident.span); + return None; + } + attributes.push(ident.name); + } + } + + // If anything else is specified, we should reject it + if let Some(next) = items.next() { + cx.expected_no_args(next.span()); + } + + Some((Some(trait_ident.name), attributes)) +} diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs index 45bfe3452071..9b86d1018408 100644 --- a/compiler/rustc_attr_parsing/src/context.rs +++ b/compiler/rustc_attr_parsing/src/context.rs @@ -38,6 +38,9 @@ use crate::attributes::must_use::MustUseParser; use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser; use crate::attributes::non_exhaustive::NonExhaustiveParser; use crate::attributes::path::PathParser as PathAttributeParser; +use crate::attributes::proc_macro_attrs::{ + ProcMacroAttributeParser, ProcMacroDeriveParser, ProcMacroParser, RustcBuiltinMacroParser, +}; use crate::attributes::repr::{AlignParser, ReprParser}; use crate::attributes::rustc_internal::{ RustcLayoutScalarValidRangeEnd, RustcLayoutScalarValidRangeStart, @@ -154,6 +157,8 @@ attribute_parsers!( Single, Single, Single, + Single, + Single, Single, Single, Single, @@ -186,6 +191,8 @@ attribute_parsers!( Single>, Single>, Single>, + Single>, + Single>, Single>, Single>, Single>,