diff options
Diffstat (limited to 'compiler/rustc_passes/src/check_attr.rs')
| -rw-r--r-- | compiler/rustc_passes/src/check_attr.rs | 161 |
1 files changed, 157 insertions, 4 deletions
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index 3fea75954b9..3009c2c3f2f 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -8,8 +8,10 @@ use rustc_middle::hir::map::Map; use rustc_middle::ty::query::Providers; use rustc_middle::ty::TyCtxt; -use rustc_ast::{AttrStyle, Attribute, Lit, LitKind, NestedMetaItem}; +use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, NestedMetaItem}; +use rustc_data_structures::stable_set::FxHashSet; use rustc_errors::{pluralize, struct_span_err, Applicability}; +use rustc_feature::{AttributeType, BUILTIN_ATTRIBUTE_MAP}; use rustc_hir as hir; use rustc_hir::def_id::LocalDefId; use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; @@ -66,9 +68,10 @@ impl CheckAttrVisitor<'tcx> { ) { let mut is_valid = true; let mut specified_inline = None; + let mut seen = FxHashSet::default(); let attrs = self.tcx.hir().attrs(hir_id); for attr in attrs { - is_valid &= match attr.name_or_empty() { + let attr_is_valid = match attr.name_or_empty() { sym::inline => self.check_inline(hir_id, attr, span, target), sym::non_exhaustive => self.check_non_exhaustive(hir_id, attr, span, target), sym::marker => self.check_marker(hir_id, attr, span, target), @@ -101,14 +104,66 @@ impl CheckAttrVisitor<'tcx> { sym::default_method_body_is_const => { self.check_default_method_body_is_const(attr, span, target) } + sym::rustc_const_unstable + | sym::rustc_const_stable + | sym::unstable + | sym::stable + | sym::rustc_promotable => self.check_stability_promotable(&attr, span, target), _ => true, }; + is_valid &= attr_is_valid; + // lint-only checks match attr.name_or_empty() { sym::cold => self.check_cold(hir_id, attr, span, target), sym::link_name => self.check_link_name(hir_id, attr, span, target), sym::link_section => self.check_link_section(hir_id, attr, span, target), sym::no_mangle => self.check_no_mangle(hir_id, attr, span, target), + sym::deprecated | sym::rustc_deprecated => { + self.check_deprecated(hir_id, attr, span, target) + } + sym::macro_use | sym::macro_escape => self.check_macro_use(hir_id, attr, target), + sym::path => self.check_generic_attr(hir_id, attr, target, &[Target::Mod]), + sym::cfg_attr => self.check_cfg_attr(hir_id, attr), + sym::plugin_registrar => self.check_plugin_registrar(hir_id, attr, target), + sym::macro_export => self.check_macro_export(hir_id, attr, target), + sym::ignore | sym::should_panic | sym::proc_macro_derive => { + self.check_generic_attr(hir_id, attr, target, &[Target::Fn]) + } + _ => {} + } + + if hir_id != CRATE_HIR_ID { + if let Some((_, AttributeType::CrateLevel, ..)) = + attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)) + { + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + let msg = match attr.style { + ast::AttrStyle::Outer => { + "crate-level attribute should be an inner attribute: add an exclamation \ + mark: `#![foo]`" + } + ast::AttrStyle::Inner => "crate-level attribute should be in the root module", + }; + lint.build(msg).emit() + }); + } + } + + // Duplicate attributes + match attr.name_or_empty() { + name @ sym::macro_use => { + let args = attr.meta_item_list().unwrap_or_else(Vec::new); + let args: Vec<_> = args.iter().map(|arg| arg.name_or_empty()).collect(); + if !seen.insert((name, args)) { + self.tcx.struct_span_lint_hir( + UNUSED_ATTRIBUTES, + hir_id, + attr.span, + |lint| lint.build("unused attribute").emit(), + ); + } + } _ => {} } } @@ -211,6 +266,38 @@ impl CheckAttrVisitor<'tcx> { } } + fn check_generic_attr( + &self, + hir_id: HirId, + attr: &Attribute, + target: Target, + allowed_targets: &[Target], + ) { + if !allowed_targets.iter().any(|t| t == &target) { + let name = attr.name_or_empty(); + let mut i = allowed_targets.iter(); + // Pluralize + let b = i.next().map_or_else(String::new, |t| t.to_string() + "s"); + let supported_names = i.enumerate().fold(b, |mut b, (i, allowed_target)| { + if allowed_targets.len() > 2 && i == allowed_targets.len() - 2 { + b.push_str(", and "); + } else if allowed_targets.len() == 2 && i == allowed_targets.len() - 2 { + b.push_str(" and "); + } else { + b.push_str(", "); + } + // Pluralize + b.push_str(&(allowed_target.to_string() + "s")); + b + }); + //let supported_names = allowed_targets.iter().fold(String::new(), |msg, t| msg + ", " + &t.to_string()); + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + lint.build(&format!("`#[{name}]` only has an effect on {}", supported_names)) + .emit(); + }); + } + } + /// Checks if `#[naked]` is applied to a function definition. fn check_naked(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { match target { @@ -1555,6 +1642,72 @@ impl CheckAttrVisitor<'tcx> { } } } + + fn check_stability_promotable(&self, attr: &Attribute, _span: &Span, target: Target) -> bool { + match target { + Target::Expression => { + self.tcx + .sess + .struct_span_err(attr.span, "attribute cannot be applied to an expression") + .emit(); + false + } + _ => true, + } + } + + fn check_deprecated(&self, hir_id: HirId, attr: &Attribute, _span: &Span, target: Target) { + match target { + Target::Closure | Target::Expression | Target::Statement | Target::Arm => { + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + lint.build("attribute is ignored here").emit(); + }); + } + _ => {} + } + } + + fn check_macro_use(&self, hir_id: HirId, attr: &Attribute, target: Target) { + let name = attr.name_or_empty(); + match target { + Target::ExternCrate | Target::Mod => {} + _ => { + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + lint.build(&format!( + "`#[{name}]` only has an effect on `extern crate` and modules" + )) + .emit(); + }); + } + } + } + + fn check_macro_export(&self, hir_id: HirId, attr: &Attribute, target: Target) { + if target != Target::MacroDef { + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + lint.build(&format!("`#[macro_export]` only has an effect on macro definitions")) + .emit(); + }); + } + } + + fn check_cfg_attr(&self, hir_id: HirId, attr: &Attribute) { + if let Some((_, attrs)) = rustc_parse::parse_cfg_attr(&attr, &self.tcx.sess.parse_sess) { + if attrs.is_empty() { + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + lint.build("`#[cfg_attr]` does not expand to any attributes").emit(); + }); + } + } + } + + fn check_plugin_registrar(&self, hir_id: HirId, attr: &Attribute, target: Target) { + if target != Target::Fn { + self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { + lint.build("`#[plugin_registrar]` only has an effect on functions").emit(); + }); + } + } } impl Visitor<'tcx> for CheckAttrVisitor<'tcx> { @@ -1675,7 +1828,7 @@ fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { for attr in attrs { for attr_to_check in ATTRS_TO_CHECK { - if tcx.sess.check_name(attr, *attr_to_check) { + if attr.has_name(*attr_to_check) { tcx.sess .struct_span_err( attr.span, @@ -1692,7 +1845,7 @@ fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { fn check_invalid_macro_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { for attr in attrs { - if tcx.sess.check_name(attr, sym::inline) { + if attr.has_name(sym::inline) { struct_span_err!( tcx.sess, attr.span, |