| use rustc_ast as ast; |
| use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor}; |
| use rustc_ast::{AssocTyConstraint, AssocTyConstraintKind, NodeId}; |
| use rustc_ast::{PatKind, RangeEnd, VariantData}; |
| use rustc_errors::struct_span_err; |
| use rustc_feature::{AttributeGate, BUILTIN_ATTRIBUTE_MAP}; |
| use rustc_feature::{Features, GateIssue}; |
| use rustc_session::parse::{feature_err, feature_err_issue}; |
| use rustc_session::Session; |
| use rustc_span::source_map::Spanned; |
| use rustc_span::symbol::sym; |
| use rustc_span::Span; |
| |
| use tracing::debug; |
| |
| macro_rules! gate_feature_fn { |
| ($visitor: expr, $has_feature: expr, $span: expr, $name: expr, $explain: expr, $help: expr) => {{ |
| let (visitor, has_feature, span, name, explain, help) = |
| (&*$visitor, $has_feature, $span, $name, $explain, $help); |
| let has_feature: bool = has_feature(visitor.features); |
| debug!("gate_feature(feature = {:?}, span = {:?}); has? {}", name, span, has_feature); |
| if !has_feature && !span.allows_unstable($name) { |
| feature_err_issue(&visitor.sess.parse_sess, name, span, GateIssue::Language, explain) |
| .help(help) |
| .emit(); |
| } |
| }}; |
| ($visitor: expr, $has_feature: expr, $span: expr, $name: expr, $explain: expr) => {{ |
| let (visitor, has_feature, span, name, explain) = |
| (&*$visitor, $has_feature, $span, $name, $explain); |
| let has_feature: bool = has_feature(visitor.features); |
| debug!("gate_feature(feature = {:?}, span = {:?}); has? {}", name, span, has_feature); |
| if !has_feature && !span.allows_unstable($name) { |
| feature_err_issue(&visitor.sess.parse_sess, name, span, GateIssue::Language, explain) |
| .emit(); |
| } |
| }}; |
| } |
| |
| macro_rules! gate_feature_post { |
| ($visitor: expr, $feature: ident, $span: expr, $explain: expr, $help: expr) => { |
| gate_feature_fn!($visitor, |x: &Features| x.$feature, $span, sym::$feature, $explain, $help) |
| }; |
| ($visitor: expr, $feature: ident, $span: expr, $explain: expr) => { |
| gate_feature_fn!($visitor, |x: &Features| x.$feature, $span, sym::$feature, $explain) |
| }; |
| } |
| |
| pub fn check_attribute(attr: &ast::Attribute, sess: &Session, features: &Features) { |
| PostExpansionVisitor { sess, features }.visit_attribute(attr) |
| } |
| |
| struct PostExpansionVisitor<'a> { |
| sess: &'a Session, |
| |
| // `sess` contains a `Features`, but this might not be that one. |
| features: &'a Features, |
| } |
| |
| impl<'a> PostExpansionVisitor<'a> { |
| fn check_abi(&self, abi: ast::StrLit) { |
| let ast::StrLit { symbol_unescaped, span, .. } = abi; |
| |
| match &*symbol_unescaped.as_str() { |
| // Stable |
| "Rust" | "C" | "cdecl" | "stdcall" | "fastcall" | "aapcs" | "win64" | "sysv64" |
| | "system" => {} |
| "rust-intrinsic" => { |
| gate_feature_post!(&self, intrinsics, span, "intrinsics are subject to change"); |
| } |
| "platform-intrinsic" => { |
| gate_feature_post!( |
| &self, |
| platform_intrinsics, |
| span, |
| "platform intrinsics are experimental and possibly buggy" |
| ); |
| } |
| "vectorcall" => { |
| gate_feature_post!( |
| &self, |
| abi_vectorcall, |
| span, |
| "vectorcall is experimental and subject to change" |
| ); |
| } |
| "thiscall" => { |
| gate_feature_post!( |
| &self, |
| abi_thiscall, |
| span, |
| "thiscall is experimental and subject to change" |
| ); |
| } |
| "rust-call" => { |
| gate_feature_post!( |
| &self, |
| unboxed_closures, |
| span, |
| "rust-call ABI is subject to change" |
| ); |
| } |
| "ptx-kernel" => { |
| gate_feature_post!( |
| &self, |
| abi_ptx, |
| span, |
| "PTX ABIs are experimental and subject to change" |
| ); |
| } |
| "unadjusted" => { |
| gate_feature_post!( |
| &self, |
| abi_unadjusted, |
| span, |
| "unadjusted ABI is an implementation detail and perma-unstable" |
| ); |
| } |
| "msp430-interrupt" => { |
| gate_feature_post!( |
| &self, |
| abi_msp430_interrupt, |
| span, |
| "msp430-interrupt ABI is experimental and subject to change" |
| ); |
| } |
| "x86-interrupt" => { |
| gate_feature_post!( |
| &self, |
| abi_x86_interrupt, |
| span, |
| "x86-interrupt ABI is experimental and subject to change" |
| ); |
| } |
| "amdgpu-kernel" => { |
| gate_feature_post!( |
| &self, |
| abi_amdgpu_kernel, |
| span, |
| "amdgpu-kernel ABI is experimental and subject to change" |
| ); |
| } |
| "avr-interrupt" | "avr-non-blocking-interrupt" => { |
| gate_feature_post!( |
| &self, |
| abi_avr_interrupt, |
| span, |
| "avr-interrupt and avr-non-blocking-interrupt ABIs are experimental and subject to change" |
| ); |
| } |
| "efiapi" => { |
| gate_feature_post!( |
| &self, |
| abi_efiapi, |
| span, |
| "efiapi ABI is experimental and subject to change" |
| ); |
| } |
| "C-cmse-nonsecure-call" => { |
| gate_feature_post!( |
| &self, |
| abi_c_cmse_nonsecure_call, |
| span, |
| "C-cmse-nonsecure-call ABI is experimental and subject to change" |
| ); |
| } |
| "C-unwind" => { |
| gate_feature_post!( |
| &self, |
| c_unwind, |
| span, |
| "C-unwind ABI is experimental and subject to change" |
| ); |
| } |
| "stdcall-unwind" => { |
| gate_feature_post!( |
| &self, |
| c_unwind, |
| span, |
| "stdcall-unwind ABI is experimental and subject to change" |
| ); |
| } |
| "system-unwind" => { |
| gate_feature_post!( |
| &self, |
| c_unwind, |
| span, |
| "system-unwind ABI is experimental and subject to change" |
| ); |
| } |
| "thiscall-unwind" => { |
| gate_feature_post!( |
| &self, |
| c_unwind, |
| span, |
| "thiscall-unwind ABI is experimental and subject to change" |
| ); |
| } |
| "wasm" => { |
| gate_feature_post!( |
| &self, |
| wasm_abi, |
| span, |
| "wasm ABI is experimental and subject to change" |
| ); |
| } |
| abi => self |
| .sess |
| .parse_sess |
| .span_diagnostic |
| .delay_span_bug(span, &format!("unrecognized ABI not caught in lowering: {}", abi)), |
| } |
| } |
| |
| fn check_extern(&self, ext: ast::Extern) { |
| if let ast::Extern::Explicit(abi) = ext { |
| self.check_abi(abi); |
| } |
| } |
| |
| fn maybe_report_invalid_custom_discriminants(&self, variants: &[ast::Variant]) { |
| let has_fields = variants.iter().any(|variant| match variant.data { |
| VariantData::Tuple(..) | VariantData::Struct(..) => true, |
| VariantData::Unit(..) => false, |
| }); |
| |
| let discriminant_spans = variants |
| .iter() |
| .filter(|variant| match variant.data { |
| VariantData::Tuple(..) | VariantData::Struct(..) => false, |
| VariantData::Unit(..) => true, |
| }) |
| .filter_map(|variant| variant.disr_expr.as_ref().map(|c| c.value.span)) |
| .collect::<Vec<_>>(); |
| |
| if !discriminant_spans.is_empty() && has_fields { |
| let mut err = feature_err( |
| &self.sess.parse_sess, |
| sym::arbitrary_enum_discriminant, |
| discriminant_spans.clone(), |
| "custom discriminant values are not allowed in enums with tuple or struct variants", |
| ); |
| for sp in discriminant_spans { |
| err.span_label(sp, "disallowed custom discriminant"); |
| } |
| for variant in variants.iter() { |
| match &variant.data { |
| VariantData::Struct(..) => { |
| err.span_label(variant.span, "struct variant defined here"); |
| } |
| VariantData::Tuple(..) => { |
| err.span_label(variant.span, "tuple variant defined here"); |
| } |
| VariantData::Unit(..) => {} |
| } |
| } |
| err.emit(); |
| } |
| } |
| |
| fn check_gat(&self, generics: &ast::Generics, span: Span) { |
| if !generics.params.is_empty() { |
| gate_feature_post!( |
| &self, |
| generic_associated_types, |
| span, |
| "generic associated types are unstable" |
| ); |
| } |
| if !generics.where_clause.predicates.is_empty() { |
| gate_feature_post!( |
| &self, |
| generic_associated_types, |
| span, |
| "where clauses on associated types are unstable" |
| ); |
| } |
| } |
| |
| /// Feature gate `impl Trait` inside `type Alias = $type_expr;`. |
| fn check_impl_trait(&self, ty: &ast::Ty) { |
| struct ImplTraitVisitor<'a> { |
| vis: &'a PostExpansionVisitor<'a>, |
| } |
| impl Visitor<'_> for ImplTraitVisitor<'_> { |
| fn visit_ty(&mut self, ty: &ast::Ty) { |
| if let ast::TyKind::ImplTrait(..) = ty.kind { |
| gate_feature_post!( |
| &self.vis, |
| min_type_alias_impl_trait, |
| ty.span, |
| "`impl Trait` in type aliases is unstable" |
| ); |
| } |
| visit::walk_ty(self, ty); |
| } |
| } |
| ImplTraitVisitor { vis: self }.visit_ty(ty); |
| } |
| } |
| |
| impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { |
| fn visit_attribute(&mut self, attr: &ast::Attribute) { |
| let attr_info = |
| attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)).map(|a| **a); |
| // Check feature gates for built-in attributes. |
| if let Some((.., AttributeGate::Gated(_, name, descr, has_feature))) = attr_info { |
| gate_feature_fn!(self, has_feature, attr.span, name, descr); |
| } |
| // Check unstable flavors of the `#[doc]` attribute. |
| if self.sess.check_name(attr, sym::doc) { |
| for nested_meta in attr.meta_item_list().unwrap_or_default() { |
| macro_rules! gate_doc { ($($name:ident => $feature:ident)*) => { |
| $(if nested_meta.has_name(sym::$name) { |
| let msg = concat!("`#[doc(", stringify!($name), ")]` is experimental"); |
| gate_feature_post!(self, $feature, attr.span, msg); |
| })* |
| }} |
| |
| gate_doc!( |
| cfg => doc_cfg |
| masked => doc_masked |
| notable_trait => doc_notable_trait |
| keyword => doc_keyword |
| ); |
| } |
| } |
| |
| // Check for unstable modifiers on `#[link(..)]` attribute |
| if self.sess.check_name(attr, sym::link) { |
| for nested_meta in attr.meta_item_list().unwrap_or_default() { |
| if nested_meta.has_name(sym::modifiers) { |
| gate_feature_post!( |
| self, |
| native_link_modifiers, |
| nested_meta.span(), |
| "native link modifiers are experimental" |
| ); |
| |
| if let Some(modifiers) = nested_meta.value_str() { |
| for modifier in modifiers.as_str().split(',') { |
| if let Some(modifier) = modifier.strip_prefix(&['+', '-'][..]) { |
| macro_rules! gate_modifier { ($($name:literal => $feature:ident)*) => { |
| $(if modifier == $name { |
| let msg = concat!("`#[link(modifiers=\"", $name, "\")]` is unstable"); |
| gate_feature_post!( |
| self, |
| $feature, |
| nested_meta.name_value_literal_span().unwrap(), |
| msg |
| ); |
| })* |
| }} |
| |
| gate_modifier!( |
| "bundle" => native_link_modifiers_bundle |
| "verbatim" => native_link_modifiers_verbatim |
| "whole-archive" => native_link_modifiers_whole_archive |
| "as-needed" => native_link_modifiers_as_needed |
| ); |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| fn visit_item(&mut self, i: &'a ast::Item) { |
| match i.kind { |
| ast::ItemKind::ForeignMod(ref foreign_module) => { |
| if let Some(abi) = foreign_module.abi { |
| self.check_abi(abi); |
| } |
| } |
| |
| ast::ItemKind::Fn(..) => { |
| if self.sess.contains_name(&i.attrs[..], sym::plugin_registrar) { |
| gate_feature_post!( |
| &self, |
| plugin_registrar, |
| i.span, |
| "compiler plugins are experimental and possibly buggy" |
| ); |
| } |
| if self.sess.contains_name(&i.attrs[..], sym::start) { |
| gate_feature_post!( |
| &self, |
| start, |
| i.span, |
| "`#[start]` functions are experimental \ |
| and their signature may change \ |
| over time" |
| ); |
| } |
| } |
| |
| ast::ItemKind::Struct(..) => { |
| for attr in self.sess.filter_by_name(&i.attrs[..], sym::repr) { |
| for item in attr.meta_item_list().unwrap_or_else(Vec::new) { |
| if item.has_name(sym::simd) { |
| gate_feature_post!( |
| &self, |
| repr_simd, |
| attr.span, |
| "SIMD types are experimental and possibly buggy" |
| ); |
| } |
| } |
| } |
| } |
| |
| ast::ItemKind::Enum(ast::EnumDef { ref variants, .. }, ..) => { |
| for variant in variants { |
| match (&variant.data, &variant.disr_expr) { |
| (ast::VariantData::Unit(..), _) => {} |
| (_, Some(disr_expr)) => gate_feature_post!( |
| &self, |
| arbitrary_enum_discriminant, |
| disr_expr.value.span, |
| "discriminants on non-unit variants are experimental" |
| ), |
| _ => {} |
| } |
| } |
| |
| let has_feature = self.features.arbitrary_enum_discriminant; |
| if !has_feature && !i.span.allows_unstable(sym::arbitrary_enum_discriminant) { |
| self.maybe_report_invalid_custom_discriminants(&variants); |
| } |
| } |
| |
| ast::ItemKind::Impl(box ast::ImplKind { |
| polarity, defaultness, ref of_trait, .. |
| }) => { |
| if let ast::ImplPolarity::Negative(span) = polarity { |
| gate_feature_post!( |
| &self, |
| negative_impls, |
| span.to(of_trait.as_ref().map_or(span, |t| t.path.span)), |
| "negative trait bounds are not yet fully implemented; \ |
| use marker types for now" |
| ); |
| } |
| |
| if let ast::Defaultness::Default(_) = defaultness { |
| gate_feature_post!(&self, specialization, i.span, "specialization is unstable"); |
| } |
| } |
| |
| ast::ItemKind::Trait(box ast::TraitKind(ast::IsAuto::Yes, ..)) => { |
| gate_feature_post!( |
| &self, |
| auto_traits, |
| i.span, |
| "auto traits are experimental and possibly buggy" |
| ); |
| } |
| |
| ast::ItemKind::TraitAlias(..) => { |
| gate_feature_post!(&self, trait_alias, i.span, "trait aliases are experimental"); |
| } |
| |
| ast::ItemKind::MacroDef(ast::MacroDef { macro_rules: false, .. }) => { |
| let msg = "`macro` is experimental"; |
| gate_feature_post!(&self, decl_macro, i.span, msg); |
| } |
| |
| ast::ItemKind::TyAlias(box ast::TyAliasKind(_, _, _, Some(ref ty))) => { |
| self.check_impl_trait(&ty) |
| } |
| |
| _ => {} |
| } |
| |
| visit::walk_item(self, i); |
| } |
| |
| fn visit_foreign_item(&mut self, i: &'a ast::ForeignItem) { |
| match i.kind { |
| ast::ForeignItemKind::Fn(..) | ast::ForeignItemKind::Static(..) => { |
| let link_name = self.sess.first_attr_value_str_by_name(&i.attrs, sym::link_name); |
| let links_to_llvm = |
| link_name.map_or(false, |val| val.as_str().starts_with("llvm.")); |
| if links_to_llvm { |
| gate_feature_post!( |
| &self, |
| link_llvm_intrinsics, |
| i.span, |
| "linking to LLVM intrinsics is experimental" |
| ); |
| } |
| } |
| ast::ForeignItemKind::TyAlias(..) => { |
| gate_feature_post!(&self, extern_types, i.span, "extern types are experimental"); |
| } |
| ast::ForeignItemKind::MacCall(..) => {} |
| } |
| |
| visit::walk_foreign_item(self, i) |
| } |
| |
| fn visit_ty(&mut self, ty: &'a ast::Ty) { |
| match ty.kind { |
| ast::TyKind::BareFn(ref bare_fn_ty) => { |
| self.check_extern(bare_fn_ty.ext); |
| } |
| ast::TyKind::Never => { |
| gate_feature_post!(&self, never_type, ty.span, "the `!` type is experimental"); |
| } |
| _ => {} |
| } |
| visit::walk_ty(self, ty) |
| } |
| |
| fn visit_fn_ret_ty(&mut self, ret_ty: &'a ast::FnRetTy) { |
| if let ast::FnRetTy::Ty(ref output_ty) = *ret_ty { |
| if let ast::TyKind::Never = output_ty.kind { |
| // Do nothing. |
| } else { |
| self.visit_ty(output_ty) |
| } |
| } |
| } |
| |
| fn visit_expr(&mut self, e: &'a ast::Expr) { |
| match e.kind { |
| ast::ExprKind::Box(_) => { |
| gate_feature_post!( |
| &self, |
| box_syntax, |
| e.span, |
| "box expression syntax is experimental; you can call `Box::new` instead" |
| ); |
| } |
| ast::ExprKind::Type(..) => { |
| // To avoid noise about type ascription in common syntax errors, only emit if it |
| // is the *only* error. |
| if self.sess.parse_sess.span_diagnostic.err_count() == 0 { |
| gate_feature_post!( |
| &self, |
| type_ascription, |
| e.span, |
| "type ascription is experimental" |
| ); |
| } |
| } |
| ast::ExprKind::TryBlock(_) => { |
| gate_feature_post!(&self, try_blocks, e.span, "`try` expression is experimental"); |
| } |
| ast::ExprKind::Block(_, opt_label) => { |
| if let Some(label) = opt_label { |
| gate_feature_post!( |
| &self, |
| label_break_value, |
| label.ident.span, |
| "labels on blocks are unstable" |
| ); |
| } |
| } |
| _ => {} |
| } |
| visit::walk_expr(self, e) |
| } |
| |
| fn visit_pat(&mut self, pattern: &'a ast::Pat) { |
| match &pattern.kind { |
| PatKind::Box(..) => { |
| gate_feature_post!( |
| &self, |
| box_patterns, |
| pattern.span, |
| "box pattern syntax is experimental" |
| ); |
| } |
| PatKind::Range(_, _, Spanned { node: RangeEnd::Excluded, .. }) => { |
| gate_feature_post!( |
| &self, |
| exclusive_range_pattern, |
| pattern.span, |
| "exclusive range pattern syntax is experimental" |
| ); |
| } |
| _ => {} |
| } |
| visit::walk_pat(self, pattern) |
| } |
| |
| fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) { |
| if let Some(header) = fn_kind.header() { |
| // Stability of const fn methods are covered in `visit_assoc_item` below. |
| self.check_extern(header.ext); |
| |
| if let (ast::Const::Yes(_), ast::Extern::Implicit) |
| | (ast::Const::Yes(_), ast::Extern::Explicit(_)) = (header.constness, header.ext) |
| { |
| gate_feature_post!( |
| &self, |
| const_extern_fn, |
| span, |
| "`const extern fn` definitions are unstable" |
| ); |
| } |
| } |
| |
| if fn_kind.ctxt() != Some(FnCtxt::Foreign) && fn_kind.decl().c_variadic() { |
| gate_feature_post!(&self, c_variadic, span, "C-variadic functions are unstable"); |
| } |
| |
| visit::walk_fn(self, fn_kind, span) |
| } |
| |
| fn visit_assoc_ty_constraint(&mut self, constraint: &'a AssocTyConstraint) { |
| if let AssocTyConstraintKind::Bound { .. } = constraint.kind { |
| gate_feature_post!( |
| &self, |
| associated_type_bounds, |
| constraint.span, |
| "associated type bounds are unstable" |
| ) |
| } |
| visit::walk_assoc_ty_constraint(self, constraint) |
| } |
| |
| fn visit_assoc_item(&mut self, i: &'a ast::AssocItem, ctxt: AssocCtxt) { |
| let is_fn = match i.kind { |
| ast::AssocItemKind::Fn(_) => true, |
| ast::AssocItemKind::TyAlias(box ast::TyAliasKind(_, ref generics, _, ref ty)) => { |
| if let (Some(_), AssocCtxt::Trait) = (ty, ctxt) { |
| gate_feature_post!( |
| &self, |
| associated_type_defaults, |
| i.span, |
| "associated type defaults are unstable" |
| ); |
| } |
| if let Some(ty) = ty { |
| self.check_impl_trait(ty); |
| } |
| self.check_gat(generics, i.span); |
| false |
| } |
| _ => false, |
| }; |
| if let ast::Defaultness::Default(_) = i.kind.defaultness() { |
| // Limit `min_specialization` to only specializing functions. |
| gate_feature_fn!( |
| &self, |
| |x: &Features| x.specialization || (is_fn && x.min_specialization), |
| i.span, |
| sym::specialization, |
| "specialization is unstable" |
| ); |
| } |
| visit::walk_assoc_item(self, i, ctxt) |
| } |
| |
| fn visit_vis(&mut self, vis: &'a ast::Visibility) { |
| if let ast::VisibilityKind::Crate(ast::CrateSugar::JustCrate) = vis.kind { |
| gate_feature_post!( |
| &self, |
| crate_visibility_modifier, |
| vis.span, |
| "`crate` visibility modifier is experimental" |
| ); |
| } |
| visit::walk_vis(self, vis) |
| } |
| } |
| |
| pub fn check_crate(krate: &ast::Crate, sess: &Session) { |
| maybe_stage_features(sess, krate); |
| check_incompatible_features(sess); |
| let mut visitor = PostExpansionVisitor { sess, features: &sess.features_untracked() }; |
| |
| let spans = sess.parse_sess.gated_spans.spans.borrow(); |
| macro_rules! gate_all { |
| ($gate:ident, $msg:literal, $help:literal) => { |
| if let Some(spans) = spans.get(&sym::$gate) { |
| for span in spans { |
| gate_feature_post!(&visitor, $gate, *span, $msg, $help); |
| } |
| } |
| }; |
| ($gate:ident, $msg:literal) => { |
| if let Some(spans) = spans.get(&sym::$gate) { |
| for span in spans { |
| gate_feature_post!(&visitor, $gate, *span, $msg); |
| } |
| } |
| }; |
| } |
| gate_all!( |
| if_let_guard, |
| "`if let` guards are experimental", |
| "you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`" |
| ); |
| gate_all!( |
| let_chains, |
| "`let` expressions in this position are experimental", |
| "you can write `matches!(<expr>, <pattern>)` instead of `let <pattern> = <expr>`" |
| ); |
| gate_all!( |
| async_closure, |
| "async closures are unstable", |
| "to use an async block, remove the `||`: `async {`" |
| ); |
| gate_all!(more_qualified_paths, "usage of qualified paths in this context is experimental"); |
| gate_all!(generators, "yield syntax is experimental"); |
| gate_all!(raw_ref_op, "raw address of syntax is experimental"); |
| gate_all!(const_trait_bound_opt_out, "`?const` on trait bounds is experimental"); |
| gate_all!(const_trait_impl, "const trait impls are experimental"); |
| gate_all!(half_open_range_patterns, "half-open range patterns are unstable"); |
| gate_all!(inline_const, "inline-const is experimental"); |
| gate_all!( |
| const_generics_defaults, |
| "default values for const generic parameters are experimental" |
| ); |
| if sess.parse_sess.span_diagnostic.err_count() == 0 { |
| // Errors for `destructuring_assignment` can get quite noisy, especially where `_` is |
| // involved, so we only emit errors where there are no other parsing errors. |
| gate_all!(destructuring_assignment, "destructuring assignments are unstable"); |
| } |
| gate_all!(unnamed_fields, "unnamed fields are not yet fully implemented"); |
| |
| // All uses of `gate_all!` below this point were added in #65742, |
| // and subsequently disabled (with the non-early gating readded). |
| macro_rules! gate_all { |
| ($gate:ident, $msg:literal) => { |
| // FIXME(eddyb) do something more useful than always |
| // disabling these uses of early feature-gatings. |
| if false { |
| for span in spans.get(&sym::$gate).unwrap_or(&vec![]) { |
| gate_feature_post!(&visitor, $gate, *span, $msg); |
| } |
| } |
| }; |
| } |
| |
| gate_all!(trait_alias, "trait aliases are experimental"); |
| gate_all!(associated_type_bounds, "associated type bounds are unstable"); |
| gate_all!(crate_visibility_modifier, "`crate` visibility modifier is experimental"); |
| gate_all!(const_generics, "const generics are unstable"); |
| gate_all!(decl_macro, "`macro` is experimental"); |
| gate_all!(box_patterns, "box pattern syntax is experimental"); |
| gate_all!(exclusive_range_pattern, "exclusive range pattern syntax is experimental"); |
| gate_all!(try_blocks, "`try` blocks are unstable"); |
| gate_all!(label_break_value, "labels on blocks are unstable"); |
| gate_all!(box_syntax, "box expression syntax is experimental; you can call `Box::new` instead"); |
| // To avoid noise about type ascription in common syntax errors, |
| // only emit if it is the *only* error. (Also check it last.) |
| if sess.parse_sess.span_diagnostic.err_count() == 0 { |
| gate_all!(type_ascription, "type ascription is experimental"); |
| } |
| |
| visit::walk_crate(&mut visitor, krate); |
| } |
| |
| fn maybe_stage_features(sess: &Session, krate: &ast::Crate) { |
| use rustc_errors::Applicability; |
| |
| if !sess.opts.unstable_features.is_nightly_build() { |
| let lang_features = &sess.features_untracked().declared_lang_features; |
| for attr in krate.attrs.iter().filter(|attr| sess.check_name(attr, sym::feature)) { |
| let mut err = struct_span_err!( |
| sess.parse_sess.span_diagnostic, |
| attr.span, |
| E0554, |
| "`#![feature]` may not be used on the {} release channel", |
| option_env!("CFG_RELEASE_CHANNEL").unwrap_or("(unknown)") |
| ); |
| let mut all_stable = true; |
| for ident in |
| attr.meta_item_list().into_iter().flatten().map(|nested| nested.ident()).flatten() |
| { |
| let name = ident.name; |
| let stable_since = lang_features |
| .iter() |
| .flat_map(|&(feature, _, since)| if feature == name { since } else { None }) |
| .next(); |
| if let Some(since) = stable_since { |
| err.help(&format!( |
| "the feature `{}` has been stable since {} and no longer requires \ |
| an attribute to enable", |
| name, since |
| )); |
| } else { |
| all_stable = false; |
| } |
| } |
| if all_stable { |
| err.span_suggestion( |
| attr.span, |
| "remove the attribute", |
| String::new(), |
| Applicability::MachineApplicable, |
| ); |
| } |
| err.emit(); |
| } |
| } |
| } |
| |
| fn check_incompatible_features(sess: &Session) { |
| let features = sess.features_untracked(); |
| |
| let declared_features = features |
| .declared_lang_features |
| .iter() |
| .copied() |
| .map(|(name, span, _)| (name, span)) |
| .chain(features.declared_lib_features.iter().copied()); |
| |
| for (f1, f2) in rustc_feature::INCOMPATIBLE_FEATURES |
| .iter() |
| .filter(|&&(f1, f2)| features.enabled(f1) && features.enabled(f2)) |
| { |
| if let Some((f1_name, f1_span)) = declared_features.clone().find(|(name, _)| name == f1) { |
| if let Some((f2_name, f2_span)) = declared_features.clone().find(|(name, _)| name == f2) |
| { |
| let spans = vec![f1_span, f2_span]; |
| sess.struct_span_err( |
| spans.clone(), |
| &format!( |
| "features `{}` and `{}` are incompatible, using them at the same time \ |
| is not allowed", |
| f1_name, f2_name |
| ), |
| ) |
| .help("remove one of these features") |
| .emit(); |
| } |
| } |
| } |
| } |