diff options
Diffstat (limited to 'compiler/rustc_expand/src/expand.rs')
| -rw-r--r-- | compiler/rustc_expand/src/expand.rs | 1428 |
1 files changed, 849 insertions, 579 deletions
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs index 89dbd64ed81..9a4daa6d750 100644 --- a/compiler/rustc_expand/src/expand.rs +++ b/compiler/rustc_expand/src/expand.rs @@ -1,6 +1,5 @@ use crate::base::*; use crate::config::StripUnconfigured; -use crate::configure; use crate::hygiene::SyntaxContext; use crate::mbe::macro_rules::annotate_err_with_kind; use crate::module::{mod_dir_path, parse_external_mod, DirOwnership, ParsedExternalMod}; @@ -12,15 +11,13 @@ use rustc_ast::ptr::P; use rustc_ast::token; use rustc_ast::tokenstream::TokenStream; use rustc_ast::visit::{self, AssocCtxt, Visitor}; -use rustc_ast::{AstLike, Block, Inline, ItemKind, MacArgs, MacCall}; -use rustc_ast::{MacCallStmt, MacStmtStyle, MetaItemKind, ModKind, NestedMetaItem}; -use rustc_ast::{NodeId, PatKind, Path, StmtKind, Unsafe}; +use rustc_ast::{AssocItemKind, AstLike, AstLikeWrapper, AttrStyle, ExprKind, ForeignItemKind}; +use rustc_ast::{Inline, ItemKind, MacArgs, MacStmtStyle, MetaItemKind, ModKind, NestedMetaItem}; +use rustc_ast::{NodeId, PatKind, StmtKind, TyKind}; use rustc_ast_pretty::pprust; -use rustc_attr::is_builtin_attr; use rustc_data_structures::map_in_place::MapInPlace; -use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_data_structures::sync::Lrc; -use rustc_errors::{Applicability, FatalError, PResult}; +use rustc_errors::{Applicability, PResult}; use rustc_feature::Features; use rustc_parse::parser::{ AttemptLocalParseRecovery, ForceCollect, Parser, RecoverColon, RecoverComma, @@ -33,8 +30,8 @@ use rustc_session::Limit; use rustc_span::symbol::{sym, Ident}; use rustc_span::{FileName, LocalExpnId, Span}; -use smallvec::{smallvec, SmallVec}; -use std::ops::DerefMut; +use smallvec::SmallVec; +use std::ops::Deref; use std::path::PathBuf; use std::rc::Rc; use std::{iter, mem}; @@ -109,6 +106,10 @@ macro_rules! ast_fragments { } })* + fn make_ast<T: InvocationCollectorNode>(self) -> T::OutputTy { + T::fragment_to_output(self) + } + pub fn mut_visit_with<F: MutVisitor>(&mut self, vis: &mut F) { match self { AstFragment::OptExpr(opt_expr) => { @@ -178,10 +179,10 @@ ast_fragments! { Arms(SmallVec<[ast::Arm; 1]>) { "match arm"; many fn flat_map_arm; fn visit_arm(); fn make_arms; } - Fields(SmallVec<[ast::ExprField; 1]>) { + ExprFields(SmallVec<[ast::ExprField; 1]>) { "field expression"; many fn flat_map_expr_field; fn visit_expr_field(); fn make_expr_fields; } - FieldPats(SmallVec<[ast::PatField; 1]>) { + PatFields(SmallVec<[ast::PatField; 1]>) { "field pattern"; many fn flat_map_pat_field; fn visit_pat_field(); @@ -196,7 +197,7 @@ ast_fragments! { Params(SmallVec<[ast::Param; 1]>) { "function parameter"; many fn flat_map_param; fn visit_param(); fn make_params; } - StructFields(SmallVec<[ast::FieldDef; 1]>) { + FieldDefs(SmallVec<[ast::FieldDef; 1]>) { "field"; many fn flat_map_field_def; fn visit_field_def(); @@ -205,6 +206,7 @@ ast_fragments! { Variants(SmallVec<[ast::Variant; 1]>) { "variant"; many fn flat_map_variant; fn visit_variant(); fn make_variants; } + Crate(ast::Crate) { "crate"; one fn visit_crate; fn visit_crate; fn make_crate; } } pub enum SupportsMacroExpansion { @@ -227,15 +229,14 @@ impl AstFragmentKind { AstFragmentKind::Items | AstFragmentKind::TraitItems | AstFragmentKind::ImplItems - | AstFragmentKind::ForeignItems => { - SupportsMacroExpansion::Yes { supports_inner_attrs: true } - } + | AstFragmentKind::ForeignItems + | AstFragmentKind::Crate => SupportsMacroExpansion::Yes { supports_inner_attrs: true }, AstFragmentKind::Arms - | AstFragmentKind::Fields - | AstFragmentKind::FieldPats + | AstFragmentKind::ExprFields + | AstFragmentKind::PatFields | AstFragmentKind::GenericParams | AstFragmentKind::Params - | AstFragmentKind::StructFields + | AstFragmentKind::FieldDefs | AstFragmentKind::Variants => SupportsMacroExpansion::No, } } @@ -249,11 +250,11 @@ impl AstFragmentKind { AstFragmentKind::Arms => { AstFragment::Arms(items.map(Annotatable::expect_arm).collect()) } - AstFragmentKind::Fields => { - AstFragment::Fields(items.map(Annotatable::expect_expr_field).collect()) + AstFragmentKind::ExprFields => { + AstFragment::ExprFields(items.map(Annotatable::expect_expr_field).collect()) } - AstFragmentKind::FieldPats => { - AstFragment::FieldPats(items.map(Annotatable::expect_pat_field).collect()) + AstFragmentKind::PatFields => { + AstFragment::PatFields(items.map(Annotatable::expect_pat_field).collect()) } AstFragmentKind::GenericParams => { AstFragment::GenericParams(items.map(Annotatable::expect_generic_param).collect()) @@ -261,8 +262,8 @@ impl AstFragmentKind { AstFragmentKind::Params => { AstFragment::Params(items.map(Annotatable::expect_param).collect()) } - AstFragmentKind::StructFields => { - AstFragment::StructFields(items.map(Annotatable::expect_field_def).collect()) + AstFragmentKind::FieldDefs => { + AstFragment::FieldDefs(items.map(Annotatable::expect_field_def).collect()) } AstFragmentKind::Variants => { AstFragment::Variants(items.map(Annotatable::expect_variant).collect()) @@ -288,6 +289,9 @@ impl AstFragmentKind { AstFragmentKind::OptExpr => { AstFragment::OptExpr(items.next().map(Annotatable::expect_expr)) } + AstFragmentKind::Crate => { + AstFragment::Crate(items.next().expect("expected exactly one crate").expect_crate()) + } AstFragmentKind::Pat | AstFragmentKind::Ty => { panic!("patterns and types aren't annotatable") } @@ -312,10 +316,10 @@ pub enum InvocationKind { pos: usize, item: Annotatable, // Required for resolving derive helper attributes. - derives: Vec<Path>, + derives: Vec<ast::Path>, }, Derive { - path: Path, + path: ast::Path, item: Annotatable, }, } @@ -359,9 +363,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { MacroExpander { cx, monotonic } } - // FIXME: Avoid visiting the crate as a `Mod` item, - // make crate a first class expansion target instead. - pub fn expand_crate(&mut self, mut krate: ast::Crate) -> ast::Crate { + pub fn expand_crate(&mut self, krate: ast::Crate) -> ast::Crate { let file_path = match self.cx.source_map().span_to_filename(krate.span) { FileName::Real(name) => name .into_local_path() @@ -375,52 +377,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> { file_path_stack: vec![file_path], dir_path, }); - - let krate_item = AstFragment::Items(smallvec![P(ast::Item { - attrs: krate.attrs, - span: krate.span, - kind: ast::ItemKind::Mod( - Unsafe::No, - ModKind::Loaded(krate.items, Inline::Yes, krate.span) - ), - ident: Ident::empty(), - id: ast::DUMMY_NODE_ID, - vis: ast::Visibility { - span: krate.span.shrink_to_lo(), - kind: ast::VisibilityKind::Public, - tokens: None, - }, - tokens: None, - })]); - - match self.fully_expand_fragment(krate_item).make_items().pop().map(P::into_inner) { - Some(ast::Item { - attrs, - kind: ast::ItemKind::Mod(_, ModKind::Loaded(items, ..)), - .. - }) => { - krate.attrs = attrs; - krate.items = items; - } - None => { - // Resolution failed so we return an empty expansion - krate.attrs = vec![]; - krate.items = vec![]; - } - Some(ast::Item { span, kind, .. }) => { - krate.attrs = vec![]; - krate.items = vec![]; - self.cx.span_err( - span, - &format!( - "expected crate top-level item to be a module after macro expansion, found {} {}", - kind.article(), kind.descr() - ), - ); - // FIXME: this workaround issue #84569 - FatalError.raise(); - } - }; + let krate = self.fully_expand_fragment(AstFragment::Crate(krate)).make_crate(); + assert_eq!(krate.id, ast::CRATE_NODE_ID); self.cx.trace_macros_diag(); krate } @@ -708,26 +666,32 @@ impl<'a, 'b> MacroExpander<'a, 'b> { SyntaxExtensionKind::Attr(expander) => { self.gate_proc_macro_input(&item); self.gate_proc_macro_attr_item(span, &item); - let mut fake_tokens = false; - if let Annotatable::Item(item_inner) = &item { - if let ItemKind::Mod(_, mod_kind) = &item_inner.kind { - // FIXME: Collect tokens and use them instead of generating - // fake ones. These are unstable, so it needs to be - // fixed prior to stabilization - // Fake tokens when we are invoking an inner attribute, and: - fake_tokens = matches!(attr.style, ast::AttrStyle::Inner) && - // We are invoking an attribute on the crate root, or an outline - // module - (item_inner.ident.name.is_empty() || !matches!(mod_kind, ast::ModKind::Loaded(_, Inline::Yes, _))); - } - } - let tokens = if fake_tokens { - rustc_parse::fake_token_stream( + let tokens = match &item { + // FIXME: Collect tokens and use them instead of generating + // fake ones. These are unstable, so it needs to be + // fixed prior to stabilization + // Fake tokens when we are invoking an inner attribute, and + // we are invoking it on an out-of-line module or crate. + Annotatable::Crate(krate) => rustc_parse::fake_token_stream_for_crate( &self.cx.sess.parse_sess, - &item.into_nonterminal(), - ) - } else { - item.into_tokens(&self.cx.sess.parse_sess) + krate, + ), + Annotatable::Item(item_inner) + if matches!(attr.style, AttrStyle::Inner) + && matches!( + item_inner.kind, + ItemKind::Mod( + _, + ModKind::Unloaded | ModKind::Loaded(_, Inline::No, _), + ) + ) => + { + rustc_parse::fake_token_stream( + &self.cx.sess.parse_sess, + &item.into_nonterminal(), + ) + } + _ => item.into_tokens(&self.cx.sess.parse_sess), }; let attr_item = attr.unwrap_normal_item(); if let MacArgs::Eq(..) = attr_item.args { @@ -781,7 +745,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { if let SyntaxExtensionKind::Derive(..) = ext { self.gate_proc_macro_input(&item); } - let meta = ast::MetaItem { kind: ast::MetaItemKind::Word, span, path }; + let meta = ast::MetaItem { kind: MetaItemKind::Word, span, path }; let items = match expander.expand(self.cx, span, &meta, item) { ExpandResult::Ready(items) => items, ExpandResult::Retry(item) => { @@ -804,7 +768,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> { Annotatable::Item(_) | Annotatable::TraitItem(_) | Annotatable::ImplItem(_) - | Annotatable::ForeignItem(_) => return, + | Annotatable::ForeignItem(_) + | Annotatable::Crate(..) => return, Annotatable::Stmt(stmt) => { // Attributes are stable on item statements, // but unstable on all other kinds of statements @@ -842,7 +807,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { impl<'ast, 'a> Visitor<'ast> for GateProcMacroInput<'a> { fn visit_item(&mut self, item: &'ast ast::Item) { match &item.kind { - ast::ItemKind::Mod(_, mod_kind) + ItemKind::Mod(_, mod_kind) if !matches!(mod_kind, ModKind::Loaded(_, Inline::Yes, _)) => { feature_err( @@ -870,7 +835,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { &mut self, toks: TokenStream, kind: AstFragmentKind, - path: &Path, + path: &ast::Path, span: Span, ) -> AstFragment { let mut parser = self.cx.new_parser_from_tts(toks); @@ -949,19 +914,20 @@ pub fn parse_ast_fragment<'a>( RecoverComma::No, RecoverColon::Yes, )?), + AstFragmentKind::Crate => AstFragment::Crate(this.parse_crate_mod()?), AstFragmentKind::Arms - | AstFragmentKind::Fields - | AstFragmentKind::FieldPats + | AstFragmentKind::ExprFields + | AstFragmentKind::PatFields | AstFragmentKind::GenericParams | AstFragmentKind::Params - | AstFragmentKind::StructFields + | AstFragmentKind::FieldDefs | AstFragmentKind::Variants => panic!("unexpected AST fragment kind"), }) } pub fn ensure_complete_parse<'a>( this: &mut Parser<'a>, - macro_path: &Path, + macro_path: &ast::Path, kind_name: &str, span: Span, ) { @@ -996,6 +962,581 @@ pub fn ensure_complete_parse<'a>( } } +/// Wraps a call to `noop_visit_*` / `noop_flat_map_*` +/// for an AST node that supports attributes +/// (see the `Annotatable` enum) +/// This method assigns a `NodeId`, and sets that `NodeId` +/// as our current 'lint node id'. If a macro call is found +/// inside this AST node, we will use this AST node's `NodeId` +/// to emit lints associated with that macro (allowing +/// `#[allow]` / `#[deny]` to be applied close to +/// the macro invocation). +/// +/// Do *not* call this for a macro AST node +/// (e.g. `ExprKind::MacCall`) - we cannot emit lints +/// at these AST nodes, since they are removed and +/// replaced with the result of macro expansion. +/// +/// All other `NodeId`s are assigned by `visit_id`. +/// * `self` is the 'self' parameter for the current method, +/// * `id` is a mutable reference to the `NodeId` field +/// of the current AST node. +/// * `closure` is a closure that executes the +/// `noop_visit_*` / `noop_flat_map_*` method +/// for the current AST node. +macro_rules! assign_id { + ($self:ident, $id:expr, $closure:expr) => {{ + let old_id = $self.cx.current_expansion.lint_node_id; + if $self.monotonic { + debug_assert_eq!(*$id, ast::DUMMY_NODE_ID); + let new_id = $self.cx.resolver.next_node_id(); + *$id = new_id; + $self.cx.current_expansion.lint_node_id = new_id; + } + let ret = ($closure)(); + $self.cx.current_expansion.lint_node_id = old_id; + ret + }}; +} + +enum AddSemicolon { + Yes, + No, +} + +/// A trait implemented for all `AstFragment` nodes and providing all pieces +/// of functionality used by `InvocationCollector`. +trait InvocationCollectorNode: AstLike { + type OutputTy = SmallVec<[Self; 1]>; + type AttrsTy: Deref<Target = [ast::Attribute]> = Vec<ast::Attribute>; + const KIND: AstFragmentKind; + fn to_annotatable(self) -> Annotatable; + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy; + fn id(&mut self) -> &mut NodeId; + fn descr() -> &'static str { + unreachable!() + } + fn noop_flat_map<V: MutVisitor>(self, _visitor: &mut V) -> Self::OutputTy { + unreachable!() + } + fn noop_visit<V: MutVisitor>(&mut self, _visitor: &mut V) { + unreachable!() + } + fn is_mac_call(&self) -> bool { + false + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + unreachable!() + } + fn pre_flat_map_node_collect_attr(_cfg: &StripUnconfigured<'_>, _attr: &ast::Attribute) {} + fn post_flat_map_node_collect_bang(_output: &mut Self::OutputTy, _add_semicolon: AddSemicolon) { + } + fn wrap_flat_map_node_noop_flat_map( + node: Self, + collector: &mut InvocationCollector<'_, '_>, + noop_flat_map: impl FnOnce(Self, &mut InvocationCollector<'_, '_>) -> Self::OutputTy, + ) -> Result<Self::OutputTy, Self> { + Ok(noop_flat_map(node, collector)) + } +} + +impl InvocationCollectorNode for P<ast::Item> { + const KIND: AstFragmentKind = AstFragmentKind::Items; + fn to_annotatable(self) -> Annotatable { + Annotatable::Item(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_items() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_item(self, visitor) + } + fn is_mac_call(&self) -> bool { + matches!(self.kind, ItemKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let node = self.into_inner(); + match node.kind { + ItemKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No), + _ => unreachable!(), + } + } + fn wrap_flat_map_node_noop_flat_map( + mut node: Self, + collector: &mut InvocationCollector<'_, '_>, + noop_flat_map: impl FnOnce(Self, &mut InvocationCollector<'_, '_>) -> Self::OutputTy, + ) -> Result<Self::OutputTy, Self> { + if !matches!(node.kind, ItemKind::Mod(..)) { + return Ok(noop_flat_map(node, collector)); + } + + // Work around borrow checker not seeing through `P`'s deref. + let (ident, span, mut attrs) = (node.ident, node.span, mem::take(&mut node.attrs)); + let ItemKind::Mod(_, mod_kind) = &mut node.kind else { + unreachable!() + }; + + let ecx = &mut collector.cx; + let (file_path, dir_path, dir_ownership) = match mod_kind { + ModKind::Loaded(_, inline, _) => { + // Inline `mod foo { ... }`, but we still need to push directories. + let (dir_path, dir_ownership) = mod_dir_path( + &ecx.sess, + ident, + &attrs, + &ecx.current_expansion.module, + ecx.current_expansion.dir_ownership, + *inline, + ); + node.attrs = attrs; + (None, dir_path, dir_ownership) + } + ModKind::Unloaded => { + // We have an outline `mod foo;` so we need to parse the file. + let old_attrs_len = attrs.len(); + let ParsedExternalMod { items, inner_span, file_path, dir_path, dir_ownership } = + parse_external_mod( + &ecx.sess, + ident, + span, + &ecx.current_expansion.module, + ecx.current_expansion.dir_ownership, + &mut attrs, + ); + + if let Some(lint_store) = ecx.lint_store { + lint_store.pre_expansion_lint( + ecx.sess, + ecx.resolver.registered_tools(), + ecx.current_expansion.lint_node_id, + &attrs, + &items, + ident.name.as_str(), + ); + } + + *mod_kind = ModKind::Loaded(items, Inline::No, inner_span); + node.attrs = attrs; + if node.attrs.len() > old_attrs_len { + // If we loaded an out-of-line module and added some inner attributes, + // then we need to re-configure it and re-collect attributes for + // resolution and expansion. + return Err(node); + } + (Some(file_path), dir_path, dir_ownership) + } + }; + + // Set the module info before we flat map. + let mut module = ecx.current_expansion.module.with_dir_path(dir_path); + module.mod_path.push(ident); + if let Some(file_path) = file_path { + module.file_path_stack.push(file_path); + } + + let orig_module = mem::replace(&mut ecx.current_expansion.module, Rc::new(module)); + let orig_dir_ownership = + mem::replace(&mut ecx.current_expansion.dir_ownership, dir_ownership); + + let res = Ok(noop_flat_map(node, collector)); + + collector.cx.current_expansion.dir_ownership = orig_dir_ownership; + collector.cx.current_expansion.module = orig_module; + res + } +} + +struct TraitItemTag; +impl InvocationCollectorNode for AstLikeWrapper<P<ast::AssocItem>, TraitItemTag> { + type OutputTy = SmallVec<[P<ast::AssocItem>; 1]>; + const KIND: AstFragmentKind = AstFragmentKind::TraitItems; + fn to_annotatable(self) -> Annotatable { + Annotatable::TraitItem(self.wrapped) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_trait_items() + } + fn id(&mut self) -> &mut NodeId { + &mut self.wrapped.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_assoc_item(self.wrapped, visitor) + } + fn is_mac_call(&self) -> bool { + matches!(self.wrapped.kind, AssocItemKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let item = self.wrapped.into_inner(); + match item.kind { + AssocItemKind::MacCall(mac) => (mac, item.attrs, AddSemicolon::No), + _ => unreachable!(), + } + } +} + +struct ImplItemTag; +impl InvocationCollectorNode for AstLikeWrapper<P<ast::AssocItem>, ImplItemTag> { + type OutputTy = SmallVec<[P<ast::AssocItem>; 1]>; + const KIND: AstFragmentKind = AstFragmentKind::ImplItems; + fn to_annotatable(self) -> Annotatable { + Annotatable::ImplItem(self.wrapped) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_impl_items() + } + fn id(&mut self) -> &mut NodeId { + &mut self.wrapped.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_assoc_item(self.wrapped, visitor) + } + fn is_mac_call(&self) -> bool { + matches!(self.wrapped.kind, AssocItemKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let item = self.wrapped.into_inner(); + match item.kind { + AssocItemKind::MacCall(mac) => (mac, item.attrs, AddSemicolon::No), + _ => unreachable!(), + } + } +} + +impl InvocationCollectorNode for P<ast::ForeignItem> { + const KIND: AstFragmentKind = AstFragmentKind::ForeignItems; + fn to_annotatable(self) -> Annotatable { + Annotatable::ForeignItem(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_foreign_items() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_foreign_item(self, visitor) + } + fn is_mac_call(&self) -> bool { + matches!(self.kind, ForeignItemKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let node = self.into_inner(); + match node.kind { + ForeignItemKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No), + _ => unreachable!(), + } + } +} + +impl InvocationCollectorNode for ast::Variant { + const KIND: AstFragmentKind = AstFragmentKind::Variants; + fn to_annotatable(self) -> Annotatable { + Annotatable::Variant(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_variants() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_variant(self, visitor) + } +} + +impl InvocationCollectorNode for ast::FieldDef { + const KIND: AstFragmentKind = AstFragmentKind::FieldDefs; + fn to_annotatable(self) -> Annotatable { + Annotatable::FieldDef(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_field_defs() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_field_def(self, visitor) + } +} + +impl InvocationCollectorNode for ast::PatField { + const KIND: AstFragmentKind = AstFragmentKind::PatFields; + fn to_annotatable(self) -> Annotatable { + Annotatable::PatField(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_pat_fields() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_pat_field(self, visitor) + } +} + +impl InvocationCollectorNode for ast::ExprField { + const KIND: AstFragmentKind = AstFragmentKind::ExprFields; + fn to_annotatable(self) -> Annotatable { + Annotatable::ExprField(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_expr_fields() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_expr_field(self, visitor) + } +} + +impl InvocationCollectorNode for ast::Param { + const KIND: AstFragmentKind = AstFragmentKind::Params; + fn to_annotatable(self) -> Annotatable { + Annotatable::Param(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_params() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_param(self, visitor) + } +} + +impl InvocationCollectorNode for ast::GenericParam { + const KIND: AstFragmentKind = AstFragmentKind::GenericParams; + fn to_annotatable(self) -> Annotatable { + Annotatable::GenericParam(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_generic_params() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_generic_param(self, visitor) + } +} + +impl InvocationCollectorNode for ast::Arm { + const KIND: AstFragmentKind = AstFragmentKind::Arms; + fn to_annotatable(self) -> Annotatable { + Annotatable::Arm(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_arms() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_arm(self, visitor) + } +} + +impl InvocationCollectorNode for ast::Stmt { + type AttrsTy = ast::AttrVec; + const KIND: AstFragmentKind = AstFragmentKind::Stmts; + fn to_annotatable(self) -> Annotatable { + Annotatable::Stmt(P(self)) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_stmts() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_flat_map<V: MutVisitor>(self, visitor: &mut V) -> Self::OutputTy { + noop_flat_map_stmt(self, visitor) + } + fn is_mac_call(&self) -> bool { + match &self.kind { + StmtKind::MacCall(..) => true, + StmtKind::Item(item) => matches!(item.kind, ItemKind::MacCall(..)), + StmtKind::Semi(expr) => matches!(expr.kind, ExprKind::MacCall(..)), + StmtKind::Expr(..) => unreachable!(), + StmtKind::Local(..) | StmtKind::Empty => false, + } + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + // We pull macro invocations (both attributes and fn-like macro calls) out of their + // `StmtKind`s and treat them as statement macro invocations, not as items or expressions. + let (add_semicolon, mac, attrs) = match self.kind { + StmtKind::MacCall(mac) => { + let ast::MacCallStmt { mac, style, attrs, .. } = mac.into_inner(); + (style == MacStmtStyle::Semicolon, mac, attrs) + } + StmtKind::Item(item) => match item.into_inner() { + ast::Item { kind: ItemKind::MacCall(mac), attrs, .. } => { + (mac.args.need_semicolon(), mac, attrs.into()) + } + _ => unreachable!(), + }, + StmtKind::Semi(expr) => match expr.into_inner() { + ast::Expr { kind: ExprKind::MacCall(mac), attrs, .. } => { + (mac.args.need_semicolon(), mac, attrs) + } + _ => unreachable!(), + }, + _ => unreachable!(), + }; + (mac, attrs, if add_semicolon { AddSemicolon::Yes } else { AddSemicolon::No }) + } + fn post_flat_map_node_collect_bang(stmts: &mut Self::OutputTy, add_semicolon: AddSemicolon) { + // If this is a macro invocation with a semicolon, then apply that + // semicolon to the final statement produced by expansion. + if matches!(add_semicolon, AddSemicolon::Yes) { + if let Some(stmt) = stmts.pop() { + stmts.push(stmt.add_trailing_semicolon()); + } + } + } +} + +impl InvocationCollectorNode for ast::Crate { + type OutputTy = ast::Crate; + const KIND: AstFragmentKind = AstFragmentKind::Crate; + fn to_annotatable(self) -> Annotatable { + Annotatable::Crate(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_crate() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_visit<V: MutVisitor>(&mut self, visitor: &mut V) { + noop_visit_crate(self, visitor) + } +} + +impl InvocationCollectorNode for P<ast::Ty> { + type OutputTy = P<ast::Ty>; + const KIND: AstFragmentKind = AstFragmentKind::Ty; + fn to_annotatable(self) -> Annotatable { + unreachable!() + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_ty() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_visit<V: MutVisitor>(&mut self, visitor: &mut V) { + noop_visit_ty(self, visitor) + } + fn is_mac_call(&self) -> bool { + matches!(self.kind, ast::TyKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let node = self.into_inner(); + match node.kind { + TyKind::MacCall(mac) => (mac, Vec::new(), AddSemicolon::No), + _ => unreachable!(), + } + } +} + +impl InvocationCollectorNode for P<ast::Pat> { + type OutputTy = P<ast::Pat>; + const KIND: AstFragmentKind = AstFragmentKind::Pat; + fn to_annotatable(self) -> Annotatable { + unreachable!() + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_pat() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn noop_visit<V: MutVisitor>(&mut self, visitor: &mut V) { + noop_visit_pat(self, visitor) + } + fn is_mac_call(&self) -> bool { + matches!(self.kind, PatKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let node = self.into_inner(); + match node.kind { + PatKind::MacCall(mac) => (mac, Vec::new(), AddSemicolon::No), + _ => unreachable!(), + } + } +} + +impl InvocationCollectorNode for P<ast::Expr> { + type OutputTy = P<ast::Expr>; + type AttrsTy = ast::AttrVec; + const KIND: AstFragmentKind = AstFragmentKind::Expr; + fn to_annotatable(self) -> Annotatable { + Annotatable::Expr(self) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_expr() + } + fn id(&mut self) -> &mut NodeId { + &mut self.id + } + fn descr() -> &'static str { + "an expression" + } + fn noop_visit<V: MutVisitor>(&mut self, visitor: &mut V) { + noop_visit_expr(self, visitor) + } + fn is_mac_call(&self) -> bool { + matches!(self.kind, ExprKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let node = self.into_inner(); + match node.kind { + ExprKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No), + _ => unreachable!(), + } + } +} + +struct OptExprTag; +impl InvocationCollectorNode for AstLikeWrapper<P<ast::Expr>, OptExprTag> { + type OutputTy = Option<P<ast::Expr>>; + type AttrsTy = ast::AttrVec; + const KIND: AstFragmentKind = AstFragmentKind::OptExpr; + fn to_annotatable(self) -> Annotatable { + Annotatable::Expr(self.wrapped) + } + fn fragment_to_output(fragment: AstFragment) -> Self::OutputTy { + fragment.make_opt_expr() + } + fn id(&mut self) -> &mut NodeId { + &mut self.wrapped.id + } + fn noop_flat_map<V: MutVisitor>(mut self, visitor: &mut V) -> Self::OutputTy { + noop_visit_expr(&mut self.wrapped, visitor); + Some(self.wrapped) + } + fn is_mac_call(&self) -> bool { + matches!(self.wrapped.kind, ast::ExprKind::MacCall(..)) + } + fn take_mac_call(self) -> (ast::MacCall, Self::AttrsTy, AddSemicolon) { + let node = self.wrapped.into_inner(); + match node.kind { + ExprKind::MacCall(mac) => (mac, node.attrs, AddSemicolon::No), + _ => unreachable!(), + } + } + fn pre_flat_map_node_collect_attr(cfg: &StripUnconfigured<'_>, attr: &ast::Attribute) { + cfg.maybe_emit_expr_attr_err(&attr); + } +} + struct InvocationCollector<'a, 'b> { cx: &'a mut ExtCtxt<'b>, cfg: StripUnconfigured<'a>, @@ -1031,7 +1572,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> { fn collect_attr( &mut self, - (attr, pos, derives): (ast::Attribute, usize, Vec<Path>), + (attr, pos, derives): (ast::Attribute, usize, Vec<ast::Path>), item: Annotatable, kind: AstFragmentKind, ) -> AstFragment { @@ -1042,18 +1583,33 @@ impl<'a, 'b> InvocationCollector<'a, 'b> { /// its position and derives following it. We have to collect the derives in order to resolve /// legacy derive helpers (helpers written before derives that introduce them). fn take_first_attr( - &mut self, + &self, item: &mut impl AstLike, - ) -> Option<(ast::Attribute, usize, Vec<Path>)> { + ) -> Option<(ast::Attribute, usize, Vec<ast::Path>)> { let mut attr = None; + let mut cfg_pos = None; + let mut attr_pos = None; + for (pos, attr) in item.attrs().iter().enumerate() { + if !attr.is_doc_comment() && !self.cx.expanded_inert_attrs.is_marked(attr) { + let name = attr.ident().map(|ident| ident.name); + if name == Some(sym::cfg) || name == Some(sym::cfg_attr) { + cfg_pos = Some(pos); // a cfg attr found, no need to search anymore + break; + } else if attr_pos.is_none() + && !name.map_or(false, rustc_feature::is_builtin_attr_name) + { + attr_pos = Some(pos); // a non-cfg attr found, still may find a cfg attr + } + } + } + item.visit_attrs(|attrs| { - attr = attrs - .iter() - .position(|a| !self.cx.expanded_inert_attrs.is_marked(a) && !is_builtin_attr(a)) - .map(|attr_pos| { - let attr = attrs.remove(attr_pos); - let following_derives = attrs[attr_pos..] + attr = Some(match (cfg_pos, attr_pos) { + (Some(pos), _) => (attrs.remove(pos), pos, Vec::new()), + (_, Some(pos)) => { + let attr = attrs.remove(pos); + let following_derives = attrs[pos..] .iter() .filter(|a| a.has_name(sym::derive)) .flat_map(|a| a.meta_item_list().unwrap_or_default()) @@ -1067,52 +1623,18 @@ impl<'a, 'b> InvocationCollector<'a, 'b> { }) .collect(); - (attr, attr_pos, following_derives) - }) + (attr, pos, following_derives) + } + _ => return, + }); }); attr } - fn take_stmt_bang( - &mut self, - stmt: ast::Stmt, - ) -> Result<(bool, MacCall, Vec<ast::Attribute>), ast::Stmt> { - match stmt.kind { - StmtKind::MacCall(mac) => { - let MacCallStmt { mac, style, attrs, .. } = mac.into_inner(); - Ok((style == MacStmtStyle::Semicolon, mac, attrs.into())) - } - StmtKind::Item(item) if matches!(item.kind, ItemKind::MacCall(..)) => { - match item.into_inner() { - ast::Item { kind: ItemKind::MacCall(mac), attrs, .. } => { - Ok((mac.args.need_semicolon(), mac, attrs)) - } - _ => unreachable!(), - } - } - StmtKind::Semi(expr) if matches!(expr.kind, ast::ExprKind::MacCall(..)) => { - match expr.into_inner() { - ast::Expr { kind: ast::ExprKind::MacCall(mac), attrs, .. } => { - Ok((mac.args.need_semicolon(), mac, attrs.into())) - } - _ => unreachable!(), - } - } - StmtKind::Local(..) | StmtKind::Empty | StmtKind::Item(..) | StmtKind::Semi(..) => { - Err(stmt) - } - StmtKind::Expr(..) => unreachable!(), - } - } - - fn configure<T: AstLike>(&mut self, node: T) -> Option<T> { - self.cfg.configure(node) - } - // Detect use of feature-gated or invalid attributes on macro invocations // since they will not be detected after macro expansion. - fn check_attributes(&self, attrs: &[ast::Attribute], call: &MacCall) { + fn check_attributes(&self, attrs: &[ast::Attribute], call: &ast::MacCall) { let features = self.cx.ecfg.features.unwrap(); let mut attrs = attrs.iter().peekable(); let mut span: Option<Span> = None; @@ -1155,483 +1677,231 @@ impl<'a, 'b> InvocationCollector<'a, 'b> { } } } -} -/// Wraps a call to `noop_visit_*` / `noop_flat_map_*` -/// for an AST node that supports attributes -/// (see the `Annotatable` enum) -/// This method assigns a `NodeId`, and sets that `NodeId` -/// as our current 'lint node id'. If a macro call is found -/// inside this AST node, we will use this AST node's `NodeId` -/// to emit lints associated with that macro (allowing -/// `#[allow]` / `#[deny]` to be applied close to -/// the macro invocation). -/// -/// Do *not* call this for a macro AST node -/// (e.g. `ExprKind::MacCall`) - we cannot emit lints -/// at these AST nodes, since they are removed and -/// replaced with the result of macro expansion. -/// -/// All other `NodeId`s are assigned by `visit_id`. -/// * `self` is the 'self' parameter for the current method, -/// * `id` is a mutable reference to the `NodeId` field -/// of the current AST node. -/// * `closure` is a closure that executes the -/// `noop_visit_*` / `noop_flat_map_*` method -/// for the current AST node. -macro_rules! assign_id { - ($self:ident, $id:expr, $closure:expr) => {{ - let old_id = $self.cx.current_expansion.lint_node_id; - if $self.monotonic { - debug_assert_eq!(*$id, ast::DUMMY_NODE_ID); - let new_id = $self.cx.resolver.next_node_id(); - *$id = new_id; - $self.cx.current_expansion.lint_node_id = new_id; + fn expand_cfg_true( + &mut self, + node: &mut impl AstLike, + attr: ast::Attribute, + pos: usize, + ) -> bool { + let res = self.cfg.cfg_true(&attr); + if res { + // FIXME: `cfg(TRUE)` attributes do not currently remove themselves during expansion, + // and some tools like rustdoc and clippy rely on that. Find a way to remove them + // while keeping the tools working. + self.cx.expanded_inert_attrs.mark(&attr); + node.visit_attrs(|attrs| attrs.insert(pos, attr)); } - let ret = ($closure)(); - $self.cx.current_expansion.lint_node_id = old_id; - ret - }}; -} - -impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> { - fn visit_expr(&mut self, expr: &mut P<ast::Expr>) { - self.cfg.configure_expr(expr); - visit_clobber(expr.deref_mut(), |mut expr| { - if let Some(attr) = self.take_first_attr(&mut expr) { - // Collect the invoc regardless of whether or not attributes are permitted here - // expansion will eat the attribute so it won't error later. - self.cfg.maybe_emit_expr_attr_err(&attr.0); - - // AstFragmentKind::Expr requires the macro to emit an expression. - return self - .collect_attr(attr, Annotatable::Expr(P(expr)), AstFragmentKind::Expr) - .make_expr() - .into_inner(); - } + res + } - if let ast::ExprKind::MacCall(mac) = expr.kind { - self.check_attributes(&expr.attrs, &mac); - self.collect_bang(mac, AstFragmentKind::Expr).make_expr().into_inner() - } else { - assign_id!(self, &mut expr.id, || { - ensure_sufficient_stack(|| noop_visit_expr(&mut expr, self)); - }); - expr - } + fn expand_cfg_attr(&self, node: &mut impl AstLike, attr: ast::Attribute, pos: usize) { + node.visit_attrs(|attrs| { + attrs.splice(pos..pos, self.cfg.expand_cfg_attr(attr, false)); }); } - fn flat_map_arm(&mut self, arm: ast::Arm) -> SmallVec<[ast::Arm; 1]> { - let mut arm = configure!(self, arm); - - if let Some(attr) = self.take_first_attr(&mut arm) { - return self - .collect_attr(attr, Annotatable::Arm(arm), AstFragmentKind::Arms) - .make_arms(); + fn flat_map_node<Node: InvocationCollectorNode<OutputTy: Default>>( + &mut self, + mut node: Node, + ) -> Node::OutputTy { + loop { + return match self.take_first_attr(&mut node) { + Some((attr, pos, derives)) => match attr.name_or_empty() { + sym::cfg => { + if self.expand_cfg_true(&mut node, attr, pos) { + continue; + } + Default::default() + } + sym::cfg_attr => { + self.expand_cfg_attr(&mut node, attr, pos); + continue; + } + _ => { + Node::pre_flat_map_node_collect_attr(&self.cfg, &attr); + self.collect_attr((attr, pos, derives), node.to_annotatable(), Node::KIND) + .make_ast::<Node>() + } + }, + None if node.is_mac_call() => { + let (mac, attrs, add_semicolon) = node.take_mac_call(); + self.check_attributes(&attrs, &mac); + let mut res = self.collect_bang(mac, Node::KIND).make_ast::<Node>(); + Node::post_flat_map_node_collect_bang(&mut res, add_semicolon); + res + } + None => { + match Node::wrap_flat_map_node_noop_flat_map(node, self, |mut node, this| { + assign_id!(this, node.id(), || node.noop_flat_map(this)) + }) { + Ok(output) => output, + Err(returned_node) => { + node = returned_node; + continue; + } + } + } + }; } - - assign_id!(self, &mut arm.id, || noop_flat_map_arm(arm, self)) } - fn flat_map_expr_field(&mut self, field: ast::ExprField) -> SmallVec<[ast::ExprField; 1]> { - let mut field = configure!(self, field); - - if let Some(attr) = self.take_first_attr(&mut field) { - return self - .collect_attr(attr, Annotatable::ExprField(field), AstFragmentKind::Fields) - .make_expr_fields(); + fn visit_node<Node: InvocationCollectorNode<OutputTy = Node> + DummyAstNode>( + &mut self, + node: &mut Node, + ) { + loop { + return match self.take_first_attr(node) { + Some((attr, pos, derives)) => match attr.name_or_empty() { + sym::cfg => { + let span = attr.span; + if self.expand_cfg_true(node, attr, pos) { + continue; + } + let msg = + format!("removing {} is not supported in this position", Node::descr()); + self.cx.span_err(span, &msg); + continue; + } + sym::cfg_attr => { + self.expand_cfg_attr(node, attr, pos); + continue; + } + _ => visit_clobber(node, |node| { + self.collect_attr((attr, pos, derives), node.to_annotatable(), Node::KIND) + .make_ast::<Node>() + }), + }, + None if node.is_mac_call() => { + visit_clobber(node, |node| { + // Do not clobber unless it's actually a macro (uncommon case). + let (mac, attrs, _) = node.take_mac_call(); + self.check_attributes(&attrs, &mac); + self.collect_bang(mac, Node::KIND).make_ast::<Node>() + }) + } + None => { + assign_id!(self, node.id(), || node.noop_visit(self)) + } + }; } - - assign_id!(self, &mut field.id, || noop_flat_map_expr_field(field, self)) } +} - fn flat_map_pat_field(&mut self, fp: ast::PatField) -> SmallVec<[ast::PatField; 1]> { - let mut fp = configure!(self, fp); - - if let Some(attr) = self.take_first_attr(&mut fp) { - return self - .collect_attr(attr, Annotatable::PatField(fp), AstFragmentKind::FieldPats) - .make_pat_fields(); - } - - assign_id!(self, &mut fp.id, || noop_flat_map_pat_field(fp, self)) +impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> { + fn flat_map_item(&mut self, node: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> { + self.flat_map_node(node) } - fn flat_map_param(&mut self, p: ast::Param) -> SmallVec<[ast::Param; 1]> { - let mut p = configure!(self, p); - - if let Some(attr) = self.take_first_attr(&mut p) { - return self - .collect_attr(attr, Annotatable::Param(p), AstFragmentKind::Params) - .make_params(); - } - - assign_id!(self, &mut p.id, || noop_flat_map_param(p, self)) + fn flat_map_trait_item(&mut self, node: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> { + self.flat_map_node(AstLikeWrapper::new(node, TraitItemTag)) } - fn flat_map_field_def(&mut self, sf: ast::FieldDef) -> SmallVec<[ast::FieldDef; 1]> { - let mut sf = configure!(self, sf); - - if let Some(attr) = self.take_first_attr(&mut sf) { - return self - .collect_attr(attr, Annotatable::FieldDef(sf), AstFragmentKind::StructFields) - .make_field_defs(); - } - - assign_id!(self, &mut sf.id, || noop_flat_map_field_def(sf, self)) + fn flat_map_impl_item(&mut self, node: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> { + self.flat_map_node(AstLikeWrapper::new(node, ImplItemTag)) } - fn flat_map_variant(&mut self, variant: ast::Variant) -> SmallVec<[ast::Variant; 1]> { - let mut variant = configure!(self, variant); - - if let Some(attr) = self.take_first_attr(&mut variant) { - return self - .collect_attr(attr, Annotatable::Variant(variant), AstFragmentKind::Variants) - .make_variants(); - } + fn flat_map_foreign_item( + &mut self, + node: P<ast::ForeignItem>, + ) -> SmallVec<[P<ast::ForeignItem>; 1]> { + self.flat_map_node(node) + } - assign_id!(self, &mut variant.id, || noop_flat_map_variant(variant, self)) + fn flat_map_variant(&mut self, node: ast::Variant) -> SmallVec<[ast::Variant; 1]> { + self.flat_map_node(node) } - fn filter_map_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> { - let expr = configure!(self, expr); - expr.filter_map(|mut expr| { - if let Some(attr) = self.take_first_attr(&mut expr) { - self.cfg.maybe_emit_expr_attr_err(&attr.0); + fn flat_map_field_def(&mut self, node: ast::FieldDef) -> SmallVec<[ast::FieldDef; 1]> { + self.flat_map_node(node) + } - return self - .collect_attr(attr, Annotatable::Expr(P(expr)), AstFragmentKind::OptExpr) - .make_opt_expr() - .map(|expr| expr.into_inner()); - } + fn flat_map_pat_field(&mut self, node: ast::PatField) -> SmallVec<[ast::PatField; 1]> { + self.flat_map_node(node) + } - if let ast::ExprKind::MacCall(mac) = expr.kind { - self.check_attributes(&expr.attrs, &mac); - self.collect_bang(mac, AstFragmentKind::OptExpr) - .make_opt_expr() - .map(|expr| expr.into_inner()) - } else { - assign_id!(self, &mut expr.id, || { - Some({ - noop_visit_expr(&mut expr, self); - expr - }) - }) - } - }) + fn flat_map_expr_field(&mut self, node: ast::ExprField) -> SmallVec<[ast::ExprField; 1]> { + self.flat_map_node(node) } - fn visit_pat(&mut self, pat: &mut P<ast::Pat>) { - match pat.kind { - PatKind::MacCall(_) => {} - _ => return noop_visit_pat(pat, self), - } + fn flat_map_param(&mut self, node: ast::Param) -> SmallVec<[ast::Param; 1]> { + self.flat_map_node(node) + } - visit_clobber(pat, |mut pat| match mem::replace(&mut pat.kind, PatKind::Wild) { - PatKind::MacCall(mac) => self.collect_bang(mac, AstFragmentKind::Pat).make_pat(), - _ => unreachable!(), - }); + fn flat_map_generic_param( + &mut self, + node: ast::GenericParam, + ) -> SmallVec<[ast::GenericParam; 1]> { + self.flat_map_node(node) } - fn flat_map_stmt(&mut self, stmt: ast::Stmt) -> SmallVec<[ast::Stmt; 1]> { - let mut stmt = configure!(self, stmt); + fn flat_map_arm(&mut self, node: ast::Arm) -> SmallVec<[ast::Arm; 1]> { + self.flat_map_node(node) + } - // We pull macro invocations (both attributes and fn-like macro calls) out of their - // `StmtKind`s and treat them as statement macro invocations, not as items or expressions. + fn flat_map_stmt(&mut self, mut node: ast::Stmt) -> SmallVec<[ast::Stmt; 1]> { // FIXME: invocations in semicolon-less expressions positions are expanded as expressions, // changing that requires some compatibility measures. - let mut stmt = if !stmt.is_expr() { - if let Some(attr) = self.take_first_attr(&mut stmt) { - return self - .collect_attr(attr, Annotatable::Stmt(P(stmt)), AstFragmentKind::Stmts) - .make_stmts(); - } - - match self.take_stmt_bang(stmt) { - Ok((add_semicolon, mac, attrs)) => { - self.check_attributes(&attrs, &mac); - let mut stmts = self.collect_bang(mac, AstFragmentKind::Stmts).make_stmts(); - - // If this is a macro invocation with a semicolon, then apply that - // semicolon to the final statement produced by expansion. - if add_semicolon { - if let Some(stmt) = stmts.pop() { - stmts.push(stmt.add_trailing_semicolon()); - } - } - - return stmts; + if node.is_expr() { + // The only way that we can end up with a `MacCall` expression statement, + // (as opposed to a `StmtKind::MacCall`) is if we have a macro as the + // traiing expression in a block (e.g. `fn foo() { my_macro!() }`). + // Record this information, so that we can report a more specific + // `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` lint if needed. + // See #78991 for an investigation of treating macros in this position + // as statements, rather than expressions, during parsing. + return match &node.kind { + StmtKind::Expr(expr) + if matches!(**expr, ast::Expr { kind: ExprKind::MacCall(..), .. }) => + { + self.cx.current_expansion.is_trailing_mac = true; + // Don't use `assign_id` for this statement - it may get removed + // entirely due to a `#[cfg]` on the contained expression + let res = noop_flat_map_stmt(node, self); + self.cx.current_expansion.is_trailing_mac = false; + res } - Err(stmt) => stmt, - } - } else { - stmt - }; - - // The only way that we can end up with a `MacCall` expression statement, - // (as opposed to a `StmtKind::MacCall`) is if we have a macro as the - // traiing expression in a block (e.g. `fn foo() { my_macro!() }`). - // Record this information, so that we can report a more specific - // `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` lint if needed. - // See #78991 for an investigation of treating macros in this position - // as statements, rather than expressions, during parsing. - let res = match &stmt.kind { - StmtKind::Expr(expr) - if matches!(**expr, ast::Expr { kind: ast::ExprKind::MacCall(..), .. }) => - { - self.cx.current_expansion.is_trailing_mac = true; - // Don't use `assign_id` for this statement - it may get removed - // entirely due to a `#[cfg]` on the contained expression - noop_flat_map_stmt(stmt, self) - } - _ => assign_id!(self, &mut stmt.id, || noop_flat_map_stmt(stmt, self)), - }; - self.cx.current_expansion.is_trailing_mac = false; - res - } - - fn visit_block(&mut self, block: &mut P<Block>) { - let orig_dir_ownership = mem::replace( - &mut self.cx.current_expansion.dir_ownership, - DirOwnership::UnownedViaBlock, - ); - noop_visit_block(block, self); - self.cx.current_expansion.dir_ownership = orig_dir_ownership; - } - - fn flat_map_item(&mut self, item: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> { - let mut item = configure!(self, item); - - if let Some(attr) = self.take_first_attr(&mut item) { - return self - .collect_attr(attr, Annotatable::Item(item), AstFragmentKind::Items) - .make_items(); + _ => assign_id!(self, &mut node.id, || noop_flat_map_stmt(node, self)), + }; } - let mut attrs = mem::take(&mut item.attrs); // We do this to please borrowck. - let ident = item.ident; - let span = item.span; - - match item.kind { - ast::ItemKind::MacCall(ref mac) => { - self.check_attributes(&attrs, &mac); - item.attrs = attrs; - item.and_then(|item| match item.kind { - ItemKind::MacCall(mac) => { - self.collect_bang(mac, AstFragmentKind::Items).make_items() - } - _ => unreachable!(), - }) - } - ast::ItemKind::Mod(_, ref mut mod_kind) if ident != Ident::empty() => { - let (file_path, dir_path, dir_ownership) = match mod_kind { - ModKind::Loaded(_, inline, _) => { - // Inline `mod foo { ... }`, but we still need to push directories. - let (dir_path, dir_ownership) = mod_dir_path( - &self.cx.sess, - ident, - &attrs, - &self.cx.current_expansion.module, - self.cx.current_expansion.dir_ownership, - *inline, - ); - item.attrs = attrs; - (None, dir_path, dir_ownership) - } - ModKind::Unloaded => { - // We have an outline `mod foo;` so we need to parse the file. - let old_attrs_len = attrs.len(); - let ParsedExternalMod { - mut items, - inner_span, - file_path, - dir_path, - dir_ownership, - } = parse_external_mod( - &self.cx.sess, - ident, - span, - &self.cx.current_expansion.module, - self.cx.current_expansion.dir_ownership, - &mut attrs, - ); - - if let Some(extern_mod_loaded) = self.cx.extern_mod_loaded { - (attrs, items) = extern_mod_loaded(ident, attrs, items, inner_span); - } - - *mod_kind = ModKind::Loaded(items, Inline::No, inner_span); - item.attrs = attrs; - if item.attrs.len() > old_attrs_len { - // If we loaded an out-of-line module and added some inner attributes, - // then we need to re-configure it and re-collect attributes for - // resolution and expansion. - item = configure!(self, item); - - if let Some(attr) = self.take_first_attr(&mut item) { - return self - .collect_attr( - attr, - Annotatable::Item(item), - AstFragmentKind::Items, - ) - .make_items(); - } - } - (Some(file_path), dir_path, dir_ownership) - } - }; - - // Set the module info before we flat map. - let mut module = self.cx.current_expansion.module.with_dir_path(dir_path); - module.mod_path.push(ident); - if let Some(file_path) = file_path { - module.file_path_stack.push(file_path); - } - - let orig_module = - mem::replace(&mut self.cx.current_expansion.module, Rc::new(module)); - let orig_dir_ownership = - mem::replace(&mut self.cx.current_expansion.dir_ownership, dir_ownership); - - let result = assign_id!(self, &mut item.id, || noop_flat_map_item(item, self)); - - // Restore the module info. - self.cx.current_expansion.dir_ownership = orig_dir_ownership; - self.cx.current_expansion.module = orig_module; - - result - } - _ => { - item.attrs = attrs; - // The crate root is special - don't assign an ID to it. - if !(matches!(item.kind, ast::ItemKind::Mod(..)) && ident == Ident::empty()) { - assign_id!(self, &mut item.id, || noop_flat_map_item(item, self)) - } else { - noop_flat_map_item(item, self) - } - } - } + self.flat_map_node(node) } - fn flat_map_trait_item(&mut self, item: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> { - let mut item = configure!(self, item); - - if let Some(attr) = self.take_first_attr(&mut item) { - return self - .collect_attr(attr, Annotatable::TraitItem(item), AstFragmentKind::TraitItems) - .make_trait_items(); - } - - match item.kind { - ast::AssocItemKind::MacCall(ref mac) => { - self.check_attributes(&item.attrs, &mac); - item.and_then(|item| match item.kind { - ast::AssocItemKind::MacCall(mac) => { - self.collect_bang(mac, AstFragmentKind::TraitItems).make_trait_items() - } - _ => unreachable!(), - }) - } - _ => { - assign_id!(self, &mut item.id, || noop_flat_map_assoc_item(item, self)) - } - } + fn visit_crate(&mut self, node: &mut ast::Crate) { + self.visit_node(node) } - fn flat_map_impl_item(&mut self, item: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> { - let mut item = configure!(self, item); - - if let Some(attr) = self.take_first_attr(&mut item) { - return self - .collect_attr(attr, Annotatable::ImplItem(item), AstFragmentKind::ImplItems) - .make_impl_items(); - } - - match item.kind { - ast::AssocItemKind::MacCall(ref mac) => { - self.check_attributes(&item.attrs, &mac); - item.and_then(|item| match item.kind { - ast::AssocItemKind::MacCall(mac) => { - self.collect_bang(mac, AstFragmentKind::ImplItems).make_impl_items() - } - _ => unreachable!(), - }) - } - _ => { - assign_id!(self, &mut item.id, || noop_flat_map_assoc_item(item, self)) - } - } + fn visit_ty(&mut self, node: &mut P<ast::Ty>) { + self.visit_node(node) } - fn visit_ty(&mut self, ty: &mut P<ast::Ty>) { - match ty.kind { - ast::TyKind::MacCall(_) => {} - _ => return noop_visit_ty(ty, self), - }; - - visit_clobber(ty, |mut ty| match mem::replace(&mut ty.kind, ast::TyKind::Err) { - ast::TyKind::MacCall(mac) => self.collect_bang(mac, AstFragmentKind::Ty).make_ty(), - _ => unreachable!(), - }); + fn visit_pat(&mut self, node: &mut P<ast::Pat>) { + self.visit_node(node) } - fn flat_map_foreign_item( - &mut self, - foreign_item: P<ast::ForeignItem>, - ) -> SmallVec<[P<ast::ForeignItem>; 1]> { - let mut foreign_item = configure!(self, foreign_item); - - if let Some(attr) = self.take_first_attr(&mut foreign_item) { - return self - .collect_attr( - attr, - Annotatable::ForeignItem(foreign_item), - AstFragmentKind::ForeignItems, - ) - .make_foreign_items(); - } - - match foreign_item.kind { - ast::ForeignItemKind::MacCall(ref mac) => { - self.check_attributes(&foreign_item.attrs, &mac); - foreign_item.and_then(|item| match item.kind { - ast::ForeignItemKind::MacCall(mac) => { - self.collect_bang(mac, AstFragmentKind::ForeignItems).make_foreign_items() - } - _ => unreachable!(), - }) - } - _ => { - assign_id!(self, &mut foreign_item.id, || noop_flat_map_foreign_item( - foreign_item, - self - )) - } + fn visit_expr(&mut self, node: &mut P<ast::Expr>) { + // FIXME: Feature gating is performed inconsistently between `Expr` and `OptExpr`. + if let Some(attr) = node.attrs.first() { + self.cfg.maybe_emit_expr_attr_err(attr); } + self.visit_node(node) } - fn flat_map_generic_param( - &mut self, - param: ast::GenericParam, - ) -> SmallVec<[ast::GenericParam; 1]> { - let mut param = configure!(self, param); - - if let Some(attr) = self.take_first_attr(&mut param) { - return self - .collect_attr( - attr, - Annotatable::GenericParam(param), - AstFragmentKind::GenericParams, - ) - .make_generic_params(); - } + fn filter_map_expr(&mut self, node: P<ast::Expr>) -> Option<P<ast::Expr>> { + self.flat_map_node(AstLikeWrapper::new(node, OptExprTag)) + } - assign_id!(self, &mut param.id, || noop_flat_map_generic_param(param, self)) + fn visit_block(&mut self, node: &mut P<ast::Block>) { + let orig_dir_ownership = mem::replace( + &mut self.cx.current_expansion.dir_ownership, + DirOwnership::UnownedViaBlock, + ); + noop_visit_block(node, self); + self.cx.current_expansion.dir_ownership = orig_dir_ownership; } - fn visit_id(&mut self, id: &mut ast::NodeId) { + fn visit_id(&mut self, id: &mut NodeId) { // We may have already assigned a `NodeId` // by calling `assign_id` if self.monotonic && *id == ast::DUMMY_NODE_ID { |