use crate::ast::{self, Block, Ident, LitKind, NodeId, PatKind, Path}; use crate::ast::{MacStmtStyle, StmtKind, ItemKind}; use crate::attr::{self, HasAttrs}; use crate::source_map::{ExpnInfo, MacroBang, MacroAttribute, dummy_spanned, respan}; use crate::config::StripUnconfigured; use crate::ext::base::*; use crate::ext::derive::{add_derived_markers, collect_derives}; use crate::ext::hygiene::{Mark, SyntaxContext}; use crate::ext::placeholders::{placeholder, PlaceholderExpander}; use crate::feature_gate::{self, Features, GateIssue, is_builtin_attr, emit_feature_err}; use crate::mut_visit::*; use crate::parse::{DirectoryOwnership, PResult, ParseSess}; use crate::parse::token::{self, Token}; use crate::parse::parser::Parser; use crate::ptr::P; use crate::symbol::Symbol; use crate::symbol::{kw, sym}; use crate::tokenstream::{TokenStream, TokenTree}; use crate::visit::{self, Visitor}; use crate::util::map_in_place::MapInPlace; use errors::{Applicability, FatalError}; use smallvec::{smallvec, SmallVec}; use syntax_pos::{Span, DUMMY_SP, FileName}; use syntax_pos::hygiene::ExpnFormat; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sync::Lrc; use std::fs; use std::io::ErrorKind; use std::{iter, mem}; use std::ops::DerefMut; use std::rc::Rc; use std::path::PathBuf; macro_rules! ast_fragments { ( $($Kind:ident($AstTy:ty) { $kind_name:expr; $(one fn $mut_visit_ast:ident; fn $visit_ast:ident;)? $(many fn $flat_map_ast_elt:ident; fn $visit_ast_elt:ident;)? fn $make_ast:ident; })* ) => { /// A fragment of AST that can be produced by a single macro expansion. /// Can also serve as an input and intermediate result for macro expansion operations. pub enum AstFragment { OptExpr(Option>), $($Kind($AstTy),)* } /// "Discriminant" of an AST fragment. #[derive(Copy, Clone, PartialEq, Eq)] pub enum AstFragmentKind { OptExpr, $($Kind,)* } impl AstFragmentKind { pub fn name(self) -> &'static str { match self { AstFragmentKind::OptExpr => "expression", $(AstFragmentKind::$Kind => $kind_name,)* } } fn make_from<'a>(self, result: Box) -> Option { match self { AstFragmentKind::OptExpr => result.make_expr().map(Some).map(AstFragment::OptExpr), $(AstFragmentKind::$Kind => result.$make_ast().map(AstFragment::$Kind),)* } } } impl AstFragment { pub fn make_opt_expr(self) -> Option> { match self { AstFragment::OptExpr(expr) => expr, _ => panic!("AstFragment::make_* called on the wrong kind of fragment"), } } $(pub fn $make_ast(self) -> $AstTy { match self { AstFragment::$Kind(ast) => ast, _ => panic!("AstFragment::make_* called on the wrong kind of fragment"), } })* pub fn mut_visit_with(&mut self, vis: &mut F) { match self { AstFragment::OptExpr(opt_expr) => { visit_clobber(opt_expr, |opt_expr| { if let Some(expr) = opt_expr { vis.filter_map_expr(expr) } else { None } }); } $($(AstFragment::$Kind(ast) => vis.$mut_visit_ast(ast),)*)* $($(AstFragment::$Kind(ast) => ast.flat_map_in_place(|ast| vis.$flat_map_ast_elt(ast)),)*)* } } pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) { match *self { AstFragment::OptExpr(Some(ref expr)) => visitor.visit_expr(expr), AstFragment::OptExpr(None) => {} $($(AstFragment::$Kind(ref ast) => visitor.$visit_ast(ast),)*)* $($(AstFragment::$Kind(ref ast) => for ast_elt in &ast[..] { visitor.$visit_ast_elt(ast_elt); })*)* } } } impl<'a, 'b> MutVisitor for MacroExpander<'a, 'b> { fn filter_map_expr(&mut self, expr: P) -> Option> { self.expand_fragment(AstFragment::OptExpr(Some(expr))).make_opt_expr() } $($(fn $mut_visit_ast(&mut self, ast: &mut $AstTy) { visit_clobber(ast, |ast| self.expand_fragment(AstFragment::$Kind(ast)).$make_ast()); })*)* $($(fn $flat_map_ast_elt(&mut self, ast_elt: <$AstTy as IntoIterator>::Item) -> $AstTy { self.expand_fragment(AstFragment::$Kind(smallvec![ast_elt])).$make_ast() })*)* } impl<'a> MacResult for crate::ext::tt::macro_rules::ParserAnyMacro<'a> { $(fn $make_ast(self: Box>) -> Option<$AstTy> { Some(self.make(AstFragmentKind::$Kind).$make_ast()) })* } } } ast_fragments! { Expr(P) { "expression"; one fn visit_expr; fn visit_expr; fn make_expr; } Pat(P) { "pattern"; one fn visit_pat; fn visit_pat; fn make_pat; } Ty(P) { "type"; one fn visit_ty; fn visit_ty; fn make_ty; } Stmts(SmallVec<[ast::Stmt; 1]>) { "statement"; many fn flat_map_stmt; fn visit_stmt; fn make_stmts; } Items(SmallVec<[P; 1]>) { "item"; many fn flat_map_item; fn visit_item; fn make_items; } TraitItems(SmallVec<[ast::TraitItem; 1]>) { "trait item"; many fn flat_map_trait_item; fn visit_trait_item; fn make_trait_items; } ImplItems(SmallVec<[ast::ImplItem; 1]>) { "impl item"; many fn flat_map_impl_item; fn visit_impl_item; fn make_impl_items; } ForeignItems(SmallVec<[ast::ForeignItem; 1]>) { "foreign item"; many fn flat_map_foreign_item; fn visit_foreign_item; fn make_foreign_items; } } impl AstFragmentKind { fn dummy(self, span: Span) -> Option { self.make_from(DummyResult::any(span)) } fn expect_from_annotatables>(self, items: I) -> AstFragment { let mut items = items.into_iter(); match self { AstFragmentKind::Items => AstFragment::Items(items.map(Annotatable::expect_item).collect()), AstFragmentKind::ImplItems => AstFragment::ImplItems(items.map(Annotatable::expect_impl_item).collect()), AstFragmentKind::TraitItems => AstFragment::TraitItems(items.map(Annotatable::expect_trait_item).collect()), AstFragmentKind::ForeignItems => AstFragment::ForeignItems(items.map(Annotatable::expect_foreign_item).collect()), AstFragmentKind::Stmts => AstFragment::Stmts(items.map(Annotatable::expect_stmt).collect()), AstFragmentKind::Expr => AstFragment::Expr( items.next().expect("expected exactly one expression").expect_expr() ), AstFragmentKind::OptExpr => AstFragment::OptExpr(items.next().map(Annotatable::expect_expr)), AstFragmentKind::Pat | AstFragmentKind::Ty => panic!("patterns and types aren't annotatable"), } } } fn macro_bang_format(path: &ast::Path) -> ExpnFormat { // We don't want to format a path using pretty-printing, // `format!("{}", path)`, because that tries to insert // line-breaks and is slow. let mut path_str = String::with_capacity(64); for (i, segment) in path.segments.iter().enumerate() { if i != 0 { path_str.push_str("::"); } if segment.ident.name != kw::PathRoot { path_str.push_str(&segment.ident.as_str()) } } MacroBang(Symbol::intern(&path_str)) } pub struct Invocation { pub kind: InvocationKind, fragment_kind: AstFragmentKind, pub expansion_data: ExpansionData, } pub enum InvocationKind { Bang { mac: ast::Mac, ident: Option, span: Span, }, Attr { attr: Option, traits: Vec, item: Annotatable, // We temporarily report errors for attribute macros placed after derives after_derive: bool, }, Derive { path: Path, item: Annotatable, }, } impl Invocation { pub fn span(&self) -> Span { match self.kind { InvocationKind::Bang { span, .. } => span, InvocationKind::Attr { attr: Some(ref attr), .. } => attr.span, InvocationKind::Attr { attr: None, .. } => DUMMY_SP, InvocationKind::Derive { ref path, .. } => path.span, } } } pub struct MacroExpander<'a, 'b:'a> { pub cx: &'a mut ExtCtxt<'b>, monotonic: bool, // cf. `cx.monotonic_expander()` } impl<'a, 'b> MacroExpander<'a, 'b> { pub fn new(cx: &'a mut ExtCtxt<'b>, monotonic: bool) -> Self { MacroExpander { cx: cx, monotonic: monotonic } } pub fn expand_crate(&mut self, mut krate: ast::Crate) -> ast::Crate { let mut module = ModuleData { mod_path: vec![Ident::from_str(&self.cx.ecfg.crate_name)], directory: match self.cx.source_map().span_to_unmapped_path(krate.span) { FileName::Real(path) => path, other => PathBuf::from(other.to_string()), }, }; module.directory.pop(); self.cx.root_path = module.directory.clone(); self.cx.current_expansion.module = Rc::new(module); self.cx.current_expansion.crate_span = Some(krate.span); let orig_mod_span = krate.module.inner; let krate_item = AstFragment::Items(smallvec![P(ast::Item { attrs: krate.attrs, span: krate.span, node: ast::ItemKind::Mod(krate.module), ident: Ident::with_empty_ctxt(kw::Invalid), id: ast::DUMMY_NODE_ID, vis: respan(krate.span.shrink_to_lo(), ast::VisibilityKind::Public), tokens: None, })]); match self.expand_fragment(krate_item).make_items().pop().map(P::into_inner) { Some(ast::Item { attrs, node: ast::ItemKind::Mod(module), .. }) => { krate.attrs = attrs; krate.module = module; }, None => { // Resolution failed so we return an empty expansion krate.attrs = vec![]; krate.module = ast::Mod { inner: orig_mod_span, items: vec![], inline: true, }; }, _ => unreachable!(), }; self.cx.trace_macros_diag(); krate } // Fully expand all macro invocations in this AST fragment. fn expand_fragment(&mut self, input_fragment: AstFragment) -> AstFragment { let orig_expansion_data = self.cx.current_expansion.clone(); self.cx.current_expansion.depth = 0; // Collect all macro invocations and replace them with placeholders. let (mut fragment_with_placeholders, mut invocations) = self.collect_invocations(input_fragment, &[]); // Optimization: if we resolve all imports now, // we'll be able to immediately resolve most of imported macros. self.resolve_imports(); // Resolve paths in all invocations and produce output expanded fragments for them, but // do not insert them into our input AST fragment yet, only store in `expanded_fragments`. // The output fragments also go through expansion recursively until no invocations are left. // Unresolved macros produce dummy outputs as a recovery measure. invocations.reverse(); let mut expanded_fragments = Vec::new(); let mut derives: FxHashMap> = FxHashMap::default(); let mut undetermined_invocations = Vec::new(); let (mut progress, mut force) = (false, !self.monotonic); loop { let invoc = if let Some(invoc) = invocations.pop() { invoc } else { self.resolve_imports(); if undetermined_invocations.is_empty() { break } invocations = mem::replace(&mut undetermined_invocations, Vec::new()); force = !mem::replace(&mut progress, false); continue }; let scope = if self.monotonic { invoc.expansion_data.mark } else { orig_expansion_data.mark }; let ext = match self.cx.resolver.resolve_macro_invocation(&invoc, scope, force) { Ok(ext) => Some(ext), Err(Determinacy::Determined) => None, Err(Determinacy::Undetermined) => { undetermined_invocations.push(invoc); continue } }; progress = true; let ExpansionData { depth, mark, .. } = invoc.expansion_data; self.cx.current_expansion = invoc.expansion_data.clone(); self.cx.current_expansion.mark = scope; // FIXME(jseyfried): Refactor out the following logic let (expanded_fragment, new_invocations) = if let Some(ext) = ext { if let Some(ext) = ext { let (invoc_fragment_kind, invoc_span) = (invoc.fragment_kind, invoc.span()); let fragment = self.expand_invoc(invoc, &*ext).unwrap_or_else(|| { invoc_fragment_kind.dummy(invoc_span).unwrap() }); self.collect_invocations(fragment, &[]) } else if let InvocationKind::Attr { attr: None, traits, item, .. } = invoc.kind { if !item.derive_allowed() { let attr = attr::find_by_name(item.attrs(), sym::derive) .expect("`derive` attribute should exist"); let span = attr.span; let mut err = self.cx.mut_span_err(span, "`derive` may only be applied to \ structs, enums and unions"); if let ast::AttrStyle::Inner = attr.style { let trait_list = traits.iter() .map(|t| t.to_string()).collect::>(); let suggestion = format!("#[derive({})]", trait_list.join(", ")); err.span_suggestion( span, "try an outer attribute", suggestion, // We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT Applicability::MaybeIncorrect ); } err.emit(); } let mut item = self.fully_configure(item); item.visit_attrs(|attrs| attrs.retain(|a| a.path != sym::derive)); let mut item_with_markers = item.clone(); add_derived_markers(&mut self.cx, item.span(), &traits, &mut item_with_markers); let derives = derives.entry(invoc.expansion_data.mark).or_default(); derives.reserve(traits.len()); invocations.reserve(traits.len()); for path in &traits { let mark = Mark::fresh(self.cx.current_expansion.mark); derives.push(mark); let item = match self.cx.resolver.resolve_macro_path( path, MacroKind::Derive, Mark::root(), Vec::new(), false) { Ok(ext) => match *ext { BuiltinDerive(..) => item_with_markers.clone(), _ => item.clone(), }, _ => item.clone(), }; invocations.push(Invocation { kind: InvocationKind::Derive { path: path.clone(), item: item }, fragment_kind: invoc.fragment_kind, expansion_data: ExpansionData { mark, ..invoc.expansion_data.clone() }, }); } let fragment = invoc.fragment_kind .expect_from_annotatables(::std::iter::once(item_with_markers)); self.collect_invocations(fragment, derives) } else { unreachable!() } } else { self.collect_invocations(invoc.fragment_kind.dummy(invoc.span()).unwrap(), &[]) }; if expanded_fragments.len() < depth { expanded_fragments.push(Vec::new()); } expanded_fragments[depth - 1].push((mark, expanded_fragment)); if !self.cx.ecfg.single_step { invocations.extend(new_invocations.into_iter().rev()); } } self.cx.current_expansion = orig_expansion_data; // Finally incorporate all the expanded macros into the input AST fragment. let mut placeholder_expander = PlaceholderExpander::new(self.cx, self.monotonic); while let Some(expanded_fragments) = expanded_fragments.pop() { for (mark, expanded_fragment) in expanded_fragments.into_iter().rev() { let derives = derives.remove(&mark).unwrap_or_else(Vec::new); placeholder_expander.add(NodeId::placeholder_from_mark(mark), expanded_fragment, derives); } } fragment_with_placeholders.mut_visit_with(&mut placeholder_expander); fragment_with_placeholders } fn resolve_imports(&mut self) { if self.monotonic { self.cx.resolver.resolve_imports(); } } /// Collects all macro invocations reachable at this time in this AST fragment, and replace /// them with "placeholders" - dummy macro invocations with specially crafted `NodeId`s. /// Then call into resolver that builds a skeleton ("reduced graph") of the fragment and /// prepares data for resolving paths of macro invocations. fn collect_invocations(&mut self, mut fragment: AstFragment, derives: &[Mark]) -> (AstFragment, Vec) { // Resolve `$crate`s in the fragment for pretty-printing. self.cx.resolver.resolve_dollar_crates(&fragment); let invocations = { let mut collector = InvocationCollector { cfg: StripUnconfigured { sess: self.cx.parse_sess, features: self.cx.ecfg.features, }, cx: self.cx, invocations: Vec::new(), monotonic: self.monotonic, }; fragment.mut_visit_with(&mut collector); collector.invocations }; if self.monotonic { self.cx.resolver.visit_ast_fragment_with_placeholders( self.cx.current_expansion.mark, &fragment, derives); } (fragment, invocations) } fn fully_configure(&mut self, item: Annotatable) -> Annotatable { let mut cfg = StripUnconfigured { sess: self.cx.parse_sess, features: self.cx.ecfg.features, }; // Since the item itself has already been configured by the InvocationCollector, // we know that fold result vector will contain exactly one element match item { Annotatable::Item(item) => { Annotatable::Item(cfg.flat_map_item(item).pop().unwrap()) } Annotatable::TraitItem(item) => { Annotatable::TraitItem( item.map(|item| cfg.flat_map_trait_item(item).pop().unwrap())) } Annotatable::ImplItem(item) => { Annotatable::ImplItem(item.map(|item| cfg.flat_map_impl_item(item).pop().unwrap())) } Annotatable::ForeignItem(item) => { Annotatable::ForeignItem( item.map(|item| cfg.flat_map_foreign_item(item).pop().unwrap()) ) } Annotatable::Stmt(stmt) => { Annotatable::Stmt(stmt.map(|stmt| cfg.flat_map_stmt(stmt).pop().unwrap())) } Annotatable::Expr(mut expr) => { Annotatable::Expr({ cfg.visit_expr(&mut expr); expr }) } } } fn expand_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtension) -> Option { if invoc.fragment_kind == AstFragmentKind::ForeignItems && !self.cx.ecfg.macros_in_extern_enabled() { if let SyntaxExtension::NonMacroAttr { .. } = *ext {} else { emit_feature_err(&self.cx.parse_sess, sym::macros_in_extern, invoc.span(), GateIssue::Language, "macro invocations in `extern {}` blocks are experimental"); } } let result = match invoc.kind { InvocationKind::Bang { .. } => self.expand_bang_invoc(invoc, ext)?, InvocationKind::Attr { .. } => self.expand_attr_invoc(invoc, ext)?, InvocationKind::Derive { .. } => self.expand_derive_invoc(invoc, ext)?, }; if self.cx.current_expansion.depth > self.cx.ecfg.recursion_limit { let info = self.cx.current_expansion.mark.expn_info().unwrap(); let suggested_limit = self.cx.ecfg.recursion_limit * 2; let mut err = self.cx.struct_span_err(info.call_site, &format!("recursion limit reached while expanding the macro `{}`", info.format.name())); err.help(&format!( "consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate", suggested_limit)); err.emit(); self.cx.trace_macros_diag(); FatalError.raise(); } Some(result) } fn expand_attr_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtension) -> Option { let (attr, mut item) = match invoc.kind { InvocationKind::Attr { attr, item, .. } => (attr?, item), _ => unreachable!(), }; if let NonMacroAttr { mark_used: false } = *ext {} else { // Macro attrs are always used when expanded, // non-macro attrs are considered used when the field says so. attr::mark_used(&attr); } invoc.expansion_data.mark.set_expn_info(ExpnInfo { call_site: attr.span, def_site: None, format: MacroAttribute(Symbol::intern(&attr.path.to_string())), allow_internal_unstable: None, allow_internal_unsafe: false, local_inner_macros: false, edition: ext.edition(self.cx.parse_sess.edition), }); match *ext { NonMacroAttr { .. } => { attr::mark_known(&attr); item.visit_attrs(|attrs| attrs.push(attr)); Some(invoc.fragment_kind.expect_from_annotatables(iter::once(item))) } MultiModifier(ref mac) => { let meta = attr.parse_meta(self.cx.parse_sess) .map_err(|mut e| { e.emit(); }).ok()?; let item = mac.expand(self.cx, attr.span, &meta, item); Some(invoc.fragment_kind.expect_from_annotatables(item)) } MultiDecorator(ref mac) => { let mut items = Vec::new(); let meta = attr.parse_meta(self.cx.parse_sess) .expect("derive meta should already have been parsed"); mac.expand(self.cx, attr.span, &meta, &item, &mut |item| items.push(item)); items.push(item); Some(invoc.fragment_kind.expect_from_annotatables(items)) } AttrProcMacro(ref mac, ..) => { self.gate_proc_macro_attr_item(attr.span, &item); let item_tok = TokenTree::Token(DUMMY_SP, Token::Interpolated(Lrc::new(match item { Annotatable::Item(item) => token::NtItem(item), Annotatable::TraitItem(item) => token::NtTraitItem(item.into_inner()), Annotatable::ImplItem(item) => token::NtImplItem(item.into_inner()), Annotatable::ForeignItem(item) => token::NtForeignItem(item.into_inner()), Annotatable::Stmt(stmt) => token::NtStmt(stmt.into_inner()), Annotatable::Expr(expr) => token::NtExpr(expr), }))).into(); let input = self.extract_proc_macro_attr_input(attr.tokens, attr.span); let tok_result = mac.expand(self.cx, attr.span, input, item_tok); let res = self.parse_ast_fragment(tok_result, invoc.fragment_kind, &attr.path, attr.span); self.gate_proc_macro_expansion(attr.span, &res); res } ProcMacroDerive(..) | BuiltinDerive(..) => { self.cx.span_err(attr.span, &format!("`{}` is a derive macro", attr.path)); self.cx.trace_macros_diag(); invoc.fragment_kind.dummy(attr.span) } _ => { let msg = &format!("macro `{}` may not be used in attributes", attr.path); self.cx.span_err(attr.span, msg); self.cx.trace_macros_diag(); invoc.fragment_kind.dummy(attr.span) } } } fn extract_proc_macro_attr_input(&self, tokens: TokenStream, span: Span) -> TokenStream { let mut trees = tokens.trees(); match trees.next() { Some(TokenTree::Delimited(_, _, tts)) => { if trees.next().is_none() { return tts.into() } } Some(TokenTree::Token(..)) => {} None => return TokenStream::empty(), } self.cx.span_err(span, "custom attribute invocations must be \ of the form #[foo] or #[foo(..)], the macro name must only be \ followed by a delimiter token"); TokenStream::empty() } fn gate_proc_macro_attr_item(&self, span: Span, item: &Annotatable) { let (kind, gate) = match *item { Annotatable::Item(ref item) => { match item.node { ItemKind::Mod(_) if self.cx.ecfg.proc_macro_hygiene() => return, ItemKind::Mod(_) => ("modules", sym::proc_macro_hygiene), _ => return, } } Annotatable::TraitItem(_) => return, Annotatable::ImplItem(_) => return, Annotatable::ForeignItem(_) => return, Annotatable::Stmt(_) | Annotatable::Expr(_) if self.cx.ecfg.proc_macro_hygiene() => return, Annotatable::Stmt(_) => ("statements", sym::proc_macro_hygiene), Annotatable::Expr(_) => ("expressions", sym::proc_macro_hygiene), }; emit_feature_err( self.cx.parse_sess, gate, span, GateIssue::Language, &format!("custom attributes cannot be applied to {}", kind), ); } fn gate_proc_macro_expansion(&self, span: Span, fragment: &Option) { if self.cx.ecfg.proc_macro_hygiene() { return } let fragment = match fragment { Some(fragment) => fragment, None => return, }; fragment.visit_with(&mut DisallowMacros { span, parse_sess: self.cx.parse_sess, }); struct DisallowMacros<'a> { span: Span, parse_sess: &'a ParseSess, } impl<'ast, 'a> Visitor<'ast> for DisallowMacros<'a> { fn visit_item(&mut self, i: &'ast ast::Item) { if let ast::ItemKind::MacroDef(_) = i.node { emit_feature_err( self.parse_sess, sym::proc_macro_hygiene, self.span, GateIssue::Language, "procedural macros cannot expand to macro definitions", ); } visit::walk_item(self, i); } fn visit_mac(&mut self, _mac: &'ast ast::Mac) { // ... } } } /// Expand a macro invocation. Returns the resulting expanded AST fragment. fn expand_bang_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtension) -> Option { let (mark, kind) = (invoc.expansion_data.mark, invoc.fragment_kind); let (mac, ident, span) = match invoc.kind { InvocationKind::Bang { mac, ident, span } => (mac, ident, span), _ => unreachable!(), }; let path = &mac.node.path; let ident = ident.unwrap_or_else(|| Ident::with_empty_ctxt(kw::Invalid)); let validate_and_set_expn_info = |this: &mut Self, // arg instead of capture def_site_span: Option, allow_internal_unstable, allow_internal_unsafe, local_inner_macros, // can't infer this type unstable_feature: Option<(Symbol, u32)>, edition| { // feature-gate the macro invocation if let Some((feature, issue)) = unstable_feature { let crate_span = this.cx.current_expansion.crate_span.unwrap(); // don't stability-check macros in the same crate // (the only time this is null is for syntax extensions registered as macros) if def_site_span.map_or(false, |def_span| !crate_span.contains(def_span)) && !span.allows_unstable(feature) && this.cx.ecfg.features.map_or(true, |feats| { // macro features will count as lib features !feats.declared_lib_features.iter().any(|&(feat, _)| feat == feature) }) { let explain = format!("macro {}! is unstable", path); emit_feature_err(this.cx.parse_sess, feature, span, GateIssue::Library(Some(issue)), &explain); this.cx.trace_macros_diag(); } } if ident.name != kw::Invalid { let msg = format!("macro {}! expects no ident argument, given '{}'", path, ident); this.cx.span_err(path.span, &msg); this.cx.trace_macros_diag(); return Err(kind.dummy(span)); } mark.set_expn_info(ExpnInfo { call_site: span, def_site: def_site_span, format: macro_bang_format(path), allow_internal_unstable, allow_internal_unsafe, local_inner_macros, edition, }); Ok(()) }; let opt_expanded = match *ext { DeclMacro { ref expander, def_info, edition, .. } => { if let Err(dummy_span) = validate_and_set_expn_info(self, def_info.map(|(_, s)| s), None, false, false, None, edition) { dummy_span } else { kind.make_from(expander.expand(self.cx, span, mac.node.stream(), None)) } } NormalTT { ref expander, def_info, ref allow_internal_unstable, allow_internal_unsafe, local_inner_macros, unstable_feature, edition, } => { if let Err(dummy_span) = validate_and_set_expn_info(self, def_info.map(|(_, s)| s), allow_internal_unstable.clone(), allow_internal_unsafe, local_inner_macros, unstable_feature, edition) { dummy_span } else { kind.make_from(expander.expand( self.cx, span, mac.node.stream(), def_info.map(|(_, s)| s), )) } } IdentTT { ref expander, span: tt_span, ref allow_internal_unstable } => { if ident.name == kw::Invalid { self.cx.span_err(path.span, &format!("macro {}! expects an ident argument", path)); self.cx.trace_macros_diag(); kind.dummy(span) } else { invoc.expansion_data.mark.set_expn_info(ExpnInfo { call_site: span, def_site: tt_span, format: macro_bang_format(path), allow_internal_unstable: allow_internal_unstable.clone(), allow_internal_unsafe: false, local_inner_macros: false, edition: self.cx.parse_sess.edition, }); let input: Vec<_> = mac.node.stream().into_trees().collect(); kind.make_from(expander.expand(self.cx, span, ident, input)) } } MultiDecorator(..) | MultiModifier(..) | AttrProcMacro(..) | SyntaxExtension::NonMacroAttr { .. } => { self.cx.span_err(path.span, &format!("`{}` can only be used in attributes", path)); self.cx.trace_macros_diag(); kind.dummy(span) } ProcMacroDerive(..) | BuiltinDerive(..) => { self.cx.span_err(path.span, &format!("`{}` is a derive macro", path)); self.cx.trace_macros_diag(); kind.dummy(span) } SyntaxExtension::ProcMacro { ref expander, ref allow_internal_unstable, edition } => { if ident.name != kw::Invalid { let msg = format!("macro {}! expects no ident argument, given '{}'", path, ident); self.cx.span_err(path.span, &msg); self.cx.trace_macros_diag(); kind.dummy(span) } else { self.gate_proc_macro_expansion_kind(span, kind); invoc.expansion_data.mark.set_expn_info(ExpnInfo { call_site: span, // FIXME procedural macros do not have proper span info // yet, when they do, we should use it here. def_site: None, format: macro_bang_format(path), // FIXME probably want to follow macro_rules macros here. allow_internal_unstable: allow_internal_unstable.clone(), allow_internal_unsafe: false, local_inner_macros: false, edition, }); let tok_result = expander.expand(self.cx, span, mac.node.stream()); let result = self.parse_ast_fragment(tok_result, kind, path, span); self.gate_proc_macro_expansion(span, &result); result } } }; if opt_expanded.is_some() { opt_expanded } else { let msg = format!("non-{kind} macro in {kind} position: {name}", name = path.segments[0].ident.name, kind = kind.name()); self.cx.span_err(path.span, &msg); self.cx.trace_macros_diag(); kind.dummy(span) } } fn gate_proc_macro_expansion_kind(&self, span: Span, kind: AstFragmentKind) { let kind = match kind { AstFragmentKind::Expr => "expressions", AstFragmentKind::OptExpr => "expressions", AstFragmentKind::Pat => "patterns", AstFragmentKind::Ty => "types", AstFragmentKind::Stmts => "statements", AstFragmentKind::Items => return, AstFragmentKind::TraitItems => return, AstFragmentKind::ImplItems => return, AstFragmentKind::ForeignItems => return, }; if self.cx.ecfg.proc_macro_hygiene() { return } emit_feature_err( self.cx.parse_sess, sym::proc_macro_hygiene, span, GateIssue::Language, &format!("procedural macros cannot be expanded to {}", kind), ); } /// Expand a derive invocation. Returns the resulting expanded AST fragment. fn expand_derive_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtension) -> Option { let (path, item) = match invoc.kind { InvocationKind::Derive { path, item } => (path, item), _ => unreachable!(), }; if !item.derive_allowed() { return None; } let pretty_name = Symbol::intern(&format!("derive({})", path)); let span = path.span; let attr = ast::Attribute { path, span, tokens: TokenStream::empty(), // irrelevant: id: ast::AttrId(0), style: ast::AttrStyle::Outer, is_sugared_doc: false, }; let mut expn_info = ExpnInfo { call_site: span, def_site: None, format: MacroAttribute(pretty_name), allow_internal_unstable: None, allow_internal_unsafe: false, local_inner_macros: false, edition: ext.edition(self.cx.parse_sess.edition), }; match *ext { ProcMacroDerive(ref ext, ..) => { invoc.expansion_data.mark.set_expn_info(expn_info); let span = span.with_ctxt(self.cx.backtrace()); let dummy = ast::MetaItem { // FIXME(jseyfried) avoid this path: Path::from_ident(Ident::with_empty_ctxt(kw::Invalid)), span: DUMMY_SP, node: ast::MetaItemKind::Word, }; let items = ext.expand(self.cx, span, &dummy, item); Some(invoc.fragment_kind.expect_from_annotatables(items)) } BuiltinDerive(func) => { expn_info.allow_internal_unstable = Some(vec![ Symbol::intern("rustc_attrs"), Symbol::intern("derive_clone_copy"), Symbol::intern("derive_eq"), Symbol::intern("libstd_sys_internals"), // RustcDeserialize and RustcSerialize ].into()); invoc.expansion_data.mark.set_expn_info(expn_info); let span = span.with_ctxt(self.cx.backtrace()); let mut items = Vec::new(); func(self.cx, span, &attr.meta()?, &item, &mut |a| items.push(a)); Some(invoc.fragment_kind.expect_from_annotatables(items)) } _ => { let msg = &format!("macro `{}` may not be used for derive attributes", attr.path); self.cx.span_err(span, msg); self.cx.trace_macros_diag(); invoc.fragment_kind.dummy(span) } } } fn parse_ast_fragment(&mut self, toks: TokenStream, kind: AstFragmentKind, path: &Path, span: Span) -> Option { let mut parser = self.cx.new_parser_from_tts(&toks.into_trees().collect::>()); match parser.parse_ast_fragment(kind, false) { Ok(fragment) => { parser.ensure_complete_parse(path, kind.name(), span); Some(fragment) } Err(mut err) => { err.set_span(span); err.emit(); self.cx.trace_macros_diag(); kind.dummy(span) } } } } impl<'a> Parser<'a> { pub fn parse_ast_fragment(&mut self, kind: AstFragmentKind, macro_legacy_warnings: bool) -> PResult<'a, AstFragment> { Ok(match kind { AstFragmentKind::Items => { let mut items = SmallVec::new(); while let Some(item) = self.parse_item()? { items.push(item); } AstFragment::Items(items) } AstFragmentKind::TraitItems => { let mut items = SmallVec::new(); while self.token != token::Eof { items.push(self.parse_trait_item(&mut false)?); } AstFragment::TraitItems(items) } AstFragmentKind::ImplItems => { let mut items = SmallVec::new(); while self.token != token::Eof { items.push(self.parse_impl_item(&mut false)?); } AstFragment::ImplItems(items) } AstFragmentKind::ForeignItems => { let mut items = SmallVec::new(); while self.token != token::Eof { items.push(self.parse_foreign_item()?); } AstFragment::ForeignItems(items) } AstFragmentKind::Stmts => { let mut stmts = SmallVec::new(); while self.token != token::Eof && // won't make progress on a `}` self.token != token::CloseDelim(token::Brace) { if let Some(stmt) = self.parse_full_stmt(macro_legacy_warnings)? { stmts.push(stmt); } } AstFragment::Stmts(stmts) } AstFragmentKind::Expr => AstFragment::Expr(self.parse_expr()?), AstFragmentKind::OptExpr => { if self.token != token::Eof { AstFragment::OptExpr(Some(self.parse_expr()?)) } else { AstFragment::OptExpr(None) } }, AstFragmentKind::Ty => AstFragment::Ty(self.parse_ty()?), AstFragmentKind::Pat => AstFragment::Pat(self.parse_pat(None)?), }) } pub fn ensure_complete_parse(&mut self, macro_path: &Path, kind_name: &str, span: Span) { if self.token != token::Eof { let msg = format!("macro expansion ignores token `{}` and any following", self.this_token_to_string()); // Avoid emitting backtrace info twice. let def_site_span = self.span.with_ctxt(SyntaxContext::empty()); let mut err = self.diagnostic().struct_span_err(def_site_span, &msg); err.span_label(span, "caused by the macro expansion here"); let msg = format!( "the usage of `{}!` is likely invalid in {} context", macro_path, kind_name, ); err.note(&msg); let semi_span = self.sess.source_map().next_point(span); let semi_full_span = semi_span.to(self.sess.source_map().next_point(semi_span)); match self.sess.source_map().span_to_snippet(semi_full_span) { Ok(ref snippet) if &snippet[..] != ";" && kind_name == "expression" => { err.span_suggestion( semi_span, "you might be missing a semicolon here", ";".to_owned(), Applicability::MaybeIncorrect, ); } _ => {} } err.emit(); } } } struct InvocationCollector<'a, 'b: 'a> { cx: &'a mut ExtCtxt<'b>, cfg: StripUnconfigured<'a>, invocations: Vec, monotonic: bool, } impl<'a, 'b> InvocationCollector<'a, 'b> { fn collect(&mut self, fragment_kind: AstFragmentKind, kind: InvocationKind) -> AstFragment { let mark = Mark::fresh(self.cx.current_expansion.mark); self.invocations.push(Invocation { kind, fragment_kind, expansion_data: ExpansionData { mark, depth: self.cx.current_expansion.depth + 1, ..self.cx.current_expansion.clone() }, }); placeholder(fragment_kind, NodeId::placeholder_from_mark(mark)) } fn collect_bang(&mut self, mac: ast::Mac, span: Span, kind: AstFragmentKind) -> AstFragment { self.collect(kind, InvocationKind::Bang { mac: mac, ident: None, span: span }) } fn collect_attr(&mut self, attr: Option, traits: Vec, item: Annotatable, kind: AstFragmentKind, after_derive: bool) -> AstFragment { self.collect(kind, InvocationKind::Attr { attr, traits, item, after_derive }) } fn find_attr_invoc(&self, attrs: &mut Vec, after_derive: &mut bool) -> Option { let attr = attrs.iter() .position(|a| { if a.path == sym::derive { *after_derive = true; } !attr::is_known(a) && !is_builtin_attr(a) }) .map(|i| attrs.remove(i)); if let Some(attr) = &attr { if !self.cx.ecfg.enable_custom_inner_attributes() && attr.style == ast::AttrStyle::Inner && attr.path != sym::test { emit_feature_err(&self.cx.parse_sess, sym::custom_inner_attributes, attr.span, GateIssue::Language, "non-builtin inner attributes are unstable"); } } attr } /// If `item` is an attr invocation, remove and return the macro attribute and derive traits. fn classify_item(&mut self, item: &mut T) -> (Option, Vec, /* after_derive */ bool) where T: HasAttrs, { let (mut attr, mut traits, mut after_derive) = (None, Vec::new(), false); item.visit_attrs(|mut attrs| { attr = self.find_attr_invoc(&mut attrs, &mut after_derive); traits = collect_derives(&mut self.cx, &mut attrs); }); (attr, traits, after_derive) } /// Alternative to `classify_item()` that ignores `#[derive]` so invocations fallthrough /// to the unused-attributes lint (making it an error on statements and expressions /// is a breaking change) fn classify_nonitem(&mut self, nonitem: &mut T) -> (Option, /* after_derive */ bool) { let (mut attr, mut after_derive) = (None, false); nonitem.visit_attrs(|mut attrs| { attr = self.find_attr_invoc(&mut attrs, &mut after_derive); }); (attr, after_derive) } fn configure(&mut self, node: T) -> Option { 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(&mut self, attrs: &[ast::Attribute]) { let features = self.cx.ecfg.features.unwrap(); for attr in attrs.iter() { self.check_attribute_inner(attr, features); // macros are expanded before any lint passes so this warning has to be hardcoded if attr.path == sym::derive { self.cx.struct_span_warn(attr.span, "`#[derive]` does nothing on macro invocations") .note("this may become a hard error in a future release") .emit(); } } } fn check_attribute(&mut self, at: &ast::Attribute) { let features = self.cx.ecfg.features.unwrap(); self.check_attribute_inner(at, features); } fn check_attribute_inner(&mut self, at: &ast::Attribute, features: &Features) { feature_gate::check_attribute(at, self.cx.parse_sess, features); } } impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> { fn visit_expr(&mut self, expr: &mut P) { self.cfg.configure_expr(expr); visit_clobber(expr.deref_mut(), |mut expr| { self.cfg.configure_expr_kind(&mut expr.node); // ignore derives so they remain unused let (attr, after_derive) = self.classify_nonitem(&mut expr); if attr.is_some() { // Collect the invoc regardless of whether or not attributes are permitted here // expansion will eat the attribute so it won't error later. attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a)); // AstFragmentKind::Expr requires the macro to emit an expression. return self.collect_attr(attr, vec![], Annotatable::Expr(P(expr)), AstFragmentKind::Expr, after_derive) .make_expr() .into_inner() } if let ast::ExprKind::Mac(mac) = expr.node { self.check_attributes(&expr.attrs); self.collect_bang(mac, expr.span, AstFragmentKind::Expr) .make_expr() .into_inner() } else { noop_visit_expr(&mut expr, self); expr } }); } fn filter_map_expr(&mut self, expr: P) -> Option> { let expr = configure!(self, expr); expr.filter_map(|mut expr| { self.cfg.configure_expr_kind(&mut expr.node); // Ignore derives so they remain unused. let (attr, after_derive) = self.classify_nonitem(&mut expr); if attr.is_some() { attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a)); return self.collect_attr(attr, vec![], Annotatable::Expr(P(expr)), AstFragmentKind::OptExpr, after_derive) .make_opt_expr() .map(|expr| expr.into_inner()) } if let ast::ExprKind::Mac(mac) = expr.node { self.check_attributes(&expr.attrs); self.collect_bang(mac, expr.span, AstFragmentKind::OptExpr) .make_opt_expr() .map(|expr| expr.into_inner()) } else { Some({ noop_visit_expr(&mut expr, self); expr }) } }) } fn visit_pat(&mut self, pat: &mut P) { self.cfg.configure_pat(pat); match pat.node { PatKind::Mac(_) => {} _ => return noop_visit_pat(pat, self), } visit_clobber(pat, |mut pat| { match mem::replace(&mut pat.node, PatKind::Wild) { PatKind::Mac(mac) => self.collect_bang(mac, pat.span, AstFragmentKind::Pat).make_pat(), _ => unreachable!(), } }); } fn flat_map_stmt(&mut self, stmt: ast::Stmt) -> SmallVec<[ast::Stmt; 1]> { let mut stmt = configure!(self, stmt); // we'll expand attributes on expressions separately if !stmt.is_expr() { let (attr, derives, after_derive) = if stmt.is_item() { self.classify_item(&mut stmt) } else { // ignore derives on non-item statements so it falls through // to the unused-attributes lint let (attr, after_derive) = self.classify_nonitem(&mut stmt); (attr, vec![], after_derive) }; if attr.is_some() || !derives.is_empty() { return self.collect_attr(attr, derives, Annotatable::Stmt(P(stmt)), AstFragmentKind::Stmts, after_derive).make_stmts(); } } if let StmtKind::Mac(mac) = stmt.node { let (mac, style, attrs) = mac.into_inner(); self.check_attributes(&attrs); let mut placeholder = self.collect_bang(mac, stmt.span, 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 style == MacStmtStyle::Semicolon { if let Some(stmt) = placeholder.pop() { placeholder.push(stmt.add_trailing_semicolon()); } } return placeholder; } // The placeholder expander gives ids to statements, so we avoid folding the id here. let ast::Stmt { id, node, span } = stmt; noop_flat_map_stmt_kind(node, self).into_iter().map(|node| { ast::Stmt { id, node, span } }).collect() } fn visit_block(&mut self, block: &mut P) { let old_directory_ownership = self.cx.current_expansion.directory_ownership; self.cx.current_expansion.directory_ownership = DirectoryOwnership::UnownedViaBlock; noop_visit_block(block, self); self.cx.current_expansion.directory_ownership = old_directory_ownership; } fn flat_map_item(&mut self, item: P) -> SmallVec<[P; 1]> { let mut item = configure!(self, item); let (attr, traits, after_derive) = self.classify_item(&mut item); if attr.is_some() || !traits.is_empty() { return self.collect_attr(attr, traits, Annotatable::Item(item), AstFragmentKind::Items, after_derive).make_items(); } match item.node { ast::ItemKind::Mac(..) => { self.check_attributes(&item.attrs); item.and_then(|item| match item.node { ItemKind::Mac(mac) => { self.collect(AstFragmentKind::Items, InvocationKind::Bang { mac, ident: Some(item.ident), span: item.span, }).make_items() } _ => unreachable!(), }) } ast::ItemKind::Mod(ast::Mod { inner, .. }) => { if item.ident == Ident::with_empty_ctxt(kw::Invalid) { return noop_flat_map_item(item, self); } let orig_directory_ownership = self.cx.current_expansion.directory_ownership; let mut module = (*self.cx.current_expansion.module).clone(); module.mod_path.push(item.ident); // Detect if this is an inline module (`mod m { ... }` as opposed to `mod m;`). // In the non-inline case, `inner` is never the dummy span (cf. `parse_item_mod`). // Thus, if `inner` is the dummy span, we know the module is inline. let inline_module = item.span.contains(inner) || inner.is_dummy(); if inline_module { if let Some(path) = attr::first_attr_value_str_by_name(&item.attrs, sym::path) { self.cx.current_expansion.directory_ownership = DirectoryOwnership::Owned { relative: None }; module.directory.push(&*path.as_str()); } else { module.directory.push(&*item.ident.as_str()); } } else { let path = self.cx.parse_sess.source_map().span_to_unmapped_path(inner); let mut path = match path { FileName::Real(path) => path, other => PathBuf::from(other.to_string()), }; let directory_ownership = match path.file_name().unwrap().to_str() { Some("mod.rs") => DirectoryOwnership::Owned { relative: None }, Some(_) => DirectoryOwnership::Owned { relative: Some(item.ident), }, None => DirectoryOwnership::UnownedViaMod(false), }; path.pop(); module.directory = path; self.cx.current_expansion.directory_ownership = directory_ownership; } let orig_module = mem::replace(&mut self.cx.current_expansion.module, Rc::new(module)); let result = noop_flat_map_item(item, self); self.cx.current_expansion.module = orig_module; self.cx.current_expansion.directory_ownership = orig_directory_ownership; result } _ => noop_flat_map_item(item, self), } } fn flat_map_trait_item(&mut self, item: ast::TraitItem) -> SmallVec<[ast::TraitItem; 1]> { let mut item = configure!(self, item); let (attr, traits, after_derive) = self.classify_item(&mut item); if attr.is_some() || !traits.is_empty() { return self.collect_attr(attr, traits, Annotatable::TraitItem(P(item)), AstFragmentKind::TraitItems, after_derive).make_trait_items() } match item.node { ast::TraitItemKind::Macro(mac) => { let ast::TraitItem { attrs, span, .. } = item; self.check_attributes(&attrs); self.collect_bang(mac, span, AstFragmentKind::TraitItems).make_trait_items() } _ => noop_flat_map_trait_item(item, self), } } fn flat_map_impl_item(&mut self, item: ast::ImplItem) -> SmallVec<[ast::ImplItem; 1]> { let mut item = configure!(self, item); let (attr, traits, after_derive) = self.classify_item(&mut item); if attr.is_some() || !traits.is_empty() { return self.collect_attr(attr, traits, Annotatable::ImplItem(P(item)), AstFragmentKind::ImplItems, after_derive).make_impl_items(); } match item.node { ast::ImplItemKind::Macro(mac) => { let ast::ImplItem { attrs, span, .. } = item; self.check_attributes(&attrs); self.collect_bang(mac, span, AstFragmentKind::ImplItems).make_impl_items() } _ => noop_flat_map_impl_item(item, self), } } fn visit_ty(&mut self, ty: &mut P) { match ty.node { ast::TyKind::Mac(_) => {} _ => return noop_visit_ty(ty, self), }; visit_clobber(ty, |mut ty| { match mem::replace(&mut ty.node, ast::TyKind::Err) { ast::TyKind::Mac(mac) => self.collect_bang(mac, ty.span, AstFragmentKind::Ty).make_ty(), _ => unreachable!(), } }); } fn visit_foreign_mod(&mut self, foreign_mod: &mut ast::ForeignMod) { self.cfg.configure_foreign_mod(foreign_mod); noop_visit_foreign_mod(foreign_mod, self); } fn flat_map_foreign_item(&mut self, mut foreign_item: ast::ForeignItem) -> SmallVec<[ast::ForeignItem; 1]> { let (attr, traits, after_derive) = self.classify_item(&mut foreign_item); if attr.is_some() || !traits.is_empty() { return self.collect_attr(attr, traits, Annotatable::ForeignItem(P(foreign_item)), AstFragmentKind::ForeignItems, after_derive) .make_foreign_items(); } if let ast::ForeignItemKind::Macro(mac) = foreign_item.node { self.check_attributes(&foreign_item.attrs); return self.collect_bang(mac, foreign_item.span, AstFragmentKind::ForeignItems) .make_foreign_items(); } noop_flat_map_foreign_item(foreign_item, self) } fn visit_item_kind(&mut self, item: &mut ast::ItemKind) { match item { ast::ItemKind::MacroDef(..) => {} _ => { self.cfg.configure_item_kind(item); noop_visit_item_kind(item, self); } } } fn visit_generic_param(&mut self, param: &mut ast::GenericParam) { self.cfg.disallow_cfg_on_generic_param(¶m); noop_visit_generic_param(param, self) } fn visit_attribute(&mut self, at: &mut ast::Attribute) { // turn `#[doc(include="filename")]` attributes into `#[doc(include(file="filename", // contents="file contents")]` attributes if !at.check_name(sym::doc) { return noop_visit_attribute(at, self); } if let Some(list) = at.meta_item_list() { if !list.iter().any(|it| it.check_name(sym::include)) { return noop_visit_attribute(at, self); } let mut items = vec![]; for mut it in list { if !it.check_name(sym::include) { items.push({ noop_visit_meta_list_item(&mut it, self); it }); continue; } if let Some(file) = it.value_str() { let err_count = self.cx.parse_sess.span_diagnostic.err_count(); self.check_attribute(&at); if self.cx.parse_sess.span_diagnostic.err_count() > err_count { // avoid loading the file if they haven't enabled the feature return noop_visit_attribute(at, self); } let filename = self.cx.root_path.join(file.to_string()); match fs::read_to_string(&filename) { Ok(src) => { let src_interned = Symbol::intern(&src); // Add this input file to the code map to make it available as // dependency information self.cx.source_map().new_source_file(filename.into(), src); let include_info = vec![ ast::NestedMetaItem::MetaItem( attr::mk_name_value_item_str( Ident::with_empty_ctxt(sym::file), dummy_spanned(file), ), ), ast::NestedMetaItem::MetaItem( attr::mk_name_value_item_str( Ident::with_empty_ctxt(sym::contents), dummy_spanned(src_interned), ), ), ]; let include_ident = Ident::with_empty_ctxt(sym::include); let item = attr::mk_list_item(DUMMY_SP, include_ident, include_info); items.push(ast::NestedMetaItem::MetaItem(item)); } Err(e) => { let lit = it .meta_item() .and_then(|item| item.name_value_literal()) .unwrap(); if e.kind() == ErrorKind::InvalidData { self.cx .struct_span_err( lit.span, &format!("{} wasn't a utf-8 file", filename.display()), ) .span_label(lit.span, "contains invalid utf-8") .emit(); } else { let mut err = self.cx.struct_span_err( lit.span, &format!("couldn't read {}: {}", filename.display(), e), ); err.span_label(lit.span, "couldn't read file"); if e.kind() == ErrorKind::NotFound { err.help("external doc paths are relative to the crate root"); } err.emit(); } } } } else { let mut err = self.cx.struct_span_err( it.span(), &format!("expected path to external documentation"), ); // Check if the user erroneously used `doc(include(...))` syntax. let literal = it.meta_item_list().and_then(|list| { if list.len() == 1 { list[0].literal().map(|literal| &literal.node) } else { None } }); let (path, applicability) = match &literal { Some(LitKind::Str(path, ..)) => { (path.to_string(), Applicability::MachineApplicable) } _ => (String::from(""), Applicability::HasPlaceholders), }; err.span_suggestion( it.span(), "provide a file path with `=`", format!("include = \"{}\"", path), applicability, ); err.emit(); } } let meta = attr::mk_list_item(DUMMY_SP, Ident::with_empty_ctxt(sym::doc), items); match at.style { ast::AttrStyle::Inner => *at = attr::mk_spanned_attr_inner(at.span, at.id, meta), ast::AttrStyle::Outer => *at = attr::mk_spanned_attr_outer(at.span, at.id, meta), } } else { noop_visit_attribute(at, self) } } fn visit_id(&mut self, id: &mut ast::NodeId) { if self.monotonic { debug_assert_eq!(*id, ast::DUMMY_NODE_ID); *id = self.cx.resolver.next_node_id() } } } pub struct ExpansionConfig<'feat> { pub crate_name: String, pub features: Option<&'feat Features>, pub recursion_limit: usize, pub trace_mac: bool, pub should_test: bool, // If false, strip `#[test]` nodes pub single_step: bool, pub keep_macs: bool, } macro_rules! feature_tests { ($( fn $getter:ident = $field:ident, )*) => { $( pub fn $getter(&self) -> bool { match self.features { Some(&Features { $field: true, .. }) => true, _ => false, } } )* } } impl<'feat> ExpansionConfig<'feat> { pub fn default(crate_name: String) -> ExpansionConfig<'static> { ExpansionConfig { crate_name, features: None, recursion_limit: 1024, trace_mac: false, should_test: false, single_step: false, keep_macs: false, } } feature_tests! { fn enable_asm = asm, fn enable_custom_test_frameworks = custom_test_frameworks, fn enable_global_asm = global_asm, fn enable_log_syntax = log_syntax, fn enable_concat_idents = concat_idents, fn enable_trace_macros = trace_macros, fn enable_allow_internal_unstable = allow_internal_unstable, fn enable_format_args_nl = format_args_nl, fn macros_in_extern_enabled = macros_in_extern, fn proc_macro_hygiene = proc_macro_hygiene, } fn enable_custom_inner_attributes(&self) -> bool { self.features.map_or(false, |features| { features.custom_inner_attributes || features.custom_attribute || features.rustc_attrs }) } } // A Marker adds the given mark to the syntax context. #[derive(Debug)] pub struct Marker(pub Mark); impl MutVisitor for Marker { fn visit_span(&mut self, span: &mut Span) { *span = span.apply_mark(self.0) } fn visit_mac(&mut self, mac: &mut ast::Mac) { noop_visit_mac(mac, self) } }