// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. use ast::{self, Block, Ident, NodeId, PatKind, Path}; use ast::{MacStmtStyle, StmtKind, ItemKind}; use attr::{self, HasAttrs}; use source_map::{ExpnInfo, MacroBang, MacroAttribute, dummy_spanned, respan}; use config::{is_test_or_bench, StripUnconfigured}; use errors::{Applicability, FatalError}; use ext::base::*; use ext::build::AstBuilder; use ext::derive::{add_derived_markers, collect_derives}; use ext::hygiene::{self, Mark, SyntaxContext}; use ext::placeholders::{placeholder, PlaceholderExpander}; use feature_gate::{self, Features, GateIssue, is_builtin_attr, emit_feature_err}; use fold; use fold::*; use parse::{DirectoryOwnership, PResult, ParseSess}; use parse::token::{self, Token}; use parse::parser::Parser; use ptr::P; use OneVector; use symbol::Symbol; use symbol::keywords; use syntax_pos::{Span, DUMMY_SP, FileName}; use syntax_pos::hygiene::ExpnFormat; use tokenstream::{TokenStream, TokenTree}; use visit::{self, Visitor}; use std::collections::HashMap; use std::fs::File; use std::io::Read; use std::iter::FromIterator; use std::{iter, mem}; use std::rc::Rc; use std::path::PathBuf; macro_rules! ast_fragments { ( $($Kind:ident($AstTy:ty) { $kind_name:expr; // FIXME: HACK: this should be `$(one ...)?` and `$(many ...)?` but `?` macro // repetition was removed from 2015 edition in #51587 because of ambiguities. $(one fn $fold_ast:ident; fn $visit_ast:ident;)* $(many fn $fold_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 fold_with(self, folder: &mut F) -> Self { match self { AstFragment::OptExpr(expr) => AstFragment::OptExpr(expr.and_then(|expr| folder.fold_opt_expr(expr))), $($(AstFragment::$Kind(ast) => AstFragment::$Kind(folder.$fold_ast(ast)),)*)* $($(AstFragment::$Kind(ast) => AstFragment::$Kind(ast.into_iter() .flat_map(|ast| folder.$fold_ast_elt(ast)) .collect()),)*)* } } 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> Folder for MacroExpander<'a, 'b> { fn fold_opt_expr(&mut self, expr: P) -> Option> { self.expand_fragment(AstFragment::OptExpr(Some(expr))).make_opt_expr() } $($(fn $fold_ast(&mut self, ast: $AstTy) -> $AstTy { self.expand_fragment(AstFragment::$Kind(ast)).$make_ast() })*)* $($(fn $fold_ast_elt(&mut self, ast_elt: <$AstTy as IntoIterator>::Item) -> $AstTy { self.expand_fragment(AstFragment::$Kind(smallvec![ast_elt])).$make_ast() })*)* } impl<'a> MacResult for ::ext::tt::macro_rules::ParserAnyMacro<'a> { $(fn $make_ast(self: Box<::ext::tt::macro_rules::ParserAnyMacro<'a>>) -> Option<$AstTy> { Some(self.make(AstFragmentKind::$Kind).$make_ast()) })* } } } ast_fragments! { Expr(P) { "expression"; one fn fold_expr; fn visit_expr; fn make_expr; } Pat(P) { "pattern"; one fn fold_pat; fn visit_pat; fn make_pat; } Ty(P) { "type"; one fn fold_ty; fn visit_ty; fn make_ty; } Stmts(OneVector) { "statement"; many fn fold_stmt; fn visit_stmt; fn make_stmts; } Items(OneVector>) { "item"; many fn fold_item; fn visit_item; fn make_items; } TraitItems(OneVector) { "trait item"; many fn fold_trait_item; fn visit_trait_item; fn make_trait_items; } ImplItems(OneVector) { "impl item"; many fn fold_impl_item; fn visit_impl_item; fn make_impl_items; } ForeignItems(OneVector) { "foreign item"; many fn fold_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 != keywords::CrateRoot.name() && segment.ident.name != keywords::DollarCrate.name() { 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, }, 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, // c.f. `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: keywords::Invalid.ident(), 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![], }; }, _ => 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 (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: HashMap> = HashMap::new(); 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 dummy = invoc.fragment_kind.dummy(invoc.span()).unwrap(); let fragment = self.expand_invoc(invoc, &*ext).unwrap_or(dummy); 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(), "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_with_applicability( span, "try an outer attribute", suggestion, // We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT Applicability::MaybeIncorrect ); } err.emit(); } let item = self.fully_configure(item) .map_attrs(|mut attrs| { attrs.retain(|a| a.path != "derive"); attrs }); let item_with_markers = add_derived_markers(&mut self.cx, item.span(), &traits, item.clone()); let derives = derives.entry(invoc.expansion_data.mark).or_default(); 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(), &[], 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.fold_with(&mut placeholder_expander) } fn resolve_imports(&mut self) { if self.monotonic { let err_count = self.cx.parse_sess.span_diagnostic.err_count(); self.cx.resolver.resolve_imports(); self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count; } } /// Collect 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, fragment: AstFragment, derives: &[Mark]) -> (AstFragment, Vec) { let (fragment_with_placeholders, invocations) = { let mut collector = InvocationCollector { cfg: StripUnconfigured { should_test: self.cx.ecfg.should_test, sess: self.cx.parse_sess, features: self.cx.ecfg.features, }, cx: self.cx, invocations: Vec::new(), monotonic: self.monotonic, tests_nameable: true, }; (fragment.fold_with(&mut collector), collector.invocations) }; if self.monotonic { let err_count = self.cx.parse_sess.span_diagnostic.err_count(); let mark = self.cx.current_expansion.mark; self.cx.resolver.visit_ast_fragment_with_placeholders(mark, &fragment_with_placeholders, derives); self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count; } (fragment_with_placeholders, invocations) } fn fully_configure(&mut self, item: Annotatable) -> Annotatable { let mut cfg = StripUnconfigured { should_test: self.cx.ecfg.should_test, 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.fold_item(item).pop().unwrap()) } Annotatable::TraitItem(item) => { Annotatable::TraitItem(item.map(|item| cfg.fold_trait_item(item).pop().unwrap())) } Annotatable::ImplItem(item) => { Annotatable::ImplItem(item.map(|item| cfg.fold_impl_item(item).pop().unwrap())) } Annotatable::ForeignItem(item) => { Annotatable::ForeignItem( item.map(|item| cfg.fold_foreign_item(item).pop().unwrap()) ) } Annotatable::Stmt(stmt) => { Annotatable::Stmt(stmt.map(|stmt| cfg.fold_stmt(stmt).pop().unwrap())) } Annotatable::Expr(expr) => { Annotatable::Expr(cfg.fold_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, "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, 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: false, allow_internal_unsafe: false, local_inner_macros: false, edition: ext.edition(), }); match *ext { NonMacroAttr { .. } => { attr::mark_known(&attr); let item = item.map_attrs(|mut attrs| { attrs.push(attr); attrs }); 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(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 mode", 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(_, delim)) => { if trees.next().is_none() { return delim.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_mod() => return, ItemKind::Mod(_) => ("modules", "proc_macro_mod"), _ => return, } } Annotatable::TraitItem(_) => return, Annotatable::ImplItem(_) => return, Annotatable::ForeignItem(_) => return, Annotatable::Stmt(_) | Annotatable::Expr(_) if self.cx.ecfg.proc_macro_expr() => return, Annotatable::Stmt(_) => ("statements", "proc_macro_expr"), Annotatable::Expr(_) => ("expressions", "proc_macro_expr"), }; 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_gen() { 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, "proc_macro_gen", self.span, GateIssue::Language, &format!("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(|| keywords::Invalid.ident()); 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() && 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.as_str(), span, GateIssue::Library(Some(issue)), &explain); this.cx.trace_macros_diag(); return Err(kind.dummy(span)); } } if ident.name != keywords::Invalid.name() { 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), false, false, false, None, edition) { dummy_span } else { kind.make_from(expander.expand(self.cx, span, mac.node.stream())) } } NormalTT { ref expander, def_info, 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, allow_internal_unsafe, local_inner_macros, unstable_feature, edition) { dummy_span } else { kind.make_from(expander.expand(self.cx, span, mac.node.stream())) } } IdentTT(ref expander, tt_span, allow_internal_unstable) => { if ident.name == keywords::Invalid.name() { 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_unsafe: false, local_inner_macros: false, edition: hygiene::default_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 mode", path)); self.cx.trace_macros_diag(); kind.dummy(span) } SyntaxExtension::ProcMacro { ref expander, allow_internal_unstable, edition } => { if ident.name != keywords::Invalid.name() { 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_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_non_items() { return } emit_feature_err( self.cx.parse_sess, "proc_macro_non_items", 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: false, allow_internal_unsafe: false, local_inner_macros: false, edition: ext.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 ident: Path::from_ident(keywords::Invalid.ident()), 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 = true; 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 = OneVector::new(); while let Some(item) = self.parse_item()? { items.push(item); } AstFragment::Items(items) } AstFragmentKind::TraitItems => { let mut items = OneVector::new(); while self.token != token::Eof { items.push(self.parse_trait_item(&mut false)?); } AstFragment::TraitItems(items) } AstFragmentKind::ImplItems => { let mut items = OneVector::new(); while self.token != token::Eof { items.push(self.parse_impl_item(&mut false)?); } AstFragment::ImplItems(items) } AstFragmentKind::ForeignItems => { let mut items = OneVector::new(); while self.token != token::Eof { if let Some(item) = self.parse_foreign_item()? { items.push(item); } } AstFragment::ForeignItems(items) } AstFragmentKind::Stmts => { let mut stmts = OneVector::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()?), }) } 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); let msg = format!("caused by the macro expansion here; the usage \ of `{}!` is likely invalid in {} context", macro_path, kind_name); err.span_note(span, &msg).emit(); } } } struct InvocationCollector<'a, 'b: 'a> { cx: &'a mut ExtCtxt<'b>, cfg: StripUnconfigured<'a>, invocations: Vec, monotonic: bool, /// Test functions need to be nameable. Tests inside functions or in other /// unnameable locations need to be ignored. `tests_nameable` tracks whether /// any test functions found in the current context would be nameable. tests_nameable: 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)) } /// Folds the item allowing tests to be expanded because they are still nameable. /// This should probably only be called with module items fn fold_nameable(&mut self, item: P) -> OneVector> { fold::noop_fold_item(item, self) } /// Folds the item but doesn't allow tests to occur within it fn fold_unnameable(&mut self, item: P) -> OneVector> { let was_nameable = mem::replace(&mut self.tests_nameable, false); let items = fold::noop_fold_item(item, self); self.tests_nameable = was_nameable; items } 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) -> AstFragment { self.collect(kind, InvocationKind::Attr { attr, traits, item }) } /// If `item` is an attr invocation, remove and return the macro attribute and derive traits. fn classify_item(&mut self, mut item: T) -> (Option, Vec, T) where T: HasAttrs, { let (mut attr, mut traits) = (None, Vec::new()); item = item.map_attrs(|mut attrs| { if let Some(legacy_attr_invoc) = self.cx.resolver.find_legacy_attr_invoc(&mut attrs, true) { attr = Some(legacy_attr_invoc); return attrs; } attr = find_attr_invoc(&mut attrs); traits = collect_derives(&mut self.cx, &mut attrs); attrs }); (attr, traits, item) } /// Alternative of `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, mut item: T) -> (Option, T) { let mut attr = None; item = item.map_attrs(|mut attrs| { if let Some(legacy_attr_invoc) = self.cx.resolver.find_legacy_attr_invoc(&mut attrs, false) { attr = Some(legacy_attr_invoc); return attrs; } attr = find_attr_invoc(&mut attrs); attrs }); (attr, item) } 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 == "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); } } pub fn find_attr_invoc(attrs: &mut Vec) -> Option { attrs.iter() .position(|a| !attr::is_known(a) && !is_builtin_attr(a)) .map(|i| attrs.remove(i)) } impl<'a, 'b> Folder for InvocationCollector<'a, 'b> { fn fold_expr(&mut self, expr: P) -> P { let mut expr = self.cfg.configure_expr(expr).into_inner(); expr.node = self.cfg.configure_expr_kind(expr.node); // ignore derives so they remain unused let (attr, expr) = self.classify_nonitem(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).make_expr(); } if let ast::ExprKind::Mac(mac) = expr.node { self.check_attributes(&expr.attrs); self.collect_bang(mac, expr.span, AstFragmentKind::Expr).make_expr() } else { P(noop_fold_expr(expr, self)) } } fn fold_opt_expr(&mut self, expr: P) -> Option> { let mut expr = configure!(self, expr).into_inner(); expr.node = self.cfg.configure_expr_kind(expr.node); // ignore derives so they remain unused let (attr, expr) = self.classify_nonitem(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) .make_opt_expr(); } if let ast::ExprKind::Mac(mac) = expr.node { self.check_attributes(&expr.attrs); self.collect_bang(mac, expr.span, AstFragmentKind::OptExpr).make_opt_expr() } else { Some(P(noop_fold_expr(expr, self))) } } fn fold_pat(&mut self, pat: P) -> P { let pat = self.cfg.configure_pat(pat); match pat.node { PatKind::Mac(_) => {} _ => return noop_fold_pat(pat, self), } pat.and_then(|pat| match pat.node { PatKind::Mac(mac) => self.collect_bang(mac, pat.span, AstFragmentKind::Pat).make_pat(), _ => unreachable!(), }) } fn fold_stmt(&mut self, stmt: ast::Stmt) -> OneVector { let mut stmt = match self.cfg.configure_stmt(stmt) { Some(stmt) => stmt, None => return OneVector::new(), }; // we'll expand attributes on expressions separately if !stmt.is_expr() { let (attr, derives, stmt_) = if stmt.is_item() { self.classify_item(stmt) } else { // ignore derives on non-item statements so it falls through // to the unused-attributes lint let (attr, stmt) = self.classify_nonitem(stmt); (attr, vec![], stmt) }; if attr.is_some() || !derives.is_empty() { return self.collect_attr(attr, derives, Annotatable::Stmt(P(stmt_)), AstFragmentKind::Stmts) .make_stmts(); } stmt = stmt_; } 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_fold_stmt_kind(node, self).into_iter().map(|node| { ast::Stmt { id, node, span } }).collect() } fn fold_block(&mut self, block: P) -> P { let old_directory_ownership = self.cx.current_expansion.directory_ownership; self.cx.current_expansion.directory_ownership = DirectoryOwnership::UnownedViaBlock; let result = noop_fold_block(block, self); self.cx.current_expansion.directory_ownership = old_directory_ownership; result } fn fold_item(&mut self, item: P) -> OneVector> { let item = configure!(self, item); let (attr, traits, mut item) = self.classify_item(item); if attr.is_some() || !traits.is_empty() { let item = Annotatable::Item(item); return self.collect_attr(attr, traits, item, AstFragmentKind::Items).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 == keywords::Invalid.ident() { return self.fold_nameable(item); } 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 (c.f. `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, "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 = self.fold_nameable(item); self.cx.current_expansion.module = orig_module; self.cx.current_expansion.directory_ownership = orig_directory_ownership; result } // Ensure that test functions are accessible from the test harness. // #[test] fn foo() {} // becomes: // #[test] pub fn foo_gensym(){} // #[allow(unused)] // use foo_gensym as foo; ast::ItemKind::Fn(..) if self.cx.ecfg.should_test => { if self.tests_nameable && item.attrs.iter().any(|attr| is_test_or_bench(attr)) { let orig_ident = item.ident; let orig_vis = item.vis.clone(); // Publicize the item under gensymed name to avoid pollution item = item.map(|mut item| { item.vis = respan(item.vis.span, ast::VisibilityKind::Public); item.ident = item.ident.gensym(); item }); // Use the gensymed name under the item's original visibility let mut use_item = self.cx.item_use_simple_( item.ident.span, orig_vis, Some(orig_ident), self.cx.path(item.ident.span, vec![keywords::SelfValue.ident(), item.ident])); // #[allow(unused)] because the test function probably isn't being referenced use_item = use_item.map(|mut ui| { ui.attrs.push( self.cx.attribute(DUMMY_SP, attr::mk_list_item(DUMMY_SP, Ident::from_str("allow"), vec![ attr::mk_nested_word_item(Ident::from_str("unused")) ] )) ); ui }); OneVector::from_iter( self.fold_unnameable(item).into_iter() .chain(self.fold_unnameable(use_item))) } else { self.fold_unnameable(item) } } _ => self.fold_unnameable(item), } } fn fold_trait_item(&mut self, item: ast::TraitItem) -> OneVector { let item = configure!(self, item); let (attr, traits, item) = self.classify_item(item); if attr.is_some() || !traits.is_empty() { let item = Annotatable::TraitItem(P(item)); return self.collect_attr(attr, traits, item, AstFragmentKind::TraitItems) .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() } _ => fold::noop_fold_trait_item(item, self), } } fn fold_impl_item(&mut self, item: ast::ImplItem) -> OneVector { let item = configure!(self, item); let (attr, traits, item) = self.classify_item(item); if attr.is_some() || !traits.is_empty() { let item = Annotatable::ImplItem(P(item)); return self.collect_attr(attr, traits, item, AstFragmentKind::ImplItems) .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() } _ => fold::noop_fold_impl_item(item, self), } } fn fold_ty(&mut self, ty: P) -> P { let ty = match ty.node { ast::TyKind::Mac(_) => ty.into_inner(), _ => return fold::noop_fold_ty(ty, self), }; match ty.node { ast::TyKind::Mac(mac) => self.collect_bang(mac, ty.span, AstFragmentKind::Ty).make_ty(), _ => unreachable!(), } } fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod { noop_fold_foreign_mod(self.cfg.configure_foreign_mod(foreign_mod), self) } fn fold_foreign_item(&mut self, foreign_item: ast::ForeignItem) -> OneVector { let (attr, traits, foreign_item) = self.classify_item(foreign_item); if attr.is_some() || !traits.is_empty() { let item = Annotatable::ForeignItem(P(foreign_item)); return self.collect_attr(attr, traits, item, AstFragmentKind::ForeignItems) .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_fold_foreign_item(foreign_item, self) } fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind { match item { ast::ItemKind::MacroDef(..) => item, _ => noop_fold_item_kind(self.cfg.configure_item_kind(item), self), } } fn fold_generic_param(&mut self, param: ast::GenericParam) -> ast::GenericParam { self.cfg.disallow_cfg_on_generic_param(¶m); noop_fold_generic_param(param, self) } fn fold_attribute(&mut self, at: ast::Attribute) -> Option { // turn `#[doc(include="filename")]` attributes into `#[doc(include(file="filename", // contents="file contents")]` attributes if !at.check_name("doc") { return noop_fold_attribute(at, self); } if let Some(list) = at.meta_item_list() { if !list.iter().any(|it| it.check_name("include")) { return noop_fold_attribute(at, self); } let mut items = vec![]; for it in list { if !it.check_name("include") { items.push(noop_fold_meta_list_item(it, self)); 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_fold_attribute(at, self); } let mut buf = vec![]; let filename = self.cx.root_path.join(file.to_string()); match File::open(&filename).and_then(|mut f| f.read_to_end(&mut buf)) { Ok(..) => {} Err(e) => { self.cx.span_err(at.span, &format!("couldn't read {}: {}", filename.display(), e)); } } match String::from_utf8(buf) { 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![ dummy_spanned(ast::NestedMetaItemKind::MetaItem( attr::mk_name_value_item_str(Ident::from_str("file"), dummy_spanned(file)))), dummy_spanned(ast::NestedMetaItemKind::MetaItem( attr::mk_name_value_item_str(Ident::from_str("contents"), dummy_spanned(src_interned)))), ]; let include_ident = Ident::from_str("include"); let item = attr::mk_list_item(DUMMY_SP, include_ident, include_info); items.push(dummy_spanned(ast::NestedMetaItemKind::MetaItem(item))); } Err(_) => { self.cx.span_err(at.span, &format!("{} wasn't a utf-8 file", filename.display())); } } } else { items.push(noop_fold_meta_list_item(it, self)); } } let meta = attr::mk_list_item(DUMMY_SP, Ident::from_str("doc"), items); match at.style { ast::AttrStyle::Inner => Some(attr::mk_spanned_attr_inner(at.span, at.id, meta)), ast::AttrStyle::Outer => Some(attr::mk_spanned_attr_outer(at.span, at.id, meta)), } } else { noop_fold_attribute(at, self) } } fn new_id(&mut self, id: ast::NodeId) -> ast::NodeId { if self.monotonic { assert_eq!(id, ast::DUMMY_NODE_ID); self.cx.resolver.next_node_id() } else { 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_quotes = quote, fn enable_asm = asm, 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_custom_derive = custom_derive, fn enable_format_args_nl = format_args_nl, fn macros_in_extern_enabled = macros_in_extern, fn proc_macro_mod = proc_macro_mod, fn proc_macro_gen = proc_macro_gen, fn proc_macro_expr = proc_macro_expr, fn proc_macro_non_items = proc_macro_non_items, } } // A Marker adds the given mark to the syntax context. #[derive(Debug)] pub struct Marker(pub Mark); impl Folder for Marker { fn new_span(&mut self, span: Span) -> Span { span.apply_mark(self.0) } fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac { noop_fold_mac(mac, self) } }