| // 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, 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<P<ast::Expr>>), |
| $($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<dyn MacResult + 'a>) -> Option<AstFragment> { |
| 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<P<ast::Expr>> { |
| 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<F: Folder>(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<ast::Expr>) -> Option<P<ast::Expr>> { |
| 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<ast::Expr>) { "expression"; one fn fold_expr; fn visit_expr; fn make_expr; } |
| Pat(P<ast::Pat>) { "pattern"; one fn fold_pat; fn visit_pat; fn make_pat; } |
| Ty(P<ast::Ty>) { "type"; one fn fold_ty; fn visit_ty; fn make_ty; } |
| Stmts(OneVector<ast::Stmt>) { "statement"; many fn fold_stmt; fn visit_stmt; fn make_stmts; } |
| Items(OneVector<P<ast::Item>>) { "item"; many fn fold_item; fn visit_item; fn make_items; } |
| TraitItems(OneVector<ast::TraitItem>) { |
| "trait item"; many fn fold_trait_item; fn visit_trait_item; fn make_trait_items; |
| } |
| ImplItems(OneVector<ast::ImplItem>) { |
| "impl item"; many fn fold_impl_item; fn visit_impl_item; fn make_impl_items; |
| } |
| ForeignItems(OneVector<ast::ForeignItem>) { |
| "foreign item"; many fn fold_foreign_item; fn visit_foreign_item; fn make_foreign_items; |
| } |
| } |
| |
| impl AstFragmentKind { |
| fn dummy(self, span: Span) -> Option<AstFragment> { |
| self.make_from(DummyResult::any(span)) |
| } |
| |
| fn expect_from_annotatables<I: IntoIterator<Item = Annotatable>>(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<Ident>, |
| span: Span, |
| }, |
| Attr { |
| attr: Option<ast::Attribute>, |
| traits: Vec<Path>, |
| 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<Mark, Vec<_>> = 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::<Vec<_>>(); |
| 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<Invocation>) { |
| 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<AstFragment> { |
| 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<AstFragment> { |
| 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<AstFragment>) { |
| if self.cx.ecfg.proc_macro_gen() { |
| return |
| } |
| let fragment = match fragment { |
| Some(fragment) => fragment, |
| None => return, |
| }; |
| |
| fragment.visit_with(&mut DisallowModules { |
| span, |
| parse_sess: self.cx.parse_sess, |
| }); |
| |
| struct DisallowModules<'a> { |
| span: Span, |
| parse_sess: &'a ParseSess, |
| } |
| |
| impl<'ast, 'a> Visitor<'ast> for DisallowModules<'a> { |
| fn visit_item(&mut self, i: &'ast ast::Item) { |
| let name = match i.node { |
| ast::ItemKind::Mod(_) => Some("modules"), |
| ast::ItemKind::MacroDef(_) => Some("macro definitions"), |
| _ => None, |
| }; |
| if let Some(name) = name { |
| emit_feature_err( |
| self.parse_sess, |
| "proc_macro_gen", |
| self.span, |
| GateIssue::Language, |
| &format!("procedural macros cannot expand to {}", name), |
| ); |
| } |
| 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<AstFragment> { |
| 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<Span>, |
| 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<AstFragment> { |
| 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<AstFragment> { |
| let mut parser = self.cx.new_parser_from_tts(&toks.into_trees().collect::<Vec<_>>()); |
| 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<Invocation>, |
| 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<ast::Item>) -> OneVector<P<ast::Item>> { |
| 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<ast::Item>) -> OneVector<P<ast::Item>> { |
| 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<ast::Attribute>, |
| traits: Vec<Path>, |
| 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<T>(&mut self, mut item: T) -> (Option<ast::Attribute>, Vec<Path>, 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<T: HasAttrs>(&mut self, mut item: T) -> (Option<ast::Attribute>, 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<T: HasAttrs>(&mut self, node: T) -> Option<T> { |
| self.cfg.configure(node) |
| } |
| |
| // Detect use of feature-gated or invalid attributes on macro invocations |
| // since they will not be detected after macro expansion. |
| fn check_attributes(&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<ast::Attribute>) -> Option<ast::Attribute> { |
| 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<ast::Expr>) -> P<ast::Expr> { |
| 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<ast::Expr>) -> Option<P<ast::Expr>> { |
| 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<ast::Pat>) -> P<ast::Pat> { |
| 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<ast::Stmt> { |
| 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<Block>) -> P<Block> { |
| 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<ast::Item>) -> OneVector<P<ast::Item>> { |
| 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<ast::TraitItem> { |
| 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<ast::ImplItem> { |
| 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<ast::Ty>) -> P<ast::Ty> { |
| 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<ast::ForeignItem> { |
| 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<ast::Attribute> { |
| // 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) |
| } |
| } |
