2 use crate::config::StripUnconfigured;
3 use crate::hygiene::{ExpnData, ExpnId, ExpnKind, SyntaxContext};
4 use crate::mbe::macro_rules::annotate_err_with_kind;
5 use crate::placeholders::{placeholder, PlaceholderExpander};
6 use crate::proc_macro::collect_derives;
8 use rustc_feature::Features;
9 use rustc_parse::configure;
10 use rustc_parse::parser::Parser;
11 use rustc_parse::validate_attr;
12 use rustc_parse::DirectoryOwnership;
13 use rustc_span::source_map::respan;
14 use rustc_span::symbol::{sym, Symbol};
15 use rustc_span::{FileName, Span, DUMMY_SP};
16 use syntax::ast::{self, AttrItem, Block, Ident, LitKind, NodeId, PatKind, Path};
17 use syntax::ast::{ItemKind, MacArgs, MacStmtStyle, StmtKind};
18 use syntax::attr::{self, is_builtin_attr, HasAttrs};
19 use syntax::feature_gate::{self, feature_err};
20 use syntax::mut_visit::*;
21 use syntax::print::pprust;
23 use syntax::sess::ParseSess;
25 use syntax::tokenstream::{TokenStream, TokenTree};
26 use syntax::util::map_in_place::MapInPlace;
27 use syntax::visit::{self, Visitor};
29 use errors::{Applicability, FatalError, PResult};
30 use smallvec::{smallvec, SmallVec};
32 use rustc_data_structures::sync::Lrc;
33 use std::io::ErrorKind;
34 use std::ops::DerefMut;
35 use std::path::PathBuf;
37 use std::{iter, mem, slice};
39 macro_rules! ast_fragments {
41 $($Kind:ident($AstTy:ty) {
43 $(one fn $mut_visit_ast:ident; fn $visit_ast:ident;)?
44 $(many fn $flat_map_ast_elt:ident; fn $visit_ast_elt:ident;)?
48 /// A fragment of AST that can be produced by a single macro expansion.
49 /// Can also serve as an input and intermediate result for macro expansion operations.
50 pub enum AstFragment {
51 OptExpr(Option<P<ast::Expr>>),
55 /// "Discriminant" of an AST fragment.
56 #[derive(Copy, Clone, PartialEq, Eq)]
57 pub enum AstFragmentKind {
62 impl AstFragmentKind {
63 pub fn name(self) -> &'static str {
65 AstFragmentKind::OptExpr => "expression",
66 $(AstFragmentKind::$Kind => $kind_name,)*
70 fn make_from<'a>(self, result: Box<dyn MacResult + 'a>) -> Option<AstFragment> {
72 AstFragmentKind::OptExpr =>
73 result.make_expr().map(Some).map(AstFragment::OptExpr),
74 $(AstFragmentKind::$Kind => result.$make_ast().map(AstFragment::$Kind),)*
80 pub fn add_placeholders(&mut self, placeholders: &[NodeId]) {
81 if placeholders.is_empty() {
85 $($(AstFragment::$Kind(ast) => ast.extend(placeholders.iter().flat_map(|id| {
86 // We are repeating through arguments with `many`, to do that we have to
87 // mention some macro variable from those arguments even if it's not used.
88 macro _repeating($flat_map_ast_elt) {}
89 placeholder(AstFragmentKind::$Kind, *id, None).$make_ast()
91 _ => panic!("unexpected AST fragment kind")
95 pub fn make_opt_expr(self) -> Option<P<ast::Expr>> {
97 AstFragment::OptExpr(expr) => expr,
98 _ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
102 $(pub fn $make_ast(self) -> $AstTy {
104 AstFragment::$Kind(ast) => ast,
105 _ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
109 pub fn mut_visit_with<F: MutVisitor>(&mut self, vis: &mut F) {
111 AstFragment::OptExpr(opt_expr) => {
112 visit_clobber(opt_expr, |opt_expr| {
113 if let Some(expr) = opt_expr {
114 vis.filter_map_expr(expr)
120 $($(AstFragment::$Kind(ast) => vis.$mut_visit_ast(ast),)?)*
121 $($(AstFragment::$Kind(ast) =>
122 ast.flat_map_in_place(|ast| vis.$flat_map_ast_elt(ast)),)?)*
126 pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
128 AstFragment::OptExpr(Some(ref expr)) => visitor.visit_expr(expr),
129 AstFragment::OptExpr(None) => {}
130 $($(AstFragment::$Kind(ref ast) => visitor.$visit_ast(ast),)?)*
131 $($(AstFragment::$Kind(ref ast) => for ast_elt in &ast[..] {
132 visitor.$visit_ast_elt(ast_elt);
138 impl<'a> MacResult for crate::mbe::macro_rules::ParserAnyMacro<'a> {
139 $(fn $make_ast(self: Box<crate::mbe::macro_rules::ParserAnyMacro<'a>>)
141 Some(self.make(AstFragmentKind::$Kind).$make_ast())
148 Expr(P<ast::Expr>) { "expression"; one fn visit_expr; fn visit_expr; fn make_expr; }
149 Pat(P<ast::Pat>) { "pattern"; one fn visit_pat; fn visit_pat; fn make_pat; }
150 Ty(P<ast::Ty>) { "type"; one fn visit_ty; fn visit_ty; fn make_ty; }
151 Stmts(SmallVec<[ast::Stmt; 1]>) {
152 "statement"; many fn flat_map_stmt; fn visit_stmt; fn make_stmts;
154 Items(SmallVec<[P<ast::Item>; 1]>) {
155 "item"; many fn flat_map_item; fn visit_item; fn make_items;
157 TraitItems(SmallVec<[ast::AssocItem; 1]>) {
158 "trait item"; many fn flat_map_trait_item; fn visit_trait_item; fn make_trait_items;
160 ImplItems(SmallVec<[ast::AssocItem; 1]>) {
161 "impl item"; many fn flat_map_impl_item; fn visit_impl_item; fn make_impl_items;
163 ForeignItems(SmallVec<[ast::ForeignItem; 1]>) {
165 many fn flat_map_foreign_item;
166 fn visit_foreign_item;
167 fn make_foreign_items;
169 Arms(SmallVec<[ast::Arm; 1]>) {
170 "match arm"; many fn flat_map_arm; fn visit_arm; fn make_arms;
172 Fields(SmallVec<[ast::Field; 1]>) {
173 "field expression"; many fn flat_map_field; fn visit_field; fn make_fields;
175 FieldPats(SmallVec<[ast::FieldPat; 1]>) {
177 many fn flat_map_field_pattern;
178 fn visit_field_pattern;
179 fn make_field_patterns;
181 GenericParams(SmallVec<[ast::GenericParam; 1]>) {
183 many fn flat_map_generic_param;
184 fn visit_generic_param;
185 fn make_generic_params;
187 Params(SmallVec<[ast::Param; 1]>) {
188 "function parameter"; many fn flat_map_param; fn visit_param; fn make_params;
190 StructFields(SmallVec<[ast::StructField; 1]>) {
192 many fn flat_map_struct_field;
193 fn visit_struct_field;
194 fn make_struct_fields;
196 Variants(SmallVec<[ast::Variant; 1]>) {
197 "variant"; many fn flat_map_variant; fn visit_variant; fn make_variants;
201 impl AstFragmentKind {
202 fn dummy(self, span: Span) -> AstFragment {
203 self.make_from(DummyResult::any(span)).expect("couldn't create a dummy AST fragment")
206 fn expect_from_annotatables<I: IntoIterator<Item = Annotatable>>(
210 let mut items = items.into_iter();
212 AstFragmentKind::Arms => {
213 AstFragment::Arms(items.map(Annotatable::expect_arm).collect())
215 AstFragmentKind::Fields => {
216 AstFragment::Fields(items.map(Annotatable::expect_field).collect())
218 AstFragmentKind::FieldPats => {
219 AstFragment::FieldPats(items.map(Annotatable::expect_field_pattern).collect())
221 AstFragmentKind::GenericParams => {
222 AstFragment::GenericParams(items.map(Annotatable::expect_generic_param).collect())
224 AstFragmentKind::Params => {
225 AstFragment::Params(items.map(Annotatable::expect_param).collect())
227 AstFragmentKind::StructFields => {
228 AstFragment::StructFields(items.map(Annotatable::expect_struct_field).collect())
230 AstFragmentKind::Variants => {
231 AstFragment::Variants(items.map(Annotatable::expect_variant).collect())
233 AstFragmentKind::Items => {
234 AstFragment::Items(items.map(Annotatable::expect_item).collect())
236 AstFragmentKind::ImplItems => {
237 AstFragment::ImplItems(items.map(Annotatable::expect_impl_item).collect())
239 AstFragmentKind::TraitItems => {
240 AstFragment::TraitItems(items.map(Annotatable::expect_trait_item).collect())
242 AstFragmentKind::ForeignItems => {
243 AstFragment::ForeignItems(items.map(Annotatable::expect_foreign_item).collect())
245 AstFragmentKind::Stmts => {
246 AstFragment::Stmts(items.map(Annotatable::expect_stmt).collect())
248 AstFragmentKind::Expr => AstFragment::Expr(
249 items.next().expect("expected exactly one expression").expect_expr(),
251 AstFragmentKind::OptExpr => {
252 AstFragment::OptExpr(items.next().map(Annotatable::expect_expr))
254 AstFragmentKind::Pat | AstFragmentKind::Ty => {
255 panic!("patterns and types aren't annotatable")
261 pub struct Invocation {
262 pub kind: InvocationKind,
263 pub fragment_kind: AstFragmentKind,
264 pub expansion_data: ExpansionData,
267 pub enum InvocationKind {
273 attr: ast::Attribute,
275 // Required for resolving derive helper attributes.
277 // We temporarily report errors for attribute macros placed after derives
284 /// "Invocation" that contains all derives from an item,
285 /// broken into multiple `Derive` invocations when expanded.
286 /// FIXME: Find a way to remove it.
293 impl InvocationKind {
294 fn placeholder_visibility(&self) -> Option<ast::Visibility> {
295 // HACK: For unnamed fields placeholders should have the same visibility as the actual
296 // fields because for tuple structs/variants resolve determines visibilities of their
297 // constructor using these field visibilities before attributes on them are are expanded.
298 // The assumption is that the attribute expansion cannot change field visibilities,
299 // and it holds because only inert attributes are supported in this position.
301 InvocationKind::Attr { item: Annotatable::StructField(field), .. }
302 | InvocationKind::Derive { item: Annotatable::StructField(field), .. }
303 | InvocationKind::DeriveContainer { item: Annotatable::StructField(field), .. }
304 if field.ident.is_none() =>
306 Some(field.vis.clone())
314 pub fn span(&self) -> Span {
316 InvocationKind::Bang { span, .. } => *span,
317 InvocationKind::Attr { attr, .. } => attr.span,
318 InvocationKind::Derive { path, .. } => path.span,
319 InvocationKind::DeriveContainer { item, .. } => item.span(),
324 pub struct MacroExpander<'a, 'b> {
325 pub cx: &'a mut ExtCtxt<'b>,
326 monotonic: bool, // cf. `cx.monotonic_expander()`
329 impl<'a, 'b> MacroExpander<'a, 'b> {
330 pub fn new(cx: &'a mut ExtCtxt<'b>, monotonic: bool) -> Self {
331 MacroExpander { cx, monotonic }
334 pub fn expand_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
335 let mut module = ModuleData {
336 mod_path: vec![Ident::from_str(&self.cx.ecfg.crate_name)],
337 directory: match self.cx.source_map().span_to_unmapped_path(krate.span) {
338 FileName::Real(path) => path,
339 other => PathBuf::from(other.to_string()),
342 module.directory.pop();
343 self.cx.root_path = module.directory.clone();
344 self.cx.current_expansion.module = Rc::new(module);
346 let orig_mod_span = krate.module.inner;
348 let krate_item = AstFragment::Items(smallvec![P(ast::Item {
351 kind: ast::ItemKind::Mod(krate.module),
352 ident: Ident::invalid(),
353 id: ast::DUMMY_NODE_ID,
354 vis: respan(krate.span.shrink_to_lo(), ast::VisibilityKind::Public),
358 match self.fully_expand_fragment(krate_item).make_items().pop().map(P::into_inner) {
359 Some(ast::Item { attrs, kind: ast::ItemKind::Mod(module), .. }) => {
361 krate.module = module;
364 // Resolution failed so we return an empty expansion
365 krate.attrs = vec![];
366 krate.module = ast::Mod { inner: orig_mod_span, items: vec![], inline: true };
370 self.cx.trace_macros_diag();
374 // Recursively expand all macro invocations in this AST fragment.
375 pub fn fully_expand_fragment(&mut self, input_fragment: AstFragment) -> AstFragment {
376 let orig_expansion_data = self.cx.current_expansion.clone();
377 self.cx.current_expansion.depth = 0;
379 // Collect all macro invocations and replace them with placeholders.
380 let (mut fragment_with_placeholders, mut invocations) =
381 self.collect_invocations(input_fragment, &[]);
383 // Optimization: if we resolve all imports now,
384 // we'll be able to immediately resolve most of imported macros.
385 self.resolve_imports();
387 // Resolve paths in all invocations and produce output expanded fragments for them, but
388 // do not insert them into our input AST fragment yet, only store in `expanded_fragments`.
389 // The output fragments also go through expansion recursively until no invocations are left.
390 // Unresolved macros produce dummy outputs as a recovery measure.
391 invocations.reverse();
392 let mut expanded_fragments = Vec::new();
393 let mut undetermined_invocations = Vec::new();
394 let (mut progress, mut force) = (false, !self.monotonic);
396 let invoc = if let Some(invoc) = invocations.pop() {
399 self.resolve_imports();
400 if undetermined_invocations.is_empty() {
403 invocations = mem::take(&mut undetermined_invocations);
404 force = !mem::replace(&mut progress, false);
408 let eager_expansion_root =
409 if self.monotonic { invoc.expansion_data.id } else { orig_expansion_data.id };
410 let res = match self.cx.resolver.resolve_macro_invocation(
412 eager_expansion_root,
416 Err(Indeterminate) => {
417 undetermined_invocations.push(invoc);
423 let ExpansionData { depth, id: expn_id, .. } = invoc.expansion_data;
424 self.cx.current_expansion = invoc.expansion_data.clone();
426 // FIXME(jseyfried): Refactor out the following logic
427 let (expanded_fragment, new_invocations) = match res {
428 InvocationRes::Single(ext) => {
429 let fragment = self.expand_invoc(invoc, &ext.kind);
430 self.collect_invocations(fragment, &[])
432 InvocationRes::DeriveContainer(_exts) => {
433 // FIXME: Consider using the derive resolutions (`_exts`) immediately,
434 // instead of enqueuing the derives to be resolved again later.
435 let (derives, item) = match invoc.kind {
436 InvocationKind::DeriveContainer { derives, item } => (derives, item),
439 if !item.derive_allowed() {
440 let attr = attr::find_by_name(item.attrs(), sym::derive)
441 .expect("`derive` attribute should exist");
442 let span = attr.span;
443 let mut err = self.cx.struct_span_err(
445 "`derive` may only be applied to structs, enums and unions",
447 if let ast::AttrStyle::Inner = attr.style {
448 let trait_list = derives
450 .map(|t| pprust::path_to_string(t))
451 .collect::<Vec<_>>();
452 let suggestion = format!("#[derive({})]", trait_list.join(", "));
455 "try an outer attribute",
457 // We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT
458 Applicability::MaybeIncorrect,
464 let mut item = self.fully_configure(item);
465 item.visit_attrs(|attrs| attrs.retain(|a| !a.has_name(sym::derive)));
467 let mut derive_placeholders = Vec::with_capacity(derives.len());
468 invocations.reserve(derives.len());
469 for path in derives {
470 let expn_id = ExpnId::fresh(None);
471 derive_placeholders.push(NodeId::placeholder_from_expn_id(expn_id));
472 invocations.push(Invocation {
473 kind: InvocationKind::Derive { path, item: item.clone() },
474 fragment_kind: invoc.fragment_kind,
475 expansion_data: ExpansionData {
477 ..invoc.expansion_data.clone()
482 invoc.fragment_kind.expect_from_annotatables(::std::iter::once(item));
483 self.collect_invocations(fragment, &derive_placeholders)
487 if expanded_fragments.len() < depth {
488 expanded_fragments.push(Vec::new());
490 expanded_fragments[depth - 1].push((expn_id, expanded_fragment));
491 if !self.cx.ecfg.single_step {
492 invocations.extend(new_invocations.into_iter().rev());
496 self.cx.current_expansion = orig_expansion_data;
498 // Finally incorporate all the expanded macros into the input AST fragment.
499 let mut placeholder_expander = PlaceholderExpander::new(self.cx, self.monotonic);
500 while let Some(expanded_fragments) = expanded_fragments.pop() {
501 for (expn_id, expanded_fragment) in expanded_fragments.into_iter().rev() {
503 .add(NodeId::placeholder_from_expn_id(expn_id), expanded_fragment);
506 fragment_with_placeholders.mut_visit_with(&mut placeholder_expander);
507 fragment_with_placeholders
510 fn resolve_imports(&mut self) {
512 self.cx.resolver.resolve_imports();
516 /// Collects all macro invocations reachable at this time in this AST fragment, and replace
517 /// them with "placeholders" - dummy macro invocations with specially crafted `NodeId`s.
518 /// Then call into resolver that builds a skeleton ("reduced graph") of the fragment and
519 /// prepares data for resolving paths of macro invocations.
520 fn collect_invocations(
522 mut fragment: AstFragment,
523 extra_placeholders: &[NodeId],
524 ) -> (AstFragment, Vec<Invocation>) {
525 // Resolve `$crate`s in the fragment for pretty-printing.
526 self.cx.resolver.resolve_dollar_crates();
529 let mut collector = InvocationCollector {
530 cfg: StripUnconfigured {
531 sess: self.cx.parse_sess,
532 features: self.cx.ecfg.features,
535 invocations: Vec::new(),
536 monotonic: self.monotonic,
538 fragment.mut_visit_with(&mut collector);
539 fragment.add_placeholders(extra_placeholders);
540 collector.invocations
546 .visit_ast_fragment_with_placeholders(self.cx.current_expansion.id, &fragment);
549 (fragment, invocations)
552 fn fully_configure(&mut self, item: Annotatable) -> Annotatable {
554 StripUnconfigured { sess: self.cx.parse_sess, features: self.cx.ecfg.features };
555 // Since the item itself has already been configured by the InvocationCollector,
556 // we know that fold result vector will contain exactly one element
558 Annotatable::Item(item) => Annotatable::Item(cfg.flat_map_item(item).pop().unwrap()),
559 Annotatable::TraitItem(item) => Annotatable::TraitItem(
560 item.map(|item| cfg.flat_map_trait_item(item).pop().unwrap()),
562 Annotatable::ImplItem(item) => {
563 Annotatable::ImplItem(item.map(|item| cfg.flat_map_impl_item(item).pop().unwrap()))
565 Annotatable::ForeignItem(item) => Annotatable::ForeignItem(
566 item.map(|item| cfg.flat_map_foreign_item(item).pop().unwrap()),
568 Annotatable::Stmt(stmt) => {
569 Annotatable::Stmt(stmt.map(|stmt| cfg.flat_map_stmt(stmt).pop().unwrap()))
571 Annotatable::Expr(mut expr) => Annotatable::Expr({
572 cfg.visit_expr(&mut expr);
575 Annotatable::Arm(arm) => Annotatable::Arm(cfg.flat_map_arm(arm).pop().unwrap()),
576 Annotatable::Field(field) => {
577 Annotatable::Field(cfg.flat_map_field(field).pop().unwrap())
579 Annotatable::FieldPat(fp) => {
580 Annotatable::FieldPat(cfg.flat_map_field_pattern(fp).pop().unwrap())
582 Annotatable::GenericParam(param) => {
583 Annotatable::GenericParam(cfg.flat_map_generic_param(param).pop().unwrap())
585 Annotatable::Param(param) => {
586 Annotatable::Param(cfg.flat_map_param(param).pop().unwrap())
588 Annotatable::StructField(sf) => {
589 Annotatable::StructField(cfg.flat_map_struct_field(sf).pop().unwrap())
591 Annotatable::Variant(v) => Annotatable::Variant(cfg.flat_map_variant(v).pop().unwrap()),
595 fn expand_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtensionKind) -> AstFragment {
596 if self.cx.current_expansion.depth > self.cx.ecfg.recursion_limit {
597 let expn_data = self.cx.current_expansion.id.expn_data();
598 let suggested_limit = self.cx.ecfg.recursion_limit * 2;
599 let mut err = self.cx.struct_span_err(
602 "recursion limit reached while expanding the macro `{}`",
603 expn_data.kind.descr()
607 "consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate",
611 self.cx.trace_macros_diag();
615 let (fragment_kind, span) = (invoc.fragment_kind, invoc.span());
617 InvocationKind::Bang { mac, .. } => match ext {
618 SyntaxExtensionKind::Bang(expander) => {
619 self.gate_proc_macro_expansion_kind(span, fragment_kind);
620 let tok_result = expander.expand(self.cx, span, mac.args.inner_tokens());
621 self.parse_ast_fragment(tok_result, fragment_kind, &mac.path, span)
623 SyntaxExtensionKind::LegacyBang(expander) => {
624 let prev = self.cx.current_expansion.prior_type_ascription;
625 self.cx.current_expansion.prior_type_ascription = mac.prior_type_ascription;
626 let tok_result = expander.expand(self.cx, span, mac.args.inner_tokens());
627 let result = if let Some(result) = fragment_kind.make_from(tok_result) {
631 "non-{kind} macro in {kind} position: {path}",
632 kind = fragment_kind.name(),
633 path = pprust::path_to_string(&mac.path),
635 self.cx.span_err(span, &msg);
636 self.cx.trace_macros_diag();
637 fragment_kind.dummy(span)
639 self.cx.current_expansion.prior_type_ascription = prev;
644 InvocationKind::Attr { attr, mut item, .. } => match ext {
645 SyntaxExtensionKind::Attr(expander) => {
646 self.gate_proc_macro_input(&item);
647 self.gate_proc_macro_attr_item(span, &item);
648 let item_tok = TokenTree::token(
649 token::Interpolated(Lrc::new(match item {
650 Annotatable::Item(item) => token::NtItem(item),
651 Annotatable::TraitItem(item) => token::NtTraitItem(item.into_inner()),
652 Annotatable::ImplItem(item) => token::NtImplItem(item.into_inner()),
653 Annotatable::ForeignItem(item) => {
654 token::NtForeignItem(item.into_inner())
656 Annotatable::Stmt(stmt) => token::NtStmt(stmt.into_inner()),
657 Annotatable::Expr(expr) => token::NtExpr(expr),
659 | Annotatable::Field(..)
660 | Annotatable::FieldPat(..)
661 | Annotatable::GenericParam(..)
662 | Annotatable::Param(..)
663 | Annotatable::StructField(..)
664 | Annotatable::Variant(..) => panic!("unexpected annotatable"),
669 let item = attr.unwrap_normal_item();
670 if let MacArgs::Eq(..) = item.args {
671 self.cx.span_err(span, "key-value macro attributes are not supported");
674 expander.expand(self.cx, span, item.args.inner_tokens(), item_tok);
675 self.parse_ast_fragment(tok_result, fragment_kind, &item.path, span)
677 SyntaxExtensionKind::LegacyAttr(expander) => {
678 match validate_attr::parse_meta(self.cx.parse_sess, &attr) {
680 let item = expander.expand(self.cx, span, &meta, item);
681 fragment_kind.expect_from_annotatables(item)
685 fragment_kind.dummy(span)
689 SyntaxExtensionKind::NonMacroAttr { mark_used } => {
690 attr::mark_known(&attr);
692 attr::mark_used(&attr);
694 item.visit_attrs(|attrs| attrs.push(attr));
695 fragment_kind.expect_from_annotatables(iter::once(item))
699 InvocationKind::Derive { path, item } => match ext {
700 SyntaxExtensionKind::Derive(expander)
701 | SyntaxExtensionKind::LegacyDerive(expander) => {
702 if !item.derive_allowed() {
703 return fragment_kind.dummy(span);
705 if let SyntaxExtensionKind::Derive(..) = ext {
706 self.gate_proc_macro_input(&item);
708 let meta = ast::MetaItem { kind: ast::MetaItemKind::Word, span, path };
709 let items = expander.expand(self.cx, span, &meta, item);
710 fragment_kind.expect_from_annotatables(items)
714 InvocationKind::DeriveContainer { .. } => unreachable!(),
718 fn gate_proc_macro_attr_item(&self, span: Span, item: &Annotatable) {
719 let kind = match item {
721 | Annotatable::TraitItem(_)
722 | Annotatable::ImplItem(_)
723 | Annotatable::ForeignItem(_) => return,
724 Annotatable::Stmt(_) => "statements",
725 Annotatable::Expr(_) => "expressions",
727 | Annotatable::Field(..)
728 | Annotatable::FieldPat(..)
729 | Annotatable::GenericParam(..)
730 | Annotatable::Param(..)
731 | Annotatable::StructField(..)
732 | Annotatable::Variant(..) => panic!("unexpected annotatable"),
734 if self.cx.ecfg.proc_macro_hygiene() {
739 sym::proc_macro_hygiene,
741 &format!("custom attributes cannot be applied to {}", kind),
746 fn gate_proc_macro_input(&self, annotatable: &Annotatable) {
747 struct GateProcMacroInput<'a> {
748 parse_sess: &'a ParseSess,
751 impl<'ast, 'a> Visitor<'ast> for GateProcMacroInput<'a> {
752 fn visit_item(&mut self, item: &'ast ast::Item) {
754 ast::ItemKind::Mod(module) if !module.inline => {
757 sym::proc_macro_hygiene,
759 "non-inline modules in proc macro input are unstable",
766 visit::walk_item(self, item);
769 fn visit_mac(&mut self, _: &'ast ast::Mac) {}
772 if !self.cx.ecfg.proc_macro_hygiene() {
773 annotatable.visit_with(&mut GateProcMacroInput { parse_sess: self.cx.parse_sess });
777 fn gate_proc_macro_expansion_kind(&self, span: Span, kind: AstFragmentKind) {
778 let kind = match kind {
779 AstFragmentKind::Expr | AstFragmentKind::OptExpr => "expressions",
780 AstFragmentKind::Pat => "patterns",
781 AstFragmentKind::Stmts => "statements",
783 | AstFragmentKind::Items
784 | AstFragmentKind::TraitItems
785 | AstFragmentKind::ImplItems
786 | AstFragmentKind::ForeignItems => return,
787 AstFragmentKind::Arms
788 | AstFragmentKind::Fields
789 | AstFragmentKind::FieldPats
790 | AstFragmentKind::GenericParams
791 | AstFragmentKind::Params
792 | AstFragmentKind::StructFields
793 | AstFragmentKind::Variants => panic!("unexpected AST fragment kind"),
795 if self.cx.ecfg.proc_macro_hygiene() {
800 sym::proc_macro_hygiene,
802 &format!("procedural macros cannot be expanded to {}", kind),
807 fn parse_ast_fragment(
810 kind: AstFragmentKind,
814 let mut parser = self.cx.new_parser_from_tts(toks);
815 match parse_ast_fragment(&mut parser, kind, false) {
817 ensure_complete_parse(&mut parser, path, kind.name(), span);
822 annotate_err_with_kind(&mut err, kind, span);
824 self.cx.trace_macros_diag();
831 pub fn parse_ast_fragment<'a>(
832 this: &mut Parser<'a>,
833 kind: AstFragmentKind,
834 macro_legacy_warnings: bool,
835 ) -> PResult<'a, AstFragment> {
837 AstFragmentKind::Items => {
838 let mut items = SmallVec::new();
839 while let Some(item) = this.parse_item()? {
842 AstFragment::Items(items)
844 AstFragmentKind::TraitItems => {
845 let mut items = SmallVec::new();
846 while this.token != token::Eof {
847 items.push(this.parse_trait_item(&mut false)?);
849 AstFragment::TraitItems(items)
851 AstFragmentKind::ImplItems => {
852 let mut items = SmallVec::new();
853 while this.token != token::Eof {
854 items.push(this.parse_impl_item(&mut false)?);
856 AstFragment::ImplItems(items)
858 AstFragmentKind::ForeignItems => {
859 let mut items = SmallVec::new();
860 while this.token != token::Eof {
861 items.push(this.parse_foreign_item(DUMMY_SP)?);
863 AstFragment::ForeignItems(items)
865 AstFragmentKind::Stmts => {
866 let mut stmts = SmallVec::new();
867 while this.token != token::Eof &&
868 // won't make progress on a `}`
869 this.token != token::CloseDelim(token::Brace)
871 if let Some(stmt) = this.parse_full_stmt(macro_legacy_warnings)? {
875 AstFragment::Stmts(stmts)
877 AstFragmentKind::Expr => AstFragment::Expr(this.parse_expr()?),
878 AstFragmentKind::OptExpr => {
879 if this.token != token::Eof {
880 AstFragment::OptExpr(Some(this.parse_expr()?))
882 AstFragment::OptExpr(None)
885 AstFragmentKind::Ty => AstFragment::Ty(this.parse_ty()?),
886 AstFragmentKind::Pat => AstFragment::Pat(this.parse_pat(None)?),
887 AstFragmentKind::Arms
888 | AstFragmentKind::Fields
889 | AstFragmentKind::FieldPats
890 | AstFragmentKind::GenericParams
891 | AstFragmentKind::Params
892 | AstFragmentKind::StructFields
893 | AstFragmentKind::Variants => panic!("unexpected AST fragment kind"),
897 pub fn ensure_complete_parse<'a>(
898 this: &mut Parser<'a>,
903 if this.token != token::Eof {
904 let token = pprust::token_to_string(&this.token);
905 let msg = format!("macro expansion ignores token `{}` and any following", token);
906 // Avoid emitting backtrace info twice.
907 let def_site_span = this.token.span.with_ctxt(SyntaxContext::root());
908 let mut err = this.struct_span_err(def_site_span, &msg);
909 err.span_label(span, "caused by the macro expansion here");
911 "the usage of `{}!` is likely invalid in {} context",
912 pprust::path_to_string(macro_path),
916 let semi_span = this.sess.source_map().next_point(span);
918 let semi_full_span = semi_span.to(this.sess.source_map().next_point(semi_span));
919 match this.sess.source_map().span_to_snippet(semi_full_span) {
920 Ok(ref snippet) if &snippet[..] != ";" && kind_name == "expression" => {
923 "you might be missing a semicolon here",
925 Applicability::MaybeIncorrect,
934 struct InvocationCollector<'a, 'b> {
935 cx: &'a mut ExtCtxt<'b>,
936 cfg: StripUnconfigured<'a>,
937 invocations: Vec<Invocation>,
941 impl<'a, 'b> InvocationCollector<'a, 'b> {
942 fn collect(&mut self, fragment_kind: AstFragmentKind, kind: InvocationKind) -> AstFragment {
943 // Expansion data for all the collected invocations is set upon their resolution,
944 // with exception of the derive container case which is not resolved and can get
945 // its expansion data immediately.
946 let expn_data = match &kind {
947 InvocationKind::DeriveContainer { item, .. } => Some(ExpnData {
948 parent: self.cx.current_expansion.id,
950 ExpnKind::Macro(MacroKind::Attr, sym::derive),
952 self.cx.parse_sess.edition,
957 let expn_id = ExpnId::fresh(expn_data);
958 let vis = kind.placeholder_visibility();
959 self.invocations.push(Invocation {
962 expansion_data: ExpansionData {
964 depth: self.cx.current_expansion.depth + 1,
965 ..self.cx.current_expansion.clone()
968 placeholder(fragment_kind, NodeId::placeholder_from_expn_id(expn_id), vis)
971 fn collect_bang(&mut self, mac: ast::Mac, span: Span, kind: AstFragmentKind) -> AstFragment {
972 self.collect(kind, InvocationKind::Bang { mac, span })
977 attr: Option<ast::Attribute>,
980 kind: AstFragmentKind,
986 Some(attr) => InvocationKind::Attr { attr, item, derives, after_derive },
987 None => InvocationKind::DeriveContainer { derives, item },
994 attrs: &mut Vec<ast::Attribute>,
995 after_derive: &mut bool,
996 ) -> Option<ast::Attribute> {
1000 if a.has_name(sym::derive) {
1001 *after_derive = true;
1003 !attr::is_known(a) && !is_builtin_attr(a)
1005 .map(|i| attrs.remove(i));
1006 if let Some(attr) = &attr {
1007 if !self.cx.ecfg.custom_inner_attributes()
1008 && attr.style == ast::AttrStyle::Inner
1009 && !attr.has_name(sym::test)
1012 &self.cx.parse_sess,
1013 sym::custom_inner_attributes,
1015 "non-builtin inner attributes are unstable",
1023 /// If `item` is an attr invocation, remove and return the macro attribute and derive traits.
1024 fn classify_item<T>(
1027 ) -> (Option<ast::Attribute>, Vec<Path>, /* after_derive */ bool)
1031 let (mut attr, mut traits, mut after_derive) = (None, Vec::new(), false);
1033 item.visit_attrs(|mut attrs| {
1034 attr = self.find_attr_invoc(&mut attrs, &mut after_derive);
1035 traits = collect_derives(&mut self.cx, &mut attrs);
1038 (attr, traits, after_derive)
1041 /// Alternative to `classify_item()` that ignores `#[derive]` so invocations fallthrough
1042 /// to the unused-attributes lint (making it an error on statements and expressions
1043 /// is a breaking change)
1044 fn classify_nonitem<T: HasAttrs>(
1047 ) -> (Option<ast::Attribute>, /* after_derive */ bool) {
1048 let (mut attr, mut after_derive) = (None, false);
1050 nonitem.visit_attrs(|mut attrs| {
1051 attr = self.find_attr_invoc(&mut attrs, &mut after_derive);
1054 (attr, after_derive)
1057 fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
1058 self.cfg.configure(node)
1061 // Detect use of feature-gated or invalid attributes on macro invocations
1062 // since they will not be detected after macro expansion.
1063 fn check_attributes(&mut self, attrs: &[ast::Attribute]) {
1064 let features = self.cx.ecfg.features.unwrap();
1065 for attr in attrs.iter() {
1066 feature_gate::check_attribute(attr, self.cx.parse_sess, features);
1067 validate_attr::check_meta(self.cx.parse_sess, attr);
1069 // macros are expanded before any lint passes so this warning has to be hardcoded
1070 if attr.has_name(sym::derive) {
1072 .struct_span_warn(attr.span, "`#[derive]` does nothing on macro invocations")
1073 .note("this may become a hard error in a future release")
1080 impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
1081 fn visit_expr(&mut self, expr: &mut P<ast::Expr>) {
1082 self.cfg.configure_expr(expr);
1083 visit_clobber(expr.deref_mut(), |mut expr| {
1084 self.cfg.configure_expr_kind(&mut expr.kind);
1086 // ignore derives so they remain unused
1087 let (attr, after_derive) = self.classify_nonitem(&mut expr);
1090 // Collect the invoc regardless of whether or not attributes are permitted here
1091 // expansion will eat the attribute so it won't error later.
1092 attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a));
1094 // AstFragmentKind::Expr requires the macro to emit an expression.
1099 Annotatable::Expr(P(expr)),
1100 AstFragmentKind::Expr,
1107 if let ast::ExprKind::Mac(mac) = expr.kind {
1108 self.check_attributes(&expr.attrs);
1109 self.collect_bang(mac, expr.span, AstFragmentKind::Expr).make_expr().into_inner()
1111 noop_visit_expr(&mut expr, self);
1117 fn flat_map_arm(&mut self, arm: ast::Arm) -> SmallVec<[ast::Arm; 1]> {
1118 let mut arm = configure!(self, arm);
1120 let (attr, traits, after_derive) = self.classify_item(&mut arm);
1121 if attr.is_some() || !traits.is_empty() {
1126 Annotatable::Arm(arm),
1127 AstFragmentKind::Arms,
1133 noop_flat_map_arm(arm, self)
1136 fn flat_map_field(&mut self, field: ast::Field) -> SmallVec<[ast::Field; 1]> {
1137 let mut field = configure!(self, field);
1139 let (attr, traits, after_derive) = self.classify_item(&mut field);
1140 if attr.is_some() || !traits.is_empty() {
1145 Annotatable::Field(field),
1146 AstFragmentKind::Fields,
1152 noop_flat_map_field(field, self)
1155 fn flat_map_field_pattern(&mut self, fp: ast::FieldPat) -> SmallVec<[ast::FieldPat; 1]> {
1156 let mut fp = configure!(self, fp);
1158 let (attr, traits, after_derive) = self.classify_item(&mut fp);
1159 if attr.is_some() || !traits.is_empty() {
1164 Annotatable::FieldPat(fp),
1165 AstFragmentKind::FieldPats,
1168 .make_field_patterns();
1171 noop_flat_map_field_pattern(fp, self)
1174 fn flat_map_param(&mut self, p: ast::Param) -> SmallVec<[ast::Param; 1]> {
1175 let mut p = configure!(self, p);
1177 let (attr, traits, after_derive) = self.classify_item(&mut p);
1178 if attr.is_some() || !traits.is_empty() {
1183 Annotatable::Param(p),
1184 AstFragmentKind::Params,
1190 noop_flat_map_param(p, self)
1193 fn flat_map_struct_field(&mut self, sf: ast::StructField) -> SmallVec<[ast::StructField; 1]> {
1194 let mut sf = configure!(self, sf);
1196 let (attr, traits, after_derive) = self.classify_item(&mut sf);
1197 if attr.is_some() || !traits.is_empty() {
1202 Annotatable::StructField(sf),
1203 AstFragmentKind::StructFields,
1206 .make_struct_fields();
1209 noop_flat_map_struct_field(sf, self)
1212 fn flat_map_variant(&mut self, variant: ast::Variant) -> SmallVec<[ast::Variant; 1]> {
1213 let mut variant = configure!(self, variant);
1215 let (attr, traits, after_derive) = self.classify_item(&mut variant);
1216 if attr.is_some() || !traits.is_empty() {
1221 Annotatable::Variant(variant),
1222 AstFragmentKind::Variants,
1228 noop_flat_map_variant(variant, self)
1231 fn filter_map_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
1232 let expr = configure!(self, expr);
1233 expr.filter_map(|mut expr| {
1234 self.cfg.configure_expr_kind(&mut expr.kind);
1236 // Ignore derives so they remain unused.
1237 let (attr, after_derive) = self.classify_nonitem(&mut expr);
1240 attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a));
1246 Annotatable::Expr(P(expr)),
1247 AstFragmentKind::OptExpr,
1251 .map(|expr| expr.into_inner());
1254 if let ast::ExprKind::Mac(mac) = expr.kind {
1255 self.check_attributes(&expr.attrs);
1256 self.collect_bang(mac, expr.span, AstFragmentKind::OptExpr)
1258 .map(|expr| expr.into_inner())
1261 noop_visit_expr(&mut expr, self);
1268 fn visit_pat(&mut self, pat: &mut P<ast::Pat>) {
1269 self.cfg.configure_pat(pat);
1271 PatKind::Mac(_) => {}
1272 _ => return noop_visit_pat(pat, self),
1275 visit_clobber(pat, |mut pat| match mem::replace(&mut pat.kind, PatKind::Wild) {
1276 PatKind::Mac(mac) => self.collect_bang(mac, pat.span, AstFragmentKind::Pat).make_pat(),
1277 _ => unreachable!(),
1281 fn flat_map_stmt(&mut self, stmt: ast::Stmt) -> SmallVec<[ast::Stmt; 1]> {
1282 let mut stmt = configure!(self, stmt);
1284 // we'll expand attributes on expressions separately
1285 if !stmt.is_expr() {
1286 let (attr, derives, after_derive) = if stmt.is_item() {
1287 self.classify_item(&mut stmt)
1289 // ignore derives on non-item statements so it falls through
1290 // to the unused-attributes lint
1291 let (attr, after_derive) = self.classify_nonitem(&mut stmt);
1292 (attr, vec![], after_derive)
1295 if attr.is_some() || !derives.is_empty() {
1300 Annotatable::Stmt(P(stmt)),
1301 AstFragmentKind::Stmts,
1308 if let StmtKind::Mac(mac) = stmt.kind {
1309 let (mac, style, attrs) = mac.into_inner();
1310 self.check_attributes(&attrs);
1311 let mut placeholder =
1312 self.collect_bang(mac, stmt.span, AstFragmentKind::Stmts).make_stmts();
1314 // If this is a macro invocation with a semicolon, then apply that
1315 // semicolon to the final statement produced by expansion.
1316 if style == MacStmtStyle::Semicolon {
1317 if let Some(stmt) = placeholder.pop() {
1318 placeholder.push(stmt.add_trailing_semicolon());
1325 // The placeholder expander gives ids to statements, so we avoid folding the id here.
1326 let ast::Stmt { id, kind, span } = stmt;
1327 noop_flat_map_stmt_kind(kind, self)
1329 .map(|kind| ast::Stmt { id, kind, span })
1333 fn visit_block(&mut self, block: &mut P<Block>) {
1334 let old_directory_ownership = self.cx.current_expansion.directory_ownership;
1335 self.cx.current_expansion.directory_ownership = DirectoryOwnership::UnownedViaBlock;
1336 noop_visit_block(block, self);
1337 self.cx.current_expansion.directory_ownership = old_directory_ownership;
1340 fn flat_map_item(&mut self, item: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
1341 let mut item = configure!(self, item);
1343 let (attr, traits, after_derive) = self.classify_item(&mut item);
1344 if attr.is_some() || !traits.is_empty() {
1349 Annotatable::Item(item),
1350 AstFragmentKind::Items,
1357 ast::ItemKind::Mac(..) => {
1358 self.check_attributes(&item.attrs);
1359 item.and_then(|item| match item.kind {
1360 ItemKind::Mac(mac) => self
1362 AstFragmentKind::Items,
1363 InvocationKind::Bang { mac, span: item.span },
1366 _ => unreachable!(),
1369 ast::ItemKind::Mod(ast::Mod { inner, .. }) => {
1370 if item.ident == Ident::invalid() {
1371 return noop_flat_map_item(item, self);
1374 let orig_directory_ownership = self.cx.current_expansion.directory_ownership;
1375 let mut module = (*self.cx.current_expansion.module).clone();
1376 module.mod_path.push(item.ident);
1378 // Detect if this is an inline module (`mod m { ... }` as opposed to `mod m;`).
1379 // In the non-inline case, `inner` is never the dummy span (cf. `parse_item_mod`).
1380 // Thus, if `inner` is the dummy span, we know the module is inline.
1381 let inline_module = item.span.contains(inner) || inner.is_dummy();
1384 if let Some(path) = attr::first_attr_value_str_by_name(&item.attrs, sym::path) {
1385 self.cx.current_expansion.directory_ownership =
1386 DirectoryOwnership::Owned { relative: None };
1387 module.directory.push(&*path.as_str());
1389 module.directory.push(&*item.ident.as_str());
1392 let path = self.cx.parse_sess.source_map().span_to_unmapped_path(inner);
1393 let mut path = match path {
1394 FileName::Real(path) => path,
1395 other => PathBuf::from(other.to_string()),
1397 let directory_ownership = match path.file_name().unwrap().to_str() {
1398 Some("mod.rs") => DirectoryOwnership::Owned { relative: None },
1399 Some(_) => DirectoryOwnership::Owned { relative: Some(item.ident) },
1400 None => DirectoryOwnership::UnownedViaMod,
1403 module.directory = path;
1404 self.cx.current_expansion.directory_ownership = directory_ownership;
1408 mem::replace(&mut self.cx.current_expansion.module, Rc::new(module));
1409 let result = noop_flat_map_item(item, self);
1410 self.cx.current_expansion.module = orig_module;
1411 self.cx.current_expansion.directory_ownership = orig_directory_ownership;
1415 _ => noop_flat_map_item(item, self),
1419 fn flat_map_trait_item(&mut self, item: ast::AssocItem) -> SmallVec<[ast::AssocItem; 1]> {
1420 let mut item = configure!(self, item);
1422 let (attr, traits, after_derive) = self.classify_item(&mut item);
1423 if attr.is_some() || !traits.is_empty() {
1428 Annotatable::TraitItem(P(item)),
1429 AstFragmentKind::TraitItems,
1432 .make_trait_items();
1436 ast::AssocItemKind::Macro(mac) => {
1437 let ast::AssocItem { attrs, span, .. } = item;
1438 self.check_attributes(&attrs);
1439 self.collect_bang(mac, span, AstFragmentKind::TraitItems).make_trait_items()
1441 _ => noop_flat_map_assoc_item(item, self),
1445 fn flat_map_impl_item(&mut self, item: ast::AssocItem) -> SmallVec<[ast::AssocItem; 1]> {
1446 let mut item = configure!(self, item);
1448 let (attr, traits, after_derive) = self.classify_item(&mut item);
1449 if attr.is_some() || !traits.is_empty() {
1454 Annotatable::ImplItem(P(item)),
1455 AstFragmentKind::ImplItems,
1462 ast::AssocItemKind::Macro(mac) => {
1463 let ast::AssocItem { attrs, span, .. } = item;
1464 self.check_attributes(&attrs);
1465 self.collect_bang(mac, span, AstFragmentKind::ImplItems).make_impl_items()
1467 _ => noop_flat_map_assoc_item(item, self),
1471 fn visit_ty(&mut self, ty: &mut P<ast::Ty>) {
1473 ast::TyKind::Mac(_) => {}
1474 _ => return noop_visit_ty(ty, self),
1477 visit_clobber(ty, |mut ty| match mem::replace(&mut ty.kind, ast::TyKind::Err) {
1478 ast::TyKind::Mac(mac) => self.collect_bang(mac, ty.span, AstFragmentKind::Ty).make_ty(),
1479 _ => unreachable!(),
1483 fn visit_foreign_mod(&mut self, foreign_mod: &mut ast::ForeignMod) {
1484 self.cfg.configure_foreign_mod(foreign_mod);
1485 noop_visit_foreign_mod(foreign_mod, self);
1488 fn flat_map_foreign_item(
1490 mut foreign_item: ast::ForeignItem,
1491 ) -> SmallVec<[ast::ForeignItem; 1]> {
1492 let (attr, traits, after_derive) = self.classify_item(&mut foreign_item);
1494 if attr.is_some() || !traits.is_empty() {
1499 Annotatable::ForeignItem(P(foreign_item)),
1500 AstFragmentKind::ForeignItems,
1503 .make_foreign_items();
1506 if let ast::ForeignItemKind::Macro(mac) = foreign_item.kind {
1507 self.check_attributes(&foreign_item.attrs);
1509 .collect_bang(mac, foreign_item.span, AstFragmentKind::ForeignItems)
1510 .make_foreign_items();
1513 noop_flat_map_foreign_item(foreign_item, self)
1516 fn visit_item_kind(&mut self, item: &mut ast::ItemKind) {
1518 ast::ItemKind::MacroDef(..) => {}
1520 self.cfg.configure_item_kind(item);
1521 noop_visit_item_kind(item, self);
1526 fn flat_map_generic_param(
1528 param: ast::GenericParam,
1529 ) -> SmallVec<[ast::GenericParam; 1]> {
1530 let mut param = configure!(self, param);
1532 let (attr, traits, after_derive) = self.classify_item(&mut param);
1533 if attr.is_some() || !traits.is_empty() {
1538 Annotatable::GenericParam(param),
1539 AstFragmentKind::GenericParams,
1542 .make_generic_params();
1545 noop_flat_map_generic_param(param, self)
1548 fn visit_attribute(&mut self, at: &mut ast::Attribute) {
1549 // turn `#[doc(include="filename")]` attributes into `#[doc(include(file="filename",
1550 // contents="file contents")]` attributes
1551 if !at.check_name(sym::doc) {
1552 return noop_visit_attribute(at, self);
1555 if let Some(list) = at.meta_item_list() {
1556 if !list.iter().any(|it| it.check_name(sym::include)) {
1557 return noop_visit_attribute(at, self);
1560 let mut items = vec![];
1562 for mut it in list {
1563 if !it.check_name(sym::include) {
1565 noop_visit_meta_list_item(&mut it, self);
1571 if let Some(file) = it.value_str() {
1572 let err_count = self.cx.parse_sess.span_diagnostic.err_count();
1573 self.check_attributes(slice::from_ref(at));
1574 if self.cx.parse_sess.span_diagnostic.err_count() > err_count {
1575 // avoid loading the file if they haven't enabled the feature
1576 return noop_visit_attribute(at, self);
1579 let filename = match self.cx.resolve_path(&*file.as_str(), it.span()) {
1580 Ok(filename) => filename,
1587 match self.cx.source_map().load_file(&filename) {
1588 Ok(source_file) => {
1589 let src = source_file
1592 .expect("freshly loaded file should have a source");
1593 let src_interned = Symbol::intern(src.as_str());
1595 let include_info = vec![
1596 ast::NestedMetaItem::MetaItem(attr::mk_name_value_item_str(
1597 Ident::with_dummy_span(sym::file),
1601 ast::NestedMetaItem::MetaItem(attr::mk_name_value_item_str(
1602 Ident::with_dummy_span(sym::contents),
1608 let include_ident = Ident::with_dummy_span(sym::include);
1609 let item = attr::mk_list_item(include_ident, include_info);
1610 items.push(ast::NestedMetaItem::MetaItem(item));
1614 it.meta_item().and_then(|item| item.name_value_literal()).unwrap();
1616 if e.kind() == ErrorKind::InvalidData {
1620 &format!("{} wasn't a utf-8 file", filename.display()),
1622 .span_label(lit.span, "contains invalid utf-8")
1625 let mut err = self.cx.struct_span_err(
1627 &format!("couldn't read {}: {}", filename.display(), e),
1629 err.span_label(lit.span, "couldn't read file");
1636 let mut err = self.cx.struct_span_err(
1638 &format!("expected path to external documentation"),
1641 // Check if the user erroneously used `doc(include(...))` syntax.
1642 let literal = it.meta_item_list().and_then(|list| {
1643 if list.len() == 1 {
1644 list[0].literal().map(|literal| &literal.kind)
1650 let (path, applicability) = match &literal {
1651 Some(LitKind::Str(path, ..)) => {
1652 (path.to_string(), Applicability::MachineApplicable)
1654 _ => (String::from("<path>"), Applicability::HasPlaceholders),
1657 err.span_suggestion(
1659 "provide a file path with `=`",
1660 format!("include = \"{}\"", path),
1668 let meta = attr::mk_list_item(Ident::with_dummy_span(sym::doc), items);
1669 *at = attr::Attribute {
1670 kind: ast::AttrKind::Normal(AttrItem {
1672 args: meta.kind.mac_args(meta.span),
1679 noop_visit_attribute(at, self)
1683 fn visit_id(&mut self, id: &mut ast::NodeId) {
1685 debug_assert_eq!(*id, ast::DUMMY_NODE_ID);
1686 *id = self.cx.resolver.next_node_id()
1690 fn visit_fn_decl(&mut self, mut fn_decl: &mut P<ast::FnDecl>) {
1691 self.cfg.configure_fn_decl(&mut fn_decl);
1692 noop_visit_fn_decl(fn_decl, self);
1696 pub struct ExpansionConfig<'feat> {
1697 pub crate_name: String,
1698 pub features: Option<&'feat Features>,
1699 pub recursion_limit: usize,
1700 pub trace_mac: bool,
1701 pub should_test: bool, // If false, strip `#[test]` nodes
1702 pub single_step: bool,
1703 pub keep_macs: bool,
1706 impl<'feat> ExpansionConfig<'feat> {
1707 pub fn default(crate_name: String) -> ExpansionConfig<'static> {
1711 recursion_limit: 1024,
1719 fn proc_macro_hygiene(&self) -> bool {
1720 self.features.map_or(false, |features| features.proc_macro_hygiene)
1722 fn custom_inner_attributes(&self) -> bool {
1723 self.features.map_or(false, |features| features.custom_inner_attributes)