1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 use ast::{self, Block, Ident, NodeId, PatKind, Path};
12 use ast::{MacStmtStyle, StmtKind, ItemKind};
13 use attr::{self, HasAttrs};
14 use codemap::{ExpnInfo, NameAndSpan, MacroBang, MacroAttribute};
15 use config::{is_test_or_bench, StripUnconfigured};
16 use errors::FatalError;
18 use ext::derive::{add_derived_markers, collect_derives};
19 use ext::hygiene::{Mark, SyntaxContext};
20 use ext::placeholders::{placeholder, PlaceholderExpander};
21 use feature_gate::{self, Features, is_builtin_attr};
24 use parse::{DirectoryOwnership, PResult};
25 use parse::token::{self, Token};
26 use parse::parser::Parser;
31 use syntax_pos::{Span, DUMMY_SP};
32 use tokenstream::{TokenStream, TokenTree};
33 use util::small_vector::SmallVector;
36 use std::collections::HashMap;
38 use std::path::PathBuf;
41 macro_rules! expansions {
42 ($($kind:ident: $ty:ty [$($vec:ident, $ty_elt:ty)*], $kind_name:expr, .$make:ident,
43 $(.$fold:ident)* $(lift .$fold_elt:ident)*,
44 $(.$visit:ident)* $(lift .$visit_elt:ident)*;)*) => {
45 #[derive(Copy, Clone, PartialEq, Eq)]
46 pub enum ExpansionKind { OptExpr, $( $kind, )* }
47 pub enum Expansion { OptExpr(Option<P<ast::Expr>>), $( $kind($ty), )* }
50 pub fn name(self) -> &'static str {
52 ExpansionKind::OptExpr => "expression",
53 $( ExpansionKind::$kind => $kind_name, )*
57 fn make_from<'a>(self, result: Box<MacResult + 'a>) -> Option<Expansion> {
59 ExpansionKind::OptExpr => result.make_expr().map(Some).map(Expansion::OptExpr),
60 $( ExpansionKind::$kind => result.$make().map(Expansion::$kind), )*
66 pub fn make_opt_expr(self) -> Option<P<ast::Expr>> {
68 Expansion::OptExpr(expr) => expr,
69 _ => panic!("Expansion::make_* called on the wrong kind of expansion"),
72 $( pub fn $make(self) -> $ty {
74 Expansion::$kind(ast) => ast,
75 _ => panic!("Expansion::make_* called on the wrong kind of expansion"),
79 pub fn fold_with<F: Folder>(self, folder: &mut F) -> Self {
80 use self::Expansion::*;
82 OptExpr(expr) => OptExpr(expr.and_then(|expr| folder.fold_opt_expr(expr))),
83 $($( $kind(ast) => $kind(folder.$fold(ast)), )*)*
85 $kind(ast.into_iter().flat_map(|ast| folder.$fold_elt(ast)).collect())
90 pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
92 Expansion::OptExpr(Some(ref expr)) => visitor.visit_expr(expr),
93 Expansion::OptExpr(None) => {}
94 $($( Expansion::$kind(ref ast) => visitor.$visit(ast), )*)*
95 $($( Expansion::$kind(ref ast) => for ast in &ast[..] {
96 visitor.$visit_elt(ast);
102 impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
103 fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
104 self.expand(Expansion::OptExpr(Some(expr))).make_opt_expr()
106 $($(fn $fold(&mut self, node: $ty) -> $ty {
107 self.expand(Expansion::$kind(node)).$make()
109 $($(fn $fold_elt(&mut self, node: $ty_elt) -> $ty {
110 self.expand(Expansion::$kind(SmallVector::one(node))).$make()
114 impl<'a> MacResult for ::ext::tt::macro_rules::ParserAnyMacro<'a> {
115 $(fn $make(self: Box<::ext::tt::macro_rules::ParserAnyMacro<'a>>) -> Option<$ty> {
116 Some(self.make(ExpansionKind::$kind).$make())
123 Expr: P<ast::Expr> [], "expression", .make_expr, .fold_expr, .visit_expr;
124 Pat: P<ast::Pat> [], "pattern", .make_pat, .fold_pat, .visit_pat;
125 Ty: P<ast::Ty> [], "type", .make_ty, .fold_ty, .visit_ty;
126 Stmts: SmallVector<ast::Stmt> [SmallVector, ast::Stmt],
127 "statement", .make_stmts, lift .fold_stmt, lift .visit_stmt;
128 Items: SmallVector<P<ast::Item>> [SmallVector, P<ast::Item>],
129 "item", .make_items, lift .fold_item, lift .visit_item;
130 TraitItems: SmallVector<ast::TraitItem> [SmallVector, ast::TraitItem],
131 "trait item", .make_trait_items, lift .fold_trait_item, lift .visit_trait_item;
132 ImplItems: SmallVector<ast::ImplItem> [SmallVector, ast::ImplItem],
133 "impl item", .make_impl_items, lift .fold_impl_item, lift .visit_impl_item;
137 fn dummy(self, span: Span) -> Expansion {
138 self.make_from(DummyResult::any(span)).unwrap()
141 fn expect_from_annotatables<I: IntoIterator<Item = Annotatable>>(self, items: I) -> Expansion {
142 let items = items.into_iter();
144 ExpansionKind::Items =>
145 Expansion::Items(items.map(Annotatable::expect_item).collect()),
146 ExpansionKind::ImplItems =>
147 Expansion::ImplItems(items.map(Annotatable::expect_impl_item).collect()),
148 ExpansionKind::TraitItems =>
149 Expansion::TraitItems(items.map(Annotatable::expect_trait_item).collect()),
155 pub struct Invocation {
156 pub kind: InvocationKind,
157 expansion_kind: ExpansionKind,
158 pub expansion_data: ExpansionData,
161 pub enum InvocationKind {
164 ident: Option<Ident>,
168 attr: Option<ast::Attribute>,
179 fn span(&self) -> Span {
181 InvocationKind::Bang { span, .. } => span,
182 InvocationKind::Attr { attr: Some(ref attr), .. } => attr.span,
183 InvocationKind::Attr { attr: None, .. } => DUMMY_SP,
184 InvocationKind::Derive { ref path, .. } => path.span,
189 pub struct MacroExpander<'a, 'b:'a> {
190 pub cx: &'a mut ExtCtxt<'b>,
191 monotonic: bool, // c.f. `cx.monotonic_expander()`
194 impl<'a, 'b> MacroExpander<'a, 'b> {
195 pub fn new(cx: &'a mut ExtCtxt<'b>, monotonic: bool) -> Self {
196 MacroExpander { cx: cx, monotonic: monotonic }
199 pub fn expand_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
200 self.cx.crate_root = std_inject::injected_crate_name(&krate);
201 let mut module = ModuleData {
202 mod_path: vec![Ident::from_str(&self.cx.ecfg.crate_name)],
203 directory: PathBuf::from(self.cx.codemap().span_to_filename(krate.span)),
205 module.directory.pop();
206 self.cx.current_expansion.module = Rc::new(module);
208 let orig_mod_span = krate.module.inner;
210 let krate_item = Expansion::Items(SmallVector::one(P(ast::Item {
213 node: ast::ItemKind::Mod(krate.module),
214 ident: keywords::Invalid.ident(),
215 id: ast::DUMMY_NODE_ID,
216 vis: ast::Visibility::Public,
220 match self.expand(krate_item).make_items().pop().map(P::unwrap) {
221 Some(ast::Item { attrs, node: ast::ItemKind::Mod(module), .. }) => {
223 krate.module = module;
226 // Resolution failed so we return an empty expansion
227 krate.attrs = vec![];
228 krate.module = ast::Mod {
229 inner: orig_mod_span,
235 self.cx.trace_macros_diag();
239 // Fully expand all the invocations in `expansion`.
240 fn expand(&mut self, expansion: Expansion) -> Expansion {
241 let orig_expansion_data = self.cx.current_expansion.clone();
242 self.cx.current_expansion.depth = 0;
244 let (expansion, mut invocations) = self.collect_invocations(expansion, &[]);
245 self.resolve_imports();
246 invocations.reverse();
248 let mut expansions = Vec::new();
249 let mut derives = HashMap::new();
250 let mut undetermined_invocations = Vec::new();
251 let (mut progress, mut force) = (false, !self.monotonic);
253 let mut invoc = if let Some(invoc) = invocations.pop() {
256 self.resolve_imports();
257 if undetermined_invocations.is_empty() { break }
258 invocations = mem::replace(&mut undetermined_invocations, Vec::new());
259 force = !mem::replace(&mut progress, false);
264 if self.monotonic { invoc.expansion_data.mark } else { orig_expansion_data.mark };
265 let ext = match self.cx.resolver.resolve_invoc(&mut invoc, scope, force) {
266 Ok(ext) => Some(ext),
267 Err(Determinacy::Determined) => None,
268 Err(Determinacy::Undetermined) => {
269 undetermined_invocations.push(invoc);
275 let ExpansionData { depth, mark, .. } = invoc.expansion_data;
276 self.cx.current_expansion = invoc.expansion_data.clone();
278 self.cx.current_expansion.mark = scope;
279 // FIXME(jseyfried): Refactor out the following logic
280 let (expansion, new_invocations) = if let Some(ext) = ext {
281 if let Some(ext) = ext {
282 let expansion = self.expand_invoc(invoc, ext);
283 self.collect_invocations(expansion, &[])
284 } else if let InvocationKind::Attr { attr: None, traits, item } = invoc.kind {
286 .map_attrs(|mut attrs| { attrs.retain(|a| a.path != "derive"); attrs });
287 let item_with_markers =
288 add_derived_markers(&mut self.cx, item.span(), &traits, item.clone());
289 let derives = derives.entry(invoc.expansion_data.mark).or_insert_with(Vec::new);
291 for path in &traits {
292 let mark = Mark::fresh(self.cx.current_expansion.mark);
294 let item = match self.cx.resolver.resolve_macro(
295 Mark::root(), path, MacroKind::Derive, false) {
296 Ok(ext) => match *ext {
297 BuiltinDerive(..) => item_with_markers.clone(),
302 invocations.push(Invocation {
303 kind: InvocationKind::Derive { path: path.clone(), item: item },
304 expansion_kind: invoc.expansion_kind,
305 expansion_data: ExpansionData {
307 ..invoc.expansion_data.clone()
311 let expansion = invoc.expansion_kind
312 .expect_from_annotatables(::std::iter::once(item_with_markers));
313 self.collect_invocations(expansion, derives)
318 self.collect_invocations(invoc.expansion_kind.dummy(invoc.span()), &[])
321 if expansions.len() < depth {
322 expansions.push(Vec::new());
324 expansions[depth - 1].push((mark, expansion));
325 if !self.cx.ecfg.single_step {
326 invocations.extend(new_invocations.into_iter().rev());
330 self.cx.current_expansion = orig_expansion_data;
332 let mut placeholder_expander = PlaceholderExpander::new(self.cx, self.monotonic);
333 while let Some(expansions) = expansions.pop() {
334 for (mark, expansion) in expansions.into_iter().rev() {
335 let derives = derives.remove(&mark).unwrap_or_else(Vec::new);
336 placeholder_expander.add(NodeId::placeholder_from_mark(mark), expansion, derives);
340 expansion.fold_with(&mut placeholder_expander)
343 fn resolve_imports(&mut self) {
345 let err_count = self.cx.parse_sess.span_diagnostic.err_count();
346 self.cx.resolver.resolve_imports();
347 self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count;
351 fn collect_invocations(&mut self, expansion: Expansion, derives: &[Mark])
352 -> (Expansion, Vec<Invocation>) {
354 let mut collector = InvocationCollector {
355 cfg: StripUnconfigured {
356 should_test: self.cx.ecfg.should_test,
357 sess: self.cx.parse_sess,
358 features: self.cx.ecfg.features,
361 invocations: Vec::new(),
362 monotonic: self.monotonic,
364 (expansion.fold_with(&mut collector), collector.invocations)
368 let err_count = self.cx.parse_sess.span_diagnostic.err_count();
369 let mark = self.cx.current_expansion.mark;
370 self.cx.resolver.visit_expansion(mark, &result.0, derives);
371 self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count;
377 fn expand_invoc(&mut self, invoc: Invocation, ext: Rc<SyntaxExtension>) -> Expansion {
378 let result = match invoc.kind {
379 InvocationKind::Bang { .. } => self.expand_bang_invoc(invoc, ext),
380 InvocationKind::Attr { .. } => self.expand_attr_invoc(invoc, ext),
381 InvocationKind::Derive { .. } => self.expand_derive_invoc(invoc, ext),
384 if self.cx.current_expansion.depth > self.cx.ecfg.recursion_limit {
385 let info = self.cx.current_expansion.mark.expn_info().unwrap();
386 let suggested_limit = self.cx.ecfg.recursion_limit * 2;
387 let mut err = self.cx.struct_span_fatal(info.call_site,
388 &format!("recursion limit reached while expanding the macro `{}`",
389 info.callee.name()));
391 "consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate",
400 fn expand_attr_invoc(&mut self, invoc: Invocation, ext: Rc<SyntaxExtension>) -> Expansion {
401 let Invocation { expansion_kind: kind, .. } = invoc;
402 let (attr, item) = match invoc.kind {
403 InvocationKind::Attr { attr, item, .. } => (attr.unwrap(), item),
407 attr::mark_used(&attr);
408 invoc.expansion_data.mark.set_expn_info(ExpnInfo {
409 call_site: attr.span,
410 callee: NameAndSpan {
411 format: MacroAttribute(Symbol::intern(&format!("{}", attr.path))),
413 allow_internal_unstable: false,
414 allow_internal_unsafe: false,
419 MultiModifier(ref mac) => {
420 let meta = panictry!(attr.parse_meta(self.cx.parse_sess));
421 let item = mac.expand(self.cx, attr.span, &meta, item);
422 kind.expect_from_annotatables(item)
424 MultiDecorator(ref mac) => {
425 let mut items = Vec::new();
426 let meta = panictry!(attr.parse_meta(self.cx.parse_sess));
427 mac.expand(self.cx, attr.span, &meta, &item, &mut |item| items.push(item));
429 kind.expect_from_annotatables(items)
431 AttrProcMacro(ref mac) => {
432 let item_tok = TokenTree::Token(DUMMY_SP, Token::interpolated(match item {
433 Annotatable::Item(item) => token::NtItem(item),
434 Annotatable::TraitItem(item) => token::NtTraitItem(item.unwrap()),
435 Annotatable::ImplItem(item) => token::NtImplItem(item.unwrap()),
437 let tok_result = mac.expand(self.cx, attr.span, attr.tokens, item_tok);
438 self.parse_expansion(tok_result, kind, &attr.path, attr.span)
440 ProcMacroDerive(..) | BuiltinDerive(..) => {
441 self.cx.span_err(attr.span, &format!("`{}` is a derive mode", attr.path));
442 kind.dummy(attr.span)
445 let msg = &format!("macro `{}` may not be used in attributes", attr.path);
446 self.cx.span_err(attr.span, msg);
447 kind.dummy(attr.span)
452 /// Expand a macro invocation. Returns the result of expansion.
453 fn expand_bang_invoc(&mut self, invoc: Invocation, ext: Rc<SyntaxExtension>) -> Expansion {
454 let (mark, kind) = (invoc.expansion_data.mark, invoc.expansion_kind);
455 let (mac, ident, span) = match invoc.kind {
456 InvocationKind::Bang { mac, ident, span } => (mac, ident, span),
459 let path = &mac.node.path;
461 let ident = ident.unwrap_or_else(|| keywords::Invalid.ident());
462 let validate_and_set_expn_info = |def_site_span,
463 allow_internal_unstable,
464 allow_internal_unsafe| {
465 if ident.name != keywords::Invalid.name() {
466 return Err(format!("macro {}! expects no ident argument, given '{}'", path, ident));
468 mark.set_expn_info(ExpnInfo {
470 callee: NameAndSpan {
471 format: MacroBang(Symbol::intern(&format!("{}", path))),
473 allow_internal_unstable,
474 allow_internal_unsafe,
480 let opt_expanded = match *ext {
481 DeclMacro(ref expand, def_span) => {
482 if let Err(msg) = validate_and_set_expn_info(def_span.map(|(_, s)| s),
484 self.cx.span_err(path.span, &msg);
485 return kind.dummy(span);
487 kind.make_from(expand.expand(self.cx, span, mac.node.stream()))
493 allow_internal_unstable,
494 allow_internal_unsafe
496 if let Err(msg) = validate_and_set_expn_info(def_info.map(|(_, s)| s),
497 allow_internal_unstable,
498 allow_internal_unsafe) {
499 self.cx.span_err(path.span, &msg);
500 return kind.dummy(span);
502 kind.make_from(expander.expand(self.cx, span, mac.node.stream()))
505 IdentTT(ref expander, tt_span, allow_internal_unstable) => {
506 if ident.name == keywords::Invalid.name() {
507 self.cx.span_err(path.span,
508 &format!("macro {}! expects an ident argument", path));
509 return kind.dummy(span);
512 invoc.expansion_data.mark.set_expn_info(ExpnInfo {
514 callee: NameAndSpan {
515 format: MacroBang(Symbol::intern(&format!("{}", path))),
517 allow_internal_unstable,
518 allow_internal_unsafe: false,
522 let input: Vec<_> = mac.node.stream().into_trees().collect();
523 kind.make_from(expander.expand(self.cx, span, ident, input))
526 MultiDecorator(..) | MultiModifier(..) | AttrProcMacro(..) => {
527 self.cx.span_err(path.span,
528 &format!("`{}` can only be used in attributes", path));
529 return kind.dummy(span);
532 ProcMacroDerive(..) | BuiltinDerive(..) => {
533 self.cx.span_err(path.span, &format!("`{}` is a derive mode", path));
534 return kind.dummy(span);
537 ProcMacro(ref expandfun) => {
538 if ident.name != keywords::Invalid.name() {
540 format!("macro {}! expects no ident argument, given '{}'", path, ident);
541 self.cx.span_err(path.span, &msg);
542 return kind.dummy(span);
545 invoc.expansion_data.mark.set_expn_info(ExpnInfo {
547 callee: NameAndSpan {
548 format: MacroBang(Symbol::intern(&format!("{}", path))),
549 // FIXME procedural macros do not have proper span info
550 // yet, when they do, we should use it here.
552 // FIXME probably want to follow macro_rules macros here.
553 allow_internal_unstable: false,
554 allow_internal_unsafe: false,
558 let tok_result = expandfun.expand(self.cx, span, mac.node.stream());
559 Some(self.parse_expansion(tok_result, kind, path, span))
563 unwrap_or!(opt_expanded, {
564 let msg = format!("non-{kind} macro in {kind} position: {name}",
565 name = path.segments[0].identifier.name, kind = kind.name());
566 self.cx.span_err(path.span, &msg);
571 /// Expand a derive invocation. Returns the result of expansion.
572 fn expand_derive_invoc(&mut self, invoc: Invocation, ext: Rc<SyntaxExtension>) -> Expansion {
573 let Invocation { expansion_kind: kind, .. } = invoc;
574 let (path, item) = match invoc.kind {
575 InvocationKind::Derive { path, item } => (path, item),
579 let pretty_name = Symbol::intern(&format!("derive({})", path));
580 let span = path.span;
581 let attr = ast::Attribute {
583 tokens: TokenStream::empty(),
585 id: ast::AttrId(0), style: ast::AttrStyle::Outer, is_sugared_doc: false,
588 let mut expn_info = ExpnInfo {
590 callee: NameAndSpan {
591 format: MacroAttribute(pretty_name),
593 allow_internal_unstable: false,
594 allow_internal_unsafe: false,
599 ProcMacroDerive(ref ext, _) => {
600 invoc.expansion_data.mark.set_expn_info(expn_info);
601 let span = Span { ctxt: self.cx.backtrace(), ..span };
602 let dummy = ast::MetaItem { // FIXME(jseyfried) avoid this
603 name: keywords::Invalid.name(),
605 node: ast::MetaItemKind::Word,
607 kind.expect_from_annotatables(ext.expand(self.cx, span, &dummy, item))
609 BuiltinDerive(func) => {
610 expn_info.callee.allow_internal_unstable = true;
611 invoc.expansion_data.mark.set_expn_info(expn_info);
612 let span = Span { ctxt: self.cx.backtrace(), ..span };
613 let mut items = Vec::new();
614 func(self.cx, span, &attr.meta().unwrap(), &item, &mut |a| items.push(a));
615 kind.expect_from_annotatables(items)
618 let msg = &format!("macro `{}` may not be used for derive attributes", attr.path);
619 self.cx.span_err(span, msg);
625 fn parse_expansion(&mut self, toks: TokenStream, kind: ExpansionKind, path: &Path, span: Span)
627 let mut parser = self.cx.new_parser_from_tts(&toks.into_trees().collect::<Vec<_>>());
628 let expansion = match parser.parse_expansion(kind, false) {
629 Ok(expansion) => expansion,
632 return kind.dummy(span);
635 parser.ensure_complete_parse(path, kind.name(), span);
640 impl<'a> Parser<'a> {
641 pub fn parse_expansion(&mut self, kind: ExpansionKind, macro_legacy_warnings: bool)
642 -> PResult<'a, Expansion> {
644 ExpansionKind::Items => {
645 let mut items = SmallVector::new();
646 while let Some(item) = self.parse_item()? {
649 Expansion::Items(items)
651 ExpansionKind::TraitItems => {
652 let mut items = SmallVector::new();
653 while self.token != token::Eof {
654 items.push(self.parse_trait_item(&mut false)?);
656 Expansion::TraitItems(items)
658 ExpansionKind::ImplItems => {
659 let mut items = SmallVector::new();
660 while self.token != token::Eof {
661 items.push(self.parse_impl_item(&mut false)?);
663 Expansion::ImplItems(items)
665 ExpansionKind::Stmts => {
666 let mut stmts = SmallVector::new();
667 while self.token != token::Eof &&
668 // won't make progress on a `}`
669 self.token != token::CloseDelim(token::Brace) {
670 if let Some(stmt) = self.parse_full_stmt(macro_legacy_warnings)? {
674 Expansion::Stmts(stmts)
676 ExpansionKind::Expr => Expansion::Expr(self.parse_expr()?),
677 ExpansionKind::OptExpr => Expansion::OptExpr(Some(self.parse_expr()?)),
678 ExpansionKind::Ty => Expansion::Ty(self.parse_ty()?),
679 ExpansionKind::Pat => Expansion::Pat(self.parse_pat()?),
683 pub fn ensure_complete_parse(&mut self, macro_path: &Path, kind_name: &str, span: Span) {
684 if self.token != token::Eof {
685 let msg = format!("macro expansion ignores token `{}` and any following",
686 self.this_token_to_string());
687 let mut def_site_span = self.span;
688 def_site_span.ctxt = SyntaxContext::empty(); // Avoid emitting backtrace info twice.
689 let mut err = self.diagnostic().struct_span_err(def_site_span, &msg);
690 let msg = format!("caused by the macro expansion here; the usage \
691 of `{}!` is likely invalid in {} context",
692 macro_path, kind_name);
693 err.span_note(span, &msg).emit();
698 struct InvocationCollector<'a, 'b: 'a> {
699 cx: &'a mut ExtCtxt<'b>,
700 cfg: StripUnconfigured<'a>,
701 invocations: Vec<Invocation>,
705 macro_rules! fully_configure {
706 ($this:ident, $node:ident, $noop_fold:ident) => {
707 match $noop_fold($node, &mut $this.cfg).pop() {
709 None => return SmallVector::new(),
714 impl<'a, 'b> InvocationCollector<'a, 'b> {
715 fn collect(&mut self, expansion_kind: ExpansionKind, kind: InvocationKind) -> Expansion {
716 let mark = Mark::fresh(self.cx.current_expansion.mark);
717 self.invocations.push(Invocation {
720 expansion_data: ExpansionData {
722 depth: self.cx.current_expansion.depth + 1,
723 ..self.cx.current_expansion.clone()
726 placeholder(expansion_kind, NodeId::placeholder_from_mark(mark))
729 fn collect_bang(&mut self, mac: ast::Mac, span: Span, kind: ExpansionKind) -> Expansion {
730 self.collect(kind, InvocationKind::Bang { mac: mac, ident: None, span: span })
733 fn collect_attr(&mut self,
734 attr: Option<ast::Attribute>,
739 if !traits.is_empty() &&
740 (kind == ExpansionKind::TraitItems || kind == ExpansionKind::ImplItems) {
741 self.cx.span_err(traits[0].span, "`derive` can be only be applied to items");
742 return kind.expect_from_annotatables(::std::iter::once(item));
744 self.collect(kind, InvocationKind::Attr { attr: attr, traits: traits, item: item })
747 // If `item` is an attr invocation, remove and return the macro attribute.
748 fn classify_item<T>(&mut self, mut item: T) -> (Option<ast::Attribute>, Vec<Path>, T)
751 let (mut attr, mut traits) = (None, Vec::new());
753 item = item.map_attrs(|mut attrs| {
754 if let Some(legacy_attr_invoc) = self.cx.resolver.find_legacy_attr_invoc(&mut attrs) {
755 attr = Some(legacy_attr_invoc);
759 if self.cx.ecfg.proc_macro_enabled() {
760 attr = find_attr_invoc(&mut attrs);
762 traits = collect_derives(&mut self.cx, &mut attrs);
769 fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
770 self.cfg.configure(node)
773 // Detect use of feature-gated or invalid attributes on macro invocations
774 // since they will not be detected after macro expansion.
775 fn check_attributes(&mut self, attrs: &[ast::Attribute]) {
776 let features = self.cx.ecfg.features.unwrap();
777 for attr in attrs.iter() {
778 feature_gate::check_attribute(attr, self.cx.parse_sess, features);
783 pub fn find_attr_invoc(attrs: &mut Vec<ast::Attribute>) -> Option<ast::Attribute> {
785 .position(|a| !attr::is_known(a) && !is_builtin_attr(a))
786 .map(|i| attrs.remove(i))
789 impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
790 fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
791 let mut expr = self.cfg.configure_expr(expr).unwrap();
792 expr.node = self.cfg.configure_expr_kind(expr.node);
794 if let ast::ExprKind::Mac(mac) = expr.node {
795 self.check_attributes(&expr.attrs);
796 self.collect_bang(mac, expr.span, ExpansionKind::Expr).make_expr()
798 P(noop_fold_expr(expr, self))
802 fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
803 let mut expr = configure!(self, expr).unwrap();
804 expr.node = self.cfg.configure_expr_kind(expr.node);
806 if let ast::ExprKind::Mac(mac) = expr.node {
807 self.check_attributes(&expr.attrs);
808 self.collect_bang(mac, expr.span, ExpansionKind::OptExpr).make_opt_expr()
810 Some(P(noop_fold_expr(expr, self)))
814 fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
815 let pat = self.cfg.configure_pat(pat);
817 PatKind::Mac(_) => {}
818 _ => return noop_fold_pat(pat, self),
821 pat.and_then(|pat| match pat.node {
822 PatKind::Mac(mac) => self.collect_bang(mac, pat.span, ExpansionKind::Pat).make_pat(),
827 fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
828 let stmt = match self.cfg.configure_stmt(stmt) {
830 None => return SmallVector::new(),
833 let (mac, style, attrs) = if let StmtKind::Mac(mac) = stmt.node {
836 // The placeholder expander gives ids to statements, so we avoid folding the id here.
837 let ast::Stmt { id, node, span } = stmt;
838 return noop_fold_stmt_kind(node, self).into_iter().map(|node| {
839 ast::Stmt { id: id, node: node, span: span }
843 self.check_attributes(&attrs);
844 let mut placeholder = self.collect_bang(mac, stmt.span, ExpansionKind::Stmts).make_stmts();
846 // If this is a macro invocation with a semicolon, then apply that
847 // semicolon to the final statement produced by expansion.
848 if style == MacStmtStyle::Semicolon {
849 if let Some(stmt) = placeholder.pop() {
850 placeholder.push(stmt.add_trailing_semicolon());
857 fn fold_block(&mut self, block: P<Block>) -> P<Block> {
858 let old_directory_ownership = self.cx.current_expansion.directory_ownership;
859 self.cx.current_expansion.directory_ownership = DirectoryOwnership::UnownedViaBlock;
860 let result = noop_fold_block(block, self);
861 self.cx.current_expansion.directory_ownership = old_directory_ownership;
865 fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
866 let item = configure!(self, item);
868 let (attr, traits, mut item) = self.classify_item(item);
869 if attr.is_some() || !traits.is_empty() {
870 let item = Annotatable::Item(fully_configure!(self, item, noop_fold_item));
871 return self.collect_attr(attr, traits, item, ExpansionKind::Items).make_items();
875 ast::ItemKind::Mac(..) => {
876 self.check_attributes(&item.attrs);
877 item.and_then(|item| match item.node {
878 ItemKind::Mac(mac) => {
879 self.collect(ExpansionKind::Items, InvocationKind::Bang {
881 ident: Some(item.ident),
888 ast::ItemKind::Mod(ast::Mod { inner, .. }) => {
889 if item.ident == keywords::Invalid.ident() {
890 return noop_fold_item(item, self);
893 let orig_directory_ownership = self.cx.current_expansion.directory_ownership;
894 let mut module = (*self.cx.current_expansion.module).clone();
895 module.mod_path.push(item.ident);
897 // Detect if this is an inline module (`mod m { ... }` as opposed to `mod m;`).
898 // In the non-inline case, `inner` is never the dummy span (c.f. `parse_item_mod`).
899 // Thus, if `inner` is the dummy span, we know the module is inline.
900 let inline_module = item.span.contains(inner) || inner == DUMMY_SP;
903 if let Some(path) = attr::first_attr_value_str_by_name(&item.attrs, "path") {
904 self.cx.current_expansion.directory_ownership = DirectoryOwnership::Owned;
905 module.directory.push(&*path.as_str());
907 module.directory.push(&*item.ident.name.as_str());
911 PathBuf::from(self.cx.parse_sess.codemap().span_to_filename(inner));
912 let directory_ownership = match path.file_name().unwrap().to_str() {
913 Some("mod.rs") => DirectoryOwnership::Owned,
914 _ => DirectoryOwnership::UnownedViaMod(false),
917 module.directory = path;
918 self.cx.current_expansion.directory_ownership = directory_ownership;
922 mem::replace(&mut self.cx.current_expansion.module, Rc::new(module));
923 let result = noop_fold_item(item, self);
924 self.cx.current_expansion.module = orig_module;
925 self.cx.current_expansion.directory_ownership = orig_directory_ownership;
928 // Ensure that test functions are accessible from the test harness.
929 ast::ItemKind::Fn(..) if self.cx.ecfg.should_test => {
930 if item.attrs.iter().any(|attr| is_test_or_bench(attr)) {
931 item = item.map(|mut item| { item.vis = ast::Visibility::Public; item });
933 noop_fold_item(item, self)
935 _ => noop_fold_item(item, self),
939 fn fold_trait_item(&mut self, item: ast::TraitItem) -> SmallVector<ast::TraitItem> {
940 let item = configure!(self, item);
942 let (attr, traits, item) = self.classify_item(item);
943 if attr.is_some() || !traits.is_empty() {
945 Annotatable::TraitItem(P(fully_configure!(self, item, noop_fold_trait_item)));
946 return self.collect_attr(attr, traits, item, ExpansionKind::TraitItems)
951 ast::TraitItemKind::Macro(mac) => {
952 let ast::TraitItem { attrs, span, .. } = item;
953 self.check_attributes(&attrs);
954 self.collect_bang(mac, span, ExpansionKind::TraitItems).make_trait_items()
956 _ => fold::noop_fold_trait_item(item, self),
960 fn fold_impl_item(&mut self, item: ast::ImplItem) -> SmallVector<ast::ImplItem> {
961 let item = configure!(self, item);
963 let (attr, traits, item) = self.classify_item(item);
964 if attr.is_some() || !traits.is_empty() {
965 let item = Annotatable::ImplItem(P(fully_configure!(self, item, noop_fold_impl_item)));
966 return self.collect_attr(attr, traits, item, ExpansionKind::ImplItems)
971 ast::ImplItemKind::Macro(mac) => {
972 let ast::ImplItem { attrs, span, .. } = item;
973 self.check_attributes(&attrs);
974 self.collect_bang(mac, span, ExpansionKind::ImplItems).make_impl_items()
976 _ => fold::noop_fold_impl_item(item, self),
980 fn fold_ty(&mut self, ty: P<ast::Ty>) -> P<ast::Ty> {
981 let ty = match ty.node {
982 ast::TyKind::Mac(_) => ty.unwrap(),
983 _ => return fold::noop_fold_ty(ty, self),
987 ast::TyKind::Mac(mac) => self.collect_bang(mac, ty.span, ExpansionKind::Ty).make_ty(),
992 fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
993 noop_fold_foreign_mod(self.cfg.configure_foreign_mod(foreign_mod), self)
996 fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
998 ast::ItemKind::MacroDef(..) => item,
999 _ => noop_fold_item_kind(self.cfg.configure_item_kind(item), self),
1003 fn new_id(&mut self, id: ast::NodeId) -> ast::NodeId {
1005 assert_eq!(id, ast::DUMMY_NODE_ID);
1006 self.cx.resolver.next_node_id()
1013 pub struct ExpansionConfig<'feat> {
1014 pub crate_name: String,
1015 pub features: Option<&'feat Features>,
1016 pub recursion_limit: usize,
1017 pub trace_mac: bool,
1018 pub should_test: bool, // If false, strip `#[test]` nodes
1019 pub single_step: bool,
1020 pub keep_macs: bool,
1023 macro_rules! feature_tests {
1024 ($( fn $getter:ident = $field:ident, )*) => {
1026 pub fn $getter(&self) -> bool {
1027 match self.features {
1028 Some(&Features { $field: true, .. }) => true,
1036 impl<'feat> ExpansionConfig<'feat> {
1037 pub fn default(crate_name: String) -> ExpansionConfig<'static> {
1041 recursion_limit: 1024,
1050 fn enable_quotes = quote,
1051 fn enable_asm = asm,
1052 fn enable_global_asm = global_asm,
1053 fn enable_log_syntax = log_syntax,
1054 fn enable_concat_idents = concat_idents,
1055 fn enable_trace_macros = trace_macros,
1056 fn enable_allow_internal_unstable = allow_internal_unstable,
1057 fn enable_custom_derive = custom_derive,
1058 fn proc_macro_enabled = proc_macro,
1062 // A Marker adds the given mark to the syntax context.
1064 pub struct Marker(pub Mark);
1066 impl Folder for Marker {
1067 fn fold_ident(&mut self, mut ident: Ident) -> Ident {
1068 ident.ctxt = ident.ctxt.apply_mark(self.0);
1072 fn new_span(&mut self, mut span: Span) -> Span {
1073 span.ctxt = span.ctxt.apply_mark(self.0);
1077 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1078 noop_fold_mac(mac, self)