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::{Block, Crate, DeclLocal, ExprMac, PatMac};
12 use ast::{Local, Ident, MacInvocTT};
13 use ast::{ItemMac, MacStmtWithSemicolon, Mrk, Stmt, StmtDecl, StmtMac};
14 use ast::{StmtExpr, StmtSemi};
17 use ast_util::path_to_ident;
19 use ext::build::AstBuilder;
21 use attr::AttrMetaMethods;
23 use codemap::{Span, Spanned, ExpnInfo, NameAndSpan, MacroBang, MacroAttribute};
28 use parse::token::{fresh_mark, fresh_name, intern};
31 use util::small_vector::SmallVector;
35 pub fn expand_type(t: P<ast::Ty>,
36 fld: &mut MacroExpander,
37 impl_ty: Option<P<ast::Ty>>)
39 debug!("expanding type {:?} with impl_ty {:?}", t, impl_ty);
40 let t = match (t.node.clone(), impl_ty) {
41 // Expand uses of `Self` in impls to the concrete type.
42 (ast::Ty_::TyPath(ref path, _), Some(ref impl_ty)) => {
43 let path_as_ident = path_to_ident(path);
44 // Note unhygenic comparison here. I think this is correct, since
45 // even though `Self` is almost just a type parameter, the treatment
46 // for this expansion is as if it were a keyword.
47 if path_as_ident.is_some() &&
48 path_as_ident.unwrap().name == token::special_idents::type_self.name {
56 fold::noop_fold_ty(t, fld)
59 pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
60 e.and_then(|ast::Expr {id, node, span}| match node {
61 // expr_mac should really be expr_ext or something; it's the
62 // entry-point for all syntax extensions.
63 ast::ExprMac(mac) => {
64 let expanded_expr = match expand_mac_invoc(mac, span,
69 return DummyResult::raw_expr(span);
73 // Keep going, outside-in.
75 let fully_expanded = fld.fold_expr(expanded_expr);
78 fully_expanded.map(|e| ast::Expr {
79 id: ast::DUMMY_NODE_ID,
85 ast::ExprWhile(cond, body, opt_ident) => {
86 let cond = fld.fold_expr(cond);
87 let (body, opt_ident) = expand_loop_block(body, opt_ident, fld);
88 fld.cx.expr(span, ast::ExprWhile(cond, body, opt_ident))
91 // Desugar ExprWhileLet
92 // From: `[opt_ident]: while let <pat> = <expr> <body>`
93 ast::ExprWhileLet(pat, expr, body, opt_ident) => {
96 // [opt_ident]: loop {
105 let body_expr = fld.cx.expr_block(body);
106 fld.cx.arm(pat.span, vec![pat], body_expr)
111 let pat_under = fld.cx.pat_wild(span);
112 let break_expr = fld.cx.expr_break(span);
113 fld.cx.arm(span, vec![pat_under], break_expr)
116 // `match <expr> { ... }`
117 let arms = vec![pat_arm, break_arm];
118 let match_expr = fld.cx.expr(span,
119 ast::ExprMatch(expr, arms, ast::MatchSource::WhileLetDesugar));
121 // `[opt_ident]: loop { ... }`
122 let loop_block = fld.cx.block_expr(match_expr);
123 let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
124 fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident))
128 // From: `if let <pat> = <expr> <body> [<elseopt>]`
129 ast::ExprIfLet(pat, expr, body, mut elseopt) => {
134 // [_ if <elseopt_if_cond> => <elseopt_if_body>,]
135 // _ => [<elseopt> | ()]
140 let body_expr = fld.cx.expr_block(body);
141 fld.cx.arm(pat.span, vec![pat], body_expr)
144 // `[_ if <elseopt_if_cond> => <elseopt_if_body>,]`
146 let mut arms = vec![];
148 let elseopt_continue = elseopt
149 .and_then(|els| els.and_then(|els| match els.node {
151 ast::ExprIf(cond, then, elseopt) => {
152 let pat_under = fld.cx.pat_wild(span);
155 pats: vec![pat_under],
157 body: fld.cx.expr_block(then)
159 elseopt.map(|elseopt| (elseopt, true))
161 _ => Some((P(els), false))
163 match elseopt_continue {
167 Some((e, false)) => {
180 let contains_else_clause = elseopt.is_some();
182 // `_ => [<elseopt> | ()]`
184 let pat_under = fld.cx.pat_wild(span);
185 let else_expr = elseopt.unwrap_or_else(|| fld.cx.expr_tuple(span, vec![]));
186 fld.cx.arm(span, vec![pat_under], else_expr)
189 let mut arms = Vec::with_capacity(else_if_arms.len() + 2);
191 arms.extend(else_if_arms.into_iter());
194 let match_expr = fld.cx.expr(span,
195 ast::ExprMatch(expr, arms,
196 ast::MatchSource::IfLetDesugar {
197 contains_else_clause: contains_else_clause,
199 fld.fold_expr(match_expr)
202 // Desugar support for ExprIfLet in the ExprIf else position
203 ast::ExprIf(cond, blk, elseopt) => {
204 let elseopt = elseopt.map(|els| els.and_then(|els| match els.node {
205 ast::ExprIfLet(..) => {
206 // wrap the if-let expr in a block
208 let blk = P(ast::Block {
211 id: ast::DUMMY_NODE_ID,
212 rules: ast::DefaultBlock,
215 fld.cx.expr_block(blk)
219 let if_expr = fld.cx.expr(span, ast::ExprIf(cond, blk, elseopt));
220 if_expr.map(|e| noop_fold_expr(e, fld))
223 ast::ExprLoop(loop_block, opt_ident) => {
224 let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
225 fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident))
228 // Desugar ExprForLoop
229 // From: `[opt_ident]: for <pat> in <head> <body>`
230 ast::ExprForLoop(pat, head, body, opt_ident) => {
233 // match ::std::iter::IntoIterator::into_iter(<head>) {
235 // [opt_ident]: loop {
236 // match ::std::iter::Iterator::next(&mut iter) {
237 // ::std::option::Option::Some(<pat>) => <body>,
238 // ::std::option::Option::None => break
245 let head = fld.fold_expr(head);
247 // create an hygienic ident
249 let ident = fld.cx.ident_of("iter");
250 let new_ident = fresh_name(&ident);
251 let rename = (ident, new_ident);
252 let mut rename_list = vec![rename];
253 let mut rename_fld = IdentRenamer{ renames: &mut rename_list };
255 rename_fld.fold_ident(ident)
258 let pat_span = pat.span;
259 // `:;std::option::Option::Some(<pat>) => <body>`
261 let body_expr = fld.cx.expr_block(body);
262 let some_pat = fld.cx.pat_some(pat_span, pat);
264 fld.cx.arm(pat_span, vec![some_pat], body_expr)
267 // `::std::option::Option::None => break`
269 let break_expr = fld.cx.expr_break(span);
271 fld.cx.arm(span, vec![fld.cx.pat_none(span)], break_expr)
274 // `match ::std::iter::Iterator::next(&mut iter) { ... }`
278 fld.cx.ident_of("std"),
279 fld.cx.ident_of("iter"),
280 fld.cx.ident_of("Iterator"),
281 fld.cx.ident_of("next"),
284 fld.cx.path_global(span, strs)
286 let ref_mut_iter = fld.cx.expr_mut_addr_of(span, fld.cx.expr_ident(span, iter));
288 fld.cx.expr_call(span, fld.cx.expr_path(next_path), vec![ref_mut_iter]);
289 let arms = vec![pat_arm, break_arm];
291 fld.cx.expr(pat_span,
292 ast::ExprMatch(next_expr, arms, ast::MatchSource::ForLoopDesugar))
295 // `[opt_ident]: loop { ... }`
296 let loop_block = fld.cx.block_expr(match_expr);
297 let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
298 let loop_expr = fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident));
300 // `mut iter => { ... }`
303 fld.cx.pat_ident_binding_mode(span, iter, ast::BindByValue(ast::MutMutable));
304 fld.cx.arm(span, vec![iter_pat], loop_expr)
307 // `match ::std::iter::IntoIterator::into_iter(<head>) { ... }`
308 let into_iter_expr = {
309 let into_iter_path = {
311 fld.cx.ident_of("std"),
312 fld.cx.ident_of("iter"),
313 fld.cx.ident_of("IntoIterator"),
314 fld.cx.ident_of("into_iter"),
317 fld.cx.path_global(span, strs)
320 fld.cx.expr_call(span, fld.cx.expr_path(into_iter_path), vec![head])
322 fld.cx.expr_match(span, into_iter_expr, vec![iter_arm])
325 ast::ExprClosure(capture_clause, fn_decl, block) => {
326 let (rewritten_fn_decl, rewritten_block)
327 = expand_and_rename_fn_decl_and_block(fn_decl, block, fld);
328 let new_node = ast::ExprClosure(capture_clause,
331 P(ast::Expr{id:id, node: new_node, span: fld.new_span(span)})
335 P(noop_fold_expr(ast::Expr {
344 /// Expand a (not-ident-style) macro invocation. Returns the result
345 /// of expansion and the mark which must be applied to the result.
346 /// Our current interface doesn't allow us to apply the mark to the
347 /// result until after calling make_expr, make_items, etc.
348 fn expand_mac_invoc<T, F, G>(mac: ast::Mac, span: codemap::Span,
351 fld: &mut MacroExpander)
353 F: FnOnce(Box<MacResult>) -> Option<T>,
354 G: FnOnce(T, Mrk) -> T,
357 // it would almost certainly be cleaner to pass the whole
358 // macro invocation in, rather than pulling it apart and
359 // marking the tts and the ctxt separately. This also goes
360 // for the other three macro invocation chunks of code
362 // Token-tree macros:
363 MacInvocTT(pth, tts, _) => {
364 if pth.segments.len() > 1 {
365 fld.cx.span_err(pth.span,
366 "expected macro name without module \
368 // let compilation continue
371 let extname = pth.segments[0].identifier;
372 let extnamestr = token::get_ident(extname);
373 match fld.cx.syntax_env.find(&extname.name) {
377 &format!("macro undefined: '{}!'",
378 extnamestr.get())[]);
380 // let compilation continue
383 Some(rc) => match *rc {
384 NormalTT(ref expandfun, exp_span) => {
385 fld.cx.bt_push(ExpnInfo {
387 callee: NameAndSpan {
388 name: extnamestr.get().to_string(),
393 let fm = fresh_mark();
394 let marked_before = mark_tts(&tts[], fm);
396 // The span that we pass to the expanders we want to
397 // be the root of the call stack. That's the most
398 // relevant span and it's the actual invocation of
400 let mac_span = fld.cx.original_span();
403 let expanded = expandfun.expand(fld.cx,
406 parse_thunk(expanded)
408 let parsed = match opt_parsed {
413 &format!("non-expression macro in expression position: {}",
419 Some(mark_thunk(parsed,fm))
424 &format!("'{}' is not a tt-style macro",
425 extnamestr.get())[]);
434 /// Rename loop label and expand its loop body
436 /// The renaming procedure for loop is different in the sense that the loop
437 /// body is in a block enclosed by loop head so the renaming of loop label
438 /// must be propagated to the enclosed context.
439 fn expand_loop_block(loop_block: P<Block>,
440 opt_ident: Option<Ident>,
441 fld: &mut MacroExpander) -> (P<Block>, Option<Ident>) {
444 let new_label = fresh_name(&label);
445 let rename = (label, new_label);
447 // The rename *must not* be added to the pending list of current
448 // syntax context otherwise an unrelated `break` or `continue` in
449 // the same context will pick that up in the deferred renaming pass
450 // and be renamed incorrectly.
451 let mut rename_list = vec!(rename);
452 let mut rename_fld = IdentRenamer{renames: &mut rename_list};
453 let renamed_ident = rename_fld.fold_ident(label);
455 // The rename *must* be added to the enclosed syntax context for
456 // `break` or `continue` to pick up because by definition they are
457 // in a block enclosed by loop head.
458 fld.cx.syntax_env.push_frame();
459 fld.cx.syntax_env.info().pending_renames.push(rename);
460 let expanded_block = expand_block_elts(loop_block, fld);
461 fld.cx.syntax_env.pop_frame();
463 (expanded_block, Some(renamed_ident))
465 None => (fld.fold_block(loop_block), opt_ident)
469 // eval $e with a new exts frame.
470 // must be a macro so that $e isn't evaluated too early.
471 macro_rules! with_exts_frame {
472 ($extsboxexpr:expr,$macros_escape:expr,$e:expr) =>
473 ({$extsboxexpr.push_frame();
474 $extsboxexpr.info().macros_escape = $macros_escape;
476 $extsboxexpr.pop_frame();
481 // When we enter a module, record it, for the sake of `module!`
482 pub fn expand_item(it: P<ast::Item>, fld: &mut MacroExpander)
483 -> SmallVector<P<ast::Item>> {
484 let it = expand_item_modifiers(it, fld);
486 expand_annotatable(Annotatable::Item(it), fld)
487 .into_iter().map(|i| i.expect_item()).collect()
490 fn expand_item_modifiers(mut it: P<ast::Item>, fld: &mut MacroExpander)
492 // partition the attributes into ItemModifiers and others
493 let (modifiers, other_attrs) = modifiers(&it.attrs, fld);
495 // update the attrs, leave everything else alone. Is this mutation really a good idea?
501 if modifiers.is_empty() {
502 let it = expand_item_multi_modifier(Annotatable::Item(it), fld);
503 return it.expect_item();
506 for attr in &modifiers {
507 let mname = attr.name();
509 match fld.cx.syntax_env.find(&intern(mname.get())) {
510 Some(rc) => match *rc {
511 Modifier(ref mac) => {
512 attr::mark_used(attr);
513 fld.cx.bt_push(ExpnInfo {
514 call_site: attr.span,
515 callee: NameAndSpan {
516 name: mname.get().to_string(),
517 format: MacroAttribute,
521 it = mac.expand(fld.cx, attr.span, &*attr.node.value, it);
530 // Expansion may have added new ItemModifiers.
531 // It is possible, that an item modifier could expand to a multi-modifier or
532 // vice versa. In this case we will expand all modifiers before multi-modifiers,
533 // which might give an odd ordering. However, I think it is unlikely that the
534 // two kinds will be mixed, and I old-style multi-modifiers should be deprecated
536 expand_item_modifiers(it, fld)
539 /// Expand item_underscore
540 fn expand_item_underscore(item: ast::Item_, fld: &mut MacroExpander) -> ast::Item_ {
542 ast::ItemFn(decl, fn_style, abi, generics, body) => {
543 let (rewritten_fn_decl, rewritten_body)
544 = expand_and_rename_fn_decl_and_block(decl, body, fld);
545 let expanded_generics = fold::noop_fold_generics(generics,fld);
546 ast::ItemFn(rewritten_fn_decl, fn_style, abi, expanded_generics, rewritten_body)
548 _ => noop_fold_item_underscore(item, fld)
552 // does this attribute list contain "macro_use" ?
553 fn contains_macro_use(fld: &mut MacroExpander, attrs: &[ast::Attribute]) -> bool {
555 let mut is_use = attr.check_name("macro_use");
556 if attr.check_name("macro_escape") {
557 fld.cx.span_warn(attr.span, "macro_escape is a deprecated synonym for macro_use");
559 if let ast::AttrInner = attr.node.style {
560 fld.cx.span_help(attr.span, "consider an outer attribute, \
561 #[macro_use] mod ...");
566 match attr.node.value.node {
567 ast::MetaWord(..) => (),
568 _ => fld.cx.span_err(attr.span, "arguments to macro_use are not allowed here"),
576 // Support for item-position macro invocations, exactly the same
577 // logic as for expression-position macro invocations.
578 pub fn expand_item_mac(it: P<ast::Item>,
579 fld: &mut MacroExpander) -> SmallVector<P<ast::Item>> {
580 let (extname, path_span, tts) = match it.node {
581 ItemMac(codemap::Spanned {
582 node: MacInvocTT(ref pth, ref tts, _),
585 (pth.segments[0].identifier, pth.span, (*tts).clone())
587 _ => fld.cx.span_bug(it.span, "invalid item macro invocation")
590 let extnamestr = token::get_ident(extname);
591 let fm = fresh_mark();
593 let expanded = match fld.cx.syntax_env.find(&extname.name) {
595 fld.cx.span_err(path_span,
596 &format!("macro undefined: '{}!'",
598 // let compilation continue
599 return SmallVector::zero();
602 Some(rc) => match *rc {
603 NormalTT(ref expander, span) => {
604 if it.ident.name != parse::token::special_idents::invalid.name {
607 &format!("macro {}! expects no ident argument, \
610 token::get_ident(it.ident))[]);
611 return SmallVector::zero();
613 fld.cx.bt_push(ExpnInfo {
615 callee: NameAndSpan {
616 name: extnamestr.get().to_string(),
621 // mark before expansion:
622 let marked_before = mark_tts(&tts[], fm);
623 expander.expand(fld.cx, it.span, &marked_before[])
625 IdentTT(ref expander, span) => {
626 if it.ident.name == parse::token::special_idents::invalid.name {
627 fld.cx.span_err(path_span,
628 &format!("macro {}! expects an ident argument",
629 extnamestr.get())[]);
630 return SmallVector::zero();
632 fld.cx.bt_push(ExpnInfo {
634 callee: NameAndSpan {
635 name: extnamestr.get().to_string(),
640 // mark before expansion:
641 let marked_tts = mark_tts(&tts[], fm);
642 expander.expand(fld.cx, it.span, it.ident, marked_tts)
645 if it.ident.name == parse::token::special_idents::invalid.name {
646 fld.cx.span_err(path_span,
647 &format!("macro_rules! expects an ident argument")
649 return SmallVector::zero();
651 fld.cx.bt_push(ExpnInfo {
653 callee: NameAndSpan {
654 name: extnamestr.get().to_string(),
659 // DON'T mark before expansion.
661 let def = ast::MacroDef {
663 attrs: it.attrs.clone(),
664 id: ast::DUMMY_NODE_ID,
667 export: attr::contains_name(&it.attrs, "macro_export"),
671 fld.cx.insert_macro(def);
673 // macro_rules! has a side effect but expands to nothing.
675 return SmallVector::zero();
678 fld.cx.span_err(it.span,
679 &format!("{}! is not legal in item position",
680 extnamestr.get())[]);
681 return SmallVector::zero();
686 expanded.make_items()
689 let items = match items {
692 .map(|i| mark_item(i, fm))
693 .flat_map(|i| fld.fold_item(i).into_iter())
697 fld.cx.span_err(path_span,
698 &format!("non-item macro in item position: {}",
699 extnamestr.get())[]);
700 return SmallVector::zero();
709 fn expand_stmt(s: Stmt, fld: &mut MacroExpander) -> SmallVector<P<Stmt>> {
710 let (mac, style) = match s.node {
711 StmtMac(mac, style) => (mac, style),
712 _ => return expand_non_macro_stmt(s, fld)
714 let expanded_stmt = match expand_mac_invoc(mac.and_then(|m| m), s.span,
719 return SmallVector::zero();
723 // Keep going, outside-in.
724 let fully_expanded = fld.fold_stmt(expanded_stmt);
727 if style == MacStmtWithSemicolon {
728 fully_expanded.into_iter().map(|s| s.map(|Spanned {node, span}| {
731 StmtExpr(e, stmt_id) => StmtSemi(e, stmt_id),
732 _ => node /* might already have a semi */
742 // expand a non-macro stmt. this is essentially the fallthrough for
743 // expand_stmt, above.
744 fn expand_non_macro_stmt(Spanned {node, span: stmt_span}: Stmt, fld: &mut MacroExpander)
745 -> SmallVector<P<Stmt>> {
748 StmtDecl(decl, node_id) => decl.and_then(|Spanned {node: decl, span}| match decl {
749 DeclLocal(local) => {
751 let rewritten_local = local.map(|Local {id, pat, ty, init, source, span}| {
752 // expand the ty since TyFixedLengthVec contains an Expr
753 // and thus may have a macro use
754 let expanded_ty = ty.map(|t| fld.fold_ty(t));
755 // expand the pat (it might contain macro uses):
756 let expanded_pat = fld.fold_pat(pat);
757 // find the PatIdents in the pattern:
758 // oh dear heaven... this is going to include the enum
759 // names, as well... but that should be okay, as long as
760 // the new names are gensyms for the old ones.
761 // generate fresh names, push them to a new pending list
762 let idents = pattern_bindings(&*expanded_pat);
763 let mut new_pending_renames =
764 idents.iter().map(|ident| (*ident, fresh_name(ident))).collect();
765 // rewrite the pattern using the new names (the old
766 // ones have already been applied):
767 let rewritten_pat = {
768 // nested binding to allow borrow to expire:
769 let mut rename_fld = IdentRenamer{renames: &mut new_pending_renames};
770 rename_fld.fold_pat(expanded_pat)
772 // add them to the existing pending renames:
773 fld.cx.syntax_env.info().pending_renames
774 .extend(new_pending_renames.into_iter());
779 // also, don't forget to expand the init:
780 init: init.map(|e| fld.fold_expr(e)),
785 SmallVector::one(P(Spanned {
786 node: StmtDecl(P(Spanned {
787 node: DeclLocal(rewritten_local),
795 noop_fold_stmt(Spanned {
796 node: StmtDecl(P(Spanned {
806 noop_fold_stmt(Spanned {
814 // expand the arm of a 'match', renaming for macro hygiene
815 fn expand_arm(arm: ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
816 // expand pats... they might contain macro uses:
817 let expanded_pats = arm.pats.move_map(|pat| fld.fold_pat(pat));
818 if expanded_pats.len() == 0 {
819 panic!("encountered match arm with 0 patterns");
821 // all of the pats must have the same set of bindings, so use the
822 // first one to extract them and generate new names:
823 let idents = pattern_bindings(&*expanded_pats[0]);
824 let new_renames = idents.into_iter().map(|id| (id, fresh_name(&id))).collect();
825 // apply the renaming, but only to the PatIdents:
826 let mut rename_pats_fld = PatIdentRenamer{renames:&new_renames};
827 let rewritten_pats = expanded_pats.move_map(|pat| rename_pats_fld.fold_pat(pat));
828 // apply renaming and then expansion to the guard and the body:
829 let mut rename_fld = IdentRenamer{renames:&new_renames};
830 let rewritten_guard =
831 arm.guard.map(|g| fld.fold_expr(rename_fld.fold_expr(g)));
832 let rewritten_body = fld.fold_expr(rename_fld.fold_expr(arm.body));
834 attrs: arm.attrs.move_map(|x| fld.fold_attribute(x)),
835 pats: rewritten_pats,
836 guard: rewritten_guard,
837 body: rewritten_body,
841 /// A visitor that extracts the PatIdent (binding) paths
842 /// from a given thingy and puts them in a mutable
845 struct PatIdentFinder {
846 ident_accumulator: Vec<ast::Ident>
849 impl<'v> Visitor<'v> for PatIdentFinder {
850 fn visit_pat(&mut self, pattern: &ast::Pat) {
852 ast::Pat { id: _, node: ast::PatIdent(_, ref path1, ref inner), span: _ } => {
853 self.ident_accumulator.push(path1.node);
854 // visit optional subpattern of PatIdent:
855 if let Some(ref subpat) = *inner {
856 self.visit_pat(&**subpat)
859 // use the default traversal for non-PatIdents
860 _ => visit::walk_pat(self, pattern)
865 /// find the PatIdent paths in a pattern
866 fn pattern_bindings(pat: &ast::Pat) -> Vec<ast::Ident> {
867 let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
868 name_finder.visit_pat(pat);
869 name_finder.ident_accumulator
872 /// find the PatIdent paths in a
873 fn fn_decl_arg_bindings(fn_decl: &ast::FnDecl) -> Vec<ast::Ident> {
874 let mut pat_idents = PatIdentFinder{ident_accumulator:Vec::new()};
875 for arg in &fn_decl.inputs {
876 pat_idents.visit_pat(&*arg.pat);
878 pat_idents.ident_accumulator
881 // expand a block. pushes a new exts_frame, then calls expand_block_elts
882 pub fn expand_block(blk: P<Block>, fld: &mut MacroExpander) -> P<Block> {
883 // see note below about treatment of exts table
884 with_exts_frame!(fld.cx.syntax_env,false,
885 expand_block_elts(blk, fld))
888 // expand the elements of a block.
889 pub fn expand_block_elts(b: P<Block>, fld: &mut MacroExpander) -> P<Block> {
890 b.map(|Block {id, stmts, expr, rules, span}| {
891 let new_stmts = stmts.into_iter().flat_map(|x| {
892 // perform all pending renames
894 let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
895 let mut rename_fld = IdentRenamer{renames:pending_renames};
896 rename_fld.fold_stmt(x).expect_one("rename_fold didn't return one value")
898 // expand macros in the statement
899 fld.fold_stmt(renamed_stmt).into_iter()
901 let new_expr = expr.map(|x| {
903 let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
904 let mut rename_fld = IdentRenamer{renames:pending_renames};
905 rename_fld.fold_expr(x)
919 fn expand_pat(p: P<ast::Pat>, fld: &mut MacroExpander) -> P<ast::Pat> {
922 _ => return noop_fold_pat(p, fld)
924 p.map(|ast::Pat {node, span, ..}| {
925 let (pth, tts) = match node {
926 PatMac(mac) => match mac.node {
927 MacInvocTT(pth, tts, _) => {
933 if pth.segments.len() > 1 {
934 fld.cx.span_err(pth.span, "expected macro name without module separators");
935 return DummyResult::raw_pat(span);
937 let extname = pth.segments[0].identifier;
938 let extnamestr = token::get_ident(extname);
939 let marked_after = match fld.cx.syntax_env.find(&extname.name) {
941 fld.cx.span_err(pth.span,
942 &format!("macro undefined: '{}!'",
944 // let compilation continue
945 return DummyResult::raw_pat(span);
948 Some(rc) => match *rc {
949 NormalTT(ref expander, tt_span) => {
950 fld.cx.bt_push(ExpnInfo {
952 callee: NameAndSpan {
953 name: extnamestr.get().to_string(),
959 let fm = fresh_mark();
960 let marked_before = mark_tts(&tts[], fm);
961 let mac_span = fld.cx.original_span();
962 let expanded = match expander.expand(fld.cx,
964 &marked_before[]).make_pat() {
970 "non-pattern macro in pattern position: {}",
974 return DummyResult::raw_pat(span);
979 mark_pat(expanded,fm)
982 fld.cx.span_err(span,
983 &format!("{}! is not legal in pattern position",
984 extnamestr.get())[]);
985 return DummyResult::raw_pat(span);
991 fld.fold_pat(marked_after).node.clone();
995 id: ast::DUMMY_NODE_ID,
996 node: fully_expanded,
1002 /// A tree-folder that applies every rename in its (mutable) list
1003 /// to every identifier, including both bindings and varrefs
1004 /// (and lots of things that will turn out to be neither)
1005 pub struct IdentRenamer<'a> {
1006 renames: &'a mtwt::RenameList,
1009 impl<'a> Folder for IdentRenamer<'a> {
1010 fn fold_ident(&mut self, id: Ident) -> Ident {
1013 ctxt: mtwt::apply_renames(self.renames, id.ctxt),
1016 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1017 fold::noop_fold_mac(mac, self)
1021 /// A tree-folder that applies every rename in its list to
1022 /// the idents that are in PatIdent patterns. This is more narrowly
1023 /// focused than IdentRenamer, and is needed for FnDecl,
1024 /// where we want to rename the args but not the fn name or the generics etc.
1025 pub struct PatIdentRenamer<'a> {
1026 renames: &'a mtwt::RenameList,
1029 impl<'a> Folder for PatIdentRenamer<'a> {
1030 fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
1032 ast::PatIdent(..) => {},
1033 _ => return noop_fold_pat(pat, self)
1036 pat.map(|ast::Pat {id, node, span}| match node {
1037 ast::PatIdent(binding_mode, Spanned{span: sp, node: ident}, sub) => {
1038 let new_ident = Ident{name: ident.name,
1039 ctxt: mtwt::apply_renames(self.renames, ident.ctxt)};
1041 ast::PatIdent(binding_mode,
1042 Spanned{span: self.new_span(sp), node: new_ident},
1043 sub.map(|p| self.fold_pat(p)));
1047 span: self.new_span(span)
1053 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1054 fold::noop_fold_mac(mac, self)
1058 fn expand_annotatable(a: Annotatable,
1059 fld: &mut MacroExpander)
1060 -> SmallVector<Annotatable> {
1061 let a = expand_item_multi_modifier(a, fld);
1063 let mut decorator_items = SmallVector::zero();
1064 let mut new_attrs = Vec::new();
1065 for attr in a.attrs() {
1066 let mname = attr.name();
1068 match fld.cx.syntax_env.find(&intern(mname.get())) {
1069 Some(rc) => match *rc {
1070 Decorator(ref dec) => {
1072 Annotatable::Item(ref it) => it,
1073 // ItemDecorators are only implemented for Items.
1077 attr::mark_used(attr);
1079 fld.cx.bt_push(ExpnInfo {
1080 call_site: attr.span,
1081 callee: NameAndSpan {
1082 name: mname.get().to_string(),
1083 format: MacroAttribute,
1088 // we'd ideally decorator_items.push_all(expand_item(item, fld)),
1089 // but that double-mut-borrows fld
1090 let mut items: SmallVector<P<ast::Item>> = SmallVector::zero();
1091 dec.expand(fld.cx, attr.span, &*attr.node.value, &**it,
1092 box |item| items.push(item));
1093 decorator_items.extend(items.into_iter()
1094 .flat_map(|item| expand_item(item, fld).into_iter()));
1098 _ => new_attrs.push((*attr).clone()),
1100 _ => new_attrs.push((*attr).clone()),
1104 let mut new_items: SmallVector<Annotatable> = match a {
1105 Annotatable::Item(it) => match it.node {
1106 ast::ItemMac(..) => {
1107 expand_item_mac(it, fld).into_iter().map(|i| Annotatable::Item(i)).collect()
1109 ast::ItemMod(_) | ast::ItemForeignMod(_) => {
1111 it.ident.name != parse::token::special_idents::invalid.name;
1114 fld.cx.mod_push(it.ident);
1116 let macro_use = contains_macro_use(fld, &new_attrs[]);
1117 let result = with_exts_frame!(fld.cx.syntax_env,
1119 noop_fold_item(it, fld));
1123 result.into_iter().map(|i| Annotatable::Item(i)).collect()
1126 let it = P(ast::Item {
1130 noop_fold_item(it, fld).into_iter().map(|i| Annotatable::Item(i)).collect()
1133 Annotatable::TraitItem(it) => match it {
1134 ast::TraitItem::ProvidedMethod(m) => {
1135 expand_method(m, fld).into_iter().map(|m|
1136 Annotatable::TraitItem(ast::TraitItem::ProvidedMethod(m))).collect()
1138 ast::TraitItem::RequiredMethod(m) => {
1139 SmallVector::one(Annotatable::TraitItem(
1140 ast::TraitItem::RequiredMethod(fld.fold_type_method(m))))
1142 ast::TraitItem::TypeTraitItem(t) => {
1143 SmallVector::one(Annotatable::TraitItem(
1144 ast::TraitItem::TypeTraitItem(P(fld.fold_associated_type((*t).clone())))))
1147 Annotatable::ImplItem(it) => match it {
1148 ast::ImplItem::MethodImplItem(m) => {
1149 expand_method(m, fld).into_iter().map(|m|
1150 Annotatable::ImplItem(ast::ImplItem::MethodImplItem(m))).collect()
1152 ast::ImplItem::TypeImplItem(t) => {
1153 SmallVector::one(Annotatable::ImplItem(
1154 ast::ImplItem::TypeImplItem(P(fld.fold_typedef((*t).clone())))))
1159 new_items.push_all(decorator_items.into_iter().map(|i| Annotatable::Item(i)).collect());
1163 fn expand_trait_item(i: ast::TraitItem,
1164 fld: &mut MacroExpander)
1165 -> SmallVector<ast::TraitItem> {
1166 expand_annotatable(Annotatable::TraitItem(i), fld)
1167 .into_iter().map(|i| i.expect_trait_item()).collect()
1171 fn expand_impl_item(i: ast::ImplItem,
1172 fld: &mut MacroExpander)
1173 -> SmallVector<ast::ImplItem> {
1174 expand_annotatable(Annotatable::ImplItem(i), fld)
1175 .into_iter().map(|i| i.expect_impl_item()).collect()
1178 // partition the attributes into ItemModifiers and others
1179 fn modifiers(attrs: &Vec<ast::Attribute>,
1180 fld: &MacroExpander)
1181 -> (Vec<ast::Attribute>, Vec<ast::Attribute>) {
1182 attrs.iter().cloned().partition(|attr| {
1183 match fld.cx.syntax_env.find(&intern(attr.name().get())) {
1184 Some(rc) => match *rc {
1185 Modifier(_) => true,
1193 // partition the attributes into MultiModifiers and others
1194 fn multi_modifiers(attrs: &[ast::Attribute],
1195 fld: &MacroExpander)
1196 -> (Vec<ast::Attribute>, Vec<ast::Attribute>) {
1197 attrs.iter().cloned().partition(|attr| {
1198 match fld.cx.syntax_env.find(&intern(attr.name().get())) {
1199 Some(rc) => match *rc {
1200 MultiModifier(_) => true,
1208 fn expand_item_multi_modifier(mut it: Annotatable,
1209 fld: &mut MacroExpander)
1211 let (modifiers, other_attrs) = multi_modifiers(it.attrs(), fld);
1213 // Update the attrs, leave everything else alone. Is this mutation really a good idea?
1214 it = it.fold_attrs(other_attrs);
1216 if modifiers.is_empty() {
1220 for attr in &modifiers {
1221 let mname = attr.name();
1223 match fld.cx.syntax_env.find(&intern(mname.get())) {
1224 Some(rc) => match *rc {
1225 MultiModifier(ref mac) => {
1226 attr::mark_used(attr);
1227 fld.cx.bt_push(ExpnInfo {
1228 call_site: attr.span,
1229 callee: NameAndSpan {
1230 name: mname.get().to_string(),
1231 format: MacroAttribute,
1235 it = mac.expand(fld.cx, attr.span, &*attr.node.value, it);
1244 // Expansion may have added new ItemModifiers.
1245 expand_item_multi_modifier(it, fld)
1249 fn expand_method(m: P<ast::Method>, fld: &mut MacroExpander) -> SmallVector<P<ast::Method>> {
1250 m.and_then(|m| match m.node {
1251 ast::MethDecl(ident,
1259 let id = fld.new_id(m.id);
1260 let (rewritten_fn_decl, rewritten_body)
1261 = expand_and_rename_fn_decl_and_block(decl, body, fld);
1262 SmallVector::one(P(ast::Method {
1263 attrs: m.attrs.move_map(|a| fld.fold_attribute(a)),
1265 span: fld.new_span(m.span),
1266 node: ast::MethDecl(fld.fold_ident(ident),
1267 noop_fold_generics(generics, fld),
1269 fld.fold_explicit_self(explicit_self),
1276 ast::MethMac(mac) => {
1277 let maybe_new_methods =
1278 expand_mac_invoc(mac, m.span,
1279 |r| r.make_methods(),
1280 |meths, mark| meths.move_map(|m| mark_method(m, mark)),
1283 match maybe_new_methods {
1285 // expand again if necessary
1286 let new_methods = methods.into_iter()
1287 .flat_map(|m| fld.fold_method(m).into_iter())
1292 None => SmallVector::zero()
1298 /// Given a fn_decl and a block and a MacroExpander, expand the fn_decl, then use the
1299 /// PatIdents in its arguments to perform renaming in the FnDecl and
1300 /// the block, returning both the new FnDecl and the new Block.
1301 fn expand_and_rename_fn_decl_and_block(fn_decl: P<ast::FnDecl>, block: P<ast::Block>,
1302 fld: &mut MacroExpander)
1303 -> (P<ast::FnDecl>, P<ast::Block>) {
1304 let expanded_decl = fld.fold_fn_decl(fn_decl);
1305 let idents = fn_decl_arg_bindings(&*expanded_decl);
1307 idents.iter().map(|id : &ast::Ident| (*id,fresh_name(id))).collect();
1308 // first, a renamer for the PatIdents, for the fn_decl:
1309 let mut rename_pat_fld = PatIdentRenamer{renames: &renames};
1310 let rewritten_fn_decl = rename_pat_fld.fold_fn_decl(expanded_decl);
1311 // now, a renamer for *all* idents, for the body:
1312 let mut rename_fld = IdentRenamer{renames: &renames};
1313 let rewritten_body = fld.fold_block(rename_fld.fold_block(block));
1314 (rewritten_fn_decl,rewritten_body)
1317 /// A tree-folder that performs macro expansion
1318 pub struct MacroExpander<'a, 'b:'a> {
1319 pub cx: &'a mut ExtCtxt<'b>,
1320 // The type of the impl currently being expanded.
1321 current_impl_type: Option<P<ast::Ty>>,
1324 impl<'a, 'b> MacroExpander<'a, 'b> {
1325 pub fn new(cx: &'a mut ExtCtxt<'b>) -> MacroExpander<'a, 'b> {
1326 MacroExpander { cx: cx, current_impl_type: None }
1330 impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
1331 fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
1332 expand_expr(expr, self)
1335 fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
1336 expand_pat(pat, self)
1339 fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
1340 let prev_type = self.current_impl_type.clone();
1341 if let ast::Item_::ItemImpl(_, _, _, _, ref ty, _) = item.node {
1342 self.current_impl_type = Some(ty.clone());
1345 let result = expand_item(item, self);
1346 self.current_impl_type = prev_type;
1350 fn fold_item_underscore(&mut self, item: ast::Item_) -> ast::Item_ {
1351 expand_item_underscore(item, self)
1354 fn fold_stmt(&mut self, stmt: P<ast::Stmt>) -> SmallVector<P<ast::Stmt>> {
1355 stmt.and_then(|stmt| expand_stmt(stmt, self))
1358 fn fold_block(&mut self, block: P<Block>) -> P<Block> {
1359 expand_block(block, self)
1362 fn fold_arm(&mut self, arm: ast::Arm) -> ast::Arm {
1363 expand_arm(arm, self)
1366 fn fold_trait_item(&mut self, i: ast::TraitItem) -> SmallVector<ast::TraitItem> {
1367 expand_trait_item(i, self)
1370 fn fold_impl_item(&mut self, i: ast::ImplItem) -> SmallVector<ast::ImplItem> {
1371 expand_impl_item(i, self)
1374 fn fold_method(&mut self, method: P<ast::Method>) -> SmallVector<P<ast::Method>> {
1375 expand_method(method, self)
1378 fn fold_ty(&mut self, t: P<ast::Ty>) -> P<ast::Ty> {
1379 let impl_type = self.current_impl_type.clone();
1380 expand_type(t, self, impl_type)
1383 fn new_span(&mut self, span: Span) -> Span {
1384 new_span(self.cx, span)
1388 fn new_span(cx: &ExtCtxt, sp: Span) -> Span {
1389 /* this discards information in the case of macro-defining macros */
1393 expn_id: cx.backtrace(),
1397 pub struct ExpansionConfig {
1398 pub crate_name: String,
1399 pub enable_quotes: bool,
1400 pub recursion_limit: usize,
1403 impl ExpansionConfig {
1404 pub fn default(crate_name: String) -> ExpansionConfig {
1406 crate_name: crate_name,
1407 enable_quotes: false,
1408 recursion_limit: 64,
1413 pub fn expand_crate(parse_sess: &parse::ParseSess,
1414 cfg: ExpansionConfig,
1415 // these are the macros being imported to this crate:
1416 imported_macros: Vec<ast::MacroDef>,
1417 user_exts: Vec<NamedSyntaxExtension>,
1418 c: Crate) -> Crate {
1419 let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg);
1420 let mut expander = MacroExpander::new(&mut cx);
1422 for def in imported_macros {
1423 expander.cx.insert_macro(def);
1426 for (name, extension) in user_exts {
1427 expander.cx.syntax_env.insert(name, extension);
1430 let mut ret = expander.fold_crate(c);
1431 ret.exported_macros = expander.cx.exported_macros.clone();
1432 parse_sess.span_diagnostic.handler().abort_if_errors();
1436 // HYGIENIC CONTEXT EXTENSION:
1437 // all of these functions are for walking over
1438 // ASTs and making some change to the context of every
1439 // element that has one. a CtxtFn is a trait-ified
1440 // version of a closure in (SyntaxContext -> SyntaxContext).
1441 // the ones defined here include:
1442 // Marker - add a mark to a context
1444 // A Marker adds the given mark to the syntax context
1445 struct Marker { mark: Mrk }
1447 impl Folder for Marker {
1448 fn fold_ident(&mut self, id: Ident) -> Ident {
1451 ctxt: mtwt::apply_mark(self.mark, id.ctxt)
1454 fn fold_mac(&mut self, Spanned {node, span}: ast::Mac) -> ast::Mac {
1457 MacInvocTT(path, tts, ctxt) => {
1458 MacInvocTT(self.fold_path(path),
1459 self.fold_tts(&tts[]),
1460 mtwt::apply_mark(self.mark, ctxt))
1468 // apply a given mark to the given token trees. Used prior to expansion of a macro.
1469 fn mark_tts(tts: &[TokenTree], m: Mrk) -> Vec<TokenTree> {
1470 noop_fold_tts(tts, &mut Marker{mark:m})
1473 // apply a given mark to the given expr. Used following the expansion of a macro.
1474 fn mark_expr(expr: P<ast::Expr>, m: Mrk) -> P<ast::Expr> {
1475 Marker{mark:m}.fold_expr(expr)
1478 // apply a given mark to the given pattern. Used following the expansion of a macro.
1479 fn mark_pat(pat: P<ast::Pat>, m: Mrk) -> P<ast::Pat> {
1480 Marker{mark:m}.fold_pat(pat)
1483 // apply a given mark to the given stmt. Used following the expansion of a macro.
1484 fn mark_stmt(expr: P<ast::Stmt>, m: Mrk) -> P<ast::Stmt> {
1485 Marker{mark:m}.fold_stmt(expr)
1486 .expect_one("marking a stmt didn't return exactly one stmt")
1489 // apply a given mark to the given item. Used following the expansion of a macro.
1490 fn mark_item(expr: P<ast::Item>, m: Mrk) -> P<ast::Item> {
1491 Marker{mark:m}.fold_item(expr)
1492 .expect_one("marking an item didn't return exactly one item")
1495 // apply a given mark to the given item. Used following the expansion of a macro.
1496 fn mark_method(expr: P<ast::Method>, m: Mrk) -> P<ast::Method> {
1497 Marker{mark:m}.fold_method(expr)
1498 .expect_one("marking an item didn't return exactly one method")
1501 /// Check that there are no macro invocations left in the AST:
1502 pub fn check_for_macros(sess: &parse::ParseSess, krate: &ast::Crate) {
1503 visit::walk_crate(&mut MacroExterminator{sess:sess}, krate);
1506 /// A visitor that ensures that no macro invocations remain in an AST.
1507 struct MacroExterminator<'a>{
1508 sess: &'a parse::ParseSess
1511 impl<'a, 'v> Visitor<'v> for MacroExterminator<'a> {
1512 fn visit_mac(&mut self, mac: &ast::Mac) {
1513 self.sess.span_diagnostic.span_bug(mac.span,
1514 "macro exterminator: expected AST \
1515 with no macro invocations");
1522 use super::{pattern_bindings, expand_crate};
1523 use super::{PatIdentFinder, IdentRenamer, PatIdentRenamer, ExpansionConfig};
1531 use util::parser_testing::{string_to_parser};
1532 use util::parser_testing::{string_to_pat, string_to_crate, strs_to_idents};
1536 // a visitor that extracts the paths
1537 // from a given thingy and puts them in a mutable
1538 // array (passed in to the traversal)
1540 struct PathExprFinderContext {
1541 path_accumulator: Vec<ast::Path> ,
1544 impl<'v> Visitor<'v> for PathExprFinderContext {
1545 fn visit_expr(&mut self, expr: &ast::Expr) {
1547 ast::ExprPath(ref p) => {
1548 self.path_accumulator.push(p.clone());
1549 // not calling visit_path, but it should be fine.
1551 _ => visit::walk_expr(self, expr)
1556 // find the variable references in a crate
1557 fn crate_varrefs(the_crate : &ast::Crate) -> Vec<ast::Path> {
1558 let mut path_finder = PathExprFinderContext{path_accumulator:Vec::new()};
1559 visit::walk_crate(&mut path_finder, the_crate);
1560 path_finder.path_accumulator
1563 /// A Visitor that extracts the identifiers from a thingy.
1564 // as a side note, I'm starting to want to abstract over these....
1565 struct IdentFinder {
1566 ident_accumulator: Vec<ast::Ident>
1569 impl<'v> Visitor<'v> for IdentFinder {
1570 fn visit_ident(&mut self, _: codemap::Span, id: ast::Ident){
1571 self.ident_accumulator.push(id);
1575 /// Find the idents in a crate
1576 fn crate_idents(the_crate: &ast::Crate) -> Vec<ast::Ident> {
1577 let mut ident_finder = IdentFinder{ident_accumulator: Vec::new()};
1578 visit::walk_crate(&mut ident_finder, the_crate);
1579 ident_finder.ident_accumulator
1582 // these following tests are quite fragile, in that they don't test what
1583 // *kind* of failure occurs.
1585 fn test_ecfg() -> ExpansionConfig {
1586 ExpansionConfig::default("test".to_string())
1589 // make sure that macros can't escape fns
1591 #[test] fn macros_cant_escape_fns_test () {
1592 let src = "fn bogus() {macro_rules! z (() => (3+4));}\
1593 fn inty() -> i32 { z!() }".to_string();
1594 let sess = parse::new_parse_sess();
1595 let crate_ast = parse::parse_crate_from_source_str(
1596 "<test>".to_string(),
1600 expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
1603 // make sure that macros can't escape modules
1605 #[test] fn macros_cant_escape_mods_test () {
1606 let src = "mod foo {macro_rules! z (() => (3+4));}\
1607 fn inty() -> i32 { z!() }".to_string();
1608 let sess = parse::new_parse_sess();
1609 let crate_ast = parse::parse_crate_from_source_str(
1610 "<test>".to_string(),
1613 expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
1616 // macro_use modules should allow macros to escape
1617 #[test] fn macros_can_escape_flattened_mods_test () {
1618 let src = "#[macro_use] mod foo {macro_rules! z (() => (3+4));}\
1619 fn inty() -> i32 { z!() }".to_string();
1620 let sess = parse::new_parse_sess();
1621 let crate_ast = parse::parse_crate_from_source_str(
1622 "<test>".to_string(),
1625 expand_crate(&sess, test_ecfg(), vec!(), vec!(), crate_ast);
1628 fn expand_crate_str(crate_str: String) -> ast::Crate {
1629 let ps = parse::new_parse_sess();
1630 let crate_ast = string_to_parser(&ps, crate_str).parse_crate_mod();
1631 // the cfg argument actually does matter, here...
1632 expand_crate(&ps,test_ecfg(),vec!(),vec!(),crate_ast)
1635 // find the pat_ident paths in a crate
1636 fn crate_bindings(the_crate : &ast::Crate) -> Vec<ast::Ident> {
1637 let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
1638 visit::walk_crate(&mut name_finder, the_crate);
1639 name_finder.ident_accumulator
1642 #[test] fn macro_tokens_should_match(){
1644 "macro_rules! m((a)=>(13)) ;fn main(){m!(a);}".to_string());
1647 // should be able to use a bound identifier as a literal in a macro definition:
1648 #[test] fn self_macro_parsing(){
1650 "macro_rules! foo ((zz) => (287;));
1651 fn f(zz: i32) {foo!(zz);}".to_string()
1655 // renaming tests expand a crate and then check that the bindings match
1656 // the right varrefs. The specification of the test case includes the
1657 // text of the crate, and also an array of arrays. Each element in the
1658 // outer array corresponds to a binding in the traversal of the AST
1659 // induced by visit. Each of these arrays contains a list of indexes,
1660 // interpreted as the varrefs in the varref traversal that this binding
1661 // should match. So, for instance, in a program with two bindings and
1662 // three varrefs, the array ~[~[1,2],~[0]] would indicate that the first
1663 // binding should match the second two varrefs, and the second binding
1664 // should match the first varref.
1666 // Put differently; this is a sparse representation of a boolean matrix
1667 // indicating which bindings capture which identifiers.
1669 // Note also that this matrix is dependent on the implicit ordering of
1670 // the bindings and the varrefs discovered by the name-finder and the path-finder.
1672 // The comparisons are done post-mtwt-resolve, so we're comparing renamed
1673 // names; differences in marks don't matter any more.
1675 // oog... I also want tests that check "bound-identifier-=?". That is,
1676 // not just "do these have the same name", but "do they have the same
1677 // name *and* the same marks"? Understanding this is really pretty painful.
1678 // in principle, you might want to control this boolean on a per-varref basis,
1679 // but that would make things even harder to understand, and might not be
1680 // necessary for thorough testing.
1681 type RenamingTest = (&'static str, Vec<Vec<usize>>, bool);
1684 fn automatic_renaming () {
1685 let tests: Vec<RenamingTest> =
1686 vec!(// b & c should get new names throughout, in the expr too:
1687 ("fn a() -> i32 { let b = 13; let c = b; b+c }",
1688 vec!(vec!(0,1),vec!(2)), false),
1689 // both x's should be renamed (how is this causing a bug?)
1690 ("fn main () {let x: i32 = 13;x;}",
1691 vec!(vec!(0)), false),
1692 // the use of b after the + should be renamed, the other one not:
1693 ("macro_rules! f (($x:ident) => (b + $x)); fn a() -> i32 { let b = 13; f!(b)}",
1694 vec!(vec!(1)), false),
1695 // the b before the plus should not be renamed (requires marks)
1696 ("macro_rules! f (($x:ident) => ({let b=9; ($x + b)})); fn a() -> i32 { f!(b)}",
1697 vec!(vec!(1)), false),
1698 // the marks going in and out of letty should cancel, allowing that $x to
1699 // capture the one following the semicolon.
1700 // this was an awesome test case, and caught a *lot* of bugs.
1701 ("macro_rules! letty(($x:ident) => (let $x = 15;));
1702 macro_rules! user(($x:ident) => ({letty!($x); $x}));
1703 fn main() -> i32 {user!(z)}",
1704 vec!(vec!(0)), false)
1706 for (idx,s) in tests.iter().enumerate() {
1707 run_renaming_test(s,idx);
1711 // no longer a fixme #8062: this test exposes a *potential* bug; our system does
1712 // not behave exactly like MTWT, but a conversation with Matthew Flatt
1713 // suggests that this can only occur in the presence of local-expand, which
1714 // we have no plans to support. ... unless it's needed for item hygiene....
1716 #[test] fn issue_8062(){
1718 &("fn main() {let hrcoo = 19; macro_rules! getx(()=>(hrcoo)); getx!();}",
1719 vec!(vec!(0)), true), 0)
1723 // the z flows into and out of two macros (g & f) along one path, and one
1724 // (just g) along the other, so the result of the whole thing should
1725 // be "let z_123 = 3; z_123"
1727 #[test] fn issue_6994(){
1729 &("macro_rules! g (($x:ident) =>
1730 ({macro_rules! f(($y:ident)=>({let $y=3;$x}));f!($x)}));
1732 vec!(vec!(0)),false),
1736 // match variable hygiene. Should expand into
1737 // fn z() {match 8 {x_1 => {match 9 {x_2 | x_2 if x_2 == x_1 => x_2 + x_1}}}}
1738 #[test] fn issue_9384(){
1740 &("macro_rules! bad_macro (($ex:expr) => ({match 9 {x | x if x == $ex => x + $ex}}));
1741 fn z() {match 8 {x => bad_macro!(x)}}",
1742 // NB: the third "binding" is the repeat of the second one.
1743 vec!(vec!(1,3),vec!(0,2),vec!(0,2)),
1748 // interpolated nodes weren't getting labeled.
1749 // should expand into
1750 // fn main(){let g1_1 = 13; g1_1}}
1751 #[test] fn pat_expand_issue_15221(){
1753 &("macro_rules! inner ( ($e:pat ) => ($e));
1754 macro_rules! outer ( ($e:pat ) => (inner!($e)));
1755 fn main() { let outer!(g) = 13; g;}",
1761 // create a really evil test case where a $x appears inside a binding of $x
1762 // but *shouldn't* bind because it was inserted by a different macro....
1763 // can't write this test case until we have macro-generating macros.
1765 // method arg hygiene
1766 // method expands to fn get_x(&self_0, x_1: i32) {self_0 + self_2 + x_3 + x_1}
1767 #[test] fn method_arg_hygiene(){
1769 &("macro_rules! inject_x (()=>(x));
1770 macro_rules! inject_self (()=>(self));
1772 impl A{fn get_x(&self, x: i32) {self + inject_self!() + inject_x!() + x;} }",
1773 vec!(vec!(0),vec!(3)),
1778 // ooh, got another bite?
1779 // expands to struct A; impl A {fn thingy(&self_1) {self_1;}}
1780 #[test] fn method_arg_hygiene_2(){
1783 macro_rules! add_method (($T:ty) =>
1784 (impl $T { fn thingy(&self) {self;} }));
1792 // expands to fn q(x_1: i32){fn g(x_2: i32){x_2 + x_1};}
1793 #[test] fn issue_9383(){
1795 &("macro_rules! bad_macro (($ex:expr) => (fn g(x: i32){ x + $ex }));
1796 fn q(x: i32) { bad_macro!(x); }",
1797 vec!(vec!(1),vec!(0)),true),
1801 // closure arg hygiene (ExprClosure)
1802 // expands to fn f(){(|x_1 : i32| {(x_2 + x_1)})(3);}
1803 #[test] fn closure_arg_hygiene(){
1805 &("macro_rules! inject_x (()=>(x));
1806 fn f(){(|x : i32| {(inject_x!() + x)})(3);}",
1812 // macro_rules in method position. Sadly, unimplemented.
1813 #[test] fn macro_in_method_posn(){
1815 "macro_rules! my_method (() => (fn thirteen(&self) -> i32 {13}));
1817 impl A{ my_method!(); }
1818 fn f(){A.thirteen;}".to_string());
1821 // another nested macro
1822 // expands to impl Entries {fn size_hint(&self_1) {self_1;}
1823 #[test] fn item_macro_workaround(){
1825 &("macro_rules! item { ($i:item) => {$i}}
1827 macro_rules! iterator_impl {
1828 () => { item!( impl Entries { fn size_hint(&self) { self;}});}}
1829 iterator_impl! { }",
1830 vec!(vec!(0)), true),
1834 // run one of the renaming tests
1835 fn run_renaming_test(t: &RenamingTest, test_idx: usize) {
1836 let invalid_name = token::special_idents::invalid.name;
1837 let (teststr, bound_connections, bound_ident_check) = match *t {
1838 (ref str,ref conns, bic) => (str.to_string(), conns.clone(), bic)
1840 let cr = expand_crate_str(teststr.to_string());
1841 let bindings = crate_bindings(&cr);
1842 let varrefs = crate_varrefs(&cr);
1844 // must be one check clause for each binding:
1845 assert_eq!(bindings.len(),bound_connections.len());
1846 for (binding_idx,shouldmatch) in bound_connections.iter().enumerate() {
1847 let binding_name = mtwt::resolve(bindings[binding_idx]);
1848 let binding_marks = mtwt::marksof(bindings[binding_idx].ctxt, invalid_name);
1849 // shouldmatch can't name varrefs that don't exist:
1850 assert!((shouldmatch.len() == 0) ||
1851 (varrefs.len() > *shouldmatch.iter().max().unwrap()));
1852 for (idx,varref) in varrefs.iter().enumerate() {
1853 let print_hygiene_debug_info = || {
1854 // good lord, you can't make a path with 0 segments, can you?
1855 let final_varref_ident = match varref.segments.last() {
1856 Some(pathsegment) => pathsegment.identifier,
1857 None => panic!("varref with 0 path segments?")
1859 let varref_name = mtwt::resolve(final_varref_ident);
1860 let varref_idents : Vec<ast::Ident>
1861 = varref.segments.iter().map(|s| s.identifier)
1863 println!("varref #{}: {:?}, resolves to {}",idx, varref_idents, varref_name);
1864 let string = token::get_ident(final_varref_ident);
1865 println!("varref's first segment's string: \"{}\"", string.get());
1866 println!("binding #{}: {}, resolves to {}",
1867 binding_idx, bindings[binding_idx], binding_name);
1868 mtwt::with_sctable(|x| mtwt::display_sctable(x));
1870 if shouldmatch.contains(&idx) {
1871 // it should be a path of length 1, and it should
1872 // be free-identifier=? or bound-identifier=? to the given binding
1873 assert_eq!(varref.segments.len(),1);
1874 let varref_name = mtwt::resolve(varref.segments[0].identifier);
1875 let varref_marks = mtwt::marksof(varref.segments[0]
1879 if !(varref_name==binding_name) {
1880 println!("uh oh, should match but doesn't:");
1881 print_hygiene_debug_info();
1883 assert_eq!(varref_name,binding_name);
1884 if bound_ident_check {
1885 // we're checking bound-identifier=?, and the marks
1886 // should be the same, too:
1887 assert_eq!(varref_marks,binding_marks.clone());
1890 let varref_name = mtwt::resolve(varref.segments[0].identifier);
1891 let fail = (varref.segments.len() == 1)
1892 && (varref_name == binding_name);
1895 println!("failure on test {}",test_idx);
1896 println!("text of test case: \"{}\"", teststr);
1898 println!("uh oh, matches but shouldn't:");
1899 print_hygiene_debug_info();
1907 #[test] fn fmt_in_macro_used_inside_module_macro() {
1908 let crate_str = "macro_rules! fmt_wrap(($b:expr)=>($b.to_string()));
1909 macro_rules! foo_module (() => (mod generated { fn a() { let xx = 147; fmt_wrap!(xx);}}));
1912 let cr = expand_crate_str(crate_str);
1913 // find the xx binding
1914 let bindings = crate_bindings(&cr);
1915 let cxbinds: Vec<&ast::Ident> =
1916 bindings.iter().filter(|b| {
1917 let ident = token::get_ident(**b);
1918 let string = ident.get();
1921 let cxbinds: &[&ast::Ident] = &cxbinds[];
1922 let cxbind = match cxbinds {
1924 _ => panic!("expected just one binding for ext_cx")
1926 let resolved_binding = mtwt::resolve(*cxbind);
1927 let varrefs = crate_varrefs(&cr);
1929 // the xx binding should bind all of the xx varrefs:
1930 for (idx,v) in varrefs.iter().filter(|p| {
1931 p.segments.len() == 1
1932 && "xx" == token::get_ident(p.segments[0].identifier).get()
1934 if mtwt::resolve(v.segments[0].identifier) != resolved_binding {
1935 println!("uh oh, xx binding didn't match xx varref:");
1936 println!("this is xx varref \\# {}", idx);
1937 println!("binding: {}", cxbind);
1938 println!("resolves to: {}", resolved_binding);
1939 println!("varref: {}", v.segments[0].identifier);
1940 println!("resolves to: {}",
1941 mtwt::resolve(v.segments[0].identifier));
1942 mtwt::with_sctable(|x| mtwt::display_sctable(x));
1944 assert_eq!(mtwt::resolve(v.segments[0].identifier),
1951 let pat = string_to_pat(
1952 "(a,Foo{x:c @ (b,9),y:Bar(4,d)})".to_string());
1953 let idents = pattern_bindings(&*pat);
1954 assert_eq!(idents, strs_to_idents(vec!("a","c","b","d")));
1957 // test the list of identifier patterns gathered by the visitor. Note that
1958 // 'None' is listed as an identifier pattern because we don't yet know that
1959 // it's the name of a 0-ary variant, and that 'i' appears twice in succession.
1961 fn crate_bindings_test(){
1962 let the_crate = string_to_crate("fn main (a: i32) -> i32 {|b| {
1963 match 34 {None => 3, Some(i) | i => j, Foo{k:z,l:y} => \"banana\"}} }".to_string());
1964 let idents = crate_bindings(&the_crate);
1965 assert_eq!(idents, strs_to_idents(vec!("a","b","None","i","i","z","y")));
1968 // test the IdentRenamer directly
1970 fn ident_renamer_test () {
1971 let the_crate = string_to_crate("fn f(x: i32){let x = x; x}".to_string());
1972 let f_ident = token::str_to_ident("f");
1973 let x_ident = token::str_to_ident("x");
1974 let int_ident = token::str_to_ident("i32");
1975 let renames = vec!((x_ident,Name(16)));
1976 let mut renamer = IdentRenamer{renames: &renames};
1977 let renamed_crate = renamer.fold_crate(the_crate);
1978 let idents = crate_idents(&renamed_crate);
1979 let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
1980 assert_eq!(resolved,vec!(f_ident.name,Name(16),int_ident.name,Name(16),Name(16),Name(16)));
1983 // test the PatIdentRenamer; only PatIdents get renamed
1985 fn pat_ident_renamer_test () {
1986 let the_crate = string_to_crate("fn f(x: i32){let x = x; x}".to_string());
1987 let f_ident = token::str_to_ident("f");
1988 let x_ident = token::str_to_ident("x");
1989 let int_ident = token::str_to_ident("i32");
1990 let renames = vec!((x_ident,Name(16)));
1991 let mut renamer = PatIdentRenamer{renames: &renames};
1992 let renamed_crate = renamer.fold_crate(the_crate);
1993 let idents = crate_idents(&renamed_crate);
1994 let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
1995 let x_name = x_ident.name;
1996 assert_eq!(resolved,vec!(f_ident.name,Name(16),int_ident.name,Name(16),x_name,x_name));