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) => {
234 // let result = match ::std::iter::IntoIterator::into_iter(<head>) {
236 // [opt_ident]: loop {
237 // match ::std::iter::Iterator::next(&mut iter) {
238 // ::std::option::Option::Some(<pat>) => <body>,
239 // ::std::option::Option::None => break
248 let head = fld.fold_expr(head);
250 // create an hygienic ident
252 let ident = fld.cx.ident_of("iter");
253 let new_ident = fresh_name(&ident);
254 let rename = (ident, new_ident);
255 let mut rename_list = vec![rename];
256 let mut rename_fld = IdentRenamer{ renames: &mut rename_list };
258 rename_fld.fold_ident(ident)
261 let pat_span = pat.span;
262 // `:;std::option::Option::Some(<pat>) => <body>`
264 let body_expr = fld.cx.expr_block(body);
265 let some_pat = fld.cx.pat_some(pat_span, pat);
267 fld.cx.arm(pat_span, vec![some_pat], body_expr)
270 // `::std::option::Option::None => break`
272 let break_expr = fld.cx.expr_break(span);
274 fld.cx.arm(span, vec![fld.cx.pat_none(span)], break_expr)
277 // `match ::std::iter::Iterator::next(&mut iter) { ... }`
281 fld.cx.ident_of("std"),
282 fld.cx.ident_of("iter"),
283 fld.cx.ident_of("Iterator"),
284 fld.cx.ident_of("next"),
287 fld.cx.path_global(span, strs)
289 let ref_mut_iter = fld.cx.expr_mut_addr_of(span, fld.cx.expr_ident(span, iter));
291 fld.cx.expr_call(span, fld.cx.expr_path(next_path), vec![ref_mut_iter]);
292 let arms = vec![pat_arm, break_arm];
294 fld.cx.expr(pat_span,
295 ast::ExprMatch(next_expr, arms, ast::MatchSource::ForLoopDesugar))
298 // `[opt_ident]: loop { ... }`
299 let loop_block = fld.cx.block_expr(match_expr);
300 let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
301 let loop_expr = fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident));
303 // `mut iter => { ... }`
306 fld.cx.pat_ident_binding_mode(span, iter, ast::BindByValue(ast::MutMutable));
307 fld.cx.arm(span, vec![iter_pat], loop_expr)
310 // `match ::std::iter::IntoIterator::into_iter(<head>) { ... }`
311 let into_iter_expr = {
312 let into_iter_path = {
314 fld.cx.ident_of("std"),
315 fld.cx.ident_of("iter"),
316 fld.cx.ident_of("IntoIterator"),
317 fld.cx.ident_of("into_iter"),
320 fld.cx.path_global(span, strs)
323 fld.cx.expr_call(span, fld.cx.expr_path(into_iter_path), vec![head])
326 let match_expr = fld.cx.expr_match(span, into_iter_expr, vec![iter_arm]);
328 // `{ let result = ...; result }`
329 let result_ident = token::gensym_ident("result");
333 vec![fld.cx.stmt_let(span, false, result_ident, match_expr)],
334 Some(fld.cx.expr_ident(span, result_ident))))
337 ast::ExprClosure(capture_clause, fn_decl, block) => {
338 let (rewritten_fn_decl, rewritten_block)
339 = expand_and_rename_fn_decl_and_block(fn_decl, block, fld);
340 let new_node = ast::ExprClosure(capture_clause,
343 P(ast::Expr{id:id, node: new_node, span: fld.new_span(span)})
347 P(noop_fold_expr(ast::Expr {
356 /// Expand a (not-ident-style) macro invocation. Returns the result
357 /// of expansion and the mark which must be applied to the result.
358 /// Our current interface doesn't allow us to apply the mark to the
359 /// result until after calling make_expr, make_items, etc.
360 fn expand_mac_invoc<T, F, G>(mac: ast::Mac, span: codemap::Span,
363 fld: &mut MacroExpander)
365 F: FnOnce(Box<MacResult>) -> Option<T>,
366 G: FnOnce(T, Mrk) -> T,
369 // it would almost certainly be cleaner to pass the whole
370 // macro invocation in, rather than pulling it apart and
371 // marking the tts and the ctxt separately. This also goes
372 // for the other three macro invocation chunks of code
374 // Token-tree macros:
375 MacInvocTT(pth, tts, _) => {
376 if pth.segments.len() > 1 {
377 fld.cx.span_err(pth.span,
378 "expected macro name without module \
380 // let compilation continue
383 let extname = pth.segments[0].identifier;
384 let extnamestr = token::get_ident(extname);
385 match fld.cx.syntax_env.find(&extname.name) {
389 &format!("macro undefined: '{}!'",
392 // let compilation continue
395 Some(rc) => match *rc {
396 NormalTT(ref expandfun, exp_span) => {
397 fld.cx.bt_push(ExpnInfo {
399 callee: NameAndSpan {
400 name: extnamestr.to_string(),
405 let fm = fresh_mark();
406 let marked_before = mark_tts(&tts[], fm);
408 // The span that we pass to the expanders we want to
409 // be the root of the call stack. That's the most
410 // relevant span and it's the actual invocation of
412 let mac_span = fld.cx.original_span();
415 let expanded = expandfun.expand(fld.cx,
418 parse_thunk(expanded)
420 let parsed = match opt_parsed {
425 &format!("non-expression macro in expression position: {}",
431 Some(mark_thunk(parsed,fm))
436 &format!("'{}' is not a tt-style macro",
446 /// Rename loop label and expand its loop body
448 /// The renaming procedure for loop is different in the sense that the loop
449 /// body is in a block enclosed by loop head so the renaming of loop label
450 /// must be propagated to the enclosed context.
451 fn expand_loop_block(loop_block: P<Block>,
452 opt_ident: Option<Ident>,
453 fld: &mut MacroExpander) -> (P<Block>, Option<Ident>) {
456 let new_label = fresh_name(&label);
457 let rename = (label, new_label);
459 // The rename *must not* be added to the pending list of current
460 // syntax context otherwise an unrelated `break` or `continue` in
461 // the same context will pick that up in the deferred renaming pass
462 // and be renamed incorrectly.
463 let mut rename_list = vec!(rename);
464 let mut rename_fld = IdentRenamer{renames: &mut rename_list};
465 let renamed_ident = rename_fld.fold_ident(label);
467 // The rename *must* be added to the enclosed syntax context for
468 // `break` or `continue` to pick up because by definition they are
469 // in a block enclosed by loop head.
470 fld.cx.syntax_env.push_frame();
471 fld.cx.syntax_env.info().pending_renames.push(rename);
472 let expanded_block = expand_block_elts(loop_block, fld);
473 fld.cx.syntax_env.pop_frame();
475 (expanded_block, Some(renamed_ident))
477 None => (fld.fold_block(loop_block), opt_ident)
481 // eval $e with a new exts frame.
482 // must be a macro so that $e isn't evaluated too early.
483 macro_rules! with_exts_frame {
484 ($extsboxexpr:expr,$macros_escape:expr,$e:expr) =>
485 ({$extsboxexpr.push_frame();
486 $extsboxexpr.info().macros_escape = $macros_escape;
488 $extsboxexpr.pop_frame();
493 // When we enter a module, record it, for the sake of `module!`
494 pub fn expand_item(it: P<ast::Item>, fld: &mut MacroExpander)
495 -> SmallVector<P<ast::Item>> {
496 let it = expand_item_modifiers(it, fld);
498 expand_annotatable(Annotatable::Item(it), fld)
499 .into_iter().map(|i| i.expect_item()).collect()
502 fn expand_item_modifiers(mut it: P<ast::Item>, fld: &mut MacroExpander)
504 // partition the attributes into ItemModifiers and others
505 let (modifiers, other_attrs) = modifiers(&it.attrs, fld);
507 // update the attrs, leave everything else alone. Is this mutation really a good idea?
513 if modifiers.is_empty() {
514 let it = expand_item_multi_modifier(Annotatable::Item(it), fld);
515 return it.expect_item();
518 for attr in &modifiers {
519 let mname = attr.name();
521 match fld.cx.syntax_env.find(&intern(&mname)) {
522 Some(rc) => match *rc {
523 Modifier(ref mac) => {
524 attr::mark_used(attr);
525 fld.cx.bt_push(ExpnInfo {
526 call_site: attr.span,
527 callee: NameAndSpan {
528 name: mname.to_string(),
529 format: MacroAttribute,
533 it = mac.expand(fld.cx, attr.span, &*attr.node.value, it);
542 // Expansion may have added new ItemModifiers.
543 // It is possible, that an item modifier could expand to a multi-modifier or
544 // vice versa. In this case we will expand all modifiers before multi-modifiers,
545 // which might give an odd ordering. However, I think it is unlikely that the
546 // two kinds will be mixed, and I old-style multi-modifiers should be deprecated
548 expand_item_modifiers(it, fld)
551 /// Expand item_underscore
552 fn expand_item_underscore(item: ast::Item_, fld: &mut MacroExpander) -> ast::Item_ {
554 ast::ItemFn(decl, fn_style, abi, generics, body) => {
555 let (rewritten_fn_decl, rewritten_body)
556 = expand_and_rename_fn_decl_and_block(decl, body, fld);
557 let expanded_generics = fold::noop_fold_generics(generics,fld);
558 ast::ItemFn(rewritten_fn_decl, fn_style, abi, expanded_generics, rewritten_body)
560 _ => noop_fold_item_underscore(item, fld)
564 // does this attribute list contain "macro_use" ?
565 fn contains_macro_use(fld: &mut MacroExpander, attrs: &[ast::Attribute]) -> bool {
567 let mut is_use = attr.check_name("macro_use");
568 if attr.check_name("macro_escape") {
569 fld.cx.span_warn(attr.span, "macro_escape is a deprecated synonym for macro_use");
571 if let ast::AttrInner = attr.node.style {
572 fld.cx.span_help(attr.span, "consider an outer attribute, \
573 #[macro_use] mod ...");
578 match attr.node.value.node {
579 ast::MetaWord(..) => (),
580 _ => fld.cx.span_err(attr.span, "arguments to macro_use are not allowed here"),
588 // Support for item-position macro invocations, exactly the same
589 // logic as for expression-position macro invocations.
590 pub fn expand_item_mac(it: P<ast::Item>,
591 fld: &mut MacroExpander) -> SmallVector<P<ast::Item>> {
592 let (extname, path_span, tts) = match it.node {
593 ItemMac(codemap::Spanned {
594 node: MacInvocTT(ref pth, ref tts, _),
597 (pth.segments[0].identifier, pth.span, (*tts).clone())
599 _ => fld.cx.span_bug(it.span, "invalid item macro invocation")
602 let extnamestr = token::get_ident(extname);
603 let fm = fresh_mark();
605 let expanded = match fld.cx.syntax_env.find(&extname.name) {
607 fld.cx.span_err(path_span,
608 &format!("macro undefined: '{}!'",
610 // let compilation continue
611 return SmallVector::zero();
614 Some(rc) => match *rc {
615 NormalTT(ref expander, span) => {
616 if it.ident.name != parse::token::special_idents::invalid.name {
619 &format!("macro {}! expects no ident argument, \
622 token::get_ident(it.ident))[]);
623 return SmallVector::zero();
625 fld.cx.bt_push(ExpnInfo {
627 callee: NameAndSpan {
628 name: extnamestr.to_string(),
633 // mark before expansion:
634 let marked_before = mark_tts(&tts[], fm);
635 expander.expand(fld.cx, it.span, &marked_before[])
637 IdentTT(ref expander, span) => {
638 if it.ident.name == parse::token::special_idents::invalid.name {
639 fld.cx.span_err(path_span,
640 &format!("macro {}! expects an ident argument",
642 return SmallVector::zero();
644 fld.cx.bt_push(ExpnInfo {
646 callee: NameAndSpan {
647 name: extnamestr.to_string(),
652 // mark before expansion:
653 let marked_tts = mark_tts(&tts[], fm);
654 expander.expand(fld.cx, it.span, it.ident, marked_tts)
657 if it.ident.name == parse::token::special_idents::invalid.name {
658 fld.cx.span_err(path_span,
659 &format!("macro_rules! expects an ident argument")
661 return SmallVector::zero();
663 fld.cx.bt_push(ExpnInfo {
665 callee: NameAndSpan {
666 name: extnamestr.to_string(),
671 // DON'T mark before expansion.
673 let def = ast::MacroDef {
675 attrs: it.attrs.clone(),
676 id: ast::DUMMY_NODE_ID,
679 export: attr::contains_name(&it.attrs, "macro_export"),
683 fld.cx.insert_macro(def);
685 // macro_rules! has a side effect but expands to nothing.
687 return SmallVector::zero();
690 fld.cx.span_err(it.span,
691 &format!("{}! is not legal in item position",
693 return SmallVector::zero();
698 expanded.make_items()
701 let items = match items {
704 .map(|i| mark_item(i, fm))
705 .flat_map(|i| fld.fold_item(i).into_iter())
709 fld.cx.span_err(path_span,
710 &format!("non-item macro in item position: {}",
712 return SmallVector::zero();
721 fn expand_stmt(s: Stmt, fld: &mut MacroExpander) -> SmallVector<P<Stmt>> {
722 let (mac, style) = match s.node {
723 StmtMac(mac, style) => (mac, style),
724 _ => return expand_non_macro_stmt(s, fld)
726 let expanded_stmt = match expand_mac_invoc(mac.and_then(|m| m), s.span,
731 return SmallVector::zero();
735 // Keep going, outside-in.
736 let fully_expanded = fld.fold_stmt(expanded_stmt);
739 if style == MacStmtWithSemicolon {
740 fully_expanded.into_iter().map(|s| s.map(|Spanned {node, span}| {
743 StmtExpr(e, stmt_id) => StmtSemi(e, stmt_id),
744 _ => node /* might already have a semi */
754 // expand a non-macro stmt. this is essentially the fallthrough for
755 // expand_stmt, above.
756 fn expand_non_macro_stmt(Spanned {node, span: stmt_span}: Stmt, fld: &mut MacroExpander)
757 -> SmallVector<P<Stmt>> {
760 StmtDecl(decl, node_id) => decl.and_then(|Spanned {node: decl, span}| match decl {
761 DeclLocal(local) => {
763 let rewritten_local = local.map(|Local {id, pat, ty, init, source, span}| {
764 // expand the ty since TyFixedLengthVec contains an Expr
765 // and thus may have a macro use
766 let expanded_ty = ty.map(|t| fld.fold_ty(t));
767 // expand the pat (it might contain macro uses):
768 let expanded_pat = fld.fold_pat(pat);
769 // find the PatIdents in the pattern:
770 // oh dear heaven... this is going to include the enum
771 // names, as well... but that should be okay, as long as
772 // the new names are gensyms for the old ones.
773 // generate fresh names, push them to a new pending list
774 let idents = pattern_bindings(&*expanded_pat);
775 let mut new_pending_renames =
776 idents.iter().map(|ident| (*ident, fresh_name(ident))).collect();
777 // rewrite the pattern using the new names (the old
778 // ones have already been applied):
779 let rewritten_pat = {
780 // nested binding to allow borrow to expire:
781 let mut rename_fld = IdentRenamer{renames: &mut new_pending_renames};
782 rename_fld.fold_pat(expanded_pat)
784 // add them to the existing pending renames:
785 fld.cx.syntax_env.info().pending_renames
786 .extend(new_pending_renames.into_iter());
791 // also, don't forget to expand the init:
792 init: init.map(|e| fld.fold_expr(e)),
797 SmallVector::one(P(Spanned {
798 node: StmtDecl(P(Spanned {
799 node: DeclLocal(rewritten_local),
807 noop_fold_stmt(Spanned {
808 node: StmtDecl(P(Spanned {
818 noop_fold_stmt(Spanned {
826 // expand the arm of a 'match', renaming for macro hygiene
827 fn expand_arm(arm: ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
828 // expand pats... they might contain macro uses:
829 let expanded_pats = arm.pats.move_map(|pat| fld.fold_pat(pat));
830 if expanded_pats.len() == 0 {
831 panic!("encountered match arm with 0 patterns");
833 // all of the pats must have the same set of bindings, so use the
834 // first one to extract them and generate new names:
835 let idents = pattern_bindings(&*expanded_pats[0]);
836 let new_renames = idents.into_iter().map(|id| (id, fresh_name(&id))).collect();
837 // apply the renaming, but only to the PatIdents:
838 let mut rename_pats_fld = PatIdentRenamer{renames:&new_renames};
839 let rewritten_pats = expanded_pats.move_map(|pat| rename_pats_fld.fold_pat(pat));
840 // apply renaming and then expansion to the guard and the body:
841 let mut rename_fld = IdentRenamer{renames:&new_renames};
842 let rewritten_guard =
843 arm.guard.map(|g| fld.fold_expr(rename_fld.fold_expr(g)));
844 let rewritten_body = fld.fold_expr(rename_fld.fold_expr(arm.body));
846 attrs: arm.attrs.move_map(|x| fld.fold_attribute(x)),
847 pats: rewritten_pats,
848 guard: rewritten_guard,
849 body: rewritten_body,
853 /// A visitor that extracts the PatIdent (binding) paths
854 /// from a given thingy and puts them in a mutable
857 struct PatIdentFinder {
858 ident_accumulator: Vec<ast::Ident>
861 impl<'v> Visitor<'v> for PatIdentFinder {
862 fn visit_pat(&mut self, pattern: &ast::Pat) {
864 ast::Pat { id: _, node: ast::PatIdent(_, ref path1, ref inner), span: _ } => {
865 self.ident_accumulator.push(path1.node);
866 // visit optional subpattern of PatIdent:
867 if let Some(ref subpat) = *inner {
868 self.visit_pat(&**subpat)
871 // use the default traversal for non-PatIdents
872 _ => visit::walk_pat(self, pattern)
877 /// find the PatIdent paths in a pattern
878 fn pattern_bindings(pat: &ast::Pat) -> Vec<ast::Ident> {
879 let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
880 name_finder.visit_pat(pat);
881 name_finder.ident_accumulator
884 /// find the PatIdent paths in a
885 fn fn_decl_arg_bindings(fn_decl: &ast::FnDecl) -> Vec<ast::Ident> {
886 let mut pat_idents = PatIdentFinder{ident_accumulator:Vec::new()};
887 for arg in &fn_decl.inputs {
888 pat_idents.visit_pat(&*arg.pat);
890 pat_idents.ident_accumulator
893 // expand a block. pushes a new exts_frame, then calls expand_block_elts
894 pub fn expand_block(blk: P<Block>, fld: &mut MacroExpander) -> P<Block> {
895 // see note below about treatment of exts table
896 with_exts_frame!(fld.cx.syntax_env,false,
897 expand_block_elts(blk, fld))
900 // expand the elements of a block.
901 pub fn expand_block_elts(b: P<Block>, fld: &mut MacroExpander) -> P<Block> {
902 b.map(|Block {id, stmts, expr, rules, span}| {
903 let new_stmts = stmts.into_iter().flat_map(|x| {
904 // perform all pending renames
906 let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
907 let mut rename_fld = IdentRenamer{renames:pending_renames};
908 rename_fld.fold_stmt(x).expect_one("rename_fold didn't return one value")
910 // expand macros in the statement
911 fld.fold_stmt(renamed_stmt).into_iter()
913 let new_expr = expr.map(|x| {
915 let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
916 let mut rename_fld = IdentRenamer{renames:pending_renames};
917 rename_fld.fold_expr(x)
931 fn expand_pat(p: P<ast::Pat>, fld: &mut MacroExpander) -> P<ast::Pat> {
934 _ => return noop_fold_pat(p, fld)
936 p.map(|ast::Pat {node, span, ..}| {
937 let (pth, tts) = match node {
938 PatMac(mac) => match mac.node {
939 MacInvocTT(pth, tts, _) => {
945 if pth.segments.len() > 1 {
946 fld.cx.span_err(pth.span, "expected macro name without module separators");
947 return DummyResult::raw_pat(span);
949 let extname = pth.segments[0].identifier;
950 let extnamestr = token::get_ident(extname);
951 let marked_after = match fld.cx.syntax_env.find(&extname.name) {
953 fld.cx.span_err(pth.span,
954 &format!("macro undefined: '{}!'",
956 // let compilation continue
957 return DummyResult::raw_pat(span);
960 Some(rc) => match *rc {
961 NormalTT(ref expander, tt_span) => {
962 fld.cx.bt_push(ExpnInfo {
964 callee: NameAndSpan {
965 name: extnamestr.to_string(),
971 let fm = fresh_mark();
972 let marked_before = mark_tts(&tts[], fm);
973 let mac_span = fld.cx.original_span();
974 let expanded = match expander.expand(fld.cx,
976 &marked_before[]).make_pat() {
982 "non-pattern macro in pattern position: {}",
986 return DummyResult::raw_pat(span);
991 mark_pat(expanded,fm)
994 fld.cx.span_err(span,
995 &format!("{}! is not legal in pattern position",
997 return DummyResult::raw_pat(span);
1002 let fully_expanded =
1003 fld.fold_pat(marked_after).node.clone();
1007 id: ast::DUMMY_NODE_ID,
1008 node: fully_expanded,
1014 /// A tree-folder that applies every rename in its (mutable) list
1015 /// to every identifier, including both bindings and varrefs
1016 /// (and lots of things that will turn out to be neither)
1017 pub struct IdentRenamer<'a> {
1018 renames: &'a mtwt::RenameList,
1021 impl<'a> Folder for IdentRenamer<'a> {
1022 fn fold_ident(&mut self, id: Ident) -> Ident {
1025 ctxt: mtwt::apply_renames(self.renames, id.ctxt),
1028 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1029 fold::noop_fold_mac(mac, self)
1033 /// A tree-folder that applies every rename in its list to
1034 /// the idents that are in PatIdent patterns. This is more narrowly
1035 /// focused than IdentRenamer, and is needed for FnDecl,
1036 /// where we want to rename the args but not the fn name or the generics etc.
1037 pub struct PatIdentRenamer<'a> {
1038 renames: &'a mtwt::RenameList,
1041 impl<'a> Folder for PatIdentRenamer<'a> {
1042 fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
1044 ast::PatIdent(..) => {},
1045 _ => return noop_fold_pat(pat, self)
1048 pat.map(|ast::Pat {id, node, span}| match node {
1049 ast::PatIdent(binding_mode, Spanned{span: sp, node: ident}, sub) => {
1050 let new_ident = Ident{name: ident.name,
1051 ctxt: mtwt::apply_renames(self.renames, ident.ctxt)};
1053 ast::PatIdent(binding_mode,
1054 Spanned{span: self.new_span(sp), node: new_ident},
1055 sub.map(|p| self.fold_pat(p)));
1059 span: self.new_span(span)
1065 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
1066 fold::noop_fold_mac(mac, self)
1070 fn expand_annotatable(a: Annotatable,
1071 fld: &mut MacroExpander)
1072 -> SmallVector<Annotatable> {
1073 let a = expand_item_multi_modifier(a, fld);
1075 let mut decorator_items = SmallVector::zero();
1076 let mut new_attrs = Vec::new();
1077 for attr in a.attrs() {
1078 let mname = attr.name();
1080 match fld.cx.syntax_env.find(&intern(&mname)) {
1081 Some(rc) => match *rc {
1082 Decorator(ref dec) => {
1084 Annotatable::Item(ref it) => it,
1085 // ItemDecorators are only implemented for Items.
1089 attr::mark_used(attr);
1091 fld.cx.bt_push(ExpnInfo {
1092 call_site: attr.span,
1093 callee: NameAndSpan {
1094 name: mname.to_string(),
1095 format: MacroAttribute,
1100 // we'd ideally decorator_items.push_all(expand_item(item, fld)),
1101 // but that double-mut-borrows fld
1102 let mut items: SmallVector<P<ast::Item>> = SmallVector::zero();
1103 dec.expand(fld.cx, attr.span, &*attr.node.value, &**it,
1104 box |item| items.push(item));
1105 decorator_items.extend(items.into_iter()
1106 .flat_map(|item| expand_item(item, fld).into_iter()));
1110 _ => new_attrs.push((*attr).clone()),
1112 _ => new_attrs.push((*attr).clone()),
1116 let mut new_items: SmallVector<Annotatable> = match a {
1117 Annotatable::Item(it) => match it.node {
1118 ast::ItemMac(..) => {
1119 expand_item_mac(it, fld).into_iter().map(|i| Annotatable::Item(i)).collect()
1121 ast::ItemMod(_) | ast::ItemForeignMod(_) => {
1123 it.ident.name != parse::token::special_idents::invalid.name;
1126 fld.cx.mod_push(it.ident);
1128 let macro_use = contains_macro_use(fld, &new_attrs[]);
1129 let result = with_exts_frame!(fld.cx.syntax_env,
1131 noop_fold_item(it, fld));
1135 result.into_iter().map(|i| Annotatable::Item(i)).collect()
1138 let it = P(ast::Item {
1142 noop_fold_item(it, fld).into_iter().map(|i| Annotatable::Item(i)).collect()
1145 Annotatable::TraitItem(it) => match it {
1146 ast::TraitItem::ProvidedMethod(m) => {
1147 expand_method(m, fld).into_iter().map(|m|
1148 Annotatable::TraitItem(ast::TraitItem::ProvidedMethod(m))).collect()
1150 ast::TraitItem::RequiredMethod(m) => {
1151 SmallVector::one(Annotatable::TraitItem(
1152 ast::TraitItem::RequiredMethod(fld.fold_type_method(m))))
1154 ast::TraitItem::TypeTraitItem(t) => {
1155 SmallVector::one(Annotatable::TraitItem(
1156 ast::TraitItem::TypeTraitItem(P(fld.fold_associated_type((*t).clone())))))
1159 Annotatable::ImplItem(it) => match it {
1160 ast::ImplItem::MethodImplItem(m) => {
1161 expand_method(m, fld).into_iter().map(|m|
1162 Annotatable::ImplItem(ast::ImplItem::MethodImplItem(m))).collect()
1164 ast::ImplItem::TypeImplItem(t) => {
1165 SmallVector::one(Annotatable::ImplItem(
1166 ast::ImplItem::TypeImplItem(P(fld.fold_typedef((*t).clone())))))
1171 new_items.push_all(decorator_items.into_iter().map(|i| Annotatable::Item(i)).collect());
1175 fn expand_trait_item(i: ast::TraitItem,
1176 fld: &mut MacroExpander)
1177 -> SmallVector<ast::TraitItem> {
1178 expand_annotatable(Annotatable::TraitItem(i), fld)
1179 .into_iter().map(|i| i.expect_trait_item()).collect()
1183 fn expand_impl_item(i: ast::ImplItem,
1184 fld: &mut MacroExpander)
1185 -> SmallVector<ast::ImplItem> {
1186 expand_annotatable(Annotatable::ImplItem(i), fld)
1187 .into_iter().map(|i| i.expect_impl_item()).collect()
1190 // partition the attributes into ItemModifiers and others
1191 fn modifiers(attrs: &Vec<ast::Attribute>,
1192 fld: &MacroExpander)
1193 -> (Vec<ast::Attribute>, Vec<ast::Attribute>) {
1194 attrs.iter().cloned().partition(|attr| {
1195 match fld.cx.syntax_env.find(&intern(&attr.name())) {
1196 Some(rc) => match *rc {
1197 Modifier(_) => true,
1205 // partition the attributes into MultiModifiers and others
1206 fn multi_modifiers(attrs: &[ast::Attribute],
1207 fld: &MacroExpander)
1208 -> (Vec<ast::Attribute>, Vec<ast::Attribute>) {
1209 attrs.iter().cloned().partition(|attr| {
1210 match fld.cx.syntax_env.find(&intern(&attr.name())) {
1211 Some(rc) => match *rc {
1212 MultiModifier(_) => true,
1220 fn expand_item_multi_modifier(mut it: Annotatable,
1221 fld: &mut MacroExpander)
1223 let (modifiers, other_attrs) = multi_modifiers(it.attrs(), fld);
1225 // Update the attrs, leave everything else alone. Is this mutation really a good idea?
1226 it = it.fold_attrs(other_attrs);
1228 if modifiers.is_empty() {
1232 for attr in &modifiers {
1233 let mname = attr.name();
1235 match fld.cx.syntax_env.find(&intern(&mname)) {
1236 Some(rc) => match *rc {
1237 MultiModifier(ref mac) => {
1238 attr::mark_used(attr);
1239 fld.cx.bt_push(ExpnInfo {
1240 call_site: attr.span,
1241 callee: NameAndSpan {
1242 name: mname.to_string(),
1243 format: MacroAttribute,
1247 it = mac.expand(fld.cx, attr.span, &*attr.node.value, it);
1256 // Expansion may have added new ItemModifiers.
1257 expand_item_multi_modifier(it, fld)
1261 fn expand_method(m: P<ast::Method>, fld: &mut MacroExpander) -> SmallVector<P<ast::Method>> {
1262 m.and_then(|m| match m.node {
1263 ast::MethDecl(ident,
1271 let id = fld.new_id(m.id);
1272 let (rewritten_fn_decl, rewritten_body)
1273 = expand_and_rename_fn_decl_and_block(decl, body, fld);
1274 SmallVector::one(P(ast::Method {
1275 attrs: m.attrs.move_map(|a| fld.fold_attribute(a)),
1277 span: fld.new_span(m.span),
1278 node: ast::MethDecl(fld.fold_ident(ident),
1279 noop_fold_generics(generics, fld),
1281 fld.fold_explicit_self(explicit_self),
1288 ast::MethMac(mac) => {
1289 let maybe_new_methods =
1290 expand_mac_invoc(mac, m.span,
1291 |r| r.make_methods(),
1292 |meths, mark| meths.move_map(|m| mark_method(m, mark)),
1295 match maybe_new_methods {
1297 // expand again if necessary
1298 let new_methods = methods.into_iter()
1299 .flat_map(|m| fld.fold_method(m).into_iter())
1304 None => SmallVector::zero()
1310 /// Given a fn_decl and a block and a MacroExpander, expand the fn_decl, then use the
1311 /// PatIdents in its arguments to perform renaming in the FnDecl and
1312 /// the block, returning both the new FnDecl and the new Block.
1313 fn expand_and_rename_fn_decl_and_block(fn_decl: P<ast::FnDecl>, block: P<ast::Block>,
1314 fld: &mut MacroExpander)
1315 -> (P<ast::FnDecl>, P<ast::Block>) {
1316 let expanded_decl = fld.fold_fn_decl(fn_decl);
1317 let idents = fn_decl_arg_bindings(&*expanded_decl);
1319 idents.iter().map(|id : &ast::Ident| (*id,fresh_name(id))).collect();
1320 // first, a renamer for the PatIdents, for the fn_decl:
1321 let mut rename_pat_fld = PatIdentRenamer{renames: &renames};
1322 let rewritten_fn_decl = rename_pat_fld.fold_fn_decl(expanded_decl);
1323 // now, a renamer for *all* idents, for the body:
1324 let mut rename_fld = IdentRenamer{renames: &renames};
1325 let rewritten_body = fld.fold_block(rename_fld.fold_block(block));
1326 (rewritten_fn_decl,rewritten_body)
1329 /// A tree-folder that performs macro expansion
1330 pub struct MacroExpander<'a, 'b:'a> {
1331 pub cx: &'a mut ExtCtxt<'b>,
1332 // The type of the impl currently being expanded.
1333 current_impl_type: Option<P<ast::Ty>>,
1336 impl<'a, 'b> MacroExpander<'a, 'b> {
1337 pub fn new(cx: &'a mut ExtCtxt<'b>) -> MacroExpander<'a, 'b> {
1338 MacroExpander { cx: cx, current_impl_type: None }
1342 impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
1343 fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
1344 expand_expr(expr, self)
1347 fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
1348 expand_pat(pat, self)
1351 fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
1352 let prev_type = self.current_impl_type.clone();
1353 if let ast::Item_::ItemImpl(_, _, _, _, ref ty, _) = item.node {
1354 self.current_impl_type = Some(ty.clone());
1357 let result = expand_item(item, self);
1358 self.current_impl_type = prev_type;
1362 fn fold_item_underscore(&mut self, item: ast::Item_) -> ast::Item_ {
1363 expand_item_underscore(item, self)
1366 fn fold_stmt(&mut self, stmt: P<ast::Stmt>) -> SmallVector<P<ast::Stmt>> {
1367 stmt.and_then(|stmt| expand_stmt(stmt, self))
1370 fn fold_block(&mut self, block: P<Block>) -> P<Block> {
1371 expand_block(block, self)
1374 fn fold_arm(&mut self, arm: ast::Arm) -> ast::Arm {
1375 expand_arm(arm, self)
1378 fn fold_trait_item(&mut self, i: ast::TraitItem) -> SmallVector<ast::TraitItem> {
1379 expand_trait_item(i, self)
1382 fn fold_impl_item(&mut self, i: ast::ImplItem) -> SmallVector<ast::ImplItem> {
1383 expand_impl_item(i, self)
1386 fn fold_method(&mut self, method: P<ast::Method>) -> SmallVector<P<ast::Method>> {
1387 expand_method(method, self)
1390 fn fold_ty(&mut self, t: P<ast::Ty>) -> P<ast::Ty> {
1391 let impl_type = self.current_impl_type.clone();
1392 expand_type(t, self, impl_type)
1395 fn new_span(&mut self, span: Span) -> Span {
1396 new_span(self.cx, span)
1400 fn new_span(cx: &ExtCtxt, sp: Span) -> Span {
1401 /* this discards information in the case of macro-defining macros */
1405 expn_id: cx.backtrace(),
1409 pub struct ExpansionConfig {
1410 pub crate_name: String,
1411 pub enable_quotes: bool,
1412 pub recursion_limit: usize,
1415 impl ExpansionConfig {
1416 pub fn default(crate_name: String) -> ExpansionConfig {
1418 crate_name: crate_name,
1419 enable_quotes: false,
1420 recursion_limit: 64,
1425 pub fn expand_crate(parse_sess: &parse::ParseSess,
1426 cfg: ExpansionConfig,
1427 // these are the macros being imported to this crate:
1428 imported_macros: Vec<ast::MacroDef>,
1429 user_exts: Vec<NamedSyntaxExtension>,
1430 c: Crate) -> Crate {
1431 let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg);
1432 let mut expander = MacroExpander::new(&mut cx);
1434 for def in imported_macros {
1435 expander.cx.insert_macro(def);
1438 for (name, extension) in user_exts {
1439 expander.cx.syntax_env.insert(name, extension);
1442 let mut ret = expander.fold_crate(c);
1443 ret.exported_macros = expander.cx.exported_macros.clone();
1444 parse_sess.span_diagnostic.handler().abort_if_errors();
1448 // HYGIENIC CONTEXT EXTENSION:
1449 // all of these functions are for walking over
1450 // ASTs and making some change to the context of every
1451 // element that has one. a CtxtFn is a trait-ified
1452 // version of a closure in (SyntaxContext -> SyntaxContext).
1453 // the ones defined here include:
1454 // Marker - add a mark to a context
1456 // A Marker adds the given mark to the syntax context
1457 struct Marker { mark: Mrk }
1459 impl Folder for Marker {
1460 fn fold_ident(&mut self, id: Ident) -> Ident {
1463 ctxt: mtwt::apply_mark(self.mark, id.ctxt)
1466 fn fold_mac(&mut self, Spanned {node, span}: ast::Mac) -> ast::Mac {
1469 MacInvocTT(path, tts, ctxt) => {
1470 MacInvocTT(self.fold_path(path),
1471 self.fold_tts(&tts[]),
1472 mtwt::apply_mark(self.mark, ctxt))
1480 // apply a given mark to the given token trees. Used prior to expansion of a macro.
1481 fn mark_tts(tts: &[TokenTree], m: Mrk) -> Vec<TokenTree> {
1482 noop_fold_tts(tts, &mut Marker{mark:m})
1485 // apply a given mark to the given expr. Used following the expansion of a macro.
1486 fn mark_expr(expr: P<ast::Expr>, m: Mrk) -> P<ast::Expr> {
1487 Marker{mark:m}.fold_expr(expr)
1490 // apply a given mark to the given pattern. Used following the expansion of a macro.
1491 fn mark_pat(pat: P<ast::Pat>, m: Mrk) -> P<ast::Pat> {
1492 Marker{mark:m}.fold_pat(pat)
1495 // apply a given mark to the given stmt. Used following the expansion of a macro.
1496 fn mark_stmt(expr: P<ast::Stmt>, m: Mrk) -> P<ast::Stmt> {
1497 Marker{mark:m}.fold_stmt(expr)
1498 .expect_one("marking a stmt didn't return exactly one stmt")
1501 // apply a given mark to the given item. Used following the expansion of a macro.
1502 fn mark_item(expr: P<ast::Item>, m: Mrk) -> P<ast::Item> {
1503 Marker{mark:m}.fold_item(expr)
1504 .expect_one("marking an item didn't return exactly one item")
1507 // apply a given mark to the given item. Used following the expansion of a macro.
1508 fn mark_method(expr: P<ast::Method>, m: Mrk) -> P<ast::Method> {
1509 Marker{mark:m}.fold_method(expr)
1510 .expect_one("marking an item didn't return exactly one method")
1513 /// Check that there are no macro invocations left in the AST:
1514 pub fn check_for_macros(sess: &parse::ParseSess, krate: &ast::Crate) {
1515 visit::walk_crate(&mut MacroExterminator{sess:sess}, krate);
1518 /// A visitor that ensures that no macro invocations remain in an AST.
1519 struct MacroExterminator<'a>{
1520 sess: &'a parse::ParseSess
1523 impl<'a, 'v> Visitor<'v> for MacroExterminator<'a> {
1524 fn visit_mac(&mut self, mac: &ast::Mac) {
1525 self.sess.span_diagnostic.span_bug(mac.span,
1526 "macro exterminator: expected AST \
1527 with no macro invocations");
1534 use super::{pattern_bindings, expand_crate};
1535 use super::{PatIdentFinder, IdentRenamer, PatIdentRenamer, ExpansionConfig};
1543 use util::parser_testing::{string_to_parser};
1544 use util::parser_testing::{string_to_pat, string_to_crate, strs_to_idents};
1548 // a visitor that extracts the paths
1549 // from a given thingy and puts them in a mutable
1550 // array (passed in to the traversal)
1552 struct PathExprFinderContext {
1553 path_accumulator: Vec<ast::Path> ,
1556 impl<'v> Visitor<'v> for PathExprFinderContext {
1557 fn visit_expr(&mut self, expr: &ast::Expr) {
1559 ast::ExprPath(ref p) => {
1560 self.path_accumulator.push(p.clone());
1561 // not calling visit_path, but it should be fine.
1563 _ => visit::walk_expr(self, expr)
1568 // find the variable references in a crate
1569 fn crate_varrefs(the_crate : &ast::Crate) -> Vec<ast::Path> {
1570 let mut path_finder = PathExprFinderContext{path_accumulator:Vec::new()};
1571 visit::walk_crate(&mut path_finder, the_crate);
1572 path_finder.path_accumulator
1575 /// A Visitor that extracts the identifiers from a thingy.
1576 // as a side note, I'm starting to want to abstract over these....
1577 struct IdentFinder {
1578 ident_accumulator: Vec<ast::Ident>
1581 impl<'v> Visitor<'v> for IdentFinder {
1582 fn visit_ident(&mut self, _: codemap::Span, id: ast::Ident){
1583 self.ident_accumulator.push(id);
1587 /// Find the idents in a crate
1588 fn crate_idents(the_crate: &ast::Crate) -> Vec<ast::Ident> {
1589 let mut ident_finder = IdentFinder{ident_accumulator: Vec::new()};
1590 visit::walk_crate(&mut ident_finder, the_crate);
1591 ident_finder.ident_accumulator
1594 // these following tests are quite fragile, in that they don't test what
1595 // *kind* of failure occurs.
1597 fn test_ecfg() -> ExpansionConfig {
1598 ExpansionConfig::default("test".to_string())
1601 // make sure that macros can't escape fns
1603 #[test] fn macros_cant_escape_fns_test () {
1604 let src = "fn bogus() {macro_rules! z (() => (3+4));}\
1605 fn inty() -> i32 { z!() }".to_string();
1606 let sess = parse::new_parse_sess();
1607 let crate_ast = parse::parse_crate_from_source_str(
1608 "<test>".to_string(),
1612 expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
1615 // make sure that macros can't escape modules
1617 #[test] fn macros_cant_escape_mods_test () {
1618 let src = "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 // macro_use modules should allow macros to escape
1629 #[test] fn macros_can_escape_flattened_mods_test () {
1630 let src = "#[macro_use] mod foo {macro_rules! z (() => (3+4));}\
1631 fn inty() -> i32 { z!() }".to_string();
1632 let sess = parse::new_parse_sess();
1633 let crate_ast = parse::parse_crate_from_source_str(
1634 "<test>".to_string(),
1637 expand_crate(&sess, test_ecfg(), vec!(), vec!(), crate_ast);
1640 fn expand_crate_str(crate_str: String) -> ast::Crate {
1641 let ps = parse::new_parse_sess();
1642 let crate_ast = string_to_parser(&ps, crate_str).parse_crate_mod();
1643 // the cfg argument actually does matter, here...
1644 expand_crate(&ps,test_ecfg(),vec!(),vec!(),crate_ast)
1647 // find the pat_ident paths in a crate
1648 fn crate_bindings(the_crate : &ast::Crate) -> Vec<ast::Ident> {
1649 let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
1650 visit::walk_crate(&mut name_finder, the_crate);
1651 name_finder.ident_accumulator
1654 #[test] fn macro_tokens_should_match(){
1656 "macro_rules! m((a)=>(13)) ;fn main(){m!(a);}".to_string());
1659 // should be able to use a bound identifier as a literal in a macro definition:
1660 #[test] fn self_macro_parsing(){
1662 "macro_rules! foo ((zz) => (287;));
1663 fn f(zz: i32) {foo!(zz);}".to_string()
1667 // renaming tests expand a crate and then check that the bindings match
1668 // the right varrefs. The specification of the test case includes the
1669 // text of the crate, and also an array of arrays. Each element in the
1670 // outer array corresponds to a binding in the traversal of the AST
1671 // induced by visit. Each of these arrays contains a list of indexes,
1672 // interpreted as the varrefs in the varref traversal that this binding
1673 // should match. So, for instance, in a program with two bindings and
1674 // three varrefs, the array ~[~[1,2],~[0]] would indicate that the first
1675 // binding should match the second two varrefs, and the second binding
1676 // should match the first varref.
1678 // Put differently; this is a sparse representation of a boolean matrix
1679 // indicating which bindings capture which identifiers.
1681 // Note also that this matrix is dependent on the implicit ordering of
1682 // the bindings and the varrefs discovered by the name-finder and the path-finder.
1684 // The comparisons are done post-mtwt-resolve, so we're comparing renamed
1685 // names; differences in marks don't matter any more.
1687 // oog... I also want tests that check "bound-identifier-=?". That is,
1688 // not just "do these have the same name", but "do they have the same
1689 // name *and* the same marks"? Understanding this is really pretty painful.
1690 // in principle, you might want to control this boolean on a per-varref basis,
1691 // but that would make things even harder to understand, and might not be
1692 // necessary for thorough testing.
1693 type RenamingTest = (&'static str, Vec<Vec<usize>>, bool);
1696 fn automatic_renaming () {
1697 let tests: Vec<RenamingTest> =
1698 vec!(// b & c should get new names throughout, in the expr too:
1699 ("fn a() -> i32 { let b = 13; let c = b; b+c }",
1700 vec!(vec!(0,1),vec!(2)), false),
1701 // both x's should be renamed (how is this causing a bug?)
1702 ("fn main () {let x: i32 = 13;x;}",
1703 vec!(vec!(0)), false),
1704 // the use of b after the + should be renamed, the other one not:
1705 ("macro_rules! f (($x:ident) => (b + $x)); fn a() -> i32 { let b = 13; f!(b)}",
1706 vec!(vec!(1)), false),
1707 // the b before the plus should not be renamed (requires marks)
1708 ("macro_rules! f (($x:ident) => ({let b=9; ($x + b)})); fn a() -> i32 { f!(b)}",
1709 vec!(vec!(1)), false),
1710 // the marks going in and out of letty should cancel, allowing that $x to
1711 // capture the one following the semicolon.
1712 // this was an awesome test case, and caught a *lot* of bugs.
1713 ("macro_rules! letty(($x:ident) => (let $x = 15;));
1714 macro_rules! user(($x:ident) => ({letty!($x); $x}));
1715 fn main() -> i32 {user!(z)}",
1716 vec!(vec!(0)), false)
1718 for (idx,s) in tests.iter().enumerate() {
1719 run_renaming_test(s,idx);
1723 // no longer a fixme #8062: this test exposes a *potential* bug; our system does
1724 // not behave exactly like MTWT, but a conversation with Matthew Flatt
1725 // suggests that this can only occur in the presence of local-expand, which
1726 // we have no plans to support. ... unless it's needed for item hygiene....
1728 #[test] fn issue_8062(){
1730 &("fn main() {let hrcoo = 19; macro_rules! getx(()=>(hrcoo)); getx!();}",
1731 vec!(vec!(0)), true), 0)
1735 // the z flows into and out of two macros (g & f) along one path, and one
1736 // (just g) along the other, so the result of the whole thing should
1737 // be "let z_123 = 3; z_123"
1739 #[test] fn issue_6994(){
1741 &("macro_rules! g (($x:ident) =>
1742 ({macro_rules! f(($y:ident)=>({let $y=3;$x}));f!($x)}));
1744 vec!(vec!(0)),false),
1748 // match variable hygiene. Should expand into
1749 // fn z() {match 8 {x_1 => {match 9 {x_2 | x_2 if x_2 == x_1 => x_2 + x_1}}}}
1750 #[test] fn issue_9384(){
1752 &("macro_rules! bad_macro (($ex:expr) => ({match 9 {x | x if x == $ex => x + $ex}}));
1753 fn z() {match 8 {x => bad_macro!(x)}}",
1754 // NB: the third "binding" is the repeat of the second one.
1755 vec!(vec!(1,3),vec!(0,2),vec!(0,2)),
1760 // interpolated nodes weren't getting labeled.
1761 // should expand into
1762 // fn main(){let g1_1 = 13; g1_1}}
1763 #[test] fn pat_expand_issue_15221(){
1765 &("macro_rules! inner ( ($e:pat ) => ($e));
1766 macro_rules! outer ( ($e:pat ) => (inner!($e)));
1767 fn main() { let outer!(g) = 13; g;}",
1773 // create a really evil test case where a $x appears inside a binding of $x
1774 // but *shouldn't* bind because it was inserted by a different macro....
1775 // can't write this test case until we have macro-generating macros.
1777 // method arg hygiene
1778 // method expands to fn get_x(&self_0, x_1: i32) {self_0 + self_2 + x_3 + x_1}
1779 #[test] fn method_arg_hygiene(){
1781 &("macro_rules! inject_x (()=>(x));
1782 macro_rules! inject_self (()=>(self));
1784 impl A{fn get_x(&self, x: i32) {self + inject_self!() + inject_x!() + x;} }",
1785 vec!(vec!(0),vec!(3)),
1790 // ooh, got another bite?
1791 // expands to struct A; impl A {fn thingy(&self_1) {self_1;}}
1792 #[test] fn method_arg_hygiene_2(){
1795 macro_rules! add_method (($T:ty) =>
1796 (impl $T { fn thingy(&self) {self;} }));
1804 // expands to fn q(x_1: i32){fn g(x_2: i32){x_2 + x_1};}
1805 #[test] fn issue_9383(){
1807 &("macro_rules! bad_macro (($ex:expr) => (fn g(x: i32){ x + $ex }));
1808 fn q(x: i32) { bad_macro!(x); }",
1809 vec!(vec!(1),vec!(0)),true),
1813 // closure arg hygiene (ExprClosure)
1814 // expands to fn f(){(|x_1 : i32| {(x_2 + x_1)})(3);}
1815 #[test] fn closure_arg_hygiene(){
1817 &("macro_rules! inject_x (()=>(x));
1818 fn f(){(|x : i32| {(inject_x!() + x)})(3);}",
1824 // macro_rules in method position. Sadly, unimplemented.
1825 #[test] fn macro_in_method_posn(){
1827 "macro_rules! my_method (() => (fn thirteen(&self) -> i32 {13}));
1829 impl A{ my_method!(); }
1830 fn f(){A.thirteen;}".to_string());
1833 // another nested macro
1834 // expands to impl Entries {fn size_hint(&self_1) {self_1;}
1835 #[test] fn item_macro_workaround(){
1837 &("macro_rules! item { ($i:item) => {$i}}
1839 macro_rules! iterator_impl {
1840 () => { item!( impl Entries { fn size_hint(&self) { self;}});}}
1841 iterator_impl! { }",
1842 vec!(vec!(0)), true),
1846 // run one of the renaming tests
1847 fn run_renaming_test(t: &RenamingTest, test_idx: usize) {
1848 let invalid_name = token::special_idents::invalid.name;
1849 let (teststr, bound_connections, bound_ident_check) = match *t {
1850 (ref str,ref conns, bic) => (str.to_string(), conns.clone(), bic)
1852 let cr = expand_crate_str(teststr.to_string());
1853 let bindings = crate_bindings(&cr);
1854 let varrefs = crate_varrefs(&cr);
1856 // must be one check clause for each binding:
1857 assert_eq!(bindings.len(),bound_connections.len());
1858 for (binding_idx,shouldmatch) in bound_connections.iter().enumerate() {
1859 let binding_name = mtwt::resolve(bindings[binding_idx]);
1860 let binding_marks = mtwt::marksof(bindings[binding_idx].ctxt, invalid_name);
1861 // shouldmatch can't name varrefs that don't exist:
1862 assert!((shouldmatch.len() == 0) ||
1863 (varrefs.len() > *shouldmatch.iter().max().unwrap()));
1864 for (idx,varref) in varrefs.iter().enumerate() {
1865 let print_hygiene_debug_info = || {
1866 // good lord, you can't make a path with 0 segments, can you?
1867 let final_varref_ident = match varref.segments.last() {
1868 Some(pathsegment) => pathsegment.identifier,
1869 None => panic!("varref with 0 path segments?")
1871 let varref_name = mtwt::resolve(final_varref_ident);
1872 let varref_idents : Vec<ast::Ident>
1873 = varref.segments.iter().map(|s| s.identifier)
1875 println!("varref #{}: {:?}, resolves to {}",idx, varref_idents, varref_name);
1876 let string = token::get_ident(final_varref_ident);
1877 println!("varref's first segment's string: \"{}\"", &string[]);
1878 println!("binding #{}: {}, resolves to {}",
1879 binding_idx, bindings[binding_idx], binding_name);
1880 mtwt::with_sctable(|x| mtwt::display_sctable(x));
1882 if shouldmatch.contains(&idx) {
1883 // it should be a path of length 1, and it should
1884 // be free-identifier=? or bound-identifier=? to the given binding
1885 assert_eq!(varref.segments.len(),1);
1886 let varref_name = mtwt::resolve(varref.segments[0].identifier);
1887 let varref_marks = mtwt::marksof(varref.segments[0]
1891 if !(varref_name==binding_name) {
1892 println!("uh oh, should match but doesn't:");
1893 print_hygiene_debug_info();
1895 assert_eq!(varref_name,binding_name);
1896 if bound_ident_check {
1897 // we're checking bound-identifier=?, and the marks
1898 // should be the same, too:
1899 assert_eq!(varref_marks,binding_marks.clone());
1902 let varref_name = mtwt::resolve(varref.segments[0].identifier);
1903 let fail = (varref.segments.len() == 1)
1904 && (varref_name == binding_name);
1907 println!("failure on test {}",test_idx);
1908 println!("text of test case: \"{}\"", teststr);
1910 println!("uh oh, matches but shouldn't:");
1911 print_hygiene_debug_info();
1919 #[test] fn fmt_in_macro_used_inside_module_macro() {
1920 let crate_str = "macro_rules! fmt_wrap(($b:expr)=>($b.to_string()));
1921 macro_rules! foo_module (() => (mod generated { fn a() { let xx = 147; fmt_wrap!(xx);}}));
1924 let cr = expand_crate_str(crate_str);
1925 // find the xx binding
1926 let bindings = crate_bindings(&cr);
1927 let cxbinds: Vec<&ast::Ident> =
1928 bindings.iter().filter(|b| {
1929 let ident = token::get_ident(**b);
1930 let string = &ident[];
1933 let cxbinds: &[&ast::Ident] = &cxbinds[];
1934 let cxbind = match cxbinds {
1936 _ => panic!("expected just one binding for ext_cx")
1938 let resolved_binding = mtwt::resolve(*cxbind);
1939 let varrefs = crate_varrefs(&cr);
1941 // the xx binding should bind all of the xx varrefs:
1942 for (idx,v) in varrefs.iter().filter(|p| {
1943 p.segments.len() == 1
1944 && "xx" == &token::get_ident(p.segments[0].identifier)[]
1946 if mtwt::resolve(v.segments[0].identifier) != resolved_binding {
1947 println!("uh oh, xx binding didn't match xx varref:");
1948 println!("this is xx varref \\# {}", idx);
1949 println!("binding: {}", cxbind);
1950 println!("resolves to: {}", resolved_binding);
1951 println!("varref: {}", v.segments[0].identifier);
1952 println!("resolves to: {}",
1953 mtwt::resolve(v.segments[0].identifier));
1954 mtwt::with_sctable(|x| mtwt::display_sctable(x));
1956 assert_eq!(mtwt::resolve(v.segments[0].identifier),
1963 let pat = string_to_pat(
1964 "(a,Foo{x:c @ (b,9),y:Bar(4,d)})".to_string());
1965 let idents = pattern_bindings(&*pat);
1966 assert_eq!(idents, strs_to_idents(vec!("a","c","b","d")));
1969 // test the list of identifier patterns gathered by the visitor. Note that
1970 // 'None' is listed as an identifier pattern because we don't yet know that
1971 // it's the name of a 0-ary variant, and that 'i' appears twice in succession.
1973 fn crate_bindings_test(){
1974 let the_crate = string_to_crate("fn main (a: i32) -> i32 {|b| {
1975 match 34 {None => 3, Some(i) | i => j, Foo{k:z,l:y} => \"banana\"}} }".to_string());
1976 let idents = crate_bindings(&the_crate);
1977 assert_eq!(idents, strs_to_idents(vec!("a","b","None","i","i","z","y")));
1980 // test the IdentRenamer directly
1982 fn ident_renamer_test () {
1983 let the_crate = string_to_crate("fn f(x: i32){let x = x; x}".to_string());
1984 let f_ident = token::str_to_ident("f");
1985 let x_ident = token::str_to_ident("x");
1986 let int_ident = token::str_to_ident("i32");
1987 let renames = vec!((x_ident,Name(16)));
1988 let mut renamer = IdentRenamer{renames: &renames};
1989 let renamed_crate = renamer.fold_crate(the_crate);
1990 let idents = crate_idents(&renamed_crate);
1991 let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
1992 assert_eq!(resolved,vec!(f_ident.name,Name(16),int_ident.name,Name(16),Name(16),Name(16)));
1995 // test the PatIdentRenamer; only PatIdents get renamed
1997 fn pat_ident_renamer_test () {
1998 let the_crate = string_to_crate("fn f(x: i32){let x = x; x}".to_string());
1999 let f_ident = token::str_to_ident("f");
2000 let x_ident = token::str_to_ident("x");
2001 let int_ident = token::str_to_ident("i32");
2002 let renames = vec!((x_ident,Name(16)));
2003 let mut renamer = PatIdentRenamer{renames: &renames};
2004 let renamed_crate = renamer.fold_crate(the_crate);
2005 let idents = crate_idents(&renamed_crate);
2006 let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
2007 let x_name = x_ident.name;
2008 assert_eq!(resolved,vec!(f_ident.name,Name(16),int_ident.name,Name(16),x_name,x_name));