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, Mac_, Name};
13 use ast::{ItemMac, MacStmtWithSemicolon, Mrk, Stmt, StmtDecl, StmtMac};
14 use ast::{StmtExpr, StmtSemi};
18 use ext::build::AstBuilder;
20 use attr::{AttrMetaMethods, WithAttrs};
22 use codemap::{Span, Spanned, ExpnInfo, NameAndSpan, MacroBang, MacroAttribute};
24 use feature_gate::{self, Features, GatedCfgAttr};
27 use util::move_map::MoveMap;
29 use parse::token::{fresh_mark, fresh_name, intern};
31 use util::small_vector::SmallVector;
36 use std::collections::HashSet;
39 pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
40 let expr_span = e.span;
41 return e.and_then(|ast::Expr {id, node, span, attrs}| match node {
43 // expr_mac should really be expr_ext or something; it's the
44 // entry-point for all syntax extensions.
45 ast::ExprMac(mac) => {
47 // Assert that we drop any macro attributes on the floor here
50 let expanded_expr = match expand_mac_invoc(mac, span,
55 return DummyResult::raw_expr(span);
59 // Keep going, outside-in.
60 let fully_expanded = fld.fold_expr(expanded_expr);
61 let span = fld.new_span(span);
64 fully_expanded.map(|e| ast::Expr {
65 id: ast::DUMMY_NODE_ID,
72 ast::ExprInPlace(placer, value_expr) => {
73 // Ensure feature-gate is enabled
74 feature_gate::check_for_placement_in(
76 &fld.cx.parse_sess.span_diagnostic,
79 let placer = fld.fold_expr(placer);
80 let value_expr = fld.fold_expr(value_expr);
81 fld.cx.expr(span, ast::ExprInPlace(placer, value_expr))
82 .with_attrs(fold_thin_attrs(attrs, fld))
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))
89 .with_attrs(fold_thin_attrs(attrs, fld))
92 ast::ExprWhileLet(pat, expr, body, opt_ident) => {
93 let pat = fld.fold_pat(pat);
94 let expr = fld.fold_expr(expr);
96 // Hygienic renaming of the body.
97 let ((body, opt_ident), mut rewritten_pats) =
98 rename_in_scope(vec![pat],
101 |rename_fld, fld, (body, opt_ident)| {
102 expand_loop_block(rename_fld.fold_block(body), opt_ident, fld)
104 assert!(rewritten_pats.len() == 1);
106 fld.cx.expr(span, ast::ExprWhileLet(rewritten_pats.remove(0), expr, body, opt_ident))
107 .with_attrs(fold_thin_attrs(attrs, fld))
110 ast::ExprLoop(loop_block, opt_ident) => {
111 let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
112 fld.cx.expr(span, ast::ExprLoop(loop_block, opt_ident))
113 .with_attrs(fold_thin_attrs(attrs, fld))
116 ast::ExprForLoop(pat, head, body, opt_ident) => {
117 let pat = fld.fold_pat(pat);
119 // Hygienic renaming of the for loop body (for loop binds its pattern).
120 let ((body, opt_ident), mut rewritten_pats) =
121 rename_in_scope(vec![pat],
124 |rename_fld, fld, (body, opt_ident)| {
125 expand_loop_block(rename_fld.fold_block(body), opt_ident, fld)
127 assert!(rewritten_pats.len() == 1);
129 let head = fld.fold_expr(head);
130 fld.cx.expr(span, ast::ExprForLoop(rewritten_pats.remove(0), head, body, opt_ident))
131 .with_attrs(fold_thin_attrs(attrs, fld))
134 ast::ExprIfLet(pat, sub_expr, body, else_opt) => {
135 let pat = fld.fold_pat(pat);
137 // Hygienic renaming of the body.
138 let (body, mut rewritten_pats) =
139 rename_in_scope(vec![pat],
142 |rename_fld, fld, body| {
143 fld.fold_block(rename_fld.fold_block(body))
145 assert!(rewritten_pats.len() == 1);
147 let else_opt = else_opt.map(|else_opt| fld.fold_expr(else_opt));
148 let sub_expr = fld.fold_expr(sub_expr);
149 fld.cx.expr(span, ast::ExprIfLet(rewritten_pats.remove(0), sub_expr, body, else_opt))
150 .with_attrs(fold_thin_attrs(attrs, fld))
153 ast::ExprClosure(capture_clause, fn_decl, block) => {
154 let (rewritten_fn_decl, rewritten_block)
155 = expand_and_rename_fn_decl_and_block(fn_decl, block, fld);
156 let new_node = ast::ExprClosure(capture_clause,
159 P(ast::Expr{id:id, node: new_node, span: fld.new_span(span),
160 attrs: fold_thin_attrs(attrs, fld)})
164 P(noop_fold_expr(ast::Expr {
174 /// Expand a (not-ident-style) macro invocation. Returns the result
175 /// of expansion and the mark which must be applied to the result.
176 /// Our current interface doesn't allow us to apply the mark to the
177 /// result until after calling make_expr, make_items, etc.
178 fn expand_mac_invoc<T, F, G>(mac: ast::Mac,
182 fld: &mut MacroExpander)
184 F: for<'a> FnOnce(Box<MacResult+'a>) -> Option<T>,
185 G: FnOnce(T, Mrk) -> T,
187 // it would almost certainly be cleaner to pass the whole
188 // macro invocation in, rather than pulling it apart and
189 // marking the tts and the ctxt separately. This also goes
190 // for the other three macro invocation chunks of code
193 let Mac_ { path: pth, tts, .. } = mac.node;
194 if pth.segments.len() > 1 {
195 fld.cx.span_err(pth.span,
196 "expected macro name without module \
198 // let compilation continue
201 let extname = pth.segments[0].identifier.name;
202 match fld.cx.syntax_env.find(extname) {
206 &format!("macro undefined: '{}!'",
209 // let compilation continue
212 Some(rc) => match *rc {
213 NormalTT(ref expandfun, exp_span, allow_internal_unstable) => {
214 fld.cx.bt_push(ExpnInfo {
216 callee: NameAndSpan {
217 format: MacroBang(extname),
219 allow_internal_unstable: allow_internal_unstable,
222 let fm = fresh_mark();
223 let marked_before = mark_tts(&tts[..], fm);
225 // The span that we pass to the expanders we want to
226 // be the root of the call stack. That's the most
227 // relevant span and it's the actual invocation of
229 let mac_span = fld.cx.original_span();
232 let expanded = expandfun.expand(fld.cx,
235 parse_thunk(expanded)
237 let parsed = match opt_parsed {
242 &format!("non-expression macro in expression position: {}",
248 Some(mark_thunk(parsed,fm))
253 &format!("'{}' is not a tt-style macro",
261 /// Rename loop label and expand its loop body
263 /// The renaming procedure for loop is different in the sense that the loop
264 /// body is in a block enclosed by loop head so the renaming of loop label
265 /// must be propagated to the enclosed context.
266 fn expand_loop_block(loop_block: P<Block>,
267 opt_ident: Option<Ident>,
268 fld: &mut MacroExpander) -> (P<Block>, Option<Ident>) {
271 let new_label = fresh_name(label);
272 let rename = (label, new_label);
274 // The rename *must not* be added to the pending list of current
275 // syntax context otherwise an unrelated `break` or `continue` in
276 // the same context will pick that up in the deferred renaming pass
277 // and be renamed incorrectly.
278 let mut rename_list = vec!(rename);
279 let mut rename_fld = IdentRenamer{renames: &mut rename_list};
280 let renamed_ident = rename_fld.fold_ident(label);
282 // The rename *must* be added to the enclosed syntax context for
283 // `break` or `continue` to pick up because by definition they are
284 // in a block enclosed by loop head.
285 fld.cx.syntax_env.push_frame();
286 fld.cx.syntax_env.info().pending_renames.push(rename);
287 let expanded_block = expand_block_elts(loop_block, fld);
288 fld.cx.syntax_env.pop_frame();
290 (expanded_block, Some(renamed_ident))
292 None => (fld.fold_block(loop_block), opt_ident)
296 // eval $e with a new exts frame.
297 // must be a macro so that $e isn't evaluated too early.
298 macro_rules! with_exts_frame {
299 ($extsboxexpr:expr,$macros_escape:expr,$e:expr) =>
300 ({$extsboxexpr.push_frame();
301 $extsboxexpr.info().macros_escape = $macros_escape;
303 $extsboxexpr.pop_frame();
308 // When we enter a module, record it, for the sake of `module!`
309 pub fn expand_item(it: P<ast::Item>, fld: &mut MacroExpander)
310 -> SmallVector<P<ast::Item>> {
311 let it = expand_item_multi_modifier(Annotatable::Item(it), fld);
313 expand_annotatable(it, fld)
314 .into_iter().map(|i| i.expect_item()).collect()
317 /// Expand item_underscore
318 fn expand_item_underscore(item: ast::Item_, fld: &mut MacroExpander) -> ast::Item_ {
320 ast::ItemFn(decl, unsafety, constness, abi, generics, body) => {
321 let (rewritten_fn_decl, rewritten_body)
322 = expand_and_rename_fn_decl_and_block(decl, body, fld);
323 let expanded_generics = fold::noop_fold_generics(generics,fld);
324 ast::ItemFn(rewritten_fn_decl, unsafety, constness, abi,
325 expanded_generics, rewritten_body)
327 _ => noop_fold_item_underscore(item, fld)
331 // does this attribute list contain "macro_use" ?
332 fn contains_macro_use(fld: &mut MacroExpander, attrs: &[ast::Attribute]) -> bool {
334 let mut is_use = attr.check_name("macro_use");
335 if attr.check_name("macro_escape") {
336 fld.cx.span_warn(attr.span, "macro_escape is a deprecated synonym for macro_use");
338 if let ast::AttrStyle::Inner = attr.node.style {
339 fld.cx.fileline_help(attr.span, "consider an outer attribute, \
340 #[macro_use] mod ...");
345 match attr.node.value.node {
346 ast::MetaWord(..) => (),
347 _ => fld.cx.span_err(attr.span, "arguments to macro_use are not allowed here"),
355 // Support for item-position macro invocations, exactly the same
356 // logic as for expression-position macro invocations.
357 pub fn expand_item_mac(it: P<ast::Item>,
358 fld: &mut MacroExpander) -> SmallVector<P<ast::Item>> {
359 let (extname, path_span, tts, span, attrs, ident) = it.and_then(|it| match it.node {
360 ItemMac(codemap::Spanned { node: Mac_ { path, tts, .. }, .. }) =>
361 (path.segments[0].identifier.name, path.span, tts, it.span, it.attrs, it.ident),
362 _ => fld.cx.span_bug(it.span, "invalid item macro invocation")
365 let fm = fresh_mark();
367 let expanded = match fld.cx.syntax_env.find(extname) {
369 fld.cx.span_err(path_span,
370 &format!("macro undefined: '{}!'",
372 // let compilation continue
373 return SmallVector::zero();
376 Some(rc) => match *rc {
377 NormalTT(ref expander, tt_span, allow_internal_unstable) => {
378 if ident.name != parse::token::special_idents::invalid.name {
381 &format!("macro {}! expects no ident argument, given '{}'",
384 return SmallVector::zero();
386 fld.cx.bt_push(ExpnInfo {
388 callee: NameAndSpan {
389 format: MacroBang(extname),
391 allow_internal_unstable: allow_internal_unstable,
394 // mark before expansion:
395 let marked_before = mark_tts(&tts[..], fm);
396 expander.expand(fld.cx, span, &marked_before[..])
398 IdentTT(ref expander, tt_span, allow_internal_unstable) => {
399 if ident.name == parse::token::special_idents::invalid.name {
400 fld.cx.span_err(path_span,
401 &format!("macro {}! expects an ident argument",
403 return SmallVector::zero();
405 fld.cx.bt_push(ExpnInfo {
407 callee: NameAndSpan {
408 format: MacroBang(extname),
410 allow_internal_unstable: allow_internal_unstable,
413 // mark before expansion:
414 let marked_tts = mark_tts(&tts[..], fm);
415 expander.expand(fld.cx, span, ident, marked_tts)
418 if ident.name == parse::token::special_idents::invalid.name {
419 fld.cx.span_err(path_span, "macro_rules! expects an ident argument");
420 return SmallVector::zero();
423 fld.cx.bt_push(ExpnInfo {
425 callee: NameAndSpan {
426 format: MacroBang(extname),
428 // `macro_rules!` doesn't directly allow
429 // unstable (this is orthogonal to whether
430 // the macro it creates allows it)
431 allow_internal_unstable: false,
434 // DON'T mark before expansion.
436 let allow_internal_unstable = attr::contains_name(&attrs,
437 "allow_internal_unstable");
439 // ensure any #[allow_internal_unstable]s are
440 // detected (including nested macro definitions
442 if allow_internal_unstable && !fld.cx.ecfg.enable_allow_internal_unstable() {
443 feature_gate::emit_feature_err(
444 &fld.cx.parse_sess.span_diagnostic,
445 "allow_internal_unstable",
447 feature_gate::GateIssue::Language,
448 feature_gate::EXPLAIN_ALLOW_INTERNAL_UNSTABLE)
451 let export = attr::contains_name(&attrs, "macro_export");
452 let def = ast::MacroDef {
455 id: ast::DUMMY_NODE_ID,
460 allow_internal_unstable: allow_internal_unstable,
463 fld.cx.insert_macro(def);
465 // macro_rules! has a side effect but expands to nothing.
467 return SmallVector::zero();
470 fld.cx.span_err(span,
471 &format!("{}! is not legal in item position",
473 return SmallVector::zero();
478 expanded.make_items()
481 let items = match items {
484 .map(|i| mark_item(i, fm))
485 .flat_map(|i| fld.fold_item(i).into_iter())
489 fld.cx.span_err(path_span,
490 &format!("non-item macro in item position: {}",
492 return SmallVector::zero();
501 fn expand_stmt(stmt: P<Stmt>, fld: &mut MacroExpander) -> SmallVector<P<Stmt>> {
502 let stmt = stmt.and_then(|stmt| stmt);
503 let (mac, style, attrs) = match stmt.node {
504 StmtMac(mac, style, attrs) => (mac, style, attrs),
505 _ => return expand_non_macro_stmt(stmt, fld)
508 // Assert that we drop any macro attributes on the floor here
511 let maybe_new_items =
512 expand_mac_invoc(mac.and_then(|m| m), stmt.span,
514 |stmts, mark| stmts.move_map(|m| mark_stmt(m, mark)),
517 let mut fully_expanded = match maybe_new_items {
519 // Keep going, outside-in.
520 let new_items = stmts.into_iter().flat_map(|s| {
521 fld.fold_stmt(s).into_iter()
526 None => SmallVector::zero()
529 // If this is a macro invocation with a semicolon, then apply that
530 // semicolon to the final statement produced by expansion.
531 if style == MacStmtWithSemicolon {
532 if let Some(stmt) = fully_expanded.pop() {
533 let new_stmt = stmt.map(|Spanned {node, span}| {
536 StmtExpr(e, stmt_id) => StmtSemi(e, stmt_id),
537 _ => node /* might already have a semi */
542 fully_expanded.push(new_stmt);
549 // expand a non-macro stmt. this is essentially the fallthrough for
550 // expand_stmt, above.
551 fn expand_non_macro_stmt(Spanned {node, span: stmt_span}: Stmt, fld: &mut MacroExpander)
552 -> SmallVector<P<Stmt>> {
555 StmtDecl(decl, node_id) => decl.and_then(|Spanned {node: decl, span}| match decl {
556 DeclLocal(local) => {
558 let rewritten_local = local.map(|Local {id, pat, ty, init, span, attrs}| {
559 // expand the ty since TyFixedLengthVec contains an Expr
560 // and thus may have a macro use
561 let expanded_ty = ty.map(|t| fld.fold_ty(t));
562 // expand the pat (it might contain macro uses):
563 let expanded_pat = fld.fold_pat(pat);
564 // find the PatIdents in the pattern:
565 // oh dear heaven... this is going to include the enum
566 // names, as well... but that should be okay, as long as
567 // the new names are gensyms for the old ones.
568 // generate fresh names, push them to a new pending list
569 let idents = pattern_bindings(&expanded_pat);
570 let mut new_pending_renames =
571 idents.iter().map(|ident| (*ident, fresh_name(*ident))).collect();
572 // rewrite the pattern using the new names (the old
573 // ones have already been applied):
574 let rewritten_pat = {
575 // nested binding to allow borrow to expire:
576 let mut rename_fld = IdentRenamer{renames: &mut new_pending_renames};
577 rename_fld.fold_pat(expanded_pat)
579 // add them to the existing pending renames:
580 fld.cx.syntax_env.info().pending_renames
581 .extend(new_pending_renames);
586 // also, don't forget to expand the init:
587 init: init.map(|e| fld.fold_expr(e)),
589 attrs: fold::fold_thin_attrs(attrs, fld),
592 SmallVector::one(P(Spanned {
593 node: StmtDecl(P(Spanned {
594 node: DeclLocal(rewritten_local),
602 noop_fold_stmt(Spanned {
603 node: StmtDecl(P(Spanned {
613 noop_fold_stmt(Spanned {
621 // expand the arm of a 'match', renaming for macro hygiene
622 fn expand_arm(arm: ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
623 // expand pats... they might contain macro uses:
624 let expanded_pats = arm.pats.move_map(|pat| fld.fold_pat(pat));
625 if expanded_pats.is_empty() {
626 panic!("encountered match arm with 0 patterns");
629 // apply renaming and then expansion to the guard and the body:
630 let ((rewritten_guard, rewritten_body), rewritten_pats) =
631 rename_in_scope(expanded_pats,
633 (arm.guard, arm.body),
634 |rename_fld, fld, (ag, ab)|{
635 let rewritten_guard = ag.map(|g| fld.fold_expr(rename_fld.fold_expr(g)));
636 let rewritten_body = fld.fold_expr(rename_fld.fold_expr(ab));
637 (rewritten_guard, rewritten_body)
641 attrs: fold::fold_attrs(arm.attrs, fld),
642 pats: rewritten_pats,
643 guard: rewritten_guard,
644 body: rewritten_body,
648 fn rename_in_scope<X, F>(pats: Vec<P<ast::Pat>>,
649 fld: &mut MacroExpander,
652 -> (X, Vec<P<ast::Pat>>)
653 where F: Fn(&mut IdentRenamer, &mut MacroExpander, X) -> X
655 // all of the pats must have the same set of bindings, so use the
656 // first one to extract them and generate new names:
657 let idents = pattern_bindings(&pats[0]);
658 let new_renames = idents.into_iter().map(|id| (id, fresh_name(id))).collect();
659 // apply the renaming, but only to the PatIdents:
660 let mut rename_pats_fld = PatIdentRenamer{renames:&new_renames};
661 let rewritten_pats = pats.move_map(|pat| rename_pats_fld.fold_pat(pat));
663 let mut rename_fld = IdentRenamer{ renames:&new_renames };
664 (f(&mut rename_fld, fld, x), rewritten_pats)
667 /// A visitor that extracts the PatIdent (binding) paths
668 /// from a given thingy and puts them in a mutable
671 struct PatIdentFinder {
672 ident_accumulator: Vec<ast::Ident>
675 impl<'v> Visitor<'v> for PatIdentFinder {
676 fn visit_pat(&mut self, pattern: &ast::Pat) {
678 ast::Pat { id: _, node: ast::PatIdent(_, ref path1, ref inner), span: _ } => {
679 self.ident_accumulator.push(path1.node);
680 // visit optional subpattern of PatIdent:
681 if let Some(ref subpat) = *inner {
682 self.visit_pat(subpat)
685 // use the default traversal for non-PatIdents
686 _ => visit::walk_pat(self, pattern)
691 /// find the PatIdent paths in a pattern
692 fn pattern_bindings(pat: &ast::Pat) -> Vec<ast::Ident> {
693 let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
694 name_finder.visit_pat(pat);
695 name_finder.ident_accumulator
698 /// find the PatIdent paths in a
699 fn fn_decl_arg_bindings(fn_decl: &ast::FnDecl) -> Vec<ast::Ident> {
700 let mut pat_idents = PatIdentFinder{ident_accumulator:Vec::new()};
701 for arg in &fn_decl.inputs {
702 pat_idents.visit_pat(&arg.pat);
704 pat_idents.ident_accumulator
707 // expand a block. pushes a new exts_frame, then calls expand_block_elts
708 pub fn expand_block(blk: P<Block>, fld: &mut MacroExpander) -> P<Block> {
709 // see note below about treatment of exts table
710 with_exts_frame!(fld.cx.syntax_env,false,
711 expand_block_elts(blk, fld))
714 // expand the elements of a block.
715 pub fn expand_block_elts(b: P<Block>, fld: &mut MacroExpander) -> P<Block> {
716 b.map(|Block {id, stmts, expr, rules, span}| {
717 let new_stmts = stmts.into_iter().flat_map(|x| {
718 // perform all pending renames
720 let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
721 let mut rename_fld = IdentRenamer{renames:pending_renames};
722 rename_fld.fold_stmt(x).expect_one("rename_fold didn't return one value")
724 // expand macros in the statement
725 fld.fold_stmt(renamed_stmt).into_iter()
727 let new_expr = expr.map(|x| {
729 let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
730 let mut rename_fld = IdentRenamer{renames:pending_renames};
731 rename_fld.fold_expr(x)
745 fn expand_pat(p: P<ast::Pat>, fld: &mut MacroExpander) -> P<ast::Pat> {
748 _ => return noop_fold_pat(p, fld)
750 p.map(|ast::Pat {node, span, ..}| {
751 let (pth, tts) = match node {
752 PatMac(mac) => (mac.node.path, mac.node.tts),
755 if pth.segments.len() > 1 {
756 fld.cx.span_err(pth.span, "expected macro name without module separators");
757 return DummyResult::raw_pat(span);
759 let extname = pth.segments[0].identifier.name;
760 let marked_after = match fld.cx.syntax_env.find(extname) {
762 fld.cx.span_err(pth.span,
763 &format!("macro undefined: '{}!'",
765 // let compilation continue
766 return DummyResult::raw_pat(span);
769 Some(rc) => match *rc {
770 NormalTT(ref expander, tt_span, allow_internal_unstable) => {
771 fld.cx.bt_push(ExpnInfo {
773 callee: NameAndSpan {
774 format: MacroBang(extname),
776 allow_internal_unstable: allow_internal_unstable,
780 let fm = fresh_mark();
781 let marked_before = mark_tts(&tts[..], fm);
782 let mac_span = fld.cx.original_span();
783 let pat = expander.expand(fld.cx,
785 &marked_before[..]).make_pat();
786 let expanded = match pat {
792 "non-pattern macro in pattern position: {}",
796 return DummyResult::raw_pat(span);
801 mark_pat(expanded,fm)
804 fld.cx.span_err(span,
805 &format!("{}! is not legal in pattern position",
807 return DummyResult::raw_pat(span);
813 fld.fold_pat(marked_after).node.clone();
817 id: ast::DUMMY_NODE_ID,
818 node: fully_expanded,
824 /// A tree-folder that applies every rename in its (mutable) list
825 /// to every identifier, including both bindings and varrefs
826 /// (and lots of things that will turn out to be neither)
827 pub struct IdentRenamer<'a> {
828 renames: &'a mtwt::RenameList,
831 impl<'a> Folder for IdentRenamer<'a> {
832 fn fold_ident(&mut self, id: Ident) -> Ident {
833 Ident::new(id.name, mtwt::apply_renames(self.renames, id.ctxt))
835 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
836 fold::noop_fold_mac(mac, self)
840 /// A tree-folder that applies every rename in its list to
841 /// the idents that are in PatIdent patterns. This is more narrowly
842 /// focused than IdentRenamer, and is needed for FnDecl,
843 /// where we want to rename the args but not the fn name or the generics etc.
844 pub struct PatIdentRenamer<'a> {
845 renames: &'a mtwt::RenameList,
848 impl<'a> Folder for PatIdentRenamer<'a> {
849 fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
851 ast::PatIdent(..) => {},
852 _ => return noop_fold_pat(pat, self)
855 pat.map(|ast::Pat {id, node, span}| match node {
856 ast::PatIdent(binding_mode, Spanned{span: sp, node: ident}, sub) => {
857 let new_ident = Ident::new(ident.name,
858 mtwt::apply_renames(self.renames, ident.ctxt));
860 ast::PatIdent(binding_mode,
861 Spanned{span: self.new_span(sp), node: new_ident},
862 sub.map(|p| self.fold_pat(p)));
866 span: self.new_span(span)
872 fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
873 fold::noop_fold_mac(mac, self)
877 fn expand_annotatable(a: Annotatable,
878 fld: &mut MacroExpander)
879 -> SmallVector<Annotatable> {
880 let a = expand_item_multi_modifier(a, fld);
882 let mut decorator_items = SmallVector::zero();
883 let mut new_attrs = Vec::new();
884 expand_decorators(a.clone(), fld, &mut decorator_items, &mut new_attrs);
886 let mut new_items: SmallVector<Annotatable> = match a {
887 Annotatable::Item(it) => match it.node {
888 ast::ItemMac(..) => {
889 expand_item_mac(it, fld).into_iter().map(|i| Annotatable::Item(i)).collect()
891 ast::ItemMod(_) | ast::ItemForeignMod(_) => {
893 it.ident.name != parse::token::special_idents::invalid.name;
896 fld.cx.mod_push(it.ident);
898 let macro_use = contains_macro_use(fld, &new_attrs[..]);
899 let result = with_exts_frame!(fld.cx.syntax_env,
901 noop_fold_item(it, fld));
905 result.into_iter().map(|i| Annotatable::Item(i)).collect()
908 let it = P(ast::Item {
912 noop_fold_item(it, fld).into_iter().map(|i| Annotatable::Item(i)).collect()
916 Annotatable::TraitItem(it) => match it.node {
917 ast::MethodTraitItem(_, Some(_)) => SmallVector::one(it.map(|ti| ast::TraitItem {
921 node: match ti.node {
922 ast::MethodTraitItem(sig, Some(body)) => {
923 let (sig, body) = expand_and_rename_method(sig, body, fld);
924 ast::MethodTraitItem(sig, Some(body))
928 span: fld.new_span(ti.span)
930 _ => fold::noop_fold_trait_item(it, fld)
931 }.into_iter().map(Annotatable::TraitItem).collect(),
933 Annotatable::ImplItem(ii) => {
934 expand_impl_item(ii, fld).into_iter().map(Annotatable::ImplItem).collect()
938 new_items.push_all(decorator_items);
942 // Partition a set of attributes into one kind of attribute, and other kinds.
943 macro_rules! partition {
944 ($fn_name: ident, $variant: ident) => {
945 #[allow(deprecated)] // The `allow` is needed because the `Modifier` variant might be used.
946 fn $fn_name(attrs: &[ast::Attribute],
948 -> (Vec<ast::Attribute>, Vec<ast::Attribute>) {
949 attrs.iter().cloned().partition(|attr| {
950 match fld.cx.syntax_env.find(intern(&attr.name())) {
951 Some(rc) => match *rc {
952 $variant(..) => true,
962 partition!(multi_modifiers, MultiModifier);
965 fn expand_decorators(a: Annotatable,
966 fld: &mut MacroExpander,
967 decorator_items: &mut SmallVector<Annotatable>,
968 new_attrs: &mut Vec<ast::Attribute>)
970 for attr in a.attrs() {
971 let mname = intern(&attr.name());
972 match fld.cx.syntax_env.find(mname) {
973 Some(rc) => match *rc {
974 MultiDecorator(ref dec) => {
975 attr::mark_used(&attr);
977 fld.cx.bt_push(ExpnInfo {
978 call_site: attr.span,
979 callee: NameAndSpan {
980 format: MacroAttribute(mname),
981 span: Some(attr.span),
982 // attributes can do whatever they like,
984 allow_internal_unstable: true,
988 // we'd ideally decorator_items.push_all(expand_annotatable(ann, fld)),
989 // but that double-mut-borrows fld
990 let mut items: SmallVector<Annotatable> = SmallVector::zero();
995 &mut |ann| items.push(ann));
996 decorator_items.extend(items.into_iter()
997 .flat_map(|ann| expand_annotatable(ann, fld).into_iter()));
1001 _ => new_attrs.push((*attr).clone()),
1003 _ => new_attrs.push((*attr).clone()),
1008 fn expand_item_multi_modifier(mut it: Annotatable,
1009 fld: &mut MacroExpander)
1011 let (modifiers, other_attrs) = multi_modifiers(it.attrs(), fld);
1013 // Update the attrs, leave everything else alone. Is this mutation really a good idea?
1014 it = it.fold_attrs(other_attrs);
1016 if modifiers.is_empty() {
1020 for attr in &modifiers {
1021 let mname = intern(&attr.name());
1023 match fld.cx.syntax_env.find(mname) {
1024 Some(rc) => match *rc {
1025 MultiModifier(ref mac) => {
1026 attr::mark_used(attr);
1027 fld.cx.bt_push(ExpnInfo {
1028 call_site: attr.span,
1029 callee: NameAndSpan {
1030 format: MacroAttribute(mname),
1031 span: Some(attr.span),
1032 // attributes can do whatever they like,
1034 allow_internal_unstable: true,
1037 it = mac.expand(fld.cx, attr.span, &*attr.node.value, it);
1046 // Expansion may have added new ItemModifiers.
1047 expand_item_multi_modifier(it, fld)
1050 fn expand_impl_item(ii: P<ast::ImplItem>, fld: &mut MacroExpander)
1051 -> SmallVector<P<ast::ImplItem>> {
1053 ast::ImplItemKind::Method(..) => SmallVector::one(ii.map(|ii| ast::ImplItem {
1058 node: match ii.node {
1059 ast::ImplItemKind::Method(sig, body) => {
1060 let (sig, body) = expand_and_rename_method(sig, body, fld);
1061 ast::ImplItemKind::Method(sig, body)
1065 span: fld.new_span(ii.span)
1067 ast::ImplItemKind::Macro(_) => {
1068 let (span, mac) = ii.and_then(|ii| match ii.node {
1069 ast::ImplItemKind::Macro(mac) => (ii.span, mac),
1072 let maybe_new_items =
1073 expand_mac_invoc(mac, span,
1074 |r| r.make_impl_items(),
1075 |meths, mark| meths.move_map(|m| mark_impl_item(m, mark)),
1078 match maybe_new_items {
1079 Some(impl_items) => {
1080 // expand again if necessary
1081 let new_items = impl_items.into_iter().flat_map(|ii| {
1082 expand_impl_item(ii, fld).into_iter()
1087 None => SmallVector::zero()
1090 _ => fold::noop_fold_impl_item(ii, fld)
1094 /// Given a fn_decl and a block and a MacroExpander, expand the fn_decl, then use the
1095 /// PatIdents in its arguments to perform renaming in the FnDecl and
1096 /// the block, returning both the new FnDecl and the new Block.
1097 fn expand_and_rename_fn_decl_and_block(fn_decl: P<ast::FnDecl>, block: P<ast::Block>,
1098 fld: &mut MacroExpander)
1099 -> (P<ast::FnDecl>, P<ast::Block>) {
1100 let expanded_decl = fld.fold_fn_decl(fn_decl);
1101 let idents = fn_decl_arg_bindings(&expanded_decl);
1103 idents.iter().map(|id| (*id,fresh_name(*id))).collect();
1104 // first, a renamer for the PatIdents, for the fn_decl:
1105 let mut rename_pat_fld = PatIdentRenamer{renames: &renames};
1106 let rewritten_fn_decl = rename_pat_fld.fold_fn_decl(expanded_decl);
1107 // now, a renamer for *all* idents, for the body:
1108 let mut rename_fld = IdentRenamer{renames: &renames};
1109 let rewritten_body = fld.fold_block(rename_fld.fold_block(block));
1110 (rewritten_fn_decl,rewritten_body)
1113 fn expand_and_rename_method(sig: ast::MethodSig, body: P<ast::Block>,
1114 fld: &mut MacroExpander)
1115 -> (ast::MethodSig, P<ast::Block>) {
1116 let (rewritten_fn_decl, rewritten_body)
1117 = expand_and_rename_fn_decl_and_block(sig.decl, body, fld);
1119 generics: fld.fold_generics(sig.generics),
1121 explicit_self: fld.fold_explicit_self(sig.explicit_self),
1122 unsafety: sig.unsafety,
1123 constness: sig.constness,
1124 decl: rewritten_fn_decl
1128 pub fn expand_type(t: P<ast::Ty>, fld: &mut MacroExpander) -> P<ast::Ty> {
1129 let t = match t.node.clone() {
1130 ast::Ty_::TyMac(mac) => {
1131 if fld.cx.ecfg.features.unwrap().type_macros {
1132 let expanded_ty = match expand_mac_invoc(mac, t.span,
1138 return DummyResult::raw_ty(t.span);
1142 // Keep going, outside-in.
1143 let fully_expanded = fld.fold_ty(expanded_ty);
1146 fully_expanded.map(|t| ast::Ty {
1147 id: ast::DUMMY_NODE_ID,
1152 feature_gate::emit_feature_err(
1153 &fld.cx.parse_sess.span_diagnostic,
1156 feature_gate::GateIssue::Language,
1157 "type macros are experimental");
1159 DummyResult::raw_ty(t.span)
1165 fold::noop_fold_ty(t, fld)
1168 /// A tree-folder that performs macro expansion
1169 pub struct MacroExpander<'a, 'b:'a> {
1170 pub cx: &'a mut ExtCtxt<'b>,
1173 impl<'a, 'b> MacroExpander<'a, 'b> {
1174 pub fn new(cx: &'a mut ExtCtxt<'b>) -> MacroExpander<'a, 'b> {
1175 MacroExpander { cx: cx }
1179 impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
1180 fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
1181 expand_expr(expr, self)
1184 fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
1185 expand_pat(pat, self)
1188 fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
1189 expand_item(item, self)
1192 fn fold_item_underscore(&mut self, item: ast::Item_) -> ast::Item_ {
1193 expand_item_underscore(item, self)
1196 fn fold_stmt(&mut self, stmt: P<ast::Stmt>) -> SmallVector<P<ast::Stmt>> {
1197 expand_stmt(stmt, self)
1200 fn fold_block(&mut self, block: P<Block>) -> P<Block> {
1201 expand_block(block, self)
1204 fn fold_arm(&mut self, arm: ast::Arm) -> ast::Arm {
1205 expand_arm(arm, self)
1208 fn fold_trait_item(&mut self, i: P<ast::TraitItem>) -> SmallVector<P<ast::TraitItem>> {
1209 expand_annotatable(Annotatable::TraitItem(i), self)
1210 .into_iter().map(|i| i.expect_trait_item()).collect()
1213 fn fold_impl_item(&mut self, i: P<ast::ImplItem>) -> SmallVector<P<ast::ImplItem>> {
1214 expand_annotatable(Annotatable::ImplItem(i), self)
1215 .into_iter().map(|i| i.expect_impl_item()).collect()
1218 fn fold_ty(&mut self, ty: P<ast::Ty>) -> P<ast::Ty> {
1219 expand_type(ty, self)
1222 fn new_span(&mut self, span: Span) -> Span {
1223 new_span(self.cx, span)
1227 fn new_span(cx: &ExtCtxt, sp: Span) -> Span {
1228 /* this discards information in the case of macro-defining macros */
1232 expn_id: cx.backtrace(),
1236 pub struct ExpansionConfig<'feat> {
1237 pub crate_name: String,
1238 pub features: Option<&'feat Features>,
1239 pub recursion_limit: usize,
1240 pub trace_mac: bool,
1243 macro_rules! feature_tests {
1244 ($( fn $getter:ident = $field:ident, )*) => {
1246 pub fn $getter(&self) -> bool {
1247 match self.features {
1248 Some(&Features { $field: true, .. }) => true,
1256 impl<'feat> ExpansionConfig<'feat> {
1257 pub fn default(crate_name: String) -> ExpansionConfig<'static> {
1259 crate_name: crate_name,
1261 recursion_limit: 64,
1267 fn enable_quotes = allow_quote,
1268 fn enable_asm = allow_asm,
1269 fn enable_log_syntax = allow_log_syntax,
1270 fn enable_concat_idents = allow_concat_idents,
1271 fn enable_trace_macros = allow_trace_macros,
1272 fn enable_allow_internal_unstable = allow_internal_unstable,
1273 fn enable_custom_derive = allow_custom_derive,
1274 fn enable_pushpop_unsafe = allow_pushpop_unsafe,
1278 pub fn expand_crate<'feat>(parse_sess: &parse::ParseSess,
1279 cfg: ExpansionConfig<'feat>,
1280 // these are the macros being imported to this crate:
1281 imported_macros: Vec<ast::MacroDef>,
1282 user_exts: Vec<NamedSyntaxExtension>,
1283 feature_gated_cfgs: &mut Vec<GatedCfgAttr>,
1284 c: Crate) -> (Crate, HashSet<Name>) {
1285 let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg,
1286 feature_gated_cfgs);
1287 if std_inject::no_core(&c) {
1288 cx.crate_root = None;
1289 } else if std_inject::no_std(&c) {
1290 cx.crate_root = Some("core");
1292 cx.crate_root = Some("std");
1295 let mut expander = MacroExpander::new(&mut cx);
1297 for def in imported_macros {
1298 expander.cx.insert_macro(def);
1301 for (name, extension) in user_exts {
1302 expander.cx.syntax_env.insert(name, extension);
1305 let mut ret = expander.fold_crate(c);
1306 ret.exported_macros = expander.cx.exported_macros.clone();
1307 parse_sess.span_diagnostic.handler().abort_if_errors();
1310 return (ret, cx.syntax_env.names);
1313 // HYGIENIC CONTEXT EXTENSION:
1314 // all of these functions are for walking over
1315 // ASTs and making some change to the context of every
1316 // element that has one. a CtxtFn is a trait-ified
1317 // version of a closure in (SyntaxContext -> SyntaxContext).
1318 // the ones defined here include:
1319 // Marker - add a mark to a context
1321 // A Marker adds the given mark to the syntax context
1322 struct Marker { mark: Mrk }
1324 impl Folder for Marker {
1325 fn fold_ident(&mut self, id: Ident) -> Ident {
1326 ast::Ident::new(id.name, mtwt::apply_mark(self.mark, id.ctxt))
1328 fn fold_mac(&mut self, Spanned {node, span}: ast::Mac) -> ast::Mac {
1331 path: self.fold_path(node.path),
1332 tts: self.fold_tts(&node.tts),
1333 ctxt: mtwt::apply_mark(self.mark, node.ctxt),
1340 // apply a given mark to the given token trees. Used prior to expansion of a macro.
1341 fn mark_tts(tts: &[TokenTree], m: Mrk) -> Vec<TokenTree> {
1342 noop_fold_tts(tts, &mut Marker{mark:m})
1345 // apply a given mark to the given expr. Used following the expansion of a macro.
1346 fn mark_expr(expr: P<ast::Expr>, m: Mrk) -> P<ast::Expr> {
1347 Marker{mark:m}.fold_expr(expr)
1350 // apply a given mark to the given pattern. Used following the expansion of a macro.
1351 fn mark_pat(pat: P<ast::Pat>, m: Mrk) -> P<ast::Pat> {
1352 Marker{mark:m}.fold_pat(pat)
1355 // apply a given mark to the given stmt. Used following the expansion of a macro.
1356 fn mark_stmt(stmt: P<ast::Stmt>, m: Mrk) -> P<ast::Stmt> {
1357 Marker{mark:m}.fold_stmt(stmt)
1358 .expect_one("marking a stmt didn't return exactly one stmt")
1361 // apply a given mark to the given item. Used following the expansion of a macro.
1362 fn mark_item(expr: P<ast::Item>, m: Mrk) -> P<ast::Item> {
1363 Marker{mark:m}.fold_item(expr)
1364 .expect_one("marking an item didn't return exactly one item")
1367 // apply a given mark to the given item. Used following the expansion of a macro.
1368 fn mark_impl_item(ii: P<ast::ImplItem>, m: Mrk) -> P<ast::ImplItem> {
1369 Marker{mark:m}.fold_impl_item(ii)
1370 .expect_one("marking an impl item didn't return exactly one impl item")
1373 fn mark_ty(ty: P<ast::Ty>, m: Mrk) -> P<ast::Ty> {
1374 Marker { mark: m }.fold_ty(ty)
1377 /// Check that there are no macro invocations left in the AST:
1378 pub fn check_for_macros(sess: &parse::ParseSess, krate: &ast::Crate) {
1379 visit::walk_crate(&mut MacroExterminator{sess:sess}, krate);
1382 /// A visitor that ensures that no macro invocations remain in an AST.
1383 struct MacroExterminator<'a>{
1384 sess: &'a parse::ParseSess
1387 impl<'a, 'v> Visitor<'v> for MacroExterminator<'a> {
1388 fn visit_mac(&mut self, mac: &ast::Mac) {
1389 self.sess.span_diagnostic.span_bug(mac.span,
1390 "macro exterminator: expected AST \
1391 with no macro invocations");
1398 use super::{pattern_bindings, expand_crate};
1399 use super::{PatIdentFinder, IdentRenamer, PatIdentRenamer, ExpansionConfig};
1407 use util::parser_testing::{string_to_parser};
1408 use util::parser_testing::{string_to_pat, string_to_crate, strs_to_idents};
1412 // a visitor that extracts the paths
1413 // from a given thingy and puts them in a mutable
1414 // array (passed in to the traversal)
1416 struct PathExprFinderContext {
1417 path_accumulator: Vec<ast::Path> ,
1420 impl<'v> Visitor<'v> for PathExprFinderContext {
1421 fn visit_expr(&mut self, expr: &ast::Expr) {
1422 if let ast::ExprPath(None, ref p) = expr.node {
1423 self.path_accumulator.push(p.clone());
1425 visit::walk_expr(self, expr);
1429 // find the variable references in a crate
1430 fn crate_varrefs(the_crate : &ast::Crate) -> Vec<ast::Path> {
1431 let mut path_finder = PathExprFinderContext{path_accumulator:Vec::new()};
1432 visit::walk_crate(&mut path_finder, the_crate);
1433 path_finder.path_accumulator
1436 /// A Visitor that extracts the identifiers from a thingy.
1437 // as a side note, I'm starting to want to abstract over these....
1438 struct IdentFinder {
1439 ident_accumulator: Vec<ast::Ident>
1442 impl<'v> Visitor<'v> for IdentFinder {
1443 fn visit_ident(&mut self, _: codemap::Span, id: ast::Ident){
1444 self.ident_accumulator.push(id);
1448 /// Find the idents in a crate
1449 fn crate_idents(the_crate: &ast::Crate) -> Vec<ast::Ident> {
1450 let mut ident_finder = IdentFinder{ident_accumulator: Vec::new()};
1451 visit::walk_crate(&mut ident_finder, the_crate);
1452 ident_finder.ident_accumulator
1455 // these following tests are quite fragile, in that they don't test what
1456 // *kind* of failure occurs.
1458 fn test_ecfg() -> ExpansionConfig<'static> {
1459 ExpansionConfig::default("test".to_string())
1462 // make sure that macros can't escape fns
1464 #[test] fn macros_cant_escape_fns_test () {
1465 let src = "fn bogus() {macro_rules! z (() => (3+4));}\
1466 fn inty() -> i32 { z!() }".to_string();
1467 let sess = parse::ParseSess::new();
1468 let crate_ast = parse::parse_crate_from_source_str(
1469 "<test>".to_string(),
1473 expand_crate(&sess,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast);
1476 // make sure that macros can't escape modules
1478 #[test] fn macros_cant_escape_mods_test () {
1479 let src = "mod foo {macro_rules! z (() => (3+4));}\
1480 fn inty() -> i32 { z!() }".to_string();
1481 let sess = parse::ParseSess::new();
1482 let crate_ast = parse::parse_crate_from_source_str(
1483 "<test>".to_string(),
1486 expand_crate(&sess,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast);
1489 // macro_use modules should allow macros to escape
1490 #[test] fn macros_can_escape_flattened_mods_test () {
1491 let src = "#[macro_use] mod foo {macro_rules! z (() => (3+4));}\
1492 fn inty() -> i32 { z!() }".to_string();
1493 let sess = parse::ParseSess::new();
1494 let crate_ast = parse::parse_crate_from_source_str(
1495 "<test>".to_string(),
1498 expand_crate(&sess, test_ecfg(), vec!(), vec!(), &mut vec![], crate_ast);
1501 fn expand_crate_str(crate_str: String) -> ast::Crate {
1502 let ps = parse::ParseSess::new();
1503 let crate_ast = panictry!(string_to_parser(&ps, crate_str).parse_crate_mod());
1504 // the cfg argument actually does matter, here...
1505 expand_crate(&ps,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast).0
1508 // find the pat_ident paths in a crate
1509 fn crate_bindings(the_crate : &ast::Crate) -> Vec<ast::Ident> {
1510 let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
1511 visit::walk_crate(&mut name_finder, the_crate);
1512 name_finder.ident_accumulator
1515 #[test] fn macro_tokens_should_match(){
1517 "macro_rules! m((a)=>(13)) ;fn main(){m!(a);}".to_string());
1520 // should be able to use a bound identifier as a literal in a macro definition:
1521 #[test] fn self_macro_parsing(){
1523 "macro_rules! foo ((zz) => (287;));
1524 fn f(zz: i32) {foo!(zz);}".to_string()
1528 // renaming tests expand a crate and then check that the bindings match
1529 // the right varrefs. The specification of the test case includes the
1530 // text of the crate, and also an array of arrays. Each element in the
1531 // outer array corresponds to a binding in the traversal of the AST
1532 // induced by visit. Each of these arrays contains a list of indexes,
1533 // interpreted as the varrefs in the varref traversal that this binding
1534 // should match. So, for instance, in a program with two bindings and
1535 // three varrefs, the array [[1, 2], [0]] would indicate that the first
1536 // binding should match the second two varrefs, and the second binding
1537 // should match the first varref.
1539 // Put differently; this is a sparse representation of a boolean matrix
1540 // indicating which bindings capture which identifiers.
1542 // Note also that this matrix is dependent on the implicit ordering of
1543 // the bindings and the varrefs discovered by the name-finder and the path-finder.
1545 // The comparisons are done post-mtwt-resolve, so we're comparing renamed
1546 // names; differences in marks don't matter any more.
1548 // oog... I also want tests that check "bound-identifier-=?". That is,
1549 // not just "do these have the same name", but "do they have the same
1550 // name *and* the same marks"? Understanding this is really pretty painful.
1551 // in principle, you might want to control this boolean on a per-varref basis,
1552 // but that would make things even harder to understand, and might not be
1553 // necessary for thorough testing.
1554 type RenamingTest = (&'static str, Vec<Vec<usize>>, bool);
1557 fn automatic_renaming () {
1558 let tests: Vec<RenamingTest> =
1559 vec!(// b & c should get new names throughout, in the expr too:
1560 ("fn a() -> i32 { let b = 13; let c = b; b+c }",
1561 vec!(vec!(0,1),vec!(2)), false),
1562 // both x's should be renamed (how is this causing a bug?)
1563 ("fn main () {let x: i32 = 13;x;}",
1564 vec!(vec!(0)), false),
1565 // the use of b after the + should be renamed, the other one not:
1566 ("macro_rules! f (($x:ident) => (b + $x)); fn a() -> i32 { let b = 13; f!(b)}",
1567 vec!(vec!(1)), false),
1568 // the b before the plus should not be renamed (requires marks)
1569 ("macro_rules! f (($x:ident) => ({let b=9; ($x + b)})); fn a() -> i32 { f!(b)}",
1570 vec!(vec!(1)), false),
1571 // the marks going in and out of letty should cancel, allowing that $x to
1572 // capture the one following the semicolon.
1573 // this was an awesome test case, and caught a *lot* of bugs.
1574 ("macro_rules! letty(($x:ident) => (let $x = 15;));
1575 macro_rules! user(($x:ident) => ({letty!($x); $x}));
1576 fn main() -> i32 {user!(z)}",
1577 vec!(vec!(0)), false)
1579 for (idx,s) in tests.iter().enumerate() {
1580 run_renaming_test(s,idx);
1584 // no longer a fixme #8062: this test exposes a *potential* bug; our system does
1585 // not behave exactly like MTWT, but a conversation with Matthew Flatt
1586 // suggests that this can only occur in the presence of local-expand, which
1587 // we have no plans to support. ... unless it's needed for item hygiene....
1592 &("fn main() {let hrcoo = 19; macro_rules! getx(()=>(hrcoo)); getx!();}",
1593 vec!(vec!(0)), true), 0)
1597 // the z flows into and out of two macros (g & f) along one path, and one
1598 // (just g) along the other, so the result of the whole thing should
1599 // be "let z_123 = 3; z_123"
1604 &("macro_rules! g (($x:ident) =>
1605 ({macro_rules! f(($y:ident)=>({let $y=3;$x}));f!($x)}));
1607 vec!(vec!(0)),false),
1611 // match variable hygiene. Should expand into
1612 // fn z() {match 8 {x_1 => {match 9 {x_2 | x_2 if x_2 == x_1 => x_2 + x_1}}}}
1616 &("macro_rules! bad_macro (($ex:expr) => ({match 9 {x | x if x == $ex => x + $ex}}));
1617 fn z() {match 8 {x => bad_macro!(x)}}",
1618 // NB: the third "binding" is the repeat of the second one.
1619 vec!(vec!(1,3),vec!(0,2),vec!(0,2)),
1624 // interpolated nodes weren't getting labeled.
1625 // should expand into
1626 // fn main(){let g1_1 = 13; g1_1}}
1628 fn pat_expand_issue_15221(){
1630 &("macro_rules! inner ( ($e:pat ) => ($e));
1631 macro_rules! outer ( ($e:pat ) => (inner!($e)));
1632 fn main() { let outer!(g) = 13; g;}",
1638 // create a really evil test case where a $x appears inside a binding of $x
1639 // but *shouldn't* bind because it was inserted by a different macro....
1640 // can't write this test case until we have macro-generating macros.
1642 // method arg hygiene
1643 // method expands to fn get_x(&self_0, x_1: i32) {self_0 + self_2 + x_3 + x_1}
1645 fn method_arg_hygiene(){
1647 &("macro_rules! inject_x (()=>(x));
1648 macro_rules! inject_self (()=>(self));
1650 impl A{fn get_x(&self, x: i32) {self + inject_self!() + inject_x!() + x;} }",
1651 vec!(vec!(0),vec!(3)),
1656 // ooh, got another bite?
1657 // expands to struct A; impl A {fn thingy(&self_1) {self_1;}}
1659 fn method_arg_hygiene_2(){
1662 macro_rules! add_method (($T:ty) =>
1663 (impl $T { fn thingy(&self) {self;} }));
1671 // expands to fn q(x_1: i32){fn g(x_2: i32){x_2 + x_1};}
1675 &("macro_rules! bad_macro (($ex:expr) => (fn g(x: i32){ x + $ex }));
1676 fn q(x: i32) { bad_macro!(x); }",
1677 vec!(vec!(1),vec!(0)),true),
1681 // closure arg hygiene (ExprClosure)
1682 // expands to fn f(){(|x_1 : i32| {(x_2 + x_1)})(3);}
1684 fn closure_arg_hygiene(){
1686 &("macro_rules! inject_x (()=>(x));
1687 fn f(){(|x : i32| {(inject_x!() + x)})(3);}",
1693 // macro_rules in method position. Sadly, unimplemented.
1695 fn macro_in_method_posn(){
1697 "macro_rules! my_method (() => (fn thirteen(&self) -> i32 {13}));
1699 impl A{ my_method!(); }
1700 fn f(){A.thirteen;}".to_string());
1703 // another nested macro
1704 // expands to impl Entries {fn size_hint(&self_1) {self_1;}
1706 fn item_macro_workaround(){
1708 &("macro_rules! item { ($i:item) => {$i}}
1710 macro_rules! iterator_impl {
1711 () => { item!( impl Entries { fn size_hint(&self) { self;}});}}
1712 iterator_impl! { }",
1713 vec!(vec!(0)), true),
1717 // run one of the renaming tests
1718 fn run_renaming_test(t: &RenamingTest, test_idx: usize) {
1719 let invalid_name = token::special_idents::invalid.name;
1720 let (teststr, bound_connections, bound_ident_check) = match *t {
1721 (ref str,ref conns, bic) => (str.to_string(), conns.clone(), bic)
1723 let cr = expand_crate_str(teststr.to_string());
1724 let bindings = crate_bindings(&cr);
1725 let varrefs = crate_varrefs(&cr);
1727 // must be one check clause for each binding:
1728 assert_eq!(bindings.len(),bound_connections.len());
1729 for (binding_idx,shouldmatch) in bound_connections.iter().enumerate() {
1730 let binding_name = mtwt::resolve(bindings[binding_idx]);
1731 let binding_marks = mtwt::marksof(bindings[binding_idx].ctxt, invalid_name);
1732 // shouldmatch can't name varrefs that don't exist:
1733 assert!((shouldmatch.is_empty()) ||
1734 (varrefs.len() > *shouldmatch.iter().max().unwrap()));
1735 for (idx,varref) in varrefs.iter().enumerate() {
1736 let print_hygiene_debug_info = || {
1737 // good lord, you can't make a path with 0 segments, can you?
1738 let final_varref_ident = match varref.segments.last() {
1739 Some(pathsegment) => pathsegment.identifier,
1740 None => panic!("varref with 0 path segments?")
1742 let varref_name = mtwt::resolve(final_varref_ident);
1743 let varref_idents : Vec<ast::Ident>
1744 = varref.segments.iter().map(|s| s.identifier)
1746 println!("varref #{}: {:?}, resolves to {}",idx, varref_idents, varref_name);
1747 println!("varref's first segment's string: \"{}\"", final_varref_ident);
1748 println!("binding #{}: {}, resolves to {}",
1749 binding_idx, bindings[binding_idx], binding_name);
1750 mtwt::with_sctable(|x| mtwt::display_sctable(x));
1752 if shouldmatch.contains(&idx) {
1753 // it should be a path of length 1, and it should
1754 // be free-identifier=? or bound-identifier=? to the given binding
1755 assert_eq!(varref.segments.len(),1);
1756 let varref_name = mtwt::resolve(varref.segments[0].identifier);
1757 let varref_marks = mtwt::marksof(varref.segments[0]
1761 if !(varref_name==binding_name) {
1762 println!("uh oh, should match but doesn't:");
1763 print_hygiene_debug_info();
1765 assert_eq!(varref_name,binding_name);
1766 if bound_ident_check {
1767 // we're checking bound-identifier=?, and the marks
1768 // should be the same, too:
1769 assert_eq!(varref_marks,binding_marks.clone());
1772 let varref_name = mtwt::resolve(varref.segments[0].identifier);
1773 let fail = (varref.segments.len() == 1)
1774 && (varref_name == binding_name);
1777 println!("failure on test {}",test_idx);
1778 println!("text of test case: \"{}\"", teststr);
1780 println!("uh oh, matches but shouldn't:");
1781 print_hygiene_debug_info();
1790 fn fmt_in_macro_used_inside_module_macro() {
1791 let crate_str = "macro_rules! fmt_wrap(($b:expr)=>($b.to_string()));
1792 macro_rules! foo_module (() => (mod generated { fn a() { let xx = 147; fmt_wrap!(xx);}}));
1795 let cr = expand_crate_str(crate_str);
1796 // find the xx binding
1797 let bindings = crate_bindings(&cr);
1798 let cxbinds: Vec<&ast::Ident> =
1799 bindings.iter().filter(|b| b.name.as_str() == "xx").collect();
1800 let cxbinds: &[&ast::Ident] = &cxbinds[..];
1801 let cxbind = match (cxbinds.len(), cxbinds.get(0)) {
1803 _ => panic!("expected just one binding for ext_cx")
1805 let resolved_binding = mtwt::resolve(*cxbind);
1806 let varrefs = crate_varrefs(&cr);
1808 // the xx binding should bind all of the xx varrefs:
1809 for (idx,v) in varrefs.iter().filter(|p| {
1810 p.segments.len() == 1
1811 && p.segments[0].identifier.name.as_str() == "xx"
1813 if mtwt::resolve(v.segments[0].identifier) != resolved_binding {
1814 println!("uh oh, xx binding didn't match xx varref:");
1815 println!("this is xx varref \\# {}", idx);
1816 println!("binding: {}", cxbind);
1817 println!("resolves to: {}", resolved_binding);
1818 println!("varref: {}", v.segments[0].identifier);
1819 println!("resolves to: {}",
1820 mtwt::resolve(v.segments[0].identifier));
1821 mtwt::with_sctable(|x| mtwt::display_sctable(x));
1823 assert_eq!(mtwt::resolve(v.segments[0].identifier),
1830 let pat = string_to_pat(
1831 "(a,Foo{x:c @ (b,9),y:Bar(4,d)})".to_string());
1832 let idents = pattern_bindings(&pat);
1833 assert_eq!(idents, strs_to_idents(vec!("a","c","b","d")));
1836 // test the list of identifier patterns gathered by the visitor. Note that
1837 // 'None' is listed as an identifier pattern because we don't yet know that
1838 // it's the name of a 0-ary variant, and that 'i' appears twice in succession.
1840 fn crate_bindings_test(){
1841 let the_crate = string_to_crate("fn main (a: i32) -> i32 {|b| {
1842 match 34 {None => 3, Some(i) | i => j, Foo{k:z,l:y} => \"banana\"}} }".to_string());
1843 let idents = crate_bindings(&the_crate);
1844 assert_eq!(idents, strs_to_idents(vec!("a","b","None","i","i","z","y")));
1847 // test the IdentRenamer directly
1849 fn ident_renamer_test () {
1850 let the_crate = string_to_crate("fn f(x: i32){let x = x; x}".to_string());
1851 let f_ident = token::str_to_ident("f");
1852 let x_ident = token::str_to_ident("x");
1853 let int_ident = token::str_to_ident("i32");
1854 let renames = vec!((x_ident,Name(16)));
1855 let mut renamer = IdentRenamer{renames: &renames};
1856 let renamed_crate = renamer.fold_crate(the_crate);
1857 let idents = crate_idents(&renamed_crate);
1858 let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
1859 assert_eq!(resolved, [f_ident.name,Name(16),int_ident.name,Name(16),Name(16),Name(16)]);
1862 // test the PatIdentRenamer; only PatIdents get renamed
1864 fn pat_ident_renamer_test () {
1865 let the_crate = string_to_crate("fn f(x: i32){let x = x; x}".to_string());
1866 let f_ident = token::str_to_ident("f");
1867 let x_ident = token::str_to_ident("x");
1868 let int_ident = token::str_to_ident("i32");
1869 let renames = vec!((x_ident,Name(16)));
1870 let mut renamer = PatIdentRenamer{renames: &renames};
1871 let renamed_crate = renamer.fold_crate(the_crate);
1872 let idents = crate_idents(&renamed_crate);
1873 let resolved : Vec<ast::Name> = idents.iter().map(|id| mtwt::resolve(*id)).collect();
1874 let x_name = x_ident.name;
1875 assert_eq!(resolved, [f_ident.name,Name(16),int_ident.name,Name(16),x_name,x_name]);