[rustc.git] / src / libsyntax / config.rs

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use attr::HasAttrs;
use feature_gate::{feature_err, EXPLAIN_STMT_ATTR_SYNTAX, Features, get_features, GateIssue};
use {fold, attr};
use ast;
use codemap::Spanned;
use parse::{token, ParseSess};
use syntax_pos::Span;

use ptr::P;
use util::small_vector::SmallVector;

/// A folder that strips out items that do not belong in the current configuration.
pub struct StripUnconfigured<'a> {
    pub should_test: bool,
    pub sess: &'a ParseSess,
    pub features: Option<&'a Features>,
}

// `cfg_attr`-process the crate's attributes and compute the crate's features.
pub fn features(mut krate: ast::Crate, sess: &ParseSess, should_test: bool)
                -> (ast::Crate, Features) {
    let features;
    {
        let mut strip_unconfigured = StripUnconfigured {
            should_test: should_test,
            sess: sess,
            features: None,
        };

        let unconfigured_attrs = krate.attrs.clone();
        let err_count = sess.span_diagnostic.err_count();
        if let Some(attrs) = strip_unconfigured.configure(krate.attrs) {
            krate.attrs = attrs;
        } else { // the entire crate is unconfigured
            krate.attrs = Vec::new();
            krate.module.items = Vec::new();
            return (krate, Features::new());
        }

        features = get_features(&sess.span_diagnostic, &krate.attrs);

        // Avoid reconfiguring malformed `cfg_attr`s
        if err_count == sess.span_diagnostic.err_count() {
            strip_unconfigured.features = Some(&features);
            strip_unconfigured.configure(unconfigured_attrs);
        }
    }

    (krate, features)
}

macro_rules! configure {
    ($this:ident, $node:ident) => {
        match $this.configure($node) {
            Some(node) => node,
            None => return Default::default(),
        }
    }
}

impl<'a> StripUnconfigured<'a> {
    pub fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
        let node = self.process_cfg_attrs(node);
        if self.in_cfg(node.attrs()) { Some(node) } else { None }
    }

    pub fn process_cfg_attrs<T: HasAttrs>(&mut self, node: T) -> T {
        node.map_attrs(|attrs| {
            attrs.into_iter().filter_map(|attr| self.process_cfg_attr(attr)).collect()
        })
    }

    fn process_cfg_attr(&mut self, attr: ast::Attribute) -> Option<ast::Attribute> {
        if !attr.check_name("cfg_attr") {
            return Some(attr);
        }

        let (cfg, path, tokens, span) = match attr.parse(self.sess, |parser| {
            parser.expect(&token::OpenDelim(token::Paren))?;
            let cfg = parser.parse_meta_item()?;
            parser.expect(&token::Comma)?;
            let lo = parser.span.lo;
            let (path, tokens) = parser.parse_path_and_tokens()?;
            parser.expect(&token::CloseDelim(token::Paren))?;
            Ok((cfg, path, tokens, Span { lo: lo, ..parser.prev_span }))
        }) {
            Ok(result) => result,
            Err(mut e) => {
                e.emit();
                return None;
            }
        };

        if attr::cfg_matches(&cfg, self.sess, self.features) {
            self.process_cfg_attr(ast::Attribute {
                id: attr::mk_attr_id(),
                style: attr.style,
                path: path,
                tokens: tokens,
                is_sugared_doc: false,
                span: span,
            })
        } else {
            None
        }
    }

    // Determine if a node with the given attributes should be included in this configuation.
    pub fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool {
        attrs.iter().all(|attr| {
            // When not compiling with --test we should not compile the #[test] functions
            if !self.should_test && is_test_or_bench(attr) {
                return false;
            }

            let mis = if !is_cfg(attr) {
                return true;
            } else if let Some(mis) = attr.meta_item_list() {
                mis
            } else {
                return true;
            };

            if mis.len() != 1 {
                self.sess.span_diagnostic.span_err(attr.span, "expected 1 cfg-pattern");
                return true;
            }

            if !mis[0].is_meta_item() {
                self.sess.span_diagnostic.span_err(mis[0].span, "unexpected literal");
                return true;
            }

            attr::cfg_matches(mis[0].meta_item().unwrap(), self.sess, self.features)
        })
    }

    // Visit attributes on expression and statements (but not attributes on items in blocks).
    fn visit_expr_attrs(&mut self, attrs: &[ast::Attribute]) {
        // flag the offending attributes
        for attr in attrs.iter() {
            if !self.features.map(|features| features.stmt_expr_attributes).unwrap_or(true) {
                let mut err = feature_err(self.sess,
                                          "stmt_expr_attributes",
                                          attr.span,
                                          GateIssue::Language,
                                          EXPLAIN_STMT_ATTR_SYNTAX);
                if attr.is_sugared_doc {
                    err.help("`///` is for documentation comments. For a plain comment, use `//`.");
                }
                err.emit();
            }
        }
    }

    pub fn configure_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
        ast::ForeignMod {
            abi: foreign_mod.abi,
            items: foreign_mod.items.into_iter().filter_map(|item| self.configure(item)).collect(),
        }
    }

    fn configure_variant_data(&mut self, vdata: ast::VariantData) -> ast::VariantData {
        match vdata {
            ast::VariantData::Struct(fields, id) => {
                let fields = fields.into_iter().filter_map(|field| self.configure(field));
                ast::VariantData::Struct(fields.collect(), id)
            }
            ast::VariantData::Tuple(fields, id) => {
                let fields = fields.into_iter().filter_map(|field| self.configure(field));
                ast::VariantData::Tuple(fields.collect(), id)
            }
            ast::VariantData::Unit(id) => ast::VariantData::Unit(id)
        }
    }

    pub fn configure_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
        match item {
            ast::ItemKind::Struct(def, generics) => {
                ast::ItemKind::Struct(self.configure_variant_data(def), generics)
            }
            ast::ItemKind::Union(def, generics) => {
                ast::ItemKind::Union(self.configure_variant_data(def), generics)
            }
            ast::ItemKind::Enum(def, generics) => {
                let variants = def.variants.into_iter().filter_map(|v| {
                    self.configure(v).map(|v| {
                        Spanned {
                            node: ast::Variant_ {
                                name: v.node.name,
                                attrs: v.node.attrs,
                                data: self.configure_variant_data(v.node.data),
                                disr_expr: v.node.disr_expr,
                            },
                            span: v.span
                        }
                    })
                });
                ast::ItemKind::Enum(ast::EnumDef {
                    variants: variants.collect(),
                }, generics)
            }
            item => item,
        }
    }

    pub fn configure_expr_kind(&mut self, expr_kind: ast::ExprKind) -> ast::ExprKind {
        match expr_kind {
            ast::ExprKind::Match(m, arms) => {
                let arms = arms.into_iter().filter_map(|a| self.configure(a)).collect();
                ast::ExprKind::Match(m, arms)
            }
            ast::ExprKind::Struct(path, fields, base) => {
                let fields = fields.into_iter()
                    .filter_map(|field| {
                        self.configure(field)
                    })
                    .collect();
                ast::ExprKind::Struct(path, fields, base)
            }
            _ => expr_kind,
        }
    }

    pub fn configure_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
        self.visit_expr_attrs(expr.attrs());

        // If an expr is valid to cfg away it will have been removed by the
        // outer stmt or expression folder before descending in here.
        // Anything else is always required, and thus has to error out
        // in case of a cfg attr.
        //
        // NB: This is intentionally not part of the fold_expr() function
        //     in order for fold_opt_expr() to be able to avoid this check
        if let Some(attr) = expr.attrs().iter().find(|a| is_cfg(a) || is_test_or_bench(a)) {
            let msg = "removing an expression is not supported in this position";
            self.sess.span_diagnostic.span_err(attr.span, msg);
        }

        self.process_cfg_attrs(expr)
    }

    pub fn configure_stmt(&mut self, stmt: ast::Stmt) -> Option<ast::Stmt> {
        self.configure(stmt)
    }

    pub fn configure_struct_expr_field(&mut self, field: ast::Field) -> Option<ast::Field> {
        self.configure(field)
    }

    pub fn configure_pat(&mut self, pattern: P<ast::Pat>) -> P<ast::Pat> {
        pattern.map(|mut pattern| {
            if let ast::PatKind::Struct(path, fields, etc) = pattern.node {
                let fields = fields.into_iter()
                    .filter_map(|field| {
                        self.configure(field)
                    })
                    .collect();
                pattern.node = ast::PatKind::Struct(path, fields, etc);
            }
            pattern
        })
    }
}

impl<'a> fold::Folder for StripUnconfigured<'a> {
    fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
        let foreign_mod = self.configure_foreign_mod(foreign_mod);
        fold::noop_fold_foreign_mod(foreign_mod, self)
    }

    fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
        let item = self.configure_item_kind(item);
        fold::noop_fold_item_kind(item, self)
    }

    fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
        let mut expr = self.configure_expr(expr).unwrap();
        expr.node = self.configure_expr_kind(expr.node);
        P(fold::noop_fold_expr(expr, self))
    }

    fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
        let mut expr = configure!(self, expr).unwrap();
        expr.node = self.configure_expr_kind(expr.node);
        Some(P(fold::noop_fold_expr(expr, self)))
    }

    fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
        match self.configure_stmt(stmt) {
            Some(stmt) => fold::noop_fold_stmt(stmt, self),
            None => return SmallVector::new(),
        }
    }

    fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
        fold::noop_fold_item(configure!(self, item), self)
    }

    fn fold_impl_item(&mut self, item: ast::ImplItem) -> SmallVector<ast::ImplItem> {
        fold::noop_fold_impl_item(configure!(self, item), self)
    }

    fn fold_trait_item(&mut self, item: ast::TraitItem) -> SmallVector<ast::TraitItem> {
        fold::noop_fold_trait_item(configure!(self, item), self)
    }

    fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
        // Don't configure interpolated AST (c.f. #34171).
        // Interpolated AST will get configured once the surrounding tokens are parsed.
        mac
    }

    fn fold_pat(&mut self, pattern: P<ast::Pat>) -> P<ast::Pat> {
        fold::noop_fold_pat(self.configure_pat(pattern), self)
    }
}

fn is_cfg(attr: &ast::Attribute) -> bool {
    attr.check_name("cfg")
}

pub fn is_test_or_bench(attr: &ast::Attribute) -> bool {
    attr.check_name("test") || attr.check_name("bench")
}
Commit	Line	Data
	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.
	4	//
	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.
	10
	11	use attr::HasAttrs;
	12	use feature_gate::{feature_err, EXPLAIN_STMT_ATTR_SYNTAX, Features, get_features, GateIssue};
	13	use {fold, attr};
	14	use ast;
	15	use codemap::Spanned;
	16	use parse::{token, ParseSess};
	17	use syntax_pos::Span;
	18
	19	use ptr::P;
	20	use util::small_vector::SmallVector;
	21
	22	/// A folder that strips out items that do not belong in the current configuration.
	23	pub struct StripUnconfigured<'a> {
	24	pub should_test: bool,
	25	pub sess: &'a ParseSess,
	26	pub features: Option<&'a Features>,
	27	}
	28
	29	// `cfg_attr`-process the crate's attributes and compute the crate's features.
	30	pub fn features(mut krate: ast::Crate, sess: &ParseSess, should_test: bool)
	31	-> (ast::Crate, Features) {
	32	let features;
	33	{
	34	let mut strip_unconfigured = StripUnconfigured {
	35	should_test: should_test,
	36	sess: sess,
	37	features: None,
	38	};
	39
	40	let unconfigured_attrs = krate.attrs.clone();
	41	let err_count = sess.span_diagnostic.err_count();
	42	if let Some(attrs) = strip_unconfigured.configure(krate.attrs) {
	43	krate.attrs = attrs;
	44	} else { // the entire crate is unconfigured
	45	krate.attrs = Vec::new();
	46	krate.module.items = Vec::new();
	47	return (krate, Features::new());
	48	}
	49
	50	features = get_features(&sess.span_diagnostic, &krate.attrs);
	51
	52	// Avoid reconfiguring malformed `cfg_attr`s
	53	if err_count == sess.span_diagnostic.err_count() {
	54	strip_unconfigured.features = Some(&features);
	55	strip_unconfigured.configure(unconfigured_attrs);
	56	}
	57	}
	58
	59	(krate, features)
	60	}
	61
	62	macro_rules! configure {
	63	($this:ident, $node:ident) => {
	64	match $this.configure($node) {
	65	Some(node) => node,
	66	None => return Default::default(),
	67	}
	68	}
	69	}
	70
	71	impl<'a> StripUnconfigured<'a> {
	72	pub fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
	73	let node = self.process_cfg_attrs(node);
	74	if self.in_cfg(node.attrs()) { Some(node) } else { None }
	75	}
	76
	77	pub fn process_cfg_attrs<T: HasAttrs>(&mut self, node: T) -> T {
	78	node.map_attrs(\|attrs\| {
	79	attrs.into_iter().filter_map(\|attr\| self.process_cfg_attr(attr)).collect()
	80	})
	81	}
	82
	83	fn process_cfg_attr(&mut self, attr: ast::Attribute) -> Option<ast::Attribute> {
	84	if !attr.check_name("cfg_attr") {
	85	return Some(attr);
	86	}
	87
	88	let (cfg, path, tokens, span) = match attr.parse(self.sess, \|parser\| {
	89	parser.expect(&token::OpenDelim(token::Paren))?;
	90	let cfg = parser.parse_meta_item()?;
	91	parser.expect(&token::Comma)?;
	92	let lo = parser.span.lo;
	93	let (path, tokens) = parser.parse_path_and_tokens()?;
	94	parser.expect(&token::CloseDelim(token::Paren))?;
	95	Ok((cfg, path, tokens, Span { lo: lo, ..parser.prev_span }))
	96	}) {
	97	Ok(result) => result,
	98	Err(mut e) => {
	99	e.emit();
	100	return None;
	101	}
	102	};
	103
	104	if attr::cfg_matches(&cfg, self.sess, self.features) {
	105	self.process_cfg_attr(ast::Attribute {
	106	id: attr::mk_attr_id(),
	107	style: attr.style,
	108	path: path,
	109	tokens: tokens,
	110	is_sugared_doc: false,
	111	span: span,
	112	})
	113	} else {
	114	None
	115	}
	116	}
	117
	118	// Determine if a node with the given attributes should be included in this configuation.
	119	pub fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool {
	120	attrs.iter().all(\|attr\| {
	121	// When not compiling with --test we should not compile the #[test] functions
	122	if !self.should_test && is_test_or_bench(attr) {
	123	return false;
	124	}
	125
	126	let mis = if !is_cfg(attr) {
	127	return true;
	128	} else if let Some(mis) = attr.meta_item_list() {
	129	mis
	130	} else {
	131	return true;
	132	};
	133
	134	if mis.len() != 1 {
	135	self.sess.span_diagnostic.span_err(attr.span, "expected 1 cfg-pattern");
	136	return true;
	137	}
	138
	139	if !mis[0].is_meta_item() {
	140	self.sess.span_diagnostic.span_err(mis[0].span, "unexpected literal");
	141	return true;
	142	}
	143
	144	attr::cfg_matches(mis[0].meta_item().unwrap(), self.sess, self.features)
	145	})
	146	}
	147
	148	// Visit attributes on expression and statements (but not attributes on items in blocks).
	149	fn visit_expr_attrs(&mut self, attrs: &[ast::Attribute]) {
	150	// flag the offending attributes
	151	for attr in attrs.iter() {
	152	if !self.features.map(\|features\| features.stmt_expr_attributes).unwrap_or(true) {
	153	let mut err = feature_err(self.sess,
	154	"stmt_expr_attributes",
	155	attr.span,
	156	GateIssue::Language,
	157	EXPLAIN_STMT_ATTR_SYNTAX);
	158	if attr.is_sugared_doc {
	159	err.help("`///` is for documentation comments. For a plain comment, use `//`.");
	160	}
	161	err.emit();
	162	}
	163	}
	164	}
	165
	166	pub fn configure_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
	167	ast::ForeignMod {
	168	abi: foreign_mod.abi,
	169	items: foreign_mod.items.into_iter().filter_map(\|item\| self.configure(item)).collect(),
	170	}
	171	}
	172
	173	fn configure_variant_data(&mut self, vdata: ast::VariantData) -> ast::VariantData {
	174	match vdata {
	175	ast::VariantData::Struct(fields, id) => {
	176	let fields = fields.into_iter().filter_map(\|field\| self.configure(field));
	177	ast::VariantData::Struct(fields.collect(), id)
	178	}
	179	ast::VariantData::Tuple(fields, id) => {
	180	let fields = fields.into_iter().filter_map(\|field\| self.configure(field));
	181	ast::VariantData::Tuple(fields.collect(), id)
	182	}
	183	ast::VariantData::Unit(id) => ast::VariantData::Unit(id)
	184	}
	185	}
	186
	187	pub fn configure_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
	188	match item {
	189	ast::ItemKind::Struct(def, generics) => {
	190	ast::ItemKind::Struct(self.configure_variant_data(def), generics)
	191	}
	192	ast::ItemKind::Union(def, generics) => {
	193	ast::ItemKind::Union(self.configure_variant_data(def), generics)
	194	}
	195	ast::ItemKind::Enum(def, generics) => {
	196	let variants = def.variants.into_iter().filter_map(\|v\| {
	197	self.configure(v).map(\|v\| {
	198	Spanned {
	199	node: ast::Variant_ {
	200	name: v.node.name,
	201	attrs: v.node.attrs,
	202	data: self.configure_variant_data(v.node.data),
	203	disr_expr: v.node.disr_expr,
	204	},
	205	span: v.span
	206	}
	207	})
	208	});
	209	ast::ItemKind::Enum(ast::EnumDef {
	210	variants: variants.collect(),
	211	}, generics)
	212	}
	213	item => item,
	214	}
	215	}
	216
	217	pub fn configure_expr_kind(&mut self, expr_kind: ast::ExprKind) -> ast::ExprKind {
	218	match expr_kind {
	219	ast::ExprKind::Match(m, arms) => {
	220	let arms = arms.into_iter().filter_map(\|a\| self.configure(a)).collect();
	221	ast::ExprKind::Match(m, arms)
	222	}
	223	ast::ExprKind::Struct(path, fields, base) => {
	224	let fields = fields.into_iter()
	225	.filter_map(\|field\| {
	226	self.configure(field)
	227	})
	228	.collect();
	229	ast::ExprKind::Struct(path, fields, base)
	230	}
	231	_ => expr_kind,
	232	}
	233	}
	234
	235	pub fn configure_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
	236	self.visit_expr_attrs(expr.attrs());
	237
	238	// If an expr is valid to cfg away it will have been removed by the
	239	// outer stmt or expression folder before descending in here.
	240	// Anything else is always required, and thus has to error out
	241	// in case of a cfg attr.
	242	//
	243	// NB: This is intentionally not part of the fold_expr() function
	244	// in order for fold_opt_expr() to be able to avoid this check
	245	if let Some(attr) = expr.attrs().iter().find(\|a\| is_cfg(a) \|\| is_test_or_bench(a)) {
	246	let msg = "removing an expression is not supported in this position";
	247	self.sess.span_diagnostic.span_err(attr.span, msg);
	248	}
	249
	250	self.process_cfg_attrs(expr)
	251	}
	252
	253	pub fn configure_stmt(&mut self, stmt: ast::Stmt) -> Option<ast::Stmt> {
	254	self.configure(stmt)
	255	}
	256
	257	pub fn configure_struct_expr_field(&mut self, field: ast::Field) -> Option<ast::Field> {
	258	self.configure(field)
	259	}
	260
	261	pub fn configure_pat(&mut self, pattern: P<ast::Pat>) -> P<ast::Pat> {
	262	pattern.map(\|mut pattern\| {
	263	if let ast::PatKind::Struct(path, fields, etc) = pattern.node {
	264	let fields = fields.into_iter()
	265	.filter_map(\|field\| {
	266	self.configure(field)
	267	})
	268	.collect();
	269	pattern.node = ast::PatKind::Struct(path, fields, etc);
	270	}
	271	pattern
	272	})
	273	}
	274	}
	275
	276	impl<'a> fold::Folder for StripUnconfigured<'a> {
	277	fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
	278	let foreign_mod = self.configure_foreign_mod(foreign_mod);
	279	fold::noop_fold_foreign_mod(foreign_mod, self)
	280	}
	281
	282	fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
	283	let item = self.configure_item_kind(item);
	284	fold::noop_fold_item_kind(item, self)
	285	}
	286
	287	fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
	288	let mut expr = self.configure_expr(expr).unwrap();
	289	expr.node = self.configure_expr_kind(expr.node);
	290	P(fold::noop_fold_expr(expr, self))
	291	}
	292
	293	fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
	294	let mut expr = configure!(self, expr).unwrap();
	295	expr.node = self.configure_expr_kind(expr.node);
	296	Some(P(fold::noop_fold_expr(expr, self)))
	297	}
	298
	299	fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
	300	match self.configure_stmt(stmt) {
	301	Some(stmt) => fold::noop_fold_stmt(stmt, self),
	302	None => return SmallVector::new(),
	303	}
	304	}
	305
	306	fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
	307	fold::noop_fold_item(configure!(self, item), self)
	308	}
	309
	310	fn fold_impl_item(&mut self, item: ast::ImplItem) -> SmallVector<ast::ImplItem> {
	311	fold::noop_fold_impl_item(configure!(self, item), self)
	312	}
	313
	314	fn fold_trait_item(&mut self, item: ast::TraitItem) -> SmallVector<ast::TraitItem> {
	315	fold::noop_fold_trait_item(configure!(self, item), self)
	316	}
	317
	318	fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
	319	// Don't configure interpolated AST (c.f. #34171).
	320	// Interpolated AST will get configured once the surrounding tokens are parsed.
	321	mac
	322	}
	323
	324	fn fold_pat(&mut self, pattern: P<ast::Pat>) -> P<ast::Pat> {
	325	fold::noop_fold_pat(self.configure_pat(pattern), self)
	326	}
	327	}
	328
	329	fn is_cfg(attr: &ast::Attribute) -> bool {
	330	attr.check_name("cfg")
	331	}
	332
	333	pub fn is_test_or_bench(attr: &ast::Attribute) -> bool {
	334	attr.check_name("test") \|\| attr.check_name("bench")
	335	}