1 //! Representation of a `#[doc(cfg(...))]` attribute.
3 // FIXME: Once the portability lint RFC is implemented (see tracking issue #41619),
4 // switch to use those structures instead.
7 use std::fmt::{self, Write};
10 use syntax::symbol::Symbol;
11 use syntax::ast::{MetaItem, MetaItemKind, NestedMetaItem, NestedMetaItemKind, LitKind};
12 use syntax::parse::ParseSess;
13 use syntax::feature_gate::Features;
17 use html::escape::Escape;
19 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, PartialEq, Eq, Hash)]
21 /// Accepts all configurations.
23 /// Denies all configurations.
25 /// A generic configuration option, e.g., `test` or `target_os = "linux"`.
26 Cfg(Symbol, Option<Symbol>),
27 /// Negate a configuration requirement, i.e., `not(x)`.
29 /// Union of a list of configuration requirements, i.e., `any(...)`.
31 /// Intersection of a list of configuration requirements, i.e., `all(...)`.
35 #[derive(PartialEq, Debug)]
36 pub struct InvalidCfgError {
37 pub msg: &'static str,
42 /// Parses a `NestedMetaItem` into a `Cfg`.
43 fn parse_nested(nested_cfg: &NestedMetaItem) -> Result<Cfg, InvalidCfgError> {
44 match nested_cfg.node {
45 NestedMetaItemKind::MetaItem(ref cfg) => Cfg::parse(cfg),
46 NestedMetaItemKind::Literal(ref lit) => Err(InvalidCfgError {
47 msg: "unexpected literal",
53 /// Parses a `MetaItem` into a `Cfg`.
55 /// The `MetaItem` should be the content of the `#[cfg(...)]`, e.g., `unix` or
56 /// `target_os = "redox"`.
58 /// If the content is not properly formatted, it will return an error indicating what and where
60 pub fn parse(cfg: &MetaItem) -> Result<Cfg, InvalidCfgError> {
61 let name = cfg.name();
63 MetaItemKind::Word => Ok(Cfg::Cfg(name, None)),
64 MetaItemKind::NameValue(ref lit) => match lit.node {
65 LitKind::Str(value, _) => Ok(Cfg::Cfg(name, Some(value))),
66 _ => Err(InvalidCfgError {
67 // FIXME: if the main #[cfg] syntax decided to support non-string literals,
68 // this should be changed as well.
69 msg: "value of cfg option should be a string literal",
73 MetaItemKind::List(ref items) => {
74 let mut sub_cfgs = items.iter().map(Cfg::parse_nested);
75 match &*name.as_str() {
76 "all" => sub_cfgs.fold(Ok(Cfg::True), |x, y| Ok(x? & y?)),
77 "any" => sub_cfgs.fold(Ok(Cfg::False), |x, y| Ok(x? | y?)),
78 "not" => if sub_cfgs.len() == 1 {
79 Ok(!sub_cfgs.next().unwrap()?)
82 msg: "expected 1 cfg-pattern",
86 _ => Err(InvalidCfgError {
87 msg: "invalid predicate",
95 /// Checks whether the given configuration can be matched in the current session.
97 /// Equivalent to `attr::cfg_matches`.
98 // FIXME: Actually make use of `features`.
99 pub fn matches(&self, parse_sess: &ParseSess, features: Option<&Features>) -> bool {
103 Cfg::Not(ref child) => !child.matches(parse_sess, features),
104 Cfg::All(ref sub_cfgs) => {
105 sub_cfgs.iter().all(|sub_cfg| sub_cfg.matches(parse_sess, features))
107 Cfg::Any(ref sub_cfgs) => {
108 sub_cfgs.iter().any(|sub_cfg| sub_cfg.matches(parse_sess, features))
110 Cfg::Cfg(name, value) => parse_sess.config.contains(&(name, value)),
114 /// Whether the configuration consists of just `Cfg` or `Not`.
115 fn is_simple(&self) -> bool {
117 Cfg::False | Cfg::True | Cfg::Cfg(..) | Cfg::Not(..) => true,
118 Cfg::All(..) | Cfg::Any(..) => false,
122 /// Whether the configuration consists of just `Cfg`, `Not` or `All`.
123 fn is_all(&self) -> bool {
125 Cfg::False | Cfg::True | Cfg::Cfg(..) | Cfg::Not(..) | Cfg::All(..) => true,
126 Cfg::Any(..) => false,
130 /// Renders the configuration for human display, as a short HTML description.
131 pub(crate) fn render_short_html(&self) -> String {
132 let mut msg = Html(self, true).to_string();
133 if self.should_capitalize_first_letter() {
134 if let Some(i) = msg.find(|c: char| c.is_ascii_alphanumeric()) {
135 msg[i .. i+1].make_ascii_uppercase();
141 /// Renders the configuration for long display, as a long HTML description.
142 pub(crate) fn render_long_html(&self) -> String {
143 let on = if self.should_use_with_in_description() {
149 let mut msg = format!("This is supported {} <strong>{}</strong>", on, Html(self, false));
150 if self.should_append_only_to_description() {
151 msg.push_str(" only");
157 fn should_capitalize_first_letter(&self) -> bool {
159 Cfg::False | Cfg::True | Cfg::Not(..) => true,
160 Cfg::Any(ref sub_cfgs) | Cfg::All(ref sub_cfgs) => {
161 sub_cfgs.first().map(Cfg::should_capitalize_first_letter).unwrap_or(false)
163 Cfg::Cfg(name, _) => match &*name.as_str() {
164 "debug_assertions" | "target_endian" => true,
170 fn should_append_only_to_description(&self) -> bool {
172 Cfg::False | Cfg::True => false,
173 Cfg::Any(..) | Cfg::All(..) | Cfg::Cfg(..) => true,
174 Cfg::Not(ref child) => match **child {
175 Cfg::Cfg(..) => true,
181 fn should_use_with_in_description(&self) -> bool {
183 Cfg::Cfg(ref name, _) if name == &"target_feature" => true,
189 impl ops::Not for Cfg {
191 fn not(self) -> Cfg {
193 Cfg::False => Cfg::True,
194 Cfg::True => Cfg::False,
195 Cfg::Not(cfg) => *cfg,
196 s => Cfg::Not(Box::new(s)),
201 impl ops::BitAndAssign for Cfg {
202 fn bitand_assign(&mut self, other: Cfg) {
203 match (self, other) {
204 (&mut Cfg::False, _) | (_, Cfg::True) => {},
205 (s, Cfg::False) => *s = Cfg::False,
206 (s @ &mut Cfg::True, b) => *s = b,
207 (&mut Cfg::All(ref mut a), Cfg::All(ref mut b)) => a.append(b),
208 (&mut Cfg::All(ref mut a), ref mut b) => a.push(mem::replace(b, Cfg::True)),
209 (s, Cfg::All(mut a)) => {
210 let b = mem::replace(s, Cfg::True);
215 let a = mem::replace(s, Cfg::True);
216 *s = Cfg::All(vec![a, b]);
222 impl ops::BitAnd for Cfg {
224 fn bitand(mut self, other: Cfg) -> Cfg {
230 impl ops::BitOrAssign for Cfg {
231 fn bitor_assign(&mut self, other: Cfg) {
232 match (self, other) {
233 (&mut Cfg::True, _) | (_, Cfg::False) => {},
234 (s, Cfg::True) => *s = Cfg::True,
235 (s @ &mut Cfg::False, b) => *s = b,
236 (&mut Cfg::Any(ref mut a), Cfg::Any(ref mut b)) => a.append(b),
237 (&mut Cfg::Any(ref mut a), ref mut b) => a.push(mem::replace(b, Cfg::True)),
238 (s, Cfg::Any(mut a)) => {
239 let b = mem::replace(s, Cfg::True);
244 let a = mem::replace(s, Cfg::True);
245 *s = Cfg::Any(vec![a, b]);
251 impl ops::BitOr for Cfg {
253 fn bitor(mut self, other: Cfg) -> Cfg {
259 /// Pretty-print wrapper for a `Cfg`. Also indicates whether the "short-form" rendering should be
261 struct Html<'a>(&'a Cfg, bool);
263 fn write_with_opt_paren<T: fmt::Display>(
264 fmt: &mut fmt::Formatter,
269 fmt.write_char('(')?;
273 fmt.write_char(')')?;
279 impl<'a> fmt::Display for Html<'a> {
280 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
282 Cfg::Not(ref child) => match **child {
283 Cfg::Any(ref sub_cfgs) => {
284 let separator = if sub_cfgs.iter().all(Cfg::is_simple) {
289 for (i, sub_cfg) in sub_cfgs.iter().enumerate() {
290 fmt.write_str(if i == 0 { "neither " } else { separator })?;
291 write_with_opt_paren(fmt, !sub_cfg.is_all(), Html(sub_cfg, self.1))?;
295 ref simple @ Cfg::Cfg(..) => write!(fmt, "non-{}", Html(simple, self.1)),
296 ref c => write!(fmt, "not ({})", Html(c, self.1)),
299 Cfg::Any(ref sub_cfgs) => {
300 let separator = if sub_cfgs.iter().all(Cfg::is_simple) {
305 for (i, sub_cfg) in sub_cfgs.iter().enumerate() {
307 fmt.write_str(separator)?;
309 write_with_opt_paren(fmt, !sub_cfg.is_all(), Html(sub_cfg, self.1))?;
314 Cfg::All(ref sub_cfgs) => {
315 for (i, sub_cfg) in sub_cfgs.iter().enumerate() {
317 fmt.write_str(" and ")?;
319 write_with_opt_paren(fmt, !sub_cfg.is_simple(), Html(sub_cfg, self.1))?;
324 Cfg::True => fmt.write_str("everywhere"),
325 Cfg::False => fmt.write_str("nowhere"),
327 Cfg::Cfg(name, value) => {
328 let n = &*name.as_str();
329 let human_readable = match (n, value) {
330 ("unix", None) => "Unix",
331 ("windows", None) => "Windows",
332 ("debug_assertions", None) => "debug-assertions enabled",
333 ("target_os", Some(os)) => match &*os.as_str() {
334 "android" => "Android",
335 "bitrig" => "Bitrig",
336 "dragonfly" => "DragonFly BSD",
337 "emscripten" => "Emscripten",
338 "freebsd" => "FreeBSD",
339 "fuchsia" => "Fuchsia",
345 "netbsd" => "NetBSD",
346 "openbsd" => "OpenBSD",
348 "solaris" => "Solaris",
349 "windows" => "Windows",
352 ("target_arch", Some(arch)) => match &*arch.as_str() {
353 "aarch64" => "AArch64",
357 "mips64" => "MIPS-64",
358 "msp430" => "MSP430",
359 "powerpc" => "PowerPC",
360 "powerpc64" => "PowerPC-64",
362 "sparc64" => "SPARC64",
363 "wasm32" => "WebAssembly",
365 "x86_64" => "x86-64",
368 ("target_vendor", Some(vendor)) => match &*vendor.as_str() {
371 "rumprun" => "Rumprun",
373 "fortanix" => "Fortanix",
376 ("target_env", Some(env)) => match &*env.as_str() {
380 "newlib" => "Newlib",
381 "uclibc" => "uClibc",
385 ("target_endian", Some(endian)) => return write!(fmt, "{}-endian", endian),
386 ("target_pointer_width", Some(bits)) => return write!(fmt, "{}-bit", bits),
387 ("target_feature", Some(feat)) =>
389 return write!(fmt, "<code>{}</code>", feat);
391 return write!(fmt, "target feature <code>{}</code>", feat);
395 if !human_readable.is_empty() {
396 fmt.write_str(human_readable)
397 } else if let Some(v) = value {
398 write!(fmt, "<code>{}=\"{}\"</code>", Escape(n), Escape(&*v.as_str()))
400 write!(fmt, "<code>{}</code>", Escape(n))
411 use syntax::symbol::Symbol;
413 use syntax::source_map::dummy_spanned;
414 use syntax_pos::DUMMY_SP;
415 use syntax::with_globals;
417 fn word_cfg(s: &str) -> Cfg {
418 Cfg::Cfg(Symbol::intern(s), None)
421 fn name_value_cfg(name: &str, value: &str) -> Cfg {
422 Cfg::Cfg(Symbol::intern(name), Some(Symbol::intern(value)))
425 fn dummy_meta_item_word(name: &str) -> MetaItem {
427 ident: Path::from_ident(Ident::from_str(name)),
428 node: MetaItemKind::Word,
433 macro_rules! dummy_meta_item_list {
434 ($name:ident, [$($list:ident),* $(,)*]) => {
436 ident: Path::from_ident(Ident::from_str(stringify!($name))),
437 node: MetaItemKind::List(vec![
439 dummy_spanned(NestedMetaItemKind::MetaItem(
440 dummy_meta_item_word(stringify!($list)),
448 ($name:ident, [$($list:expr),* $(,)*]) => {
450 ident: Path::from_ident(Ident::from_str(stringify!($name))),
451 node: MetaItemKind::List(vec![
453 dummy_spanned(NestedMetaItemKind::MetaItem($list)),
464 assert_eq!(!Cfg::False, Cfg::True);
465 assert_eq!(!Cfg::True, Cfg::False);
466 assert_eq!(!word_cfg("test"), Cfg::Not(Box::new(word_cfg("test"))));
468 !Cfg::All(vec![word_cfg("a"), word_cfg("b")]),
469 Cfg::Not(Box::new(Cfg::All(vec![word_cfg("a"), word_cfg("b")])))
472 !Cfg::Any(vec![word_cfg("a"), word_cfg("b")]),
473 Cfg::Not(Box::new(Cfg::Any(vec![word_cfg("a"), word_cfg("b")])))
475 assert_eq!(!Cfg::Not(Box::new(word_cfg("test"))), word_cfg("test"));
482 let mut x = Cfg::False;
484 assert_eq!(x, Cfg::False);
486 x = word_cfg("test");
488 assert_eq!(x, Cfg::False);
490 x = word_cfg("test2");
492 assert_eq!(x, word_cfg("test2"));
495 x &= word_cfg("test3");
496 assert_eq!(x, word_cfg("test3"));
498 x &= word_cfg("test4");
499 assert_eq!(x, Cfg::All(vec![word_cfg("test3"), word_cfg("test4")]));
501 x &= word_cfg("test5");
502 assert_eq!(x, Cfg::All(vec![word_cfg("test3"), word_cfg("test4"), word_cfg("test5")]));
504 x &= Cfg::All(vec![word_cfg("test6"), word_cfg("test7")]);
505 assert_eq!(x, Cfg::All(vec![
513 let mut y = Cfg::Any(vec![word_cfg("a"), word_cfg("b")]);
515 assert_eq!(y, Cfg::All(vec![
521 Cfg::Any(vec![word_cfg("a"), word_cfg("b")]),
525 word_cfg("a") & word_cfg("b") & word_cfg("c"),
526 Cfg::All(vec![word_cfg("a"), word_cfg("b"), word_cfg("c")])
534 let mut x = Cfg::True;
536 assert_eq!(x, Cfg::True);
538 x = word_cfg("test");
540 assert_eq!(x, Cfg::True);
542 x = word_cfg("test2");
544 assert_eq!(x, word_cfg("test2"));
547 x |= word_cfg("test3");
548 assert_eq!(x, word_cfg("test3"));
550 x |= word_cfg("test4");
551 assert_eq!(x, Cfg::Any(vec![word_cfg("test3"), word_cfg("test4")]));
553 x |= word_cfg("test5");
554 assert_eq!(x, Cfg::Any(vec![word_cfg("test3"), word_cfg("test4"), word_cfg("test5")]));
556 x |= Cfg::Any(vec![word_cfg("test6"), word_cfg("test7")]);
557 assert_eq!(x, Cfg::Any(vec![
565 let mut y = Cfg::All(vec![word_cfg("a"), word_cfg("b")]);
567 assert_eq!(y, Cfg::Any(vec![
573 Cfg::All(vec![word_cfg("a"), word_cfg("b")]),
577 word_cfg("a") | word_cfg("b") | word_cfg("c"),
578 Cfg::Any(vec![word_cfg("a"), word_cfg("b"), word_cfg("c")])
586 let mi = dummy_meta_item_word("all");
587 assert_eq!(Cfg::parse(&mi), Ok(word_cfg("all")));
590 ident: Path::from_ident(Ident::from_str("all")),
591 node: MetaItemKind::NameValue(dummy_spanned(LitKind::Str(
592 Symbol::intern("done"),
597 assert_eq!(Cfg::parse(&mi), Ok(name_value_cfg("all", "done")));
599 let mi = dummy_meta_item_list!(all, [a, b]);
600 assert_eq!(Cfg::parse(&mi), Ok(word_cfg("a") & word_cfg("b")));
602 let mi = dummy_meta_item_list!(any, [a, b]);
603 assert_eq!(Cfg::parse(&mi), Ok(word_cfg("a") | word_cfg("b")));
605 let mi = dummy_meta_item_list!(not, [a]);
606 assert_eq!(Cfg::parse(&mi), Ok(!word_cfg("a")));
608 let mi = dummy_meta_item_list!(not, [
609 dummy_meta_item_list!(any, [
610 dummy_meta_item_word("a"),
611 dummy_meta_item_list!(all, [b, c]),
614 assert_eq!(Cfg::parse(&mi), Ok(!(word_cfg("a") | (word_cfg("b") & word_cfg("c")))));
616 let mi = dummy_meta_item_list!(all, [a, b, c]);
617 assert_eq!(Cfg::parse(&mi), Ok(word_cfg("a") & word_cfg("b") & word_cfg("c")));
622 fn test_parse_err() {
625 ident: Path::from_ident(Ident::from_str("foo")),
626 node: MetaItemKind::NameValue(dummy_spanned(LitKind::Bool(false))),
629 assert!(Cfg::parse(&mi).is_err());
631 let mi = dummy_meta_item_list!(not, [a, b]);
632 assert!(Cfg::parse(&mi).is_err());
634 let mi = dummy_meta_item_list!(not, []);
635 assert!(Cfg::parse(&mi).is_err());
637 let mi = dummy_meta_item_list!(foo, []);
638 assert!(Cfg::parse(&mi).is_err());
640 let mi = dummy_meta_item_list!(all, [
641 dummy_meta_item_list!(foo, []),
642 dummy_meta_item_word("b"),
644 assert!(Cfg::parse(&mi).is_err());
646 let mi = dummy_meta_item_list!(any, [
647 dummy_meta_item_word("a"),
648 dummy_meta_item_list!(foo, []),
650 assert!(Cfg::parse(&mi).is_err());
652 let mi = dummy_meta_item_list!(not, [
653 dummy_meta_item_list!(foo, []),
655 assert!(Cfg::parse(&mi).is_err());
660 fn test_render_short_html() {
663 word_cfg("unix").render_short_html(),
667 name_value_cfg("target_os", "macos").render_short_html(),
671 name_value_cfg("target_pointer_width", "16").render_short_html(),
675 name_value_cfg("target_endian", "little").render_short_html(),
679 (!word_cfg("windows")).render_short_html(),
683 (word_cfg("unix") & word_cfg("windows")).render_short_html(),
687 (word_cfg("unix") | word_cfg("windows")).render_short_html(),
692 word_cfg("unix") & word_cfg("windows") & word_cfg("debug_assertions")
693 ).render_short_html(),
694 "Unix and Windows and debug-assertions enabled"
698 word_cfg("unix") | word_cfg("windows") | word_cfg("debug_assertions")
699 ).render_short_html(),
700 "Unix or Windows or debug-assertions enabled"
704 !(word_cfg("unix") | word_cfg("windows") | word_cfg("debug_assertions"))
705 ).render_short_html(),
706 "Neither Unix nor Windows nor debug-assertions enabled"
710 (word_cfg("unix") & name_value_cfg("target_arch", "x86_64")) |
711 (word_cfg("windows") & name_value_cfg("target_pointer_width", "64"))
712 ).render_short_html(),
713 "Unix and x86-64, or Windows and 64-bit"
716 (!(word_cfg("unix") & word_cfg("windows"))).render_short_html(),
717 "Not (Unix and Windows)"
721 (word_cfg("debug_assertions") | word_cfg("windows")) & word_cfg("unix")
722 ).render_short_html(),
723 "(Debug-assertions enabled or Windows) and Unix"
726 name_value_cfg("target_feature", "sse2").render_short_html(),
731 name_value_cfg("target_arch", "x86_64") &
732 name_value_cfg("target_feature", "sse2")
733 ).render_short_html(),
734 "x86-64 and <code>sse2</code>"
740 fn test_render_long_html() {
743 word_cfg("unix").render_long_html(),
744 "This is supported on <strong>Unix</strong> only."
747 name_value_cfg("target_os", "macos").render_long_html(),
748 "This is supported on <strong>macOS</strong> only."
751 name_value_cfg("target_pointer_width", "16").render_long_html(),
752 "This is supported on <strong>16-bit</strong> only."
755 name_value_cfg("target_endian", "little").render_long_html(),
756 "This is supported on <strong>little-endian</strong> only."
759 (!word_cfg("windows")).render_long_html(),
760 "This is supported on <strong>non-Windows</strong> only."
763 (word_cfg("unix") & word_cfg("windows")).render_long_html(),
764 "This is supported on <strong>Unix and Windows</strong> only."
767 (word_cfg("unix") | word_cfg("windows")).render_long_html(),
768 "This is supported on <strong>Unix or Windows</strong> only."
772 word_cfg("unix") & word_cfg("windows") & word_cfg("debug_assertions")
773 ).render_long_html(),
774 "This is supported on <strong>Unix and Windows and debug-assertions enabled\
779 word_cfg("unix") | word_cfg("windows") | word_cfg("debug_assertions")
780 ).render_long_html(),
781 "This is supported on <strong>Unix or Windows or debug-assertions enabled\
786 !(word_cfg("unix") | word_cfg("windows") | word_cfg("debug_assertions"))
787 ).render_long_html(),
788 "This is supported on <strong>neither Unix nor Windows nor debug-assertions \
793 (word_cfg("unix") & name_value_cfg("target_arch", "x86_64")) |
794 (word_cfg("windows") & name_value_cfg("target_pointer_width", "64"))
795 ).render_long_html(),
796 "This is supported on <strong>Unix and x86-64, or Windows and 64-bit</strong> \
800 (!(word_cfg("unix") & word_cfg("windows"))).render_long_html(),
801 "This is supported on <strong>not (Unix and Windows)</strong>."
805 (word_cfg("debug_assertions") | word_cfg("windows")) & word_cfg("unix")
806 ).render_long_html(),
807 "This is supported on <strong>(debug-assertions enabled or Windows) and Unix\
811 name_value_cfg("target_feature", "sse2").render_long_html(),
812 "This is supported with <strong>target feature <code>sse2</code></strong> only."
816 name_value_cfg("target_arch", "x86_64") &
817 name_value_cfg("target_feature", "sse2")
818 ).render_long_html(),
819 "This is supported on <strong>x86-64 and target feature \
820 <code>sse2</code></strong> only."