1 //! A support library for macro authors when defining new macros.
3 //! This library, provided by the standard distribution, provides the types
4 //! consumed in the interfaces of procedurally defined macro definitions such as
5 //! function-like macros `#[proc_macro]`, macro attributes `#[proc_macro_attribute]` and
6 //! custom derive attributes`#[proc_macro_derive]`.
8 //! See [the book] for more.
10 //! [the book]: ../book/ch19-06-macros.html#procedural-macros-for-generating-code-from-attributes
12 #![stable(feature = "proc_macro_lib", since = "1.15.0")]
13 #![deny(missing_docs)]
15 html_playground_url = "https://play.rust-lang.org/",
16 issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
17 test(no_crate_inject, attr(deny(warnings))),
18 test(attr(allow(dead_code, deprecated, unused_variables, unused_mut)))
20 #![feature(rustc_allow_const_fn_unstable)]
22 #![feature(staged_api)]
23 #![feature(const_fn_trait_bound)]
24 #![feature(const_fn_fn_ptr_basics)]
25 #![feature(allow_internal_unstable)]
26 #![feature(decl_macro)]
27 #![feature(extern_types)]
28 #![feature(negative_impls)]
29 #![feature(auto_traits)]
30 #![feature(restricted_std)]
31 #![feature(rustc_attrs)]
32 #![feature(min_specialization)]
33 #![recursion_limit = "256"]
35 #[unstable(feature = "proc_macro_internals", issue = "27812")]
41 #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
42 pub use diagnostic::{Diagnostic, Level, MultiSpan};
44 use std::cmp::Ordering;
45 use std::ops::RangeBounds;
46 use std::path::PathBuf;
47 use std::str::FromStr;
48 use std::{error, fmt, iter, mem};
50 /// Determines whether proc_macro has been made accessible to the currently
53 /// The proc_macro crate is only intended for use inside the implementation of
54 /// procedural macros. All the functions in this crate panic if invoked from
55 /// outside of a procedural macro, such as from a build script or unit test or
56 /// ordinary Rust binary.
58 /// With consideration for Rust libraries that are designed to support both
59 /// macro and non-macro use cases, `proc_macro::is_available()` provides a
60 /// non-panicking way to detect whether the infrastructure required to use the
61 /// API of proc_macro is presently available. Returns true if invoked from
62 /// inside of a procedural macro, false if invoked from any other binary.
63 #[stable(feature = "proc_macro_is_available", since = "1.57.0")]
64 pub fn is_available() -> bool {
65 bridge::Bridge::is_available()
68 /// The main type provided by this crate, representing an abstract stream of
69 /// tokens, or, more specifically, a sequence of token trees.
70 /// The type provide interfaces for iterating over those token trees and, conversely,
71 /// collecting a number of token trees into one stream.
73 /// This is both the input and output of `#[proc_macro]`, `#[proc_macro_attribute]`
74 /// and `#[proc_macro_derive]` definitions.
75 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
77 pub struct TokenStream(bridge::client::TokenStream);
79 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
80 impl !Send for TokenStream {}
81 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
82 impl !Sync for TokenStream {}
84 /// Error returned from `TokenStream::from_str`.
85 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
90 #[stable(feature = "proc_macro_lexerror_impls", since = "1.44.0")]
91 impl fmt::Display for LexError {
92 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
93 f.write_str("cannot parse string into token stream")
97 #[stable(feature = "proc_macro_lexerror_impls", since = "1.44.0")]
98 impl error::Error for LexError {}
100 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
101 impl !Send for LexError {}
102 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
103 impl !Sync for LexError {}
105 /// Error returned from `TokenStream::expand_expr`.
106 #[unstable(feature = "proc_macro_expand", issue = "90765")]
109 pub struct ExpandError;
111 #[unstable(feature = "proc_macro_expand", issue = "90765")]
112 impl fmt::Display for ExpandError {
113 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
114 f.write_str("macro expansion failed")
118 #[unstable(feature = "proc_macro_expand", issue = "90765")]
119 impl error::Error for ExpandError {}
121 #[unstable(feature = "proc_macro_expand", issue = "90765")]
122 impl !Send for ExpandError {}
124 #[unstable(feature = "proc_macro_expand", issue = "90765")]
125 impl !Sync for ExpandError {}
128 /// Returns an empty `TokenStream` containing no token trees.
129 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
130 pub fn new() -> TokenStream {
131 TokenStream(bridge::client::TokenStream::new())
134 /// Checks if this `TokenStream` is empty.
135 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
136 pub fn is_empty(&self) -> bool {
140 /// Parses this `TokenStream` as an expression and attempts to expand any
141 /// macros within it. Returns the expanded `TokenStream`.
143 /// Currently only expressions expanding to literals will succeed, although
144 /// this may be relaxed in the future.
146 /// NOTE: In error conditions, `expand_expr` may leave macros unexpanded,
147 /// report an error, failing compilation, and/or return an `Err(..)`. The
148 /// specific behavior for any error condition, and what conditions are
149 /// considered errors, is unspecified and may change in the future.
150 #[unstable(feature = "proc_macro_expand", issue = "90765")]
151 pub fn expand_expr(&self) -> Result<TokenStream, ExpandError> {
152 match bridge::client::TokenStream::expand_expr(&self.0) {
153 Ok(stream) => Ok(TokenStream(stream)),
154 Err(_) => Err(ExpandError),
159 /// Attempts to break the string into tokens and parse those tokens into a token stream.
160 /// May fail for a number of reasons, for example, if the string contains unbalanced delimiters
161 /// or characters not existing in the language.
162 /// All tokens in the parsed stream get `Span::call_site()` spans.
164 /// NOTE: some errors may cause panics instead of returning `LexError`. We reserve the right to
165 /// change these errors into `LexError`s later.
166 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
167 impl FromStr for TokenStream {
170 fn from_str(src: &str) -> Result<TokenStream, LexError> {
171 Ok(TokenStream(bridge::client::TokenStream::from_str(src)))
175 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
176 // based on it (the reverse of the usual relationship between the two).
177 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
178 impl ToString for TokenStream {
179 fn to_string(&self) -> String {
184 /// Prints the token stream as a string that is supposed to be losslessly convertible back
185 /// into the same token stream (modulo spans), except for possibly `TokenTree::Group`s
186 /// with `Delimiter::None` delimiters and negative numeric literals.
187 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
188 impl fmt::Display for TokenStream {
189 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
190 f.write_str(&self.to_string())
194 /// Prints token in a form convenient for debugging.
195 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
196 impl fmt::Debug for TokenStream {
197 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
198 f.write_str("TokenStream ")?;
199 f.debug_list().entries(self.clone()).finish()
203 #[stable(feature = "proc_macro_token_stream_default", since = "1.45.0")]
204 impl Default for TokenStream {
205 fn default() -> Self {
210 #[unstable(feature = "proc_macro_quote", issue = "54722")]
211 pub use quote::{quote, quote_span};
213 /// Creates a token stream containing a single token tree.
214 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
215 impl From<TokenTree> for TokenStream {
216 fn from(tree: TokenTree) -> TokenStream {
217 TokenStream(bridge::client::TokenStream::from_token_tree(match tree {
218 TokenTree::Group(tt) => bridge::TokenTree::Group(tt.0),
219 TokenTree::Punct(tt) => bridge::TokenTree::Punct(tt.0),
220 TokenTree::Ident(tt) => bridge::TokenTree::Ident(tt.0),
221 TokenTree::Literal(tt) => bridge::TokenTree::Literal(tt.0),
226 /// Collects a number of token trees into a single stream.
227 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
228 impl iter::FromIterator<TokenTree> for TokenStream {
229 fn from_iter<I: IntoIterator<Item = TokenTree>>(trees: I) -> Self {
230 trees.into_iter().map(TokenStream::from).collect()
234 /// A "flattening" operation on token streams, collects token trees
235 /// from multiple token streams into a single stream.
236 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
237 impl iter::FromIterator<TokenStream> for TokenStream {
238 fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
239 let mut builder = bridge::client::TokenStreamBuilder::new();
240 streams.into_iter().for_each(|stream| builder.push(stream.0));
241 TokenStream(builder.build())
245 #[stable(feature = "token_stream_extend", since = "1.30.0")]
246 impl Extend<TokenTree> for TokenStream {
247 fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, trees: I) {
248 self.extend(trees.into_iter().map(TokenStream::from));
252 #[stable(feature = "token_stream_extend", since = "1.30.0")]
253 impl Extend<TokenStream> for TokenStream {
254 fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
255 // FIXME(eddyb) Use an optimized implementation if/when possible.
256 *self = iter::once(mem::replace(self, Self::new())).chain(streams).collect();
260 /// Public implementation details for the `TokenStream` type, such as iterators.
261 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
262 pub mod token_stream {
263 use crate::{bridge, Group, Ident, Literal, Punct, TokenStream, TokenTree};
265 /// An iterator over `TokenStream`'s `TokenTree`s.
266 /// The iteration is "shallow", e.g., the iterator doesn't recurse into delimited groups,
267 /// and returns whole groups as token trees.
269 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
270 pub struct IntoIter(bridge::client::TokenStreamIter);
272 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
273 impl Iterator for IntoIter {
274 type Item = TokenTree;
276 fn next(&mut self) -> Option<TokenTree> {
277 self.0.next().map(|tree| match tree {
278 bridge::TokenTree::Group(tt) => TokenTree::Group(Group(tt)),
279 bridge::TokenTree::Punct(tt) => TokenTree::Punct(Punct(tt)),
280 bridge::TokenTree::Ident(tt) => TokenTree::Ident(Ident(tt)),
281 bridge::TokenTree::Literal(tt) => TokenTree::Literal(Literal(tt)),
286 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
287 impl IntoIterator for TokenStream {
288 type Item = TokenTree;
289 type IntoIter = IntoIter;
291 fn into_iter(self) -> IntoIter {
292 IntoIter(self.0.into_iter())
297 /// `quote!(..)` accepts arbitrary tokens and expands into a `TokenStream` describing the input.
298 /// For example, `quote!(a + b)` will produce an expression, that, when evaluated, constructs
299 /// the `TokenStream` `[Ident("a"), Punct('+', Alone), Ident("b")]`.
301 /// Unquoting is done with `$`, and works by taking the single next ident as the unquoted term.
302 /// To quote `$` itself, use `$$`.
303 #[unstable(feature = "proc_macro_quote", issue = "54722")]
304 #[allow_internal_unstable(proc_macro_def_site, proc_macro_internals)]
305 #[rustc_builtin_macro]
306 pub macro quote($($t:tt)*) {
307 /* compiler built-in */
310 #[unstable(feature = "proc_macro_internals", issue = "27812")]
314 /// A region of source code, along with macro expansion information.
315 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
316 #[derive(Copy, Clone)]
317 pub struct Span(bridge::client::Span);
319 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
320 impl !Send for Span {}
321 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
322 impl !Sync for Span {}
324 macro_rules! diagnostic_method {
325 ($name:ident, $level:expr) => {
326 /// Creates a new `Diagnostic` with the given `message` at the span
328 #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
329 pub fn $name<T: Into<String>>(self, message: T) -> Diagnostic {
330 Diagnostic::spanned(self, $level, message)
336 /// A span that resolves at the macro definition site.
337 #[unstable(feature = "proc_macro_def_site", issue = "54724")]
338 pub fn def_site() -> Span {
339 Span(bridge::client::Span::def_site())
342 /// The span of the invocation of the current procedural macro.
343 /// Identifiers created with this span will be resolved as if they were written
344 /// directly at the macro call location (call-site hygiene) and other code
345 /// at the macro call site will be able to refer to them as well.
346 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
347 pub fn call_site() -> Span {
348 Span(bridge::client::Span::call_site())
351 /// A span that represents `macro_rules` hygiene, and sometimes resolves at the macro
352 /// definition site (local variables, labels, `$crate`) and sometimes at the macro
353 /// call site (everything else).
354 /// The span location is taken from the call-site.
355 #[stable(feature = "proc_macro_mixed_site", since = "1.45.0")]
356 pub fn mixed_site() -> Span {
357 Span(bridge::client::Span::mixed_site())
360 /// The original source file into which this span points.
361 #[unstable(feature = "proc_macro_span", issue = "54725")]
362 pub fn source_file(&self) -> SourceFile {
363 SourceFile(self.0.source_file())
366 /// The `Span` for the tokens in the previous macro expansion from which
367 /// `self` was generated from, if any.
368 #[unstable(feature = "proc_macro_span", issue = "54725")]
369 pub fn parent(&self) -> Option<Span> {
370 self.0.parent().map(Span)
373 /// The span for the origin source code that `self` was generated from. If
374 /// this `Span` wasn't generated from other macro expansions then the return
375 /// value is the same as `*self`.
376 #[unstable(feature = "proc_macro_span", issue = "54725")]
377 pub fn source(&self) -> Span {
378 Span(self.0.source())
381 /// Gets the starting line/column in the source file for this span.
382 #[unstable(feature = "proc_macro_span", issue = "54725")]
383 pub fn start(&self) -> LineColumn {
384 self.0.start().add_1_to_column()
387 /// Gets the ending line/column in the source file for this span.
388 #[unstable(feature = "proc_macro_span", issue = "54725")]
389 pub fn end(&self) -> LineColumn {
390 self.0.end().add_1_to_column()
393 /// Creates an empty span pointing to directly before this span.
394 #[unstable(feature = "proc_macro_span_shrink", issue = "87552")]
395 pub fn before(&self) -> Span {
396 Span(self.0.before())
399 /// Creates an empty span pointing to directly after this span.
400 #[unstable(feature = "proc_macro_span_shrink", issue = "87552")]
401 pub fn after(&self) -> Span {
405 /// Creates a new span encompassing `self` and `other`.
407 /// Returns `None` if `self` and `other` are from different files.
408 #[unstable(feature = "proc_macro_span", issue = "54725")]
409 pub fn join(&self, other: Span) -> Option<Span> {
410 self.0.join(other.0).map(Span)
413 /// Creates a new span with the same line/column information as `self` but
414 /// that resolves symbols as though it were at `other`.
415 #[stable(feature = "proc_macro_span_resolved_at", since = "1.45.0")]
416 pub fn resolved_at(&self, other: Span) -> Span {
417 Span(self.0.resolved_at(other.0))
420 /// Creates a new span with the same name resolution behavior as `self` but
421 /// with the line/column information of `other`.
422 #[stable(feature = "proc_macro_span_located_at", since = "1.45.0")]
423 pub fn located_at(&self, other: Span) -> Span {
424 other.resolved_at(*self)
427 /// Compares to spans to see if they're equal.
428 #[unstable(feature = "proc_macro_span", issue = "54725")]
429 pub fn eq(&self, other: &Span) -> bool {
433 /// Returns the source text behind a span. This preserves the original source
434 /// code, including spaces and comments. It only returns a result if the span
435 /// corresponds to real source code.
437 /// Note: The observable result of a macro should only rely on the tokens and
438 /// not on this source text. The result of this function is a best effort to
439 /// be used for diagnostics only.
440 #[unstable(feature = "proc_macro_span", issue = "54725")]
441 pub fn source_text(&self) -> Option<String> {
445 // Used by the implementation of `Span::quote`
447 #[unstable(feature = "proc_macro_internals", issue = "27812")]
448 pub fn save_span(&self) -> usize {
452 // Used by the implementation of `Span::quote`
454 #[unstable(feature = "proc_macro_internals", issue = "27812")]
455 pub fn recover_proc_macro_span(id: usize) -> Span {
456 Span(bridge::client::Span::recover_proc_macro_span(id))
459 diagnostic_method!(error, Level::Error);
460 diagnostic_method!(warning, Level::Warning);
461 diagnostic_method!(note, Level::Note);
462 diagnostic_method!(help, Level::Help);
465 /// Prints a span in a form convenient for debugging.
466 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
467 impl fmt::Debug for Span {
468 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
473 /// A line-column pair representing the start or end of a `Span`.
474 #[unstable(feature = "proc_macro_span", issue = "54725")]
475 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
476 pub struct LineColumn {
477 /// The 1-indexed line in the source file on which the span starts or ends (inclusive).
478 #[unstable(feature = "proc_macro_span", issue = "54725")]
480 /// The 1-indexed column (number of bytes in UTF-8 encoding) in the source
481 /// file on which the span starts or ends (inclusive).
482 #[unstable(feature = "proc_macro_span", issue = "54725")]
487 fn add_1_to_column(self) -> Self {
488 LineColumn { line: self.line, column: self.column + 1 }
492 #[unstable(feature = "proc_macro_span", issue = "54725")]
493 impl !Send for LineColumn {}
494 #[unstable(feature = "proc_macro_span", issue = "54725")]
495 impl !Sync for LineColumn {}
497 #[unstable(feature = "proc_macro_span", issue = "54725")]
498 impl Ord for LineColumn {
499 fn cmp(&self, other: &Self) -> Ordering {
500 self.line.cmp(&other.line).then(self.column.cmp(&other.column))
504 #[unstable(feature = "proc_macro_span", issue = "54725")]
505 impl PartialOrd for LineColumn {
506 fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
507 Some(self.cmp(other))
511 /// The source file of a given `Span`.
512 #[unstable(feature = "proc_macro_span", issue = "54725")]
514 pub struct SourceFile(bridge::client::SourceFile);
517 /// Gets the path to this source file.
520 /// If the code span associated with this `SourceFile` was generated by an external macro, this
521 /// macro, this might not be an actual path on the filesystem. Use [`is_real`] to check.
523 /// Also note that even if `is_real` returns `true`, if `--remap-path-prefix` was passed on
524 /// the command line, the path as given might not actually be valid.
526 /// [`is_real`]: Self::is_real
527 #[unstable(feature = "proc_macro_span", issue = "54725")]
528 pub fn path(&self) -> PathBuf {
529 PathBuf::from(self.0.path())
532 /// Returns `true` if this source file is a real source file, and not generated by an external
533 /// macro's expansion.
534 #[unstable(feature = "proc_macro_span", issue = "54725")]
535 pub fn is_real(&self) -> bool {
536 // This is a hack until intercrate spans are implemented and we can have real source files
537 // for spans generated in external macros.
538 // https://github.com/rust-lang/rust/pull/43604#issuecomment-333334368
543 #[unstable(feature = "proc_macro_span", issue = "54725")]
544 impl fmt::Debug for SourceFile {
545 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
546 f.debug_struct("SourceFile")
547 .field("path", &self.path())
548 .field("is_real", &self.is_real())
553 #[unstable(feature = "proc_macro_span", issue = "54725")]
554 impl PartialEq for SourceFile {
555 fn eq(&self, other: &Self) -> bool {
560 #[unstable(feature = "proc_macro_span", issue = "54725")]
561 impl Eq for SourceFile {}
563 /// A single token or a delimited sequence of token trees (e.g., `[1, (), ..]`).
564 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
567 /// A token stream surrounded by bracket delimiters.
568 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
569 Group(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Group),
571 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
572 Ident(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Ident),
573 /// A single punctuation character (`+`, `,`, `$`, etc.).
574 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
575 Punct(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Punct),
576 /// A literal character (`'a'`), string (`"hello"`), number (`2.3`), etc.
577 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
578 Literal(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Literal),
581 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
582 impl !Send for TokenTree {}
583 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
584 impl !Sync for TokenTree {}
587 /// Returns the span of this tree, delegating to the `span` method of
588 /// the contained token or a delimited stream.
589 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
590 pub fn span(&self) -> Span {
592 TokenTree::Group(ref t) => t.span(),
593 TokenTree::Ident(ref t) => t.span(),
594 TokenTree::Punct(ref t) => t.span(),
595 TokenTree::Literal(ref t) => t.span(),
599 /// Configures the span for *only this token*.
601 /// Note that if this token is a `Group` then this method will not configure
602 /// the span of each of the internal tokens, this will simply delegate to
603 /// the `set_span` method of each variant.
604 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
605 pub fn set_span(&mut self, span: Span) {
607 TokenTree::Group(ref mut t) => t.set_span(span),
608 TokenTree::Ident(ref mut t) => t.set_span(span),
609 TokenTree::Punct(ref mut t) => t.set_span(span),
610 TokenTree::Literal(ref mut t) => t.set_span(span),
615 /// Prints token tree in a form convenient for debugging.
616 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
617 impl fmt::Debug for TokenTree {
618 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
619 // Each of these has the name in the struct type in the derived debug,
620 // so don't bother with an extra layer of indirection
622 TokenTree::Group(ref tt) => tt.fmt(f),
623 TokenTree::Ident(ref tt) => tt.fmt(f),
624 TokenTree::Punct(ref tt) => tt.fmt(f),
625 TokenTree::Literal(ref tt) => tt.fmt(f),
630 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
631 impl From<Group> for TokenTree {
632 fn from(g: Group) -> TokenTree {
637 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
638 impl From<Ident> for TokenTree {
639 fn from(g: Ident) -> TokenTree {
644 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
645 impl From<Punct> for TokenTree {
646 fn from(g: Punct) -> TokenTree {
651 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
652 impl From<Literal> for TokenTree {
653 fn from(g: Literal) -> TokenTree {
654 TokenTree::Literal(g)
658 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
659 // based on it (the reverse of the usual relationship between the two).
660 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
661 impl ToString for TokenTree {
662 fn to_string(&self) -> String {
664 TokenTree::Group(ref t) => t.to_string(),
665 TokenTree::Ident(ref t) => t.to_string(),
666 TokenTree::Punct(ref t) => t.to_string(),
667 TokenTree::Literal(ref t) => t.to_string(),
672 /// Prints the token tree as a string that is supposed to be losslessly convertible back
673 /// into the same token tree (modulo spans), except for possibly `TokenTree::Group`s
674 /// with `Delimiter::None` delimiters and negative numeric literals.
675 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
676 impl fmt::Display for TokenTree {
677 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
678 f.write_str(&self.to_string())
682 /// A delimited token stream.
684 /// A `Group` internally contains a `TokenStream` which is surrounded by `Delimiter`s.
686 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
687 pub struct Group(bridge::client::Group);
689 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
690 impl !Send for Group {}
691 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
692 impl !Sync for Group {}
694 /// Describes how a sequence of token trees is delimited.
695 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
696 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
699 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
702 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
705 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
708 /// An implicit delimiter, that may, for example, appear around tokens coming from a
709 /// "macro variable" `$var`. It is important to preserve operator priorities in cases like
710 /// `$var * 3` where `$var` is `1 + 2`.
711 /// Implicit delimiters might not survive roundtrip of a token stream through a string.
712 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
717 /// Creates a new `Group` with the given delimiter and token stream.
719 /// This constructor will set the span for this group to
720 /// `Span::call_site()`. To change the span you can use the `set_span`
722 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
723 pub fn new(delimiter: Delimiter, stream: TokenStream) -> Group {
724 Group(bridge::client::Group::new(delimiter, stream.0))
727 /// Returns the delimiter of this `Group`
728 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
729 pub fn delimiter(&self) -> Delimiter {
733 /// Returns the `TokenStream` of tokens that are delimited in this `Group`.
735 /// Note that the returned token stream does not include the delimiter
737 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
738 pub fn stream(&self) -> TokenStream {
739 TokenStream(self.0.stream())
742 /// Returns the span for the delimiters of this token stream, spanning the
746 /// pub fn span(&self) -> Span {
749 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
750 pub fn span(&self) -> Span {
754 /// Returns the span pointing to the opening delimiter of this group.
757 /// pub fn span_open(&self) -> Span {
760 #[stable(feature = "proc_macro_group_span", since = "1.55.0")]
761 pub fn span_open(&self) -> Span {
762 Span(self.0.span_open())
765 /// Returns the span pointing to the closing delimiter of this group.
768 /// pub fn span_close(&self) -> Span {
771 #[stable(feature = "proc_macro_group_span", since = "1.55.0")]
772 pub fn span_close(&self) -> Span {
773 Span(self.0.span_close())
776 /// Configures the span for this `Group`'s delimiters, but not its internal
779 /// This method will **not** set the span of all the internal tokens spanned
780 /// by this group, but rather it will only set the span of the delimiter
781 /// tokens at the level of the `Group`.
782 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
783 pub fn set_span(&mut self, span: Span) {
784 self.0.set_span(span.0);
788 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
789 // based on it (the reverse of the usual relationship between the two).
790 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
791 impl ToString for Group {
792 fn to_string(&self) -> String {
793 TokenStream::from(TokenTree::from(self.clone())).to_string()
797 /// Prints the group as a string that should be losslessly convertible back
798 /// into the same group (modulo spans), except for possibly `TokenTree::Group`s
799 /// with `Delimiter::None` delimiters.
800 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
801 impl fmt::Display for Group {
802 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
803 f.write_str(&self.to_string())
807 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
808 impl fmt::Debug for Group {
809 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
810 f.debug_struct("Group")
811 .field("delimiter", &self.delimiter())
812 .field("stream", &self.stream())
813 .field("span", &self.span())
818 /// A `Punct` is a single punctuation character such as `+`, `-` or `#`.
820 /// Multi-character operators like `+=` are represented as two instances of `Punct` with different
821 /// forms of `Spacing` returned.
822 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
824 pub struct Punct(bridge::client::Punct);
826 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
827 impl !Send for Punct {}
828 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
829 impl !Sync for Punct {}
831 /// Describes whether a `Punct` is followed immediately by another `Punct` ([`Spacing::Joint`]) or
832 /// by a different token or whitespace ([`Spacing::Alone`]).
833 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
834 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
836 /// A `Punct` is not immediately followed by another `Punct`.
837 /// E.g. `+` is `Alone` in `+ =`, `+ident` and `+()`.
838 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
840 /// A `Punct` is immediately followed by another `Punct`.
841 /// E.g. `+` is `Joint` in `+=` and `++`.
843 /// Additionally, single quote `'` can join with identifiers to form lifetimes: `'ident`.
844 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
849 /// Creates a new `Punct` from the given character and spacing.
850 /// The `ch` argument must be a valid punctuation character permitted by the language,
851 /// otherwise the function will panic.
853 /// The returned `Punct` will have the default span of `Span::call_site()`
854 /// which can be further configured with the `set_span` method below.
855 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
856 pub fn new(ch: char, spacing: Spacing) -> Punct {
857 Punct(bridge::client::Punct::new(ch, spacing))
860 /// Returns the value of this punctuation character as `char`.
861 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
862 pub fn as_char(&self) -> char {
866 /// Returns the spacing of this punctuation character, indicating whether it's immediately
867 /// followed by another `Punct` in the token stream, so they can potentially be combined into
868 /// a multi-character operator (`Joint`), or it's followed by some other token or whitespace
869 /// (`Alone`) so the operator has certainly ended.
870 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
871 pub fn spacing(&self) -> Spacing {
875 /// Returns the span for this punctuation character.
876 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
877 pub fn span(&self) -> Span {
881 /// Configure the span for this punctuation character.
882 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
883 pub fn set_span(&mut self, span: Span) {
884 self.0 = self.0.with_span(span.0);
888 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
889 // based on it (the reverse of the usual relationship between the two).
890 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
891 impl ToString for Punct {
892 fn to_string(&self) -> String {
893 TokenStream::from(TokenTree::from(self.clone())).to_string()
897 /// Prints the punctuation character as a string that should be losslessly convertible
898 /// back into the same character.
899 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
900 impl fmt::Display for Punct {
901 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
902 f.write_str(&self.to_string())
906 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
907 impl fmt::Debug for Punct {
908 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
909 f.debug_struct("Punct")
910 .field("ch", &self.as_char())
911 .field("spacing", &self.spacing())
912 .field("span", &self.span())
917 #[stable(feature = "proc_macro_punct_eq", since = "1.50.0")]
918 impl PartialEq<char> for Punct {
919 fn eq(&self, rhs: &char) -> bool {
920 self.as_char() == *rhs
924 #[stable(feature = "proc_macro_punct_eq_flipped", since = "1.52.0")]
925 impl PartialEq<Punct> for char {
926 fn eq(&self, rhs: &Punct) -> bool {
927 *self == rhs.as_char()
931 /// An identifier (`ident`).
933 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
934 pub struct Ident(bridge::client::Ident);
937 /// Creates a new `Ident` with the given `string` as well as the specified
939 /// The `string` argument must be a valid identifier permitted by the
940 /// language (including keywords, e.g. `self` or `fn`). Otherwise, the function will panic.
942 /// Note that `span`, currently in rustc, configures the hygiene information
943 /// for this identifier.
945 /// As of this time `Span::call_site()` explicitly opts-in to "call-site" hygiene
946 /// meaning that identifiers created with this span will be resolved as if they were written
947 /// directly at the location of the macro call, and other code at the macro call site will be
948 /// able to refer to them as well.
950 /// Later spans like `Span::def_site()` will allow to opt-in to "definition-site" hygiene
951 /// meaning that identifiers created with this span will be resolved at the location of the
952 /// macro definition and other code at the macro call site will not be able to refer to them.
954 /// Due to the current importance of hygiene this constructor, unlike other
955 /// tokens, requires a `Span` to be specified at construction.
956 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
957 pub fn new(string: &str, span: Span) -> Ident {
958 Ident(bridge::client::Ident::new(string, span.0, false))
961 /// Same as `Ident::new`, but creates a raw identifier (`r#ident`).
962 /// The `string` argument be a valid identifier permitted by the language
963 /// (including keywords, e.g. `fn`). Keywords which are usable in path segments
964 /// (e.g. `self`, `super`) are not supported, and will cause a panic.
965 #[stable(feature = "proc_macro_raw_ident", since = "1.47.0")]
966 pub fn new_raw(string: &str, span: Span) -> Ident {
967 Ident(bridge::client::Ident::new(string, span.0, true))
970 /// Returns the span of this `Ident`, encompassing the entire string returned
971 /// by [`to_string`](Self::to_string).
972 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
973 pub fn span(&self) -> Span {
977 /// Configures the span of this `Ident`, possibly changing its hygiene context.
978 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
979 pub fn set_span(&mut self, span: Span) {
980 self.0 = self.0.with_span(span.0);
984 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
985 // based on it (the reverse of the usual relationship between the two).
986 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
987 impl ToString for Ident {
988 fn to_string(&self) -> String {
989 TokenStream::from(TokenTree::from(self.clone())).to_string()
993 /// Prints the identifier as a string that should be losslessly convertible
994 /// back into the same identifier.
995 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
996 impl fmt::Display for Ident {
997 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
998 f.write_str(&self.to_string())
1002 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1003 impl fmt::Debug for Ident {
1004 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1005 f.debug_struct("Ident")
1006 .field("ident", &self.to_string())
1007 .field("span", &self.span())
1012 /// A literal string (`"hello"`), byte string (`b"hello"`),
1013 /// character (`'a'`), byte character (`b'a'`), an integer or floating point number
1014 /// with or without a suffix (`1`, `1u8`, `2.3`, `2.3f32`).
1015 /// Boolean literals like `true` and `false` do not belong here, they are `Ident`s.
1017 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1018 pub struct Literal(bridge::client::Literal);
1020 macro_rules! suffixed_int_literals {
1021 ($($name:ident => $kind:ident,)*) => ($(
1022 /// Creates a new suffixed integer literal with the specified value.
1024 /// This function will create an integer like `1u32` where the integer
1025 /// value specified is the first part of the token and the integral is
1026 /// also suffixed at the end.
1027 /// Literals created from negative numbers might not survive round-trips through
1028 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1030 /// Literals created through this method have the `Span::call_site()`
1031 /// span by default, which can be configured with the `set_span` method
1033 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1034 pub fn $name(n: $kind) -> Literal {
1035 Literal(bridge::client::Literal::typed_integer(&n.to_string(), stringify!($kind)))
1040 macro_rules! unsuffixed_int_literals {
1041 ($($name:ident => $kind:ident,)*) => ($(
1042 /// Creates a new unsuffixed integer literal with the specified value.
1044 /// This function will create an integer like `1` where the integer
1045 /// value specified is the first part of the token. No suffix is
1046 /// specified on this token, meaning that invocations like
1047 /// `Literal::i8_unsuffixed(1)` are equivalent to
1048 /// `Literal::u32_unsuffixed(1)`.
1049 /// Literals created from negative numbers might not survive rountrips through
1050 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1052 /// Literals created through this method have the `Span::call_site()`
1053 /// span by default, which can be configured with the `set_span` method
1055 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1056 pub fn $name(n: $kind) -> Literal {
1057 Literal(bridge::client::Literal::integer(&n.to_string()))
1063 suffixed_int_literals! {
1065 u16_suffixed => u16,
1066 u32_suffixed => u32,
1067 u64_suffixed => u64,
1068 u128_suffixed => u128,
1069 usize_suffixed => usize,
1071 i16_suffixed => i16,
1072 i32_suffixed => i32,
1073 i64_suffixed => i64,
1074 i128_suffixed => i128,
1075 isize_suffixed => isize,
1078 unsuffixed_int_literals! {
1079 u8_unsuffixed => u8,
1080 u16_unsuffixed => u16,
1081 u32_unsuffixed => u32,
1082 u64_unsuffixed => u64,
1083 u128_unsuffixed => u128,
1084 usize_unsuffixed => usize,
1085 i8_unsuffixed => i8,
1086 i16_unsuffixed => i16,
1087 i32_unsuffixed => i32,
1088 i64_unsuffixed => i64,
1089 i128_unsuffixed => i128,
1090 isize_unsuffixed => isize,
1093 /// Creates a new unsuffixed floating-point literal.
1095 /// This constructor is similar to those like `Literal::i8_unsuffixed` where
1096 /// the float's value is emitted directly into the token but no suffix is
1097 /// used, so it may be inferred to be a `f64` later in the compiler.
1098 /// Literals created from negative numbers might not survive rountrips through
1099 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1103 /// This function requires that the specified float is finite, for
1104 /// example if it is infinity or NaN this function will panic.
1105 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1106 pub fn f32_unsuffixed(n: f32) -> Literal {
1108 panic!("Invalid float literal {}", n);
1110 let mut repr = n.to_string();
1111 if !repr.contains('.') {
1112 repr.push_str(".0");
1114 Literal(bridge::client::Literal::float(&repr))
1117 /// Creates a new suffixed floating-point literal.
1119 /// This constructor will create a literal like `1.0f32` where the value
1120 /// specified is the preceding part of the token and `f32` is the suffix of
1121 /// the token. This token will always be inferred to be an `f32` in the
1123 /// Literals created from negative numbers might not survive rountrips through
1124 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1128 /// This function requires that the specified float is finite, for
1129 /// example if it is infinity or NaN this function will panic.
1130 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1131 pub fn f32_suffixed(n: f32) -> Literal {
1133 panic!("Invalid float literal {}", n);
1135 Literal(bridge::client::Literal::f32(&n.to_string()))
1138 /// Creates a new unsuffixed floating-point literal.
1140 /// This constructor is similar to those like `Literal::i8_unsuffixed` where
1141 /// the float's value is emitted directly into the token but no suffix is
1142 /// used, so it may be inferred to be a `f64` later in the compiler.
1143 /// Literals created from negative numbers might not survive rountrips through
1144 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1148 /// This function requires that the specified float is finite, for
1149 /// example if it is infinity or NaN this function will panic.
1150 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1151 pub fn f64_unsuffixed(n: f64) -> Literal {
1153 panic!("Invalid float literal {}", n);
1155 let mut repr = n.to_string();
1156 if !repr.contains('.') {
1157 repr.push_str(".0");
1159 Literal(bridge::client::Literal::float(&repr))
1162 /// Creates a new suffixed floating-point literal.
1164 /// This constructor will create a literal like `1.0f64` where the value
1165 /// specified is the preceding part of the token and `f64` is the suffix of
1166 /// the token. This token will always be inferred to be an `f64` in the
1168 /// Literals created from negative numbers might not survive rountrips through
1169 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1173 /// This function requires that the specified float is finite, for
1174 /// example if it is infinity or NaN this function will panic.
1175 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1176 pub fn f64_suffixed(n: f64) -> Literal {
1178 panic!("Invalid float literal {}", n);
1180 Literal(bridge::client::Literal::f64(&n.to_string()))
1184 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1185 pub fn string(string: &str) -> Literal {
1186 Literal(bridge::client::Literal::string(string))
1189 /// Character literal.
1190 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1191 pub fn character(ch: char) -> Literal {
1192 Literal(bridge::client::Literal::character(ch))
1195 /// Byte string literal.
1196 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1197 pub fn byte_string(bytes: &[u8]) -> Literal {
1198 Literal(bridge::client::Literal::byte_string(bytes))
1201 /// Returns the span encompassing this literal.
1202 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1203 pub fn span(&self) -> Span {
1207 /// Configures the span associated for this literal.
1208 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1209 pub fn set_span(&mut self, span: Span) {
1210 self.0.set_span(span.0);
1213 /// Returns a `Span` that is a subset of `self.span()` containing only the
1214 /// source bytes in range `range`. Returns `None` if the would-be trimmed
1215 /// span is outside the bounds of `self`.
1216 // FIXME(SergioBenitez): check that the byte range starts and ends at a
1217 // UTF-8 boundary of the source. otherwise, it's likely that a panic will
1218 // occur elsewhere when the source text is printed.
1219 // FIXME(SergioBenitez): there is no way for the user to know what
1220 // `self.span()` actually maps to, so this method can currently only be
1221 // called blindly. For example, `to_string()` for the character 'c' returns
1222 // "'\u{63}'"; there is no way for the user to know whether the source text
1223 // was 'c' or whether it was '\u{63}'.
1224 #[unstable(feature = "proc_macro_span", issue = "54725")]
1225 pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
1226 self.0.subspan(range.start_bound().cloned(), range.end_bound().cloned()).map(Span)
1230 /// Parse a single literal from its stringified representation.
1232 /// In order to parse successfully, the input string must not contain anything
1233 /// but the literal token. Specifically, it must not contain whitespace or
1234 /// comments in addition to the literal.
1236 /// The resulting literal token will have a `Span::call_site()` span.
1238 /// NOTE: some errors may cause panics instead of returning `LexError`. We
1239 /// reserve the right to change these errors into `LexError`s later.
1240 #[stable(feature = "proc_macro_literal_parse", since = "1.54.0")]
1241 impl FromStr for Literal {
1242 type Err = LexError;
1244 fn from_str(src: &str) -> Result<Self, LexError> {
1245 match bridge::client::Literal::from_str(src) {
1246 Ok(literal) => Ok(Literal(literal)),
1247 Err(()) => Err(LexError),
1252 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
1253 // based on it (the reverse of the usual relationship between the two).
1254 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
1255 impl ToString for Literal {
1256 fn to_string(&self) -> String {
1261 /// Prints the literal as a string that should be losslessly convertible
1262 /// back into the same literal (except for possible rounding for floating point literals).
1263 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1264 impl fmt::Display for Literal {
1265 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1266 f.write_str(&self.to_string())
1270 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1271 impl fmt::Debug for Literal {
1272 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1277 /// Tracked access to environment variables.
1278 #[unstable(feature = "proc_macro_tracked_env", issue = "74690")]
1279 pub mod tracked_env {
1280 use std::env::{self, VarError};
1281 use std::ffi::OsStr;
1283 /// Retrieve an environment variable and add it to build dependency info.
1284 /// Build system executing the compiler will know that the variable was accessed during
1285 /// compilation, and will be able to rerun the build when the value of that variable changes.
1286 /// Besides the dependency tracking this function should be equivalent to `env::var` from the
1287 /// standard library, except that the argument must be UTF-8.
1288 #[unstable(feature = "proc_macro_tracked_env", issue = "74690")]
1289 pub fn var<K: AsRef<OsStr> + AsRef<str>>(key: K) -> Result<String, VarError> {
1290 let key: &str = key.as_ref();
1291 let value = env::var(key);
1292 crate::bridge::client::FreeFunctions::track_env_var(key, value.as_deref().ok());
1297 /// Tracked access to additional files.
1298 #[unstable(feature = "track_path", issue = "73921")]
1299 pub mod tracked_path {
1301 /// Track a file explicitly.
1303 /// Commonly used for tracking asset preprocessing.
1304 #[unstable(feature = "track_path", issue = "73921")]
1305 pub fn path<P: AsRef<str>>(path: P) {
1306 let path: &str = path.as_ref();
1307 crate::bridge::client::FreeFunctions::track_path(path);