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 // This library is copied into rust-analyzer to allow loading rustc compiled proc macros.
21 // Please avoid unstable features where possible to minimize the amount of changes necessary
22 // to make it compile with rust-analyzer on stable.
23 #![feature(rustc_allow_const_fn_unstable)]
25 #![feature(staged_api)]
26 #![feature(allow_internal_unstable)]
27 #![feature(decl_macro)]
28 #![feature(negative_impls)]
29 #![feature(restricted_std)]
30 #![feature(rustc_attrs)]
31 #![feature(min_specialization)]
32 #![recursion_limit = "256"]
34 #[unstable(feature = "proc_macro_internals", issue = "27812")]
40 #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
41 pub use diagnostic::{Diagnostic, Level, MultiSpan};
43 use std::cmp::Ordering;
44 use std::ops::RangeBounds;
45 use std::path::PathBuf;
46 use std::str::FromStr;
47 use std::{error, fmt, iter, mem};
49 /// Determines whether proc_macro has been made accessible to the currently
52 /// The proc_macro crate is only intended for use inside the implementation of
53 /// procedural macros. All the functions in this crate panic if invoked from
54 /// outside of a procedural macro, such as from a build script or unit test or
55 /// ordinary Rust binary.
57 /// With consideration for Rust libraries that are designed to support both
58 /// macro and non-macro use cases, `proc_macro::is_available()` provides a
59 /// non-panicking way to detect whether the infrastructure required to use the
60 /// API of proc_macro is presently available. Returns true if invoked from
61 /// inside of a procedural macro, false if invoked from any other binary.
62 #[stable(feature = "proc_macro_is_available", since = "1.57.0")]
63 pub fn is_available() -> bool {
64 bridge::Bridge::is_available()
67 /// The main type provided by this crate, representing an abstract stream of
68 /// tokens, or, more specifically, a sequence of token trees.
69 /// The type provide interfaces for iterating over those token trees and, conversely,
70 /// collecting a number of token trees into one stream.
72 /// This is both the input and output of `#[proc_macro]`, `#[proc_macro_attribute]`
73 /// and `#[proc_macro_derive]` definitions.
74 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
76 pub struct TokenStream(bridge::client::TokenStream);
78 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
79 impl !Send for TokenStream {}
80 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
81 impl !Sync for TokenStream {}
83 /// Error returned from `TokenStream::from_str`.
84 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
89 #[stable(feature = "proc_macro_lexerror_impls", since = "1.44.0")]
90 impl fmt::Display for LexError {
91 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
92 f.write_str("cannot parse string into token stream")
96 #[stable(feature = "proc_macro_lexerror_impls", since = "1.44.0")]
97 impl error::Error for LexError {}
99 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
100 impl !Send for LexError {}
101 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
102 impl !Sync for LexError {}
104 /// Error returned from `TokenStream::expand_expr`.
105 #[unstable(feature = "proc_macro_expand", issue = "90765")]
108 pub struct ExpandError;
110 #[unstable(feature = "proc_macro_expand", issue = "90765")]
111 impl fmt::Display for ExpandError {
112 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
113 f.write_str("macro expansion failed")
117 #[unstable(feature = "proc_macro_expand", issue = "90765")]
118 impl error::Error for ExpandError {}
120 #[unstable(feature = "proc_macro_expand", issue = "90765")]
121 impl !Send for ExpandError {}
123 #[unstable(feature = "proc_macro_expand", issue = "90765")]
124 impl !Sync for ExpandError {}
127 /// Returns an empty `TokenStream` containing no token trees.
128 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
129 pub fn new() -> TokenStream {
130 TokenStream(bridge::client::TokenStream::new())
133 /// Checks if this `TokenStream` is empty.
134 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
135 pub fn is_empty(&self) -> bool {
139 /// Parses this `TokenStream` as an expression and attempts to expand any
140 /// macros within it. Returns the expanded `TokenStream`.
142 /// Currently only expressions expanding to literals will succeed, although
143 /// this may be relaxed in the future.
145 /// NOTE: In error conditions, `expand_expr` may leave macros unexpanded,
146 /// report an error, failing compilation, and/or return an `Err(..)`. The
147 /// specific behavior for any error condition, and what conditions are
148 /// considered errors, is unspecified and may change in the future.
149 #[unstable(feature = "proc_macro_expand", issue = "90765")]
150 pub fn expand_expr(&self) -> Result<TokenStream, ExpandError> {
151 match bridge::client::TokenStream::expand_expr(&self.0) {
152 Ok(stream) => Ok(TokenStream(stream)),
153 Err(_) => Err(ExpandError),
158 /// Attempts to break the string into tokens and parse those tokens into a token stream.
159 /// May fail for a number of reasons, for example, if the string contains unbalanced delimiters
160 /// or characters not existing in the language.
161 /// All tokens in the parsed stream get `Span::call_site()` spans.
163 /// NOTE: some errors may cause panics instead of returning `LexError`. We reserve the right to
164 /// change these errors into `LexError`s later.
165 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
166 impl FromStr for TokenStream {
169 fn from_str(src: &str) -> Result<TokenStream, LexError> {
170 Ok(TokenStream(bridge::client::TokenStream::from_str(src)))
174 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
175 // based on it (the reverse of the usual relationship between the two).
176 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
177 impl ToString for TokenStream {
178 fn to_string(&self) -> String {
183 /// Prints the token stream as a string that is supposed to be losslessly convertible back
184 /// into the same token stream (modulo spans), except for possibly `TokenTree::Group`s
185 /// with `Delimiter::None` delimiters and negative numeric literals.
186 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
187 impl fmt::Display for TokenStream {
188 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
189 f.write_str(&self.to_string())
193 /// Prints token in a form convenient for debugging.
194 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
195 impl fmt::Debug for TokenStream {
196 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
197 f.write_str("TokenStream ")?;
198 f.debug_list().entries(self.clone()).finish()
202 #[stable(feature = "proc_macro_token_stream_default", since = "1.45.0")]
203 impl Default for TokenStream {
204 fn default() -> Self {
209 #[unstable(feature = "proc_macro_quote", issue = "54722")]
210 pub use quote::{quote, quote_span};
212 /// Creates a token stream containing a single token tree.
213 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
214 impl From<TokenTree> for TokenStream {
215 fn from(tree: TokenTree) -> TokenStream {
216 TokenStream(bridge::client::TokenStream::from_token_tree(match tree {
217 TokenTree::Group(tt) => bridge::TokenTree::Group(tt.0),
218 TokenTree::Punct(tt) => bridge::TokenTree::Punct(tt.0),
219 TokenTree::Ident(tt) => bridge::TokenTree::Ident(tt.0),
220 TokenTree::Literal(tt) => bridge::TokenTree::Literal(tt.0),
225 /// Collects a number of token trees into a single stream.
226 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
227 impl iter::FromIterator<TokenTree> for TokenStream {
228 fn from_iter<I: IntoIterator<Item = TokenTree>>(trees: I) -> Self {
229 trees.into_iter().map(TokenStream::from).collect()
233 /// A "flattening" operation on token streams, collects token trees
234 /// from multiple token streams into a single stream.
235 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
236 impl iter::FromIterator<TokenStream> for TokenStream {
237 fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
238 let mut builder = bridge::client::TokenStreamBuilder::new();
239 streams.into_iter().for_each(|stream| builder.push(stream.0));
240 TokenStream(builder.build())
244 #[stable(feature = "token_stream_extend", since = "1.30.0")]
245 impl Extend<TokenTree> for TokenStream {
246 fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, trees: I) {
247 self.extend(trees.into_iter().map(TokenStream::from));
251 #[stable(feature = "token_stream_extend", since = "1.30.0")]
252 impl Extend<TokenStream> for TokenStream {
253 fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
254 // FIXME(eddyb) Use an optimized implementation if/when possible.
255 *self = iter::once(mem::replace(self, Self::new())).chain(streams).collect();
259 /// Public implementation details for the `TokenStream` type, such as iterators.
260 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
261 pub mod token_stream {
262 use crate::{bridge, Group, Ident, Literal, Punct, TokenStream, TokenTree};
264 /// An iterator over `TokenStream`'s `TokenTree`s.
265 /// The iteration is "shallow", e.g., the iterator doesn't recurse into delimited groups,
266 /// and returns whole groups as token trees.
268 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
269 pub struct IntoIter(bridge::client::TokenStreamIter);
271 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
272 impl Iterator for IntoIter {
273 type Item = TokenTree;
275 fn next(&mut self) -> Option<TokenTree> {
276 self.0.next().map(|tree| match tree {
277 bridge::TokenTree::Group(tt) => TokenTree::Group(Group(tt)),
278 bridge::TokenTree::Punct(tt) => TokenTree::Punct(Punct(tt)),
279 bridge::TokenTree::Ident(tt) => TokenTree::Ident(Ident(tt)),
280 bridge::TokenTree::Literal(tt) => TokenTree::Literal(Literal(tt)),
285 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
286 impl IntoIterator for TokenStream {
287 type Item = TokenTree;
288 type IntoIter = IntoIter;
290 fn into_iter(self) -> IntoIter {
291 IntoIter(self.0.into_iter())
296 /// `quote!(..)` accepts arbitrary tokens and expands into a `TokenStream` describing the input.
297 /// For example, `quote!(a + b)` will produce an expression, that, when evaluated, constructs
298 /// the `TokenStream` `[Ident("a"), Punct('+', Alone), Ident("b")]`.
300 /// Unquoting is done with `$`, and works by taking the single next ident as the unquoted term.
301 /// To quote `$` itself, use `$$`.
302 #[unstable(feature = "proc_macro_quote", issue = "54722")]
303 #[allow_internal_unstable(proc_macro_def_site, proc_macro_internals)]
304 #[rustc_builtin_macro]
305 pub macro quote($($t:tt)*) {
306 /* compiler built-in */
309 #[unstable(feature = "proc_macro_internals", issue = "27812")]
313 /// A region of source code, along with macro expansion information.
314 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
315 #[derive(Copy, Clone)]
316 pub struct Span(bridge::client::Span);
318 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
319 impl !Send for Span {}
320 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
321 impl !Sync for Span {}
323 macro_rules! diagnostic_method {
324 ($name:ident, $level:expr) => {
325 /// Creates a new `Diagnostic` with the given `message` at the span
327 #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
328 pub fn $name<T: Into<String>>(self, message: T) -> Diagnostic {
329 Diagnostic::spanned(self, $level, message)
335 /// A span that resolves at the macro definition site.
336 #[unstable(feature = "proc_macro_def_site", issue = "54724")]
337 pub fn def_site() -> Span {
338 Span(bridge::client::Span::def_site())
341 /// The span of the invocation of the current procedural macro.
342 /// Identifiers created with this span will be resolved as if they were written
343 /// directly at the macro call location (call-site hygiene) and other code
344 /// at the macro call site will be able to refer to them as well.
345 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
346 pub fn call_site() -> Span {
347 Span(bridge::client::Span::call_site())
350 /// A span that represents `macro_rules` hygiene, and sometimes resolves at the macro
351 /// definition site (local variables, labels, `$crate`) and sometimes at the macro
352 /// call site (everything else).
353 /// The span location is taken from the call-site.
354 #[stable(feature = "proc_macro_mixed_site", since = "1.45.0")]
355 pub fn mixed_site() -> Span {
356 Span(bridge::client::Span::mixed_site())
359 /// The original source file into which this span points.
360 #[unstable(feature = "proc_macro_span", issue = "54725")]
361 pub fn source_file(&self) -> SourceFile {
362 SourceFile(self.0.source_file())
365 /// The `Span` for the tokens in the previous macro expansion from which
366 /// `self` was generated from, if any.
367 #[unstable(feature = "proc_macro_span", issue = "54725")]
368 pub fn parent(&self) -> Option<Span> {
369 self.0.parent().map(Span)
372 /// The span for the origin source code that `self` was generated from. If
373 /// this `Span` wasn't generated from other macro expansions then the return
374 /// value is the same as `*self`.
375 #[unstable(feature = "proc_macro_span", issue = "54725")]
376 pub fn source(&self) -> Span {
377 Span(self.0.source())
380 /// Gets the starting line/column in the source file for this span.
381 #[unstable(feature = "proc_macro_span", issue = "54725")]
382 pub fn start(&self) -> LineColumn {
383 self.0.start().add_1_to_column()
386 /// Gets the ending line/column in the source file for this span.
387 #[unstable(feature = "proc_macro_span", issue = "54725")]
388 pub fn end(&self) -> LineColumn {
389 self.0.end().add_1_to_column()
392 /// Creates an empty span pointing to directly before this span.
393 #[unstable(feature = "proc_macro_span_shrink", issue = "87552")]
394 pub fn before(&self) -> Span {
395 Span(self.0.before())
398 /// Creates an empty span pointing to directly after this span.
399 #[unstable(feature = "proc_macro_span_shrink", issue = "87552")]
400 pub fn after(&self) -> Span {
404 /// Creates a new span encompassing `self` and `other`.
406 /// Returns `None` if `self` and `other` are from different files.
407 #[unstable(feature = "proc_macro_span", issue = "54725")]
408 pub fn join(&self, other: Span) -> Option<Span> {
409 self.0.join(other.0).map(Span)
412 /// Creates a new span with the same line/column information as `self` but
413 /// that resolves symbols as though it were at `other`.
414 #[stable(feature = "proc_macro_span_resolved_at", since = "1.45.0")]
415 pub fn resolved_at(&self, other: Span) -> Span {
416 Span(self.0.resolved_at(other.0))
419 /// Creates a new span with the same name resolution behavior as `self` but
420 /// with the line/column information of `other`.
421 #[stable(feature = "proc_macro_span_located_at", since = "1.45.0")]
422 pub fn located_at(&self, other: Span) -> Span {
423 other.resolved_at(*self)
426 /// Compares to spans to see if they're equal.
427 #[unstable(feature = "proc_macro_span", issue = "54725")]
428 pub fn eq(&self, other: &Span) -> bool {
432 /// Returns the source text behind a span. This preserves the original source
433 /// code, including spaces and comments. It only returns a result if the span
434 /// corresponds to real source code.
436 /// Note: The observable result of a macro should only rely on the tokens and
437 /// not on this source text. The result of this function is a best effort to
438 /// be used for diagnostics only.
439 #[unstable(feature = "proc_macro_span", issue = "54725")]
440 pub fn source_text(&self) -> Option<String> {
444 // Used by the implementation of `Span::quote`
446 #[unstable(feature = "proc_macro_internals", issue = "27812")]
447 pub fn save_span(&self) -> usize {
451 // Used by the implementation of `Span::quote`
453 #[unstable(feature = "proc_macro_internals", issue = "27812")]
454 pub fn recover_proc_macro_span(id: usize) -> Span {
455 Span(bridge::client::Span::recover_proc_macro_span(id))
458 diagnostic_method!(error, Level::Error);
459 diagnostic_method!(warning, Level::Warning);
460 diagnostic_method!(note, Level::Note);
461 diagnostic_method!(help, Level::Help);
464 /// Prints a span in a form convenient for debugging.
465 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
466 impl fmt::Debug for Span {
467 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
472 /// A line-column pair representing the start or end of a `Span`.
473 #[unstable(feature = "proc_macro_span", issue = "54725")]
474 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
475 pub struct LineColumn {
476 /// The 1-indexed line in the source file on which the span starts or ends (inclusive).
477 #[unstable(feature = "proc_macro_span", issue = "54725")]
479 /// The 1-indexed column (number of bytes in UTF-8 encoding) in the source
480 /// file on which the span starts or ends (inclusive).
481 #[unstable(feature = "proc_macro_span", issue = "54725")]
486 fn add_1_to_column(self) -> Self {
487 LineColumn { line: self.line, column: self.column + 1 }
491 #[unstable(feature = "proc_macro_span", issue = "54725")]
492 impl !Send for LineColumn {}
493 #[unstable(feature = "proc_macro_span", issue = "54725")]
494 impl !Sync for LineColumn {}
496 #[unstable(feature = "proc_macro_span", issue = "54725")]
497 impl Ord for LineColumn {
498 fn cmp(&self, other: &Self) -> Ordering {
499 self.line.cmp(&other.line).then(self.column.cmp(&other.column))
503 #[unstable(feature = "proc_macro_span", issue = "54725")]
504 impl PartialOrd for LineColumn {
505 fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
506 Some(self.cmp(other))
510 /// The source file of a given `Span`.
511 #[unstable(feature = "proc_macro_span", issue = "54725")]
513 pub struct SourceFile(bridge::client::SourceFile);
516 /// Gets the path to this source file.
519 /// If the code span associated with this `SourceFile` was generated by an external macro, this
520 /// macro, this might not be an actual path on the filesystem. Use [`is_real`] to check.
522 /// Also note that even if `is_real` returns `true`, if `--remap-path-prefix` was passed on
523 /// the command line, the path as given might not actually be valid.
525 /// [`is_real`]: Self::is_real
526 #[unstable(feature = "proc_macro_span", issue = "54725")]
527 pub fn path(&self) -> PathBuf {
528 PathBuf::from(self.0.path())
531 /// Returns `true` if this source file is a real source file, and not generated by an external
532 /// macro's expansion.
533 #[unstable(feature = "proc_macro_span", issue = "54725")]
534 pub fn is_real(&self) -> bool {
535 // This is a hack until intercrate spans are implemented and we can have real source files
536 // for spans generated in external macros.
537 // https://github.com/rust-lang/rust/pull/43604#issuecomment-333334368
542 #[unstable(feature = "proc_macro_span", issue = "54725")]
543 impl fmt::Debug for SourceFile {
544 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
545 f.debug_struct("SourceFile")
546 .field("path", &self.path())
547 .field("is_real", &self.is_real())
552 #[unstable(feature = "proc_macro_span", issue = "54725")]
553 impl PartialEq for SourceFile {
554 fn eq(&self, other: &Self) -> bool {
559 #[unstable(feature = "proc_macro_span", issue = "54725")]
560 impl Eq for SourceFile {}
562 /// A single token or a delimited sequence of token trees (e.g., `[1, (), ..]`).
563 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
566 /// A token stream surrounded by bracket delimiters.
567 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
568 Group(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Group),
570 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
571 Ident(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Ident),
572 /// A single punctuation character (`+`, `,`, `$`, etc.).
573 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
574 Punct(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Punct),
575 /// A literal character (`'a'`), string (`"hello"`), number (`2.3`), etc.
576 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
577 Literal(#[stable(feature = "proc_macro_lib2", since = "1.29.0")] Literal),
580 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
581 impl !Send for TokenTree {}
582 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
583 impl !Sync for TokenTree {}
586 /// Returns the span of this tree, delegating to the `span` method of
587 /// the contained token or a delimited stream.
588 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
589 pub fn span(&self) -> Span {
591 TokenTree::Group(ref t) => t.span(),
592 TokenTree::Ident(ref t) => t.span(),
593 TokenTree::Punct(ref t) => t.span(),
594 TokenTree::Literal(ref t) => t.span(),
598 /// Configures the span for *only this token*.
600 /// Note that if this token is a `Group` then this method will not configure
601 /// the span of each of the internal tokens, this will simply delegate to
602 /// the `set_span` method of each variant.
603 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
604 pub fn set_span(&mut self, span: Span) {
606 TokenTree::Group(ref mut t) => t.set_span(span),
607 TokenTree::Ident(ref mut t) => t.set_span(span),
608 TokenTree::Punct(ref mut t) => t.set_span(span),
609 TokenTree::Literal(ref mut t) => t.set_span(span),
614 /// Prints token tree in a form convenient for debugging.
615 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
616 impl fmt::Debug for TokenTree {
617 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
618 // Each of these has the name in the struct type in the derived debug,
619 // so don't bother with an extra layer of indirection
621 TokenTree::Group(ref tt) => tt.fmt(f),
622 TokenTree::Ident(ref tt) => tt.fmt(f),
623 TokenTree::Punct(ref tt) => tt.fmt(f),
624 TokenTree::Literal(ref tt) => tt.fmt(f),
629 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
630 impl From<Group> for TokenTree {
631 fn from(g: Group) -> TokenTree {
636 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
637 impl From<Ident> for TokenTree {
638 fn from(g: Ident) -> TokenTree {
643 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
644 impl From<Punct> for TokenTree {
645 fn from(g: Punct) -> TokenTree {
650 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
651 impl From<Literal> for TokenTree {
652 fn from(g: Literal) -> TokenTree {
653 TokenTree::Literal(g)
657 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
658 // based on it (the reverse of the usual relationship between the two).
659 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
660 impl ToString for TokenTree {
661 fn to_string(&self) -> String {
663 TokenTree::Group(ref t) => t.to_string(),
664 TokenTree::Ident(ref t) => t.to_string(),
665 TokenTree::Punct(ref t) => t.to_string(),
666 TokenTree::Literal(ref t) => t.to_string(),
671 /// Prints the token tree as a string that is supposed to be losslessly convertible back
672 /// into the same token tree (modulo spans), except for possibly `TokenTree::Group`s
673 /// with `Delimiter::None` delimiters and negative numeric literals.
674 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
675 impl fmt::Display for TokenTree {
676 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
677 f.write_str(&self.to_string())
681 /// A delimited token stream.
683 /// A `Group` internally contains a `TokenStream` which is surrounded by `Delimiter`s.
685 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
686 pub struct Group(bridge::client::Group);
688 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
689 impl !Send for Group {}
690 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
691 impl !Sync for Group {}
693 /// Describes how a sequence of token trees is delimited.
694 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
695 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
698 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
701 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
704 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
707 /// An invisible delimiter, that may, for example, appear around tokens coming from a
708 /// "macro variable" `$var`. It is important to preserve operator priorities in cases like
709 /// `$var * 3` where `$var` is `1 + 2`.
710 /// Invisible delimiters might not survive roundtrip of a token stream through a string.
711 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
716 /// Creates a new `Group` with the given delimiter and token stream.
718 /// This constructor will set the span for this group to
719 /// `Span::call_site()`. To change the span you can use the `set_span`
721 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
722 pub fn new(delimiter: Delimiter, stream: TokenStream) -> Group {
723 Group(bridge::client::Group::new(delimiter, stream.0))
726 /// Returns the delimiter of this `Group`
727 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
728 pub fn delimiter(&self) -> Delimiter {
732 /// Returns the `TokenStream` of tokens that are delimited in this `Group`.
734 /// Note that the returned token stream does not include the delimiter
736 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
737 pub fn stream(&self) -> TokenStream {
738 TokenStream(self.0.stream())
741 /// Returns the span for the delimiters of this token stream, spanning the
745 /// pub fn span(&self) -> Span {
748 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
749 pub fn span(&self) -> Span {
753 /// Returns the span pointing to the opening delimiter of this group.
756 /// pub fn span_open(&self) -> Span {
759 #[stable(feature = "proc_macro_group_span", since = "1.55.0")]
760 pub fn span_open(&self) -> Span {
761 Span(self.0.span_open())
764 /// Returns the span pointing to the closing delimiter of this group.
767 /// pub fn span_close(&self) -> Span {
770 #[stable(feature = "proc_macro_group_span", since = "1.55.0")]
771 pub fn span_close(&self) -> Span {
772 Span(self.0.span_close())
775 /// Configures the span for this `Group`'s delimiters, but not its internal
778 /// This method will **not** set the span of all the internal tokens spanned
779 /// by this group, but rather it will only set the span of the delimiter
780 /// tokens at the level of the `Group`.
781 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
782 pub fn set_span(&mut self, span: Span) {
783 self.0.set_span(span.0);
787 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
788 // based on it (the reverse of the usual relationship between the two).
789 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
790 impl ToString for Group {
791 fn to_string(&self) -> String {
792 TokenStream::from(TokenTree::from(self.clone())).to_string()
796 /// Prints the group as a string that should be losslessly convertible back
797 /// into the same group (modulo spans), except for possibly `TokenTree::Group`s
798 /// with `Delimiter::None` delimiters.
799 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
800 impl fmt::Display for Group {
801 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
802 f.write_str(&self.to_string())
806 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
807 impl fmt::Debug for Group {
808 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
809 f.debug_struct("Group")
810 .field("delimiter", &self.delimiter())
811 .field("stream", &self.stream())
812 .field("span", &self.span())
817 /// A `Punct` is a single punctuation character such as `+`, `-` or `#`.
819 /// Multi-character operators like `+=` are represented as two instances of `Punct` with different
820 /// forms of `Spacing` returned.
821 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
823 pub struct Punct(bridge::client::Punct);
825 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
826 impl !Send for Punct {}
827 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
828 impl !Sync for Punct {}
830 /// Describes whether a `Punct` is followed immediately by another `Punct` ([`Spacing::Joint`]) or
831 /// by a different token or whitespace ([`Spacing::Alone`]).
832 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
833 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
835 /// A `Punct` is not immediately followed by another `Punct`.
836 /// E.g. `+` is `Alone` in `+ =`, `+ident` and `+()`.
837 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
839 /// A `Punct` is immediately followed by another `Punct`.
840 /// E.g. `+` is `Joint` in `+=` and `++`.
842 /// Additionally, single quote `'` can join with identifiers to form lifetimes: `'ident`.
843 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
848 /// Creates a new `Punct` from the given character and spacing.
849 /// The `ch` argument must be a valid punctuation character permitted by the language,
850 /// otherwise the function will panic.
852 /// The returned `Punct` will have the default span of `Span::call_site()`
853 /// which can be further configured with the `set_span` method below.
854 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
855 pub fn new(ch: char, spacing: Spacing) -> Punct {
856 Punct(bridge::client::Punct::new(ch, spacing))
859 /// Returns the value of this punctuation character as `char`.
860 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
861 pub fn as_char(&self) -> char {
865 /// Returns the spacing of this punctuation character, indicating whether it's immediately
866 /// followed by another `Punct` in the token stream, so they can potentially be combined into
867 /// a multi-character operator (`Joint`), or it's followed by some other token or whitespace
868 /// (`Alone`) so the operator has certainly ended.
869 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
870 pub fn spacing(&self) -> Spacing {
874 /// Returns the span for this punctuation character.
875 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
876 pub fn span(&self) -> Span {
880 /// Configure the span for this punctuation character.
881 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
882 pub fn set_span(&mut self, span: Span) {
883 self.0 = self.0.with_span(span.0);
887 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
888 // based on it (the reverse of the usual relationship between the two).
889 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
890 impl ToString for Punct {
891 fn to_string(&self) -> String {
892 TokenStream::from(TokenTree::from(self.clone())).to_string()
896 /// Prints the punctuation character as a string that should be losslessly convertible
897 /// back into the same character.
898 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
899 impl fmt::Display for Punct {
900 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
901 f.write_str(&self.to_string())
905 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
906 impl fmt::Debug for Punct {
907 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
908 f.debug_struct("Punct")
909 .field("ch", &self.as_char())
910 .field("spacing", &self.spacing())
911 .field("span", &self.span())
916 #[stable(feature = "proc_macro_punct_eq", since = "1.50.0")]
917 impl PartialEq<char> for Punct {
918 fn eq(&self, rhs: &char) -> bool {
919 self.as_char() == *rhs
923 #[stable(feature = "proc_macro_punct_eq_flipped", since = "1.52.0")]
924 impl PartialEq<Punct> for char {
925 fn eq(&self, rhs: &Punct) -> bool {
926 *self == rhs.as_char()
930 /// An identifier (`ident`).
932 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
933 pub struct Ident(bridge::client::Ident);
936 /// Creates a new `Ident` with the given `string` as well as the specified
938 /// The `string` argument must be a valid identifier permitted by the
939 /// language (including keywords, e.g. `self` or `fn`). Otherwise, the function will panic.
941 /// Note that `span`, currently in rustc, configures the hygiene information
942 /// for this identifier.
944 /// As of this time `Span::call_site()` explicitly opts-in to "call-site" hygiene
945 /// meaning that identifiers created with this span will be resolved as if they were written
946 /// directly at the location of the macro call, and other code at the macro call site will be
947 /// able to refer to them as well.
949 /// Later spans like `Span::def_site()` will allow to opt-in to "definition-site" hygiene
950 /// meaning that identifiers created with this span will be resolved at the location of the
951 /// macro definition and other code at the macro call site will not be able to refer to them.
953 /// Due to the current importance of hygiene this constructor, unlike other
954 /// tokens, requires a `Span` to be specified at construction.
955 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
956 pub fn new(string: &str, span: Span) -> Ident {
957 Ident(bridge::client::Ident::new(string, span.0, false))
960 /// Same as `Ident::new`, but creates a raw identifier (`r#ident`).
961 /// The `string` argument be a valid identifier permitted by the language
962 /// (including keywords, e.g. `fn`). Keywords which are usable in path segments
963 /// (e.g. `self`, `super`) are not supported, and will cause a panic.
964 #[stable(feature = "proc_macro_raw_ident", since = "1.47.0")]
965 pub fn new_raw(string: &str, span: Span) -> Ident {
966 Ident(bridge::client::Ident::new(string, span.0, true))
969 /// Returns the span of this `Ident`, encompassing the entire string returned
970 /// by [`to_string`](Self::to_string).
971 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
972 pub fn span(&self) -> Span {
976 /// Configures the span of this `Ident`, possibly changing its hygiene context.
977 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
978 pub fn set_span(&mut self, span: Span) {
979 self.0 = self.0.with_span(span.0);
983 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
984 // based on it (the reverse of the usual relationship between the two).
985 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
986 impl ToString for Ident {
987 fn to_string(&self) -> String {
988 TokenStream::from(TokenTree::from(self.clone())).to_string()
992 /// Prints the identifier as a string that should be losslessly convertible
993 /// back into the same identifier.
994 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
995 impl fmt::Display for Ident {
996 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
997 f.write_str(&self.to_string())
1001 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1002 impl fmt::Debug for Ident {
1003 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1004 f.debug_struct("Ident")
1005 .field("ident", &self.to_string())
1006 .field("span", &self.span())
1011 /// A literal string (`"hello"`), byte string (`b"hello"`),
1012 /// character (`'a'`), byte character (`b'a'`), an integer or floating point number
1013 /// with or without a suffix (`1`, `1u8`, `2.3`, `2.3f32`).
1014 /// Boolean literals like `true` and `false` do not belong here, they are `Ident`s.
1016 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1017 pub struct Literal(bridge::client::Literal);
1019 macro_rules! suffixed_int_literals {
1020 ($($name:ident => $kind:ident,)*) => ($(
1021 /// Creates a new suffixed integer literal with the specified value.
1023 /// This function will create an integer like `1u32` where the integer
1024 /// value specified is the first part of the token and the integral is
1025 /// also suffixed at the end.
1026 /// Literals created from negative numbers might not survive round-trips through
1027 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1029 /// Literals created through this method have the `Span::call_site()`
1030 /// span by default, which can be configured with the `set_span` method
1032 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1033 pub fn $name(n: $kind) -> Literal {
1034 Literal(bridge::client::Literal::typed_integer(&n.to_string(), stringify!($kind)))
1039 macro_rules! unsuffixed_int_literals {
1040 ($($name:ident => $kind:ident,)*) => ($(
1041 /// Creates a new unsuffixed integer literal with the specified value.
1043 /// This function will create an integer like `1` where the integer
1044 /// value specified is the first part of the token. No suffix is
1045 /// specified on this token, meaning that invocations like
1046 /// `Literal::i8_unsuffixed(1)` are equivalent to
1047 /// `Literal::u32_unsuffixed(1)`.
1048 /// Literals created from negative numbers might not survive rountrips through
1049 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1051 /// Literals created through this method have the `Span::call_site()`
1052 /// span by default, which can be configured with the `set_span` method
1054 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1055 pub fn $name(n: $kind) -> Literal {
1056 Literal(bridge::client::Literal::integer(&n.to_string()))
1062 suffixed_int_literals! {
1064 u16_suffixed => u16,
1065 u32_suffixed => u32,
1066 u64_suffixed => u64,
1067 u128_suffixed => u128,
1068 usize_suffixed => usize,
1070 i16_suffixed => i16,
1071 i32_suffixed => i32,
1072 i64_suffixed => i64,
1073 i128_suffixed => i128,
1074 isize_suffixed => isize,
1077 unsuffixed_int_literals! {
1078 u8_unsuffixed => u8,
1079 u16_unsuffixed => u16,
1080 u32_unsuffixed => u32,
1081 u64_unsuffixed => u64,
1082 u128_unsuffixed => u128,
1083 usize_unsuffixed => usize,
1084 i8_unsuffixed => i8,
1085 i16_unsuffixed => i16,
1086 i32_unsuffixed => i32,
1087 i64_unsuffixed => i64,
1088 i128_unsuffixed => i128,
1089 isize_unsuffixed => isize,
1092 /// Creates a new unsuffixed floating-point literal.
1094 /// This constructor is similar to those like `Literal::i8_unsuffixed` where
1095 /// the float's value is emitted directly into the token but no suffix is
1096 /// used, so it may be inferred to be a `f64` later in the compiler.
1097 /// Literals created from negative numbers might not survive rountrips through
1098 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1102 /// This function requires that the specified float is finite, for
1103 /// example if it is infinity or NaN this function will panic.
1104 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1105 pub fn f32_unsuffixed(n: f32) -> Literal {
1107 panic!("Invalid float literal {n}");
1109 let mut repr = n.to_string();
1110 if !repr.contains('.') {
1111 repr.push_str(".0");
1113 Literal(bridge::client::Literal::float(&repr))
1116 /// Creates a new suffixed floating-point literal.
1118 /// This constructor will create a literal like `1.0f32` where the value
1119 /// specified is the preceding part of the token and `f32` is the suffix of
1120 /// the token. This token will always be inferred to be an `f32` in the
1122 /// Literals created from negative numbers might not survive rountrips through
1123 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1127 /// This function requires that the specified float is finite, for
1128 /// example if it is infinity or NaN this function will panic.
1129 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1130 pub fn f32_suffixed(n: f32) -> Literal {
1132 panic!("Invalid float literal {n}");
1134 Literal(bridge::client::Literal::f32(&n.to_string()))
1137 /// Creates a new unsuffixed floating-point literal.
1139 /// This constructor is similar to those like `Literal::i8_unsuffixed` where
1140 /// the float's value is emitted directly into the token but no suffix is
1141 /// used, so it may be inferred to be a `f64` later in the compiler.
1142 /// Literals created from negative numbers might not survive rountrips through
1143 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1147 /// This function requires that the specified float is finite, for
1148 /// example if it is infinity or NaN this function will panic.
1149 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1150 pub fn f64_unsuffixed(n: f64) -> Literal {
1152 panic!("Invalid float literal {n}");
1154 let mut repr = n.to_string();
1155 if !repr.contains('.') {
1156 repr.push_str(".0");
1158 Literal(bridge::client::Literal::float(&repr))
1161 /// Creates a new suffixed floating-point literal.
1163 /// This constructor will create a literal like `1.0f64` where the value
1164 /// specified is the preceding part of the token and `f64` is the suffix of
1165 /// the token. This token will always be inferred to be an `f64` in the
1167 /// Literals created from negative numbers might not survive rountrips through
1168 /// `TokenStream` or strings and may be broken into two tokens (`-` and positive literal).
1172 /// This function requires that the specified float is finite, for
1173 /// example if it is infinity or NaN this function will panic.
1174 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1175 pub fn f64_suffixed(n: f64) -> Literal {
1177 panic!("Invalid float literal {n}");
1179 Literal(bridge::client::Literal::f64(&n.to_string()))
1183 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1184 pub fn string(string: &str) -> Literal {
1185 Literal(bridge::client::Literal::string(string))
1188 /// Character literal.
1189 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1190 pub fn character(ch: char) -> Literal {
1191 Literal(bridge::client::Literal::character(ch))
1194 /// Byte string literal.
1195 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1196 pub fn byte_string(bytes: &[u8]) -> Literal {
1197 Literal(bridge::client::Literal::byte_string(bytes))
1200 /// Returns the span encompassing this literal.
1201 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1202 pub fn span(&self) -> Span {
1206 /// Configures the span associated for this literal.
1207 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1208 pub fn set_span(&mut self, span: Span) {
1209 self.0.set_span(span.0);
1212 /// Returns a `Span` that is a subset of `self.span()` containing only the
1213 /// source bytes in range `range`. Returns `None` if the would-be trimmed
1214 /// span is outside the bounds of `self`.
1215 // FIXME(SergioBenitez): check that the byte range starts and ends at a
1216 // UTF-8 boundary of the source. otherwise, it's likely that a panic will
1217 // occur elsewhere when the source text is printed.
1218 // FIXME(SergioBenitez): there is no way for the user to know what
1219 // `self.span()` actually maps to, so this method can currently only be
1220 // called blindly. For example, `to_string()` for the character 'c' returns
1221 // "'\u{63}'"; there is no way for the user to know whether the source text
1222 // was 'c' or whether it was '\u{63}'.
1223 #[unstable(feature = "proc_macro_span", issue = "54725")]
1224 pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
1225 self.0.subspan(range.start_bound().cloned(), range.end_bound().cloned()).map(Span)
1229 /// Parse a single literal from its stringified representation.
1231 /// In order to parse successfully, the input string must not contain anything
1232 /// but the literal token. Specifically, it must not contain whitespace or
1233 /// comments in addition to the literal.
1235 /// The resulting literal token will have a `Span::call_site()` span.
1237 /// NOTE: some errors may cause panics instead of returning `LexError`. We
1238 /// reserve the right to change these errors into `LexError`s later.
1239 #[stable(feature = "proc_macro_literal_parse", since = "1.54.0")]
1240 impl FromStr for Literal {
1241 type Err = LexError;
1243 fn from_str(src: &str) -> Result<Self, LexError> {
1244 match bridge::client::Literal::from_str(src) {
1245 Ok(literal) => Ok(Literal(literal)),
1246 Err(()) => Err(LexError),
1251 // N.B., the bridge only provides `to_string`, implement `fmt::Display`
1252 // based on it (the reverse of the usual relationship between the two).
1253 #[stable(feature = "proc_macro_lib", since = "1.15.0")]
1254 impl ToString for Literal {
1255 fn to_string(&self) -> String {
1260 /// Prints the literal as a string that should be losslessly convertible
1261 /// back into the same literal (except for possible rounding for floating point literals).
1262 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1263 impl fmt::Display for Literal {
1264 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1265 f.write_str(&self.to_string())
1269 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
1270 impl fmt::Debug for Literal {
1271 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1276 /// Tracked access to environment variables.
1277 #[unstable(feature = "proc_macro_tracked_env", issue = "74690")]
1278 pub mod tracked_env {
1279 use std::env::{self, VarError};
1280 use std::ffi::OsStr;
1282 /// Retrieve an environment variable and add it to build dependency info.
1283 /// Build system executing the compiler will know that the variable was accessed during
1284 /// compilation, and will be able to rerun the build when the value of that variable changes.
1285 /// Besides the dependency tracking this function should be equivalent to `env::var` from the
1286 /// standard library, except that the argument must be UTF-8.
1287 #[unstable(feature = "proc_macro_tracked_env", issue = "74690")]
1288 pub fn var<K: AsRef<OsStr> + AsRef<str>>(key: K) -> Result<String, VarError> {
1289 let key: &str = key.as_ref();
1290 let value = env::var(key);
1291 crate::bridge::client::FreeFunctions::track_env_var(key, value.as_deref().ok());
1296 /// Tracked access to additional files.
1297 #[unstable(feature = "track_path", issue = "73921")]
1298 pub mod tracked_path {
1300 /// Track a file explicitly.
1302 /// Commonly used for tracking asset preprocessing.
1303 #[unstable(feature = "track_path", issue = "73921")]
1304 pub fn path<P: AsRef<str>>(path: P) {
1305 let path: &str = path.as_ref();
1306 crate::bridge::client::FreeFunctions::track_path(path);