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Message-ID: <20251110095025.1475896-6-ojeda@kernel.org>
Date: Mon, 10 Nov 2025 10:50:10 +0100
From: Miguel Ojeda <ojeda@...nel.org>
To: Miguel Ojeda <ojeda@...nel.org>,
Alex Gaynor <alex.gaynor@...il.com>,
Nathan Chancellor <nathan@...nel.org>,
Nicolas Schier <nicolas@...sle.eu>
Cc: Boqun Feng <boqun.feng@...il.com>,
Gary Guo <gary@...yguo.net>,
Björn Roy Baron <bjorn3_gh@...tonmail.com>,
Benno Lossin <lossin@...nel.org>,
Andreas Hindborg <a.hindborg@...nel.org>,
Alice Ryhl <aliceryhl@...gle.com>,
Trevor Gross <tmgross@...ch.edu>,
Danilo Krummrich <dakr@...nel.org>,
rust-for-linux@...r.kernel.org,
linux-kbuild@...r.kernel.org,
linux-kernel@...r.kernel.org,
patches@...ts.linux.dev
Subject: [PATCH 05/18] rust: proc-macro2: import crate
This is a subset of the Rust `proc-macro2` crate, version 1.0.101
(released 2025-08-16), licensed under "Apache-2.0 OR MIT", from:
https://github.com/dtolnay/proc-macro2/raw/1.0.101/src
The files are copied as-is, with no modifications whatsoever (not even
adding the SPDX identifiers).
For copyright details, please see:
https://github.com/dtolnay/proc-macro2/blob/1.0.101/README.md#license
https://github.com/dtolnay/proc-macro2/blob/1.0.101/LICENSE-APACHE
https://github.com/dtolnay/proc-macro2/blob/1.0.101/LICENSE-MIT
The next two patches modify these files as needed for use within the
kernel. This patch split allows reviewers to double-check the import
and to clearly see the differences introduced.
The following script may be used to verify the contents:
for path in $(cd rust/proc-macro2/ && find . -type f -name '*.rs'); do
curl --silent --show-error --location \
https://github.com/dtolnay/proc-macro2/raw/1.0.101/src/$path \
| diff --unified rust/proc-macro2/$path - && echo $path: OK
done
Signed-off-by: Miguel Ojeda <ojeda@...nel.org>
---
rust/proc-macro2/detection.rs | 75 +
rust/proc-macro2/extra.rs | 151 ++
rust/proc-macro2/fallback.rs | 1256 +++++++++++++++
rust/proc-macro2/lib.rs | 1349 +++++++++++++++++
rust/proc-macro2/location.rs | 29 +
rust/proc-macro2/marker.rs | 17 +
rust/proc-macro2/parse.rs | 995 ++++++++++++
rust/proc-macro2/probe.rs | 10 +
rust/proc-macro2/probe/proc_macro_span.rs | 51 +
.../proc-macro2/probe/proc_macro_span_file.rs | 14 +
.../probe/proc_macro_span_location.rs | 21 +
rust/proc-macro2/rcvec.rs | 146 ++
rust/proc-macro2/wrapper.rs | 984 ++++++++++++
13 files changed, 5098 insertions(+)
create mode 100644 rust/proc-macro2/detection.rs
create mode 100644 rust/proc-macro2/extra.rs
create mode 100644 rust/proc-macro2/fallback.rs
create mode 100644 rust/proc-macro2/lib.rs
create mode 100644 rust/proc-macro2/location.rs
create mode 100644 rust/proc-macro2/marker.rs
create mode 100644 rust/proc-macro2/parse.rs
create mode 100644 rust/proc-macro2/probe.rs
create mode 100644 rust/proc-macro2/probe/proc_macro_span.rs
create mode 100644 rust/proc-macro2/probe/proc_macro_span_file.rs
create mode 100644 rust/proc-macro2/probe/proc_macro_span_location.rs
create mode 100644 rust/proc-macro2/rcvec.rs
create mode 100644 rust/proc-macro2/wrapper.rs
diff --git a/rust/proc-macro2/detection.rs b/rust/proc-macro2/detection.rs
new file mode 100644
index 000000000000..beba7b237395
--- /dev/null
+++ b/rust/proc-macro2/detection.rs
@@ -0,0 +1,75 @@
+use core::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Once;
+
+static WORKS: AtomicUsize = AtomicUsize::new(0);
+static INIT: Once = Once::new();
+
+pub(crate) fn inside_proc_macro() -> bool {
+ match WORKS.load(Ordering::Relaxed) {
+ 1 => return false,
+ 2 => return true,
+ _ => {}
+ }
+
+ INIT.call_once(initialize);
+ inside_proc_macro()
+}
+
+pub(crate) fn force_fallback() {
+ WORKS.store(1, Ordering::Relaxed);
+}
+
+pub(crate) fn unforce_fallback() {
+ initialize();
+}
+
+#[cfg(not(no_is_available))]
+fn initialize() {
+ let available = proc_macro::is_available();
+ WORKS.store(available as usize + 1, Ordering::Relaxed);
+}
+
+// Swap in a null panic hook to avoid printing "thread panicked" to stderr,
+// then use catch_unwind to determine whether the compiler's proc_macro is
+// working. When proc-macro2 is used from outside of a procedural macro all
+// of the proc_macro crate's APIs currently panic.
+//
+// The Once is to prevent the possibility of this ordering:
+//
+// thread 1 calls take_hook, gets the user's original hook
+// thread 1 calls set_hook with the null hook
+// thread 2 calls take_hook, thinks null hook is the original hook
+// thread 2 calls set_hook with the null hook
+// thread 1 calls set_hook with the actual original hook
+// thread 2 calls set_hook with what it thinks is the original hook
+//
+// in which the user's hook has been lost.
+//
+// There is still a race condition where a panic in a different thread can
+// happen during the interval that the user's original panic hook is
+// unregistered such that their hook is incorrectly not called. This is
+// sufficiently unlikely and less bad than printing panic messages to stderr
+// on correct use of this crate. Maybe there is a libstd feature request
+// here. For now, if a user needs to guarantee that this failure mode does
+// not occur, they need to call e.g. `proc_macro2::Span::call_site()` from
+// the main thread before launching any other threads.
+#[cfg(no_is_available)]
+fn initialize() {
+ use std::panic::{self, PanicInfo};
+
+ type PanicHook = dyn Fn(&PanicInfo) + Sync + Send + 'static;
+
+ let null_hook: Box<PanicHook> = Box::new(|_panic_info| { /* ignore */ });
+ let sanity_check = &*null_hook as *const PanicHook;
+ let original_hook = panic::take_hook();
+ panic::set_hook(null_hook);
+
+ let works = panic::catch_unwind(proc_macro::Span::call_site).is_ok();
+ WORKS.store(works as usize + 1, Ordering::Relaxed);
+
+ let hopefully_null_hook = panic::take_hook();
+ panic::set_hook(original_hook);
+ if sanity_check != &*hopefully_null_hook {
+ panic!("observed race condition in proc_macro2::inside_proc_macro");
+ }
+}
diff --git a/rust/proc-macro2/extra.rs b/rust/proc-macro2/extra.rs
new file mode 100644
index 000000000000..522a90e136be
--- /dev/null
+++ b/rust/proc-macro2/extra.rs
@@ -0,0 +1,151 @@
+//! Items which do not have a correspondence to any API in the proc_macro crate,
+//! but are necessary to include in proc-macro2.
+
+use crate::fallback;
+use crate::imp;
+use crate::marker::{ProcMacroAutoTraits, MARKER};
+use crate::Span;
+use core::fmt::{self, Debug};
+
+/// Invalidate any `proc_macro2::Span` that exist on the current thread.
+///
+/// The implementation of `Span` uses thread-local data structures and this
+/// function clears them. Calling any method on a `Span` on the current thread
+/// created prior to the invalidation will return incorrect values or crash.
+///
+/// This function is useful for programs that process more than 2<sup>32</sup>
+/// bytes of Rust source code on the same thread. Just like rustc, proc-macro2
+/// uses 32-bit source locations, and these wrap around when the total source
+/// code processed by the same thread exceeds 2<sup>32</sup> bytes (4
+/// gigabytes). After a wraparound, `Span` methods such as `source_text()` can
+/// return wrong data.
+///
+/// # Example
+///
+/// As of late 2023, there is 200 GB of Rust code published on crates.io.
+/// Looking at just the newest version of every crate, it is 16 GB of code. So a
+/// workload that involves parsing it all would overflow a 32-bit source
+/// location unless spans are being invalidated.
+///
+/// ```
+/// use flate2::read::GzDecoder;
+/// use std::ffi::OsStr;
+/// use std::io::{BufReader, Read};
+/// use std::str::FromStr;
+/// use tar::Archive;
+///
+/// rayon::scope(|s| {
+/// for krate in every_version_of_every_crate() {
+/// s.spawn(move |_| {
+/// proc_macro2::extra::invalidate_current_thread_spans();
+///
+/// let reader = BufReader::new(krate);
+/// let tar = GzDecoder::new(reader);
+/// let mut archive = Archive::new(tar);
+/// for entry in archive.entries().unwrap() {
+/// let mut entry = entry.unwrap();
+/// let path = entry.path().unwrap();
+/// if path.extension() != Some(OsStr::new("rs")) {
+/// continue;
+/// }
+/// let mut content = String::new();
+/// entry.read_to_string(&mut content).unwrap();
+/// match proc_macro2::TokenStream::from_str(&content) {
+/// Ok(tokens) => {/* ... */},
+/// Err(_) => continue,
+/// }
+/// }
+/// });
+/// }
+/// });
+/// #
+/// # fn every_version_of_every_crate() -> Vec<std::fs::File> {
+/// # Vec::new()
+/// # }
+/// ```
+///
+/// # Panics
+///
+/// This function is not applicable to and will panic if called from a
+/// procedural macro.
+#[cfg(span_locations)]
+#[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+pub fn invalidate_current_thread_spans() {
+ crate::imp::invalidate_current_thread_spans();
+}
+
+/// An object that holds a [`Group`]'s `span_open()` and `span_close()` together
+/// in a more compact representation than holding those 2 spans individually.
+///
+/// [`Group`]: crate::Group
+#[derive(Copy, Clone)]
+pub struct DelimSpan {
+ inner: DelimSpanEnum,
+ _marker: ProcMacroAutoTraits,
+}
+
+#[derive(Copy, Clone)]
+enum DelimSpanEnum {
+ #[cfg(wrap_proc_macro)]
+ Compiler {
+ join: proc_macro::Span,
+ open: proc_macro::Span,
+ close: proc_macro::Span,
+ },
+ Fallback(fallback::Span),
+}
+
+impl DelimSpan {
+ pub(crate) fn new(group: &imp::Group) -> Self {
+ #[cfg(wrap_proc_macro)]
+ let inner = match group {
+ imp::Group::Compiler(group) => DelimSpanEnum::Compiler {
+ join: group.span(),
+ open: group.span_open(),
+ close: group.span_close(),
+ },
+ imp::Group::Fallback(group) => DelimSpanEnum::Fallback(group.span()),
+ };
+
+ #[cfg(not(wrap_proc_macro))]
+ let inner = DelimSpanEnum::Fallback(group.span());
+
+ DelimSpan {
+ inner,
+ _marker: MARKER,
+ }
+ }
+
+ /// Returns a span covering the entire delimited group.
+ pub fn join(&self) -> Span {
+ match &self.inner {
+ #[cfg(wrap_proc_macro)]
+ DelimSpanEnum::Compiler { join, .. } => Span::_new(imp::Span::Compiler(*join)),
+ DelimSpanEnum::Fallback(span) => Span::_new_fallback(*span),
+ }
+ }
+
+ /// Returns a span for the opening punctuation of the group only.
+ pub fn open(&self) -> Span {
+ match &self.inner {
+ #[cfg(wrap_proc_macro)]
+ DelimSpanEnum::Compiler { open, .. } => Span::_new(imp::Span::Compiler(*open)),
+ DelimSpanEnum::Fallback(span) => Span::_new_fallback(span.first_byte()),
+ }
+ }
+
+ /// Returns a span for the closing punctuation of the group only.
+ pub fn close(&self) -> Span {
+ match &self.inner {
+ #[cfg(wrap_proc_macro)]
+ DelimSpanEnum::Compiler { close, .. } => Span::_new(imp::Span::Compiler(*close)),
+ DelimSpanEnum::Fallback(span) => Span::_new_fallback(span.last_byte()),
+ }
+ }
+}
+
+impl Debug for DelimSpan {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Debug::fmt(&self.join(), f)
+ }
+}
diff --git a/rust/proc-macro2/fallback.rs b/rust/proc-macro2/fallback.rs
new file mode 100644
index 000000000000..1560105cfd25
--- /dev/null
+++ b/rust/proc-macro2/fallback.rs
@@ -0,0 +1,1256 @@
+#[cfg(wrap_proc_macro)]
+use crate::imp;
+#[cfg(span_locations)]
+use crate::location::LineColumn;
+use crate::parse::{self, Cursor};
+use crate::rcvec::{RcVec, RcVecBuilder, RcVecIntoIter, RcVecMut};
+use crate::{Delimiter, Spacing, TokenTree};
+#[cfg(all(span_locations, not(fuzzing)))]
+use alloc::collections::BTreeMap;
+#[cfg(all(span_locations, not(fuzzing)))]
+use core::cell::RefCell;
+#[cfg(span_locations)]
+use core::cmp;
+#[cfg(all(span_locations, not(fuzzing)))]
+use core::cmp::Ordering;
+use core::fmt::{self, Debug, Display, Write};
+use core::mem::ManuallyDrop;
+#[cfg(span_locations)]
+use core::ops::Range;
+use core::ops::RangeBounds;
+use core::ptr;
+use core::str;
+#[cfg(feature = "proc-macro")]
+use core::str::FromStr;
+use std::ffi::CStr;
+#[cfg(wrap_proc_macro)]
+use std::panic;
+#[cfg(span_locations)]
+use std::path::PathBuf;
+
+/// Force use of proc-macro2's fallback implementation of the API for now, even
+/// if the compiler's implementation is available.
+pub fn force() {
+ #[cfg(wrap_proc_macro)]
+ crate::detection::force_fallback();
+}
+
+/// Resume using the compiler's implementation of the proc macro API if it is
+/// available.
+pub fn unforce() {
+ #[cfg(wrap_proc_macro)]
+ crate::detection::unforce_fallback();
+}
+
+#[derive(Clone)]
+pub(crate) struct TokenStream {
+ inner: RcVec<TokenTree>,
+}
+
+#[derive(Debug)]
+pub(crate) struct LexError {
+ pub(crate) span: Span,
+}
+
+impl LexError {
+ pub(crate) fn span(&self) -> Span {
+ self.span
+ }
+
+ pub(crate) fn call_site() -> Self {
+ LexError {
+ span: Span::call_site(),
+ }
+ }
+}
+
+impl TokenStream {
+ pub(crate) fn new() -> Self {
+ TokenStream {
+ inner: RcVecBuilder::new().build(),
+ }
+ }
+
+ pub(crate) fn from_str_checked(src: &str) -> Result<Self, LexError> {
+ // Create a dummy file & add it to the source map
+ let mut cursor = get_cursor(src);
+
+ // Strip a byte order mark if present
+ const BYTE_ORDER_MARK: &str = "\u{feff}";
+ if cursor.starts_with(BYTE_ORDER_MARK) {
+ cursor = cursor.advance(BYTE_ORDER_MARK.len());
+ }
+
+ parse::token_stream(cursor)
+ }
+
+ #[cfg(feature = "proc-macro")]
+ pub(crate) fn from_str_unchecked(src: &str) -> Self {
+ Self::from_str_checked(src).unwrap()
+ }
+
+ pub(crate) fn is_empty(&self) -> bool {
+ self.inner.len() == 0
+ }
+
+ fn take_inner(self) -> RcVecBuilder<TokenTree> {
+ let nodrop = ManuallyDrop::new(self);
+ unsafe { ptr::read(&nodrop.inner) }.make_owned()
+ }
+}
+
+fn push_token_from_proc_macro(mut vec: RcVecMut<TokenTree>, token: TokenTree) {
+ // https://github.com/dtolnay/proc-macro2/issues/235
+ match token {
+ TokenTree::Literal(crate::Literal {
+ #[cfg(wrap_proc_macro)]
+ inner: crate::imp::Literal::Fallback(literal),
+ #[cfg(not(wrap_proc_macro))]
+ inner: literal,
+ ..
+ }) if literal.repr.starts_with('-') => {
+ push_negative_literal(vec, literal);
+ }
+ _ => vec.push(token),
+ }
+
+ #[cold]
+ fn push_negative_literal(mut vec: RcVecMut<TokenTree>, mut literal: Literal) {
+ literal.repr.remove(0);
+ let mut punct = crate::Punct::new('-', Spacing::Alone);
+ punct.set_span(crate::Span::_new_fallback(literal.span));
+ vec.push(TokenTree::Punct(punct));
+ vec.push(TokenTree::Literal(crate::Literal::_new_fallback(literal)));
+ }
+}
+
+// Nonrecursive to prevent stack overflow.
+impl Drop for TokenStream {
+ fn drop(&mut self) {
+ let mut stack = Vec::new();
+ let mut current = match self.inner.get_mut() {
+ Some(inner) => inner.take().into_iter(),
+ None => return,
+ };
+ loop {
+ while let Some(token) = current.next() {
+ let group = match token {
+ TokenTree::Group(group) => group.inner,
+ _ => continue,
+ };
+ #[cfg(wrap_proc_macro)]
+ let group = match group {
+ crate::imp::Group::Fallback(group) => group,
+ crate::imp::Group::Compiler(_) => continue,
+ };
+ let mut group = group;
+ if let Some(inner) = group.stream.inner.get_mut() {
+ stack.push(current);
+ current = inner.take().into_iter();
+ }
+ }
+ match stack.pop() {
+ Some(next) => current = next,
+ None => return,
+ }
+ }
+ }
+}
+
+pub(crate) struct TokenStreamBuilder {
+ inner: RcVecBuilder<TokenTree>,
+}
+
+impl TokenStreamBuilder {
+ pub(crate) fn new() -> Self {
+ TokenStreamBuilder {
+ inner: RcVecBuilder::new(),
+ }
+ }
+
+ pub(crate) fn with_capacity(cap: usize) -> Self {
+ TokenStreamBuilder {
+ inner: RcVecBuilder::with_capacity(cap),
+ }
+ }
+
+ pub(crate) fn push_token_from_parser(&mut self, tt: TokenTree) {
+ self.inner.push(tt);
+ }
+
+ pub(crate) fn build(self) -> TokenStream {
+ TokenStream {
+ inner: self.inner.build(),
+ }
+ }
+}
+
+#[cfg(span_locations)]
+fn get_cursor(src: &str) -> Cursor {
+ #[cfg(fuzzing)]
+ return Cursor { rest: src, off: 1 };
+
+ // Create a dummy file & add it to the source map
+ #[cfg(not(fuzzing))]
+ SOURCE_MAP.with(|sm| {
+ let mut sm = sm.borrow_mut();
+ let span = sm.add_file(src);
+ Cursor {
+ rest: src,
+ off: span.lo,
+ }
+ })
+}
+
+#[cfg(not(span_locations))]
+fn get_cursor(src: &str) -> Cursor {
+ Cursor { rest: src }
+}
+
+impl Display for LexError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ f.write_str("cannot parse string into token stream")
+ }
+}
+
+impl Display for TokenStream {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ let mut joint = false;
+ for (i, tt) in self.inner.iter().enumerate() {
+ if i != 0 && !joint {
+ write!(f, " ")?;
+ }
+ joint = false;
+ match tt {
+ TokenTree::Group(tt) => Display::fmt(tt, f),
+ TokenTree::Ident(tt) => Display::fmt(tt, f),
+ TokenTree::Punct(tt) => {
+ joint = tt.spacing() == Spacing::Joint;
+ Display::fmt(tt, f)
+ }
+ TokenTree::Literal(tt) => Display::fmt(tt, f),
+ }?;
+ }
+
+ Ok(())
+ }
+}
+
+impl Debug for TokenStream {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ f.write_str("TokenStream ")?;
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+#[cfg(feature = "proc-macro")]
+impl From<proc_macro::TokenStream> for TokenStream {
+ fn from(inner: proc_macro::TokenStream) -> Self {
+ TokenStream::from_str_unchecked(&inner.to_string())
+ }
+}
+
+#[cfg(feature = "proc-macro")]
+impl From<TokenStream> for proc_macro::TokenStream {
+ fn from(inner: TokenStream) -> Self {
+ proc_macro::TokenStream::from_str_unchecked(&inner.to_string())
+ }
+}
+
+impl From<TokenTree> for TokenStream {
+ fn from(tree: TokenTree) -> Self {
+ let mut stream = RcVecBuilder::new();
+ push_token_from_proc_macro(stream.as_mut(), tree);
+ TokenStream {
+ inner: stream.build(),
+ }
+ }
+}
+
+impl FromIterator<TokenTree> for TokenStream {
+ fn from_iter<I: IntoIterator<Item = TokenTree>>(tokens: I) -> Self {
+ let mut stream = TokenStream::new();
+ stream.extend(tokens);
+ stream
+ }
+}
+
+impl FromIterator<TokenStream> for TokenStream {
+ fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
+ let mut v = RcVecBuilder::new();
+
+ for stream in streams {
+ v.extend(stream.take_inner());
+ }
+
+ TokenStream { inner: v.build() }
+ }
+}
+
+impl Extend<TokenTree> for TokenStream {
+ fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, tokens: I) {
+ let mut vec = self.inner.make_mut();
+ tokens
+ .into_iter()
+ .for_each(|token| push_token_from_proc_macro(vec.as_mut(), token));
+ }
+}
+
+impl Extend<TokenStream> for TokenStream {
+ fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
+ self.inner.make_mut().extend(streams.into_iter().flatten());
+ }
+}
+
+pub(crate) type TokenTreeIter = RcVecIntoIter<TokenTree>;
+
+impl IntoIterator for TokenStream {
+ type Item = TokenTree;
+ type IntoIter = TokenTreeIter;
+
+ fn into_iter(self) -> TokenTreeIter {
+ self.take_inner().into_iter()
+ }
+}
+
+#[cfg(all(span_locations, not(fuzzing)))]
+thread_local! {
+ static SOURCE_MAP: RefCell<SourceMap> = RefCell::new(SourceMap {
+ // Start with a single dummy file which all call_site() and def_site()
+ // spans reference.
+ files: vec![FileInfo {
+ source_text: String::new(),
+ span: Span { lo: 0, hi: 0 },
+ lines: vec![0],
+ char_index_to_byte_offset: BTreeMap::new(),
+ }],
+ });
+}
+
+#[cfg(span_locations)]
+pub(crate) fn invalidate_current_thread_spans() {
+ #[cfg(not(fuzzing))]
+ SOURCE_MAP.with(|sm| sm.borrow_mut().files.truncate(1));
+}
+
+#[cfg(all(span_locations, not(fuzzing)))]
+struct FileInfo {
+ source_text: String,
+ span: Span,
+ lines: Vec<usize>,
+ char_index_to_byte_offset: BTreeMap<usize, usize>,
+}
+
+#[cfg(all(span_locations, not(fuzzing)))]
+impl FileInfo {
+ fn offset_line_column(&self, offset: usize) -> LineColumn {
+ assert!(self.span_within(Span {
+ lo: offset as u32,
+ hi: offset as u32,
+ }));
+ let offset = offset - self.span.lo as usize;
+ match self.lines.binary_search(&offset) {
+ Ok(found) => LineColumn {
+ line: found + 1,
+ column: 0,
+ },
+ Err(idx) => LineColumn {
+ line: idx,
+ column: offset - self.lines[idx - 1],
+ },
+ }
+ }
+
+ fn span_within(&self, span: Span) -> bool {
+ span.lo >= self.span.lo && span.hi <= self.span.hi
+ }
+
+ fn byte_range(&mut self, span: Span) -> Range<usize> {
+ let lo_char = (span.lo - self.span.lo) as usize;
+
+ // Look up offset of the largest already-computed char index that is
+ // less than or equal to the current requested one. We resume counting
+ // chars from that point.
+ let (&last_char_index, &last_byte_offset) = self
+ .char_index_to_byte_offset
+ .range(..=lo_char)
+ .next_back()
+ .unwrap_or((&0, &0));
+
+ let lo_byte = if last_char_index == lo_char {
+ last_byte_offset
+ } else {
+ let total_byte_offset = match self.source_text[last_byte_offset..]
+ .char_indices()
+ .nth(lo_char - last_char_index)
+ {
+ Some((additional_offset, _ch)) => last_byte_offset + additional_offset,
+ None => self.source_text.len(),
+ };
+ self.char_index_to_byte_offset
+ .insert(lo_char, total_byte_offset);
+ total_byte_offset
+ };
+
+ let trunc_lo = &self.source_text[lo_byte..];
+ let char_len = (span.hi - span.lo) as usize;
+ lo_byte..match trunc_lo.char_indices().nth(char_len) {
+ Some((offset, _ch)) => lo_byte + offset,
+ None => self.source_text.len(),
+ }
+ }
+
+ fn source_text(&mut self, span: Span) -> String {
+ let byte_range = self.byte_range(span);
+ self.source_text[byte_range].to_owned()
+ }
+}
+
+/// Computes the offsets of each line in the given source string
+/// and the total number of characters
+#[cfg(all(span_locations, not(fuzzing)))]
+fn lines_offsets(s: &str) -> (usize, Vec<usize>) {
+ let mut lines = vec![0];
+ let mut total = 0;
+
+ for ch in s.chars() {
+ total += 1;
+ if ch == '\n' {
+ lines.push(total);
+ }
+ }
+
+ (total, lines)
+}
+
+#[cfg(all(span_locations, not(fuzzing)))]
+struct SourceMap {
+ files: Vec<FileInfo>,
+}
+
+#[cfg(all(span_locations, not(fuzzing)))]
+impl SourceMap {
+ fn next_start_pos(&self) -> u32 {
+ // Add 1 so there's always space between files.
+ //
+ // We'll always have at least 1 file, as we initialize our files list
+ // with a dummy file.
+ self.files.last().unwrap().span.hi + 1
+ }
+
+ fn add_file(&mut self, src: &str) -> Span {
+ let (len, lines) = lines_offsets(src);
+ let lo = self.next_start_pos();
+ let span = Span {
+ lo,
+ hi: lo + (len as u32),
+ };
+
+ self.files.push(FileInfo {
+ source_text: src.to_owned(),
+ span,
+ lines,
+ // Populated lazily by source_text().
+ char_index_to_byte_offset: BTreeMap::new(),
+ });
+
+ span
+ }
+
+ fn find(&self, span: Span) -> usize {
+ match self.files.binary_search_by(|file| {
+ if file.span.hi < span.lo {
+ Ordering::Less
+ } else if file.span.lo > span.hi {
+ Ordering::Greater
+ } else {
+ assert!(file.span_within(span));
+ Ordering::Equal
+ }
+ }) {
+ Ok(i) => i,
+ Err(_) => unreachable!("Invalid span with no related FileInfo!"),
+ }
+ }
+
+ fn filepath(&self, span: Span) -> String {
+ let i = self.find(span);
+ if i == 0 {
+ "<unspecified>".to_owned()
+ } else {
+ format!("<parsed string {}>", i)
+ }
+ }
+
+ fn fileinfo(&self, span: Span) -> &FileInfo {
+ let i = self.find(span);
+ &self.files[i]
+ }
+
+ fn fileinfo_mut(&mut self, span: Span) -> &mut FileInfo {
+ let i = self.find(span);
+ &mut self.files[i]
+ }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub(crate) struct Span {
+ #[cfg(span_locations)]
+ pub(crate) lo: u32,
+ #[cfg(span_locations)]
+ pub(crate) hi: u32,
+}
+
+impl Span {
+ #[cfg(not(span_locations))]
+ pub(crate) fn call_site() -> Self {
+ Span {}
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn call_site() -> Self {
+ Span { lo: 0, hi: 0 }
+ }
+
+ pub(crate) fn mixed_site() -> Self {
+ Span::call_site()
+ }
+
+ #[cfg(procmacro2_semver_exempt)]
+ pub(crate) fn def_site() -> Self {
+ Span::call_site()
+ }
+
+ pub(crate) fn resolved_at(&self, _other: Span) -> Span {
+ // Stable spans consist only of line/column information, so
+ // `resolved_at` and `located_at` only select which span the
+ // caller wants line/column information from.
+ *self
+ }
+
+ pub(crate) fn located_at(&self, other: Span) -> Span {
+ other
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn byte_range(&self) -> Range<usize> {
+ #[cfg(fuzzing)]
+ return 0..0;
+
+ #[cfg(not(fuzzing))]
+ {
+ if self.is_call_site() {
+ 0..0
+ } else {
+ SOURCE_MAP.with(|sm| sm.borrow_mut().fileinfo_mut(*self).byte_range(*self))
+ }
+ }
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn start(&self) -> LineColumn {
+ #[cfg(fuzzing)]
+ return LineColumn { line: 0, column: 0 };
+
+ #[cfg(not(fuzzing))]
+ SOURCE_MAP.with(|sm| {
+ let sm = sm.borrow();
+ let fi = sm.fileinfo(*self);
+ fi.offset_line_column(self.lo as usize)
+ })
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn end(&self) -> LineColumn {
+ #[cfg(fuzzing)]
+ return LineColumn { line: 0, column: 0 };
+
+ #[cfg(not(fuzzing))]
+ SOURCE_MAP.with(|sm| {
+ let sm = sm.borrow();
+ let fi = sm.fileinfo(*self);
+ fi.offset_line_column(self.hi as usize)
+ })
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn file(&self) -> String {
+ #[cfg(fuzzing)]
+ return "<unspecified>".to_owned();
+
+ #[cfg(not(fuzzing))]
+ SOURCE_MAP.with(|sm| {
+ let sm = sm.borrow();
+ sm.filepath(*self)
+ })
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn local_file(&self) -> Option<PathBuf> {
+ None
+ }
+
+ #[cfg(not(span_locations))]
+ pub(crate) fn join(&self, _other: Span) -> Option<Span> {
+ Some(Span {})
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn join(&self, other: Span) -> Option<Span> {
+ #[cfg(fuzzing)]
+ return {
+ let _ = other;
+ None
+ };
+
+ #[cfg(not(fuzzing))]
+ SOURCE_MAP.with(|sm| {
+ let sm = sm.borrow();
+ // If `other` is not within the same FileInfo as us, return None.
+ if !sm.fileinfo(*self).span_within(other) {
+ return None;
+ }
+ Some(Span {
+ lo: cmp::min(self.lo, other.lo),
+ hi: cmp::max(self.hi, other.hi),
+ })
+ })
+ }
+
+ #[cfg(not(span_locations))]
+ pub(crate) fn source_text(&self) -> Option<String> {
+ None
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn source_text(&self) -> Option<String> {
+ #[cfg(fuzzing)]
+ return None;
+
+ #[cfg(not(fuzzing))]
+ {
+ if self.is_call_site() {
+ None
+ } else {
+ Some(SOURCE_MAP.with(|sm| sm.borrow_mut().fileinfo_mut(*self).source_text(*self)))
+ }
+ }
+ }
+
+ #[cfg(not(span_locations))]
+ pub(crate) fn first_byte(self) -> Self {
+ self
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn first_byte(self) -> Self {
+ Span {
+ lo: self.lo,
+ hi: cmp::min(self.lo.saturating_add(1), self.hi),
+ }
+ }
+
+ #[cfg(not(span_locations))]
+ pub(crate) fn last_byte(self) -> Self {
+ self
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn last_byte(self) -> Self {
+ Span {
+ lo: cmp::max(self.hi.saturating_sub(1), self.lo),
+ hi: self.hi,
+ }
+ }
+
+ #[cfg(span_locations)]
+ fn is_call_site(&self) -> bool {
+ self.lo == 0 && self.hi == 0
+ }
+}
+
+impl Debug for Span {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ #[cfg(span_locations)]
+ return write!(f, "bytes({}..{})", self.lo, self.hi);
+
+ #[cfg(not(span_locations))]
+ write!(f, "Span")
+ }
+}
+
+pub(crate) fn debug_span_field_if_nontrivial(debug: &mut fmt::DebugStruct, span: Span) {
+ #[cfg(span_locations)]
+ {
+ if span.is_call_site() {
+ return;
+ }
+ }
+
+ if cfg!(span_locations) {
+ debug.field("span", &span);
+ }
+}
+
+#[derive(Clone)]
+pub(crate) struct Group {
+ delimiter: Delimiter,
+ stream: TokenStream,
+ span: Span,
+}
+
+impl Group {
+ pub(crate) fn new(delimiter: Delimiter, stream: TokenStream) -> Self {
+ Group {
+ delimiter,
+ stream,
+ span: Span::call_site(),
+ }
+ }
+
+ pub(crate) fn delimiter(&self) -> Delimiter {
+ self.delimiter
+ }
+
+ pub(crate) fn stream(&self) -> TokenStream {
+ self.stream.clone()
+ }
+
+ pub(crate) fn span(&self) -> Span {
+ self.span
+ }
+
+ pub(crate) fn span_open(&self) -> Span {
+ self.span.first_byte()
+ }
+
+ pub(crate) fn span_close(&self) -> Span {
+ self.span.last_byte()
+ }
+
+ pub(crate) fn set_span(&mut self, span: Span) {
+ self.span = span;
+ }
+}
+
+impl Display for Group {
+ // We attempt to match libproc_macro's formatting.
+ // Empty parens: ()
+ // Nonempty parens: (...)
+ // Empty brackets: []
+ // Nonempty brackets: [...]
+ // Empty braces: { }
+ // Nonempty braces: { ... }
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ let (open, close) = match self.delimiter {
+ Delimiter::Parenthesis => ("(", ")"),
+ Delimiter::Brace => ("{ ", "}"),
+ Delimiter::Bracket => ("[", "]"),
+ Delimiter::None => ("", ""),
+ };
+
+ f.write_str(open)?;
+ Display::fmt(&self.stream, f)?;
+ if self.delimiter == Delimiter::Brace && !self.stream.inner.is_empty() {
+ f.write_str(" ")?;
+ }
+ f.write_str(close)?;
+
+ Ok(())
+ }
+}
+
+impl Debug for Group {
+ fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+ let mut debug = fmt.debug_struct("Group");
+ debug.field("delimiter", &self.delimiter);
+ debug.field("stream", &self.stream);
+ debug_span_field_if_nontrivial(&mut debug, self.span);
+ debug.finish()
+ }
+}
+
+#[derive(Clone)]
+pub(crate) struct Ident {
+ sym: Box<str>,
+ span: Span,
+ raw: bool,
+}
+
+impl Ident {
+ #[track_caller]
+ pub(crate) fn new_checked(string: &str, span: Span) -> Self {
+ validate_ident(string);
+ Ident::new_unchecked(string, span)
+ }
+
+ pub(crate) fn new_unchecked(string: &str, span: Span) -> Self {
+ Ident {
+ sym: Box::from(string),
+ span,
+ raw: false,
+ }
+ }
+
+ #[track_caller]
+ pub(crate) fn new_raw_checked(string: &str, span: Span) -> Self {
+ validate_ident_raw(string);
+ Ident::new_raw_unchecked(string, span)
+ }
+
+ pub(crate) fn new_raw_unchecked(string: &str, span: Span) -> Self {
+ Ident {
+ sym: Box::from(string),
+ span,
+ raw: true,
+ }
+ }
+
+ pub(crate) fn span(&self) -> Span {
+ self.span
+ }
+
+ pub(crate) fn set_span(&mut self, span: Span) {
+ self.span = span;
+ }
+}
+
+pub(crate) fn is_ident_start(c: char) -> bool {
+ c == '_' || unicode_ident::is_xid_start(c)
+}
+
+pub(crate) fn is_ident_continue(c: char) -> bool {
+ unicode_ident::is_xid_continue(c)
+}
+
+#[track_caller]
+fn validate_ident(string: &str) {
+ if string.is_empty() {
+ panic!("Ident is not allowed to be empty; use Option<Ident>");
+ }
+
+ if string.bytes().all(|digit| b'0' <= digit && digit <= b'9') {
+ panic!("Ident cannot be a number; use Literal instead");
+ }
+
+ fn ident_ok(string: &str) -> bool {
+ let mut chars = string.chars();
+ let first = chars.next().unwrap();
+ if !is_ident_start(first) {
+ return false;
+ }
+ for ch in chars {
+ if !is_ident_continue(ch) {
+ return false;
+ }
+ }
+ true
+ }
+
+ if !ident_ok(string) {
+ panic!("{:?} is not a valid Ident", string);
+ }
+}
+
+#[track_caller]
+fn validate_ident_raw(string: &str) {
+ validate_ident(string);
+
+ match string {
+ "_" | "super" | "self" | "Self" | "crate" => {
+ panic!("`r#{}` cannot be a raw identifier", string);
+ }
+ _ => {}
+ }
+}
+
+impl PartialEq for Ident {
+ fn eq(&self, other: &Ident) -> bool {
+ self.sym == other.sym && self.raw == other.raw
+ }
+}
+
+impl<T> PartialEq<T> for Ident
+where
+ T: ?Sized + AsRef<str>,
+{
+ fn eq(&self, other: &T) -> bool {
+ let other = other.as_ref();
+ if self.raw {
+ other.starts_with("r#") && *self.sym == other[2..]
+ } else {
+ *self.sym == *other
+ }
+ }
+}
+
+impl Display for Ident {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ if self.raw {
+ f.write_str("r#")?;
+ }
+ Display::fmt(&self.sym, f)
+ }
+}
+
+#[allow(clippy::missing_fields_in_debug)]
+impl Debug for Ident {
+ // Ident(proc_macro), Ident(r#union)
+ #[cfg(not(span_locations))]
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ let mut debug = f.debug_tuple("Ident");
+ debug.field(&format_args!("{}", self));
+ debug.finish()
+ }
+
+ // Ident {
+ // sym: proc_macro,
+ // span: bytes(128..138)
+ // }
+ #[cfg(span_locations)]
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ let mut debug = f.debug_struct("Ident");
+ debug.field("sym", &format_args!("{}", self));
+ debug_span_field_if_nontrivial(&mut debug, self.span);
+ debug.finish()
+ }
+}
+
+#[derive(Clone)]
+pub(crate) struct Literal {
+ pub(crate) repr: String,
+ span: Span,
+}
+
+macro_rules! suffixed_numbers {
+ ($($name:ident => $kind:ident,)*) => ($(
+ pub(crate) fn $name(n: $kind) -> Literal {
+ Literal::_new(format!(concat!("{}", stringify!($kind)), n))
+ }
+ )*)
+}
+
+macro_rules! unsuffixed_numbers {
+ ($($name:ident => $kind:ident,)*) => ($(
+ pub(crate) fn $name(n: $kind) -> Literal {
+ Literal::_new(n.to_string())
+ }
+ )*)
+}
+
+impl Literal {
+ pub(crate) fn _new(repr: String) -> Self {
+ Literal {
+ repr,
+ span: Span::call_site(),
+ }
+ }
+
+ pub(crate) fn from_str_checked(repr: &str) -> Result<Self, LexError> {
+ let mut cursor = get_cursor(repr);
+ #[cfg(span_locations)]
+ let lo = cursor.off;
+
+ let negative = cursor.starts_with_char('-');
+ if negative {
+ cursor = cursor.advance(1);
+ if !cursor.starts_with_fn(|ch| ch.is_ascii_digit()) {
+ return Err(LexError::call_site());
+ }
+ }
+
+ if let Ok((rest, mut literal)) = parse::literal(cursor) {
+ if rest.is_empty() {
+ if negative {
+ literal.repr.insert(0, '-');
+ }
+ literal.span = Span {
+ #[cfg(span_locations)]
+ lo,
+ #[cfg(span_locations)]
+ hi: rest.off,
+ };
+ return Ok(literal);
+ }
+ }
+ Err(LexError::call_site())
+ }
+
+ pub(crate) unsafe fn from_str_unchecked(repr: &str) -> Self {
+ Literal::_new(repr.to_owned())
+ }
+
+ suffixed_numbers! {
+ u8_suffixed => u8,
+ u16_suffixed => u16,
+ u32_suffixed => u32,
+ u64_suffixed => u64,
+ u128_suffixed => u128,
+ usize_suffixed => usize,
+ i8_suffixed => i8,
+ i16_suffixed => i16,
+ i32_suffixed => i32,
+ i64_suffixed => i64,
+ i128_suffixed => i128,
+ isize_suffixed => isize,
+
+ f32_suffixed => f32,
+ f64_suffixed => f64,
+ }
+
+ unsuffixed_numbers! {
+ u8_unsuffixed => u8,
+ u16_unsuffixed => u16,
+ u32_unsuffixed => u32,
+ u64_unsuffixed => u64,
+ u128_unsuffixed => u128,
+ usize_unsuffixed => usize,
+ i8_unsuffixed => i8,
+ i16_unsuffixed => i16,
+ i32_unsuffixed => i32,
+ i64_unsuffixed => i64,
+ i128_unsuffixed => i128,
+ isize_unsuffixed => isize,
+ }
+
+ pub(crate) fn f32_unsuffixed(f: f32) -> Literal {
+ let mut s = f.to_string();
+ if !s.contains('.') {
+ s.push_str(".0");
+ }
+ Literal::_new(s)
+ }
+
+ pub(crate) fn f64_unsuffixed(f: f64) -> Literal {
+ let mut s = f.to_string();
+ if !s.contains('.') {
+ s.push_str(".0");
+ }
+ Literal::_new(s)
+ }
+
+ pub(crate) fn string(string: &str) -> Literal {
+ let mut repr = String::with_capacity(string.len() + 2);
+ repr.push('"');
+ escape_utf8(string, &mut repr);
+ repr.push('"');
+ Literal::_new(repr)
+ }
+
+ pub(crate) fn character(ch: char) -> Literal {
+ let mut repr = String::new();
+ repr.push('\'');
+ if ch == '"' {
+ // escape_debug turns this into '\"' which is unnecessary.
+ repr.push(ch);
+ } else {
+ repr.extend(ch.escape_debug());
+ }
+ repr.push('\'');
+ Literal::_new(repr)
+ }
+
+ pub(crate) fn byte_character(byte: u8) -> Literal {
+ let mut repr = "b'".to_string();
+ #[allow(clippy::match_overlapping_arm)]
+ match byte {
+ b'\0' => repr.push_str(r"\0"),
+ b'\t' => repr.push_str(r"\t"),
+ b'\n' => repr.push_str(r"\n"),
+ b'\r' => repr.push_str(r"\r"),
+ b'\'' => repr.push_str(r"\'"),
+ b'\\' => repr.push_str(r"\\"),
+ b'\x20'..=b'\x7E' => repr.push(byte as char),
+ _ => {
+ let _ = write!(repr, r"\x{:02X}", byte);
+ }
+ }
+ repr.push('\'');
+ Literal::_new(repr)
+ }
+
+ pub(crate) fn byte_string(bytes: &[u8]) -> Literal {
+ let mut repr = "b\"".to_string();
+ let mut bytes = bytes.iter();
+ while let Some(&b) = bytes.next() {
+ #[allow(clippy::match_overlapping_arm)]
+ match b {
+ b'\0' => repr.push_str(match bytes.as_slice().first() {
+ // circumvent clippy::octal_escapes lint
+ Some(b'0'..=b'7') => r"\x00",
+ _ => r"\0",
+ }),
+ b'\t' => repr.push_str(r"\t"),
+ b'\n' => repr.push_str(r"\n"),
+ b'\r' => repr.push_str(r"\r"),
+ b'"' => repr.push_str("\\\""),
+ b'\\' => repr.push_str(r"\\"),
+ b'\x20'..=b'\x7E' => repr.push(b as char),
+ _ => {
+ let _ = write!(repr, r"\x{:02X}", b);
+ }
+ }
+ }
+ repr.push('"');
+ Literal::_new(repr)
+ }
+
+ pub(crate) fn c_string(string: &CStr) -> Literal {
+ let mut repr = "c\"".to_string();
+ let mut bytes = string.to_bytes();
+ while !bytes.is_empty() {
+ let (valid, invalid) = match str::from_utf8(bytes) {
+ Ok(all_valid) => {
+ bytes = b"";
+ (all_valid, bytes)
+ }
+ Err(utf8_error) => {
+ let (valid, rest) = bytes.split_at(utf8_error.valid_up_to());
+ let valid = str::from_utf8(valid).unwrap();
+ let invalid = utf8_error
+ .error_len()
+ .map_or(rest, |error_len| &rest[..error_len]);
+ bytes = &bytes[valid.len() + invalid.len()..];
+ (valid, invalid)
+ }
+ };
+ escape_utf8(valid, &mut repr);
+ for &byte in invalid {
+ let _ = write!(repr, r"\x{:02X}", byte);
+ }
+ }
+ repr.push('"');
+ Literal::_new(repr)
+ }
+
+ pub(crate) fn span(&self) -> Span {
+ self.span
+ }
+
+ pub(crate) fn set_span(&mut self, span: Span) {
+ self.span = span;
+ }
+
+ pub(crate) fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
+ #[cfg(not(span_locations))]
+ {
+ let _ = range;
+ None
+ }
+
+ #[cfg(span_locations)]
+ {
+ use core::ops::Bound;
+
+ let lo = match range.start_bound() {
+ Bound::Included(start) => {
+ let start = u32::try_from(*start).ok()?;
+ self.span.lo.checked_add(start)?
+ }
+ Bound::Excluded(start) => {
+ let start = u32::try_from(*start).ok()?;
+ self.span.lo.checked_add(start)?.checked_add(1)?
+ }
+ Bound::Unbounded => self.span.lo,
+ };
+ let hi = match range.end_bound() {
+ Bound::Included(end) => {
+ let end = u32::try_from(*end).ok()?;
+ self.span.lo.checked_add(end)?.checked_add(1)?
+ }
+ Bound::Excluded(end) => {
+ let end = u32::try_from(*end).ok()?;
+ self.span.lo.checked_add(end)?
+ }
+ Bound::Unbounded => self.span.hi,
+ };
+ if lo <= hi && hi <= self.span.hi {
+ Some(Span { lo, hi })
+ } else {
+ None
+ }
+ }
+ }
+}
+
+impl Display for Literal {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Display::fmt(&self.repr, f)
+ }
+}
+
+impl Debug for Literal {
+ fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+ let mut debug = fmt.debug_struct("Literal");
+ debug.field("lit", &format_args!("{}", self.repr));
+ debug_span_field_if_nontrivial(&mut debug, self.span);
+ debug.finish()
+ }
+}
+
+fn escape_utf8(string: &str, repr: &mut String) {
+ let mut chars = string.chars();
+ while let Some(ch) = chars.next() {
+ if ch == '\0' {
+ repr.push_str(
+ if chars
+ .as_str()
+ .starts_with(|next| '0' <= next && next <= '7')
+ {
+ // circumvent clippy::octal_escapes lint
+ r"\x00"
+ } else {
+ r"\0"
+ },
+ );
+ } else if ch == '\'' {
+ // escape_debug turns this into "\'" which is unnecessary.
+ repr.push(ch);
+ } else {
+ repr.extend(ch.escape_debug());
+ }
+ }
+}
+
+#[cfg(feature = "proc-macro")]
+pub(crate) trait FromStr2: FromStr<Err = proc_macro::LexError> {
+ #[cfg(wrap_proc_macro)]
+ fn valid(src: &str) -> bool;
+
+ #[cfg(wrap_proc_macro)]
+ fn from_str_checked(src: &str) -> Result<Self, imp::LexError> {
+ // Validate using fallback parser, because rustc is incapable of
+ // returning a recoverable Err for certain invalid token streams, and
+ // will instead permanently poison the compilation.
+ if !Self::valid(src) {
+ return Err(imp::LexError::CompilerPanic);
+ }
+
+ // Catch panic to work around https://github.com/rust-lang/rust/issues/58736.
+ match panic::catch_unwind(|| Self::from_str(src)) {
+ Ok(Ok(ok)) => Ok(ok),
+ Ok(Err(lex)) => Err(imp::LexError::Compiler(lex)),
+ Err(_panic) => Err(imp::LexError::CompilerPanic),
+ }
+ }
+
+ fn from_str_unchecked(src: &str) -> Self {
+ Self::from_str(src).unwrap()
+ }
+}
+
+#[cfg(feature = "proc-macro")]
+impl FromStr2 for proc_macro::TokenStream {
+ #[cfg(wrap_proc_macro)]
+ fn valid(src: &str) -> bool {
+ TokenStream::from_str_checked(src).is_ok()
+ }
+}
+
+#[cfg(feature = "proc-macro")]
+impl FromStr2 for proc_macro::Literal {
+ #[cfg(wrap_proc_macro)]
+ fn valid(src: &str) -> bool {
+ Literal::from_str_checked(src).is_ok()
+ }
+}
diff --git a/rust/proc-macro2/lib.rs b/rust/proc-macro2/lib.rs
new file mode 100644
index 000000000000..2984af335adc
--- /dev/null
+++ b/rust/proc-macro2/lib.rs
@@ -0,0 +1,1349 @@
+//! [![github]](https://github.com/dtolnay/proc-macro2) [![crates-io]](https://crates.io/crates/proc-macro2) [![docs-rs]](crate)
+//!
+//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
+//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
+//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs
+//!
+//! <br>
+//!
+//! A wrapper around the procedural macro API of the compiler's [`proc_macro`]
+//! crate. This library serves two purposes:
+//!
+//! - **Bring proc-macro-like functionality to other contexts like build.rs and
+//! main.rs.** Types from `proc_macro` are entirely specific to procedural
+//! macros and cannot ever exist in code outside of a procedural macro.
+//! Meanwhile `proc_macro2` types may exist anywhere including non-macro code.
+//! By developing foundational libraries like [syn] and [quote] against
+//! `proc_macro2` rather than `proc_macro`, the procedural macro ecosystem
+//! becomes easily applicable to many other use cases and we avoid
+//! reimplementing non-macro equivalents of those libraries.
+//!
+//! - **Make procedural macros unit testable.** As a consequence of being
+//! specific to procedural macros, nothing that uses `proc_macro` can be
+//! executed from a unit test. In order for helper libraries or components of
+//! a macro to be testable in isolation, they must be implemented using
+//! `proc_macro2`.
+//!
+//! [syn]: https://github.com/dtolnay/syn
+//! [quote]: https://github.com/dtolnay/quote
+//!
+//! # Usage
+//!
+//! The skeleton of a typical procedural macro typically looks like this:
+//!
+//! ```
+//! extern crate proc_macro;
+//!
+//! # const IGNORE: &str = stringify! {
+//! #[proc_macro_derive(MyDerive)]
+//! # };
+//! # #[cfg(wrap_proc_macro)]
+//! pub fn my_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+//! let input = proc_macro2::TokenStream::from(input);
+//!
+//! let output: proc_macro2::TokenStream = {
+//! /* transform input */
+//! # input
+//! };
+//!
+//! proc_macro::TokenStream::from(output)
+//! }
+//! ```
+//!
+//! If parsing with [Syn], you'll use [`parse_macro_input!`] instead to
+//! propagate parse errors correctly back to the compiler when parsing fails.
+//!
+//! [`parse_macro_input!`]: https://docs.rs/syn/2.0/syn/macro.parse_macro_input.html
+//!
+//! # Unstable features
+//!
+//! The default feature set of proc-macro2 tracks the most recent stable
+//! compiler API. Functionality in `proc_macro` that is not yet stable is not
+//! exposed by proc-macro2 by default.
+//!
+//! To opt into the additional APIs available in the most recent nightly
+//! compiler, the `procmacro2_semver_exempt` config flag must be passed to
+//! rustc. We will polyfill those nightly-only APIs back to Rust 1.56.0. As
+//! these are unstable APIs that track the nightly compiler, minor versions of
+//! proc-macro2 may make breaking changes to them at any time.
+//!
+//! ```sh
+//! RUSTFLAGS='--cfg procmacro2_semver_exempt' cargo build
+//! ```
+//!
+//! Note that this must not only be done for your crate, but for any crate that
+//! depends on your crate. This infectious nature is intentional, as it serves
+//! as a reminder that you are outside of the normal semver guarantees.
+//!
+//! Semver exempt methods are marked as such in the proc-macro2 documentation.
+//!
+//! # Thread-Safety
+//!
+//! Most types in this crate are `!Sync` because the underlying compiler
+//! types make use of thread-local memory, meaning they cannot be accessed from
+//! a different thread.
+
+// Proc-macro2 types in rustdoc of other crates get linked to here.
+#![doc(html_root_url = "https://docs.rs/proc-macro2/1.0.101")]
+#![cfg_attr(any(proc_macro_span, super_unstable), feature(proc_macro_span))]
+#![cfg_attr(super_unstable, feature(proc_macro_def_site))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![deny(unsafe_op_in_unsafe_fn)]
+#![allow(
+ clippy::cast_lossless,
+ clippy::cast_possible_truncation,
+ clippy::checked_conversions,
+ clippy::doc_markdown,
+ clippy::elidable_lifetime_names,
+ clippy::incompatible_msrv,
+ clippy::items_after_statements,
+ clippy::iter_without_into_iter,
+ clippy::let_underscore_untyped,
+ clippy::manual_assert,
+ clippy::manual_range_contains,
+ clippy::missing_panics_doc,
+ clippy::missing_safety_doc,
+ clippy::must_use_candidate,
+ clippy::needless_doctest_main,
+ clippy::needless_lifetimes,
+ clippy::new_without_default,
+ clippy::return_self_not_must_use,
+ clippy::shadow_unrelated,
+ clippy::trivially_copy_pass_by_ref,
+ clippy::unnecessary_wraps,
+ clippy::unused_self,
+ clippy::used_underscore_binding,
+ clippy::vec_init_then_push
+)]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
+
+#[cfg(all(procmacro2_semver_exempt, wrap_proc_macro, not(super_unstable)))]
+compile_error! {"\
+ Something is not right. If you've tried to turn on \
+ procmacro2_semver_exempt, you need to ensure that it \
+ is turned on for the compilation of the proc-macro2 \
+ build script as well.
+"}
+
+#[cfg(all(
+ procmacro2_nightly_testing,
+ feature = "proc-macro",
+ not(proc_macro_span)
+))]
+compile_error! {"\
+ Build script probe failed to compile.
+"}
+
+extern crate alloc;
+
+#[cfg(feature = "proc-macro")]
+extern crate proc_macro;
+
+mod marker;
+mod parse;
+mod probe;
+mod rcvec;
+
+#[cfg(wrap_proc_macro)]
+mod detection;
+
+// Public for proc_macro2::fallback::force() and unforce(), but those are quite
+// a niche use case so we omit it from rustdoc.
+#[doc(hidden)]
+pub mod fallback;
+
+pub mod extra;
+
+#[cfg(not(wrap_proc_macro))]
+use crate::fallback as imp;
+#[path = "wrapper.rs"]
+#[cfg(wrap_proc_macro)]
+mod imp;
+
+#[cfg(span_locations)]
+mod location;
+
+use crate::extra::DelimSpan;
+use crate::marker::{ProcMacroAutoTraits, MARKER};
+use core::cmp::Ordering;
+use core::fmt::{self, Debug, Display};
+use core::hash::{Hash, Hasher};
+#[cfg(span_locations)]
+use core::ops::Range;
+use core::ops::RangeBounds;
+use core::str::FromStr;
+use std::error::Error;
+use std::ffi::CStr;
+#[cfg(span_locations)]
+use std::path::PathBuf;
+
+#[cfg(span_locations)]
+#[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+pub use crate::location::LineColumn;
+
+/// An abstract stream of tokens, or more concretely a sequence of token trees.
+///
+/// This type provides interfaces for iterating over token trees and for
+/// collecting token trees into one stream.
+///
+/// Token stream is both the input and output of `#[proc_macro]`,
+/// `#[proc_macro_attribute]` and `#[proc_macro_derive]` definitions.
+#[derive(Clone)]
+pub struct TokenStream {
+ inner: imp::TokenStream,
+ _marker: ProcMacroAutoTraits,
+}
+
+/// Error returned from `TokenStream::from_str`.
+pub struct LexError {
+ inner: imp::LexError,
+ _marker: ProcMacroAutoTraits,
+}
+
+impl TokenStream {
+ fn _new(inner: imp::TokenStream) -> Self {
+ TokenStream {
+ inner,
+ _marker: MARKER,
+ }
+ }
+
+ fn _new_fallback(inner: fallback::TokenStream) -> Self {
+ TokenStream {
+ inner: imp::TokenStream::from(inner),
+ _marker: MARKER,
+ }
+ }
+
+ /// Returns an empty `TokenStream` containing no token trees.
+ pub fn new() -> Self {
+ TokenStream::_new(imp::TokenStream::new())
+ }
+
+ /// Checks if this `TokenStream` is empty.
+ pub fn is_empty(&self) -> bool {
+ self.inner.is_empty()
+ }
+}
+
+/// `TokenStream::default()` returns an empty stream,
+/// i.e. this is equivalent with `TokenStream::new()`.
+impl Default for TokenStream {
+ fn default() -> Self {
+ TokenStream::new()
+ }
+}
+
+/// Attempts to break the string into tokens and parse those tokens into a token
+/// stream.
+///
+/// May fail for a number of reasons, for example, if the string contains
+/// unbalanced delimiters or characters not existing in the language.
+///
+/// NOTE: Some errors may cause panics instead of returning `LexError`. We
+/// reserve the right to change these errors into `LexError`s later.
+impl FromStr for TokenStream {
+ type Err = LexError;
+
+ fn from_str(src: &str) -> Result<TokenStream, LexError> {
+ match imp::TokenStream::from_str_checked(src) {
+ Ok(tokens) => Ok(TokenStream::_new(tokens)),
+ Err(lex) => Err(LexError {
+ inner: lex,
+ _marker: MARKER,
+ }),
+ }
+ }
+}
+
+#[cfg(feature = "proc-macro")]
+#[cfg_attr(docsrs, doc(cfg(feature = "proc-macro")))]
+impl From<proc_macro::TokenStream> for TokenStream {
+ fn from(inner: proc_macro::TokenStream) -> Self {
+ TokenStream::_new(imp::TokenStream::from(inner))
+ }
+}
+
+#[cfg(feature = "proc-macro")]
+#[cfg_attr(docsrs, doc(cfg(feature = "proc-macro")))]
+impl From<TokenStream> for proc_macro::TokenStream {
+ fn from(inner: TokenStream) -> Self {
+ proc_macro::TokenStream::from(inner.inner)
+ }
+}
+
+impl From<TokenTree> for TokenStream {
+ fn from(token: TokenTree) -> Self {
+ TokenStream::_new(imp::TokenStream::from(token))
+ }
+}
+
+impl Extend<TokenTree> for TokenStream {
+ fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, streams: I) {
+ self.inner.extend(streams);
+ }
+}
+
+impl Extend<TokenStream> for TokenStream {
+ fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
+ self.inner
+ .extend(streams.into_iter().map(|stream| stream.inner));
+ }
+}
+
+/// Collects a number of token trees into a single stream.
+impl FromIterator<TokenTree> for TokenStream {
+ fn from_iter<I: IntoIterator<Item = TokenTree>>(streams: I) -> Self {
+ TokenStream::_new(streams.into_iter().collect())
+ }
+}
+impl FromIterator<TokenStream> for TokenStream {
+ fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
+ TokenStream::_new(streams.into_iter().map(|i| i.inner).collect())
+ }
+}
+
+/// Prints the token stream as a string that is supposed to be losslessly
+/// convertible back into the same token stream (modulo spans), except for
+/// possibly `TokenTree::Group`s with `Delimiter::None` delimiters and negative
+/// numeric literals.
+impl Display for TokenStream {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Display::fmt(&self.inner, f)
+ }
+}
+
+/// Prints token in a form convenient for debugging.
+impl Debug for TokenStream {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Debug::fmt(&self.inner, f)
+ }
+}
+
+impl LexError {
+ pub fn span(&self) -> Span {
+ Span::_new(self.inner.span())
+ }
+}
+
+impl Debug for LexError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Debug::fmt(&self.inner, f)
+ }
+}
+
+impl Display for LexError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Display::fmt(&self.inner, f)
+ }
+}
+
+impl Error for LexError {}
+
+/// A region of source code, along with macro expansion information.
+#[derive(Copy, Clone)]
+pub struct Span {
+ inner: imp::Span,
+ _marker: ProcMacroAutoTraits,
+}
+
+impl Span {
+ fn _new(inner: imp::Span) -> Self {
+ Span {
+ inner,
+ _marker: MARKER,
+ }
+ }
+
+ fn _new_fallback(inner: fallback::Span) -> Self {
+ Span {
+ inner: imp::Span::from(inner),
+ _marker: MARKER,
+ }
+ }
+
+ /// The span of the invocation of the current procedural macro.
+ ///
+ /// Identifiers created with this span will be resolved as if they were
+ /// written directly at the macro call location (call-site hygiene) and
+ /// other code at the macro call site will be able to refer to them as well.
+ pub fn call_site() -> Self {
+ Span::_new(imp::Span::call_site())
+ }
+
+ /// The span located at the invocation of the procedural macro, but with
+ /// local variables, labels, and `$crate` resolved at the definition site
+ /// of the macro. This is the same hygiene behavior as `macro_rules`.
+ pub fn mixed_site() -> Self {
+ Span::_new(imp::Span::mixed_site())
+ }
+
+ /// A span that resolves at the macro definition site.
+ ///
+ /// This method is semver exempt and not exposed by default.
+ #[cfg(procmacro2_semver_exempt)]
+ #[cfg_attr(docsrs, doc(cfg(procmacro2_semver_exempt)))]
+ pub fn def_site() -> Self {
+ Span::_new(imp::Span::def_site())
+ }
+
+ /// Creates a new span with the same line/column information as `self` but
+ /// that resolves symbols as though it were at `other`.
+ pub fn resolved_at(&self, other: Span) -> Span {
+ Span::_new(self.inner.resolved_at(other.inner))
+ }
+
+ /// Creates a new span with the same name resolution behavior as `self` but
+ /// with the line/column information of `other`.
+ pub fn located_at(&self, other: Span) -> Span {
+ Span::_new(self.inner.located_at(other.inner))
+ }
+
+ /// Convert `proc_macro2::Span` to `proc_macro::Span`.
+ ///
+ /// This method is available when building with a nightly compiler, or when
+ /// building with rustc 1.29+ *without* semver exempt features.
+ ///
+ /// # Panics
+ ///
+ /// Panics if called from outside of a procedural macro. Unlike
+ /// `proc_macro2::Span`, the `proc_macro::Span` type can only exist within
+ /// the context of a procedural macro invocation.
+ #[cfg(wrap_proc_macro)]
+ pub fn unwrap(self) -> proc_macro::Span {
+ self.inner.unwrap()
+ }
+
+ // Soft deprecated. Please use Span::unwrap.
+ #[cfg(wrap_proc_macro)]
+ #[doc(hidden)]
+ pub fn unstable(self) -> proc_macro::Span {
+ self.unwrap()
+ }
+
+ /// Returns the span's byte position range in the source file.
+ ///
+ /// This method requires the `"span-locations"` feature to be enabled.
+ ///
+ /// When executing in a procedural macro context, the returned range is only
+ /// accurate if compiled with a nightly toolchain. The stable toolchain does
+ /// not have this information available. When executing outside of a
+ /// procedural macro, such as main.rs or build.rs, the byte range is always
+ /// accurate regardless of toolchain.
+ #[cfg(span_locations)]
+ #[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+ pub fn byte_range(&self) -> Range<usize> {
+ self.inner.byte_range()
+ }
+
+ /// Get the starting line/column in the source file for this span.
+ ///
+ /// This method requires the `"span-locations"` feature to be enabled.
+ ///
+ /// When executing in a procedural macro context, the returned line/column
+ /// are only meaningful if compiled with a nightly toolchain. The stable
+ /// toolchain does not have this information available. When executing
+ /// outside of a procedural macro, such as main.rs or build.rs, the
+ /// line/column are always meaningful regardless of toolchain.
+ #[cfg(span_locations)]
+ #[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+ pub fn start(&self) -> LineColumn {
+ self.inner.start()
+ }
+
+ /// Get the ending line/column in the source file for this span.
+ ///
+ /// This method requires the `"span-locations"` feature to be enabled.
+ ///
+ /// When executing in a procedural macro context, the returned line/column
+ /// are only meaningful if compiled with a nightly toolchain. The stable
+ /// toolchain does not have this information available. When executing
+ /// outside of a procedural macro, such as main.rs or build.rs, the
+ /// line/column are always meaningful regardless of toolchain.
+ #[cfg(span_locations)]
+ #[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+ pub fn end(&self) -> LineColumn {
+ self.inner.end()
+ }
+
+ /// The path to the source file in which this span occurs, for display
+ /// purposes.
+ ///
+ /// This might not correspond to a valid file system path. It might be
+ /// remapped, or might be an artificial path such as `"<macro expansion>"`.
+ #[cfg(span_locations)]
+ #[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+ pub fn file(&self) -> String {
+ self.inner.file()
+ }
+
+ /// The path to the source file in which this span occurs on disk.
+ ///
+ /// This is the actual path on disk. It is unaffected by path remapping.
+ ///
+ /// This path should not be embedded in the output of the macro; prefer
+ /// `file()` instead.
+ #[cfg(span_locations)]
+ #[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+ pub fn local_file(&self) -> Option<PathBuf> {
+ self.inner.local_file()
+ }
+
+ /// Create a new span encompassing `self` and `other`.
+ ///
+ /// Returns `None` if `self` and `other` are from different files.
+ ///
+ /// Warning: the underlying [`proc_macro::Span::join`] method is
+ /// nightly-only. When called from within a procedural macro not using a
+ /// nightly compiler, this method will always return `None`.
+ pub fn join(&self, other: Span) -> Option<Span> {
+ self.inner.join(other.inner).map(Span::_new)
+ }
+
+ /// Compares two spans to see if they're equal.
+ ///
+ /// This method is semver exempt and not exposed by default.
+ #[cfg(procmacro2_semver_exempt)]
+ #[cfg_attr(docsrs, doc(cfg(procmacro2_semver_exempt)))]
+ pub fn eq(&self, other: &Span) -> bool {
+ self.inner.eq(&other.inner)
+ }
+
+ /// Returns the source text behind a span. This preserves the original
+ /// source code, including spaces and comments. It only returns a result if
+ /// the span corresponds to real source code.
+ ///
+ /// Note: The observable result of a macro should only rely on the tokens
+ /// and not on this source text. The result of this function is a best
+ /// effort to be used for diagnostics only.
+ pub fn source_text(&self) -> Option<String> {
+ self.inner.source_text()
+ }
+}
+
+/// Prints a span in a form convenient for debugging.
+impl Debug for Span {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Debug::fmt(&self.inner, f)
+ }
+}
+
+/// A single token or a delimited sequence of token trees (e.g. `[1, (), ..]`).
+#[derive(Clone)]
+pub enum TokenTree {
+ /// A token stream surrounded by bracket delimiters.
+ Group(Group),
+ /// An identifier.
+ Ident(Ident),
+ /// A single punctuation character (`+`, `,`, `$`, etc.).
+ Punct(Punct),
+ /// A literal character (`'a'`), string (`"hello"`), number (`2.3`), etc.
+ Literal(Literal),
+}
+
+impl TokenTree {
+ /// Returns the span of this tree, delegating to the `span` method of
+ /// the contained token or a delimited stream.
+ pub fn span(&self) -> Span {
+ match self {
+ TokenTree::Group(t) => t.span(),
+ TokenTree::Ident(t) => t.span(),
+ TokenTree::Punct(t) => t.span(),
+ TokenTree::Literal(t) => t.span(),
+ }
+ }
+
+ /// Configures the span for *only this token*.
+ ///
+ /// Note that if this token is a `Group` then this method will not configure
+ /// the span of each of the internal tokens, this will simply delegate to
+ /// the `set_span` method of each variant.
+ pub fn set_span(&mut self, span: Span) {
+ match self {
+ TokenTree::Group(t) => t.set_span(span),
+ TokenTree::Ident(t) => t.set_span(span),
+ TokenTree::Punct(t) => t.set_span(span),
+ TokenTree::Literal(t) => t.set_span(span),
+ }
+ }
+}
+
+impl From<Group> for TokenTree {
+ fn from(g: Group) -> Self {
+ TokenTree::Group(g)
+ }
+}
+
+impl From<Ident> for TokenTree {
+ fn from(g: Ident) -> Self {
+ TokenTree::Ident(g)
+ }
+}
+
+impl From<Punct> for TokenTree {
+ fn from(g: Punct) -> Self {
+ TokenTree::Punct(g)
+ }
+}
+
+impl From<Literal> for TokenTree {
+ fn from(g: Literal) -> Self {
+ TokenTree::Literal(g)
+ }
+}
+
+/// Prints the token tree as a string that is supposed to be losslessly
+/// convertible back into the same token tree (modulo spans), except for
+/// possibly `TokenTree::Group`s with `Delimiter::None` delimiters and negative
+/// numeric literals.
+impl Display for TokenTree {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ TokenTree::Group(t) => Display::fmt(t, f),
+ TokenTree::Ident(t) => Display::fmt(t, f),
+ TokenTree::Punct(t) => Display::fmt(t, f),
+ TokenTree::Literal(t) => Display::fmt(t, f),
+ }
+ }
+}
+
+/// Prints token tree in a form convenient for debugging.
+impl Debug for TokenTree {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ // Each of these has the name in the struct type in the derived debug,
+ // so don't bother with an extra layer of indirection
+ match self {
+ TokenTree::Group(t) => Debug::fmt(t, f),
+ TokenTree::Ident(t) => {
+ let mut debug = f.debug_struct("Ident");
+ debug.field("sym", &format_args!("{}", t));
+ imp::debug_span_field_if_nontrivial(&mut debug, t.span().inner);
+ debug.finish()
+ }
+ TokenTree::Punct(t) => Debug::fmt(t, f),
+ TokenTree::Literal(t) => Debug::fmt(t, f),
+ }
+ }
+}
+
+/// A delimited token stream.
+///
+/// A `Group` internally contains a `TokenStream` which is surrounded by
+/// `Delimiter`s.
+#[derive(Clone)]
+pub struct Group {
+ inner: imp::Group,
+}
+
+/// Describes how a sequence of token trees is delimited.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Delimiter {
+ /// `( ... )`
+ Parenthesis,
+ /// `{ ... }`
+ Brace,
+ /// `[ ... ]`
+ Bracket,
+ /// `∅ ... ∅`
+ ///
+ /// An invisible delimiter, that may, for example, appear around tokens
+ /// coming from a "macro variable" `$var`. It is important to preserve
+ /// operator priorities in cases like `$var * 3` where `$var` is `1 + 2`.
+ /// Invisible delimiters may not survive roundtrip of a token stream through
+ /// a string.
+ ///
+ /// <div class="warning">
+ ///
+ /// Note: rustc currently can ignore the grouping of tokens delimited by `None` in the output
+ /// of a proc_macro. Only `None`-delimited groups created by a macro_rules macro in the input
+ /// of a proc_macro macro are preserved, and only in very specific circumstances.
+ /// Any `None`-delimited groups (re)created by a proc_macro will therefore not preserve
+ /// operator priorities as indicated above. The other `Delimiter` variants should be used
+ /// instead in this context. This is a rustc bug. For details, see
+ /// [rust-lang/rust#67062](https://github.com/rust-lang/rust/issues/67062).
+ ///
+ /// </div>
+ None,
+}
+
+impl Group {
+ fn _new(inner: imp::Group) -> Self {
+ Group { inner }
+ }
+
+ fn _new_fallback(inner: fallback::Group) -> Self {
+ Group {
+ inner: imp::Group::from(inner),
+ }
+ }
+
+ /// Creates a new `Group` with the given delimiter and token stream.
+ ///
+ /// This constructor will set the span for this group to
+ /// `Span::call_site()`. To change the span you can use the `set_span`
+ /// method below.
+ pub fn new(delimiter: Delimiter, stream: TokenStream) -> Self {
+ Group {
+ inner: imp::Group::new(delimiter, stream.inner),
+ }
+ }
+
+ /// Returns the punctuation used as the delimiter for this group: a set of
+ /// parentheses, square brackets, or curly braces.
+ pub fn delimiter(&self) -> Delimiter {
+ self.inner.delimiter()
+ }
+
+ /// Returns the `TokenStream` of tokens that are delimited in this `Group`.
+ ///
+ /// Note that the returned token stream does not include the delimiter
+ /// returned above.
+ pub fn stream(&self) -> TokenStream {
+ TokenStream::_new(self.inner.stream())
+ }
+
+ /// Returns the span for the delimiters of this token stream, spanning the
+ /// entire `Group`.
+ ///
+ /// ```text
+ /// pub fn span(&self) -> Span {
+ /// ^^^^^^^
+ /// ```
+ pub fn span(&self) -> Span {
+ Span::_new(self.inner.span())
+ }
+
+ /// Returns the span pointing to the opening delimiter of this group.
+ ///
+ /// ```text
+ /// pub fn span_open(&self) -> Span {
+ /// ^
+ /// ```
+ pub fn span_open(&self) -> Span {
+ Span::_new(self.inner.span_open())
+ }
+
+ /// Returns the span pointing to the closing delimiter of this group.
+ ///
+ /// ```text
+ /// pub fn span_close(&self) -> Span {
+ /// ^
+ /// ```
+ pub fn span_close(&self) -> Span {
+ Span::_new(self.inner.span_close())
+ }
+
+ /// Returns an object that holds this group's `span_open()` and
+ /// `span_close()` together (in a more compact representation than holding
+ /// those 2 spans individually).
+ pub fn delim_span(&self) -> DelimSpan {
+ DelimSpan::new(&self.inner)
+ }
+
+ /// Configures the span for this `Group`'s delimiters, but not its internal
+ /// tokens.
+ ///
+ /// This method will **not** set the span of all the internal tokens spanned
+ /// by this group, but rather it will only set the span of the delimiter
+ /// tokens at the level of the `Group`.
+ pub fn set_span(&mut self, span: Span) {
+ self.inner.set_span(span.inner);
+ }
+}
+
+/// Prints the group as a string that should be losslessly convertible back
+/// into the same group (modulo spans), except for possibly `TokenTree::Group`s
+/// with `Delimiter::None` delimiters.
+impl Display for Group {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ Display::fmt(&self.inner, formatter)
+ }
+}
+
+impl Debug for Group {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ Debug::fmt(&self.inner, formatter)
+ }
+}
+
+/// A `Punct` is a single punctuation character like `+`, `-` or `#`.
+///
+/// Multicharacter operators like `+=` are represented as two instances of
+/// `Punct` with different forms of `Spacing` returned.
+#[derive(Clone)]
+pub struct Punct {
+ ch: char,
+ spacing: Spacing,
+ span: Span,
+}
+
+/// Whether a `Punct` is followed immediately by another `Punct` or followed by
+/// another token or whitespace.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Spacing {
+ /// E.g. `+` is `Alone` in `+ =`, `+ident` or `+()`.
+ Alone,
+ /// E.g. `+` is `Joint` in `+=` or `'` is `Joint` in `'#`.
+ ///
+ /// Additionally, single quote `'` can join with identifiers to form
+ /// lifetimes `'ident`.
+ Joint,
+}
+
+impl Punct {
+ /// Creates a new `Punct` from the given character and spacing.
+ ///
+ /// The `ch` argument must be a valid punctuation character permitted by the
+ /// language, otherwise the function will panic.
+ ///
+ /// The returned `Punct` will have the default span of `Span::call_site()`
+ /// which can be further configured with the `set_span` method below.
+ pub fn new(ch: char, spacing: Spacing) -> Self {
+ if let '!' | '#' | '$' | '%' | '&' | '\'' | '*' | '+' | ',' | '-' | '.' | '/' | ':' | ';'
+ | '<' | '=' | '>' | '?' | '@' | '^' | '|' | '~' = ch
+ {
+ Punct {
+ ch,
+ spacing,
+ span: Span::call_site(),
+ }
+ } else {
+ panic!("unsupported proc macro punctuation character {:?}", ch);
+ }
+ }
+
+ /// Returns the value of this punctuation character as `char`.
+ pub fn as_char(&self) -> char {
+ self.ch
+ }
+
+ /// Returns the spacing of this punctuation character, indicating whether
+ /// it's immediately followed by another `Punct` in the token stream, so
+ /// they can potentially be combined into a multicharacter operator
+ /// (`Joint`), or it's followed by some other token or whitespace (`Alone`)
+ /// so the operator has certainly ended.
+ pub fn spacing(&self) -> Spacing {
+ self.spacing
+ }
+
+ /// Returns the span for this punctuation character.
+ pub fn span(&self) -> Span {
+ self.span
+ }
+
+ /// Configure the span for this punctuation character.
+ pub fn set_span(&mut self, span: Span) {
+ self.span = span;
+ }
+}
+
+/// Prints the punctuation character as a string that should be losslessly
+/// convertible back into the same character.
+impl Display for Punct {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Display::fmt(&self.ch, f)
+ }
+}
+
+impl Debug for Punct {
+ fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+ let mut debug = fmt.debug_struct("Punct");
+ debug.field("char", &self.ch);
+ debug.field("spacing", &self.spacing);
+ imp::debug_span_field_if_nontrivial(&mut debug, self.span.inner);
+ debug.finish()
+ }
+}
+
+/// A word of Rust code, which may be a keyword or legal variable name.
+///
+/// An identifier consists of at least one Unicode code point, the first of
+/// which has the XID_Start property and the rest of which have the XID_Continue
+/// property.
+///
+/// - The empty string is not an identifier. Use `Option<Ident>`.
+/// - A lifetime is not an identifier. Use `syn::Lifetime` instead.
+///
+/// An identifier constructed with `Ident::new` is permitted to be a Rust
+/// keyword, though parsing one through its [`Parse`] implementation rejects
+/// Rust keywords. Use `input.call(Ident::parse_any)` when parsing to match the
+/// behaviour of `Ident::new`.
+///
+/// [`Parse`]: https://docs.rs/syn/2.0/syn/parse/trait.Parse.html
+///
+/// # Examples
+///
+/// A new ident can be created from a string using the `Ident::new` function.
+/// A span must be provided explicitly which governs the name resolution
+/// behavior of the resulting identifier.
+///
+/// ```
+/// use proc_macro2::{Ident, Span};
+///
+/// fn main() {
+/// let call_ident = Ident::new("calligraphy", Span::call_site());
+///
+/// println!("{}", call_ident);
+/// }
+/// ```
+///
+/// An ident can be interpolated into a token stream using the `quote!` macro.
+///
+/// ```
+/// use proc_macro2::{Ident, Span};
+/// use quote::quote;
+///
+/// fn main() {
+/// let ident = Ident::new("demo", Span::call_site());
+///
+/// // Create a variable binding whose name is this ident.
+/// let expanded = quote! { let #ident = 10; };
+///
+/// // Create a variable binding with a slightly different name.
+/// let temp_ident = Ident::new(&format!("new_{}", ident), Span::call_site());
+/// let expanded = quote! { let #temp_ident = 10; };
+/// }
+/// ```
+///
+/// A string representation of the ident is available through the `to_string()`
+/// method.
+///
+/// ```
+/// # use proc_macro2::{Ident, Span};
+/// #
+/// # let ident = Ident::new("another_identifier", Span::call_site());
+/// #
+/// // Examine the ident as a string.
+/// let ident_string = ident.to_string();
+/// if ident_string.len() > 60 {
+/// println!("Very long identifier: {}", ident_string)
+/// }
+/// ```
+#[derive(Clone)]
+pub struct Ident {
+ inner: imp::Ident,
+ _marker: ProcMacroAutoTraits,
+}
+
+impl Ident {
+ fn _new(inner: imp::Ident) -> Self {
+ Ident {
+ inner,
+ _marker: MARKER,
+ }
+ }
+
+ fn _new_fallback(inner: fallback::Ident) -> Self {
+ Ident {
+ inner: imp::Ident::from(inner),
+ _marker: MARKER,
+ }
+ }
+
+ /// Creates a new `Ident` with the given `string` as well as the specified
+ /// `span`.
+ ///
+ /// The `string` argument must be a valid identifier permitted by the
+ /// language, otherwise the function will panic.
+ ///
+ /// Note that `span`, currently in rustc, configures the hygiene information
+ /// for this identifier.
+ ///
+ /// As of this time `Span::call_site()` explicitly opts-in to "call-site"
+ /// hygiene meaning that identifiers created with this span will be resolved
+ /// as if they were written directly at the location of the macro call, and
+ /// other code at the macro call site will be able to refer to them as well.
+ ///
+ /// Later spans like `Span::def_site()` will allow to opt-in to
+ /// "definition-site" hygiene meaning that identifiers created with this
+ /// span will be resolved at the location of the macro definition and other
+ /// code at the macro call site will not be able to refer to them.
+ ///
+ /// Due to the current importance of hygiene this constructor, unlike other
+ /// tokens, requires a `Span` to be specified at construction.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the input string is neither a keyword nor a legal variable
+ /// name. If you are not sure whether the string contains an identifier and
+ /// need to handle an error case, use
+ /// <a href="https://docs.rs/syn/2.0/syn/fn.parse_str.html"><code
+ /// style="padding-right:0;">syn::parse_str</code></a><code
+ /// style="padding-left:0;">::<Ident></code>
+ /// rather than `Ident::new`.
+ #[track_caller]
+ pub fn new(string: &str, span: Span) -> Self {
+ Ident::_new(imp::Ident::new_checked(string, span.inner))
+ }
+
+ /// Same as `Ident::new`, but creates a raw identifier (`r#ident`). The
+ /// `string` argument must be a valid identifier permitted by the language
+ /// (including keywords, e.g. `fn`). Keywords which are usable in path
+ /// segments (e.g. `self`, `super`) are not supported, and will cause a
+ /// panic.
+ #[track_caller]
+ pub fn new_raw(string: &str, span: Span) -> Self {
+ Ident::_new(imp::Ident::new_raw_checked(string, span.inner))
+ }
+
+ /// Returns the span of this `Ident`.
+ pub fn span(&self) -> Span {
+ Span::_new(self.inner.span())
+ }
+
+ /// Configures the span of this `Ident`, possibly changing its hygiene
+ /// context.
+ pub fn set_span(&mut self, span: Span) {
+ self.inner.set_span(span.inner);
+ }
+}
+
+impl PartialEq for Ident {
+ fn eq(&self, other: &Ident) -> bool {
+ self.inner == other.inner
+ }
+}
+
+impl<T> PartialEq<T> for Ident
+where
+ T: ?Sized + AsRef<str>,
+{
+ fn eq(&self, other: &T) -> bool {
+ self.inner == other
+ }
+}
+
+impl Eq for Ident {}
+
+impl PartialOrd for Ident {
+ fn partial_cmp(&self, other: &Ident) -> Option<Ordering> {
+ Some(self.cmp(other))
+ }
+}
+
+impl Ord for Ident {
+ fn cmp(&self, other: &Ident) -> Ordering {
+ self.to_string().cmp(&other.to_string())
+ }
+}
+
+impl Hash for Ident {
+ fn hash<H: Hasher>(&self, hasher: &mut H) {
+ self.to_string().hash(hasher);
+ }
+}
+
+/// Prints the identifier as a string that should be losslessly convertible back
+/// into the same identifier.
+impl Display for Ident {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Display::fmt(&self.inner, f)
+ }
+}
+
+impl Debug for Ident {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Debug::fmt(&self.inner, f)
+ }
+}
+
+/// A literal string (`"hello"`), byte string (`b"hello"`), character (`'a'`),
+/// byte character (`b'a'`), an integer or floating point number with or without
+/// a suffix (`1`, `1u8`, `2.3`, `2.3f32`).
+///
+/// Boolean literals like `true` and `false` do not belong here, they are
+/// `Ident`s.
+#[derive(Clone)]
+pub struct Literal {
+ inner: imp::Literal,
+ _marker: ProcMacroAutoTraits,
+}
+
+macro_rules! suffixed_int_literals {
+ ($($name:ident => $kind:ident,)*) => ($(
+ /// Creates a new suffixed integer literal with the specified value.
+ ///
+ /// This function will create an integer like `1u32` where the integer
+ /// value specified is the first part of the token and the integral is
+ /// also suffixed at the end. Literals created from negative numbers may
+ /// not survive roundtrips through `TokenStream` or strings and may be
+ /// broken into two tokens (`-` and positive literal).
+ ///
+ /// Literals created through this method have the `Span::call_site()`
+ /// span by default, which can be configured with the `set_span` method
+ /// below.
+ pub fn $name(n: $kind) -> Literal {
+ Literal::_new(imp::Literal::$name(n))
+ }
+ )*)
+}
+
+macro_rules! unsuffixed_int_literals {
+ ($($name:ident => $kind:ident,)*) => ($(
+ /// Creates a new unsuffixed integer literal with the specified value.
+ ///
+ /// This function will create an integer like `1` where the integer
+ /// value specified is the first part of the token. No suffix is
+ /// specified on this token, meaning that invocations like
+ /// `Literal::i8_unsuffixed(1)` are equivalent to
+ /// `Literal::u32_unsuffixed(1)`. Literals created from negative numbers
+ /// may not survive roundtrips through `TokenStream` or strings and may
+ /// be broken into two tokens (`-` and positive literal).
+ ///
+ /// Literals created through this method have the `Span::call_site()`
+ /// span by default, which can be configured with the `set_span` method
+ /// below.
+ pub fn $name(n: $kind) -> Literal {
+ Literal::_new(imp::Literal::$name(n))
+ }
+ )*)
+}
+
+impl Literal {
+ fn _new(inner: imp::Literal) -> Self {
+ Literal {
+ inner,
+ _marker: MARKER,
+ }
+ }
+
+ fn _new_fallback(inner: fallback::Literal) -> Self {
+ Literal {
+ inner: imp::Literal::from(inner),
+ _marker: MARKER,
+ }
+ }
+
+ suffixed_int_literals! {
+ u8_suffixed => u8,
+ u16_suffixed => u16,
+ u32_suffixed => u32,
+ u64_suffixed => u64,
+ u128_suffixed => u128,
+ usize_suffixed => usize,
+ i8_suffixed => i8,
+ i16_suffixed => i16,
+ i32_suffixed => i32,
+ i64_suffixed => i64,
+ i128_suffixed => i128,
+ isize_suffixed => isize,
+ }
+
+ unsuffixed_int_literals! {
+ u8_unsuffixed => u8,
+ u16_unsuffixed => u16,
+ u32_unsuffixed => u32,
+ u64_unsuffixed => u64,
+ u128_unsuffixed => u128,
+ usize_unsuffixed => usize,
+ i8_unsuffixed => i8,
+ i16_unsuffixed => i16,
+ i32_unsuffixed => i32,
+ i64_unsuffixed => i64,
+ i128_unsuffixed => i128,
+ isize_unsuffixed => isize,
+ }
+
+ /// Creates a new unsuffixed floating-point literal.
+ ///
+ /// This constructor is similar to those like `Literal::i8_unsuffixed` where
+ /// the float's value is emitted directly into the token but no suffix is
+ /// used, so it may be inferred to be a `f64` later in the compiler.
+ /// Literals created from negative numbers may not survive round-trips
+ /// through `TokenStream` or strings and may be broken into two tokens (`-`
+ /// and positive literal).
+ ///
+ /// # Panics
+ ///
+ /// This function requires that the specified float is finite, for example
+ /// if it is infinity or NaN this function will panic.
+ pub fn f64_unsuffixed(f: f64) -> Literal {
+ assert!(f.is_finite());
+ Literal::_new(imp::Literal::f64_unsuffixed(f))
+ }
+
+ /// Creates a new suffixed floating-point literal.
+ ///
+ /// This constructor will create a literal like `1.0f64` where the value
+ /// specified is the preceding part of the token and `f64` is the suffix of
+ /// the token. This token will always be inferred to be an `f64` in the
+ /// compiler. Literals created from negative numbers may not survive
+ /// round-trips through `TokenStream` or strings and may be broken into two
+ /// tokens (`-` and positive literal).
+ ///
+ /// # Panics
+ ///
+ /// This function requires that the specified float is finite, for example
+ /// if it is infinity or NaN this function will panic.
+ pub fn f64_suffixed(f: f64) -> Literal {
+ assert!(f.is_finite());
+ Literal::_new(imp::Literal::f64_suffixed(f))
+ }
+
+ /// Creates a new unsuffixed floating-point literal.
+ ///
+ /// This constructor is similar to those like `Literal::i8_unsuffixed` where
+ /// the float's value is emitted directly into the token but no suffix is
+ /// used, so it may be inferred to be a `f64` later in the compiler.
+ /// Literals created from negative numbers may not survive round-trips
+ /// through `TokenStream` or strings and may be broken into two tokens (`-`
+ /// and positive literal).
+ ///
+ /// # Panics
+ ///
+ /// This function requires that the specified float is finite, for example
+ /// if it is infinity or NaN this function will panic.
+ pub fn f32_unsuffixed(f: f32) -> Literal {
+ assert!(f.is_finite());
+ Literal::_new(imp::Literal::f32_unsuffixed(f))
+ }
+
+ /// Creates a new suffixed floating-point literal.
+ ///
+ /// This constructor will create a literal like `1.0f32` where the value
+ /// specified is the preceding part of the token and `f32` is the suffix of
+ /// the token. This token will always be inferred to be an `f32` in the
+ /// compiler. Literals created from negative numbers may not survive
+ /// round-trips through `TokenStream` or strings and may be broken into two
+ /// tokens (`-` and positive literal).
+ ///
+ /// # Panics
+ ///
+ /// This function requires that the specified float is finite, for example
+ /// if it is infinity or NaN this function will panic.
+ pub fn f32_suffixed(f: f32) -> Literal {
+ assert!(f.is_finite());
+ Literal::_new(imp::Literal::f32_suffixed(f))
+ }
+
+ /// String literal.
+ pub fn string(string: &str) -> Literal {
+ Literal::_new(imp::Literal::string(string))
+ }
+
+ /// Character literal.
+ pub fn character(ch: char) -> Literal {
+ Literal::_new(imp::Literal::character(ch))
+ }
+
+ /// Byte character literal.
+ pub fn byte_character(byte: u8) -> Literal {
+ Literal::_new(imp::Literal::byte_character(byte))
+ }
+
+ /// Byte string literal.
+ pub fn byte_string(bytes: &[u8]) -> Literal {
+ Literal::_new(imp::Literal::byte_string(bytes))
+ }
+
+ /// C string literal.
+ pub fn c_string(string: &CStr) -> Literal {
+ Literal::_new(imp::Literal::c_string(string))
+ }
+
+ /// Returns the span encompassing this literal.
+ pub fn span(&self) -> Span {
+ Span::_new(self.inner.span())
+ }
+
+ /// Configures the span associated for this literal.
+ pub fn set_span(&mut self, span: Span) {
+ self.inner.set_span(span.inner);
+ }
+
+ /// Returns a `Span` that is a subset of `self.span()` containing only
+ /// the source bytes in range `range`. Returns `None` if the would-be
+ /// trimmed span is outside the bounds of `self`.
+ ///
+ /// Warning: the underlying [`proc_macro::Literal::subspan`] method is
+ /// nightly-only. When called from within a procedural macro not using a
+ /// nightly compiler, this method will always return `None`.
+ pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
+ self.inner.subspan(range).map(Span::_new)
+ }
+
+ // Intended for the `quote!` macro to use when constructing a proc-macro2
+ // token out of a macro_rules $:literal token, which is already known to be
+ // a valid literal. This avoids reparsing/validating the literal's string
+ // representation. This is not public API other than for quote.
+ #[doc(hidden)]
+ pub unsafe fn from_str_unchecked(repr: &str) -> Self {
+ Literal::_new(unsafe { imp::Literal::from_str_unchecked(repr) })
+ }
+}
+
+impl FromStr for Literal {
+ type Err = LexError;
+
+ fn from_str(repr: &str) -> Result<Self, LexError> {
+ match imp::Literal::from_str_checked(repr) {
+ Ok(lit) => Ok(Literal::_new(lit)),
+ Err(lex) => Err(LexError {
+ inner: lex,
+ _marker: MARKER,
+ }),
+ }
+ }
+}
+
+impl Debug for Literal {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Debug::fmt(&self.inner, f)
+ }
+}
+
+impl Display for Literal {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ Display::fmt(&self.inner, f)
+ }
+}
+
+/// Public implementation details for the `TokenStream` type, such as iterators.
+pub mod token_stream {
+ use crate::marker::{ProcMacroAutoTraits, MARKER};
+ use crate::{imp, TokenTree};
+ use core::fmt::{self, Debug};
+
+ pub use crate::TokenStream;
+
+ /// An iterator over `TokenStream`'s `TokenTree`s.
+ ///
+ /// The iteration is "shallow", e.g. the iterator doesn't recurse into
+ /// delimited groups, and returns whole groups as token trees.
+ #[derive(Clone)]
+ pub struct IntoIter {
+ inner: imp::TokenTreeIter,
+ _marker: ProcMacroAutoTraits,
+ }
+
+ impl Iterator for IntoIter {
+ type Item = TokenTree;
+
+ fn next(&mut self) -> Option<TokenTree> {
+ self.inner.next()
+ }
+
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+ }
+
+ impl Debug for IntoIter {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ f.write_str("TokenStream ")?;
+ f.debug_list().entries(self.clone()).finish()
+ }
+ }
+
+ impl IntoIterator for TokenStream {
+ type Item = TokenTree;
+ type IntoIter = IntoIter;
+
+ fn into_iter(self) -> IntoIter {
+ IntoIter {
+ inner: self.inner.into_iter(),
+ _marker: MARKER,
+ }
+ }
+ }
+}
diff --git a/rust/proc-macro2/location.rs b/rust/proc-macro2/location.rs
new file mode 100644
index 000000000000..7190e2d05255
--- /dev/null
+++ b/rust/proc-macro2/location.rs
@@ -0,0 +1,29 @@
+use core::cmp::Ordering;
+
+/// A line-column pair representing the start or end of a `Span`.
+///
+/// This type is semver exempt and not exposed by default.
+#[cfg_attr(docsrs, doc(cfg(feature = "span-locations")))]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub struct LineColumn {
+ /// The 1-indexed line in the source file on which the span starts or ends
+ /// (inclusive).
+ pub line: usize,
+ /// The 0-indexed column (in UTF-8 characters) in the source file on which
+ /// the span starts or ends (inclusive).
+ pub column: usize,
+}
+
+impl Ord for LineColumn {
+ fn cmp(&self, other: &Self) -> Ordering {
+ self.line
+ .cmp(&other.line)
+ .then(self.column.cmp(&other.column))
+ }
+}
+
+impl PartialOrd for LineColumn {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ Some(self.cmp(other))
+ }
+}
diff --git a/rust/proc-macro2/marker.rs b/rust/proc-macro2/marker.rs
new file mode 100644
index 000000000000..23b94ce6fa85
--- /dev/null
+++ b/rust/proc-macro2/marker.rs
@@ -0,0 +1,17 @@
+use alloc::rc::Rc;
+use core::marker::PhantomData;
+use core::panic::{RefUnwindSafe, UnwindSafe};
+
+// Zero sized marker with the correct set of autotrait impls we want all proc
+// macro types to have.
+#[derive(Copy, Clone)]
+#[cfg_attr(
+ all(procmacro2_semver_exempt, any(not(wrap_proc_macro), super_unstable)),
+ derive(PartialEq, Eq)
+)]
+pub(crate) struct ProcMacroAutoTraits(PhantomData<Rc<()>>);
+
+pub(crate) const MARKER: ProcMacroAutoTraits = ProcMacroAutoTraits(PhantomData);
+
+impl UnwindSafe for ProcMacroAutoTraits {}
+impl RefUnwindSafe for ProcMacroAutoTraits {}
diff --git a/rust/proc-macro2/parse.rs b/rust/proc-macro2/parse.rs
new file mode 100644
index 000000000000..b8be403f842f
--- /dev/null
+++ b/rust/proc-macro2/parse.rs
@@ -0,0 +1,995 @@
+use crate::fallback::{
+ self, is_ident_continue, is_ident_start, Group, Ident, LexError, Literal, Span, TokenStream,
+ TokenStreamBuilder,
+};
+use crate::{Delimiter, Punct, Spacing, TokenTree};
+use core::char;
+use core::str::{Bytes, CharIndices, Chars};
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub(crate) struct Cursor<'a> {
+ pub(crate) rest: &'a str,
+ #[cfg(span_locations)]
+ pub(crate) off: u32,
+}
+
+impl<'a> Cursor<'a> {
+ pub(crate) fn advance(&self, bytes: usize) -> Cursor<'a> {
+ let (_front, rest) = self.rest.split_at(bytes);
+ Cursor {
+ rest,
+ #[cfg(span_locations)]
+ off: self.off + _front.chars().count() as u32,
+ }
+ }
+
+ pub(crate) fn starts_with(&self, s: &str) -> bool {
+ self.rest.starts_with(s)
+ }
+
+ pub(crate) fn starts_with_char(&self, ch: char) -> bool {
+ self.rest.starts_with(ch)
+ }
+
+ pub(crate) fn starts_with_fn<Pattern>(&self, f: Pattern) -> bool
+ where
+ Pattern: FnMut(char) -> bool,
+ {
+ self.rest.starts_with(f)
+ }
+
+ pub(crate) fn is_empty(&self) -> bool {
+ self.rest.is_empty()
+ }
+
+ fn len(&self) -> usize {
+ self.rest.len()
+ }
+
+ fn as_bytes(&self) -> &'a [u8] {
+ self.rest.as_bytes()
+ }
+
+ fn bytes(&self) -> Bytes<'a> {
+ self.rest.bytes()
+ }
+
+ fn chars(&self) -> Chars<'a> {
+ self.rest.chars()
+ }
+
+ fn char_indices(&self) -> CharIndices<'a> {
+ self.rest.char_indices()
+ }
+
+ fn parse(&self, tag: &str) -> Result<Cursor<'a>, Reject> {
+ if self.starts_with(tag) {
+ Ok(self.advance(tag.len()))
+ } else {
+ Err(Reject)
+ }
+ }
+}
+
+pub(crate) struct Reject;
+type PResult<'a, O> = Result<(Cursor<'a>, O), Reject>;
+
+fn skip_whitespace(input: Cursor) -> Cursor {
+ let mut s = input;
+
+ while !s.is_empty() {
+ let byte = s.as_bytes()[0];
+ if byte == b'/' {
+ if s.starts_with("//")
+ && (!s.starts_with("///") || s.starts_with("////"))
+ && !s.starts_with("//!")
+ {
+ let (cursor, _) = take_until_newline_or_eof(s);
+ s = cursor;
+ continue;
+ } else if s.starts_with("/**/") {
+ s = s.advance(4);
+ continue;
+ } else if s.starts_with("/*")
+ && (!s.starts_with("/**") || s.starts_with("/***"))
+ && !s.starts_with("/*!")
+ {
+ match block_comment(s) {
+ Ok((rest, _)) => {
+ s = rest;
+ continue;
+ }
+ Err(Reject) => return s,
+ }
+ }
+ }
+ match byte {
+ b' ' | 0x09..=0x0d => {
+ s = s.advance(1);
+ continue;
+ }
+ b if b.is_ascii() => {}
+ _ => {
+ let ch = s.chars().next().unwrap();
+ if is_whitespace(ch) {
+ s = s.advance(ch.len_utf8());
+ continue;
+ }
+ }
+ }
+ return s;
+ }
+ s
+}
+
+fn block_comment(input: Cursor) -> PResult<&str> {
+ if !input.starts_with("/*") {
+ return Err(Reject);
+ }
+
+ let mut depth = 0usize;
+ let bytes = input.as_bytes();
+ let mut i = 0usize;
+ let upper = bytes.len() - 1;
+
+ while i < upper {
+ if bytes[i] == b'/' && bytes[i + 1] == b'*' {
+ depth += 1;
+ i += 1; // eat '*'
+ } else if bytes[i] == b'*' && bytes[i + 1] == b'/' {
+ depth -= 1;
+ if depth == 0 {
+ return Ok((input.advance(i + 2), &input.rest[..i + 2]));
+ }
+ i += 1; // eat '/'
+ }
+ i += 1;
+ }
+
+ Err(Reject)
+}
+
+fn is_whitespace(ch: char) -> bool {
+ // Rust treats left-to-right mark and right-to-left mark as whitespace
+ ch.is_whitespace() || ch == '\u{200e}' || ch == '\u{200f}'
+}
+
+fn word_break(input: Cursor) -> Result<Cursor, Reject> {
+ match input.chars().next() {
+ Some(ch) if is_ident_continue(ch) => Err(Reject),
+ Some(_) | None => Ok(input),
+ }
+}
+
+// Rustc's representation of a macro expansion error in expression position or
+// type position.
+const ERROR: &str = "(/*ERROR*/)";
+
+pub(crate) fn token_stream(mut input: Cursor) -> Result<TokenStream, LexError> {
+ let mut trees = TokenStreamBuilder::new();
+ let mut stack = Vec::new();
+
+ loop {
+ input = skip_whitespace(input);
+
+ if let Ok((rest, ())) = doc_comment(input, &mut trees) {
+ input = rest;
+ continue;
+ }
+
+ #[cfg(span_locations)]
+ let lo = input.off;
+
+ let first = match input.bytes().next() {
+ Some(first) => first,
+ None => match stack.last() {
+ None => return Ok(trees.build()),
+ #[cfg(span_locations)]
+ Some((lo, _frame)) => {
+ return Err(LexError {
+ span: Span { lo: *lo, hi: *lo },
+ })
+ }
+ #[cfg(not(span_locations))]
+ Some(_frame) => return Err(LexError { span: Span {} }),
+ },
+ };
+
+ if let Some(open_delimiter) = match first {
+ b'(' if !input.starts_with(ERROR) => Some(Delimiter::Parenthesis),
+ b'[' => Some(Delimiter::Bracket),
+ b'{' => Some(Delimiter::Brace),
+ _ => None,
+ } {
+ input = input.advance(1);
+ let frame = (open_delimiter, trees);
+ #[cfg(span_locations)]
+ let frame = (lo, frame);
+ stack.push(frame);
+ trees = TokenStreamBuilder::new();
+ } else if let Some(close_delimiter) = match first {
+ b')' => Some(Delimiter::Parenthesis),
+ b']' => Some(Delimiter::Bracket),
+ b'}' => Some(Delimiter::Brace),
+ _ => None,
+ } {
+ let frame = match stack.pop() {
+ Some(frame) => frame,
+ None => return Err(lex_error(input)),
+ };
+ #[cfg(span_locations)]
+ let (lo, frame) = frame;
+ let (open_delimiter, outer) = frame;
+ if open_delimiter != close_delimiter {
+ return Err(lex_error(input));
+ }
+ input = input.advance(1);
+ let mut g = Group::new(open_delimiter, trees.build());
+ g.set_span(Span {
+ #[cfg(span_locations)]
+ lo,
+ #[cfg(span_locations)]
+ hi: input.off,
+ });
+ trees = outer;
+ trees.push_token_from_parser(TokenTree::Group(crate::Group::_new_fallback(g)));
+ } else {
+ let (rest, mut tt) = match leaf_token(input) {
+ Ok((rest, tt)) => (rest, tt),
+ Err(Reject) => return Err(lex_error(input)),
+ };
+ tt.set_span(crate::Span::_new_fallback(Span {
+ #[cfg(span_locations)]
+ lo,
+ #[cfg(span_locations)]
+ hi: rest.off,
+ }));
+ trees.push_token_from_parser(tt);
+ input = rest;
+ }
+ }
+}
+
+fn lex_error(cursor: Cursor) -> LexError {
+ #[cfg(not(span_locations))]
+ let _ = cursor;
+ LexError {
+ span: Span {
+ #[cfg(span_locations)]
+ lo: cursor.off,
+ #[cfg(span_locations)]
+ hi: cursor.off,
+ },
+ }
+}
+
+fn leaf_token(input: Cursor) -> PResult<TokenTree> {
+ if let Ok((input, l)) = literal(input) {
+ // must be parsed before ident
+ Ok((input, TokenTree::Literal(crate::Literal::_new_fallback(l))))
+ } else if let Ok((input, p)) = punct(input) {
+ Ok((input, TokenTree::Punct(p)))
+ } else if let Ok((input, i)) = ident(input) {
+ Ok((input, TokenTree::Ident(i)))
+ } else if input.starts_with(ERROR) {
+ let rest = input.advance(ERROR.len());
+ let repr = crate::Literal::_new_fallback(Literal::_new(ERROR.to_owned()));
+ Ok((rest, TokenTree::Literal(repr)))
+ } else {
+ Err(Reject)
+ }
+}
+
+fn ident(input: Cursor) -> PResult<crate::Ident> {
+ if [
+ "r\"", "r#\"", "r##", "b\"", "b\'", "br\"", "br#", "c\"", "cr\"", "cr#",
+ ]
+ .iter()
+ .any(|prefix| input.starts_with(prefix))
+ {
+ Err(Reject)
+ } else {
+ ident_any(input)
+ }
+}
+
+fn ident_any(input: Cursor) -> PResult<crate::Ident> {
+ let raw = input.starts_with("r#");
+ let rest = input.advance((raw as usize) << 1);
+
+ let (rest, sym) = ident_not_raw(rest)?;
+
+ if !raw {
+ let ident =
+ crate::Ident::_new_fallback(Ident::new_unchecked(sym, fallback::Span::call_site()));
+ return Ok((rest, ident));
+ }
+
+ match sym {
+ "_" | "super" | "self" | "Self" | "crate" => return Err(Reject),
+ _ => {}
+ }
+
+ let ident =
+ crate::Ident::_new_fallback(Ident::new_raw_unchecked(sym, fallback::Span::call_site()));
+ Ok((rest, ident))
+}
+
+fn ident_not_raw(input: Cursor) -> PResult<&str> {
+ let mut chars = input.char_indices();
+
+ match chars.next() {
+ Some((_, ch)) if is_ident_start(ch) => {}
+ _ => return Err(Reject),
+ }
+
+ let mut end = input.len();
+ for (i, ch) in chars {
+ if !is_ident_continue(ch) {
+ end = i;
+ break;
+ }
+ }
+
+ Ok((input.advance(end), &input.rest[..end]))
+}
+
+pub(crate) fn literal(input: Cursor) -> PResult<Literal> {
+ let rest = literal_nocapture(input)?;
+ let end = input.len() - rest.len();
+ Ok((rest, Literal::_new(input.rest[..end].to_string())))
+}
+
+fn literal_nocapture(input: Cursor) -> Result<Cursor, Reject> {
+ if let Ok(ok) = string(input) {
+ Ok(ok)
+ } else if let Ok(ok) = byte_string(input) {
+ Ok(ok)
+ } else if let Ok(ok) = c_string(input) {
+ Ok(ok)
+ } else if let Ok(ok) = byte(input) {
+ Ok(ok)
+ } else if let Ok(ok) = character(input) {
+ Ok(ok)
+ } else if let Ok(ok) = float(input) {
+ Ok(ok)
+ } else if let Ok(ok) = int(input) {
+ Ok(ok)
+ } else {
+ Err(Reject)
+ }
+}
+
+fn literal_suffix(input: Cursor) -> Cursor {
+ match ident_not_raw(input) {
+ Ok((input, _)) => input,
+ Err(Reject) => input,
+ }
+}
+
+fn string(input: Cursor) -> Result<Cursor, Reject> {
+ if let Ok(input) = input.parse("\"") {
+ cooked_string(input)
+ } else if let Ok(input) = input.parse("r") {
+ raw_string(input)
+ } else {
+ Err(Reject)
+ }
+}
+
+fn cooked_string(mut input: Cursor) -> Result<Cursor, Reject> {
+ let mut chars = input.char_indices();
+
+ while let Some((i, ch)) = chars.next() {
+ match ch {
+ '"' => {
+ let input = input.advance(i + 1);
+ return Ok(literal_suffix(input));
+ }
+ '\r' => match chars.next() {
+ Some((_, '\n')) => {}
+ _ => break,
+ },
+ '\\' => match chars.next() {
+ Some((_, 'x')) => {
+ backslash_x_char(&mut chars)?;
+ }
+ Some((_, 'n' | 'r' | 't' | '\\' | '\'' | '"' | '0')) => {}
+ Some((_, 'u')) => {
+ backslash_u(&mut chars)?;
+ }
+ Some((newline, ch @ ('\n' | '\r'))) => {
+ input = input.advance(newline + 1);
+ trailing_backslash(&mut input, ch as u8)?;
+ chars = input.char_indices();
+ }
+ _ => break,
+ },
+ _ch => {}
+ }
+ }
+ Err(Reject)
+}
+
+fn raw_string(input: Cursor) -> Result<Cursor, Reject> {
+ let (input, delimiter) = delimiter_of_raw_string(input)?;
+ let mut bytes = input.bytes().enumerate();
+ while let Some((i, byte)) = bytes.next() {
+ match byte {
+ b'"' if input.rest[i + 1..].starts_with(delimiter) => {
+ let rest = input.advance(i + 1 + delimiter.len());
+ return Ok(literal_suffix(rest));
+ }
+ b'\r' => match bytes.next() {
+ Some((_, b'\n')) => {}
+ _ => break,
+ },
+ _ => {}
+ }
+ }
+ Err(Reject)
+}
+
+fn byte_string(input: Cursor) -> Result<Cursor, Reject> {
+ if let Ok(input) = input.parse("b\"") {
+ cooked_byte_string(input)
+ } else if let Ok(input) = input.parse("br") {
+ raw_byte_string(input)
+ } else {
+ Err(Reject)
+ }
+}
+
+fn cooked_byte_string(mut input: Cursor) -> Result<Cursor, Reject> {
+ let mut bytes = input.bytes().enumerate();
+ while let Some((offset, b)) = bytes.next() {
+ match b {
+ b'"' => {
+ let input = input.advance(offset + 1);
+ return Ok(literal_suffix(input));
+ }
+ b'\r' => match bytes.next() {
+ Some((_, b'\n')) => {}
+ _ => break,
+ },
+ b'\\' => match bytes.next() {
+ Some((_, b'x')) => {
+ backslash_x_byte(&mut bytes)?;
+ }
+ Some((_, b'n' | b'r' | b't' | b'\\' | b'0' | b'\'' | b'"')) => {}
+ Some((newline, b @ (b'\n' | b'\r'))) => {
+ input = input.advance(newline + 1);
+ trailing_backslash(&mut input, b)?;
+ bytes = input.bytes().enumerate();
+ }
+ _ => break,
+ },
+ b if b.is_ascii() => {}
+ _ => break,
+ }
+ }
+ Err(Reject)
+}
+
+fn delimiter_of_raw_string(input: Cursor) -> PResult<&str> {
+ for (i, byte) in input.bytes().enumerate() {
+ match byte {
+ b'"' => {
+ if i > 255 {
+ // https://github.com/rust-lang/rust/pull/95251
+ return Err(Reject);
+ }
+ return Ok((input.advance(i + 1), &input.rest[..i]));
+ }
+ b'#' => {}
+ _ => break,
+ }
+ }
+ Err(Reject)
+}
+
+fn raw_byte_string(input: Cursor) -> Result<Cursor, Reject> {
+ let (input, delimiter) = delimiter_of_raw_string(input)?;
+ let mut bytes = input.bytes().enumerate();
+ while let Some((i, byte)) = bytes.next() {
+ match byte {
+ b'"' if input.rest[i + 1..].starts_with(delimiter) => {
+ let rest = input.advance(i + 1 + delimiter.len());
+ return Ok(literal_suffix(rest));
+ }
+ b'\r' => match bytes.next() {
+ Some((_, b'\n')) => {}
+ _ => break,
+ },
+ other => {
+ if !other.is_ascii() {
+ break;
+ }
+ }
+ }
+ }
+ Err(Reject)
+}
+
+fn c_string(input: Cursor) -> Result<Cursor, Reject> {
+ if let Ok(input) = input.parse("c\"") {
+ cooked_c_string(input)
+ } else if let Ok(input) = input.parse("cr") {
+ raw_c_string(input)
+ } else {
+ Err(Reject)
+ }
+}
+
+fn raw_c_string(input: Cursor) -> Result<Cursor, Reject> {
+ let (input, delimiter) = delimiter_of_raw_string(input)?;
+ let mut bytes = input.bytes().enumerate();
+ while let Some((i, byte)) = bytes.next() {
+ match byte {
+ b'"' if input.rest[i + 1..].starts_with(delimiter) => {
+ let rest = input.advance(i + 1 + delimiter.len());
+ return Ok(literal_suffix(rest));
+ }
+ b'\r' => match bytes.next() {
+ Some((_, b'\n')) => {}
+ _ => break,
+ },
+ b'\0' => break,
+ _ => {}
+ }
+ }
+ Err(Reject)
+}
+
+fn cooked_c_string(mut input: Cursor) -> Result<Cursor, Reject> {
+ let mut chars = input.char_indices();
+
+ while let Some((i, ch)) = chars.next() {
+ match ch {
+ '"' => {
+ let input = input.advance(i + 1);
+ return Ok(literal_suffix(input));
+ }
+ '\r' => match chars.next() {
+ Some((_, '\n')) => {}
+ _ => break,
+ },
+ '\\' => match chars.next() {
+ Some((_, 'x')) => {
+ backslash_x_nonzero(&mut chars)?;
+ }
+ Some((_, 'n' | 'r' | 't' | '\\' | '\'' | '"')) => {}
+ Some((_, 'u')) => {
+ if backslash_u(&mut chars)? == '\0' {
+ break;
+ }
+ }
+ Some((newline, ch @ ('\n' | '\r'))) => {
+ input = input.advance(newline + 1);
+ trailing_backslash(&mut input, ch as u8)?;
+ chars = input.char_indices();
+ }
+ _ => break,
+ },
+ '\0' => break,
+ _ch => {}
+ }
+ }
+ Err(Reject)
+}
+
+fn byte(input: Cursor) -> Result<Cursor, Reject> {
+ let input = input.parse("b'")?;
+ let mut bytes = input.bytes().enumerate();
+ let ok = match bytes.next().map(|(_, b)| b) {
+ Some(b'\\') => match bytes.next().map(|(_, b)| b) {
+ Some(b'x') => backslash_x_byte(&mut bytes).is_ok(),
+ Some(b'n' | b'r' | b't' | b'\\' | b'0' | b'\'' | b'"') => true,
+ _ => false,
+ },
+ b => b.is_some(),
+ };
+ if !ok {
+ return Err(Reject);
+ }
+ let (offset, _) = bytes.next().ok_or(Reject)?;
+ if !input.chars().as_str().is_char_boundary(offset) {
+ return Err(Reject);
+ }
+ let input = input.advance(offset).parse("'")?;
+ Ok(literal_suffix(input))
+}
+
+fn character(input: Cursor) -> Result<Cursor, Reject> {
+ let input = input.parse("'")?;
+ let mut chars = input.char_indices();
+ let ok = match chars.next().map(|(_, ch)| ch) {
+ Some('\\') => match chars.next().map(|(_, ch)| ch) {
+ Some('x') => backslash_x_char(&mut chars).is_ok(),
+ Some('u') => backslash_u(&mut chars).is_ok(),
+ Some('n' | 'r' | 't' | '\\' | '0' | '\'' | '"') => true,
+ _ => false,
+ },
+ ch => ch.is_some(),
+ };
+ if !ok {
+ return Err(Reject);
+ }
+ let (idx, _) = chars.next().ok_or(Reject)?;
+ let input = input.advance(idx).parse("'")?;
+ Ok(literal_suffix(input))
+}
+
+macro_rules! next_ch {
+ ($chars:ident @ $pat:pat) => {
+ match $chars.next() {
+ Some((_, ch)) => match ch {
+ $pat => ch,
+ _ => return Err(Reject),
+ },
+ None => return Err(Reject),
+ }
+ };
+}
+
+fn backslash_x_char<I>(chars: &mut I) -> Result<(), Reject>
+where
+ I: Iterator<Item = (usize, char)>,
+{
+ next_ch!(chars @ '0'..='7');
+ next_ch!(chars @ '0'..='9' | 'a'..='f' | 'A'..='F');
+ Ok(())
+}
+
+fn backslash_x_byte<I>(chars: &mut I) -> Result<(), Reject>
+where
+ I: Iterator<Item = (usize, u8)>,
+{
+ next_ch!(chars @ b'0'..=b'9' | b'a'..=b'f' | b'A'..=b'F');
+ next_ch!(chars @ b'0'..=b'9' | b'a'..=b'f' | b'A'..=b'F');
+ Ok(())
+}
+
+fn backslash_x_nonzero<I>(chars: &mut I) -> Result<(), Reject>
+where
+ I: Iterator<Item = (usize, char)>,
+{
+ let first = next_ch!(chars @ '0'..='9' | 'a'..='f' | 'A'..='F');
+ let second = next_ch!(chars @ '0'..='9' | 'a'..='f' | 'A'..='F');
+ if first == '0' && second == '0' {
+ Err(Reject)
+ } else {
+ Ok(())
+ }
+}
+
+fn backslash_u<I>(chars: &mut I) -> Result<char, Reject>
+where
+ I: Iterator<Item = (usize, char)>,
+{
+ next_ch!(chars @ '{');
+ let mut value = 0;
+ let mut len = 0;
+ for (_, ch) in chars {
+ let digit = match ch {
+ '0'..='9' => ch as u8 - b'0',
+ 'a'..='f' => 10 + ch as u8 - b'a',
+ 'A'..='F' => 10 + ch as u8 - b'A',
+ '_' if len > 0 => continue,
+ '}' if len > 0 => return char::from_u32(value).ok_or(Reject),
+ _ => break,
+ };
+ if len == 6 {
+ break;
+ }
+ value *= 0x10;
+ value += u32::from(digit);
+ len += 1;
+ }
+ Err(Reject)
+}
+
+fn trailing_backslash(input: &mut Cursor, mut last: u8) -> Result<(), Reject> {
+ let mut whitespace = input.bytes().enumerate();
+ loop {
+ if last == b'\r' && whitespace.next().map_or(true, |(_, b)| b != b'\n') {
+ return Err(Reject);
+ }
+ match whitespace.next() {
+ Some((_, b @ (b' ' | b'\t' | b'\n' | b'\r'))) => {
+ last = b;
+ }
+ Some((offset, _)) => {
+ *input = input.advance(offset);
+ return Ok(());
+ }
+ None => return Err(Reject),
+ }
+ }
+}
+
+fn float(input: Cursor) -> Result<Cursor, Reject> {
+ let mut rest = float_digits(input)?;
+ if let Some(ch) = rest.chars().next() {
+ if is_ident_start(ch) {
+ rest = ident_not_raw(rest)?.0;
+ }
+ }
+ word_break(rest)
+}
+
+fn float_digits(input: Cursor) -> Result<Cursor, Reject> {
+ let mut chars = input.chars().peekable();
+ match chars.next() {
+ Some(ch) if '0' <= ch && ch <= '9' => {}
+ _ => return Err(Reject),
+ }
+
+ let mut len = 1;
+ let mut has_dot = false;
+ let mut has_exp = false;
+ while let Some(&ch) = chars.peek() {
+ match ch {
+ '0'..='9' | '_' => {
+ chars.next();
+ len += 1;
+ }
+ '.' => {
+ if has_dot {
+ break;
+ }
+ chars.next();
+ if chars
+ .peek()
+ .map_or(false, |&ch| ch == '.' || is_ident_start(ch))
+ {
+ return Err(Reject);
+ }
+ len += 1;
+ has_dot = true;
+ }
+ 'e' | 'E' => {
+ chars.next();
+ len += 1;
+ has_exp = true;
+ break;
+ }
+ _ => break,
+ }
+ }
+
+ if !(has_dot || has_exp) {
+ return Err(Reject);
+ }
+
+ if has_exp {
+ let token_before_exp = if has_dot {
+ Ok(input.advance(len - 1))
+ } else {
+ Err(Reject)
+ };
+ let mut has_sign = false;
+ let mut has_exp_value = false;
+ while let Some(&ch) = chars.peek() {
+ match ch {
+ '+' | '-' => {
+ if has_exp_value {
+ break;
+ }
+ if has_sign {
+ return token_before_exp;
+ }
+ chars.next();
+ len += 1;
+ has_sign = true;
+ }
+ '0'..='9' => {
+ chars.next();
+ len += 1;
+ has_exp_value = true;
+ }
+ '_' => {
+ chars.next();
+ len += 1;
+ }
+ _ => break,
+ }
+ }
+ if !has_exp_value {
+ return token_before_exp;
+ }
+ }
+
+ Ok(input.advance(len))
+}
+
+fn int(input: Cursor) -> Result<Cursor, Reject> {
+ let mut rest = digits(input)?;
+ if let Some(ch) = rest.chars().next() {
+ if is_ident_start(ch) {
+ rest = ident_not_raw(rest)?.0;
+ }
+ }
+ word_break(rest)
+}
+
+fn digits(mut input: Cursor) -> Result<Cursor, Reject> {
+ let base = if input.starts_with("0x") {
+ input = input.advance(2);
+ 16
+ } else if input.starts_with("0o") {
+ input = input.advance(2);
+ 8
+ } else if input.starts_with("0b") {
+ input = input.advance(2);
+ 2
+ } else {
+ 10
+ };
+
+ let mut len = 0;
+ let mut empty = true;
+ for b in input.bytes() {
+ match b {
+ b'0'..=b'9' => {
+ let digit = (b - b'0') as u64;
+ if digit >= base {
+ return Err(Reject);
+ }
+ }
+ b'a'..=b'f' => {
+ let digit = 10 + (b - b'a') as u64;
+ if digit >= base {
+ break;
+ }
+ }
+ b'A'..=b'F' => {
+ let digit = 10 + (b - b'A') as u64;
+ if digit >= base {
+ break;
+ }
+ }
+ b'_' => {
+ if empty && base == 10 {
+ return Err(Reject);
+ }
+ len += 1;
+ continue;
+ }
+ _ => break,
+ }
+ len += 1;
+ empty = false;
+ }
+ if empty {
+ Err(Reject)
+ } else {
+ Ok(input.advance(len))
+ }
+}
+
+fn punct(input: Cursor) -> PResult<Punct> {
+ let (rest, ch) = punct_char(input)?;
+ if ch == '\'' {
+ let (after_lifetime, _ident) = ident_any(rest)?;
+ if after_lifetime.starts_with_char('\'')
+ || (after_lifetime.starts_with_char('#') && !rest.starts_with("r#"))
+ {
+ Err(Reject)
+ } else {
+ Ok((rest, Punct::new('\'', Spacing::Joint)))
+ }
+ } else {
+ let kind = match punct_char(rest) {
+ Ok(_) => Spacing::Joint,
+ Err(Reject) => Spacing::Alone,
+ };
+ Ok((rest, Punct::new(ch, kind)))
+ }
+}
+
+fn punct_char(input: Cursor) -> PResult<char> {
+ if input.starts_with("//") || input.starts_with("/*") {
+ // Do not accept `/` of a comment as a punct.
+ return Err(Reject);
+ }
+
+ let mut chars = input.chars();
+ let first = match chars.next() {
+ Some(ch) => ch,
+ None => {
+ return Err(Reject);
+ }
+ };
+ let recognized = "~!@...^&*-=+|;:,<.>/?'";
+ if recognized.contains(first) {
+ Ok((input.advance(first.len_utf8()), first))
+ } else {
+ Err(Reject)
+ }
+}
+
+fn doc_comment<'a>(input: Cursor<'a>, trees: &mut TokenStreamBuilder) -> PResult<'a, ()> {
+ #[cfg(span_locations)]
+ let lo = input.off;
+ let (rest, (comment, inner)) = doc_comment_contents(input)?;
+ let fallback_span = Span {
+ #[cfg(span_locations)]
+ lo,
+ #[cfg(span_locations)]
+ hi: rest.off,
+ };
+ let span = crate::Span::_new_fallback(fallback_span);
+
+ let mut scan_for_bare_cr = comment;
+ while let Some(cr) = scan_for_bare_cr.find('\r') {
+ let rest = &scan_for_bare_cr[cr + 1..];
+ if !rest.starts_with('\n') {
+ return Err(Reject);
+ }
+ scan_for_bare_cr = rest;
+ }
+
+ let mut pound = Punct::new('#', Spacing::Alone);
+ pound.set_span(span);
+ trees.push_token_from_parser(TokenTree::Punct(pound));
+
+ if inner {
+ let mut bang = Punct::new('!', Spacing::Alone);
+ bang.set_span(span);
+ trees.push_token_from_parser(TokenTree::Punct(bang));
+ }
+
+ let doc_ident = crate::Ident::_new_fallback(Ident::new_unchecked("doc", fallback_span));
+ let mut equal = Punct::new('=', Spacing::Alone);
+ equal.set_span(span);
+ let mut literal = crate::Literal::_new_fallback(Literal::string(comment));
+ literal.set_span(span);
+ let mut bracketed = TokenStreamBuilder::with_capacity(3);
+ bracketed.push_token_from_parser(TokenTree::Ident(doc_ident));
+ bracketed.push_token_from_parser(TokenTree::Punct(equal));
+ bracketed.push_token_from_parser(TokenTree::Literal(literal));
+ let group = Group::new(Delimiter::Bracket, bracketed.build());
+ let mut group = crate::Group::_new_fallback(group);
+ group.set_span(span);
+ trees.push_token_from_parser(TokenTree::Group(group));
+
+ Ok((rest, ()))
+}
+
+fn doc_comment_contents(input: Cursor) -> PResult<(&str, bool)> {
+ if input.starts_with("//!") {
+ let input = input.advance(3);
+ let (input, s) = take_until_newline_or_eof(input);
+ Ok((input, (s, true)))
+ } else if input.starts_with("/*!") {
+ let (input, s) = block_comment(input)?;
+ Ok((input, (&s[3..s.len() - 2], true)))
+ } else if input.starts_with("///") {
+ let input = input.advance(3);
+ if input.starts_with_char('/') {
+ return Err(Reject);
+ }
+ let (input, s) = take_until_newline_or_eof(input);
+ Ok((input, (s, false)))
+ } else if input.starts_with("/**") && !input.rest[3..].starts_with('*') {
+ let (input, s) = block_comment(input)?;
+ Ok((input, (&s[3..s.len() - 2], false)))
+ } else {
+ Err(Reject)
+ }
+}
+
+fn take_until_newline_or_eof(input: Cursor) -> (Cursor, &str) {
+ let chars = input.char_indices();
+
+ for (i, ch) in chars {
+ if ch == '\n' {
+ return (input.advance(i), &input.rest[..i]);
+ } else if ch == '\r' && input.rest[i + 1..].starts_with('\n') {
+ return (input.advance(i + 1), &input.rest[..i]);
+ }
+ }
+
+ (input.advance(input.len()), input.rest)
+}
diff --git a/rust/proc-macro2/probe.rs b/rust/proc-macro2/probe.rs
new file mode 100644
index 000000000000..b67f52036218
--- /dev/null
+++ b/rust/proc-macro2/probe.rs
@@ -0,0 +1,10 @@
+#![allow(dead_code)]
+
+#[cfg(proc_macro_span)]
+pub(crate) mod proc_macro_span;
+
+#[cfg(proc_macro_span_file)]
+pub(crate) mod proc_macro_span_file;
+
+#[cfg(proc_macro_span_location)]
+pub(crate) mod proc_macro_span_location;
diff --git a/rust/proc-macro2/probe/proc_macro_span.rs b/rust/proc-macro2/probe/proc_macro_span.rs
new file mode 100644
index 000000000000..2d7d44e07708
--- /dev/null
+++ b/rust/proc-macro2/probe/proc_macro_span.rs
@@ -0,0 +1,51 @@
+// This code exercises the surface area that we expect of Span's unstable API.
+// If the current toolchain is able to compile it, then proc-macro2 is able to
+// offer these APIs too.
+
+#![cfg_attr(procmacro2_build_probe, feature(proc_macro_span))]
+
+extern crate proc_macro;
+
+use core::ops::{Range, RangeBounds};
+use proc_macro::{Literal, Span};
+use std::path::PathBuf;
+
+pub fn byte_range(this: &Span) -> Range<usize> {
+ this.byte_range()
+}
+
+pub fn start(this: &Span) -> Span {
+ this.start()
+}
+
+pub fn end(this: &Span) -> Span {
+ this.end()
+}
+
+pub fn line(this: &Span) -> usize {
+ this.line()
+}
+
+pub fn column(this: &Span) -> usize {
+ this.column()
+}
+
+pub fn file(this: &Span) -> String {
+ this.file()
+}
+
+pub fn local_file(this: &Span) -> Option<PathBuf> {
+ this.local_file()
+}
+
+pub fn join(this: &Span, other: Span) -> Option<Span> {
+ this.join(other)
+}
+
+pub fn subspan<R: RangeBounds<usize>>(this: &Literal, range: R) -> Option<Span> {
+ this.subspan(range)
+}
+
+// Include in sccache cache key.
+#[cfg(procmacro2_build_probe)]
+const _: Option<&str> = option_env!("RUSTC_BOOTSTRAP");
diff --git a/rust/proc-macro2/probe/proc_macro_span_file.rs b/rust/proc-macro2/probe/proc_macro_span_file.rs
new file mode 100644
index 000000000000..8b76bdf5007b
--- /dev/null
+++ b/rust/proc-macro2/probe/proc_macro_span_file.rs
@@ -0,0 +1,14 @@
+// The subset of Span's API stabilized in Rust 1.88.
+
+extern crate proc_macro;
+
+use proc_macro::Span;
+use std::path::PathBuf;
+
+pub fn file(this: &Span) -> String {
+ this.file()
+}
+
+pub fn local_file(this: &Span) -> Option<PathBuf> {
+ this.local_file()
+}
diff --git a/rust/proc-macro2/probe/proc_macro_span_location.rs b/rust/proc-macro2/probe/proc_macro_span_location.rs
new file mode 100644
index 000000000000..79da34af54af
--- /dev/null
+++ b/rust/proc-macro2/probe/proc_macro_span_location.rs
@@ -0,0 +1,21 @@
+// The subset of Span's API stabilized in Rust 1.88.
+
+extern crate proc_macro;
+
+use proc_macro::Span;
+
+pub fn start(this: &Span) -> Span {
+ this.start()
+}
+
+pub fn end(this: &Span) -> Span {
+ this.end()
+}
+
+pub fn line(this: &Span) -> usize {
+ this.line()
+}
+
+pub fn column(this: &Span) -> usize {
+ this.column()
+}
diff --git a/rust/proc-macro2/rcvec.rs b/rust/proc-macro2/rcvec.rs
new file mode 100644
index 000000000000..23edc77d597f
--- /dev/null
+++ b/rust/proc-macro2/rcvec.rs
@@ -0,0 +1,146 @@
+use alloc::rc::Rc;
+use alloc::vec;
+use core::mem;
+use core::panic::RefUnwindSafe;
+use core::slice;
+
+pub(crate) struct RcVec<T> {
+ inner: Rc<Vec<T>>,
+}
+
+pub(crate) struct RcVecBuilder<T> {
+ inner: Vec<T>,
+}
+
+pub(crate) struct RcVecMut<'a, T> {
+ inner: &'a mut Vec<T>,
+}
+
+#[derive(Clone)]
+pub(crate) struct RcVecIntoIter<T> {
+ inner: vec::IntoIter<T>,
+}
+
+impl<T> RcVec<T> {
+ pub(crate) fn is_empty(&self) -> bool {
+ self.inner.is_empty()
+ }
+
+ pub(crate) fn len(&self) -> usize {
+ self.inner.len()
+ }
+
+ pub(crate) fn iter(&self) -> slice::Iter<T> {
+ self.inner.iter()
+ }
+
+ pub(crate) fn make_mut(&mut self) -> RcVecMut<T>
+ where
+ T: Clone,
+ {
+ RcVecMut {
+ inner: Rc::make_mut(&mut self.inner),
+ }
+ }
+
+ pub(crate) fn get_mut(&mut self) -> Option<RcVecMut<T>> {
+ let inner = Rc::get_mut(&mut self.inner)?;
+ Some(RcVecMut { inner })
+ }
+
+ pub(crate) fn make_owned(mut self) -> RcVecBuilder<T>
+ where
+ T: Clone,
+ {
+ let vec = if let Some(owned) = Rc::get_mut(&mut self.inner) {
+ mem::take(owned)
+ } else {
+ Vec::clone(&self.inner)
+ };
+ RcVecBuilder { inner: vec }
+ }
+}
+
+impl<T> RcVecBuilder<T> {
+ pub(crate) fn new() -> Self {
+ RcVecBuilder { inner: Vec::new() }
+ }
+
+ pub(crate) fn with_capacity(cap: usize) -> Self {
+ RcVecBuilder {
+ inner: Vec::with_capacity(cap),
+ }
+ }
+
+ pub(crate) fn push(&mut self, element: T) {
+ self.inner.push(element);
+ }
+
+ pub(crate) fn extend(&mut self, iter: impl IntoIterator<Item = T>) {
+ self.inner.extend(iter);
+ }
+
+ pub(crate) fn as_mut(&mut self) -> RcVecMut<T> {
+ RcVecMut {
+ inner: &mut self.inner,
+ }
+ }
+
+ pub(crate) fn build(self) -> RcVec<T> {
+ RcVec {
+ inner: Rc::new(self.inner),
+ }
+ }
+}
+
+impl<'a, T> RcVecMut<'a, T> {
+ pub(crate) fn push(&mut self, element: T) {
+ self.inner.push(element);
+ }
+
+ pub(crate) fn extend(&mut self, iter: impl IntoIterator<Item = T>) {
+ self.inner.extend(iter);
+ }
+
+ pub(crate) fn as_mut(&mut self) -> RcVecMut<T> {
+ RcVecMut { inner: self.inner }
+ }
+
+ pub(crate) fn take(self) -> RcVecBuilder<T> {
+ let vec = mem::take(self.inner);
+ RcVecBuilder { inner: vec }
+ }
+}
+
+impl<T> Clone for RcVec<T> {
+ fn clone(&self) -> Self {
+ RcVec {
+ inner: Rc::clone(&self.inner),
+ }
+ }
+}
+
+impl<T> IntoIterator for RcVecBuilder<T> {
+ type Item = T;
+ type IntoIter = RcVecIntoIter<T>;
+
+ fn into_iter(self) -> Self::IntoIter {
+ RcVecIntoIter {
+ inner: self.inner.into_iter(),
+ }
+ }
+}
+
+impl<T> Iterator for RcVecIntoIter<T> {
+ type Item = T;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ self.inner.next()
+ }
+
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+
+impl<T> RefUnwindSafe for RcVec<T> where T: RefUnwindSafe {}
diff --git a/rust/proc-macro2/wrapper.rs b/rust/proc-macro2/wrapper.rs
new file mode 100644
index 000000000000..2e3eb5b4d04e
--- /dev/null
+++ b/rust/proc-macro2/wrapper.rs
@@ -0,0 +1,984 @@
+use crate::detection::inside_proc_macro;
+use crate::fallback::{self, FromStr2 as _};
+#[cfg(span_locations)]
+use crate::location::LineColumn;
+#[cfg(proc_macro_span)]
+use crate::probe::proc_macro_span;
+#[cfg(all(span_locations, proc_macro_span_file))]
+use crate::probe::proc_macro_span_file;
+#[cfg(all(span_locations, proc_macro_span_location))]
+use crate::probe::proc_macro_span_location;
+use crate::{Delimiter, Punct, Spacing, TokenTree};
+use core::fmt::{self, Debug, Display};
+#[cfg(span_locations)]
+use core::ops::Range;
+use core::ops::RangeBounds;
+use std::ffi::CStr;
+#[cfg(span_locations)]
+use std::path::PathBuf;
+
+#[derive(Clone)]
+pub(crate) enum TokenStream {
+ Compiler(DeferredTokenStream),
+ Fallback(fallback::TokenStream),
+}
+
+// Work around https://github.com/rust-lang/rust/issues/65080.
+// In `impl Extend<TokenTree> for TokenStream` which is used heavily by quote,
+// we hold on to the appended tokens and do proc_macro::TokenStream::extend as
+// late as possible to batch together consecutive uses of the Extend impl.
+#[derive(Clone)]
+pub(crate) struct DeferredTokenStream {
+ stream: proc_macro::TokenStream,
+ extra: Vec<proc_macro::TokenTree>,
+}
+
+pub(crate) enum LexError {
+ Compiler(proc_macro::LexError),
+ Fallback(fallback::LexError),
+
+ // Rustc was supposed to return a LexError, but it panicked instead.
+ // https://github.com/rust-lang/rust/issues/58736
+ CompilerPanic,
+}
+
+#[cold]
+fn mismatch(line: u32) -> ! {
+ #[cfg(procmacro2_backtrace)]
+ {
+ let backtrace = std::backtrace::Backtrace::force_capture();
+ panic!("compiler/fallback mismatch L{}\n\n{}", line, backtrace)
+ }
+ #[cfg(not(procmacro2_backtrace))]
+ {
+ panic!("compiler/fallback mismatch L{}", line)
+ }
+}
+
+impl DeferredTokenStream {
+ fn new(stream: proc_macro::TokenStream) -> Self {
+ DeferredTokenStream {
+ stream,
+ extra: Vec::new(),
+ }
+ }
+
+ fn is_empty(&self) -> bool {
+ self.stream.is_empty() && self.extra.is_empty()
+ }
+
+ fn evaluate_now(&mut self) {
+ // If-check provides a fast short circuit for the common case of `extra`
+ // being empty, which saves a round trip over the proc macro bridge.
+ // Improves macro expansion time in winrt by 6% in debug mode.
+ if !self.extra.is_empty() {
+ self.stream.extend(self.extra.drain(..));
+ }
+ }
+
+ fn into_token_stream(mut self) -> proc_macro::TokenStream {
+ self.evaluate_now();
+ self.stream
+ }
+}
+
+impl TokenStream {
+ pub(crate) fn new() -> Self {
+ if inside_proc_macro() {
+ TokenStream::Compiler(DeferredTokenStream::new(proc_macro::TokenStream::new()))
+ } else {
+ TokenStream::Fallback(fallback::TokenStream::new())
+ }
+ }
+
+ pub(crate) fn from_str_checked(src: &str) -> Result<Self, LexError> {
+ if inside_proc_macro() {
+ Ok(TokenStream::Compiler(DeferredTokenStream::new(
+ proc_macro::TokenStream::from_str_checked(src)?,
+ )))
+ } else {
+ Ok(TokenStream::Fallback(
+ fallback::TokenStream::from_str_checked(src)?,
+ ))
+ }
+ }
+
+ pub(crate) fn is_empty(&self) -> bool {
+ match self {
+ TokenStream::Compiler(tts) => tts.is_empty(),
+ TokenStream::Fallback(tts) => tts.is_empty(),
+ }
+ }
+
+ fn unwrap_nightly(self) -> proc_macro::TokenStream {
+ match self {
+ TokenStream::Compiler(s) => s.into_token_stream(),
+ TokenStream::Fallback(_) => mismatch(line!()),
+ }
+ }
+
+ fn unwrap_stable(self) -> fallback::TokenStream {
+ match self {
+ TokenStream::Compiler(_) => mismatch(line!()),
+ TokenStream::Fallback(s) => s,
+ }
+ }
+}
+
+impl Display for TokenStream {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ TokenStream::Compiler(tts) => Display::fmt(&tts.clone().into_token_stream(), f),
+ TokenStream::Fallback(tts) => Display::fmt(tts, f),
+ }
+ }
+}
+
+impl From<proc_macro::TokenStream> for TokenStream {
+ fn from(inner: proc_macro::TokenStream) -> Self {
+ TokenStream::Compiler(DeferredTokenStream::new(inner))
+ }
+}
+
+impl From<TokenStream> for proc_macro::TokenStream {
+ fn from(inner: TokenStream) -> Self {
+ match inner {
+ TokenStream::Compiler(inner) => inner.into_token_stream(),
+ TokenStream::Fallback(inner) => {
+ proc_macro::TokenStream::from_str_unchecked(&inner.to_string())
+ }
+ }
+ }
+}
+
+impl From<fallback::TokenStream> for TokenStream {
+ fn from(inner: fallback::TokenStream) -> Self {
+ TokenStream::Fallback(inner)
+ }
+}
+
+// Assumes inside_proc_macro().
+fn into_compiler_token(token: TokenTree) -> proc_macro::TokenTree {
+ match token {
+ TokenTree::Group(tt) => proc_macro::TokenTree::Group(tt.inner.unwrap_nightly()),
+ TokenTree::Punct(tt) => {
+ let spacing = match tt.spacing() {
+ Spacing::Joint => proc_macro::Spacing::Joint,
+ Spacing::Alone => proc_macro::Spacing::Alone,
+ };
+ let mut punct = proc_macro::Punct::new(tt.as_char(), spacing);
+ punct.set_span(tt.span().inner.unwrap_nightly());
+ proc_macro::TokenTree::Punct(punct)
+ }
+ TokenTree::Ident(tt) => proc_macro::TokenTree::Ident(tt.inner.unwrap_nightly()),
+ TokenTree::Literal(tt) => proc_macro::TokenTree::Literal(tt.inner.unwrap_nightly()),
+ }
+}
+
+impl From<TokenTree> for TokenStream {
+ fn from(token: TokenTree) -> Self {
+ if inside_proc_macro() {
+ TokenStream::Compiler(DeferredTokenStream::new(proc_macro::TokenStream::from(
+ into_compiler_token(token),
+ )))
+ } else {
+ TokenStream::Fallback(fallback::TokenStream::from(token))
+ }
+ }
+}
+
+impl FromIterator<TokenTree> for TokenStream {
+ fn from_iter<I: IntoIterator<Item = TokenTree>>(trees: I) -> Self {
+ if inside_proc_macro() {
+ TokenStream::Compiler(DeferredTokenStream::new(
+ trees.into_iter().map(into_compiler_token).collect(),
+ ))
+ } else {
+ TokenStream::Fallback(trees.into_iter().collect())
+ }
+ }
+}
+
+impl FromIterator<TokenStream> for TokenStream {
+ fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
+ let mut streams = streams.into_iter();
+ match streams.next() {
+ Some(TokenStream::Compiler(mut first)) => {
+ first.evaluate_now();
+ first.stream.extend(streams.map(|s| match s {
+ TokenStream::Compiler(s) => s.into_token_stream(),
+ TokenStream::Fallback(_) => mismatch(line!()),
+ }));
+ TokenStream::Compiler(first)
+ }
+ Some(TokenStream::Fallback(mut first)) => {
+ first.extend(streams.map(|s| match s {
+ TokenStream::Fallback(s) => s,
+ TokenStream::Compiler(_) => mismatch(line!()),
+ }));
+ TokenStream::Fallback(first)
+ }
+ None => TokenStream::new(),
+ }
+ }
+}
+
+impl Extend<TokenTree> for TokenStream {
+ fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, stream: I) {
+ match self {
+ TokenStream::Compiler(tts) => {
+ // Here is the reason for DeferredTokenStream.
+ for token in stream {
+ tts.extra.push(into_compiler_token(token));
+ }
+ }
+ TokenStream::Fallback(tts) => tts.extend(stream),
+ }
+ }
+}
+
+impl Extend<TokenStream> for TokenStream {
+ fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
+ match self {
+ TokenStream::Compiler(tts) => {
+ tts.evaluate_now();
+ tts.stream
+ .extend(streams.into_iter().map(TokenStream::unwrap_nightly));
+ }
+ TokenStream::Fallback(tts) => {
+ tts.extend(streams.into_iter().map(TokenStream::unwrap_stable));
+ }
+ }
+ }
+}
+
+impl Debug for TokenStream {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ TokenStream::Compiler(tts) => Debug::fmt(&tts.clone().into_token_stream(), f),
+ TokenStream::Fallback(tts) => Debug::fmt(tts, f),
+ }
+ }
+}
+
+impl LexError {
+ pub(crate) fn span(&self) -> Span {
+ match self {
+ LexError::Compiler(_) | LexError::CompilerPanic => Span::call_site(),
+ LexError::Fallback(e) => Span::Fallback(e.span()),
+ }
+ }
+}
+
+impl From<proc_macro::LexError> for LexError {
+ fn from(e: proc_macro::LexError) -> Self {
+ LexError::Compiler(e)
+ }
+}
+
+impl From<fallback::LexError> for LexError {
+ fn from(e: fallback::LexError) -> Self {
+ LexError::Fallback(e)
+ }
+}
+
+impl Debug for LexError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ LexError::Compiler(e) => Debug::fmt(e, f),
+ LexError::Fallback(e) => Debug::fmt(e, f),
+ LexError::CompilerPanic => {
+ let fallback = fallback::LexError::call_site();
+ Debug::fmt(&fallback, f)
+ }
+ }
+ }
+}
+
+impl Display for LexError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ LexError::Compiler(e) => Display::fmt(e, f),
+ LexError::Fallback(e) => Display::fmt(e, f),
+ LexError::CompilerPanic => {
+ let fallback = fallback::LexError::call_site();
+ Display::fmt(&fallback, f)
+ }
+ }
+ }
+}
+
+#[derive(Clone)]
+pub(crate) enum TokenTreeIter {
+ Compiler(proc_macro::token_stream::IntoIter),
+ Fallback(fallback::TokenTreeIter),
+}
+
+impl IntoIterator for TokenStream {
+ type Item = TokenTree;
+ type IntoIter = TokenTreeIter;
+
+ fn into_iter(self) -> TokenTreeIter {
+ match self {
+ TokenStream::Compiler(tts) => {
+ TokenTreeIter::Compiler(tts.into_token_stream().into_iter())
+ }
+ TokenStream::Fallback(tts) => TokenTreeIter::Fallback(tts.into_iter()),
+ }
+ }
+}
+
+impl Iterator for TokenTreeIter {
+ type Item = TokenTree;
+
+ fn next(&mut self) -> Option<TokenTree> {
+ let token = match self {
+ TokenTreeIter::Compiler(iter) => iter.next()?,
+ TokenTreeIter::Fallback(iter) => return iter.next(),
+ };
+ Some(match token {
+ proc_macro::TokenTree::Group(tt) => {
+ TokenTree::Group(crate::Group::_new(Group::Compiler(tt)))
+ }
+ proc_macro::TokenTree::Punct(tt) => {
+ let spacing = match tt.spacing() {
+ proc_macro::Spacing::Joint => Spacing::Joint,
+ proc_macro::Spacing::Alone => Spacing::Alone,
+ };
+ let mut o = Punct::new(tt.as_char(), spacing);
+ o.set_span(crate::Span::_new(Span::Compiler(tt.span())));
+ TokenTree::Punct(o)
+ }
+ proc_macro::TokenTree::Ident(s) => {
+ TokenTree::Ident(crate::Ident::_new(Ident::Compiler(s)))
+ }
+ proc_macro::TokenTree::Literal(l) => {
+ TokenTree::Literal(crate::Literal::_new(Literal::Compiler(l)))
+ }
+ })
+ }
+
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ match self {
+ TokenTreeIter::Compiler(tts) => tts.size_hint(),
+ TokenTreeIter::Fallback(tts) => tts.size_hint(),
+ }
+ }
+}
+
+#[derive(Copy, Clone)]
+pub(crate) enum Span {
+ Compiler(proc_macro::Span),
+ Fallback(fallback::Span),
+}
+
+impl Span {
+ pub(crate) fn call_site() -> Self {
+ if inside_proc_macro() {
+ Span::Compiler(proc_macro::Span::call_site())
+ } else {
+ Span::Fallback(fallback::Span::call_site())
+ }
+ }
+
+ pub(crate) fn mixed_site() -> Self {
+ if inside_proc_macro() {
+ Span::Compiler(proc_macro::Span::mixed_site())
+ } else {
+ Span::Fallback(fallback::Span::mixed_site())
+ }
+ }
+
+ #[cfg(super_unstable)]
+ pub(crate) fn def_site() -> Self {
+ if inside_proc_macro() {
+ Span::Compiler(proc_macro::Span::def_site())
+ } else {
+ Span::Fallback(fallback::Span::def_site())
+ }
+ }
+
+ pub(crate) fn resolved_at(&self, other: Span) -> Span {
+ match (self, other) {
+ (Span::Compiler(a), Span::Compiler(b)) => Span::Compiler(a.resolved_at(b)),
+ (Span::Fallback(a), Span::Fallback(b)) => Span::Fallback(a.resolved_at(b)),
+ (Span::Compiler(_), Span::Fallback(_)) => mismatch(line!()),
+ (Span::Fallback(_), Span::Compiler(_)) => mismatch(line!()),
+ }
+ }
+
+ pub(crate) fn located_at(&self, other: Span) -> Span {
+ match (self, other) {
+ (Span::Compiler(a), Span::Compiler(b)) => Span::Compiler(a.located_at(b)),
+ (Span::Fallback(a), Span::Fallback(b)) => Span::Fallback(a.located_at(b)),
+ (Span::Compiler(_), Span::Fallback(_)) => mismatch(line!()),
+ (Span::Fallback(_), Span::Compiler(_)) => mismatch(line!()),
+ }
+ }
+
+ pub(crate) fn unwrap(self) -> proc_macro::Span {
+ match self {
+ Span::Compiler(s) => s,
+ Span::Fallback(_) => panic!("proc_macro::Span is only available in procedural macros"),
+ }
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn byte_range(&self) -> Range<usize> {
+ match self {
+ #[cfg(proc_macro_span)]
+ Span::Compiler(s) => proc_macro_span::byte_range(s),
+ #[cfg(not(proc_macro_span))]
+ Span::Compiler(_) => 0..0,
+ Span::Fallback(s) => s.byte_range(),
+ }
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn start(&self) -> LineColumn {
+ match self {
+ #[cfg(proc_macro_span_location)]
+ Span::Compiler(s) => LineColumn {
+ line: proc_macro_span_location::line(s),
+ column: proc_macro_span_location::column(s).saturating_sub(1),
+ },
+ #[cfg(not(proc_macro_span_location))]
+ Span::Compiler(_) => LineColumn { line: 0, column: 0 },
+ Span::Fallback(s) => s.start(),
+ }
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn end(&self) -> LineColumn {
+ match self {
+ #[cfg(proc_macro_span_location)]
+ Span::Compiler(s) => {
+ let end = proc_macro_span_location::end(s);
+ LineColumn {
+ line: proc_macro_span_location::line(&end),
+ column: proc_macro_span_location::column(&end).saturating_sub(1),
+ }
+ }
+ #[cfg(not(proc_macro_span_location))]
+ Span::Compiler(_) => LineColumn { line: 0, column: 0 },
+ Span::Fallback(s) => s.end(),
+ }
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn file(&self) -> String {
+ match self {
+ #[cfg(proc_macro_span_file)]
+ Span::Compiler(s) => proc_macro_span_file::file(s),
+ #[cfg(not(proc_macro_span_file))]
+ Span::Compiler(_) => "<token stream>".to_owned(),
+ Span::Fallback(s) => s.file(),
+ }
+ }
+
+ #[cfg(span_locations)]
+ pub(crate) fn local_file(&self) -> Option<PathBuf> {
+ match self {
+ #[cfg(proc_macro_span_file)]
+ Span::Compiler(s) => proc_macro_span_file::local_file(s),
+ #[cfg(not(proc_macro_span_file))]
+ Span::Compiler(_) => None,
+ Span::Fallback(s) => s.local_file(),
+ }
+ }
+
+ pub(crate) fn join(&self, other: Span) -> Option<Span> {
+ let ret = match (self, other) {
+ #[cfg(proc_macro_span)]
+ (Span::Compiler(a), Span::Compiler(b)) => Span::Compiler(proc_macro_span::join(a, b)?),
+ (Span::Fallback(a), Span::Fallback(b)) => Span::Fallback(a.join(b)?),
+ _ => return None,
+ };
+ Some(ret)
+ }
+
+ #[cfg(super_unstable)]
+ pub(crate) fn eq(&self, other: &Span) -> bool {
+ match (self, other) {
+ (Span::Compiler(a), Span::Compiler(b)) => a.eq(b),
+ (Span::Fallback(a), Span::Fallback(b)) => a.eq(b),
+ _ => false,
+ }
+ }
+
+ pub(crate) fn source_text(&self) -> Option<String> {
+ match self {
+ #[cfg(not(no_source_text))]
+ Span::Compiler(s) => s.source_text(),
+ #[cfg(no_source_text)]
+ Span::Compiler(_) => None,
+ Span::Fallback(s) => s.source_text(),
+ }
+ }
+
+ fn unwrap_nightly(self) -> proc_macro::Span {
+ match self {
+ Span::Compiler(s) => s,
+ Span::Fallback(_) => mismatch(line!()),
+ }
+ }
+}
+
+impl From<proc_macro::Span> for crate::Span {
+ fn from(proc_span: proc_macro::Span) -> Self {
+ crate::Span::_new(Span::Compiler(proc_span))
+ }
+}
+
+impl From<fallback::Span> for Span {
+ fn from(inner: fallback::Span) -> Self {
+ Span::Fallback(inner)
+ }
+}
+
+impl Debug for Span {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Span::Compiler(s) => Debug::fmt(s, f),
+ Span::Fallback(s) => Debug::fmt(s, f),
+ }
+ }
+}
+
+pub(crate) fn debug_span_field_if_nontrivial(debug: &mut fmt::DebugStruct, span: Span) {
+ match span {
+ Span::Compiler(s) => {
+ debug.field("span", &s);
+ }
+ Span::Fallback(s) => fallback::debug_span_field_if_nontrivial(debug, s),
+ }
+}
+
+#[derive(Clone)]
+pub(crate) enum Group {
+ Compiler(proc_macro::Group),
+ Fallback(fallback::Group),
+}
+
+impl Group {
+ pub(crate) fn new(delimiter: Delimiter, stream: TokenStream) -> Self {
+ match stream {
+ TokenStream::Compiler(tts) => {
+ let delimiter = match delimiter {
+ Delimiter::Parenthesis => proc_macro::Delimiter::Parenthesis,
+ Delimiter::Bracket => proc_macro::Delimiter::Bracket,
+ Delimiter::Brace => proc_macro::Delimiter::Brace,
+ Delimiter::None => proc_macro::Delimiter::None,
+ };
+ Group::Compiler(proc_macro::Group::new(delimiter, tts.into_token_stream()))
+ }
+ TokenStream::Fallback(stream) => {
+ Group::Fallback(fallback::Group::new(delimiter, stream))
+ }
+ }
+ }
+
+ pub(crate) fn delimiter(&self) -> Delimiter {
+ match self {
+ Group::Compiler(g) => match g.delimiter() {
+ proc_macro::Delimiter::Parenthesis => Delimiter::Parenthesis,
+ proc_macro::Delimiter::Bracket => Delimiter::Bracket,
+ proc_macro::Delimiter::Brace => Delimiter::Brace,
+ proc_macro::Delimiter::None => Delimiter::None,
+ },
+ Group::Fallback(g) => g.delimiter(),
+ }
+ }
+
+ pub(crate) fn stream(&self) -> TokenStream {
+ match self {
+ Group::Compiler(g) => TokenStream::Compiler(DeferredTokenStream::new(g.stream())),
+ Group::Fallback(g) => TokenStream::Fallback(g.stream()),
+ }
+ }
+
+ pub(crate) fn span(&self) -> Span {
+ match self {
+ Group::Compiler(g) => Span::Compiler(g.span()),
+ Group::Fallback(g) => Span::Fallback(g.span()),
+ }
+ }
+
+ pub(crate) fn span_open(&self) -> Span {
+ match self {
+ Group::Compiler(g) => Span::Compiler(g.span_open()),
+ Group::Fallback(g) => Span::Fallback(g.span_open()),
+ }
+ }
+
+ pub(crate) fn span_close(&self) -> Span {
+ match self {
+ Group::Compiler(g) => Span::Compiler(g.span_close()),
+ Group::Fallback(g) => Span::Fallback(g.span_close()),
+ }
+ }
+
+ pub(crate) fn set_span(&mut self, span: Span) {
+ match (self, span) {
+ (Group::Compiler(g), Span::Compiler(s)) => g.set_span(s),
+ (Group::Fallback(g), Span::Fallback(s)) => g.set_span(s),
+ (Group::Compiler(_), Span::Fallback(_)) => mismatch(line!()),
+ (Group::Fallback(_), Span::Compiler(_)) => mismatch(line!()),
+ }
+ }
+
+ fn unwrap_nightly(self) -> proc_macro::Group {
+ match self {
+ Group::Compiler(g) => g,
+ Group::Fallback(_) => mismatch(line!()),
+ }
+ }
+}
+
+impl From<fallback::Group> for Group {
+ fn from(g: fallback::Group) -> Self {
+ Group::Fallback(g)
+ }
+}
+
+impl Display for Group {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Group::Compiler(group) => Display::fmt(group, formatter),
+ Group::Fallback(group) => Display::fmt(group, formatter),
+ }
+ }
+}
+
+impl Debug for Group {
+ fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Group::Compiler(group) => Debug::fmt(group, formatter),
+ Group::Fallback(group) => Debug::fmt(group, formatter),
+ }
+ }
+}
+
+#[derive(Clone)]
+pub(crate) enum Ident {
+ Compiler(proc_macro::Ident),
+ Fallback(fallback::Ident),
+}
+
+impl Ident {
+ #[track_caller]
+ pub(crate) fn new_checked(string: &str, span: Span) -> Self {
+ match span {
+ Span::Compiler(s) => Ident::Compiler(proc_macro::Ident::new(string, s)),
+ Span::Fallback(s) => Ident::Fallback(fallback::Ident::new_checked(string, s)),
+ }
+ }
+
+ #[track_caller]
+ pub(crate) fn new_raw_checked(string: &str, span: Span) -> Self {
+ match span {
+ Span::Compiler(s) => Ident::Compiler(proc_macro::Ident::new_raw(string, s)),
+ Span::Fallback(s) => Ident::Fallback(fallback::Ident::new_raw_checked(string, s)),
+ }
+ }
+
+ pub(crate) fn span(&self) -> Span {
+ match self {
+ Ident::Compiler(t) => Span::Compiler(t.span()),
+ Ident::Fallback(t) => Span::Fallback(t.span()),
+ }
+ }
+
+ pub(crate) fn set_span(&mut self, span: Span) {
+ match (self, span) {
+ (Ident::Compiler(t), Span::Compiler(s)) => t.set_span(s),
+ (Ident::Fallback(t), Span::Fallback(s)) => t.set_span(s),
+ (Ident::Compiler(_), Span::Fallback(_)) => mismatch(line!()),
+ (Ident::Fallback(_), Span::Compiler(_)) => mismatch(line!()),
+ }
+ }
+
+ fn unwrap_nightly(self) -> proc_macro::Ident {
+ match self {
+ Ident::Compiler(s) => s,
+ Ident::Fallback(_) => mismatch(line!()),
+ }
+ }
+}
+
+impl From<fallback::Ident> for Ident {
+ fn from(inner: fallback::Ident) -> Self {
+ Ident::Fallback(inner)
+ }
+}
+
+impl PartialEq for Ident {
+ fn eq(&self, other: &Ident) -> bool {
+ match (self, other) {
+ (Ident::Compiler(t), Ident::Compiler(o)) => t.to_string() == o.to_string(),
+ (Ident::Fallback(t), Ident::Fallback(o)) => t == o,
+ (Ident::Compiler(_), Ident::Fallback(_)) => mismatch(line!()),
+ (Ident::Fallback(_), Ident::Compiler(_)) => mismatch(line!()),
+ }
+ }
+}
+
+impl<T> PartialEq<T> for Ident
+where
+ T: ?Sized + AsRef<str>,
+{
+ fn eq(&self, other: &T) -> bool {
+ let other = other.as_ref();
+ match self {
+ Ident::Compiler(t) => t.to_string() == other,
+ Ident::Fallback(t) => t == other,
+ }
+ }
+}
+
+impl Display for Ident {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Ident::Compiler(t) => Display::fmt(t, f),
+ Ident::Fallback(t) => Display::fmt(t, f),
+ }
+ }
+}
+
+impl Debug for Ident {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Ident::Compiler(t) => Debug::fmt(t, f),
+ Ident::Fallback(t) => Debug::fmt(t, f),
+ }
+ }
+}
+
+#[derive(Clone)]
+pub(crate) enum Literal {
+ Compiler(proc_macro::Literal),
+ Fallback(fallback::Literal),
+}
+
+macro_rules! suffixed_numbers {
+ ($($name:ident => $kind:ident,)*) => ($(
+ pub(crate) fn $name(n: $kind) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::$name(n))
+ } else {
+ Literal::Fallback(fallback::Literal::$name(n))
+ }
+ }
+ )*)
+}
+
+macro_rules! unsuffixed_integers {
+ ($($name:ident => $kind:ident,)*) => ($(
+ pub(crate) fn $name(n: $kind) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::$name(n))
+ } else {
+ Literal::Fallback(fallback::Literal::$name(n))
+ }
+ }
+ )*)
+}
+
+impl Literal {
+ pub(crate) fn from_str_checked(repr: &str) -> Result<Self, LexError> {
+ if inside_proc_macro() {
+ let literal = proc_macro::Literal::from_str_checked(repr)?;
+ Ok(Literal::Compiler(literal))
+ } else {
+ let literal = fallback::Literal::from_str_checked(repr)?;
+ Ok(Literal::Fallback(literal))
+ }
+ }
+
+ pub(crate) unsafe fn from_str_unchecked(repr: &str) -> Self {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::from_str_unchecked(repr))
+ } else {
+ Literal::Fallback(unsafe { fallback::Literal::from_str_unchecked(repr) })
+ }
+ }
+
+ suffixed_numbers! {
+ u8_suffixed => u8,
+ u16_suffixed => u16,
+ u32_suffixed => u32,
+ u64_suffixed => u64,
+ u128_suffixed => u128,
+ usize_suffixed => usize,
+ i8_suffixed => i8,
+ i16_suffixed => i16,
+ i32_suffixed => i32,
+ i64_suffixed => i64,
+ i128_suffixed => i128,
+ isize_suffixed => isize,
+
+ f32_suffixed => f32,
+ f64_suffixed => f64,
+ }
+
+ unsuffixed_integers! {
+ u8_unsuffixed => u8,
+ u16_unsuffixed => u16,
+ u32_unsuffixed => u32,
+ u64_unsuffixed => u64,
+ u128_unsuffixed => u128,
+ usize_unsuffixed => usize,
+ i8_unsuffixed => i8,
+ i16_unsuffixed => i16,
+ i32_unsuffixed => i32,
+ i64_unsuffixed => i64,
+ i128_unsuffixed => i128,
+ isize_unsuffixed => isize,
+ }
+
+ pub(crate) fn f32_unsuffixed(f: f32) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::f32_unsuffixed(f))
+ } else {
+ Literal::Fallback(fallback::Literal::f32_unsuffixed(f))
+ }
+ }
+
+ pub(crate) fn f64_unsuffixed(f: f64) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::f64_unsuffixed(f))
+ } else {
+ Literal::Fallback(fallback::Literal::f64_unsuffixed(f))
+ }
+ }
+
+ pub(crate) fn string(string: &str) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::string(string))
+ } else {
+ Literal::Fallback(fallback::Literal::string(string))
+ }
+ }
+
+ pub(crate) fn character(ch: char) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::character(ch))
+ } else {
+ Literal::Fallback(fallback::Literal::character(ch))
+ }
+ }
+
+ pub(crate) fn byte_character(byte: u8) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler({
+ #[cfg(not(no_literal_byte_character))]
+ {
+ proc_macro::Literal::byte_character(byte)
+ }
+
+ #[cfg(no_literal_byte_character)]
+ {
+ let fallback = fallback::Literal::byte_character(byte);
+ proc_macro::Literal::from_str_unchecked(&fallback.repr)
+ }
+ })
+ } else {
+ Literal::Fallback(fallback::Literal::byte_character(byte))
+ }
+ }
+
+ pub(crate) fn byte_string(bytes: &[u8]) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler(proc_macro::Literal::byte_string(bytes))
+ } else {
+ Literal::Fallback(fallback::Literal::byte_string(bytes))
+ }
+ }
+
+ pub(crate) fn c_string(string: &CStr) -> Literal {
+ if inside_proc_macro() {
+ Literal::Compiler({
+ #[cfg(not(no_literal_c_string))]
+ {
+ proc_macro::Literal::c_string(string)
+ }
+
+ #[cfg(no_literal_c_string)]
+ {
+ let fallback = fallback::Literal::c_string(string);
+ proc_macro::Literal::from_str_unchecked(&fallback.repr)
+ }
+ })
+ } else {
+ Literal::Fallback(fallback::Literal::c_string(string))
+ }
+ }
+
+ pub(crate) fn span(&self) -> Span {
+ match self {
+ Literal::Compiler(lit) => Span::Compiler(lit.span()),
+ Literal::Fallback(lit) => Span::Fallback(lit.span()),
+ }
+ }
+
+ pub(crate) fn set_span(&mut self, span: Span) {
+ match (self, span) {
+ (Literal::Compiler(lit), Span::Compiler(s)) => lit.set_span(s),
+ (Literal::Fallback(lit), Span::Fallback(s)) => lit.set_span(s),
+ (Literal::Compiler(_), Span::Fallback(_)) => mismatch(line!()),
+ (Literal::Fallback(_), Span::Compiler(_)) => mismatch(line!()),
+ }
+ }
+
+ pub(crate) fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
+ match self {
+ #[cfg(proc_macro_span)]
+ Literal::Compiler(lit) => proc_macro_span::subspan(lit, range).map(Span::Compiler),
+ #[cfg(not(proc_macro_span))]
+ Literal::Compiler(_lit) => None,
+ Literal::Fallback(lit) => lit.subspan(range).map(Span::Fallback),
+ }
+ }
+
+ fn unwrap_nightly(self) -> proc_macro::Literal {
+ match self {
+ Literal::Compiler(s) => s,
+ Literal::Fallback(_) => mismatch(line!()),
+ }
+ }
+}
+
+impl From<fallback::Literal> for Literal {
+ fn from(s: fallback::Literal) -> Self {
+ Literal::Fallback(s)
+ }
+}
+
+impl Display for Literal {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Literal::Compiler(t) => Display::fmt(t, f),
+ Literal::Fallback(t) => Display::fmt(t, f),
+ }
+ }
+}
+
+impl Debug for Literal {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Literal::Compiler(t) => Debug::fmt(t, f),
+ Literal::Fallback(t) => Debug::fmt(t, f),
+ }
+ }
+}
+
+#[cfg(span_locations)]
+pub(crate) fn invalidate_current_thread_spans() {
+ if inside_proc_macro() {
+ panic!(
+ "proc_macro2::extra::invalidate_current_thread_spans is not available in procedural macros"
+ );
+ } else {
+ crate::fallback::invalidate_current_thread_spans();
+ }
+}
--
2.51.2
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