#[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; 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::{self, FromStr}; use std::ffi::CStr; #[cfg(procmacro2_semver_exempt)] 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, } #[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 fn new() -> Self { TokenStream { inner: RcVecBuilder::new().build(), } } pub fn is_empty(&self) -> bool { self.inner.len() == 0 } fn take_inner(self) -> RcVecBuilder { let nodrop = ManuallyDrop::new(self); unsafe { ptr::read(&nodrop.inner) }.make_owned() } } fn push_token_from_proc_macro(mut vec: RcVecMut, 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, 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 inner = match self.inner.get_mut() { Some(inner) => inner, None => return, }; while let Some(token) = inner.pop() { 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, }; inner.extend(group.stream.take_inner()); } } } pub(crate) struct TokenStreamBuilder { inner: RcVecBuilder, } impl TokenStreamBuilder { pub fn new() -> Self { TokenStreamBuilder { inner: RcVecBuilder::new(), } } pub fn with_capacity(cap: usize) -> Self { TokenStreamBuilder { inner: RcVecBuilder::with_capacity(cap), } } pub fn push_token_from_parser(&mut self, tt: TokenTree) { self.inner.push(tt); } pub 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 FromStr for TokenStream { type Err = LexError; fn from_str(src: &str) -> Result { // 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) } } 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 for TokenStream { fn from(inner: proc_macro::TokenStream) -> Self { inner .to_string() .parse() .expect("compiler token stream parse failed") } } #[cfg(feature = "proc-macro")] impl From for proc_macro::TokenStream { fn from(inner: TokenStream) -> Self { inner .to_string() .parse() .expect("failed to parse to compiler tokens") } } impl From 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 for TokenStream { fn from_iter>(tokens: I) -> Self { let mut stream = TokenStream::new(); stream.extend(tokens); stream } } impl FromIterator for TokenStream { fn from_iter>(streams: I) -> Self { let mut v = RcVecBuilder::new(); for stream in streams { v.extend(stream.take_inner()); } TokenStream { inner: v.build() } } } impl Extend for TokenStream { fn extend>(&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 for TokenStream { fn extend>(&mut self, streams: I) { self.inner.make_mut().extend(streams.into_iter().flatten()); } } pub(crate) type TokenTreeIter = RcVecIntoIter; impl IntoIterator for TokenStream { type Item = TokenTree; type IntoIter = TokenTreeIter; fn into_iter(self) -> TokenTreeIter { self.take_inner().into_iter() } } #[cfg(procmacro2_semver_exempt)] #[derive(Clone, PartialEq, Eq)] pub(crate) struct SourceFile { path: PathBuf, } #[cfg(procmacro2_semver_exempt)] impl SourceFile { /// Get the path to this source file as a string. pub fn path(&self) -> PathBuf { self.path.clone() } pub fn is_real(&self) -> bool { false } } #[cfg(procmacro2_semver_exempt)] impl Debug for SourceFile { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { f.debug_struct("SourceFile") .field("path", &self.path()) .field("is_real", &self.is_real()) .finish() } } #[cfg(all(span_locations, not(fuzzing)))] thread_local! { static SOURCE_MAP: RefCell = 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, char_index_to_byte_offset: BTreeMap, } #[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 { 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) { 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, } #[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 } #[cfg(procmacro2_semver_exempt)] fn filepath(&self, span: Span) -> PathBuf { for (i, file) in self.files.iter().enumerate() { if file.span_within(span) { return PathBuf::from(if i == 0 { "".to_owned() } else { format!("", i) }); } } unreachable!("Invalid span with no related FileInfo!"); } fn fileinfo(&self, span: Span) -> &FileInfo { for file in &self.files { if file.span_within(span) { return file; } } unreachable!("Invalid span with no related FileInfo!"); } fn fileinfo_mut(&mut self, span: Span) -> &mut FileInfo { for file in &mut self.files { if file.span_within(span) { return file; } } unreachable!("Invalid span with no related FileInfo!"); } } #[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 fn call_site() -> Self { Span {} } #[cfg(span_locations)] pub fn call_site() -> Self { Span { lo: 0, hi: 0 } } pub fn mixed_site() -> Self { Span::call_site() } #[cfg(procmacro2_semver_exempt)] pub fn def_site() -> Self { Span::call_site() } pub 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 fn located_at(&self, other: Span) -> Span { other } #[cfg(procmacro2_semver_exempt)] pub fn source_file(&self) -> SourceFile { #[cfg(fuzzing)] return SourceFile { path: PathBuf::from(""), }; #[cfg(not(fuzzing))] SOURCE_MAP.with(|sm| { let sm = sm.borrow(); let path = sm.filepath(*self); SourceFile { path } }) } #[cfg(span_locations)] pub fn byte_range(&self) -> Range { #[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 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 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(not(span_locations))] pub fn join(&self, _other: Span) -> Option { Some(Span {}) } #[cfg(span_locations)] pub fn join(&self, other: Span) -> Option { #[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 fn source_text(&self) -> Option { None } #[cfg(span_locations)] pub fn source_text(&self) -> Option { #[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 fn new(delimiter: Delimiter, stream: TokenStream) -> Self { Group { delimiter, stream, span: Span::call_site(), } } pub fn delimiter(&self) -> Delimiter { self.delimiter } pub fn stream(&self) -> TokenStream { self.stream.clone() } pub fn span(&self) -> Span { self.span } pub fn span_open(&self) -> Span { self.span.first_byte() } pub fn span_close(&self) -> Span { self.span.last_byte() } pub 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: String, span: Span, raw: bool, } impl Ident { #[track_caller] pub fn new_checked(string: &str, span: Span) -> Self { validate_ident(string); Ident::new_unchecked(string, span) } pub fn new_unchecked(string: &str, span: Span) -> Self { Ident { sym: string.to_owned(), span, raw: false, } } #[track_caller] pub fn new_raw_checked(string: &str, span: Span) -> Self { validate_ident_raw(string); Ident::new_raw_unchecked(string, span) } pub fn new_raw_unchecked(string: &str, span: Span) -> Self { Ident { sym: string.to_owned(), span, raw: true, } } pub fn span(&self) -> Span { self.span } pub 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"); } 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 PartialEq for Ident where T: ?Sized + AsRef, { 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 fn $name(n: $kind) -> Literal { Literal::_new(format!(concat!("{}", stringify!($kind)), n)) } )*) } macro_rules! unsuffixed_numbers { ($($name:ident => $kind:ident,)*) => ($( pub 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) 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 fn f32_unsuffixed(f: f32) -> Literal { let mut s = f.to_string(); if !s.contains('.') { s.push_str(".0"); } Literal::_new(s) } pub fn f64_unsuffixed(f: f64) -> Literal { let mut s = f.to_string(); if !s.contains('.') { s.push_str(".0"); } Literal::_new(s) } pub 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 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 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 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 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 fn span(&self) -> Span { self.span } pub fn set_span(&mut self, span: Span) { self.span = span; } pub fn subspan>(&self, range: R) -> Option { #[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 FromStr for Literal { type Err = LexError; fn from_str(repr: &str) -> Result { 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()) } } 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()); } } }