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-rw-r--r--compiler/rustc_expand/src/proc_macro_server.rs766
1 files changed, 766 insertions, 0 deletions
diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
new file mode 100644
index 000000000..7d9a4aed0
--- /dev/null
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -0,0 +1,766 @@
+use crate::base::ExtCtxt;
+
+use rustc_ast as ast;
+use rustc_ast::token;
+use rustc_ast::tokenstream::{self, Spacing::*, TokenStream};
+use rustc_ast_pretty::pprust;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::sync::Lrc;
+use rustc_errors::{Diagnostic, MultiSpan, PResult};
+use rustc_parse::lexer::nfc_normalize;
+use rustc_parse::parse_stream_from_source_str;
+use rustc_session::parse::ParseSess;
+use rustc_span::def_id::CrateNum;
+use rustc_span::symbol::{self, sym, Symbol};
+use rustc_span::{BytePos, FileName, Pos, SourceFile, Span};
+
+use pm::bridge::{
+ server, DelimSpan, ExpnGlobals, Group, Ident, LitKind, Literal, Punct, TokenTree,
+};
+use pm::{Delimiter, Level, LineColumn};
+use std::ops::Bound;
+
+trait FromInternal<T> {
+ fn from_internal(x: T) -> Self;
+}
+
+trait ToInternal<T> {
+ fn to_internal(self) -> T;
+}
+
+impl FromInternal<token::Delimiter> for Delimiter {
+ fn from_internal(delim: token::Delimiter) -> Delimiter {
+ match delim {
+ token::Delimiter::Parenthesis => Delimiter::Parenthesis,
+ token::Delimiter::Brace => Delimiter::Brace,
+ token::Delimiter::Bracket => Delimiter::Bracket,
+ token::Delimiter::Invisible => Delimiter::None,
+ }
+ }
+}
+
+impl ToInternal<token::Delimiter> for Delimiter {
+ fn to_internal(self) -> token::Delimiter {
+ match self {
+ Delimiter::Parenthesis => token::Delimiter::Parenthesis,
+ Delimiter::Brace => token::Delimiter::Brace,
+ Delimiter::Bracket => token::Delimiter::Bracket,
+ Delimiter::None => token::Delimiter::Invisible,
+ }
+ }
+}
+
+impl FromInternal<token::LitKind> for LitKind {
+ fn from_internal(kind: token::LitKind) -> Self {
+ match kind {
+ token::Byte => LitKind::Byte,
+ token::Char => LitKind::Char,
+ token::Integer => LitKind::Integer,
+ token::Float => LitKind::Float,
+ token::Str => LitKind::Str,
+ token::StrRaw(n) => LitKind::StrRaw(n),
+ token::ByteStr => LitKind::ByteStr,
+ token::ByteStrRaw(n) => LitKind::ByteStrRaw(n),
+ token::Err => LitKind::Err,
+ token::Bool => unreachable!(),
+ }
+ }
+}
+
+impl ToInternal<token::LitKind> for LitKind {
+ fn to_internal(self) -> token::LitKind {
+ match self {
+ LitKind::Byte => token::Byte,
+ LitKind::Char => token::Char,
+ LitKind::Integer => token::Integer,
+ LitKind::Float => token::Float,
+ LitKind::Str => token::Str,
+ LitKind::StrRaw(n) => token::StrRaw(n),
+ LitKind::ByteStr => token::ByteStr,
+ LitKind::ByteStrRaw(n) => token::ByteStrRaw(n),
+ LitKind::Err => token::Err,
+ }
+ }
+}
+
+impl FromInternal<(TokenStream, &mut Rustc<'_, '_>)> for Vec<TokenTree<TokenStream, Span, Symbol>> {
+ fn from_internal((stream, rustc): (TokenStream, &mut Rustc<'_, '_>)) -> Self {
+ use rustc_ast::token::*;
+
+ // Estimate the capacity as `stream.len()` rounded up to the next power
+ // of two to limit the number of required reallocations.
+ let mut trees = Vec::with_capacity(stream.len().next_power_of_two());
+ let mut cursor = stream.into_trees();
+
+ while let Some(tree) = cursor.next() {
+ let (Token { kind, span }, joint) = match tree {
+ tokenstream::TokenTree::Delimited(span, delim, tts) => {
+ let delimiter = pm::Delimiter::from_internal(delim);
+ trees.push(TokenTree::Group(Group {
+ delimiter,
+ stream: Some(tts),
+ span: DelimSpan {
+ open: span.open,
+ close: span.close,
+ entire: span.entire(),
+ },
+ }));
+ continue;
+ }
+ tokenstream::TokenTree::Token(token, spacing) => (token, spacing == Joint),
+ };
+
+ let mut op = |s: &str| {
+ assert!(s.is_ascii());
+ trees.extend(s.as_bytes().iter().enumerate().map(|(idx, &ch)| {
+ TokenTree::Punct(Punct { ch, joint: joint || idx != s.len() - 1, span })
+ }));
+ };
+
+ match kind {
+ Eq => op("="),
+ Lt => op("<"),
+ Le => op("<="),
+ EqEq => op("=="),
+ Ne => op("!="),
+ Ge => op(">="),
+ Gt => op(">"),
+ AndAnd => op("&&"),
+ OrOr => op("||"),
+ Not => op("!"),
+ Tilde => op("~"),
+ BinOp(Plus) => op("+"),
+ BinOp(Minus) => op("-"),
+ BinOp(Star) => op("*"),
+ BinOp(Slash) => op("/"),
+ BinOp(Percent) => op("%"),
+ BinOp(Caret) => op("^"),
+ BinOp(And) => op("&"),
+ BinOp(Or) => op("|"),
+ BinOp(Shl) => op("<<"),
+ BinOp(Shr) => op(">>"),
+ BinOpEq(Plus) => op("+="),
+ BinOpEq(Minus) => op("-="),
+ BinOpEq(Star) => op("*="),
+ BinOpEq(Slash) => op("/="),
+ BinOpEq(Percent) => op("%="),
+ BinOpEq(Caret) => op("^="),
+ BinOpEq(And) => op("&="),
+ BinOpEq(Or) => op("|="),
+ BinOpEq(Shl) => op("<<="),
+ BinOpEq(Shr) => op(">>="),
+ At => op("@"),
+ Dot => op("."),
+ DotDot => op(".."),
+ DotDotDot => op("..."),
+ DotDotEq => op("..="),
+ Comma => op(","),
+ Semi => op(";"),
+ Colon => op(":"),
+ ModSep => op("::"),
+ RArrow => op("->"),
+ LArrow => op("<-"),
+ FatArrow => op("=>"),
+ Pound => op("#"),
+ Dollar => op("$"),
+ Question => op("?"),
+ SingleQuote => op("'"),
+
+ Ident(sym, is_raw) => trees.push(TokenTree::Ident(Ident { sym, is_raw, span })),
+ Lifetime(name) => {
+ let ident = symbol::Ident::new(name, span).without_first_quote();
+ trees.extend([
+ TokenTree::Punct(Punct { ch: b'\'', joint: true, span }),
+ TokenTree::Ident(Ident { sym: ident.name, is_raw: false, span }),
+ ]);
+ }
+ Literal(token::Lit { kind, symbol, suffix }) => {
+ trees.push(TokenTree::Literal(self::Literal {
+ kind: FromInternal::from_internal(kind),
+ symbol,
+ suffix,
+ span,
+ }));
+ }
+ DocComment(_, attr_style, data) => {
+ let mut escaped = String::new();
+ for ch in data.as_str().chars() {
+ escaped.extend(ch.escape_debug());
+ }
+ let stream = [
+ Ident(sym::doc, false),
+ Eq,
+ TokenKind::lit(token::Str, Symbol::intern(&escaped), None),
+ ]
+ .into_iter()
+ .map(|kind| tokenstream::TokenTree::token_alone(kind, span))
+ .collect();
+ trees.push(TokenTree::Punct(Punct { ch: b'#', joint: false, span }));
+ if attr_style == ast::AttrStyle::Inner {
+ trees.push(TokenTree::Punct(Punct { ch: b'!', joint: false, span }));
+ }
+ trees.push(TokenTree::Group(Group {
+ delimiter: pm::Delimiter::Bracket,
+ stream: Some(stream),
+ span: DelimSpan::from_single(span),
+ }));
+ }
+
+ Interpolated(nt) if let NtIdent(ident, is_raw) = *nt => {
+ trees.push(TokenTree::Ident(Ident { sym: ident.name, is_raw, span: ident.span }))
+ }
+
+ Interpolated(nt) => {
+ let stream = TokenStream::from_nonterminal_ast(&nt);
+ // A hack used to pass AST fragments to attribute and derive
+ // macros as a single nonterminal token instead of a token
+ // stream. Such token needs to be "unwrapped" and not
+ // represented as a delimited group.
+ // FIXME: It needs to be removed, but there are some
+ // compatibility issues (see #73345).
+ if crate::base::nt_pretty_printing_compatibility_hack(&nt, rustc.sess()) {
+ trees.extend(Self::from_internal((stream, rustc)));
+ } else {
+ trees.push(TokenTree::Group(Group {
+ delimiter: pm::Delimiter::None,
+ stream: Some(stream),
+ span: DelimSpan::from_single(span),
+ }))
+ }
+ }
+
+ OpenDelim(..) | CloseDelim(..) => unreachable!(),
+ Eof => unreachable!(),
+ }
+ }
+ trees
+ }
+}
+
+impl ToInternal<TokenStream> for (TokenTree<TokenStream, Span, Symbol>, &mut Rustc<'_, '_>) {
+ fn to_internal(self) -> TokenStream {
+ use rustc_ast::token::*;
+
+ let (tree, rustc) = self;
+ let (ch, joint, span) = match tree {
+ TokenTree::Punct(Punct { ch, joint, span }) => (ch, joint, span),
+ TokenTree::Group(Group { delimiter, stream, span: DelimSpan { open, close, .. } }) => {
+ return tokenstream::TokenStream::delimited(
+ tokenstream::DelimSpan { open, close },
+ delimiter.to_internal(),
+ stream.unwrap_or_default(),
+ );
+ }
+ TokenTree::Ident(self::Ident { sym, is_raw, span }) => {
+ rustc.sess().symbol_gallery.insert(sym, span);
+ return tokenstream::TokenStream::token_alone(Ident(sym, is_raw), span);
+ }
+ TokenTree::Literal(self::Literal {
+ kind: self::LitKind::Integer,
+ symbol,
+ suffix,
+ span,
+ }) if symbol.as_str().starts_with('-') => {
+ let minus = BinOp(BinOpToken::Minus);
+ let symbol = Symbol::intern(&symbol.as_str()[1..]);
+ let integer = TokenKind::lit(token::Integer, symbol, suffix);
+ let a = tokenstream::TokenTree::token_alone(minus, span);
+ let b = tokenstream::TokenTree::token_alone(integer, span);
+ return [a, b].into_iter().collect();
+ }
+ TokenTree::Literal(self::Literal {
+ kind: self::LitKind::Float,
+ symbol,
+ suffix,
+ span,
+ }) if symbol.as_str().starts_with('-') => {
+ let minus = BinOp(BinOpToken::Minus);
+ let symbol = Symbol::intern(&symbol.as_str()[1..]);
+ let float = TokenKind::lit(token::Float, symbol, suffix);
+ let a = tokenstream::TokenTree::token_alone(minus, span);
+ let b = tokenstream::TokenTree::token_alone(float, span);
+ return [a, b].into_iter().collect();
+ }
+ TokenTree::Literal(self::Literal { kind, symbol, suffix, span }) => {
+ return tokenstream::TokenStream::token_alone(
+ TokenKind::lit(kind.to_internal(), symbol, suffix),
+ span,
+ );
+ }
+ };
+
+ let kind = match ch {
+ b'=' => Eq,
+ b'<' => Lt,
+ b'>' => Gt,
+ b'!' => Not,
+ b'~' => Tilde,
+ b'+' => BinOp(Plus),
+ b'-' => BinOp(Minus),
+ b'*' => BinOp(Star),
+ b'/' => BinOp(Slash),
+ b'%' => BinOp(Percent),
+ b'^' => BinOp(Caret),
+ b'&' => BinOp(And),
+ b'|' => BinOp(Or),
+ b'@' => At,
+ b'.' => Dot,
+ b',' => Comma,
+ b';' => Semi,
+ b':' => Colon,
+ b'#' => Pound,
+ b'$' => Dollar,
+ b'?' => Question,
+ b'\'' => SingleQuote,
+ _ => unreachable!(),
+ };
+
+ if joint {
+ tokenstream::TokenStream::token_joint(kind, span)
+ } else {
+ tokenstream::TokenStream::token_alone(kind, span)
+ }
+ }
+}
+
+impl ToInternal<rustc_errors::Level> for Level {
+ fn to_internal(self) -> rustc_errors::Level {
+ match self {
+ Level::Error => rustc_errors::Level::Error { lint: false },
+ Level::Warning => rustc_errors::Level::Warning(None),
+ Level::Note => rustc_errors::Level::Note,
+ Level::Help => rustc_errors::Level::Help,
+ _ => unreachable!("unknown proc_macro::Level variant: {:?}", self),
+ }
+ }
+}
+
+pub struct FreeFunctions;
+
+pub(crate) struct Rustc<'a, 'b> {
+ ecx: &'a mut ExtCtxt<'b>,
+ def_site: Span,
+ call_site: Span,
+ mixed_site: Span,
+ krate: CrateNum,
+ rebased_spans: FxHashMap<usize, Span>,
+}
+
+impl<'a, 'b> Rustc<'a, 'b> {
+ pub fn new(ecx: &'a mut ExtCtxt<'b>) -> Self {
+ let expn_data = ecx.current_expansion.id.expn_data();
+ Rustc {
+ def_site: ecx.with_def_site_ctxt(expn_data.def_site),
+ call_site: ecx.with_call_site_ctxt(expn_data.call_site),
+ mixed_site: ecx.with_mixed_site_ctxt(expn_data.call_site),
+ krate: expn_data.macro_def_id.unwrap().krate,
+ rebased_spans: FxHashMap::default(),
+ ecx,
+ }
+ }
+
+ fn sess(&self) -> &ParseSess {
+ self.ecx.parse_sess()
+ }
+}
+
+impl server::Types for Rustc<'_, '_> {
+ type FreeFunctions = FreeFunctions;
+ type TokenStream = TokenStream;
+ type SourceFile = Lrc<SourceFile>;
+ type MultiSpan = Vec<Span>;
+ type Diagnostic = Diagnostic;
+ type Span = Span;
+ type Symbol = Symbol;
+}
+
+impl server::FreeFunctions for Rustc<'_, '_> {
+ fn track_env_var(&mut self, var: &str, value: Option<&str>) {
+ self.sess()
+ .env_depinfo
+ .borrow_mut()
+ .insert((Symbol::intern(var), value.map(Symbol::intern)));
+ }
+
+ fn track_path(&mut self, path: &str) {
+ self.sess().file_depinfo.borrow_mut().insert(Symbol::intern(path));
+ }
+
+ fn literal_from_str(&mut self, s: &str) -> Result<Literal<Self::Span, Self::Symbol>, ()> {
+ let name = FileName::proc_macro_source_code(s);
+ let mut parser = rustc_parse::new_parser_from_source_str(self.sess(), name, s.to_owned());
+
+ let first_span = parser.token.span.data();
+ let minus_present = parser.eat(&token::BinOp(token::Minus));
+
+ let lit_span = parser.token.span.data();
+ let token::Literal(mut lit) = parser.token.kind else {
+ return Err(());
+ };
+
+ // Check no comment or whitespace surrounding the (possibly negative)
+ // literal, or more tokens after it.
+ if (lit_span.hi.0 - first_span.lo.0) as usize != s.len() {
+ return Err(());
+ }
+
+ if minus_present {
+ // If minus is present, check no comment or whitespace in between it
+ // and the literal token.
+ if first_span.hi.0 != lit_span.lo.0 {
+ return Err(());
+ }
+
+ // Check literal is a kind we allow to be negated in a proc macro token.
+ match lit.kind {
+ token::LitKind::Bool
+ | token::LitKind::Byte
+ | token::LitKind::Char
+ | token::LitKind::Str
+ | token::LitKind::StrRaw(_)
+ | token::LitKind::ByteStr
+ | token::LitKind::ByteStrRaw(_)
+ | token::LitKind::Err => return Err(()),
+ token::LitKind::Integer | token::LitKind::Float => {}
+ }
+
+ // Synthesize a new symbol that includes the minus sign.
+ let symbol = Symbol::intern(&s[..1 + lit.symbol.as_str().len()]);
+ lit = token::Lit::new(lit.kind, symbol, lit.suffix);
+ }
+ let token::Lit { kind, symbol, suffix } = lit;
+ Ok(Literal {
+ kind: FromInternal::from_internal(kind),
+ symbol,
+ suffix,
+ span: self.call_site,
+ })
+ }
+}
+
+impl server::TokenStream for Rustc<'_, '_> {
+ fn is_empty(&mut self, stream: &Self::TokenStream) -> bool {
+ stream.is_empty()
+ }
+
+ fn from_str(&mut self, src: &str) -> Self::TokenStream {
+ parse_stream_from_source_str(
+ FileName::proc_macro_source_code(src),
+ src.to_string(),
+ self.sess(),
+ Some(self.call_site),
+ )
+ }
+
+ fn to_string(&mut self, stream: &Self::TokenStream) -> String {
+ pprust::tts_to_string(stream)
+ }
+
+ fn expand_expr(&mut self, stream: &Self::TokenStream) -> Result<Self::TokenStream, ()> {
+ // Parse the expression from our tokenstream.
+ let expr: PResult<'_, _> = try {
+ let mut p = rustc_parse::stream_to_parser(
+ self.sess(),
+ stream.clone(),
+ Some("proc_macro expand expr"),
+ );
+ let expr = p.parse_expr()?;
+ if p.token != token::Eof {
+ p.unexpected()?;
+ }
+ expr
+ };
+ let expr = expr.map_err(|mut err| {
+ err.emit();
+ })?;
+
+ // Perform eager expansion on the expression.
+ let expr = self
+ .ecx
+ .expander()
+ .fully_expand_fragment(crate::expand::AstFragment::Expr(expr))
+ .make_expr();
+
+ // NOTE: For now, limit `expand_expr` to exclusively expand to literals.
+ // This may be relaxed in the future.
+ // We don't use `TokenStream::from_ast` as the tokenstream currently cannot
+ // be recovered in the general case.
+ match &expr.kind {
+ ast::ExprKind::Lit(l) if l.token.kind == token::Bool => Ok(
+ tokenstream::TokenStream::token_alone(token::Ident(l.token.symbol, false), l.span),
+ ),
+ ast::ExprKind::Lit(l) => {
+ Ok(tokenstream::TokenStream::token_alone(token::Literal(l.token), l.span))
+ }
+ ast::ExprKind::Unary(ast::UnOp::Neg, e) => match &e.kind {
+ ast::ExprKind::Lit(l) => match l.token {
+ token::Lit { kind: token::Integer | token::Float, .. } => {
+ Ok(Self::TokenStream::from_iter([
+ // FIXME: The span of the `-` token is lost when
+ // parsing, so we cannot faithfully recover it here.
+ tokenstream::TokenTree::token_alone(token::BinOp(token::Minus), e.span),
+ tokenstream::TokenTree::token_alone(token::Literal(l.token), l.span),
+ ]))
+ }
+ _ => Err(()),
+ },
+ _ => Err(()),
+ },
+ _ => Err(()),
+ }
+ }
+
+ fn from_token_tree(
+ &mut self,
+ tree: TokenTree<Self::TokenStream, Self::Span, Self::Symbol>,
+ ) -> Self::TokenStream {
+ (tree, &mut *self).to_internal()
+ }
+
+ fn concat_trees(
+ &mut self,
+ base: Option<Self::TokenStream>,
+ trees: Vec<TokenTree<Self::TokenStream, Self::Span, Self::Symbol>>,
+ ) -> Self::TokenStream {
+ let mut builder = tokenstream::TokenStreamBuilder::new();
+ if let Some(base) = base {
+ builder.push(base);
+ }
+ for tree in trees {
+ builder.push((tree, &mut *self).to_internal());
+ }
+ builder.build()
+ }
+
+ fn concat_streams(
+ &mut self,
+ base: Option<Self::TokenStream>,
+ streams: Vec<Self::TokenStream>,
+ ) -> Self::TokenStream {
+ let mut builder = tokenstream::TokenStreamBuilder::new();
+ if let Some(base) = base {
+ builder.push(base);
+ }
+ for stream in streams {
+ builder.push(stream);
+ }
+ builder.build()
+ }
+
+ fn into_trees(
+ &mut self,
+ stream: Self::TokenStream,
+ ) -> Vec<TokenTree<Self::TokenStream, Self::Span, Self::Symbol>> {
+ FromInternal::from_internal((stream, self))
+ }
+}
+
+impl server::SourceFile for Rustc<'_, '_> {
+ fn eq(&mut self, file1: &Self::SourceFile, file2: &Self::SourceFile) -> bool {
+ Lrc::ptr_eq(file1, file2)
+ }
+
+ fn path(&mut self, file: &Self::SourceFile) -> String {
+ match file.name {
+ FileName::Real(ref name) => name
+ .local_path()
+ .expect("attempting to get a file path in an imported file in `proc_macro::SourceFile::path`")
+ .to_str()
+ .expect("non-UTF8 file path in `proc_macro::SourceFile::path`")
+ .to_string(),
+ _ => file.name.prefer_local().to_string(),
+ }
+ }
+
+ fn is_real(&mut self, file: &Self::SourceFile) -> bool {
+ file.is_real_file()
+ }
+}
+
+impl server::MultiSpan for Rustc<'_, '_> {
+ fn new(&mut self) -> Self::MultiSpan {
+ vec![]
+ }
+
+ fn push(&mut self, spans: &mut Self::MultiSpan, span: Self::Span) {
+ spans.push(span)
+ }
+}
+
+impl server::Diagnostic for Rustc<'_, '_> {
+ fn new(&mut self, level: Level, msg: &str, spans: Self::MultiSpan) -> Self::Diagnostic {
+ let mut diag = Diagnostic::new(level.to_internal(), msg);
+ diag.set_span(MultiSpan::from_spans(spans));
+ diag
+ }
+
+ fn sub(
+ &mut self,
+ diag: &mut Self::Diagnostic,
+ level: Level,
+ msg: &str,
+ spans: Self::MultiSpan,
+ ) {
+ diag.sub(level.to_internal(), msg, MultiSpan::from_spans(spans), None);
+ }
+
+ fn emit(&mut self, mut diag: Self::Diagnostic) {
+ self.sess().span_diagnostic.emit_diagnostic(&mut diag);
+ }
+}
+
+impl server::Span for Rustc<'_, '_> {
+ fn debug(&mut self, span: Self::Span) -> String {
+ if self.ecx.ecfg.span_debug {
+ format!("{:?}", span)
+ } else {
+ format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0)
+ }
+ }
+
+ fn source_file(&mut self, span: Self::Span) -> Self::SourceFile {
+ self.sess().source_map().lookup_char_pos(span.lo()).file
+ }
+
+ fn parent(&mut self, span: Self::Span) -> Option<Self::Span> {
+ span.parent_callsite()
+ }
+
+ fn source(&mut self, span: Self::Span) -> Self::Span {
+ span.source_callsite()
+ }
+
+ fn start(&mut self, span: Self::Span) -> LineColumn {
+ let loc = self.sess().source_map().lookup_char_pos(span.lo());
+ LineColumn { line: loc.line, column: loc.col.to_usize() }
+ }
+
+ fn end(&mut self, span: Self::Span) -> LineColumn {
+ let loc = self.sess().source_map().lookup_char_pos(span.hi());
+ LineColumn { line: loc.line, column: loc.col.to_usize() }
+ }
+
+ fn before(&mut self, span: Self::Span) -> Self::Span {
+ span.shrink_to_lo()
+ }
+
+ fn after(&mut self, span: Self::Span) -> Self::Span {
+ span.shrink_to_hi()
+ }
+
+ fn join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {
+ let self_loc = self.sess().source_map().lookup_char_pos(first.lo());
+ let other_loc = self.sess().source_map().lookup_char_pos(second.lo());
+
+ if self_loc.file.name != other_loc.file.name {
+ return None;
+ }
+
+ Some(first.to(second))
+ }
+
+ fn subspan(
+ &mut self,
+ span: Self::Span,
+ start: Bound<usize>,
+ end: Bound<usize>,
+ ) -> Option<Self::Span> {
+ let length = span.hi().to_usize() - span.lo().to_usize();
+
+ let start = match start {
+ Bound::Included(lo) => lo,
+ Bound::Excluded(lo) => lo.checked_add(1)?,
+ Bound::Unbounded => 0,
+ };
+
+ let end = match end {
+ Bound::Included(hi) => hi.checked_add(1)?,
+ Bound::Excluded(hi) => hi,
+ Bound::Unbounded => length,
+ };
+
+ // Bounds check the values, preventing addition overflow and OOB spans.
+ if start > u32::MAX as usize
+ || end > u32::MAX as usize
+ || (u32::MAX - start as u32) < span.lo().to_u32()
+ || (u32::MAX - end as u32) < span.lo().to_u32()
+ || start >= end
+ || end > length
+ {
+ return None;
+ }
+
+ let new_lo = span.lo() + BytePos::from_usize(start);
+ let new_hi = span.lo() + BytePos::from_usize(end);
+ Some(span.with_lo(new_lo).with_hi(new_hi))
+ }
+
+ fn resolved_at(&mut self, span: Self::Span, at: Self::Span) -> Self::Span {
+ span.with_ctxt(at.ctxt())
+ }
+
+ fn source_text(&mut self, span: Self::Span) -> Option<String> {
+ self.sess().source_map().span_to_snippet(span).ok()
+ }
+ /// Saves the provided span into the metadata of
+ /// *the crate we are currently compiling*, which must
+ /// be a proc-macro crate. This id can be passed to
+ /// `recover_proc_macro_span` when our current crate
+ /// is *run* as a proc-macro.
+ ///
+ /// Let's suppose that we have two crates - `my_client`
+ /// and `my_proc_macro`. The `my_proc_macro` crate
+ /// contains a procedural macro `my_macro`, which
+ /// is implemented as: `quote! { "hello" }`
+ ///
+ /// When we *compile* `my_proc_macro`, we will execute
+ /// the `quote` proc-macro. This will save the span of
+ /// "hello" into the metadata of `my_proc_macro`. As a result,
+ /// the body of `my_proc_macro` (after expansion) will end
+ /// up containing a call that looks like this:
+ /// `proc_macro::Ident::new("hello", proc_macro::Span::recover_proc_macro_span(0))`
+ ///
+ /// where `0` is the id returned by this function.
+ /// When `my_proc_macro` *executes* (during the compilation of `my_client`),
+ /// the call to `recover_proc_macro_span` will load the corresponding
+ /// span from the metadata of `my_proc_macro` (which we have access to,
+ /// since we've loaded `my_proc_macro` from disk in order to execute it).
+ /// In this way, we have obtained a span pointing into `my_proc_macro`
+ fn save_span(&mut self, span: Self::Span) -> usize {
+ self.sess().save_proc_macro_span(span)
+ }
+
+ fn recover_proc_macro_span(&mut self, id: usize) -> Self::Span {
+ let (resolver, krate, def_site) = (&*self.ecx.resolver, self.krate, self.def_site);
+ *self.rebased_spans.entry(id).or_insert_with(|| {
+ // FIXME: `SyntaxContext` for spans from proc macro crates is lost during encoding,
+ // replace it with a def-site context until we are encoding it properly.
+ resolver.get_proc_macro_quoted_span(krate, id).with_ctxt(def_site.ctxt())
+ })
+ }
+}
+
+impl server::Symbol for Rustc<'_, '_> {
+ fn normalize_and_validate_ident(&mut self, string: &str) -> Result<Self::Symbol, ()> {
+ let sym = nfc_normalize(string);
+ if rustc_lexer::is_ident(sym.as_str()) { Ok(sym) } else { Err(()) }
+ }
+}
+
+impl server::Server for Rustc<'_, '_> {
+ fn globals(&mut self) -> ExpnGlobals<Self::Span> {
+ ExpnGlobals {
+ def_site: self.def_site,
+ call_site: self.call_site,
+ mixed_site: self.mixed_site,
+ }
+ }
+
+ fn intern_symbol(string: &str) -> Self::Symbol {
+ Symbol::intern(string)
+ }
+
+ fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str)) {
+ f(&symbol.as_str())
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 19:28:47 +0000