Merge commit 'aa9bc86125' into sync-from-ra

crates/proc-macro-srv/src/server.rs

@@ -0,0 +1,485 @@
+//! proc-macro server implementation
+//!
+//! Based on idea from <https://github.com/fedochet/rust-proc-macro-expander>
+//! The lib-proc-macro server backend is `TokenStream`-agnostic, such that
+//! we could provide any TokenStream implementation.
+//! The original idea from fedochet is using proc-macro2 as backend,
+//! we use tt instead for better integration with RA.
+//!
+//! FIXME: No span and source file information is implemented yet
+
+use proc_macro::{
+    bridge::{self, server},
+    LineColumn,
+};
+
+mod token_stream;
+pub use token_stream::TokenStream;
+use token_stream::TokenStreamBuilder;
+
+mod symbol;
+pub use symbol::*;
+
+use std::ops::{Bound, Range};
+
+use crate::tt;
+
+type Group = tt::Subtree;
+type TokenTree = tt::TokenTree;
+#[allow(unused)]
+type Punct = tt::Punct;
+type Spacing = tt::Spacing;
+#[allow(unused)]
+type Literal = tt::Literal;
+type Span = tt::TokenId;
+
+#[derive(Clone)]
+pub struct SourceFile {
+    // FIXME stub
+}
+
+pub struct FreeFunctions;
+
+pub struct RustAnalyzer {
+    // FIXME: store span information here.
+    pub(crate) interner: SymbolInternerRef,
+}
+
+impl server::Types for RustAnalyzer {
+    type FreeFunctions = FreeFunctions;
+    type TokenStream = TokenStream;
+    type SourceFile = SourceFile;
+    type Span = Span;
+    type Symbol = Symbol;
+}
+
+impl server::FreeFunctions for RustAnalyzer {
+    fn track_env_var(&mut self, _var: &str, _value: Option<&str>) {
+        // FIXME: track env var accesses
+        // https://github.com/rust-lang/rust/pull/71858
+    }
+    fn track_path(&mut self, _path: &str) {}
+
+    fn literal_from_str(
+        &mut self,
+        s: &str,
+    ) -> Result<bridge::Literal<Self::Span, Self::Symbol>, ()> {
+        // FIXME: keep track of LitKind and Suffix
+        Ok(bridge::Literal {
+            kind: bridge::LitKind::Err,
+            symbol: Symbol::intern(self.interner, s),
+            suffix: None,
+            span: tt::TokenId::unspecified(),
+        })
+    }
+
+    fn emit_diagnostic(&mut self, _: bridge::Diagnostic<Self::Span>) {
+        // FIXME handle diagnostic
+    }
+}
+
+impl server::TokenStream for RustAnalyzer {
+    fn is_empty(&mut self, stream: &Self::TokenStream) -> bool {
+        stream.is_empty()
+    }
+    fn from_str(&mut self, src: &str) -> Self::TokenStream {
+        use std::str::FromStr;
+
+        Self::TokenStream::from_str(src).expect("cannot parse string")
+    }
+    fn to_string(&mut self, stream: &Self::TokenStream) -> String {
+        stream.to_string()
+    }
+    fn from_token_tree(
+        &mut self,
+        tree: bridge::TokenTree<Self::TokenStream, Self::Span, Self::Symbol>,
+    ) -> Self::TokenStream {
+        match tree {
+            bridge::TokenTree::Group(group) => {
+                let group = Group {
+                    delimiter: delim_to_internal(group.delimiter),
+                    token_trees: match group.stream {
+                        Some(stream) => stream.into_iter().collect(),
+                        None => Vec::new(),
+                    },
+                };
+                let tree = TokenTree::from(group);
+                Self::TokenStream::from_iter(vec![tree])
+            }
+
+            bridge::TokenTree::Ident(ident) => {
+                let text = ident.sym.text(self.interner);
+                let text =
+                    if ident.is_raw { ::tt::SmolStr::from_iter(["r#", &text]) } else { text };
+                let ident: tt::Ident = tt::Ident { text, span: ident.span };
+                let leaf = tt::Leaf::from(ident);
+                let tree = TokenTree::from(leaf);
+                Self::TokenStream::from_iter(vec![tree])
+            }
+
+            bridge::TokenTree::Literal(literal) => {
+                let literal = LiteralFormatter(literal);
+                let text = literal.with_stringify_parts(self.interner, |parts| {
+                    ::tt::SmolStr::from_iter(parts.iter().copied())
+                });
+
+                let literal = tt::Literal { text, span: literal.0.span };
+                let leaf = tt::Leaf::from(literal);
+                let tree = TokenTree::from(leaf);
+                Self::TokenStream::from_iter(vec![tree])
+            }
+
+            bridge::TokenTree::Punct(p) => {
+                let punct = tt::Punct {
+                    char: p.ch as char,
+                    spacing: if p.joint { Spacing::Joint } else { Spacing::Alone },
+                    span: p.span,
+                };
+                let leaf = tt::Leaf::from(punct);
+                let tree = TokenTree::from(leaf);
+                Self::TokenStream::from_iter(vec![tree])
+            }
+        }
+    }
+
+    fn expand_expr(&mut self, self_: &Self::TokenStream) -> Result<Self::TokenStream, ()> {
+        Ok(self_.clone())
+    }
+
+    fn concat_trees(
+        &mut self,
+        base: Option<Self::TokenStream>,
+        trees: Vec<bridge::TokenTree<Self::TokenStream, Self::Span, Self::Symbol>>,
+    ) -> Self::TokenStream {
+        let mut builder = TokenStreamBuilder::new();
+        if let Some(base) = base {
+            builder.push(base);
+        }
+        for tree in trees {
+            builder.push(self.from_token_tree(tree));
+        }
+        builder.build()
+    }
+
+    fn concat_streams(
+        &mut self,
+        base: Option<Self::TokenStream>,
+        streams: Vec<Self::TokenStream>,
+    ) -> Self::TokenStream {
+        let mut builder = 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<bridge::TokenTree<Self::TokenStream, Self::Span, Self::Symbol>> {
+        stream
+            .into_iter()
+            .map(|tree| match tree {
+                tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => {
+                    bridge::TokenTree::Ident(bridge::Ident {
+                        sym: Symbol::intern(self.interner, ident.text.trim_start_matches("r#")),
+                        is_raw: ident.text.starts_with("r#"),
+                        span: ident.span,
+                    })
+                }
+                tt::TokenTree::Leaf(tt::Leaf::Literal(lit)) => {
+                    bridge::TokenTree::Literal(bridge::Literal {
+                        // FIXME: handle literal kinds
+                        kind: bridge::LitKind::Err,
+                        symbol: Symbol::intern(self.interner, &lit.text),
+                        // FIXME: handle suffixes
+                        suffix: None,
+                        span: lit.span,
+                    })
+                }
+                tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) => {
+                    bridge::TokenTree::Punct(bridge::Punct {
+                        ch: punct.char as u8,
+                        joint: punct.spacing == Spacing::Joint,
+                        span: punct.span,
+                    })
+                }
+                tt::TokenTree::Subtree(subtree) => bridge::TokenTree::Group(bridge::Group {
+                    delimiter: delim_to_external(subtree.delimiter),
+                    stream: if subtree.token_trees.is_empty() {
+                        None
+                    } else {
+                        Some(subtree.token_trees.into_iter().collect())
+                    },
+                    span: bridge::DelimSpan::from_single(subtree.delimiter.open),
+                }),
+            })
+            .collect()
+    }
+}
+
+fn delim_to_internal(d: proc_macro::Delimiter) -> tt::Delimiter {
+    let kind = match d {
+        proc_macro::Delimiter::Parenthesis => tt::DelimiterKind::Parenthesis,
+        proc_macro::Delimiter::Brace => tt::DelimiterKind::Brace,
+        proc_macro::Delimiter::Bracket => tt::DelimiterKind::Bracket,
+        proc_macro::Delimiter::None => tt::DelimiterKind::Invisible,
+    };
+    tt::Delimiter { open: tt::TokenId::unspecified(), close: tt::TokenId::unspecified(), kind }
+}
+
+fn delim_to_external(d: tt::Delimiter) -> proc_macro::Delimiter {
+    match d.kind {
+        tt::DelimiterKind::Parenthesis => proc_macro::Delimiter::Parenthesis,
+        tt::DelimiterKind::Brace => proc_macro::Delimiter::Brace,
+        tt::DelimiterKind::Bracket => proc_macro::Delimiter::Bracket,
+        tt::DelimiterKind::Invisible => proc_macro::Delimiter::None,
+    }
+}
+
+#[allow(unused)]
+fn spacing_to_internal(spacing: proc_macro::Spacing) -> Spacing {
+    match spacing {
+        proc_macro::Spacing::Alone => Spacing::Alone,
+        proc_macro::Spacing::Joint => Spacing::Joint,
+    }
+}
+
+#[allow(unused)]
+fn spacing_to_external(spacing: Spacing) -> proc_macro::Spacing {
+    match spacing {
+        Spacing::Alone => proc_macro::Spacing::Alone,
+        Spacing::Joint => proc_macro::Spacing::Joint,
+    }
+}
+
+impl server::SourceFile for RustAnalyzer {
+    // FIXME these are all stubs
+    fn eq(&mut self, _file1: &Self::SourceFile, _file2: &Self::SourceFile) -> bool {
+        true
+    }
+    fn path(&mut self, _file: &Self::SourceFile) -> String {
+        String::new()
+    }
+    fn is_real(&mut self, _file: &Self::SourceFile) -> bool {
+        true
+    }
+}
+
+impl server::Span for RustAnalyzer {
+    fn debug(&mut self, span: Self::Span) -> String {
+        format!("{:?}", span.0)
+    }
+    fn source_file(&mut self, _span: Self::Span) -> Self::SourceFile {
+        SourceFile {}
+    }
+    fn save_span(&mut self, _span: Self::Span) -> usize {
+        // FIXME stub
+        0
+    }
+    fn recover_proc_macro_span(&mut self, _id: usize) -> Self::Span {
+        // FIXME stub
+        tt::TokenId::unspecified()
+    }
+    /// Recent feature, not yet in the proc_macro
+    ///
+    /// See PR:
+    /// https://github.com/rust-lang/rust/pull/55780
+    fn source_text(&mut self, _span: Self::Span) -> Option<String> {
+        None
+    }
+
+    fn parent(&mut self, _span: Self::Span) -> Option<Self::Span> {
+        // FIXME handle span
+        None
+    }
+    fn source(&mut self, span: Self::Span) -> Self::Span {
+        // FIXME handle span
+        span
+    }
+    fn byte_range(&mut self, _span: Self::Span) -> Range<usize> {
+        // FIXME handle span
+        Range { start: 0, end: 0 }
+    }
+    fn start(&mut self, _span: Self::Span) -> LineColumn {
+        // FIXME handle span
+        LineColumn { line: 0, column: 0 }
+    }
+    fn end(&mut self, _span: Self::Span) -> LineColumn {
+        // FIXME handle span
+        LineColumn { line: 0, column: 0 }
+    }
+    fn join(&mut self, first: Self::Span, _second: Self::Span) -> Option<Self::Span> {
+        // Just return the first span again, because some macros will unwrap the result.
+        Some(first)
+    }
+    fn subspan(
+        &mut self,
+        span: Self::Span,
+        _start: Bound<usize>,
+        _end: Bound<usize>,
+    ) -> Option<Self::Span> {
+        // Just return the span again, because some macros will unwrap the result.
+        Some(span)
+    }
+    fn resolved_at(&mut self, _span: Self::Span, _at: Self::Span) -> Self::Span {
+        // FIXME handle span
+        tt::TokenId::unspecified()
+    }
+
+    fn after(&mut self, _self_: Self::Span) -> Self::Span {
+        tt::TokenId::unspecified()
+    }
+
+    fn before(&mut self, _self_: Self::Span) -> Self::Span {
+        tt::TokenId::unspecified()
+    }
+}
+
+impl server::Symbol for RustAnalyzer {
+    fn normalize_and_validate_ident(&mut self, string: &str) -> Result<Self::Symbol, ()> {
+        // FIXME: nfc-normalize and validate idents
+        Ok(<Self as server::Server>::intern_symbol(string))
+    }
+}
+
+impl server::Server for RustAnalyzer {
+    fn globals(&mut self) -> bridge::ExpnGlobals<Self::Span> {
+        bridge::ExpnGlobals {
+            def_site: Span::unspecified(),
+            call_site: Span::unspecified(),
+            mixed_site: Span::unspecified(),
+        }
+    }
+
+    fn intern_symbol(ident: &str) -> Self::Symbol {
+        // FIXME: should be self.interner once the proc-macro api allows is
+        Symbol::intern(&SYMBOL_INTERNER, &::tt::SmolStr::from(ident))
+    }
+
+    fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str)) {
+        // FIXME: should be self.interner once the proc-macro api allows is
+        f(symbol.text(&SYMBOL_INTERNER).as_str())
+    }
+}
+
+struct LiteralFormatter(bridge::Literal<tt::TokenId, Symbol>);
+
+impl LiteralFormatter {
+    /// Invokes the callback with a `&[&str]` consisting of each part of the
+    /// literal's representation. This is done to allow the `ToString` and
+    /// `Display` implementations to borrow references to symbol values, and
+    /// both be optimized to reduce overhead.
+    fn with_stringify_parts<R>(
+        &self,
+        interner: SymbolInternerRef,
+        f: impl FnOnce(&[&str]) -> R,
+    ) -> R {
+        /// Returns a string containing exactly `num` '#' characters.
+        /// Uses a 256-character source string literal which is always safe to
+        /// index with a `u8` index.
+        fn get_hashes_str(num: u8) -> &'static str {
+            const HASHES: &str = "\
+                        ################################################################\
+                        ################################################################\
+                        ################################################################\
+                        ################################################################\
+                        ";
+            const _: () = assert!(HASHES.len() == 256);
+            &HASHES[..num as usize]
+        }
+
+        self.with_symbol_and_suffix(interner, |symbol, suffix| match self.0.kind {
+            bridge::LitKind::Byte => f(&["b'", symbol, "'", suffix]),
+            bridge::LitKind::Char => f(&["'", symbol, "'", suffix]),
+            bridge::LitKind::Str => f(&["\"", symbol, "\"", suffix]),
+            bridge::LitKind::StrRaw(n) => {
+                let hashes = get_hashes_str(n);
+                f(&["r", hashes, "\"", symbol, "\"", hashes, suffix])
+            }
+            bridge::LitKind::ByteStr => f(&["b\"", symbol, "\"", suffix]),
+            bridge::LitKind::ByteStrRaw(n) => {
+                let hashes = get_hashes_str(n);
+                f(&["br", hashes, "\"", symbol, "\"", hashes, suffix])
+            }
+            _ => f(&[symbol, suffix]),
+        })
+    }
+
+    fn with_symbol_and_suffix<R>(
+        &self,
+        interner: SymbolInternerRef,
+        f: impl FnOnce(&str, &str) -> R,
+    ) -> R {
+        let symbol = self.0.symbol.text(interner);
+        let suffix = self.0.suffix.map(|s| s.text(interner)).unwrap_or_default();
+        f(symbol.as_str(), suffix.as_str())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_ra_server_to_string() {
+        let s = TokenStream {
+            token_trees: vec![
+                tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                    text: "struct".into(),
+                    span: tt::TokenId::unspecified(),
+                })),
+                tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                    text: "T".into(),
+                    span: tt::TokenId::unspecified(),
+                })),
+                tt::TokenTree::Subtree(tt::Subtree {
+                    delimiter: tt::Delimiter {
+                        open: tt::TokenId::unspecified(),
+                        close: tt::TokenId::unspecified(),
+                        kind: tt::DelimiterKind::Brace,
+                    },
+                    token_trees: vec![],
+                }),
+            ],
+        };
+
+        assert_eq!(s.to_string(), "struct T {}");
+    }
+
+    #[test]
+    fn test_ra_server_from_str() {
+        use std::str::FromStr;
+        let subtree_paren_a = tt::TokenTree::Subtree(tt::Subtree {
+            delimiter: tt::Delimiter {
+                open: tt::TokenId::unspecified(),
+                close: tt::TokenId::unspecified(),
+                kind: tt::DelimiterKind::Parenthesis,
+            },
+            token_trees: vec![tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                text: "a".into(),
+                span: tt::TokenId::unspecified(),
+            }))],
+        });
+
+        let t1 = TokenStream::from_str("(a)").unwrap();
+        assert_eq!(t1.token_trees.len(), 1);
+        assert_eq!(t1.token_trees[0], subtree_paren_a);
+
+        let t2 = TokenStream::from_str("(a);").unwrap();
+        assert_eq!(t2.token_trees.len(), 2);
+        assert_eq!(t2.token_trees[0], subtree_paren_a);
+
+        let underscore = TokenStream::from_str("_").unwrap();
+        assert_eq!(
+            underscore.token_trees[0],
+            tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                text: "_".into(),
+                span: tt::TokenId::unspecified(),
+            }))
+        );
+    }
+}