rust-analyzer/crates/ra_mbe/src/syntax_bridge.rs
2019-05-28 00:38:55 +08:00

429 lines
15 KiB
Rust

use ra_parser::{TreeSink, ParseError};
use ra_syntax::{
AstNode, SyntaxNode, TextRange, SyntaxKind, SmolStr, SyntaxTreeBuilder, TreeArc, SyntaxElement,
ast, SyntaxKind::*, TextUnit, T
};
use tt::buffer::Cursor;
use crate::subtree_source::{SubtreeTokenSource};
use crate::ExpandError;
/// Maps `tt::TokenId` to the relative range of the original token.
#[derive(Default)]
pub struct TokenMap {
/// Maps `tt::TokenId` to the *relative* source range.
tokens: Vec<TextRange>,
}
/// Convert the syntax tree (what user has written) to a `TokenTree` (what macro
/// will consume).
pub fn ast_to_token_tree(ast: &ast::TokenTree) -> Option<(tt::Subtree, TokenMap)> {
let mut token_map = TokenMap::default();
let node = ast.syntax();
let tt = convert_tt(&mut token_map, node.range().start(), node)?;
Some((tt, token_map))
}
/// Convert the syntax node to a `TokenTree` (what macro
/// will consume).
pub fn syntax_node_to_token_tree(node: &SyntaxNode) -> Option<(tt::Subtree, TokenMap)> {
let mut token_map = TokenMap::default();
let tt = convert_tt(&mut token_map, node.range().start(), node)?;
Some((tt, token_map))
}
// The following items are what `rustc` macro can be parsed into :
// link: https://github.com/rust-lang/rust/blob/9ebf47851a357faa4cd97f4b1dc7835f6376e639/src/libsyntax/ext/expand.rs#L141
// * Expr(P<ast::Expr>) -> token_tree_to_expr
// * Pat(P<ast::Pat>) -> token_tree_to_pat
// * Ty(P<ast::Ty>) -> token_tree_to_ty
// * Stmts(SmallVec<[ast::Stmt; 1]>) -> token_tree_to_stmts
// * Items(SmallVec<[P<ast::Item>; 1]>) -> token_tree_to_items
//
// * TraitItems(SmallVec<[ast::TraitItem; 1]>)
// * ImplItems(SmallVec<[ast::ImplItem; 1]>)
// * ForeignItems(SmallVec<[ast::ForeignItem; 1]>
//
//
fn token_tree_to_syntax_node<F>(tt: &tt::Subtree, f: F) -> Result<TreeArc<SyntaxNode>, ExpandError>
where
F: Fn(&mut ra_parser::TokenSource, &mut ra_parser::TreeSink),
{
let buffer = tt::buffer::TokenBuffer::new(&[tt.clone().into()]);
let mut token_source = SubtreeTokenSource::new(&buffer);
let mut tree_sink = TtTreeSink::new(buffer.begin());
f(&mut token_source, &mut tree_sink);
if tree_sink.roots.len() != 1 {
return Err(ExpandError::ConversionError);
}
Ok(tree_sink.inner.finish())
}
/// Parses the token tree (result of macro expansion) to an expression
pub fn token_tree_to_expr(tt: &tt::Subtree) -> Result<TreeArc<ast::Expr>, ExpandError> {
let syntax = token_tree_to_syntax_node(tt, ra_parser::parse_expr)?;
ast::Expr::cast(&syntax)
.map(|m| m.to_owned())
.ok_or_else(|| crate::ExpandError::ConversionError)
}
/// Parses the token tree (result of macro expansion) to a Pattern
pub fn token_tree_to_pat(tt: &tt::Subtree) -> Result<TreeArc<ast::Pat>, ExpandError> {
let syntax = token_tree_to_syntax_node(tt, ra_parser::parse_pat)?;
ast::Pat::cast(&syntax).map(|m| m.to_owned()).ok_or_else(|| ExpandError::ConversionError)
}
/// Parses the token tree (result of macro expansion) to a Type
pub fn token_tree_to_ty(tt: &tt::Subtree) -> Result<TreeArc<ast::TypeRef>, ExpandError> {
let syntax = token_tree_to_syntax_node(tt, ra_parser::parse_ty)?;
ast::TypeRef::cast(&syntax).map(|m| m.to_owned()).ok_or_else(|| ExpandError::ConversionError)
}
/// Parses the token tree (result of macro expansion) as a sequence of stmts
pub fn token_tree_to_macro_stmts(
tt: &tt::Subtree,
) -> Result<TreeArc<ast::MacroStmts>, ExpandError> {
let syntax = token_tree_to_syntax_node(tt, ra_parser::parse_macro_stmts)?;
ast::MacroStmts::cast(&syntax).map(|m| m.to_owned()).ok_or_else(|| ExpandError::ConversionError)
}
/// Parses the token tree (result of macro expansion) as a sequence of items
pub fn token_tree_to_macro_items(
tt: &tt::Subtree,
) -> Result<TreeArc<ast::MacroItems>, ExpandError> {
let syntax = token_tree_to_syntax_node(tt, ra_parser::parse_macro_items)?;
ast::MacroItems::cast(&syntax).map(|m| m.to_owned()).ok_or_else(|| ExpandError::ConversionError)
}
/// Parses the token tree (result of macro expansion) as a sequence of items
pub fn token_tree_to_ast_item_list(tt: &tt::Subtree) -> TreeArc<ast::SourceFile> {
let syntax = token_tree_to_syntax_node(tt, ra_parser::parse).unwrap();
ast::SourceFile::cast(&syntax).unwrap().to_owned()
}
impl TokenMap {
pub fn relative_range_of(&self, tt: tt::TokenId) -> Option<TextRange> {
let idx = tt.0 as usize;
self.tokens.get(idx).map(|&it| it)
}
fn alloc(&mut self, relative_range: TextRange) -> tt::TokenId {
let id = self.tokens.len();
self.tokens.push(relative_range);
tt::TokenId(id as u32)
}
}
/// Returns the textual content of a doc comment block as a quoted string
/// That is, strips leading `///` (or `/**`, etc)
/// and strips the ending `*/`
/// And then quote the string, which is needed to convert to `tt::Literal`
fn doc_comment_text(comment: &ast::Comment) -> SmolStr {
use ast::AstToken;
let prefix_len = comment.prefix().len();
let mut text = &comment.text()[prefix_len..];
// Remove ending "*/"
if comment.kind().shape == ast::CommentShape::Block {
text = &text[0..text.len() - 2];
}
// Quote the string
// Note that `tt::Literal` expect an escaped string
let text = format!("{:?}", text.escape_default().to_string());
text.into()
}
fn convert_doc_comment<'a>(token: &ra_syntax::SyntaxToken<'a>) -> Option<Vec<tt::TokenTree>> {
use ast::AstToken;
let comment = ast::Comment::cast(*token)?;
let doc = comment.kind().doc?;
// Make `doc="\" Comments\""
let mut meta_tkns = Vec::new();
meta_tkns.push(mk_ident("doc"));
meta_tkns.push(mk_punct('='));
meta_tkns.push(mk_doc_literal(&comment));
// Make `#![]`
let mut token_trees = Vec::new();
token_trees.push(mk_punct('#'));
if let ast::CommentPlacement::Inner = doc {
token_trees.push(mk_punct('!'));
}
token_trees.push(tt::TokenTree::from(tt::Subtree::from(
tt::Subtree { delimiter: tt::Delimiter::Bracket, token_trees: meta_tkns }.into(),
)));
return Some(token_trees);
// Helper functions
fn mk_ident(s: &str) -> tt::TokenTree {
tt::TokenTree::from(tt::Leaf::from(tt::Ident {
text: s.into(),
id: tt::TokenId::unspecified(),
}))
}
fn mk_punct(c: char) -> tt::TokenTree {
tt::TokenTree::from(tt::Leaf::from(tt::Punct { char: c, spacing: tt::Spacing::Alone }))
}
fn mk_doc_literal(comment: &ast::Comment) -> tt::TokenTree {
let lit = tt::Literal { text: doc_comment_text(comment) };
tt::TokenTree::from(tt::Leaf::from(lit))
}
}
fn convert_tt(
token_map: &mut TokenMap,
global_offset: TextUnit,
tt: &SyntaxNode,
) -> Option<tt::Subtree> {
// This tree is empty
if tt.first_child_or_token().is_none() {
return Some(tt::Subtree { token_trees: vec![], delimiter: tt::Delimiter::None });
}
let first_child = tt.first_child_or_token()?;
let last_child = tt.last_child_or_token()?;
let (delimiter, skip_first) = match (first_child.kind(), last_child.kind()) {
(T!['('], T![')']) => (tt::Delimiter::Parenthesis, true),
(T!['{'], T!['}']) => (tt::Delimiter::Brace, true),
(T!['['], T![']']) => (tt::Delimiter::Bracket, true),
_ => (tt::Delimiter::None, false),
};
let mut token_trees = Vec::new();
let mut child_iter = tt.children_with_tokens().skip(skip_first as usize).peekable();
while let Some(child) = child_iter.next() {
if skip_first && (child == first_child || child == last_child) {
continue;
}
match child {
SyntaxElement::Token(token) => {
if let Some(doc_tokens) = convert_doc_comment(&token) {
token_trees.extend(doc_tokens);
} else if token.kind().is_trivia() {
continue;
} else if token.kind().is_punct() {
assert!(token.text().len() == 1, "Input ast::token punct must be single char.");
let char = token.text().chars().next().unwrap();
let spacing = match child_iter.peek() {
Some(SyntaxElement::Token(token)) => {
if token.kind().is_punct() {
tt::Spacing::Joint
} else {
tt::Spacing::Alone
}
}
_ => tt::Spacing::Alone,
};
token_trees.push(tt::Leaf::from(tt::Punct { char, spacing }).into());
} else {
let child: tt::TokenTree =
if token.kind() == T![true] || token.kind() == T![false] {
tt::Leaf::from(tt::Literal { text: token.text().clone() }).into()
} else if token.kind().is_keyword()
|| token.kind() == IDENT
|| token.kind() == LIFETIME
{
let relative_range = token.range() - global_offset;
let id = token_map.alloc(relative_range);
let text = token.text().clone();
tt::Leaf::from(tt::Ident { text, id }).into()
} else if token.kind().is_literal() {
tt::Leaf::from(tt::Literal { text: token.text().clone() }).into()
} else {
return None;
};
token_trees.push(child);
}
}
SyntaxElement::Node(node) => {
let child = convert_tt(token_map, global_offset, node)?.into();
token_trees.push(child);
}
};
}
let res = tt::Subtree { delimiter, token_trees };
Some(res)
}
struct TtTreeSink<'a> {
buf: String,
cursor: Cursor<'a>,
text_pos: TextUnit,
inner: SyntaxTreeBuilder,
// Number of roots
// Use for detect ill-form tree which is not single root
roots: smallvec::SmallVec<[usize; 1]>,
}
impl<'a> TtTreeSink<'a> {
fn new(cursor: Cursor<'a>) -> Self {
TtTreeSink {
buf: String::new(),
cursor,
text_pos: 0.into(),
inner: SyntaxTreeBuilder::default(),
roots: smallvec::SmallVec::new(),
}
}
}
fn delim_to_str(d: tt::Delimiter, closing: bool) -> SmolStr {
let texts = match d {
tt::Delimiter::Parenthesis => "()",
tt::Delimiter::Brace => "{}",
tt::Delimiter::Bracket => "[]",
tt::Delimiter::None => "",
};
let idx = closing as usize;
let text = if texts.len() > 0 { &texts[idx..texts.len() - (1 - idx)] } else { "" };
text.into()
}
impl<'a> TreeSink for TtTreeSink<'a> {
fn token(&mut self, kind: SyntaxKind, n_tokens: u8) {
if kind == L_DOLLAR || kind == R_DOLLAR {
self.cursor = self.cursor.bump_subtree();
return;
}
for _ in 0..n_tokens {
if self.cursor.eof() {
break;
}
match self.cursor.token_tree() {
Some(tt::TokenTree::Leaf(leaf)) => {
self.cursor = self.cursor.bump();
self.buf += &format!("{}", leaf);
}
Some(tt::TokenTree::Subtree(subtree)) => {
self.cursor = self.cursor.subtree().unwrap();
self.buf += &delim_to_str(subtree.delimiter, false);
}
None => {
if let Some(parent) = self.cursor.end() {
self.cursor = self.cursor.bump();
self.buf += &delim_to_str(parent.delimiter, true);
}
}
};
}
self.text_pos += TextUnit::of_str(&self.buf);
let text = SmolStr::new(self.buf.as_str());
self.buf.clear();
self.inner.token(kind, text);
// Add whitespace between adjoint puncts
let next = self.cursor.bump();
if let (
Some(tt::TokenTree::Leaf(tt::Leaf::Punct(curr))),
Some(tt::TokenTree::Leaf(tt::Leaf::Punct(_))),
) = (self.cursor.token_tree(), next.token_tree())
{
if curr.spacing == tt::Spacing::Alone {
self.inner.token(WHITESPACE, " ".into());
}
}
}
fn start_node(&mut self, kind: SyntaxKind) {
self.inner.start_node(kind);
match self.roots.last_mut() {
None | Some(0) => self.roots.push(1),
Some(ref mut n) => **n += 1,
};
}
fn finish_node(&mut self) {
self.inner.finish_node();
*self.roots.last_mut().unwrap() -= 1;
}
fn error(&mut self, error: ParseError) {
self.inner.error(error, self.text_pos)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::tests::{expand, create_rules};
use ra_parser::TokenSource;
#[test]
fn convert_tt_token_source() {
let rules = create_rules(
r#"
macro_rules! literals {
($i:ident) => {
{
let a = 'c';
let c = 1000;
let f = 12E+99_f64;
let s = "rust1";
}
}
}
"#,
);
let expansion = expand(&rules, "literals!(foo)");
let buffer = tt::buffer::TokenBuffer::new(&[expansion.clone().into()]);
let mut tt_src = SubtreeTokenSource::new(&buffer);
let mut tokens = vec![];
while tt_src.current().kind != EOF {
tokens.push((tt_src.current().kind, tt_src.text()));
tt_src.bump();
}
// [${]
// [let] [a] [=] ['c'] [;]
assert_eq!(tokens[2 + 3].1, "'c'");
assert_eq!(tokens[2 + 3].0, CHAR);
// [let] [c] [=] [1000] [;]
assert_eq!(tokens[2 + 5 + 3].1, "1000");
assert_eq!(tokens[2 + 5 + 3].0, INT_NUMBER);
// [let] [f] [=] [12E+99_f64] [;]
assert_eq!(tokens[2 + 10 + 3].1, "12E+99_f64");
assert_eq!(tokens[2 + 10 + 3].0, FLOAT_NUMBER);
// [let] [s] [=] ["rust1"] [;]
assert_eq!(tokens[2 + 15 + 3].1, "\"rust1\"");
assert_eq!(tokens[2 + 15 + 3].0, STRING);
}
#[test]
fn stmts_token_trees_to_expr_is_err() {
let rules = create_rules(
r#"
macro_rules! stmts {
() => {
let a = 0;
let b = 0;
let c = 0;
let d = 0;
}
}
"#,
);
let expansion = expand(&rules, "stmts!()");
assert!(token_tree_to_expr(&expansion).is_err());
}
}