rust/crates/ra_mbe/src/syntax_bridge.rs
2020-03-04 23:41:14 +08:00

596 lines
20 KiB
Rust

//! FIXME: write short doc here
use ra_parser::{FragmentKind, ParseError, TreeSink};
use ra_syntax::{
ast, AstToken, NodeOrToken, Parse, SmolStr, SyntaxKind, SyntaxKind::*, SyntaxNode,
SyntaxTreeBuilder, TextRange, TextUnit, T,
};
use rustc_hash::FxHashMap;
use std::iter::successors;
use tt::buffer::{Cursor, TokenBuffer};
use crate::subtree_source::SubtreeTokenSource;
use crate::ExpandError;
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum TokenTextRange {
Token(TextRange),
Delimiter(TextRange, TextRange),
}
impl TokenTextRange {
pub fn by_kind(self, kind: SyntaxKind) -> Option<TextRange> {
match self {
TokenTextRange::Token(it) => Some(it),
TokenTextRange::Delimiter(open, close) => match kind {
T!['{'] | T!['('] | T!['['] => Some(open),
T!['}'] | T![')'] | T![']'] => Some(close),
_ => None,
},
}
}
}
/// Maps `tt::TokenId` to the relative range of the original token.
#[derive(Debug, PartialEq, Eq, Default)]
pub struct TokenMap {
/// Maps `tt::TokenId` to the *relative* source range.
entries: Vec<(tt::TokenId, TokenTextRange)>,
}
/// Convert the syntax tree (what user has written) to a `TokenTree` (what macro
/// will consume).
pub fn ast_to_token_tree(ast: &impl ast::AstNode) -> Option<(tt::Subtree, TokenMap)> {
syntax_node_to_token_tree(ast.syntax())
}
/// 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 global_offset = node.text_range().start();
let mut c = Convertor { map: TokenMap::default(), global_offset, next_id: 0 };
let subtree = c.go(node)?;
Some((subtree, c.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]>
pub fn token_tree_to_syntax_node(
tt: &tt::Subtree,
fragment_kind: FragmentKind,
) -> Result<(Parse<SyntaxNode>, TokenMap), ExpandError> {
let tmp;
let tokens = match tt {
tt::Subtree { delimiter: None, token_trees } => token_trees.as_slice(),
_ => {
tmp = [tt.clone().into()];
&tmp[..]
}
};
let buffer = TokenBuffer::new(&tokens);
let mut token_source = SubtreeTokenSource::new(&buffer);
let mut tree_sink = TtTreeSink::new(buffer.begin());
ra_parser::parse_fragment(&mut token_source, &mut tree_sink, fragment_kind);
if tree_sink.roots.len() != 1 {
return Err(ExpandError::ConversionError);
}
//FIXME: would be cool to report errors
let (parse, range_map) = tree_sink.finish();
Ok((parse, range_map))
}
impl TokenMap {
pub fn token_by_range(&self, relative_range: TextRange) -> Option<tt::TokenId> {
let &(token_id, _) = self.entries.iter().find(|(_, range)| match range {
TokenTextRange::Token(it) => *it == relative_range,
TokenTextRange::Delimiter(open, close) => {
*open == relative_range || *close == relative_range
}
})?;
Some(token_id)
}
pub fn range_by_token(&self, token_id: tt::TokenId) -> Option<TokenTextRange> {
let &(_, range) = self.entries.iter().find(|(tid, _)| *tid == token_id)?;
Some(range)
}
fn insert(&mut self, token_id: tt::TokenId, relative_range: TextRange) {
self.entries.push((token_id, TokenTextRange::Token(relative_range)));
}
fn insert_delim(
&mut self,
token_id: tt::TokenId,
open_relative_range: TextRange,
close_relative_range: TextRange,
) {
self.entries
.push((token_id, TokenTextRange::Delimiter(open_relative_range, close_relative_range)));
}
}
/// 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 {
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(token: &ra_syntax::SyntaxToken) -> Option<Vec<tt::TokenTree>> {
let comment = ast::Comment::cast(token.clone())?;
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 {
delimiter: Some(tt::Delimiter {
kind: tt::DelimiterKind::Bracket,
id: tt::TokenId::unspecified(),
}),
token_trees: meta_tkns,
}));
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,
id: tt::TokenId::unspecified(),
}))
}
fn mk_doc_literal(comment: &ast::Comment) -> tt::TokenTree {
let lit = tt::Literal { text: doc_comment_text(comment), id: tt::TokenId::unspecified() };
tt::TokenTree::from(tt::Leaf::from(lit))
}
}
struct Convertor {
map: TokenMap,
global_offset: TextUnit,
next_id: u32,
}
impl Convertor {
fn go(&mut self, 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: None });
}
let first_child = tt.first_child_or_token()?;
let last_child = tt.last_child_or_token()?;
// ignore trivial first_child and last_child
let first_child = successors(Some(first_child), |it| {
if it.kind().is_trivia() {
it.next_sibling_or_token()
} else {
None
}
})
.last()
.unwrap();
if first_child.kind().is_trivia() {
return Some(tt::Subtree { token_trees: vec![], delimiter: None });
}
let last_child = successors(Some(last_child), |it| {
if it.kind().is_trivia() {
it.prev_sibling_or_token()
} else {
None
}
})
.last()
.unwrap();
let (delimiter_kind, skip_first) = match (first_child.kind(), last_child.kind()) {
(T!['('], T![')']) => (Some(tt::DelimiterKind::Parenthesis), true),
(T!['{'], T!['}']) => (Some(tt::DelimiterKind::Brace), true),
(T!['['], T![']']) => (Some(tt::DelimiterKind::Bracket), true),
_ => (None, false),
};
let delimiter = delimiter_kind.map(|kind| tt::Delimiter {
kind,
id: self.alloc_delim(first_child.text_range(), last_child.text_range()),
});
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 {
NodeOrToken::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() {
// we need to pull apart joined punctuation tokens
let last_spacing = match child_iter.peek() {
Some(NodeOrToken::Token(token)) => {
if token.kind().is_punct() {
tt::Spacing::Joint
} else {
tt::Spacing::Alone
}
}
_ => tt::Spacing::Alone,
};
let spacing_iter = std::iter::repeat(tt::Spacing::Joint)
.take(token.text().len() - 1)
.chain(std::iter::once(last_spacing));
for (char, spacing) in token.text().chars().zip(spacing_iter) {
token_trees.push(
tt::Leaf::from(tt::Punct {
char,
spacing,
id: self.alloc(token.text_range()),
})
.into(),
);
}
} else {
macro_rules! make_leaf {
($i:ident) => {
tt::$i {
id: self.alloc(token.text_range()),
text: token.text().clone(),
}
.into()
};
}
let child: tt::Leaf = match token.kind() {
T![true] | T![false] => make_leaf!(Literal),
IDENT | LIFETIME => make_leaf!(Ident),
k if k.is_keyword() => make_leaf!(Ident),
k if k.is_literal() => make_leaf!(Literal),
_ => return None,
};
token_trees.push(child.into());
}
}
NodeOrToken::Node(node) => {
let child_subtree = self.go(&node)?;
if child_subtree.delimiter.is_none() && node.kind() != SyntaxKind::TOKEN_TREE {
token_trees.extend(child_subtree.token_trees);
} else {
token_trees.push(child_subtree.into());
}
}
};
}
let res = tt::Subtree { delimiter, token_trees };
Some(res)
}
fn alloc(&mut self, absolute_range: TextRange) -> tt::TokenId {
let relative_range = absolute_range - self.global_offset;
let token_id = tt::TokenId(self.next_id);
self.next_id += 1;
self.map.insert(token_id, relative_range);
token_id
}
fn alloc_delim(
&mut self,
open_abs_range: TextRange,
close_abs_range: TextRange,
) -> tt::TokenId {
let open_relative_range = open_abs_range - self.global_offset;
let close_relative_range = close_abs_range - self.global_offset;
let token_id = tt::TokenId(self.next_id);
self.next_id += 1;
self.map.insert_delim(token_id, open_relative_range, close_relative_range);
token_id
}
}
struct TtTreeSink<'a> {
buf: String,
cursor: Cursor<'a>,
open_delims: FxHashMap<tt::TokenId, TextUnit>,
text_pos: TextUnit,
inner: SyntaxTreeBuilder,
token_map: TokenMap,
// 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,
open_delims: FxHashMap::default(),
text_pos: 0.into(),
inner: SyntaxTreeBuilder::default(),
roots: smallvec::SmallVec::new(),
token_map: TokenMap::default(),
}
}
fn finish(self) -> (Parse<SyntaxNode>, TokenMap) {
(self.inner.finish(), self.token_map)
}
}
fn delim_to_str(d: Option<tt::DelimiterKind>, closing: bool) -> SmolStr {
let texts = match d {
Some(tt::DelimiterKind::Parenthesis) => "()",
Some(tt::DelimiterKind::Brace) => "{}",
Some(tt::DelimiterKind::Bracket) => "[]",
None => return "".into(),
};
let idx = closing as usize;
let text = &texts[idx..texts.len() - (1 - idx)];
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;
}
let mut last = self.cursor;
for _ in 0..n_tokens {
if self.cursor.eof() {
break;
}
last = self.cursor;
let text: SmolStr = match self.cursor.token_tree() {
Some(tt::TokenTree::Leaf(leaf)) => {
// Mark the range if needed
let id = match leaf {
tt::Leaf::Ident(ident) => ident.id,
tt::Leaf::Punct(punct) => punct.id,
tt::Leaf::Literal(lit) => lit.id,
};
let text = SmolStr::new(format!("{}", leaf));
let range = TextRange::offset_len(self.text_pos, TextUnit::of_str(&text));
self.token_map.insert(id, range);
self.cursor = self.cursor.bump();
text
}
Some(tt::TokenTree::Subtree(subtree)) => {
self.cursor = self.cursor.subtree().unwrap();
if let Some(id) = subtree.delimiter.map(|it| it.id) {
self.open_delims.insert(id, self.text_pos);
}
delim_to_str(subtree.delimiter_kind(), false)
}
None => {
if let Some(parent) = self.cursor.end() {
self.cursor = self.cursor.bump();
if let Some(id) = parent.delimiter.map(|it| it.id) {
if let Some(open_delim) = self.open_delims.get(&id) {
let open_range =
TextRange::offset_len(*open_delim, TextUnit::from_usize(1));
let close_range =
TextRange::offset_len(self.text_pos, TextUnit::from_usize(1));
self.token_map.insert_delim(id, open_range, close_range);
}
}
delim_to_str(parent.delimiter_kind(), true)
} else {
continue;
}
}
};
self.buf += &text;
self.text_pos += TextUnit::of_str(&text);
}
let text = SmolStr::new(self.buf.as_str());
self.buf.clear();
self.inner.token(kind, text);
// Add whitespace between adjoint puncts
let next = last.bump();
if let (
Some(tt::TokenTree::Leaf(tt::Leaf::Punct(curr))),
Some(tt::TokenTree::Leaf(tt::Leaf::Punct(_))),
) = (last.token_tree(), next.token_tree())
{
if curr.spacing == tt::Spacing::Alone {
self.inner.token(WHITESPACE, " ".into());
self.text_pos += TextUnit::of_char(' ');
}
}
}
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::parse_macro;
use ra_parser::TokenSource;
use ra_syntax::{
algo::{insert_children, InsertPosition},
ast::AstNode,
};
#[test]
fn convert_tt_token_source() {
let expansion = parse_macro(
r#"
macro_rules! literals {
($i:ident) => {
{
let a = 'c';
let c = 1000;
let f = 12E+99_f64;
let s = "rust1";
}
}
}
"#,
)
.expand_tt("literals!(foo);");
let tts = &[expansion.into()];
let buffer = tt::buffer::TokenBuffer::new(tts);
let mut tt_src = SubtreeTokenSource::new(&buffer);
let mut tokens = vec![];
while tt_src.current().kind != EOF {
tokens.push((tt_src.current().kind, tt_src.text()));
tt_src.bump();
}
// [${]
// [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 expansion = parse_macro(
r#"
macro_rules! stmts {
() => {
let a = 0;
let b = 0;
let c = 0;
let d = 0;
}
}
"#,
)
.expand_tt("stmts!();");
assert!(token_tree_to_syntax_node(&expansion, FragmentKind::Expr).is_err());
}
#[test]
fn test_token_tree_last_child_is_white_space() {
let source_file = ast::SourceFile::parse("f!({} );").ok().unwrap();
let macro_call = source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
let token_tree = macro_call.token_tree().unwrap();
// Token Tree now is :
// TokenTree
// - T!['(']
// - TokenTree
// - T!['{']
// - T!['}']
// - WHITE_SPACE
// - T![')']
let rbrace =
token_tree.syntax().descendants_with_tokens().find(|it| it.kind() == T!['}']).unwrap();
let space = token_tree
.syntax()
.descendants_with_tokens()
.find(|it| it.kind() == SyntaxKind::WHITESPACE)
.unwrap();
// reorder th white space, such that the white is inside the inner token-tree.
let token_tree = insert_children(
&rbrace.parent().unwrap(),
InsertPosition::Last,
std::iter::once(space),
);
// Token Tree now is :
// TokenTree
// - T!['{']
// - T!['}']
// - WHITE_SPACE
let token_tree = ast::TokenTree::cast(token_tree).unwrap();
let tt = ast_to_token_tree(&token_tree).unwrap().0;
assert_eq!(tt.delimiter_kind(), Some(tt::DelimiterKind::Brace));
}
#[test]
fn test_token_tree_multi_char_punct() {
let source_file = ast::SourceFile::parse("struct Foo { a: x::Y }").ok().unwrap();
let struct_def = source_file.syntax().descendants().find_map(ast::StructDef::cast).unwrap();
let tt = ast_to_token_tree(&struct_def).unwrap().0;
token_tree_to_syntax_node(&tt, FragmentKind::Item).unwrap();
}
}