1 //! This module generates AST datatype used by rust-analyzer.
3 //! Specifically, it generates the `SyntaxKind` enum and a number of newtype
4 //! wrappers around `SyntaxNode` which implement `syntax::AstNode`.
7 collections::{BTreeSet, HashSet},
11 use itertools::Itertools;
12 use proc_macro2::{Punct, Spacing};
13 use quote::{format_ident, quote};
14 use ungrammar::{Grammar, Rule};
16 use crate::tests::ast_src::{
17 AstEnumSrc, AstNodeSrc, AstSrc, Cardinality, Field, KindsSrc, KINDS_SRC,
22 let syntax_kinds = generate_syntax_kinds(KINDS_SRC);
23 let syntax_kinds_file =
24 sourcegen::project_root().join("crates/parser/src/syntax_kind/generated.rs");
25 sourcegen::ensure_file_contents(syntax_kinds_file.as_path(), &syntax_kinds);
28 include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/rust.ungram")).parse().unwrap();
29 let ast = lower(&grammar);
31 let ast_tokens = generate_tokens(&ast);
33 sourcegen::project_root().join("crates/syntax/src/ast/generated/tokens.rs");
34 sourcegen::ensure_file_contents(ast_tokens_file.as_path(), &ast_tokens);
36 let ast_nodes = generate_nodes(KINDS_SRC, &ast);
37 let ast_nodes_file = sourcegen::project_root().join("crates/syntax/src/ast/generated/nodes.rs");
38 sourcegen::ensure_file_contents(ast_nodes_file.as_path(), &ast_nodes);
41 fn generate_tokens(grammar: &AstSrc) -> String {
42 let tokens = grammar.tokens.iter().map(|token| {
43 let name = format_ident!("{}", token);
44 let kind = format_ident!("{}", to_upper_snake_case(token));
46 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
48 pub(crate) syntax: SyntaxToken,
50 impl std::fmt::Display for #name {
51 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
52 std::fmt::Display::fmt(&self.syntax, f)
55 impl AstToken for #name {
56 fn can_cast(kind: SyntaxKind) -> bool { kind == #kind }
57 fn cast(syntax: SyntaxToken) -> Option<Self> {
58 if Self::can_cast(syntax.kind()) { Some(Self { syntax }) } else { None }
60 fn syntax(&self) -> &SyntaxToken { &self.syntax }
65 sourcegen::add_preamble(
69 use crate::{SyntaxKind::{self, *}, SyntaxToken, ast::AstToken};
75 .replace("#[derive", "\n#[derive")
78 fn generate_nodes(kinds: KindsSrc<'_>, grammar: &AstSrc) -> String {
79 let (node_defs, node_boilerplate_impls): (Vec<_>, Vec<_>) = grammar
83 let name = format_ident!("{}", node.name);
84 let kind = format_ident!("{}", to_upper_snake_case(&node.name));
88 .filter(|trait_name| {
89 // Loops have two expressions so this might collide, therefor manual impl it
90 node.name != "ForExpr" && node.name != "WhileExpr"
91 || trait_name.as_str() != "HasLoopBody"
94 let trait_name = format_ident!("{}", trait_name);
95 quote!(impl ast::#trait_name for #name {})
98 let methods = node.fields.iter().map(|field| {
99 let method_name = field.method_name();
104 pub fn #method_name(&self) -> AstChildren<#ty> {
105 support::children(&self.syntax)
108 } else if let Some(token_kind) = field.token_kind() {
110 pub fn #method_name(&self) -> Option<#ty> {
111 support::token(&self.syntax, #token_kind)
116 pub fn #method_name(&self) -> Option<#ty> {
117 support::child(&self.syntax)
124 #[pretty_doc_comment_placeholder_workaround]
125 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
127 pub(crate) syntax: SyntaxNode,
137 impl AstNode for #name {
138 fn can_cast(kind: SyntaxKind) -> bool {
141 fn cast(syntax: SyntaxNode) -> Option<Self> {
142 if Self::can_cast(syntax.kind()) { Some(Self { syntax }) } else { None }
144 fn syntax(&self) -> &SyntaxNode { &self.syntax }
151 let (enum_defs, enum_boilerplate_impls): (Vec<_>, Vec<_>) = grammar
155 let variants: Vec<_> = en.variants.iter().map(|var| format_ident!("{}", var)).collect();
156 let name = format_ident!("{}", en.name);
157 let kinds: Vec<_> = variants
159 .map(|name| format_ident!("{}", to_upper_snake_case(&name.to_string())))
161 let traits = en.traits.iter().map(|trait_name| {
162 let trait_name = format_ident!("{}", trait_name);
163 quote!(impl ast::#trait_name for #name {})
166 let ast_node = if en.name == "Stmt" {
170 impl AstNode for #name {
171 fn can_cast(kind: SyntaxKind) -> bool {
177 fn cast(syntax: SyntaxNode) -> Option<Self> {
178 let res = match syntax.kind() {
180 #kinds => #name::#variants(#variants { syntax }),
186 fn syntax(&self) -> &SyntaxNode {
189 #name::#variants(it) => &it.syntax,
199 #[pretty_doc_comment_placeholder_workaround]
200 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
202 #(#variants(#variants),)*
209 impl From<#variants> for #name {
210 fn from(node: #variants) -> #name {
211 #name::#variants(node)
221 let (any_node_defs, any_node_boilerplate_impls): (Vec<_>, Vec<_>) = grammar
224 .flat_map(|node| node.traits.iter().map(move |t| (t, node)))
227 .sorted_by_key(|(k, _)| *k)
228 .map(|(trait_name, nodes)| {
229 let name = format_ident!("Any{}", trait_name);
230 let trait_name = format_ident!("{}", trait_name);
231 let kinds: Vec<_> = nodes
233 .map(|name| format_ident!("{}", to_upper_snake_case(&name.name.to_string())))
238 #[pretty_doc_comment_placeholder_workaround]
239 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
241 pub(crate) syntax: SyntaxNode,
243 impl ast::#trait_name for #name {}
248 pub fn new<T: ast::#trait_name>(node: T) -> #name {
250 syntax: node.syntax().clone()
254 impl AstNode for #name {
255 fn can_cast(kind: SyntaxKind) -> bool {
261 fn cast(syntax: SyntaxNode) -> Option<Self> {
262 Self::can_cast(syntax.kind()).then(|| #name { syntax })
264 fn syntax(&self) -> &SyntaxNode {
273 let enum_names = grammar.enums.iter().map(|it| &it.name);
274 let node_names = grammar.nodes.iter().map(|it| &it.name);
277 enum_names.chain(node_names.clone()).map(|it| format_ident!("{}", it)).map(|name| {
279 impl std::fmt::Display for #name {
280 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
281 std::fmt::Display::fmt(self.syntax(), f)
287 let defined_nodes: HashSet<_> = node_names.collect();
292 .map(|kind| to_pascal_case(kind))
293 .filter(|name| !defined_nodes.iter().any(|&it| it == name))
296 // FIXME: restore this
297 // eprintln!("Warning: node {} not defined in ast source", node);
301 #![allow(non_snake_case)]
303 SyntaxNode, SyntaxToken, SyntaxKind::{self, *},
304 ast::{self, AstNode, AstChildren, support},
311 #(#node_boilerplate_impls)*
312 #(#enum_boilerplate_impls)*
313 #(#any_node_boilerplate_impls)*
317 let ast = ast.to_string().replace("T ! [", "T![");
319 let mut res = String::with_capacity(ast.len() * 2);
322 grammar.nodes.iter().map(|it| &it.doc).chain(grammar.enums.iter().map(|it| &it.doc));
324 for chunk in ast.split("# [pretty_doc_comment_placeholder_workaround] ") {
326 if let Some(doc) = docs.next() {
327 write_doc_comment(doc, &mut res);
331 let res = sourcegen::add_preamble("sourcegen_ast", sourcegen::reformat(res));
332 res.replace("#[derive", "\n#[derive")
335 fn write_doc_comment(contents: &[String], dest: &mut String) {
336 for line in contents {
337 writeln!(dest, "///{}", line).unwrap();
341 fn generate_syntax_kinds(grammar: KindsSrc<'_>) -> String {
342 let (single_byte_tokens_values, single_byte_tokens): (Vec<_>, Vec<_>) = grammar
345 .filter(|(token, _name)| token.len() == 1)
346 .map(|(token, name)| (token.chars().next().unwrap(), format_ident!("{}", name)))
349 let punctuation_values = grammar.punct.iter().map(|(token, _name)| {
350 if "{}[]()".contains(token) {
351 let c = token.chars().next().unwrap();
354 let cs = token.chars().map(|c| Punct::new(c, Spacing::Joint));
359 grammar.punct.iter().map(|(_token, name)| format_ident!("{}", name)).collect::<Vec<_>>();
361 let x = |&name| match name {
362 "Self" => format_ident!("SELF_TYPE_KW"),
363 name => format_ident!("{}_KW", to_upper_snake_case(name)),
365 let full_keywords_values = grammar.keywords;
366 let full_keywords = full_keywords_values.iter().map(x);
368 let contextual_keywords_values = &grammar.contextual_keywords;
369 let contextual_keywords = contextual_keywords_values.iter().map(x);
371 let all_keywords_values = grammar
374 .chain(grammar.contextual_keywords.iter())
376 .collect::<Vec<_>>();
377 let all_keywords_idents = all_keywords_values.iter().map(|kw| format_ident!("{}", kw));
378 let all_keywords = all_keywords_values.iter().map(x).collect::<Vec<_>>();
381 grammar.literals.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>();
383 let tokens = grammar.tokens.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>();
385 let nodes = grammar.nodes.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>();
388 #![allow(bad_style, missing_docs, unreachable_pub)]
389 /// The kind of syntax node, e.g. `IDENT`, `USE_KW`, or `STRUCT`.
390 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
392 pub enum SyntaxKind {
393 // Technical SyntaxKinds: they appear temporally during parsing,
394 // but never end up in the final tree
405 // Technical kind so that we can cast from u16 safely
409 use self::SyntaxKind::*;
412 pub fn is_keyword(self) -> bool {
414 #(#all_keywords)|* => true,
419 pub fn is_punct(self) -> bool {
421 #(#punctuation)|* => true,
426 pub fn is_literal(self) -> bool {
428 #(#literals)|* => true,
433 pub fn from_keyword(ident: &str) -> Option<SyntaxKind> {
434 let kw = match ident {
435 #(#full_keywords_values => #full_keywords,)*
441 pub fn from_contextual_keyword(ident: &str) -> Option<SyntaxKind> {
442 let kw = match ident {
443 #(#contextual_keywords_values => #contextual_keywords,)*
449 pub fn from_char(c: char) -> Option<SyntaxKind> {
451 #(#single_byte_tokens_values => #single_byte_tokens,)*
460 #([#punctuation_values] => { $crate::SyntaxKind::#punctuation };)*
461 #([#all_keywords_idents] => { $crate::SyntaxKind::#all_keywords };)*
462 [lifetime_ident] => { $crate::SyntaxKind::LIFETIME_IDENT };
463 [ident] => { $crate::SyntaxKind::IDENT };
464 [shebang] => { $crate::SyntaxKind::SHEBANG };
469 sourcegen::add_preamble("sourcegen_ast", sourcegen::reformat(ast.to_string()))
472 fn to_upper_snake_case(s: &str) -> String {
473 let mut buf = String::with_capacity(s.len());
474 let mut prev = false;
476 if c.is_ascii_uppercase() && prev {
481 buf.push(c.to_ascii_uppercase());
486 fn to_lower_snake_case(s: &str) -> String {
487 let mut buf = String::with_capacity(s.len());
488 let mut prev = false;
490 if c.is_ascii_uppercase() && prev {
495 buf.push(c.to_ascii_lowercase());
500 fn to_pascal_case(s: &str) -> String {
501 let mut buf = String::with_capacity(s.len());
502 let mut prev_is_underscore = true;
505 prev_is_underscore = true;
506 } else if prev_is_underscore {
507 buf.push(c.to_ascii_uppercase());
508 prev_is_underscore = false;
510 buf.push(c.to_ascii_lowercase());
516 fn pluralize(s: &str) -> String {
521 fn is_many(&self) -> bool {
522 matches!(self, Field::Node { cardinality: Cardinality::Many, .. })
524 fn token_kind(&self) -> Option<proc_macro2::TokenStream> {
526 Field::Token(token) => {
527 let token: proc_macro2::TokenStream = token.parse().unwrap();
528 Some(quote! { T![#token] })
533 fn method_name(&self) -> proc_macro2::Ident {
535 Field::Token(name) => {
536 let name = match name.as_str() {
538 "->" => "thin_arrow",
554 "..." => "dotdotdot",
559 "::" => "coloncolon",
561 "?" => "question_mark",
567 format_ident!("{}_token", name)
569 Field::Node { name, .. } => {
573 format_ident!("{}", name)
578 fn ty(&self) -> proc_macro2::Ident {
580 Field::Token(_) => format_ident!("SyntaxToken"),
581 Field::Node { ty, .. } => format_ident!("{}", ty),
586 fn lower(grammar: &Grammar) -> AstSrc {
587 let mut res = AstSrc {
588 tokens: "Whitespace Comment String ByteString IntNumber FloatNumber Char Byte Ident"
589 .split_ascii_whitespace()
590 .map(|it| it.to_string())
591 .collect::<Vec<_>>(),
595 let nodes = grammar.iter().collect::<Vec<_>>();
597 for &node in &nodes {
598 let name = grammar[node].name.clone();
599 let rule = &grammar[node].rule;
600 match lower_enum(grammar, rule) {
602 let enum_src = AstEnumSrc { doc: Vec::new(), name, traits: Vec::new(), variants };
603 res.enums.push(enum_src);
606 let mut fields = Vec::new();
607 lower_rule(&mut fields, grammar, None, rule);
608 res.nodes.push(AstNodeSrc { doc: Vec::new(), name, traits: Vec::new(), fields });
613 deduplicate_fields(&mut res);
614 extract_enums(&mut res);
615 extract_struct_traits(&mut res);
616 extract_enum_traits(&mut res);
620 fn lower_enum(grammar: &Grammar, rule: &Rule) -> Option<Vec<String>> {
621 let alternatives = match rule {
625 let mut variants = Vec::new();
626 for alternative in alternatives {
628 Rule::Node(it) => variants.push(grammar[*it].name.clone()),
629 Rule::Token(it) if grammar[*it].name == ";" => (),
636 fn lower_rule(acc: &mut Vec<Field>, grammar: &Grammar, label: Option<&String>, rule: &Rule) {
637 if lower_comma_list(acc, grammar, label, rule) {
642 Rule::Node(node) => {
643 let ty = grammar[*node].name.clone();
644 let name = label.cloned().unwrap_or_else(|| to_lower_snake_case(&ty));
645 let field = Field::Node { name, ty, cardinality: Cardinality::Optional };
648 Rule::Token(token) => {
649 assert!(label.is_none());
650 let mut name = grammar[*token].name.clone();
651 if name != "int_number" && name != "string" {
652 if "[]{}()".contains(&name) {
653 name = format!("'{}'", name);
655 let field = Field::Token(name);
659 Rule::Rep(inner) => {
660 if let Rule::Node(node) = &**inner {
661 let ty = grammar[*node].name.clone();
662 let name = label.cloned().unwrap_or_else(|| pluralize(&to_lower_snake_case(&ty)));
663 let field = Field::Node { name, ty, cardinality: Cardinality::Many };
667 panic!("unhandled rule: {:?}", rule)
669 Rule::Labeled { label: l, rule } => {
670 assert!(label.is_none());
671 let manually_implemented = matches!(
686 if manually_implemented {
689 lower_rule(acc, grammar, Some(l), rule);
691 Rule::Seq(rules) | Rule::Alt(rules) => {
693 lower_rule(acc, grammar, label, rule)
696 Rule::Opt(rule) => lower_rule(acc, grammar, label, rule),
702 acc: &mut Vec<Field>,
704 label: Option<&String>,
707 let rule = match rule {
711 let (node, repeat, trailing_comma) = match rule.as_slice() {
712 [Rule::Node(node), Rule::Rep(repeat), Rule::Opt(trailing_comma)] => {
713 (node, repeat, trailing_comma)
717 let repeat = match &**repeat {
721 match repeat.as_slice() {
722 [comma, Rule::Node(n)] if comma == &**trailing_comma && n == node => (),
725 let ty = grammar[*node].name.clone();
726 let name = label.cloned().unwrap_or_else(|| pluralize(&to_lower_snake_case(&ty)));
727 let field = Field::Node { name, ty, cardinality: Cardinality::Many };
732 fn deduplicate_fields(ast: &mut AstSrc) {
733 for node in &mut ast.nodes {
735 'outer: while i < node.fields.len() {
737 let f1 = &node.fields[i];
738 let f2 = &node.fields[j];
740 node.fields.remove(i);
749 fn extract_enums(ast: &mut AstSrc) {
750 for node in &mut ast.nodes {
751 for enm in &ast.enums {
752 let mut to_remove = Vec::new();
753 for (i, field) in node.fields.iter().enumerate() {
754 let ty = field.ty().to_string();
755 if enm.variants.iter().any(|it| it == &ty) {
759 if to_remove.len() == enm.variants.len() {
760 node.remove_field(to_remove);
761 let ty = enm.name.clone();
762 let name = to_lower_snake_case(&ty);
763 node.fields.push(Field::Node { name, ty, cardinality: Cardinality::Optional });
769 fn extract_struct_traits(ast: &mut AstSrc) {
770 let traits: &[(&str, &[&str])] = &[
771 ("HasAttrs", &["attrs"]),
772 ("HasName", &["name"]),
773 ("HasVisibility", &["visibility"]),
774 ("HasGenericParams", &["generic_param_list", "where_clause"]),
775 ("HasTypeBounds", &["type_bound_list", "colon_token"]),
776 ("HasModuleItem", &["items"]),
777 ("HasLoopBody", &["label", "loop_body"]),
778 ("HasArgList", &["arg_list"]),
781 for node in &mut ast.nodes {
782 for (name, methods) in traits {
783 extract_struct_trait(node, name, methods);
787 let nodes_with_doc_comments = [
810 for node in &mut ast.nodes {
811 if nodes_with_doc_comments.contains(&&*node.name) {
812 node.traits.push("HasDocComments".into());
817 fn extract_struct_trait(node: &mut AstNodeSrc, trait_name: &str, methods: &[&str]) {
818 let mut to_remove = Vec::new();
819 for (i, field) in node.fields.iter().enumerate() {
820 let method_name = field.method_name().to_string();
821 if methods.iter().any(|&it| it == method_name) {
825 if to_remove.len() == methods.len() {
826 node.traits.push(trait_name.to_string());
827 node.remove_field(to_remove);
831 fn extract_enum_traits(ast: &mut AstSrc) {
832 for enm in &mut ast.enums {
833 if enm.name == "Stmt" {
836 let nodes = &ast.nodes;
837 let mut variant_traits = enm
840 .map(|var| nodes.iter().find(|it| &it.name == var).unwrap())
841 .map(|node| node.traits.iter().cloned().collect::<BTreeSet<_>>());
843 let mut enum_traits = match variant_traits.next() {
847 for traits in variant_traits {
848 enum_traits = enum_traits.intersection(&traits).cloned().collect();
850 enm.traits = enum_traits.into_iter().collect();
855 fn remove_field(&mut self, to_remove: Vec<usize>) {
856 to_remove.into_iter().rev().for_each(|idx| {
857 self.fields.remove(idx);