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, therefore 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 {
172 matches!(kind, #(#kinds)|*)
174 fn cast(syntax: SyntaxNode) -> Option<Self> {
175 let res = match syntax.kind() {
177 #kinds => #name::#variants(#variants { syntax }),
183 fn syntax(&self) -> &SyntaxNode {
186 #name::#variants(it) => &it.syntax,
196 #[pretty_doc_comment_placeholder_workaround]
197 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
199 #(#variants(#variants),)*
206 impl From<#variants> for #name {
207 fn from(node: #variants) -> #name {
208 #name::#variants(node)
218 let (any_node_defs, any_node_boilerplate_impls): (Vec<_>, Vec<_>) = grammar
221 .flat_map(|node| node.traits.iter().map(move |t| (t, node)))
224 .sorted_by_key(|(k, _)| *k)
225 .map(|(trait_name, nodes)| {
226 let name = format_ident!("Any{}", trait_name);
227 let trait_name = format_ident!("{}", trait_name);
228 let kinds: Vec<_> = nodes
230 .map(|name| format_ident!("{}", to_upper_snake_case(&name.name.to_string())))
235 #[pretty_doc_comment_placeholder_workaround]
236 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
238 pub(crate) syntax: SyntaxNode,
240 impl ast::#trait_name for #name {}
245 pub fn new<T: ast::#trait_name>(node: T) -> #name {
247 syntax: node.syntax().clone()
251 impl AstNode for #name {
252 fn can_cast(kind: SyntaxKind) -> bool {
253 matches!(kind, #(#kinds)|*)
255 fn cast(syntax: SyntaxNode) -> Option<Self> {
256 Self::can_cast(syntax.kind()).then_some(#name { syntax })
258 fn syntax(&self) -> &SyntaxNode {
267 let enum_names = grammar.enums.iter().map(|it| &it.name);
268 let node_names = grammar.nodes.iter().map(|it| &it.name);
271 enum_names.chain(node_names.clone()).map(|it| format_ident!("{}", it)).map(|name| {
273 impl std::fmt::Display for #name {
274 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
275 std::fmt::Display::fmt(self.syntax(), f)
281 let defined_nodes: HashSet<_> = node_names.collect();
286 .map(|kind| to_pascal_case(kind))
287 .filter(|name| !defined_nodes.iter().any(|&it| it == name))
290 // FIXME: restore this
291 // eprintln!("Warning: node {} not defined in ast source", node);
295 #![allow(non_snake_case)]
297 SyntaxNode, SyntaxToken, SyntaxKind::{self, *},
298 ast::{self, AstNode, AstChildren, support},
305 #(#node_boilerplate_impls)*
306 #(#enum_boilerplate_impls)*
307 #(#any_node_boilerplate_impls)*
311 let ast = ast.to_string().replace("T ! [", "T![");
313 let mut res = String::with_capacity(ast.len() * 2);
316 grammar.nodes.iter().map(|it| &it.doc).chain(grammar.enums.iter().map(|it| &it.doc));
318 for chunk in ast.split("# [pretty_doc_comment_placeholder_workaround] ") {
320 if let Some(doc) = docs.next() {
321 write_doc_comment(doc, &mut res);
325 let res = sourcegen::add_preamble("sourcegen_ast", sourcegen::reformat(res));
326 res.replace("#[derive", "\n#[derive")
329 fn write_doc_comment(contents: &[String], dest: &mut String) {
330 for line in contents {
331 writeln!(dest, "///{line}").unwrap();
335 fn generate_syntax_kinds(grammar: KindsSrc<'_>) -> String {
336 let (single_byte_tokens_values, single_byte_tokens): (Vec<_>, Vec<_>) = grammar
339 .filter(|(token, _name)| token.len() == 1)
340 .map(|(token, name)| (token.chars().next().unwrap(), format_ident!("{}", name)))
343 let punctuation_values = grammar.punct.iter().map(|(token, _name)| {
344 if "{}[]()".contains(token) {
345 let c = token.chars().next().unwrap();
348 let cs = token.chars().map(|c| Punct::new(c, Spacing::Joint));
353 grammar.punct.iter().map(|(_token, name)| format_ident!("{}", name)).collect::<Vec<_>>();
355 let x = |&name| match name {
356 "Self" => format_ident!("SELF_TYPE_KW"),
357 name => format_ident!("{}_KW", to_upper_snake_case(name)),
359 let full_keywords_values = grammar.keywords;
360 let full_keywords = full_keywords_values.iter().map(x);
362 let contextual_keywords_values = &grammar.contextual_keywords;
363 let contextual_keywords = contextual_keywords_values.iter().map(x);
365 let all_keywords_values = grammar
368 .chain(grammar.contextual_keywords.iter())
370 .collect::<Vec<_>>();
371 let all_keywords_idents = all_keywords_values.iter().map(|kw| format_ident!("{}", kw));
372 let all_keywords = all_keywords_values.iter().map(x).collect::<Vec<_>>();
375 grammar.literals.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>();
377 let tokens = grammar.tokens.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>();
379 let nodes = grammar.nodes.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>();
382 #![allow(bad_style, missing_docs, unreachable_pub)]
383 /// The kind of syntax node, e.g. `IDENT`, `USE_KW`, or `STRUCT`.
384 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
386 pub enum SyntaxKind {
387 // Technical SyntaxKinds: they appear temporally during parsing,
388 // but never end up in the final tree
399 // Technical kind so that we can cast from u16 safely
403 use self::SyntaxKind::*;
406 pub fn is_keyword(self) -> bool {
407 matches!(self, #(#all_keywords)|*)
410 pub fn is_punct(self) -> bool {
412 matches!(self, #(#punctuation)|*)
416 pub fn is_literal(self) -> bool {
417 matches!(self, #(#literals)|*)
420 pub fn from_keyword(ident: &str) -> Option<SyntaxKind> {
421 let kw = match ident {
422 #(#full_keywords_values => #full_keywords,)*
428 pub fn from_contextual_keyword(ident: &str) -> Option<SyntaxKind> {
429 let kw = match ident {
430 #(#contextual_keywords_values => #contextual_keywords,)*
436 pub fn from_char(c: char) -> Option<SyntaxKind> {
438 #(#single_byte_tokens_values => #single_byte_tokens,)*
447 #([#punctuation_values] => { $crate::SyntaxKind::#punctuation };)*
448 #([#all_keywords_idents] => { $crate::SyntaxKind::#all_keywords };)*
449 [lifetime_ident] => { $crate::SyntaxKind::LIFETIME_IDENT };
450 [ident] => { $crate::SyntaxKind::IDENT };
451 [shebang] => { $crate::SyntaxKind::SHEBANG };
456 sourcegen::add_preamble("sourcegen_ast", sourcegen::reformat(ast.to_string()))
459 fn to_upper_snake_case(s: &str) -> String {
460 let mut buf = String::with_capacity(s.len());
461 let mut prev = false;
463 if c.is_ascii_uppercase() && prev {
468 buf.push(c.to_ascii_uppercase());
473 fn to_lower_snake_case(s: &str) -> String {
474 let mut buf = String::with_capacity(s.len());
475 let mut prev = false;
477 if c.is_ascii_uppercase() && prev {
482 buf.push(c.to_ascii_lowercase());
487 fn to_pascal_case(s: &str) -> String {
488 let mut buf = String::with_capacity(s.len());
489 let mut prev_is_underscore = true;
492 prev_is_underscore = true;
493 } else if prev_is_underscore {
494 buf.push(c.to_ascii_uppercase());
495 prev_is_underscore = false;
497 buf.push(c.to_ascii_lowercase());
503 fn pluralize(s: &str) -> String {
508 fn is_many(&self) -> bool {
509 matches!(self, Field::Node { cardinality: Cardinality::Many, .. })
511 fn token_kind(&self) -> Option<proc_macro2::TokenStream> {
513 Field::Token(token) => {
514 let token: proc_macro2::TokenStream = token.parse().unwrap();
515 Some(quote! { T![#token] })
520 fn method_name(&self) -> proc_macro2::Ident {
522 Field::Token(name) => {
523 let name = match name.as_str() {
525 "->" => "thin_arrow",
541 "..." => "dotdotdot",
546 "::" => "coloncolon",
548 "?" => "question_mark",
554 format_ident!("{}_token", name)
556 Field::Node { name, .. } => {
560 format_ident!("{}", name)
565 fn ty(&self) -> proc_macro2::Ident {
567 Field::Token(_) => format_ident!("SyntaxToken"),
568 Field::Node { ty, .. } => format_ident!("{}", ty),
573 fn lower(grammar: &Grammar) -> AstSrc {
574 let mut res = AstSrc {
575 tokens: "Whitespace Comment String ByteString IntNumber FloatNumber Char Byte Ident"
576 .split_ascii_whitespace()
577 .map(|it| it.to_string())
578 .collect::<Vec<_>>(),
582 let nodes = grammar.iter().collect::<Vec<_>>();
584 for &node in &nodes {
585 let name = grammar[node].name.clone();
586 let rule = &grammar[node].rule;
587 match lower_enum(grammar, rule) {
589 let enum_src = AstEnumSrc { doc: Vec::new(), name, traits: Vec::new(), variants };
590 res.enums.push(enum_src);
593 let mut fields = Vec::new();
594 lower_rule(&mut fields, grammar, None, rule);
595 res.nodes.push(AstNodeSrc { doc: Vec::new(), name, traits: Vec::new(), fields });
600 deduplicate_fields(&mut res);
601 extract_enums(&mut res);
602 extract_struct_traits(&mut res);
603 extract_enum_traits(&mut res);
607 fn lower_enum(grammar: &Grammar, rule: &Rule) -> Option<Vec<String>> {
608 let alternatives = match rule {
612 let mut variants = Vec::new();
613 for alternative in alternatives {
615 Rule::Node(it) => variants.push(grammar[*it].name.clone()),
616 Rule::Token(it) if grammar[*it].name == ";" => (),
623 fn lower_rule(acc: &mut Vec<Field>, grammar: &Grammar, label: Option<&String>, rule: &Rule) {
624 if lower_comma_list(acc, grammar, label, rule) {
629 Rule::Node(node) => {
630 let ty = grammar[*node].name.clone();
631 let name = label.cloned().unwrap_or_else(|| to_lower_snake_case(&ty));
632 let field = Field::Node { name, ty, cardinality: Cardinality::Optional };
635 Rule::Token(token) => {
636 assert!(label.is_none());
637 let mut name = grammar[*token].name.clone();
638 if name != "int_number" && name != "string" {
639 if "[]{}()".contains(&name) {
640 name = format!("'{name}'");
642 let field = Field::Token(name);
646 Rule::Rep(inner) => {
647 if let Rule::Node(node) = &**inner {
648 let ty = grammar[*node].name.clone();
649 let name = label.cloned().unwrap_or_else(|| pluralize(&to_lower_snake_case(&ty)));
650 let field = Field::Node { name, ty, cardinality: Cardinality::Many };
654 panic!("unhandled rule: {rule:?}")
656 Rule::Labeled { label: l, rule } => {
657 assert!(label.is_none());
658 let manually_implemented = matches!(
675 if manually_implemented {
678 lower_rule(acc, grammar, Some(l), rule);
680 Rule::Seq(rules) | Rule::Alt(rules) => {
682 lower_rule(acc, grammar, label, rule)
685 Rule::Opt(rule) => lower_rule(acc, grammar, label, rule),
691 acc: &mut Vec<Field>,
693 label: Option<&String>,
696 let rule = match rule {
700 let (node, repeat, trailing_comma) = match rule.as_slice() {
701 [Rule::Node(node), Rule::Rep(repeat), Rule::Opt(trailing_comma)] => {
702 (node, repeat, trailing_comma)
706 let repeat = match &**repeat {
710 match repeat.as_slice() {
711 [comma, Rule::Node(n)] if comma == &**trailing_comma && n == node => (),
714 let ty = grammar[*node].name.clone();
715 let name = label.cloned().unwrap_or_else(|| pluralize(&to_lower_snake_case(&ty)));
716 let field = Field::Node { name, ty, cardinality: Cardinality::Many };
721 fn deduplicate_fields(ast: &mut AstSrc) {
722 for node in &mut ast.nodes {
724 'outer: while i < node.fields.len() {
726 let f1 = &node.fields[i];
727 let f2 = &node.fields[j];
729 node.fields.remove(i);
738 fn extract_enums(ast: &mut AstSrc) {
739 for node in &mut ast.nodes {
740 for enm in &ast.enums {
741 let mut to_remove = Vec::new();
742 for (i, field) in node.fields.iter().enumerate() {
743 let ty = field.ty().to_string();
744 if enm.variants.iter().any(|it| it == &ty) {
748 if to_remove.len() == enm.variants.len() {
749 node.remove_field(to_remove);
750 let ty = enm.name.clone();
751 let name = to_lower_snake_case(&ty);
752 node.fields.push(Field::Node { name, ty, cardinality: Cardinality::Optional });
758 fn extract_struct_traits(ast: &mut AstSrc) {
759 let traits: &[(&str, &[&str])] = &[
760 ("HasAttrs", &["attrs"]),
761 ("HasName", &["name"]),
762 ("HasVisibility", &["visibility"]),
763 ("HasGenericParams", &["generic_param_list", "where_clause"]),
764 ("HasTypeBounds", &["type_bound_list", "colon_token"]),
765 ("HasModuleItem", &["items"]),
766 ("HasLoopBody", &["label", "loop_body"]),
767 ("HasArgList", &["arg_list"]),
770 for node in &mut ast.nodes {
771 for (name, methods) in traits {
772 extract_struct_trait(node, name, methods);
776 let nodes_with_doc_comments = [
799 for node in &mut ast.nodes {
800 if nodes_with_doc_comments.contains(&&*node.name) {
801 node.traits.push("HasDocComments".into());
806 fn extract_struct_trait(node: &mut AstNodeSrc, trait_name: &str, methods: &[&str]) {
807 let mut to_remove = Vec::new();
808 for (i, field) in node.fields.iter().enumerate() {
809 let method_name = field.method_name().to_string();
810 if methods.iter().any(|&it| it == method_name) {
814 if to_remove.len() == methods.len() {
815 node.traits.push(trait_name.to_string());
816 node.remove_field(to_remove);
820 fn extract_enum_traits(ast: &mut AstSrc) {
821 for enm in &mut ast.enums {
822 if enm.name == "Stmt" {
825 let nodes = &ast.nodes;
826 let mut variant_traits = enm
829 .map(|var| nodes.iter().find(|it| &it.name == var).unwrap())
830 .map(|node| node.traits.iter().cloned().collect::<BTreeSet<_>>());
832 let mut enum_traits = match variant_traits.next() {
836 for traits in variant_traits {
837 enum_traits = enum_traits.intersection(&traits).cloned().collect();
839 enm.traits = enum_traits.into_iter().collect();
844 fn remove_field(&mut self, to_remove: Vec<usize>) {
845 to_remove.into_iter().rev().for_each(|idx| {
846 self.fields.remove(idx);