//! This module generates AST datatype used by rust-analyzer. //! //! Specifically, it generates the `SyntaxKind` enum and a number of newtype //! wrappers around `SyntaxNode` which implement `ra_syntax::AstNode`. use proc_macro2::{Punct, Spacing}; use quote::{format_ident, quote}; use crate::{ ast_src::{AstSrc, FieldSrc, KindsSrc, AST_SRC, KINDS_SRC}, codegen::{self, update, Mode}, project_root, Result, }; pub fn generate_syntax(mode: Mode) -> Result<()> { let syntax_kinds_file = project_root().join(codegen::SYNTAX_KINDS); let syntax_kinds = generate_syntax_kinds(KINDS_SRC)?; update(syntax_kinds_file.as_path(), &syntax_kinds, mode)?; let ast_file = project_root().join(codegen::AST); let ast = generate_ast(AST_SRC)?; update(ast_file.as_path(), &ast, mode)?; Ok(()) } fn generate_ast(grammar: AstSrc<'_>) -> Result<String> { let nodes = grammar.nodes.iter().map(|node| { let name = format_ident!("{}", node.name); let kind = format_ident!("{}", to_upper_snake_case(&name.to_string())); let traits = node.traits.iter().map(|trait_name| { let trait_name = format_ident!("{}", trait_name); quote!(impl ast::#trait_name for #name {}) }); let methods = node.fields.iter().map(|(name, field)| { let method_name = match field { FieldSrc::Shorthand => format_ident!("{}", to_lower_snake_case(&name)), _ => format_ident!("{}", name), }; let ty = match field { FieldSrc::Optional(ty) | FieldSrc::Many(ty) => ty, FieldSrc::Shorthand => name, }; let ty = format_ident!("{}", ty); match field { FieldSrc::Many(_) => { quote! { pub fn #method_name(&self) -> AstChildren<#ty> { AstChildren::new(&self.syntax) } } } FieldSrc::Optional(_) | FieldSrc::Shorthand => { quote! { pub fn #method_name(&self) -> Option<#ty> { AstChildren::new(&self.syntax).next() } } } } }); quote! { #[derive(Debug, Clone, PartialEq, Eq, Hash)] pub struct #name { pub(crate) syntax: SyntaxNode, } impl AstNode for #name { fn can_cast(kind: SyntaxKind) -> bool { match kind { #kind => true, _ => false, } } fn cast(syntax: SyntaxNode) -> Option<Self> { if Self::can_cast(syntax.kind()) { Some(Self { syntax }) } else { None } } fn syntax(&self) -> &SyntaxNode { &self.syntax } } #(#traits)* impl #name { #(#methods)* } } }); let enums = grammar.enums.iter().map(|en| { let variants = en.variants.iter().map(|var| format_ident!("{}", var)).collect::<Vec<_>>(); let name = format_ident!("{}", en.name); let kinds = variants .iter() .map(|name| format_ident!("{}", to_upper_snake_case(&name.to_string()))) .collect::<Vec<_>>(); let traits = en.traits.iter().map(|trait_name| { let trait_name = format_ident!("{}", trait_name); quote!(impl ast::#trait_name for #name {}) }); quote! { #[derive(Debug, Clone, PartialEq, Eq, Hash)] pub enum #name { #(#variants(#variants),)* } #( impl From<#variants> for #name { fn from(node: #variants) -> #name { #name::#variants(node) } } )* impl AstNode for #name { fn can_cast(kind: SyntaxKind) -> bool { match kind { #(#kinds)|* => true, _ => false, } } fn cast(syntax: SyntaxNode) -> Option<Self> { let res = match syntax.kind() { #( #kinds => #name::#variants(#variants { syntax }), )* _ => return None, }; Some(res) } fn syntax(&self) -> &SyntaxNode { match self { #( #name::#variants(it) => &it.syntax, )* } } } #(#traits)* } }); let ast = quote! { use crate::{ SyntaxNode, SyntaxKind::{self, *}, ast::{self, AstNode, AstChildren}, }; #(#nodes)* #(#enums)* }; let pretty = crate::reformat(ast)?; Ok(pretty) } fn generate_syntax_kinds(grammar: KindsSrc<'_>) -> Result<String> { let (single_byte_tokens_values, single_byte_tokens): (Vec<_>, Vec<_>) = grammar .punct .iter() .filter(|(token, _name)| token.len() == 1) .map(|(token, name)| (token.chars().next().unwrap(), format_ident!("{}", name))) .unzip(); let punctuation_values = grammar.punct.iter().map(|(token, _name)| { if "{}[]()".contains(token) { let c = token.chars().next().unwrap(); quote! { #c } } else { let cs = token.chars().map(|c| Punct::new(c, Spacing::Joint)); quote! { #(#cs)* } } }); let punctuation = grammar.punct.iter().map(|(_token, name)| format_ident!("{}", name)).collect::<Vec<_>>(); let full_keywords_values = &grammar.keywords; let full_keywords = full_keywords_values.iter().map(|kw| format_ident!("{}_KW", to_upper_snake_case(&kw))); let all_keywords_values = grammar.keywords.iter().chain(grammar.contextual_keywords.iter()).collect::<Vec<_>>(); let all_keywords_idents = all_keywords_values.iter().map(|kw| format_ident!("{}", kw)); let all_keywords = all_keywords_values .iter() .map(|name| format_ident!("{}_KW", to_upper_snake_case(&name))) .collect::<Vec<_>>(); let literals = grammar.literals.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>(); let tokens = grammar.tokens.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>(); let nodes = grammar.nodes.iter().map(|name| format_ident!("{}", name)).collect::<Vec<_>>(); let ast = quote! { #![allow(bad_style, missing_docs, unreachable_pub)] /// The kind of syntax node, e.g. `IDENT`, `USE_KW`, or `STRUCT_DEF`. #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] #[repr(u16)] pub enum SyntaxKind { // Technical SyntaxKinds: they appear temporally during parsing, // but never end up in the final tree #[doc(hidden)] TOMBSTONE, #[doc(hidden)] EOF, #(#punctuation,)* #(#all_keywords,)* #(#literals,)* #(#tokens,)* #(#nodes,)* // Technical kind so that we can cast from u16 safely #[doc(hidden)] __LAST, } use self::SyntaxKind::*; impl SyntaxKind { pub fn is_keyword(self) -> bool { match self { #(#all_keywords)|* => true, _ => false, } } pub fn is_punct(self) -> bool { match self { #(#punctuation)|* => true, _ => false, } } pub fn is_literal(self) -> bool { match self { #(#literals)|* => true, _ => false, } } pub fn from_keyword(ident: &str) -> Option<SyntaxKind> { let kw = match ident { #(#full_keywords_values => #full_keywords,)* _ => return None, }; Some(kw) } pub fn from_char(c: char) -> Option<SyntaxKind> { let tok = match c { #(#single_byte_tokens_values => #single_byte_tokens,)* _ => return None, }; Some(tok) } } #[macro_export] macro_rules! T { #((#punctuation_values) => { $crate::SyntaxKind::#punctuation };)* #((#all_keywords_idents) => { $crate::SyntaxKind::#all_keywords };)* } }; crate::reformat(ast) } fn to_upper_snake_case(s: &str) -> String { let mut buf = String::with_capacity(s.len()); let mut prev_is_upper = None; for c in s.chars() { if c.is_ascii_uppercase() && prev_is_upper == Some(false) { buf.push('_') } prev_is_upper = Some(c.is_ascii_uppercase()); buf.push(c.to_ascii_uppercase()); } buf } fn to_lower_snake_case(s: &str) -> String { let mut buf = String::with_capacity(s.len()); let mut prev_is_upper = None; for c in s.chars() { if c.is_ascii_uppercase() && prev_is_upper == Some(false) { buf.push('_') } prev_is_upper = Some(c.is_ascii_uppercase()); buf.push(c.to_ascii_lowercase()); } buf }