Split the visit and visit_mut codegen
diff --git a/codegen/src/gen.rs b/codegen/src/gen.rs
deleted file mode 100644
index 6dd6349..0000000
--- a/codegen/src/gen.rs
+++ /dev/null
@@ -1,549 +0,0 @@
-use crate::file;
-use quote::quote;
-use syn_codegen as types;
-
-const VISIT_SRC: &str = "../src/gen/visit.rs";
-const VISIT_MUT_SRC: &str = "../src/gen/visit_mut.rs";
-
-mod codegen {
- use inflections::Inflect;
- use proc_macro2::{Span, TokenStream};
- use quote::{quote, TokenStreamExt};
- use syn::*;
- use syn_codegen as types;
-
- #[derive(Default)]
- pub struct State {
- pub visit_trait: TokenStream,
- pub visit_impl: TokenStream,
- pub visit_mut_trait: TokenStream,
- pub visit_mut_impl: TokenStream,
- }
-
- fn under_name(name: &str) -> Ident {
- Ident::new(&name.to_snake_case(), Span::call_site())
- }
-
- #[derive(Debug, Eq, PartialEq, Copy, Clone)]
- enum Kind {
- Visit,
- VisitMut,
- }
-
- enum Operand {
- Borrowed(TokenStream),
- Owned(TokenStream),
- }
-
- use self::Kind::*;
- use self::Operand::*;
-
- impl Operand {
- fn tokens(&self) -> &TokenStream {
- match *self {
- Borrowed(ref n) | Owned(ref n) => n,
- }
- }
-
- fn ref_tokens(&self) -> TokenStream {
- match *self {
- Borrowed(ref n) => n.clone(),
- Owned(ref n) => quote!(&#n),
- }
- }
-
- fn ref_mut_tokens(&self) -> TokenStream {
- match *self {
- Borrowed(ref n) => n.clone(),
- Owned(ref n) => quote!(&mut #n),
- }
- }
-
- fn owned_tokens(&self) -> TokenStream {
- match *self {
- Borrowed(ref n) => quote!(*#n),
- Owned(ref n) => n.clone(),
- }
- }
- }
-
- fn simple_visit(item: &str, kind: Kind, name: &Operand) -> TokenStream {
- let ident = under_name(item);
-
- match kind {
- Visit => {
- let method = Ident::new(&format!("visit_{}", ident), Span::call_site());
- let name = name.ref_tokens();
- quote! {
- _visitor.#method(#name)
- }
- }
- VisitMut => {
- let method = Ident::new(&format!("visit_{}_mut", ident), Span::call_site());
- let name = name.ref_mut_tokens();
- quote! {
- _visitor.#method(#name)
- }
- }
- }
- }
-
- fn box_visit(
- elem: &types::Type,
- features: &types::Features,
- defs: &types::Definitions,
- kind: Kind,
- name: &Operand,
- ) -> Option<TokenStream> {
- let name = name.owned_tokens();
- let res = visit(elem, features, defs, kind, &Owned(quote!(*#name)))?;
- Some(res)
- }
-
- fn vec_visit(
- elem: &types::Type,
- features: &types::Features,
- defs: &types::Definitions,
- kind: Kind,
- name: &Operand,
- ) -> Option<TokenStream> {
- let operand = Borrowed(quote!(it));
- let val = visit(elem, features, defs, kind, &operand)?;
- Some(match kind {
- Visit => {
- let name = name.ref_tokens();
- quote! {
- for it in #name {
- #val
- }
- }
- }
- VisitMut => {
- let name = name.ref_mut_tokens();
- quote! {
- for it in #name {
- #val
- }
- }
- }
- })
- }
-
- fn punctuated_visit(
- elem: &types::Type,
- features: &types::Features,
- defs: &types::Definitions,
- kind: Kind,
- name: &Operand,
- ) -> Option<TokenStream> {
- let operand = Borrowed(quote!(it));
- let val = visit(elem, features, defs, kind, &operand)?;
- Some(match kind {
- Visit => {
- let name = name.ref_tokens();
- quote! {
- for el in Punctuated::pairs(#name) {
- let it = el.value();
- #val
- }
- }
- }
- VisitMut => {
- let name = name.ref_mut_tokens();
- quote! {
- for mut el in Punctuated::pairs_mut(#name) {
- let it = el.value_mut();
- #val
- }
- }
- }
- })
- }
-
- fn option_visit(
- elem: &types::Type,
- features: &types::Features,
- defs: &types::Definitions,
- kind: Kind,
- name: &Operand,
- ) -> Option<TokenStream> {
- let it = Borrowed(quote!(it));
- let val = visit(elem, features, defs, kind, &it)?;
- let name = name.owned_tokens();
- Some(match kind {
- Visit => quote! {
- if let Some(ref it) = #name {
- #val
- }
- },
- VisitMut => quote! {
- if let Some(ref mut it) = #name {
- #val
- }
- },
- })
- }
-
- fn tuple_visit(
- elems: &[types::Type],
- features: &types::Features,
- defs: &types::Definitions,
- kind: Kind,
- name: &Operand,
- ) -> Option<TokenStream> {
- if elems.is_empty() {
- return None;
- }
-
- let mut code = TokenStream::new();
- for (i, elem) in elems.iter().enumerate() {
- let name = name.tokens();
- let i = Index::from(i);
- let it = Owned(quote!((#name).#i));
- let val = visit(elem, features, defs, kind, &it).unwrap_or_else(|| noop_visit(&it));
- code.append_all(val);
- code.append_all(quote!(;));
- }
- Some(code)
- }
-
- fn token_punct_visit(kind: Kind, name: &Operand) -> TokenStream {
- let name = name.tokens();
- match kind {
- Visit => quote! {
- tokens_helper(_visitor, &#name.spans)
- },
- VisitMut => quote! {
- tokens_helper(_visitor, &mut #name.spans)
- },
- }
- }
-
- fn token_keyword_visit(kind: Kind, name: &Operand) -> TokenStream {
- let name = name.tokens();
- match kind {
- Visit => quote! {
- tokens_helper(_visitor, &#name.span)
- },
- VisitMut => quote! {
- tokens_helper(_visitor, &mut #name.span)
- },
- }
- }
-
- fn token_group_visit(kind: Kind, name: &Operand) -> TokenStream {
- let name = name.tokens();
- match kind {
- Visit => quote! {
- tokens_helper(_visitor, &#name.span)
- },
- VisitMut => quote! {
- tokens_helper(_visitor, &mut #name.span)
- },
- }
- }
-
- fn noop_visit(name: &Operand) -> TokenStream {
- let name = name.tokens();
- quote! {
- skip!(#name)
- }
- }
-
- fn visit(
- ty: &types::Type,
- features: &types::Features,
- defs: &types::Definitions,
- kind: Kind,
- name: &Operand,
- ) -> Option<TokenStream> {
- match ty {
- types::Type::Box(t) => box_visit(&*t, features, defs, kind, name),
- types::Type::Vec(t) => vec_visit(&*t, features, defs, kind, name),
- types::Type::Punctuated(p) => punctuated_visit(&p.element, features, defs, kind, name),
- types::Type::Option(t) => option_visit(&*t, features, defs, kind, name),
- types::Type::Tuple(t) => tuple_visit(t, features, defs, kind, name),
- types::Type::Token(t) => {
- let repr = &defs.tokens[t];
- let is_keyword = repr.chars().next().unwrap().is_alphabetic();
- if is_keyword {
- Some(token_keyword_visit(kind, name))
- } else {
- Some(token_punct_visit(kind, name))
- }
- }
- types::Type::Group(_) => Some(token_group_visit(kind, name)),
- types::Type::Syn(t) => {
- fn requires_full(features: &types::Features) -> bool {
- features.any.contains("full") && features.any.len() == 1
- }
-
- let res = simple_visit(t, kind, name);
-
- let target = defs.types.iter().find(|ty| ty.ident == *t).unwrap();
-
- Some(
- if requires_full(&target.features) && !requires_full(features) {
- quote! {
- full!(#res)
- }
- } else {
- res
- },
- )
- }
- types::Type::Ext(t) if super::TERMINAL_TYPES.contains(&&t[..]) => {
- Some(simple_visit(t, kind, name))
- }
- types::Type::Ext(_) | types::Type::Std(_) => None,
- }
- }
-
- fn visit_features(features: &types::Features) -> TokenStream {
- let features = &features.any;
- match features.len() {
- 0 => quote!(),
- 1 => quote!(#[cfg(feature = #(#features)*)]),
- _ => quote!(#[cfg(any(#(feature = #features),*))]),
- }
- }
-
- pub fn generate(state: &mut State, s: &types::Node, defs: &types::Definitions) {
- let features = visit_features(&s.features);
- let under_name = under_name(&s.ident);
- let ty = Ident::new(&s.ident, Span::call_site());
- let visit_fn = Ident::new(&format!("visit_{}", under_name), Span::call_site());
- let visit_mut_fn = Ident::new(&format!("visit_{}_mut", under_name), Span::call_site());
-
- let mut visit_impl = TokenStream::new();
- let mut visit_mut_impl = TokenStream::new();
-
- match &s.data {
- types::Data::Enum(variants) => {
- let mut visit_variants = TokenStream::new();
- let mut visit_mut_variants = TokenStream::new();
-
- for (variant, fields) in variants {
- let variant_ident = Ident::new(variant, Span::call_site());
-
- if fields.is_empty() {
- visit_variants.append_all(quote! {
- #ty::#variant_ident => {}
- });
- visit_mut_variants.append_all(quote! {
- #ty::#variant_ident => {}
- });
- } else {
- let mut bind_visit_fields = TokenStream::new();
- let mut bind_visit_mut_fields = TokenStream::new();
-
- let mut visit_fields = TokenStream::new();
- let mut visit_mut_fields = TokenStream::new();
-
- for (idx, ty) in fields.iter().enumerate() {
- let name = format!("_binding_{}", idx);
- let binding = Ident::new(&name, Span::call_site());
-
- bind_visit_fields.append_all(quote! {
- ref #binding,
- });
- bind_visit_mut_fields.append_all(quote! {
- ref mut #binding,
- });
-
- let borrowed_binding = Borrowed(quote!(#binding));
-
- visit_fields.append_all(
- visit(ty, &s.features, defs, Visit, &borrowed_binding)
- .unwrap_or_else(|| noop_visit(&borrowed_binding)),
- );
- visit_mut_fields.append_all(
- visit(ty, &s.features, defs, VisitMut, &borrowed_binding)
- .unwrap_or_else(|| noop_visit(&borrowed_binding)),
- );
-
- visit_fields.append_all(quote!(;));
- visit_mut_fields.append_all(quote!(;));
- }
-
- visit_variants.append_all(quote! {
- #ty::#variant_ident(#bind_visit_fields) => {
- #visit_fields
- }
- });
-
- visit_mut_variants.append_all(quote! {
- #ty::#variant_ident(#bind_visit_mut_fields) => {
- #visit_mut_fields
- }
- });
- }
- }
-
- visit_impl.append_all(quote! {
- match *_i {
- #visit_variants
- }
- });
-
- visit_mut_impl.append_all(quote! {
- match *_i {
- #visit_mut_variants
- }
- });
- }
- types::Data::Struct(fields) => {
- for (field, ty) in fields {
- let id = Ident::new(&field, Span::call_site());
- let ref_toks = Owned(quote!(_i.#id));
- let visit_field = visit(&ty, &s.features, defs, Visit, &ref_toks)
- .unwrap_or_else(|| noop_visit(&ref_toks));
- visit_impl.append_all(quote! {
- #visit_field;
- });
- let visit_mut_field = visit(&ty, &s.features, defs, VisitMut, &ref_toks)
- .unwrap_or_else(|| noop_visit(&ref_toks));
- visit_mut_impl.append_all(quote! {
- #visit_mut_field;
- });
- }
- }
- types::Data::Private => {}
- }
-
- state.visit_trait.append_all(quote! {
- #features
- fn #visit_fn(&mut self, i: &'ast #ty) {
- #visit_fn(self, i)
- }
- });
-
- state.visit_impl.append_all(quote! {
- #features
- pub fn #visit_fn<'ast, V: Visit<'ast> + ?Sized>(
- _visitor: &mut V, _i: &'ast #ty
- ) {
- #visit_impl
- }
- });
-
- state.visit_mut_trait.append_all(quote! {
- #features
- fn #visit_mut_fn(&mut self, i: &mut #ty) {
- #visit_mut_fn(self, i)
- }
- });
-
- state.visit_mut_impl.append_all(quote! {
- #features
- pub fn #visit_mut_fn<V: VisitMut + ?Sized>(
- _visitor: &mut V, _i: &mut #ty
- ) {
- #visit_mut_impl
- }
- });
- }
-}
-
-const TERMINAL_TYPES: &[&str] = &["Span", "Ident"];
-
-pub fn generate(defs: &types::Definitions) {
- let mut state = codegen::State::default();
- for s in &defs.types {
- codegen::generate(&mut state, s, defs);
- }
- for tt in TERMINAL_TYPES {
- let s = types::Node {
- ident: tt.to_string(),
- features: types::Features::default(),
- data: types::Data::Private,
- };
- codegen::generate(&mut state, &s, defs);
- }
-
- let full_macro = quote! {
- #[cfg(feature = "full")]
- macro_rules! full {
- ($e:expr) => {
- $e
- };
- }
-
- #[cfg(all(feature = "derive", not(feature = "full")))]
- macro_rules! full {
- ($e:expr) => {
- unreachable!()
- };
- }
- };
-
- let skip_macro = quote! {
- #[cfg(any(feature = "full", feature = "derive"))]
- macro_rules! skip {
- ($($tt:tt)*) => {};
- }
- };
-
- let visit_trait = state.visit_trait;
- let visit_impl = state.visit_impl;
- file::write(
- VISIT_SRC,
- quote! {
- #![cfg_attr(feature = "cargo-clippy", allow(trivially_copy_pass_by_ref))]
-
- use *;
- #[cfg(any(feature = "full", feature = "derive"))]
- use punctuated::Punctuated;
- use proc_macro2::Span;
- #[cfg(any(feature = "full", feature = "derive"))]
- use gen::helper::visit::*;
-
- #full_macro
- #skip_macro
-
- /// Syntax tree traversal to walk a shared borrow of a syntax tree.
- ///
- /// See the [module documentation] for details.
- ///
- /// [module documentation]: index.html
- ///
- /// *This trait is available if Syn is built with the `"visit"` feature.*
- pub trait Visit<'ast> {
- #visit_trait
- }
-
- #visit_impl
- },
- );
-
- let visit_mut_trait = state.visit_mut_trait;
- let visit_mut_impl = state.visit_mut_impl;
- file::write(
- VISIT_MUT_SRC,
- quote! {
- use *;
- #[cfg(any(feature = "full", feature = "derive"))]
- use punctuated::Punctuated;
- use proc_macro2::Span;
- #[cfg(any(feature = "full", feature = "derive"))]
- use gen::helper::visit_mut::*;
-
- #full_macro
- #skip_macro
-
- /// Syntax tree traversal to mutate an exclusive borrow of a syntax tree in
- /// place.
- ///
- /// See the [module documentation] for details.
- ///
- /// [module documentation]: index.html
- ///
- /// *This trait is available if Syn is built with the `"visit-mut"` feature.*
- pub trait VisitMut {
- #visit_mut_trait
- }
-
- #visit_mut_impl
- },
- );
-}
diff --git a/codegen/src/main.rs b/codegen/src/main.rs
index a83cbfc..8fd5cf9 100644
--- a/codegen/src/main.rs
+++ b/codegen/src/main.rs
@@ -14,14 +14,16 @@
mod file;
mod fold;
-mod gen;
mod json;
mod parse;
mod version;
+mod visit;
+mod visit_mut;
fn main() {
let defs = parse::parse();
json::generate(&defs);
- gen::generate(&defs);
fold::generate(&defs);
+ visit::generate(&defs);
+ visit_mut::generate(&defs);
}
diff --git a/codegen/src/visit.rs b/codegen/src/visit.rs
new file mode 100644
index 0000000..c13e95d
--- /dev/null
+++ b/codegen/src/visit.rs
@@ -0,0 +1,386 @@
+use crate::file;
+use quote::quote;
+use syn_codegen as types;
+
+const VISIT_SRC: &str = "../src/gen/visit.rs";
+
+mod codegen {
+ use inflections::Inflect;
+ use proc_macro2::{Span, TokenStream};
+ use quote::{quote, TokenStreamExt};
+ use syn::*;
+ use syn_codegen as types;
+
+ #[derive(Default)]
+ pub struct State {
+ pub visit_trait: TokenStream,
+ pub visit_impl: TokenStream,
+ }
+
+ fn under_name(name: &str) -> Ident {
+ Ident::new(&name.to_snake_case(), Span::call_site())
+ }
+
+ enum Operand {
+ Borrowed(TokenStream),
+ Owned(TokenStream),
+ }
+
+ use self::Operand::*;
+
+ impl Operand {
+ fn tokens(&self) -> &TokenStream {
+ match *self {
+ Borrowed(ref n) | Owned(ref n) => n,
+ }
+ }
+
+ fn ref_tokens(&self) -> TokenStream {
+ match *self {
+ Borrowed(ref n) => n.clone(),
+ Owned(ref n) => quote!(&#n),
+ }
+ }
+
+ fn owned_tokens(&self) -> TokenStream {
+ match *self {
+ Borrowed(ref n) => quote!(*#n),
+ Owned(ref n) => n.clone(),
+ }
+ }
+ }
+
+ fn simple_visit(item: &str, name: &Operand) -> TokenStream {
+ let ident = under_name(item);
+ let method = Ident::new(&format!("visit_{}", ident), Span::call_site());
+ let name = name.ref_tokens();
+ quote! {
+ _visitor.#method(#name)
+ }
+ }
+
+ fn box_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let name = name.owned_tokens();
+ let res = visit(elem, features, defs, &Owned(quote!(*#name)))?;
+ Some(res)
+ }
+
+ fn vec_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let operand = Borrowed(quote!(it));
+ let val = visit(elem, features, defs, &operand)?;
+ let name = name.ref_tokens();
+ Some(quote! {
+ for it in #name {
+ #val
+ }
+ })
+ }
+
+ fn punctuated_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let operand = Borrowed(quote!(it));
+ let val = visit(elem, features, defs, &operand)?;
+ let name = name.ref_tokens();
+ Some(quote! {
+ for el in Punctuated::pairs(#name) {
+ let it = el.value();
+ #val
+ }
+ })
+ }
+
+ fn option_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let it = Borrowed(quote!(it));
+ let val = visit(elem, features, defs, &it)?;
+ let name = name.owned_tokens();
+ Some(quote! {
+ if let Some(ref it) = #name {
+ #val
+ }
+ })
+ }
+
+ fn tuple_visit(
+ elems: &[types::Type],
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ if elems.is_empty() {
+ return None;
+ }
+
+ let mut code = TokenStream::new();
+ for (i, elem) in elems.iter().enumerate() {
+ let name = name.tokens();
+ let i = Index::from(i);
+ let it = Owned(quote!((#name).#i));
+ let val = visit(elem, features, defs, &it).unwrap_or_else(|| noop_visit(&it));
+ code.append_all(val);
+ code.append_all(quote!(;));
+ }
+ Some(code)
+ }
+
+ fn token_punct_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ tokens_helper(_visitor, &#name.spans)
+ }
+ }
+
+ fn token_keyword_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ tokens_helper(_visitor, &#name.span)
+ }
+ }
+
+ fn token_group_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ tokens_helper(_visitor, &#name.span)
+ }
+ }
+
+ fn noop_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ skip!(#name)
+ }
+ }
+
+ fn visit(
+ ty: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ match ty {
+ types::Type::Box(t) => box_visit(&*t, features, defs, name),
+ types::Type::Vec(t) => vec_visit(&*t, features, defs, name),
+ types::Type::Punctuated(p) => punctuated_visit(&p.element, features, defs, name),
+ types::Type::Option(t) => option_visit(&*t, features, defs, name),
+ types::Type::Tuple(t) => tuple_visit(t, features, defs, name),
+ types::Type::Token(t) => {
+ let repr = &defs.tokens[t];
+ let is_keyword = repr.chars().next().unwrap().is_alphabetic();
+ if is_keyword {
+ Some(token_keyword_visit(name))
+ } else {
+ Some(token_punct_visit(name))
+ }
+ }
+ types::Type::Group(_) => Some(token_group_visit(name)),
+ types::Type::Syn(t) => {
+ fn requires_full(features: &types::Features) -> bool {
+ features.any.contains("full") && features.any.len() == 1
+ }
+
+ let res = simple_visit(t, name);
+
+ let target = defs.types.iter().find(|ty| ty.ident == *t).unwrap();
+
+ Some(
+ if requires_full(&target.features) && !requires_full(features) {
+ quote! {
+ full!(#res)
+ }
+ } else {
+ res
+ },
+ )
+ }
+ types::Type::Ext(t) if super::TERMINAL_TYPES.contains(&&t[..]) => {
+ Some(simple_visit(t, name))
+ }
+ types::Type::Ext(_) | types::Type::Std(_) => None,
+ }
+ }
+
+ fn visit_features(features: &types::Features) -> TokenStream {
+ let features = &features.any;
+ match features.len() {
+ 0 => quote!(),
+ 1 => quote!(#[cfg(feature = #(#features)*)]),
+ _ => quote!(#[cfg(any(#(feature = #features),*))]),
+ }
+ }
+
+ pub fn generate(state: &mut State, s: &types::Node, defs: &types::Definitions) {
+ let features = visit_features(&s.features);
+ let under_name = under_name(&s.ident);
+ let ty = Ident::new(&s.ident, Span::call_site());
+ let visit_fn = Ident::new(&format!("visit_{}", under_name), Span::call_site());
+
+ let mut visit_impl = TokenStream::new();
+
+ match &s.data {
+ types::Data::Enum(variants) => {
+ let mut visit_variants = TokenStream::new();
+
+ for (variant, fields) in variants {
+ let variant_ident = Ident::new(variant, Span::call_site());
+
+ if fields.is_empty() {
+ visit_variants.append_all(quote! {
+ #ty::#variant_ident => {}
+ });
+ } else {
+ let mut bind_visit_fields = TokenStream::new();
+ let mut visit_fields = TokenStream::new();
+
+ for (idx, ty) in fields.iter().enumerate() {
+ let name = format!("_binding_{}", idx);
+ let binding = Ident::new(&name, Span::call_site());
+
+ bind_visit_fields.append_all(quote! {
+ ref #binding,
+ });
+
+ let borrowed_binding = Borrowed(quote!(#binding));
+
+ visit_fields.append_all(
+ visit(ty, &s.features, defs, &borrowed_binding)
+ .unwrap_or_else(|| noop_visit(&borrowed_binding)),
+ );
+
+ visit_fields.append_all(quote!(;));
+ }
+
+ visit_variants.append_all(quote! {
+ #ty::#variant_ident(#bind_visit_fields) => {
+ #visit_fields
+ }
+ });
+ }
+ }
+
+ visit_impl.append_all(quote! {
+ match *_i {
+ #visit_variants
+ }
+ });
+ }
+ types::Data::Struct(fields) => {
+ for (field, ty) in fields {
+ let id = Ident::new(&field, Span::call_site());
+ let ref_toks = Owned(quote!(_i.#id));
+ let visit_field = visit(&ty, &s.features, defs, &ref_toks)
+ .unwrap_or_else(|| noop_visit(&ref_toks));
+ visit_impl.append_all(quote! {
+ #visit_field;
+ });
+ }
+ }
+ types::Data::Private => {}
+ }
+
+ state.visit_trait.append_all(quote! {
+ #features
+ fn #visit_fn(&mut self, i: &'ast #ty) {
+ #visit_fn(self, i)
+ }
+ });
+
+ state.visit_impl.append_all(quote! {
+ #features
+ pub fn #visit_fn<'ast, V: Visit<'ast> + ?Sized>(
+ _visitor: &mut V, _i: &'ast #ty
+ ) {
+ #visit_impl
+ }
+ });
+ }
+}
+
+const TERMINAL_TYPES: &[&str] = &["Span", "Ident"];
+
+pub fn generate(defs: &types::Definitions) {
+ let mut state = codegen::State::default();
+ for s in &defs.types {
+ codegen::generate(&mut state, s, defs);
+ }
+ for tt in TERMINAL_TYPES {
+ let s = types::Node {
+ ident: tt.to_string(),
+ features: types::Features::default(),
+ data: types::Data::Private,
+ };
+ codegen::generate(&mut state, &s, defs);
+ }
+
+ let full_macro = quote! {
+ #[cfg(feature = "full")]
+ macro_rules! full {
+ ($e:expr) => {
+ $e
+ };
+ }
+
+ #[cfg(all(feature = "derive", not(feature = "full")))]
+ macro_rules! full {
+ ($e:expr) => {
+ unreachable!()
+ };
+ }
+ };
+
+ let skip_macro = quote! {
+ #[cfg(any(feature = "full", feature = "derive"))]
+ macro_rules! skip {
+ ($($tt:tt)*) => {};
+ }
+ };
+
+ let visit_trait = state.visit_trait;
+ let visit_impl = state.visit_impl;
+ file::write(
+ VISIT_SRC,
+ quote! {
+ #![cfg_attr(feature = "cargo-clippy", allow(trivially_copy_pass_by_ref))]
+
+ use *;
+ #[cfg(any(feature = "full", feature = "derive"))]
+ use punctuated::Punctuated;
+ use proc_macro2::Span;
+ #[cfg(any(feature = "full", feature = "derive"))]
+ use gen::helper::visit::*;
+
+ #full_macro
+ #skip_macro
+
+ /// Syntax tree traversal to walk a shared borrow of a syntax tree.
+ ///
+ /// See the [module documentation] for details.
+ ///
+ /// [module documentation]: index.html
+ ///
+ /// *This trait is available if Syn is built with the `"visit"` feature.*
+ pub trait Visit<'ast> {
+ #visit_trait
+ }
+
+ #visit_impl
+ },
+ );
+}
diff --git a/codegen/src/visit_mut.rs b/codegen/src/visit_mut.rs
new file mode 100644
index 0000000..f293765
--- /dev/null
+++ b/codegen/src/visit_mut.rs
@@ -0,0 +1,385 @@
+use crate::file;
+use quote::quote;
+use syn_codegen as types;
+
+const VISIT_MUT_SRC: &str = "../src/gen/visit_mut.rs";
+
+mod codegen {
+ use inflections::Inflect;
+ use proc_macro2::{Span, TokenStream};
+ use quote::{quote, TokenStreamExt};
+ use syn::*;
+ use syn_codegen as types;
+
+ #[derive(Default)]
+ pub struct State {
+ pub visit_mut_trait: TokenStream,
+ pub visit_mut_impl: TokenStream,
+ }
+
+ fn under_name(name: &str) -> Ident {
+ Ident::new(&name.to_snake_case(), Span::call_site())
+ }
+
+ enum Operand {
+ Borrowed(TokenStream),
+ Owned(TokenStream),
+ }
+
+ use self::Operand::*;
+
+ impl Operand {
+ fn tokens(&self) -> &TokenStream {
+ match *self {
+ Borrowed(ref n) | Owned(ref n) => n,
+ }
+ }
+
+ fn ref_mut_tokens(&self) -> TokenStream {
+ match *self {
+ Borrowed(ref n) => n.clone(),
+ Owned(ref n) => quote!(&mut #n),
+ }
+ }
+
+ fn owned_tokens(&self) -> TokenStream {
+ match *self {
+ Borrowed(ref n) => quote!(*#n),
+ Owned(ref n) => n.clone(),
+ }
+ }
+ }
+
+ fn simple_visit(item: &str, name: &Operand) -> TokenStream {
+ let ident = under_name(item);
+ let method = Ident::new(&format!("visit_{}_mut", ident), Span::call_site());
+ let name = name.ref_mut_tokens();
+ quote! {
+ _visitor.#method(#name)
+ }
+ }
+
+ fn box_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let name = name.owned_tokens();
+ let res = visit(elem, features, defs, &Owned(quote!(*#name)))?;
+ Some(res)
+ }
+
+ fn vec_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let operand = Borrowed(quote!(it));
+ let val = visit(elem, features, defs, &operand)?;
+ let name = name.ref_mut_tokens();
+ Some(quote! {
+ for it in #name {
+ #val
+ }
+ })
+ }
+
+ fn punctuated_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let operand = Borrowed(quote!(it));
+ let val = visit(elem, features, defs, &operand)?;
+ let name = name.ref_mut_tokens();
+ Some(quote! {
+ for mut el in Punctuated::pairs_mut(#name) {
+ let it = el.value_mut();
+ #val
+ }
+ })
+ }
+
+ fn option_visit(
+ elem: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ let it = Borrowed(quote!(it));
+ let val = visit(elem, features, defs, &it)?;
+ let name = name.owned_tokens();
+ Some(quote! {
+ if let Some(ref mut it) = #name {
+ #val
+ }
+ })
+ }
+
+ fn tuple_visit(
+ elems: &[types::Type],
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ if elems.is_empty() {
+ return None;
+ }
+
+ let mut code = TokenStream::new();
+ for (i, elem) in elems.iter().enumerate() {
+ let name = name.tokens();
+ let i = Index::from(i);
+ let it = Owned(quote!((#name).#i));
+ let val = visit(elem, features, defs, &it).unwrap_or_else(|| noop_visit(&it));
+ code.append_all(val);
+ code.append_all(quote!(;));
+ }
+ Some(code)
+ }
+
+ fn token_punct_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ tokens_helper(_visitor, &mut #name.spans)
+ }
+ }
+
+ fn token_keyword_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ tokens_helper(_visitor, &mut #name.span)
+ }
+ }
+
+ fn token_group_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ tokens_helper(_visitor, &mut #name.span)
+ }
+ }
+
+ fn noop_visit(name: &Operand) -> TokenStream {
+ let name = name.tokens();
+ quote! {
+ skip!(#name)
+ }
+ }
+
+ fn visit(
+ ty: &types::Type,
+ features: &types::Features,
+ defs: &types::Definitions,
+ name: &Operand,
+ ) -> Option<TokenStream> {
+ match ty {
+ types::Type::Box(t) => box_visit(&*t, features, defs, name),
+ types::Type::Vec(t) => vec_visit(&*t, features, defs, name),
+ types::Type::Punctuated(p) => punctuated_visit(&p.element, features, defs, name),
+ types::Type::Option(t) => option_visit(&*t, features, defs, name),
+ types::Type::Tuple(t) => tuple_visit(t, features, defs, name),
+ types::Type::Token(t) => {
+ let repr = &defs.tokens[t];
+ let is_keyword = repr.chars().next().unwrap().is_alphabetic();
+ if is_keyword {
+ Some(token_keyword_visit(name))
+ } else {
+ Some(token_punct_visit(name))
+ }
+ }
+ types::Type::Group(_) => Some(token_group_visit(name)),
+ types::Type::Syn(t) => {
+ fn requires_full(features: &types::Features) -> bool {
+ features.any.contains("full") && features.any.len() == 1
+ }
+
+ let res = simple_visit(t, name);
+
+ let target = defs.types.iter().find(|ty| ty.ident == *t).unwrap();
+
+ Some(
+ if requires_full(&target.features) && !requires_full(features) {
+ quote! {
+ full!(#res)
+ }
+ } else {
+ res
+ },
+ )
+ }
+ types::Type::Ext(t) if super::TERMINAL_TYPES.contains(&&t[..]) => {
+ Some(simple_visit(t, name))
+ }
+ types::Type::Ext(_) | types::Type::Std(_) => None,
+ }
+ }
+
+ fn visit_features(features: &types::Features) -> TokenStream {
+ let features = &features.any;
+ match features.len() {
+ 0 => quote!(),
+ 1 => quote!(#[cfg(feature = #(#features)*)]),
+ _ => quote!(#[cfg(any(#(feature = #features),*))]),
+ }
+ }
+
+ pub fn generate(state: &mut State, s: &types::Node, defs: &types::Definitions) {
+ let features = visit_features(&s.features);
+ let under_name = under_name(&s.ident);
+ let ty = Ident::new(&s.ident, Span::call_site());
+ let visit_mut_fn = Ident::new(&format!("visit_{}_mut", under_name), Span::call_site());
+
+ let mut visit_mut_impl = TokenStream::new();
+
+ match &s.data {
+ types::Data::Enum(variants) => {
+ let mut visit_mut_variants = TokenStream::new();
+
+ for (variant, fields) in variants {
+ let variant_ident = Ident::new(variant, Span::call_site());
+
+ if fields.is_empty() {
+ visit_mut_variants.append_all(quote! {
+ #ty::#variant_ident => {}
+ });
+ } else {
+ let mut bind_visit_mut_fields = TokenStream::new();
+ let mut visit_mut_fields = TokenStream::new();
+
+ for (idx, ty) in fields.iter().enumerate() {
+ let name = format!("_binding_{}", idx);
+ let binding = Ident::new(&name, Span::call_site());
+
+ bind_visit_mut_fields.append_all(quote! {
+ ref mut #binding,
+ });
+
+ let borrowed_binding = Borrowed(quote!(#binding));
+
+ visit_mut_fields.append_all(
+ visit(ty, &s.features, defs, &borrowed_binding)
+ .unwrap_or_else(|| noop_visit(&borrowed_binding)),
+ );
+
+ visit_mut_fields.append_all(quote!(;));
+ }
+
+ visit_mut_variants.append_all(quote! {
+ #ty::#variant_ident(#bind_visit_mut_fields) => {
+ #visit_mut_fields
+ }
+ });
+ }
+ }
+
+ visit_mut_impl.append_all(quote! {
+ match *_i {
+ #visit_mut_variants
+ }
+ });
+ }
+ types::Data::Struct(fields) => {
+ for (field, ty) in fields {
+ let id = Ident::new(&field, Span::call_site());
+ let ref_toks = Owned(quote!(_i.#id));
+ let visit_mut_field = visit(&ty, &s.features, defs, &ref_toks)
+ .unwrap_or_else(|| noop_visit(&ref_toks));
+ visit_mut_impl.append_all(quote! {
+ #visit_mut_field;
+ });
+ }
+ }
+ types::Data::Private => {}
+ }
+
+ state.visit_mut_trait.append_all(quote! {
+ #features
+ fn #visit_mut_fn(&mut self, i: &mut #ty) {
+ #visit_mut_fn(self, i)
+ }
+ });
+
+ state.visit_mut_impl.append_all(quote! {
+ #features
+ pub fn #visit_mut_fn<V: VisitMut + ?Sized>(
+ _visitor: &mut V, _i: &mut #ty
+ ) {
+ #visit_mut_impl
+ }
+ });
+ }
+}
+
+const TERMINAL_TYPES: &[&str] = &["Span", "Ident"];
+
+pub fn generate(defs: &types::Definitions) {
+ let mut state = codegen::State::default();
+ for s in &defs.types {
+ codegen::generate(&mut state, s, defs);
+ }
+ for tt in TERMINAL_TYPES {
+ let s = types::Node {
+ ident: tt.to_string(),
+ features: types::Features::default(),
+ data: types::Data::Private,
+ };
+ codegen::generate(&mut state, &s, defs);
+ }
+
+ let full_macro = quote! {
+ #[cfg(feature = "full")]
+ macro_rules! full {
+ ($e:expr) => {
+ $e
+ };
+ }
+
+ #[cfg(all(feature = "derive", not(feature = "full")))]
+ macro_rules! full {
+ ($e:expr) => {
+ unreachable!()
+ };
+ }
+ };
+
+ let skip_macro = quote! {
+ #[cfg(any(feature = "full", feature = "derive"))]
+ macro_rules! skip {
+ ($($tt:tt)*) => {};
+ }
+ };
+
+ let visit_mut_trait = state.visit_mut_trait;
+ let visit_mut_impl = state.visit_mut_impl;
+ file::write(
+ VISIT_MUT_SRC,
+ quote! {
+ use *;
+ #[cfg(any(feature = "full", feature = "derive"))]
+ use punctuated::Punctuated;
+ use proc_macro2::Span;
+ #[cfg(any(feature = "full", feature = "derive"))]
+ use gen::helper::visit_mut::*;
+
+ #full_macro
+ #skip_macro
+
+ /// Syntax tree traversal to mutate an exclusive borrow of a syntax tree in
+ /// place.
+ ///
+ /// See the [module documentation] for details.
+ ///
+ /// [module documentation]: index.html
+ ///
+ /// *This trait is available if Syn is built with the `"visit-mut"` feature.*
+ pub trait VisitMut {
+ #visit_mut_trait
+ }
+
+ #visit_mut_impl
+ },
+ );
+}