use proc_macro::TokenStream; use quote::quote;use syn::{ Data, DeriveInput, Field, Fields, ItemEnum, ItemStruct, Type, parse_macro_input, parse_quote,}; /// Derives the `MergeFrom` trait for a struct.////// This macro automatically implements `MergeFrom` by calling `merge_from`/// on all fields in the struct.////// # Example////// ```ignore/// #[derive(Clone, MergeFrom)]/// struct MySettings {/// field1: Option<String>,/// field2: SomeOtherSettings,/// }/// ```#[proc_macro_derive(MergeFrom)]pub fn derive_merge_from(input: TokenStream) -> TokenStream { let input = parse_macro_input!(input as DeriveInput); let name = &input.ident; let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl(); let merge_body = match &input.data { Data::Struct(data_struct) => match &data_struct.fields { Fields::Named(fields) => { let field_merges = fields.named.iter().map(|field| { let field_name = &field.ident; quote! { self.#field_name.merge_from(&other.#field_name); } }); quote! { #(#field_merges)* } } Fields::Unnamed(fields) => { let field_merges = fields.unnamed.iter().enumerate().map(|(i, _)| { let field_index = syn::Index::from(i); quote! { self.#field_index.merge_from(&other.#field_index); } }); quote! { #(#field_merges)* } } Fields::Unit => { quote! { // No fields to merge for unit structs } } }, Data::Enum(_) => { quote! { *self = other.clone(); } } Data::Union(_) => { panic!("MergeFrom cannot be derived for unions"); } }; let expanded = quote! { impl #impl_generics crate::merge_from::MergeFrom for #name #ty_generics #where_clause { fn merge_from(&mut self, other: &Self) { use crate::merge_from::MergeFrom as _; #merge_body } } }; TokenStream::from(expanded)} /// Registers the setting type with the SettingsStore. Note that you need to/// have `gpui` in your dependencies for this to work.#[proc_macro_derive(RegisterSetting)]pub fn derive_register_setting(input: TokenStream) -> TokenStream { let input = syn::parse_macro_input!(input as DeriveInput); let type_name = &input.ident; quote! { settings::private::inventory::submit! { settings::private::RegisteredSetting { settings_value: || { Box::new(settings::private::SettingValue::<#type_name> { global_value: None, local_values: Vec::new(), }) }, from_settings: |content| Box::new(<#type_name as settings::Settings>::from_settings(content)), id: || std::any::TypeId::of::<#type_name>(), } } } .into()} // Adds serde attributes to each field with type Option<T>:// #serde(default, skip_serializing_if = "Option::is_none", deserialize_with = "settings::deserialize_fallible")#[proc_macro_attribute]pub fn with_fallible_options(_args: TokenStream, input: TokenStream) -> TokenStream { fn apply_on_fields(fields: &mut Fields) { match fields { Fields::Unit => {} Fields::Named(fields) => { for field in &mut fields.named { add_if_option(field) } } Fields::Unnamed(fields) => { for field in &mut fields.unnamed { add_if_option(field) } } } } fn add_if_option(field: &mut Field) { match &field.ty { Type::Path(syn::TypePath { qself: None, path }) if path.leading_colon.is_none() && path.segments.len() == 1 && path.segments[0].ident == "Option" => {} _ => return, } let attr = parse_quote!( #[serde(default, skip_serializing_if = "Option::is_none", deserialize_with="crate::fallible_options::deserialize")] ); field.attrs.push(attr); } if let Ok(mut input) = syn::parse::<ItemStruct>(input.clone()) { apply_on_fields(&mut input.fields); quote!(#input).into() } else if let Ok(mut input) = syn::parse::<ItemEnum>(input) { for variant in &mut input.variants { apply_on_fields(&mut variant.fields); } quote!(#input).into() } else { panic!("with_fallible_options can only be applied to struct or enum definitions."); }}
use proc_macro::TokenStream;
use quote::quote;
use syn::{
Data, DeriveInput, Field, Fields, ItemEnum, ItemStruct, Type, parse_macro_input, parse_quote,
};
/// Derives the `MergeFrom` trait for a struct.
///
/// This macro automatically implements `MergeFrom` by calling `merge_from`
/// on all fields in the struct.
///
/// # Example
///
/// ```ignore
/// #[derive(Clone, MergeFrom)]
/// struct MySettings {
/// field1: Option<String>,
/// field2: SomeOtherSettings,
/// }
/// ```
#[proc_macro_derive(MergeFrom)]
pub fn derive_merge_from(input: TokenStream) -> TokenStream {
let input = parse_macro_input!(input as DeriveInput);
let name = &input.ident;
let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
let merge_body = match &input.data {
Data::Struct(data_struct) => match &data_struct.fields {
Fields::Named(fields) => {
let field_merges = fields.named.iter().map(|field| {
let field_name = &field.ident;
quote! {
self.#field_name.merge_from(&other.#field_name);
}
});
quote! {
#(#field_merges)*
}
}
Fields::Unnamed(fields) => {
let field_merges = fields.unnamed.iter().enumerate().map(|(i, _)| {
let field_index = syn::Index::from(i);
quote! {
self.#field_index.merge_from(&other.#field_index);
}
});
quote! {
#(#field_merges)*
}
}
Fields::Unit => {
quote! {
// No fields to merge for unit structs
}
}
},
Data::Enum(_) => {
quote! {
*self = other.clone();
}
}
Data::Union(_) => {
panic!("MergeFrom cannot be derived for unions");
}
};
let expanded = quote! {
impl #impl_generics crate::merge_from::MergeFrom for #name #ty_generics #where_clause {
fn merge_from(&mut self, other: &Self) {
use crate::merge_from::MergeFrom as _;
#merge_body
}
}
};
TokenStream::from(expanded)
}
/// Registers the setting type with the SettingsStore. Note that you need to
/// have `gpui` in your dependencies for this to work.
#[proc_macro_derive(RegisterSetting)]
pub fn derive_register_setting(input: TokenStream) -> TokenStream {
let input = syn::parse_macro_input!(input as DeriveInput);
let type_name = &input.ident;
quote! {
settings::private::inventory::submit! {
settings::private::RegisteredSetting {
settings_value: || {
Box::new(settings::private::SettingValue::<#type_name> {
global_value: None,
local_values: Vec::new(),
})
},
from_settings: |content| Box::new(<#type_name as settings::Settings>::from_settings(content)),
id: || std::any::TypeId::of::<#type_name>(),
}
}
}
.into()
}
// Adds serde attributes to each field with type Option<T>:
// #serde(default, skip_serializing_if = "Option::is_none", deserialize_with = "settings::deserialize_fallible")
#[proc_macro_attribute]
pub fn with_fallible_options(_args: TokenStream, input: TokenStream) -> TokenStream {
fn apply_on_fields(fields: &mut Fields) {
match fields {
Fields::Unit => {}
Fields::Named(fields) => {
for field in &mut fields.named {
add_if_option(field)
}
}
Fields::Unnamed(fields) => {
for field in &mut fields.unnamed {
add_if_option(field)
}
}
}
}
fn add_if_option(field: &mut Field) {
match &field.ty {
Type::Path(syn::TypePath { qself: None, path })
if path.leading_colon.is_none()
&& path.segments.len() == 1
&& path.segments[0].ident == "Option" => {}
_ => return,
}
let attr = parse_quote!(
#[serde(default, skip_serializing_if = "Option::is_none", deserialize_with="crate::fallible_options::deserialize")]
);
field.attrs.push(attr);
}
if let Ok(mut input) = syn::parse::<ItemStruct>(input.clone()) {
apply_on_fields(&mut input.fields);
quote!(#input).into()
} else if let Ok(mut input) = syn::parse::<ItemEnum>(input) {
for variant in &mut input.variants {
apply_on_fields(&mut variant.fields);
}
quote!(#input).into()
} else {
panic!("with_fallible_options can only be applied to struct or enum definitions.");
}
}