Refactor of AST parsing

This commit is contained in:
Graham Esau 2020-05-10 22:09:15 +01:00
parent 08886799bb
commit 70b5a1a2e6
4 changed files with 197 additions and 76 deletions

View file

@ -0,0 +1,76 @@
use super::*;
use crate::attr::get_with_from_attrs;
use serde_derive_internals::ast as serde_ast;
use serde_derive_internals::Ctxt;
pub trait FromSerde: Sized {
type SerdeType;
fn from_serde(errors: &Ctxt, serde: Self::SerdeType) -> Result<Self, ()>;
fn vec_from_serde(errors: &Ctxt, serdes: Vec<Self::SerdeType>) -> Result<Vec<Self>, ()> {
let mut result = Vec::with_capacity(serdes.len());
for s in serdes {
result.push(Self::from_serde(errors, s)?)
}
Ok(result)
}
}
impl<'a> FromSerde for Container<'a> {
type SerdeType = serde_ast::Container<'a>;
fn from_serde(errors: &Ctxt, serde: Self::SerdeType) -> Result<Self, ()> {
Ok(Self {
ident: serde.ident,
serde_attrs: serde.attrs,
data: Data::from_serde(errors, serde.data)?,
generics: serde.generics,
original: serde.original,
})
}
}
impl<'a> FromSerde for Data<'a> {
type SerdeType = serde_ast::Data<'a>;
fn from_serde(errors: &Ctxt, serde: Self::SerdeType) -> Result<Self, ()> {
Ok(match serde {
Self::SerdeType::Enum(variants) => {
Self::Enum(Variant::vec_from_serde(errors, variants)?)
}
Self::SerdeType::Struct(style, fields) => {
Self::Struct(style, Field::vec_from_serde(errors, fields)?)
}
})
}
}
impl<'a> FromSerde for Variant<'a> {
type SerdeType = serde_ast::Variant<'a>;
fn from_serde(errors: &Ctxt, serde: Self::SerdeType) -> Result<Self, ()> {
Ok(Self {
ident: serde.ident,
serde_attrs: serde.attrs,
style: serde.style,
fields: Field::vec_from_serde(errors, serde.fields)?,
original: serde.original,
with: get_with_from_attrs(&serde.original.attrs, errors)?,
})
}
}
impl<'a> FromSerde for Field<'a> {
type SerdeType = serde_ast::Field<'a>;
fn from_serde(errors: &Ctxt, serde: Self::SerdeType) -> Result<Self, ()> {
Ok(Self {
member: serde.member,
serde_attrs: serde.attrs,
ty: serde.ty,
original: serde.original,
with: get_with_from_attrs(&serde.original.attrs, errors)?,
})
}
}

View file

@ -0,0 +1,63 @@
mod from_serde;
use from_serde::FromSerde;
use serde_derive_internals::ast as serde_ast;
use serde_derive_internals::{Ctxt, Derive};
pub struct Container<'a> {
pub ident: syn::Ident,
pub serde_attrs: serde_derive_internals::attr::Container,
pub data: Data<'a>,
pub generics: &'a syn::Generics,
pub original: &'a syn::DeriveInput,
}
pub enum Data<'a> {
Enum(Vec<Variant<'a>>),
Struct(serde_ast::Style, Vec<Field<'a>>),
}
pub struct Variant<'a> {
pub ident: syn::Ident,
pub serde_attrs: serde_derive_internals::attr::Variant,
pub style: serde_ast::Style,
pub fields: Vec<Field<'a>>,
pub original: &'a syn::Variant,
pub with: Option<syn::Type>,
}
pub struct Field<'a> {
pub member: syn::Member,
pub serde_attrs: serde_derive_internals::attr::Field,
pub ty: &'a syn::Type,
pub original: &'a syn::Field,
pub with: Option<syn::Type>,
}
impl<'a> Container<'a> {
pub fn from_ast(item: &'a syn::DeriveInput) -> Result<Container<'a>, Vec<syn::Error>> {
let ctxt = Ctxt::new();
let result = serde_ast::Container::from_ast(&ctxt, item, Derive::Deserialize)
.ok_or(())
.and_then(|serde| Self::from_serde(&ctxt, serde));
ctxt.check()
.map(|_| result.expect("from_ast set no errors on Ctxt, so should have returned Ok"))
}
pub fn name(&self) -> String {
self.serde_attrs.name().deserialize_name()
}
}
impl<'a> Variant<'a> {
pub fn name(&self) -> String {
self.serde_attrs.name().deserialize_name()
}
}
impl<'a> Field<'a> {
pub fn name(&self) -> String {
self.serde_attrs.name().deserialize_name()
}
}

View file

@ -5,9 +5,13 @@ pub use doc::get_title_and_desc_from_doc;
pub use schemars_to_serde::process_serde_attrs;
use proc_macro2::{Group, Span, TokenStream, TokenTree};
use serde_derive_internals::Ctxt;
use syn::parse::{self, Parse};
pub fn get_with_from_attrs(attrs: &[syn::Attribute]) -> Option<syn::Result<syn::Type>> {
pub fn get_with_from_attrs(
attrs: &[syn::Attribute],
errors: &Ctxt,
) -> Result<Option<syn::Type>, ()> {
attrs
.iter()
.filter(|at| match at.path.get_ident() {
@ -17,7 +21,13 @@ pub fn get_with_from_attrs(attrs: &[syn::Attribute]) -> Option<syn::Result<syn::
})
.filter_map(get_with_from_attr)
.next()
.map(|lit| parse_lit_str(&lit))
.map_or(Ok(None), |lit| match parse_lit_str::<syn::Type>(&lit) {
Ok(t) => Ok(Some(t)),
Err(e) => {
errors.error_spanned_by(lit, e);
Err(())
}
})
}
fn get_with_from_attr(attr: &syn::Attribute) -> Option<syn::LitStr> {

View file

@ -4,52 +4,54 @@ extern crate quote;
extern crate syn;
extern crate proc_macro;
mod ast;
mod attr;
mod metadata;
use ast::*;
use metadata::*;
use proc_macro2::TokenStream;
use quote::ToTokens;
use serde_derive_internals::ast::{Container, Data, Field, Style, Variant as SerdeVariant};
use serde_derive_internals::ast::Style;
use serde_derive_internals::attr::{self as serde_attr, Default as SerdeDefault, TagType};
use serde_derive_internals::{Ctxt, Derive};
use std::ops::Deref;
use syn::spanned::Spanned;
#[proc_macro_derive(JsonSchema, attributes(schemars, serde))]
pub fn derive_json_schema(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let mut input = parse_macro_input!(input as syn::DeriveInput);
pub fn derive_json_schema_wrapper(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let input = parse_macro_input!(input as syn::DeriveInput);
derive_json_schema(input).into()
}
fn derive_json_schema(mut input: syn::DeriveInput) -> TokenStream {
add_trait_bounds(&mut input.generics);
if let Err(e) = attr::process_serde_attrs(&mut input) {
return compile_error(&e).into();
return compile_error(&e);
}
let ctxt = Ctxt::new();
let cont = Container::from_ast(&ctxt, &input, Derive::Deserialize);
if let Err(e) = ctxt.check() {
return compile_error(&e).into();
}
let cont = cont.expect("from_ast set no errors on Ctxt, so should have returned Some");
let cont = match Container::from_ast(&input) {
Ok(c) => c,
Err(e) => return compile_error(&e),
};
let schema_expr = match cont.data {
let schema_expr = match &cont.data {
Data::Struct(Style::Unit, _) => schema_for_unit_struct(),
Data::Struct(Style::Newtype, ref fields) => schema_for_newtype_struct(&fields[0]),
Data::Struct(Style::Tuple, ref fields) => schema_for_tuple_struct(fields),
Data::Struct(Style::Struct, ref fields) => schema_for_struct(fields, Some(&cont.attrs)),
Data::Enum(variants) => schema_for_enum(&Variant::vec_new(variants), &cont.attrs),
Data::Struct(Style::Newtype, fields) => schema_for_newtype_struct(&fields[0]),
Data::Struct(Style::Tuple, fields) => schema_for_tuple_struct(fields),
Data::Struct(Style::Struct, fields) => schema_for_struct(fields, Some(&cont.serde_attrs)),
Data::Enum(variants) => schema_for_enum(variants, &cont.serde_attrs),
};
let doc_metadata = SchemaMetadata::from_doc_attrs(&cont.original.attrs);
let schema_expr = doc_metadata.apply_to_schema(schema_expr);
let type_name = cont.ident;
let type_name = &cont.ident;
let type_params: Vec<_> = cont.generics.type_params().map(|ty| &ty.ident).collect();
let mut schema_base_name = cont.attrs.name().deserialize_name();
let schema_is_renamed = type_name != schema_base_name;
let mut schema_base_name = cont.name();
let schema_is_renamed = *type_name != schema_base_name;
if !schema_is_renamed {
if let Some(path) = cont.attrs.remote() {
if let Some(path) = cont.serde_attrs.remote() {
if let Some(segment) = path.segments.last() {
schema_base_name = segment.ident.to_string();
}
@ -79,7 +81,7 @@ pub fn derive_json_schema(input: proc_macro::TokenStream) -> proc_macro::TokenSt
let (impl_generics, ty_generics, where_clause) = cont.generics.split_for_impl();
let impl_block = quote! {
quote! {
#[automatically_derived]
impl #impl_generics schemars::JsonSchema for #type_name #ty_generics #where_clause {
fn schema_name() -> std::string::String {
@ -90,8 +92,7 @@ pub fn derive_json_schema(input: proc_macro::TokenStream) -> proc_macro::TokenSt
#schema_expr
}
};
};
proc_macro::TokenStream::from(impl_block)
}
}
fn add_trait_bounds(generics: &mut syn::Generics) {
@ -127,7 +128,9 @@ fn is_unit_variant(v: &Variant) -> bool {
}
fn schema_for_enum(variants: &[Variant], cattrs: &serde_attr::Container) -> TokenStream {
let variants = variants.iter().filter(|v| !v.attrs.skip_deserializing());
let variants = variants
.iter()
.filter(|v| !v.serde_attrs.skip_deserializing());
match cattrs.tag() {
TagType::External => schema_for_external_tagged_enum(variants),
TagType::None => schema_for_untagged_enum(variants),
@ -145,9 +148,7 @@ fn schema_for_external_tagged_enum<'a>(
variants.partition(|v| is_unit_variant(v));
let unit_count = unit_variants.len();
let unit_names = unit_variants
.into_iter()
.map(|v| v.attrs.name().deserialize_name());
let unit_names = unit_variants.into_iter().map(|v| v.name());
let unit_schema = wrap_schema_fields(quote! {
enum_values: Some(vec![#(#unit_names.into()),*]),
});
@ -162,7 +163,7 @@ fn schema_for_external_tagged_enum<'a>(
}
schemas.extend(complex_variants.into_iter().map(|variant| {
let name = variant.attrs.name().deserialize_name();
let name = variant.name();
let sub_schema = schema_for_untagged_enum_variant(variant);
let schema_expr = wrap_schema_fields(quote! {
instance_type: Some(schemars::schema::InstanceType::Object.into()),
@ -197,7 +198,7 @@ fn schema_for_internal_tagged_enum<'a>(
tag_name: &str,
) -> TokenStream {
let schemas = variants.map(|variant| {
let name = variant.attrs.name().deserialize_name();
let name = variant.name();
let type_schema = wrap_schema_fields(quote! {
instance_type: Some(schemars::schema::InstanceType::String.into()),
enum_values: Some(vec![#name.into()]),
@ -315,7 +316,7 @@ fn schema_for_adjacent_tagged_enum<'a>(
})
.unwrap_or_default();
let name = variant.attrs.name().deserialize_name();
let name = variant.name();
let tag_schema = wrap_schema_fields(quote! {
instance_type: Some(schemars::schema::InstanceType::String.into()),
enum_values: Some(vec![#name.into()]),
@ -368,7 +369,7 @@ fn schema_for_newtype_struct(field: &Field) -> TokenStream {
fn schema_for_tuple_struct(fields: &[Field]) -> TokenStream {
let types = fields
.iter()
.filter(|f| !f.attrs.skip_deserializing())
.filter(|f| !f.serde_attrs.skip_deserializing())
.map(get_json_schema_type);
quote! {
gen.subschema_for::<(#(#types),*)>()
@ -378,8 +379,8 @@ fn schema_for_tuple_struct(fields: &[Field]) -> TokenStream {
fn schema_for_struct(fields: &[Field], cattrs: Option<&serde_attr::Container>) -> TokenStream {
let (flattened_fields, property_fields): (Vec<_>, Vec<_>) = fields
.iter()
.filter(|f| !f.attrs.skip_deserializing() || !f.attrs.skip_serializing())
.partition(|f| f.attrs.flatten());
.filter(|f| !f.serde_attrs.skip_deserializing() || !f.serde_attrs.skip_serializing())
.partition(|f| f.serde_attrs.flatten());
let set_container_default = match cattrs.map_or(&SerdeDefault::None, |c| c.default()) {
SerdeDefault::None => None,
@ -388,7 +389,7 @@ fn schema_for_struct(fields: &[Field], cattrs: Option<&serde_attr::Container>) -
};
let properties = property_fields.iter().map(|field| {
let name = field.attrs.name().deserialize_name();
let name = field.name();
let default = field_default_expr(field, set_container_default.is_some());
let required = match default {
@ -397,8 +398,8 @@ fn schema_for_struct(fields: &[Field], cattrs: Option<&serde_attr::Container>) -
};
let metadata = &SchemaMetadata {
read_only: field.attrs.skip_deserializing(),
write_only: field.attrs.skip_serializing(),
read_only: field.serde_attrs.skip_deserializing(),
write_only: field.serde_attrs.skip_serializing(),
default,
..SchemaMetadata::from_doc_attrs(&field.original.attrs)
};
@ -435,8 +436,8 @@ fn schema_for_struct(fields: &[Field], cattrs: Option<&serde_attr::Container>) -
}
fn field_default_expr(field: &Field, container_has_default: bool) -> Option<TokenStream> {
let field_default = field.attrs.default();
if field.attrs.skip_serializing() || (field_default.is_none() && !container_has_default) {
let field_default = field.serde_attrs.default();
if field.serde_attrs.skip_serializing() || (field_default.is_none() && !container_has_default) {
return None;
}
@ -450,7 +451,7 @@ fn field_default_expr(field: &Field, container_has_default: bool) -> Option<Toke
SerdeDefault::Path(path) => quote!(#path()),
};
let default_expr = match field.attrs.skip_serializing_if() {
let default_expr = match field.serde_attrs.skip_serializing_if() {
Some(skip_if) => {
quote! {
{
@ -466,7 +467,7 @@ fn field_default_expr(field: &Field, container_has_default: bool) -> Option<Toke
None => quote!(Some(#default_expr)),
};
Some(if let Some(ser_with) = field.attrs.serialize_with() {
Some(if let Some(ser_with) = field.serde_attrs.serialize_with() {
quote! {
{
struct _SchemarsDefaultSerialize<T>(T);
@ -491,37 +492,8 @@ fn field_default_expr(field: &Field, container_has_default: bool) -> Option<Toke
fn get_json_schema_type(field: &Field) -> TokenStream {
// TODO support [schemars(schema_with= "...")] or equivalent
match attr::get_with_from_attrs(&field.original.attrs) {
None => field.ty.to_token_stream(),
Some(Ok(expr_path)) => expr_path.to_token_stream(),
Some(Err(e)) => compile_error(&[e]),
}
}
struct Variant<'a> {
serde: SerdeVariant<'a>,
with: Option<TokenStream>,
}
impl<'a> Variant<'a> {
fn new(serde: SerdeVariant<'a>) -> Self {
let with = match attr::get_with_from_attrs(&serde.original.attrs) {
None => None,
Some(Ok(expr_path)) => Some(expr_path.to_token_stream()),
Some(Err(e)) => Some(compile_error(&[e])),
};
Self { serde, with }
}
fn vec_new(serdes: Vec<SerdeVariant<'a>>) -> Vec<Variant<'a>> {
serdes.into_iter().map(Self::new).collect()
}
}
impl<'a> Deref for Variant<'a> {
type Target = SerdeVariant<'a>;
fn deref(&self) -> &Self::Target {
&self.serde
}
field
.with
.as_ref()
.map_or_else(|| field.ty.to_token_stream(), |w| w.to_token_stream())
}