No more syntex for serde_derive

This commit is contained in:
David Tolnay
2016-09-10 21:53:14 -07:00
parent 7cc36a9cd3
commit c34baa1e5f
15 changed files with 611 additions and 859 deletions
+25 -31
View File
@@ -1,9 +1,6 @@
use std::collections::HashSet;
use aster::AstBuilder;
use syntax::ast;
use syntax::visit;
use syn::{self, aster, visit};
use internals::ast::Item;
use internals::attr;
@@ -11,10 +8,10 @@ use internals::attr;
// Remove the default from every type parameter because in the generated impls
// they look like associated types: "error: associated type bindings are not
// allowed here".
pub fn without_defaults(generics: &ast::Generics) -> ast::Generics {
ast::Generics {
pub fn without_defaults(generics: &syn::Generics) -> syn::Generics {
syn::Generics {
ty_params: generics.ty_params.iter().map(|ty_param| {
ast::TyParam {
syn::TyParam {
default: None,
.. ty_param.clone()
}}).collect(),
@@ -23,24 +20,22 @@ pub fn without_defaults(generics: &ast::Generics) -> ast::Generics {
}
pub fn with_where_predicates(
builder: &AstBuilder,
generics: &ast::Generics,
predicates: &[ast::WherePredicate],
) -> ast::Generics {
builder.from_generics(generics.clone())
generics: &syn::Generics,
predicates: &[syn::WherePredicate],
) -> syn::Generics {
aster::from_generics(generics.clone())
.with_predicates(predicates.to_vec())
.build()
}
pub fn with_where_predicates_from_fields<F>(
builder: &AstBuilder,
item: &Item,
generics: &ast::Generics,
generics: &syn::Generics,
from_field: F,
) -> ast::Generics
where F: Fn(&attr::Field) -> Option<&[ast::WherePredicate]>,
) -> syn::Generics
where F: Fn(&attr::Field) -> Option<&[syn::WherePredicate]>,
{
builder.from_generics(generics.clone())
aster::from_generics(generics.clone())
.with_predicates(
item.body.all_fields()
.flat_map(|field| from_field(&field.attrs))
@@ -60,34 +55,33 @@ pub fn with_where_predicates_from_fields<F>(
// c: C,
// }
pub fn with_bound<F>(
builder: &AstBuilder,
item: &Item,
generics: &ast::Generics,
generics: &syn::Generics,
filter: F,
bound: &ast::Path,
) -> ast::Generics
bound: &syn::Path,
) -> syn::Generics
where F: Fn(&attr::Field) -> bool,
{
struct FindTyParams {
// Set of all generic type parameters on the current struct (A, B, C in
// the example). Initialized up front.
all_ty_params: HashSet<ast::Name>,
all_ty_params: HashSet<syn::Ident>,
// Set of generic type parameters used in fields for which filter
// returns true (A and B in the example). Filled in as the visitor sees
// them.
relevant_ty_params: HashSet<ast::Name>,
relevant_ty_params: HashSet<syn::Ident>,
}
impl visit::Visitor for FindTyParams {
fn visit_path(&mut self, path: &ast::Path, _id: ast::NodeId) {
fn visit_path(&mut self, path: &syn::Path) {
if let Some(seg) = path.segments.last() {
if seg.identifier.name.as_str() == "PhantomData" {
if seg.ident == "PhantomData" {
// Hardcoded exception, because PhantomData<T> implements
// Serialize and Deserialize whether or not T implements it.
return;
}
}
if !path.global && path.segments.len() == 1 {
let id = path.segments[0].identifier.name;
let id = path.segments[0].ident.clone();
if self.all_ty_params.contains(&id) {
self.relevant_ty_params.insert(id);
}
@@ -97,7 +91,7 @@ pub fn with_bound<F>(
}
let all_ty_params: HashSet<_> = generics.ty_params.iter()
.map(|ty_param| ty_param.ident.name)
.map(|ty_param| ty_param.ident.clone())
.collect();
let relevant_tys = item.body.all_fields()
@@ -112,14 +106,14 @@ pub fn with_bound<F>(
visit::walk_ty(&mut visitor, ty);
}
builder.from_generics(generics.clone())
aster::from_generics(generics.clone())
.with_predicates(
generics.ty_params.iter()
.map(|ty_param| ty_param.ident.name)
.map(|ty_param| ty_param.ident.clone())
.filter(|id| visitor.relevant_ty_params.contains(id))
.map(|id| builder.where_predicate()
.map(|id| aster::where_predicate()
// the type parameter that is being bounded e.g. T
.bound().build(builder.ty().id(id))
.bound().build(aster::ty().id(id))
// the bound e.g. Serialize
.bound().trait_(bound.clone()).build()
.build()))