Move derive internals into serde_derive crate

We can continue to publish serde_derive_internals independently but
serde_derive no longer has a dependency on it. This improves compile
time of serde_derive by 7%.

serde_derive/src/internals/ast.rs

@@ -0,0 +1,175 @@
+// Copyright 2017 Serde Developers
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use internals::attr;
+use internals::check;
+use internals::Ctxt;
+use syn;
+use syn::punctuated::Punctuated;
+
+pub struct Container<'a> {
+    pub ident: syn::Ident,
+    pub attrs: attr::Container,
+    pub data: Data<'a>,
+    pub generics: &'a syn::Generics,
+}
+
+pub enum Data<'a> {
+    Enum(Vec<Variant<'a>>),
+    Struct(Style, Vec<Field<'a>>),
+}
+
+pub struct Variant<'a> {
+    pub ident: syn::Ident,
+    pub attrs: attr::Variant,
+    pub style: Style,
+    pub fields: Vec<Field<'a>>,
+}
+
+pub struct Field<'a> {
+    pub ident: Option<syn::Ident>,
+    pub attrs: attr::Field,
+    pub ty: &'a syn::Type,
+    pub original: &'a syn::Field,
+}
+
+#[derive(Copy, Clone)]
+pub enum Style {
+    Struct,
+    Tuple,
+    Newtype,
+    Unit,
+}
+
+impl<'a> Container<'a> {
+    pub fn from_ast(cx: &Ctxt, item: &'a syn::DeriveInput) -> Container<'a> {
+        let mut attrs = attr::Container::from_ast(cx, item);
+
+        let mut data = match item.data {
+            syn::Data::Enum(ref data) => {
+                Data::Enum(enum_from_ast(cx, &data.variants, attrs.default()))
+            }
+            syn::Data::Struct(ref data) => {
+                let (style, fields) = struct_from_ast(cx, &data.fields, None, attrs.default());
+                Data::Struct(style, fields)
+            }
+            syn::Data::Union(_) => {
+                panic!("Serde does not support derive for unions");
+            }
+        };
+
+        let mut has_flatten = false;
+        match data {
+            Data::Enum(ref mut variants) => for variant in variants {
+                variant.attrs.rename_by_rule(attrs.rename_all());
+                for field in &mut variant.fields {
+                    if field.attrs.flatten() {
+                        has_flatten = true;
+                    }
+                    field.attrs.rename_by_rule(variant.attrs.rename_all());
+                }
+            },
+            Data::Struct(_, ref mut fields) => for field in fields {
+                if field.attrs.flatten() {
+                    has_flatten = true;
+                }
+                field.attrs.rename_by_rule(attrs.rename_all());
+            },
+        }
+
+        if has_flatten {
+            attrs.mark_has_flatten();
+        }
+
+        let item = Container {
+            ident: item.ident,
+            attrs: attrs,
+            data: data,
+            generics: &item.generics,
+        };
+        check::check(cx, &item);
+        item
+    }
+}
+
+impl<'a> Data<'a> {
+    pub fn all_fields(&'a self) -> Box<Iterator<Item = &'a Field<'a>> + 'a> {
+        match *self {
+            Data::Enum(ref variants) => {
+                Box::new(variants.iter().flat_map(|variant| variant.fields.iter()))
+            }
+            Data::Struct(_, ref fields) => Box::new(fields.iter()),
+        }
+    }
+
+    pub fn has_getter(&self) -> bool {
+        self.all_fields().any(|f| f.attrs.getter().is_some())
+    }
+}
+
+fn enum_from_ast<'a>(
+    cx: &Ctxt,
+    variants: &'a Punctuated<syn::Variant, Token![,]>,
+    container_default: &attr::Default,
+) -> Vec<Variant<'a>> {
+    variants
+        .iter()
+        .map(|variant| {
+            let attrs = attr::Variant::from_ast(cx, variant);
+            let (style, fields) =
+                struct_from_ast(cx, &variant.fields, Some(&attrs), container_default);
+            Variant {
+                ident: variant.ident,
+                attrs: attrs,
+                style: style,
+                fields: fields,
+            }
+        })
+        .collect()
+}
+
+fn struct_from_ast<'a>(
+    cx: &Ctxt,
+    fields: &'a syn::Fields,
+    attrs: Option<&attr::Variant>,
+    container_default: &attr::Default,
+) -> (Style, Vec<Field<'a>>) {
+    match *fields {
+        syn::Fields::Named(ref fields) => (
+            Style::Struct,
+            fields_from_ast(cx, &fields.named, attrs, container_default),
+        ),
+        syn::Fields::Unnamed(ref fields) if fields.unnamed.len() == 1 => (
+            Style::Newtype,
+            fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+        ),
+        syn::Fields::Unnamed(ref fields) => (
+            Style::Tuple,
+            fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+        ),
+        syn::Fields::Unit => (Style::Unit, Vec::new()),
+    }
+}
+
+fn fields_from_ast<'a>(
+    cx: &Ctxt,
+    fields: &'a Punctuated<syn::Field, Token![,]>,
+    attrs: Option<&attr::Variant>,
+    container_default: &attr::Default,
+) -> Vec<Field<'a>> {
+    fields
+        .iter()
+        .enumerate()
+        .map(|(i, field)| Field {
+            ident: field.ident,
+            attrs: attr::Field::from_ast(cx, i, field, attrs, container_default),
+            ty: &field.ty,
+            original: field,
+        })
+        .collect()
+}