Attribute for handwritten where clauses
This commit is contained in:
parent
7052833512
commit
660ea7bd7b
@ -4,7 +4,7 @@ use syntax::attr;
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use syntax::codemap::Span;
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use syntax::ext::base::ExtCtxt;
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use syntax::fold::Folder;
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use syntax::parse::parser::PathStyle;
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use syntax::parse::parser::{Parser, PathStyle};
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use syntax::parse::token::{self, InternedString};
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use syntax::parse;
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use syntax::print::pprust::{lit_to_string, meta_item_to_string};
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@ -62,6 +62,8 @@ impl Name {
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pub struct ContainerAttrs {
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name: Name,
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deny_unknown_fields: bool,
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ser_where: Option<Vec<ast::WherePredicate>>,
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de_where: Option<Vec<ast::WherePredicate>>,
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}
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impl ContainerAttrs {
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@ -70,6 +72,8 @@ impl ContainerAttrs {
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let mut container_attrs = ContainerAttrs {
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name: Name::new(item.ident),
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deny_unknown_fields: false,
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ser_where: None,
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de_where: None,
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};
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for meta_items in item.attrs().iter().filter_map(get_serde_meta_items) {
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@ -96,6 +100,20 @@ impl ContainerAttrs {
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container_attrs.deny_unknown_fields = true;
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}
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// Parse `#[serde(where="D: Serialize")]`
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ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"where" => {
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let where_predicates = try!(parse_lit_into_where(cx, name, lit));
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container_attrs.ser_where = Some(where_predicates.clone());
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container_attrs.de_where = Some(where_predicates.clone());
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}
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// Parse `#[serde(where(serialize="D: Serialize", deserialize="D: Deserialize"))]`
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ast::MetaItemKind::List(ref name, ref meta_items) if name == &"where" => {
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let (ser_where, de_where) = try!(get_where_predicates(cx, meta_items));
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container_attrs.ser_where = ser_where;
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container_attrs.de_where = de_where;
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}
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_ => {
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cx.span_err(
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meta_item.span,
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@ -118,6 +136,14 @@ impl ContainerAttrs {
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pub fn deny_unknown_fields(&self) -> bool {
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self.deny_unknown_fields
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}
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pub fn ser_where(&self) -> Option<&Vec<ast::WherePredicate>> {
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self.ser_where.as_ref()
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}
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pub fn de_where(&self) -> Option<&Vec<ast::WherePredicate>> {
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self.de_where.as_ref()
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}
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}
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/// Represents variant attribute information
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@ -181,6 +207,8 @@ pub struct FieldAttrs {
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default_expr_if_missing: Option<P<ast::Expr>>,
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serialize_with: Option<ast::Path>,
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deserialize_with: Option<ast::Path>,
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ser_where: Option<Vec<ast::WherePredicate>>,
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de_where: Option<Vec<ast::WherePredicate>>,
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}
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impl FieldAttrs {
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@ -203,6 +231,8 @@ impl FieldAttrs {
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default_expr_if_missing: None,
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serialize_with: None,
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deserialize_with: None,
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ser_where: None,
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de_where: None,
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};
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for meta_items in field.attrs.iter().filter_map(get_serde_meta_items) {
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@ -274,6 +304,20 @@ impl FieldAttrs {
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field_attrs.deserialize_with = Some(path);
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}
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// Parse `#[serde(where="D: Serialize")]`
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ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"where" => {
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let where_predicates = try!(parse_lit_into_where(cx, name, lit));
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field_attrs.ser_where = Some(where_predicates.clone());
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field_attrs.de_where = Some(where_predicates.clone());
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}
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// Parse `#[serde(where(serialize="D: Serialize", deserialize="D: Deserialize"))]`
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ast::MetaItemKind::List(ref name, ref meta_items) if name == &"where" => {
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let (ser_where, de_where) = try!(get_where_predicates(cx, meta_items));
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field_attrs.ser_where = ser_where;
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field_attrs.de_where = de_where;
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}
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_ => {
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cx.span_err(
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meta_item.span,
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@ -316,45 +360,59 @@ impl FieldAttrs {
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pub fn deserialize_with(&self) -> Option<&ast::Path> {
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self.deserialize_with.as_ref()
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}
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pub fn ser_where(&self) -> Option<&Vec<ast::WherePredicate>> {
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self.ser_where.as_ref()
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}
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pub fn de_where(&self) -> Option<&Vec<ast::WherePredicate>> {
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self.de_where.as_ref()
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}
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}
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/// Zip together fields and `#[serde(...)]` attributes on those fields.
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pub fn fields_with_attrs<'a>(
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pub fn fields_with_attrs(
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cx: &ExtCtxt,
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fields: &'a [ast::StructField],
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) -> Result<Vec<(&'a ast::StructField, FieldAttrs)>, Error> {
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fields: &[ast::StructField],
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) -> Result<Vec<(ast::StructField, FieldAttrs)>, Error> {
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fields.iter()
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.enumerate()
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.map(|(i, field)| {
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let attrs = try!(FieldAttrs::from_field(cx, i, field));
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Ok((field, attrs))
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Ok((field.clone(), attrs))
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})
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.collect()
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}
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fn get_renames(cx: &ExtCtxt,
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items: &[P<ast::MetaItem>],
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)-> Result<(Option<InternedString>, Option<InternedString>), Error> {
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let mut ser_name = None;
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let mut de_name = None;
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fn get_ser_and_de<T, F>(
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cx: &ExtCtxt,
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attribute: &str,
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items: &[P<ast::MetaItem>],
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f: F
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) -> Result<(Option<T>, Option<T>), Error>
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where F: Fn(&ExtCtxt, &str, &ast::Lit) -> Result<T, Error>,
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{
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let mut ser_item = None;
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let mut de_item = None;
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for item in items {
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match item.node {
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ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"serialize" => {
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let s = try!(get_str_from_lit(cx, name, lit));
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ser_name = Some(s);
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let s = try!(f(cx, name, lit));
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ser_item = Some(s);
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}
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ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"deserialize" => {
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let s = try!(get_str_from_lit(cx, name, lit));
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de_name = Some(s);
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let s = try!(f(cx, name, lit));
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de_item = Some(s);
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}
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_ => {
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cx.span_err(
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item.span,
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&format!("unknown rename attribute `{}`",
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&format!("unknown {} attribute `{}`",
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attribute,
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meta_item_to_string(item)));
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return Err(Error);
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@ -362,7 +420,21 @@ fn get_renames(cx: &ExtCtxt,
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}
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}
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Ok((ser_name, de_name))
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Ok((ser_item, de_item))
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}
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fn get_renames(
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cx: &ExtCtxt,
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items: &[P<ast::MetaItem>],
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) -> Result<(Option<InternedString>, Option<InternedString>), Error> {
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get_ser_and_de(cx, "rename", items, get_str_from_lit)
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}
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fn get_where_predicates(
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cx: &ExtCtxt,
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items: &[P<ast::MetaItem>],
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) -> Result<(Option<Vec<ast::WherePredicate>>, Option<Vec<ast::WherePredicate>>), Error> {
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get_ser_and_de(cx, "where", items, parse_lit_into_where)
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}
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pub fn get_serde_meta_items(attr: &ast::Attribute) -> Option<&[P<ast::MetaItem>]> {
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@ -437,17 +509,18 @@ fn get_str_from_lit(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<Interned
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}
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}
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fn parse_lit_into_path(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<ast::Path, Error> {
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let source = try!(get_str_from_lit(cx, name, lit));
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// If we just parse the string into an expression, any syntax errors in the source will only
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// have spans that point inside the string, and not back to the attribute. So to have better
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// error reporting, we'll first parse the string into a token tree. Then we'll update those
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// spans to say they're coming from a macro context that originally came from the attribute,
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// and then finally parse them into an expression.
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// If we just parse a string literal from an attibute, any syntax errors in the
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// source will only have spans that point inside the string and not back to the
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// attribute. So to have better error reporting, we'll first parse the string
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// into a token tree. Then we'll update those spans to say they're coming from a
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// macro context that originally came from the attribnute, and then finally
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// parse them into an expression or where-clause.
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fn parse_string_via_tts<T, F>(cx: &ExtCtxt, name: &str, string: String, action: F) -> Result<T, Error>
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where F: for<'a> Fn(&'a mut Parser) -> parse::PResult<'a, T>,
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{
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let tts = panictry!(parse::parse_tts_from_source_str(
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format!("<serde {} expansion>", name),
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(*source).to_owned(),
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string,
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cx.cfg(),
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cx.parse_sess()));
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@ -456,7 +529,7 @@ fn parse_lit_into_path(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<ast::
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let mut parser = parse::new_parser_from_tts(cx.parse_sess(), cx.cfg(), tts);
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let path = match parser.parse_path(PathStyle::Type) {
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let path = match action(&mut parser) {
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Ok(path) => path,
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Err(mut e) => {
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e.emit();
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@ -476,6 +549,28 @@ fn parse_lit_into_path(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<ast::
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Ok(path)
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}
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fn parse_lit_into_path(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<ast::Path, Error> {
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let string = try!(get_str_from_lit(cx, name, lit)).to_string();
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parse_string_via_tts(cx, name, string, |parser| {
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parser.parse_path(PathStyle::Type)
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})
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}
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fn parse_lit_into_where(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<Vec<ast::WherePredicate>, Error> {
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let string = try!(get_str_from_lit(cx, name, lit));
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if string.is_empty() {
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return Ok(Vec::new());
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}
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let where_string = format!("where {}", string);
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parse_string_via_tts(cx, name, where_string, |parser| {
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let where_clause = try!(parser.parse_where_clause());
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Ok(where_clause.predicates)
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})
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}
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/// This function wraps the expression in `#[serde(default="...")]` in a function to prevent it
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/// from accessing the internal `Deserialize` state.
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fn wrap_default(path: ast::Path) -> P<ast::Expr> {
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@ -7,6 +7,9 @@ use syntax::ext::base::ExtCtxt;
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use syntax::ptr::P;
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use syntax::visit;
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use attr;
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use error::Error;
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// Remove the default from every type parameter because in the generated impls
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// they look like associated types: "error: associated type bindings are not
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// allowed here".
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@ -21,20 +24,50 @@ pub fn without_defaults(generics: &ast::Generics) -> ast::Generics {
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}
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}
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pub fn with_bound(
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pub fn with_where_predicates(
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builder: &AstBuilder,
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generics: &ast::Generics,
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predicates: &Vec<ast::WherePredicate>,
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) -> ast::Generics {
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builder.from_generics(generics.clone())
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.with_predicates(predicates.clone())
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.build()
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}
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pub fn with_where_predicates_from_fields<F>(
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cx: &ExtCtxt,
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builder: &AstBuilder,
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item: &ast::Item,
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generics: &ast::Generics,
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filter: &Fn(&ast::StructField) -> bool,
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bound: &ast::Path,
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) -> ast::Generics {
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builder.from_generics(generics.clone())
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from_field: F,
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) -> Result<ast::Generics, Error>
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where F: Fn(&attr::FieldAttrs) -> Option<&Vec<ast::WherePredicate>>,
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{
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Ok(builder.from_generics(generics.clone())
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.with_predicates(
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all_variants(cx, item).iter()
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.flat_map(|variant_data| all_struct_fields(variant_data))
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.filter(|field| filter(field))
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.map(|field| &field.ty)
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try!(all_fields_with_attrs(cx, item))
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.iter()
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.flat_map(|&(_, ref attrs)| from_field(attrs))
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.flat_map(|predicates| predicates.clone()))
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.build())
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}
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pub fn with_bound<F>(
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cx: &ExtCtxt,
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builder: &AstBuilder,
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item: &ast::Item,
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generics: &ast::Generics,
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filter: F,
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bound: &ast::Path,
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) -> Result<ast::Generics, Error>
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where F: Fn(&ast::StructField, &attr::FieldAttrs) -> bool,
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{
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Ok(builder.from_generics(generics.clone())
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.with_predicates(
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try!(all_fields_with_attrs(cx, item))
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.iter()
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.filter(|&&(ref field, ref attrs)| filter(field, attrs))
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.map(|&(ref field, _)| &field.ty)
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// TODO this filter can be removed later, see comment on function
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.filter(|ty| contains_generic(ty, generics))
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.map(|ty| strip_reference(ty))
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@ -44,7 +77,20 @@ pub fn with_bound(
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// the bound e.g. Serialize
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.bound().trait_(bound.clone()).build()
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.build()))
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.build()
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.build())
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}
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fn all_fields_with_attrs(
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cx: &ExtCtxt,
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item: &ast::Item,
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) -> Result<Vec<(ast::StructField, attr::FieldAttrs)>, Error> {
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let fields: Vec<ast::StructField> =
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all_variants(cx, item).iter()
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.flat_map(|variant_data| all_struct_fields(variant_data))
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.cloned()
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.collect();
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attr::fields_with_attrs(cx, &fields)
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}
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fn all_variants<'a>(cx: &ExtCtxt, item: &'a ast::Item) -> Vec<&'a ast::VariantData> {
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@ -35,36 +35,53 @@ pub fn expand_derive_deserialize(
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let builder = aster::AstBuilder::new().span(span);
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let generics = match item.node {
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ast::ItemKind::Struct(_, ref generics) => generics,
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ast::ItemKind::Enum(_, ref generics) => generics,
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_ => {
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cx.span_err(
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meta_item.span,
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"`#[derive(Deserialize)]` may only be applied to structs and enums");
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return;
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}
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};
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let impl_generics = build_impl_generics(cx, &builder, item, generics);
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let ty = builder.ty().path()
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.segment(item.ident).with_generics(impl_generics.clone()).build()
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.build();
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let body = match deserialize_body(cx, &builder, &item, &impl_generics, ty.clone()) {
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Ok(body) => body,
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let impl_item = match deserialize_item(cx, &builder, &item) {
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Ok(item) => item,
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Err(Error) => {
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// An error occured, but it should have been reported already.
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return;
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}
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};
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push(Annotatable::Item(impl_item))
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}
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fn deserialize_item(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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item: &Item,
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) -> Result<P<ast::Item>, Error> {
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let generics = match item.node {
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ast::ItemKind::Struct(_, ref generics) => generics,
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ast::ItemKind::Enum(_, ref generics) => generics,
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_ => {
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cx.span_err(
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item.span,
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"`#[derive(Deserialize)]` may only be applied to structs and enums");
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return Err(Error);
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}
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};
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let container_attrs = try!(attr::ContainerAttrs::from_item(cx, item));
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let impl_generics = try!(build_impl_generics(cx, &builder, item, generics, &container_attrs));
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let ty = builder.ty().path()
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.segment(item.ident).with_generics(impl_generics.clone()).build()
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.build();
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let body = try!(deserialize_body(cx,
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&builder,
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&item,
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&impl_generics,
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ty.clone(),
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&container_attrs));
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let where_clause = &impl_generics.where_clause;
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let dummy_const = builder.id(format!("_IMPL_DESERIALIZE_FOR_{}", item.ident));
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let impl_item = quote_item!(cx,
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Ok(quote_item!(cx,
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#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
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const $dummy_const: () = {
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extern crate serde as _serde;
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@ -77,9 +94,7 @@ pub fn expand_derive_deserialize(
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}
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}
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};
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).unwrap();
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push(Annotatable::Item(impl_item))
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).unwrap())
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}
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// All the generics in the input, plus a bound `T: Deserialize` for each generic
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@ -90,41 +105,43 @@ fn build_impl_generics(
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builder: &aster::AstBuilder,
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item: &Item,
|
||||
generics: &ast::Generics,
|
||||
) -> ast::Generics {
|
||||
container_attrs: &attr::ContainerAttrs,
|
||||
) -> Result<ast::Generics, Error> {
|
||||
let generics = bound::without_defaults(generics);
|
||||
let generics = bound::with_bound(cx, builder, item, &generics,
|
||||
&deserialized_by_us,
|
||||
&builder.path().ids(&["_serde", "de", "Deserialize"]).build());
|
||||
let generics = bound::with_bound(cx, builder, item, &generics,
|
||||
&requires_default,
|
||||
&builder.path().global().ids(&["std", "default", "Default"]).build());
|
||||
generics
|
||||
|
||||
let generics = try!(bound::with_where_predicates_from_fields(
|
||||
cx, builder, item, &generics,
|
||||
|attrs| attrs.de_where()));
|
||||
|
||||
match container_attrs.de_where() {
|
||||
Some(predicates) => {
|
||||
let generics = bound::with_where_predicates(builder, &generics, predicates);
|
||||
Ok(generics)
|
||||
}
|
||||
None => {
|
||||
let generics = try!(bound::with_bound(cx, builder, item, &generics,
|
||||
deserialized_by_us,
|
||||
&builder.path().ids(&["_serde", "de", "Deserialize"]).build()));
|
||||
let generics = try!(bound::with_bound(cx, builder, item, &generics,
|
||||
requires_default,
|
||||
&builder.path().global().ids(&["std", "default", "Default"]).build()));
|
||||
Ok(generics)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Fields with a `skip_deserializing` or `deserialize_with` attribute are not
|
||||
// deserialized by us. All other fields may need a `T: Deserialize` bound where
|
||||
// T is the type of the field.
|
||||
fn deserialized_by_us(field: &ast::StructField) -> bool {
|
||||
for meta_items in field.attrs.iter().filter_map(attr::get_serde_meta_items) {
|
||||
for meta_item in meta_items {
|
||||
match meta_item.node {
|
||||
ast::MetaItemKind::Word(ref name) if name == &"skip_deserializing" => {
|
||||
return false
|
||||
}
|
||||
ast::MetaItemKind::NameValue(ref name, _) if name == &"deserialize_with" => {
|
||||
return false
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
}
|
||||
true
|
||||
fn deserialized_by_us(_: &ast::StructField, attrs: &attr::FieldAttrs) -> bool {
|
||||
!attrs.skip_deserializing_field()
|
||||
&& attrs.deserialize_with().is_none()
|
||||
&& attrs.de_where().is_none()
|
||||
}
|
||||
|
||||
// Fields with a `default` attribute (not `default=...`), and fields with a
|
||||
// `skip_deserializing` attribute that do not also have `default=...`.
|
||||
fn requires_default(field: &ast::StructField) -> bool {
|
||||
let mut has_skip_deserializing = false;
|
||||
fn requires_default(field: &ast::StructField, attrs: &attr::FieldAttrs) -> bool {
|
||||
for meta_items in field.attrs.iter().filter_map(attr::get_serde_meta_items) {
|
||||
for meta_item in meta_items {
|
||||
match meta_item.node {
|
||||
@ -134,14 +151,11 @@ fn requires_default(field: &ast::StructField) -> bool {
|
||||
ast::MetaItemKind::NameValue(ref name, _) if name == &"default" => {
|
||||
return false
|
||||
}
|
||||
ast::MetaItemKind::Word(ref name) if name == &"skip_deserializing" => {
|
||||
has_skip_deserializing = true
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
}
|
||||
has_skip_deserializing
|
||||
attrs.skip_deserializing_field()
|
||||
}
|
||||
|
||||
fn deserialize_body(
|
||||
@ -150,9 +164,8 @@ fn deserialize_body(
|
||||
item: &Item,
|
||||
impl_generics: &ast::Generics,
|
||||
ty: P<ast::Ty>,
|
||||
container_attrs: &attr::ContainerAttrs,
|
||||
) -> Result<P<ast::Expr>, Error> {
|
||||
let container_attrs = try!(attr::ContainerAttrs::from_item(cx, item));
|
||||
|
||||
match item.node {
|
||||
ast::ItemKind::Struct(ref variant_data, _) => {
|
||||
deserialize_item_struct(
|
||||
@ -163,7 +176,7 @@ fn deserialize_body(
|
||||
ty,
|
||||
item.span,
|
||||
variant_data,
|
||||
&container_attrs,
|
||||
container_attrs,
|
||||
)
|
||||
}
|
||||
ast::ItemKind::Enum(ref enum_def, _) => {
|
||||
@ -174,7 +187,7 @@ fn deserialize_body(
|
||||
impl_generics,
|
||||
ty,
|
||||
enum_def,
|
||||
&container_attrs,
|
||||
container_attrs,
|
||||
)
|
||||
}
|
||||
_ => {
|
||||
@ -441,12 +454,12 @@ fn deserialize_seq(
|
||||
type_ident: Ident,
|
||||
type_path: ast::Path,
|
||||
impl_generics: &ast::Generics,
|
||||
fields: &[(&ast::StructField, attr::FieldAttrs)],
|
||||
fields: &[(ast::StructField, attr::FieldAttrs)],
|
||||
is_struct: bool,
|
||||
) -> Result<P<ast::Expr>, Error> {
|
||||
let let_values: Vec<_> = fields.iter()
|
||||
.enumerate()
|
||||
.map(|(i, &(field, ref attrs))| {
|
||||
.map(|(i, &(ref field, ref attrs))| {
|
||||
let name = builder.id(format!("__field{}", i));
|
||||
if attrs.skip_deserializing_field() {
|
||||
let default = expr_is_missing(cx, attrs);
|
||||
@ -486,7 +499,7 @@ fn deserialize_seq(
|
||||
.with_id_exprs(
|
||||
fields.iter()
|
||||
.enumerate()
|
||||
.map(|(i, &(field, _))| {
|
||||
.map(|(i, &(ref field, _))| {
|
||||
(
|
||||
match field.ident {
|
||||
Some(name) => name.clone(),
|
||||
@ -521,9 +534,9 @@ fn deserialize_newtype_struct(
|
||||
type_ident: Ident,
|
||||
type_path: &ast::Path,
|
||||
impl_generics: &ast::Generics,
|
||||
field: &(&ast::StructField, attr::FieldAttrs),
|
||||
field: &(ast::StructField, attr::FieldAttrs),
|
||||
) -> Result<Vec<ast::TokenTree>, Error> {
|
||||
let &(field, ref attrs) = field;
|
||||
let &(ref field, ref attrs) = field;
|
||||
let value = match attrs.deserialize_with() {
|
||||
None => {
|
||||
let field_ty = &field.ty;
|
||||
@ -982,7 +995,7 @@ fn deserialize_struct_visitor(
|
||||
type_ident: Ident,
|
||||
struct_path: ast::Path,
|
||||
impl_generics: &ast::Generics,
|
||||
fields: &[(&ast::StructField, attr::FieldAttrs)],
|
||||
fields: &[(ast::StructField, attr::FieldAttrs)],
|
||||
container_attrs: &attr::ContainerAttrs,
|
||||
) -> Result<(Vec<P<ast::Item>>, ast::Stmt, P<ast::Expr>), Error> {
|
||||
let field_exprs = fields.iter()
|
||||
@ -1010,7 +1023,7 @@ fn deserialize_struct_visitor(
|
||||
let fields_expr = builder.expr().ref_().slice()
|
||||
.with_exprs(
|
||||
fields.iter()
|
||||
.map(|&(field, _)| {
|
||||
.map(|&(ref field, _)| {
|
||||
match field.ident {
|
||||
Some(name) => builder.expr().str(name),
|
||||
None => {
|
||||
@ -1034,7 +1047,7 @@ fn deserialize_map(
|
||||
type_ident: Ident,
|
||||
struct_path: ast::Path,
|
||||
impl_generics: &ast::Generics,
|
||||
fields: &[(&ast::StructField, attr::FieldAttrs)],
|
||||
fields: &[(ast::StructField, attr::FieldAttrs)],
|
||||
container_attrs: &attr::ContainerAttrs,
|
||||
) -> Result<P<ast::Expr>, Error> {
|
||||
// Create the field names for the fields.
|
||||
@ -1056,7 +1069,7 @@ fn deserialize_map(
|
||||
// Match arms to extract a value for a field.
|
||||
let value_arms = fields_attrs_names.iter()
|
||||
.filter(|&&(_, ref attrs, _)| !attrs.skip_deserializing_field())
|
||||
.map(|&(field, ref attrs, name)| {
|
||||
.map(|&(ref field, ref attrs, name)| {
|
||||
let deser_name = attrs.name().deserialize_name();
|
||||
let name_str = builder.expr().lit().str(deser_name);
|
||||
|
||||
|
@ -60,7 +60,9 @@ fn serialize_item(
|
||||
}
|
||||
};
|
||||
|
||||
let impl_generics = build_impl_generics(cx, builder, item, generics);
|
||||
let container_attrs = try!(attr::ContainerAttrs::from_item(cx, item));
|
||||
|
||||
let impl_generics = try!(build_impl_generics(cx, builder, item, generics, &container_attrs));
|
||||
|
||||
let ty = builder.ty().path()
|
||||
.segment(item.ident).with_generics(impl_generics.clone()).build()
|
||||
@ -70,7 +72,8 @@ fn serialize_item(
|
||||
&builder,
|
||||
&item,
|
||||
&impl_generics,
|
||||
ty.clone()));
|
||||
ty.clone(),
|
||||
&container_attrs));
|
||||
|
||||
let where_clause = &impl_generics.where_clause;
|
||||
|
||||
@ -99,32 +102,36 @@ fn build_impl_generics(
|
||||
builder: &aster::AstBuilder,
|
||||
item: &Item,
|
||||
generics: &ast::Generics,
|
||||
) -> ast::Generics {
|
||||
container_attrs: &attr::ContainerAttrs,
|
||||
) -> Result<ast::Generics, Error> {
|
||||
let generics = bound::without_defaults(generics);
|
||||
let generics = bound::with_bound(cx, builder, item, &generics,
|
||||
&serialized_by_us,
|
||||
&builder.path().ids(&["_serde", "ser", "Serialize"]).build());
|
||||
generics
|
||||
|
||||
let generics = try!(bound::with_where_predicates_from_fields(
|
||||
cx, builder, item, &generics,
|
||||
|attrs| attrs.ser_where()));
|
||||
|
||||
match container_attrs.ser_where() {
|
||||
Some(predicates) => {
|
||||
let generics = bound::with_where_predicates(builder, &generics, predicates);
|
||||
Ok(generics)
|
||||
}
|
||||
None => {
|
||||
let generics = try!(bound::with_bound(cx, builder, item, &generics,
|
||||
needs_serialize_bound,
|
||||
&builder.path().ids(&["_serde", "ser", "Serialize"]).build()));
|
||||
Ok(generics)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Fields with a `skip_serializing` or `serialize_with` attribute are not
|
||||
// serialized by us. All other fields may need a `T: Serialize` bound where T is
|
||||
// the type of the field.
|
||||
fn serialized_by_us(field: &ast::StructField) -> bool {
|
||||
for meta_items in field.attrs.iter().filter_map(attr::get_serde_meta_items) {
|
||||
for meta_item in meta_items {
|
||||
match meta_item.node {
|
||||
ast::MetaItemKind::Word(ref name) if name == &"skip_serializing" => {
|
||||
return false
|
||||
}
|
||||
ast::MetaItemKind::NameValue(ref name, _) if name == &"serialize_with" => {
|
||||
return false
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
}
|
||||
true
|
||||
// serialized by us so we do not generate a bound. Fields with a `where`
|
||||
// attribute specify their own bound so we do not generate one. All other fields
|
||||
// may need a `T: Serialize` bound where T is the type of the field.
|
||||
fn needs_serialize_bound(_: &ast::StructField, attrs: &attr::FieldAttrs) -> bool {
|
||||
!attrs.skip_serializing_field()
|
||||
&& attrs.serialize_with().is_none()
|
||||
&& attrs.ser_where().is_none()
|
||||
}
|
||||
|
||||
fn serialize_body(
|
||||
@ -133,9 +140,8 @@ fn serialize_body(
|
||||
item: &Item,
|
||||
impl_generics: &ast::Generics,
|
||||
ty: P<ast::Ty>,
|
||||
container_attrs: &attr::ContainerAttrs,
|
||||
) -> Result<P<ast::Expr>, Error> {
|
||||
let container_attrs = try!(attr::ContainerAttrs::from_item(cx, item));
|
||||
|
||||
match item.node {
|
||||
ast::ItemKind::Struct(ref variant_data, _) => {
|
||||
serialize_item_struct(
|
||||
@ -145,7 +151,7 @@ fn serialize_body(
|
||||
ty,
|
||||
item.span,
|
||||
variant_data,
|
||||
&container_attrs,
|
||||
container_attrs,
|
||||
)
|
||||
}
|
||||
ast::ItemKind::Enum(ref enum_def, _) => {
|
||||
@ -156,7 +162,7 @@ fn serialize_body(
|
||||
impl_generics,
|
||||
ty,
|
||||
enum_def,
|
||||
&container_attrs,
|
||||
container_attrs,
|
||||
)
|
||||
}
|
||||
_ => {
|
||||
@ -661,7 +667,7 @@ fn serialize_tuple_struct_visitor(
|
||||
|
||||
let arms: Vec<_> = fields_with_attrs.iter()
|
||||
.enumerate()
|
||||
.map(|(i, &(field, ref attrs))| {
|
||||
.map(|(i, &(ref field, ref attrs))| {
|
||||
let mut field_expr = builder.expr().tup_field(i).field("value").self_();
|
||||
if !is_enum {
|
||||
field_expr = quote_expr!(cx, &$field_expr);
|
||||
@ -745,7 +751,7 @@ fn serialize_struct_visitor(
|
||||
let arms: Vec<ast::Arm> = fields_with_attrs.iter()
|
||||
.filter(|&&(_, ref attrs)| !attrs.skip_serializing_field())
|
||||
.enumerate()
|
||||
.map(|(i, &(field, ref attrs))| {
|
||||
.map(|(i, &(ref field, ref attrs))| {
|
||||
let ident = field.ident.expect("struct has unnamed field");
|
||||
let mut field_expr = quote_expr!(cx, self.value.$ident);
|
||||
if !is_enum {
|
||||
@ -789,7 +795,7 @@ fn serialize_struct_visitor(
|
||||
|
||||
let len = fields_with_attrs.iter()
|
||||
.filter(|&&(_, ref attrs)| !attrs.skip_serializing_field())
|
||||
.map(|&(field, ref attrs)| {
|
||||
.map(|&(ref field, ref attrs)| {
|
||||
let ident = field.ident.expect("struct has unnamed fields");
|
||||
let mut field_expr = quote_expr!(cx, self.value.$ident);
|
||||
if !is_enum {
|
||||
|
@ -74,8 +74,44 @@ struct Tuple<T>(
|
||||
X,
|
||||
);
|
||||
|
||||
#[derive(Serialize, Deserialize)]
|
||||
#[serde(where(serialize="D: Serialize", deserialize="D: Deserialize"))]
|
||||
enum TreeNode<D> {
|
||||
Split {
|
||||
left: Box<TreeNode<D>>,
|
||||
right: Box<TreeNode<D>>,
|
||||
},
|
||||
Leaf {
|
||||
data: D,
|
||||
},
|
||||
}
|
||||
|
||||
#[derive(Serialize, Deserialize)]
|
||||
struct ListNode<D> {
|
||||
data: D,
|
||||
#[serde(where="")]
|
||||
next: Box<ListNode<D>>,
|
||||
}
|
||||
|
||||
#[derive(Serialize, Deserialize)]
|
||||
struct SerializeWithTrait<D> {
|
||||
#[serde(serialize_with="SerializeWith::serialize_with",
|
||||
deserialize_with="DeserializeWith::deserialize_with",
|
||||
where(serialize="D: SerializeWith",
|
||||
deserialize="D: DeserializeWith"))]
|
||||
data: D,
|
||||
}
|
||||
|
||||
//////////////////////////////////////////////////////////////////////////
|
||||
|
||||
trait SerializeWith {
|
||||
fn serialize_with<S: Serializer>(_: &Self, _: &mut S) -> Result<(), S::Error>;
|
||||
}
|
||||
|
||||
trait DeserializeWith: Sized {
|
||||
fn deserialize_with<D: Deserializer>(_: &mut D) -> Result<Self, D::Error>;
|
||||
}
|
||||
|
||||
// Implements neither Serialize nor Deserialize
|
||||
struct X;
|
||||
fn ser_x<S: Serializer>(_: &X, _: &mut S) -> Result<(), S::Error> { panic!() }
|
||||
|
Loading…
x
Reference in New Issue
Block a user