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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /vendor/serde_derive/src/internals/check.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/serde_derive/src/internals/check.rs')
-rw-r--r--vendor/serde_derive/src/internals/check.rs420
1 files changed, 420 insertions, 0 deletions
diff --git a/vendor/serde_derive/src/internals/check.rs b/vendor/serde_derive/src/internals/check.rs
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+++ b/vendor/serde_derive/src/internals/check.rs
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+use internals::ast::{Container, Data, Field, Style};
+use internals::attr::{Identifier, TagType};
+use internals::{ungroup, Ctxt, Derive};
+use syn::{Member, Type};
+
+/// Cross-cutting checks that require looking at more than a single attrs
+/// object. Simpler checks should happen when parsing and building the attrs.
+pub fn check(cx: &Ctxt, cont: &mut Container, derive: Derive) {
+ check_getter(cx, cont);
+ check_flatten(cx, cont);
+ check_identifier(cx, cont);
+ check_variant_skip_attrs(cx, cont);
+ check_internal_tag_field_name_conflict(cx, cont);
+ check_adjacent_tag_conflict(cx, cont);
+ check_transparent(cx, cont, derive);
+ check_from_and_try_from(cx, cont);
+}
+
+/// Getters are only allowed inside structs (not enums) with the `remote`
+/// attribute.
+fn check_getter(cx: &Ctxt, cont: &Container) {
+ match cont.data {
+ Data::Enum(_) => {
+ if cont.data.has_getter() {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(getter = \"...\")] is not allowed in an enum",
+ );
+ }
+ }
+ Data::Struct(_, _) => {
+ if cont.data.has_getter() && cont.attrs.remote().is_none() {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(getter = \"...\")] can only be used in structs that have #[serde(remote = \"...\")]",
+ );
+ }
+ }
+ }
+}
+
+/// Flattening has some restrictions we can test.
+fn check_flatten(cx: &Ctxt, cont: &Container) {
+ match &cont.data {
+ Data::Enum(variants) => {
+ for variant in variants {
+ for field in &variant.fields {
+ check_flatten_field(cx, variant.style, field);
+ }
+ }
+ }
+ Data::Struct(style, fields) => {
+ for field in fields {
+ check_flatten_field(cx, *style, field);
+ }
+ }
+ }
+}
+
+fn check_flatten_field(cx: &Ctxt, style: Style, field: &Field) {
+ if !field.attrs.flatten() {
+ return;
+ }
+ match style {
+ Style::Tuple => {
+ cx.error_spanned_by(
+ field.original,
+ "#[serde(flatten)] cannot be used on tuple structs",
+ );
+ }
+ Style::Newtype => {
+ cx.error_spanned_by(
+ field.original,
+ "#[serde(flatten)] cannot be used on newtype structs",
+ );
+ }
+ _ => {}
+ }
+}
+
+/// The `other` attribute must be used at most once and it must be the last
+/// variant of an enum.
+///
+/// Inside a `variant_identifier` all variants must be unit variants. Inside a
+/// `field_identifier` all but possibly one variant must be unit variants. The
+/// last variant may be a newtype variant which is an implicit "other" case.
+fn check_identifier(cx: &Ctxt, cont: &Container) {
+ let variants = match &cont.data {
+ Data::Enum(variants) => variants,
+ Data::Struct(_, _) => {
+ return;
+ }
+ };
+
+ for (i, variant) in variants.iter().enumerate() {
+ match (
+ variant.style,
+ cont.attrs.identifier(),
+ variant.attrs.other(),
+ cont.attrs.tag(),
+ ) {
+ // The `other` attribute may not be used in a variant_identifier.
+ (_, Identifier::Variant, true, _) => {
+ cx.error_spanned_by(
+ variant.original,
+ "#[serde(other)] may not be used on a variant identifier",
+ );
+ }
+
+ // Variant with `other` attribute cannot appear in untagged enum
+ (_, Identifier::No, true, &TagType::None) => {
+ cx.error_spanned_by(
+ variant.original,
+ "#[serde(other)] cannot appear on untagged enum",
+ );
+ }
+
+ // Variant with `other` attribute must be the last one.
+ (Style::Unit, Identifier::Field, true, _) | (Style::Unit, Identifier::No, true, _) => {
+ if i < variants.len() - 1 {
+ cx.error_spanned_by(
+ variant.original,
+ "#[serde(other)] must be on the last variant",
+ );
+ }
+ }
+
+ // Variant with `other` attribute must be a unit variant.
+ (_, Identifier::Field, true, _) | (_, Identifier::No, true, _) => {
+ cx.error_spanned_by(
+ variant.original,
+ "#[serde(other)] must be on a unit variant",
+ );
+ }
+
+ // Any sort of variant is allowed if this is not an identifier.
+ (_, Identifier::No, false, _) => {}
+
+ // Unit variant without `other` attribute is always fine.
+ (Style::Unit, _, false, _) => {}
+
+ // The last field is allowed to be a newtype catch-all.
+ (Style::Newtype, Identifier::Field, false, _) => {
+ if i < variants.len() - 1 {
+ cx.error_spanned_by(
+ variant.original,
+ format!("`{}` must be the last variant", variant.ident),
+ );
+ }
+ }
+
+ (_, Identifier::Field, false, _) => {
+ cx.error_spanned_by(
+ variant.original,
+ "#[serde(field_identifier)] may only contain unit variants",
+ );
+ }
+
+ (_, Identifier::Variant, false, _) => {
+ cx.error_spanned_by(
+ variant.original,
+ "#[serde(variant_identifier)] may only contain unit variants",
+ );
+ }
+ }
+ }
+}
+
+/// Skip-(de)serializing attributes are not allowed on variants marked
+/// (de)serialize_with.
+fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
+ let variants = match &cont.data {
+ Data::Enum(variants) => variants,
+ Data::Struct(_, _) => {
+ return;
+ }
+ };
+
+ for variant in variants.iter() {
+ if variant.attrs.serialize_with().is_some() {
+ if variant.attrs.skip_serializing() {
+ cx.error_spanned_by(
+ variant.original,
+ format!(
+ "variant `{}` cannot have both #[serde(serialize_with)] and #[serde(skip_serializing)]",
+ variant.ident
+ ),
+ );
+ }
+
+ for field in &variant.fields {
+ let member = member_message(&field.member);
+
+ if field.attrs.skip_serializing() {
+ cx.error_spanned_by(
+ variant.original,
+ format!(
+ "variant `{}` cannot have both #[serde(serialize_with)] and a field {} marked with #[serde(skip_serializing)]",
+ variant.ident, member
+ ),
+ );
+ }
+
+ if field.attrs.skip_serializing_if().is_some() {
+ cx.error_spanned_by(
+ variant.original,
+ format!(
+ "variant `{}` cannot have both #[serde(serialize_with)] and a field {} marked with #[serde(skip_serializing_if)]",
+ variant.ident, member
+ ),
+ );
+ }
+ }
+ }
+
+ if variant.attrs.deserialize_with().is_some() {
+ if variant.attrs.skip_deserializing() {
+ cx.error_spanned_by(
+ variant.original,
+ format!(
+ "variant `{}` cannot have both #[serde(deserialize_with)] and #[serde(skip_deserializing)]",
+ variant.ident
+ ),
+ );
+ }
+
+ for field in &variant.fields {
+ if field.attrs.skip_deserializing() {
+ let member = member_message(&field.member);
+
+ cx.error_spanned_by(
+ variant.original,
+ format!(
+ "variant `{}` cannot have both #[serde(deserialize_with)] and a field {} marked with #[serde(skip_deserializing)]",
+ variant.ident, member
+ ),
+ );
+ }
+ }
+ }
+ }
+}
+
+/// The tag of an internally-tagged struct variant must not be
+/// the same as either one of its fields, as this would result in
+/// duplicate keys in the serialized output and/or ambiguity in
+/// the to-be-deserialized input.
+fn check_internal_tag_field_name_conflict(cx: &Ctxt, cont: &Container) {
+ let variants = match &cont.data {
+ Data::Enum(variants) => variants,
+ Data::Struct(_, _) => return,
+ };
+
+ let tag = match cont.attrs.tag() {
+ TagType::Internal { tag } => tag.as_str(),
+ TagType::External | TagType::Adjacent { .. } | TagType::None => return,
+ };
+
+ let diagnose_conflict = || {
+ cx.error_spanned_by(
+ cont.original,
+ format!("variant field name `{}` conflicts with internal tag", tag),
+ );
+ };
+
+ for variant in variants {
+ match variant.style {
+ Style::Struct => {
+ for field in &variant.fields {
+ let check_ser = !field.attrs.skip_serializing();
+ let check_de = !field.attrs.skip_deserializing();
+ let name = field.attrs.name();
+ let ser_name = name.serialize_name();
+
+ if check_ser && ser_name == tag {
+ diagnose_conflict();
+ return;
+ }
+
+ for de_name in field.attrs.aliases() {
+ if check_de && de_name == tag {
+ diagnose_conflict();
+ return;
+ }
+ }
+ }
+ }
+ Style::Unit | Style::Newtype | Style::Tuple => {}
+ }
+ }
+}
+
+/// In the case of adjacently-tagged enums, the type and the
+/// contents tag must differ, for the same reason.
+fn check_adjacent_tag_conflict(cx: &Ctxt, cont: &Container) {
+ let (type_tag, content_tag) = match cont.attrs.tag() {
+ TagType::Adjacent { tag, content } => (tag, content),
+ TagType::Internal { .. } | TagType::External | TagType::None => return,
+ };
+
+ if type_tag == content_tag {
+ cx.error_spanned_by(
+ cont.original,
+ format!(
+ "enum tags `{}` for type and content conflict with each other",
+ type_tag
+ ),
+ );
+ }
+}
+
+/// Enums and unit structs cannot be transparent.
+fn check_transparent(cx: &Ctxt, cont: &mut Container, derive: Derive) {
+ if !cont.attrs.transparent() {
+ return;
+ }
+
+ if cont.attrs.type_from().is_some() {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] is not allowed with #[serde(from = \"...\")]",
+ );
+ }
+
+ if cont.attrs.type_try_from().is_some() {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] is not allowed with #[serde(try_from = \"...\")]",
+ );
+ }
+
+ if cont.attrs.type_into().is_some() {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] is not allowed with #[serde(into = \"...\")]",
+ );
+ }
+
+ let fields = match &mut cont.data {
+ Data::Enum(_) => {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] is not allowed on an enum",
+ );
+ return;
+ }
+ Data::Struct(Style::Unit, _) => {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] is not allowed on a unit struct",
+ );
+ return;
+ }
+ Data::Struct(_, fields) => fields,
+ };
+
+ let mut transparent_field = None;
+
+ for field in fields {
+ if allow_transparent(field, derive) {
+ if transparent_field.is_some() {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] requires struct to have at most one transparent field",
+ );
+ return;
+ }
+ transparent_field = Some(field);
+ }
+ }
+
+ match transparent_field {
+ Some(transparent_field) => transparent_field.attrs.mark_transparent(),
+ None => match derive {
+ Derive::Serialize => {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] requires at least one field that is not skipped",
+ );
+ }
+ Derive::Deserialize => {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(transparent)] requires at least one field that is neither skipped nor has a default",
+ );
+ }
+ },
+ }
+}
+
+fn member_message(member: &Member) -> String {
+ match member {
+ Member::Named(ident) => format!("`{}`", ident),
+ Member::Unnamed(i) => format!("#{}", i.index),
+ }
+}
+
+fn allow_transparent(field: &Field, derive: Derive) -> bool {
+ if let Type::Path(ty) = ungroup(field.ty) {
+ if let Some(seg) = ty.path.segments.last() {
+ if seg.ident == "PhantomData" {
+ return false;
+ }
+ }
+ }
+
+ match derive {
+ Derive::Serialize => !field.attrs.skip_serializing(),
+ Derive::Deserialize => !field.attrs.skip_deserializing() && field.attrs.default().is_none(),
+ }
+}
+
+fn check_from_and_try_from(cx: &Ctxt, cont: &mut Container) {
+ if cont.attrs.type_from().is_some() && cont.attrs.type_try_from().is_some() {
+ cx.error_spanned_by(
+ cont.original,
+ "#[serde(from = \"...\")] and #[serde(try_from = \"...\")] conflict with each other",
+ );
+ }
+}