Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 317 insertions, 0 deletions

diff --git a/third_party/rust/serde_derive/src/bound.rs b/third_party/rust/serde_derive/src/bound.rs
new file mode 100644
index 0000000000..ec2eafe89f
--- /dev/null
+++ b/third_party/rust/serde_derive/src/bound.rs
@@ -0,0 +1,317 @@
+use std::collections::HashSet;
+
+use syn;
+use syn::punctuated::{Pair, Punctuated};
+use syn::visit::{self, Visit};
+
+use internals::ast::{Container, Data};
+use internals::{attr, ungroup};
+
+use proc_macro2::Span;
+
+// 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: &syn::Generics) -> syn::Generics {
+    syn::Generics {
+        params: generics
+            .params
+            .iter()
+            .map(|param| match param {
+                syn::GenericParam::Type(param) => syn::GenericParam::Type(syn::TypeParam {
+                    eq_token: None,
+                    default: None,
+                    ..param.clone()
+                }),
+                _ => param.clone(),
+            })
+            .collect(),
+        ..generics.clone()
+    }
+}
+
+pub fn with_where_predicates(
+    generics: &syn::Generics,
+    predicates: &[syn::WherePredicate],
+) -> syn::Generics {
+    let mut generics = generics.clone();
+    generics
+        .make_where_clause()
+        .predicates
+        .extend(predicates.iter().cloned());
+    generics
+}
+
+pub fn with_where_predicates_from_fields(
+    cont: &Container,
+    generics: &syn::Generics,
+    from_field: fn(&attr::Field) -> Option<&[syn::WherePredicate]>,
+) -> syn::Generics {
+    let predicates = cont
+        .data
+        .all_fields()
+        .flat_map(|field| from_field(&field.attrs))
+        .flat_map(|predicates| predicates.to_vec());
+
+    let mut generics = generics.clone();
+    generics.make_where_clause().predicates.extend(predicates);
+    generics
+}
+
+pub fn with_where_predicates_from_variants(
+    cont: &Container,
+    generics: &syn::Generics,
+    from_variant: fn(&attr::Variant) -> Option<&[syn::WherePredicate]>,
+) -> syn::Generics {
+    let variants = match &cont.data {
+        Data::Enum(variants) => variants,
+        Data::Struct(_, _) => {
+            return generics.clone();
+        }
+    };
+
+    let predicates = variants
+        .iter()
+        .flat_map(|variant| from_variant(&variant.attrs))
+        .flat_map(|predicates| predicates.to_vec());
+
+    let mut generics = generics.clone();
+    generics.make_where_clause().predicates.extend(predicates);
+    generics
+}
+
+// Puts the given bound on any generic type parameters that are used in fields
+// for which filter returns true.
+//
+// For example, the following struct needs the bound `A: Serialize, B:
+// Serialize`.
+//
+//     struct S<'b, A, B: 'b, C> {
+//         a: A,
+//         b: Option<&'b B>
+//         #[serde(skip_serializing)]
+//         c: C,
+//     }
+pub fn with_bound(
+    cont: &Container,
+    generics: &syn::Generics,
+    filter: fn(&attr::Field, Option<&attr::Variant>) -> bool,
+    bound: &syn::Path,
+) -> syn::Generics {
+    struct FindTyParams<'ast> {
+        // Set of all generic type parameters on the current struct (A, B, C in
+        // the example). Initialized up front.
+        all_type_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_type_params: HashSet<syn::Ident>,
+
+        // Fields whose type is an associated type of one of the generic type
+        // parameters.
+        associated_type_usage: Vec<&'ast syn::TypePath>,
+    }
+    impl<'ast> Visit<'ast> for FindTyParams<'ast> {
+        fn visit_field(&mut self, field: &'ast syn::Field) {
+            if let syn::Type::Path(ty) = ungroup(&field.ty) {
+                if let Some(Pair::Punctuated(t, _)) = ty.path.segments.pairs().next() {
+                    if self.all_type_params.contains(&t.ident) {
+                        self.associated_type_usage.push(ty);
+                    }
+                }
+            }
+            self.visit_type(&field.ty);
+        }
+
+        fn visit_path(&mut self, path: &'ast syn::Path) {
+            if let Some(seg) = path.segments.last() {
+                if seg.ident == "PhantomData" {
+                    // Hardcoded exception, because PhantomData<T> implements
+                    // Serialize and Deserialize whether or not T implements it.
+                    return;
+                }
+            }
+            if path.leading_colon.is_none() && path.segments.len() == 1 {
+                let id = &path.segments[0].ident;
+                if self.all_type_params.contains(id) {
+                    self.relevant_type_params.insert(id.clone());
+                }
+            }
+            visit::visit_path(self, path);
+        }
+
+        // Type parameter should not be considered used by a macro path.
+        //
+        //     struct TypeMacro<T> {
+        //         mac: T!(),
+        //         marker: PhantomData<T>,
+        //     }
+        fn visit_macro(&mut self, _mac: &'ast syn::Macro) {}
+    }
+
+    let all_type_params = generics
+        .type_params()
+        .map(|param| param.ident.clone())
+        .collect();
+
+    let mut visitor = FindTyParams {
+        all_type_params,
+        relevant_type_params: HashSet::new(),
+        associated_type_usage: Vec::new(),
+    };
+    match &cont.data {
+        Data::Enum(variants) => {
+            for variant in variants.iter() {
+                let relevant_fields = variant
+                    .fields
+                    .iter()
+                    .filter(|field| filter(&field.attrs, Some(&variant.attrs)));
+                for field in relevant_fields {
+                    visitor.visit_field(field.original);
+                }
+            }
+        }
+        Data::Struct(_, fields) => {
+            for field in fields.iter().filter(|field| filter(&field.attrs, None)) {
+                visitor.visit_field(field.original);
+            }
+        }
+    }
+
+    let relevant_type_params = visitor.relevant_type_params;
+    let associated_type_usage = visitor.associated_type_usage;
+    let new_predicates = generics
+        .type_params()
+        .map(|param| param.ident.clone())
+        .filter(|id| relevant_type_params.contains(id))
+        .map(|id| syn::TypePath {
+            qself: None,
+            path: id.into(),
+        })
+        .chain(associated_type_usage.into_iter().cloned())
+        .map(|bounded_ty| {
+            syn::WherePredicate::Type(syn::PredicateType {
+                lifetimes: None,
+                // the type parameter that is being bounded e.g. T
+                bounded_ty: syn::Type::Path(bounded_ty),
+                colon_token: <Token![:]>::default(),
+                // the bound e.g. Serialize
+                bounds: vec![syn::TypeParamBound::Trait(syn::TraitBound {
+                    paren_token: None,
+                    modifier: syn::TraitBoundModifier::None,
+                    lifetimes: None,
+                    path: bound.clone(),
+                })]
+                .into_iter()
+                .collect(),
+            })
+        });
+
+    let mut generics = generics.clone();
+    generics
+        .make_where_clause()
+        .predicates
+        .extend(new_predicates);
+    generics
+}
+
+pub fn with_self_bound(
+    cont: &Container,
+    generics: &syn::Generics,
+    bound: &syn::Path,
+) -> syn::Generics {
+    let mut generics = generics.clone();
+    generics
+        .make_where_clause()
+        .predicates
+        .push(syn::WherePredicate::Type(syn::PredicateType {
+            lifetimes: None,
+            // the type that is being bounded e.g. MyStruct<'a, T>
+            bounded_ty: type_of_item(cont),
+            colon_token: <Token![:]>::default(),
+            // the bound e.g. Default
+            bounds: vec![syn::TypeParamBound::Trait(syn::TraitBound {
+                paren_token: None,
+                modifier: syn::TraitBoundModifier::None,
+                lifetimes: None,
+                path: bound.clone(),
+            })]
+            .into_iter()
+            .collect(),
+        }));
+    generics
+}
+
+pub fn with_lifetime_bound(generics: &syn::Generics, lifetime: &str) -> syn::Generics {
+    let bound = syn::Lifetime::new(lifetime, Span::call_site());
+    let def = syn::LifetimeDef {
+        attrs: Vec::new(),
+        lifetime: bound.clone(),
+        colon_token: None,
+        bounds: Punctuated::new(),
+    };
+
+    let params = Some(syn::GenericParam::Lifetime(def))
+        .into_iter()
+        .chain(generics.params.iter().cloned().map(|mut param| {
+            match &mut param {
+                syn::GenericParam::Lifetime(param) => {
+                    param.bounds.push(bound.clone());
+                }
+                syn::GenericParam::Type(param) => {
+                    param
+                        .bounds
+                        .push(syn::TypeParamBound::Lifetime(bound.clone()));
+                }
+                syn::GenericParam::Const(_) => {}
+            }
+            param
+        }))
+        .collect();
+
+    syn::Generics {
+        params,
+        ..generics.clone()
+    }
+}
+
+fn type_of_item(cont: &Container) -> syn::Type {
+    syn::Type::Path(syn::TypePath {
+        qself: None,
+        path: syn::Path {
+            leading_colon: None,
+            segments: vec![syn::PathSegment {
+                ident: cont.ident.clone(),
+                arguments: syn::PathArguments::AngleBracketed(
+                    syn::AngleBracketedGenericArguments {
+                        colon2_token: None,
+                        lt_token: <Token![<]>::default(),
+                        args: cont
+                            .generics
+                            .params
+                            .iter()
+                            .map(|param| match param {
+                                syn::GenericParam::Type(param) => {
+                                    syn::GenericArgument::Type(syn::Type::Path(syn::TypePath {
+                                        qself: None,
+                                        path: param.ident.clone().into(),
+                                    }))
+                                }
+                                syn::GenericParam::Lifetime(param) => {
+                                    syn::GenericArgument::Lifetime(param.lifetime.clone())
+                                }
+                                syn::GenericParam::Const(_) => {
+                                    panic!("Serde does not support const generics yet");
+                                }
+                            })
+                            .collect(),
+                        gt_token: <Token![>]>::default(),
+                    },
+                ),
+            }]
+            .into_iter()
+            .collect(),
+        },
+    })
+}