Make AST non_exhaustive

core/src/ast/attrs.rs

@@ -7,6 +7,7 @@ use syn::{Attribute, Ident, LitStr, Meta, Token};
 
 /// The list of attributes on a type
 #[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
+#[non_exhaustive]
 pub struct Attrs {
     pub cfg: Vec<Attribute>,
     pub attrs: Vec<DiplomatBackendAttr>,
@@ -89,6 +90,7 @@ impl Serialize for Attrs {
 /// and `all()`, `not()`, and `any()` combiners), and then be followed by one
 /// or more backend-specific attributes, which can be any valid meta-item
 #[derive(Clone, PartialEq, Eq, Hash, Debug, Serialize)]
+#[non_exhaustive]
 pub struct DiplomatBackendAttr {
     pub cfg: DiplomatBackendAttrCfg,
     #[serde(serialize_with = "serialize_meta")]
@@ -103,6 +105,7 @@ where
 }
 
 #[derive(Clone, PartialEq, Eq, Hash, Debug, Serialize)]
+#[non_exhaustive]
 pub enum DiplomatBackendAttrCfg {
     Not(Box<DiplomatBackendAttrCfg>),
     Any(Vec<DiplomatBackendAttrCfg>),

core/src/ast/docs.rs

@@ -14,6 +14,7 @@ pub struct Docs(String, Vec<RustLink>);
 /// Note that this only controls markdown generated by this code. Existing markdown
 /// in the Rust documentation will not be sanitized in any way.
 #[derive(PartialEq, Eq, Clone, Debug)]
+#[non_exhaustive]
 pub enum MarkdownStyle {
     /// Regular markdown with no specific extensions, compatible with most common flavors
     Normal,
@@ -111,6 +112,7 @@ impl Docs {
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
+#[non_exhaustive]
 pub enum RustLinkDisplay {
     /// A nice expanded representation that includes the type name
     ///
@@ -125,6 +127,7 @@ pub enum RustLinkDisplay {
 }
 
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Deserialize, Debug, PartialOrd, Ord)]
+#[non_exhaustive]
 pub struct RustLink {
     pub path: Path,
     pub typ: DocType,
@@ -189,6 +192,7 @@ impl fmt::Display for RustLink {
 }
 
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Deserialize, Debug, PartialOrd, Ord)]
+#[non_exhaustive]
 pub enum DocType {
     Struct,
     StructField,

core/src/ast/enums.rs

@@ -6,6 +6,7 @@ use quote::ToTokens;
 
 /// A fieldless enum declaration in an FFI module.
 #[derive(Clone, Serialize, Debug, Hash, PartialEq, Eq)]
+#[non_exhaustive]
 pub struct Enum {
     pub name: Ident,
     pub docs: Docs,

core/src/ast/lifetimes.rs

@@ -395,6 +395,7 @@ pub(crate) struct LifetimeNode {
 
 /// A lifetime, analogous to [`syn::Lifetime`].
 #[derive(Clone, Debug, Hash, Eq, PartialEq, Serialize, Deserialize)]
+#[non_exhaustive]
 pub enum Lifetime {
     /// The `'static` lifetime.
     Static,

core/src/ast/methods.rs

@@ -11,6 +11,7 @@ use crate::Env;
 /// Includes both static and non-static methods, which can be distinguished
 /// by inspecting [`Method::self_param`].
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Debug)]
+#[non_exhaustive]
 pub struct Method {
     /// The name of the method as initially declared.
     pub name: Ident,
@@ -244,6 +245,7 @@ impl Method {
 
 /// The `self` parameter taken by a [`Method`].
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Debug)]
+#[non_exhaustive]
 pub struct SelfParam {
     /// The lifetime and mutability of the `self` param, if it's a reference.
     pub reference: Option<(Lifetime, Mutability)>,
@@ -275,6 +277,7 @@ impl SelfParam {
 
 /// A parameter taken by a [`Method`], not including `self`.
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Debug)]
+#[non_exhaustive]
 pub struct Param {
     /// The name of the parameter in the original method declaration.
     pub name: Ident,
@@ -316,6 +319,7 @@ pub enum LifetimeKind {
 
 #[derive(Default, Debug)]
 /// Parameters in a method that might be borrowed in the return type.
+#[non_exhaustive]
 pub struct BorrowedParams<'a>(
     pub Option<&'a SelfParam>,
     pub Vec<(&'a Param, LifetimeKind)>,

core/src/ast/modules.rs

@@ -60,6 +60,7 @@ impl DiplomatStructAttribute {
 }
 
 #[derive(Clone, Serialize, Debug)]
+#[non_exhaustive]
 pub struct Module {
     pub name: Ident,
     pub imports: Vec<(Path, Ident)>,
@@ -243,6 +244,7 @@ fn extract_imports(base_path: &Path, use_tree: &UseTree, out: &mut Vec<(Path, Id
 }
 
 #[derive(Serialize, Clone, Debug)]
+#[non_exhaustive]
 pub struct File {
     pub modules: BTreeMap<String, Module>,
 }

core/src/ast/paths.rs

@@ -4,6 +4,7 @@ use std::fmt;
 use super::Ident;
 
 #[derive(Hash, Eq, PartialEq, Deserialize, Serialize, Clone, Debug, Ord, PartialOrd)]
+#[non_exhaustive]
 pub struct Path {
     pub elements: Vec<Ident>,
 }

core/src/ast/structs.rs

@@ -5,6 +5,7 @@ use super::{Attrs, Ident, LifetimeEnv, Method, Mutability, PathType, TypeName};
 
 /// A struct declaration in an FFI module that is not opaque.
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Debug)]
+#[non_exhaustive]
 pub struct Struct {
     pub name: Ident,
     pub docs: Docs,
@@ -54,6 +55,7 @@ impl Struct {
 /// Opaque structs cannot be passed by-value across the FFI boundary, so they
 /// must be boxed or passed as references.
 #[derive(Clone, Serialize, Debug, Hash, PartialEq, Eq)]
+#[non_exhaustive]
 pub struct OpaqueStruct {
     pub name: Ident,
     pub docs: Docs,

core/src/ast/types.rs

@@ -16,6 +16,7 @@ use crate::Env;
 
 /// A type declared inside a Diplomat-annotated module.
 #[derive(Clone, Serialize, Debug, Hash, PartialEq, Eq)]
+#[non_exhaustive]
 pub enum CustomType {
     /// A non-opaque struct whose fields will be visible across the FFI boundary.
     Struct(Struct),
@@ -127,6 +128,7 @@ impl CustomType {
 /// A symbol declared in a module, which can either be a pointer to another path,
 /// or a custom type defined directly inside that module
 #[derive(Clone, Serialize, Debug)]
+#[non_exhaustive]
 pub enum ModSymbol {
     /// A symbol that is a pointer to another path.
     Alias(Path),
@@ -138,6 +140,7 @@ pub enum ModSymbol {
 
 /// A named type that is just a path, e.g. `std::borrow::Cow<'a, T>`.
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Deserialize, Debug)]
+#[non_exhaustive]
 pub struct PathType {
     pub path: Path,
     pub lifetimes: Vec<Lifetime>,
@@ -299,6 +302,7 @@ impl From<Path> for PathType {
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, Debug)]
+#[allow(clippy::exhaustive_enums)] // there are only two kinds of mutability we care about
 pub enum Mutability {
     Mutable,
     Immutable,
@@ -361,6 +365,7 @@ impl Mutability {
 /// Unlike [`CustomType`], which represents a type declaration, [`TypeName`]s can compose
 /// types through references and boxing, and can also capture unresolved paths.
 #[derive(Clone, PartialEq, Eq, Hash, Serialize, Deserialize, Debug)]
+#[non_exhaustive]
 pub enum TypeName {
     /// A built-in Rust scalar primitive.
     Primitive(PrimitiveType),
@@ -882,6 +887,7 @@ impl TypeName {
     }
 }
 
+#[non_exhaustive]
 pub enum LifetimeOrigin {
     Named,
     Reference,
@@ -973,6 +979,7 @@ impl fmt::Display for PathType {
 /// A built-in Rust primitive scalar type.
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize, Debug)]
 #[allow(non_camel_case_types)]
+#[allow(clippy::exhaustive_enums)] // there are only these (scalar types)
 pub enum PrimitiveType {
     i8,
     u8,

core/src/ast/validity.rs

@@ -2,6 +2,7 @@ use super::{Ident, Path, TypeName};
 
 #[cfg_attr(feature = "displaydoc", derive(displaydoc::Display))]
 #[derive(Debug, Clone)]
+#[non_exhaustive]
 pub enum ValidityError {
     /// An oqaue type crosses the FFI boundary as a value.
     #[cfg_attr(

core/src/hir/defs.rs

@@ -3,12 +3,14 @@
 use super::{Attrs, Everywhere, IdentBuf, Method, OutputOnly, TyPosition, Type};
 use crate::ast::Docs;
 
+#[non_exhaustive]
 pub enum ReturnableStructDef<'tcx> {
     Struct(&'tcx StructDef),
     OutStruct(&'tcx OutStructDef),
 }
 
 #[derive(Copy, Clone, Debug)]
+#[non_exhaustive]
 pub enum TypeDef<'tcx> {
     Struct(&'tcx StructDef),
     OutStruct(&'tcx OutStructDef),
@@ -21,6 +23,7 @@ pub type OutStructDef = StructDef<OutputOnly>;
 
 /// Structs that can be either inputs or outputs in methods.
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct StructDef<P: TyPosition = Everywhere> {
     pub docs: Docs,
     pub name: IdentBuf,
@@ -38,6 +41,7 @@ pub struct StructDef<P: TyPosition = Everywhere> {
 ///
 /// A struct marked with `#[diplomat::opaque]`.
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct OpaqueDef {
     pub docs: Docs,
     pub name: IdentBuf,
@@ -47,6 +51,7 @@ pub struct OpaqueDef {
 
 /// The enum type.
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct EnumDef {
     pub docs: Docs,
     pub name: IdentBuf,
@@ -60,6 +65,7 @@ pub type OutStructField = StructField<OutputOnly>;
 
 /// A field on a [`Struct`]s.
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct StructField<P: TyPosition = Everywhere> {
     pub docs: Docs,
     pub name: IdentBuf,
@@ -68,6 +74,7 @@ pub struct StructField<P: TyPosition = Everywhere> {
 
 /// A variant of an [`Enum`].
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct EnumVariant {
     pub docs: Docs,
     pub name: IdentBuf,

core/src/hir/lifetimes.rs

@@ -96,6 +96,7 @@ where
 /// Wrapper type for `TypeLifetime` and `MethodLifetime`, indicating that it may
 /// be the `'static` lifetime.
 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[allow(clippy::exhaustive_enums)] // this will only ever have two variants
 pub enum MaybeStatic<T> {
     Static,
     NonStatic(T),

core/src/hir/lowering.rs

@@ -12,6 +12,7 @@ use strck_ident::IntoCk;
 
 /// An error from lowering the AST to the HIR.
 #[derive(Debug)]
+#[non_exhaustive]
 pub enum LoweringError {
     /// The purpose of having this is that translating to the HIR has enormous
     /// potential for really detailed error handling and giving suggestions.

core/src/hir/methods.rs

@@ -11,6 +11,7 @@ use super::{
 
 /// A method exposed to Diplomat.
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct Method {
     pub docs: Docs,
     pub name: IdentBuf,
@@ -24,26 +25,30 @@ pub struct Method {
 
 /// Type that the method returns.
 #[derive(Debug)]
+#[non_exhaustive]
 pub enum SuccessType {
     Writeable,
     OutType(OutType),
 }
 
 /// Whether or not the method returns a value or a result.
 #[derive(Debug)]
+#[allow(clippy::exhaustive_enums)] // this only exists for fallible/infallible, breaking changes for more complex returns are ok
 pub enum ReturnType {
     Infallible(Option<SuccessType>),
     Fallible(Option<SuccessType>, Option<OutType>),
 }
 
 /// The `self` parameter of a method.
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct ParamSelf {
     pub ty: SelfType,
 }
 
 /// A parameter in a method.
 #[derive(Debug)]
+#[non_exhaustive]
 pub struct Param {
     pub name: IdentBuf,
     pub ty: Type,

core/src/hir/paths.rs

@@ -5,6 +5,7 @@ use super::{
 
 /// Path to a struct that may appear as an output.
 #[derive(Debug, Clone)]
+#[non_exhaustive]
 pub enum ReturnableStructPath {
     Struct(StructPath),
     OutStruct(OutStructPath),
@@ -15,6 +16,7 @@ pub type OutStructPath = StructPath<OutputOnly>;
 
 /// Path to a struct that can be used in inputs and outputs.
 #[derive(Debug, Clone)]
+#[non_exhaustive]
 pub struct StructPath<P: TyPosition = Everywhere> {
     pub lifetimes: TypeLifetimes,
     pub tcx_id: P::StructId,
@@ -35,6 +37,7 @@ pub struct StructPath<P: TyPosition = Everywhere> {
 /// 3. `OpaquePath<NonOptional, Borrow>`: Opaques in the `&self` position, which
 /// cannot be optional and must be borrowed for the same reason as above.
 #[derive(Debug, Clone)]
+#[non_exhaustive]
 pub struct OpaquePath<Opt, Owner> {
     pub lifetimes: TypeLifetimes,
     pub optional: Opt,
@@ -46,6 +49,7 @@ pub struct OpaquePath<Opt, Owner> {
 pub struct Optional(pub(super) bool);
 
 #[derive(Debug, Copy, Clone)]
+#[allow(clippy::exhaustive_enums)] // marker type
 pub struct NonOptional;
 
 impl<Owner: OpaqueOwner> OpaquePath<Optional, Owner> {
@@ -79,6 +83,7 @@ impl<Opt> OpaquePath<Opt, Borrow> {
 
 /// Path to an enum.
 #[derive(Debug, Clone)]
+#[non_exhaustive]
 pub struct EnumPath {
     pub tcx_id: EnumId,
 }
@@ -87,6 +92,7 @@ pub struct EnumPath {
 ///
 /// Since owned opaques cannot be used as inputs, this only appears in output types.
 #[derive(Copy, Clone, Debug)]
+#[allow(clippy::exhaustive_enums)] // only two answers to this question
 pub enum MaybeOwn {
     Own,
     Borrow(Borrow),