| // vim: tw=80 |
| use super::*; |
| use std::collections::HashMap; |
| use syn::parse::{Parse, ParseStream}; |
| |
| /// A single automock attribute |
| // This enum is very short-lived, so it's fine not to box it. |
| #[allow(clippy::large_enum_variant)] |
| enum Attr { |
| Mod(ItemMod), |
| Type(TraitItemType), |
| } |
| |
| impl Parse for Attr { |
| fn parse(input: ParseStream) -> parse::Result<Self> { |
| let lookahead = input.lookahead1(); |
| if lookahead.peek(Token![mod]) { |
| input.parse().map(Attr::Mod) |
| } else if lookahead.peek(Token![type]) { |
| input.parse().map(Attr::Type) |
| } else { |
| Err(lookahead.error()) |
| } |
| } |
| } |
| |
| /// automock attributes |
| #[derive(Debug, Default)] |
| pub(crate) struct Attrs { |
| pub attrs: HashMap<Ident, Type>, |
| pub modname: Option<Ident> |
| } |
| |
| impl Attrs { |
| fn get_path(&self, path: &Path) -> Option<Type> { |
| if path.leading_colon.is_none() & (path.segments.len() == 2) { |
| if path.segments.first().unwrap().ident == "Self" { |
| let ident = &path.segments.last().unwrap().ident; |
| self.attrs.get(ident).cloned() |
| } else { |
| None |
| } |
| } else { |
| None |
| } |
| } |
| |
| fn substitute_path_segment(&self, seg: &mut PathSegment, traitname: &Ident) |
| { |
| match &mut seg.arguments { |
| PathArguments::None => /* nothing to do */(), |
| PathArguments::Parenthesized(p) => { |
| compile_error(p.span(), |
| "Mockall does not support mocking Fn objects. See https://github.com/asomers/mockall/issues/139"); |
| }, |
| PathArguments::AngleBracketed(abga) => { |
| for arg in abga.args.iter_mut() { |
| match arg { |
| GenericArgument::Type(ty) => { |
| self.substitute_type(ty, traitname) |
| }, |
| GenericArgument::Binding(binding) => { |
| self.substitute_type(&mut binding.ty, traitname); |
| }, |
| _ => { |
| /* |
| * Nothing to do, as long as lifetimes can't be |
| * associated types |
| */ |
| } |
| } |
| } |
| }, |
| } |
| } |
| |
| /// Recursively substitute types in the input |
| fn substitute_type(&self, ty: &mut Type, traitname: &Ident) { |
| match ty { |
| Type::Slice(s) => { |
| self.substitute_type(s.elem.as_mut(), traitname) |
| }, |
| Type::Array(a) => { |
| self.substitute_type(a.elem.as_mut(), traitname) |
| }, |
| Type::Ptr(p) => { |
| self.substitute_type(p.elem.as_mut(), traitname) |
| }, |
| Type::Reference(r) => { |
| self.substitute_type(r.elem.as_mut(), traitname) |
| }, |
| Type::BareFn(bfn) => { |
| for fn_arg in bfn.inputs.iter_mut() { |
| self.substitute_type(&mut fn_arg.ty, traitname); |
| } |
| if let ReturnType::Type(_, ref mut ty) = &mut bfn.output { |
| self.substitute_type(ty, traitname); |
| } |
| }, |
| Type::Tuple(tuple) => { |
| for elem in tuple.elems.iter_mut() { |
| self.substitute_type(elem, traitname) |
| } |
| } |
| Type::Path(path) => { |
| if let Some(ref qself) = path.qself { |
| let qp = if let Type::Path(p) = qself.ty.as_ref() { |
| &p.path |
| } else { |
| panic!("QSelf's type isn't a path?") |
| }; |
| let qident = &qp.segments.first().unwrap().ident; |
| if qself.position != 1 |
| || qp.segments.len() != 1 |
| || path.path.segments.len() != 2 |
| || qident != "Self" { |
| compile_error(path.span(), |
| "QSelf is a work in progress"); |
| } |
| |
| let mut seg_iter = path.path.segments.iter().rev(); |
| let last_seg = seg_iter.next().unwrap(); |
| let to_sub = &last_seg.ident; |
| let penultimate_seg = seg_iter.next().unwrap(); |
| let qident = &penultimate_seg.ident; |
| drop(seg_iter); |
| |
| if qident != traitname { |
| compile_error(qident.span(), |
| "Mockall does not support QSelf substitutions except for the trait being mocked"); |
| } |
| if let Some(new_type) = self.attrs.get(to_sub) { |
| *ty = new_type.clone(); |
| } else { |
| compile_error(to_sub.span(), |
| "Unknown type substitution for QSelf"); |
| } |
| } else if let Some(newty) = self.get_path(&path.path) { |
| *ty = newty; |
| } else { |
| for seg in path.path.segments.iter_mut() { |
| self.substitute_path_segment(seg, &traitname); |
| } |
| } |
| }, |
| Type::TraitObject(to) => { |
| for bound in to.bounds.iter_mut() { |
| self.substitute_type_param_bound(bound, traitname); |
| } |
| }, |
| Type::ImplTrait(it) => { |
| for bound in it.bounds.iter_mut() { |
| self.substitute_type_param_bound(bound, traitname); |
| } |
| }, |
| Type::Paren(p) => { |
| self.substitute_type(p.elem.as_mut(), traitname) |
| }, |
| Type::Group(g) => { |
| self.substitute_type(g.elem.as_mut(), traitname) |
| }, |
| Type::Macro(_) | Type::Verbatim(_) => { |
| compile_error(ty.span(), |
| "mockall_derive does not support this type when using associated types"); |
| }, |
| Type::Infer(_) | Type::Never(_) => { |
| /* Nothing to do */ |
| }, |
| _ => compile_error(ty.span(), "Unsupported type"), |
| } |
| } |
| |
| fn substitute_type_param_bound(&self, |
| bound: &mut TypeParamBound, |
| traitname: &Ident) |
| { |
| if let TypeParamBound::Trait(t) = bound { |
| match self.get_path(&t.path) { |
| None => { |
| for seg in t.path.segments.iter_mut() { |
| self.substitute_path_segment(seg, &traitname); |
| } |
| }, |
| Some(Type::Path(type_path)) => { |
| t.path = type_path.path; |
| }, |
| Some(_) => { |
| compile_error(t.path.span(), |
| "Can only substitute paths for trait bounds"); |
| } |
| } |
| } |
| } |
| |
| pub(crate) fn substitute_trait(&self, item: &ItemTrait) -> ItemTrait { |
| let mut output = item.clone(); |
| for trait_item in output.items.iter_mut() { |
| match trait_item { |
| TraitItem::Type(tity) => { |
| if let Some(ty) = self.attrs.get(&tity.ident) { |
| let span = tity.span(); |
| tity.default = Some((Token, ty.clone())); |
| // Concrete associated types aren't allowed to have |
| // bounds |
| tity.bounds = Punctuated::new(); |
| } else { |
| compile_error(tity.span(), |
| "Default value not given for associated type"); |
| } |
| }, |
| TraitItem::Method(method) => { |
| let sig = &mut method.sig; |
| for fn_arg in sig.inputs.iter_mut() { |
| if let FnArg::Typed(arg) = fn_arg { |
| self.substitute_type(&mut arg.ty, &item.ident); |
| } |
| } |
| if let ReturnType::Type(_, ref mut ty) = &mut sig.output { |
| self.substitute_type(ty, &item.ident); |
| } |
| }, |
| _ => { |
| // Nothing to do |
| } |
| } |
| } |
| output |
| } |
| } |
| |
| impl Parse for Attrs { |
| fn parse(input: ParseStream) -> parse::Result<Self> { |
| let mut attrs = HashMap::new(); |
| let mut modname = None; |
| while !input.is_empty() { |
| let attr: Attr = input.parse()?; |
| match attr { |
| Attr::Mod(item_mod) => { |
| if let Some((br, _)) = item_mod.content { |
| compile_error(br.span, |
| "mod name attributes must have the form \"mod my_name;\""); |
| } |
| modname = Some(item_mod.ident.clone()); |
| }, |
| Attr::Type(trait_item_type) => { |
| let ident = trait_item_type.ident.clone(); |
| if let Some((_, ty)) = trait_item_type.default { |
| attrs.insert(ident, ty.clone()); |
| } else { |
| compile_error(trait_item_type.span(), |
| "automock type attributes must have a default value"); |
| } |
| } |
| } |
| } |
| Ok(Attrs{attrs, modname}) |
| } |
| } |
| |
| /// Unit tests for `Attrs`. |
| #[cfg(test)] |
| mod t { |
| use super::super::*; |
| use pretty_assertions::assert_eq; |
| |
| fn check_substitute_type( |
| attrs: TokenStream, |
| input: TokenStream, |
| traitname: Ident, |
| expected: TokenStream) |
| { |
| let _self: super::Attrs = parse2(attrs).unwrap(); |
| let mut in_ty: Type = parse2(input).unwrap(); |
| let expect_ty: Type = parse2(expected).unwrap(); |
| _self.substitute_type(&mut in_ty, &traitname); |
| assert_eq!(in_ty, expect_ty); |
| } |
| |
| #[test] |
| fn qself() { |
| check_substitute_type(quote!(type T = u32;), |
| quote!(<Self as Foo>::T), |
| format_ident!("Foo"), |
| quote!(u32)); |
| } |
| |
| #[test] |
| #[should_panic(expected = "Mockall does not support QSelf substitutions except for the trait being mocked")] |
| fn qself_other() { |
| check_substitute_type(quote!(type T = u32;), |
| quote!(<Self as AsRef>::T), |
| format_ident!("Foo"), |
| quote!(u32)); |
| } |
| |
| #[test] |
| #[should_panic(expected = "Unknown type substitution for QSelf")] |
| fn unknown_substitution() { |
| check_substitute_type(quote!(type T = u32;), |
| quote!(<Self as Foo>::Q), |
| format_ident!("Foo"), |
| quote!(u32)); |
| } |
| } |
