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Merged
merged 1 commit into from
Apr 7, 2023
Merged

Add bounds for fields in derive macro #14521

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12 changes: 6 additions & 6 deletions crates/hir-def/src/macro_expansion_tests/builtin_derive_macro.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ struct Foo;
#[derive(Copy)]
struct Foo;

impl < > core::marker::Copy for Foo< > {}"#]],
impl < > core::marker::Copy for Foo< > where {}"#]],
);
}

Expand All @@ -41,7 +41,7 @@ macro Copy {}
#[derive(Copy)]
struct Foo;

impl < > crate ::marker::Copy for Foo< > {}"#]],
impl < > crate ::marker::Copy for Foo< > where {}"#]],
);
}

Expand All @@ -57,7 +57,7 @@ struct Foo<A, B>;
#[derive(Copy)]
struct Foo<A, B>;

impl <T0: core::marker::Copy, T1: core::marker::Copy, > core::marker::Copy for Foo<T0, T1, > {}"#]],
impl <A: core::marker::Copy, B: core::marker::Copy, > core::marker::Copy for Foo<A, B, > where {}"#]],
);
}

Expand All @@ -74,7 +74,7 @@ struct Foo<A, B, 'a, 'b>;
#[derive(Copy)]
struct Foo<A, B, 'a, 'b>;

impl <T0: core::marker::Copy, T1: core::marker::Copy, > core::marker::Copy for Foo<T0, T1, > {}"#]],
impl <A: core::marker::Copy, B: core::marker::Copy, > core::marker::Copy for Foo<A, B, > where {}"#]],
);
}

Expand All @@ -90,7 +90,7 @@ struct Foo<A, B>;
#[derive(Clone)]
struct Foo<A, B>;

impl <T0: core::clone::Clone, T1: core::clone::Clone, > core::clone::Clone for Foo<T0, T1, > {}"#]],
impl <A: core::clone::Clone, B: core::clone::Clone, > core::clone::Clone for Foo<A, B, > where {}"#]],
);
}

Expand All @@ -106,6 +106,6 @@ struct Foo<const X: usize, T>(u32);
#[derive(Clone)]
struct Foo<const X: usize, T>(u32);

impl <const T0: usize, T1: core::clone::Clone, > core::clone::Clone for Foo<T0, T1, > {}"#]],
impl <const X: usize, T: core::clone::Clone, > core::clone::Clone for Foo<X, T, > where u32: core::clone::Clone, {}"#]],
);
}
73 changes: 56 additions & 17 deletions crates/hir-expand/src/builtin_derive_macro.rs
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Original file line number Diff line number Diff line change
@@ -1,11 +1,12 @@
//! Builtin derives.

use base_db::{CrateOrigin, LangCrateOrigin};
use either::Either;
use tracing::debug;

use crate::tt::{self, TokenId};
use syntax::{
ast::{self, AstNode, HasGenericParams, HasModuleItem, HasName},
ast::{self, AstNode, HasGenericParams, HasModuleItem, HasName, HasTypeBounds},
match_ast,
};

Expand Down Expand Up @@ -60,8 +61,11 @@ pub fn find_builtin_derive(ident: &name::Name) -> Option<BuiltinDeriveExpander>

struct BasicAdtInfo {
name: tt::Ident,
/// `Some(ty)` if it's a const param of type `ty`, `None` if it's a type param.
param_types: Vec<Option<tt::Subtree>>,
/// first field is the name, and
/// second field is `Some(ty)` if it's a const param of type `ty`, `None` if it's a type param.
/// third fields is where bounds, if any
param_types: Vec<(tt::Subtree, Option<tt::Subtree>, Option<tt::Subtree>)>,
field_types: Vec<tt::Subtree>,
}

fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
Expand All @@ -75,17 +79,34 @@ fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
ExpandError::Other("no item found".into())
})?;
let node = item.syntax();
let (name, params) = match_ast! {
let (name, params, fields) = match_ast! {
match node {
ast::Struct(it) => (it.name(), it.generic_param_list()),
ast::Enum(it) => (it.name(), it.generic_param_list()),
ast::Union(it) => (it.name(), it.generic_param_list()),
ast::Struct(it) => {
(it.name(), it.generic_param_list(), it.field_list().into_iter().collect::<Vec<_>>())
},
ast::Enum(it) => (it.name(), it.generic_param_list(), it.variant_list().into_iter().flat_map(|x| x.variants()).filter_map(|x| x.field_list()).collect()),
ast::Union(it) => (it.name(), it.generic_param_list(), it.record_field_list().into_iter().map(|x| ast::FieldList::RecordFieldList(x)).collect()),
_ => {
debug!("unexpected node is {:?}", node);
return Err(ExpandError::Other("expected struct, enum or union".into()))
},
}
};
let field_types = fields
.into_iter()
.flat_map(|f| match f {
ast::FieldList::RecordFieldList(x) => Either::Left(
x.fields()
.filter_map(|x| x.ty())
.map(|x| mbe::syntax_node_to_token_tree(x.syntax()).0),
),
ast::FieldList::TupleFieldList(x) => Either::Right(
x.fields()
.filter_map(|x| x.ty())
.map(|x| mbe::syntax_node_to_token_tree(x.syntax()).0),
),
})
.collect::<Vec<_>>();
let name = name.ok_or_else(|| {
debug!("parsed item has no name");
ExpandError::Other("missing name".into())
Expand All @@ -97,35 +118,46 @@ fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
.into_iter()
.flat_map(|param_list| param_list.type_or_const_params())
.map(|param| {
if let ast::TypeOrConstParam::Const(param) = param {
let name = param
.name()
.map(|x| mbe::syntax_node_to_token_tree(x.syntax()).0)
.unwrap_or_else(tt::Subtree::empty);
let bounds = match &param {
ast::TypeOrConstParam::Type(x) => {
x.type_bound_list().map(|x| mbe::syntax_node_to_token_tree(x.syntax()).0)
}
ast::TypeOrConstParam::Const(_) => None,
};
let ty = if let ast::TypeOrConstParam::Const(param) = param {
let ty = param
.ty()
.map(|ty| mbe::syntax_node_to_token_tree(ty.syntax()).0)
.unwrap_or_else(tt::Subtree::empty);
Some(ty)
} else {
None
}
};
(name, ty, bounds)
})
.collect();
Ok(BasicAdtInfo { name: name_token, param_types })
Ok(BasicAdtInfo { name: name_token, param_types, field_types })
}

fn expand_simple_derive(tt: &tt::Subtree, trait_path: tt::Subtree) -> ExpandResult<tt::Subtree> {
let info = match parse_adt(tt) {
Ok(info) => info,
Err(e) => return ExpandResult::with_err(tt::Subtree::empty(), e),
};
let mut where_block = vec![];
let (params, args): (Vec<_>, Vec<_>) = info
.param_types
.into_iter()
.enumerate()
.map(|(idx, param_ty)| {
let ident = tt::Leaf::Ident(tt::Ident {
span: tt::TokenId::unspecified(),
text: format!("T{idx}").into(),
});
.map(|(ident, param_ty, bound)| {
let ident_ = ident.clone();
if let Some(b) = bound {
let ident = ident.clone();
where_block.push(quote! { #ident : #b , });
}
if let Some(ty) = param_ty {
(quote! { const #ident : #ty , }, quote! { #ident_ , })
} else {
Expand All @@ -134,9 +166,16 @@ fn expand_simple_derive(tt: &tt::Subtree, trait_path: tt::Subtree) -> ExpandResu
}
})
.unzip();

where_block.extend(info.field_types.iter().map(|x| {
let x = x.clone();
let bound = trait_path.clone();
quote! { #x : #bound , }
}));

let name = info.name;
let expanded = quote! {
impl < ##params > #trait_path for #name < ##args > {}
impl < ##params > #trait_path for #name < ##args > where ##where_block {}
};
ExpandResult::ok(expanded)
}
Expand Down
8 changes: 4 additions & 4 deletions crates/ide/src/expand_macro.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -471,7 +471,7 @@ struct Foo {}
"#,
expect![[r#"
Clone
impl < >core::clone::Clone for Foo< >{}
impl < >core::clone::Clone for Foo< >where{}
"#]],
);
}
Expand All @@ -488,7 +488,7 @@ struct Foo {}
"#,
expect![[r#"
Copy
impl < >core::marker::Copy for Foo< >{}
impl < >core::marker::Copy for Foo< >where{}
"#]],
);
}
Expand All @@ -504,7 +504,7 @@ struct Foo {}
"#,
expect![[r#"
Copy
impl < >core::marker::Copy for Foo< >{}
impl < >core::marker::Copy for Foo< >where{}
"#]],
);
check(
Expand All @@ -516,7 +516,7 @@ struct Foo {}
"#,
expect![[r#"
Clone
impl < >core::clone::Clone for Foo< >{}
impl < >core::clone::Clone for Foo< >where{}
"#]],
);
}
Expand Down