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Jan 2, 2021
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Parameterize shim trait impl blocks over lifetimes #635

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c417977
Distinguish Impl's impl generics vs generics on the Self type
dtolnay Jan 2, 2021
dc79f24
Parameterize shim trait impl blocks over lifetimes
dtolnay Jan 2, 2021
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82 changes: 59 additions & 23 deletions macro/src/expand.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1048,27 +1048,33 @@ fn expand_rust_box(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>) -
let local_dealloc = format_ident!("{}dealloc", local_prefix);
let local_drop = format_ident!("{}drop", local_prefix);

let (impl_generics, ty_generics) = if let Some(imp) = explicit_impl {
(&imp.impl_generics, &imp.ty_generics)
} else {
(resolve.generics, resolve.generics)
};

let begin_span =
explicit_impl.map_or_else(Span::call_site, |explicit| explicit.impl_token.span);
let end_span = explicit_impl.map_or_else(Span::call_site, |explicit| explicit.brace_token.span);
let unsafe_token = format_ident!("unsafe", span = begin_span);

quote_spanned! {end_span=>
#[doc(hidden)]
#unsafe_token impl ::cxx::private::ImplBox for #ident {}
#unsafe_token impl #impl_generics ::cxx::private::ImplBox for #ident #ty_generics {}
#[doc(hidden)]
#[export_name = #link_alloc]
unsafe extern "C" fn #local_alloc() -> *mut ::std::mem::MaybeUninit<#ident> {
unsafe extern "C" fn #local_alloc #impl_generics() -> *mut ::std::mem::MaybeUninit<#ident #ty_generics> {
::std::boxed::Box::into_raw(::std::boxed::Box::new(::std::mem::MaybeUninit::uninit()))
}
#[doc(hidden)]
#[export_name = #link_dealloc]
unsafe extern "C" fn #local_dealloc(ptr: *mut ::std::mem::MaybeUninit<#ident>) {
unsafe extern "C" fn #local_dealloc #impl_generics(ptr: *mut ::std::mem::MaybeUninit<#ident #ty_generics>) {
::std::boxed::Box::from_raw(ptr);
}
#[doc(hidden)]
#[export_name = #link_drop]
unsafe extern "C" fn #local_drop(this: *mut ::std::boxed::Box<#ident>) {
unsafe extern "C" fn #local_drop #impl_generics(this: *mut ::std::boxed::Box<#ident #ty_generics>) {
::std::ptr::drop_in_place(this);
}
}
Expand All @@ -1094,47 +1100,53 @@ fn expand_rust_vec(elem: &Ident, types: &Types, explicit_impl: Option<&Impl>) ->
let local_reserve_total = format_ident!("{}reserve_total", local_prefix);
let local_set_len = format_ident!("{}set_len", local_prefix);

let (impl_generics, ty_generics) = if let Some(imp) = explicit_impl {
(&imp.impl_generics, &imp.ty_generics)
} else {
(resolve.generics, resolve.generics)
};

let begin_span =
explicit_impl.map_or_else(Span::call_site, |explicit| explicit.impl_token.span);
let end_span = explicit_impl.map_or_else(Span::call_site, |explicit| explicit.brace_token.span);
let unsafe_token = format_ident!("unsafe", span = begin_span);

quote_spanned! {end_span=>
#[doc(hidden)]
#unsafe_token impl ::cxx::private::ImplVec for #elem {}
#unsafe_token impl #impl_generics ::cxx::private::ImplVec for #elem #ty_generics {}
#[doc(hidden)]
#[export_name = #link_new]
unsafe extern "C" fn #local_new(this: *mut ::cxx::private::RustVec<#elem>) {
unsafe extern "C" fn #local_new #impl_generics(this: *mut ::cxx::private::RustVec<#elem #ty_generics>) {
::std::ptr::write(this, ::cxx::private::RustVec::new());
}
#[doc(hidden)]
#[export_name = #link_drop]
unsafe extern "C" fn #local_drop(this: *mut ::cxx::private::RustVec<#elem>) {
unsafe extern "C" fn #local_drop #impl_generics(this: *mut ::cxx::private::RustVec<#elem #ty_generics>) {
::std::ptr::drop_in_place(this);
}
#[doc(hidden)]
#[export_name = #link_len]
unsafe extern "C" fn #local_len(this: *const ::cxx::private::RustVec<#elem>) -> usize {
unsafe extern "C" fn #local_len #impl_generics(this: *const ::cxx::private::RustVec<#elem #ty_generics>) -> usize {
(*this).len()
}
#[doc(hidden)]
#[export_name = #link_capacity]
unsafe extern "C" fn #local_capacity(this: *const ::cxx::private::RustVec<#elem>) -> usize {
unsafe extern "C" fn #local_capacity #impl_generics(this: *const ::cxx::private::RustVec<#elem #ty_generics>) -> usize {
(*this).capacity()
}
#[doc(hidden)]
#[export_name = #link_data]
unsafe extern "C" fn #local_data(this: *const ::cxx::private::RustVec<#elem>) -> *const #elem {
unsafe extern "C" fn #local_data #impl_generics(this: *const ::cxx::private::RustVec<#elem #ty_generics>) -> *const #elem #ty_generics {
(*this).as_ptr()
}
#[doc(hidden)]
#[export_name = #link_reserve_total]
unsafe extern "C" fn #local_reserve_total(this: *mut ::cxx::private::RustVec<#elem>, cap: usize) {
unsafe extern "C" fn #local_reserve_total #impl_generics(this: *mut ::cxx::private::RustVec<#elem #ty_generics>, cap: usize) {
(*this).reserve_total(cap);
}
#[doc(hidden)]
#[export_name = #link_set_len]
unsafe extern "C" fn #local_set_len(this: *mut ::cxx::private::RustVec<#elem>, len: usize) {
unsafe extern "C" fn #local_set_len #impl_generics(this: *mut ::cxx::private::RustVec<#elem #ty_generics>, len: usize) {
(*this).set_len(len);
}
}
Expand All @@ -1151,6 +1163,12 @@ fn expand_unique_ptr(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>)
let link_release = format!("{}release", prefix);
let link_drop = format!("{}drop", prefix);

let (impl_generics, ty_generics) = if let Some(imp) = explicit_impl {
(&imp.impl_generics, &imp.ty_generics)
} else {
(resolve.generics, resolve.generics)
};

let can_construct_from_value = types.structs.contains_key(ident)
|| types.enums.contains_key(ident)
|| types.aliases.contains_key(ident);
Expand All @@ -1162,7 +1180,7 @@ fn expand_unique_ptr(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>)
fn __uninit(this: *mut *mut ::std::ffi::c_void) -> *mut ::std::ffi::c_void;
}
let mut repr = ::std::ptr::null_mut::<::std::ffi::c_void>();
unsafe { __uninit(&mut repr).cast::<#ident>().write(value) }
unsafe { __uninit(&mut repr).cast::<#ident #ty_generics>().write(value) }
repr
}
})
Expand All @@ -1176,7 +1194,7 @@ fn expand_unique_ptr(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>)
let unsafe_token = format_ident!("unsafe", span = begin_span);

quote_spanned! {end_span=>
#unsafe_token impl ::cxx::private::UniquePtrTarget for #ident {
#unsafe_token impl #impl_generics ::cxx::private::UniquePtrTarget for #ident #ty_generics {
const __NAME: &'static dyn ::std::fmt::Display = &#name;
fn __null() -> *mut ::std::ffi::c_void {
extern "C" {
Expand Down Expand Up @@ -1232,6 +1250,12 @@ fn expand_shared_ptr(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>)
let link_get = format!("{}get", prefix);
let link_drop = format!("{}drop", prefix);

let (impl_generics, ty_generics) = if let Some(imp) = explicit_impl {
(&imp.impl_generics, &imp.ty_generics)
} else {
(resolve.generics, resolve.generics)
};

let can_construct_from_value = types.structs.contains_key(ident)
|| types.enums.contains_key(ident)
|| types.aliases.contains_key(ident);
Expand All @@ -1242,7 +1266,7 @@ fn expand_shared_ptr(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>)
#[link_name = #link_uninit]
fn __uninit(new: *mut ::std::ffi::c_void) -> *mut ::std::ffi::c_void;
}
__uninit(new).cast::<#ident>().write(value);
__uninit(new).cast::<#ident #ty_generics>().write(value);
}
})
} else {
Expand All @@ -1255,7 +1279,7 @@ fn expand_shared_ptr(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>)
let unsafe_token = format_ident!("unsafe", span = begin_span);

quote_spanned! {end_span=>
#unsafe_token impl ::cxx::private::SharedPtrTarget for #ident {
#unsafe_token impl #impl_generics ::cxx::private::SharedPtrTarget for #ident #ty_generics {
const __NAME: &'static dyn ::std::fmt::Display = &#name;
unsafe fn __null(new: *mut ::std::ffi::c_void) {
extern "C" {
Expand Down Expand Up @@ -1300,13 +1324,19 @@ fn expand_weak_ptr(ident: &Ident, types: &Types, explicit_impl: Option<&Impl>) -
let link_upgrade = format!("{}upgrade", prefix);
let link_drop = format!("{}drop", prefix);

let (impl_generics, ty_generics) = if let Some(imp) = explicit_impl {
(&imp.impl_generics, &imp.ty_generics)
} else {
(resolve.generics, resolve.generics)
};

let begin_span =
explicit_impl.map_or_else(Span::call_site, |explicit| explicit.impl_token.span);
let end_span = explicit_impl.map_or_else(Span::call_site, |explicit| explicit.brace_token.span);
let unsafe_token = format_ident!("unsafe", span = begin_span);

quote_spanned! {end_span=>
#unsafe_token impl ::cxx::private::WeakPtrTarget for #ident {
#unsafe_token impl #impl_generics ::cxx::private::WeakPtrTarget for #ident #ty_generics {
const __NAME: &'static dyn ::std::fmt::Display = &#name;
unsafe fn __null(new: *mut ::std::ffi::c_void) {
extern "C" {
Expand Down Expand Up @@ -1363,25 +1393,31 @@ fn expand_cxx_vector(elem: &Ident, explicit_impl: Option<&Impl>, types: &Types)
let link_unique_ptr_release = format!("{}release", unique_ptr_prefix);
let link_unique_ptr_drop = format!("{}drop", unique_ptr_prefix);

let (impl_generics, ty_generics) = if let Some(imp) = explicit_impl {
(&imp.impl_generics, &imp.ty_generics)
} else {
(resolve.generics, resolve.generics)
};

let begin_span =
explicit_impl.map_or_else(Span::call_site, |explicit| explicit.impl_token.span);
let end_span = explicit_impl.map_or_else(Span::call_site, |explicit| explicit.brace_token.span);
let unsafe_token = format_ident!("unsafe", span = begin_span);

quote_spanned! {end_span=>
#unsafe_token impl ::cxx::private::VectorElement for #elem {
#unsafe_token impl #impl_generics ::cxx::private::VectorElement for #elem #ty_generics {
const __NAME: &'static dyn ::std::fmt::Display = &#name;
fn __vector_size(v: &::cxx::CxxVector<Self>) -> usize {
extern "C" {
#[link_name = #link_size]
fn __vector_size(_: &::cxx::CxxVector<#elem>) -> usize;
fn __vector_size #impl_generics(_: &::cxx::CxxVector<#elem #ty_generics>) -> usize;
}
unsafe { __vector_size(v) }
}
unsafe fn __get_unchecked(v: *mut ::cxx::CxxVector<Self>, pos: usize) -> *mut Self {
extern "C" {
#[link_name = #link_get_unchecked]
fn __get_unchecked(_: *mut ::cxx::CxxVector<#elem>, _: usize) -> *mut #elem;
fn __get_unchecked #impl_generics(_: *mut ::cxx::CxxVector<#elem #ty_generics>, _: usize) -> *mut #elem #ty_generics;
}
__get_unchecked(v, pos)
}
Expand All @@ -1397,7 +1433,7 @@ fn expand_cxx_vector(elem: &Ident, explicit_impl: Option<&Impl>, types: &Types)
unsafe fn __unique_ptr_raw(raw: *mut ::cxx::CxxVector<Self>) -> *mut ::std::ffi::c_void {
extern "C" {
#[link_name = #link_unique_ptr_raw]
fn __unique_ptr_raw(this: *mut *mut ::std::ffi::c_void, raw: *mut ::cxx::CxxVector<#elem>);
fn __unique_ptr_raw #impl_generics(this: *mut *mut ::std::ffi::c_void, raw: *mut ::cxx::CxxVector<#elem #ty_generics>);
}
let mut repr = ::std::ptr::null_mut::<::std::ffi::c_void>();
__unique_ptr_raw(&mut repr, raw);
Expand All @@ -1406,14 +1442,14 @@ fn expand_cxx_vector(elem: &Ident, explicit_impl: Option<&Impl>, types: &Types)
unsafe fn __unique_ptr_get(repr: *mut ::std::ffi::c_void) -> *const ::cxx::CxxVector<Self> {
extern "C" {
#[link_name = #link_unique_ptr_get]
fn __unique_ptr_get(this: *const *mut ::std::ffi::c_void) -> *const ::cxx::CxxVector<#elem>;
fn __unique_ptr_get #impl_generics(this: *const *mut ::std::ffi::c_void) -> *const ::cxx::CxxVector<#elem #ty_generics>;
}
__unique_ptr_get(&repr)
}
unsafe fn __unique_ptr_release(mut repr: *mut ::std::ffi::c_void) -> *mut ::cxx::CxxVector<Self> {
extern "C" {
#[link_name = #link_unique_ptr_release]
fn __unique_ptr_release(this: *mut *mut ::std::ffi::c_void) -> *mut ::cxx::CxxVector<#elem>;
fn __unique_ptr_release #impl_generics(this: *mut *mut ::std::ffi::c_void) -> *mut ::cxx::CxxVector<#elem #ty_generics>;
}
__unique_ptr_release(&mut repr)
}
Expand Down
4 changes: 3 additions & 1 deletion syntax/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -141,13 +141,15 @@ pub struct TypeAlias {

pub struct Impl {
pub impl_token: Token![impl],
pub generics: Lifetimes,
pub impl_generics: Lifetimes,
pub negative: bool,
pub ty: Type,
pub ty_generics: Lifetimes,
pub brace_token: Brace,
pub negative_token: Option<Token![!]>,
}

#[derive(Clone, Default)]
pub struct Lifetimes {
pub lt_token: Option<Token![<]>,
pub lifetimes: Punctuated<Lifetime, Token![,]>,
Expand Down
32 changes: 26 additions & 6 deletions syntax/parse.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -868,7 +868,7 @@ fn parse_impl(imp: ItemImpl) -> Result<Api> {
"where-clause on an impl is not supported yet",
));
}
let mut generics = Lifetimes {
let mut impl_generics = Lifetimes {
lt_token: imp.generics.lt_token,
lifetimes: Punctuated::new(),
gt_token: imp.generics.gt_token,
Expand All @@ -877,13 +877,13 @@ fn parse_impl(imp: ItemImpl) -> Result<Api> {
let (param, punct) = pair.into_tuple();
match param {
GenericParam::Lifetime(def) if def.bounds.is_empty() => {
generics.lifetimes.push_value(def.lifetime);
impl_generics.lifetimes.push_value(def.lifetime);
if let Some(punct) = punct {
generics.lifetimes.push_punct(punct);
impl_generics.lifetimes.push_punct(punct);
}
}
_ => {
let span = quote!(#impl_token #generics);
let span = quote!(#impl_token #impl_generics);
return Err(Error::new_spanned(
span,
"generic parameter on an impl is not supported yet",
Expand All @@ -907,15 +907,35 @@ fn parse_impl(imp: ItemImpl) -> Result<Api> {
}
}

let negative = negative_token.is_some();
let ty = parse_type(&self_ty)?;
let ty_generics = match &ty {
Type::RustBox(ty)
| Type::RustVec(ty)
| Type::UniquePtr(ty)
| Type::SharedPtr(ty)
| Type::WeakPtr(ty)
| Type::CxxVector(ty) => match &ty.inner {
Type::Ident(ident) => ident.generics.clone(),
_ => Lifetimes::default(),
},
Type::Ident(_)
| Type::Ref(_)
| Type::Str(_)
| Type::Fn(_)
| Type::Void(_)
| Type::SliceRef(_)
| Type::Array(_) => Lifetimes::default(),
};

let negative = negative_token.is_some();
let brace_token = imp.brace_token;

Ok(Api::Impl(Impl {
impl_token,
generics,
impl_generics,
negative,
ty,
ty_generics,
brace_token,
negative_token,
}))
Expand Down
5 changes: 3 additions & 2 deletions syntax/tokens.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -192,14 +192,15 @@ impl ToTokens for Impl {
fn to_tokens(&self, tokens: &mut TokenStream) {
let Impl {
impl_token,
generics,
impl_generics,
negative: _,
ty,
ty_generics: _,
brace_token,
negative_token,
} = self;
impl_token.to_tokens(tokens);
generics.to_tokens(tokens);
impl_generics.to_tokens(tokens);
negative_token.to_tokens(tokens);
ty.to_tokens(tokens);
brace_token.surround(tokens, |_tokens| {});
Expand Down