wip: fix issue 68

taiki-e · Sep 5, 2019 · abf3700 · abf3700
1 parent 3a6ded0
commit abf3700
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Showing 5 changed files with 56 additions and 15 deletions.
diff --git a/pin-project-internal/Cargo.toml b/pin-project-internal/Cargo.toml
@@ -25,7 +25,7 @@ renamed = ["proc-macro-crate", "serde", "lazy_static"]
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", features = ["full"] }
+syn = { version = "1.0", features = ["full", "extra-traits"] }
 
 proc-macro-crate = { version = "0.1.4", optional = true }
 # Required until a new toml-rs release is made with https://github.com/alexcrichton/toml-rs/pull/311,

diff --git a/pin-project-internal/src/pin_project/enums.rs b/pin-project-internal/src/pin_project/enums.rs
@@ -2,7 +2,7 @@ use proc_macro2::TokenStream;
 use quote::{format_ident, quote, ToTokens};
 use syn::{parse::Nothing, Field, Fields, FieldsNamed, FieldsUnnamed, ItemEnum, Result, Variant};
 
-use crate::utils::VecExt;
+use crate::utils::{cfg_attrs, VecExt};
 
 use super::{Context, PIN};
 
@@ -95,11 +95,13 @@ fn named(
             let _: Nothing = syn::parse2(attr.tokens)?;
             cx.push_unpin_bounds(ty.clone());
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(#ident: ::core::pin::Pin<&#lifetime mut #ty>));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* #ident: ::core::pin::Pin<&#lifetime mut #ty>));
             proj_body.push(quote!(#ident: ::core::pin::Pin::new_unchecked(#ident)));
         } else {
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(#ident: &#lifetime mut #ty));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* #ident: &#lifetime mut #ty));
             proj_body.push(quote!(#ident));
         }
         proj_pat.push(ident);
@@ -124,11 +126,13 @@ fn unnamed(
             let _: Nothing = syn::parse2(attr.tokens)?;
             cx.push_unpin_bounds(ty.clone());
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(::core::pin::Pin<&#lifetime mut #ty>));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* ::core::pin::Pin<&#lifetime mut #ty>));
             proj_body.push(quote!(::core::pin::Pin::new_unchecked(#x)));
         } else {
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(&#lifetime mut #ty));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* &#lifetime mut #ty));
             proj_body.push(quote!(#x));
         }
         proj_pat.push(x);

diff --git a/pin-project-internal/src/pin_project/structs.rs b/pin-project-internal/src/pin_project/structs.rs
@@ -2,7 +2,7 @@ use proc_macro2::TokenStream;
 use quote::{quote, ToTokens};
 use syn::{parse::Nothing, Field, Fields, FieldsNamed, FieldsUnnamed, Index, ItemStruct, Result};
 
-use crate::utils::VecExt;
+use crate::utils::{cfg_attrs, VecExt};
 
 use super::{Context, PIN};
 
@@ -70,12 +70,15 @@ fn named(
             let _: Nothing = syn::parse2(attr.tokens)?;
             cx.push_unpin_bounds(ty.clone());
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(#ident: ::core::pin::Pin<&#lifetime mut #ty>));
-            proj_init.push(quote!(#ident: ::core::pin::Pin::new_unchecked(&mut this.#ident)));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* #ident: ::core::pin::Pin<&#lifetime mut #ty>));
+            proj_init
+                .push(quote!(#(#cfgs)* #ident: ::core::pin::Pin::new_unchecked(&mut this.#ident)));
         } else {
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(#ident: &#lifetime mut #ty));
-            proj_init.push(quote!(#ident: &mut this.#ident));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* #ident: &#lifetime mut #ty));
+            proj_init.push(quote!(#(#cfgs)* #ident: &mut this.#ident));
         }
     }
 
@@ -96,12 +99,14 @@ fn unnamed(
             let _: Nothing = syn::parse2(attr.tokens)?;
             cx.push_unpin_bounds(ty.clone());
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(::core::pin::Pin<&#lifetime mut #ty>));
-            proj_init.push(quote!(::core::pin::Pin::new_unchecked(&mut this.#i)));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* ::core::pin::Pin<&#lifetime mut #ty>));
+            proj_init.push(quote!(#(#cfgs)* { ::core::pin::Pin::new_unchecked(&mut this.#i) }));
         } else {
             let lifetime = &cx.lifetime;
-            proj_fields.push(quote!(&#lifetime mut #ty));
-            proj_init.push(quote!(&mut this.#i));
+            let cfgs = cfg_attrs(attrs);
+            proj_fields.push(quote!(#(#cfgs)* &#lifetime mut #ty));
+            proj_init.push(quote!(#(#cfgs)* { &mut this.#i }));
         }
     }
 

diff --git a/pin-project-internal/src/utils.rs b/pin-project-internal/src/utils.rs
@@ -58,6 +58,10 @@ pub(crate) fn proj_generics(generics: &mut Generics, lifetime: Lifetime) {
     );
 }
 
+pub(crate) fn cfg_attrs(attrs: &[Attribute]) -> Vec<Attribute> {
+    attrs.iter().filter(|attr| attr.path.is_ident("cfg")).cloned().collect()
+}
+
 pub(crate) trait VecExt {
     fn find_remove(&mut self, ident: &str) -> Option<Attribute>;
 }

diff --git a/tests/pin_project.rs b/tests/pin_project.rs
@@ -322,3 +322,31 @@ fn lifetime_project() {
         }
     }
 }
+
+#[test]
+fn cfgs() {
+    #[pin_project]
+    pub struct Simple {
+        #[cfg(target_os = "macos")]
+        #[pin]
+        inner: u8,
+        #[cfg(not(target_os = "macos"))]
+        #[pin]
+        inner: u16,
+    }
+
+    #[cfg(target_os = "macos")]
+    struct Foo;
+    #[cfg(not(target_os = "macos"))]
+    struct Bar;
+
+    #[pin_project]
+    pub struct DiffNames {
+        #[cfg(target_os = "macos")]
+        #[pin]
+        inner: Foo,
+        #[cfg(not(target_os = "macos"))]
+        #[pin]
+        inner: Bar,
+    }
+}