Use bevy_reflect as path in case of no direct references (#1875)

Fixes #1844


Co-authored-by: Carter Anderson <[email protected]>

Author: YohDeadfall

crates/bevy_derive/Cargo.toml

@@ -16,8 +16,9 @@ keywords = ["bevy"]
 proc-macro = true
 
 [dependencies]
+bevy_macro_utils = { path = "../bevy_macro_utils", version = "0.5.0" }
+
 Inflector = { version = "0.11.4", default-features = false }
-find-crate = "0.6"
 proc-macro2 = "1.0"
 quote = "1.0"
 syn = "1.0"

crates/bevy_derive/src/bytes.rs

@@ -1,4 +1,4 @@
-use crate::modules::{get_modules, get_path};
+use bevy_macro_utils::BevyManifest;
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::{parse_macro_input, Data, DataStruct, DeriveInput, Fields};
@@ -13,8 +13,7 @@ pub fn derive_bytes(input: TokenStream) -> TokenStream {
         _ => panic!("Expected a struct with named fields."),
     };
 
-    let modules = get_modules(&ast.attrs);
-    let bevy_core_path = get_path(&modules.bevy_core);
+    let bevy_core_path = BevyManifest::default().get_path(crate::modules::BEVY_CORE);
 
     let fields = fields
         .iter()

crates/bevy_derive/src/enum_variant_meta.rs

@@ -1,4 +1,4 @@
-use crate::modules::{get_modules, get_path};
+use bevy_macro_utils::BevyManifest;
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::{parse_macro_input, Data, DeriveInput};
@@ -10,8 +10,7 @@ pub fn derive_enum_variant_meta(input: TokenStream) -> TokenStream {
         _ => panic!("Expected an enum."),
     };
 
-    let modules = get_modules(&ast.attrs);
-    let bevy_util_path = get_path(&modules.bevy_utils);
+    let bevy_util_path = BevyManifest::default().get_path(crate::modules::BEVY_UTILS);
 
     let generics = ast.generics;
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();

crates/bevy_derive/src/lib.rs

@@ -14,33 +14,33 @@ use proc_macro::TokenStream;
 
 /// Derives the FromResources trait. Each field must also implement the FromResources trait or this
 /// will fail. FromResources is automatically implemented for types that implement Default.
-#[proc_macro_derive(FromResources, attributes(as_crate))]
+#[proc_macro_derive(FromResources)]
 pub fn derive_from_resources(input: TokenStream) -> TokenStream {
     resource::derive_from_resources(input)
 }
 
 /// Derives the Bytes trait. Each field must also implements Bytes or this will fail.
-#[proc_macro_derive(Bytes, attributes(as_crate))]
+#[proc_macro_derive(Bytes)]
 pub fn derive_bytes(input: TokenStream) -> TokenStream {
     bytes::derive_bytes(input)
 }
 
 /// Derives the RenderResources trait. Each field must implement RenderResource or this will fail.
 /// You can ignore fields using `#[render_resources(ignore)]`.
-#[proc_macro_derive(RenderResources, attributes(render_resources, as_crate))]
+#[proc_macro_derive(RenderResources, attributes(render_resources))]
 pub fn derive_render_resources(input: TokenStream) -> TokenStream {
     render_resources::derive_render_resources(input)
 }
 
 /// Derives the RenderResource trait. The type must also implement `Bytes` or this will fail.
-#[proc_macro_derive(RenderResource, attributes(as_crate))]
+#[proc_macro_derive(RenderResource)]
 pub fn derive_render_resource(input: TokenStream) -> TokenStream {
     render_resource::derive_render_resource(input)
 }
 
 /// Derives the ShaderDefs trait. Each field must implement ShaderDef or this will fail.
 /// You can ignore fields using `#[shader_defs(ignore)]`.
-#[proc_macro_derive(ShaderDefs, attributes(shader_def, as_crate))]
+#[proc_macro_derive(ShaderDefs, attributes(shader_def))]
 pub fn derive_shader_defs(input: TokenStream) -> TokenStream {
     shader_defs::derive_shader_defs(input)
 }
@@ -56,7 +56,7 @@ pub fn bevy_main(attr: TokenStream, item: TokenStream) -> TokenStream {
     bevy_main::bevy_main(attr, item)
 }
 
-#[proc_macro_derive(EnumVariantMeta, attributes(as_crate))]
+#[proc_macro_derive(EnumVariantMeta)]
 pub fn derive_enum_variant_meta(input: TokenStream) -> TokenStream {
     enum_variant_meta::derive_enum_variant_meta(input)
 }

crates/bevy_derive/src/modules.rs

@@ -1,71 +1,5 @@
-use find_crate::Manifest;
-use proc_macro::TokenStream;
-use syn::{Attribute, Path};
-
-#[derive(Debug)]
-pub struct Modules {
-    pub bevy_render: String,
-    pub bevy_asset: String,
-    pub bevy_core: String,
-    pub bevy_utils: String,
-    pub bevy_app: String,
-}
-
-impl Modules {
-    pub fn meta(name: &str) -> Modules {
-        Modules {
-            bevy_asset: format!("{}::asset", name),
-            bevy_render: format!("{}::render", name),
-            bevy_core: format!("{}::core", name),
-            bevy_utils: format!("{}::utils", name),
-            bevy_app: format!("{}::app", name),
-        }
-    }
-
-    pub fn external() -> Modules {
-        Modules {
-            bevy_asset: "bevy_asset".to_string(),
-            bevy_render: "bevy_render".to_string(),
-            bevy_core: "bevy_core".to_string(),
-            bevy_utils: "bevy_utils".to_string(),
-            bevy_app: "bevy_app".to_string(),
-        }
-    }
-}
-
-fn get_meta() -> Option<Modules> {
-    let manifest = Manifest::new().unwrap();
-    if let Some(package) = manifest.find(|name| name == "bevy") {
-        Some(Modules::meta(&package.name))
-    } else if let Some(package) = manifest.find(|name| name == "bevy_internal") {
-        Some(Modules::meta(&package.name))
-    } else {
-        None
-    }
-}
-
-const AS_CRATE_ATTRIBUTE_NAME: &str = "as_crate";
-
-fn validate_as_crate_attribute(tokens: &str) -> bool {
-    tokens.len() > 2 && tokens.starts_with('(') && tokens.ends_with(')')
-}
-
-pub fn get_modules(attributes: &[Attribute]) -> Modules {
-    let mut modules = get_meta().unwrap_or_else(Modules::external);
-    for attribute in attributes.iter() {
-        if *attribute.path.get_ident().as_ref().unwrap() == AS_CRATE_ATTRIBUTE_NAME {
-            let value = attribute.tokens.to_string();
-            if !validate_as_crate_attribute(&value) {
-                panic!("The attribute `#[as_crate{}]` is invalid. It must follow the format `#[as_crate(<crate name>)]`", value);
-            } else if value[1..value.len() - 1] == modules.bevy_render {
-                modules.bevy_render = "crate".to_string();
-            }
-        }
-    }
-
-    modules
-}
-
-pub fn get_path(path_str: &str) -> Path {
-    syn::parse(path_str.parse::<TokenStream>().unwrap()).unwrap()
-}
+pub const BEVY_APP: &str = "bevy_app";
+pub const BEVY_ASSET: &str = "bevy_asset";
+pub const BEVY_CORE: &str = "bevy_core";
+pub const BEVY_RENDER: &str = "bevy_render";
+pub const BEVY_UTILS: &str = "bevy_utils";

crates/bevy_derive/src/render_resource.rs

@@ -1,15 +1,15 @@
-use crate::modules::{get_modules, get_path};
+use bevy_macro_utils::BevyManifest;
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::{parse_macro_input, DeriveInput, Path};
 
 pub fn derive_render_resource(input: TokenStream) -> TokenStream {
     let ast = parse_macro_input!(input as DeriveInput);
-    let modules = get_modules(&ast.attrs);
+    let manifest = BevyManifest::default();
 
-    let bevy_render_path: Path = get_path(&modules.bevy_render);
-    let bevy_asset_path: Path = get_path(&modules.bevy_asset);
-    let bevy_core_path: Path = get_path(&modules.bevy_core);
+    let bevy_render_path: Path = manifest.get_path(crate::modules::BEVY_RENDER);
+    let bevy_asset_path: Path = manifest.get_path(crate::modules::BEVY_ASSET);
+    let bevy_core_path: Path = manifest.get_path(crate::modules::BEVY_CORE);
     let struct_name = &ast.ident;
     let (impl_generics, type_generics, where_clause) = &ast.generics.split_for_impl();
 

crates/bevy_derive/src/render_resources.rs

@@ -1,4 +1,4 @@
-use crate::modules::{get_modules, get_path};
+use bevy_macro_utils::BevyManifest;
 use proc_macro::TokenStream;
 use quote::{format_ident, quote};
 use syn::{
@@ -21,9 +21,8 @@ static RENDER_RESOURCE_ATTRIBUTE_NAME: &str = "render_resources";
 
 pub fn derive_render_resources(input: TokenStream) -> TokenStream {
     let ast = parse_macro_input!(input as DeriveInput);
-    let modules = get_modules(&ast.attrs);
 
-    let bevy_render_path: Path = get_path(&modules.bevy_render);
+    let bevy_render_path: Path = BevyManifest::default().get_path(crate::modules::BEVY_RENDER);
     let attributes = ast
         .attrs
         .iter()

crates/bevy_derive/src/resource.rs

@@ -1,4 +1,4 @@
-use crate::modules::{get_modules, get_path};
+use bevy_macro_utils::BevyManifest;
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::{parse_macro_input, Data, DataStruct, DeriveInput, Fields};
@@ -13,16 +13,11 @@ pub fn derive_from_resources(input: TokenStream) -> TokenStream {
         _ => panic!("Expected a struct with named fields."),
     };
 
-    let modules = get_modules(&ast.attrs);
-    let bevy_app_path = get_path(&modules.bevy_app);
-
+    let bevy_app_path = BevyManifest::default().get_path(crate::modules::BEVY_APP);
     let field_types = fields.iter().map(|field| &field.ty);
-
     let fields = fields.iter().map(|field| field.ident.as_ref().unwrap());
-
     let generics = ast.generics;
     let (impl_generics, ty_generics, _where_clause) = generics.split_for_impl();
-
     let struct_name = &ast.ident;
 
     TokenStream::from(quote! {

crates/bevy_derive/src/shader_defs.rs

@@ -1,4 +1,4 @@
-use crate::modules::{get_modules, get_path};
+use bevy_macro_utils::BevyManifest;
 use inflector::Inflector;
 use proc_macro::TokenStream;
 use proc_macro2::Ident;
@@ -9,8 +9,7 @@ static SHADER_DEF_ATTRIBUTE_NAME: &str = "shader_def";
 
 pub fn derive_shader_defs(input: TokenStream) -> TokenStream {
     let ast = parse_macro_input!(input as DeriveInput);
-    let modules = get_modules(&ast.attrs);
-    let bevy_render_path: Path = get_path(&modules.bevy_render);
+    let bevy_render_path: Path = BevyManifest::default().get_path(crate::modules::BEVY_RENDER);
 
     let fields = match &ast.data {
         Data::Struct(DataStruct {

crates/bevy_ecs/macros/Cargo.toml

@@ -13,7 +13,8 @@ license = "MIT"
 proc-macro = true
 
 [dependencies]
+bevy_macro_utils = { path = "../../bevy_macro_utils", version = "0.5.0" }
+
 syn = "1.0"
 quote = "1.0"
 proc-macro2 = "1.0"
-find-crate = "0.6"

crates/bevy_ecs/macros/src/lib.rs

@@ -1,6 +1,6 @@
 extern crate proc_macro;
 
-use find_crate::{Dependencies, Manifest};
+use bevy_macro_utils::BevyManifest;
 use proc_macro::TokenStream;
 use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::{format_ident, quote};
@@ -471,24 +471,5 @@ fn derive_label(input: DeriveInput, label_type: Ident) -> TokenStream2 {
 }
 
 fn bevy_ecs_path() -> syn::Path {
-    fn find_in_manifest(manifest: &mut Manifest, dependencies: Dependencies) -> Option<String> {
-        manifest.dependencies = dependencies;
-        if let Some(package) = manifest.find(|name| name == "bevy") {
-            Some(format!("{}::ecs", package.name))
-        } else if let Some(package) = manifest.find(|name| name == "bevy_internal") {
-            Some(format!("{}::ecs", package.name))
-        } else if let Some(package) = manifest.find(|name| name == "bevy_ecs") {
-            Some(package.name)
-        } else {
-            None
-        }
-    }
-
-    let mut manifest = Manifest::new().unwrap();
-    let path_str = find_in_manifest(&mut manifest, Dependencies::Release)
-        .or_else(|| find_in_manifest(&mut manifest, Dependencies::Dev))
-        .unwrap_or_else(|| "bevy_ecs".to_string());
-
-    let path: Path = syn::parse(path_str.parse::<TokenStream>().unwrap()).unwrap();
-    path
+    BevyManifest::default().get_path("bevy_ecs")
 }

crates/bevy_ecs/src/lib.rs

@@ -36,6 +36,7 @@ pub mod prelude {
 
 #[cfg(test)]
 mod tests {
+    use crate as bevy_ecs;
     use crate::{
         bundle::Bundle,
         component::{Component, ComponentDescriptor, ComponentId, StorageType, TypeInfo},
@@ -78,7 +79,6 @@ mod tests {
 
     #[test]
     fn bundle_derive() {
-        use crate as bevy_ecs;
         #[derive(Bundle, PartialEq, Debug)]
         struct Foo {
             x: &'static str,

crates/bevy_macro_utils/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "bevy_macro_utils"
+version = "0.5.0"
+edition = "2018"
+authors = [
+    "Bevy Contributors <[email protected]>",
+    "Carter Anderson <[email protected]>",
+]
+description = "A collection of utils for Bevy Engine"
+homepage = "https://bevyengine.org"
+repository = "https://github.com/bevyengine/bevy"
+license = "MIT"
+keywords = ["bevy"]
+
+[dependencies]
+cargo-manifest = "0.2.3"
+proc-macro2 = "1.0"
+syn = "1.0"

crates/bevy_macro_utils/src/lib.rs

@@ -0,0 +1,61 @@
+extern crate proc_macro;
+
+use cargo_manifest::{DepsSet, Manifest};
+use proc_macro::TokenStream;
+use std::{env, path::PathBuf};
+
+pub struct BevyManifest {
+    manifest: Manifest,
+}
+
+impl Default for BevyManifest {
+    fn default() -> Self {
+        Self {
+            manifest: env::var_os("CARGO_MANIFEST_DIR")
+                .map(PathBuf::from)
+                .map(|mut path| {
+                    path.push("Cargo.toml");
+                    Manifest::from_path(path).unwrap()
+                })
+                .unwrap(),
+        }
+    }
+}
+
+impl BevyManifest {
+    pub fn get_path(&self, name: &str) -> syn::Path {
+        const BEVY: &str = "bevy";
+        const BEVY_INTERNAL: &str = "bevy_internal";
+
+        let find_in_deps = |deps: &DepsSet| -> Option<syn::Path> {
+            let package = if let Some(dep) = deps.get(BEVY) {
+                dep.package().unwrap_or(BEVY)
+            } else if let Some(dep) = deps.get(BEVY_INTERNAL) {
+                dep.package().unwrap_or(BEVY_INTERNAL)
+            } else {
+                return None;
+            };
+
+            let mut path = get_path(package);
+            if let Some(module) = name.strip_prefix("bevy_") {
+                path.segments.push(parse_str(module));
+            }
+            Some(path)
+        };
+
+        let deps = self.manifest.dependencies.as_ref();
+        let deps_dev = self.manifest.dev_dependencies.as_ref();
+
+        deps.and_then(find_in_deps)
+            .or_else(|| deps_dev.and_then(find_in_deps))
+            .unwrap_or_else(|| get_path(name))
+    }
+}
+
+fn get_path(path: &str) -> syn::Path {
+    parse_str(path)
+}
+
+fn parse_str<T: syn::parse::Parse>(path: &str) -> T {
+    syn::parse(path.parse::<TokenStream>().unwrap()).unwrap()
+}

crates/bevy_reflect/bevy_reflect_derive/Cargo.toml

@@ -16,8 +16,9 @@ keywords = ["bevy"]
 proc-macro = true
 
 [dependencies]
+bevy_macro_utils = { path = "../../bevy_macro_utils", version = "0.5.0" }
+
 syn = "1.0"
 proc-macro2 = "1.0"
 quote = "1.0"
-find-crate = "0.6"
 uuid = { version = "0.8", features = ["v4", "serde"] }