Feature gate use_shortnames (#15348)

# Objective

- use_shortnames only does anything if bevy_reflect feature is enabled,
so it makes sense to put it behind a feature.

## Solution

- #[cfg] on the if block and the field declaration

## Testing

- CI

## Migration Guide

- If you've disabled bevy_reflect feature of bevy_ecs, remove references
to that field.


## Context

See: #15340

---------

Co-authored-by: François Mockers <francois.mockers@vleue.com>

crates/bevy_asset/src/handle.rs

@@ -3,8 +3,7 @@ use crate::{
     UntypedAssetId,
 };
 use bevy_ecs::prelude::*;
-use bevy_reflect::{std_traits::ReflectDefault, Reflect, TypePath};
-use bevy_utils::ShortName;
+use bevy_reflect::{std_traits::ReflectDefault, Reflect, ShortName, TypePath};
 use crossbeam_channel::{Receiver, Sender};
 use std::{
     any::TypeId,

crates/bevy_ecs/src/schedule/schedule.rs

@@ -246,7 +246,7 @@ pub enum Chain {
 /// fn system_one() { println!("System 1 works!") }
 /// fn system_two() { println!("System 2 works!") }
 /// fn system_three() { println!("System 3 works!") }
-///    
+///
 /// fn main() {
 ///     let mut world = World::new();
 ///     let mut schedule = Schedule::default();
@@ -1607,8 +1607,11 @@ impl ScheduleGraph {
                 }
             }
         };
-        if self.settings.use_shortnames {
-            name = bevy_utils::ShortName(&name).to_string();
+        #[cfg(feature = "bevy_reflect")]
+        {
+            if self.settings.use_shortnames {
+                name = bevy_reflect::ShortName(&name).to_string();
+            }
         }
         name
     }
@@ -2012,6 +2015,7 @@ pub struct ScheduleBuildSettings {
     /// If set to true, node names will be shortened instead of the fully qualified type path.
     ///
     /// Defaults to `true`.
+    #[cfg(feature = "bevy_reflect")]
     pub use_shortnames: bool,
     /// If set to true, report all system sets the conflicting systems are part of.
     ///
@@ -2033,6 +2037,7 @@ impl ScheduleBuildSettings {
             ambiguity_detection: LogLevel::Ignore,
             hierarchy_detection: LogLevel::Warn,
             auto_insert_apply_deferred: true,
+            #[cfg(feature = "bevy_reflect")]
             use_shortnames: true,
             report_sets: true,
         }

crates/bevy_hierarchy/src/valid_parent_check_plugin.rs

@@ -4,7 +4,9 @@ use std::marker::PhantomData;
 use crate::Parent;
 use bevy_ecs::prelude::*;
 #[cfg(feature = "bevy_app")]
-use bevy_utils::{HashSet, ShortName};
+use bevy_reflect::ShortName;
+#[cfg(feature = "bevy_app")]
+use bevy_utils::HashSet;
 
 /// When enabled, runs [`check_hierarchy_component_has_valid_parent<T>`].
 ///

crates/bevy_reflect/Cargo.toml

@@ -10,7 +10,7 @@ keywords = ["bevy"]
 rust-version = "1.76.0"
 
 [features]
-default = ["smallvec", "debug"]
+default = ["smallvec", "debug", "alloc"]
 # When enabled, provides Bevy-related reflection implementations
 bevy = ["smallvec", "smol_str"]
 glam = ["dep:glam"]
@@ -25,6 +25,7 @@ debug_stack = []
 documentation = ["bevy_reflect_derive/documentation"]
 # Enables function reflection
 functions = ["bevy_reflect_derive/functions"]
+alloc = []
 
 [dependencies]
 # bevy

crates/bevy_reflect/src/lib.rs

@@ -549,6 +549,7 @@ mod reflect;
 mod reflectable;
 mod remote;
 mod set;
+mod short_name;
 mod struct_trait;
 mod tuple;
 mod tuple_struct;
@@ -615,6 +616,7 @@ pub use type_registry::*;
 
 pub use bevy_reflect_derive::*;
 pub use erased_serde;
+pub use short_name::ShortName;
 
 extern crate alloc;
 
@@ -2366,7 +2368,7 @@ bevy_reflect::tests::Test {
 
             fn short_type_path() -> &'static str {
                 static CELL: GenericTypePathCell = GenericTypePathCell::new();
-                CELL.get_or_insert::<Self, _>(|| bevy_utils::ShortName::of::<Self>().to_string())
+                CELL.get_or_insert::<Self, _>(|| ShortName::of::<Self>().to_string())
             }
 
             fn type_ident() -> Option<&'static str> {

crates/bevy_utils/src/short_names.rs → crates/bevy_reflect/src/short_name.rs

@@ -14,7 +14,7 @@
 /// # Examples
 ///
 /// ```rust
-/// # use bevy_utils::ShortName;
+/// # use bevy_reflect::ShortName;
 /// #
 /// # mod foo {
 /// #     pub mod bar {

crates/bevy_utils/src/lib.rs

@@ -25,8 +25,6 @@ pub mod prelude {
 }
 
 pub mod futures;
-mod short_names;
-pub use short_names::ShortName;
 pub mod synccell;
 pub mod syncunsafecell;