render buffer debug label type prepopulation (#22698)

# Objective

- The vast majority of our buffers are unlabelled. This makes debugging
wgpu errors really annoying, cus they lack context.

## Solution

- We have type information, and buffers predominantly are custom struct
types, and the few cases in which they arent they seem to be manually
named anyways. Let's exploit the type info to populate the buffer names
under a debug gate.

## Testing

- ran occlusion_culling example with and without the debug feature, it
currently crashes due to a wgpu 28 change.

## Showcase

Before:
```
Caused by:
  In a CommandEncoder
    In a dispatch command, indirect:true
      Attempted to use Buffer with '' label with conflicting usages. Current usage BufferUses(STORAGE_READ_WRITE) and new usage BufferUses(INDIRECT). BufferUses(STORAGE_READ_WRITE) is an exclusive usage and cannot be used with any other usages within the usage scope (renderpass or compute dispatch).
```

After:
```
Caused by:
  In a CommandEncoder
    In a dispatch command, indirect:true
      Attempted to use Buffer with 'bevy_render::render_resource::buffer_vec::RawBufferVec<bevy_render::batching::gpu_preprocessing::LatePreprocessWorkItemIndirectParameters>' label with conflicting usages. Current usage BufferUses(STORAGE_READ_WRITE) and new usage BufferUses(INDIRECT). BufferUses(STORAGE_READ_WRITE) is an exclusive usage and cannot be used with any other usages within the usage scope (renderpass or compute dispatch).
```

Note that now we know 1. its a `RawBufferVec`, 2. of
`LatePreprocessWorkItemIndirectParameters`. This lets us greatly narrow
the scope of the search for an offender.



Note: this is the evolution of several different attempts at improving
debug info. First attempt was with `#[track_caller]`, but that doesn't
work in const contexts because Location isnt allowed there. Second
attempt was to prepopulate type name info in constructors, but
`std::any::type_name()` returns a `&'static str`, and label is
`Option<String>`, and `.into()` and `.to_string()` are both not const
because `String` is heap allocated. Finally, i moved it to the buffer
creation site, and then extracted it into a generic function to
deduplicate.

Author: atlv24

Cargo.toml

@@ -423,6 +423,9 @@ statically-linked-dxc = ["bevy_internal/statically-linked-dxc"]
 # Forces the wgpu instance to be initialized using the raw Vulkan HAL, enabling additional configuration
 raw_vulkan_init = ["bevy_internal/raw_vulkan_init"]
 
+# Pre-populate buffer labels with buffer types for debugging.
+type_label_buffers = ["bevy_internal/type_label_buffers"]
+
 # Tracing support, saving a file in Chrome Tracing format
 trace_chrome = ["trace", "bevy_internal/trace_chrome"]
 

crates/bevy_internal/Cargo.toml

@@ -65,6 +65,9 @@ statically-linked-dxc = ["bevy_render/statically-linked-dxc"]
 # Forces the wgpu instance to be initialized using the raw Vulkan HAL, enabling additional configuration
 raw_vulkan_init = ["bevy_render/raw_vulkan_init"]
 
+# Pre-populate buffer labels with buffer types for debugging.
+type_label_buffers = ["bevy_render/type_label_buffers"]
+
 # Include tonemapping LUT KTX2 files.
 tonemapping_luts = [
   "bevy_core_pipeline?/tonemapping_luts",
@@ -438,7 +441,7 @@ gestures = ["bevy_input/gestures"]
 
 hotpatching = ["bevy_app/hotpatching", "bevy_ecs/hotpatching"]
 
-debug = ["bevy_utils/debug", "bevy_ecs/debug"]
+debug = ["bevy_utils/debug", "bevy_ecs/debug", "bevy_render/debug"]
 
 screenrecording = ["bevy_dev_tools/screenrecording"]
 

crates/bevy_render/Cargo.toml

@@ -45,6 +45,10 @@ webgpu = ["wgpu/webgpu"]
 vulkan-portability = ["wgpu/vulkan-portability"]
 gles = ["wgpu/gles"]
 detailed_trace = []
+# Pre-populate buffer labels with buffer types for debugging.
+type_label_buffers = []
+# Enables collecting extra information for debugging.
+debug = ["type_label_buffers"]
 ## Adds serialization support through `serde`.
 serialize = ["bevy_mesh/serialize"]
 

crates/bevy_render/src/render_resource/buffer_vec.rs

@@ -158,7 +158,7 @@ impl<T: NoUninit> RawBufferVec<T> {
         if capacity > self.capacity || (self.changed && size > 0) {
             self.capacity = capacity;
             self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
-                label: self.label.as_deref(),
+                label: make_buffer_label::<Self>(&self.label),
                 size: size as BufferAddress,
                 usage: BufferUsages::COPY_DST | self.buffer_usage,
                 mapped_at_creation: false,
@@ -406,7 +406,7 @@ where
         self.capacity = capacity;
         let size = u64::from(T::min_size()) as usize * capacity;
         self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
-            label: self.label.as_deref(),
+            label: make_buffer_label::<Self>(&self.label),
             size: size as BufferAddress,
             usage: BufferUsages::COPY_DST | self.buffer_usage,
             mapped_at_creation: false,
@@ -590,7 +590,7 @@ where
         self.capacity = capacity;
         let size = self.item_size * capacity;
         self.buffer = Some(device.create_buffer(&wgpu::BufferDescriptor {
-            label: self.label.as_deref(),
+            label: make_buffer_label::<Self>(&self.label),
             size: size as BufferAddress,
             usage: BufferUsages::COPY_DST | self.buffer_usage,
             mapped_at_creation: false,
@@ -620,3 +620,12 @@ pub enum WriteBufferRangeError {
     #[error("there are no values to upload")]
     NoValuesToUpload,
 }
+
+#[inline]
+pub(crate) fn make_buffer_label<'a, T>(label: &'a Option<String>) -> Option<&'a str> {
+    #[cfg(feature = "type_label_buffers")]
+    if label.is_none() {
+        return Some(core::any::type_name::<T>());
+    }
+    label.as_deref()
+}

crates/bevy_render/src/render_resource/storage_buffer.rs

@@ -1,7 +1,10 @@
 use core::marker::PhantomData;
 
 use super::Buffer;
-use crate::renderer::{RenderDevice, RenderQueue};
+use crate::{
+    render_resource::make_buffer_label,
+    renderer::{RenderDevice, RenderQueue},
+};
 use encase::{
     internal::WriteInto, DynamicStorageBuffer as DynamicStorageBufferWrapper, ShaderType,
     StorageBuffer as StorageBufferWrapper,
@@ -133,7 +136,7 @@ impl<T: ShaderType + WriteInto> StorageBuffer<T> {
 
         if capacity < size || self.changed {
             self.buffer = Some(device.create_buffer_with_data(&BufferInitDescriptor {
-                label: self.label.as_deref(),
+                label: make_buffer_label::<Self>(&self.label),
                 usage: self.buffer_usage,
                 contents: self.scratch.as_ref(),
             }));
@@ -258,7 +261,7 @@ impl<T: ShaderType + WriteInto> DynamicStorageBuffer<T> {
 
         if capacity < size || (self.changed && size > 0) {
             self.buffer = Some(device.create_buffer_with_data(&BufferInitDescriptor {
-                label: self.label.as_deref(),
+                label: make_buffer_label::<Self>(&self.label),
                 usage: self.buffer_usage,
                 contents: self.scratch.as_ref(),
             }));

crates/bevy_render/src/render_resource/uniform_buffer.rs

@@ -1,7 +1,7 @@
 use core::{marker::PhantomData, num::NonZero};
 
 use crate::{
-    render_resource::Buffer,
+    render_resource::{make_buffer_label, Buffer},
     renderer::{RenderDevice, RenderQueue},
 };
 use encase::{
@@ -131,7 +131,7 @@ impl<T: ShaderType + WriteInto> UniformBuffer<T> {
 
         if self.changed || self.buffer.is_none() {
             self.buffer = Some(device.create_buffer_with_data(&BufferInitDescriptor {
-                label: self.label.as_deref(),
+                label: make_buffer_label::<Self>(&self.label),
                 usage: self.buffer_usage,
                 contents: self.scratch.as_ref(),
             }));
@@ -296,7 +296,7 @@ impl<T: ShaderType + WriteInto> DynamicUniformBuffer<T> {
 
         if capacity < size || (self.changed && size > 0) {
             let buffer = device.create_buffer(&BufferDescriptor {
-                label: self.label.as_deref(),
+                label: make_buffer_label::<Self>(&self.label),
                 usage: self.buffer_usage,
                 size,
                 mapped_at_creation: false,

docs/cargo_features.md

@@ -189,6 +189,7 @@ This is the complete `bevy` cargo feature list, without "profiles" or "collectio
 |trace_tracy|Tracing support, exposing a port for Tracy|
 |trace_tracy_memory|Tracing support, with memory profiling, exposing a port for Tracy|
 |track_location|Enables source location tracking for change detection and spawning/despawning, which can assist with debugging|
+|type_label_buffers|Pre-populate buffer labels with buffer types for debugging.|
 |ui_picking|Provides an implementation for picking UI|
 |vorbis|OGG/VORBIS audio format support|
 |wav|WAV audio format support|