From 76c0334e5601151d96a5629bb4ee317f1bb8d8b9 Mon Sep 17 00:00:00 2001
From: Jim Blandy <jimb@red-bean.com>
Date: Mon, 21 Nov 2022 16:28:25 -0800
Subject: [PATCH] Introduce boxes and vectors to reduce Result sizes.

The following error variants were large enough to trip Clippy's
`result_large_err` lint:

- RenderPassCompatibilityError::IncompatibleColorAttachment
- CreateShaderModuleError::Validation

Large error types are a problem, because they make the `Result` type
large, requiring the program to copy around large numbers of bytes
even in the success case. Since the failure case is rare, it's usually
not a problem to just heap-allocate the contents to keep the `Ok` case
small.
---
 .clippy.toml                |  1 -
 CHANGELOG.md                |  1 +
 wgpu-core/src/device/mod.rs | 13 +++++--------
 wgpu-core/src/pipeline.rs   |  2 +-
 4 files changed, 7 insertions(+), 10 deletions(-)
 delete mode 100644 .clippy.toml

diff --git a/.clippy.toml b/.clippy.toml
deleted file mode 100644
index 1fdcf3e5ac..0000000000
--- a/.clippy.toml
+++ /dev/null
@@ -1 +0,0 @@
-large-error-threshold = 225 # bytes
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2a9bc5f0fd..1385d77d74 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -85,6 +85,7 @@ Bottom level categories:
 - Avoid panicking in some interactions with invalid resources by @nical in (#3094)[https://github.com/gfx-rs/wgpu/pull/3094]
 - Remove `wgpu_types::Features::DEPTH24PLUS_STENCIL8`, making `wgpu::TextureFormat::Depth24PlusStencil8` available on all backends. By @Healthire in (#3151)[https://github.com/gfx-rs/wgpu/pull/3151]
 - Fix an integer overflow in `queue_write_texture` by @nical in (#3146)[https://github.com/gfx-rs/wgpu/pull/3146]
+- Make `RenderPassCompatibilityError` and `CreateShaderModuleError` not so huge. By @jimblandy in (#3226)[https://github.com/gfx-rs/wgpu/pull/3226]
 
 #### WebGPU
 
diff --git a/wgpu-core/src/device/mod.rs b/wgpu-core/src/device/mod.rs
index 7a7e0be4c9..494fa41b7a 100644
--- a/wgpu-core/src/device/mod.rs
+++ b/wgpu-core/src/device/mod.rs
@@ -80,10 +80,7 @@ pub(crate) struct RenderPassContext {
 #[derive(Clone, Debug, Error)]
 pub enum RenderPassCompatibilityError {
     #[error("Incompatible color attachment: the renderpass expected {0:?} but was given {1:?}")]
-    IncompatibleColorAttachment(
-        ArrayVec<Option<TextureFormat>, { hal::MAX_COLOR_ATTACHMENTS }>,
-        ArrayVec<Option<TextureFormat>, { hal::MAX_COLOR_ATTACHMENTS }>,
-    ),
+    IncompatibleColorAttachment(Vec<Option<TextureFormat>>, Vec<Option<TextureFormat>>),
     #[error(
         "Incompatible depth-stencil attachment: the renderpass expected {0:?} but was given {1:?}"
     )]
@@ -102,8 +99,8 @@ impl RenderPassContext {
     ) -> Result<(), RenderPassCompatibilityError> {
         if self.attachments.colors != other.attachments.colors {
             return Err(RenderPassCompatibilityError::IncompatibleColorAttachment(
-                self.attachments.colors.clone(),
-                other.attachments.colors.clone(),
+                self.attachments.colors.iter().cloned().collect(),
+                other.attachments.colors.iter().cloned().collect(),
             ));
         }
         if self.attachments.depth_stencil != other.attachments.depth_stencil {
@@ -1245,7 +1242,7 @@ impl<A: HalApi> Device<A> {
                     pipeline::CreateShaderModuleError::Parsing(pipeline::ShaderError {
                         source: code.to_string(),
                         label: desc.label.as_ref().map(|l| l.to_string()),
-                        inner,
+                        inner: Box::new(inner),
                     })
                 })?;
                 (Cow::Owned(module), code.into_owned())
@@ -1308,7 +1305,7 @@ impl<A: HalApi> Device<A> {
                 pipeline::CreateShaderModuleError::Validation(pipeline::ShaderError {
                     source,
                     label: desc.label.as_ref().map(|l| l.to_string()),
-                    inner,
+                    inner: Box::new(inner),
                 })
             })?;
         let interface =
diff --git a/wgpu-core/src/pipeline.rs b/wgpu-core/src/pipeline.rs
index 667b8b96ed..5c091e1d96 100644
--- a/wgpu-core/src/pipeline.rs
+++ b/wgpu-core/src/pipeline.rs
@@ -66,7 +66,7 @@ impl<A: hal::Api> Resource for ShaderModule<A> {
 pub struct ShaderError<E> {
     pub source: String,
     pub label: Option<String>,
-    pub inner: E,
+    pub inner: Box<E>,
 }
 #[cfg(feature = "wgsl")]
 impl fmt::Display for ShaderError<naga::front::wgsl::ParseError> {