From 0c2265d6359d5b1cc744f0603509fcceafd208df Mon Sep 17 00:00:00 2001
From: Erich Gubler <erichdongubler@gmail.com>
Date: Mon, 19 Sep 2022 10:14:32 -0400
Subject: [PATCH] chore: separate new `unsafe` ops into blocks

Unsafe operations can be exhausting to validate by themselves. Therefore, it's often interesting to
separate these out so we can justify each individual operation, and let a human reader accumulate
and drop supporting safety context in the smallest increments necessary. To that end, this commit
can pave the way for future work where we may do something like enable
[`clippy::undocumented_unsafe_blocks`], which calls out `unsafe` blocks that do not have a `SAFETY`
comment immediately above them.

This commit only separates the operations in `unsafe` blocks I added in this same PR; I'm
deliberately leaving existing `unsafe` blocks alone, ATM.

[`clippy::undocumented_unsafe_blocks`]: https://rust-lang.github.io/rust-clippy/stable/index.html#undocumented_unsafe_blocks
---
 wgpu-core/src/track/mod.rs     |  9 +++------
 wgpu-core/src/track/texture.rs | 18 ++++++++----------
 wgpu-hal/src/vulkan/device.rs  |  5 ++++-
 3 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/wgpu-core/src/track/mod.rs b/wgpu-core/src/track/mod.rs
index bf37b256184..86133bd2b33 100644
--- a/wgpu-core/src/track/mod.rs
+++ b/wgpu-core/src/track/mod.rs
@@ -420,12 +420,9 @@ impl<A: hub::HalApi> ResourceMetadataProvider<'_, A> {
             }
             ResourceMetadataProvider::Indirect { metadata } => {
                 metadata.tracker_assert_in_bounds(index);
-                (unsafe { *metadata.epochs.get_unchecked(index) }, unsafe {
-                    metadata
-                        .ref_counts
-                        .get_unchecked(index)
-                        .clone()
-                        .unwrap_unchecked()
+                (unsafe { *metadata.epochs.get_unchecked(index) }, {
+                    let ref_count = unsafe { metadata.ref_counts.get_unchecked(index) };
+                    unsafe { ref_count.clone().unwrap_unchecked() }
                 })
             }
             ResourceMetadataProvider::Resource { epoch } => {
diff --git a/wgpu-core/src/track/texture.rs b/wgpu-core/src/track/texture.rs
index 2e06b1dedec..125eb268434 100644
--- a/wgpu-core/src/track/texture.rs
+++ b/wgpu-core/src/track/texture.rs
@@ -291,9 +291,10 @@ impl<A: hub::HalApi> TextureUsageScope<A> {
             self.tracker_assert_in_bounds(index);
             scope.tracker_assert_in_bounds(index);
 
+            let texture_data = unsafe { texture_data_from_texture(storage, index32) };
             unsafe {
                 insert_or_merge(
-                    texture_data_from_texture(storage, index32),
+                    texture_data,
                     &mut self.set,
                     &mut self.metadata,
                     index32,
@@ -359,9 +360,10 @@ impl<A: hub::HalApi> TextureUsageScope<A> {
 
         self.tracker_assert_in_bounds(index);
 
+        let texture_data = unsafe { texture_data_from_texture(storage, index32) };
         unsafe {
             insert_or_merge(
-                texture_data_from_texture(storage, index32),
+                texture_data,
                 &mut self.set,
                 &mut self.metadata,
                 index32,
@@ -467,13 +469,8 @@ impl<A: hub::HalApi> TextureTracker<A> {
 
         self.tracker_assert_in_bounds(index);
 
-        unsafe {
-            self.metadata
-                .ref_counts
-                .get_unchecked(index)
-                .as_ref()
-                .unwrap_unchecked()
-        }
+        let ref_count = unsafe { self.metadata.ref_counts.get_unchecked(index) };
+        unsafe { ref_count.as_ref().unwrap_unchecked() }
     }
 
     /// Inserts a single texture and a state into the resource tracker.
@@ -683,9 +680,10 @@ impl<A: hub::HalApi> TextureTracker<A> {
             if unsafe { !scope.metadata.owned.get(index).unwrap_unchecked() } {
                 continue;
             }
+            let texture_data = unsafe { texture_data_from_texture(storage, index32) };
             unsafe {
                 insert_or_barrier_update(
-                    texture_data_from_texture(storage, index32),
+                    texture_data,
                     Some(&mut self.start_set),
                     &mut self.end_set,
                     &mut self.metadata,
diff --git a/wgpu-hal/src/vulkan/device.rs b/wgpu-hal/src/vulkan/device.rs
index af22f8e0391..4de2b06a57b 100644
--- a/wgpu-hal/src/vulkan/device.rs
+++ b/wgpu-hal/src/vulkan/device.rs
@@ -48,13 +48,16 @@ impl super::DeviceShared {
                 .collect();
             &buffer_vec
         };
+
+        let name = unsafe { CStr::from_bytes_with_nul_unchecked(name_bytes) };
+
         let _result = unsafe {
             extension.debug_utils_set_object_name(
                 self.raw.handle(),
                 &vk::DebugUtilsObjectNameInfoEXT::builder()
                     .object_type(object_type)
                     .object_handle(object.as_raw())
-                    .object_name(CStr::from_bytes_with_nul_unchecked(name_bytes)),
+                    .object_name(name),
             )
         };
     }