Actually make it possible to run tests with hal auditing enabled.

Author: jimblandy

wgpu-core/src/instance.rs

@@ -138,8 +138,16 @@ impl Instance {
         match unsafe { A::Instance::init(&hal_desc) } {
             Ok(instance) => {
                 log::debug!("Instance::new: created {:?} backend", A::VARIANT);
+
+                let mut instance: Box<dyn hal::DynInstance> = Box::new(instance);
+
+                // If requested, wrap the new instance in the hal auditing layer.
+                if instance_desc.flags.contains(wgt::InstanceFlags::AUDIT_HAL_USAGE) {
+                    instance = Box::new(hal::audit::Instance::new(instance, A::VARIANT));
+                }
+
                 self.instance_per_backend
-                    .push((A::VARIANT, Box::new(instance)));
+                    .push((A::VARIANT, instance));
             }
             Err(err) => {
                 log::debug!(

wgpu-hal/src/audit/instance.rs

@@ -9,7 +9,7 @@ use alloc::sync::Arc;
 use alloc::vec::Vec;
 
 impl audit::Instance {
-    fn new(backend: wgpu_types::Backend, inner: Box<dyn DynInstance>) -> Self {
+    pub fn new(inner: Box<dyn DynInstance>, backend: wgpu_types::Backend) -> Self {
         let state = state::State::new(backend);
         let id = state.new_id();
         // Instances are their own parents.

wgpu-hal/src/lib.rs

@@ -281,7 +281,7 @@ mod validation_canary;
 #[cfg(feature = "validation_canary")]
 pub use validation_canary::{ValidationCanary, VALIDATION_CANARY};
 
-mod audit;
+pub mod audit;
 
 pub(crate) use dynamic::impl_dyn_resource;
 pub use dynamic::{

wgpu-types/src/instance.rs

@@ -139,6 +139,13 @@ bitflags::bitflags! {
         ///
         /// [rqs]: ../wgpu/struct.CommandEncoder.html#method.resolve_query_set
         const AUTOMATIC_TIMESTAMP_NORMALIZATION = 1 << 6;
+
+        /// Enable `wgpu_hal` safety invariant auditing layer.
+        ///
+        /// When `Self::from_env()` is used, this flag is set if the
+        /// `WGPU_AUDIT_HAL_USAGE` environment variable is set to a value other
+        /// than `0`.
+        const AUDIT_HAL_USAGE = 1 << 7;
     }
 }
 
@@ -224,6 +231,9 @@ impl InstanceFlags {
         if let Some(bit) = env("WGPU_VALIDATION_INDIRECT_CALL") {
             self.set(Self::VALIDATION_INDIRECT_CALL, bit);
         }
+        if let Some(bit) = env("WGPU_AUDIT_HAL_USAGE") {
+            self.set(Self::AUDIT_HAL_USAGE, bit);
+        }
 
         self
     }