Add Compile Test and Fix

Cargo.toml

@@ -124,6 +124,7 @@ serde_json = "1.0.133"
 smallvec = "1"
 static_assertions = "1.1.0"
 strum = { version = "0.25.0", features = ["derive"] }
+trybuild = "1"
 tracy-client = "0.17"
 thiserror = "1.0.69"
 wgpu = { version = "23.0.1", path = "./wgpu", default-features = false }

tests/Cargo.toml

@@ -16,6 +16,11 @@ name = "wgpu-test"
 path = "tests/root.rs"
 harness = false
 
+[[test]]
+name = "wgpu-compile-test"
+path = "compile_tests/root.rs"
+harness = true
+
 [features]
 webgl = ["wgpu/webgl"]
 
@@ -27,6 +32,7 @@ bytemuck.workspace = true
 cfg-if.workspace = true
 ctor.workspace = true
 futures-lite.workspace = true
+glam.workspace = true
 itertools.workspace = true
 libtest-mimic.workspace = true
 log.workspace = true
@@ -37,10 +43,10 @@ profiling.workspace = true
 serde_json.workspace = true
 serde.workspace = true
 strum = { workspace = true, features = ["derive"] }
-wgpu-macros.workspace = true
+trybuild.workspace = true
 wgpu = { workspace = true, features = ["wgsl"] }
+wgpu-macros.workspace = true
 wgt = { workspace = true, features = ["serde"] }
-glam.workspace = true
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 env_logger.workspace = true

tests/compile_tests/fail/cpass_lifetime.rs

@@ -0,0 +1,16 @@
+// Test to ensure that ComputePass without forget_lifetime does not compile
+// when the ComputePass is dropped before the CommandBuffer is finished.
+
+fn main() {
+    let instance = wgpu::Instance::new(Default::default());
+    let adapter = pollster::block_on(instance.request_adapter(&Default::default())).unwrap();
+    let (device, queue) =
+        pollster::block_on(adapter.request_device(&Default::default(), None)).unwrap();
+
+    let mut encoder = device.create_command_encoder(&Default::default());
+    let _compute_pass = encoder.begin_compute_pass(&Default::default());
+    // set up the compute pass...
+
+    let cmd_buffer = encoder.finish();
+    queue.submit([cmd_buffer]);
+}

tests/compile_tests/fail/cpass_lifetime.stderr

@@ -0,0 +1,13 @@
+error[E0505]: cannot move out of `encoder` because it is borrowed
+  --> compile_tests/fail/cpass_lifetime.rs:14:22
+   |
+10 |     let mut encoder = device.create_command_encoder(&Default::default());
+   |         ----------- binding `encoder` declared here
+11 |     let _compute_pass = encoder.begin_compute_pass(&Default::default());
+   |                         ------- borrow of `encoder` occurs here
+...
+14 |     let cmd_buffer = encoder.finish();
+   |                      ^^^^^^^ move out of `encoder` occurs here
+15 |     queue.submit([cmd_buffer]);
+16 | }
+   | - borrow might be used here, when `_compute_pass` is dropped and runs the destructor for type `wgpu::ComputePass<'_>`

tests/compile_tests/fail/rpass_lifetime.rs

@@ -0,0 +1,16 @@
+// Test to ensure that ComputePass without forget_lifetime does not compile
+// when the ComputePass is dropped before the CommandBuffer is finished.
+
+fn main() {
+    let instance = wgpu::Instance::new(Default::default());
+    let adapter = pollster::block_on(instance.request_adapter(&Default::default())).unwrap();
+    let (device, queue) =
+        pollster::block_on(adapter.request_device(&Default::default(), None)).unwrap();
+
+    let mut encoder = device.create_command_encoder(&Default::default());
+    let _render_pass = encoder.begin_render_pass(&Default::default());
+    // set up the render pass...
+
+    let cmd_buffer = encoder.finish();
+    queue.submit([cmd_buffer]);
+}

tests/compile_tests/fail/rpass_lifetime.stderr

@@ -0,0 +1,13 @@
+error[E0505]: cannot move out of `encoder` because it is borrowed
+  --> compile_tests/fail/rpass_lifetime.rs:14:22
+   |
+10 |     let mut encoder = device.create_command_encoder(&Default::default());
+   |         ----------- binding `encoder` declared here
+11 |     let _render_pass = encoder.begin_render_pass(&Default::default());
+   |                        ------- borrow of `encoder` occurs here
+...
+14 |     let cmd_buffer = encoder.finish();
+   |                      ^^^^^^^ move out of `encoder` occurs here
+15 |     queue.submit([cmd_buffer]);
+16 | }
+   | - borrow might be used here, when `_render_pass` is dropped and runs the destructor for type `wgpu::RenderPass<'_>`

tests/compile_tests/root.rs

@@ -0,0 +1,7 @@
+// Tests that ensure that various constructs that should not compile do not compile.
+
+#[test]
+fn compile_fail() {
+    let t = trybuild::TestCases::new();
+    t.compile_fail("compile_tests/fail/*.rs");
+}

wgpu-types/Cargo.toml

@@ -35,7 +35,7 @@ serde = ["dep:serde"]
 counters = []
 
 [dependencies]
-bitflags.workspace = true
+bitflags = { workspace = true, features = ["serde"] }
 serde = { workspace = true, features = ["derive"], optional = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]

wgpu/src/api/command_encoder.rs

@@ -1,4 +1,4 @@
-use std::{marker::PhantomData, ops::Range};
+use std::ops::Range;
 
 use crate::{
     api::{
@@ -79,8 +79,8 @@ impl CommandEncoder {
     ) -> RenderPass<'encoder> {
         let rpass = self.inner.begin_render_pass(desc);
         RenderPass {
-            inner: RenderPassInner { inner: rpass },
-            encoder_guard: PhantomData,
+            inner: rpass,
+            _encoder_guard: api::PhantomDrop::default(),
         }
     }
 
@@ -100,8 +100,8 @@ impl CommandEncoder {
     ) -> ComputePass<'encoder> {
         let cpass = self.inner.begin_compute_pass(desc);
         ComputePass {
-            inner: ComputePassInner { inner: cpass },
-            encoder_guard: PhantomData,
+            inner: cpass,
+            _encoder_guard: api::PhantomDrop::default(),
         }
     }