Fix clippy warnings about using if-let over match

The specific lint triggered was
https://rust-lang.github.io/rust-clippy/master/index.html#single_match.

wgpu-core/src/command/bundle.rs

@@ -931,19 +931,16 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             .register_identity(id_in, render_bundle, &mut token);
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => {
-                use crate::device::trace;
-                let (bundle_guard, _) = hub.render_bundles.read(&mut token);
-                let bundle = &bundle_guard[id];
-                let label = desc.label.as_ref().map(|l| l.as_ref());
-                trace.lock().add(trace::Action::CreateRenderBundle {
-                    id: id.0,
-                    desc: trace::new_render_bundle_encoder_descriptor(label, &bundle.context),
-                    base: BasePass::from_ref(bundle.base.as_ref()),
-                });
-            }
-            None => {}
+        if let Some(ref trace) = device.trace {
+            use crate::device::trace;
+            let (bundle_guard, _) = hub.render_bundles.read(&mut token);
+            let bundle = &bundle_guard[id];
+            let label = desc.label.as_ref().map(|l| l.as_ref());
+            trace.lock().add(trace::Action::CreateRenderBundle {
+                id: id.0,
+                desc: trace::new_render_bundle_encoder_descriptor(label, &bundle.context),
+                base: BasePass::from_ref(bundle.base.as_ref()),
+            });
         }
 
         device

wgpu-core/src/command/compute.rs

@@ -220,13 +220,10 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let raw = cmd_buf.raw.last_mut().unwrap();
 
         #[cfg(feature = "trace")]
-        match cmd_buf.commands {
-            Some(ref mut list) => {
-                list.push(crate::device::trace::Command::RunComputePass {
-                    base: BasePass::from_ref(base),
-                });
-            }
-            None => {}
+        if let Some(ref mut list) = cmd_buf.commands {
+            list.push(crate::device::trace::Command::RunComputePass {
+                base: BasePass::from_ref(base),
+            });
         }
 
         let (_, mut token) = hub.render_bundles.read(&mut token);

wgpu-core/src/command/render.rs

@@ -434,15 +434,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let mut raw = device.cmd_allocator.extend(cmd_buf);
 
         #[cfg(feature = "trace")]
-        match cmd_buf.commands {
-            Some(ref mut list) => {
-                list.push(crate::device::trace::Command::RunRenderPass {
-                    base: BasePass::from_ref(base),
-                    target_colors: color_attachments.iter().cloned().collect(),
-                    target_depth_stencil: depth_stencil_attachment.cloned(),
-                });
-            }
-            None => {}
+        if let Some(ref mut list) = cmd_buf.commands {
+            list.push(crate::device::trace::Command::RunRenderPass {
+                base: BasePass::from_ref(base),
+                target_colors: color_attachments.iter().cloned().collect(),
+                target_depth_stencil: depth_stencil_attachment.cloned(),
+            });
         }
 
         unsafe {

wgpu-core/src/command/transfer.rs

@@ -315,15 +315,14 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let mut barriers = Vec::new();
 
         #[cfg(feature = "trace")]
-        match cmd_buf.commands {
-            Some(ref mut list) => list.push(TraceCommand::CopyBufferToBuffer {
+        if let Some(ref mut list) = cmd_buf.commands {
+            list.push(TraceCommand::CopyBufferToBuffer {
                 src: source,
                 src_offset: source_offset,
                 dst: destination,
                 dst_offset: destination_offset,
                 size,
-            }),
-            None => (),
+            });
         }
 
         let (src_buffer, src_pending) = cmd_buf
@@ -416,13 +415,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             texture_copy_view_to_hal(destination, copy_size, &*texture_guard)?;
 
         #[cfg(feature = "trace")]
-        match cmd_buf.commands {
-            Some(ref mut list) => list.push(TraceCommand::CopyBufferToTexture {
+        if let Some(ref mut list) = cmd_buf.commands {
+            list.push(TraceCommand::CopyBufferToTexture {
                 src: source.clone(),
                 dst: destination.clone(),
                 size: *copy_size,
-            }),
-            None => (),
+            });
         }
 
         if copy_size.width == 0 || copy_size.height == 0 || copy_size.width == 0 {
@@ -535,13 +533,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             texture_copy_view_to_hal(source, copy_size, &*texture_guard)?;
 
         #[cfg(feature = "trace")]
-        match cmd_buf.commands {
-            Some(ref mut list) => list.push(TraceCommand::CopyTextureToBuffer {
+        if let Some(ref mut list) = cmd_buf.commands {
+            list.push(TraceCommand::CopyTextureToBuffer {
                 src: source.clone(),
                 dst: destination.clone(),
                 size: *copy_size,
-            }),
-            None => (),
+            });
         }
 
         if copy_size.width == 0 || copy_size.height == 0 || copy_size.width == 0 {
@@ -663,13 +660,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         }
 
         #[cfg(feature = "trace")]
-        match cmd_buf.commands {
-            Some(ref mut list) => list.push(TraceCommand::CopyTextureToTexture {
+        if let Some(ref mut list) = cmd_buf.commands {
+            list.push(TraceCommand::CopyTextureToTexture {
                 src: source.clone(),
                 dst: destination.clone(),
                 size: *copy_size,
-            }),
-            None => (),
+            });
         }
 
         if copy_size.width == 0 || copy_size.height == 0 || copy_size.width == 0 {

wgpu-core/src/device/mod.rs

@@ -1051,17 +1051,14 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let id = hub.buffers.register_identity(id_in, buffer, &mut token);
         tracing::info!("Created buffer {:?} with {:?}", id, desc);
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => {
-                let mut desc = desc.clone();
-                let mapped_at_creation = mem::replace(&mut desc.mapped_at_creation, false);
-                if mapped_at_creation && !desc.usage.contains(wgt::BufferUsage::MAP_WRITE) {
-                    desc.usage |= wgt::BufferUsage::COPY_DST;
-                }
-                trace.lock().add(trace::Action::CreateBuffer(id.0, desc))
+        if let Some(ref trace) = device.trace {
+            let mut desc = desc.clone();
+            let mapped_at_creation = mem::replace(&mut desc.mapped_at_creation, false);
+            if mapped_at_creation && !desc.usage.contains(wgt::BufferUsage::MAP_WRITE) {
+                desc.usage |= wgt::BufferUsage::COPY_DST;
             }
-            None => (),
-        };
+            trace.lock().add(trace::Action::CreateBuffer(id.0, desc));
+        }
 
         device
             .trackers
@@ -1119,19 +1116,16 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         //assert!(buffer isn't used by the GPU);
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => {
-                let mut trace = trace.lock();
-                let data_path = trace.make_binary("bin", data);
-                trace.add(trace::Action::WriteBuffer {
-                    id: buffer_id,
-                    data: data_path,
-                    range: offset..offset + data.len() as BufferAddress,
-                    queued: false,
-                });
-            }
-            None => (),
-        };
+        if let Some(ref trace) = device.trace {
+            let mut trace = trace.lock();
+            let data_path = trace.make_binary("bin", data);
+            trace.add(trace::Action::WriteBuffer {
+                id: buffer_id,
+                data: data_path,
+                range: offset..offset + data.len() as BufferAddress,
+                queued: false,
+            });
+        }
 
         let ptr = map_buffer(
             &device.raw,
@@ -1279,12 +1273,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let id = hub.textures.register_identity(id_in, texture, &mut token);
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace
+        if let Some(ref trace) = device.trace {
+            trace
                 .lock()
-                .add(trace::Action::CreateTexture(id.0, desc.clone())),
-            None => (),
-        };
+                .add(trace::Action::CreateTexture(id.0, desc.clone()));
+        }
 
         device
             .trackers
@@ -1443,14 +1436,13 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let id = hub.texture_views.register_identity(id_in, view, &mut token);
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace.lock().add(trace::Action::CreateTextureView {
+        if let Some(ref trace) = device.trace {
+            trace.lock().add(trace::Action::CreateTextureView {
                 id: id.0,
                 parent_id: texture_id,
                 desc: desc.clone(),
-            }),
-            None => (),
-        };
+            });
+        }
 
         device
             .trackers
@@ -1605,12 +1597,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let id = hub.samplers.register_identity(id_in, sampler, &mut token);
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace
+        if let Some(ref trace) = device.trace {
+            trace
                 .lock()
-                .add(trace::Action::CreateSampler(id.0, desc.clone())),
-            None => (),
-        };
+                .add(trace::Action::CreateSampler(id.0, desc.clone()));
+        }
 
         device
             .trackers
@@ -1702,12 +1693,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             .bind_group_layouts
             .register_identity(id_in, layout, &mut token);
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace
+        if let Some(ref trace) = device.trace {
+            trace
                 .lock()
-                .add(trace::Action::CreateBindGroupLayout(id.0, desc.clone())),
-            None => (),
-        };
+                .add(trace::Action::CreateBindGroupLayout(id.0, desc.clone()));
+        }
         Ok(id.0)
     }
 
@@ -1773,12 +1763,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             .pipeline_layouts
             .register_identity(id_in, layout, &mut token);
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace
+        if let Some(ref trace) = device.trace {
+            trace
                 .lock()
-                .add(trace::Action::CreatePipelineLayout(id.0, desc.clone())),
-            None => (),
-        };
+                .add(trace::Action::CreatePipelineLayout(id.0, desc.clone()));
+        }
         Ok(id.0)
     }
 
@@ -1881,12 +1870,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                             bgl_guard,
                         );
                         #[cfg(feature = "trace")]
-                        match device.trace {
-                            Some(ref trace) => trace
+                        if let Some(ref trace) = device.trace {
+                            trace
                                 .lock()
-                                .add(trace::Action::CreateBindGroupLayout(out_id.0, bgl_desc)),
-                            None => (),
-                        };
+                                .add(trace::Action::CreateBindGroupLayout(out_id.0, bgl_desc));
+                        }
                         out_id.0
                     }
                 };
@@ -1905,13 +1893,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             pipeline_layout_guard,
         );
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace.lock().add(trace::Action::CreatePipelineLayout(
+        if let Some(ref trace) = device.trace {
+            trace.lock().add(trace::Action::CreatePipelineLayout(
                 layout_id.0,
                 layout_desc,
-            )),
-            None => (),
-        };
+            ));
+        }
         Ok((layout_id.0, derived_bind_group_count))
     }
 
@@ -2264,12 +2251,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             hub.bind_groups.read(&mut token).0[id].used
         );
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace
+        if let Some(ref trace) = device.trace {
+            trace
                 .lock()
-                .add(trace::Action::CreateBindGroup(id.0, desc.clone())),
-            None => (),
-        };
+                .add(trace::Action::CreateBindGroup(id.0, desc.clone()));
+        }
 
         device
             .trackers
@@ -2410,16 +2396,13 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             .shader_modules
             .register_identity(id_in, shader, &mut token);
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => {
-                let mut trace = trace.lock();
-                let data = trace.make_binary("spv", unsafe {
-                    std::slice::from_raw_parts(spv.as_ptr() as *const u8, spv.len() * 4)
-                });
-                trace.add(trace::Action::CreateShaderModule { id: id.0, data });
-            }
-            None => {}
-        };
+        if let Some(ref trace) = device.trace {
+            let mut trace = trace.lock();
+            let data = trace.make_binary("spv", unsafe {
+                std::slice::from_raw_parts(spv.as_ptr() as *const u8, spv.len() * 4)
+            });
+            trace.add(trace::Action::CreateShaderModule { id: id.0, data });
+        }
         Ok(id.0)
     }
 
@@ -2443,12 +2426,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         if let Some(module) = module {
             let device = &device_guard[module.device_id.value];
             #[cfg(feature = "trace")]
-            match device.trace {
-                Some(ref trace) => trace
+            if let Some(ref trace) = device.trace {
+                trace
                     .lock()
-                    .add(trace::Action::DestroyShaderModule(shader_module_id)),
-                None => (),
-            };
+                    .add(trace::Action::DestroyShaderModule(shader_module_id));
+            }
             unsafe {
                 device.raw.destroy_shader_module(module.raw);
             }
@@ -3028,16 +3010,15 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             .register_identity(id_in, pipeline, &mut token);
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace.lock().add(trace::Action::CreateRenderPipeline(
+        if let Some(ref trace) = device.trace {
+            trace.lock().add(trace::Action::CreateRenderPipeline(
                 id.0,
                 pipeline::RenderPipelineDescriptor {
                     layout: Some(layout_id),
                     ..desc.clone()
                 },
-            )),
-            None => (),
-        };
+            ));
+        }
         Ok((id.0, derived_bind_group_count))
     }
 
@@ -3250,16 +3231,15 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             .register_identity(id_in, pipeline, &mut token);
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace.lock().add(trace::Action::CreateComputePipeline(
+        if let Some(ref trace) = device.trace {
+            trace.lock().add(trace::Action::CreateComputePipeline(
                 id.0,
                 pipeline::ComputePipelineDescriptor {
                     layout: Some(layout_id),
                     ..desc.clone()
                 },
-            )),
-            None => (),
-        };
+            ));
+        }
         Ok((id.0, derived_bind_group_count))
     }
 
@@ -3440,12 +3420,11 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             }
         }
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace
+        if let Some(ref trace) = device.trace {
+            trace
                 .lock()
-                .add(Action::CreateSwapChain(sc_id, desc.clone())),
-            None => (),
-        };
+                .add(Action::CreateSwapChain(sc_id, desc.clone()));
+        }
 
         let swap_chain = swap_chain::SwapChain {
             life_guard: LifeGuard::new(),
@@ -3697,21 +3676,18 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                 needs_flush,
             } => {
                 #[cfg(feature = "trace")]
-                match device.trace {
-                    Some(ref trace) => {
-                        let mut trace = trace.lock();
-                        let data = trace.make_binary("bin", unsafe {
-                            std::slice::from_raw_parts(ptr.as_ptr(), buffer.size as usize)
-                        });
-                        trace.add(trace::Action::WriteBuffer {
-                            id: buffer_id,
-                            data,
-                            range: 0..buffer.size,
-                            queued: true,
-                        });
-                    }
-                    None => (),
-                };
+                if let Some(ref trace) = device.trace {
+                    let mut trace = trace.lock();
+                    let data = trace.make_binary("bin", unsafe {
+                        std::slice::from_raw_parts(ptr.as_ptr(), buffer.size as usize)
+                    });
+                    trace.add(trace::Action::WriteBuffer {
+                        id: buffer_id,
+                        data,
+                        range: 0..buffer.size,
+                        queued: true,
+                    });
+                }
                 let _ = ptr;
 
                 if needs_flush {
@@ -3772,22 +3748,19 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             } => {
                 if host == HostMap::Write {
                     #[cfg(feature = "trace")]
-                    match device.trace {
-                        Some(ref trace) => {
-                            let mut trace = trace.lock();
-                            let size = sub_range.size_to(buffer.size);
-                            let data = trace.make_binary("bin", unsafe {
-                                std::slice::from_raw_parts(ptr.as_ptr(), size as usize)
-                            });
-                            trace.add(trace::Action::WriteBuffer {
-                                id: buffer_id,
-                                data,
-                                range: sub_range.offset..sub_range.offset + size,
-                                queued: false,
-                            });
-                        }
-                        None => (),
-                    };
+                    if let Some(ref trace) = device.trace {
+                        let mut trace = trace.lock();
+                        let size = sub_range.size_to(buffer.size);
+                        let data = trace.make_binary("bin", unsafe {
+                            std::slice::from_raw_parts(ptr.as_ptr(), size as usize)
+                        });
+                        trace.add(trace::Action::WriteBuffer {
+                            id: buffer_id,
+                            data,
+                            range: sub_range.offset..sub_range.offset + size,
+                            queued: false,
+                        });
+                    }
                     let _ = (ptr, sub_range);
                 }
                 unmap_buffer(&device.raw, buffer)?;

wgpu-core/src/device/queue.rs

@@ -172,18 +172,15 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let (buffer_guard, _) = hub.buffers.read(&mut token);
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => {
-                let mut trace = trace.lock();
-                let data_path = trace.make_binary("bin", data);
-                trace.add(Action::WriteBuffer {
-                    id: buffer_id,
-                    data: data_path,
-                    range: buffer_offset..buffer_offset + data.len() as wgt::BufferAddress,
-                    queued: true,
-                });
-            }
-            None => {}
+        if let Some(ref trace) = device.trace {
+            let mut trace = trace.lock();
+            let data_path = trace.make_binary("bin", data);
+            trace.add(Action::WriteBuffer {
+                id: buffer_id,
+                data: data_path,
+                range: buffer_offset..buffer_offset + data.len() as wgt::BufferAddress,
+                queued: true,
+            });
         }
 
         let data_size = data.len() as wgt::BufferAddress;
@@ -280,18 +277,15 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             texture_copy_view_to_hal(destination, size, &*texture_guard)?;
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => {
-                let mut trace = trace.lock();
-                let data_path = trace.make_binary("bin", data);
-                trace.add(Action::WriteTexture {
-                    to: destination.clone(),
-                    data: data_path,
-                    layout: data_layout.clone(),
-                    size: *size,
-                });
-            }
-            None => {}
+        if let Some(ref trace) = device.trace {
+            let mut trace = trace.lock();
+            let data_path = trace.make_binary("bin", data);
+            trace.add(Action::WriteTexture {
+                to: destination.clone(),
+                data: data_path,
+                layout: data_layout.clone(),
+                size: *size,
+            });
         }
 
         if size.width == 0 || size.height == 0 || size.depth == 0 {
@@ -475,13 +469,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                             .get_mut(cmb_id)
                             .map_err(|_| QueueSubmitError::InvalidCommandBuffer(cmb_id))?;
                         #[cfg(feature = "trace")]
-                        match device.trace {
-                            Some(ref trace) => trace.lock().add(Action::Submit(
+                        if let Some(ref trace) = device.trace {
+                            trace.lock().add(Action::Submit(
                                 submit_index,
                                 cmdbuf.commands.take().unwrap(),
-                            )),
-                            None => (),
-                        };
+                            ));
+                        }
 
                         if let Some((sc_id, fbo)) = cmdbuf.used_swap_chain.take() {
                             let sc = &mut swap_chain_guard[sc_id.value];

wgpu-core/src/swap_chain.rs

@@ -206,13 +206,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         };
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace.lock().add(Action::GetSwapChainTexture {
+        if let Some(ref trace) = device.trace {
+            trace.lock().add(Action::GetSwapChainTexture {
                 id: view_id,
                 parent_id: swap_chain_id,
-            }),
-            None => (),
-        };
+            });
+        }
 
         Ok(SwapChainOutput { status, view_id })
     }
@@ -238,10 +237,9 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let device = &mut device_guard[sc.device_id.value];
 
         #[cfg(feature = "trace")]
-        match device.trace {
-            Some(ref trace) => trace.lock().add(Action::PresentSwapChain(swap_chain_id)),
-            None => (),
-        };
+        if let Some(ref trace) = device.trace {
+            trace.lock().add(Action::PresentSwapChain(swap_chain_id));
+        }
 
         let view_id = sc
             .acquired_view_id