Fix -Wunreachable-code-aggressive.

Bug: chromium:1066980
Change-Id: I9e00d3707972307e1c5395156c39aa153d5e170e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/56522
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Peter Kasting <pkasting@google.com>
Commit-Queue: Peter Kasting <pkasting@google.com>
Auto-Submit: Peter Kasting <pkasting@google.com>

generator/templates/dawn_wire/server/ServerDoers.cpp

@@ -118,8 +118,6 @@ namespace dawn_wire { namespace server {
             default:
                 return false;
         }
-
-        return true;
     }
 
 }}  // namespace dawn_wire::server

src/common/BUILD.gn

@@ -119,6 +119,7 @@ config("dawn_internal") {
       "-Wshadow-field",
       "-Wstrict-prototypes",
       "-Wtautological-unsigned-zero-compare",
+      "-Wunreachable-code-aggressive",
     ]
 
     if (is_win) {

src/dawn_native/CommandEncoder.cpp

@@ -105,7 +105,6 @@ namespace dawn_native {
                         return DAWN_VALIDATION_ERROR(
                             "The depth aspect of depth24plus texture cannot be selected in a "
                             "texture to buffer copy");
-                        break;
                     case wgpu::TextureFormat::Depth32Float:
                         break;
 

src/dawn_native/CommandValidation.cpp

@@ -368,12 +368,10 @@ namespace dawn_native {
                 if (HasOneBit(format.aspects)) {
                     Aspect single = format.aspects;
                     return single;
-                } else {
+                }
                 return DAWN_VALIDATION_ERROR(
                     "A single aspect must be selected for multi-planar formats in "
                     "texture <-> linear data copies");
-                }
-                break;
             case wgpu::TextureAspect::DepthOnly:
                 ASSERT(format.aspects & Aspect::Depth);
                 return Aspect::Depth;

src/dawn_native/ShaderModule.cpp

@@ -784,7 +784,6 @@ namespace dawn_native {
                         }
                         case BindingInfoType::ExternalTexture: {
                             return DAWN_VALIDATION_ERROR("External textures are not supported.");
-                            break;
                         }
                     }
                 }

src/dawn_native/Surface.cpp

@@ -50,13 +50,13 @@ namespace dawn_native {
 #if defined(DAWN_ENABLE_BACKEND_METAL)
         const SurfaceDescriptorFromMetalLayer* metalDesc = nullptr;
         FindInChain(descriptor->nextInChain, &metalDesc);
-        if (!metalDesc) {
-            return DAWN_VALIDATION_ERROR("Unsupported sType");
-        }
+        if (metalDesc) {
             // Check that the layer is a CAMetalLayer (or a derived class).
             if (!InheritsFromCAMetalLayer(metalDesc->layer)) {
                 return DAWN_VALIDATION_ERROR("layer must be a CAMetalLayer");
             }
+            return {};
+        }
 #endif  // defined(DAWN_ENABLE_BACKEND_METAL)
 
 #if defined(DAWN_PLATFORM_WINDOWS)
@@ -94,15 +94,12 @@ namespace dawn_native {
             }
             return {};
         }
-        return DAWN_VALIDATION_ERROR("Unsupported sType");
 #endif  // defined(DAWN_PLATFORM_WINDOWS)
 
 #if defined(DAWN_USE_X11)
         const SurfaceDescriptorFromXlib* xDesc = nullptr;
         FindInChain(descriptor->nextInChain, &xDesc);
-        if (!xDesc) {
-            return DAWN_VALIDATION_ERROR("Unsupported sType");
-        }
+        if (xDesc) {
             // Check the validity of the window by calling a getter function on the window that
             // returns a status code. If the window is bad the call return a status of zero. We
             // need to set a temporary X11 error handler while doing this because the default
@@ -117,9 +114,11 @@ namespace dawn_native {
             if (status == 0) {
                 return DAWN_VALIDATION_ERROR("Invalid X Window");
             }
+            return {};
+        }
 #endif  // defined(DAWN_USE_X11)
 
-        return {};
+        return DAWN_VALIDATION_ERROR("Unsupported sType");
     }
 
     Surface::Surface(InstanceBase* instance, const SurfaceDescriptor* descriptor)