Remove support for macOS 10.11 and 10.12

Fixed: dawn:1397
Change-Id: I58c899bb58c445d56c544828a52eddd720bc4847
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/129840
Reviewed-by: Brandon Jones <bajones@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>

src/dawn/native/metal/BufferMTL.mm

@@ -45,21 +45,12 @@ uint64_t Buffer::QueryMaxBufferLength(id<MTLDevice> mtlDevice) {
 #if DAWN_PLATFORM_IS(MACOS)
     // 10.12 and 10.13 have a 1Gb limit.
     if (@available(macOS 10.12, *)) {
-        // |maxBufferLength| isn't always available on older systems. If available, use
-        // |recommendedMaxWorkingSetSize| instead. We can probably allocate more than this,
-        // but don't have a way to discover a better limit. MoltenVK also uses this heuristic.
         return 1024 * 1024 * 1024;
     }
-    // 10.11 has a 256Mb limit
-    if (@available(macOS 10.11, *)) {
-        return 256 * 1024 * 1024;
-    }
-    // 256Mb for other platform if any. (Need to have a return for all branches).
-    return 256 * 1024 * 1024;
-#else
-    // macOS / tvOS: 256Mb limit in versions without [MTLDevice maxBufferLength]
-    return 256 * 1024 * 1024;
 #endif
+
+    // 256Mb limit in versions without based on the data in the feature set tables.
+    return 256 * 1024 * 1024;
 }
 
 Buffer::Buffer(DeviceBase* dev, const BufferDescriptor* desc) : BufferBase(dev, desc) {}

src/dawn/native/metal/CommandBufferMTL.mm

@@ -213,7 +213,7 @@ NSRef<MTLRenderPassDescriptor> CreateMTLRenderPassDescriptor(
             switch (attachmentInfo.storeOp) {
                 case wgpu::StoreOp::Store:
                     descriptor.colorAttachments[i].storeAction =
-                        kMTLStoreActionStoreAndMultisampleResolve;
+                        MTLStoreActionStoreAndMultisampleResolve;
                     break;
                 case wgpu::StoreOp::Discard:
                     descriptor.colorAttachments[i].storeAction = MTLStoreActionMultisampleResolve;

src/dawn/native/metal/TextureMTL.mm

@@ -43,10 +43,8 @@ MTLTextureUsage MetalTextureUsage(const Format& format, wgpu::TextureUsage usage
         // See TextureView::Initialize.
         // Depth views for depth/stencil textures in Metal simply use the original
         // texture's format, but stencil views require format reinterpretation.
-        if (@available(macOS 10.12, iOS 10.0, *)) {
-            if (IsSubset(Aspect::Depth | Aspect::Stencil, format.aspects)) {
-                result |= MTLTextureUsagePixelFormatView;
-            }
+        if (IsSubset(Aspect::Depth | Aspect::Stencil, format.aspects)) {
+            result |= MTLTextureUsagePixelFormatView;
         }
     }
 
@@ -332,10 +330,8 @@ MTLPixelFormat MetalPixelFormat(const DeviceBase* device, wgpu::TextureFormat fo
         case wgpu::TextureFormat::Depth16Unorm:
             if (@available(macOS 10.12, iOS 13.0, *)) {
                 return MTLPixelFormatDepth16Unorm;
-            } else {
-                // TODO(dawn:1181): Allow non-conformant implementation on macOS 10.11
-                UNREACHABLE();
             }
+            UNREACHABLE();
         case wgpu::TextureFormat::Stencil8:
             if (device->IsToggleEnabled(Toggle::MetalUseCombinedDepthStencilFormatForStencil8)) {
                 return MTLPixelFormatDepth32Float_Stencil8;
@@ -1169,19 +1165,8 @@ MaybeError TextureView::Initialize(const TextureViewDescriptor* descriptor) {
 
         Aspect aspect = SelectFormatAspects(GetFormat(), descriptor->aspect);
         if (aspect == Aspect::Stencil && textureFormat != MTLPixelFormatStencil8) {
-            if (@available(macOS 10.12, iOS 10.0, *)) {
-                if (textureFormat == MTLPixelFormatDepth32Float_Stencil8) {
-                    viewFormat = MTLPixelFormatX32_Stencil8;
-                } else {
-                    UNREACHABLE();
-                }
-            } else {
-                // TODO(enga): Add a workaround to back combined depth/stencil textures
-                // with Sampled usage using two separate textures.
-                // Or, consider always using the workaround for D32S8.
-                return DAWN_INTERNAL_ERROR("Cannot create stencil-only texture view of combined "
-                                           "depth/stencil format.");
-            }
+            ASSERT(textureFormat == MTLPixelFormatDepth32Float_Stencil8);
+            viewFormat = MTLPixelFormatX32_Stencil8;
         } else if (GetTexture()->GetFormat().HasDepth() && GetTexture()->GetFormat().HasStencil()) {
             // Depth-only views for depth/stencil textures in Metal simply use the original
             // texture's format.

src/dawn/native/metal/UtilsMetal.h

@@ -80,15 +80,6 @@ MaybeError EnsureDestinationTextureInitialized(CommandRecordingContext* commandC
                                                const TextureCopy& dst,
                                                const Extent3D& size);
 
-// Allow use MTLStoreActionStoreAndMultismapleResolve because the logic in the backend is
-// first to compute what the "best" Metal render pass descriptor is, then fix it up if we
-// are not on macOS 10.12 (i.e. the EmulateStoreAndMSAAResolve toggle is on).
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunguarded-availability"
-constexpr MTLStoreAction kMTLStoreActionStoreAndMultisampleResolve =
-    MTLStoreActionStoreAndMultisampleResolve;
-#pragma clang diagnostic pop
-
 // Helper functions to encode Metal render passes that take care of multiple workarounds that
 // happen at the render pass start and end. Because workarounds wrap the encoding of the render
 // pass, the encoding must be entirely done by the `encodeInside` callback.

src/dawn/native/metal/UtilsMetal.mm

@@ -452,7 +452,7 @@ MaybeError EncodeMetalRenderPass(Device* device,
         std::array<id<MTLTexture>, kMaxColorAttachments> resolveTextures = {};
         for (uint32_t i = 0; i < kMaxColorAttachments; ++i) {
             if (mtlRenderPass.colorAttachments[i].storeAction ==
-                kMTLStoreActionStoreAndMultisampleResolve) {
+                MTLStoreActionStoreAndMultisampleResolve) {
                 hasStoreAndMSAAResolve = true;
                 resolveTextures[i] = mtlRenderPass.colorAttachments[i].resolveTexture;