From fe9e28c0860e7a8195d291d0a47b40440e1e3947 Mon Sep 17 00:00:00 2001
From: Brecht Van Lommel <brecht@blender.org>
Date: Mon, 6 Nov 2023 18:50:25 +0100
Subject: [PATCH] Fix build error on macOS x86, after Metal motion blur
 workaround

Ref #114544
---
 intern/cycles/device/metal/bvh.mm | 110 +++++++++++++++---------------
 1 file changed, 54 insertions(+), 56 deletions(-)

diff --git a/intern/cycles/device/metal/bvh.mm b/intern/cycles/device/metal/bvh.mm
index ba86e80f587..45780b4f166 100644
--- a/intern/cycles/device/metal/bvh.mm
+++ b/intern/cycles/device/metal/bvh.mm
@@ -131,62 +131,6 @@ BVHMetal::~BVHMetal()
   }
 }
 
-id<MTLAccelerationStructure> make_null_BLAS(id<MTLDevice> device, id<MTLCommandQueue> queue)
-{
-  if (@available(macos 12.0, *)) {
-    MTLResourceOptions storage_mode = MTLResourceStorageModeManaged;
-    if (device.hasUnifiedMemory) {
-      storage_mode = MTLResourceStorageModeShared;
-    }
-
-    id<MTLBuffer> nullBuf = [device newBufferWithLength:0 options:storage_mode];
-
-    /* Create an acceleration structure. */
-    MTLAccelerationStructureTriangleGeometryDescriptor *geomDesc =
-        [MTLAccelerationStructureTriangleGeometryDescriptor descriptor];
-    geomDesc.vertexBuffer = nullBuf;
-    geomDesc.vertexBufferOffset = 0;
-    geomDesc.vertexStride = sizeof(float3);
-    geomDesc.indexBuffer = nullBuf;
-    geomDesc.indexBufferOffset = 0;
-    geomDesc.indexType = MTLIndexTypeUInt32;
-    geomDesc.triangleCount = 0;
-    geomDesc.intersectionFunctionTableOffset = 0;
-    geomDesc.opaque = true;
-    geomDesc.allowDuplicateIntersectionFunctionInvocation = false;
-
-    MTLPrimitiveAccelerationStructureDescriptor *accelDesc =
-        [MTLPrimitiveAccelerationStructureDescriptor descriptor];
-    accelDesc.geometryDescriptors = @[ geomDesc ];
-    accelDesc.usage |= MTLAccelerationStructureUsageExtendedLimits;
-
-    MTLAccelerationStructureSizes accelSizes = [device
-        accelerationStructureSizesWithDescriptor:accelDesc];
-    id<MTLAccelerationStructure> accel_struct = [device
-        newAccelerationStructureWithSize:accelSizes.accelerationStructureSize];
-    id<MTLBuffer> scratchBuf = [device newBufferWithLength:accelSizes.buildScratchBufferSize
-                                                   options:MTLResourceStorageModePrivate];
-    id<MTLBuffer> sizeBuf = [device newBufferWithLength:8 options:MTLResourceStorageModeShared];
-    id<MTLCommandBuffer> accelCommands = [queue commandBuffer];
-    id<MTLAccelerationStructureCommandEncoder> accelEnc =
-        [accelCommands accelerationStructureCommandEncoder];
-    [accelEnc buildAccelerationStructure:accel_struct
-                              descriptor:accelDesc
-                           scratchBuffer:scratchBuf
-                     scratchBufferOffset:0];
-    [accelEnc endEncoding];
-    [accelCommands commit];
-    [accelCommands waitUntilCompleted];
-
-    /* free temp resources */
-    [scratchBuf release];
-    [nullBuf release];
-    [sizeBuf release];
-
-    return accel_struct;
-  }
-}
-
 bool BVHMetal::build_BLAS_mesh(Progress &progress,
                                id<MTLDevice> device,
                                id<MTLCommandQueue> queue,
@@ -1024,6 +968,60 @@ bool BVHMetal::build_TLAS(Progress &progress,
   g_bvh_build_throttler.wait_for_all();
 
   if (@available(macos 12.0, *)) {
+    /* Defined inside available check, for return type to be available. */
+    auto make_null_BLAS = [](id<MTLDevice> device,
+                             id<MTLCommandQueue> queue) -> id<MTLAccelerationStructure> {
+      MTLResourceOptions storage_mode = MTLResourceStorageModeManaged;
+      if (device.hasUnifiedMemory) {
+        storage_mode = MTLResourceStorageModeShared;
+      }
+
+      id<MTLBuffer> nullBuf = [device newBufferWithLength:0 options:storage_mode];
+
+      /* Create an acceleration structure. */
+      MTLAccelerationStructureTriangleGeometryDescriptor *geomDesc =
+          [MTLAccelerationStructureTriangleGeometryDescriptor descriptor];
+      geomDesc.vertexBuffer = nullBuf;
+      geomDesc.vertexBufferOffset = 0;
+      geomDesc.vertexStride = sizeof(float3);
+      geomDesc.indexBuffer = nullBuf;
+      geomDesc.indexBufferOffset = 0;
+      geomDesc.indexType = MTLIndexTypeUInt32;
+      geomDesc.triangleCount = 0;
+      geomDesc.intersectionFunctionTableOffset = 0;
+      geomDesc.opaque = true;
+      geomDesc.allowDuplicateIntersectionFunctionInvocation = false;
+
+      MTLPrimitiveAccelerationStructureDescriptor *accelDesc =
+          [MTLPrimitiveAccelerationStructureDescriptor descriptor];
+      accelDesc.geometryDescriptors = @[ geomDesc ];
+      accelDesc.usage |= MTLAccelerationStructureUsageExtendedLimits;
+
+      MTLAccelerationStructureSizes accelSizes = [device
+          accelerationStructureSizesWithDescriptor:accelDesc];
+      id<MTLAccelerationStructure> accel_struct = [device
+          newAccelerationStructureWithSize:accelSizes.accelerationStructureSize];
+      id<MTLBuffer> scratchBuf = [device newBufferWithLength:accelSizes.buildScratchBufferSize
+                                                     options:MTLResourceStorageModePrivate];
+      id<MTLBuffer> sizeBuf = [device newBufferWithLength:8 options:MTLResourceStorageModeShared];
+      id<MTLCommandBuffer> accelCommands = [queue commandBuffer];
+      id<MTLAccelerationStructureCommandEncoder> accelEnc =
+          [accelCommands accelerationStructureCommandEncoder];
+      [accelEnc buildAccelerationStructure:accel_struct
+                                descriptor:accelDesc
+                             scratchBuffer:scratchBuf
+                       scratchBufferOffset:0];
+      [accelEnc endEncoding];
+      [accelCommands commit];
+      [accelCommands waitUntilCompleted];
+
+      /* free temp resources */
+      [scratchBuf release];
+      [nullBuf release];
+      [sizeBuf release];
+
+      return accel_struct;
+    };
 
     uint32_t num_instances = 0;
     uint32_t num_motion_transforms = 0;