1 files changed, 76 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/AggregateAssignStructsInSSBOs.cpp b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/AggregateAssignStructsInSSBOs.cpp
new file mode 100644
index 0000000000..4293f4c4da
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/AggregateAssignStructsInSSBOs.cpp
@@ -0,0 +1,76 @@
+//
+// Copyright 2022 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "compiler/translator/tree_ops/d3d/AggregateAssignStructsInSSBOs.h"
+
+#include "compiler/translator/StaticType.h"
+#include "compiler/translator/Symbol.h"
+#include "compiler/translator/tree_util/IntermNode_util.h"
+#include "compiler/translator/tree_util/IntermTraverse.h"
+#include "compiler/translator/util.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class AggregateAssignStructsInSSBOsTraverser : public TIntermTraverser
+{
+  public:
+    AggregateAssignStructsInSSBOsTraverser(TSymbolTable *symbolTable)
+        : TIntermTraverser(true, false, false, symbolTable)
+    {}
+
+  protected:
+    bool visitBinary(Visit visit, TIntermBinary *node) override
+    {
+        // Replace all assignments to structs in SSBOs with field-by-field asignments.
+        // TODO(anglebug.com/7362): this implementation only works for the simple case (assignment
+        // statement), not more complex cases such as assignment-as-expression or functions with
+        // side effects in the RHS.
+        const TStructure *s;
+        if (node->getOp() != EOpAssign)
+        {
+            return true;
+        }
+        else if (!IsInShaderStorageBlock(node->getLeft()))
+        {
+            return true;
+        }
+        else if (!(s = node->getLeft()->getType().getStruct()))
+        {
+            return true;
+        }
+        ASSERT(node->getRight()->getType().getStruct() == s);
+        auto *block = new TIntermBlock();
+        for (int i = 0; i < static_cast<int>(s->fields().size()); ++i)
+        {
+            auto *left   = new TIntermBinary(EOpIndexDirectStruct, node->getLeft()->deepCopy(),
+                                             CreateIndexNode(i));
+            auto *right  = new TIntermBinary(EOpIndexDirectStruct, node->getRight()->deepCopy(),
+                                             CreateIndexNode(i));
+            auto *assign = new TIntermBinary(TOperator::EOpAssign, left, right);
+            block->appendStatement(assign);
+        }
+
+        queueReplacement(block, OriginalNode::IS_DROPPED);
+        return false;
+    }
+};
+
+}  // namespace
+
+bool AggregateAssignStructsInSSBOs(TCompiler *compiler,
+                                   TIntermBlock *root,
+                                   TSymbolTable *symbolTable)
+{
+    AggregateAssignStructsInSSBOsTraverser traverser(symbolTable);
+    root->traverse(&traverser);
+    return traverser.updateTree(compiler, root);
+}
+
+}  // namespace sh