1 files changed, 89 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/SeparateArrayInitialization.cpp b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/SeparateArrayInitialization.cpp
new file mode 100644
index 0000000000..de5c393cf6
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/SeparateArrayInitialization.cpp
@@ -0,0 +1,89 @@
+//
+// Copyright 2002 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.
+//
+// The SeparateArrayInitialization function splits each array initialization into a declaration and
+// an assignment.
+// Example:
+//     type[n] a = initializer;
+// will effectively become
+//     type[n] a;
+//     a = initializer;
+//
+// Note that if the array is declared as const, the initialization may still be split, making the
+// AST technically invalid. Because of that this transformation should only be used when subsequent
+// stages don't care about const qualifiers. However, the initialization will not be split if the
+// initializer can be written as a HLSL literal.
+
+#include "compiler/translator/tree_ops/d3d/SeparateArrayInitialization.h"
+
+#include "compiler/translator/IntermNode.h"
+#include "compiler/translator/OutputHLSL.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class SeparateArrayInitTraverser : private TIntermTraverser
+{
+  public:
+    [[nodiscard]] static bool apply(TCompiler *compiler, TIntermNode *root);
+
+  private:
+    SeparateArrayInitTraverser();
+    bool visitDeclaration(Visit, TIntermDeclaration *node) override;
+};
+
+bool SeparateArrayInitTraverser::apply(TCompiler *compiler, TIntermNode *root)
+{
+    SeparateArrayInitTraverser separateInit;
+    root->traverse(&separateInit);
+    return separateInit.updateTree(compiler, root);
+}
+
+SeparateArrayInitTraverser::SeparateArrayInitTraverser() : TIntermTraverser(true, false, false) {}
+
+bool SeparateArrayInitTraverser::visitDeclaration(Visit, TIntermDeclaration *node)
+{
+    TIntermSequence *sequence = node->getSequence();
+    TIntermBinary *initNode   = sequence->back()->getAsBinaryNode();
+    if (initNode != nullptr && initNode->getOp() == EOpInitialize)
+    {
+        TIntermTyped *initializer = initNode->getRight();
+        if (initializer->isArray() && !initializer->hasConstantValue())
+        {
+            // We rely on that array declarations have been isolated to single declarations.
+            ASSERT(sequence->size() == 1);
+            TIntermTyped *symbol      = initNode->getLeft();
+            TIntermBlock *parentBlock = getParentNode()->getAsBlock();
+            ASSERT(parentBlock != nullptr);
+
+            TIntermSequence replacements;
+
+            TIntermDeclaration *replacementDeclaration = new TIntermDeclaration();
+            replacementDeclaration->appendDeclarator(symbol);
+            replacementDeclaration->setLine(symbol->getLine());
+            replacements.push_back(replacementDeclaration);
+
+            TIntermBinary *replacementAssignment =
+                new TIntermBinary(EOpAssign, symbol, initializer);
+            replacementAssignment->setLine(symbol->getLine());
+            replacements.push_back(replacementAssignment);
+
+            mMultiReplacements.emplace_back(parentBlock, node, std::move(replacements));
+        }
+    }
+    return false;
+}
+
+}  // namespace
+
+bool SeparateArrayInitialization(TCompiler *compiler, TIntermNode *root)
+{
+    return SeparateArrayInitTraverser::apply(compiler, root);
+}
+
+}  // namespace sh