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-rwxr-xr-xgfx/angle/src/compiler/translator/PruneEmptyDeclarations.cpp113
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diff --git a/gfx/angle/src/compiler/translator/PruneEmptyDeclarations.cpp b/gfx/angle/src/compiler/translator/PruneEmptyDeclarations.cpp
new file mode 100755
index 000000000..7ec434796
--- /dev/null
+++ b/gfx/angle/src/compiler/translator/PruneEmptyDeclarations.cpp
@@ -0,0 +1,113 @@
+//
+// Copyright (c) 2002-2015 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 PruneEmptyDeclarations function prunes unnecessary empty declarations and declarators from the AST.
+
+#include "compiler/translator/PruneEmptyDeclarations.h"
+
+#include "compiler/translator/IntermNode.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class PruneEmptyDeclarationsTraverser : private TIntermTraverser
+{
+ public:
+ static void apply(TIntermNode *root);
+ private:
+ PruneEmptyDeclarationsTraverser();
+ bool visitDeclaration(Visit, TIntermDeclaration *node) override;
+};
+
+void PruneEmptyDeclarationsTraverser::apply(TIntermNode *root)
+{
+ PruneEmptyDeclarationsTraverser prune;
+ root->traverse(&prune);
+ prune.updateTree();
+}
+
+PruneEmptyDeclarationsTraverser::PruneEmptyDeclarationsTraverser()
+ : TIntermTraverser(true, false, false)
+{
+}
+
+bool PruneEmptyDeclarationsTraverser::visitDeclaration(Visit, TIntermDeclaration *node)
+{
+ TIntermSequence *sequence = node->getSequence();
+ if (sequence->size() >= 1)
+ {
+ TIntermSymbol *sym = sequence->front()->getAsSymbolNode();
+ // Prune declarations without a variable name, unless it's an interface block declaration.
+ if (sym != nullptr && sym->getSymbol() == "" && !sym->isInterfaceBlock())
+ {
+ if (sequence->size() > 1)
+ {
+ // Generate a replacement that will remove the empty declarator in the beginning of
+ // a declarator list. Example of a declaration that will be changed:
+ // float, a;
+ // will be changed to
+ // float a;
+ // This applies also to struct declarations.
+ TIntermSequence emptyReplacement;
+ mMultiReplacements.push_back(
+ NodeReplaceWithMultipleEntry(node, sym, emptyReplacement));
+ }
+ else if (sym->getBasicType() != EbtStruct)
+ {
+ // Single struct declarations may just declare the struct type and no variables, so
+ // they should not be pruned. All other single empty declarations can be pruned
+ // entirely. Example of an empty declaration that will be pruned:
+ // float;
+ TIntermSequence emptyReplacement;
+ TIntermBlock *parentAsBlock = getParentNode()->getAsBlock();
+ // The declaration may be inside a block or in a loop init expression.
+ ASSERT(parentAsBlock != nullptr || getParentNode()->getAsLoopNode() != nullptr);
+ if (parentAsBlock)
+ {
+ mMultiReplacements.push_back(
+ NodeReplaceWithMultipleEntry(parentAsBlock, node, emptyReplacement));
+ }
+ else
+ {
+ queueReplacement(node, nullptr, OriginalNode::IS_DROPPED);
+ }
+ }
+ else if (sym->getType().getQualifier() != EvqGlobal &&
+ sym->getType().getQualifier() != EvqTemporary)
+ {
+ // We've hit an empty struct declaration with a qualifier, for example like
+ // this:
+ // const struct a { int i; };
+ // NVIDIA GL driver version 367.27 doesn't accept this kind of declarations, so
+ // we convert the declaration to a regular struct declaration. This is okay,
+ // since ESSL 1.00 spec section 4.1.8 says about structs that "The optional
+ // qualifiers only apply to any declarators, and are not part of the type being
+ // defined for name."
+
+ if (mInGlobalScope)
+ {
+ sym->getTypePointer()->setQualifier(EvqGlobal);
+ }
+ else
+ {
+ sym->getTypePointer()->setQualifier(EvqTemporary);
+ }
+ }
+ }
+ }
+ return false;
+}
+
+} // namespace
+
+void PruneEmptyDeclarations(TIntermNode *root)
+{
+ PruneEmptyDeclarationsTraverser::apply(root);
+}
+
+} // namespace sh