1 files changed, 94 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/HashNames.cpp b/gfx/angle/checkout/src/compiler/translator/HashNames.cpp
new file mode 100644
index 0000000000..6994c10afa
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/HashNames.cpp
@@ -0,0 +1,94 @@
+//
+// Copyright (c) 2017 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/HashNames.h"
+
+#include "compiler/translator/ImmutableString.h"
+#include "compiler/translator/ImmutableStringBuilder.h"
+#include "compiler/translator/IntermNode.h"
+#include "compiler/translator/Symbol.h"
+
+namespace sh
+{
+
+namespace
+{
+constexpr const ImmutableString kHashedNamePrefix("webgl_");
+
+// Can't prefix with just _ because then we might introduce a double underscore, which is not safe
+// in GLSL (ESSL 3.00.6 section 3.8: All identifiers containing a double underscore are reserved for
+// use by the underlying implementation). u is short for user-defined.
+constexpr const ImmutableString kUnhashedNamePrefix("_u");
+
+ImmutableString HashName(const ImmutableString &name, ShHashFunction64 hashFunction)
+{
+    ASSERT(!name.empty());
+    ASSERT(hashFunction);
+    khronos_uint64_t number = (*hashFunction)(name.data(), name.length());
+
+    // Build the hashed name in place.
+    static const unsigned int kHexStrMaxLength = sizeof(number) * 2;
+    static const size_t kHashedNameMaxLength   = kHashedNamePrefix.length() + kHexStrMaxLength;
+
+    ImmutableStringBuilder hashedName(kHashedNameMaxLength);
+    hashedName << kHashedNamePrefix;
+
+    hashedName.appendHex(number);
+
+    return hashedName;
+}
+
+}  // anonymous namespace
+
+ImmutableString HashName(const ImmutableString &name,
+                         ShHashFunction64 hashFunction,
+                         NameMap *nameMap)
+{
+    if (hashFunction == nullptr)
+    {
+        if (name.length() + kUnhashedNamePrefix.length() > kESSLMaxIdentifierLength)
+        {
+            // If the identifier length is already close to the limit, we can't prefix it. This is
+            // not a problem since there are no builtins or ANGLE's internal variables that would
+            // have as long names and could conflict.
+            return name;
+        }
+        ImmutableStringBuilder prefixedName(kUnhashedNamePrefix.length() + name.length());
+        prefixedName << kUnhashedNamePrefix << name;
+        return prefixedName;
+    }
+    if (nameMap)
+    {
+        NameMap::const_iterator it = nameMap->find(name.data());
+        if (it != nameMap->end())
+        {
+            // TODO(oetuaho): Would be nice if we didn't need to allocate a string here.
+            return ImmutableString(it->second);
+        }
+    }
+    ImmutableString hashedName = HashName(name, hashFunction);
+    if (nameMap)
+    {
+        (*nameMap)[name.data()] = hashedName.data();
+    }
+    return hashedName;
+}
+
+ImmutableString HashName(const TSymbol *symbol, ShHashFunction64 hashFunction, NameMap *nameMap)
+{
+    if (symbol->symbolType() == SymbolType::Empty)
+    {
+        return kEmptyImmutableString;
+    }
+    if (symbol->symbolType() == SymbolType::AngleInternal ||
+        symbol->symbolType() == SymbolType::BuiltIn)
+    {
+        return symbol->name();
+    }
+    return HashName(symbol->name(), hashFunction, nameMap);
+}
+
+}  // namespace sh