1 files changed, 157 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wasm/WasmSignature.cpp b/Source/JavaScriptCore/wasm/WasmSignature.cpp
new file mode 100644
index 000000000..0966dab51
--- /dev/null
+++ b/Source/JavaScriptCore/wasm/WasmSignature.cpp
@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "WasmSignature.h"
+
+#if ENABLE(WEBASSEMBLY)
+
+#include "VM.h"
+#include <wtf/FastMalloc.h>
+#include <wtf/HashFunctions.h>
+#include <wtf/PrintStream.h>
+
+namespace JSC { namespace Wasm {
+
+namespace {
+const bool verbose = false;
+}
+
+const constexpr SignatureIndex Signature::invalidIndex;
+
+String Signature::toString() const
+{
+    String result(makeString(returnType()));
+    result.append(" (");
+    for (SignatureArgCount arg = 0; arg < argumentCount(); ++arg) {
+        if (arg)
+            result.append(", ");
+        result.append(makeString(argument(arg)));
+    }
+    result.append(')');
+    return result;
+}
+
+void Signature::dump(PrintStream& out) const
+{
+    out.print(toString());
+}
+
+unsigned Signature::hash() const
+{
+    uint32_t sizeToHash = allocatedSize(argumentCount()) / sizeof(allocationSizeRoundsUpTo);
+    // Assumes over-allocated memory was zero-initialized, and rounded-up to allocationSizeRoundsUpTo so that a wider hash can be performed.
+    ASSERT(sizeToHash * sizeof(allocationSizeRoundsUpTo) == allocatedSize(argumentCount()));
+    unsigned accumulator = 0xa1bcedd8u;
+    const auto* pos = reinterpret_cast<const allocationSizeRoundsUpTo*>(this);
+    for (uint32_t i = 0; i < sizeToHash; ++i)
+        accumulator = WTF::pairIntHash(accumulator, WTF::IntHash<allocationSizeRoundsUpTo>::hash(*pos));
+    return accumulator;
+}
+
+Signature* Signature::create(SignatureArgCount argumentCount)
+{
+    // Hashing relies on allocation zero-initializing trailing elements.
+    auto allocated = tryFastCalloc(allocatedSize(argumentCount), 1);
+    Signature* signature;
+    if (!allocated.getValue(signature))
+        return nullptr;
+    new (signature) Signature(argumentCount);
+    return signature;
+}
+
+Signature* Signature::createInvalid()
+{
+    Signature* signature = create(0);
+    RELEASE_ASSERT(signature);
+    new (signature) Signature(std::numeric_limits<SignatureArgCount>::max());
+    return signature;
+}
+
+void Signature::destroy(Signature* signature)
+{
+    fastFree(signature);
+}
+
+SignatureInformation::~SignatureInformation()
+{
+    for (size_t i = 0; i < m_signatures.size(); ++i)
+        Signature::destroy(m_signatures[i]);
+}
+
+SignatureInformation::SignatureInformation()
+{
+    // The zeroth entry is an invalid signature, to match invalidIndex.
+    ASSERT(!Signature::invalidIndex);
+    Signature* invalidSignature = Signature::createInvalid();
+    auto addResult = m_signatureMap.add(SignatureHash { invalidSignature }, Signature::invalidIndex);
+    RELEASE_ASSERT(addResult.isNewEntry);
+    ASSERT(Signature::invalidIndex == addResult.iterator->value);
+    m_signatures.append(invalidSignature);
+}
+
+SignatureInformation* SignatureInformation::get(VM* vm)
+{
+    std::call_once(vm->m_wasmSignatureInformationOnceFlag, [vm] {
+        vm->m_wasmSignatureInformation = std::unique_ptr<SignatureInformation>(new SignatureInformation());
+    });
+    return vm->m_wasmSignatureInformation.get();
+}
+
+SignatureIndex SignatureInformation::adopt(VM* vm, Signature* signature)
+{
+    SignatureInformation* info = get(vm);
+    LockHolder lock(info->m_lock);
+
+    SignatureIndex nextValue = info->m_signatures.size();
+    auto addResult = info->m_signatureMap.add(SignatureHash { signature }, nextValue);
+    if (addResult.isNewEntry) {
+        ASSERT(nextValue == addResult.iterator->value);
+        if (verbose)
+            dataLogLn("Adopt new signature ", *signature, " with index ", addResult.iterator->value, " hash: ", signature->hash());
+        info->m_signatures.append(signature);
+        return nextValue;
+    }
+    if (verbose)
+        dataLogLn("Existing signature ", *signature, " with index ", addResult.iterator->value, " hash: ", signature->hash());
+    Signature::destroy(signature);
+    ASSERT(addResult.iterator->value != Signature::invalidIndex);
+    return addResult.iterator->value;
+}
+
+const Signature* SignatureInformation::get(VM* vm, SignatureIndex index)
+{
+    ASSERT(index != Signature::invalidIndex);
+    SignatureInformation* info = get(vm);
+    LockHolder lock(info->m_lock);
+
+    if (verbose)
+        dataLogLn("Got signature ", *info->m_signatures.at(index), " at index ", index);
+    return info->m_signatures.at(index);
+}
+
+} } // namespace JSC::Wasm
+
+#endif // ENABLE(WEBASSEMBLY)