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 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
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 * 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
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 * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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package com.oracle.truffle.llvm.runtime.nodes.func;

import com.oracle.truffle.api.CompilerAsserts;
import com.oracle.truffle.api.CompilerDirectives;
import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import com.oracle.truffle.api.TruffleLanguage.ContextReference;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.CachedContext;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.interop.InteropLibrary;
import com.oracle.truffle.api.library.CachedLibrary;
import com.oracle.truffle.api.nodes.ExplodeLoop;
import com.oracle.truffle.api.source.Source;
import com.oracle.truffle.llvm.runtime.ContextExtension;
import com.oracle.truffle.llvm.runtime.LLVMContext;
import com.oracle.truffle.llvm.runtime.LLVMLanguage;
import com.oracle.truffle.llvm.runtime.NativeContextExtension;
import com.oracle.truffle.llvm.runtime.except.LLVMNativePointerException;
import com.oracle.truffle.llvm.runtime.interop.nfi.LLVMNativeConvertNode;
import com.oracle.truffle.llvm.runtime.nodes.api.LLVMNode;
import com.oracle.truffle.llvm.runtime.pointer.LLVMNativePointer;
import com.oracle.truffle.llvm.runtime.types.FunctionType;

public abstract class LLVMNativeDispatchNode extends LLVMNode {

    private final FunctionType type;
    private final Source signatureSource;

    @CompilationFinal private ContextExtension.Key<NativeContextExtension> nativeCtxExtKey;

    protected LLVMNativeDispatchNode(FunctionType type, Source signatureSource) {
        this.type = type;
        this.signatureSource = signatureSource;
    }

    public abstract Object executeDispatch(Object function, Object[] arguments);

    NativeContextExtension getNativeCtxExt(ContextReference<LLVMContext> ctxRef) {
        if (nativeCtxExtKey == null) {
            CompilerDirectives.transferToInterpreterAndInvalidate();
            nativeCtxExtKey = ctxRef.get().getLanguage().lookupContextExtension(NativeContextExtension.class);
        }
        return nativeCtxExtKey.get(ctxRef.get());
    }

    @TruffleBoundary
    protected Object bindSignature(NativeContextExtension ctxExt, long pointer) {
        return ctxExt.bindSignature(pointer, signatureSource);
    }

    @ExplodeLoop
    protected LLVMNativeConvertNode[] createToNativeNodes() {
        LLVMNativeConvertNode[] ret = new LLVMNativeConvertNode[type.getNumberOfArguments() - LLVMCallNode.USER_ARGUMENT_OFFSET];
        for (int i = LLVMCallNode.USER_ARGUMENT_OFFSET; i < type.getNumberOfArguments(); i++) {
            ret[i - LLVMCallNode.USER_ARGUMENT_OFFSET] = LLVMNativeConvertNode.createToNative(type.getArgumentType(i));
        }
        return ret;
    }

    protected LLVMNativeConvertNode createFromNativeNode() {
        CompilerAsserts.neverPartOfCompilation();
        return LLVMNativeConvertNode.createFromNative(type.getReturnType());
    }

    @ExplodeLoop
    private static Object[] prepareNativeArguments(Object[] arguments, LLVMNativeConvertNode[] toNative) {
        Object[] nativeArgs = new Object[arguments.length - LLVMCallNode.USER_ARGUMENT_OFFSET];
        for (int i = LLVMCallNode.USER_ARGUMENT_OFFSET; i < arguments.length; i++) {
            nativeArgs[i - LLVMCallNode.USER_ARGUMENT_OFFSET] = toNative[i - LLVMCallNode.USER_ARGUMENT_OFFSET].executeConvert(arguments[i]);
        }
        return nativeArgs;
    }

    
Params:
function – 
See Also:
executeDispatch(Object, Object[])/**
     * @param function
     * @see #executeDispatch(Object, Object[])
     */
    @Specialization(guards = {"function.asNative() == cachedFunction.asNative()", "!cachedFunction.isNull()"}, assumptions = "singleContextAssumption()")
    protected Object doCached(LLVMNativePointer function, Object[] arguments,
                    @CachedContext(LLVMLanguage.class) ContextReference<LLVMContext> context,
                    @Cached("function") @SuppressWarnings("unused") LLVMNativePointer cachedFunction,
                    @Cached("bindSignature(getNativeCtxExt(context), cachedFunction.asNative())") Object nativeFunctionHandle,
                    @CachedLibrary("nativeFunctionHandle") InteropLibrary nativeCall,
                    @Cached("createToNativeNodes()") LLVMNativeConvertNode[] toNative,
                    @Cached("createFromNativeNode()") LLVMNativeConvertNode fromNative,
                    @Cached("nativeCallStatisticsEnabled(context)") boolean statistics) {
        Object[] nativeArgs = prepareNativeArguments(arguments, toNative);
        Object returnValue;
        returnValue = LLVMNativeCallUtils.callNativeFunction(statistics, context, nativeCall, nativeFunctionHandle, nativeArgs, null);
        return fromNative.executeConvert(returnValue);
    }

    @Specialization(replaces = "doCached", guards = "!function.isNull()")
    protected Object doGeneric(LLVMNativePointer function, Object[] arguments,
                    @CachedContext(LLVMLanguage.class) ContextReference<LLVMContext> context,
                    @Cached("createToNativeNodes()") LLVMNativeConvertNode[] toNative,
                    @Cached("createFromNativeNode()") LLVMNativeConvertNode fromNative,
                    @CachedLibrary(limit = "5") InteropLibrary nativeCall,
                    @Cached("nativeCallStatisticsEnabled(context)") boolean statistics) {
        Object[] nativeArgs = prepareNativeArguments(arguments, toNative);
        Object returnValue;
        Object bound = bindSignature(getNativeCtxExt(context), function.asNative());
        returnValue = LLVMNativeCallUtils.callNativeFunction(statistics, context, nativeCall, bound, nativeArgs, null);
        return fromNative.executeConvert(returnValue);
    }

    @Specialization(guards = "function.isNull()")
    protected Object doNull(@SuppressWarnings("unused") LLVMNativePointer function, @SuppressWarnings("unused") Object[] arguments) {
        throw new LLVMNativePointerException(this, "Invalid native function pointer", null);
    }
}