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 * The Universal Permissive License (UPL), Version 1.0
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 * person obtaining a copy of this software, associated documentation and/or
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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
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 * without restriction, including without limitation the rights to copy, create
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
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 * This license is subject to the following condition:
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 * portions of the Software.
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package org.graalvm.wasm.nodes;

import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
import com.oracle.truffle.api.frame.VirtualFrame;
import com.oracle.truffle.api.nodes.Node;
import org.graalvm.wasm.WasmCodeEntry;
import org.graalvm.wasm.WasmContext;
import org.graalvm.wasm.WasmInstance;

public abstract class WasmNode extends Node implements WasmNodeInterface {
    // TODO: We should not cache the instance in the nodes, only the symbol table.
    private final WasmInstance wasmInstance;
    private final WasmCodeEntry codeEntry;

    
The length (in bytes) of the control structure in the instructions stream, without the
initial opcode and the block return type.
/**
     * The length (in bytes) of the control structure in the instructions stream, without the
     * initial opcode and the block return type.
     */
    @CompilationFinal private int byteLength;

    public WasmNode(WasmInstance wasmInstance, WasmCodeEntry codeEntry, int byteLength) {
        this.wasmInstance = wasmInstance;
        this.codeEntry = codeEntry;
        this.byteLength = byteLength;
    }

    
Execute the current node within the given frame and return the branch target.
Params:
frame – The frame to use for execution.
stacklocals – The local combined variable and operand-stack array, used for execution.
Returns:
The return value of this method indicates whether a branch is to be executed, in case
        of nested blocks. An offset with value -1 means no branch, whereas a return value n
        greater than or equal to 0 means that the execution engine has to branch n levels up
        the block execution stack./**
     * Execute the current node within the given frame and return the branch target.
     *
     * @param frame The frame to use for execution.
     * @param stacklocals The local combined variable and operand-stack array, used for execution.
     * @return The return value of this method indicates whether a branch is to be executed, in case
     *         of nested blocks. An offset with value -1 means no branch, whereas a return value n
     *         greater than or equal to 0 means that the execution engine has to branch n levels up
     *         the block execution stack.
     */
    public abstract int execute(WasmContext context, VirtualFrame frame, long[] stacklocals);

    public abstract byte returnTypeId();

    @SuppressWarnings("hiding")
    protected final void initialize(int byteLength) {
        this.byteLength = byteLength;
    }

    
Number of parameters that this block takes.
As of WebAssembly 1.0, this is always 0. The multi-values feature merged in WebAssembly 1.1
lifts this restriction.
Returns:
0/**
     * Number of parameters that this block takes.
     *
     * As of WebAssembly 1.0, this is always 0. The multi-values feature merged in WebAssembly 1.1
     * lifts this restriction.
     *
     * @return 0
     */
    @SuppressWarnings("unused")
    public int inputLength() {
        return 0;
    }

    public int returnLength() {
        switch (returnTypeId()) {
            case 0x00:
            case 0x40:
                return 0;
            default:
                return 1;
        }
    }

    @Override
    public final WasmCodeEntry codeEntry() {
        return codeEntry;
    }

    public final WasmInstance instance() {
        return wasmInstance;
    }

    int byteLength() {
        return byteLength;
    }

    abstract int intConstantLength();

    abstract int branchTableLength();

    abstract int profileCount();

}