Java Type.isEquivalentTo方法代码示例

import jdk.nashorn.internal.codegen.types.Type; //导入方法依赖的package包/类
boolean matchesCallSite(final MethodType other, final boolean pickVarArg) {
    if (other.equals(this.callSiteType)) {
        return true;
    }
    final MethodType type  = type();
    final int fnParamCount = getParamCount(type);
    final boolean isVarArg = fnParamCount == Integer.MAX_VALUE;
    if (isVarArg) {
        return pickVarArg;
    }

    final int csParamCount = getParamCount(other);
    final boolean csIsVarArg = csParamCount == Integer.MAX_VALUE;
    final int thisThisIndex = needsCallee() ? 1 : 0; // Index of "this" parameter in this function's type

    final int fnParamCountNoCallee = fnParamCount - thisThisIndex;
    final int minParams = Math.min(csParamCount - 1, fnParamCountNoCallee); // callSiteType always has callee, so subtract 1
    // We must match all incoming parameters, except "this". Starting from 1 to skip "this".
    for(int i = 1; i < minParams; ++i) {
        final Type fnType = Type.typeFor(type.parameterType(i + thisThisIndex));
        final Type csType = csIsVarArg ? Type.OBJECT : Type.typeFor(other.parameterType(i + 1));
        if(!fnType.isEquivalentTo(csType)) {
            return false;
        }
    }

    // Must match any undefined parameters to Object type.
    for(int i = minParams; i < fnParamCountNoCallee; ++i) {
        if(!Type.typeFor(type.parameterType(i + thisThisIndex)).isEquivalentTo(Type.OBJECT)) {
            return false;
        }
    }

    return true;
}
 

import jdk.nashorn.internal.codegen.types.Type; //导入方法依赖的package包/类
/**
 * Pop element from stack, convert to given type
 *
 * @param to type to convert to
 *
 * @return the method emitter
 */
MethodEmitter convert(final Type to) {
    final Type from = peekType();
    final Type type = from.convert(method, to);
    if (type != null) {
        if (!from.isEquivalentTo(to)) {
            debug("convert", from, "->", to);
        }
        if (type != from) {
            final int l0 = stack.getTopLocalLoad();
            popType();
            pushType(type);
            // NOTE: conversions from a primitive type are considered to preserve the "load" property of the value
            // on the stack. Otherwise we could introduce temporary locals in a deoptimized rest-of (e.g. doing an
            // "i < x.length" where "i" is int and ".length" gets deoptimized to long would end up converting i to
            // long with "ILOAD i; I2L; LSTORE tmp; LLOAD tmp;"). Such additional temporary would cause an error
            // when restoring the state of the function for rest-of execution, as the not-yet deoptimized variant
            // would have the (now invalidated) assumption that "x.length" is an int, so it wouldn't have the I2L,
            // and therefore neither the subsequent LSTORE tmp; LLOAD tmp;. By making sure conversions from a
            // primitive type don't erase the "load" information, we don't introduce temporaries in the deoptimized
            // rest-of that didn't exist in the more optimistic version that triggered the deoptimization.
            // NOTE: as a more general observation, we could theoretically track the operations required to
            // reproduce any stack value as long as they are all local loads, constant loads, and stack operations.
            // We won't go there in the current system
            if(!from.isObject()) {
                stack.markLocalLoad(l0);
            }
        }
    }
    return this;
}
 

import jdk.nashorn.internal.codegen.types.Type; //导入方法依赖的package包/类
boolean matchesCallSite(final MethodType other, final boolean pickVarArg) {
    if (other.equals(this.callSiteType)) {
        return true;
    }
    final MethodType type  = type();
    final int fnParamCount = getParamCount(type);
    final boolean isVarArg = fnParamCount == Integer.MAX_VALUE;
    if (isVarArg) {
        return pickVarArg;
    }

    final int csParamCount = getParamCount(other);
    final boolean csIsVarArg = csParamCount == Integer.MAX_VALUE;
    final int thisThisIndex = needsCallee() ? 1 : 0; // Index of "this" parameter in this function's type

    final int fnParamCountNoCallee = fnParamCount - thisThisIndex;
    final int minParams = Math.min(csParamCount - 1, fnParamCountNoCallee); // callSiteType always has callee, so subtract 1
    // We must match all incoming parameters, including "this". "this" will usually be Object, but there
    // are exceptions, e.g. when calling functions with primitive "this" in strict mode or through call/apply.
    for(int i = 0; i < minParams; ++i) {
        final Type fnType = Type.typeFor(type.parameterType(i + thisThisIndex));
        final Type csType = csIsVarArg ? Type.OBJECT : Type.typeFor(other.parameterType(i + 1));
        if(!fnType.isEquivalentTo(csType)) {
            return false;
        }
    }

    // Must match any undefined parameters to Object type.
    for(int i = minParams; i < fnParamCountNoCallee; ++i) {
        if(!Type.typeFor(type.parameterType(i + thisThisIndex)).isEquivalentTo(Type.OBJECT)) {
            return false;
        }
    }

    return true;
}