oracle/graal · error · IllegalArgumentException

illegal call to maxValue on

Error message

illegal call to maxValue on 

What it means

JavaKind.getMaxValue is the counterpart of getMinValue: it returns the maximum bit-pattern value for Boolean..Double only. Invoking it on Void, Illegal, or Object throws IllegalArgumentException 'illegal call to maxValue on <kind>'.

Source

Thrown at espresso-shared/src/com.oracle.truffle.espresso.classfile/src/com/oracle/truffle/espresso/classfile/JavaKind.java:370

        switch (this) {
            case Boolean:
                return 1;
            case Byte:
                return java.lang.Byte.MAX_VALUE;
            case Char:
                return java.lang.Character.MAX_VALUE;
            case Short:
                return java.lang.Short.MAX_VALUE;
            case Int:
                return java.lang.Integer.MAX_VALUE;
            case Long:
                return java.lang.Long.MAX_VALUE;
            case Float:
                return java.lang.Float.floatToRawIntBits(java.lang.Float.MAX_VALUE);
            case Double:
                return java.lang.Double.doubleToRawLongBits(java.lang.Double.MAX_VALUE);
            default:
                throw new IllegalArgumentException("illegal call to maxValue on " + this);
        }
    }

    /**
     * Number of bytes that are necessary to represent a value of this kind.
     *
     * @return the number of bytes
     */
    public int getByteCount() {
        if (this == Boolean) {
            return 1;
        } else {
            return getBitCount() >> 3;
        }
    }

    /**
     * Number of bits that are necessary to represent a value of this kind.

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Filter non-numeric kinds first: only call getMaxValue() when kind.isPrimitive() && kind != JavaKind.Void
2. Add an explicit default branch in your switch for Object/Void/Illegal instead of falling through

Example fix

// before
long max = kind.getMaxValue(); // crashes for Object/Void/Illegal

// after
if (kind.isPrimitive() && kind != JavaKind.Void) {
    long max = kind.getMaxValue();
}

if (!kind.isPrimitive() || kind == JavaKind.Void) throw new IllegalArgumentException("no maxValue for " + kind);

static boolean hasMinMax(JavaKind k) { return k.isPrimitive() && k != JavaKind.Void; }

When it happens

Trigger: Calling kind.getMaxValue() on JavaKind.Object, JavaKind.Void, or JavaKind.Illegal, usually from generic range-analysis, interval, or test-harness code that walks every JavaKind constant.

Common situations: Range/bounds logic shared across all kinds; generated exhaustive switch over JavaKind.values(); refactoring code that previously only received primitive kinds.

Related errors

• illegal call to minValue on
• illegal call to bits on
• Expected value kind {} but got {}
• Bad argument kind at index {}: expected Boolean, got {}
• Bad argument kind at index {}: expected Byte, got {}

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/9c5559cf1b0b8bd7. Report an issue: GitHub.