checker.src.org.checkerframework.checker.nullness.qual.NonNull Maven / Gradle / Ivy

package org.checkerframework.checker.nullness.qual;

import org.checkerframework.checker.initialization.InitializationChecker;
import org.checkerframework.checker.nullness.AbstractNullnessChecker;
import org.checkerframework.framework.qual.DefaultFor;
import org.checkerframework.framework.qual.DefaultInUncheckedCodeFor;
import org.checkerframework.framework.qual.DefaultQualifierInHierarchy;
import org.checkerframework.framework.qual.ImplicitFor;
import org.checkerframework.framework.qual.LiteralKind;
import org.checkerframework.framework.qual.SubtypeOf;
import org.checkerframework.framework.qual.TypeUseLocation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import javax.lang.model.type.TypeKind;

/**
 * {@link NonNull} is a type annotation that indicates that an expression is
 * never {@code null}.
 *
 * 
 * For fields of a class, the {@link NonNull} annotation indicates that this
 * field is never {@code null}
 * after the class has been fully initialized. Class initialization is
 * controlled by the Freedom Before Commitment type system, see
 * {@link InitializationChecker} for more details.
 *
 * 

 * For static fields, the {@link NonNull} annotation indicates that this field
 * is never {@code null} after the containing class is initialized.
 *
 * 

 * This annotation is rarely written in source code, because it is the default.
 *
 * 
 * This annotation is associated with the {@link AbstractNullnessChecker}.
 *
 * @see Nullable
 * @see MonotonicNonNull
 * @see AbstractNullnessChecker
 * @checker_framework.manual #nullness-checker Nullness Checker
 */
@SubtypeOf(MonotonicNonNull.class)
@ImplicitFor(types = { TypeKind.PACKAGE,
                       TypeKind.INT, TypeKind.BOOLEAN, TypeKind.CHAR,
                       TypeKind.DOUBLE, TypeKind.FLOAT, TypeKind.LONG,
                       TypeKind.SHORT, TypeKind.BYTE },
    // All literals except NULL_LITERAL:
    literals = { LiteralKind.STRING })
@DefaultQualifierInHierarchy
@DefaultFor({ TypeUseLocation.EXCEPTION_PARAMETER })
@DefaultInUncheckedCodeFor({ TypeUseLocation.PARAMETER, TypeUseLocation.LOWER_BOUND })
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE_USE, ElementType.TYPE_PARAMETER })
public @interface NonNull {
}