tech.ydb.shaded.checkerframework.checker.index.qual.EnsuresLTLengthOf Maven / Gradle / Ivy
package org.checkerframework.checker.index.qual;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.checkerframework.framework.qual.InheritedAnnotation;
import org.checkerframework.framework.qual.JavaExpression;
import org.checkerframework.framework.qual.PostconditionAnnotation;
import org.checkerframework.framework.qual.QualifierArgument;
/**
* Indicates that the value expressions evaluate to an integer whose value is less than the lengths
* of all the given sequences, if the method terminates successfully.
*
* Consider the following example, from the Index Checker's regression tests:
*
*
* {@code @EnsuresLTLengthOf(value = "end", targetValue = "array", offset = "#1 - 1")
* public void shiftIndex(@NonNegative int x) {
* int newEnd = end - x;
* if (newEnd < 0) throw new RuntimeException();
* end = newEnd;
* }
* }
*
*
* where {@code end} is annotated as {@code @NonNegative @LTEqLengthOf("array") int end;}
*
* This method guarantees that {@code end} has type {@code @LTLengthOf(value="array", offset="x -
* 1")} after the method returns. This is useful in cases like this one:
*
*
{@code
* public void useShiftIndex(@NonNegative int x) {
* // :: error: (argument)
* Arrays.fill(array, end, end + x, null);
* shiftIndex(x);
* Arrays.fill(array, end, end + x, null);
* }
* }
*
* The first call to {@code Arrays.fill} is rejected (hence the comment about an error). But, after
* calling {@code shiftIndex(x)}, {@code end} has an annotation that allows the {@code end + x} to
* be accepted as {@code @LTLengthOf("array")}.
*
* @see EnsuresLTLengthOfIf
* @see LTLengthOf
* @checker_framework.manual #index-checker Index Checker
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.CONSTRUCTOR})
@PostconditionAnnotation(qualifier = LTLengthOf.class)
@InheritedAnnotation
@Repeatable(EnsuresLTLengthOf.List.class)
public @interface EnsuresLTLengthOf {
/**
* The Java expressions that are less than the length of the given sequences on successful method
* termination.
*
* @checker_framework.manual #java-expressions-as-arguments Syntax of Java expressions
*/
@JavaExpression
String[] value();
/**
* Sequences, each of which is longer than the each of the expressions' value on successful method
* termination.
*/
@JavaExpression
@QualifierArgument("value")
String[] targetValue();
/**
* This expression plus each of the value expressions is less than the length of the sequence on
* successful method termination. The {@code offset} element must ether be empty or the same
* length as {@code targetValue}.
*
* @return the offset expressions
*/
@JavaExpression
@QualifierArgument("offset")
String[] offset() default {};
/**
* A wrapper annotation that makes the {@link EnsuresLTLengthOf} annotation repeatable.
*
* Programmers generally do not need to write this. It is created by Java when a programmer
* writes more than one {@link EnsuresLTLengthOf} annotation at the same location.
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.CONSTRUCTOR})
@PostconditionAnnotation(qualifier = LTLengthOf.class)
@InheritedAnnotation
public static @interface List {
/**
* Return the repeatable annotations.
*
* @return the repeatable annotations
*/
EnsuresLTLengthOf[] value();
}
}