org.graalvm.nativeimage.c.struct.CField Maven / Gradle / Ivy
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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
* data (collectively the "Software"), free of charge and under any and all
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* unmodified Software as contributed to or provided by such licensor, or (ii)
* the Larger Works (as defined below), to deal in both
*
* (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
* is contributed by such licensors),
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* Software and the Larger Work(s), and to sublicense the foregoing rights on
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package org.graalvm.nativeimage.c.struct;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.graalvm.word.LocationIdentity;
import org.graalvm.word.WordBase;
/**
* Denotes a method as a field access of a {@link CStruct C struct}.
*
* If the method has a non-void return type, it is a get-method of the field. Calls of the method
* are replaced with a memory read. The possible signatures are
* {@code FieldType getFieldName([IntType index], [LocationIdentity locationIdentity]);}
*
* If the method has the return type void, it is a set-method of the field. Calls of the method are
* replaced with a memory write. The possible signatures are
* {@code void setFieldName([IntType index], FieldType value, [LocationIdentity locationIdentity]);}
*
* The receiver is the pointer to the struct that is accessed, i.e., the base address of the memory
* access.
*
* The {@code FieldType} must be the Java-equivalent of the C type used in the C struct. The
* additional annotations {@link AllowNarrowingCast} or {@link AllowWideningCast} can be used to
* relax the strict type requirements.
*
* The optional parameter {@code index} (always the first parameter when it is present) denotes an
* index, i.e., the receiver is treated as an array of the struct. The type must be a primitive
* integer type or a {@link WordBase word type}. Address arithmetic is used to scale the index with
* the size of the struct.
*
* The optional parameter {@code locationIdentity} specifies the {@link LocationIdentity} to be used
* for the memory access. Two memory accesses with two different location identities are guaranteed
* to not alias. The parameter cannot be used together with the {@link UniqueLocationIdentity}
* annotation, which is another way of providing a location identity for the memory access.
*
* Multiple accessor methods, with different signatures according to the rules of allowed
* signatures, are allowed for a single field.
*
* @since 19.0
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
public @interface CField {
/**
* Specifies the field name inside the {@link CStruct C struct}. If no name is provided, the
* method name is used as the field name. A possible "get" or "set" prefix of the method name is
* removed.
*
* @since 19.0
*/
String value() default "";
}