<td colspan="2"><b>Annotation Based Null Analysis</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a></b>)</td>

</tr>

<tr valign="top">

<td rowspan="2">This option controls whether the compiler will use null annotations for

  improved analysis of (potential) null references.

<p>When enabled, the compiler will interpret the annotation types defined using

  <a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a>

 and <a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NULLABLE_ANNOTATION_NAME">COMPILER_NULLABLE_ANNOTATION_NAME</a>

  as specifying whether or not a given type includes the value <code>null</code>.</p>

<p>The effect of these analyses is further controlled by the options

  <a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_NULL_SPECIFICATION_VIOLATION</a>,

  <a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION</a> and

  <a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO">COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO</a>.</p></td>

<td><b><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#ENABLED">ENABLED</a></b></td>

</tr>

<tr valign="top">

<td><b><i><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#DISABLED">DISABLED</a></i></b></td>

</tr>

<tr>

<tr>

<td colspan="2"><b>Name of Annotation Type for Non-Null Types</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a></b>)</td>

</tr>

<tr valign="top">

<td>This option defines a fully qualified Java type name that the compiler may use

	to perform special null analysis.

 <p>If the annotation specified by this option is applied to a type in a method

    signature or variable declaration, this will be interpreted as a specification

    that <code>null</code> is <b>not</b> a legal value in that position. Currently

    supported positions are: method parameters, method return type and local variables.</p>

 <p>For values declared with this annotation, the compiler will never trigger a null

    reference diagnostic (as controlled by <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_POTENTIAL_NULL_REFERENCE">COMPILER_PB_POTENTIAL_NULL_REFERENCE</a>

    and <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_REFERENCE">COMPILER_PB_NULL_REFERENCE</a>), because the assumption is made that null

    will never occur at runtime in these positions.</p>

 <p>The compiler may furthermore check adherence to the null specification as

    further controlled by <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_NULL_SPECIFICATION_VIOLATION</a>,

    <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION</a> and

    <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO">COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO</a>.</p>

 <p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td>The qualified name of a Java annotation type<br>

<b>Default is: <code>org.eclipse.jdt.annotation.NonNull</code></td>

</tr>

<tr>

<td colspan="2"><b>Name of Annotation Type for Nullable Types</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NULLABLE_ANNOTATION_NAME">COMPILER_NULLABLE_ANNOTATION_NAME</a></b>)</td>

</tr>

<tr valign="top">

<td>This option defines a fully qualified Java type name that the compiler may use

	to perform special null analysis.

 <p>If the annotation specified by this option is applied to a type in a method

    signature or variable declaration, this will be interpreted as a specification

    that <code>null</code> is a legal value in that position. Currently supported

    positions are: method parameters, method return type and local variables.</p>

 <p>If a value whose type

    is annotated with this annotation is dereferenced without checking for null,

    the compiler will trigger a diagnostic as further controlled by

    <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_POTENTIAL_NULL_REFERENCE>COMPILER_PB_POTENTIAL_NULL_REFERENCE</a>.</p>

 <p>The compiler may furthermore check adherence to the null specification as

    further controlled by <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_NULL_SPECIFICATION_VIOLATION</a>,

    <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION</a> and

    <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO">COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO</a>.</p>

 <p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td>The qualified name of a Java annotation type<br>

<b>Default is: <code>org.eclipse.jdt.annotation.Nullable</code></td>

</tr>

<tr>

<td colspan="2"><b>Name of Annotation Type to specify a nullness default for unannotated types.</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_BY_DEFAULT_ANNOTATION_NAME">COMPILER_NONNULL_BY_DEFAULT_ANNOTATION_NAME</a></b>)</td>

</tr>

<tr valign="top">

<td>This option defines a fully qualified Java type name that the compiler may use

   to perform special null analysis.

<p>If the annotation is applied without an argument, all unannotated types in method signatures

   within the annotated element will be treated as if they were specified with the non-null annotation

   (see <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a>).</p>

<p>If the annotation is applied with the constant <code>false</code> as its argument,

   all corresponding defaults at outer scopes will be canceled for the annotated element.

   This includes defaults specified using this annotation type or a default defined using

   the compiler option <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_IS_DEFAULT">COMPILER_NONNULL_IS_DEFAULT</a>.</p>

 <p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td>The qualified name of a Java annotatin type<br>

<b>Default is: <code>org.eclipse.jdt.annotation.NonNullByDefault</code></td>

</tr>

<tr>

<td colspan="2"><b>Globally specify non-null as the assumed default for unannotated types.</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_IS_DEFAULT">COMPILER_NONNULL_IS_DEFAULT</a></b>)</td>

</tr>

<tr valign="top">

<td rowspan="2">When enabled, this option globally achieves the same effect 

  as specifying <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a> does for individual elements.</p>

 <p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td><b><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#ENABLED">ENABLED</a></b></td>

</tr>

<tr valign="top">

<td><b><i><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#DISABLED">DISABLED</a></i></b></td>

</tr>

<tr>

<td colspan="2"><b>Reporting Insufficient Information for Analysing Adherence to Null Specifications</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO">COMPILER_PB_NULL_SPECIFICATION_INSUFFICIENT_INFO</a></b>)</td>

</tr>

<tr valign="top">

<td rowspan="3">When enabled, the compiler will issue an error or a warning whenever one of the

 following situations is detected:

 <ol>

 <li>A method declared with a nonnull annotation returns an expression for which

     insufficient nullness information is available for statically proving that no

     flow will pass a null value at runtime.</li>

 <li>An expression for which insufficient nullness information is available for

     statically proving that it will never evaluate to a null value at runtime

     is passed as an argument in a method call where the corresponding parameter of

     the called method is declared with a nonnull annotation.</li>

 <li>An expression for which insufficient nullness information is available for

     statically proving that it will never evaluate to a null value at runtime

     is assigned to a local variable that is declared with a nonnull annotation.</li>

 </ol>

 Insufficient nullness information is usually a consequence of using other unannotated

 variables or methods.

<p>The compiler options <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a> and

   <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NULLABLE_ANNOTATION_NAME">COMPILER_NULLABLE_ANNOTATION_NAME</a> control which annotations the compiler

   shall interpret as nonnull or nullable annotations, respectively.</p>

<p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td><b><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#ERROR">ERROR</a></b></td>

</tr>

<tr>

<td><b><i><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#WARNING">WARNING</a></i></b></td>

</tr>

<tr valign="top">

<td><b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#IGNORE">IGNORE</a></b></td>

</tr>

<tr>

<td colspan="2"><b>Reporting Violations of Null Specifications</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_NULL_SPECIFICATION_VIOLATION</a></b>)</td>

</tr>

<tr valign="top">

<td rowspan="2">When enabled, the compiler will issue an error or a warning whenever one of the

following situations is detected:

<ol>

<li>A method declared with a nonnull annotation returns an expression	that is

      statically known to evaluate to a null value.</li>

<li>An expression that is statically known to evaluate to a null value is	passed

    as an argument in a method call where the corresponding parameter of the called

    method is declared with a nonnull annotation.</li>

<li>An expression that is statically known to evaluate to a null value is	assigned

    to a local variable that is declared with a nonnull annotation.</li>

<li>A method that overrides an inherited method declared with a nonnull annotation

    tries to relax that contract by specifying a nullable annotation

    (prohibition of contravariant return).</li>

<li>A method that overrides an inherited method which has a nullable declaration

    for at least one of its parameters, tries to tighten that null contract by

    specifying a nonnull annotation for its corresponding parameter

    (prohibition of covariant parameters).</li>

</ol>

<p>The compiler options <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a> and

   <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NULLABLE_ANNOTATION_NAME">COMPILER_NULLABLE_ANNOTATION_NAME</a> control which annotations the compiler

   shall interpret as nonnull or nullable annotations, respectively.</p>

<p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td><b><i><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#ERROR">ERROR</a></i></b></td>

</tr>

<tr valign="top">

<td><b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#WARNING">WARNING</a></b></td>

</tr>

<tr>

<td colspan="2"><b>Reporting Violations of Null Specifications with Potential Null Value.</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION">COMPILER_PB_POTENTIAL_NULL_SPECIFICATION_VIOLATION</a></b>)</td>

</tr>

<tr valign="top">

<td rowspan="3">When enabled, the compiler will issue an error or a warning whenever one of the

following situations is detected:

<ol>

<li>A method declared with a nonnull annotation returns an expression for	which

    insufficient nullness information is available for statically proving that no

    flow will pass a null value at runtime.</li>

<li>An expression for which insufficient nullness information is available for

    statically proving that it will never evaluate to a null value at runtime

    is passed as an argument in a method call where the corresponding	parameter of

    the called method is declared with a nonnull annotation.</li>

<li>An expression for which insufficient nullness information is available for

    statically proving that it will never evaluate to a null value at runtime

    is assigned to a local variable that is declared with a nonnull annotation.</li>

</ol>

Insufficient nullness information is usually a consequence of using other unannotated

variables or methods.

<p>The compiler options <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a> and

   <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NULLABLE_ANNOTATION_NAME">COMPILER_NULLABLE_ANNOTATION_NAME</a> control which annotations the compiler

   shall interpret as nonnull or nullable annotations, respectively.</p>

<p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td><b><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#ERROR">ERROR</a></b></td>

</tr>

<tr valign="top">

<td><b><i><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#WARNING">WARNING</a></i></b></td>

</tr>

<tr valign="top">

<td><b><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#IGNORE">IGNORE</a></b></td>

</tr>

<tr>

<td colspan="2"><b>Reporting Redundant Null Annotations.</b> (<b><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_PB_REDUNDANT_NULL_ANNOTATION">COMPILER_PB_REDUNDANT_NULL_ANNOTATION</a></b>)</td>

</tr>

<tr valign="top">

<td rowspan="3">When enabled, the compiler will issue an error or a warning when a non-null annotation

(see <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a>)

is applied although the same effect is already achieved by a default applicable at the

current location. Such a default may be effective by enabling the option

<a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_IS_DEFAULT">COMPILER_NONNULL_IS_DEFAULT</a> or by using the annotation specified by the option

<a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_BY_DEFAULT_ANNOTATION_NAME">COMPILER_NONNULL_BY_DEFAULT_ANNOTATION_NAME</a>.

Insufficient nullness information is usually a consequence of using other unannotated

variables or methods.

<p>The compiler options <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NONNULL_ANNOTATION_NAME">COMPILER_NONNULL_ANNOTATION_NAME</a> and

   <a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#COMPILER_NULLABLE_ANNOTATION_NAME">COMPILER_NULLABLE_ANNOTATION_NAME</a> control which annotations the compiler

   shall interpret as nonnull or nullable annotations, respectively.

</p>

<p>This option only has an effect if the option <a href="../reference/api/org/eclipse/jdt/core/JavaCore#COMPILER_ANNOTATION_NULL_ANALYSIS">COMPILER_ANNOTATION_NULL_ANALYSIS</a> is enabled.</p>

</td>

<td><b><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#ERROR">ERROR</a></b></td>

</tr>

<tr valign="top">

<td><b><i><a href=

"../reference/api/org/eclipse/jdt/core/JavaCore.html#WARNING">WARNING</a></i></b></td>

</tr>

<tr valign="top">

<td><b><a href="../reference/api/org/eclipse/jdt/core/JavaCore.html#IGNORE">IGNORE</a></b></td>

</tr>