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 <a name="Function-Properties"></a>
 <div class="header">
 <p>
 Previous: <a href="Function-Basics.html#Function-Basics" accesskey="p" rel="prev">Function Basics</a>, Up: <a href="Functions.html#Functions" accesskey="u" rel="up">Functions</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
 </div>
 <hr>
 <a name="Function-Properties-1"></a>
 <h4 class="subsection">10.8.2 Function Properties</h4>
 <a name="index-function-properties"></a>
 <a name="index-statements"></a>

 <p>To determine the scope of a function, you can use the
 <code>DECL_CONTEXT</code> macro.  This macro will return the class
 (either a <code>RECORD_TYPE</code> or a <code>UNION_TYPE</code>) or namespace (a
 <code>NAMESPACE_DECL</code>) of which the function is a member.  For a virtual
 function, this macro returns the class in which the function was
 actually defined, not the base class in which the virtual declaration
 occurred.
 </p>
 <p>In C, the <code>DECL_CONTEXT</code> for a function maybe another function.
 This representation indicates that the GNU nested function extension
 is in use.  For details on the semantics of nested functions, see the
 GCC Manual.  The nested function can refer to local variables in its
 containing function.  Such references are not explicitly marked in the
 tree structure; back ends must look at the <code>DECL_CONTEXT</code> for the
 referenced <code>VAR_DECL</code>.  If the <code>DECL_CONTEXT</code> for the
 referenced <code>VAR_DECL</code> is not the same as the function currently
 being processed, and neither <code>DECL_EXTERNAL</code> nor
 <code>TREE_STATIC</code> hold, then the reference is to a local variable in
 a containing function, and the back end must take appropriate action.
 </p>
 <dl compact="compact">
 <dt><code>DECL_EXTERNAL</code>
 <a name="index-DECL_005fEXTERNAL-1"></a>
 </dt>
 <dd><p>This predicate holds if the function is undefined.
 </p>
 </dd>
 <dt><code>TREE_PUBLIC</code>
 <a name="index-TREE_005fPUBLIC-1"></a>
 </dt>
 <dd><p>This predicate holds if the function has external linkage.
 </p>
 </dd>
 <dt><code>TREE_STATIC</code>
 <a name="index-TREE_005fSTATIC"></a>
 </dt>
 <dd><p>This predicate holds if the function has been defined.
 </p>
 </dd>
 <dt><code>TREE_THIS_VOLATILE</code>
 <a name="index-TREE_005fTHIS_005fVOLATILE"></a>
 </dt>
 <dd><p>This predicate holds if the function does not return normally.
 </p>
 </dd>
 <dt><code>TREE_READONLY</code>
 <a name="index-TREE_005fREADONLY"></a>
 </dt>
 <dd><p>This predicate holds if the function can only read its arguments.
 </p>
 </dd>
 <dt><code>DECL_PURE_P</code>
 <a name="index-DECL_005fPURE_005fP"></a>
 </dt>
 <dd><p>This predicate holds if the function can only read its arguments, but
 may also read global memory.
 </p>
 </dd>
 <dt><code>DECL_VIRTUAL_P</code>
 <a name="index-DECL_005fVIRTUAL_005fP"></a>
 </dt>
 <dd><p>This predicate holds if the function is virtual.
 </p>
 </dd>
 <dt><code>DECL_ARTIFICIAL</code>
 <a name="index-DECL_005fARTIFICIAL-2"></a>
 </dt>
 <dd><p>This macro holds if the function was implicitly generated by the
 compiler, rather than explicitly declared.  In addition to implicitly
 generated class member functions, this macro holds for the special
 functions created to implement static initialization and destruction, to
 compute run-time type information, and so forth.
 </p>
 </dd>
 <dt><code>DECL_FUNCTION_SPECIFIC_TARGET</code>
 <a name="index-DECL_005fFUNCTION_005fSPECIFIC_005fTARGET-1"></a>
 </dt>
 <dd><p>This macro returns a tree node that holds the target options that are
 to be used to compile this particular function or <code>NULL_TREE</code> if
 the function is to be compiled with the target options specified on
 the command line.
 </p>
 </dd>
 <dt><code>DECL_FUNCTION_SPECIFIC_OPTIMIZATION</code>
 <a name="index-DECL_005fFUNCTION_005fSPECIFIC_005fOPTIMIZATION-1"></a>
 </dt>
 <dd><p>This macro returns a tree node that holds the optimization options
 that are to be used to compile this particular function or
 <code>NULL_TREE</code> if the function is to be compiled with the
 optimization options specified on the command line.
 </p>
 </dd>
 </dl>


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	<a name="Function-Properties"></a>
	<div class="header">
	<p>
	Previous: <a href="Function-Basics.html#Function-Basics" accesskey="p" rel="prev">Function Basics</a>, Up: <a href="Functions.html#Functions" accesskey="u" rel="up">Functions</a>   [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
	</div>
	<hr>
	<a name="Function-Properties-1"></a>
	<h4 class="subsection">10.8.2 Function Properties</h4>
	<a name="index-function-properties"></a>
	<a name="index-statements"></a>

	<p>To determine the scope of a function, you can use the
	<code>DECL_CONTEXT</code> macro. This macro will return the class
	(either a <code>RECORD_TYPE</code> or a <code>UNION_TYPE</code>) or namespace (a
	<code>NAMESPACE_DECL</code>) of which the function is a member. For a virtual
	function, this macro returns the class in which the function was
	actually defined, not the base class in which the virtual declaration
	occurred.
	</p>
	<p>In C, the <code>DECL_CONTEXT</code> for a function maybe another function.
	This representation indicates that the GNU nested function extension
	is in use. For details on the semantics of nested functions, see the
	GCC Manual. The nested function can refer to local variables in its
	containing function. Such references are not explicitly marked in the
	tree structure; back ends must look at the <code>DECL_CONTEXT</code> for the
	referenced <code>VAR_DECL</code>. If the <code>DECL_CONTEXT</code> for the
	referenced <code>VAR_DECL</code> is not the same as the function currently
	being processed, and neither <code>DECL_EXTERNAL</code> nor
	<code>TREE_STATIC</code> hold, then the reference is to a local variable in
	a containing function, and the back end must take appropriate action.
	</p>
	<dl compact="compact">
	<dt><code>DECL_EXTERNAL</code>
	<a name="index-DECL_005fEXTERNAL-1"></a>
	</dt>
	<dd><p>This predicate holds if the function is undefined.
	</p>
	</dd>
	<dt><code>TREE_PUBLIC</code>
	<a name="index-TREE_005fPUBLIC-1"></a>
	</dt>
	<dd><p>This predicate holds if the function has external linkage.
	</p>
	</dd>
	<dt><code>TREE_STATIC</code>
	<a name="index-TREE_005fSTATIC"></a>
	</dt>
	<dd><p>This predicate holds if the function has been defined.
	</p>
	</dd>
	<dt><code>TREE_THIS_VOLATILE</code>
	<a name="index-TREE_005fTHIS_005fVOLATILE"></a>
	</dt>
	<dd><p>This predicate holds if the function does not return normally.
	</p>
	</dd>
	<dt><code>TREE_READONLY</code>
	<a name="index-TREE_005fREADONLY"></a>
	</dt>
	<dd><p>This predicate holds if the function can only read its arguments.
	</p>
	</dd>
	<dt><code>DECL_PURE_P</code>
	<a name="index-DECL_005fPURE_005fP"></a>
	</dt>
	<dd><p>This predicate holds if the function can only read its arguments, but
	may also read global memory.
	</p>
	</dd>
	<dt><code>DECL_VIRTUAL_P</code>
	<a name="index-DECL_005fVIRTUAL_005fP"></a>
	</dt>
	<dd><p>This predicate holds if the function is virtual.
	</p>
	</dd>
	<dt><code>DECL_ARTIFICIAL</code>
	<a name="index-DECL_005fARTIFICIAL-2"></a>
	</dt>
	<dd><p>This macro holds if the function was implicitly generated by the
	compiler, rather than explicitly declared. In addition to implicitly
	generated class member functions, this macro holds for the special
	functions created to implement static initialization and destruction, to
	compute run-time type information, and so forth.
	</p>
	</dd>
	<dt><code>DECL_FUNCTION_SPECIFIC_TARGET</code>
	<a name="index-DECL_005fFUNCTION_005fSPECIFIC_005fTARGET-1"></a>
	</dt>
	<dd><p>This macro returns a tree node that holds the target options that are
	to be used to compile this particular function or <code>NULL_TREE</code> if
	the function is to be compiled with the target options specified on
	the command line.
	</p>
	</dd>
	<dt><code>DECL_FUNCTION_SPECIFIC_OPTIMIZATION</code>
	<a name="index-DECL_005fFUNCTION_005fSPECIFIC_005fOPTIMIZATION-1"></a>
	</dt>
	<dd><p>This macro returns a tree node that holds the optimization options
	that are to be used to compile this particular function or
	<code>NULL_TREE</code> if the function is to be compiled with the
	optimization options specified on the command line.
	</p>
	</dd>
	</dl>


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