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<h5 class="subsubsection">3.2.4.8 Status of an Obstack</h5>

<p><a name="index-obstack-status-331"></a><a name="index-status-of-obstack-332"></a>
Here are functions that provide information on the current status of
allocation in an obstack.  You can use them to learn about an object while
still growing it.

<!-- obstack.h -->
<!-- GNU -->
<div class="defun">
&mdash; Function: void * <b>obstack_base</b> (<var>struct obstack *obstack-ptr</var>)<var><a name="index-obstack_005fbase-333"></a></var><br>
<blockquote><p>This function returns the tentative address of the beginning of the
currently growing object in <var>obstack-ptr</var>.  If you finish the object
immediately, it will have that address.  If you make it larger first, it
may outgrow the current chunk&mdash;then its address will change!

        <p>If no object is growing, this value says where the next object you
allocate will start (once again assuming it fits in the current
chunk). 
</p></blockquote></div>

<!-- obstack.h -->
<!-- GNU -->
<div class="defun">
&mdash; Function: void * <b>obstack_next_free</b> (<var>struct obstack *obstack-ptr</var>)<var><a name="index-obstack_005fnext_005ffree-334"></a></var><br>
<blockquote><p>This function returns the address of the first free byte in the current
chunk of obstack <var>obstack-ptr</var>.  This is the end of the currently
growing object.  If no object is growing, <code>obstack_next_free</code>
returns the same value as <code>obstack_base</code>. 
</p></blockquote></div>

<!-- obstack.h -->
<!-- GNU -->
<div class="defun">
&mdash; Function: int <b>obstack_object_size</b> (<var>struct obstack *obstack-ptr</var>)<var><a name="index-obstack_005fobject_005fsize-335"></a></var><br>
<blockquote><p>This function returns the size in bytes of the currently growing object. 
This is equivalent to

     <pre class="smallexample">          obstack_next_free (<var>obstack-ptr</var>) - obstack_base (<var>obstack-ptr</var>)
</pre>
        </blockquote></div>

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