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| <h5 class="subsubsection">23.2.2.31 Finish Breakpoints</h5> |
| |
| <p><a name="index-python-finish-breakpoints-2422"></a><a name="index-gdb_002eFinishBreakpoint-2423"></a> |
| A finish breakpoint is a temporary breakpoint set at the return address of |
| a frame, based on the <code>finish</code> command. <code>gdb.FinishBreakpoint</code> |
| extends <code>gdb.Breakpoint</code>. The underlying breakpoint will be disabled |
| and deleted when the execution will run out of the breakpoint scope (i.e. |
| <code>Breakpoint.stop</code> or <code>FinishBreakpoint.out_of_scope</code> triggered). |
| Finish breakpoints are thread specific and must be create with the right |
| thread selected. |
| |
| <div class="defun"> |
| — Function: <b>FinishBreakpoint.__init__</b> (<span class="roman">[</span><var>frame</var><span class="roman">]</span> <span class="roman">[</span><var>, internal</var><span class="roman">]</span>)<var><a name="index-FinishBreakpoint_002e_005f_005finit_005f_005f-2424"></a></var><br> |
| <blockquote><p>Create a finish breakpoint at the return address of the <code>gdb.Frame</code> |
| object <var>frame</var>. If <var>frame</var> is not provided, this defaults to the |
| newest frame. The optional <var>internal</var> argument allows the breakpoint to |
| become invisible to the user. See <a href="Breakpoints-In-Python.html#Breakpoints-In-Python">Breakpoints In Python</a>, for further |
| details about this argument. |
| </p></blockquote></div> |
| |
| <div class="defun"> |
| — Function: <b>FinishBreakpoint.out_of_scope</b> (<var>self</var>)<var><a name="index-FinishBreakpoint_002eout_005fof_005fscope-2425"></a></var><br> |
| <blockquote><p>In some circumstances (e.g. <code>longjmp</code>, C<tt>++</tt> exceptions, <span class="sc">gdb</span> |
| <code>return</code> command, <small class="dots">...</small>), a function may not properly terminate, and |
| thus never hit the finish breakpoint. When <span class="sc">gdb</span> notices such a |
| situation, the <code>out_of_scope</code> callback will be triggered. |
| |
| <p>You may want to sub-class <code>gdb.FinishBreakpoint</code> and override this |
| method: |
| |
| <pre class="smallexample"> class MyFinishBreakpoint (gdb.FinishBreakpoint) |
| def stop (self): |
| print "normal finish" |
| return True |
| |
| def out_of_scope (): |
| print "abnormal finish" |
| </pre> |
| </blockquote></div> |
| |
| <div class="defun"> |
| — Variable: <b>FinishBreakpoint.return_value</b><var><a name="index-FinishBreakpoint_002ereturn_005fvalue-2426"></a></var><br> |
| <blockquote><p>When <span class="sc">gdb</span> is stopped at a finish breakpoint and the frame |
| used to build the <code>gdb.FinishBreakpoint</code> object had debug symbols, this |
| attribute will contain a <code>gdb.Value</code> object corresponding to the return |
| value of the function. The value will be <code>None</code> if the function return |
| type is <code>void</code> or if the return value was not computable. This attribute |
| is not writable. |
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