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| <h3 class="section">29.2 Registering Code</h3> |
| |
| <p>To register code with <span class="sc">gdb</span>, the JIT should follow this protocol: |
| |
| <ul> |
| <li>Generate an object file in memory with symbols and other desired debug |
| information. The file must include the virtual addresses of the sections. |
| |
| <li>Create a code entry for the file, which gives the start and size of the symbol |
| file. |
| |
| <li>Add it to the linked list in the JIT descriptor. |
| |
| <li>Point the relevant_entry field of the descriptor at the entry. |
| |
| <li>Set <code>action_flag</code> to <code>JIT_REGISTER</code> and call |
| <code>__jit_debug_register_code</code>. |
| </ul> |
| |
| <p>When <span class="sc">gdb</span> is attached and the breakpoint fires, <span class="sc">gdb</span> uses the |
| <code>relevant_entry</code> pointer so it doesn't have to walk the list looking for |
| new code. However, the linked list must still be maintained in order to allow |
| <span class="sc">gdb</span> to attach to a running process and still find the symbol files. |
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