Thank you! One small question, does this work to print DNF types?

Yes it does. Here is what it looks like for null|A|(B&C):

(gdb) p arg_infos->type
$4 = [union,arena] null|"A"|([intersection,arena] "B"&"C") = {ptr = 0x7ffff7a02130, type_mask = 5505026}

Thank you! Would be nice to add support for ASTs and op_arrays at some point.

That would be super useful indeed. I've added one for zend_ast here: #13520

Probably redundant to print the string twice for zend_string (once at start and once for val)
Otherwise, nice addition :-)

Also question: Can this sourcing be added directly to .gdbinit, so that sourcing the .gdbinit also loads this python file? (I don't know anything about the details of this)

I've updated the string pretty printer to not print the string twice.

Can this sourcing be added directly to .gdbinit, so that sourcing the .gdbinit also loads this python file?

We can add source .gdb.py in .gdbinit, but this will only work when the script is either in the current directory, or in directories except that $cdir is ignored. I didn't found any way to search relatively to the .gdbinit file.

Python autoloading searches in the same way.

The only reliable way to load .gdb.py by default may be to embed it in the php binary as described in the second section of the python autoloading page.

Embedding .gdbinit / .gdb.py sounds very interesting to me. The files are relatively small ... and it saves me to always either manually load it (to the point that it annoys me) or set it up in the env ... which is annoying if these are various production envs sometimes.

It will look into this, then :) (in a separate PR)

I'm going to merge this in a few days unless there are objections