[Rd] Viewing R objects in gdb

From: Duncan Murdoch <murdoch_at_stats.uwo.ca>
Date: Wed 29 Jun 2005 - 17:49:54 GMT

I'm trying to track down a bug in some experimental code, where an object's attribute is getting messed up. This means I'd like to examine R objects while within gdb.

One of the things I'd like to do is to examine the names of all the attributes. This is exactly what an example in the R Extensions manual section 4.11.2 "Inspecting R objects when debugging" does, but the code there doesn't work, presumably because the R internals have changed since it was written.

Specifically, I get

(gdb) p $a->u.listsxp.tagval->u.symsxp.pname->u.vecsxp.type.c
Error: There is no member named vecsxp.

where $a was set to be the attrib member of an SEXP.

Could someone let me know what needs to be fixed for this to work? I imagine it's a typecast, but I haven't been able to put it together.

(An example using R_PV to print the attributes of an SEXP would also be
welcome, but I can probably figure that one out once I get this...)

Duncan Murdoch

R-devel@r-project.org mailing list

https://stat.ethz.ch/mailman/listinfo/r-devel Received on Thu Jun 30 03:52:28 2005

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