Re: [PATCH] gdb/python: fix gdb.Objfile.__repr__ () for dynamically compiled code

[Jan Vrany <jan.vrany@labware.com>]

On Tue, 2022-02-01 at 09:22 -0500, Simon Marchi wrote:
> 
> On 2022-02-01 08:05, Jan Vrany via Gdb-patches wrote:
> > While experimenting with JIT reader API I realized that calling repr ()
> > on objfile created by JIT reader crashes GDB.
> > 
> > The problem was that objfpy_repr () called objfile_filename () which
> > returned NULL, causing PyString_FromFormat () to crash.
> > 
> > This commit fixes this problem by using objfile_name () instead of
> > objfile_filename (). This also makes consistent with the value of gdb.Objfile.filename variable.
> > ---
> >  gdb/python/py-objfile.c               | 2 +-
> >  gdb/testsuite/gdb.base/jit-reader.exp | 8 ++++++++
> >  2 files changed, 9 insertions(+), 1 deletion(-)
> > 
> > diff --git a/gdb/python/py-objfile.c b/gdb/python/py-objfile.c
> > index 6055a42260b..48d2eb306d1 100644
> > --- a/gdb/python/py-objfile.c
> > +++ b/gdb/python/py-objfile.c
> > @@ -513,7 +513,7 @@ objfpy_repr (PyObject *self_)
> >      return PyString_FromString ("<gdb.Objfile (invalid)>");
> >  
> > 
> > 
> > 
> >    return PyString_FromFormat ("<gdb.Objfile filename=%s>",
> > -			      objfile_filename (obj));
> > +			      objfile_name (obj));
> >  }
> >  
> > 
> > 
> > 
> >  /* Subroutine of gdbpy_lookup_objfile_by_build_id to simplify it.
> > diff --git a/gdb/testsuite/gdb.base/jit-reader.exp b/gdb/testsuite/gdb.base/jit-reader.exp
> > index 7ee16d69c84..3084f755a02 100644
> > --- a/gdb/testsuite/gdb.base/jit-reader.exp
> > +++ b/gdb/testsuite/gdb.base/jit-reader.exp
> > @@ -227,6 +227,14 @@ proc jit_reader_test {} {
> >  		    "Attempt to assign to an unmodifiable value\." \
> >  		    "cannot assign to register"
> >  	    }
> > +
> > +	    gdb_test "python print(gdb.objfiles())" \
> > +		"$any<gdb.Objfile filename=<< JIT compiled code >>>$any" \
> > +		"python gdb.Objfile.__repr__ ()"
> > +
> > +	    gdb_test "python print(list(map(lambda objf : objf.filename, gdb.objfiles())))" \
> > +		"$any'<< JIT compiled code >>'$any" \
> > +		"python gdb.Objfile.filename"
> >  	}
> >      }
> >  
> > 
> > 
> > 
> 
> LGTM, except that these tests should probably be guarded by a
> 
>   if { ![skip_python_tests] } {
>       ...
>   }

True! I'll add the guard and push.

> 
> so that they don't fail on a build without Python.
> 
> Orthogonal to this patch, but IWBN to make these objfiles have a better
> name, at least so that we can differentiate them from one another.
> Like, maybe include the address of the jited object:
> 
>   << JIT compiled code at 0x%x >>

I'll make another patch for this. 

Thanks! 

Jan