From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elena Zannoni To: Fernando Nasser Cc: Elena Zannoni , Stan Shebs , Fernando Nasser , Michael Snyder , gdb@sources.redhat.com, vinschen@redhat.com Subject: Re: Stabs or Dwarf Was: [PATCH]: testsuite/gdb.base/constvars.exp Date: Thu, 27 Sep 2001 08:24:00 -0000 Message-id: <15283.17918.885559.144596@krustylu.cygnus.com> References: <20010925192434.M29024@cygbert.vinschen.de> <3BB0C224.AB324D56@cygnus.com> <3BB0CB81.8385E123@redhat.com> <3BB0F122.3E45B3ED@cygnus.com> <3BB236BB.F50E045E@cygnus.com> <3BB24ABF.1072EE55@apple.com> <3BB24F75.A33E707E@redhat.com> <15282.22221.826751.449834@krustylu.cygnus.com> <3BB31E31.EECD98EC@redhat.com> X-SW-Source: 2001-09/msg00245.html Fernando Nasser writes: > Elena Zannoni wrote: > > > > Fernando Nasser writes: > > > Hi Stan, > > > > > > Thanks for your comments. > > > > > > Stan Shebs wrote: > > > > > > > > I can't think of a completely reliable test on binary files. For > > > > instance, in original a.out, stabs are plain symbols, not in a > > > > distinctly-named section. You also have the problem of an executable > > > > maybe having libraries compiled with stabs, and main prog with dwarf, > > > > and objdump can't distinguish. > > > > > > > > > > True. > > > > > > I was thinking just in terms of the testsuite. Most test programs are > > > a single file. Could we test just the object file for that one? > > > > I have seen cases in which we have both a .mdebug and a .stabs (or was > > that dwarf2) sections (for the same program segment), and even gdb > > itself gets confused as to which one is the reliable debug > > info. Frankly I wouldn't be able to say exactly under which > > circumstances you get this, but I have seen it. > > > > I think this is basically what Stan is saying, the heuristic is > > unreliable. > > > > When you mean that gdb itself gets confused what is the end result of > that? > Does it pick one at the end (after a warning or something)? No warning. For instance I have seen it pick the mdebug info which is incomplete/incorrect. I have looked back at some old mail, and it was with mdebug and dwarf2. I'll see if I can figure out what was happening. > > Another question: does it happen even with the simple testsuite > programs? > Don't know. I would think so. If the compiler emits 2 types of debug info, it, in theory, should behave the same with any program. > If it is that unreliable, we could make sure the tests run with dwarf > only > when we are sure it is there and skip when we are not sure (if we can > determine that we are not sure from some gdb warning message). > It would be probably reliable 'in general'. Probably not that many platforms emit both mdebug & dwarf2. > P.S.: We can also be more aggressive and try and see where gdb gets > confused > and thinks it is dwarf (and so fail the tests). We could dig for the > reason > that happens. Just a thought. > > Yep. Elena > -- > Fernando Nasser > Red Hat Canada Ltd. E-Mail: fnasser@redhat.com > 2323 Yonge Street, Suite #300 > Toronto, Ontario M4P 2C9