RE: trouble locating source files through relative paths

Dave Korn
2005-08-23T09:20:41Z

----Original Message----
>From: Craig Jeffree
>Sent: 23 August 2005 06:03

>> Have you tried using the cdir command? That might work.
>
> (gdb) help cdir
> Undefined command: "cdir". Try "help".
>
> What's cdir? What version of gdb is it available in?

I think he's probably just referring to 'cd'.

> That is what I would expect because the binary is not in the current
> working directory. Since the path shown in the stat64 (above) for
> GeAttribute.H is the correct relative path compared to the binary
> location I expect that I should be able to specify the binary's location
> using dir:
>
> dir /staff/taam/taam/bin/x86-Linux/nostrip/
>
> and then see gdb search with this as one of the starting points for the
> relative path to GeAttribute.H. However strace now shows the following:
>
> stat64("/staff/taam/taam/bin/x86-Linux/nostrip/GeAttribute.H",
> 0xbfffed8c) = -1 ENOENT (No such file or directory)
> stat64("../../../include/General/GeAttribute.H", 0xbfffed8c) = -1 ENOENT
> (No such file or directory)
> stat64("/staff/cjeffree/taam/GeAttribute.H", 0xbfffed8c) = -1 ENOENT (No
> such file or directory)
>
>
> So as you can see the newly specified path is now searched, but not with
> the full relative path specified in the debug symbols added to it.
> Instead gdb strips off the path and just adds the filename. I would
> expect to see a stat64 call looking for "/staff/taam/taam/bin/x86-
> Linux/nostrip/../../../include/General/GeAttribute.H". At least that's
> what the gdb documentation promises.

> I then looked inside the function find_and_open_source() in gdb/source.c
> at the first call to openp. Stepping through this code in gdb you get
> to see that find_and_open_source() is given char
> *filename="GeAttribute.H" and char *dirname="../../../include/General/"
> separately. 'dirname' is then added to the source search path in place
> of $cdir, so it now looks like this: "/staff/taam/taam/bin/x86-
> Linux/nostrip:../../../include/General:$cwd". The call to openp would
> work if 'dirname' was not separated from 'filename' and added to
> 'path'.
>
> Is this a bug in gdb?

I believe you have identified a real bug. I recall someone having a
problem getting directory concatenation to work a while ago, and it looks to
me like you've identified the problem. The solution needs a bit of thinking
about; it may suffice to notice when we have a relative path, and in those
cases try calling find_and_open_source (fullpath, NULL or "" as appropriate)
before splitting it and trying again if the first attempt fails, but I
haven't looked at the source yet.

cheers,
DaveK
--
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