This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Android native build of GCC
- From: Cyd Haselton <chaselton at gmail dot com>
- To: Andrew Haley <aph at redhat dot com>
- Cc: Hans-Peter Nilsson <hp at bitrange dot com>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Wed, 11 Feb 2015 06:08:47 -0600
- Subject: Re: Android native build of GCC
- Authentication-results: sourceware.org; auth=none
- References: <54AE581C dot 5070003 at redhat dot com> <alpine dot BSF dot 2 dot 02 dot 1502060258210 dot 10842 at arjuna dot pair dot com> <54D48673 dot 9070901 at redhat dot com> <alpine dot BSF dot 2 dot 02 dot 1502060458370 dot 29537 at arjuna dot pair dot com> <54D49731 dot 7030407 at redhat dot com> <F47323AC-2C7B-47B8-B630-D03A629DD347 at gmail dot com> <54D4A6C2 dot 1040808 at redhat dot com> <CAHu5Prbo2J1p2ueC3G5A6r-ZUo0z6JG1X_9OmshEyKPjjh0hTQ at mail dot gmail dot com> <54D4EA79 dot 10909 at redhat dot com> <6A2D97AB-19B8-4A78-ABE7-B486D1C41FCC at gmail dot com> <54DB14AB dot 3040501 at redhat dot com> <87A6FCF6-9A36-43DE-9981-6663EF51D81F at gmail dot com> <54DB3CB7 dot 1040108 at redhat dot com>
On Wed, Feb 11, 2015 at 5:27 AM, Andrew Haley <aph@redhat.com> wrote:
> On 02/11/2015 10:00 AM, Cyd Haselton wrote:
>>
>>
>> On February 11, 2015 2:36:59 AM CST, Andrew Haley <aph@redhat.com> wrote:
>>> On 11/02/15 00:41, Cyd Haselton wrote:
>>>>
>>>>>
>>>>> I'd rather leave it on-list for future reference. The best thing
>>>>> would be for libfakechroot to be linked against libdl: that way,
>>> when
>>>>> dlopen() was called the link would be correctly satisfied. If that
>>>>> isn't possible (if dlopen() doesn't work or is incompatible) then
>>>>> libfakechroot shouldn't export the symbol for dlopen().
>>>>
>>>> After experimenting with several builds of the fakechroot library I
>>>> can't see how this would be possible. Even when libdl is linked in,
>>>> hiding dlopen guarantees that the resulting library doesn't
>>>> intercept dlopen calls, which breaks the fakechroot environment and
>>>> removing the fakechroot dlopen code also ensures that dlopen calls
>>>> aren't intercepted.
>>>
>>> I don't get it. If libdl is linked in, why would you hide dlopen() ?
>>
>> libdl was linked in the original, buggy libfakechroot...the one that exported dlopen().
>
> But if it was linked in, where did the dlopen() link error come from? It
> should have succeeded because dlopen() should have been found in libdl.
> I still don't get it.
>
Neither do I...hence my confusion. Even more so because neither this
nor Linux are systems I usually work with.
I have an idea of what may be the problem, but it's just a guess,
given my rudimentary understanding of how the linker, shared and
dynamic libraries work.
The original libfakechroot was cross-compiled to link against the
system libc, and not the system libdl....hence libdl not being found.
The experiments I did with libfakechroot linked the sysroot libdl and
not the system libdl, therefore all dlopen() calls went straight to
the system libdl, bypassing the fakechroot environment.
Does that sound plausible?
Cyd