This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] pass -no_pie to LINK_GCC_C_SEQUENCE_SPEC on darwin


On Sun, Dec 04, 2011 at 08:18:32PM +0100, Jakub Jelinek wrote:
> On Sun, Dec 04, 2011 at 02:00:20PM -0500, Jack Howarth wrote:
> > > > at -m32/-m64 on x86_64-apple-darwin11 due to the -pie linker default. Iain had wanted
> > > > to leave these in place to encourage boehm-gc to be fixed but I doubt that is a realistic
> > > > goal in the near/middle term. Perhaps we could patch boehm-gc/testsuite/lib/boehm-gc.exp
> > > > to pass -fno-pie on darwin (now that it is functional)?
> > > 
> > > I think we should just find a way to add -fno-pie...  Are there any
> > > flags that are added because we are doing gc that we can key off of?
> 
> -f{pic,PIC,pie,PIE,no-pic} aren't option that should have any effect on how
> are binaries/shared libraries linked, these options control solely
> compilation.  -shared, -pie or lack of these options determines how are
> things linked.  So, either you should pass -no-pie or whatever linker option
> you need to generate position dependent binaries by default, unless -shared
> or -pie is specified, or you should add -no-pie or something similar, but
> IMHO it shouldn't be -fno-pie, that is a compilation option/too similar to
> them.

Jakub,
   This isn't really an option on darwin11 and later since the linker defaults to
-pie and this results in warnings from the linker of the form...

ld: warning: PIE disabled. Absolute addressing (perhaps -mdynamic-no-pic) not allowed in code signed PIE, but used in _f from /var/tmp//ccVNy9V9.o. To fix this warning, don't compile with -mdynamic-no-pic or link with -Wl,-no_pie

Author: mrs
Date: Sun Dec  4 07:09:56 2011
New Revision: 181982

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181982
Log:
2011-12-03  Jack Howarth  <howarth@bromo.med.uc.edu>

       * config/darwin10.h (LINK_GCC_C_SEQUENCE_SPEC):
         Pass -no_pie for non-PIC code when targeting 10.7 or later.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/darwin10.h

is designed to inhibit this linker noise by explicitly disabling pie linkage. Also, FSF gcc previously wasn't
honoring -fno-pie since this didn't inhibit the darwin11 linker from creating a PIE executable. 
   Unfortunately the linker option -no_pie isn't recognized by earlier darwin linkers which makes -fno-pie
preferred since it only passes -no_pie to the linker when targeting 10.7 or later. So we may have to make
the change darwin-specific.
        Jack


> 
> 	Jakub


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]