Re: [PATCH]Replace -shared with -r -nostdlib in gcc.dg/lto/pr61526 pr54709 pr64415 test cases.

[Renlin Li <renlin dot li at foss dot arm dot com>]

Hi Richard,

On 01/03/16 09:16, Richard Biener wrote:
> On Mon, Feb 29, 2016 at 5:13 PM, Renlin Li <renlin.li@foss.arm.com> wrote:
> > Hi all,
> >
> > The gcc.dg/lto/pr54709, pr61526, pr64415 linking testcases keep failing on
> > arm/aarch64 bare-metal target.
> >
> > It's because statically built newlib library is used to link with shared
> > object.
> > And the linker complains about relocations which cannot be used in
> > shared object.
> >
> > For example, the following errors are produced:
> >
> > crtbegin.o: relocation R_ARM_MOVW_ABS_NC against `a local symbol' can not be
> > used when making a shared object; recompile with -fPIC
> >
> > crtbegin.o: relocation R_ARM_THM_MOVW_ABS_NC against `a local symbol' can
> > not
> > be used when making a shared object; recompile with -fPIC
> >
> > librdimon.a(rdimon-syscalls.o): relocation R_AARCH64_ADR_PREL_PG_HI21
> > against
> > external symbol `_impure_ptr' can not be used when making a shared object;
> > recompile with -fPIC
> >
> > Presumably, bare-metal toolchain for other architecture have those test case
> > failures as well?
> >
> > In this patch, -shared option is replace by -r -nostdlib. So that the
> > standard
> > system startup files or libraries are not used when linking.
> Note that -shared is not equivalent to -r -nostdlib so please verify that the
> original issue can be still reproduced with its fix reverted but -r -nostdlib
> used with the new -r -nostdlib handling on trunk.

pr54709_0.c: Cannot be reproduced with even -shared. The error message 
is the same as shown above.
pr64415_0.c: Reproduced with "-r -nostdlib".
pr61526_0.c: Reproduced with "-r -nostdlib".

By the way, those linking test cases all pass for linux toolchain. Only 
fail for aarch64/arm baremetal toolchain.

Andrew, I saw you have done similar things in r153555
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=153555

Do you have any thoughts?

And also here, the last comments in this ticket suggests to add
check_effective_target_shared to the exp file to limit it to linux 
targets only:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61526

Regards,
Renlin

> Otherwise simply dg-skip for aarch64.
>
> Richard.
>
> > arm-none-eabi, aarch64-none-elf regression test OK, OK for trunk?
> >
> > Regards,
> > Renlin Li
> >
> > gcc/testsuite/ChangeLog:
> >
> > 2016-02-29  Renlin Li<renlin.li@arm.com>
> >
> >          * gcc.dg/lto/pr54709_0.c: Replace -shard with -r -nostdlib.
> >          * gcc.dg/lto/pr61526_0.c: Ditto.
> >          * gcc.dg/lto/pr64415_0.c: Ditto.