From: Richard Earnshaw <Richard.Earnshaw@foss.arm.com>
To: Christophe Lyon <christophe.lyon@linaro.org>,
binutils <binutils@sourceware.org>,
gcc@gcc.gnu.org
Subject: Re: [arm] Too strict linker assert?
Date: Tue, 09 Apr 2019 22:30:00 -0000 [thread overview]
Message-ID: <78f68a64-5ad9-31aa-1c3f-b65f3d1a9584@foss.arm.com> (raw)
In-Reply-To: <CAKdteOZCwjc9apmmtfKeOne-E3D1ucWtMsQCafrK6mejpKa0rw@mail.gmail.com>
On 09/04/2019 13:26, Christophe Lyon wrote:
> Hi,
>
> While building a newlib-based arm-eabi toolchain with
> --with-multilib-list=rmprofile, I faced a linker assertion failure in
> elf32_arm_merge_eabi_attributes (bfd/elf32-arm.c):
> BFD_ASSERT (in_attr[Tag_ABI_HardFP_use].i == 0)
>
> I traced this down to newlib's impure.o containing only data, and thus
> GCC does not emit a .fpu directive when compiling impure.c.
>
> When the linker merges impure.o's attributes with the other
> contributions that already have
> Tag_FP_arch, this assertion fails because in my multilib case (-mthumb
> -march=armv7e-m+fp -mfloat-abi=softfp) all the object files have
> Tag_ABI_HardFP_use: SP only
>
> Put differently, all objects but impure.o have
> Tag_ABI_HardFP_use: SP only
> Tag_FP_arch: VFPv4-D16
> but impure.o has only:
> Tag_ABI_HardFP_use: SP only
> (and no Tag_FP_arch)
>
> Removing the linker assertion makes the build succeed, so I guess my
> question is: should I submit a linker patch to remove the assert
> because it is too strict, or should I find a way to make GCC emit the
> needed .fpu directive?
>
> Thanks,
>
> Christophe
>
I think removing the assert will remove entirely the check that a user
is not mixing code with incompatible ABIs. So probably this is a bug.
Which version of GCC were you using, and which version of binutils? I
thought I'd addressed this when doing the rework of the FPU option code;
but perhaps I've missed something somewhere. I'll check in more detail
tomorrow.
R.
next prev parent reply other threads:[~2019-04-09 22:30 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-09 12:27 Christophe Lyon
2019-04-09 22:30 ` Richard Earnshaw [this message]
2019-04-10 9:16 ` Christophe Lyon
2019-04-10 9:42 ` Richard Earnshaw (lists)
2019-04-10 11:28 ` Christophe Lyon
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