[arm] Too strict linker assert?

[Christophe Lyon <christophe.lyon@linaro.org>]

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