Cureently, passing -frwpi/-fropi for assmebling causes assertion.
This patch teaches the cc1as driver to accept the flags
Do you mean the attributes like:
Tag_ABI_PCS_R9_use: SB Tag_ABI_PCS_RW_data: SB-relative Tag_ABI_PCS_GOT_use: direct
For cc1as, it won't add such tags no matter PIC or static relocation model. The PIC value only affects MIPS target and some DWARF info.
For asm file, I think it's the asm file's responsibility to set the corresponding .eabi_attribute. I tried to assemble a .S with -fPIC and don't see any attributes is generated by assembler. And linker should catch if objs with incompatible ABIs are used.