[PATCH][AsmParser][MC] Allow asm parser to emit elf header flags

[Rafael Espíndola]

On 24 October 2013 11:34, Vladimir Medic <Vladimir.Medic at imgtec.com> wrote:
> Hi Rafael,
> I'd just like to clarify one thing:
>>>There is also a helper method emitMipsELFFlags, which in case of AsmStreamer does nothing, and for >>ElfStreamer actual value is emitted to the output.
>
>>>This part looks wrong. How would you get the correct flags when using
> l>>lvm-mc to parse an assembly file? If these flag differences are from
>>>command line options (instead of assembly directives) then llvm-mc
>>>should implement equivalent options to the gnu assembler ones. They
>>>should then be mapped to flags that are passed to the target object
>>>streamer constructor (like a isMips16 for example).
> are you referring to the method which sets command line options during the initialization(virtual void emitElfHeaderFlags(MCSubtargetInfo &STI);), is that what you suggest should be moved to MCStreamer class?

I am referring to emitMipsELFFlags. If there is no .mips_elf_flags
directive is mips assembly, then that is not a good match for the
streamer interface.

My understanding (please correct if I am wrong), is that the gnu
assembly sets some flags based on command line option. So there is a
-foo option that causes bit number X to be set. Given that, this
should not be a streamer method at all. What should happen is that the
mips target *object* streamer constructor should take foo as an
option. Since option foo is not present on the assembly file, the mips
asm target streamer constructor doesn't need the option.

Cheers,
Rafael