[lld] r234009 - [ARM] Implementation of R_ARM_TARGET1 relocation

[Simon Atanasyan]

Hi,

On Fri, Apr 3, 2015 at 3:03 PM, Leny Kholodov
<lkholodov at accesssoftek.com> wrote:
> +def grp_targetopts : OptionGroup<"opts">,
> +     HelpText<"ARCH SPECIFIC OPTIONS">;
> +def arm_target1_rel : Flag<["--"], "arm-target1-rel">,
> +     Group<grp_targetopts>, HelpText<"Interpret R_ARM_TARGET1 as R_ARM_REL32">;
> +def arm_target1_abs : Flag<["--"], "arm-target1-abs">,
> +     Group<grp_targetopts>, HelpText<"Interpret R_ARM_TARGET1 as R_ARM_ABS32">;

Is it really necessary to add the target name prefix to these options?
That prevents LLD to be a drop in replacement for GNU (bfd/gold)
linkers.

When we handle target specific options in the `GnuLdDriver` we know
selected target and can process these options accordingly. To separate
say arm specific options in the GnuLdOptions.td we can introduce new
options group:

```
def grp_arm_targetopts : OptionGroup<"ARM SPECIFIC OPTIONS">,
                         Group<grp_targetopts>;
def target1_rel : Flag<["--"], "target1-rel">,
                  Group<grp_arm_targetopts>,
                  HelpText<"Interpret R_ARM_TARGET1 as R_ARM_REL32">;
def target1_abs : Flag<["--"], "target1-abs">,
                  Group<grp_arm_targetopts>,
                  HelpText<"Interpret R_ARM_TARGET1 as R_ARM_ABS32">;
```

The only problem is that `llvm::OptTable::PrintHelp()` does not take
in account sub-groups and does not print their names. But I think it
is better to fix this problem.

By the way, the Clang driver does not add any target specific prefix
to option names.

-- 
Simon