Messages in this thread | | | From | Masahiro Yamada <> | Date | Sat, 16 Feb 2019 12:07:59 +0900 | Subject | Re: [PATCH v2 3/4] Makefile: lld: tell clang to use lld |
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On Thu, Feb 14, 2019 at 8:08 AM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Wed, Feb 13, 2019 at 6:59 AM Masahiro Yamada > <yamada.masahiro@socionext.com> wrote: > > > > On Tue, Feb 12, 2019 at 5:42 AM <ndesaulniers@google.com> wrote: > > > > > > This is needed because clang doesn't select which linker to use based on > > > $LD but rather -fuse-ld=lld. This is problematic especially for > > > cc-ldoption, which checks for linker flag support via invoking the > > > compiler, rather than the linker. > > > > > > Sorry, please explain what kind of problem > > this patch solves. > > > > > > > > [1] $(LD) is used to link vmlinux, modules, etc. > > > > [2] $(CC) is used to link vdso, etc. > > and -fuse-ld= selects which linker is invoked from $(CC) > > It solves case 2. > > > > > > > Is it a problem to use a different > > type of linker for [1] and [2] ? > > Ideally, no, but I can think of at least one case where it might be > problematic to mix linkers like that: > You might be mixing linker flags added via ld-option from one linker > that aren't actually supported by the other linker.
You can do this only when you are sure that the _exactly_ same linker is used.
In my understanding, -fuse-ld=lld does not guarantee it.
-- Best Regards Masahiro Yamada
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