When building with the LLVM linker this error occurrs:
LD arch/riscv/kernel/vdso/vdso-syms.o
ld.lld: error: no input files
This happens because the lld treats -R as an alias to -rpath, as opposed
to ld where -R means --just-symbols.
Use the long option name for compatibility between the two.
Link: https://github.com/ClangBuiltLinux/linux/issues/805
Reported-by: Dmitry Golovin <[email protected]>
Signed-off-by: Ilie Halip <[email protected]>
---
arch/riscv/kernel/vdso/Makefile | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 33b16f4212f7..19f7b9ea10ab 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -41,7 +41,8 @@ SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
$(call if_changed,vdsold)
-LDFLAGS_vdso-syms.o := -r -R
+# lld aliases -R to -rpath; use the longer option name
+LDFLAGS_vdso-syms.o := -r --just-symbols
$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
$(call if_changed,ld)
--
2.17.1
+ Jordan, Fangrui
On Thu, Apr 2, 2020 at 1:56 AM Ilie Halip <[email protected]> wrote:
>
> When building with the LLVM linker this error occurrs:
> LD arch/riscv/kernel/vdso/vdso-syms.o
> ld.lld: error: no input files
>
> This happens because the lld treats -R as an alias to -rpath, as opposed
> to ld where -R means --just-symbols.
>
> Use the long option name for compatibility between the two.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/805
> Reported-by: Dmitry Golovin <[email protected]>
> Signed-off-by: Ilie Halip <[email protected]>
> ---
> arch/riscv/kernel/vdso/Makefile | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
> index 33b16f4212f7..19f7b9ea10ab 100644
> --- a/arch/riscv/kernel/vdso/Makefile
> +++ b/arch/riscv/kernel/vdso/Makefile
> @@ -41,7 +41,8 @@ SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
> $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
> $(call if_changed,vdsold)
>
> -LDFLAGS_vdso-syms.o := -r -R
> +# lld aliases -R to -rpath; use the longer option name
Thanks for the patch. Maybe the comment can be dropped? It doesn't
make sense if there's no -R in the source file you're touching. If
someone cares about why `--just-symbols` is spelled out, that's what
`git log` or vim fugitive is for. Maybe the maintainer would be kind
enough to just drop that line for you when merging?
Reviewed-by: Nick Desaulniers <[email protected]>
Jordan, Fangrui, thoughts on this? Sounds like something other users
of LLD might run into porting their codebase to LLVM's linker.
$ ld.lld --help | grep \\-R
-R <value> Alias for --rpath
$ ld.bfd --help | grep \\-R
-R FILE, --just-symbols FILE
> +LDFLAGS_vdso-syms.o := -r --just-symbols
> $(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
> $(call if_changed,ld)
>
> --
> 2.17.1
>
--
Thanks,
~Nick Desaulniers
The comment of `With ld -R we can then ...` should be fixed as well.
On 2020-04-02, Nick Desaulniers wrote:
>+ Jordan, Fangrui
>
>On Thu, Apr 2, 2020 at 1:56 AM Ilie Halip <[email protected]> wrote:
>>
>> When building with the LLVM linker this error occurrs:
>> LD arch/riscv/kernel/vdso/vdso-syms.o
>> ld.lld: error: no input files
>>
>> This happens because the lld treats -R as an alias to -rpath, as opposed
>> to ld where -R means --just-symbols.
>>
>> Use the long option name for compatibility between the two.
>>
>> Link: https://github.com/ClangBuiltLinux/linux/issues/805
>> Reported-by: Dmitry Golovin <[email protected]>
>> Signed-off-by: Ilie Halip <[email protected]>
>> ---
>> arch/riscv/kernel/vdso/Makefile | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
>> index 33b16f4212f7..19f7b9ea10ab 100644
>> --- a/arch/riscv/kernel/vdso/Makefile
>> +++ b/arch/riscv/kernel/vdso/Makefile
>> @@ -41,7 +41,8 @@ SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
>> $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
>> $(call if_changed,vdsold)
>>
>> -LDFLAGS_vdso-syms.o := -r -R
>> +# lld aliases -R to -rpath; use the longer option name
>
>Thanks for the patch. Maybe the comment can be dropped? It doesn't
>make sense if there's no -R in the source file you're touching. If
>someone cares about why `--just-symbols` is spelled out, that's what
>`git log` or vim fugitive is for. Maybe the maintainer would be kind
>enough to just drop that line for you when merging?
>
>Reviewed-by: Nick Desaulniers <[email protected]>
>
>Jordan, Fangrui, thoughts on this? Sounds like something other users
>of LLD might run into porting their codebase to LLVM's linker.
Independently, I noticed this ~2 days ago.
https://reviews.llvm.org/D76885#1952860
GNU ld parses options with getopt_long and -j is recognized as
--just-symbols ('R') because there is no other long options prefixed with -j.
Now, the following comment applies. Basically, --just-symbols/-R is an
overloaded option. It can be used as an -rpath if the argument is a directory.
The best practice is to use either -rpath or --just-symbols, never -R.
// binutils-gdb/ld/lexsup.c
case 'R':
/* The GNU linker traditionally uses -R to mean to include
only the symbols from a file. The Solaris linker uses -R
to set the path used by the runtime linker to find
libraries. This is the GNU linker -rpath argument. We
try to support both simultaneously by checking the file
named. If it is a directory, rather than a regular file,
we assume -rpath was meant. */
{
struct stat s;
if (stat (optarg, &s) >= 0
&& ! S_ISDIR (s.st_mode))
{
lang_add_input_file (optarg,
lang_input_file_is_symbols_only_enum,
NULL);
break;
}
}
>$ ld.lld --help | grep \\-R
> -R <value> Alias for --rpath
>$ ld.bfd --help | grep \\-R
> -R FILE, --just-symbols FILE
>
>> +LDFLAGS_vdso-syms.o := -r --just-symbols
>> $(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
>> $(call if_changed,ld)
>>
>> --
>> 2.17.1
>>
>
>
>--
>Thanks,
>~Nick Desaulniers