| Message ID | 53A9D326.9060409@myspectrum.nl |
|---|---|
| State | Not Applicable |
| Delegated to: | Tom Rini |
| Headers | show |
Hi Jeroen, On Tue, 24 Jun 2014 21:36:06 +0200 Jeroen Hofstee <jeroen@myspectrum.nl> wrote: > >> KBuild (ab)uses the asm statement to write to a file and > >> llvm integrated as chokes about these invalid asm statements. > >> Workaround it by making it look like valid asm code. > >> > >> Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl> > > I think Linux has the same problem. > > > > Are you willing to this patch to linux-kbuild ML? > > Or fixing U-Boot only? > I don't mind in general, but it is just noise for them (cc-ing them to > create some). For u-boot (ARM) you actually get a valid binary with > this patch after clang support has landed, for linux you just get other > errors as far as I tried (native only), patch below. > > However in linux there seem more spots relying on the format, e.g. > arch/ia64/kvm/Makefile > arch/ia64/kernel/Makefile > arch/um/Makefile > > So if anything, I think this should be made a general rules first > in the makefiles. It seems stupid to potentially break something > while it gains nothing. > > So yes, u-boot only afaic, or does that make your syncing more difficult? I don't think syncing would be difficult. BTW, do you know how they resolve this build error in other projects, for example, in llvmlinux ? http://llvm.linuxfoundation.org/index.php/Main_Page Linux folks merged Clang support into the top Makefile, but not into ./Kbuild. I don't know why. Best Regards Masahiro Yamada
Hello Masahiro, On 27-06-14 08:38, Masahiro Yamada wrote: > KBuild (ab)uses the asm statement to write to a file and > llvm integrated as chokes about these invalid asm statements. > Workaround it by making it look like valid asm code. > > Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl> >>> I think Linux has the same problem. >>> >>> Are you willing to this patch to linux-kbuild ML? >>> Or fixing U-Boot only? >> I don't mind in general, but it is just noise for them (cc-ing them to >> create some). For u-boot (ARM) you actually get a valid binary with >> this patch after clang support has landed, for linux you just get other >> errors as far as I tried (native only), patch below. >> >> However in linux there seem more spots relying on the format, e.g. >> arch/ia64/kvm/Makefile >> arch/ia64/kernel/Makefile >> arch/um/Makefile >> >> So if anything, I think this should be made a general rules first >> in the makefiles. It seems stupid to potentially break something >> while it gains nothing. >> >> So yes, u-boot only afaic, or does that make your syncing more difficult? > I don't think syncing would be difficult. > > BTW, do you know how they resolve this build error in other projects, > for example, in llvmlinux ? > http://llvm.linuxfoundation.org/index.php/Main_Page > > Linux folks merged Clang support into the top Makefile, but not into ./Kbuild. > I don't know why. I don't know how the llvmlinux people do it, but the alternative is to add -no-integrated-as for clang when compiling such files (or use an older clang version, since that used to be the default). Since gcc's LTO dislikes the asm-offset.c technique as well, I think it is better to actually create valid asm, so it no longer depends on compiler features at all. I will leave it up to the llvmlinux folks to come up with a solution for linux though... Regards, Jeroen
--- a/Kbuild +++ b/Kbuild @@ -52,7 +52,8 @@ targets += arch/$(SRCARCH)/kernel/asm-offsets.s # Default sed regexp - multiline due to syntax constraints define sed-y - "/^->/{s:->#\(.*\):/* \1 */:; \ + "s:[[:space:]]*\.ascii[[:space:]]*\"\(.*\)\":\1:; \ + /^->/{s:->#\(.*\):/* \1 */:; \ s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \ s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \ s:->::; p;}" diff --git a/include/linux/kbuild.h b/include/linux/kbuild.h index 22a7219..4e80f3a 100644 --- a/include/linux/kbuild.h +++ b/include/linux/kbuild.h @@ -2,14 +2,14 @@ #define __LINUX_KBUILD_H #define DEFINE(sym, val) \ - asm volatile("\n->" #sym " %0 " #val : : "i" (val)) + asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val)) -#define BLANK() asm volatile("\n->" : : ) +#define BLANK() asm volatile("\n.ascii \"->\"" : : ) #define OFFSET(sym, str, mem) \ DEFINE(sym, offsetof(struct str, mem)) #define COMMENT(x) \ - asm volatile("\n->#" x) + asm volatile("\n.ascii \"->#" x "\"") #endif diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile index c11212f..0698af3 100644 --- a/scripts/mod/Makefile +++ b/scripts/mod/Makefile @@ -6,7 +6,8 @@ modpost-objs := modpost.o file2alias.o sumversion.o devicetable-offsets-file := devicetable-offsets.h define sed-y - "/^->/{s:->#\(.*\):/* \1 */:; \ + "s:[[:space:]]*\.ascii[[:space:]]*\"\(.*\)\":\1:; \ + /^->/{s:->#\(.*\):/* \1 */:; \ s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \ s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \ s:->::; p;}"