Re: [PATCH] parisc: suppress error messages for 'make clean'

[Helge Deller]

* Masahiro Yamada <masahiroy@xxxxxxxxxx>:
> On Sat, Apr 25, 2020 at 2:47 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
> >
> > 'make ARCH=parisc clean' emits a tons of error messages as follows:
> >
> >   $ make ARCH=parisc clean
> >   gcc: error: unrecognized command line option '-mno-space-regs'
> >   gcc: error: unrecognized command line option '-mfast-indirect-calls'; did you mean '-mforce-indirect-call'?
> >   gcc: error: unrecognized command line option '-mdisable-fpregs'
> >   gcc: error: missing argument to '-Wframe-larger-than='
> >   gcc: error: unrecognized command line option '-mno-space-regs'
> >   gcc: error: unrecognized command line option '-mfast-indirect-calls'; did you mean '-mforce-indirect-call'?
> >   gcc: error: unrecognized command line option '-mdisable-fpregs'
> >   gcc: error: missing argument to '-Wframe-larger-than='
> >     ...
> >
> > You can supporess them except '-Wframe-larger-than' by setting correct
> > CROSS_COMPILE=, but we should not require any compiler for cleaning.
> >
> > This $(shell ...) is evaluated so many times because LIBGCC is exported.
> > Use the ':=' operator to evaluate it just once, and sink the stderr.
> >
>
> Applied to linux-kbuild.

That patch breaks then building the boot loader/compressor:
...
  hppa-linux-gnu-ld    -X -e startup --as-needed -T arch/parisc/boot/compressed/vmlinux.lds arch/parisc/boot/compressed/head.o arch/parisc/boot/compressed/real2.o arch/parisc/boot/compressed/firmware.o arch/parisc/boot/compressed/misc.o arch/parisc/boot/compressed/piggy.o -o arch/parisc/boot/compressed/vmlinux
hppa-linux-gnu-ld: arch/parisc/boot/compressed/misc.o: in function `dec_vli':
(.text+0x104): undefined reference to `__ashldi3'
hppa-linux-gnu-ld: arch/parisc/boot/compressed/misc.o: in function `lzma_len':
(.text+0x2b0): undefined reference to `$$mulI'
hppa-linux-gnu-ld: (.text+0x344): undefined reference to `$$mulI'
hppa-linux-gnu-ld: (.text+0x3f8): undefined reference to `$$mulI'


The patch below works, but I wonder if it's possible to avoid
to examine LIBGCC twice....?

Helge


diff --git a/arch/parisc/Makefile b/arch/parisc/Makefile
index 628cd8bb7ad8..aeea20abbf01 100644
--- a/arch/parisc/Makefile
+++ b/arch/parisc/Makefile
@@ -21,8 +21,7 @@ KBUILD_IMAGE := vmlinuz

 NM		= sh $(srctree)/arch/parisc/nm
 CHECKFLAGS	+= -D__hppa__=1
-LIBGCC		= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
-export LIBGCC
+LIBGCC		:= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)

 ifdef CONFIG_64BIT
 UTS_MACHINE	:= parisc64
diff --git a/arch/parisc/boot/compressed/Makefile b/arch/parisc/boot/compressed/Makefile
index 1e5879c6a752..b008cf1b5c1e 100644
--- a/arch/parisc/boot/compressed/Makefile
+++ b/arch/parisc/boot/compressed/Makefile
@@ -22,6 +22,8 @@ ifndef CONFIG_64BIT
 KBUILD_CFLAGS += -mfast-indirect-calls
 endif

+LIBGCC  := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
+
 OBJECTS += $(obj)/head.o $(obj)/real2.o $(obj)/firmware.o $(obj)/misc.o $(obj)/piggy.o

 LDFLAGS_vmlinux := -X -e startup --as-needed -T