Re: clang 7.0.1 build fails with `error: argument unused during compilation: '-Qn'`

[Daniel Kiper]

Hi Paul,

On Tue, Feb 05, 2019 at 05:45:50PM +0100, Paul Menzel wrote:
> Dear GRUB folks,
>
> Building GRUB from the master branch fails with clang 7.0.1 fails
> with the error below. The error is not shown with clang 6.0.1.
>
> ```
> $ ./autogen.sh
> $ ./configure CC=clang
> $ make -j`nproc`
> […]
> clang -DHAVE_CONFIG_H -I. -I..  -Wall -W  -DGRUB_MACHINE_PCBIOS=1 
> -DGRUB_MACHINE=I386_PC -m32 -msoft-float -Xclang -msoft-float -Xclang 
> -no-implicit-float -nostdinc -isystem /usr/lib/clang/7.0.1/include 
> -I../include -I../include -DGRUB_FILE=\"bus/cs5536.c\" -I. -I. -I.. -I.. 
> -I../include -I../include -I../grub-core/lib/libgcrypt-grub/src/    
> -D_FILE_OFFSET_BITS=64 -Os -Wall -W -Wshadow -Wpointer-arith -Wundef 
> -Wchar-subscripts -Wcomment -Wdeprecated-declarations -Wdisabled-optimization 
> -Wdiv-by-zero -Wfloat-equal -Wformat-extra-args -Wformat-security 
> -Wformat-y2k -Wimplicit -Wimplicit-function-declaration -Wimplicit-int -Wmain 
> -Wmissing-braces -Wmissing-format-attribute -Wmultichar -Wparentheses 
> -Wreturn-type -Wsequence-point -Wshadow -Wsign-compare -Wswitch -Wtrigraphs 
> -Wunknown-pragmas -Wunused -Wunused-function -Wunused-label 
> -Wunused-parameter -Wunused-value  -Wunused-variable -Wwrite-strings 
> -Wnested-externs -Wstrict-prototypes -g -Wredundant-decls 
> -Wmissing-prototypes -Wmissing-declarations  -Wextra -Wattributes 
> -Wendif-labels -Winit-self -Wint-to-pointer-cast -Winvalid-pch 
> -Wmissing-field-initializers -Wnonnull -Woverflow -Wvla -Wpointer-to-int-cast 
> -Wstrict-aliasing -Wvariadic-macros -Wvolatile-register-var -Wpointer-sign 
> -Wmissing-include-dirs -Wmissing-prototypes -Wmissing-declarations -Wformat=2 
> -march=i386 -m32 -malign-jumps=1 -malign-loops=1 -malign-functions=1 
> -freg-struct-return -mno-mmx -mno-sse -mno-sse2 -mno-sse3 -mno-3dnow 
> -fno-dwarf2-cfi-asm -mno-stack-arg-probe -fno-asynchronous-unwind-tables 
> -fno-unwind-tables -Qn -fno-stack-protector -Werror   -ffreestanding   -MT 
> bus/cs5536_module-cs5536.o -MD -MP -MF 
> bus/.deps-core/cs5536_module-cs5536.Tpo -c -o bus/cs5536_module-cs5536.o 
> `test -f 'bus/cs5536.c' || echo './'`bus/cs5536.c
> clang-7grep 'MARKER' gcry_twofish.marker.new > gcry_twofish.marker; rm -f 
> gcry_twofish.marker.new
> : error: argument unused during compilation: '-Qn' 
> [-Werror,-Wunused-command-line-argument]
> make[3]: *** [Makefile:28232: trig.module] Error 1

I am not sure what the problem is. May I ask you to take closer look and fix it?

Daniel