[U-Boot] [PATCH 1/2] Makefile: fix clang warnings due to clang support
Jeroen Hofstee
jeroen at myspectrum.nl
Fri May 30 15:45:27 CEST 2014
Building u-boot tools with clang as a host compiler e.g. on
FreeBSD with `gmake HOSTCC=clang CONFIG_USE_PRIVATE_LIBGCC=y tools`
leads to many warnings [1] for every compiler invocation since
commit 598e2d33. Part of mentioned commit imports linux patches:
- kbuild: LLVMLinux: Adapt warnings for compilation with clang
- kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
No version of clang supports the gcc fno-delete-null-pointer-checks
though, but it is only passed to clang. Gcc does not have the clang
specific Qunused-arguments for the target. Furthermore several
warnings are disabled which aren't encountered in u-boot. Since such
a build has worked for quite some time and works after removing these
changes, just remove the clang specific handling to restore normal
building with clang as hostcc.
[1] Actual warnings
-------------------
GEN include/autoconf.mk.dep
arm-freebsd-gcc: unrecognized option '-Qunused-arguments'
HOSTCC scripts/basic/fixdep
clang: warning: argument unused during compilation:
'-fno-delete-null-pointer-checks'
cc: Masahiro Yamada <yamada.m at jp.panasonic.com>
Signed-off-by: Jeroen Hofstee <jeroen at myspectrum.nl>
---
Makefile | 28 ----------------------------
1 file changed, 28 deletions(-)
diff --git a/Makefile b/Makefile
index e38fd2f..bde41aa 100644
--- a/Makefile
+++ b/Makefile
@@ -209,11 +209,6 @@ HOSTCXX = g++
HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
HOSTCXXFLAGS = -O2
-ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
-HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \
- -Wno-missing-field-initializers -fno-delete-null-pointer-checks
-endif
-
ifeq ($(HOSTOS),cygwin)
HOSTCFLAGS += -ansi
endif
@@ -320,15 +315,6 @@ endif
export quiet Q KBUILD_VERBOSE
-ifneq ($(CC),)
-ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)
-COMPILER := clang
-else
-COMPILER := gcc
-endif
-export COMPILER
-endif
-
# Look for make include files relative to root of kernel src
MAKEFLAGS += --include-dir=$(srctree)
@@ -545,20 +531,6 @@ endif
KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
-ifeq ($(COMPILER),clang)
-KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
-KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,)
-KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
-KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
-KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
-# Quiet clang warning: comparison of unsigned expression < 0 is always false
-KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
-# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
-# source of a reference will be _MergedGlobals and not on of the whitelisted names.
-# See modpost pattern 2
-KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
-endif
-
KBUILD_CFLAGS += -g
# $(KBUILD_AFLAGS) sets -g, which causes gcc to pass a suitable -g<format>
# option to the assembler.
--
1.8.3.2
More information about the U-Boot
mailing list