busybox/Makefile.flags
Bernhard Reutner-Fischer f6107c7e88 - add CONFIG_EXTRA_CFLAGS (thanks to keesj)
This helps with remembering additional flags like e.g. cpu settings for
  people who did not configured their compiler to produce code for their cpu
  per default.
2009-01-22 13:27:14 +00:00

122 lines
3.8 KiB
Makefile

# ==========================================================================
# Build system
# ==========================================================================
BB_VER = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
export BB_VER
SKIP_STRIP = n
# -std=gnu99 needed for [U]LLONG_MAX on some systems
CPPFLAGS += $(call cc-option,-std=gnu99,)
CPPFLAGS += \
-Iinclude -Ilibbb \
$(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include -I$(srctree)/libbb) \
-include include/autoconf.h \
-D_GNU_SOURCE -DNDEBUG \
$(if $(CONFIG_LFS),-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64) \
-D"BB_VER=KBUILD_STR($(BB_VER))" -DBB_BT=AUTOCONF_TIMESTAMP
CFLAGS += $(call cc-option,-Wall,)
CFLAGS += $(call cc-option,-Wshadow,)
CFLAGS += $(call cc-option,-Wwrite-strings,)
CFLAGS += $(call cc-option,-Wundef,)
CFLAGS += $(call cc-option,-Wstrict-prototypes,)
CFLAGS += $(call cc-option,-Wunused -Wunused-parameter,)
CFLAGS += $(call cc-option,-Wmissing-prototypes -Wmissing-declarations,)
# warn about C99 declaration after statement
CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
# If you want to add more -Wsomething above, make sure that it is
# still possible to build bbox without warnings.
ifeq ($(CONFIG_WERROR),y)
CFLAGS += $(call cc-option,-Werror,)
endif
# gcc 3.x emits bogus "old style proto" warning on find.c:alloc_action()
CFLAGS += $(call cc-ifversion, -ge, 0400, -Wold-style-definition)
CFLAGS += $(call cc-option,-fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections,)
# -fno-guess-branch-probability: prohibit pseudo-random guessing
# of branch probabilities (hopefully makes bloatcheck more stable):
CFLAGS += $(call cc-option,-fno-guess-branch-probability,)
CFLAGS += $(call cc-option,-funsigned-char -static-libgcc,)
CFLAGS += $(call cc-option,-falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1,)
# FIXME: These warnings are at least partially to be concerned about and should
# be fixed..
#CFLAGS += $(call cc-option,-Wconversion,)
ifneq ($(CONFIG_DEBUG),y)
CFLAGS += $(call cc-option,-Os,)
else
CFLAGS += $(call cc-option,-g,)
#CFLAGS += "-D_FORTIFY_SOURCE=2"
ifeq ($(CONFIG_DEBUG_PESSIMIZE),y)
CFLAGS += $(call cc-option,-O0,)
else
CFLAGS += $(call cc-option,-Os,)
endif
endif
# If arch/$(ARCH)/Makefile did not override it (with, say, -fPIC)...
ARCH_FPIC ?= -fpic
ARCH_FPIE ?= -fpie
ARCH_PIE ?= -pie
ifeq ($(CONFIG_BUILD_LIBBUSYBOX),y)
# on i386: 14% smaller libbusybox.so
# (code itself is 9% bigger, we save on relocs/PLT/GOT)
CFLAGS += $(ARCH_FPIC)
# and another 4% reduction of libbusybox.so:
# (external entry points must be marked EXTERNALLY_VISIBLE)
CFLAGS += $(call cc-option,-fvisibility=hidden)
endif
ifeq ($(CONFIG_STATIC),y)
CFLAGS_busybox += -static
endif
ifeq ($(CONFIG_PIE),y)
CFLAGS_busybox += $(ARCH_PIE)
CFLAGS += $(ARCH_FPIE)
endif
ifneq ($(CONFIG_EXTRA_CFLAGS),)
CFLAGS += $(strip $(subst ",,$(CONFIG_EXTRA_CFLAGS)))
#"))
endif
LDLIBS += m crypt
ifeq ($(CONFIG_PAM),y)
LDLIBS += pam pam_misc
endif
ifeq ($(CONFIG_SELINUX),y)
LDLIBS += selinux sepol
endif
ifeq ($(CONFIG_EFENCE),y)
LDLIBS += efence
endif
ifeq ($(CONFIG_DMALLOC),y)
LDLIBS += dmalloc
endif
# If a flat binary should be built, CFLAGS_busybox="-Wl,-elf2flt"
# env var should be set for make invocation.
# Here we check whether CFLAGS_busybox indeed contains that flag.
# (For historical reasons, we also check LDFLAGS, which doesn't
# seem to be entirely correct variable to put "-Wl,-elf2flt" into).
W_ELF2FLT = -Wl,-elf2flt
ifneq (,$(findstring $(W_ELF2FLT),$(LDFLAGS) $(CFLAGS_busybox)))
SKIP_STRIP = y
endif
# Busybox is a stack-fatty so make sure we increase default size
# TODO: use "make stksizes" to find & fix big stack users
# (we stole scripts/checkstack.pl from the kernel... thanks guys!)
# Reduced from 20k to 16k in 1.9.0.
FLTFLAGS += -s 16000