# ==========================================================================
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 \
+ $(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 \
- -Wall -Wstrict-prototypes -Wshadow -Werror \
- -funsigned-char -fno-builtin-strlen -finline-limit=0 -static-libgcc \
- -Os -falign-functions=1 -falign-jumps=1 -falign-loops=1 \
- -fomit-frame-pointer -ffunction-sections -fdata-sections
+ -D"BB_VER=KBUILD_STR($(BB_VER))"
+
+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,-Wunused-function -Wunused-value,)
+CFLAGS += $(call cc-option,-Wmissing-prototypes -Wmissing-declarations,)
+CFLAGS += $(call cc-option,-Wno-format-security,)
+# 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,)
+## TODO:
+## gcc version 4.4.0 20090506 (Red Hat 4.4.0-4) (GCC) is a PITA:
+## const char *ptr; ... off_t v = *(off_t*)ptr; -> BOOM
+## and no easy way to convince it to shut the hell up.
+## We have a lot of such things all over the place.
+## Classic *(off_t*)(void*)ptr does not work,
+## and I am unwilling to do crazy gcc specific ({ void *ppp = ...; })
+## stuff in macros. This would obfuscate the code too much.
+## Maybe try __attribute__((__may_alias__))?
+#CFLAGS += $(call cc-ifversion, -eq, 0404, -fno-strict-aliasing)
+endif
+# gcc 3.x emits bogus "old style proto" warning on find.c:alloc_action()
+CFLAGS += $(call cc-ifversion, -ge, 0400, -Wold-style-definition)
+
+ifneq ($(CC),clang)
+# "clang-9: warning: optimization flag '-finline-limit=0' is not supported
+CFLAGS += $(call cc-option,-finline-limit=0,)
+endif
+
+CFLAGS += $(call cc-option,-fno-builtin-strlen -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 += $(call cc-option,-funsigned-char,)
+
+ifneq ($(CC),clang)
+# "clang-9: warning: argument unused during compilation: '-static-libgcc'"
+CFLAGS += $(call cc-option,-static-libgcc,)
+endif
+
+CFLAGS += $(call cc-option,-falign-functions=1,)
+ifneq ($(CC),clang)
+# "clang-9: warning: optimization flag '-falign-jumps=1' is not supported" (and same for other two)
+CFLAGS += $(call cc-option,-falign-jumps=1 -falign-labels=1 -falign-loops=1,)
+endif
+
+# Defeat .eh_frame bloat (gcc 4.6.3 x86-32 defconfig: 20% smaller busybox binary):
+CFLAGS += $(call cc-option,-fno-unwind-tables,)
+CFLAGS += $(call cc-option,-fno-asynchronous-unwind-tables,)
+# No automatic printf->puts,putchar conversions
+# (try disabling this and comparing assembly, it's instructive)
+CFLAGS += $(call cc-option,-fno-builtin-printf,)
+
+# clang-9 does not like "str" + N and "if (CONFIG_ITEM && cond)" constructs
+CFLAGS += $(call cc-option,-Wno-string-plus-int -Wno-constant-logical-operand)
+
+# 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 += $(call cc-option,-Os,$(call cc-option,-O2,))
+else
+CFLAGS += $(call cc-option,-g,)
+#CFLAGS += "-D_FORTIFY_SOURCE=2"
+ifeq ($(CONFIG_DEBUG_PESSIMIZE),y)
+CFLAGS += $(call cc-option,-O0,)
+else
+CFLAGS += $(call cc-option,-Os,$(call cc-option,-O2,))
+endif
+endif
+ifeq ($(CONFIG_DEBUG_SANITIZE),y)
+CFLAGS += $(call cc-option,-fsanitize=address,)
+CFLAGS += $(call cc-option,-fsanitize=leak,)
+CFLAGS += $(call cc-option,-fsanitize=undefined,)
+endif
+
+# If arch/$(ARCH)/Makefile did not override it (with, say, -fPIC)...
+ARCH_FPIC ?= -fpic
+ARCH_FPIE ?= -fpie
+ARCH_PIE ?= -pie
+
+# Usage: $(eval $(call pkg_check_modules,VARIABLE-PREFIX,MODULES))
+define pkg_check_modules
+$(1)_CFLAGS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --cflags $(2))
+$(1)_LIBS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --libs $(2))
+endef
+
+ifeq ($(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
+PKG_CONFIG_FLAGS += --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
+
+# Note: both "" (string consisting of two quote chars) and empty string
+# are possible, and should be skipped below.
+ifneq ($(subst "",,$(CONFIG_SYSROOT)),)
+CFLAGS += --sysroot=$(CONFIG_SYSROOT)
+export SYSROOT=$(CONFIG_SYSROOT)
+endif
+
+# Android has no separate crypt library
+# gcc-4.2.1 fails if we try to feed C source on stdin:
+# echo 'int main(void){return 0;}' | $(CC) $(CFLAGS) -lcrypt -o /dev/null -xc -
+# fall back to using a temp file:
+CRYPT_AVAILABLE := $(shell echo 'int main(void){return 0;}' >crypttest.c; $(CC) $(CFLAGS) -lcrypt -o /dev/null crypttest.c >/dev/null 2>&1 && echo "y"; rm crypttest.c)
+ifeq ($(CRYPT_AVAILABLE),y)
+LDLIBS += m rt crypt
+else
+LDLIBS += m rt
+endif
+# libm may be needed for dc, awk, ntpd
+# librt may be needed for clock_gettime()
+
+# libpam may use libpthread, libdl and/or libaudit.
+# On some platforms that requires an explicit -lpthread, -ldl, -laudit.
+# However, on *other platforms* it fails when some of those flags
+# given needlessly. On some systems, crypt needs pthread.
+#
+# I even had a system where a runtime test for pthread
+# (similar to CRYPT_AVAILABLE test above) was not reliable.
+#
+# Do not propagate this mess by adding libraries to CONFIG_PAM/CRYPT_AVAILABLE blocks.
+# Add libraries you need to CONFIG_EXTRA_LDLIBS instead.
+
+ifeq ($(CONFIG_PAM),y)
+LDLIBS += pam pam_misc
+endif
+
+ifeq ($(CONFIG_SELINUX),y)
+SELINUX_PC_MODULES = libselinux libsepol
+$(eval $(call pkg_check_modules,SELINUX,$(SELINUX_PC_MODULES)))
+CPPFLAGS += $(SELINUX_CFLAGS)
+LDLIBS += $(if $(SELINUX_LIBS),$(SELINUX_LIBS:-l%=%),$(SELINUX_PC_MODULES:lib%=%))
+endif
+
+ifeq ($(CONFIG_FEATURE_NSLOOKUP_BIG),y)
+LDLIBS += resolv
+endif
+
+ifeq ($(CONFIG_EFENCE),y)
+LDLIBS += efence
+endif
+
+ifeq ($(CONFIG_DMALLOC),y)
+LDLIBS += dmalloc
+endif
+
+# If a flat binary should be built, CFLAGS_busybox="-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 "-elf2flt" into).
+W_ELF2FLT = -elf2flt
+ifneq (,$(findstring $(W_ELF2FLT),$(LDFLAGS) $(CFLAGS_busybox)))
+SKIP_STRIP = y
+endif
+
+ifneq ($(CONFIG_EXTRA_LDFLAGS),)
+LDFLAGS += $(strip $(subst ",,$(CONFIG_EXTRA_LDFLAGS)))
+#"))
+endif
+
+ifneq ($(CONFIG_EXTRA_LDLIBS),)
+LDLIBS += $(strip $(subst ",,$(CONFIG_EXTRA_LDLIBS)))
+#"))
+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
projects / oweals / busybox.git / blobdiff