1 # ==========================================================================
3 # ==========================================================================
5 BB_VER = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
9 # -std=gnu99 needed for [U]LLONG_MAX on some systems
10 CPPFLAGS += $(call cc-option,-std=gnu99,)
14 $(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include -I$(srctree)/libbb) \
15 -include include/autoconf.h \
16 -D_GNU_SOURCE -DNDEBUG \
17 $(if $(CONFIG_LFS),-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64) \
18 $(if $(CONFIG_TIME64),-D_TIME_BITS=64) \
19 -DBB_VER=$(squote)$(quote)$(BB_VER)$(quote)$(squote)
21 CFLAGS += $(call cc-option,-Wall,)
22 CFLAGS += $(call cc-option,-Wshadow,)
23 CFLAGS += $(call cc-option,-Wwrite-strings,)
24 CFLAGS += $(call cc-option,-Wundef,)
25 CFLAGS += $(call cc-option,-Wstrict-prototypes,)
26 CFLAGS += $(call cc-option,-Wunused -Wunused-parameter,)
27 CFLAGS += $(call cc-option,-Wunused-function -Wunused-value,)
28 CFLAGS += $(call cc-option,-Wmissing-prototypes -Wmissing-declarations,)
29 CFLAGS += $(call cc-option,-Wno-format-security,)
30 # warn about C99 declaration after statement
31 CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
32 # If you want to add more -Wsomething above, make sure that it is
33 # still possible to build bbox without warnings.
35 ifeq ($(CONFIG_WERROR),y)
36 CFLAGS += $(call cc-option,-Werror,)
38 ## gcc version 4.4.0 20090506 (Red Hat 4.4.0-4) (GCC) is a PITA:
39 ## const char *ptr; ... off_t v = *(off_t*)ptr; -> BOOM
40 ## and no easy way to convince it to shut the hell up.
41 ## We have a lot of such things all over the place.
42 ## Classic *(off_t*)(void*)ptr does not work,
43 ## and I am unwilling to do crazy gcc specific ({ void *ppp = ...; })
44 ## stuff in macros. This would obfuscate the code too much.
45 ## Maybe try __attribute__((__may_alias__))?
46 #CFLAGS += $(call cc-ifversion, -eq, 0404, -fno-strict-aliasing)
48 # gcc 3.x emits bogus "old style proto" warning on find.c:alloc_action()
49 CFLAGS += $(call cc-ifversion, -ge, 0400, -Wold-style-definition)
52 # "clang-9: warning: optimization flag '-finline-limit=0' is not supported
53 CFLAGS += $(call cc-option,-finline-limit=0,)
56 CFLAGS += $(call cc-option,-fno-builtin-strlen -fomit-frame-pointer -ffunction-sections -fdata-sections,)
57 # -fno-guess-branch-probability: prohibit pseudo-random guessing
58 # of branch probabilities (hopefully makes bloatcheck more stable):
59 CFLAGS += $(call cc-option,-fno-guess-branch-probability,)
60 CFLAGS += $(call cc-option,-funsigned-char,)
62 ifeq ($(CONFIG_STATIC_LIBGCC),y)
63 # Disable it, for example, if you get
64 # "clang-9: warning: argument unused during compilation: '-static-libgcc'"
65 CFLAGS += $(call cc-option,-static-libgcc,)
68 CFLAGS += $(call cc-option,-falign-functions=1,)
70 # "clang-9: warning: optimization flag '-falign-jumps=1' is not supported" (and same for other two)
71 CFLAGS += $(call cc-option,-falign-jumps=1 -falign-labels=1 -falign-loops=1,)
74 # Defeat .eh_frame bloat (gcc 4.6.3 x86-32 defconfig: 20% smaller busybox binary):
75 CFLAGS += $(call cc-option,-fno-unwind-tables,)
76 CFLAGS += $(call cc-option,-fno-asynchronous-unwind-tables,)
77 # No automatic printf->puts,putchar conversions
78 # (try disabling this and comparing assembly, it's instructive)
79 CFLAGS += $(call cc-option,-fno-builtin-printf,)
81 # clang-9 does not like "str" + N and "if (CONFIG_ITEM && cond)" constructs
83 CFLAGS += $(call cc-option,-Wno-string-plus-int -Wno-constant-logical-operand)
86 # FIXME: These warnings are at least partially to be concerned about and should
88 #CFLAGS += $(call cc-option,-Wconversion,)
90 ifneq ($(CONFIG_DEBUG),y)
91 CFLAGS += $(call cc-option,-Oz,$(call cc-option,-Os,$(call cc-option,-O2,)))
93 CFLAGS += $(call cc-option,-g,)
94 #CFLAGS += "-D_FORTIFY_SOURCE=2"
95 ifeq ($(CONFIG_DEBUG_PESSIMIZE),y)
96 CFLAGS += $(call cc-option,-O0,)
98 CFLAGS += $(call cc-option,-Oz,$(call cc-option,-Os,$(call cc-option,-O2,)))
101 ifeq ($(CONFIG_DEBUG_SANITIZE),y)
102 CFLAGS += $(call cc-option,-fsanitize=address,)
103 CFLAGS += $(call cc-option,-fsanitize=leak,)
104 CFLAGS += $(call cc-option,-fsanitize=undefined,)
107 # If arch/$(ARCH)/Makefile did not override it (with, say, -fPIC)...
112 # Usage: $(eval $(call pkg_check_modules,VARIABLE-PREFIX,MODULES))
113 define pkg_check_modules
114 $(1)_CFLAGS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --cflags $(2))
115 $(1)_LIBS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --libs $(2))
118 ifeq ($(CONFIG_BUILD_LIBBUSYBOX),y)
119 # on i386: 14% smaller libbusybox.so
120 # (code itself is 9% bigger, we save on relocs/PLT/GOT)
121 CFLAGS += $(ARCH_FPIC)
122 # and another 4% reduction of libbusybox.so:
123 # (external entry points must be marked EXTERNALLY_VISIBLE)
124 CFLAGS += $(call cc-option,-fvisibility=hidden)
127 ifeq ($(CONFIG_STATIC),y)
128 CFLAGS_busybox += -static
129 PKG_CONFIG_FLAGS += --static
132 ifeq ($(CONFIG_PIE),y)
133 CFLAGS_busybox += $(ARCH_PIE)
134 CFLAGS += $(ARCH_FPIE)
137 ifneq ($(CONFIG_EXTRA_CFLAGS),)
138 CFLAGS += $(strip $(subst ",,$(CONFIG_EXTRA_CFLAGS)))
142 # Note: both "" (string consisting of two quote chars) and empty string
143 # are possible, and should be skipped below.
144 ifneq ($(subst "",,$(CONFIG_SYSROOT)),)
145 CFLAGS += --sysroot=$(CONFIG_SYSROOT)
146 export SYSROOT=$(CONFIG_SYSROOT)
149 # libm may be needed for dc, awk, ntpd
151 # Android has no separate crypt library
152 # gcc-4.2.1 fails if we try to feed C source on stdin:
153 # echo 'int main(void){return 0;}' | $(CC) $(CFLAGS) -lcrypt -o /dev/null -xc -
154 # fall back to using a temp file:
155 CRYPT_AVAILABLE := $(shell echo 'int main(void){return 0;}' >bb_libtest.c; $(CC) $(CFLAGS) $(CFLAGS_busybox) -lcrypt -o /dev/null bb_libtest.c >/dev/null 2>&1 && echo "y"; rm bb_libtest.c)
156 RT_AVAILABLE := $(shell echo 'int main(void){return 0;}' >bb_libtest.c; $(CC) $(CFLAGS) $(CFLAGS_busybox) -lrt -o /dev/null bb_libtest.c >/dev/null 2>&1 && echo "y"; rm bb_libtest.c)
157 ifeq ($(CRYPT_AVAILABLE),y)
160 # librt may be needed for clock_gettime()
161 ifeq ($(RT_AVAILABLE),y)
165 # libpam may use libpthread, libdl and/or libaudit.
166 # On some platforms that requires an explicit -lpthread, -ldl, -laudit.
167 # However, on *other platforms* it fails when some of those flags
168 # given needlessly. On some systems, crypt needs pthread.
170 # I even had a system where a runtime test for pthread
171 # (similar to CRYPT_AVAILABLE test above) was not reliable.
173 # Do not propagate this mess by adding libraries to CONFIG_PAM/CRYPT_AVAILABLE blocks.
174 # Add libraries you need to CONFIG_EXTRA_LDLIBS instead.
176 ifeq ($(CONFIG_PAM),y)
177 LDLIBS += pam pam_misc
180 ifeq ($(CONFIG_SELINUX),y)
181 SELINUX_PC_MODULES = libselinux libsepol
182 $(eval $(call pkg_check_modules,SELINUX,$(SELINUX_PC_MODULES)))
183 CPPFLAGS += $(SELINUX_CFLAGS)
184 LDLIBS += $(if $(SELINUX_LIBS),$(SELINUX_LIBS:-l%=%),$(SELINUX_PC_MODULES:lib%=%))
187 ifeq ($(CONFIG_FEATURE_NSLOOKUP_BIG),y)
188 ifneq (,$(findstring linux,$(shell $(CC) $(CFLAGS) -dumpmachine)))
191 ifneq (,$(findstring gnu,$(shell $(CC) $(CFLAGS) -dumpmachine)))
196 ifeq ($(CONFIG_EFENCE),y)
200 ifeq ($(CONFIG_DMALLOC),y)
204 # If a flat binary should be built, CFLAGS_busybox="-elf2flt"
205 # env var should be set for make invocation.
206 # Here we check whether CFLAGS_busybox indeed contains that flag.
207 # (For historical reasons, we also check LDFLAGS, which doesn't
208 # seem to be entirely correct variable to put "-elf2flt" into).
210 ifneq (,$(findstring $(W_ELF2FLT),$(LDFLAGS) $(CFLAGS_busybox)))
214 ifneq ($(CONFIG_EXTRA_LDFLAGS),)
215 LDFLAGS += $(strip $(subst ",,$(CONFIG_EXTRA_LDFLAGS)))
219 # Busybox is a stack-fatty so make sure we increase default size
220 # TODO: use "make stksizes" to find & fix big stack users
221 # (we stole scripts/checkstack.pl from the kernel... thanks guys!)
222 # Reduced from 20k to 16k in 1.9.0.