LXR busybox/Makefile.flags

   1# ==========================================================================
   2# Build system
   3# ==========================================================================
   4
   5BB_VER = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
   6export BB_VER
   7SKIP_STRIP = n
   8
   9# -std=gnu99 needed for [U]LLONG_MAX on some systems
  10CPPFLAGS += $(call cc-option,-std=gnu99,)
  11
  12CPPFLAGS += \
  13        -Iinclude -Ilibbb \
  14        $(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include -I$(srctree)/libbb) \
  15        -include include/autoconf.h \
  16        -D_GNU_SOURCE -DNDEBUG \
  17        $(if $(CONFIG_LFS),-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64) \
  18        -D"BB_VER=KBUILD_STR($(BB_VER))" -DBB_BT=AUTOCONF_TIMESTAMP
  19
  20CFLAGS += $(call cc-option,-Wall,)
  21CFLAGS += $(call cc-option,-Wshadow,)
  22CFLAGS += $(call cc-option,-Wwrite-strings,)
  23CFLAGS += $(call cc-option,-Wundef,)
  24CFLAGS += $(call cc-option,-Wstrict-prototypes,)
  25CFLAGS += $(call cc-option,-Wunused -Wunused-parameter,)
  26CFLAGS += $(call cc-option,-Wunused-function -Wunused-value,)
  27CFLAGS += $(call cc-option,-Wmissing-prototypes -Wmissing-declarations,)
  28# warn about C99 declaration after statement
  29CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
  30# If you want to add more -Wsomething above, make sure that it is
  31# still possible to build bbox without warnings.
  32
  33ifeq ($(CONFIG_WERROR),y)
  34CFLAGS += $(call cc-option,-Werror,)
  35## TODO:
  36## gcc version 4.4.0 20090506 (Red Hat 4.4.0-4) (GCC) is a PITA:
  37## const char *ptr; ... off_t v = *(off_t*)ptr; -> BOOM
  38## and no easy way to convince it to shut the hell up.
  39## We have a lot of such things all over the place.
  40## Classic *(off_t*)(void*)ptr does not work,
  41## and I am unwilling to do crazy gcc specific ({ void *ppp = ...; })
  42## stuff in macros. This would obfuscate the code too much.
  43#CFLAGS += $(call cc-ifversion, -eq, 0404, -fno-strict-aliasing)
  44endif
  45# gcc 3.x emits bogus "old style proto" warning on find.c:alloc_action()
  46CFLAGS += $(call cc-ifversion, -ge, 0400, -Wold-style-definition)
  47
  48CFLAGS += $(call cc-option,-fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections,)
  49# -fno-guess-branch-probability: prohibit pseudo-random guessing
  50# of branch probabilities (hopefully makes bloatcheck more stable):
  51CFLAGS += $(call cc-option,-fno-guess-branch-probability,)
  52CFLAGS += $(call cc-option,-funsigned-char -static-libgcc,)
  53CFLAGS += $(call cc-option,-falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1,)
  54
  55# FIXME: These warnings are at least partially to be concerned about and should
  56# be fixed..
  57#CFLAGS += $(call cc-option,-Wconversion,)
  58
  59ifneq ($(CONFIG_DEBUG),y)
  60CFLAGS += $(call cc-option,-Os,)
  61else
  62CFLAGS += $(call cc-option,-g,)
  63#CFLAGS += "-D_FORTIFY_SOURCE=2"
  64ifeq ($(CONFIG_DEBUG_PESSIMIZE),y)
  65CFLAGS += $(call cc-option,-O0,)
  66else
  67CFLAGS += $(call cc-option,-Os,)
  68endif
  69endif
  70
  71# If arch/$(ARCH)/Makefile did not override it (with, say, -fPIC)...
  72ARCH_FPIC ?= -fpic
  73ARCH_FPIE ?= -fpie
  74ARCH_PIE ?= -pie
  75
  76ifeq ($(CONFIG_BUILD_LIBBUSYBOX),y)
  77# on i386: 14% smaller libbusybox.so
  78# (code itself is 9% bigger, we save on relocs/PLT/GOT)
  79CFLAGS += $(ARCH_FPIC)
  80# and another 4% reduction of libbusybox.so:
  81# (external entry points must be marked EXTERNALLY_VISIBLE)
  82CFLAGS += $(call cc-option,-fvisibility=hidden)
  83endif
  84
  85ifeq ($(CONFIG_STATIC),y)
  86CFLAGS_busybox += -static
  87endif
  88
  89ifeq ($(CONFIG_PIE),y)
  90CFLAGS_busybox += $(ARCH_PIE)
  91CFLAGS += $(ARCH_FPIE)
  92endif
  93
  94ifneq ($(CONFIG_EXTRA_CFLAGS),)
  95CFLAGS += $(strip $(subst ",,$(CONFIG_EXTRA_CFLAGS)))
  96#"))
  97endif
  98
  99LDLIBS += m crypt
 100
 101ifeq ($(CONFIG_PAM),y)
 102LDLIBS += pam pam_misc
 103endif
 104
 105ifeq ($(CONFIG_SELINUX),y)
 106LDLIBS += selinux sepol
 107endif
 108
 109ifeq ($(CONFIG_EFENCE),y)
 110LDLIBS += efence
 111endif
 112
 113ifeq ($(CONFIG_DMALLOC),y)
 114LDLIBS += dmalloc
 115endif
 116
 117# If a flat binary should be built, CFLAGS_busybox="-elf2flt"
 118# env var should be set for make invocation.
 119# Here we check whether CFLAGS_busybox indeed contains that flag.
 120# (For historical reasons, we also check LDFLAGS, which doesn't
 121# seem to be entirely correct variable to put "-elf2flt" into).
 122W_ELF2FLT = -elf2flt
 123ifneq (,$(findstring $(W_ELF2FLT),$(LDFLAGS) $(CFLAGS_busybox)))
 124SKIP_STRIP = y
 125endif
 126
 127# Busybox is a stack-fatty so make sure we increase default size
 128# TODO: use "make stksizes" to find & fix big stack users
 129# (we stole scripts/checkstack.pl from the kernel... thanks guys!)
 130# Reduced from 20k to 16k in 1.9.0.
 131FLTFLAGS += -s 16000
 132