1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
# ==========================================================================
# 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 $(CONFIG_LFS),-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64) \
-DBB_VER=$(squote)$(quote)$(BB_VER)$(quote)$(squote)
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
|
