X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=Makefile.flags;h=cff935ff57decab7435bc5eb10574abc2f714dc5;hb=505eeae402a84dc5208986c5ad611f5e485cbe34;hp=cb2c8780a5ec32090a7a0256ec712bdd373e3fbc;hpb=1a9bbfb96f0c136b2748edbf7cba7ec8b496a44b;p=oweals%2Fbusybox.git diff --git a/Makefile.flags b/Makefile.flags index cb2c8780a..cff935ff5 100644 --- a/Makefile.flags +++ b/Makefile.flags @@ -4,7 +4,7 @@ BB_VER = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION) export BB_VER -SKIP_STRIP = n +SKIP_STRIP ?= n # -std=gnu99 needed for [U]LLONG_MAX on some systems CPPFLAGS += $(call cc-option,-std=gnu99,) @@ -15,7 +15,7 @@ CPPFLAGS += \ -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 + -DBB_VER=$(squote)$(quote)$(BB_VER)$(quote)$(squote) CFLAGS += $(call cc-option,-Wall,) CFLAGS += $(call cc-option,-Wshadow,) @@ -23,7 +23,9 @@ 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 @@ -31,23 +33,73 @@ CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) ifeq ($(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) -CFLAGS += $(call cc-option,-Os -fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections,) +ifneq ($(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 -static-libgcc,) -CFLAGS += $(call cc-option,-falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1,) +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 += $(call cc-option,-fno-builtin-printf,) + +# clang-9 does not like "str" + N and "if (CONFIG_ITEM && cond)" constructs +ifeq ($(CC),clang) +CFLAGS += $(call cc-option,-Wno-string-plus-int -Wno-constant-logical-operand) +endif # FIXME: These warnings are at least partially to be concerned about and should # be fixed.. -#CFLAGS+=$(call cc-option,-Wconversion,) - -ifeq ($(CONFIG_DEBUG),y) -CFLAGS += $(call cc-option,-g) +#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)... @@ -55,6 +107,12 @@ 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) @@ -66,6 +124,7 @@ endif ifeq ($(CONFIG_STATIC),y) CFLAGS_busybox += -static +PKG_CONFIG_FLAGS += --static endif ifeq ($(CONFIG_PIE),y) @@ -73,14 +132,55 @@ CFLAGS_busybox += $(ARCH_PIE) CFLAGS += $(ARCH_FPIE) endif -LDLIBS += m crypt +ifneq ($(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) -LDLIBS += selinux sepol +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 ($(CONFIG_EFENCE),y) @@ -91,11 +191,26 @@ ifeq ($(CONFIG_DMALLOC),y) LDLIBS += dmalloc endif -LDFLAGS_ELF2FLT = -Wl,-elf2flt -ifneq (,$(findstring $(LDFLAGS_ELF2FLT),$(LDFLAGS))) +# 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!)