kumquat-buildroot/toolchain/toolchain-wrapper.mk
Atharva Lele b285c80143 toolchain/toolchain-wrapper: explicitly pass --build-id=none if BR2_REPRODUCIBLE
Build ID is added to binaries at link time. Building in different
output directories causes some packages to have different Build IDs,
thus resulting in non-reproducibility.

Adding "-Wl,--build-id=none" fixes this issue by disabling setting of
Build ID.

Diffoscope output for Build ID issue:
https://gitlab.com/snippets/1886180/raw

After this patch, build is reproducible - i.e. diffoscope does not
produce any output.

Signed-off-by: Atharva Lele <itsatharva@gmail.com>
Reviewed-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
2019-10-26 16:56:23 +02:00

77 lines
2.2 KiB
Makefile

################################################################################
#
# definition of the toolchain wrapper build commands
#
################################################################################
# We use --hash-style=both to increase the compatibility of the generated
# binary with older platforms, except for MIPS, where the only acceptable
# hash style is 'sysv'
ifeq ($(findstring mips,$(HOSTARCH)),mips)
TOOLCHAIN_WRAPPER_HASH_STYLE = sysv
else
TOOLCHAIN_WRAPPER_HASH_STYLE = both
endif
TOOLCHAIN_WRAPPER_ARGS = $($(PKG)_TOOLCHAIN_WRAPPER_ARGS)
TOOLCHAIN_WRAPPER_ARGS += -DBR_SYSROOT='"$(STAGING_SUBDIR)"'
TOOLCHAIN_WRAPPER_OPTS = \
$(ARCH_TOOLCHAIN_WRAPPER_OPTS) \
$(call qstrip,$(BR2_SSP_OPTION)) \
$(call qstrip,$(BR2_TARGET_OPTIMIZATION))
ifeq ($(BR2_REPRODUCIBLE),y)
TOOLCHAIN_WRAPPER_OPTS += -Wl,--build-id=none
endif
# We create a list like '"-mfoo", "-mbar", "-mbarfoo"' so that each flag is a
# separate argument when used in execv() by the toolchain wrapper.
TOOLCHAIN_WRAPPER_ARGS += \
-DBR_ADDITIONAL_CFLAGS='$(foreach f,$(TOOLCHAIN_WRAPPER_OPTS),"$(f)"$(comma))'
ifeq ($(BR2_CCACHE),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR_CCACHE
endif
ifeq ($(BR2_x86_x1000),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR_OMIT_LOCK_PREFIX
endif
# Avoid FPU bug on XBurst CPUs
ifeq ($(BR2_mips_xburst),y)
# Before gcc 4.6, -mno-fused-madd was needed, after -ffp-contract is
# needed
ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_4_6),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR_FP_CONTRACT_OFF
else
TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD
endif
endif
ifeq ($(BR2_CCACHE_USE_BASEDIR),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR_CCACHE_BASEDIR='"$(BASE_DIR)"'
endif
ifeq ($(BR2_PIC_PIE),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR2_PIC_PIE
endif
ifeq ($(BR2_RELRO_PARTIAL),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR2_RELRO_PARTIAL
else ifeq ($(BR2_RELRO_FULL),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR2_RELRO_FULL
endif
define TOOLCHAIN_WRAPPER_BUILD
$(HOSTCC) $(HOST_CFLAGS) $(TOOLCHAIN_WRAPPER_ARGS) \
-s -Wl,--hash-style=$(TOOLCHAIN_WRAPPER_HASH_STYLE) \
toolchain/toolchain-wrapper.c \
-o $(@D)/toolchain-wrapper
endef
define TOOLCHAIN_WRAPPER_INSTALL
$(INSTALL) -D -m 0755 $(@D)/toolchain-wrapper \
$(HOST_DIR)/bin/toolchain-wrapper
endef