freebsd-dev/share/mk/bsd.linker.mk
Bryan Drewery 1930b98d49 Stop using head(1) which is not available in installworld.
installworld should not be executing this anyhow but there is some
obscure case doing it still.  The head(1) binary is not part of
ITOOLS and there's no need to add it.

MFC after:	1 week
Sponsored by:	Dell EMC
2018-06-07 16:16:22 +00:00

103 lines
3.1 KiB
Makefile

# $FreeBSD$
# Setup variables for the linker.
#
# LINKER_TYPE is the major type of linker. Currently binutils and lld support
# automatic detection.
#
# LINKER_VERSION is a numeric constant equal to:
# major * 10000 + minor * 100 + tiny
# It too can be overridden on the command line.
#
# LINKER_FEATURES may contain one or more of the following, based on
# linker support for that feature:
#
# - build-id: support for generating a Build-ID note
# - retpoline: support for generating PLT with retpoline speculative
# execution vulnerability mitigation
#
# These variables with an X_ prefix will also be provided if XLD is set.
#
# This file may be included multiple times, but only has effect the first time.
#
.if !target(__<bsd.linker.mk>__)
__<bsd.linker.mk>__:
.for ld X_ in LD $${_empty_var_} XLD X_
.if ${ld} == "LD" || !empty(XLD)
# Try to import LINKER_TYPE and LINKER_VERSION from parent make.
# The value is only used/exported for the same environment that impacts
# LD and LINKER_* settings here.
_exported_vars= ${X_}LINKER_TYPE ${X_}LINKER_VERSION ${X_}LINKER_FEATURES
${X_}_ld_hash= ${${ld}}${MACHINE}${PATH}
${X_}_ld_hash:= ${${X_}_ld_hash:hash}
# Only import if none of the vars are set somehow else.
_can_export= yes
.for var in ${_exported_vars}
.if defined(${var})
_can_export= no
.endif
.endfor
.if ${_can_export} == yes
.for var in ${_exported_vars}
.if defined(${var}.${${X_}_ld_hash})
${var}= ${${var}.${${X_}_ld_hash}}
.endif
.endfor
.endif
.if ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD})
.if !defined(${X_}LINKER_TYPE) || !defined(${X_}LINKER_VERSION)
_ld_version!= (${${ld}} --version || echo none) | sed -n '1,1p'
.if ${_ld_version} == "none"
.warning Unable to determine linker type from ${ld}=${${ld}}
.endif
.if ${_ld_version:[1..2]} == "GNU ld"
${X_}LINKER_TYPE= bfd
_v= ${_ld_version:M[1-9].[0-9]*:[1]}
.elif ${_ld_version:[1]} == "LLD"
${X_}LINKER_TYPE= lld
_v= ${_ld_version:[2]}
.else
.warning Unknown linker from ${ld}=${${ld}}: ${_ld_version}, defaulting to bfd
${X_}LINKER_TYPE= bfd
_v= 2.17.50
.endif
${X_}LINKER_VERSION!= echo "${_v:M[1-9].[0-9]*}" | \
awk -F. '{print $$1 * 10000 + $$2 * 100 + $$3;}'
.undef _ld_version
.undef _v
${X_}LINKER_FEATURES=
.if ${${X_}LINKER_TYPE} != "bfd" || ${${X_}LINKER_VERSION} > 21750
${X_}LINKER_FEATURES+= build-id
${X_}LINKER_FEATURES+= ifunc
.endif
.if ${${X_}LINKER_TYPE} != "lld" || ${${X_}LINKER_VERSION} >= 50000
${X_}LINKER_FEATURES+= filter
.endif
.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 60000
${X_}LINKER_FEATURES+= retpoline
.endif
.endif
.else
# Use LD's values
X_LINKER_TYPE= ${LINKER_TYPE}
X_LINKER_VERSION= ${LINKER_VERSION}
X_LINKER_FEATURES= ${LINKER_FEATURES}
.endif # ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD})
# Export the values so sub-makes don't have to look them up again, using the
# hash key computed above.
.for var in ${_exported_vars}
${var}.${${X_}_ld_hash}:= ${${var}}
.export-env ${var}.${${X_}_ld_hash}
.undef ${var}.${${X_}_ld_hash}
.endfor
.endif # ${ld} == "LD" || !empty(XLD)
.endfor # .for ld in LD XLD
.endif # !target(__<bsd.linker.mk>__)