freebsd-dev/share/mk/bsd.linker.mk
Alex Richardson 01c4f3a763 Make bsd.linker.mk work with the MacOS linker
This is not strictly required for crossbuilding but having lots of warnings
from bsd.linker.mk in the output was making it hard to see the actual
warning messages.

Reviewed By:	imp
Differential Revision: https://reviews.freebsd.org/D14318
2020-08-13 14:14:51 +00:00

133 lines
4.0 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
#
# LINKER_FREEBSD_VERSION is the linker's internal source version.
#
# 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>__:
_ld_vars=LD $${_empty_var_}
.if !empty(_WANT_TOOLCHAIN_CROSS_VARS)
# Only the toplevel makefile needs to compute the X_LINKER_* variables.
_ld_vars+=XLD X_
.endif
.for ld X_ in ${_ld_vars}
.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_}LINKER_FREEBSD_VERSION
${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}} -v 2>&1 || echo none) | sed -n 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
${X_}LINKER_FREEBSD_VERSION= 0
_v= ${_ld_version:M[1-9]*.[0-9]*:[1]}
.elif ${_ld_version:[1]} == "LLD"
${X_}LINKER_TYPE= lld
_v= ${_ld_version:[2]}
.if ${_ld_version:[3]} == "(FreeBSD"
${X_}LINKER_FREEBSD_VERSION:= ${_ld_version:[4]:C/.*-([^-]*)\)/\1/}
.else
${X_}LINKER_FREEBSD_VERSION= 0
.endif
.elif ${_ld_version:[1]} == "@(\#)PROGRAM:ld"
# bootstrap linker on MacOS
${X_}LINKER_TYPE= mac
_v= ${_ld_version:[2]:S/PROJECT:ld64-//}
# Convert version 409.12 to 409.12.0 so that the echo + awk below works
.if empty(_v:M[1-9]*.[0-9]*.[0-9]*) && !empty(_v:M[1-9]*.[0-9]*)
_v:=${_v}.0
.else
# Some versions do not contain a minor version so we need to append .0.0 there
_v:=${_v}.0.0
.endif
.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} == "bfd" && ${${X_}LINKER_VERSION} > 21750
${X_}LINKER_FEATURES+= riscv-relaxations
.endif
.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 60000
${X_}LINKER_FEATURES+= retpoline
.endif
.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 90000
${X_}LINKER_FEATURES+= ifunc-noplt
.endif
.endif
.else
# Use LD's values
X_LINKER_TYPE= ${LINKER_TYPE}
X_LINKER_VERSION= ${LINKER_VERSION}
X_LINKER_FEATURES= ${LINKER_FEATURES}
X_LINKER_FREEBSD_VERSION= ${LINKER_FREEBSD_VERSION}
.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>__)