1 2# Setup variables for the linker. 3# 4# LINKER_TYPE is the major type of linker. Currently binutils and lld support 5# automatic detection. 6# 7# LINKER_VERSION is a numeric constant equal to: 8# major * 10000 + minor * 100 + tiny 9# It too can be overridden on the command line. 10# 11# LINKER_FEATURES may contain one or more of the following, based on 12# linker support for that feature: 13# 14# - build-id: support for generating a Build-ID note 15# - retpoline: support for generating PLT with retpoline speculative 16# execution vulnerability mitigation 17# - bti-report: support for specifying how to report the missing 18# Branch Target Identification (BTI) property (AArch64) 19# 20# LINKER_FREEBSD_VERSION is the linker's internal source version. 21# 22# These variables with an X_ prefix will also be provided if XLD is set. 23# 24# This file may be included multiple times, but only has effect the first time. 25# 26 27.if !target(__<bsd.linker.mk>__) 28__<bsd.linker.mk>__: 29 30_ld_vars=LD $${_empty_var_} 31.if !empty(_WANT_TOOLCHAIN_CROSS_VARS) 32# Only the toplevel makefile needs to compute the X_LINKER_* variables. 33_ld_vars+=XLD X_ 34.endif 35 36.for ld X_ in ${_ld_vars} 37.if ${ld} == "LD" || !empty(XLD) 38# Try to import LINKER_TYPE and LINKER_VERSION from parent make. 39# The value is only used/exported for the same environment that impacts 40# LD and LINKER_* settings here. 41_exported_vars= ${X_}LINKER_TYPE ${X_}LINKER_VERSION ${X_}LINKER_FEATURES \ 42 ${X_}LINKER_FREEBSD_VERSION 43${X_}_ld_hash= ${${ld}}${MACHINE}${PATH} 44${X_}_ld_hash:= ${${X_}_ld_hash:hash} 45# Only import if none of the vars are set differently somehow else. 46_can_export= yes 47.for var in ${_exported_vars} 48.if defined(${var}) && (!defined(${var}__${${X_}_ld_hash}) || ${${var}__${${X_}_ld_hash}} != ${${var}}) 49.if defined(${var}__${${X_}_ld_hash}) 50.info Cannot import ${X_}LINKER variables since cached ${var} is different: ${${var}__${${X_}_ld_hash}} != ${${var}} 51.endif 52_can_export= no 53.endif 54.endfor 55.if ${_can_export} == yes 56.for var in ${_exported_vars} 57.if defined(${var}__${${X_}_ld_hash}) 58${var}= ${${var}__${${X_}_ld_hash}} 59.endif 60.endfor 61.endif 62 63.if ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD}) 64.if !defined(${X_}LINKER_TYPE) || !defined(${X_}LINKER_VERSION) 65_ld_version!= (${${ld}} -v 2>&1 || echo none) | sed -n 1p 66.if ${_ld_version} == "none" 67.warning Unable to determine linker type from ${ld}=${${ld}} 68.endif 69.if ${_ld_version:[1..2]} == "GNU ld" 70${X_}LINKER_TYPE= bfd 71${X_}LINKER_FREEBSD_VERSION= 0 72_v= ${_ld_version:M[1-9]*.[0-9]*:[1]} 73.elif ${_ld_version:MLLD} 74# Strip any leading PACKAGE_VENDOR string (e.g. "Homebrew") 75_ld_version:=${_ld_version:[*]:C/^.* LLD /LLD /:[@]} 76${X_}LINKER_TYPE= lld 77_v= ${_ld_version:[2]} 78.if ${_ld_version:[3]} == "(FreeBSD" 79${X_}LINKER_FREEBSD_VERSION:= ${_ld_version:[4]:C/.*-([^-]*)\)/\1/} 80.else 81${X_}LINKER_FREEBSD_VERSION= 0 82.endif 83.elif ${_ld_version:[1]:S/-classic$//} == "@(\#)PROGRAM:ld" 84# bootstrap linker on MacOS 85${X_}LINKER_TYPE= mac 86_v= ${_ld_version:[2]:C/PROJECT:(ld64|dyld)-//} 87# Convert version 409.12 to 409.12.0 so that the echo + awk below works 88.if empty(_v:M[1-9]*.[0-9]*.[0-9]*) && !empty(_v:M[1-9]*.[0-9]*) 89_v:=${_v}.0 90.else 91# Some versions do not contain a minor version so we need to append .0.0 there 92_v:=${_v}.0.0 93.endif 94.else 95.warning Unknown linker from ${ld}=${${ld}}: ${_ld_version}, defaulting to bfd 96${X_}LINKER_TYPE= bfd 97_v= 2.17.50 98.endif 99${X_}LINKER_VERSION!= echo "${_v:M[1-9]*.[0-9]*}" | \ 100 awk -F. '{print $$1 * 10000 + $$2 * 100 + $$3;}' 101.undef _ld_version 102.undef _v 103${X_}LINKER_FEATURES= 104.if ${${X_}LINKER_TYPE} != "bfd" || ${${X_}LINKER_VERSION} > 21750 105${X_}LINKER_FEATURES+= build-id 106${X_}LINKER_FEATURES+= ifunc 107.endif 108.if ${${X_}LINKER_TYPE} == "bfd" && ${${X_}LINKER_VERSION} > 21750 109${X_}LINKER_FEATURES+= riscv-relaxations 110.endif 111.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 60000 112${X_}LINKER_FEATURES+= retpoline 113.endif 114.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 90000 115${X_}LINKER_FEATURES+= ifunc-noplt 116.endif 117.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 140000 118${X_}LINKER_FEATURES+= bti-report 119.endif 120.endif 121.else 122# Use LD's values 123X_LINKER_TYPE= ${LINKER_TYPE} 124X_LINKER_VERSION= ${LINKER_VERSION} 125X_LINKER_FEATURES= ${LINKER_FEATURES} 126X_LINKER_FREEBSD_VERSION= ${LINKER_FREEBSD_VERSION} 127.endif # ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD}) 128 129# Export the values so sub-makes don't have to look them up again, using the 130# hash key computed above. 131.for var in ${_exported_vars} 132${var}__${${X_}_ld_hash}:= ${${var}} 133.export-env ${var}__${${X_}_ld_hash} 134.undef ${var}__${${X_}_ld_hash} 135.endfor 136 137.endif # ${ld} == "LD" || !empty(XLD) 138.endfor # .for ld in LD XLD 139 140 141.endif # !target(__<bsd.linker.mk>__) 142