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# - bti-report: support for specifying how to report the missing 15# Branch Target Identification (BTI) property (AArch64) 16# - build-id: support for generating a Build-ID note 17# - ifunc: support for indirect functions 18# - ifunc-noplt: support for indirect functions without PLT stubs 19# - retpoline: support for generating PLT with retpoline speculative 20# execution vulnerability mitigation 21# - riscv-relaxations: support for RISC-V relocation relaxations 22# 23# LINKER_FREEBSD_VERSION is the linker's internal source version. 24# 25# These variables with an X_ prefix will also be provided if XLD is set. 26# 27# This file may be included multiple times, but only has effect the first time. 28# 29 30.if !target(__<bsd.linker.mk>__) 31__<bsd.linker.mk>__: .NOTMAIN 32 33_ld_vars=LD $${_empty_var_} 34.if !empty(_WANT_TOOLCHAIN_CROSS_VARS) 35# Only the toplevel makefile needs to compute the X_LINKER_* variables. 36_ld_vars+=XLD X_ 37.endif 38 39.for ld X_ in ${_ld_vars} 40.if ${ld} == "LD" || !empty(XLD) 41# Try to import LINKER_TYPE and LINKER_VERSION from parent make. 42# The value is only used/exported for the same environment that impacts 43# LD and LINKER_* settings here. 44_exported_vars= ${X_}LINKER_TYPE ${X_}LINKER_VERSION ${X_}LINKER_FEATURES \ 45 ${X_}LINKER_FREEBSD_VERSION 46${X_}_ld_hash= ${${ld}}${MACHINE}${PATH} 47${X_}_ld_hash:= ${${X_}_ld_hash:hash} 48# Only import if none of the vars are set differently somehow else. 49_can_export= yes 50.for var in ${_exported_vars} 51.if defined(${var}) && (!defined(${var}__${${X_}_ld_hash}) || ${${var}__${${X_}_ld_hash}} != ${${var}}) 52.if defined(${var}__${${X_}_ld_hash}) 53.info Cannot import ${X_}LINKER variables since cached ${var} is different: ${${var}__${${X_}_ld_hash}} != ${${var}} 54.endif 55_can_export= no 56.endif 57.endfor 58.if ${_can_export} == yes 59.for var in ${_exported_vars} 60.if defined(${var}__${${X_}_ld_hash}) 61${var}= ${${var}__${${X_}_ld_hash}} 62.endif 63.endfor 64.endif 65 66.if ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD}) 67.if !defined(${X_}LINKER_TYPE) || !defined(${X_}LINKER_VERSION) 68_ld_version!= (${${ld}} -v 2>&1 || echo none) | sed -n 1p 69.if ${_ld_version} == "none" 70.warning Unable to determine linker type from ${ld}=${${ld}} 71.endif 72.if ${_ld_version:[1..2]} == "GNU ld" 73${X_}LINKER_TYPE= bfd 74${X_}LINKER_FREEBSD_VERSION= 0 75_v= ${_ld_version:M[1-9]*.[0-9]*:[1]} 76.elif ${_ld_version:MLLD} 77# Strip any leading PACKAGE_VENDOR string (e.g. "Homebrew") 78_ld_version:=${_ld_version:[*]:C/^.* LLD /LLD /:[@]} 79${X_}LINKER_TYPE= lld 80_v= ${_ld_version:[2]} 81.if ${_ld_version:[3]} == "(FreeBSD" 82${X_}LINKER_FREEBSD_VERSION:= ${_ld_version:[4]:C/.*-([^-]*)\)/\1/} 83.else 84${X_}LINKER_FREEBSD_VERSION= 0 85.endif 86.elif ${_ld_version:[1]:S/-classic$//} == "@(\#)PROGRAM:ld" 87# bootstrap linker on MacOS 88${X_}LINKER_TYPE= mac 89_v= ${_ld_version:[2]:C/PROJECT:(ld64|dyld)-//} 90# Convert version 409.12 to 409.12.0 so that the echo + awk below works 91.if empty(_v:M[1-9]*.[0-9]*.[0-9]*) && !empty(_v:M[1-9]*.[0-9]*) 92_v:=${_v}.0 93.else 94# Some versions do not contain a minor version so we need to append .0.0 there 95_v:=${_v}.0.0 96.endif 97.else 98.warning Unknown linker from ${ld}=${${ld}}: ${_ld_version}, defaulting to bfd 99${X_}LINKER_TYPE= bfd 100_v= 2.17.50 101.endif 102${X_}LINKER_VERSION!= echo "${_v:M[1-9]*.[0-9]*}" | \ 103 awk -F. '{print $$1 * 10000 + $$2 * 100 + $$3;}' 104.undef _ld_version 105.undef _v 106${X_}LINKER_FEATURES= 107${X_}LINKER_FEATURES+= build-id 108${X_}LINKER_FEATURES+= ifunc 109.if ${${X_}LINKER_TYPE} == "bfd" 110${X_}LINKER_FEATURES+= riscv-relaxations 111.endif 112.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 60000 113${X_}LINKER_FEATURES+= retpoline 114.endif 115.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 90000 116${X_}LINKER_FEATURES+= ifunc-noplt 117.endif 118.if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 140000 119${X_}LINKER_FEATURES+= bti-report 120.endif 121.endif 122.else 123# Use LD's values 124X_LINKER_TYPE= ${LINKER_TYPE} 125X_LINKER_VERSION= ${LINKER_VERSION} 126X_LINKER_FEATURES= ${LINKER_FEATURES} 127X_LINKER_FREEBSD_VERSION= ${LINKER_FREEBSD_VERSION} 128.endif # ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD}) 129 130# Export the values so sub-makes don't have to look them up again, using the 131# hash key computed above. 132.for var in ${_exported_vars} 133${var}__${${X_}_ld_hash}:= ${${var}} 134.export-env ${var}__${${X_}_ld_hash} 135.undef ${var}__${${X_}_ld_hash} 136.endfor 137 138.endif # ${ld} == "LD" || !empty(XLD) 139.endfor # .for ld in LD XLD 140 141 142.endif # !target(__<bsd.linker.mk>__) 143