3 # Setup variables for the linker.
5 # LINKER_TYPE is the major type of linker. Currently binutils and lld support
8 # LINKER_VERSION is a numeric constant equal to:
9 # major * 10000 + minor * 100 + tiny
10 # It too can be overridden on the command line.
12 # LINKER_FEATURES may contain one or more of the following, based on
13 # linker support for that feature:
15 # - build-id: support for generating a Build-ID note
16 # - retpoline: support for generating PLT with retpoline speculative
17 # execution vulnerability mitigation
19 # These variables with an X_ prefix will also be provided if XLD is set.
21 # This file may be included multiple times, but only has effect the first time.
24 .if !target(__<bsd.linker.mk>__)
27 .for ld X_ in LD $${_empty_var_} XLD X_
28 .if ${ld} == "LD" || !empty(XLD)
29 # Try to import LINKER_TYPE and LINKER_VERSION from parent make.
30 # The value is only used/exported for the same environment that impacts
31 # LD and LINKER_* settings here.
32 _exported_vars= ${X_}LINKER_TYPE ${X_}LINKER_VERSION ${X_}LINKER_FEATURES
33 ${X_}_ld_hash= ${${ld}}${MACHINE}${PATH}
34 ${X_}_ld_hash:= ${${X_}_ld_hash:hash}
35 # Only import if none of the vars are set somehow else.
37 .for var in ${_exported_vars}
42 .if ${_can_export} == yes
43 .for var in ${_exported_vars}
44 .if defined(${var}.${${X_}_ld_hash})
45 ${var}= ${${var}.${${X_}_ld_hash}}
50 .if ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD})
51 .if !defined(${X_}LINKER_TYPE) || !defined(${X_}LINKER_VERSION)
52 _ld_version!= (${${ld}} --version || echo none) | head -n 1
53 .if ${_ld_version} == "none"
54 .warning Unable to determine linker type from ${ld}=${${ld}}
56 .if ${_ld_version:[1..2]} == "GNU ld"
58 _v= ${_ld_version:M[1-9].[0-9]*:[1]}
59 .elif ${_ld_version:[1]} == "LLD"
61 _v= ${_ld_version:[2]}
63 .warning Unknown linker from ${ld}=${${ld}}: ${_ld_version}, defaulting to bfd
67 ${X_}LINKER_VERSION!= echo "${_v:M[1-9].[0-9]*}" | \
68 awk -F. '{print $$1 * 10000 + $$2 * 100 + $$3;}'
72 .if ${${X_}LINKER_TYPE} != "bfd" || ${${X_}LINKER_VERSION} > 21750
73 ${X_}LINKER_FEATURES+= build-id
75 .if ${${X_}LINKER_TYPE} != "lld" || ${${X_}LINKER_VERSION} >= 50000
76 ${X_}LINKER_FEATURES+= filter
78 .if ${${X_}LINKER_TYPE} == "lld" && ${${X_}LINKER_VERSION} >= 60000
79 ${X_}LINKER_FEATURES+= retpoline
84 X_LINKER_TYPE= ${LINKER_TYPE}
85 X_LINKER_VERSION= ${LINKER_VERSION}
86 X_LINKER_FEATURES= ${LINKER_FEATURES}
87 .endif # ${ld} == "LD" || (${ld} == "XLD" && ${XLD} != ${LD})
89 # Export the values so sub-makes don't have to look them up again, using the
90 # hash key computed above.
91 .for var in ${_exported_vars}
92 ${var}.${${X_}_ld_hash}:= ${${var}}
93 .export-env ${var}.${${X_}_ld_hash}
94 .undef ${var}.${${X_}_ld_hash}
97 .endif # ${ld} == "LD" || !empty(XLD)
98 .endfor # .for ld in LD XLD
101 .endif # !target(__<bsd.linker.mk>__)