Optimize opt_IMPLIES.

PR:		191144
Submitted by:	hrs
Sponsored by:	Absolight

1 files changed, 29 insertions, 3 deletions

diff --git a/Mk/bsd.options.mk b/Mk/bsd.options.mk
index 16a59fe1924c..d1359f330343 100644
--- a/Mk/bsd.options.mk
+++ b/Mk/bsd.options.mk
@@ -373,11 +373,37 @@ NEW_OPTIONS:=	${NEW_OPTIONS:N${opt}}
 
 ## Enable options implied by other options
 # _PREVENTS is handled in bsd.port.mk:pre-check-config
-.for count in ${PORT_OPTIONS}
-.  for opt in ${PORT_OPTIONS}
-PORT_OPTIONS+=	${${opt}_IMPLIES}
+## 1) Build dependency chain in A.B format:
+_DEPCHAIN=
+.for opt in ${COMPLETE_OPTIONS_LIST}
+.  for o in ${${opt}_IMPLIES}
+_DEPCHAIN+=	${opt}.$o
 .  endfor
 .endfor
+## 2) Check each dependency pair and if LHS is in PORT_OPTIONS then add RHS.
+##    All of RHS of "RHS.*" (i.e. indirect dependency) are also added for
+##    fast convergence.
+_PORT_OPTIONS:=	${PORT_OPTIONS}
+.for count in _0 ${COMPLETE_OPTIONS_LIST}
+### Check if all of the nested dependency are resolved already.
+.  if ${count} == _0 || ${_PORT_OPTIONS} != ${PORT_OPTIONS}
+PORT_OPTIONS:=	${_PORT_OPTIONS}
+.    for dc in ${_DEPCHAIN}
+.      for opt in ${_PORT_OPTIONS}
+_opt=${opt}
+### Add all of direct and indirect dependency only if
+### they are not in ${PORT_OPTIONS}.
+.        if !empty(_opt:M${dc:R})
+.          for d in ${dc:E} ${_DEPCHAIN:M${dc:E}.*:E}
+.            if empty(_PORT_OPTIONS:M$d)
+_PORT_OPTIONS+=	$d
+.            endif
+.          endfor
+.        endif
+.      endfor
+.    endfor
+.  endif
+.endfor
 
 # Finally, add options required by slave ports
 PORT_OPTIONS+=	${OPTIONS_SLAVE}