WITH_CTF can now be specified in src.conf (not recommended, there

are some problems with static executables), make.conf (would also affect ports which do not use GNU make and do not override the compile targets) or in the kernel config (via "makeoptions WITH_CTF=yes"). Additional (related) changes: - propagate WITH_CTF to module builds - do not add -g to the linker flags, it's a noop there anyway (at least according to the man page of ld) - do not add -g to CFLAGS unconditionally we need to have a look if it is really needed (IMO not) or if there is a way to add it only when WITH_CTF is used Note: ctfconvert / ctfmerge lines will not appear in the build output, to protect the innocent (those which do not build with WITH_CTF would see the shell-test and may think WITH_CTF is used). Reviewed by: imp, jhb, scottl (earlier version) Discussed on: arch@
svn path=/head/; revision=206082
2024-07-21 10:19:04 +00:00 · 2010-04-02 06:55:31 +00:00 · 2010-04-02 06:55:31 +00:00 · 21edb039c6 · 2020-12-20 02:59:44 +00:00
parent fc825cc346
commit 21edb039c6
10 changed files with 92 additions and 118 deletions
--- a/10
+++ b/10
@ -22,6 +22,16 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 9.x IS SLOW:
 	machines to maximize performance.  (To disable malloc debugging, run
 	ln -s aj /etc/malloc.conf.)

+20100402:
+	WITH_CTF can now be specified in src.conf (not recommended, there
+	are some problems with static executables), make.conf (would also
+	affect ports which do not use GNU make and do not override the
+	compile targets) or in the kernel config (via "makeoptions
+	WITH_CTF=yes").
+	When WITH_CTF was specified there before this was silently ignored,
+	so make sure that WITH_CTF is not used in places which could lead
+	to unwanted behavior.
+
 20100311:
 	The kernel option COMPAT_IA32 has been replaced with COMPAT_FREEBSD32
 	to allow 32-bit compatibility on non-x86 platforms. All kernel
--- a/share/man/man7/build.7
+++ b/share/man/man7/build.7
@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 31, 2010
+.Dd April 02, 2010
 .Dt BUILD 7
 .Os
 .Sh NAME
@ -341,6 +341,15 @@ or the command line.
 .It Va NO_WERROR
 If defined, compiler warnings will not cause the build to halt,
 even if the makefile says otherwise.
+.It Va WITH_CTF
+If defined, the build process will run the DTrace CTF conversion
+tools on built objects.
+Please note that this WITH_ option is handled differently than all
+other WITH_ options (there is no
+.Va WITHOUT_CTF ,
+or corresponding
+.Va MK_CTF
+in the build system).
 .El
 .Pp
 Additionally, builds in
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@ -33,6 +33,11 @@ CFLAGS+= -DNDEBUG
 NO_WERROR=
 .endif

+# Enable CTF conversion on request.
+.if defined(WITH_CTF)
+.undef NO_CTF
+.endif
+
 .if defined(DEBUG_FLAGS)
 CFLAGS+= ${DEBUG_FLAGS}

@ -68,15 +73,11 @@ PO_FLAG=-pg

 .c.po:
 	${CC} ${PO_FLAG} ${PO_CFLAGS} -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .c.So:
 	${CC} ${PICFLAG} -DPIC ${CFLAGS} -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .cc.po .C.po .cpp.po .cxx.po:
 	${CXX} ${PO_FLAG} ${PO_CXXFLAGS} -c ${.IMPSRC} -o ${.TARGET}
@ -86,58 +87,40 @@ PO_FLAG=-pg

 .f.po:
 	${FC} -pg ${FFLAGS} -o ${.TARGET} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .f.So:
 	${FC} ${PICFLAG} -DPIC ${FFLAGS} -o ${.TARGET} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .m.po:
 	${OBJC} ${OBJCFLAGS} -pg -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .m.So:
 	${OBJC} ${PICFLAG} -DPIC ${OBJCFLAGS} -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .s.po .s.So:
 	${AS} ${AFLAGS} -o ${.TARGET} ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .asm.po:
 	${CC} -x assembler-with-cpp -DPROF ${PO_CFLAGS} -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .asm.So:
 	${CC} -x assembler-with-cpp ${PICFLAG} -DPIC ${CFLAGS} \
 	    -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .S.po:
 	${CC} -DPROF ${PO_CFLAGS} -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .S.So:
 	${CC} ${PICFLAG} -DPIC ${CFLAGS} -c ${.IMPSRC} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 all: objwarn

@ -208,9 +191,7 @@ ${SHLIB_NAME}: ${SOBJS}
 	    -o ${.TARGET} -Wl,-soname,${SONAME} \
 	    `NM='${NM}' lorder ${SOBJS} | tsort -q` ${LDADD}
 .endif
-.if defined(CTFMERGE)
-	${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${SOBJS}
-.endif
+	@[ -z "${CTFMERGE}" -o -n "${NO_CTF}" ] || ${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${SOBJS}
 .endif

 .if defined(INSTALL_PIC_ARCHIVE) && defined(LIB) && !empty(LIB) && ${MK_TOOLCHAIN} != "no"
--- a/share/mk/bsd.port.mk
+++ b/share/mk/bsd.port.mk
@ -7,5 +7,10 @@ BSDPORTMK?=	${PORTSDIR}/Mk/bsd.port.mk
 # and setting MK_* variables when building ports.
 _WITHOUT_SRCCONF=

+# Enable CTF conversion on request.
+.if defined(WITH_CTF)
+.undef NO_CTF
+.endif
+
 .include <bsd.own.mk>
 .include "${BSDPORTMK}"
--- a/share/mk/bsd.prog.mk
+++ b/share/mk/bsd.prog.mk
@ -15,6 +15,11 @@ CFLAGS+= -DNDEBUG
 NO_WERROR=
 .endif

+# Enable CTF conversion on request.
+.if defined(WITH_CTF)
+.undef NO_CTF
+.endif
+
 .if defined(DEBUG_FLAGS)
 CFLAGS+=${DEBUG_FLAGS}
 CXXFLAGS+=${DEBUG_FLAGS}
@ -61,9 +66,7 @@ ${PROG}: ${OBJS}
 .else
 	${CC} ${CFLAGS} ${LDFLAGS} -o ${.TARGET} ${OBJS} ${LDADD}
 .endif
-.if defined(CTFMERGE)
-	${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${OBJS}
-.endif
+	@[ -z "${CTFMERGE}" -o -n "${NO_CTF}" ] || ${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${OBJS}

 .else	# !defined(SRCS)

@ -87,9 +90,7 @@ ${PROG}: ${OBJS}
 .else
 	${CC} ${CFLAGS} ${LDFLAGS} -o ${.TARGET} ${OBJS} ${LDADD}
 .endif
-.if defined(CTFMERGE)
-	${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${OBJS}
-.endif
+	@[ -z "${CTFMERGE}" -o -n "${NO_CTF}" ] || ${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${OBJS}
 .endif

 .endif
--- a/share/mk/sys.mk
+++ b/share/mk/sys.mk
@ -55,14 +55,14 @@ NO_CTF		=	1
 # C Type Format data is required for DTrace
 CTFFLAGS	?=	-L VERSION

-.if !defined(NO_CTF)
 CTFCONVERT	?=	ctfconvert
 CTFMERGE	?=	ctfmerge
 .if defined(CFLAGS) && (${CFLAGS:M-g} != "")
 CTFFLAGS	+=	-g
 .else
-CFLAGS		+=	-g
-.endif
+# XXX: What to do here? Is removing the CFLAGS part completely ok here?
+# For now comment it out to not compile with -g unconditionally.
+#CFLAGS		+=	-g
 .endif

 CXX		?=	c++
@ -144,15 +144,11 @@ YFLAGS		?=	-d
 # SINGLE SUFFIX RULES
 .c:
 	${CC} ${CFLAGS} ${LDFLAGS} -o ${.TARGET} ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .f:
 	${FC} ${FFLAGS} ${LDFLAGS} -o ${.TARGET} ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .sh:
 	cp ${.IMPSRC} ${.TARGET}
@ -162,33 +158,25 @@ YFLAGS		?=	-d

 .c.o:
 	${CC} ${CFLAGS} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .f.o:
 	${FC} ${FFLAGS} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .y.o:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} -c y.tab.c
 	rm -f y.tab.c
 	mv y.tab.o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .l.o:
 	${LEX} ${LFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} -c lex.yy.c
 	rm -f lex.yy.c
 	mv lex.yy.o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .y.c:
 	${YACC} ${YFLAGS} ${.IMPSRC}
@ -226,15 +214,11 @@ YFLAGS		?=	-d

 .c:
 	${CC} ${CFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .c.o:
 	${CC} ${CFLAGS} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .cc .cpp .cxx .C:
 	${CXX} ${CXXFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} -o ${.TARGET}
@ -244,15 +228,11 @@ YFLAGS		?=	-d

 .m.o:
 	${OBJC} ${OBJCFLAGS} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .p.o:
 	${PC} ${PFLAGS} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .e .r .F .f:
 	${FC} ${RFLAGS} ${EFLAGS} ${FFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} \
@ -263,38 +243,28 @@ YFLAGS		?=	-d

 .S.o:
 	${CC} ${CFLAGS} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .asm.o:
 	${CC} -x assembler-with-cpp ${CFLAGS} -c ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .s.o:
 	${AS} ${AFLAGS} -o ${.TARGET} ${.IMPSRC}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 # XXX not -j safe
 .y.o:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} -c y.tab.c -o ${.TARGET}
 	rm -f y.tab.c
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .l.o:
 	${LEX} -t ${LFLAGS} ${.IMPSRC} > ${.PREFIX}.tmp.c
 	${CC} ${CFLAGS} -c ${.PREFIX}.tmp.c -o ${.TARGET}
 	rm -f ${.PREFIX}.tmp.c
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 # XXX not -j safe
 .y.c:
@ -306,34 +276,26 @@ YFLAGS		?=	-d

 .s.out .c.out .o.out:
 	${CC} ${CFLAGS} ${LDFLAGS} ${.IMPSRC} ${LDLIBS} -o ${.TARGET}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .f.out .F.out .r.out .e.out:
 	${FC} ${EFLAGS} ${RFLAGS} ${FFLAGS} ${LDFLAGS} ${.IMPSRC} \
 	    ${LDLIBS} -o ${.TARGET}
 	rm -f ${.PREFIX}.o
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 # XXX not -j safe
 .y.out:
 	${YACC} ${YFLAGS} ${.IMPSRC}
 	${CC} ${CFLAGS} ${LDFLAGS} y.tab.c ${LDLIBS} -ly -o ${.TARGET}
 	rm -f y.tab.c
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 .l.out:
 	${LEX} -t ${LFLAGS} ${.IMPSRC} > ${.PREFIX}.tmp.c
 	${CC} ${CFLAGS} ${LDFLAGS} ${.PREFIX}.tmp.c ${LDLIBS} -ll -o ${.TARGET}
 	rm -f ${.PREFIX}.tmp.c
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 # FreeBSD build pollution.  Hide it in the non-POSIX part of the ifdef.
 __MAKE_CONF?=/etc/make.conf
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@ -108,3 +108,11 @@ CFLAGS+=	-restrict
 	${MACHINE_ARCH} != "arm" && ${MACHINE_ARCH} != "mips"
 CFLAGS+=	-fstack-protector
 .endif
+
+#
+# Enable CTF conversation on request.
+#
+.if defined(WITH_CTF)
+.undef NO_CTF
+.endif
+
--- a/sys/conf/kern.post.mk
+++ b/sys/conf/kern.post.mk
@ -19,6 +19,10 @@ MKMODULESENV+=	KERNBUILDDIR="${.CURDIR}" SYSDIR="${SYSDIR}"
 MKMODULESENV+=	CONF_CFLAGS="${CONF_CFLAGS}"
 .endif

+.if defined(WITH_CTF)
+MKMODULESENV+=	WITH_CTF="${WITH_CTF}"
+.endif
+
 .MAIN: all

 .for target in all clean cleandepend cleandir clobber depend install \
@ -90,9 +94,7 @@ ${FULLKERNEL}: ${SYSTEM_DEP} vers.o
 	@rm -f ${.TARGET}
 	@echo linking ${.TARGET}
 	${SYSTEM_LD}
-.if defined(CTFMERGE)
-	${SYSTEM_CTFMERGE}
-.endif
+	@${SYSTEM_CTFMERGE}
 .if !defined(DEBUG)
 	${OBJCOPY} --strip-debug ${.TARGET}
 .endif
@ -240,9 +242,7 @@ kernel-reinstall:

 config.o env.o hints.o vers.o vnode_if.o:
 	${NORMAL_C}
-.if defined(CTFCONVERT)
-	${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.endif
+	@[ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 config.ln env.ln hints.ln vers.ln vnode_if.ln:
 	${NORMAL_LINT}
--- a/sys/conf/kern.pre.mk
+++ b/sys/conf/kern.pre.mk
@ -128,11 +128,7 @@ NORMAL_C_NOWERROR= ${CC} -c ${CFLAGS} ${PROF} ${.IMPSRC}
 NORMAL_M= ${AWK} -f $S/tools/makeobjops.awk ${.IMPSRC} -c ; \
 	  ${CC} -c ${CFLAGS} ${WERROR} ${PROF} ${.PREFIX}.c

-.if defined(CTFCONVERT)
-NORMAL_CTFCONVERT= ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
-.else
-NORMAL_CTFCONVERT=
-.endif
+NORMAL_CTFCONVERT= [ -z "${CTFCONVERT}" -o -n "${NO_CTF}" ] || ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}

 NORMAL_LINT=	${LINT} ${LINTFLAGS} ${CFLAGS:M-[DIU]*} ${.IMPSRC}

@ -142,10 +138,7 @@ SYSTEM_DEP= Makefile ${SYSTEM_OBJS}
 SYSTEM_OBJS= locore.o ${MDOBJS} ${OBJS}
 SYSTEM_OBJS+= ${SYSTEM_CFILES:.c=.o}
 SYSTEM_OBJS+= hack.So
-.if defined(CTFMERGE)
-SYSTEM_CTFMERGE= ${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${SYSTEM_OBJS} vers.o
-LD+= -g
-.endif
+SYSTEM_CTFMERGE= [ -z "${CTFMERGE}" -o -n "${NO_CTF}" ] || ${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${SYSTEM_OBJS} vers.o
 SYSTEM_LD= @${LD} -Bdynamic -T ${LDSCRIPT} \
 	-warn-common -export-dynamic -dynamic-linker /red/herring \
 	-o ${.TARGET} -X ${SYSTEM_OBJS} vers.o
--- a/sys/conf/kmod.mk
+++ b/sys/conf/kmod.mk
@ -69,6 +69,11 @@ OBJCOPY?=	objcopy
 .error "Do not use KMODDEPS on 5.0+; use MODULE_VERSION/MODULE_DEPEND"
 .endif

+# Enable CTF conversion on request.
+.if defined(WITH_CTF)
+.undef NO_CTF
+.endif
+
 .include <bsd.init.mk>

 .SUFFIXES: .out .o .c .cc .cxx .C .y .l .s .S