From 6ee34e709d69b86d67884fc04ff5e05560e242fd Mon Sep 17 00:00:00 2001
From: Landon Curt Noll <github-mail@asthe.com>
Date: Mon, 14 Aug 2023 01:26:52 -0700
Subject: [PATCH] fix calc when CUSTOM is undefined, remove PASSDOWN values

Removed the ${CAL_PASSDOWN}, ${HELP_PASSDOWN}, ${HELP_PASSDOWN},
${CSCRIPT_PASSDOWN} Makefile variables as the new Makefile
include files keep Makefile variables in sync.

Fixed the ability of calc to compile when CUSTOM is undefined
(i.e., -UCUSTOM).  The libcustcalc is always built, regardless
of the $(ALLOW_CUSTOM} Makefile variable.  However when CUSTOM
is undefined, the bulk of custom functions are not defined.
---
 CHANGES             |   9 ++
 Makefile            | 315 +++++++-------------------------------------
 Makefile.target     |  56 ++------
 cal/Makefile        |   3 +-
 cscript/Makefile    |   3 +-
 custom.h            |   2 +
 custom/Makefile     |   3 +-
 custom/c_argv.c     |  25 +++-
 custom/c_devnull.c  |  23 +++-
 custom/c_help.c     |  25 +++-
 custom/c_pmodm127.c |  25 +++-
 custom/c_pzasusb8.c |  25 +++-
 custom/c_register.c |  27 ++--
 custom/c_sysinfo.c  |  51 ++++---
 custom/custtbl.c    |   8 +-
 help/Makefile       |   3 +-
 16 files changed, 221 insertions(+), 382 deletions(-)

diff --git a/CHANGES b/CHANGES
index b176dd9..ad5d24c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -69,6 +69,15 @@ The following are the changes from calc version 2.14.3.1 to date:
     Thus, one may modify or append many Makefile variables
     in all calc Makefiles.
 
+    Removed the ${CAL_PASSDOWN}, ${HELP_PASSDOWN}, ${HELP_PASSDOWN},
+    ${CSCRIPT_PASSDOWN} Makefile variables as the new Makefile
+    include files keep Makefile variables in sync.
+
+    Fixed the ability of calc to compile when CUSTOM is undefined
+    (i.e., -UCUSTOM).  The libcustcalc is always built, regardless
+    of the $(ALLOW_CUSTOM} Makefile variable.  However when CUSTOM
+    is undefined, the bulk of custom functions are not defined.
+
     Added comments in Makefile.local for how to reduce dependency chains
     under macOS.  XXX - this doesn't yet work so don't uncomment - XXX.
 
diff --git a/Makefile b/Makefile
index df40887..0136a2c 100644
--- a/Makefile
+++ b/Makefile
@@ -47,8 +47,7 @@ MAKE_FILE= Makefile
 #
 CONFIG_MKF= Makefile.config
 
-# Host targets that are shared in common with both Makefile
-# and custom/Makefile.
+# Host target information.
 #
 TARGET_MKF= Makefile.target
 
@@ -252,201 +251,6 @@ SAMPLE_C_SRC= sample_many.c sample_rand.c
 #
 SAMPLE_OBJ= sample_many.o sample_rand.o
 
-# The complete list of Makefile vars passed down to custom/Makefile.
-#
-CUSTOM_PASSDOWN=  \
-    ALLOW_CUSTOM="${ALLOW_CUSTOM}" \
-    AR="${AR}" \
-    ARCH_CFLAGS="${ARCH_CFLAGS}" \
-    AWK="${AWK}" \
-    BINDIR="${BINDIR}" \
-    BLD_TYPE="${BLD_TYPE}" \
-    CALC_INCDIR="${CALC_INCDIR}" \
-    CALC_SHAREDIR="${CALC_SHAREDIR}" \
-    CAT="${CAT}" \
-    CC="${CC}" \
-    CCBAN="${CCBAN}" \
-    CCERR="${CCERR}" \
-    CCMISC="${CCMISC}" \
-    CCOPT="${CCOPT}" \
-    CCWARN="${CCWARN}" \
-    CC_SHARE="${CC_SHARE}" \
-    CFLAGS="${CFLAGS} -I.." \
-    CHMOD="${CHMOD}" \
-    CMP="${CMP}" \
-    CO="${CO}" \
-    COMMON_ADD="${COMMON_ADD}" \
-    COMMON_CFLAGS="${COMMON_CFLAGS} -I.." \
-    COMMON_LDFLAGS="${COMMON_LDFLAGS}" \
-    CP="${CP}" \
-    CUSTOMCALDIR="${CUSTOMCALDIR}" \
-    CUSTOMHELPDIR="${CUSTOMHELPDIR}" \
-    CUSTOMINCDIR="${CUSTOMINCDIR}" \
-    DEBUG="${DEBUG}" \
-    DEFAULT_LIB_INSTALL_PATH="${DEFAULT_LIB_INSTALL_PATH}" \
-    DIFF="${DIFF}" \
-    E="${E}" \
-    FMT="${FMT}" \
-    GREP="${GREP}" \
-    H="${H}" \
-    HELPDIR="${HELPDIR}" \
-    ICFLAGS="${ICFLAGS} -I.." \
-    ILDFLAGS="${ILDFLAGS}" \
-    INCDIR="${INCDIR}" \
-    LANG="${LANG}" \
-    LCC="${LCC}" \
-    LDCONFIG="${LDCONFIG}" \
-    LDFLAGS="${LDFLAGS}" \
-    LD_SHARE="${LD_SHARE}" \
-    LIBCUSTCALC_SHLIB="${LIBCUSTCALC_SHLIB}" \
-    LIBDIR="${LIBDIR}" \
-    LN="${LN}" \
-    LS="${LS}" \
-    MAKE="${MAKE}" \
-    MAKEDEPEND="${MAKEDEPEND}" \
-    MAKE_FILE=Makefile \
-    MKDIR="${MKDIR}" \
-    MV="${MV}" \
-    MINGW="${MINGW}" \
-    PREFIX="${PREFIX}" \
-    PURIFY="${PURIFY}" \
-    Q="${Q}" \
-    RANLIB="${RANLIB}" \
-    RM="${RM}" \
-    RMDIR="${RMDIR}" \
-    S="${S}" \
-    SCRIPTDIR="${SCRIPTDIR}" \
-    SED="${SED}" \
-    SHELL="${SHELL}" \
-    SORT="${SORT}" \
-    T="${T}" \
-    TAIL="${TAIL}" \
-    TOUCH="${TOUCH}" \
-    TRUE="${TRUE}" \
-    V="${V}" \
-    VERSION="${VERSION}" \
-    WNO_IMPLICT="${WNO_IMPLICT}" \
-    WNO_ERROR_LONG_LONG="${WNO_ERROR_LONG_LONG}" \
-    WNO_LONG_LONG="${WNO_LONG_LONG}" \
-    target="${target}"
-
-# The complete list of Makefile vars passed down to help/Makefile.
-#
-HELP_PASSDOWN= \
-    AR="${AR}" \
-    BINDIR="${BINDIR}" \
-    CALC_INCDIR="${CALC_INCDIR}" \
-    CALC_SHAREDIR="${CALC_SHAREDIR}" \
-    CAT="${CAT}" \
-    CFLAGS="${CFLAGS}" \
-    CHMOD="${CHMOD}" \
-    CMP="${CMP}" \
-    CO="${CO}" \
-    COMMON_ADD="${COMMON_ADD}" \
-    COMMON_CFLAGS="${COMMON_CFLAGS}" \
-    COMMON_LDFLAGS="${COMMON_LDFLAGS}" \
-    CP="${CP}" \
-    E="${E}" \
-    EXT="${EXT}" \
-    FMT="${FMT}" \
-    GREP="${GREP}" \
-    H="${H}" \
-    HELPDIR="${HELPDIR}" \
-    ICFLAGS="${ICFLAGS}" \
-    ILDFLAGS="${ILDFLAGS}" \
-    INCDIR="${INCDIR}" \
-    LANG="${LANG}" \
-    LCC="${LCC}" \
-    LIBDIR="${LIBDIR}" \
-    MAKE_FILE=Makefile \
-    MKDIR="${MKDIR}" \
-    MINGW="${MINGW}" \
-    MV="${MV}" \
-    PREFIX="${PREFIX}" \
-    Q="${Q}" \
-    RM="${RM}" \
-    RMDIR="${RMDIR}" \
-    S="${S}" \
-    SCRIPTDIR="${SCRIPTDIR}" \
-    SED="${SED}" \
-    SHELL="${SHELL}" \
-    T="${T}" \
-    TOUCH="${TOUCH}" \
-    TRUE="${TRUE}" \
-    V="${V}"
-
-# The complete list of Makefile vars passed down to cal/Makefile.
-#
-CAL_PASSDOWN= \
-    AR="${AR}" \
-    BINDIR="${BINDIR}" \
-    CALC_INCDIR="${CALC_INCDIR}" \
-    CALC_SHAREDIR="${CALC_SHAREDIR}" \
-    CAT="${CAT}" \
-    CHMOD="${CHMOD}" \
-    CMP="${CMP}" \
-    CO="${CO}" \
-    CP="${CP}" \
-    E="${E}" \
-    H="${H}" \
-    HELPDIR="${HELPDIR}" \
-    INCDIR="${INCDIR}" \
-    LANG="${LANG}" \
-    LIBDIR="${LIBDIR}" \
-    MAKE_FILE=Makefile \
-    MKDIR="${MKDIR}" \
-    MINGW="${MINGW}" \
-    MV="${MV}" \
-    PREFIX="${PREFIX}" \
-    Q="${Q}" \
-    RM="${RM}" \
-    RMDIR="${RMDIR}" \
-    S="${S}" \
-    SCRIPTDIR="${SCRIPTDIR}" \
-    SHELL="${SHELL}" \
-    T="${T}" \
-    TOUCH="${TOUCH}" \
-    TRUE="${TRUE}" \
-    V="${V}"
-
-# The complete list of Makefile vars passed down to cscript/Makefile.
-#
-CSCRIPT_PASSDOWN= \
-    AR="${AR}" \
-    BINDIR="${BINDIR}" \
-    CALC_INCDIR="${CALC_INCDIR}" \
-    CALC_SHAREDIR="${CALC_SHAREDIR}" \
-    CAT="${CAT}" \
-    CHMOD="${CHMOD}" \
-    CMP="${CMP}" \
-    CO="${CO}" \
-    CP="${CP}" \
-    E="${E}" \
-    ECHON="${ECHON}" \
-    FMT="${FMT}" \
-    H="${H}" \
-    HELPDIR="${HELPDIR}" \
-    INCDIR="${INCDIR}" \
-    LANG="${LANG}" \
-    LIBDIR="${LIBDIR}" \
-    MAKE_FILE=Makefile \
-    MKDIR="${MKDIR}" \
-    MINGW="${MINGW}" \
-    MV="${MV}" \
-    PREFIX="${PREFIX}" \
-    Q="${Q}" \
-    RM="${RM}" \
-    RMDIR="${RMDIR}" \
-    S="${S}" \
-    SCRIPTDIR="${SCRIPTDIR}" \
-    SED="${SED}" \
-    SHELL="${SHELL}" \
-    SORT="${SORT}" \
-    T="${T}" \
-    TOUCH="${TOUCH}" \
-    TRUE="${TRUE}" \
-    V="${V}"
-
 # complete list of .h files found (but not built) in the distribution
 #
 H_SRC= ${LIB_H_SRC} ${SAMPLE_H_SRC}
@@ -480,18 +284,11 @@ OBJS= ${LIBOBJS} ${CALCOBJS} ${UTIL_OBJS} ${SAMPLE_OBJ}
 # Symlinks of dynamic shared libraries
 # Early targets - things needed before the main build phase can begin
 #
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 CALC_STATIC_LIBS= libcalc.a libcustcalc.a
 CALC_DYNAMIC_LIBS= libcalc${LIB_EXT_VERSION} libcustcalc${LIB_EXT_VERSION}
 SYM_DYNAMIC_LIBS= libcalc${LIB_EXT} \
-	libcustcalc${LIB_EXT_VERSION}  libcustcalc${LIB_EXT}
+	libcustcalc${LIB_EXT_VERSION} libcustcalc${LIB_EXT}
 EARLY_TARGETS= hsrc .hsrc custom/.all custom/Makefile
-else	# ($(ALLOW_CUSTOM),-DCUSTOM)
-CALC_STATIC_LIBS= libcalc.a
-CALC_DYNAMIC_LIBS= libcalc${LIB_EXT_VERSION}
-SYM_DYNAMIC_LIBS= libcalc${LIB_EXT}
-EARLY_TARGETS= hsrc .hsrc
-endif	# ($(ALLOW_CUSTOM),-DCUSTOM)
 
 # list of sample programs that need to be built to satisfy sample rule
 #
@@ -801,7 +598,6 @@ else	# RPM_TOP
 endif	# RPM_TOP
 	${Q} echo '#endif /* HELPDIR */' >> $@
 	${Q} echo '' >> $@
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 	${Q} echo '/* the location of the custom help directory */' >> $@
 	${Q} echo '#if !defined(CUSTOMHELPDIR)' >> $@
 ifdef RPM_TOP
@@ -811,7 +607,6 @@ else	# RPM_TOP
 endif	# RPM_TOP
 	${Q} echo '#endif /* CUSTOMHELPDIR */' >> $@
 	${Q} echo '' >> $@
-endif	# ($(ALLOW_CUSTOM),-DCUSTOM)
 	${Q} echo '/* the default pager to use */' >> $@
 	${Q} echo '#if !defined(DEFAULTCALCPAGER)' >> $@
 	${Q} echo '#define DEFAULTCALCPAGER "${CALCPAGER}"' >> $@
@@ -2517,7 +2312,7 @@ cal/.all: cal/Makefile
 	${V} echo '=-=-=-=-= ${MAKE_FILE} start of $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking all rule for cal =-=-=-=-='
 	${RM} -f $@
-	cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} all
+	cd cal; ${MAKE} -f Makefile all
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= ${MAKE_FILE} end of $@ rule =-=-=-=-='
 
@@ -2525,7 +2320,7 @@ help/.all: help/Makefile
 	${V} echo '=-=-=-=-= ${MAKE_FILE} start of $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking all rule for help =-=-=-=-='
 	${RM} -f $@
-	cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} all
+	cd help; ${MAKE} -f Makefile all
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= ${MAKE_FILE} end of $@ rule =-=-=-=-='
 
@@ -2534,7 +2329,7 @@ help/builtin: help/Makefile \
 	${V} echo '=-=-=-=-= ${MAKE_FILE} start of $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking builtin rule for help =-=-=-=-='
 	${RM} -f $@
-	cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} builtin
+	cd help; ${MAKE} -f Makefile builtin
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= ${MAKE_FILE} end of $@ rule =-=-=-=-='
 
@@ -2544,23 +2339,22 @@ ${CSCRIPT_TARGETS}: cscript/Makefile
 	${V} echo '=-=-=-=-= ${MAKE_FILE} start of $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking all rule for cscript =-=-=-=-='
 	${RM} -f cscript/.all
-	cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} all
+	cd cscript; ${MAKE} -f Makefile all
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= ${MAKE_FILE} end of $@ rule =-=-=-=-='
 
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 custom/.all: custom/Makefile
 	${V} echo '=-=-=-=-= ${MAKE_FILE} start of $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking all rule for custom =-=-=-=-='
 	${RM} -f $@
-	cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} all
+	cd custom; ${MAKE} -f Makefile all
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= ${MAKE_FILE} end of $@ rule =-=-=-=-='
 
 custom/libcustcalc${LIB_EXT_VERSION}: custom/Makefile
 	${V} echo '=-=-=-=-= ${MAKE_FILE} start of $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking all rule for custom =-=-=-=-='
-	cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} $@
+	cd custom; ${MAKE} -f Makefile $@
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= ${MAKE_FILE} end of $@ rule =-=-=-=-='
 
@@ -2571,7 +2365,6 @@ libcustcalc${LIB_EXT_VERSION}: custom/libcustcalc${LIB_EXT_VERSION}
 libcustcalc${LIB_EXT}: libcustcalc${LIB_EXT_VERSION}
 	${Q} ${RM} -f $@
 	${LN} -s $? $@
-endif	# ($(ALLOW_CUSTOM),-DCUSTOM)
 
 ###
 #
@@ -2585,20 +2378,18 @@ calc-static${EXT}: .hsrc ${CALCOBJS} \
 	${CC} ${LDFLAGS} ${CALCOBJS} ${LD_STATIC} ${CALC_STATIC_LIBS} \
 	      ${READLINE_LIB} ${READLINE_EXTRAS} -o $@
 
-libcustcalc.a: custom/libcustcalc.a
-	${Q} ${RM} -f $@
-	${CP} -f $? $@
-
 libcalc.a: ${LIBOBJS} ${MK_SET}
 	${RM} -f libcalc.a
 	${AR} qc libcalc.a ${LIBOBJS}
 	${RANLIB} libcalc.a
 	${CHMOD} 0644 libcalc.a
 
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
+libcustcalc.a: custom/libcustcalc.a
+	${Q} ${RM} -f $@
+	${CP} -f $? $@
+
 custom/libcustcalc.a: custom/Makefile
-	cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} libcustcalc.a
-endif	# ($(ALLOW_CUSTOM),-DCUSTOM)
+	cd custom; ${MAKE} -f Makefile libcustcalc.a
 
 sample_rand-static${EXT}: sample_rand.o ${CALC_STATIC_LIBS} \
 			  ${MK_SET}
@@ -2636,10 +2427,10 @@ depend: hsrc custom/Makefile
 	    exit 1; \
 	fi
 	${V} echo '=-=-=-=-= Invoking depend rule for cscript =-=-=-=-='
-	${Q} cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} depend
+	${Q} cd cscript; ${MAKE} -f Makefile depend
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking depend rule for custom =-=-=-=-='
-	${Q} cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} depend
+	${Q} cd custom; ${MAKE} -f Makefile depend
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${Q} echo forming skel
 	${Q} ${RM} -rf skel
@@ -2751,19 +2542,19 @@ distlist: ${DISTLIST} custom/Makefile
 		echo win32/$$i; \
 	    fi; \
 	done; \
-	(cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} $@); \
-	(cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} $@); \
-	(cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} $@); \
-	(cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} $@) \
+	(cd help; ${MAKE} -f Makefile $@); \
+	(cd cal; ${MAKE} -f Makefile $@); \
+	(cd custom; ${MAKE} -f Makefile $@); \
+	(cd cscript; ${MAKE} -f Makefile $@) \
 	) | LANG=C ${SORT}
 
 distdir: custom/Makefile
 	${Q} (echo .; \
 	echo win32; \
-	(cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} $@); \
-	(cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} $@); \
-	(cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} $@); \
-	(cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} $@) \
+	(cd help; ${MAKE} -f Makefile $@); \
+	(cd cal; ${MAKE} -f Makefile $@); \
+	(cd custom; ${MAKE} -f Makefile $@); \
+	(cd cscript; ${MAKE} -f Makefile $@) \
 	) | LANG=C ${SORT}
 
 calcliblist: custom/Makefile
@@ -2772,10 +2563,10 @@ calcliblist: custom/Makefile
 		echo $$i; \
 	    fi; \
 	done; \
-	(cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} $@); \
-	(cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} $@); \
-	(cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} $@); \
-	(cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} $@) \
+	(cd help; ${MAKE} -f Makefile $@); \
+	(cd cal; ${MAKE} -f Makefile $@); \
+	(cd custom; ${MAKE} -f Makefile $@); \
+	(cd cscript; ${MAKE} -f Makefile $@) \
 	) | LANG=C ${SORT}
 
 calcliblistfmt:
@@ -2930,7 +2721,6 @@ env:
 	@echo 'CALC_SHAREDIR=${CALC_SHAREDIR}'; echo ''
 	@echo 'CALCSRC=${CALCSRC}'; echo ''
 	@echo 'CALC_STATIC_LIBS=${CALC_STATIC_LIBS}'; echo ''
-	@echo 'CAL_PASSDOWN=${CAL_PASSDOWN}'; echo ''
 	@echo 'CAT=${CAT}'; echo ''
 	@echo 'CATDIR=${CATDIR}'; echo ''
 	@echo 'CATEXT=${CATEXT}'; echo ''
@@ -2951,14 +2741,12 @@ env:
 	@echo 'COMMON_LDFLAGS=${COMMON_LDFLAGS}'; echo ''
 	@echo 'CONFIG_MKF=${CONFIG_MKF}'; echo ''
 	@echo 'CP=${CP}'; echo ''
-	@echo 'CSCRIPT_PASSDOWN=${CSCRIPT_PASSDOWN}'; echo ''
 	@echo 'CSCRIPT_TARGETS=${CSCRIPT_TARGETS}'; echo ''
 	@echo 'C_SRC=${C_SRC}'; echo ''
 	@echo 'CTAGS=${CTAGS}'; echo ''
 	@echo 'CUSTOMCALDIR=${CUSTOMCALDIR}'; echo ''
 	@echo 'CUSTOMHELPDIR=${CUSTOMHELPDIR}'; echo ''
 	@echo 'CUSTOMINCDIR=${CUSTOMINCDIR}'; echo ''
-	@echo 'CUSTOM_PASSDOWN=${CUSTOM_PASSDOWN}'; echo ''
 	@echo 'DATE=${DATE}'; echo ''
 	@echo 'DEBUG=${DEBUG}'; echo ''
 	@echo 'DEFAULT_LIB_INSTALL_PATH=${DEFAULT_LIB_INSTALL_PATH}'; echo ''
@@ -3010,7 +2798,6 @@ env:
 	@echo 'HAVE_USTAT=${HAVE_USTAT}'; echo ''
 	@echo 'HAVE_VSNPRINTF=${HAVE_VSNPRINTF}'; echo ''
 	@echo 'HELPDIR=${HELPDIR}'; echo ''
-	@echo 'HELP_PASSDOWN=${HELP_PASSDOWN}'; echo ''
 	@echo 'HOSTNAME=${HOSTNAME}'; echo ''
 	@echo 'H_SRC=${H_SRC}'; echo ''
 	@echo 'ICFLAGS=${ICFLAGS}'; echo ''
@@ -3220,7 +3007,8 @@ rpm-hide-static:
 	${RM} -rf static
 	${MKDIR} -p static
 	${CP} -f -p calc-static${EXT} ${SAMPLE_STATIC_TARGETS} static
-	${CP} -f -p libcalc.a custom/libcustcalc.a static
+	${CP} -f -p libcalc.a static
+	${CP} -f -p custom/libcustcalc.a static
 	${V} echo '=-=-=-=-= ${MAKE_FILE} end of $@ rule =-=-=-=-='
 
 rpm-unhide-static:
@@ -3258,16 +3046,16 @@ inst_files: ${MK_SET} help/Makefile cal/Makefile \
 	${Q} ${RM} -f inst_files
 	${Q} echo ${BINDIR}/calc${EXT} > inst_files
 	${Q} cd help; LANG=C \
-	    ${MAKE} -f Makefile ${HELP_PASSDOWN} echo_inst_files | \
+	    ${MAKE} -f Makefile echo_inst_files | \
 	    ${GREP} -E '__file__..' | ${SED} -e s'/.*__file__ //' >> ../inst_files
 	${Q} cd cal; LANG=C \
-	    ${MAKE} -f Makefile ${CAL_PASSDOWN} echo_inst_files | \
+	    ${MAKE} -f Makefile echo_inst_files | \
 	    ${GREP} -E '__file__..' | ${SED} -e s'/.*__file__ //' >> ../inst_files
 	${Q} cd custom; LANG=C \
-	    ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} echo_inst_files | \
+	    ${MAKE} -f Makefile echo_inst_files | \
 	    ${GREP} -E '__file__..' | ${SED} -e s'/.*__file__ //' >> ../inst_files
 	${Q} cd cscript; LANG=C \
-	    ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} echo_inst_files | \
+	    ${MAKE} -f Makefile echo_inst_files | \
 	    ${GREP} -E '__file__..' | ${SED} -e s'/.*__file__ //' >> ../inst_files
 	${Q} echo ${LIBDIR}/libcalc.a >> inst_files
 	${Q} for i in ${LIB_H_SRC} ${BUILD_H_SRC} /dev/null; do \
@@ -3336,17 +3124,16 @@ clean:
 	${RM} -f .libcustcalc_error
 	${RM} -f calc.spec.sed
 	${Q} echo '=-=-=-=-= Invoking $@ rule for help =-=-=-=-='
-	cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} clean
+	cd help; ${MAKE} -f Makefile clean
 	${Q} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${Q} echo '=-=-=-=-= Invoking $@ rule for cal =-=-=-=-='
-	cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} clean
+	cd cal; ${MAKE} -f Makefile clean
 	${Q} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for custom =-=-=-=-='
-	cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} clean
+	cd custom; ${MAKE} -f Makefile clean
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for cscript =-=-=-=-='
-	${MAKE} custom/Makefile
-	cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} clean
+	cd cscript; ${MAKE} -f Makefile clean
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${Q} echo remove files that are obsolete
 	${RM} -rf lib
@@ -3384,20 +3171,20 @@ clobber: clean
 	${RM} -f all
 	${V} echo '=-=-=-=-= Invoking $@ rule for help =-=-=-=-='
 	-${RM} -f help/all; \
-	    cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} $@
+	    cd help; ${MAKE} -f Makefile $@
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for cal =-=-=-=-='
 	-${RM} -f cal/all; \
-	    cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} $@
+	    cd cal; ${MAKE} -f Makefile $@
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for custom =-=-=-=-='
 	-${RM} -f custom/all; \
 	    ${MAKE} custom/Makefile; \
-	    cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} $@
+	    cd custom; ${MAKE} -f Makefile $@
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for cscript =-=-=-=-='
 	-${RM} -f cscript/all; \
-	    cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} $@
+	    cd cscript; ${MAKE} -f Makefile $@
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo remove files that are obsolete
 	${RM} -rf win32 build
@@ -3472,7 +3259,6 @@ install: ${LIB_H_SRC} ${BUILD_H_SRC} calc.1 all custom/Makefile
 	else \
 	    ${TRUE}; \
 	fi
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 	-${Q} if [ ! -d ${T}${CUSTOMCALDIR} ]; then \
 	    echo ${MKDIR} -p ${T}${CUSTOMCALDIR}; \
 	    ${MKDIR} -p ${T}${CUSTOMCALDIR}; \
@@ -3497,7 +3283,6 @@ ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 	else \
 	    ${TRUE}; \
 	fi
-endif	# ($(ALLOW_CUSTOM),-DCUSTOM)
 	-${Q} if [ ! -d ${T}${SCRIPTDIR} ]; then \
 	    echo ${MKDIR} -p ${T}${SCRIPTDIR}; \
 	    ${MKDIR} -p ${T}${SCRIPTDIR}; \
@@ -3575,18 +3360,16 @@ endif	# ($(ALLOW_CUSTOM),-DCUSTOM)
 	    echo "installed ${T}${BINDIR}/calc${EXT}"; \
 	fi
 	${V} echo '=-=-=-=-= Invoking $@ rule for help =-=-=-=-='
-	${Q} cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} install
+	${Q} cd help; ${MAKE} -f Makefile install
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for cal =-=-=-=-='
-	${Q} cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} install
+	${Q} cd cal; ${MAKE} -f Makefile install
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 	${V} echo '=-=-=-=-= Invoking $@ rule for custom =-=-=-=-='
-	${Q} cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} install
+	${Q} cd custom; ${MAKE} -f Makefile install
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
-endif	# ($(ALLOW_CUSTOM),-DCUSTOM)
 	${V} echo '=-=-=-=-= Invoking $@ rule for cscript =-=-=-=-='
-	${Q} cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} install
+	${Q} cd cscript; ${MAKE} -f Makefile install
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	-${Q} if [ -f libcalc.a ]; then \
 	    if ${CMP} -s libcalc.a ${T}${LIBDIR}/libcalc.a; then \
@@ -3841,16 +3624,16 @@ uninstall: custom/Makefile
 	    fi; \
 	fi
 	${V} echo '=-=-=-=-= Invoking $@ rule for cscript =-=-=-=-='
-	${Q} cd cscript; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} uninstall
+	${Q} cd cscript; ${MAKE} -f Makefile uninstall
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for custom =-=-=-=-='
-	${Q} cd custom; ${MAKE} -f Makefile ${CUSTOM_PASSDOWN} uninstall
+	${Q} cd custom; ${MAKE} -f Makefile uninstall
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for cal =-=-=-=-='
-	${Q} cd cal; ${MAKE} -f Makefile ${CAL_PASSDOWN} uninstall
+	${Q} cd cal; ${MAKE} -f Makefile uninstall
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo '=-=-=-=-= Invoking $@ rule for help =-=-=-=-='
-	${Q} cd help; ${MAKE} -f Makefile ${HELP_PASSDOWN} uninstall
+	${Q} cd help; ${MAKE} -f Makefile uninstall
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	-${Q} if [ -f "${T}${BINDIR}/calc-static${EXT}" ]; then \
 	    ${RM} -f "${T}${BINDIR}/calc-static${EXT}"; \
diff --git a/Makefile.target b/Makefile.target
index 2f99404..c50c322 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -99,11 +99,7 @@ DEFAULT_LIB_INSTALL_PATH= ${PWD}:/lib:/usr/lib:${LIBDIR}:${PREFIX}/lib
 LD_SHARE= "-Wl,-rpath,${DEFAULT_LIB_INSTALL_PATH}" \
     "-Wl,-rpath-link,${DEFAULT_LIB_INSTALL_PATH}"
 LIBCALC_SHLIB= -shared "-Wl,-soname,libcalc${LIB_EXT_VERSION}"
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 LIBCUSTCALC_SHLIB= -shared "-Wl,-soname,libcustcalc${LIB_EXT_VERSION}"
-else
-LIBCUSTCALC_SHLIB=
-endif
 #
 CC_STATIC=
 LD_STATIC=
@@ -137,7 +133,7 @@ CCMISC=
 LCC= gcc
 CC= ${PURIFY} ${LCC} ${CCWERR}
 #
-endif
+endif	# ($(target),Linux)
 
 ###############################
 # Apple macOS / Darwin target #
@@ -151,7 +147,7 @@ ifeq ($(arch),powerpc)
 COMMON_CFLAGS+= -std=gnu99
 COMMON_LDFLAGS+= -std=gnu99
 ARCH_CFLAGS+= -arch ppc
-endif
+endif	# ($(arch),powerpc)
 
 ifeq ($(target),Darwin)
 #
@@ -165,21 +161,17 @@ SET_INSTALL_NAME= yes
 ifeq ($(SET_INSTALL_NAME),yes)
 LIBCALC_SHLIB= -single_module -undefined dynamic_lookup -dynamiclib \
     -install_name ${LIBDIR}/libcalc${LIB_EXT_VERSION} ${ARCH_CFLAGS}
-else
+else	# ($(SET_INSTALL_NAME),yes)
 LIBCALC_SHLIB= -single_module -undefined dynamic_lookup -dynamiclib \
     ${ARCH_CFLAGS}
-endif
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
+endif	# ($(SET_INSTALL_NAME),yes)
 ifeq ($(SET_INSTALL_NAME),yes)
 LIBCUSTCALC_SHLIB= -single_module -undefined dynamic_lookup -dynamiclib \
     -install_name ${LIBDIR}/libcustcalc${LIB_EXT_VERSION} ${ARCH_CFLAGS}
-else
+else	# ($(SET_INSTALL_NAME),yes)
 LIBCUSTCALC_SHLIB= -single_module -undefined dynamic_lookup -dynamiclib \
     ${ARCH_CFLAGS}
-endif
-else
-LIBCUSTCALC_SHLIB=
-endif
+endif	# ($(SET_INSTALL_NAME),yes)
 #
 CC_STATIC=
 LD_STATIC= ${ARCH_CFLAGS}
@@ -218,7 +210,7 @@ LIB_EXT:= .dylib
 LIB_EXT_VERSION:= .${VERSION}${LIB_EXT}
 # LDCONFIG not required on this platform, so we redefine it to an empty string
 LDCONFIG:=
-endif
+endif	# ($(target),Darwin)
 
 ##################
 # FreeBSD target #
@@ -233,11 +225,7 @@ DEFAULT_LIB_INSTALL_PATH= ${PWD}:/lib:/usr/lib:${LIBDIR}:${PREFIX}/lib
 LD_SHARE= "-Wl,-rpath,${DEFAULT_LIB_INSTALL_PATH}" \
     "-Wl,-rpath-link,${DEFAULT_LIB_INSTALL_PATH}"
 LIBCALC_SHLIB= -shared "-Wl,-soname,libcalc${LIB_EXT_VERSION}"
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 LIBCUSTCALC_SHLIB= -shared "-Wl,-soname,libcustcalc${LIB_EXT_VERSION}"
-else
-LIBCUSTCALC_SHLIB=
-endif
 #
 CC_STATIC=
 LD_STATIC=
@@ -273,7 +261,7 @@ CC= ${PURIFY} ${LCC} ${CCWERR}
 #
 MAKE= gmake
 #
-endif
+endif	# ($(target),FreeBSD)
 
 ##################
 # OpenBSD target #
@@ -288,11 +276,7 @@ DEFAULT_LIB_INSTALL_PATH= ${PWD}:/lib:/usr/lib:${LIBDIR}:${PREFIX}/lib
 LD_SHARE= "-Wl,-rpath,${DEFAULT_LIB_INSTALL_PATH}" \
     "-Wl,-rpath-link,${DEFAULT_LIB_INSTALL_PATH}"
 LIBCALC_SHLIB= -shared "-Wl,-soname,libcalc${LIB_EXT_VERSION}"
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 LIBCUSTCALC_SHLIB= -shared "-Wl,-soname,libcustcalc${LIB_EXT_VERSION}"
-else
-LIBCUSTCALC_SHLIB=
-endif
 #
 CC_STATIC=
 LD_STATIC=
@@ -328,7 +312,7 @@ CC= ${PURIFY} ${LCC} ${CCWERR}
 #
 MAKE= gmake
 #
-endif
+endif	# ($(target),OpenBSD)
 
 #################
 # Cygwin target #
@@ -343,11 +327,7 @@ DEFAULT_LIB_INSTALL_PATH= ${PWD}:/lib:/usr/lib:${LIBDIR}:${PREFIX}/lib
 LD_SHARE= "-Wl,-rpath,${DEFAULT_LIB_INSTALL_PATH}" \
     "-Wl,-rpath-link,${DEFAULT_LIB_INSTALL_PATH}"
 LIBCALC_SHLIB= -shared "-Wl,-soname,libcalc${LIB_EXT_VERSION}"
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 LIBCUSTCALC_SHLIB= -shared "-Wl,-soname,libcustcalc${LIB_EXT_VERSION}"
-else
-LIBCUSTCALC_SHLIB=
-endif
 #
 CC_STATIC=
 LIBCALC_STATIC=
@@ -381,7 +361,7 @@ CCMISC=
 LCC= cc
 CC= ${PURIFY} ${LCC} ${CCWERR}
 #
-endif
+endif	# ($(target),Cygwin)
 
 #################
 # simple target #
@@ -399,11 +379,7 @@ DEFAULT_LIB_INSTALL_PATH= ${PWD}:/lib:/usr/lib:${LIBDIR}:${PREFIX}/lib
 LD_SHARE= "-Wl,-rpath,${DEFAULT_LIB_INSTALL_PATH}" \
     "-Wl,-rpath-link,${DEFAULT_LIB_INSTALL_PATH}"
 LIBCALC_SHLIB= -shared "-Wl,-soname,libcalc${LIB_EXT_VERSION}"
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 LIBCUSTCALC_SHLIB= -shared "-Wl,-soname,libcustcalc${LIB_EXT_VERSION}"
-else
-LIBCUSTCALC_SHLIB=
-endif
 #
 CC_STATIC=
 LD_STATIC=
@@ -435,7 +411,7 @@ CFLAGS= ${ICFLAGS} ${CCOPT}
 ILDFLAGS= ${COMMON_LDFLAGS} ${LD_STATIC}
 LDFLAGS= ${LD_DEBUG} ${ILDFLAGS} ${LIBCALC_STATIC} ${LIBCUSTCALC_STATIC}
 #
-endif
+endif	# ($(target),simple)
 
 ###########################################
 # default target - (when target is empty) #
@@ -453,11 +429,7 @@ DEFAULT_LIB_INSTALL_PATH= ${PWD}:/lib:/usr/lib:${LIBDIR}:${PREFIX}/lib
 LD_SHARE= "-Wl,-rpath,${DEFAULT_LIB_INSTALL_PATH}" \
     "-Wl,-rpath-link,${DEFAULT_LIB_INSTALL_PATH}"
 LIBCALC_SHLIB= -shared "-Wl,-soname,libcalc${LIB_EXT_VERSION}"
-ifeq ($(ALLOW_CUSTOM),-DCUSTOM)
 LIBCUSTCALC_SHLIB= -shared "-Wl,-soname,libcustcalc${LIB_EXT_VERSION}"
-else
-LIBCUSTCALC_SHLIB=
-endif
 #
 CC_STATIC=
 LIBCALC_STATIC=
@@ -490,7 +462,7 @@ CCMISC=
 #
 LCC= gcc
 CC= ${PURIFY} ${LCC} ${CCWERR}
-endif
+endif	# ($(target),)
 
 ###########################################
 # Set the default compile flags for ${CC} #
@@ -505,9 +477,9 @@ endif
 #
 ifeq ($(BLD_TYPE),calc-static-only)
 ICFLAGS= ${COMMON_CFLAGS} ${CCBAN} ${CC_STATIC}
-else
+else	# ($(BLD_TYPE),calc-static-only)
 ICFLAGS= ${COMMON_CFLAGS} ${CCBAN} ${CC_SHARE}
-endif
+endif	# ($(BLD_TYPE),calc-static-only)
 CFLAGS= ${ICFLAGS} ${CCOPT}
 
 # Required flags to link files for calc
diff --git a/cal/Makefile b/cal/Makefile
index 9e58d4b..499092d 100644
--- a/cal/Makefile
+++ b/cal/Makefile
@@ -53,8 +53,7 @@ MAKE_FILE= Makefile
 #
 CONFIG_MKF= ../Makefile.config
 
-# Host targets that are shared in common with both Makefile
-# and custom/Makefile.
+# Host target information.
 #
 TARGET_MKF= ../Makefile.target
 
diff --git a/cscript/Makefile b/cscript/Makefile
index 1b7bf1c..8db249b 100644
--- a/cscript/Makefile
+++ b/cscript/Makefile
@@ -58,8 +58,7 @@ CONFIG_MKF= ../Makefile.config
 #
 TARGET_MKF= ../Makefile.target
 
-# Local file that is included just prior to the first rule,
-# that allows one to override any values set in this Makefile.
+# Host target information.
 #
 LOCAL_MKF= ../Makefile.local
 
diff --git a/custom.h b/custom.h
index 2c69ab5..a694c3b 100644
--- a/custom.h
+++ b/custom.h
@@ -77,7 +77,9 @@ E_FUNC VALUE custom(char*, int, VALUE**);	/* master custom interface */
 EXTERN BOOL allow_custom;		/* TRUE => custom builtins allowed */
 E_FUNC void showcustom(void);		/* print custom functions */
 E_FUNC void customhelp(char *);		/* direct custom help */
+#if defined(CUSTOM)
 EXTERN CONST struct custom cust[];	/* custom interface table */
+#endif /* CUSTOM */
 E_FUNC void init_custreg(void);		/* initialize custom registers */
 
 #endif /* !CUSTOM_H */
diff --git a/custom/Makefile b/custom/Makefile
index f94c09c..9de539e 100644
--- a/custom/Makefile
+++ b/custom/Makefile
@@ -52,8 +52,7 @@ CONFIG_MKF= ../Makefile.config
 #
 TARGET_MKF= ../Makefile.target
 
-# Local file that is included just prior to the first rule,
-# that allows one to override any values set in this Makefile.
+# Host target information.
 #
 LOCAL_MKF= ../Makefile.local
 
diff --git a/custom/c_argv.c b/custom/c_argv.c
index 4a73246..c9bb6e2 100644
--- a/custom/c_argv.c
+++ b/custom/c_argv.c
@@ -25,21 +25,32 @@
  */
 
 
+/*
+ * ISO C requires a translation unit to contain at least one declaration,
+ * so we declare a global variable whose value is based on if CUSTOM is defined.
+ */
+#if defined(CUSTOM)
+int c_argv_allowed = 1;		/* CUSTOM defined */
+#else /* CUSTOM */
+int c_argv_allowed = 0;		/* CUSTOM defined */
+#endif /* CUSTOM */
+
+
 #if defined(CUSTOM)
 
 #include <stdio.h>
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
 
-#include "config.h"
-#include "calc.h"
+#include "../config.h"
+#include "../calc.h"
 
-#include "have_unused.h"
+#include "../have_unused.h"
 
 
-#include "banned.h"	/* include after system header <> includes */
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /*
diff --git a/custom/c_devnull.c b/custom/c_devnull.c
index 1c02c09..89d2e40 100644
--- a/custom/c_devnull.c
+++ b/custom/c_devnull.c
@@ -25,21 +25,32 @@
  */
 
 
+/*
+ * ISO C requires a translation unit to contain at least one declaration,
+ * so we declare a global variable whose value is based on if CUSTOM is defined.
+ */
+#if defined(CUSTOM)
+int c_devnull_allowed = 1;	/* CUSTOM defined */
+#else /* CUSTOM */
+int c_devnull_allowed = 0;	/* CUSTOM defined */
+#endif /* CUSTOM */
+
+
 #if defined(CUSTOM)
 
-#include "have_unistd.h"
+#include "../have_unistd.h"
 #if defined(HAVE_UNISTD_H)
 #include <unistd.h>
 #endif
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
 
-#include "have_unused.h"
+#include "../have_unused.h"
 
 
-#include "banned.h"	/* include after system header <> includes */
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /*
diff --git a/custom/c_help.c b/custom/c_help.c
index fa2b28e..52eb1d0 100644
--- a/custom/c_help.c
+++ b/custom/c_help.c
@@ -25,22 +25,33 @@
  */
 
 
+/*
+ * ISO C requires a translation unit to contain at least one declaration,
+ * so we declare a global variable whose value is based on if CUSTOM is defined.
+ */
+#if defined(CUSTOM)
+int c_help_allowed = 1;		/* CUSTOM defined */
+#else /* CUSTOM */
+int c_help_allowed = 0;		/* CUSTOM defined */
+#endif /* CUSTOM */
+
+
 #if defined(CUSTOM)
 
-#include "have_unistd.h"
+#include "../have_unistd.h"
 #if defined(HAVE_UNISTD_H)
 #include <unistd.h>
 #endif
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
 
-#include "have_unused.h"
+#include "../have_unused.h"
 
 
-#include "attribute.h"
-#include "banned.h"	/* include after system header <> includes */
+#include "../attribute.h"
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /*
diff --git a/custom/c_pmodm127.c b/custom/c_pmodm127.c
index 03c5f99..6ea19f1 100644
--- a/custom/c_pmodm127.c
+++ b/custom/c_pmodm127.c
@@ -24,20 +24,31 @@
  */
 
 
+/*
+ * ISO C requires a translation unit to contain at least one declaration,
+ * so we declare a global variable whose value is based on if CUSTOM is defined.
+ */
+#if defined(CUSTOM)
+int c_pmodm127_allowed = 1;	/* CUSTOM defined */
+#else /* CUSTOM */
+int c_pmodm127_allowed = 0;	/* CUSTOM defined */
+#endif /* CUSTOM */
+
+
 #if defined(CUSTOM)
 
 #include <stdio.h>
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
-#include "zmath.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
+#include "../zmath.h"
 
-#include "have_unused.h"
+#include "../have_unused.h"
 
 
-#include "attribute.h"
-#include "banned.h"	/* include after system header <> includes */
+#include "../attribute.h"
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /* 2^255 */
diff --git a/custom/c_pzasusb8.c b/custom/c_pzasusb8.c
index 78e5441..4b50503 100644
--- a/custom/c_pzasusb8.c
+++ b/custom/c_pzasusb8.c
@@ -24,20 +24,31 @@
  */
 
 
+/*
+ * ISO C requires a translation unit to contain at least one declaration,
+ * so we declare a global variable whose value is based on if CUSTOM is defined.
+ */
+#if defined(CUSTOM)
+int c_pzasusb8_allowed = 1;	/* CUSTOM defined */
+#else /* CUSTOM */
+int c_pzasusb8_allowed = 0;	/* CUSTOM defined */
+#endif /* CUSTOM */
+
+
 #if defined(CUSTOM)
 
 #include <stdio.h>
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
-#include "zmath.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
+#include "../zmath.h"
 
-#include "have_unused.h"
+#include "../have_unused.h"
 
 
-#include "attribute.h"
-#include "banned.h"	/* include after system header <> includes */
+#include "../attribute.h"
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /*
diff --git a/custom/c_register.c b/custom/c_register.c
index df5e99a..f841fa4 100644
--- a/custom/c_register.c
+++ b/custom/c_register.c
@@ -25,22 +25,33 @@
  */
 
 
+/*
+ * ISO C requires a translation unit to contain at least one declaration,
+ * so we declare a global variable whose value is based on if CUSTOM is defined.
+ */
+#if defined(CUSTOM)
+int c_register_allowed = 1;	/* CUSTOM defined */
+#else /* CUSTOM */
+int c_register_allowed = 0;	/* CUSTOM defined */
+#endif /* CUSTOM */
+
+
 #if defined(CUSTOM)
 
 #include <stdio.h>
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
 
-#include "config.h"
-#include "calc.h"
+#include "../config.h"
+#include "../calc.h"
 
-#include "have_unused.h"
+#include "../have_unused.h"
 
 
-#include "attribute.h"
-#include "banned.h"	/* include after system header <> includes */
+#include "../attribute.h"
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /*
diff --git a/custom/c_sysinfo.c b/custom/c_sysinfo.c
index 49b4610..2cbf4e6 100644
--- a/custom/c_sysinfo.c
+++ b/custom/c_sysinfo.c
@@ -25,40 +25,51 @@
  */
 
 
+/*
+ * ISO C requires a translation unit to contain at least one declaration,
+ * so we declare a global variable whose value is based on if CUSTOM is defined.
+ */
+#if defined(CUSTOM)
+int c_sysinfo_allowed = 1;	/* CUSTOM defined */
+#else /* CUSTOM */
+int c_sysinfo_allowed = 0;	/* CUSTOM defined */
+#endif /* CUSTOM */
+
+
 #if defined(CUSTOM)
 
 #include <stdio.h>
 #include <ctype.h>
 
-#include "have_string.h"
+#include "../have_string.h"
 #if defined(HAVE_STRING_H)
 #include <string.h>
 #endif
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
 
-#include "config.h"
-#include "lib_calc.h"
-#include "calc.h"
-#include "longbits.h"
+#include "../config.h"
+#include "../lib_calc.h"
+#include "../calc.h"
+#include "../longbits.h"
 #define CHECK_L_FORMAT
-#include "block.h"
-#include "calcerr.h"
-#include "conf.h"
-#include "endian_calc.h"
-#include "fposval.h"
-#include "hist.h"
-#include "prime.h"
-#include "zrand.h"
-#include "zrandom.h"
+#include "../block.h"
+#include "../calcerr.h"
+#include "../conf.h"
+#include "../endian_calc.h"
+#include "../fposval.h"
+#include "../hist.h"
+#include "../prime.h"
+#include "../zrand.h"
+#include "../zrandom.h"
 
-#include "have_unused.h"
+#include "../have_unused.h"
 
 
-#include "attribute.h"
-#include "banned.h"	/* include after system header <> includes */
+#include "../attribute.h"
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /*
diff --git a/custom/custtbl.c b/custom/custtbl.c
index 028c91c..f312a22 100644
--- a/custom/custtbl.c
+++ b/custom/custtbl.c
@@ -26,12 +26,12 @@
 
 #include <unistd.h>
 
-#include "have_const.h"
-#include "value.h"
-#include "custom.h"
+#include "../have_const.h"
+#include "../value.h"
+#include "../custom.h"
 
 
-#include "banned.h"	/* include after system header <> includes */
+#include "../banned.h"	/* include after system header <> includes */
 
 
 /*
diff --git a/help/Makefile b/help/Makefile
index 8040e0c..d85d7c2 100644
--- a/help/Makefile
+++ b/help/Makefile
@@ -58,8 +58,7 @@ CONFIG_MKF= ../Makefile.config
 #
 TARGET_MKF= ../Makefile.target
 
-# Local file that is included just prior to the first rule,
-# that allows one to override any values set in this Makefile.
+# Host target information.
 #
 LOCAL_MKF= ../Makefile.local