build: Make almost all exposed interfaces use the new ABI selection

Explicitly select what to include as part of the target ABI, instead of
letting autoconfiguration potentially break ABI if the system grows
functionality provided by the library.

Make almost all the library selectable per target. Do not install manual
pages for interfaces not included in the library. Control inclusion of
symbols in map file via pre-processor macros, and move the comments
describing the ABI selection to configure.ac.

For now the header files are included as is and filtered through
pre-processor conditionals. Eventually they might get switched to be
autogenerated at build time.

6 files changed, 728 insertions, 117 deletions

diff --git a/configure.ac b/configure.ac
index ef79d0a..a761d9c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -41,85 +41,212 @@ LIBBSD_LINKER_VERSION_SCRIPT
 
 is_windows=no
 
+abi_accmode=unknown
 abi_arc4random=unknown
+abi_arc4random_stir=unknown
 abi_bsd_getopt=unknown
+abi_closefrom=unknown
 abi_err=unknown
 abi_errc=unknown
+abi_expand_number=unknown
+abi_explicit_bzero=unknown
+abi_fgetln=unknown
+abi_flopen=unknown
+abi_fmtcheck=unknown
 abi_fpurge=unknown
+abi_freezero=unknown
 abi_funopen=unknown
+abi_getbsize=unknown
+abi_getpeereid=unknown
+abi_humanize_number=unknown
+abi_id_from_name=unknown
+abi_inet_net_pton=unknown
 abi_md5=unknown
 abi_name_from_id=unknown
 abi_nlist=unknown
+abi_pidfile=unknown
+abi_proctitle=unknown
 abi_progname=unknown
+abi_readpassphrase=unknown
+abi_reallocarray=unknown
+abi_reallocf=unknown
+abi_recallocarray=unknown
+abi_stringlist=unknown
+abi_sort=unknown
 abi_strl=unknown
 abi_strmode=unknown
+abi_strnstr=unknown
+abi_strtonum=unknown
+abi_strtox=unknown
+abi_timeconv=unknown
+abi_vis=unknown
 abi_wcsl=unknown
 
 AS_CASE([$host_os],
   [*-gnu*], [
-    # DROP: On glibc >= 2.36, parts the arc4random() API got added.
+    abi_accmode=yes
+    # DROP: On glibc >= 2.36.
     #abi_arc4random=no
     abi_arc4random=yes
+    abi_arc4random_stir=yes
     abi_bsd_getopt=yes
+    # DROP: On glibc >= 2.34.
+    #abi_closefrom=no
+    abi_closefrom=yes
     abi_err=no
     abi_errc=yes
+    abi_expand_number=yes
+    # DROP: On glibc >= 2.25.
+    #abi_explicit_bzero=no
+    abi_explicit_bzero=yes
+    abi_fgetln=yes
+    abi_flopen=yes
+    abi_fmtcheck=yes
     abi_fpurge=yes
+    abi_freezero=yes
     abi_funopen=yes
+    abi_getbsize=yes
+    abi_getpeereid=yes
+    abi_humanize_number=yes
+    abi_id_from_name=yes
+    # DROP: On glibc.
+    #abi_inet_net_pton=no
+    abi_inet_net_pton=yes
     # DROP: On libmd.
     #abi_md5=no
     abi_md5=yes
     abi_name_from_id=yes
     abi_nlist=yes
+    abi_pidfile=yes
+    abi_proctitle=yes
     abi_progname=yes
+    abi_readpassphrase=yes
+    # DROP: On glibc >= 2.26.
+    #abi_reallocarray=no
+    abi_reallocarray=yes
+    abi_reallocf=yes
+    abi_recallocarray=yes
+    abi_stringlist=yes
+    abi_sort=yes
     # DROP: On glibc >= 2.38.
     #abi_strl=no
     abi_strl=yes
     abi_strmode=yes
+    abi_strnstr=yes
+    abi_strtonum=yes
+    abi_strtox=yes
+    abi_timeconv=yes
+    # DROP: On libmd.
+    abi_transparent_libmd=yes
+    abi_vis=yes
     abi_wcsl=yes
   ],
   [*-musl*], [
+    abi_accmode=yes
     abi_arc4random=yes
+    abi_arc4random_stir=yes
     # DROP: On musl >= 0.9.7, optreset got implemented.
     #abi_bsd_getopt=no
     abi_bsd_getopt=yes
+    abi_closefrom=yes
     abi_err=no
     abi_errc=yes
+    abi_expand_number=yes
+    # DROP: On musl >= 1.1.20.
+    #abi_explicit_bzero=no
+    abi_explicit_bzero=yes
+    # DROP: On musl >= 0.9.4.
+    #abi_fgetln=no
+    abi_fgetln=yes
+    abi_flopen=yes
+    abi_fmtcheck=yes
     abi_fpurge=yes
+    abi_freezero=yes
     # On musl >= 1.1.19, fopencookie() got implemented, and because we were
     # checking for its presence to decide whether to build funopen(), it got
     # included in builds even when previously it had not been included, which
     # is partially an ABI issue, but given that disabling it now would be
     # worse, we'll ignore this as this is only a problem with downgrades. And
     # enable it explicitly
+    #abi_funopen=no
     abi_funopen=yes
+    abi_getbsize=yes
+    abi_getpeereid=yes
+    abi_humanize_number=yes
+    abi_id_from_name=yes
+    abi_inet_net_pton=yes
     # DROP: On libmd.
     #abi_md5=no
     abi_md5=yes
     abi_name_from_id=yes
     abi_nlist=yes
+    abi_pidfile=yes
+    abi_proctitle=yes
     abi_progname=yes
+    abi_readpassphrase=yes
+    # DROP: On musl >= 1.2.2.
+    #abi_reallocarray=no
+    abi_reallocarray=yes
+    abi_reallocf=ues
+    abi_recallocarray=yes
+    abi_stringlist=yes
+    abi_sort=yes
     # DROP: On musl >= 0.5.0, strlcpy() and strlcat() were already implemented.
     #abi_strl=no
     abi_strl=yes
     abi_strmode=yes
+    abi_strnstr=yes
+    abi_strtonum=yes
+    abi_strtox=yes
+    abi_timeconv=yes
+    # DROP: On libmd.
+    abi_transparent_libmd=yes
+    abi_vis=yes
     abi_wcsl=yes
   ],
   [darwin*], [
-    # On macOS these are provided by the system, and libbsd has never built
-    # there, so we can avoid providing these with no ABI breakage.
+    abi_accmode=no
     abi_arc4random=no
+    abi_arc4random_stir=no
     abi_bsd_getopt=no
+    abi_closefrom=yes
     abi_err=no
     abi_errc=no
+    abi_expand_number=yes
+    abi_explicit_bzero=yes
+    abi_fgetln=no
+    abi_flopen=yes
+    abi_fmtcheck=no
     abi_fpurge=no
+    abi_freezero=yes
     abi_funopen=no
+    abi_getbsize=yes
+    abi_getpeereid=no
+    abi_humanize_number=yes
+    abi_id_from_name=yes
+    abi_inet_net_pton=no
+    # On libmd.
     abi_md5=no
     abi_name_from_id=no
     abi_nlist=no
+    abi_pidfile=yes
+    abi_proctitle=yes
     abi_progname=no
+    abi_readpassphrase=no
+    abi_reallocarray=yes
+    abi_reallocf=no
+    abi_recallocarray=yes
+    abi_stringlist=no
+    abi_sort=no
     abi_strl=no
     abi_strmode=no
+    abi_strnstr=no
+    abi_strtonum=no
+    abi_strtox=yes
+    abi_timeconv=no
+    # On libmd.
     abi_transparent_libmd=no
+    abi_vis=no
     abi_wcsl=no
   ],
   [mingw*], [
@@ -127,6 +254,13 @@ AS_CASE([$host_os],
   ],
 )
 
+# Handle artificial ABI selections that are combinations of others.
+AS_IF([test "$abi_name_from_id" = "yes" || test "$abi_id_from_name" = "yes"], [
+  abi_pwcache=yes
+], [
+  abi_pwcache=no
+])
+
 AM_CONDITIONAL([OS_WINDOWS], [test "x$is_windows" = "xyes"])
 
 # Checks for programs.
@@ -308,19 +442,47 @@ AC_CHECK_FUNCS([\
 AM_CONDITIONAL([HAVE_GETENTROPY], [test "x$ac_cv_func_getentropy" = "xyes"])
 
 # ABI selection
+LIBBSD_SELECT_ABI([accmode], [setmode()/getmode()])
 LIBBSD_SELECT_ABI([arc4random], [arc4random() API])
+LIBBSD_SELECT_ABI([arc4random_stir], [arc4random_stir()/arc4random_addrandom()])
 LIBBSD_SELECT_ABI([bsd_getopt], [BSD getopt()])
+LIBBSD_SELECT_ABI([closefrom], [closefrom()])
 LIBBSD_SELECT_ABI([err], [err API])
 LIBBSD_SELECT_ABI([errc], [errc API])
+LIBBSD_SELECT_ABI([expand_number], [expand_number()])
+LIBBSD_SELECT_ABI([explicit_bzero], [explicit_bzero()])
+LIBBSD_SELECT_ABI([fgetln], [fgetln/fgetwln()])
+LIBBSD_SELECT_ABI([flopen], [flopen()/flopenat()])
+LIBBSD_SELECT_ABI([fmtcheck], [fmtcheck()])
 LIBBSD_SELECT_ABI([fpurge], [fpurge()])
+LIBBSD_SELECT_ABI([freezero], [freezero()])
 LIBBSD_SELECT_ABI([funopen], [funopen()])
+LIBBSD_SELECT_ABI([getbsize], [getbsize()])
+LIBBSD_SELECT_ABI([getpeereid], [getpeereid()])
+LIBBSD_SELECT_ABI([humanize_number], [humanize_number()/dehumanize_number()])
+LIBBSD_SELECT_ABI([id_from_name], [uid_from_user()/gid_from_user()])
+LIBBSD_SELECT_ABI([inet_net_pton], [inet_net_pton()])
 LIBBSD_SELECT_ABI([md5], [MD5 digest functions])
 LIBBSD_SELECT_ABI([name_from_id], [user_from_uid()/group_from_gid()])
 LIBBSD_SELECT_ABI([nlist], [nlist()])
+LIBBSD_SELECT_ABI([pidfile], [pidfile API])
+LIBBSD_SELECT_ABI([proctitle], [setproctitle() API])
 LIBBSD_SELECT_ABI([progname], [setprogname()/getprogname()])
+LIBBSD_SELECT_ABI([pwcache], [password cache API])
+LIBBSD_SELECT_ABI([readpassphrase], [readpassphrase()])
+LIBBSD_SELECT_ABI([reallocarray], [reallocarray()])
+LIBBSD_SELECT_ABI([reallocf], [reallocf()])
+LIBBSD_SELECT_ABI([recallocarray], [recallocarray()])
+LIBBSD_SELECT_ABI([stringlist], [stringlist sl_*() API])
+LIBBSD_SELECT_ABI([sort], [BSD sort functions])
 LIBBSD_SELECT_ABI([strl], [strlcpy()/strlcat()])
 LIBBSD_SELECT_ABI([strmode], [strmode()])
+LIBBSD_SELECT_ABI([strnstr], [strnstr()])
+LIBBSD_SELECT_ABI([strtonum], [strtonum()])
+LIBBSD_SELECT_ABI([strtox], [strtoi()/strtou()])
+LIBBSD_SELECT_ABI([timeconv], [timeconf.h API])
 LIBBSD_SELECT_ABI([transparent_libmd], [transparent libmd support])
+LIBBSD_SELECT_ABI([vis], [vis API])
 LIBBSD_SELECT_ABI([wcsl], [wcslcpy()/wcslcat()])
 
 AS_IF([test "x$abi_funopen" = "xno" && \
diff --git a/include/Makefile.am b/include/Makefile.am
index 46925b6..9a75b97 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -12,23 +12,27 @@ nobase_include_HEADERS = \
 	bsd/netinet/ip_icmp.h \
 	bsd/bitstring.h \
 	bsd/bsd.h \
-	bsd/err.h \
-	bsd/getopt.h \
-	bsd/grp.h \
 	bsd/inttypes.h \
 	bsd/libutil.h \
-	bsd/pwd.h \
-	bsd/readpassphrase.h \
 	bsd/stdio.h \
 	bsd/stdlib.h \
 	bsd/string.h \
-	bsd/stringlist.h \
-	bsd/timeconv.h \
 	bsd/unistd.h \
-	bsd/vis.h \
 	bsd/wchar.h \
 	# EOL
 
+if ABI_ERR
+nobase_include_HEADERS += \
+	bsd/err.h \
+	# EOL
+endif
+
+if ABI_BSD_GETOPT
+nobase_include_HEADERS += \
+	bsd/getopt.h \
+	# EOL
+endif
+
 if ABI_MD5
 nobase_include_HEADERS += \
 	bsd/md5.h \
@@ -40,3 +44,34 @@ nobase_include_HEADERS += \
 	bsd/nlist.h \
 	# EOL
 endif
+
+if ABI_READPASSPHRASE
+nobase_include_HEADERS += \
+	bsd/readpassphrase.h \
+	# EOL
+endif
+
+if ABI_PWCACHE
+nobase_include_HEADERS += \
+	bsd/grp.h \
+	bsd/pwd.h \
+	# EOL
+endif
+
+if ABI_STRINGLIST
+nobase_include_HEADERS += \
+	bsd/stringlist.h \
+	# EOL
+endif
+
+if ABI_TIMECONV
+nobase_include_HEADERS += \
+	bsd/timeconv.h \
+	# EOL
+endif
+
+if ABI_VIS
+nobase_include_HEADERS += \
+	bsd/vis.h \
+	# EOL
+endif
diff --git a/man/Makefile.am b/man/Makefile.am
index ed55988..27aae67 100644
--- a/man/Makefile.am
+++ b/man/Makefile.am
@@ -143,11 +143,6 @@ dist_man_MANS = \
 	TAILQ_SWAP.3bsd \
 	TIMESPEC_TO_TIMEVAL.3bsd \
 	TIMEVAL_TO_TIMESPEC.3bsd \
-	arc4random.3bsd \
-	arc4random_addrandom.3bsd \
-	arc4random_buf.3bsd \
-	arc4random_stir.3bsd \
-	arc4random_uniform.3bsd \
 	be16dec.3bsd \
 	be16enc.3bsd \
 	be32dec.3bsd \
@@ -166,21 +161,6 @@ dist_man_MANS = \
 	bitstr_size.3bsd \
 	bitstring.3bsd \
 	byteorder.3bsd \
-	closefrom.3bsd \
-	dehumanize_number.3bsd \
-	expand_number.3bsd \
-	explicit_bzero.3bsd \
-	fgetln.3bsd \
-	fgetwln.3bsd \
-	flopen.3bsd \
-	fmtcheck.3bsd \
-	fparseln.3bsd \
-	freezero.3bsd \
-	getbsize.3bsd \
-	getmode.3bsd \
-	getpeereid.3bsd \
-	heapsort.3bsd \
-	humanize_number.3bsd \
 	le16dec.3bsd \
 	le16enc.3bsd \
 	le32dec.3bsd \
@@ -188,38 +168,7 @@ dist_man_MANS = \
 	le64dec.3bsd \
 	le64enc.3bsd \
 	libbsd.7 \
-	mergesort.3bsd \
-	pidfile.3bsd \
-	pidfile_close.3bsd \
-	pidfile_open.3bsd \
-	pidfile_remove.3bsd \
-	pidfile_write.3bsd \
-	pwcache.3bsd \
 	queue.3bsd \
-	radixsort.3bsd \
-	readpassphrase.3bsd \
-	reallocarray.3bsd \
-	reallocf.3bsd \
-	recallocarray.3bsd \
-	setmode.3bsd \
-	setproctitle.3bsd \
-	setproctitle_init.3bsd \
-	sl_add.3bsd \
-	sl_delete.3bsd \
-	sl_find.3bsd \
-	sl_free.3bsd \
-	sl_init.3bsd \
-	sradixsort.3bsd \
-	stringlist.3bsd \
-	strnstr.3bsd \
-	strnunvis.3bsd \
-	strnvis.3bsd \
-	strtoi.3bsd \
-	strtonum.3bsd \
-	strtou.3bsd \
-	strunvis.3bsd \
-	strvis.3bsd \
-	strvisx.3bsd \
 	timeradd.3bsd \
 	timerclear.3bsd \
 	timercmp.3bsd \
@@ -233,28 +182,106 @@ dist_man_MANS = \
 	timespecsub.3bsd \
 	timeval.3bsd \
 	tree.3bsd \
-	unvis.3bsd \
-	vis.3bsd \
 	# EOL
 
+if ABI_ACCMODE
+dist_man_MANS += \
+	getmode.3bsd \
+	setmode.3bsd \
+	# EOL
+endif
+
+if ABI_ARC4RANDOM
+dist_man_MANS += \
+	arc4random.3bsd \
+	arc4random_addrandom.3bsd \
+	arc4random_buf.3bsd \
+	arc4random_stir.3bsd \
+	arc4random_uniform.3bsd \
+	# EOL
+endif
+
+if ABI_CLOSEFROM
+dist_man_MANS += \
+	closefrom.3bsd \
+	# EOL
+endif
+
 if ABI_ERRC
 dist_man_MANS += \
 	errc.3bsd \
 	# EOL
 endif
 
+if ABI_EXPAND_NUMBER
+dist_man_MANS += \
+	expand_number.3bsd \
+	# EOL
+endif
+
+if ABI_EXPLICIT_BZERO
+dist_man_MANS += \
+	explicit_bzero.3bsd \
+	# EOL
+endif
+
+if ABI_FGETLN
+dist_man_MANS += \
+	fgetln.3bsd \
+	fgetwln.3bsd \
+	fparseln.3bsd \
+	# EOL
+endif
+
+if ABI_FLOPEN
+dist_man_MANS += \
+	flopen.3bsd \
+	# EOL
+endif
+
+if ABI_FMTCHECK
+dist_man_MANS += \
+	fmtcheck.3bsd \
+	# EOL
+endif
+
 if ABI_FPURGE
 dist_man_MANS += \
 	fpurge.3bsd \
 	# EOL
 endif
 
+if ABI_FREEZERO
+dist_man_MANS += \
+	freezero.3bsd \
+	# EOL
+endif
+
 if ABI_FUNOPEN
 dist_man_MANS += \
 	funopen.3bsd \
 	# EOL
 endif
 
+if ABI_GETBSIZE
+dist_man_MANS += \
+	getbsize.3bsd \
+	# EOL
+endif
+
+if ABI_GETPEEREID
+dist_man_MANS += \
+	getpeereid.3bsd \
+	# EOL
+endif
+
+if ABI_HUMANIZE_NUMBER
+dist_man_MANS += \
+	dehumanize_number.3bsd \
+	humanize_number.3bsd \
+	# EOL
+endif
+
 if ABI_MD5
 dist_man_MANS += \
 	md5.3bsd \
@@ -267,6 +294,23 @@ dist_man_MANS += \
 	# EOL
 endif
 
+if ABI_PIDFILE
+dist_man_MANS += \
+	pidfile.3bsd \
+	pidfile_close.3bsd \
+	pidfile_open.3bsd \
+	pidfile_remove.3bsd \
+	pidfile_write.3bsd \
+	# EOL
+endif
+
+if ABI_PROCTITLE
+dist_man_MANS += \
+	setproctitle.3bsd \
+	setproctitle_init.3bsd \
+	# EOL
+endif
+
 if ABI_PROGNAME
 dist_man_MANS += \
 	getprogname.3bsd \
@@ -274,7 +318,9 @@ dist_man_MANS += \
 	# EOL
 endif
 
+if ABI_PWCACHE
 dist_man_MANS += \
+	pwcache.3bsd \
 	gid_from_group.3bsd \
 	uid_from_user.3bsd \
 	# EOL
@@ -285,6 +331,51 @@ dist_man_MANS += \
 	user_from_uid.3bsd \
 	# EOL
 endif
+endif
+
+if ABI_READPASSPHRASE
+dist_man_MANS += \
+	readpassphrase.3bsd \
+	# EOL
+endif
+
+if ABI_REALLOCARRAY
+dist_man_MANS += \
+	reallocarray.3bsd \
+	# EOL
+endif
+
+if ABI_REALLOCF
+dist_man_MANS += \
+	reallocf.3bsd \
+	# EOL
+endif
+
+if ABI_RECALLOCARRAY
+dist_man_MANS += \
+	recallocarray.3bsd \
+	# EOL
+endif
+
+if ABI_SORT
+dist_man_MANS += \
+	heapsort.3bsd \
+	mergesort.3bsd \
+	radixsort.3bsd \
+	sradixsort.3bsd \
+	# EOL
+endif
+
+if ABI_STRINGLIST
+dist_man_MANS += \
+	sl_add.3bsd \
+	sl_delete.3bsd \
+	sl_find.3bsd \
+	sl_free.3bsd \
+	sl_init.3bsd \
+	stringlist.3bsd \
+	# EOL
+endif
 
 if ABI_STRL
 dist_man_MANS += \
@@ -299,6 +390,37 @@ dist_man_MANS += \
 	# EOL
 endif
 
+if ABI_STRNSTR
+dist_man_MANS += \
+	strnstr.3bsd \
+	# EOL
+endif
+
+if ABI_STRTOX
+dist_man_MANS += \
+	strtoi.3bsd \
+	strtou.3bsd \
+	# EOL
+endif
+
+if ABI_STRTONUM
+dist_man_MANS += \
+	strtonum.3bsd \
+	# EOL
+endif
+
+if ABI_VIS
+dist_man_MANS += \
+	strnunvis.3bsd \
+	strnvis.3bsd \
+	strunvis.3bsd \
+	strvis.3bsd \
+	strvisx.3bsd \
+	unvis.3bsd \
+	vis.3bsd \
+	# EOL
+endif
+
 if ABI_WCSL
 dist_man_MANS += \
 	wcslcat.3bsd \
diff --git a/src/Makefile.am b/src/Makefile.am
index 21ed1c7..a85b705 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -76,42 +76,15 @@ EXTRA_libbsd_la_DEPENDENCIES += \
 	# EOL
 endif
 libbsd_la_SOURCES = \
-	closefrom.c \
-	dehumanize_number.c \
-	expand_number.c \
-	explicit_bzero.c \
-	fgetln.c \
-	fgetwln.c \
-	flopen.c \
-	fmtcheck.c \
-	fparseln.c \
-	freezero.c \
-	getbsize.c \
-	getpeereid.c \
-	heapsort.c \
-	humanize_number.c \
-	inet_net_pton.c \
 	local-elf.h \
 	local-link.h \
-	merge.c \
-	pidfile.c \
-	pwcache.c \
-	radixsort.c \
-	readpassphrase.c \
-	reallocarray.c \
-	reallocf.c \
-	recallocarray.c \
+	# EOL
+
+if ABI_ACCMODE
+libbsd_la_SOURCES += \
 	setmode.c \
-	setproctitle.c \
-	stringlist.c \
-	strnstr.c \
-	strtoi.c \
-	strtonum.c \
-	strtou.c \
-	timeconv.c \
-	unvis.c \
-	vis.c \
 	# EOL
+endif
 
 if ABI_ARC4RANDOM
 if !HAVE_GETENTROPY
@@ -136,6 +109,12 @@ libbsd_la_SOURCES += \
 	# EOL
 endif
 
+if ABI_CLOSEFROM
+libbsd_la_SOURCES += \
+	closefrom.c \
+	# EOL
+endif
+
 if ABI_ERR
 libbsd_la_SOURCES += \
 	err.c \
@@ -148,18 +127,81 @@ libbsd_la_SOURCES += \
 	# EOL
 endif
 
+if ABI_EXPAND_NUMBER
+libbsd_la_SOURCES += \
+	expand_number.c \
+	# EOL
+endif
+
+if ABI_EXPLICIT_BZERO
+libbsd_la_SOURCES += \
+	explicit_bzero.c \
+	# EOL
+endif
+
+if ABI_FGETLN
+libbsd_la_SOURCES += \
+	fgetln.c \
+	fgetwln.c \
+	fparseln.c \
+	# EOL
+endif
+
+if ABI_FLOPEN
+libbsd_la_SOURCES += \
+	flopen.c \
+	# EOL
+endif
+
+if ABI_FMTCHECK
+libbsd_la_SOURCES += \
+	fmtcheck.c \
+	# EOL
+endif
+
 if ABI_FPURGE
 libbsd_la_SOURCES += \
 	fpurge.c \
 	# EOL
 endif
 
+if ABI_FREEZERO
+libbsd_la_SOURCES += \
+	freezero.c \
+	# EOL
+endif
+
 if ABI_FUNOPEN
 libbsd_la_SOURCES += \
 	funopen.c \
 	# EOL
 endif
 
+if ABI_GETBSIZE
+libbsd_la_SOURCES += \
+	getbsize.c \
+	# EOL
+endif
+
+if ABI_GETPEEREID
+libbsd_la_SOURCES += \
+	getpeereid.c \
+	# EOL
+endif
+
+if ABI_HUMANIZE_NUMBER
+libbsd_la_SOURCES += \
+	dehumanize_number.c \
+	humanize_number.c \
+	# EOL
+endif
+
+if ABI_INET_NET_PTON
+libbsd_la_SOURCES += \
+	inet_net_pton.c \
+	# EOL
+endif
+
 if ABI_MD5
 libbsd_la_SOURCES += \
 	md5.c \
@@ -172,12 +214,68 @@ libbsd_la_SOURCES += \
 	# EOL
 endif
 
+if ABI_PIDFILE
+libbsd_la_SOURCES += \
+	pidfile.c \
+	# EOL
+endif
+
+if ABI_PROCTITLE
+libbsd_la_SOURCES += \
+	setproctitle.c \
+	# EOL
+endif
+
 if ABI_PROGNAME
 libbsd_la_SOURCES += \
 	progname.c \
 	# EOL
 endif
 
+if ABI_PWCACHE
+libbsd_la_SOURCES += \
+	pwcache.c \
+	# EOL
+endif
+
+if ABI_READPASSPHRASE
+libbsd_la_SOURCES += \
+	readpassphrase.c \
+	# EOL
+endif
+
+if ABI_REALLOCARRAY
+libbsd_la_SOURCES += \
+	reallocarray.c \
+	# EOL
+endif
+
+if ABI_REALLOCF
+libbsd_la_SOURCES += \
+	reallocf.c \
+	# EOL
+endif
+
+if ABI_RECALLOCARRAY
+libbsd_la_SOURCES += \
+	recallocarray.c \
+	# EOL
+endif
+
+if ABI_SORT
+libbsd_la_SOURCES += \
+	heapsort.c \
+	merge.c \
+	radixsort.c \
+	# EOL
+endif
+
+if ABI_STRINGLIST
+libbsd_la_SOURCES += \
+	stringlist.c \
+	# EOL
+endif
+
 if ABI_STRL
 libbsd_la_SOURCES += \
 	strlcat.c \
@@ -191,6 +289,38 @@ libbsd_la_SOURCES += \
 	# EOL
 endif
 
+if ABI_STRNSTR
+libbsd_la_SOURCES += \
+	strnstr.c \
+	# EOL
+endif
+
+if ABI_STRTONUM
+libbsd_la_SOURCES += \
+	strtonum.c \
+	# EOL
+endif
+
+if ABI_STRTOX
+libbsd_la_SOURCES += \
+	strtoi.c \
+	strtou.c \
+	# EOL
+endif
+
+if ABI_TIMECONV
+libbsd_la_SOURCES += \
+	timeconv.c \
+	# EOL
+endif
+
+if ABI_VIS
+libbsd_la_SOURCES += \
+	unvis.c \
+	vis.c \
+	# EOL
+endif
+
 if ABI_WCSL
 libbsd_la_SOURCES += \
 	wcslcat.c \
diff --git a/src/libbsd.map.in b/src/libbsd.map.in
index 06550ea..81e431f 100644
--- a/src/libbsd.map.in
+++ b/src/libbsd.map.in
@@ -2,44 +2,71 @@
 
 LIBBSD_0.0 {
   global:
+#if LIBBSD_ABI_ARC4RANDOM
     arc4random;
+#endif
+#if LIBBSD_ABI_ARC4RANDOM_STIR
     arc4random_stir;
     arc4random_addrandom;
+#endif
 
+#if LIBBSD_ABI_BSD_GETOPT
     bsd_getopt;
     optreset;
+#endif
 
+#if LIBBSD_ABI_ERRC
     errc;
     warnc;
     verrc;
     vwarnc;
+#endif
 
+#if LIBBSD_ABI_FGETLN
     fgetln;
+#endif
+
+#if LIBBSD_ABI_FMTCHECK
     fmtcheck;
+#endif
+
+#if LIBBSD_ABI_SORT
     heapsort;
+#endif
+
+#if LIBBSD_ABI_HUMANIZE_NUMBER
     humanize_number;
+#endif
 
-    /* XXX: Already provided by glibc, remove. */
+#if LIBBSD_ABI_INET_NET_PTON
     inet_net_pton;
+#endif
 
+#if LIBBSD_ABI_PROGNAME
     getprogname;
     setprogname;
+#endif
 
+#if LIBBSD_ABI_STRL
     strlcpy;
     strlcat;
+#endif
 
+#if LIBBSD_ABI_ACCMODE
     setmode;
     getmode;
+#endif
 
+#if LIBBSD_ABI_VIS
     vis;
     strvis;
     strvisx;
     unvis;
     strunvis;
     strunvisx;
+#endif
 
-    /* The following functions are provided via the system libc or libmd
-     * implementations. */
+#if LIBBSD_ABI_MD5
     MD5Init;
     MD5Update;
     MD5Pad;
@@ -49,89 +76,138 @@ LIBBSD_0.0 {
     MD5File;
     MD5FileChunk;
     MD5Data;
+#endif
 
   local:
     *;
 };
 
 LIBBSD_0.1 {
+#if LIBBSD_ABI_STRMODE
     strmode;
+#endif
 
+#if LIBBSD_ABI_NLIST
     /* Private symbol, but libkvm uses it. */
     __fdnlist;
     nlist;
+#endif
 } LIBBSD_0.0;
 
 LIBBSD_0.2 {
+#if LIBBSD_ABI_STRTONUM
     strtonum;
+#endif
 
+#if LIBBSD_ABI_VIS
     strnvis;
     strnunvis;
+#endif
 
+#if LIBBSD_ABI_HUMANIZE_NUMBER
     dehumanize_number;
+#endif
 
+#if LIBBSD_ABI_READPASSPHRASE
     readpassphrase;
+#endif
 
+#if LIBBSD_ABI_FLOPEN
     flopen;
+#endif
 
+#if LIBBSD_ABI_PIDFILE
     pidfile_open;
     pidfile_write;
     pidfile_close;
     pidfile_remove;
+#endif
 
+#if LIBBSD_ABI_ARC4RANDOM
     arc4random_buf;
     arc4random_uniform;
+#endif
 } LIBBSD_0.1;
 
 LIBBSD_0.3 {
+#if LIBBSD_ABI_REALLOCF
     reallocf;
+#endif
+
+#if LIBBSD_ABI_GETPEEREID
     getpeereid;
+#endif
 
+#if LIBBSD_ABI_SORT
     mergesort;
     radixsort;
     sradixsort;
+#endif
 
+#if LIBBSD_ABI_FPURGE
     fpurge;
+#endif
 } LIBBSD_0.2;
 
 LIBBSD_0.4 {
+#if LIBBSD_ABI_CLOSEFROM
     closefrom;
+#endif
+
+#if LIBBSD_ABI_EXPAND_NUMBER
     expand_number;
+#endif
 } LIBBSD_0.3;
 
 LIBBSD_0.5 {
+#if LIBBSD_ABI_FGETLN
     fgetwln;
     fparseln;
+#endif
 
+#if LIBBSD_ABI_PROCTITLE
     /* Introduced in 0.2 as a stub, implemented in 0.5. */
     setproctitle;
+#endif
 
+#if LIBBSD_ABI_STRNSTR
     strnstr;
+#endif
 
+#if LIBBSD_ABI_WCSL
     wcslcat;
     wcslcpy;
+#endif
 } LIBBSD_0.4;
 
 LIBBSD_0.6 {
+#if LIBBSD_ABI_PROCTITLE
     /* Exported to cope with the constructor+dlopen+threads mess. */
     setproctitle_init;
+#endif
 } LIBBSD_0.5;
 
 LIBBSD_0.7 {
+#if LIBBSD_ABI_GETBSIZE
     getbsize;
+#endif
 
-    /* This symbol might not be present on some specific systems, such
-     * as musl based ones. It might need to be removed on SOVERSION bump,
-     * as it cannot be portabily implemented everywhere. */
+#if LIBBSD_ABI_FUNOPEN
     funopen;
+#endif
 
+#if LIBBSD_ABI_REALLOCARRAY
     reallocarray;
+#endif
 
+#if LIBBSD_ABI_STRINGLIST
     sl_init;
     sl_add;
     sl_free;
     sl_find;
+#endif
 
+#if LIBBSD_ABI_TIMECONV
     _time32_to_time;
     _time_to_time32;
     _time64_to_time;
@@ -140,20 +216,30 @@ LIBBSD_0.7 {
     _long_to_time;
     _time_to_int;
     _int_to_time;
+#endif
 } LIBBSD_0.6;
 
 LIBBSD_0.8 {
+#if LIBBSD_ABI_EXPLICIT_BZERO
     explicit_bzero;
+#endif
 } LIBBSD_0.7;
 
 LIBBSD_0.9 {
+#if LIBBSD_ABI_FLOPEN
     flopenat;
+#endif
 
+#if LIBBSD_ABI_PIDFILE
     pidfile_fileno;
+#endif
 
+#if LIBBSD_ABI_STRTOX
     strtoi;
     strtou;
+#endif
 
+#if LIBBSD_ABI_VIS
     nvis;
     snvis;
     stravis;
@@ -165,19 +251,21 @@ LIBBSD_0.9 {
     strsvis;
     strsvisx;
     svis;
+#endif
 } LIBBSD_0.8;
 
 LIBBSD_0.9.1 {
+#if LIBBSD_ABI_VIS
     /* The strnvis() and strnunvis() symbols changed prototype to match
      * the NetBSD implementation. Provided as versioned nodes in 0.9.1, and
      * exposed here explicitly so that we can redirect at compile-time. */
     strnvis_netbsd;
     strnunvis_netbsd;
+#endif
 } LIBBSD_0.9;
 
 LIBBSD_0.10.0 {
-    /* These BSD extensions are available on GNU systems, but not on other
-     * systems such as Windows or musl libc based ones. */
+#if LIBBSD_ABI_ERR
     vwarn;
     vwarnx;
     warn;
@@ -186,16 +274,28 @@ LIBBSD_0.10.0 {
     verrx;
     err;
     errx;
+#endif
 } LIBBSD_0.9.1;
 
 LIBBSD_0.11.0 {
+#if LIBBSD_ABI_VIS
     strnvisx;
+#endif
 
+#if LIBBSD_ABI_RECALLOCARRAY
     recallocarray;
+#endif
+
+#if LIBBSD_ABI_FREEZERO
     freezero;
+#endif
 
+#if LIBBSD_ABI_ID_FROM_NAME
     gid_from_group;
-    group_from_gid;
     uid_from_user;
+#endif
+#if LIBBSD_ABI_NAME_FROM_ID
     user_from_uid;
+    group_from_gid;
+#endif
 } LIBBSD_0.10.0;
diff --git a/test/Makefile.am b/test/Makefile.am
index 64c6610..1c64abb 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -33,21 +33,14 @@ check_SCRIPTS = \
 
 check_PROGRAMS = \
 	overlay \
-	bzero \
-	closefrom \
 	endian \
-	explicit_bzero \
-	humanize \
-	fgetln \
-	fparseln \
-	proctitle-init \
-	pwcache \
+	# EOL
+
+if ABI_ACCMODE
+check_PROGRAMS += \
 	setmode \
-	strnstr \
-	strtonum \
-	vis \
-	vis-openbsd \
 	# EOL
+endif
 
 if ABI_ARC4RANDOM
 if HAVE_LIBTESTU01
@@ -57,6 +50,25 @@ arc4random_LDADD = $(LDADD) $(TESTU01_LIBS)
 endif
 endif
 
+if ABI_CLOSEFROM
+check_PROGRAMS += \
+	closefrom \
+	# EOL
+endif
+
+if ABI_EXPLICIT_BZERO
+check_PROGRAMS += \
+	bzero \
+	explicit_bzero \
+	# EOL
+endif
+
+if ABI_FGETLN
+check_PROGRAMS += \
+	fgetln \
+	fparseln \
+	# EOL
+
 fgetln_SOURCES = \
 	test-stream.c \
 	test-stream.h \
@@ -70,6 +82,21 @@ fparseln_SOURCES = \
 	test-stream.h \
 	fparseln.c \
 	# EOL
+endif
+
+if ABI_FPURGE
+check_PROGRAMS += fpurge
+endif
+
+if ABI_FUNOPEN
+check_PROGRAMS += funopen
+endif
+
+if ABI_HUMANIZE_NUMBER
+check_PROGRAMS += \
+	humanize \
+	# EOL
+endif
 
 if ABI_FPURGE
 check_PROGRAMS += fpurge
@@ -92,6 +119,15 @@ if ABI_NLIST
 check_PROGRAMS += nlist
 endif
 
+if ABI_PROGNAME
+check_PROGRAMS += progname
+endif
+
+if ABI_PROCTITLE
+check_PROGRAMS += \
+	proctitle-init \
+	# EOL
+
 proctitle_init_SOURCES = \
 	proctitle.c \
 	# EOL
@@ -107,6 +143,13 @@ proctitle_LDFLAGS = \
 	$(top_builddir)/src/libbsd.la \
 	# EOL
 endif
+endif
+
+if ABI_PWCACHE
+check_PROGRAMS += \
+	pwcache \
+	# EOL
+endif
 
 if ABI_PROGNAME
 check_PROGRAMS += progname
@@ -120,4 +163,23 @@ if ABI_STRMODE
 check_PROGRAMS += strmode
 endif
 
+if ABI_STRNSTR
+check_PROGRAMS += \
+	strnstr \
+	# EOL
+endif
+
+if ABI_STRTONUM
+check_PROGRAMS += \
+	strtonum \
+	# EOL
+endif
+
+if ABI_VIS
+check_PROGRAMS += \
+	vis \
+	vis-openbsd \
+	# EOL
+endif
+
 TESTS = $(check_SCRIPTS) $(check_PROGRAMS)