build: Conditionalize getprogname()/setprogname on macOS

These functions are provided by the system libc, so there is no need for
us to provide them.

configure.ac

@@ -320,6 +320,7 @@ AC_CHECK_FUNCS([\
 
 need_arc4random=yes
 need_bsd_getopt=yes
+need_progname=yes
 need_md5=yes
 need_nlist=yes
 need_strl=yes
@@ -348,6 +349,7 @@ AS_CASE([$host_os],
     # there, so we can avoid providing these with no ABI breakage.
     need_arc4random=no
     need_bsd_getopt=no
+    need_progname=no
     need_transparent_libmd=no
     need_md5=no
     need_nlist=no
@@ -364,6 +366,7 @@ AM_CONDITIONAL([HAVE_GETENTROPY], [test "x$ac_cv_func_getentropy" = "xyes"])
 
 AM_CONDITIONAL([NEED_ARC4RANDOM], [test "x$need_arc4random" = "xyes"])
 AM_CONDITIONAL([NEED_BSD_GETOPT], [test "x$need_bsd_getopt" = "xyes"])
+AM_CONDITIONAL([NEED_PROGNAME], [test "x$need_progname" = "xyes"])
 AM_CONDITIONAL([NEED_TRANSPARENT_LIBMD], [test "x$need_transparent_libmd" = "xyes"])
 AM_CONDITIONAL([NEED_MD5], [test "x$need_md5" = "xyes"])
 AM_CONDITIONAL([NEED_NLIST], [test "x$need_nlist" = "xyes"])

include/bsd/stdlib.h

@@ -65,8 +65,10 @@ void arc4random_addrandom(unsigned char *dat, int datlen);
 
 int dehumanize_number(const char *str, int64_t *size);
 
+#if !defined(__APPLE__)
 const char *getprogname(void);
 void setprogname(const char *);
+#endif
 
 int heapsort(void *, size_t, size_t, int (*)(const void *, const void *));
 int mergesort(void *base, size_t nmemb, size_t size,

man/Makefile.am

@@ -180,7 +180,6 @@ dist_man_MANS = \
 	getbsize.3bsd \
 	getmode.3bsd \
 	getpeereid.3bsd \
-	getprogname.3bsd \
 	heapsort.3bsd \
 	humanize_number.3bsd \
 	le16dec.3bsd \
@@ -205,7 +204,6 @@ dist_man_MANS = \
 	setmode.3bsd \
 	setproctitle.3bsd \
 	setproctitle_init.3bsd \
-	setprogname.3bsd \
 	sl_add.3bsd \
 	sl_delete.3bsd \
 	sl_find.3bsd \
@@ -241,6 +239,13 @@ dist_man_MANS = \
 	wcslcpy.3bsd \
 	# EOL
 
+if NEED_PROGNAME
+dist_man_MANS += \
+	getprogname.3bsd \
+	setprogname.3bsd \
+	# EOL
+endif
+
 if NEED_MD5
 dist_man_MANS += \
 	md5.3bsd \

test/Makefile.am

@@ -41,7 +41,6 @@ check_PROGRAMS = \
 	fgetln \
 	fparseln \
 	proctitle-init \
-	progname \
 	setmode \
 	strnstr \
 	strtonum \
@@ -49,6 +48,10 @@ check_PROGRAMS = \
 	vis-openbsd \
 	# EOL
 
+if NEED_PROGNAME
+check_PROGRAMS += progname
+endif
+
 if NEED_NLIST
 check_PROGRAMS += nlist
 endif