diff --git a/src/cmd/ksh93/data/builtins.c b/src/cmd/ksh93/data/builtins.c
index dc1132fcb016..d018e59be414 100644
--- a/src/cmd/ksh93/data/builtins.c
+++ b/src/cmd/ksh93/data/builtins.c
@@ -47,6 +47,7 @@
 
 #undef	basename
 #undef	dirname
+#undef	mktemp		/* undo possible map-libc mktemp => _ast_mktemp */
 
 /*
  * IMPORTANT: The order of these struct members must be synchronous
@@ -127,7 +128,6 @@ const struct shtable3 shtab_builtins[] =
 	"type",		NV_BLTIN|BLT_ENV,		bltin(whence),
 	"whence",	NV_BLTIN|BLT_ENV,		bltin(whence),
 #ifdef SHOPT_CMDLIB_HDR
-#undef	mktemp		/* undo possible map-libc mktemp => _ast_mktemp */
 #include SHOPT_CMDLIB_HDR
 #else
 #if SHOPT_ALL_LIBCMD
diff --git a/src/lib/libast/Mamfile b/src/lib/libast/Mamfile
index 41159a76c82c..a22f6f09202e 100644
--- a/src/lib/libast/Mamfile
+++ b/src/lib/libast/Mamfile
@@ -138,6 +138,12 @@ make install virtual
 		exec - invoke_iffe %{<}
 	done
 
+	note * ast_random.h *
+	make FEATURE/random
+		makp features/random
+		exec - invoke_iffe %{<}
+	done
+
 	note * sig.h: AST replacement for <signal.h>
 	make FEATURE/sig
 		makp features/sig.sh
@@ -187,6 +193,7 @@ make install virtual
 		make FEATURE/map
 			make features/map.c
 				prev sig.h
+				prev FEATURE/random
 				prev FEATURE/api
 				prev FEATURE/eaccess
 				prev FEATURE/options
@@ -576,12 +583,6 @@ make install virtual
 		exec - invoke_iffe %{<} -I.
 	done
 
-	note * ast_random.h *
-	make FEATURE/random
-		makp features/random
-		exec - invoke_iffe %{<}
-	done
-
 	note * copy most of the FEATURE/* results above to canonically named header files; separating
 	note * this allows all of the above tests, which don't depend on each other, to run in parallel
 
diff --git a/src/lib/libast/features/map.c b/src/lib/libast/features/map.c
index b51316e2a10e..2574dcb485fc 100644
--- a/src/lib/libast/features/map.c
+++ b/src/lib/libast/features/map.c
@@ -30,12 +30,20 @@
 #include "FEATURE/options"
 #include "FEATURE/eaccess"
 #include "FEATURE/api"
+#include "FEATURE/random"
 #include <sig.h>
 
 #if _opt_map_libc && !defined(_map_libc)
 #define _map_libc	1
 #endif
 
+/*
+ * NOTE: for conditionally compiled AST functions, the preprocessor directives below
+ * must be kept in sync with the directives in the corresponding C source files, so
+ * that the rename is not done if the AST version of the function is not compiled
+ * in; otherwise a build with _map_libc defined will fail with linking errors.
+ */
+
 int
 main(void)
 {
@@ -59,6 +67,20 @@ main(void)
 	printf("\n");
 	printf("#define	_map_libc	1\n");
 #endif
+#if _map_libc
+#if !_lib_arc4random
+	printf("#undef	arc4random\n");
+	printf("#define arc4random	_ast_arc4random\n");
+#endif
+#if !_lib_arc4random_buf
+	printf("#undef	arc4random_buf\n");
+	printf("#define arc4random_buf	_ast_arc4random_buf\n");
+#endif
+#if !_lib_arc4random_uniform
+	printf("#undef	arc4random_uniform\n");
+	printf("#define arc4random_uniform	_ast_arc4random_uniform\n");
+#endif
+#endif
 #if _map_libc || defined(__linux__)
 	printf("#undef	basename\n");
 	printf("#define basename	_ast_basename\n");
@@ -110,8 +132,10 @@ main(void)
 	printf("#undef	sigunblock\n");
 	printf("#define sigunblock      _ast_sigunblock\n");
 #if _map_libc
+#if !_lib_memdup
 	printf("#undef	memdup\n");
 	printf("#define memdup		_ast_memdup\n");
+#endif
 	printf("#undef	memhash\n");
 	printf("#define memhash		_ast_memhash\n");
 	printf("#undef	memsum\n");
@@ -158,6 +182,8 @@ main(void)
 	printf("#define pathfind	_ast_pathfind\n");
 	printf("#undef	pathgetlink\n");
 	printf("#define pathgetlink	_ast_pathgetlink\n");
+	printf("#undef	pathicase\n");
+	printf("#define pathicase	_ast_pathicase\n");
 	printf("#undef	pathinclude\n");
 	printf("#define pathinclude	_ast_pathinclude\n");
 	printf("#undef	pathkey\n");
@@ -251,21 +277,27 @@ main(void)
 	printf("#undef	regsubfree\n");
 	printf("#define regsubfree	_ast_regsubfree\n");
 #if _map_libc
+#if !(_std_remove || !_lib_unlink)
 	printf("#undef	remove\n");
 	printf("#define remove		_ast_remove\n");
 	printf("extern int		remove(const char*);\n");
+#endif
 	printf("#undef	resolvepath\n");
 	printf("#define resolvepath	_ast_resolvepath\n");
 	printf("extern int		resolvepath(const char*, char*, size_t);\n");
+#if !_lib_setenv
 	printf("#undef	setenv\n");
 	printf("#define setenv		_ast_setenv\n");
 	printf("extern int		setenv(const char*, const char*, int);\n");
+#endif
 	printf("#undef	setenviron\n");
 	printf("#define setenviron      _ast_setenviron\n");
 	printf("#undef	sigcritical\n");
 	printf("#define sigcritical      _ast_sigcritical\n");
+#if !_lib_stracmp
 	printf("#undef	stracmp\n");
 	printf("#define stracmp		_ast_stracmp\n");
+#endif
 	printf("#undef	strcopy\n");
 	printf("#define strcopy		_ast_strcopy\n");
 	printf("#undef	strelapsed\n");
@@ -288,12 +320,16 @@ main(void)
 	printf("#define strhash		_ast_strhash\n");
 	printf("#undef	strkey\n");
 	printf("#define strkey		_ast_strkey\n");
+#if !_lib_strlcat
 	printf("#undef	strlcat\n");
 	printf("#define strlcat		_ast_strlcat\n");
 	printf("extern size_t		strlcat(char*, const char*, size_t);\n");
+#endif
+#if !_lib_strlcpy
 	printf("#undef	strlcpy\n");
 	printf("#define strlcpy		_ast_strlcpy\n");
 	printf("extern size_t		strlcpy(char*, const char*, size_t);\n");
+#endif
 	printf("#undef	strlook\n");
 	printf("#define strlook		_ast_strlook\n");
 	printf("#undef	strmatch\n");
@@ -304,8 +340,10 @@ main(void)
 	printf("#define strmode		_ast_strmode\n");
 #endif
 #if _map_libc
+#if !_lib_strnacmp
 	printf("#undef	strnacmp\n");
 	printf("#define strnacmp	_ast_strnacmp\n");
+#endif
 	printf("#undef	strncopy\n");
 	printf("#define strncopy	_ast_strncopy\n");
 	printf("#undef	strntod\n");
@@ -365,8 +403,10 @@ main(void)
 	printf("#define wordexp		_ast_wordexp\n");
 	printf("#undef	wordfree\n");
 	printf("#define wordfree	_ast_wordfree\n");
+#if !_lib_unsetenv
 	printf("#undef	unsetenv\n");
 	printf("#define unsetenv	_ast_unsetenv\n");
+#endif
 #endif
 	/* we always use the libast strdup implementation */
 	printf("#undef	strdup\n");
@@ -472,11 +512,9 @@ main(void)
 		do
 		{
 			for (s = t; *t && *t != ' '; t++);
-			printf("#define %-.*s	_ast_%-.*s\n", t - s, s, t - s, s);
+			printf("#define %-.*s	_ast_%-.*s\n", (int)(t - s), s, (int)(t - s), s);
 		} while (*t++);
 	}
 #endif
-	printf("\n");
-	printf("#undef	extern\n");
 	return 0;
 }
diff --git a/src/lib/libast/features/random b/src/lib/libast/features/random
index 3827b9f86205..a9b858650648 100644
--- a/src/lib/libast/features/random
+++ b/src/lib/libast/features/random
@@ -38,7 +38,7 @@ tst note{ does arc4random(3) become predictable after forking }end output{
 		pid_t		child;
 		uint32_t	r[3], r2[3];
 		/* create data file */
-		while (*t = *f++ && t < &file[PATHSIZE-4])
+		while ((*t = *f++) && t < &file[PATHSIZE-4])
 			t++;
 		*t++ = '.', *t++ = 'D', *t = 0;
 		if ((fd = open(file, O_CREAT|O_TRUNC|O_WRONLY, 0666)) < 0)
diff --git a/src/lib/libast/man/strperm.3 b/src/lib/libast/man/strperm.3
index 8aff82d8ddb6..6b11afb7b6d1 100644
--- a/src/lib/libast/man/strperm.3
+++ b/src/lib/libast/man/strperm.3
@@ -55,7 +55,7 @@ not 0 then
 is set to point to the first unrecognized character in
 .IR s .
 .PP
-A tape device specification is composed of one or more
+A file permission expression is composed of one or more
 .I who-op-permission
 terms separated by
 .BR , .