lib/string/strdup/strndupa.h: strndupa(3): Add macro

musl doesn't provide strndupa(3).

Signed-off-by: Alejandro Colomar <alx@kernel.org>

diff --git a/lib/string/strdup/strndupa.h b/lib/string/strdup/strndupa.h
index cefc298205664ba66ccbe8b9942b682ea0758466..c8d53f30b2be10c9c9e96dba48f09431465fa795 100644 (file)
--- a/lib/string/strdup/strndupa.h
+++ b/lib/string/strdup/strndupa.h
@@ -15,6 +15,12 @@
 #include "string/strcpy/strncat.h"
 
 
+// string n-bounded-read duplicate using-alloca(3)
+#ifndef  strndupa
+# define strndupa(s, n)  strncat(strcpy(alloca(n + 1), ""), s, n)
+#endif
+
+
 // Similar to strndupa(3), but ensure that 's' is an array.
 #define STRNDUPA(s)                                                           \
 (                                                                             \