fixup! fixup! Use portable implementation for basename API

Move basename to the missing.h header, relying on the build system to
check for differences between musl and glibc, like done for other
functions.

with glibc:
checking whether strndupa is declared... yes
checking whether basename is declared... yes
checking whether be32toh is declared... yes

with musl 1.2.5:
checking whether strndupa is declared... no
checking whether basename is declared... no
checking whether be32toh is declared... yes

Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>

configure.ac

@@ -53,7 +53,9 @@ CC_CHECK_FUNC_BUILTIN([__builtin_uaddll_overflow], [ ], [ ])
 AC_CHECK_MEMBERS([struct stat.st_mtim], [], [], [#include <sys/stat.h>])
 
 # musl 1.0 and bionic 4.4 don't have strndupa
-AC_CHECK_DECLS_ONCE([strndupa])
+# basename may be only available in libgen.h with the POSIX behavior,
+# not desired here
+AC_CHECK_DECLS_ONCE([[strndupa], [basename]], [], [], [[#include <string.h>]])
 
 # RHEL 5 and older do not have be32toh
 AC_CHECK_DECLS_ONCE([be32toh])

shared/missing.h

@@ -38,6 +38,7 @@ static inline int finit_module(int fd, const char *uargs, int flags)
 #endif
 
 #if !HAVE_DECL_STRNDUPA
+#include <string.h>
 #define strndupa(s, n)							\
 	({								\
 		const char *__old = (s);				\
@@ -48,6 +49,15 @@ static inline int finit_module(int fd, const char *uargs, int flags)
 	 })
 #endif
 
+#if !HAVE_DECL_BASENAME
+#include <string.h>
+static inline const char *basename(const char *s)
+{
+	const char *p = strrchr(s, '/');
+	return p ? p + 1 : s;
+}
+#endif
+
 #if !HAVE_DECL_BE32TOH
 #include <endian.h>
 #include <byteswap.h>

shared/util.h

@@ -77,12 +77,6 @@ do {						\
 	__p->__v = (val);			\
 } while(0)
 
-static _always_inline_ const char *basename(const char *s)
-{
-  const char *p = strrchr(s, '/');
-  return p ? p+1 : s;
-}
-
 static _always_inline_ unsigned int ALIGN_POWER2(unsigned int u)
 {
 	return 1 << ((sizeof(u) * 8) - __builtin_clz(u - 1));

tools/kmod.c

@@ -24,6 +24,7 @@
 #include <string.h>
 
 #include <shared/util.h>
+#include <shared/missing.h>
 
 #include <libkmod/libkmod.h>