linux/usr/dummy-include/stdlib.h

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef _STDLIB_H
#define _STDLIB_H

#error "Please do not include <stdlib.h> from exported headers"

#endif /* _STDLIB_H */
kbuild: prevent exported headers from including <stdlib.h>, <stdbool.h> Some UAPI headers included <stdlib.h>, like this: #ifndef __KERNEL__ #include <stdlib.h> #endif As it turned out, they just included it for no good reason. After some fixes, now I can compile-test UAPI headers (CONFIG_UAPI_HEADER_TEST=y) without including <stdlib.h> from the system header search paths. To avoid somebody getting it back again, this commit adds the dummy header, usr/dummy-include/stdlib.h I added $(srctree)/usr/dummy-include to the header search paths. Because it is searched before the system directories, if someone tries to include <stdlib.h>, they will see the error message. While I am here, I also replaced $(objtree)/usr/include with $(obj), but it has no functional change. If we can make kernel headers self-contained (that is, none of exported kernel headers includes system headers), we will be able to add the -nostdinc flag, but that is much far from where we stand now. As a realistic solution, we can ban header inclusion individually by putting a dummy header into usr/dummy-include/. Currently, no header include <stdbool.h>. I put it as well before somebody attempts to use it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2022-04-04 06:19:42 +00:00			`/* SPDX-License-Identifier: GPL-2.0-only */`
			`#ifndef _STDLIB_H`
			`#define _STDLIB_H`

			`#error "Please do not include <stdlib.h> from exported headers"`

			`#endif /* _STDLIB_H */`