[RFC] UAPI: Check headers by compiling all together as C++

David Howells
2018-09-06T09:18:29Z

Here's a set of patches that inserts a step into the build process to make
sure that the UAPI headers can all be built together with C++ (if the
compiler being used supports C++).

Note that it's based on a commit from the sound tree to fix usage of u32
and co..

Most of the patches perform fixups, including:

(1) Fix member names that conflict with C++ reserved words by providing
alternates that can be used anywhere. An anonymous union is used so
that that the conflicting name is still available outside of C++.

(2) Fix the use of flexible arrays in structs that get embedded (which is
illegal in C++).

(3) Remove the use of internal kernel structs in UAPI structures.

(4) Fix symbol collisions.

(5) Fix use of sparsely initialised arrays (which g++ doesn't implement).

(6) Remove some use of PAGE_SIZE since this isn't valid outside of the
kernel.

There's also:

(7) Move the coda_psdev.h header file to fs/coda/.

And lastly:

(8) Compile all of the UAPI headers (with a few exceptions) together as
C++ to catch new errors occurring as part of the regular build
process.

Changes for v2:

- Merge commit from sound tree to fix u32 usage issues
- Use a switch to fix sparse array initialisation
- Simplify nilfs2 by performing bitwise ops in LE space not CPU space
- Handle conflicting fix to use of 'private' in keyctl.h
- Move kernel internal coda bits to coda internal headers
- Move coda_psdev.h header to fs/coda/.

The patches can also be found here:

http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=uapi-check

Thanks,
David
---
David Howells (11):
UAPI: drm: Fix use of C++ keywords as structural members
UAPI: keys: Fix use of C++ keywords as structural members
UAPI: virtio_net: Fix use of C++ keywords as structural members
UAPI: bcache: Fix use of embedded flexible array
UAPI: coda: Move kernel internals out of public view
coda: Move internal defs out of include/linux/
UAPI: netfilter: Fix symbol collision issues
UAPI: nilfs2: Fix use of undefined byteswapping functions
UAPI: ndctl: Fix g++-unsupported initialisation in headers
UAPI: ndctl: Remove use of PAGE_SIZE
UAPI: Check headers build for C++

Makefile | 1
fs/coda/cache.c | 2
fs/coda/cnode.c | 2
fs/coda/coda_linux.c | 2
fs/coda/coda_psdev.h | 88 +++++++++++++++
fs/coda/dir.c | 2
fs/coda/file.c | 3 -
fs/coda/inode.c | 2
fs/coda/pioctl.c | 3 -
fs/coda/psdev.c | 3 -
fs/coda/symlink.c | 3 -
fs/coda/upcall.c | 2
include/linux/coda_psdev.h | 72 ------------
include/linux/ndctl.h | 22 ++++
include/uapi/drm/i810_drm.h | 7 +
include/uapi/drm/msm_drm.h | 7 +
include/uapi/linux/bcache.h | 2
include/uapi/linux/coda_psdev.h | 18 ---
include/uapi/linux/keyctl.h | 7 +
include/uapi/linux/ndctl.h | 52 ++++-----
include/uapi/linux/netfilter/nfnetlink_cthelper.h | 2
include/uapi/linux/netfilter_ipv4/ipt_ECN.h | 9 --
include/uapi/linux/nilfs2_ondisk.h | 28 ++---
include/uapi/linux/virtio_net.h | 7 +
scripts/headers-c++.sh | 124 +++++++++++++++++++++
25 files changed, 304 insertions(+), 166 deletions(-)
create mode 100644 fs/coda/coda_psdev.h
delete mode 100644 include/linux/coda_psdev.h
create mode 100644 include/linux/ndctl.h
create mode 100755 scripts/headers-c++.sh