#
# We try to detect the specific api incompatibilities with simple tests
# because distros regularly backport features without changing the
# version.
#

ccflags-y += -include $(src)/kernelcompat.h

#
# v5.19-rc4-96-g342a72a33407
#
# Adds `typedef __u32 __bitwise blk_opf_t` to aid flag checking
ifneq (,$(shell grep 'typedef __u32 __bitwise blk_opf_t' include/linux/blk_types.h))
ccflags-y += -DKC_HAVE_BLK_OPF_T=1
endif

#
# v5.12-rc6-9-g4f0f586bf0c8
#
# list_sort cmp function takes const list_head args
ifneq (,$(shell grep 'const struct list_head ., const struct list_head .' include/linux/list_sort.h))
ccflags-y += -DKC_LIST_CMP_CONST_ARG_LIST_HEAD
endif

# v5.7-523-g88dca4ca5a93
#
# The pgprot argument to vmalloc is always PAGE_KERNEL, so it is removed.
ifneq (,$(shell grep 'extern void .__vmalloc.unsigned long size, gfp_t gfp_mask, pgprot_t prot' include/linux/vmalloc.h))
ccflags-y += -DKC_VMALLOC_PGPROT_T
endif

# v6.2-rc1-18-g01beba7957a2
#
# fs: port inode_owner_or_capable() to mnt_idmap
ifneq (,$(shell grep 'bool inode_owner_or_capable.struct user_namespace .mnt_userns' include/linux/fs.h))
ccflags-y += -DKC_INODE_OWNER_OR_CAPABLE_USERNS
endif

#
# v5.11-rc4-5-g47291baa8ddf
#
# namei: make permission helpers idmapped mount aware
ifneq (,$(shell grep 'int inode_permission.struct user_namespace' include/linux/fs.h))
ccflags-y += -DKC_INODE_PERMISSION_USERNS
endif

#
# v5.11-rc4-24-g549c7297717c
#
# fs: make helpers idmap mount aware
# Enlarges the VFS API methods to include user namespace argument.
ifneq (,$(shell grep 'int ..mknod. .struct user_namespace' include/linux/fs.h))
ccflags-y += -DKC_VFS_METHOD_USER_NAMESPACE_ARG
endif

#
# v6.2-rc1-2-gabf08576afe3
#
# fs: vfs methods use struct mnt_idmap instead of struct user_namespace
ifneq (,$(shell grep 'int vfs_mknod.struct mnt_idmap' include/linux/fs.h))
ccflags-y += -DKC_VFS_METHOD_MNT_IDMAP_ARG
endif

#
# v5.17-rc2-21-g07888c665b40
#
# Detect new style bio_alloc - pass bdev and opf.
ifneq (,$(shell grep 'struct bio .bio_alloc.struct block_device .bdev' include/linux/bio.h))
ccflags-y += -DKC_BIO_ALLOC_DEV_OPF_ARGS
endif

#
# v5.7-rc4-53-gcddf8a2c4a82
#
# fiemap_prep() replaces fiemap_check_flags()
ifneq (,$(shell grep -s 'int fiemap_prep.struct inode' include/linux/fiemap.h))
ccflags-y += -DKC_FIEMAP_PREP
endif

#
# v5.17-13043-g800ba29547e1
#
# generic_perform_write args use kiocb for passing filp and pos
ifneq (,$(shell grep 'ssize_t generic_perform_write.struct kiocb ., struct iov_iter' include/linux/fs.h))
ccflags-y += -DKC_GENERIC_PERFORM_WRITE_KIOCB_IOV_ITER
endif

#
# v5.7-rc6-2496-g76ee0785f42a
#
# net: add sock_set_sndtimeo
ifneq (,$(shell grep 'void sock_set_sndtimeo.struct sock' include/net/sock.h))
ccflags-y += -DKC_SOCK_SET_SNDTIMEO
endif

#
# v5.8-rc4-1931-gba423fdaa589
#
# setsockopt functions are now passed a sockptr_t value instead of char*
ifneq (,$(shell grep -s 'include .linux/sockptr.h.' include/linux/net.h))
ccflags-y += -DKC_SETSOCKOPT_SOCKPTR_T
endif

#
# v5.7-rc6-2507-g71c48eb81c9e
#
# Adds a bunch of low level TCP sock parameter functions that we want to use.
ifneq (,$(shell grep 'int tcp_sock_set_keepintvl' include/linux/tcp.h))
ccflags-y += -DKC_HAVE_TCP_SET_SOCKFN
endif

#
# v5.19-rc4-52-ge33c267ab70d
#
# register_shrinker now requires a name, used for debug stats etc.
ifneq (,$(shell grep 'int __printf.*register_shrinker.struct shrinker .shrinker,' include/linux/shrinker.h))
ccflags-y += -DKC_SHRINKER_NAME
endif

#
# v5.18-rc5-246-gf132ab7d3ab0
#
# mpage_readpage() is now replaced with mpage_read_folio.
ifneq (,$(shell grep 'int mpage_read_folio.struct folio .folio' include/linux/mpage.h))
ccflags-y += -DKC_MPAGE_READ_FOLIO
endif

#
# v5.18-rc5-219-gb3992d1e2ebc
#
# block_write_begin() no longer is being passed aop_flags
ifneq (,$(shell grep -C1 'int block_write_begin' include/linux/buffer_head.h | tail -n 2 | grep 'unsigned flags'))
ccflags-y += -DKC_BLOCK_WRITE_BEGIN_AOP_FLAGS
endif

#
# v6.0-rc6-9-g863f144f12ad
#
# the .tmpfile() vfs method calling convention changed and now a struct
# file* is passed to this metiond instead of a dentry. The function also
# should open the created file and call finish_open_simple() before returning.
ifneq (,$(shell grep 'extern void d_tmpfile.struct dentry' include/linux/dcache.h))
ccflags-y += -DKC_D_TMPFILE_DENTRY
endif

#
# v6.4-rc2-201-g0733ad800291
#
# New blk_mode_t replaces abuse of fmode_t
ifneq (,$(shell grep 'typedef unsigned int __bitwise blk_mode_t' include/linux/blkdev.h))
ccflags-y += -DKC_HAVE_BLK_MODE_T
endif

#
# v6.4-rc2-186-g2736e8eeb0cc
#
# Reworks FMODE_EXCL kludge and instead modifies the blkdev_put() call to pass in
# the (exclusive) holder to implement FMODE_EXCL handling.
ifneq (,$(shell grep 'blkdev_put.struct block_device .bdev, void .holder' include/linux/blkdev.h))
ccflags-y += -DKC_BLKDEV_PUT_HOLDER_ARG
endif

#
# v6.4-rc4-163-g0d625446d0a4
#
# Entirely removes current->backing_dev_info to ultimately remove buffer_head
# completely at some point.
ifneq (,$(shell grep 'struct backing_dev_info.*backing_dev_info;' include/linux/sched.h))
ccflags-y += -DKC_CURRENT_BACKING_DEV_INFO
endif

#
# v6.8-rc1-4-gf3a608827d1f
#
# adds bdev_file_open_by_path() and later in v6.8-rc1-30-ge97d06a46526 removes bdev_open_by_path()
# which requires us to use the file method from now on.
ifneq (,$(shell grep 'struct file.*bdev_file_open_by_path.const char.*path' include/linux/blkdev.h))
ccflags-y += -DKC_BDEV_FILE_OPEN_BY_PATH
endif

#
# v6.7-rc4-153-g0a97c01cd20b
#
# list_lru_{add,del} -> list_lru_{add,del}_obj
#
ifneq (,$(shell grep '^bool list_lru_add_obj' include/linux/list_lru.h))
ccflags-y += -DKC_LIST_LRU_ADD_OBJ
endif

#
# v6.12-rc6-227-gda0c02516c50
#
# lru_list_walk_cb lock arg removed
#
ifneq (,$(shell grep 'struct list_lru_one \*list, spinlock_t \*lock, void \*cb_arg' include/linux/list_lru.h))
ccflags-y += -DKC_LIST_LRU_WALK_CB_LIST_LOCK
endif

#
# v6.1-rc1-2-g138060ba92b3
#
# set_acl now passed a struct dentry instead of inode.
#
ifneq (,$(shell grep 'int ..set_acl.*struct dentry' include/linux/fs.h))
ccflags-y += -DKC_SET_ACL_DENTRY
endif

#
# v6.1-rc1-3-gcac2f8b8d8b5
#
# get_acl renamed to get_inode_acl.
#
ifneq (,$(shell grep 'struct posix_acl.*get_inode_acl' include/linux/fs.h))
ccflags-y += -DKC_GET_INODE_ACL
endif

#
# v6.15-13744-g41cb08555c41
#
# from_timer renamed to timer_container_of.
#
ifneq (,$(shell grep 'define timer_container_of' include/linux/timer.h))
ccflags-y += -DKC_TIMER_CONTAINER_OF
endif

#
# v6.4-rc1-4f80818b4a58c
#
# iomap needs iterator nofault support in the read/write paths. We can still
# use iomap for fiemap and llseek though.
#
ifneq (,$(shell grep 'copy_page_to_iter_nofault' include/linux/uio.h))
ccflags-y += -DKC_USE_IOMAP_FOR_IO
endif