* [PATCH 1/2] add typeof_member() macro @ 2019-05-29 19:07 Alexey Dobriyan 2019-05-29 19:11 ` [PATCH 2/2] proc: use " Alexey Dobriyan 2019-05-30 11:37 ` [PATCH 1/2] add " David Laight 0 siblings, 2 replies; 6+ messages in thread From: Alexey Dobriyan @ 2019-05-29 19:07 UTC (permalink / raw) To: akpm; +Cc: linux-kernel Add typeof_member() macro so that types can be exctracted without introducing dummy variables. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> --- include/linux/kernel.h | 2 ++ 1 file changed, 2 insertions(+) --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -88,6 +88,8 @@ */ #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) +#define typeof_member(T, m) typeof(((T*)0)->m) + #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP #define DIV_ROUND_DOWN_ULL(ll, d) \ ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/2] proc: use typeof_member() macro 2019-05-29 19:07 [PATCH 1/2] add typeof_member() macro Alexey Dobriyan @ 2019-05-29 19:11 ` Alexey Dobriyan 2019-05-29 22:33 ` Andrew Morton 2019-05-30 11:37 ` [PATCH 1/2] add " David Laight 1 sibling, 1 reply; 6+ messages in thread From: Alexey Dobriyan @ 2019-05-29 19:11 UTC (permalink / raw) To: akpm; +Cc: linux-kernel Don't repeat function signatures twice. This is a kind-of-precursor for "struct proc_ops". Note: typeof(pde->proc_fops->...) ...; can't be used because ->proc_fops is "const struct file_operations *". "const" prevents assignment down the code and it can't be deleted in the type system. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> --- Note 2: 100% false positives with checkpatch.pl :^) fs/proc/inode.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -200,7 +200,8 @@ static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) struct proc_dir_entry *pde = PDE(file_inode(file)); loff_t rv = -EINVAL; if (use_pde(pde)) { - loff_t (*llseek)(struct file *, loff_t, int); + typeof_member(struct file_operations, llseek) llseek; + llseek = pde->proc_fops->llseek; if (!llseek) llseek = default_llseek; @@ -212,10 +213,11 @@ static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); struct proc_dir_entry *pde = PDE(file_inode(file)); ssize_t rv = -EIO; if (use_pde(pde)) { + typeof_member(struct file_operations, read) read; + read = pde->proc_fops->read; if (read) rv = read(file, buf, count, ppos); @@ -226,10 +228,11 @@ static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); struct proc_dir_entry *pde = PDE(file_inode(file)); ssize_t rv = -EIO; if (use_pde(pde)) { + typeof_member(struct file_operations, write) write; + write = pde->proc_fops->write; if (write) rv = write(file, buf, count, ppos); @@ -242,8 +245,9 @@ static __poll_t proc_reg_poll(struct file *file, struct poll_table_struct *pts) { struct proc_dir_entry *pde = PDE(file_inode(file)); __poll_t rv = DEFAULT_POLLMASK; - __poll_t (*poll)(struct file *, struct poll_table_struct *); if (use_pde(pde)) { + typeof_member(struct file_operations, poll) poll; + poll = pde->proc_fops->poll; if (poll) rv = poll(file, pts); @@ -256,8 +260,9 @@ static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigne { struct proc_dir_entry *pde = PDE(file_inode(file)); long rv = -ENOTTY; - long (*ioctl)(struct file *, unsigned int, unsigned long); if (use_pde(pde)) { + typeof_member(struct file_operations, unlocked_ioctl) ioctl; + ioctl = pde->proc_fops->unlocked_ioctl; if (ioctl) rv = ioctl(file, cmd, arg); @@ -271,8 +276,9 @@ static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned { struct proc_dir_entry *pde = PDE(file_inode(file)); long rv = -ENOTTY; - long (*compat_ioctl)(struct file *, unsigned int, unsigned long); if (use_pde(pde)) { + typeof_member(struct file_operations, compat_ioctl) compat_ioctl; + compat_ioctl = pde->proc_fops->compat_ioctl; if (compat_ioctl) rv = compat_ioctl(file, cmd, arg); @@ -286,8 +292,9 @@ static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) { struct proc_dir_entry *pde = PDE(file_inode(file)); int rv = -EIO; - int (*mmap)(struct file *, struct vm_area_struct *); if (use_pde(pde)) { + typeof_member(struct file_operations, mmap) mmap; + mmap = pde->proc_fops->mmap; if (mmap) rv = mmap(file, vma); @@ -305,7 +312,7 @@ proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, unsigned long rv = -EIO; if (use_pde(pde)) { - typeof(proc_reg_get_unmapped_area) *get_area; + typeof_member(struct file_operations, get_unmapped_area) get_area; get_area = pde->proc_fops->get_unmapped_area; #ifdef CONFIG_MMU @@ -326,8 +333,8 @@ static int proc_reg_open(struct inode *inode, struct file *file) { struct proc_dir_entry *pde = PDE(inode); int rv = 0; - int (*open)(struct inode *, struct file *); - int (*release)(struct inode *, struct file *); + typeof_member(struct file_operations, open) open; + typeof_member(struct file_operations, release) release; struct pde_opener *pdeo; /* ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] proc: use typeof_member() macro 2019-05-29 19:11 ` [PATCH 2/2] proc: use " Alexey Dobriyan @ 2019-05-29 22:33 ` Andrew Morton 0 siblings, 0 replies; 6+ messages in thread From: Andrew Morton @ 2019-05-29 22:33 UTC (permalink / raw) To: Alexey Dobriyan; +Cc: linux-kernel On Wed, 29 May 2019 22:11:10 +0300 Alexey Dobriyan <adobriyan@gmail.com> wrote: > Don't repeat function signatures twice. > > This is a kind-of-precursor for "struct proc_ops". > > Note: > > typeof(pde->proc_fops->...) ...; > > can't be used because ->proc_fops is "const struct file_operations *". > "const" prevents assignment down the code and it can't be deleted > in the type system. > > ... > > --- a/fs/proc/inode.c > +++ b/fs/proc/inode.c > @@ -200,7 +200,8 @@ static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) > struct proc_dir_entry *pde = PDE(file_inode(file)); > loff_t rv = -EINVAL; > if (use_pde(pde)) { > - loff_t (*llseek)(struct file *, loff_t, int); > + typeof_member(struct file_operations, llseek) llseek; ooh. That's pretty nifty. ^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH 1/2] add typeof_member() macro 2019-05-29 19:07 [PATCH 1/2] add typeof_member() macro Alexey Dobriyan 2019-05-29 19:11 ` [PATCH 2/2] proc: use " Alexey Dobriyan @ 2019-05-30 11:37 ` David Laight 2019-05-30 11:53 ` Joe Perches 2019-05-30 19:57 ` Alexey Dobriyan 1 sibling, 2 replies; 6+ messages in thread From: David Laight @ 2019-05-30 11:37 UTC (permalink / raw) To: 'Alexey Dobriyan', akpm; +Cc: linux-kernel From: Alexey Dobriyan > Sent: 29 May 2019 20:07 > > Add typeof_member() macro so that types can be exctracted without > introducing dummy variables. > > Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> > --- > > include/linux/kernel.h | 2 ++ > 1 file changed, 2 insertions(+) > > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -88,6 +88,8 @@ > */ > #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) > > +#define typeof_member(T, m) typeof(((T*)0)->m) Should probably be 't' (not 'T') and upper case ? Hmmm.... the #define is longer that what it expands to ... David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] add typeof_member() macro 2019-05-30 11:37 ` [PATCH 1/2] add " David Laight @ 2019-05-30 11:53 ` Joe Perches 2019-05-30 19:57 ` Alexey Dobriyan 1 sibling, 0 replies; 6+ messages in thread From: Joe Perches @ 2019-05-30 11:53 UTC (permalink / raw) To: David Laight, 'Alexey Dobriyan', akpm; +Cc: linux-kernel On Thu, 2019-05-30 at 11:37 +0000, David Laight wrote: > From: Alexey Dobriyan > > Sent: 29 May 2019 20:07 > > > > Add typeof_member() macro so that types can be exctracted without > > introducing dummy variables. > > > > Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> > > --- > > > > include/linux/kernel.h | 2 ++ > > 1 file changed, 2 insertions(+) > > > > --- a/include/linux/kernel.h > > +++ b/include/linux/kernel.h > > @@ -88,6 +88,8 @@ > > */ > > #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) > > > > +#define typeof_member(T, m) typeof(((T*)0)->m) > > Should probably be 't' (not 'T') and upper case ? > > Hmmm.... the #define is longer that what it expands to ... While I did object to the avoidance in the obvious misnaming of FIELD_SIZEOF, this could reasonably be named FIELD_TYPEOF for symmetry. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] add typeof_member() macro 2019-05-30 11:37 ` [PATCH 1/2] add " David Laight 2019-05-30 11:53 ` Joe Perches @ 2019-05-30 19:57 ` Alexey Dobriyan 1 sibling, 0 replies; 6+ messages in thread From: Alexey Dobriyan @ 2019-05-30 19:57 UTC (permalink / raw) To: David Laight; +Cc: akpm, linux-kernel On Thu, May 30, 2019 at 11:37:42AM +0000, David Laight wrote: > From: Alexey Dobriyan > > +#define typeof_member(T, m) typeof(((T*)0)->m) > > Should probably be 't' (not 'T') and upper case ? T comes from C++ where they uppercase types in template arguments. It makes sense as types stand out sligthly around lowercase identifiers. > Hmmm.... the #define is longer that what it expands to ... It hides cast of 0 which is implementation detail :^) Proper syntax would be typeof(struct foo::bar) but one can only dream. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-05-30 19:57 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-05-29 19:07 [PATCH 1/2] add typeof_member() macro Alexey Dobriyan 2019-05-29 19:11 ` [PATCH 2/2] proc: use " Alexey Dobriyan 2019-05-29 22:33 ` Andrew Morton 2019-05-30 11:37 ` [PATCH 1/2] add " David Laight 2019-05-30 11:53 ` Joe Perches 2019-05-30 19:57 ` Alexey Dobriyan
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).