diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-03 08:11:39 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-03 08:11:39 +0300 |
commit | 624ad333d49e136c54a342ce0009a05b439616be (patch) | |
tree | 199d58e6fdbc1273f43f6022e62256ccd4601a30 /Documentation/process/coding-style.rst | |
parent | 313b6ffc8e90173f1709b2f4bf9d30c4730a1dde (diff) | |
parent | 603bdf5d6c092eb05666decd84288dfda71eee90 (diff) | |
download | linux-624ad333d49e136c54a342ce0009a05b439616be.tar.xz |
Merge tag 'docs-5.16' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"This is a relatively unexciting cycle for documentation.
- Some small scripts/kerneldoc fixes
- More Chinese translation work, but at a much reduced rate.
- The tip-tree maintainer's handbook
...plus the usual array of build fixes, typo fixes, etc"
* tag 'docs-5.16' of git://git.lwn.net/linux: (53 commits)
kernel-doc: support DECLARE_PHY_INTERFACE_MASK()
docs/zh_CN: add core-api xarray translation
docs/zh_CN: add core-api assoc_array translation
speakup: Fix typo in documentation "boo" -> "boot"
docs: submitting-patches: make section about the Link: tag more explicit
docs: deprecated.rst: Clarify open-coded arithmetic with literals
scripts: documentation-file-ref-check: fix bpf selftests path
scripts: documentation-file-ref-check: ignore hidden files
coding-style.rst: trivial: fix location of driver model macros
docs: f2fs: fix text alignment
docs/zh_CN add PCI pci.rst translation
docs/zh_CN add PCI index.rst translation
docs: translations: zh_CN: memory-hotplug.rst: fix a typo
docs: translations: zn_CN: irq-affinity.rst: add a missing extension
block: add documentation for inflight
scripts: kernel-doc: Ignore __alloc_size() attribute
docs: pdfdocs: Adjust \headheight for fancyhdr
docs: UML: user_mode_linux_howto_v2 edits
docs: use the lore redirector everywhere
docs: proc.rst: mountinfo: align columns
...
Diffstat (limited to 'Documentation/process/coding-style.rst')
-rw-r--r-- | Documentation/process/coding-style.rst | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst index 42969ab37b34..03eb53fd029a 100644 --- a/Documentation/process/coding-style.rst +++ b/Documentation/process/coding-style.rst @@ -480,13 +480,48 @@ closing function brace line. E.g.: } EXPORT_SYMBOL(system_is_up); +6.1) Function prototypes +************************ + In function prototypes, include parameter names with their data types. Although this is not required by the C language, it is preferred in Linux because it is a simple way to add valuable information for the reader. -Do not use the ``extern`` keyword with function prototypes as this makes +Do not use the ``extern`` keyword with function declarations as this makes lines longer and isn't strictly necessary. +When writing function prototypes, please keep the `order of elements regular +<https://lore.kernel.org/mm-commits/CAHk-=wiOCLRny5aifWNhr621kYrJwhfURsa0vFPeUEm8mF0ufg@mail.gmail.com/>`_. +For example, using this function declaration example:: + + __init void * __must_check action(enum magic value, size_t size, u8 count, + char *fmt, ...) __printf(4, 5) __malloc; + +The preferred order of elements for a function prototype is: + +- storage class (below, ``static __always_inline``, noting that ``__always_inline`` + is technically an attribute but is treated like ``inline``) +- storage class attributes (here, ``__init`` -- i.e. section declarations, but also + things like ``__cold``) +- return type (here, ``void *``) +- return type attributes (here, ``__must_check``) +- function name (here, ``action``) +- function parameters (here, ``(enum magic value, size_t size, u8 count, char *fmt, ...)``, + noting that parameter names should always be included) +- function parameter attributes (here, ``__printf(4, 5)``) +- function behavior attributes (here, ``__malloc``) + +Note that for a function **definition** (i.e. the actual function body), +the compiler does not allow function parameter attributes after the +function parameters. In these cases, they should go after the storage +class attributes (e.g. note the changed position of ``__printf(4, 5)`` +below, compared to the **declaration** example above):: + + static __always_inline __init __printf(4, 5) void * __must_check action(enum magic value, + size_t size, u8 count, char *fmt, ...) __malloc + { + ... + } 7) Centralized exiting of functions ----------------------------------- @@ -855,7 +890,7 @@ Kernel messages do not have to be terminated with a period. Printing numbers in parentheses (%d) adds no value and should be avoided. -There are a number of driver model diagnostic macros in <linux/device.h> +There are a number of driver model diagnostic macros in <linux/dev_printk.h> which you should use to make sure messages are matched to the right device and driver, and are tagged with the right level: dev_err(), dev_warn(), dev_info(), and so forth. For messages that aren't associated with a |