diff mbox series

[v1,3/4] lib/vsprintf: Remove implied inclusions

Message ID 20230804082619.61833-4-andriy.shevchenko@linux.intel.com (mailing list archive)
State New
Headers show
Series lib/vsprintf: Rework header inclusions | expand

Commit Message

Andy Shevchenko Aug. 4, 2023, 8:26 a.m. UTC
Remove inclusions that are implied and guaranteed to be provided by others:

  compiler.h	by types.h
  string.hi	by string_helpers.h

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 lib/vsprintf.c | 2 --
 1 file changed, 2 deletions(-)

Comments

Rasmus Villemoes Aug. 4, 2023, 9:36 a.m. UTC | #1
On 04/08/2023 10.26, Andy Shevchenko wrote:
> Remove inclusions that are implied and guaranteed to be provided by others:
> 
>   compiler.h	by types.h
>   string.hi	by string_helpers.h

What? No. That's not what we want. Each .c and each .h file should
include the headers that declare the stuff they're using. So if
string_helpers.h magically stops referring to anything from string.h,
one should be allowed to stop including string.h from string_helpers.h.

Sure, those two may forever be so intertwined that it never happens, but
one really can't maintain some matrix of "X always includes Y so if you
include X you don't have to include Y" in one's head.

Rasmus
Andy Shevchenko Aug. 4, 2023, 8:31 p.m. UTC | #2
On Fri, Aug 04, 2023 at 11:36:15AM +0200, Rasmus Villemoes wrote:
> On 04/08/2023 10.26, Andy Shevchenko wrote:
> > Remove inclusions that are implied and guaranteed to be provided by others:
> > 
> >   compiler.h	by types.h
> >   string.hi	by string_helpers.h
> 
> What? No. That's not what we want. Each .c and each .h file should
> include the headers that declare the stuff they're using.

99.99% of kernel if not more doesn't follow this rule pedantically.
We have to have a compromise between what is guaranteed and what is not.

For example, I'm pretty sure the types.h will always include compiler*.h.

> So if string_helpers.h magically stops referring to anything from string.h,
> one should be allowed to stop including string.h from string_helpers.h.

That's how agreements work. We may agree to guarantee such inclusion or
not. The kernel headers as of today is a complete mess (refer to the
Ingo's 2k+ patch series). But still, some order / agreement is good to have.

> Sure, those two may forever be so intertwined that it never happens, but
> one really can't maintain some matrix of "X always includes Y so if you
> include X you don't have to include Y" in one's head.

Somebody should do that at some point, otherwise it becomes even more mess.

If you want your way, iwyu should be part of the kernel build. And be prepared
for dozens of headers to be added to the every single C file in the kernel.
diff mbox series

Patch

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 63afffab4249..eb0934d02722 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -20,7 +20,6 @@ 
 #include <linux/build_bug.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
-#include <linux/compiler.h>
 #include <linux/cred.h>
 #include <linux/ctype.h>
 #include <linux/dcache.h>
@@ -36,7 +35,6 @@ 
 #include <linux/rtc.h>
 #include <linux/siphash.h>
 #include <linux/stdarg.h>
-#include <linux/string.h>
 #include <linux/string_helpers.h>
 #include <linux/time.h>
 #include <linux/types.h>