Skip to contentSkip to conversation

Add missing #include <linux/bug.h>

RFC In review Eric Engestrom 2 participants 2 messages Apr 25, 2016

lore
Share & tools
lore

Eric Engestrom

author
#0 lore raw

RFC 1/1 Add missing #include <linux/bug.h>

ARRAY_SIZE uses BUILD_BUG_ON_ZERO, which is undefined is you don't include linux/bug.h first, which just happened to me.

Is there any reason this include isn't here? A quick grep found 595 other files using a define from bug.h without ever including it.

If this is a simple mistake and was forgotten, I can send an actual patchset to fix this, but it feels like it was left out on purpose.

Cheers,
Eric Engestrom

PS: If this is a cleanup that needs to be done, I might to it for other headers as well.

---
 include/linux/compiler-gcc.h | 2 ++
 1 file changed, 2 insertions(+)
include/linux/compiler-gcc.h +2 -0
index eeae401..01e6869 100644
@@ -2,6 +2,8 @@
 #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
 #endif
 
+#include <linux/bug.h>
+
 /*
  * Common definitions for all gcc versions go here.
  */
Signature · 1 line
2.8.1
#1 lore raw
Quoted 5 lines · On Mon, 25 Apr 2016 19:10:55 +0100 Eric Engestrom <[email protected]>…

ARRAY_SIZE uses BUILD_BUG_ON_ZERO, which is undefined is you don't include linux/bug.h first, which just happened to me.

Is there any reason this include isn't here? A quick grep found 595 other files using a define from bug.h without ever including it.

yeah. A lot of the kernel compiles by accident ;) We just fix stuff when it blows up - it ain't pretty but this process works acceptably well.

include/linux/compiler-gcc.h line 9

Quoted 11 lines
include/linux/compiler-gcc.h +2 -0
@@ -2,6 +2,8 @@
 #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
 #endif
 
+#include <linux/bug.h>
+
 /*
  * Common definitions for all gcc versions go here.
  */

hm, it Seems Wrong to include bug.h into compiler.h - the latter is such a low-level infrastructury thing. As evidenced by the fact that bug.h explicitly includes compiler.h!

The bottom line is that our headers are just too large and complex and try to do too much stuff. Going finer-grained is always a good fix, but I don't think you want to be adding a new array_size.h!

I guess we could move __must_be_array() into kernel.h and use #ifdef __GNUC__ (or whatever). But that adds to kernel.h (another) dependency on bug.h, which kernel.h doesn't (and probably shouldn't and possibly can't) include. Sucks.