scripts/coccinelle/misc/bugon.cocci: update bug_on conversion warning

if()/BUG conversion to BUG_ON must be avoided when there's side effect
in condition.  The reason being BUG_ON won't execute the condition when
CONFIG_BUG is not defined.

With inspiration from Bruce Fields.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/coccinelle/misc/bugon.cocci b/scripts/coccinelle/misc/bugon.cocci
index 3b7eec24fb5a2a7cf6b55c4f003e363591888164..27c97f1f2767f6145349752e0500b1c87ad6052e 100644 (file)
--- a/scripts/coccinelle/misc/bugon.cocci
+++ b/scripts/coccinelle/misc/bugon.cocci
@@ -57,6 +57,6 @@ coccilib.org.print_todo(p[0], "WARNING use BUG_ON")
 p << r.p;
 @@
 
-msg="WARNING: Use BUG_ON"
+msg="WARNING: Use BUG_ON instead of if condition followed by BUG.\nPlease make sure the condition has no side effects (see conditional BUG_ON definition in include/asm-generic/bug.h)"
 coccilib.report.print_report(p[0], msg)