This patch makes checkpatch.pl complain if you break up conditions in
the wrong way.

Wrong:
	if ((really_long_condition)
		&& (second_condition)) { ...
Right:
	if ((really_long_condition) &&
		(second_condition)) { ...

If you do it in the wrong way the message is:  "put the && or || at the
end of the previous line"

Signed-off-by: Dan Carpenter <error27@gmail.com>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index e3c7fc0..0a813db 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1509,6 +1509,11 @@ sub process {
 			WARN("please, no space before tabs\n" . $herevet);
 		}
 
+# check for && or || at the start of a line
+		if ($rawline =~ /^\+\W+(&&|\|\|)/) {
+			WARN("put the && or || at the end of the previous line\n" . $herecurr);
+		}
+
 # check for spaces at the beginning of a line.
 # Exceptions:
 #  1) within comments
--

[ message continues ]

I've submitted something like this a couple of times and gotten
various objections but I think it's sensible.

https://lkml.org/lkml/2009/12/5/65
https://lkml.org/lkml/2010/7/11/92


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[ message continues ]

If everyone except you thinks it's a waste of time, then stop asking me
to redo my patches.  :/  I don't care either way so long as CodingStyle
and checkpatch reflect the rules.

regards,
dan carpenter

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[ message continues ]

As far as I can tell, the convention in mathematical typesetting is to
put operators on the left, not the right.  When the conditions are short
of there are more lines, that allows you to left-align on the repeated
operator.

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[ message continues ]

I personnally find the left approach more readable.

Samuel
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[ message continues ]

As do I, but perhaps coding style in a project like this
shouldn't be personal but collective.

The trailing style outnumbers the leading style ~ 5:1.

$ grep -rP --include=*.[ch] "(\|\||&&)[ \t]*$" * | wc -l
39890
$ grep -rP --include=*.[ch] "^[ \t]*(\|\||&&)" * | wc -l
8244

If you take out drivers/staging, trailing is used ~ 6:1.

I think that high enough to be declared the preferred style.

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