On 07/09/15 16:22, Paolo Bonzini wrote: > > On 07/09/2015 15:18, Thomas Huth wrote: >> On 07/09/15 11:53, Paolo Bonzini wrote: >>> Line lengths above 80 characters do exist. They are rare, but >>> they happen from time to time. An ignored rule is worse than an >>> exception to the rule, so do the latter. >>> >>> Based on remarks from the list, make the preferred line length >>> slightly lower than 80 characters, to account for extra characters >>> in unified diffs (including three-way diffs) and for email quoting. >>> >>> Checkpatch has some code to detect doc comments that doesn't apply >>> to QEMU; the usual limits apply even for doc comments in our case. >>> >>> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> >>> --- >>> CODING_STYLE | 13 ++++++++++--- >>> scripts/checkpatch.pl | 21 +++++++++++++++------ >>> 2 files changed, 25 insertions(+), 9 deletions(-) >>> >>> diff --git a/CODING_STYLE b/CODING_STYLE >>> index 3c6978f..34d5526 100644 >>> --- a/CODING_STYLE >>> +++ b/CODING_STYLE >>> @@ -31,14 +31,21 @@ Do not leave whitespace dangling off the ends of lines. >>> >>> 2. Line width >>> >>> -Lines are 80 characters; not longer. >>> +Lines should be 76 characters; try not to make them longer. [...] >> Sorry, this is _ugly_! First, the limit in QEMU has always been 80 >> columns in the past, thus we've got tons of code that is written with 80 >> columns already, so you suddenly even can not even copy-n-paste / move >> around code anymore that was valid before?!? That'll be a PITA since you >> have to reformat all patches that move code around - and it will also be >> a PITA for all reviewers since checking whether old code matches new >> code becomes more difficult. [...] > Some other interesting data: > > - However, only 605 files have 5 or more lines with 77+ columns, so the > odds of warnings after copy-n-paste are pretty slim.
Apart from copy-n-pasting, there is also the problem that you can run "checkpatch.pl -f" on a whole file ... it would also be ugly to suddenly have (much) more warnings here. > Based on the above data, I suggest having 79 columns as the limit (with > the "BSD exception" unfortunately). This still makes it possible to > watch diffs on an 80-column terminal without wrapping. 79 sounds at least better to me than 76. So if you really want to change the limit, please go for 79 instead of 76. Thomas