> On April 4, 2015, 12:40 a.m., rmudgett wrote: > > /branches/13/channels/chan_iax2.c, lines 2009-2013 > > <https://reviewboard.asterisk.org/r/4554/diff/2/?file=73276#file73276line2009> > > > > This change causes bugs. It is supposed to return peer because it > > increased the ref. > > Diederik de Groot wrote: > Stupid me. If should actually also check if ao2_ref did not return an > error (-1). > > rmudgett wrote: > The return value of ao2_ref is rarely used. When it is it is to get the > number of refs the object had before the call. The -1 error return value is > practically useless. That value means a programming error because the object > is invalid and you get bad magic number messages logged, assertion failures, > and very likely crashes.
Ok, point taken. So that would mean that ao2_ref will be the biggest cause of "-Wunused-value" warning, even if we changed everything else, because it's return is rarely used :-) I still think it is valid to NULL a pointer that might/might not vanish in the future (as with ao2_ref(xx, -1)). Same goes for example for ast_free, which does not null the pointer afterwards (or did i overlook something ?. It makes NULL pointer checks after such a free or unref a little bit pointless. I know everything is working and asterisk-11 and asterisk-13 are pretty stable as far as i can tell, so not looking for extra work for any of us, just want to finish this point and move on. - Diederik ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviewboard.asterisk.org/r/4554/#review15053 ----------------------------------------------------------- On April 4, 2015, 1:15 a.m., Diederik de Groot wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviewboard.asterisk.org/r/4554/ > ----------------------------------------------------------- > > (Updated April 4, 2015, 1:15 a.m.) > > > Review request for Asterisk Developers. > > > Bugs: ASTERISK-24917 > https://issues.asterisk.org/jira/browse/ASTERISK-24917 > > > Repository: Asterisk > > > Description > ------- > > clang's static analyzer will throw quite a number warnings / errors during > compilation, some of which can be very helpfull in finding corner-case bugs. > > clang compiler warning:-Wunused-value > > Changes: > apps/app_agent_pool.c > multiple occasions where return value from ast_channel_ref and > ast_channel_unref is not checked not used. > return value from AST_LIST_REMOVE should be checked. > Possible issues with leaked logged reference (added remark) > > channels/chan_iax2.c > return values from ast_callid_ref and ast_callid_unref can/should be used to > update the pointer > return value from AST_SCHED_DEL should be used to update the scheduled > variable > return value from AST_LIST_REMOVE should be checked. > > channels/iax2/parser.c > return value from AST_LIST_REMOVE should be checked. > > include/asterisk/stringfields.h > Quick fix to send the returned value from ast_string_field_ptr_set into the > void. > > Work in Progress: > There are too many sources issues with "-Wunused-value" for one person to > create all the fixes. If we want to actually use this warning we will need a > couple of extra hands-on. > > Should we suppress "-Wunused-value" ? : > I think some of the issues pointed out by clang could be very helpfull, for > example the "unref/ref/AST_LIST_REMOVE" changes that where needed in > chan_iax2.c and apps/app_agent_pool.c. Some others a less interesting, for > example the SCHED_DEL fixes. > > > Diffs > ----- > > /branches/13/include/asterisk/stringfields.h 433444 > /branches/13/channels/iax2/parser.c 433444 > /branches/13/channels/chan_iax2.c 433444 > /branches/13/apps/app_agent_pool.c 433444 > > Diff: https://reviewboard.asterisk.org/r/4554/diff/ > > > Testing > ------- > > Just to make it clear, this was just a sample / proposal to work through > large set of -Wunused-value warnings return. Some of them could be > interesting, others might not be be. > > Mostly looking for a discussion about which path to follow, and see if we can > divvy up the work a little. > > Compiles / Untested / Pretty certain it contains issue because of different > way of dealing with return value from ..._unref. > > > File Attachments > ---------------- > > ASTCFLAGS="-Wno-error=unused-value" make &| grep "[-W" -B1 -A2 > > https://reviewboard.asterisk.org/media/uploaded/files/2015/03/28/83f2f382-9ef2-41cf-8e7a-c188c014c17e__make.report > > > Thanks, > > Diederik de Groot > >
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