On Thu, Jan 06, 2011 at 11:59:07PM +0100, Erik Cederstrand wrote: > > Den 06/01/2011 kl. 20.56 skrev Tijl Coosemans: > > > On Thursday 06 January 2011 09:01:09 Erik Cederstrand wrote: > >> Den 05/01/2011 kl. 20.36 skrev Jilles Tjoelker: > >>> On Wed, Jan 05, 2011 at 05:55:45PM +0100, Ulrich Sp?rlein wrote: > >>>> - get IPA to work with clang, or at least file a bug > >>>> - mark functions as __dead2 (please don't do that) > >>> > >>> Why not? > >> > >> Because the analyzer is supposed to find bugs. Only the function that > >> really doesn't return should be marked as such. If we begin spewing > >> __dead2's everywhere, it's bound to silence a valid bug somewhere > >> down the line when e.g. a conditional in a print_help() function is > >> changed subtly so it doesn't always reach exit(). > > > > On the other hand you can't really expect the compiler/analyser to know > > what a procedure in another file does, so in that case you need __dead2 > > anyway. [...] > > I have high expectations of LLVM :-) LLVM already has some knowledge of what's going on in other files (see LTO) so why shouldn't it be able to detect the __noreturn__ ? All the necessary information should be readily available. the static analyzer has nothing to do with LLVM. it's a clang component and uses only the info that clang knows. and clang (ie. the C frontend) does not perform any analysis of this kind, thus it does not know that stuff is dead. fwiw - my trivial (but working) patch brought down the number of reports by mere 5% so the bulk is probably somewhere else...Received on Fri Jan 07 2011 - 06:49:02 UTC
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