On Sun, Aug 1, 2010 at 7:40 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > I tried to duplicate your results using what I believe to be the latest > version of clang,
I'm using SVN tip of llvm+clang from ~one week ago. >> (2) clang doesn't support (or require) "-no-cpp-precomp", which >> src/template/darwin adds to $CC unconditionally. Adding the flag >> unconditionally seems wrong regardless: e.g., -no-cpp-precomp isn't >> supported by FSF GCC on OSX either. clang is happy to ignore the flag, >> but it just emits countless "warning: argument unused during >> compilation: '-no-cpp-precomp'" > > I do see that, but I also see it complaining about -fwrapv: > [...] > > We're certainly not going to just drop -fwrapv, as that would break the > code on many modern versions of gcc. (I'm a bit surprised and concerned > that clang hasn't got this flag, btw.) Support for -fwrapv was apparently implemented recently: https://llvm.org/viewvc/llvm-project?view=rev&sortby=date&revision=106956 FWIW, I think we should aim to eventually remove the dependency on -fwrapv, and instead make the code correct under the semantics guaranteed by the C spec. That will be hard to do without a tool that checks for code that makes incorrect assumptions about integer overflow behavior, but there seems to be progress in that area recently: http://blog.regehr.org/archives/226 (As it happens, their checker uses llvm, which is what motivated me to start poking around in the first place...) >> (3) There are countless warnings emitted during the compilation of >> regcomp.c and related files, due to unused values returned by ERR(), >> VERR(), FAILW(), and similar macros. > > I fixed this in HEAD, or at least my copy of clang doesn't complain > anymore. Yep, looks good here. Thanks! Neil -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
