On Dec 7, 2009, at 7:36 AM, Ralf Wildenhues wrote: > Hello Tomas, > > * Tomas Carnecky wrote on Sun, Dec 06, 2009 at 09:10:47PM CET: >> I just ran the clang static analyzer on the xserver configure script and >> it reported a few issues. Most of them were dead assignments/increments, >> but there also was one dereference of an undefined pointer value. I >> don't know which tests the conftest.c belongs to, but I doubt it's to >> test if an application can safely write to unknown memory ;). The test >> contains the following code: > > The code is from AC_C_CONST. If your package requires anything near a > C89 (or newer) compiler, then you don't need and shouldn't use > AC_C_CONST. Compilers not grokking 'const' are old (I don't know how > old, but I've never met one). > > Last time we looked at this code because someone reported oddities, we > concluded that we shouldn't change the test because we had no way of > verifying whether the test would still expose the documented issue > afterwards. In general, you are of course right that tests shouldn't > have undefined behavior, but sometimes that is unavoidable. I see. It was interesting to run the configure script through clang and see which warnings it would generate. I'll just ignore those in the future. tom _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
