Jeffrey Holle wrote: > On release builds, wxWidgets code emits a lot of these warnings: > warning: dereferencing type-punned pointer will break strict-aliasing > rules > > Questions: > > 1. Are these warnings benign? If so can they be suppressed? > 2. If not, what level of optimization should I regress to avoid these > warnings? I would certainly not ignore them. They indicate that the code being compiled probably violates the ISO C standard rules for type aliasing, which means there's a very real chance that gcc will generate code that does something very different than what the author intended as this is the realm of undefined behavior. With earlier versions of gcc you could get away with it, and in fact there is a great deal of code out there that is technically invalid C due to violating this aspect of the standard. But nobody really cared until newer versions of gcc started actually using a type-based alias system to perform optimizations that were not possible before. The best bet is to fix the invalid code. The next best thing is probably -fno-strict-aliasing. This is a frequent and somewhat sensitive topic on this mailing list, so I suggest you read the past threads, e.g. <http://www.google.com/search?num=100&q=site%3Agcc.gnu.org+inurl%3Aml+inurl%3A%22gcc-help%22+strict+aliasing+rules>. Brian
