"Kevin P. Fleming" <kpfleming@xxxxxxxxxx> writes: >> This approach is controlled on a target-by-target basis, by the way. If >> OpenBSD's header files are C++ ready, gcc's OpenBSD target configuration >> should be changed to define NO_IMPLICIT_EXTERN_C. > > Does '-isystem' factor into this in any way? I would hope that using > -isystem' to specify an additional directory of 'system' header files > would not also turn on implicit 'extern "C"' mode. > > If you are curious, we use '-isystem' to have GCC relax our > warning/error modes on header files that are nominally part of our > project but are installed into 'system' locations (like > /opt/<package>/include). Using -isystem causes the directory to be treated as a standard system directory, which does indeed include implicit wrapping in extern "C" if that is customary for the target. Of course most targets these days do define NO_IMPLICIT_EXTERN_C, OpenBSD seems to be a bit of an outlier in that regard, and that may simply be a bug in gcc's OpenBSD support. Ian
