Hello- If I use visibility.m4 on a platform with a recent GCC (4.x) on Cygwin, the visibility.m4 correctly discovers that gcc can compile with -fvisibility="hidden". But, on Cygwin (and probably most non-ELF) gcc does not actualy implement the visibility and emits the warning "visibility attribute not supported in this configuration" instead. Even so, the tests in visibility.m4 pass, and HAVE_VISIBILITY is set in the affirmative.
In my humble opinion, it would be a good idea to add a "-werror" to the test in visibility.m4 so that it won't set CFLAGS_VISIBILITY and HAVE_VISIBILITY on those platforms that don't actually support it. What do you think? Thanks -Mike Gran
