Using -fvisibility=hidden makes the current cygwin gcc emit a warning "warning: visibility attribute not supported in this configuration; ignored" for every single non-static symbol
$ make clean && make 2>&1 | grep "ignored" | wc -l 6457 This is pretty annoying and makes it hard to spot other errors and warnings in the compiler output. It's not clear how to fix this. Possibly the correct solution is explicitly decorate all symbols with macros which annotate the expected visibility and evaluate to attribute(hidden/default) or dllexport depending on the target, as suggested at [1], but this would be a lot of work and misses the main advantage of -fvisibility=hidden (that you don't have to explicitly annotate everything :-)), so I guess we are supposed to know when -fvisibility isn't going to be useful and not use it. [1] http://gcc.gnu.org/wiki/Visibility Alternatively, the configuration check could be made more complex to avoid using this flag is the target isn't ELF or using the flag generates a warning For the moment, I've gone for the crude solution of explicitly disabling the use of this flag for the cygwin target Signed-off-by: Jon TURNEY <jon.tur...@dronecode.org.uk> --- configure.ac | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/configure.ac b/configure.ac index 37ea5e7..b1e1de1 100644 --- a/configure.ac +++ b/configure.ac @@ -182,6 +182,15 @@ if test "x$GXX" = xyes; then CXXFLAGS="$CXXFLAGS -fno-strict-aliasing" fi +dnl even if the compiler appears to support it, using visibility attributes isn't +dnl going to do anything useful currently on cygwin apart from emit lots of warnings +case "$host_os" in +cygwin*) + VISIBILITY_CFLAGS="" + VISIBILITY_CXXFLAGS="" + ;; +esac + AC_SUBST([VISIBILITY_CFLAGS]) AC_SUBST([VISIBILITY_CXXFLAGS]) -- 1.7.4 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
