Commit 19e83f6b authored Apr 26, 2011 by Peter Maydell Committed by Blue Swirl Apr 26, 2011

configure: Make epoll_create1 test work around SPARC glibc bug



Work around a SPARC glibc bug which caused the epoll_create1 configure
test to wrongly claim that the function was present. Some versions of
SPARC glibc provided the function in the library but didn't declare
it in the include file; the result is that gcc warns about an implicit
declaration but a link succeeds. So we reference the function as a
value rather than a function call to induce a compile time error
if the declaration was not present.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

parent 143f6ffe

configure

+9 −1

Original line number	Diff line number	Diff line
		@@ -2225,7 +2225,15 @@ cat > $TMPC << EOF

		int main(void)
		{
		epoll_create1(0);
		/* Note that we use epoll_create1 as a value, not as
		* a function being called. This is necessary so that on
		* old SPARC glibc versions where the function was present in
		* the library but not declared in the header file we will
		* fail the configure check. (Otherwise we will get a compiler
		* warning but not an error, and will proceed to fail the
		* qemu compile where we compile with -Werror.)
		*/
		epoll_create1;
		return 0;
		}
		EOF