From f80ea9862fed7ca89a672785bdce0e2611f9ba97 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Tue, 1 Jul 2014 17:30:27 +1000 Subject: [PATCH] configure: Fix -lm test, so that tools can be compiled on hosts that require -lm The existing test whether "-lm" needs to be included or not is insufficient as it reports false negative on Fedora20/ppc64. This happens because sin(0.0) is a constant value which compiler can safely throw away and therefore there is no need to add "-lm". As the result, qemu-nbd/qemu-io/qemu-img tools cannot compile. This adds a global variable and uses it in the test to prevent from optimization. Signed-off-by: Alexey Kardashevskiy [Use Peter's improvement on the test to fool LTO, and remove the now useless -lm addition in Makefile.target. - Paolo] Signed-off-by: Paolo Bonzini --- Makefile.target | 4 ---- configure | 2 +- 2 files changed, 1 insertion(+), 5 deletions(-) diff --git a/Makefile.target b/Makefile.target index 6089d290df..137d0b0517 100644 --- a/Makefile.target +++ b/Makefile.target @@ -163,10 +163,6 @@ dummy := $(call unnest-vars,.., \ all-obj-y += $(common-obj-y) all-obj-$(CONFIG_SOFTMMU) += $(block-obj-y) -ifndef CONFIG_HAIKU -LIBS+=-lm -endif - # build either PROG or PROGW $(QEMU_PROG_BUILD): $(all-obj-y) ../libqemuutil.a ../libqemustub.a $(call LINK,$^) diff --git a/configure b/configure index 23ecb37c43..ed41eda4d3 100755 --- a/configure +++ b/configure @@ -3453,7 +3453,7 @@ fi # Do we need libm cat > $TMPC << EOF #include -int main(void) { return isnan(sin(0.0)); } +int main(int argc, char **argv) { return isnan(sin((double)argc)); } EOF if compile_prog "" "" ; then : -- 2.11.0