hw/ipmi/isa_ipmi_bt.c:283: suspect use of macro ? I just had a go at compiling qemu trunk with llvm trunk. It said: hw/ipmi/isa_ipmi_bt.c:283:31: warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses] Source code is IPMI_BT_SET_HBUSY(ib->control_reg, !IPMI_BT_GET_HBUSY(ib->control_reg)); That use of ! causes trouble. The SET and GET macros are defined as: #define IPMI_BT_GET_HBUSY(d) (((d) >> IPMI_BT_HBUSY_BIT) & 0x1) #define IPMI_BT_SET_HBUSY(d, v) (d) = (((d) & ~IPMI_BT_HBUSY_MASK) | \ (((v & 1) << IPMI_BT_HBUSY_BIT))) I can make the compiler shut up by adding extra () in the last use of v in the SET macro, like this: #define IPMI_BT_SET_HBUSY(d, v) (d) = (((d) & ~IPMI_BT_HBUSY_MASK) | \ ((((v) & 1) << IPMI_BT_HBUSY_BIT))) I think this is standard good practice when using macro parameters anyway. From: Corey Minyard