8d3bc5178f
Make's multiple output syntax x.c x.h: x.template gen < x.template actually invokes the command once for x.c and once for x.h (with differing $@ in each invocation). During a parallel build, the two commands may be invoked in parallel; this opens up a race, where the second invocation trashes a file supposedly produced during the first, and now in use by a dependent command. The various qapi code generators are susceptible to this; fix by making them generate just one file per invocation. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>