Makefile: preserve --jobserver-auth argument when calling ninja

Qemu wraps its call to ninja in a Makefile. Since ninja, as opposed to
make, utilizes all CPU cores by default, the qemu Makefile translates
the absense of a `-jN` argument into `-j1`. This breaks jobserver
functionality, so update the -jN mangling to take the --jobserver-auth
argument into considerationa too.

Signed-off-by: Martin Hundebøll <martin@geanix.com>
Message-Id: <20240402081738.1051560-1-martin@geanix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/Makefile b/Makefile
index 8f369903356ced3097b1caf1120f923728a7b8d1..183756018ff905f3b6f1c385fd9f9d92c3cf81e1 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -142,7 +142,7 @@ MAKE.k = $(findstring k,$(firstword $(filter-out --%,$(MAKEFLAGS))))
 MAKE.q = $(findstring q,$(firstword $(filter-out --%,$(MAKEFLAGS))))
 MAKE.nq = $(if $(word 2, $(MAKE.n) $(MAKE.q)),nq)
 NINJAFLAGS = $(if $V,-v) $(if $(MAKE.n), -n) $(if $(MAKE.k), -k0) \
-        $(filter-out -j, $(lastword -j1 $(filter -l% -j%, $(MAKEFLAGS)))) \
+        $(or $(filter -l% -j%, $(MAKEFLAGS)), $(if $(filter --jobserver-auth=%, $(MAKEFLAGS)),, -j1)) \
         -d keepdepfile
 ninja-cmd-goals = $(or $(MAKECMDGOALS), all)
 ninja-cmd-goals += $(foreach g, $(MAKECMDGOALS), $(.ninja-goals.$g))