makefile: handle -n / -k / -q correctly

Use $(findstring) instead of $(filter) to detect -n/-k
as different versions of MAKE fill in $(MAKEFLAGS) differently.
Do not bother running ninja at all if -nq is passed.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20201026155854.3074290-1-pbonzini@redhat.com>

Makefile

@@ -146,9 +146,12 @@ endif
 # 4. Rules to bridge to other makefiles
 
 ifneq ($(NINJA),)
-NINJAFLAGS = $(if $V,-v,) \
+MAKE.n = $(findstring n,$(firstword $(MAKEFLAGS)))
+MAKE.k = $(findstring k,$(firstword $(MAKEFLAGS)))
+MAKE.q = $(findstring q,$(firstword $(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)))) \
-        $(subst -k, -k0, $(filter -n -k,$(MAKEFLAGS)))
 
 ninja-cmd-goals = $(or $(MAKECMDGOALS), all)
 ninja-cmd-goals += $(foreach t, $(.tests), $(.test.deps.$t))
@@ -165,7 +168,8 @@ $(ninja-targets): run-ninja
 # --output-sync line.
 run-ninja: config-host.mak
 ifneq ($(filter $(ninja-targets), $(ninja-cmd-goals)),)
-	+@$(NINJA) $(NINJAFLAGS) $(sort $(filter $(ninja-targets), $(ninja-cmd-goals))) | cat
+	+$(quiet-@)$(if $(MAKE.nq),@:, $(NINJA) \
+	   $(NINJAFLAGS) $(sort $(filter $(ninja-targets), $(ninja-cmd-goals))) | cat)
 endif
 endif