[PULL 2/7] Makefile: ignore long options

[Paolo Bonzini]

From: Alexey Neyman <stilor@att.net>

When searching for options like -n in MAKEFLAGS, current code may result
in a false positive match when make is invoked with long options like
--no-print-directory. This has been observed with certain versions of
host make (e.g. 3.82) while building the Qemu package in buildroot.

Filter out such long options before searching for one-character options.

Signed-off-by: Alexey Neyman <stilor@att.net>
Message-Id: <20210722020846.3678817-1-stilor@att.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Makefile | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 6c36330eef..401c623a65 100644
--- a/Makefile
+++ b/Makefile
@@ -129,9 +129,11 @@ endif
 # 4. Rules to bridge to other makefiles
 
 ifneq ($(NINJA),)
-MAKE.n = $(findstring n,$(firstword $(MAKEFLAGS)))
-MAKE.k = $(findstring k,$(firstword $(MAKEFLAGS)))
-MAKE.q = $(findstring q,$(firstword $(MAKEFLAGS)))
+# Filter out long options to avoid flags like --no-print-directory which
+# may result in false positive match for MAKE.n
+MAKE.n = $(findstring n,$(firstword $(filter-out --%,$(MAKEFLAGS))))
+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)))) \
-- 
2.31.1