build-sys: add a rule to print a variable
$ make print-CFLAGS
CFLAGS=-fsanitize=address -Og -g
Trick from various sources:
https://stackoverflow.com/questions/16467718/how-to-print-out-a-variable-in-makefile
https://www.cmcrossroads.com/article/printing-value-makefile-variable
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180104160523.22995-4-marcandre.lureau@redhat.com>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/Makefile b/Makefile
index 1671db3..f26ef1b 100644
--- a/Makefile
+++ b/Makefile
@@ -8,9 +8,12 @@
UNCHECKED_GOALS := %clean TAGS cscope ctags dist \
html info pdf txt \
- help check-help \
+ help check-help print-% \
docker docker-% vm-test vm-build-%
+print-%:
+ @echo '$*=$($*)'
+
# All following code might depend on configuration variables
ifneq ($(wildcard config-host.mak),)
# Put the all: rule here so that config-host.mak can contain dependencies.
