In my makefile, I have a variable 'NDK_PROJECT_PATH', my question is how can I print it out when it compiles?
I read Make file echo displaying "$PATH" string and I tried:
@echo $(NDK_PROJECT_PATH)
@echo $(value NDK_PROJECT_PATH)
Both gives me
"build-local.mk:102: *** missing separator. Stop."
Any one knows why it is not working for me?
You can print out variables as the makefile is read (assuming GNU make as you have tagged this question appropriately) using this method (with a variable named "var"):
$(info $$var is [${var}])
You can add this construct to any recipe to see what make will pass to the shell:
.PHONY: all
all: ; $(info $$var is [${var}])echo Hello world
Now, what happens here is that make stores the entire recipe ($(info $$var is [${var}])echo Hello world
) as a single recursively expanded variable. When make decides to run the recipe (for instance when you tell it to build all
), it expands the variable, and then passes each resulting line separately to the shell.
So, in painful detail:
$(info $$var is [${var}])echo Hello world
$(info $$var is [${var}])
$$
becomes literal $
${var}
becomes :-)
(say)$var is [:-)]
appears on standard out$(info...)
though is emptyecho Hello world
echo Hello world
on stdout first to let you know what it's going to ask the shell to doHello world
on stdout.