Re: [PATCH v3 1/2] Makefile: use curl-config to determine curl flags

Dave Borowitz <dborowitz@google.com> writes:

This "ifeq" is redundant and will never set CURL_LIBCURL to empty without running the "else" part, I think. In a Makefile, a variable explicitly set to empty and a variable that is unset are treated the same.

	$ cat >Makefile <<EOF
	CURL_CONFIG ?= curl-config
	ifeq "$(CURL_CONFIG)" ""
		X=Empty
	else
		X=NotEmpty
	endif

	ifdef "$(CURL_CONFIG)"
		Z=Defined
	else
		Z=Undefined
	endif

	all::
		@echo "$(X) $(Z)"
	EOF
	$ make -f Makefile CURL_CONFIG=""
	Empty Undefined

That does not mean the patch will give us a broken behaviour, though. It just means the ifeq/else part will be redundant.

This will catch the "$(shell $(CURL_CONFIG) --libs) assigned an empty string to CURL_LIBCURL" case, so the result is good.

I haven't checked what it would look like if we turn this into an incremental patch to be applied on top of 'master' (which would give us a place to document better why we do not rely on the presense of curl-config), but if we can do so, that would be more preferable than having to revert the merge of the previous one and then applying these two patches anew.

Thanks.