how to give inline comment at variable declaration in Makefile w/o including space..?

mayankmehta83 · 12-04-2009, 02:18 AM

Makefile -->
VAR1 = first # comment 1
VAR2 = first# comment 2
VAR3 = $(VAR1)_last
VAR4 = $(VAR2)_last
default:
@echo $(VAR3)
@echo $(VAR4)

output (unexpected) -->
first _last
first_last

output (expected) -->
first_last
first_last

Thanks in advance.

lupusarcanus · 12-04-2009, 06:56 PM

VAR1 = first # comment 1 <--------> VAR1 = first# comment 1
VAR2 = first# comment 2
...
I know nothing about this subject.
But please take note that in VAR1, you have a space before the #.
In VAR2, this space is not present.

Sorry if I wasted your time. Just trying to help.

Valery Reznic · 12-05-2009, 01:06 AM

You can use strip function. It will guard not just against (visible) spaces before comment, but also against invisible spaces before EOL

Code:

VAR1 = first	# comment 1
VAR2 = first# comment 2
VAR3 = $(strip($(VAR1))_last
VAR4 = $(strip($(VAR2))_last

mayankmehta83 · 12-06-2009, 10:57 PM

Quote:

Originally Posted by Valery Reznic

You can use strip function. It will guard not just against (visible) spaces before comment, but also against invisible spaces before EOL

Code:

VAR1 = first	# comment 1
VAR2 = first# comment 2
VAR3 = $(strip($(VAR1))_last
VAR4 = $(strip($(VAR2))_last

Makefile -->
VAR1 = first # comment 1
VAR2 = first# comment 2
VAR3 = $(strip($(VAR1)))_last
VAR4 = $(strip($(VAR2)))_last

default:
@echo $(VAR3)
@echo $(VAR4)

Output

-->
_last
_last

Version -->
GNU Make 3.80

Can you look again if usage is correct ??

Valery Reznic · 12-06-2009, 11:45 PM

Ooops

Instead of

Code:

VAR1 = first    # comment 1
VAR2 = first# comment 2
VAR3 = $(strip($(VAR1)))_last
VAR4 = $(strip($(VAR2)))_last

Should be

Code:

VAR1 = first    # comment 1
VAR2 = first# comment 2
VAR3 = $(strip $(VAR1)))_last
VAR4 = $(strip $(VAR2)))_last

paulsm4 · 12-07-2009, 12:08 AM

Very simply:

Code:

VAR1 = first # correct - valid comment
VAR2 = second# Might work on some platforms - but not necessarily portable
VAR3 = $(VAR1)_last  # OK: will always work
VAR4 = $(VAR2)_last  # Might work, might not work
default:
	@echo $(VAR3)
	@echo $(VAR4)

For example, it works fine with MSVS "nmake":

Quote:

But your mileage may vary from platform to platform.

That's even MORE true of "special" (and completely non-standard) functions like "strip()".

Unless you're very, very sure you really WANT to render your makefile non-portable, you should use standard "make" syntax whenever/wherever possible.

IMHO .. PSM

Valery Reznic · 12-07-2009, 04:33 AM

Quote:

Originally Posted by paulsm4

Very simply:

Code:

VAR1 = first # correct - valid comment
VAR2 = second# Might work on some platforms - but not necessarily portable
VAR3 = $(VAR1)_last  # OK: will always work
VAR4 = $(VAR2)_last  # Might work, might not work
default:
	@echo $(VAR3)
	@echo $(VAR4)

For example, it works fine with MSVS "nmake":

But your mileage may vary from platform to platform.

That's even MORE true of "special" (and completely non-standard) functions like "strip()".

Unless you're very, very sure you really WANT to render your makefile non-portable, you should use standard "make" syntax whenever/wherever possible.

IMHO .. PSM

Yes, there a re a lot of make flavors around (the most strange one IMO is BSD's)

Trying to be portable have its cost.
Ages ago I saw advice: "Don't write portable Makefile, use portable make instead". i.e gmake.