Make/makefile progress indication!

Look at this makefile, it has some sort of primitive progress indication (could have been a progress bar).

Please give me suggestions/comments on it!

---

# BUILD is initially undefined
ifndef BUILD

# max equals 256 x's
sixteen := x x x x x x x x x x x x x x x x
MAX := $(foreach x,$(sixteen),$(sixteen))

# T estimates how many targets we are building by replacing BUILD with a special string
T := $(shell $(MAKE) -nrRf $(firstword $(MAKEFILE_LIST)) $(MAKECMDGOALS) \
            BUILD="COUNTTHIS" | grep -c "COUNTTHIS")

# N is the number of pending targets in base 1, well in fact, base x :-)
N := $(wordlist 1,$T,$(MAX))

# auto-decrementing counter that returns the number of pending targets in base 10
counter = $(words $N)$(eval N := $(wordlist 2,$(words $N),$N))

# BUILD is now defined to show the progress, this also avoids redefining T in loop
BUILD = @echo $(counter) of $(T)
endif

# dummy phony targets

.PHONY: all clean

all: target
    @echo done

clean:
    @rm -f target *.c

# dummy build rules

target: a.c b.c c.c d.c e.c f.c g.c
    @touch $@
    $(BUILD)

%.c:
    @touch $@
    $(BUILD)

---

All suggestions welcome!

From stackoverflow

• Nice trick! (-:

  But not really scalable for growing projects that are distributed across many directories with lots of makefiles.

  I'd be more inclined to have logging sprinkled through the [Mm]akefiles* in your project and use that to keep track of progress.

  Just a thought. BTW Thanks for sharing this.

  Edit: Just had a thought. This could be useful in a modified form to display a throbber to show progress while a long task proceeds, e.g unpacking a large distribution tarball instead of just specifying the -v option to the tar command. Still a bit of sugar coating but a bit of fun aswell. (-:

  cheers,

  Rob

  Helltone : Thanks for your comment, can you please explain why you think this does not scales? Ok the code is just a sketch, but MAX can hold 64k x's if needed, and the calculation of the T variable is quite fast.

  Scottie T : It doesn't scale because it won't work if you use make over multiple directories, with each sub-directory having it's own makefile.

  Rob Wells : @ScottieT812, cheers, that was the main reason for my comment! (-: The other one is continually having to calculate and update the number of x's needed as the project expands. Still. nice trick though.

  Helltone : Rob you did not understood my script. It WORKS if you have makefiles over multiple directories (although I do not recommend recursive make) and the x's are NOT number of targets, its just an upper-bound (256, can be more). The exact number of targets is automatically discovered (see code of $T)

• See http://snippets.dzone.com/posts/show/6843