Correction to Makefile

Adding -p just preserves the modification times, the copy will still happen.

make should only be running the command if ${LIB} is older than ${ACTIVE_CONFIG_LIB} - so that should suppress the code when not needed.

So something else funny must be going on, possibly another dependency line somewhere.

What you might need is something that only updates the config file if it has actually changed - that needs to be done before the makefile above is run.

Assigning to CP on the make command line and/or the environment should suppress the assignment in the makefle itself.

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Adding -p just preserves the modification times, the copy will still happen.

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Yes, true. I should have been clearer that the time-stamp remains the same and therefore dependencies on the lib(s) don't build unnecessarily. That was the point - to stop unnecessary builds and backups.

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make should only be running the command if ${LIB} is older than ${ACTIVE_CONFIG_LIB} - so that should suppress the code when not needed.

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Which I don't understand because it's the same 2 targets of the CP. How could they be different if the LIB wasn't built? And it isn't because AR isn't run. I didn't understand the problem but still I wanted a solution. I'm obviously not a make expert.

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So something else funny must be going on, possibly another dependency line somewhere.

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I agree

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What you might need is something that only updates the config file if it has actually changed - that needs to be done before the makefile above is run.

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Rebuilds occur (because of the CP) even if the config isn't changed. With the -p it still works if the config *is* changed. Although I don't understand the failure the solution (work around) is sound.

Thanks for replying,

Bill

Try adding an 'echo xxx $*' line before the $(CP) $< $@ one.

That will show all the dependencies.

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Try adding an 'echo xxx $*' line before the $(CP) $< $@ one.

That will show all the dependencies.

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I have

$(LIB) : $(ACTIVE_CONFIG_LIB)
	echo xxx $*
	echo $(LIB)
	echo $(ACTIVE_CONFIG_LIB)
	$(CP) $< $@

and get:

echo xxx liblwip_altera_tse_FALCON

xxx liblwip_altera_tse_FALCON

echo liblwip_altera_tse_FALCON.a

liblwip_altera_tse_FALCON.a

echo obj/Release/liblwip_altera_tse_FALCON.a

obj/Release/liblwip_altera_tse_FALCON.a

cp -f -p obj/Release/liblwip_altera_tse_FALCON.a liblwip_altera_tse_FALCON.a

And the time-stamps of $(LIB ) and $(ACTIVE_CONFIG) are identical.

Thanks for your suggestion. I wouldn't mind knowing if I can do this without hand-modifying a makefile.

Bill

Hmmmm .... I should have checked the manual! I've clearly not written enough makefiles recently.

It seems I meant $^ not $*.

Since the makefile is echoeing the commands, you could use : instead of echo

Now I get:

xxx obj/Release/liblwip_altera_tse_FALCON.a

liblwip_altera_tse_FALCON.a

obj/Release/liblwip_altera_tse_FALCON.a

cp -f -p obj/Release/liblwip_altera_tse_FALCON.a liblwip_altera_tse_FALCON.a

(I changed to @echo). There seems to be something wrong with the time-stamp check between the source and target. The project is simply a "Create NIOS II Lib" with 3 source files with everything else auto-generated.

Bill

I wonder what 'ls -l $@ $^' generates (just before the copy)?

make (and I doubt gmake is very different) ends up checking the timestamps on everything twice, once at the start and again just before running each command.

There might also be something odd about the way that definition file doesn't get updated when nothing changes - since I suspect it is rewritten. Getting that wrong could cause make to rebuild the following items.

As I said earlier, you should be able to override the in-makefile assignment to $(CP) by putting it on the command line "make CP='cp -fp' xxxx", or maybe in the environment "CP='cp -fp' make xxx".

Or look at $PATH and add the script file "cp" containing:

#!/bin/sh
/bin/cp -p "$@"

in one of the first directories searched.

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I wonder what 'ls -l $@ $^' generates (just before the copy)?

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ls -l liblwip_altera_tse_FALCON.a obj/Release/liblwip_altera_tse_FALCON.a
-rwxr-xr-x+ 1 xxxxxxxxx mkpasswd 138792 Oct  3 14:23 liblwip_altera_tse_FALCON.a
-rwxr-xr-x+ 1 xxxxxxxxx mkpasswd 138792 Oct  3 14:23 obj/Release/liblwip_altera_tse_FALCON.a
cp -f -p obj/Release/liblwip_altera_tse_FALCON.a liblwip_altera_tse_FALCON.a

Looke like it *should* be working, no?

I will try your other suggestions so as to not have to edit the Makefile, although I'm not sure when they regenerate. So far it never has.

Thanks for your continued input. Although it's not a show-stopper it's one of those things that are good to know (and fix if we can). Eventually it helps everyone.

Bill