>>> I can't believe I've just spent an entire day writing Makefiles... At
>>> this rate, it would almost be simpler to just write a loop to compile
>>> every source file in every directory and then link them all! But, alas,
>>> it turns out that you have to actually link them in the right order, or
>>> it doesn't work.
>>
>> Isn't there some tool to do that automatically?
>
> Absolutely. It is called "make", and needs a Makefile to work ;)

Oh, what you can use make to make a makefile? Sounds like some IOCCC 
entry...

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Am 2016-05-27 08:39, also sprach clipka:
> Am 27.05.2016 um 12:31 schrieb scott:
>>> I can't believe I've just spent an entire day writing Makefiles... At
>>> this rate, it would almost be simpler to just write a loop to compile
>>> every source file in every directory and then link them all! But, alas,
>>> it turns out that you have to actually link them in the right order, or
>>> it doesn't work.
>>
>> Isn't there some tool to do that automatically?
>
> Absolutely. It is called "make", and needs a Makefile to work ;)

It's weird that in 2016 a 1980s program is still in charge of assembling 
large swaths of code. Ant /tried/ to take over, but that's even worse.


-- 
dik

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Le 27/05/2016 14:39, clipka a écrit :
> Am 27.05.2016 um 12:31 schrieb scott:
>>> I can't believe I've just spent an entire day writing Makefiles... At
>>> this rate, it would almost be simpler to just write a loop to compile
>>> every source file in every directory and then link them all! But, alas,
>>> it turns out that you have to actually link them in the right order, or
>>> it doesn't work.
>>
>> Isn't there some tool to do that automatically?
> 
> Absolutely. It is called "make", and needs a Makefile to work ;)
> 

Actually you can ask gcc/g++ to output the dependencies on sources files. Then you can
have them read back by "make".

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On 26/05/2016 08:28 PM, Le_Forgeron wrote:
> Le 26/05/2016 20:11, Orchid Win7 v1 a écrit :
>> I also enjoy how if you try to link an executable, it whines about unresolved
symbols, but if you link an SO file, it's NOT considered an error to have missed half
of the necessary object files... (!)
>
> Shared lib (.so) are allowed to be completed later by other libs, or even the
loading binary.

Presumably this requires the executable to load everything in exactly 
the right order though?

> It's at runtime that you will get your problems.

Indeed. This is what I feared... So at some point, when the program is 
running, it will suddenly segfault for no apparent reason, and it will 
be mathematically impossible to ever determine why. Great.

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On 26/05/2016 08:31 PM, Le_Forgeron wrote:
> Another trick against the "right order" of linking: put everything but the main in a
single archive library ( .a ).
>
> Then compile the main source into a binary with the library on the command line.

Heh, don't even get me started on archive files!

I had the "brilliant idea" of turning each folder into an archive, and 
then linking those together. Trouble is... it only works 95% of the 
time. About 5% of the time, the resulting object behaves differently 
(i.e., wrong). GTest in particular seems to not like it. I have no idea why.

I stripped all traces of .a files out of the Makefile, and half my 
problems went away...

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On 27/05/2016 01:39 PM, clipka wrote:
> Am 27.05.2016 um 12:31 schrieb scott:
>>> I can't believe I've just spent an entire day writing Makefiles... At
>>> this rate, it would almost be simpler to just write a loop to compile
>>> every source file in every directory and then link them all! But, alas,
>>> it turns out that you have to actually link them in the right order, or
>>> it doesn't work.
>>
>> Isn't there some tool to do that automatically?
>
> Absolutely. It is called "make", and needs a Makefile to work ;)

LMAO! :-D

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On 27/05/2016 02:23 PM, scott wrote:
> Oh, what you can use make to make a makefile? Sounds like some IOCCC
> entry...

Weirdly, Make actually has implicit rules for how to make the Makefile 
itself... If you run it in debug mode, you can see it "considering" 
whether your Makefile is up-to-date or not.

I have no idea what these rules *are*, mind you... Perhaps it's looking 
for a Makefile.am to run AutoMake on or something?

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On 27/05/2016 04:10 PM, dick balaska wrote:
> It's weird that in 2016 a 1980s program is still in charge of assembling
> large swaths of code. Ant /tried/ to take over, but that's even worse.

Make is a nice *concept*... sadly, the *implementation* leaves something 
to be desired.

(I want to find the person who decided to use tabs as part of the 
language syntax and BEAT HIM TO DEATH! >_< My text editor is rightly 
configured to strip all tabs and turn them to spaces, but then noooo... 
As soon as you want to edit a Makefile, you have to turn that off.)

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On 27/05/2016 04:36 PM, Le_Forgeron wrote:

> Actually you can ask gcc/g++ to output the dependencies on sources files. Then you
can have them read back by "make".

Yes, this is the main thing I did.

Originally, the Makefile had one entry for every source file in the 
entire project, some (but not all) listing the header files they depend 
on. (Hey, at least the exact compilation command was a variable!)

I replaced that with a rule that says how to build any object file from 
a source file. That crunched the file size down to a fraction of its 
former self. I also made G++ spit out dependency information that then 
gets included back into the Makefile. Our CI server probably won't care, 
but it'll help the next poor sod who tries to build it by hand.

Finally, I wrote some crazy Make macro [yes, Make has macros] that 
generates a list of all the object files in a folder. Before they exist. 
So that I can depend on them.

...and then I did it all over again, since apparently SO files have to 
be built with -fPIC, whatever that does...

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hi,

On 27/05/2016 18:54, Orchid Win7 v1 wrote:
> Weirdly, Make actually has implicit rules for how to make the Makefile
> itself... If you run it in debug mode, you can see it "considering"
> whether your Makefile is up-to-date or not.
> 
> I have no idea what these rules *are*, mind you... Perhaps it's looking
> for a Makefile.am to run AutoMake on or something?

'make -p' dumps default rules & vars.   'info make' is your friend.

jr.

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