How to understand this SWI-Prolog makefile - how Linux executable is created? - linux

Question

I am trying to compile grammar parser https://github.com/RichardMoot/Grail into Linux program according to instructions https://github.com/RichardMoot/Grail/blob/master/README and http://www.labri.fr/perso/moot/tutorial/install.html. There is manual how to create Linux executable from SWI-Prolog code http://www.swi-prolog.org/FAQ/UnixExe.html. All that is fine. But I can not find in the Makefile https://github.com/RichardMoot/Grail/blob/master/Makefile any compilation command. SWI-Prolo uses swipl command for compilation but this Makefile swipl calls only once - for displaying the version of the swipl.
I experience some hardship in installation and compilation, that is fine, I can execute/debug Makefile line by line and arrive at the result. But there is problem in my case - I can not see the ultimate goal in my makefile: which lines are responsible for the production of object files (if necessary) and which lines are responsible for the creation of the final Linux executable.
This is windowed program. The source code and documentation contains warnings about incompatibility with the SWI-Prolog 7, but that is fine, I can resolvem them myself, but as I said - I can not see the Makefile lines for creation of exe.
The source code is created by eminent scientist and I certainly don't want to disturb him by so low-level technical question. I would be happy if he continues work on theory and doesn't waste time on low level programming questions. Hope, that there are SWI-Prolog experts.
I am using latest (7.x) SWI-Prolog on Ubuntu 16.x and I have already installed all the mentioned prerequisites.

Answer 1

If you look closely at the provided Makefile, you'll find that the rules all and install are defined as follows (comments added by me):
all:
-cd source ; $(edit) g3 > g3.tmp # Replaces placeholders for your
# ... GRAIL_ROOT install directory.
-cd source ; mv -f g3.tmp g3 # Overwrites `g3` with the filled file.
cd source ; chmod a+x g3 # Makes it executable.
install: # Essentially copies all files to
-mkdir $(datarootdir) # ... your install directory.
-mkdir $(datadir)
cp -f $(images) $(datadir)
-mkdir $(bindir)
cp -f source/insertdot $(bindir)
chmod a+x $(bindir)/insertdot
cp -f $(resources) $(datadir)
cp -f source/*.pl $(bindir)
cp -f source/g3 $(bindir)
If you then do the common make && make install you'll end up with two folders installed in your Grail directory: bin and share. Inside the binary directory you'll have the g3 file that, regardless of being a SWI-Prolog source, has this initial line:
#!/usr/bin/swipl -q -g start -f
% [... prolog code.]
This header should allow your console terminal to determine what interpreter to use for this script (in this case, swipl). In my case, executing Grail with ./g3 returned a SWI-Prolog message indicating that wrong options/command arguments were used.
According to the man, Unix systems have to use option -s at the end of the header (but this didn't work either in my case):
From the manual:
-s file
Load file as a script. This option may be used from the shell to
make Prolog load a file before entering the toplevel.
It is also used to turn a file into an executable Prolog script
on Unix systems using the following first line
#!/usr/bin/swipl option ... -s
If you want to run this program, simply call the same command from your terminal:
swipl -q -g start -s g3