make - Revision history

Kate: /* Introduction to '''make''' */

2008-06-12T17:56:37Z

Introduction to '''make'''

← Older revision		Revision as of 17:56, 12 June 2008
Line 6:		Line 6:
	Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.		Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.

	'''Make''' gets its instructions from a description file, by default named '''Makefile'''. This file is also called the '''makefile''', but other files can be used by invoking '''make''' with the '''-f''' option, e.g.:		'''Make''' gets its instructions from a description file, by default named '''makefile''' or '''Makefile'''. This file is also called the '''makefile''', but other files can be used by invoking '''make''' with the '''-f''' option, e.g.:
	<span class="red">make -f Makefile.yukon</span>		<span class="red">make -f Makefile.yukon</span>
	When I first got our ocean model, its '''Makefile''' looked something like:		When I first got our ocean model, its '''Makefile''' looked something like:
Line 25:		Line 25:
	<TAB> command</span>		<TAB> command</span>

	The target '''model''' depends on the object files, '''main.o''' and friends. They have to exist and be up to date before '''model''''s link command can be run. ~~The other targets tell '''make''' how~~ to ~~create~~ the ~~object files. The original version of this '''Makefile''' turned off optimization~~ on ~~'''plot~~.~~f''' due to a compiler bug, but hopefully you won't ever have to worry about~~ that.		The target '''model''' depends on the object files, '''main.o''' and friends. They have to exist and be up to date before '''model''''s link command can be run. If the target is out of date according to the timestamp on the file, then the commands will be run. Note that the tab is required on the command lines.

	~~Compiling~~ '''model''' ~~is simple~~, ~~just~~ type '''make'''. '''Make''' will look for the file '''makefile''' or '''Makefile''', read it, and do whatever is necessary to make '''model''' up to date. If you edit '''init.f''', that file will be newer than '''init.o'''. '''Make''' would see that '''init.o''' is out of date and run the <span class="red">f90 -c -O init.f</span> command. Now '''init.o''' is newer than '''model''', so the link command <span class="red">f90 -o model main.o init.o plot.o</span> must be executed.		The other targets tell '''make''' how to create the object files and that they in turn have dependencies. To compile '''model''', simply type '''make'''. '''Make''' will look for the file '''makefile''' or '''Makefile''', read it, and do whatever is necessary to make '''model''' up to date. If you edit '''init.f''', that file will be newer than '''init.o'''. '''Make''' would see that '''init.o''' is out of date and run the <span class="red">f90 -c -O init.f</span> command. Now '''init.o''' is newer than '''model''', so the link command <span class="red">f90 -o model main.o init.o plot.o</span> must be executed.

	~~Clean~~ up ~~by typing~~ "'''make clean'''"~~. The~~ '''clean''' target will be brought up to date. '''clean''' has no dependencies~~, so~~ the command <span class="red">rm -f *.o core</span> will always be executed.		To clean up, type "'''make clean'''" and the '''clean''' target will be brought up to date. '''clean''' has no dependencies. What happens in that case is that the command <span class="red">rm -f *.o core</span> will always be executed.

			The original version of this '''Makefile''' turned off optimization on '''plot.f''' due to a compiler bug, but hopefully you won't ever have to worry about that.

	==Macros==		==Macros==

Arango: /* Dependencies */

2007-06-07T14:07:30Z

Dependencies

← Older revision		Revision as of 14:07, 7 June 2007
Line 94:		Line 94:
	Fortran 90 introduces module dependencies as well, briefly mentioned in [[MakeDepend]].		Fortran 90 introduces module dependencies as well, briefly mentioned in [[MakeDepend]].

	In conclusion, '''make''' is a very powerful tool. The book to read is [http://www.oreilly.com/catalog/make3/ Managing Projects with ~~Gnu~~ Make] by Robert Mecklenburg, 2005, O'Reilly.		In conclusion, '''make''' is a very powerful tool. The book to read is [http://www.oreilly.com/catalog/make3/ Managing Projects with GNU Make] by Robert Mecklenburg, 2005, O'Reilly.

	'''Make''' has a portable subset of features, with system-dependent extensions. If you want to use extensions, I suggest sticking with those supported by [http://www.gnu.org/software/make/ GNU make] ('''gmake'''), since it is available most everywhere. The newest ROMS versions make use of the power of '''gmake''' and depend on it to be the '''make''' used. These more advanced features are described in [[gmake]].		'''Make''' has a portable subset of features, with system-dependent extensions. If you want to use extensions, I suggest sticking with those supported by [http://www.gnu.org/software/make/ GNU make] ('''gmake'''), since it is available most everywhere. The newest ROMS versions make use of the power of '''gmake''' and depend on it to be the '''make''' used. These more advanced features are described in [[gmake]].

	The most common newbie mistake is to forget that the commands after a target ''have'' to start with a '''tab'''.		The most common newbie mistake is to forget that the commands after a target ''have'' to start with a '''tab'''.

Arango at 14:06, 7 June 2007

2007-06-07T14:06:54Z

← Older revision		Revision as of 14:06, 7 June 2007
Line 6:		Line 6:
	Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.		Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.

	'''Make''' gets its instructions from a description file, by default named '''Makefile'''. This file is also called the '''makefile''', but other files can be used by invoking '''make''' with the '''-f''' option, e.g.:<~~br /~~>~~<code>~~		'''Make''' gets its instructions from a description file, by default named '''Makefile'''. This file is also called the '''makefile''', but other files can be used by invoking '''make''' with the '''-f''' option, e.g.:
	make -f Makefile.yukon</~~code~~>		<span class="red">make -f Makefile.yukon</span>
	When I first got our ocean model, its '''Makefile''' looked something like:<~~br /~~>~~<code>~~		When I first got our ocean model, its '''Makefile''' looked something like:
	model: main.o init.o plot.o		<span class="red">model: main.o init.o plot.o
	<TAB> f90 -o model main.o init.o plot.o<br />		<TAB> f90 -o model main.o init.o plot.o<br />
	main.o: main.f		main.o: main.f
Line 18:		Line 18:
	<TAB> f90 -c -O0 plot.f<br />		<TAB> f90 -c -O0 plot.f<br />
	clean:		clean:
	<TAB> rm -f *.o core</~~code~~>		<TAB> rm -f *.o core</span>

	The default thing to build is '''model''', the first target. The syntax is:<~~br /><code~~>		The default thing to build is '''model''', the first target. The syntax is:
	target: dependencies		<span class="red">target: dependencies
	<TAB> command		<TAB> command
	<TAB> command</~~code~~>		<TAB> command</span>

	The target '''model''' depends on the object files, '''main.o''' and friends. They have to exist and be up to date before '''model''''s link command can be run. The other targets tell '''make''' how to create the object files. The original version of this '''Makefile''' turned off optimization on '''plot.f''' due to a compiler bug, but hopefully you won't ever have to worry about that.		The target '''model''' depends on the object files, '''main.o''' and friends. They have to exist and be up to date before '''model''''s link command can be run. The other targets tell '''make''' how to create the object files. The original version of this '''Makefile''' turned off optimization on '''plot.f''' due to a compiler bug, but hopefully you won't ever have to worry about that.
Line 33:		Line 33:
	==Macros==		==Macros==

	Make supports a simple string substitution macro. Set it with:<~~br /><code~~>		Make supports a simple string substitution macro. Set it with:
	MY_MACRO = nothing today</~~code~~>		<span class="red">MY_MACRO = nothing today</span>
	and refer to it with:<br /><code>		and refer to it with:<br /><code>
	$(MY_MACRO)</~~code~~>		<span class="red">$(MY_MACRO)</span>
	The convention is to put the macros near the top of your '''Makefile''' and to use upper case. Also, use separate macros for the name of your compiler and the flags it needs:<~~br /~~>~~<code>~~		The convention is to put the macros near the top of your '''Makefile''' and to use upper case. Also, use separate macros for the name of your compiler and the flags it needs:
	F90 = f90		<span class="red">F90 = f90
	F90FLAGS = -O3		F90FLAGS = -O3
	LIBDIR = /usr/local/lib		LIBDIR = /usr/local/lib
	LIBS = -L$(LIBDIR) -lmylib</~~code~~>		LIBS = -L$(LIBDIR) -lmylib</span>
	Let's rewrite our '''Makefile''' using macros:<~~br /><code~~>		Let's rewrite our '''Makefile''' using macros:
	#		<span class="red">#
	# IBM version		# IBM version
	#		#
Line 58:		Line 58:
	<TAB> $(F90) -c $(F90FLAGS) plot.f<br />		<TAB> $(F90) -c $(F90FLAGS) plot.f<br />
	clean:		clean:
	<TAB> rm -f *.o core</~~code~~>		<TAB> rm -f *.o core</span>

	Now when we change computers, we only have to change the compiler name in one place. Likewise, if we want to try different optimization levels, we only specify that in one place. Notice that you can use comments by starting the line with a <span class="red">#</span>.		Now when we change computers, we only have to change the compiler name in one place. Likewise, if we want to try different optimization levels, we only specify that in one place. Notice that you can use comments by starting the line with a <span class="red">#</span>.
Line 64:		Line 64:
	==Implicit Rules==		==Implicit Rules==

	'''Make''' has some rules already built in. For Fortran, you might be able to get away with:<~~br /><code~~>		'''Make''' has some rules already built in. For Fortran, you might be able to get away with:
	OBJS = main.o init.o plot.o<br />		<span class="red">OBJS = main.o init.o plot.o<br />
	model: $(OBJS)		model: $(OBJS)
	<TAB> $(FC) $(LDFLAGS) -o model $(OBJS)</~~code~~>		<TAB> $(FC) $(LDFLAGS) -o model $(OBJS)</span>
	as your whole '''Makefile. Make''' will automatically invoke its default Fortran compiler, possibly '''f77''' or '''g77''', with whatever default compile options it happens to have ('''FFLAGS'''). One built in rule often looks like:<~~br /~~>~~<code>~~		as your whole '''Makefile. Make''' will automatically invoke its default Fortran compiler, possibly '''f77''' or '''g77''', with whatever default compile options it happens to have ('''FFLAGS'''). One built in rule often looks like:
	.c.o:		<span class="red">.c.o:
	<TAB> $(CC) $(CFLAGS) -c $<</~~code~~>		<TAB> $(CC) $(CFLAGS) -c $<</span>
	which says to compile '''.c''' files to '''.o''' files using the compiler '''CC''' and options '''CFLAGS'''. We can write our own suffix rules in this same style. The only thing to watch for is that '''make''' by default has a limited set of file extensions that it knows about. Let's write our '''Makefile''' using a suffix rule:<~~br /~~>~~<code>~~		which says to compile '''.c''' files to '''.o''' files using the compiler '''CC''' and options '''CFLAGS'''. We can write our own suffix rules in this same style. The only thing to watch for is that '''make''' by default has a limited set of file extensions that it knows about. Let's write our '''Makefile''' using a suffix rule:
	#		<span class="red">#
	# Cray version		# Cray version
	#		#
Line 83:		Line 83:
	<TAB> $(F90) $(LDFLAGS) -o model main.o init.o plot.o<br />		<TAB> $(F90) $(LDFLAGS) -o model main.o init.o plot.o<br />
	clean:		clean:
	<TAB> rm -f *.o core</~~code~~>		<TAB> rm -f *.o core</span>

	==Dependencies==		==Dependencies==

	There may be additional dependencies beyond the '''source->object''' ones. In our little example, all our source files include a file called '''commons.h'''. If '''commons.h''' gets modified to add a new variable, everything must be recompiled. '''Make''' won't know that unless you tell it, using the syntax:<~~br /><code~~>		There may be additional dependencies beyond the '''source->object''' ones. In our little example, all our source files include a file called '''commons.h'''. If '''commons.h''' gets modified to add a new variable, everything must be recompiled. '''Make''' won't know that unless you tell it, using the syntax:
	# include dependencies<br />		<span class="red"># include dependencies<br />
	main.o: commons.h		main.o: commons.h
	init.o: commons.h		init.o: commons.h
	plot.o: commons.h</~~code~~>		plot.o: commons.h</span>
	Fortran 90 introduces module dependencies as well, briefly mentioned in [[MakeDepend]].		Fortran 90 introduces module dependencies as well, briefly mentioned in [[MakeDepend]].

Arango at 13:51, 7 June 2007

2007-06-07T13:51:27Z

Show changes

Arango: /* Introduction to '''make''' */

2007-06-07T13:02:15Z

Introduction to '''make'''

← Older revision		Revision as of 13:02, 7 June 2007
Line 6:		Line 6:
	Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.		Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.

	'''Make''' gets its instructions from a description file, by default named '''Makefile'''. This file is also called the '''~~Makefile~~''', but other files can be used by invoking '''make''' with the '''-f''' option, e.g.:		'''Make''' gets its instructions from a description file, by default named '''Makefile'''. This file is also called the '''makefile''', but other files can be used by invoking '''make''' with the '''-f''' option, e.g.:
	:<code>make -f Makefile.yukon</code>		:<code>make -f Makefile.yukon</code>

Robertson at 19:02, 8 December 2006

2006-12-08T19:02:38Z

← Older revision		Revision as of 19:02, 8 December 2006
Line 1:		Line 1:
	=~~'''~~make~~'''=~~		<div class="title">make</div>
	This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].		This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].
	__TOC__		__TOC__

Robertson at 20:17, 22 November 2006

2006-11-22T20:17:16Z

← Older revision		Revision as of 20:17, 22 November 2006
Line 1:		Line 1:
	='''make'''=		='''make'''=
			This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].
	__TOC__		__TOC__
	~~This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].~~
	==Introduction to '''make'''==		==Introduction to '''make'''==

Robertson at 20:16, 22 November 2006

2006-11-22T20:16:30Z

← Older revision		Revision as of 20:16, 22 November 2006
Line 1:		Line 1:
	='''make''=		='''make'''=
	__TOC__		__TOC__
	This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].		This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].

Robertson at 20:16, 22 November 2006

2006-11-22T20:16:21Z

← Older revision		Revision as of 20:16, 22 November 2006
Line 1:		Line 1:
			='''make''=
			__TOC__
	This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].		This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].
	==Introduction to '''make'''==		==Introduction to '''make'''==

Robertson at 20:54, 17 November 2006

2006-11-17T20:54:08Z

← Older revision		Revision as of 20:54, 17 November 2006
Line 1:		Line 1:
	This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].		This article first appeared in the [http://www.arsc.edu/support/news/HPCnews.shtml\|ARSC HPC Newsletter].
	==Introduction to ~~Make~~==		==Introduction to '''make'''==

	Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.		Make is a tool which is almost as old as Unix, designed primarily for keeping track of how programs are compiled. That is what we will describe here, although it can be used for other things, including web page maintenance. It is just a matter of telling '''make''' what commands need to be run to update your files.