Makefile - Deduce targets from sources (on iSeries system) - makefile

On an IBM i system, using PASE (AIX emulator), i try to compile RPG sources using a makefile.
I have RPG sources and try to build a PGM program.
Every single source will be compile in a distinct PGM.
Here is the syntax i tried first
VPATH=.
SYSTEM=system -iv
CRTRPGMOD=CRTRPGMOD
BIN_LIB=MR_CH
CURRENT_PATH=/currentPath #${PWD} doesn't work
#With this line active, it works
SRC_RPGLE = src1.rpgle src2.rpgle
#With this line active, it doesn't work
#SRC_RPGLE = $(shell echo *.rpgle) #Should list every sources i want to compile
TARGETS = $(SRC_RPGLE:.rpgle=.rpgleMod) #Should list every program i want to build
.SUFFIXES: .rpgle .rpgleMod
.rpgle.rpgleMod:
$(SYSTEM) "$(CRTRPGMOD) MODULE($(BIN_LIB)/$(*F)) SRCSTMF('$(CURRENT_PATH)/$<')" > $(*F)_1_crtrpgmod.log
ln -fs $(*F).rpgMod
all: $(TARGETS)
I tried to apply GNU shell syntax using AIX make command
Any suggestions ?

I'm not familiar with the AIX implementation of make but assuming that the linked man page is all there is to it, then it looks like a bare-bones implementation of POSIX make (for an older POSIX spec).
Therefore, the only way to do what you want (expand a list of files) is to use recursion, so that you get access to the shell, like this:
SYSTEM=system -iv
CRTRPGMOD=CRTRPGMOD
BIN_LIB=MR_CH
CURRENT_PATH=/currentPath
CURRENT_PATH=/home/CHARLES/Projets/MRSRC/tmp
recurse:
$(MAKE) all SRC_RPGLE="`echo *.rpgle`"
TARGETS = $(SRC_RPGLE:.rpgle=.rpgleMod)
.SUFFIXES: .rpgle .rpgleMod
.rpgle.rpgleMod:
$(SYSTEM) "$(CRTRPGMOD) MODULE($(BIN_LIB)/$(*F)) SRCSTMF('$(CURRENT_PATH)/$<')" > $(*F)_1_crtrpgmod.log
ln -fs $(*F).rpgMod
all: $(TARGETS)
The recurse rule MUST be the first target in the makefile. Also this won't help if you want to run other targets like make foobar; it will only help you run all properly.
Alternatively you can obtain GNU make and build it for your system, and use that. In the end that might be a more straightforward approach.

Related

Symbols ($(bindir), $(sysconfdir),...) unknown in (sub) Makefiles

I'm working with autotools for the first time, for a tool that's written in perl (SQLTeX), so only installation is required, no compilation.
The toplevel contains a simple Makefile.am:
AUTOMAKE_OPTIONS = foreign
SUBDIRS = src man doc
EXTRA_DIST = README.md
.PHONY: all-am
all-am:
#echo "Done!"
If I create Makefile.am files in the sub-directories too, nothing seems to happen there so I just stick to Makefile. A snippet from src/Makefile (EDIT: this file is now renamed to Makefile.am):
SQLTeX: SQLTeX.pl
cat $^ | sed -e 's#{PERLDIR}#$(PL)#;s#{SYSCONFDIR}#$(sysconfdir)#' > $#
#chmod +x $#
The symbol PL is set as expect (defined in the same makefile), but sysconfdir is empty, although it is defined in the top-level Makefile generated by ./configure.
What am I doing wrong?
Thanks in advance!
What am I doing wrong?
Although the Autotools support, with some caveats, recursing into directories where you provide pre-built makefiles, you cannot expect those pre-built makefiles to be able to rely on autotools-provided variables such as the standard directory variables bindir and sysconfdir. Thus, although it is allowed to rely on hand-written makefiles in subdirectories, this is probably a false trail for you.
I recommend going back to this:
If I create Makefile.am files in the sub-directories too, nothing seems to happen there
and working out what's wrong. The Autotools definitely support generating recursive build systems, and one Makefile.am per directory is part of the usual approach to that. If it didn't work for you then my first guess would be that you forgot to list the extra makefiles in your AC_CONFIG_FILES list.
As an alternative, just because you have multiple directories does not mean that you need to use recursive make. It is quite possible to build such a project with the support of a single makefile, and the Autotools can help with such a makefile.

Makefile pattern rules not working

I am learning makefiles, and can't just wrap my head around this problem i am having, and would like to understand how/why this fail.
I have half a dozen erlang files in a src directory. I want to compile these into a ebin directory, without having to define a rule for each and every one of them. According to the Gnu make documentation, pattern rules should be right up my alley.
However, with the following makefile, all I get from make is make: *** No targets. Stop. Why is that?
ebin/%.beam: src/%.erl
mkdir -p ebin
erlc -o ebin $<
Edit: Based on this answer, I now understand that i would have to explicitly declare the targets, for instance by using make ebin/cmplx.beam. However, i still do not understand how i should write my makefile to get my desired behaviour - since I have half a dozen targets (and in other projects even more), this seems like an unnecessary hassle. Is there not a way to define targets based on the source file names?
The target rule tells make that whenever it needs to produce a beam file in the ebin directory, and there exists a corresponding erl file in the src directory, it can use erlc.
However, this doesn't tell make that this is what it needs to do. You could explicitly tell make what it needs to do by giving it a target on the command line:
make ebin/foo.beam
If you don't give a target on the command line, make will pick the first non-pattern rule in the makefile as its target. However, your makefile doesn't have any non-pattern rules, so there is no target.
What you probably want is that for each existing erl file in src, make should consider the corresponding beam file in ebin to be a target. You can achieve that by calling wildcard and patsubst:
erl_files=$(wildcard src/*.erl)
beam_files=$(patsubst src/%.erl,ebin/%.beam,$(erl_files))
ebin/%.beam: src/%.erl
mkdir -p ebin
erlc -o ebin $<
all: $(beam_files)
(The indented lines need to be actual physical tabs, not spaces.)
That way, running make will rebuild all beam files that are out of date. all gets chosen as the default target, and it in turn depends on all beam existing or potential, each of which in turn depends on the corresponding erl file.
This trick is described in the GNU make manual.

OpenCobol Makefile

I am trying to compile an OpenCobol program using make. I am always getting "make: Nothing to be done for test1.cob". Here is my makefile. I had put a TAB before cobc. But still I am getting that message. Please help.
Thanks.
COBCWARN = -W
%: %.cob
cobc $(COBCWARN) -free -x $^ -o $#
And here is my cobol program.
IDENTIFICATION DIVISION.
PROGRAM-ID. TEST1.
PROCEDURE DIVISION.
DISPLAY 'Hello world!'.
STOP RUN.
Your makefile contains no actual targets. You have defined only a pattern rule which tells make how to build targets that match the pattern. But make doesn't go looking for targets out on the filesystem that could match the pattern, it only checks the pattern against targets that have been specifically requested.
You don't have any specific targets (files) listed in your makefile, so the only way make can know about a target is if you give the target to be built on the command line.
You are running this command from within vim, using the % special token, which expands to the name of the file currently being edited. That means you are running the command:
make test1.cob
because you are editing the file test1.cob. So, you are telling make "please try to create the target (file) test1.cob". But, that file already exists (it's the file you're writing). So make says "nothing to do".
If you run make and ask it to create the target you really want created, it will work:
make test1
Now the file test1 doesn't exist, and make can find a pattern rule that knows how to build it, so make will run that rule.
Alternatively, you can edit your makefile to add the specific target, like this:
COBCWARN = -W
test1: test1.cob
%: %.cob
cobc $(COBCWARN) -free -x $^ -o $#
Then you can run make with no arguments at all. Without any command line arguments, make will look in the makefile for explicit targets and find test1 as the first one. It sees that there is a rule (the pattern rule) that matches that target, so it will build that target.
UPDATE
If you want to allow a simple command make to build multiple programs, write your makefile like this:
COBCWARN = -W
all: test1 test2 test3
.PHONY: all
%: %.cob
cobc $(COBCWARN) -free -x $^ -o $#
Now from vim you can just say :!make and that's it.
If you run make with no arguments then it will find the first explicit target in the makefile and build that. In this example the first target is all, and its prerequisites are the possible programs to build. To build each one make sees that it can apply the pattern rule, and so it will do so (if the .cob file has been modified since the last time the program was built).

Alias target name in Makefile

The Problem:
Is it possible to give a target a different name or alias, such that it can be invoked using either the original target name or the alias.
For example something like
/very/long/path/my_binary: dep_a dep_b dep_c
# Compile
# Desired command
ALIAS my_binary = /very/long/path/my_binary
# NOTE: Notice the use of 'my_binary' in the dependencies
data1: my_binary datafile
# Build data file using compiled my_binary
Attempt 1: .PHONY
I have tried using a .PHONY target:
.PHONY: my_binary
my_binary: /very/long/path/my_binary
This works great when invoked from the command-line:
# Runs rule 'my_binary' and then *only* runs rule '/very/long/path/my_binary'
# if the rule '/very/long/path/my_binary' needs updating.
make my_binary
However, this does not work well when the alias my_binary is listed as a dependency:
# *Always* thinks that rule 'data1' needs updating, because it always thinks that
# the .PHONY target 'my_binary' "needs updating". As a result, 'data1' is
# rebuilt every time.
make /very/long/path/my_binary
Possible hack?
A possible hack is to use an empty target as suggested in an answer to this question, but that would require introducing fake files with names corresponding to the alias:
my_binary: /very/long/path/my_binary
touch my_binary
This will clutter the main directory with files! Placing the fake files in a sub-directory would defeat the purpose, as the alias would have to be referred to as 'directory/my_binary'
Okay, I needed something similar. The path to my output artifacts were quite long, but I wanted short target names and also benefit easily from bash-completion.
Here is what I'm came up with:
os := [arbitrary long path to an artifact]
platform := [arbitrary long path to a differ artifact]
packer := [common parts of my packer build command]
.PHONY: all
all: $(platform)
.PHONY: platform
platform: $(platform)
$(platform): platform.json $(os)
#$(packer) $<
.PHONY: os
os: $(os)
$(os): os.json
#$(packer) $<
.PHONY: clean
clean:
rm -fr build/
With the Makefile above you can say:
$ make os
$ make platform
Which will be aliases for the long artifact names. I've made the snippet above quite long, because it's important to see the relationships between the .PHONY aliases and the real targets. I hope that works for you.
Note: I did not delete the clean target from the above example, because many people does not make that a .PHONY target. However, semantically it should be.
I don't think there's any way to do it so that you can use the alias from within your makefile as well as the command line, except by creating those temporary files.
Why can't you just set a variable in the makefile, like:
my_binary = /very/long/path/my_binary
then use $(my_binary) everywhere in the makefile? I don't see any point in creating a real alias target for use inside the makefile.
I had a somewhat similar need. I wanted users of my makefile to be able to enter any of the following to accomplish the same result, such that the following were effectively synonyms of each other:
make hit list
make hitlist
make hit_list
What I did in my makefile was the following:
hit_list:
#echo Got here
<the real recipe goes here>
hit: hit_list
hitlist: hit_list
.PHONY: list
list:
#echo > /dev/null
Then, when I tested it using any of the commands "make hit list", "make hitlist", or "make hit_list", I got identical results, as intended.
By extension, if one of your targets was the one with the long name but you used this approach whereby a simple short name identified the target with the long name as a prerequisite, I think that you should be able to say "make short_name" and accomplish what you're asking about.
This differs from your Approach 1 in that none of the synonyms is defined as a phony target (considering that "make hit list" is a command to make two targets, the second being effectively a noop), so the complication that you described would not arise.

How does "make" app know default target to build if no target is specified?

Most Linux apps are compiled with:
make
make install clean
As I understand it, the make command takes names of build targets as arguments. So for example install is usually a target that copies some files to standard locations, and clean is a target that removes temporary files.
But what target will make build if no arguments are specified (e.g. the first command in my example)?
By default, it begins by processing the first target that does not begin with a . aka the default goal; to do that, it may have to process other targets - specifically, ones the first target depends on.
The GNU Make Manual covers all this stuff, and is a surprisingly easy and informative read.
To save others a few seconds, and to save them from having to read the manual, here's the short answer. Add this to the top of your make file:
.DEFAULT_GOAL := mytarget
mytarget will now be the target that is run if "make" is executed and no target is specified.
If you have an older version of make (<= 3.80), this won't work. If this is the case, then you can do what anon mentions, simply add this to the top of your make file:
.PHONY: default
default: mytarget ;
References:
https://www.gnu.org/software/make/manual/html_node/How-Make-Works.html
GNU Make also allows you to specify the default make target using a special variable called .DEFAULT_GOAL. You can even unset this variable in the middle of the Makefile, causing the next target in the file to become the default target.
Ref: The Gnu Make manual - Special Variables
bmake's equivalent of GNU Make's .DEFAULT_GOAL is .MAIN:
$ cat Makefile
.MAIN: foo
all:
#echo all
foo:
#echo foo
$ bmake
foo
See the bmake(1) manual page.

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