TODO.private - toolchain/make - Git at Google

                                                             -*-Indented-Text-*-
 GNU Make TODO List
 ------------------

 This list comes both from the authors and from users of GNU make.

 They are listed in no particular order!

 Also, I don't guarantee that all of them will be ultimately deemed "good
 ideas" and implemented.  These are just the ones that, at first blush,
 seem to have some merit (and that I can remember).

 However, if you see something here you really, really want, speak up.
 All other things being equal, I will tend to implement things that seem
 to maximize user satisfaction.

 If you want to implement some of them yourself, barring the ones I've
 marked below, have at it!  Please contact me first to let me know you're
 working on it, and give me some info about the design--and, critically,
 information about any user-visible syntax change, etc.


 The Top Item
 ------------

 If you know perl (or want to learn DejaGNU or similar), the number one
 priority on my list of things I don't have time to do right now is
 fixing up the GNU make test suite.  Most importantly it needs to be made
 "parallelizable", so more than one regression can run at the same time
 (essentially, make the "work" directory local).  Also, the CWD during
 the test should be in the work directory or, better, a test-specific
 temporary directory so each test gets a new directory; right now
 sometimes tests leak files into the main directory which causes
 subsequent tests to fail (some tests may need to be tweaked).  Beyond
 that, any cleanup done to make writing, reading, or handling tests
 simpler would be great!  Please feel free to make whatever changes you
 like to the current tests, given some high-level goals, and that you'll
 port the current tests to whatever you do :).


 The Rest of the List
 --------------------

  1) Option to check more than timestamps to determine if targets have
     changed.  This is also a very big one.  It's _close_ to my plate :),
     and I have very definite ideas about how I would like it done.
     Please pick something else unless you must have this feature.  If
     you try it, please work _extremely_ closely with me on it.

  1a) Possibly a special case of this is the .KEEP_STATE feature of Sun's
      make.  Some great folks at W U. in Canada did an implementation of
      this for a class project.  Their approach is reasonable and
      workable, but doesn't really fit into my ideas for #2.  Maybe
      that's OK.  I have paperwork for their work so if you want to do
      this one talk to me to get what they've already done.

      [K R Praveen <praveen@cair.res.in>]

  2) Currently you can use "%.foo %.bar : %.baz" to mean that one
     invocation of the rule builds both targets.  GNU make needs a way to
     do that for explicit rules, too.  I heard a rumor that some versions
     of make all you to say "a.foo + a.bar : a.baz" to do this (i.e., a
     "+" means one invocation builds both).  Don't know if this is the
     best syntax or not... what if you say "a.foo + a.bar a.bam : a.baz";
     what does that mean?

  3) Multi-token pattern rule matching (allow %1/%2.c : %1/obj/%2.o,
     etc., or something like that).  Maybe using regex?

  4) Provide a .TARGETS variable, containing the names of the targets
     defined in the makefile.

     Actually, I now think a $(targets ...) function, at least, might be
     better than a MAKETARGETS variable.  The argument would be types of
     targets to list: "phony" is the most useful one.  I suppose
     "default" might also be useful.  Maybe some others; check the
     bitfields to see what might be handy.

  5) Some sort of operating-system independent way of handling paths
     would be outstanding, so makefiles can be written for UNIX, VMS,
     DOS, MS-Windows, Amiga, etc. with a minimum of specialization.

     Or, perhaps related/instead of, some sort of meta-quoting syntax so
     make can deal with filenames containing spaces, colons, etc.  I
     dunno, maybe something like $[...]?  This may well not be worth
     doing until #1 is done.

  6) Right now the .PRECIOUS, .INTERMEDIATE, and .SECONDARY
     pseudo-targets have different capabilities.  For example, .PRECIOUS
     can take a "%", the others can't.  Etc.  These should all work the
     same, insofar as that makes sense.

  7) Improved debugging/logging/etc. capabilities.  Part of this is done:
     I introduced a number of debugging enhancements.  Tim Magill is (I
     think) looking into options to control output more selectively.
     One thing I want to do in debugging is add a flag to allow debugging
     of variables as they're expanded (!).  This would be incredibly
     verbose, but could be invaluable when nothing else seems to work and
     you just can't figure it out.  The way variables are expanded now
     means this isn't 100% trivial, but it probably won't be hard.


 -------------------------------------------------------------------------------
 Copyright (C) 1997-2020 Free Software Foundation, Inc.
 This file is part of GNU Make.

 GNU Make is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3 of the License, or (at your option) any later
 version.

 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 this program.  If not, see <http://www.gnu.org/licenses/>.
	--Indented-Text--
	GNU Make TODO List
	------------------

	This list comes both from the authors and from users of GNU make.

	They are listed in no particular order!

	Also, I don't guarantee that all of them will be ultimately deemed "good
	ideas" and implemented. These are just the ones that, at first blush,
	seem to have some merit (and that I can remember).

	However, if you see something here you really, really want, speak up.
	All other things being equal, I will tend to implement things that seem
	to maximize user satisfaction.

	If you want to implement some of them yourself, barring the ones I've
	marked below, have at it! Please contact me first to let me know you're
	working on it, and give me some info about the design--and, critically,
	information about any user-visible syntax change, etc.


	The Top Item
	------------

	If you know perl (or want to learn DejaGNU or similar), the number one
	priority on my list of things I don't have time to do right now is
	fixing up the GNU make test suite. Most importantly it needs to be made
	"parallelizable", so more than one regression can run at the same time
	(essentially, make the "work" directory local). Also, the CWD during
	the test should be in the work directory or, better, a test-specific
	temporary directory so each test gets a new directory; right now
	sometimes tests leak files into the main directory which causes
	subsequent tests to fail (some tests may need to be tweaked). Beyond
	that, any cleanup done to make writing, reading, or handling tests
	simpler would be great! Please feel free to make whatever changes you
	like to the current tests, given some high-level goals, and that you'll
	port the current tests to whatever you do :).


	The Rest of the List
	--------------------

	1) Option to check more than timestamps to determine if targets have
	changed. This is also a very big one. It's _close_ to my plate :),
	and I have very definite ideas about how I would like it done.
	Please pick something else unless you must have this feature. If
	you try it, please work _extremely_ closely with me on it.

	1a) Possibly a special case of this is the .KEEP_STATE feature of Sun's
	make. Some great folks at W U. in Canada did an implementation of
	this for a class project. Their approach is reasonable and
	workable, but doesn't really fit into my ideas for #2. Maybe
	that's OK. I have paperwork for their work so if you want to do
	this one talk to me to get what they've already done.

	[K R Praveen <praveen@cair.res.in>]

	2) Currently you can use "%.foo %.bar : %.baz" to mean that one
	invocation of the rule builds both targets. GNU make needs a way to
	do that for explicit rules, too. I heard a rumor that some versions
	of make all you to say "a.foo + a.bar : a.baz" to do this (i.e., a
	"+" means one invocation builds both). Don't know if this is the
	best syntax or not... what if you say "a.foo + a.bar a.bam : a.baz";
	what does that mean?

	3) Multi-token pattern rule matching (allow %1/%2.c : %1/obj/%2.o,
	etc., or something like that). Maybe using regex?

	4) Provide a .TARGETS variable, containing the names of the targets
	defined in the makefile.

	Actually, I now think a $(targets ...) function, at least, might be
	better than a MAKETARGETS variable. The argument would be types of
	targets to list: "phony" is the most useful one. I suppose
	"default" might also be useful. Maybe some others; check the
	bitfields to see what might be handy.

	5) Some sort of operating-system independent way of handling paths
	would be outstanding, so makefiles can be written for UNIX, VMS,
	DOS, MS-Windows, Amiga, etc. with a minimum of specialization.

	Or, perhaps related/instead of, some sort of meta-quoting syntax so
	make can deal with filenames containing spaces, colons, etc. I
	dunno, maybe something like $[...]? This may well not be worth
	doing until #1 is done.

	6) Right now the .PRECIOUS, .INTERMEDIATE, and .SECONDARY
	pseudo-targets have different capabilities. For example, .PRECIOUS
	can take a "%", the others can't. Etc. These should all work the
	same, insofar as that makes sense.

	7) Improved debugging/logging/etc. capabilities. Part of this is done:
	I introduced a number of debugging enhancements. Tim Magill is (I
	think) looking into options to control output more selectively.
	One thing I want to do in debugging is add a flag to allow debugging
	of variables as they're expanded (!). This would be incredibly
	verbose, but could be invaluable when nothing else seems to work and
	you just can't figure it out. The way variables are expanded now
	means this isn't 100% trivial, but it probably won't be hard.


	-------------------------------------------------------------------------------
	Copyright (C) 1997-2020 Free Software Foundation, Inc.
	This file is part of GNU Make.

	GNU Make is free software; you can redistribute it and/or modify it under the
	terms of the GNU General Public License as published by the Free Software
	Foundation; either version 3 of the License, or (at your option) any later
	version.

	GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
	A PARTICULAR PURPOSE. See the GNU General Public License for more details.

	You should have received a copy of the GNU General Public License along with
	this program. If not, see <http://www.gnu.org/licenses/>.