I like it... but could you check if you don't need to change

config.mak.in accordingly for ./configure script to generate proper

config.mak.autogen?

--

Jakub Narebski

Warsaw, Poland

ShadeHawk on #git
-

I couldn't see anything, but while I was looking at it, I also added

support for non-srcdir builds. Can someone with a perl clue look over

the braindamaged messing-around with perl/perl.mak  and figure out why

perl insists
make -C perl PERL_PATH='/usr/bin/perl' prefix='/tmp/test' perl.mak

make[1]: Entering directory `/home/lilydev/vc/go2/perl'

'/usr/bin/perl' -I/home/lilydev/vc/g2/perl /home/lilydev/vc/g2/perl/Makefile.PL FIRST_MAKEFILE='perl.mak' PREFIX='/tmp/test'

Could not open 'Git.pm': No such file or directory at /usr/lib/perl5/5.8.8/ExtUtils/MM_Unix.pm line 2649.
despite the -I option?
From 7bbd698891d9102fa26ae53848c9812f6d1b665e Mon Sep 17 00:00:00 2001

From: Han-Wen Nienhuys <hanwen@lilypond.org>

Date: Wed, 6 Dec 2006 15:14:08 +0100

Subject: [PATCH] Allow non-srcdir builds using cd $builddir && $srcdir/configure
Signed-off-by: Han-Wen Nienhuys <hanwen@xs4all.nl>

---

 Makefile            |   19 +++++++++++--------

 config.mak.in       |    5 +----

 configure.ac        |   31 ++++++++++++++++++++++++++++++-

 generate-cmdlist.sh |    2 +-

 perl/Makefile       |    2 +-

 5 files changed, 44 insertions(+), 15 deletions(-)
diff --git a/Makefile b/Makefile

index cb9b745..d64a5bd 100644

--- a/Makefile

+++ b/Makefile

@@ -97,7 +97,7 @@ all:

 #
 GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE

-	@$(SHELL_PATH) ./GIT-VERSION-GEN

+	@$(SHELL_PATH) $(srcdir)/GIT-VERSION-GEN

 -include GIT-VERSION-FILE
 uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')

@@ -120,7 +120,10 @@ datadir = $(prefix)/share

 GIT_datadir = $(datadir)/git-core

 gitexecdir = $(bindir)

 template_dir = $(GIT_datadir)/templates/

-# DESTDIR=

+srcdir = .

+

+# this is usually set on the make command line.

+DESTDIR=
 # default configuration for gitweb

 GITWEB_CONFIG = gitweb_config.perl

@@ -598,8 +601,8 @@ git-merge-recur$X: git-merge-recursive$X

 $(BUILT_INS): git$X

 	rm -f $@ && ln git$X $@
-common-cmds.h: Documentation/git-*.txt

-	./generate-...
[ message continues ]

Why have you removed setting datarootdir and template_dir? I would

have thought that you would rather change it to
  #gitexecdir = @libexecdir@/git-core/

  datarootdir = @datarootdir@

  GIT_datadir = @datadir@/git-core/

  template_dir= @datadir@/git-core/templates/
in config.mak.in
I have been told that setting 'datarootdir' is required to avoid
What is this for? The ./configure script, generated by autoconf from

configure.ac (by "make configure"), generates config.mak.autogen file

from config.mak.in, which is included in main (top) Makefile.
The variables defined in config.mak.autogen are of course visible in

make in subdirectories (make invoked from main makefile). Why the change?

What about user-generated config.mak?
This part IMHO has no sense, and has no place here.

--

Jakub Narebski

Poland

-

The Makefile already has this code, so adding it here is duplication of work

and code.
If you think putting code in the generated file is a good idea, I

propose we just generate the entire Makefile, as is the standard usage
in some cases, the files can also be called stand alone, eg.
  [lilydev@haring perl]$ pwd

  /home/lilydev/vc/git/perl
  [lilydev@haring perl]$ make

  make -f perl.mak all

  make[1]: Entering directory `/home/lilydev/vc/git/perl'

  make[1]: Leaving directory `/home/lilydev/vc/git/perl'
The above Makefile generation makes sure that this behavior is

mirrored in the builddir. Also, I'm not sure if the vpath settings get

exported automatically.
Having multiple Makefiles in the builddir is the standard behavior for
--

 Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

-

More detailed description what "Allow non-srcdir builds using cd

$builddir && $srcdir/configure" mean and why we might want to do that.
For example:
  We might want to build git from outside source directory. For this we

  need...
By the way, I think this patch is about _two_ changes. Allow to build

outside source directory, by providing srcdir AND separate change to

allow builds of separate parts of git, with separate Makefile, to

include user-generated configuration file config.mak and ./configure

generated config.mak.autogen configuration file.
Good call. Well, at least now, when ./configure script doesn't provide

means to change template_dir etc. from command line, via options.
Still I think that at least
  datarootdir = @datarootdir@
The stance on autoconf is that it has to be _optional_ part of
Git is not autotool'ed package. Autoconf is used only for _optional_
If you want to create or modify Makefiles, do that. Not generate

"minimal" Makefiles in every and each subdirectory.
You would be able to compile git fully only from top directory. So what?

--

Jakub Narebski

Poland

-

Look more closely at the patch. It only generates Makefiles in

directories that have makefiles in the source dir. The makefiles are

short because that is the easiest to do.
I'm happy to amend the patch, bUt I can't properly test

it until the perl problem gets sorted out. 
--

 Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen
-

Dnia

make -D doesn't exist.
This is about 
  mkdir git-build

  cd git-build

  $my_git_source/configure

  make 
this _was_ actually documented in that one-line commit message, that

you found to be too short.
Since git does recursive makes, among others in 
 perl/

 Documentation/

 templates/

 contrib/
there should be Makefiles in said directories. Otherwise, every rule

in the toplevel Makefile saying
  $(MAKE) -C subdir/
will fail because $builddir/ does not have a Makefile in

$builddir/subdir.
The part you don't understand is a generic way of duplicating the

Makefiles from the git sources, while making sure that they work when

$srcdir != $builddir
Yes, if builddir != srcdir , then configure is about more than

generating config.mak.autogen
--

 Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

-

This part should have been in the commit message, possibly without the

"among others ... (examples)" and possibly with an added "This patch

makes it so by letting fnurg create them through smurfing the frotz".
--

Andreas Ericsson                   andreas.ericsson@op5.se

OP5 AB                             www.op5.se

Tel: +46 8-230225                  Fax: +46 8-230231

-

Dnia

that doesn't work.
  make -C foo bla
just does 
  (cd foo && make bla)
If you did this, part of the object files would end up in the source dir;

The idea of separate srcdir builds,is to keep the srcdir completely clean

of generated files.  That can't really be done without aid of a script,

to setup the builddir. In this case that is the configure script.
I did forget to add a check 
  if "$srcdir" != "." ; then

    ..

  fi
around the messy stuff.
--

 Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen
-

Thanks for an explanation. At least some of it should be in commit

message, to explain what you want the patch to do.
I don't know autotools enough to check if autotools (autoconf) doesn't

have it's own way to do this, some autoconf macro, to not need to write

this script creating redirect Makefiles.
I'm still not sure if this has place in git. Is it really common to

support building outside source directory? If git didn't support this,

so what?

--

Jakub Narebski

Poland

-

lots of serious tools support it, as it this comes automatically

when using automake. Eg. emacs, gcc, make, pango, lilypond, etc etc. 
It's a quite standard feature ; you should be asking why git

shouldn't support it.
Another option is to make a special solution based on makefiles, so

make is run inside the srcdir, but output shunted output to a

separate objects/ subdirectory.  However, it's more work, and less

standardized.
--

 Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen
-

Dnia