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[Automake-commit] [SCM] GNU Automake branch, master, updated. v1.11-1862
|
From: |
Stefano Lattarini |
|
Subject: |
[Automake-commit] [SCM] GNU Automake branch, master, updated. v1.11-1862-g7604b2e |
|
Date: |
Tue, 14 Feb 2012 20:42:05 +0000 |
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the project "GNU Automake".
http://git.sv.gnu.org/gitweb/?p=automake.git;a=commitdiff;h=7604b2eede07b84b2f22c81a11db2078f8ffe3da
The branch, master has been updated
via 7604b2eede07b84b2f22c81a11db2078f8ffe3da (commit)
via bdfd2295149398a2872f1794abffd1292f8c0492 (commit)
from b2c1adfe1e118ed8fb5fc68ced68ef69ea39b543 (commit)
Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
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- Log -----------------------------------------------------------------
commit 7604b2eede07b84b2f22c81a11db2078f8ffe3da
Merge: b2c1adf bdfd229
Author: Stefano Lattarini <address@hidden>
Date: Tue Feb 14 21:30:56 2012 +0100
Merge branch 'doc-no-history'
* doc-no-history:
docs: move chapter on automake history out of main manual
commit bdfd2295149398a2872f1794abffd1292f8c0492
Author: Stefano Lattarini <address@hidden>
Date: Sun Feb 12 11:02:32 2012 +0100
docs: move chapter on automake history out of main manual
The chapter on Automake history, while certainly interesting and
even fascinating, does not truly pertain to a reference manual,
so move it out from there and into its own dedicated file. This
change is made more advisable and pressing by the fact that such
and "Automake history" chapter hasn't been updated since the 1.9.6
release, so it has been becoming less faithful and useful since
then.
* doc/history.texi: New, manual on the history of the automake
package; extracted from ...
* doc/automake.texi: ... this file, with related adjustments.
* doc/Makefile.am (info_TEXINFOS): Add 'history.texi'.
(history_TEXINFOS): New, list included file 'fdl.texi'.
* Makefile.am (release-stats): Remove as obsolete.
* HACKING (Release Procedure): Don't advise anymore to run the
"release-stats" target and to update the manual with its output.
* NEWS: Update.
* .gitignore: Likewise.
-----------------------------------------------------------------------
Summary of changes:
.gitignore | 44 +-
HACKING | 3 -
Makefile.am | 31 --
NEWS | 3 +
doc/Makefile.am | 3 +-
doc/automake-history.texi | 1216 +++++++++++++++++++++++++++++++++++++++++++++
doc/automake.texi | 1166 +------------------------------------------
7 files changed, 1251 insertions(+), 1215 deletions(-)
create mode 100644 doc/automake-history.texi
diff --git a/.gitignore b/.gitignore
index c95a193..59e80ab 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,32 +12,32 @@ Makefile
/aclocal
/automake
/doc/amhello-*.tar.gz
-/doc/automake.info
-/doc/automake.info-[0-9]
+/doc/automake*.info
+/doc/automake*.info-[0-9]
/doc/automake*.1
/doc/aclocal*.1
/doc/stamp-vti
/doc/version.texi
-/doc/automake.ac
-/doc/automake.aux
-/doc/automake.cm
-/doc/automake.cp
-/doc/automake.cps
-/doc/automake.dvi
-/doc/automake.fn
-/doc/automake.fns
-/doc/automake.html
-/doc/automake.ky
-/doc/automake.log
-/doc/automake.op
-/doc/automake.pdf
-/doc/automake.pg
-/doc/automake.ps
-/doc/automake.toc
-/doc/automake.tp
-/doc/automake.tr
-/doc/automake.vr
-/doc/automake.vrs
+/doc/automake*.ac
+/doc/automake*.aux
+/doc/automake*.cm
+/doc/automake*.cp
+/doc/automake*.cps
+/doc/automake*.dvi
+/doc/automake*.fn
+/doc/automake*.fns
+/doc/automake*.html
+/doc/automake*.ky
+/doc/automake*.log
+/doc/automake*.op
+/doc/automake*.pdf
+/doc/automake*.pg
+/doc/automake*.ps
+/doc/automake*.toc
+/doc/automake*.tp
+/doc/automake*.tr
+/doc/automake*.vr
+/doc/automake*.vrs
/doc/amhello/Makefile.in
/doc/amhello/aclocal.m4
/doc/amhello/config.h.in
diff --git a/HACKING b/HACKING
index 5420fbc..1c98795 100644
--- a/HACKING
+++ b/HACKING
@@ -200,9 +200,6 @@
* Run this:
./bootstrap && ./configure && make && make check && make distcheck
-* Run `make release-stats' if release statistics in doc/automake.texi
- have not been updated yet.
-
* Run `make git-release'.
This will run "make dist" to create the tarballs, commit the last
changes to NEWS, configure.ac and m4/amversion.m4, tag the repository,
diff --git a/Makefile.am b/Makefile.am
index a493e3f..83071f1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -369,34 +369,3 @@ fetch:
echo "See Fetchdir/update.patch for a log of the changes."; \
exit $$stat
.PHONY: fetch
-
-## Generate release statistics, for the table in automake.texi.
-## This has to be run in an up to date build tree, but there must
-## be no temp files nor unused other files lying around!
-release-stats: ps
- $(AM_V_GEN): && \
- am=`wc -l < automake` && \
- acl=`wc -l < aclocal` && \
- pmfiles="lib/Automake/*.pm" && \
- if test . != '$(srcdir)'; then pmfiles="$$pmfiles
$(srcdir)/lib/Automake/*.pm"; \
- else :; fi && \
- pm=`cat $$pmfiles | wc -l` && \
- dot_am_files=`ls -1 $(srcdir)/lib/am/*.am | grep -v Makefile.am` && \
- amf=`echo "$$dot_am_files" | wc -l` && \
- aml=`cat $$dot_am_files | wc -l` && \
- m4f=`ls -1 $(srcdir)/m4/*.m4 | wc -l` && \
- m4l=`cat $(srcdir)/m4/*.m4 | wc -l` && \
- doc_text=`$(am__cd) doc && LC_ALL=C pstops 0 automake.ps unused.ps
2>&1` && \
- echo "$$doc_text" && \
- rm -f doc/unused.ps && \
- doc=`echo "$$doc_text" | sed -n 's/.*Wrote \([1-9][0-9]*\)
pages.*/\1/p'` && \
- tests="tests/*.test"; \
- if test . != '$(srcdir)'; then tests="$$tests $(srcdir)/tests/*.test"; \
- else :; fi && \
- t=`ls -1 $$tests | wc -l` && \
- tgen=`grep 'GENERATED AUTOMATICALLY' $$tests | wc -l` && \
- today=`date +%Y-%m-%d` && \
- echo "add this to the table in doc/automake.texi after verification:"
&& \
- printf '@item %s @tab %-6s @tab %4d @tab %4d @tab %4d @tab %4d %-4s
@tab %4d %-4s @tab %3d @tab %d %-4s\n' \
- $$today $(VERSION) $$am $$acl $$pm $$aml
"($$amf)" $$m4l "($$m4f)" $$doc $$t "($$tgen)"
-.PHONY: release-stats
diff --git a/NEWS b/NEWS
index 63796cc..54d9ca5 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,9 @@ New in 1.11a:
- The deprecated options `--output-dir', `--Werror' and `--Wno-error'
have been removed.
+ - The chapter on the history of Automake has been moved out of the
+ reference manual, into a new dedicated Texinfo file.
+
* New targets:
- New `cscope' target to build a cscope database for the source tree.
diff --git a/doc/Makefile.am b/doc/Makefile.am
index a2dde22..07c2867 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -18,8 +18,9 @@
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
-info_TEXINFOS = automake.texi
+info_TEXINFOS = automake.texi automake-history.texi
automake_TEXINFOS = fdl.texi
+history_TEXINFOS = fdl.texi
dist_man1_MANS = \
$(srcdir)/aclocal.1 \
diff --git a/doc/automake-history.texi b/doc/automake-history.texi
new file mode 100644
index 0000000..d26ba0e
--- /dev/null
+++ b/doc/automake-history.texi
@@ -0,0 +1,1216 @@
+\input texinfo @c -*-texinfo-*-
address@hidden %**start of header
address@hidden automake-history.info
address@hidden automake-history
address@hidden on
address@hidden %**end of header
+
address@hidden
+
+This manual describes (part of) the history of GNU Automake, a program
+that creates GNU standards-compliant Makefiles from template files.
+
+Copyright @copyright{} 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
+2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Free Software
+Foundation, Inc.
+
address@hidden
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License,
+Version 1.3 or any later version published by the Free Software
+Foundation; with no Invariant Sections, with no Front-Cover texts,
+and with no Back-Cover Texts. A copy of the license is included in the
+section entitled ``GNU Free Documentation License.''
+
address@hidden quotation
address@hidden copying
+
address@hidden
address@hidden Brief History of Automake
address@hidden David MacKenzie
address@hidden Tom Tromey
address@hidden Alexandre Duret-Lutz
address@hidden
address@hidden 0pt plus 1filll
address@hidden
address@hidden titlepage
+
address@hidden
+
address@hidden
address@hidden Top
address@hidden node-name, next, previous, up
address@hidden Brief History of Automake
+
address@hidden
+
address@hidden
+* Timeline:: The Automake story.
+* Dependency Tracking Evolution:: Evolution of Automatic Dependency Tracking
+* Releases:: Release statistics
+* Copying This Manual:: How to make copies of this manual
+
address@hidden
+ --- The Detailed Node Listing ---
+
+Evolution of Automatic Dependency Tracking
+
+* First Take on Dependencies:: Precomputed dependency tracking
+* Dependencies As Side Effects:: Update at developer compile time
+* Dependencies for the User:: Update at user compile time
+* Techniques for Dependencies:: Alternative approaches
+
+Techniques for Computing Dependencies
+
+* Recommendations for Tool Writers::
+* Future Directions for Dependencies::
+
+Copying This Manual
+
+* GNU Free Documentation License:: License for copying this manual
+
address@hidden detailmenu
address@hidden menu
+
address@hidden ifnottex
+
address@hidden Timeline
address@hidden Timeline
+
address@hidden @asis
address@hidden 1994-09-19 First CVS commit.
+
+If we can trust the CVS repository, David address@hidden (djm) started
+working on Automake (or AutoMake, as it was spelt then) this Monday.
+
+The first version of the @command{automake} script looks as follows.
+
address@hidden
+#!/bin/sh
+
+status=0
+
+for makefile
+do
+ if test ! -f address@hidden@}.am; then
+ echo "automake: address@hidden@}.am: No such honkin' file"
+ status=1
+ continue
+ fi
+
+ exec 4> address@hidden@}.in
+
+done
address@hidden example
+
+From this you can already see that Automake will be about reading
address@hidden file and producing @file{*.in} files. You cannot see
+anything else, but if you also know that David is the one who created
+Autoconf two years before you can guess the rest.
+
+Several commits follow, and by the end of the day Automake is
+reported to work for GNU fileutils and GNU m4.
+
+The modus operandi is the one that is still used today: variable
+assignments in @file{Makefile.am} files trigger injections of
+precanned @file{Makefile} fragments into the generated
address@hidden The use of @file{Makefile} fragments was inspired
+by the 4.4BSD @command{make} and include files, however Automake aims
+to be portable and to conform to the GNU standards for @file{Makefile}
+variables and targets.
+
+At this point, the most recent release of Autoconf is version 1.11,
+and David is preparing to release Autoconf 2.0 in late October. As a
+matter of fact, he will barely touch Automake after September.
+
address@hidden 1994-11-05 David MacKenzie's last commit.
+
+At this point Automake is a 200 line portable shell script, plus 332
+lines of @file{Makefile} fragments. In the @file{README}, David
+states his ambivalence between ``portable shell'' and ``more
+appropriate language'':
+
address@hidden
+I wrote it keeping in mind the possibility of it becoming an Autoconf
+macro, so it would run at configure-time. That would slow
+configuration down a bit, but allow users to modify the Makefile.am
+without needing to fetch the AutoMake package. And, the Makefile.in
+files wouldn't need to be distributed. But all of AutoMake would. So
+I might reimplement AutoMake in Perl, m4, or some other more
+appropriate language.
address@hidden quotation
+
+Automake is described as ``an experimental Makefile generator''.
+There is no documentation. Adventurous users are referred to the
+examples and patches needed to use Automake with GNU m4 1.3, fileutils
+3.9, time 1.6, and development versions of find and indent.
+
+These examples seem to have been lost. However at the time of writing
+(10 years later in September, 2004) the FSF still distributes a
+package that uses this version of Automake: check out GNU termutils
+2.0.
+
address@hidden 1995-11-12 Tom Tromey's first commit.
+
+After one year of inactivity, Tom Tromey takes over the package.
+Tom was working on GNU cpio back then, and doing this just for fun,
+having trouble finding a project to contribute to. So while hacking
+he wanted to bring the @file{Makefile.in} up to GNU standards. This
+was hard, and one day he saw Automake on @url{ftp://alpha.gnu.org/},
+grabbed it and tried it out.
+
+Tom didn't talk to djm about it until later, just to make sure he
+didn't mind if he made a release. He did a bunch of early releases to
+the Gnits folks.
+
+Gnits was (and still is) totally informal, just a few GNU friends who
+Fran@,cois Pinard knew, who were all interested in making a common
+infrastructure for GNU projects, and shared a similar outlook on how
+to do it. So they were able to make some progress. It came along
+with Autoconf and extensions thereof, and then Automake from David and
+Tom (who were both gnitsians). One of their ideas was to write a
+document paralleling the GNU standards, that was more strict in some
+ways and more detailed. They never finished the GNITS standards, but
+the ideas mostly made their way into Automake.
+
address@hidden 1995-11-23 Automake 0.20
+
+Besides introducing automatic dependency tracking (@pxref{Dependency
+Tracking Evolution}), this version also supplies a 9-page manual.
+
+At this time @command{aclocal} and @code{AM_INIT_AUTOMAKE} did not
+exist, so many things had to be done by hand. For instance, here is
+what a configure.in (this is the former name of the
address@hidden we use today) must contain in order to use
+Automake 0.20:
+
address@hidden
+PACKAGE=cpio
+VERSION=2.3.911
+AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE")
+AC_DEFINE_UNQUOTED(VERSION, "$VERSION")
+AC_SUBST(PACKAGE)
+AC_SUBST(VERSION)
+AC_ARG_PROGRAM
+AC_PROG_INSTALL
address@hidden example
+
+(Today all of the above is achieved by @code{AC_INIT} and
address@hidden)
+
+Here is how programs are specified in @file{Makefile.am}:
+
address@hidden
+PROGRAMS = hello
+hello_SOURCES = hello.c
address@hidden example
+
+This looks pretty much like what we do today, except the
address@hidden variable has no directory prefix specifying where
address@hidden should be installed: all programs are installed in
address@hidden(bindir)}. @code{LIBPROGRAMS} can be used to specify programs
+that must be built but not installed (it is called
address@hidden nowadays).
+
+Programs can be built conditionally using @code{AC_SUBST}itutions:
+
address@hidden
+PROGRAMS = @@progs@@
+AM_PROGRAMS = foo bar baz
address@hidden example
+
+(@code{AM_PROGRAMS} has since then been renamed to
address@hidden)
+
+Similarly scripts, static libraries, and data can be built and installed
+using the @code{LIBRARIES}, @code{SCRIPTS}, and @code{DATA} variables.
+However @code{LIBRARIES} were treated a bit specially in that Automake
+did automatically supply the @file{lib} and @file{.a} prefixes.
+Therefore to build @file{libcpio.a}, one had to write
+
address@hidden
+LIBRARIES = cpio
+cpio_SOURCES = ...
address@hidden example
+
+Extra files to distribute must be listed in @code{DIST_OTHER} (the
+ancestor of @code{EXTRA_DIST}). Also extra directories that are to be
+distributed should appear in @code{DIST_SUBDIRS}, but the manual
+describes this as a temporary ugly hack (today extra directories should
+also be listed in @code{EXTRA_DIST}, and @code{DIST_SUBDIRS} is used
+for another purpose, @pxref{Conditional Subdirectories, , Conditional
+Subdirectories, automake, GNU Automake}).
+
address@hidden 1995-11-26 Automake 0.21
+
+In less time than it takes to cook a frozen pizza, Tom rewrites
+Automake using Perl. At this time Perl 5 is only one year old, and
+Perl 4.036 is in use at many sites. Supporting several Perl versions
+has been a source of problems through the whole history of Automake.
+
+If you never used Perl 4, imagine Perl 5 without objects, without
address@hidden variables (only dynamically scoped @samp{local} variables),
+without function prototypes, with function calls that needs to be
+prefixed with @samp{&}, etc. Traces of this old style can still be
+found in today's @command{automake}.
+
address@hidden 1995-11-28 Automake 0.22
address@hidden 1995-11-29 Automake 0.23
+
+Bug fixes.
+
address@hidden 1995-12-08 Automake 0.24
address@hidden 1995-12-10 Automake 0.25
+
+Releases are raining. 0.24 introduces the uniform naming scheme we
+use today, i.e., @code{bin_PROGRAMS} instead of @code{PROGRAMS},
address@hidden instead of @code{LIBLIBRARIES}, etc. (However
address@hidden does not exist yet, @code{AM_PROGRAMS} is still
+in use; and @code{TEXINFOS} and @code{MANS} still have no directory
+prefixes.) Adding support for prefixes like that was one of the major
+ideas in @command{automake}; it has lasted pretty well.
+
+AutoMake is renamed to Automake (Tom seems to recall it was Fran@,cois
+Pinard's doing).
+
+0.25 fixes a Perl 4 portability bug.
+
address@hidden 1995-12-18 Jim Meyering starts using Automake in GNU Textutils.
address@hidden 1995-12-31 Fran@,cois Pinard starts using Automake in GNU tar.
+
address@hidden 1996-01-03 Automake 0.26
address@hidden 1996-01-03 Automake 0.27
+
+Of the many changes and suggestions sent by Fran@,cois Pinard and
+included in 0.26, perhaps the most important is the advice that to
+ease customization a user rule or variable definition should always
+override an Automake rule or definition.
+
+Gordon Matzigkeit and Jim Meyering are two other early contributors
+that have been sending fixes.
+
+0.27 fixes yet another Perl 4 portability bug.
+
address@hidden 1996-01-13 Automake 0.28
+
+Automake starts scanning @file{configure.in} for @code{LIBOBJS}
+support. This is an important step because until this version
+Automake only knew about the @file{Makefile.am}s it processed.
address@hidden was Autoconf's world and the link between Autoconf
+and Automake had to be done by the @file{Makefile.am} author. For
+instance, if @file{config.h} was generated by @file{configure}, it was the
+package maintainer's responsibility to define the @code{CONFIG_HEADER}
+variable in each @file{Makefile.am}.
+
+Succeeding releases will rely more and more on scanning
address@hidden to better automate the Autoconf integration.
+
+0.28 also introduces the @code{AUTOMAKE_OPTIONS} variable and the
address@hidden and @option{--gnits} options, the latter being stricter.
+
address@hidden 1996-02-07 Automake 0.29
+
+Thanks to @file{configure.in} scanning, @code{CONFIG_HEADER} is gone,
+and rebuild rules for @file{configure}-generated file are
+automatically output.
+
address@hidden and @code{MANS} converted to the uniform naming
+scheme.
+
address@hidden 1996-02-24 Automake 0.30
+
+The test suite is born. It contains 9 tests. From now on test cases
+will be added pretty regularly (@pxref{Releases}), and this proved to
+be really helpful later on.
+
address@hidden finally replaces @code{AM_PROGRAMS}.
+
+All the third-party Autoconf macros, written mostly by Fran@,cois
+Pinard (and later Jim Meyering), are distributed in Automake's
+hand-written @file{aclocal.m4} file. Package maintainers are expected
+to extract the necessary macros from this file. (In previous versions
+you had to copy and paste them from the manual...)
+
address@hidden 1996-03-11 Automake 0.31
+
+The test suite in 0.30 was run via a long @code{check-local} rule. Upon
+Ulrich Drepper's suggestion, 0.31 makes it an Automake rule output
+whenever the @code{TESTS} variable is defined.
+
address@hidden is renamed to @code{EXTRA_DIST}, and the @code{check_}
+prefix is introduced. The syntax is now the same as today.
+
address@hidden 1996-03-15 Gordon Matzigkeit starts writing libtool.
+
address@hidden 1996-04-27 Automake 0.32
+
address@hidden targets are introduced; an idea from Dieter Baron.
+
address@hidden files, which were output in the build directory are
+now built in the source directory, because they are distributed. It
+seems these files like to move back and forth as that will happen
+again in future versions.
+
address@hidden 1996-05-18 Automake 0.33
+
+Gord Matzigkeit's main two contributions:
+
address@hidden
address@hidden very preliminary libtool support
address@hidden the distcheck rule
address@hidden itemize
+
+Although they were very basic at this point, these are probably
+among the top features for Automake today.
+
+Jim Meyering also provides the infamous @code{jm_MAINTAINER_MODE}, since
+then renamed to @code{AM_MAINTAINER_MODE} and abandoned by its author
+(@pxref{maintainer-mode, , maintainer-mode, automake, GNU Automake}).
+
address@hidden 1996-05-28 Automake 1.0
+
+After only six months of heavy development, the @command{automake} script is
+3134 lines long, plus 973 lines of @file{Makefile} fragments. The
+package has 30 pages of documentation, and 38 test cases.
address@hidden contains 4 macros.
+
+From now on and until version 1.4, new releases will occur at a rate
+of about one a year. 1.1 did not exist, actually 1.1b to 1.1p have
+been the name of beta releases for 1.2. This is the first time
+Automake uses suffix letters to designate beta releases, a habit that
+lasts.
+
address@hidden 1996-10-10 Kevin Dalley packages Automake 1.0 for Debian
GNU/Linux.
+
address@hidden 1996-11-26 David address@hidden releases Autoconf 2.12.
+
+Between June and October, the Autoconf development is almost stalled.
+Roland McGrath has been working at the beginning of the year. David
+comes back in November to release 2.12, but he won't touch Autoconf
+anymore after this year, and Autoconf then really stagnates. The
+desolate Autoconf @file{ChangeLog} for 1997 lists only 7 commits.
+
address@hidden 1997-02-28 @email{automake@@gnu.ai.mit.edu} list alive
+
+The mailing list is announced as follows:
address@hidden
+I've created the "automake" mailing list. It is
+"automake@@gnu.ai.mit.edu". Administrivia, as always, to
+automake-request@@gnu.ai.mit.edu.
+
+The charter of this list is discussion of automake, autoconf, and
+other configuration/portability tools (e.g., libtool). It is expected
+that discussion will range from pleas for help all the way up to
+patches.
+
+This list is archived on the FSF machines. Offhand I don't know if
+you can get the archive without an account there.
+
+This list is open to anybody who wants to join. Tell all your
+friends!
+-- Tom Tromey
address@hidden smallexample
+
+Before that people were discussing Automake privately, on the Gnits
+mailing list (which is not public either), and less frequently on
address@hidden
+
address@hidden is now @code{gnu.org}, in case you never
+noticed. The archives of the early years of the
address@hidden@@gnu.org} list have been lost, so today it is almost
+impossible to find traces of discussions that occurred before 1999.
+This has been annoying more than once, as such discussions can be
+useful to understand the rationale behind a piece of uncommented code
+that was introduced back then.
+
address@hidden 1997-06-22 Automake 1.2
+
+Automake developments continues, and more and more new Autoconf macros
+are required. Distributing them in @file{aclocal.m4} and requiring
+people to browse this file to extract the relevant macros becomes
+uncomfortable. Ideally, some of them should be contributed to
+Autoconf so that they can be used directly, however Autoconf is
+currently inactive. Automake 1.2 consequently introduces
address@hidden (@command{aclocal} was actually started on
+1996-07-28), a tool that automatically constructs an @file{aclocal.m4}
+file from a repository of third-party macros. Because Autoconf has
+stalled, Automake also becomes a kind of repository for such
+third-party macros, even macros completely unrelated to Automake (for
+instance macros that fix broken Autoconf macros).
+
+The 1.2 release contains 20 macros, including the
address@hidden macro that simplifies the creation of
address@hidden
+
+Libtool is fully supported using @code{*_LTLIBRARIES}.
+
+The missing script is introduced by Fran@,cois Pinard; it is meant
+to be a better solution than @code{AM_MAINTAINER_MODE}
+(@pxref{maintainer-mode, , maintainer-mode, automake, GNU Automake}).
+
+Conditionals support was implemented by Ian Lance Taylor. At the
+time, Tom and Ian were working on an internal project at Cygnus. They
+were using ILU, which is pretty similar to address@hidden They wanted to
+integrate ILU into their build, which was all @file{configure}-based,
+and Ian thought that adding conditionals to @command{automake} was
+simpler than doing all the work in @file{configure} (which was the
+standard at the time). So this was actually funded by Cygnus.
+
+This very useful but tricky feature will take a lot of time to
+stabilize. (At the time this text is written, there are still
+primaries that have not been updated to support conditional
+definitions in Automake 1.9.)
+
+The @command{automake} script has almost doubled: 6089 lines of Perl,
+plus 1294 lines of @file{Makefile} fragments.
+
address@hidden 1997-07-08 Gordon Matzigkeit releases Libtool 1.0.
+
address@hidden 1998-04-05 Automake 1.3
+
+This is a small advance compared to 1.2.
+It adds support for assembly, and preliminary support for Java.
+
+Perl 5.004_04 is out, but fixes to support Perl 4 are still
+regularly submitted whenever Automake breaks it.
+
address@hidden 1998-09-06 @code{sourceware.cygnus.com} is on-line.
+
+Sourceware was setup by Jason Molenda to host open source projects.
+
address@hidden 1998-09-19 Automake CVS repository moved to
@code{sourceware.cygnus.com}
address@hidden 1998-10-26 @code{sourceware.cygnus.com} announces it hosts
Automake:
+Automake is now hosted on @code{sourceware.cygnus.com}. It has a
+publicly accessible CVS repository. This CVS repository is a copy of
+the one Tom was using on his machine, which in turn is based on
+a copy of the CVS repository of David MacKenzie. This is why we still
+have to full source history. (Automake was on Sourceware until 2007-10-29,
+when it moved to a git repository on @code{savannah.gnu.org},
+but the Sourceware host had been renamed to @code{sources.redhat.com}.)
+
+The oldest file in the administrative directory of the CVS repository
+that was created on Sourceware is dated 1998-09-19, while the
+announcement that @command{automake} and @command{autoconf} had joined
address@hidden was made on 1998-10-26. They were among the
+first projects to be hosted there.
+
+The heedful reader will have noticed Automake was exactly 4 years old
+on 1998-09-19.
+
address@hidden 1999-01-05 Ben Elliston releases Autoconf 2.13.
+
address@hidden 1999-01-14 Automake 1.4
+
+This release adds support for Fortran 77 and for the @code{include}
+statement. Also, @samp{+=} assignments are introduced, but it is
+still quite easy to fool Automake when mixing this with conditionals.
+
+These two releases, Automake 1.4 and Autoconf 2.13 make a duo that
+will be used together for years.
+
address@hidden is 7228 lines, plus 1591 lines of Makefile
+fragment, 20 macros (some 1.3 macros were finally contributed back to
+Autoconf), 197 test cases, and 51 pages of documentation.
+
address@hidden 1999-03-27 The @code{user-dep-branch} is created on the CVS
repository.
+
+This implements a new dependency tracking schemed that should be
+able to handle automatic dependency tracking using any compiler (not
+just gcc) and any make (not just GNU @command{make}). In addition,
+the new scheme should be more reliable than the old one, as
+dependencies are generated on the end user's machine. Alexandre Oliva
+creates depcomp for this purpose.
+
address@hidden Tracking Evolution}, for more details about the
+evolution of automatic dependency tracking in Automake.
+
address@hidden 1999-11-21 The @code{user-dep-branch} is merged into the main
trunk.
+
+This was a huge problem since we also had patches going in on the
+trunk. The merge took a long time and was very painful.
+
address@hidden 2000-05-10
+
+Since September 1999 and until 2003, Akim Demaille will be zealously
+revamping Autoconf.
+
address@hidden
+I think the next release should be called "3.0"address@hidden
+Let's face it: you've basically rewritten address@hidden
+Every weekend there are 30 new address@hidden
+I don't see how we could call this "2.15" with a straight address@hidden
+-- Tom Tromey on @email{autoconf@@gnu.org}
address@hidden quotation
+
+Actually Akim works like a submarine: he will pile up patches while he
+works off-line during the weekend, and flush them in batch when he
+resurfaces on Monday.
+
address@hidden 2001-01-24
+
+On this Wednesday, Autoconf 2.49c, the last beta before Autoconf 2.50
+is out, and Akim has to find something to do during his week-end :)
+
address@hidden 2001-01-28
+
+Akim sends a batch of 14 patches to @email{automake@@gnu.org}.
+
address@hidden
+Aiieeee! I was dreading the day that the Demaillator turned his
+sights on address@hidden and now it has arrived! -- Tom Tromey
address@hidden quotation
+
+It's only the beginning: in two months he will send 192 patches. Then
+he would slow down so Tom can catch up and review all this. Initially
+Tom actually read all these patches, then he probably trustingly
+answered OK to most of them, and finally gave up and let Akim apply
+whatever he wanted. There was no way to keep up with that patch rate.
+
address@hidden
+Anyway the patch below won't apply since it predates Akim's
+sourcequake; I have yet to figure where the relevant passage has
+been moved :) -- Alexandre Duret-Lutz
address@hidden quotation
+
+All these patches were sent to and discussed on
address@hidden@@gnu.org}, so subscribed users were literally drowning in
+technical mails. Eventually, the @email{automake-patches@@gnu.org}
+mailing list was created in May.
+
+Year after year, Automake had drifted away from its initial design:
+construct @file{Makefile.in} by assembling various @file{Makefile}
+fragments. In 1.4, lots of @file{Makefile} rules are being emitted at
+various places in the @command{automake} script itself; this does not
+help ensuring a consistent treatment of these rules (for instance
+making sure that user-defined rules override Automake's own rules).
+One of Akim's goal was moving all these hard-coded rules to separate
address@hidden fragments, so the logic could be centralized in a
address@hidden fragment processor.
+
+Another significant contribution of Akim is the interface with the
+``trace'' feature of Autoconf. The way to scan @file{configure.in} at
+this time was to read the file and grep the various macro of interest
+to Automake. Doing so could break in many unexpected ways; @command{automake}
+could miss some definition (for instance @samp{AC_SUBST([$1], [$2])}
+where the arguments are known only when M4 is run), or conversely it
+could detect some macro that was not expanded (because it is called
+conditionally). In the CVS version of Autoconf, Akim had implemented
+the @option{--trace} option, which provides accurate information about
+where macros are actually called and with what arguments. Akim will
+equip Automake with a second @file{configure.in} scanner that uses
+this @option{--trace} interface. Since it was not sensible to drop the
+Autoconf 2.13 compatibility yet, this experimental scanner was only
+used when an environment variable was set, the traditional
+grep-scanner being still the default.
+
address@hidden 2001-04-25 Gary address@hidden releases Libtool 1.4
+
+It has been more than two years since Automake 1.4, CVS Automake has
+suffered lot's of heavy changes and still is not ready for release.
+Libtool 1.4 had to be distributed with a patch against Automake 1.4.
+
address@hidden 2001-05-08 Automake 1.4-p1
address@hidden 2001-05-24 Automake 1.4-p2
+
+Gary address@hidden, the principal Libtool maintainer, makes a ``patch
+release'' of Automake:
+
address@hidden
+The main purpose of this release is to have a stable automake
+which is compatible with the latest stable libtool.
address@hidden quotation
+
+The release also contains obvious fixes for bugs in Automake 1.4,
+some of which were reported almost monthly.
+
address@hidden 2001-05-21 Akim Demaille releases Autoconf 2.50
+
address@hidden 2001-06-07 Automake 1.4-p3
address@hidden 2001-06-10 Automake 1.4-p4
address@hidden 2001-07-15 Automake 1.4-p5
+
+Gary continues his patch-release series. These also add support for
+some new Autoconf 2.50 idioms. Essentially, Autoconf now advocates
address@hidden over @file{configure.in}, and it introduces a new
+syntax for @code{AC_OUTPUT}ing files.
+
address@hidden 2001-08-23 Automake 1.5
+
+A major and long-awaited release, that comes more than two years after
+1.4. It brings many changes, among which:
address@hidden
address@hidden The new dependency tracking scheme that uses @command{depcomp}.
+Aside from the improvement on the dependency tracking itself
+(@pxref{Dependency Tracking Evolution}), this also streamlines the use
+of @command{automake}-generated @file{Makefile.in}s as the @file{Makefile.in}s
+used during development are now the same as those used in
+distributions. Before that the @file{Makefile.in}s generated for
+maintainers required GNU @command{make} and GCC, they were different
+from the portable @file{Makefile} generated for distribution; this was
+causing some confusion.
+
address@hidden Support for per-target compilation flags.
+
address@hidden Support for reference to files in subdirectories in most
address@hidden variables.
+
address@hidden Introduction of the @code{dist_}, @code{nodist_}, and
@code{nobase_}
+prefixes.
address@hidden Perl 4 support is finally dropped.
address@hidden itemize
+
+1.5 did break several packages that worked with 1.4. Enough so that
+Linux distributions could not easily install the new Automake version
+without breaking many of the packages for which they had to run
address@hidden
+
+Some of these breakages were effectively bugs that would eventually be
+fixed in the next release. However, a lot of damage was caused by
+some changes made deliberately to render Automake stricter on some
+setup we did consider bogus. For instance, @samp{make distcheck} was
+improved to check that @samp{make uninstall} did remove all the files
address@hidden install} installed, that @samp{make distclean} did not omit
+some file, and that a VPATH build would work even if the source
+directory was read-only. Similarly, Automake now rejects multiple
+definitions of the same variable (because that would mix very badly
+with conditionals), and @samp{+=} assignments with no previous
+definition. Because these changes all occurred suddenly after 1.4 had
+been established for more than two years, it hurt users.
+
+To make matter worse, meanwhile Autoconf (now at version 2.52) was
+facing similar troubles, for similar reasons.
+
address@hidden 2002-03-05 Automake 1.6
+
+This release introduced versioned installation (@pxref{API Versioning, ,
+API Versioning, automake, GNU Automake}). This was mainly pushed by
+Havoc Pennington, taking the GNOME source tree as motive: due to
+incompatibilities between the autotools it's impossible for the GNOME
+packages to switch to Autoconf 2.53 and Automake 1.5 all at once, so
+they are currently stuck with Autoconf 2.13 and Automake 1.4.
+
+The idea was to call this version @file{automake-1.6}, call all its
+bug-fix versions identically, and switch to @file{automake-1.7} for
+the next release that adds new features or changes some rules. This
+scheme implies maintaining a bug-fix branch in addition to the
+development trunk, which means more work from the maintainer, but
+providing regular bug-fix releases proved to be really worthwhile.
+
+Like 1.5, 1.6 also introduced a bunch of incompatibilities, intentional or
+not. Perhaps the more annoying was the dependence on the newly
+released Autoconf 2.53. Autoconf seemed to have stabilized enough
+since its explosive 2.50 release and included changes required to fix
+some bugs in Automake. In order to upgrade to Automake 1.6, people
+now had to upgrade Autoconf too; for some packages it was no picnic.
+
+While versioned installation helped people to upgrade, it also
+unfortunately allowed people not to upgrade. At the time of writing,
+some Linux distributions are shipping packages for Automake 1.4, 1.5,
+1.6, 1.7, 1.8, and 1.9. Most of these still install 1.4 by default.
+Some distribution also call 1.4 the ``stable'' version, and present
+``1.9'' as the development version; this does not really makes sense
+since 1.9 is way more solid than 1.4. All this does not help the
+newcomer.
+
address@hidden 2002-04-11 Automake 1.6.1
+
+1.6, and the upcoming 1.4-p6 release were the last release by Tom.
+This one and those following will be handled by Alexandre
+Duret-Lutz. Tom is still around, and will be there until about 1.7,
+but his interest into Automake is drifting away towards projects like
address@hidden
+
+Alexandre has been using Automake since 2000, and started to
+contribute mostly on Akim's incitement (Akim and Alexandre have been
+working in the same room from 1999 to 2002). In 2001 and 2002 he had
+a lot of free time to enjoy hacking Automake.
+
address@hidden 2002-06-14 Automake 1.6.2
+
address@hidden 2002-07-28 Automake 1.6.3
address@hidden 2002-07-28 Automake 1.4-p6
+
+Two releases on the same day. 1.6.3 is a bug-fix release.
+
+Tom Tromey backported the versioned installation mechanism on the 1.4
+branch, so that Automake 1.6.x and Automake 1.4-p6 could be installed
+side by side. Another request from the GNOME folks.
+
address@hidden 2002-09-25 Automake 1.7
+
+This release switches to the new @file{configure.ac} scanner Akim
+was experimenting in 1.5.
+
address@hidden 2002-10-16 Automake 1.7.1
address@hidden 2002-12-06 Automake 1.7.2
address@hidden 2003-02-20 Automake 1.7.3
address@hidden 2003-04-23 Automake 1.7.4
address@hidden 2003-05-18 Automake 1.7.5
address@hidden 2003-07-10 Automake 1.7.6
address@hidden 2003-09-07 Automake 1.7.7
address@hidden 2003-10-07 Automake 1.7.8
+
+Many bug-fix releases. 1.7 lasted because the development version
+(upcoming 1.8) was suffering some major internal revamping.
+
address@hidden 2003-10-26 Automake on screen
+
+Episode 49, `Repercussions', in the third season of the `Alias' TV
+show is first aired.
+
+Marshall, one of the characters, is working on a computer virus that he
+has to modify before it gets into the wrong hands or something like
+that. The screenshots you see do not show any program code, they show
+a @file{Makefile.in} generated by automake...
+
address@hidden 2003-11-09 Automake 1.7.9
+
address@hidden 2003-12-10 Automake 1.8
+
+The most striking update is probably that of @command{aclocal}.
+
address@hidden now uses @code{m4_include} in the produced
address@hidden when the included macros are already distributed
+with the package (an idiom used in many packages), which reduces code
+duplication. Many people liked that, but in fact this change was
+really introduced to fix a bug in rebuild rules: @file{Makefile.in}
+must be rebuilt whenever a dependency of @file{configure} changes, but
+all the @file{m4} files included in @file{aclocal.m4} where unknown
+from @command{automake}. Now @command{automake} can just trace the
address@hidden to discover the dependencies.
+
address@hidden also starts using the @option{--trace} Autoconf option
+in order to discover used macros more accurately. This will turn out
+to be very tricky (later releases will improve this) as people had
+devised many ways to cope with the limitation of previous
address@hidden versions, notably using handwritten
address@hidden: @command{aclocal} must make sure not to redefine a
+rule that is already included by such statement.
+
+Automake also has seen its guts rewritten. Although this rewriting
+took a lot of efforts, it is only apparent to the users in that some
+constructions previously disallowed by the implementation now work
+nicely. Conditionals, Locations, Variable and Rule definitions,
+Options: these items on which Automake works have been rewritten as
+separate Perl modules, and documented.
+
address@hidden 2004-01-11 Automake 1.8.1
address@hidden 2004-01-12 Automake 1.8.2
address@hidden 2004-03-07 Automake 1.8.3
address@hidden 2004-04-25 Automake 1.8.4
address@hidden 2004-05-16 Automake 1.8.5
+
address@hidden 2004-07-28 Automake 1.9
+
+This release tries to simplify the compilation rules it outputs to
+reduce the size of the Makefile. The complaint initially come from
+the libgcj developers. Their @file{Makefile.in} generated with
+Automake 1.4 and custom build rules (1.4 did not support compiled
+Java) is address@hidden The one generated by 1.8 was over address@hidden 1.9
gets it
+down to address@hidden
+
+Aside from this it contains mainly minor changes and bug-fixes.
+
address@hidden 2004-08-11 Automake 1.9.1
address@hidden 2004-09-19 Automake 1.9.2
+
+Automake has ten years. This chapter of the manual was initially
+written for this occasion.
+
address@hidden 2007-10-29 Automake repository moves to @code{savannah.gnu.org}
+and uses git as primary repository.
+
address@hidden table
+
address@hidden Dependency Tracking Evolution
address@hidden Evolution of Automatic Dependency Tracking
+
+Over the years Automake has deployed three different dependency
+tracking methods. Each method, including the current one, has had
+flaws of various sorts. Here we lay out the different dependency
+tracking methods, their flaws, and their fixes. We conclude with
+recommendations for tool writers, and by indicating future directions
+for dependency tracking work in Automake.
+
address@hidden
+* First Take on Dependencies:: Precomputed dependency tracking
+* Dependencies As Side Effects:: Update at developer compile time
+* Dependencies for the User:: Update at user compile time
+* Techniques for Dependencies:: Alternative approaches
address@hidden menu
+
address@hidden First Take on Dependencies
address@hidden First Take on Dependency Tracking
address@hidden Description
+
+Our first attempt at automatic dependency tracking was based on the
+method recommended by GNU @command{make}. (@pxref{Automatic
+Prerequisites, , Generating Prerequisites Automatically, make, The GNU
+make Manual})
+
+This version worked by precomputing dependencies ahead of time. For
+each source file, it had a special @file{.P} file that held the
+dependencies. There was a rule to generate a @file{.P} file by
+invoking the compiler appropriately. All such @file{.P} files were
+included by the @file{Makefile}, thus implicitly becoming dependencies
+of @file{Makefile}.
+
address@hidden Bugs
+
+This approach had several critical bugs.
+
address@hidden
address@hidden
+The code to generate the @file{.P} file relied on @command{gcc}.
+(A limitation, not technically a bug.)
address@hidden
+The dependency tracking mechanism itself relied on GNU @command{make}.
+(A limitation, not technically a bug.)
address@hidden
+Because each @file{.P} file was a dependency of @file{Makefile}, this
+meant that dependency tracking was done eagerly by @command{make}.
+For instance, @samp{make clean} would cause all the dependency files
+to be updated, and then immediately removed. This eagerness also
+caused problems with some configurations; if a certain source file
+could not be compiled on a given architecture for some reason,
+dependency tracking would fail, aborting the entire build.
address@hidden
+As dependency tracking was done as a pre-pass, compile times were
+doubled--the compiler had to be run twice per source file.
address@hidden
address@hidden dist} re-ran @command{automake} to generate a
address@hidden that did not have automatic dependency tracking (and
+that was thus portable to any version of @command{make}). In order to
+do this portably, Automake had to scan the dependency files and remove
+any reference that was to a source file not in the distribution.
+This process was error-prone. Also, if @samp{make dist} was run in an
+environment where some object file had a dependency on a source file
+that was only conditionally created, Automake would generate a
address@hidden that referred to a file that might not appear in the
+end user's build. A special, hacky mechanism was required to work
+around this.
address@hidden itemize
+
address@hidden Historical Note
+
+The code generated by Automake is often inspired by the
address@hidden style of a particular author. In the case of the first
+implementation of dependency tracking, I believe the impetus and
+inspiration was Jim Meyering. (I could be mistaken. If you know
+otherwise feel free to correct me.)
+
address@hidden Dependencies As Side Effects
address@hidden Dependencies As Side Effects
address@hidden Description
+
+The next refinement of Automake's automatic dependency tracking scheme
+was to implement dependencies as side effects of the compilation.
+This was aimed at solving the most commonly reported problems with the
+first approach. In particular we were most concerned with eliminating
+the weird rebuilding effect associated with make clean.
+
+In this approach, the @file{.P} files were included using the
address@hidden command, which let us create these files lazily. This
+avoided the @samp{make clean} problem.
+
+We only computed dependencies when a file was actually compiled. This
+avoided the performance penalty associated with scanning each file
+twice. It also let us avoid the other problems associated with the
+first, eager, implementation. For instance, dependencies would never
+be generated for a source file that was not compilable on a given
+architecture (because it in fact would never be compiled).
+
address@hidden Bugs
+
address@hidden
address@hidden
+This approach also relied on the existence of @command{gcc} and GNU
address@hidden (A limitation, not technically a bug.)
address@hidden
+Dependency tracking was still done by the developer, so the problems
+from the first implementation relating to massaging of dependencies by
address@hidden dist} were still in effect.
address@hidden
+This implementation suffered from the ``deleted header file'' problem.
+Suppose a lazily-created @file{.P} file includes a dependency on a
+given header file, like this:
+
address@hidden
+maude.o: maude.c something.h
address@hidden example
+
+Now suppose that you remove @file{something.h} and update @file{maude.c}
+so that this include is no longer needed. If you run @command{make},
+you will get an error because there is no way to create
address@hidden
+
+We fixed this problem in a later release by further massaging the
+output of @command{gcc} to include a dummy dependency for each header
+file.
address@hidden itemize
+
address@hidden Dependencies for the User
address@hidden Dependencies for the User
address@hidden Description
+
+The bugs associated with @samp{make dist}, over time, became a real
+problem. Packages using Automake were being built on a large number
+of platforms, and were becoming increasingly complex. Broken
+dependencies were distributed in ``portable'' @file{Makefile.in}s,
+leading to user complaints. Also, the requirement for @command{gcc}
+and GNU @command{make} was a constant source of bug reports. The next
+implementation of dependency tracking aimed to remove these problems.
+
+We realized that the only truly reliable way to automatically track
+dependencies was to do it when the package itself was built. This
+meant discovering a method portable to any version of make and any
+compiler. Also, we wanted to preserve what we saw as the best point
+of the second implementation: dependency computation as a side effect
+of compilation.
+
+In the end we found that most modern make implementations support some
+form of include directive. Also, we wrote a wrapper script that let
+us abstract away differences between dependency tracking methods for
+compilers. For instance, some compilers cannot generate dependencies
+as a side effect of compilation. In this case we simply have the
+script run the compiler twice. Currently our wrapper script
+(@command{depcomp}) knows about twelve different compilers (including
+a "compiler" that simply invokes @command{makedepend} and then the
+real compiler, which is assumed to be a standard Unix-like C compiler
+with no way to do dependency tracking).
+
address@hidden Bugs
+
address@hidden
address@hidden
+Running a wrapper script for each compilation slows down the build.
address@hidden
+Many users don't really care about precise dependencies.
address@hidden
+This implementation, like every other automatic dependency tracking
+scheme in common use today (indeed, every one we've ever heard of),
+suffers from the ``duplicated new header'' bug.
+
+This bug occurs because dependency tracking tools, such as the
+compiler, only generate dependencies on the successful opening of a
+file, and not on every probe.
+
+Suppose for instance that the compiler searches three directories for
+a given header, and that the header is found in the third directory.
+If the programmer erroneously adds a header file with the same name to
+the first directory, then a clean rebuild from scratch could fail
+(suppose the new header file is buggy), whereas an incremental rebuild
+will succeed.
+
+What has happened here is that people have a misunderstanding of what
+a dependency is. Tool writers think a dependency encodes information
+about which files were read by the compiler. However, a dependency
+must actually encode information about what the compiler tried to do.
+
+This problem is not serious in practice. Programmers typically do not
+use the same name for a header file twice in a given project. (At
+least, not in C or C++. This problem may be more troublesome in
+Java.) This problem is easy to fix, by modifying dependency
+generators to record every probe, instead of every successful open.
+
address@hidden
+Since Automake generates dependencies as a side effect of compilation,
+there is a bootstrapping problem when header files are generated by
+running a program. The problem is that, the first time the build is
+done, there is no way by default to know that the headers are
+required, so make might try to run a compilation for which the headers
+have not yet been built.
+
+This was also a problem in the previous dependency tracking implementation.
+
+The current fix is to use @code{BUILT_SOURCES} to list built headers
+(@pxref{Sources, , Sources, automake, GNU Automake}). This causes them
+to be built before any other build rules are run. This is unsatisfactory
+as a general solution, however in practice it seems sufficient for most
+actual programs.
address@hidden itemize
+
+This code is used since Automake 1.5.
+
+In GCC 3.0, we managed to convince the maintainers to add special
+command-line options to help Automake more efficiently do its job. We
+hoped this would let us avoid the use of a wrapper script when
+Automake's automatic dependency tracking was used with @command{gcc}.
+
+Unfortunately, this code doesn't quite do what we want. In
+particular, it removes the dependency file if the compilation fails;
+we'd prefer that it instead only touch the file in any way if the
+compilation succeeds.
+
+Nevertheless, since Automake 1.7, when a recent @command{gcc} is
+detected at @command{configure} time, we inline the
+dependency-generation code and do not use the @command{depcomp}
+wrapper script. This makes compilations faster for those using this
+compiler (probably our primary user base). The counterpart is that
+because we have to encode two compilation rules in @file{Makefile}
+(with or without @command{depcomp}), the produced @file{Makefile}s are
+larger.
+
address@hidden Techniques for Dependencies
address@hidden Techniques for Computing Dependencies
+
+There are actually several ways for a build tool like Automake to
+cause tools to generate dependencies.
+
address@hidden @asis
address@hidden @command{makedepend}
+This was a commonly-used method in the past. The idea is to run a
+special program over the source and have it generate dependency
+information. Traditional implementations of @command{makedepend} are
+not completely precise; ordinarily they were conservative and
+discovered too many dependencies.
address@hidden The tool
+An obvious way to generate dependencies is to simply write the tool so
+that it can generate the information needed by the build tool. This is
+also the most portable method. Many compilers have an option to
+generate dependencies. Unfortunately, not all tools provide such an
+option.
address@hidden The file system
+It is possible to write a special file system that tracks opens,
+reads, writes, etc, and then feed this information back to the build
+tool. @command{clearmake} does this. This is a very powerful
+technique, as it doesn't require cooperation from the
+tool. Unfortunately it is also very difficult to implement and also
+not practical in the general case.
address@hidden @code{LD_PRELOAD}
+Rather than use the file system, one could write a special library to
+intercept @code{open} and other syscalls. This technique is also quite
+powerful, but unfortunately it is not portable enough for use in
address@hidden
address@hidden table
+
address@hidden
+* Recommendations for Tool Writers::
+* Future Directions for Dependencies::
address@hidden menu
+
address@hidden Recommendations for Tool Writers
address@hidden Recommendations for Tool Writers
+
+We think that every compilation tool ought to be able to generate
+dependencies as a side effect of compilation. Furthermore, at least
+while @command{make}-based tools are nearly universally in use (at
+least in the free software community), the tool itself should generate
+dummy dependencies for header files, to avoid the deleted header file
+bug. Finally, the tool should generate a dependency for each probe,
+instead of each successful file open, in order to avoid the duplicated
+new header bug.
+
address@hidden Future Directions for Dependencies
address@hidden Future Directions for Dependencies
+
+Currently, only languages and compilers understood by Automake can
+have dependency tracking enabled. We would like to see if it is
+practical (and worthwhile) to let this support be extended by the user
+to languages unknown to Automake.
+
address@hidden Releases
address@hidden Release Statistics
+
+The following table (inspired by @samp{perlhist(1)}) quantifies the
+evolution of Automake using these metrics:
+
address@hidden @asis
address@hidden Date, Rel
+The date and version of the release.
address@hidden am
+The number of lines of the @command{automake} script.
address@hidden acl
+The number of lines of the @command{aclocal} script.
address@hidden pm
+The number of lines of the @command{Perl} supporting modules.
address@hidden @file{*.am}
+The number of lines of the @file{Makefile} fragments. The number in
+parentheses is the number of files.
address@hidden m4
+The number of lines (and files) of Autoconf macros.
address@hidden doc
+The number of pages of the documentation (the Postscript version).
address@hidden t
+The number of test cases in the test suite. Of those, the number in
+parentheses is the number of generated test cases.
address@hidden table
+
address@hidden {8888-88-88} {8.8-p8} {8888} {8888} {8888} {8888 (88)} {8888
(88)} {888} {888 (88)}
address@hidden Date @tab Rel @tab am @tab acl @tab pm @tab @file{*.am}
@tab m4 @tab doc @tab t
address@hidden 1994-09-19 @tab CVS @tab 141 @tab @tab @tab 299
(24) @tab @tab @tab
address@hidden 1994-11-05 @tab CVS @tab 208 @tab @tab @tab 332
(28) @tab @tab @tab
address@hidden 1995-11-23 @tab 0.20 @tab 533 @tab @tab @tab 458
(35) @tab @tab 9 @tab
address@hidden 1995-11-26 @tab 0.21 @tab 613 @tab @tab @tab 480
(36) @tab @tab 11 @tab
address@hidden 1995-11-28 @tab 0.22 @tab 1116 @tab @tab @tab 539
(38) @tab @tab 12 @tab
address@hidden 1995-11-29 @tab 0.23 @tab 1240 @tab @tab @tab 541
(38) @tab @tab 12 @tab
address@hidden 1995-12-08 @tab 0.24 @tab 1462 @tab @tab @tab 504
(33) @tab @tab 14 @tab
address@hidden 1995-12-10 @tab 0.25 @tab 1513 @tab @tab @tab 511
(37) @tab @tab 15 @tab
address@hidden 1996-01-03 @tab 0.26 @tab 1706 @tab @tab @tab 438
(36) @tab @tab 16 @tab
address@hidden 1996-01-03 @tab 0.27 @tab 1706 @tab @tab @tab 438
(36) @tab @tab 16 @tab
address@hidden 1996-01-13 @tab 0.28 @tab 1964 @tab @tab @tab 934
(33) @tab @tab 16 @tab
address@hidden 1996-02-07 @tab 0.29 @tab 2299 @tab @tab @tab 936
(33) @tab @tab 17 @tab
address@hidden 1996-02-24 @tab 0.30 @tab 2544 @tab @tab @tab 919
(32) @tab 85 (1) @tab 20 @tab 9
address@hidden 1996-03-11 @tab 0.31 @tab 2877 @tab @tab @tab 919
(32) @tab 85 (1) @tab 29 @tab 17
address@hidden 1996-04-27 @tab 0.32 @tab 3058 @tab @tab @tab 921
(31) @tab 85 (1) @tab 30 @tab 26
address@hidden 1996-05-18 @tab 0.33 @tab 3110 @tab @tab @tab 926
(31) @tab 105 (1) @tab 30 @tab 35
address@hidden 1996-05-28 @tab 1.0 @tab 3134 @tab @tab @tab 973
(32) @tab 105 (1) @tab 30 @tab 38
address@hidden 1997-06-22 @tab 1.2 @tab 6089 @tab 385 @tab @tab 1294
(36) @tab 592 (20) @tab 37 @tab 126
address@hidden 1998-04-05 @tab 1.3 @tab 6415 @tab 422 @tab @tab 1470
(39) @tab 741 (23) @tab 39 @tab 156
address@hidden 1999-01-14 @tab 1.4 @tab 7240 @tab 426 @tab @tab 1591
(40) @tab 734 (20) @tab 51 @tab 197
address@hidden 2001-05-08 @tab 1.4-p1 @tab 7251 @tab 426 @tab @tab 1591
(40) @tab 734 (20) @tab 51 @tab 197
address@hidden 2001-05-24 @tab 1.4-p2 @tab 7268 @tab 439 @tab @tab 1591
(40) @tab 734 (20) @tab 49 @tab 197
address@hidden 2001-06-07 @tab 1.4-p3 @tab 7312 @tab 439 @tab @tab 1591
(40) @tab 734 (20) @tab 49 @tab 197
address@hidden 2001-06-10 @tab 1.4-p4 @tab 7321 @tab 439 @tab @tab 1591
(40) @tab 734 (20) @tab 49 @tab 198
address@hidden 2001-07-15 @tab 1.4-p5 @tab 7228 @tab 426 @tab @tab 1596
(40) @tab 734 (20) @tab 51 @tab 198
address@hidden 2001-08-23 @tab 1.5 @tab 8016 @tab 475 @tab 600 @tab 2654
(39) @tab 1166 (29) @tab 63 @tab 327
address@hidden 2002-03-05 @tab 1.6 @tab 8465 @tab 475 @tab 1136 @tab 2732
(39) @tab 1603 (27) @tab 66 @tab 365
address@hidden 2002-04-11 @tab 1.6.1 @tab 8544 @tab 475 @tab 1136 @tab 2741
(39) @tab 1603 (27) @tab 66 @tab 372
address@hidden 2002-06-14 @tab 1.6.2 @tab 8575 @tab 475 @tab 1136 @tab 2800
(39) @tab 1609 (27) @tab 67 @tab 386
address@hidden 2002-07-28 @tab 1.6.3 @tab 8600 @tab 475 @tab 1153 @tab 2809
(39) @tab 1609 (27) @tab 67 @tab 391
address@hidden 2002-07-28 @tab 1.4-p6 @tab 7332 @tab 455 @tab @tab 1596
(40) @tab 735 (20) @tab 49 @tab 197
address@hidden 2002-09-25 @tab 1.7 @tab 9189 @tab 471 @tab 1790 @tab 2965
(39) @tab 1606 (28) @tab 73 @tab 430
address@hidden 2002-10-16 @tab 1.7.1 @tab 9229 @tab 475 @tab 1790 @tab 2977
(39) @tab 1606 (28) @tab 73 @tab 437
address@hidden 2002-12-06 @tab 1.7.2 @tab 9334 @tab 475 @tab 1790 @tab 2988
(39) @tab 1606 (28) @tab 77 @tab 445
address@hidden 2003-02-20 @tab 1.7.3 @tab 9389 @tab 475 @tab 1790 @tab 3023
(39) @tab 1651 (29) @tab 84 @tab 448
address@hidden 2003-04-23 @tab 1.7.4 @tab 9429 @tab 475 @tab 1790 @tab 3031
(39) @tab 1644 (29) @tab 85 @tab 458
address@hidden 2003-05-18 @tab 1.7.5 @tab 9429 @tab 475 @tab 1790 @tab 3033
(39) @tab 1645 (29) @tab 85 @tab 459
address@hidden 2003-07-10 @tab 1.7.6 @tab 9442 @tab 475 @tab 1790 @tab 3033
(39) @tab 1660 (29) @tab 85 @tab 461
address@hidden 2003-09-07 @tab 1.7.7 @tab 9443 @tab 475 @tab 1790 @tab 3041
(39) @tab 1660 (29) @tab 90 @tab 467
address@hidden 2003-10-07 @tab 1.7.8 @tab 9444 @tab 475 @tab 1790 @tab 3041
(39) @tab 1660 (29) @tab 90 @tab 468
address@hidden 2003-11-09 @tab 1.7.9 @tab 9444 @tab 475 @tab 1790 @tab 3048
(39) @tab 1660 (29) @tab 90 @tab 468
address@hidden 2003-12-10 @tab 1.8 @tab 7171 @tab 585 @tab 7730 @tab 3236
(39) @tab 1666 (31) @tab 104 @tab 521
address@hidden 2004-01-11 @tab 1.8.1 @tab 7217 @tab 663 @tab 7726 @tab 3287
(39) @tab 1686 (31) @tab 104 @tab 525
address@hidden 2004-01-12 @tab 1.8.2 @tab 7217 @tab 663 @tab 7726 @tab 3288
(39) @tab 1686 (31) @tab 104 @tab 526
address@hidden 2004-03-07 @tab 1.8.3 @tab 7214 @tab 686 @tab 7735 @tab 3303
(39) @tab 1695 (31) @tab 111 @tab 530
address@hidden 2004-04-25 @tab 1.8.4 @tab 7214 @tab 686 @tab 7736 @tab 3310
(39) @tab 1701 (31) @tab 112 @tab 531
address@hidden 2004-05-16 @tab 1.8.5 @tab 7240 @tab 686 @tab 7736 @tab 3299
(39) @tab 1701 (31) @tab 112 @tab 533
address@hidden 2004-07-28 @tab 1.9 @tab 7508 @tab 715 @tab 7794 @tab 3352
(40) @tab 1812 (32) @tab 115 @tab 551
address@hidden 2004-08-11 @tab 1.9.1 @tab 7512 @tab 715 @tab 7794 @tab 3354
(40) @tab 1812 (32) @tab 115 @tab 552
address@hidden 2004-09-19 @tab 1.9.2 @tab 7512 @tab 715 @tab 7794 @tab 3354
(40) @tab 1812 (32) @tab 132 @tab 554
address@hidden 2004-11-01 @tab 1.9.3 @tab 7507 @tab 718 @tab 7804 @tab 3354
(40) @tab 1812 (32) @tab 134 @tab 556
address@hidden 2004-12-18 @tab 1.9.4 @tab 7508 @tab 718 @tab 7856 @tab 3361
(40) @tab 1811 (32) @tab 140 @tab 560
address@hidden 2005-02-13 @tab 1.9.5 @tab 7523 @tab 719 @tab 7859 @tab 3373
(40) @tab 1453 (32) @tab 142 @tab 562
address@hidden 2005-07-10 @tab 1.9.6 @tab 7539 @tab 699 @tab 7867 @tab 3400
(40) @tab 1453 (32) @tab 144 @tab 570
address@hidden 2006-10-15 @tab 1.10 @tab 7859 @tab 1072 @tab 8024 @tab 3512
(40) @tab 1496 (34) @tab 172 @tab 604
address@hidden 2008-01-19 @tab 1.10.1 @tab 7870 @tab 1089 @tab 8025 @tab 3520
(40) @tab 1499 (34) @tab 173 @tab 617
address@hidden 2008-11-23 @tab 1.10.2 @tab 7882 @tab 1089 @tab 8027 @tab 3540
(40) @tab 1509 (34) @tab 176 @tab 628
address@hidden 2009-05-17 @tab 1.11 @tab 8721 @tab 1092 @tab 8289 @tab 4164
(42) @tab 1714 (37) @tab 181 @tab 732 (20)
address@hidden multitable
+
+
address@hidden ==========================================================
Appendices
+
address@hidden
address@hidden Copying This Manual
address@hidden Copying This Manual
+
address@hidden
+* GNU Free Documentation License:: License for copying this manual
address@hidden menu
+
address@hidden GNU Free Documentation License
address@hidden GNU Free Documentation License
address@hidden fdl.texi
+
address@hidden
diff --git a/doc/automake.texi b/doc/automake.texi
index a0ac380..9c148f9 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -123,7 +123,6 @@ section entitled ``GNU Free Documentation License.''
* API Versioning:: About compatibility between Automake versions
* Upgrading:: Upgrading to a Newer Automake Version
* FAQ:: Frequently Asked Questions
-* History:: Notes about the history of Automake
* Copying This Manual:: How to make copies of this manual
* Indices:: Indices of variables, macros, and concepts
@@ -386,21 +385,6 @@ Frequently Asked Questions about Automake
* Debugging Make Rules:: Strategies when things don't work as expected
* Reporting Bugs:: Feedback on bugs and feature requests
-History of Automake
-
-* Timeline:: The Automake story.
-* Dependency Tracking Evolution:: Evolution of Automatic Dependency Tracking
-* Releases:: Statistics about Automake Releases
-
-Dependency Tracking in Automake
-
-* First Take on Dependencies:: Precomputed dependency tracking
-* Dependencies As Side Effects:: Update at developer compile time
-* Dependencies for the User:: Update at user compile time
-* Techniques for Dependencies:: Alternative approaches
-* Recommendations for Tool Writers:: What tool writers can do to help
-* Future Directions for Dependencies:: Languages Automake does not know
-
Copying This Manual
* GNU Free Documentation License:: License for copying this manual
@@ -1332,8 +1316,9 @@ must be passed to @command{configure} to activate them.
Do not reject slow dependency extractors.
@end table
address@hidden Tracking Evolution}, for some discussion about the
-different dependency tracking schemes used by Automake over the years.
address@hidden Tracking Evolution, , Dependency Tracking Evolution,
+automake-history, Brief History of Automake}, for some discussion about
+the different dependency tracking schemes used by Automake over the years.
@node Nested Packages
@subsection Nested Packages
@@ -6902,11 +6887,11 @@ your build.
@cindex @command{depcomp}
-Experience with earlier versions of Automake (@pxref{Dependency
-Tracking Evolution}) taught us that it is not reliable to generate
-dependencies only on the maintainer's system, as configurations vary
-too much. So instead Automake implements dependency tracking at build
-time.
+Experience with earlier versions of Automake (@pxref{Dependency Tracking
+Evolution, , Dependency Tracking Evolution, automake-history, Brief History
+of Automake}) taught us that it is not reliable to generate dependencies
+only on the maintainer's system, as configurations vary too much. So
+instead Automake implements dependency tracking at build time.
Automatic dependency tracking can be suppressed by putting
@option{no-dependencies} in the variable @code{AUTOMAKE_OPTIONS}, or
@@ -13041,1141 +13026,6 @@ Ideally, post a minimal @file{Makefile.am} and
@file{configure.ac} that
reproduces the problem you encounter. If you have encountered test
suite failures, please attach the @file{tests/test-suite.log} file.
-
address@hidden History
address@hidden History of Automake
-
-This chapter presents various aspects of the history of Automake. The
-exhausted reader can safely skip it; this will be more of interest to
-nostalgic people, or to those curious to learn about the evolution of
-Automake.
-
address@hidden
-* Timeline:: The Automake story.
-* Dependency Tracking Evolution:: Evolution of Automatic Dependency Tracking
-* Releases:: Statistics about Automake Releases
address@hidden menu
-
address@hidden Timeline
address@hidden Timeline
-
address@hidden @asis
address@hidden 1994-09-19 First CVS commit.
-
-If we can trust the CVS repository, David address@hidden (djm) started
-working on Automake (or AutoMake, as it was spelt then) this Monday.
-
-The first version of the @command{automake} script looks as follows.
-
address@hidden
-#!/bin/sh
-
-status=0
-
-for makefile
-do
- if test ! -f address@hidden@}.am; then
- echo "automake: address@hidden@}.am: No such honkin' file"
- status=1
- continue
- fi
-
- exec 4> address@hidden@}.in
-
-done
address@hidden example
-
-From this you can already see that Automake will be about reading
address@hidden file and producing @file{*.in} files. You cannot see
-anything else, but if you also know that David is the one who created
-Autoconf two years before you can guess the rest.
-
-Several commits follow, and by the end of the day Automake is
-reported to work for GNU fileutils and GNU m4.
-
-The modus operandi is the one that is still used today: variable
-assignments in @file{Makefile.am} files trigger injections of
-precanned @file{Makefile} fragments into the generated
address@hidden The use of @file{Makefile} fragments was inspired
-by the 4.4BSD @command{make} and include files, however Automake aims
-to be portable and to conform to the GNU standards for @file{Makefile}
-variables and targets.
-
-At this point, the most recent release of Autoconf is version 1.11,
-and David is preparing to release Autoconf 2.0 in late October. As a
-matter of fact, he will barely touch Automake after September.
-
address@hidden 1994-11-05 David MacKenzie's last commit.
-
-At this point Automake is a 200 line portable shell script, plus 332
-lines of @file{Makefile} fragments. In the @file{README}, David
-states his ambivalence between ``portable shell'' and ``more
-appropriate language'':
-
address@hidden
-I wrote it keeping in mind the possibility of it becoming an Autoconf
-macro, so it would run at configure-time. That would slow
-configuration down a bit, but allow users to modify the Makefile.am
-without needing to fetch the AutoMake package. And, the Makefile.in
-files wouldn't need to be distributed. But all of AutoMake would. So
-I might reimplement AutoMake in Perl, m4, or some other more
-appropriate language.
address@hidden quotation
-
-Automake is described as ``an experimental Makefile generator''.
-There is no documentation. Adventurous users are referred to the
-examples and patches needed to use Automake with GNU m4 1.3, fileutils
-3.9, time 1.6, and development versions of find and indent.
-
-These examples seem to have been lost. However at the time of writing
-(10 years later in September, 2004) the FSF still distributes a
-package that uses this version of Automake: check out GNU termutils
-2.0.
-
address@hidden 1995-11-12 Tom Tromey's first commit.
-
-After one year of inactivity, Tom Tromey takes over the package.
-Tom was working on GNU cpio back then, and doing this just for fun,
-having trouble finding a project to contribute to. So while hacking
-he wanted to bring the @file{Makefile.in} up to GNU standards. This
-was hard, and one day he saw Automake on @url{ftp://alpha.gnu.org/},
-grabbed it and tried it out.
-
-Tom didn't talk to djm about it until later, just to make sure he
-didn't mind if he made a release. He did a bunch of early releases to
-the Gnits folks.
-
-Gnits was (and still is) totally informal, just a few GNU friends who
-Fran@,cois Pinard knew, who were all interested in making a common
-infrastructure for GNU projects, and shared a similar outlook on how
-to do it. So they were able to make some progress. It came along
-with Autoconf and extensions thereof, and then Automake from David and
-Tom (who were both gnitsians). One of their ideas was to write a
-document paralleling the GNU standards, that was more strict in some
-ways and more detailed. They never finished the GNITS standards, but
-the ideas mostly made their way into Automake.
-
address@hidden 1995-11-23 Automake 0.20
-
-Besides introducing automatic dependency tracking (@pxref{Dependency
-Tracking Evolution}), this version also supplies a 9-page manual.
-
-At this time @command{aclocal} and @code{AM_INIT_AUTOMAKE} did not
-exist, so many things had to be done by hand. For instance, here is
-what a configure.in (this is the former name of the
address@hidden we use today) must contain in order to use
-Automake 0.20:
-
address@hidden
-PACKAGE=cpio
-VERSION=2.3.911
-AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE")
-AC_DEFINE_UNQUOTED(VERSION, "$VERSION")
-AC_SUBST(PACKAGE)
-AC_SUBST(VERSION)
-AC_ARG_PROGRAM
-AC_PROG_INSTALL
address@hidden example
-
-(Today all of the above is achieved by @code{AC_INIT} and
address@hidden)
-
-Here is how programs are specified in @file{Makefile.am}:
-
address@hidden
-PROGRAMS = hello
-hello_SOURCES = hello.c
address@hidden example
-
-This looks pretty much like what we do today, except the
address@hidden variable has no directory prefix specifying where
address@hidden should be installed: all programs are installed in
address@hidden(bindir)}. @code{LIBPROGRAMS} can be used to specify programs
-that must be built but not installed (it is called
address@hidden nowadays).
-
-Programs can be built conditionally using @code{AC_SUBST}itutions:
-
address@hidden
-PROGRAMS = @@progs@@
-AM_PROGRAMS = foo bar baz
address@hidden example
-
-(@code{AM_PROGRAMS} has since then been renamed to
address@hidden)
-
-Similarly scripts, static libraries, and data can be built and installed
-using the @code{LIBRARIES}, @code{SCRIPTS}, and @code{DATA} variables.
-However @code{LIBRARIES} were treated a bit specially in that Automake
-did automatically supply the @file{lib} and @file{.a} prefixes.
-Therefore to build @file{libcpio.a}, one had to write
-
address@hidden
-LIBRARIES = cpio
-cpio_SOURCES = ...
address@hidden example
-
-Extra files to distribute must be listed in @code{DIST_OTHER} (the
-ancestor of @code{EXTRA_DIST}). Also extra directories that are to be
-distributed should appear in @code{DIST_SUBDIRS}, but the manual
-describes this as a temporary ugly hack (today extra directories should
-also be listed in @code{EXTRA_DIST}, and @code{DIST_SUBDIRS} is used
-for another purpose, @pxref{Conditional Subdirectories}).
-
address@hidden 1995-11-26 Automake 0.21
-
-In less time than it takes to cook a frozen pizza, Tom rewrites
-Automake using Perl. At this time Perl 5 is only one year old, and
-Perl 4.036 is in use at many sites. Supporting several Perl versions
-has been a source of problems through the whole history of Automake.
-
-If you never used Perl 4, imagine Perl 5 without objects, without
address@hidden variables (only dynamically scoped @samp{local} variables),
-without function prototypes, with function calls that needs to be
-prefixed with @samp{&}, etc. Traces of this old style can still be
-found in today's @command{automake}.
-
address@hidden 1995-11-28 Automake 0.22
address@hidden 1995-11-29 Automake 0.23
-
-Bug fixes.
-
address@hidden 1995-12-08 Automake 0.24
address@hidden 1995-12-10 Automake 0.25
-
-Releases are raining. 0.24 introduces the uniform naming scheme we
-use today, i.e., @code{bin_PROGRAMS} instead of @code{PROGRAMS},
address@hidden instead of @code{LIBLIBRARIES}, etc. (However
address@hidden does not exist yet, @code{AM_PROGRAMS} is still
-in use; and @code{TEXINFOS} and @code{MANS} still have no directory
-prefixes.) Adding support for prefixes like that was one of the major
-ideas in @command{automake}; it has lasted pretty well.
-
-AutoMake is renamed to Automake (Tom seems to recall it was Fran@,cois
-Pinard's doing).
-
-0.25 fixes a Perl 4 portability bug.
-
address@hidden 1995-12-18 Jim Meyering starts using Automake in GNU Textutils.
address@hidden 1995-12-31 Fran@,cois Pinard starts using Automake in GNU tar.
-
address@hidden 1996-01-03 Automake 0.26
address@hidden 1996-01-03 Automake 0.27
-
-Of the many changes and suggestions sent by Fran@,cois Pinard and
-included in 0.26, perhaps the most important is the advice that to
-ease customization a user rule or variable definition should always
-override an Automake rule or definition.
-
-Gordon Matzigkeit and Jim Meyering are two other early contributors
-that have been sending fixes.
-
-0.27 fixes yet another Perl 4 portability bug.
-
address@hidden 1996-01-13 Automake 0.28
-
-Automake starts scanning @file{configure.in} for @code{LIBOBJS}
-support. This is an important step because until this version
-Automake only knew about the @file{Makefile.am}s it processed.
address@hidden was Autoconf's world and the link between Autoconf
-and Automake had to be done by the @file{Makefile.am} author. For
-instance, if @file{config.h} was generated by @file{configure}, it was the
-package maintainer's responsibility to define the @code{CONFIG_HEADER}
-variable in each @file{Makefile.am}.
-
-Succeeding releases will rely more and more on scanning
address@hidden to better automate the Autoconf integration.
-
-0.28 also introduces the @code{AUTOMAKE_OPTIONS} variable and the
address@hidden and @option{--gnits} options, the latter being stricter.
-
address@hidden 1996-02-07 Automake 0.29
-
-Thanks to @file{configure.in} scanning, @code{CONFIG_HEADER} is gone,
-and rebuild rules for @file{configure}-generated file are
-automatically output.
-
address@hidden and @code{MANS} converted to the uniform naming
-scheme.
-
address@hidden 1996-02-24 Automake 0.30
-
-The test suite is born. It contains 9 tests. From now on test cases
-will be added pretty regularly (@pxref{Releases}), and this proved to
-be really helpful later on.
-
address@hidden finally replaces @code{AM_PROGRAMS}.
-
-All the third-party Autoconf macros, written mostly by Fran@,cois
-Pinard (and later Jim Meyering), are distributed in Automake's
-hand-written @file{aclocal.m4} file. Package maintainers are expected
-to extract the necessary macros from this file. (In previous versions
-you had to copy and paste them from the manual...)
-
address@hidden 1996-03-11 Automake 0.31
-
-The test suite in 0.30 was run via a long @code{check-local} rule. Upon
-Ulrich Drepper's suggestion, 0.31 makes it an Automake rule output
-whenever the @code{TESTS} variable is defined.
-
address@hidden is renamed to @code{EXTRA_DIST}, and the @code{check_}
-prefix is introduced. The syntax is now the same as today.
-
address@hidden 1996-03-15 Gordon Matzigkeit starts writing libtool.
-
address@hidden 1996-04-27 Automake 0.32
-
address@hidden targets are introduced; an idea from Dieter Baron.
-
address@hidden files, which were output in the build directory are
-now built in the source directory, because they are distributed. It
-seems these files like to move back and forth as that will happen
-again in future versions.
-
address@hidden 1996-05-18 Automake 0.33
-
-Gord Matzigkeit's main two contributions:
-
address@hidden
address@hidden very preliminary libtool support
address@hidden the distcheck rule
address@hidden itemize
-
-Although they were very basic at this point, these are probably
-among the top features for Automake today.
-
-Jim Meyering also provides the infamous @code{jm_MAINTAINER_MODE},
-since then renamed to @code{AM_MAINTAINER_MODE} and abandoned by its
-author (@pxref{maintainer-mode}).
-
address@hidden 1996-05-28 Automake 1.0
-
-After only six months of heavy development, the @command{automake} script is
-3134 lines long, plus 973 lines of @file{Makefile} fragments. The
-package has 30 pages of documentation, and 38 test cases.
address@hidden contains 4 macros.
-
-From now on and until version 1.4, new releases will occur at a rate
-of about one a year. 1.1 did not exist, actually 1.1b to 1.1p have
-been the name of beta releases for 1.2. This is the first time
-Automake uses suffix letters to designate beta releases, a habit that
-lasts.
-
address@hidden 1996-10-10 Kevin Dalley packages Automake 1.0 for Debian
GNU/Linux.
-
address@hidden 1996-11-26 David address@hidden releases Autoconf 2.12.
-
-Between June and October, the Autoconf development is almost stalled.
-Roland McGrath has been working at the beginning of the year. David
-comes back in November to release 2.12, but he won't touch Autoconf
-anymore after this year, and Autoconf then really stagnates. The
-desolate Autoconf @file{ChangeLog} for 1997 lists only 7 commits.
-
address@hidden 1997-02-28 @email{automake@@gnu.ai.mit.edu} list alive
-
-The mailing list is announced as follows:
address@hidden
-I've created the "automake" mailing list. It is
-"automake@@gnu.ai.mit.edu". Administrivia, as always, to
-automake-request@@gnu.ai.mit.edu.
-
-The charter of this list is discussion of automake, autoconf, and
-other configuration/portability tools (e.g., libtool). It is expected
-that discussion will range from pleas for help all the way up to
-patches.
-
-This list is archived on the FSF machines. Offhand I don't know if
-you can get the archive without an account there.
-
-This list is open to anybody who wants to join. Tell all your
-friends!
--- Tom Tromey
address@hidden smallexample
-
-Before that people were discussing Automake privately, on the Gnits
-mailing list (which is not public either), and less frequently on
address@hidden
-
address@hidden is now @code{gnu.org}, in case you never
-noticed. The archives of the early years of the
address@hidden@@gnu.org} list have been lost, so today it is almost
-impossible to find traces of discussions that occurred before 1999.
-This has been annoying more than once, as such discussions can be
-useful to understand the rationale behind a piece of uncommented code
-that was introduced back then.
-
address@hidden 1997-06-22 Automake 1.2
-
-Automake developments continues, and more and more new Autoconf macros
-are required. Distributing them in @file{aclocal.m4} and requiring
-people to browse this file to extract the relevant macros becomes
-uncomfortable. Ideally, some of them should be contributed to
-Autoconf so that they can be used directly, however Autoconf is
-currently inactive. Automake 1.2 consequently introduces
address@hidden (@command{aclocal} was actually started on
-1996-07-28), a tool that automatically constructs an @file{aclocal.m4}
-file from a repository of third-party macros. Because Autoconf has
-stalled, Automake also becomes a kind of repository for such
-third-party macros, even macros completely unrelated to Automake (for
-instance macros that fix broken Autoconf macros).
-
-The 1.2 release contains 20 macros, including the
address@hidden macro that simplifies the creation of
address@hidden
-
-Libtool is fully supported using @code{*_LTLIBRARIES}.
-
-The missing script is introduced by Fran@,cois Pinard; it is meant to be
-a better solution than @code{AM_MAINTAINER_MODE}
-(@pxref{maintainer-mode}).
-
-Conditionals support was implemented by Ian Lance Taylor. At the
-time, Tom and Ian were working on an internal project at Cygnus. They
-were using ILU, which is pretty similar to address@hidden They wanted to
-integrate ILU into their build, which was all @file{configure}-based,
-and Ian thought that adding conditionals to @command{automake} was
-simpler than doing all the work in @file{configure} (which was the
-standard at the time). So this was actually funded by Cygnus.
-
-This very useful but tricky feature will take a lot of time to
-stabilize. (At the time this text is written, there are still
-primaries that have not been updated to support conditional
-definitions in Automake 1.9.)
-
-The @command{automake} script has almost doubled: 6089 lines of Perl,
-plus 1294 lines of @file{Makefile} fragments.
-
address@hidden 1997-07-08 Gordon Matzigkeit releases Libtool 1.0.
-
address@hidden 1998-04-05 Automake 1.3
-
-This is a small advance compared to 1.2.
-It adds support for assembly, and preliminary support for Java.
-
-Perl 5.004_04 is out, but fixes to support Perl 4 are still
-regularly submitted whenever Automake breaks it.
-
address@hidden 1998-09-06 @code{sourceware.cygnus.com} is on-line.
-
-Sourceware was setup by Jason Molenda to host open source projects.
-
address@hidden 1998-09-19 Automake CVS repository moved to
@code{sourceware.cygnus.com}
address@hidden 1998-10-26 @code{sourceware.cygnus.com} announces it hosts
Automake:
-Automake is now hosted on @code{sourceware.cygnus.com}. It has a
-publicly accessible CVS repository. This CVS repository is a copy of
-the one Tom was using on his machine, which in turn is based on
-a copy of the CVS repository of David MacKenzie. This is why we still
-have to full source history. (Automake was on Sourceware until 2007-10-29,
-when it moved to a git repository on @code{savannah.gnu.org},
-but the Sourceware host had been renamed to @code{sources.redhat.com}.)
-
-The oldest file in the administrative directory of the CVS repository
-that was created on Sourceware is dated 1998-09-19, while the
-announcement that @command{automake} and @command{autoconf} had joined
address@hidden was made on 1998-10-26. They were among the
-first projects to be hosted there.
-
-The heedful reader will have noticed Automake was exactly 4 years old
-on 1998-09-19.
-
address@hidden 1999-01-05 Ben Elliston releases Autoconf 2.13.
-
address@hidden 1999-01-14 Automake 1.4
-
-This release adds support for Fortran 77 and for the @code{include}
-statement. Also, @samp{+=} assignments are introduced, but it is
-still quite easy to fool Automake when mixing this with conditionals.
-
-These two releases, Automake 1.4 and Autoconf 2.13 make a duo that
-will be used together for years.
-
address@hidden is 7228 lines, plus 1591 lines of Makefile
-fragment, 20 macros (some 1.3 macros were finally contributed back to
-Autoconf), 197 test cases, and 51 pages of documentation.
-
address@hidden 1999-03-27 The @code{user-dep-branch} is created on the CVS
repository.
-
-This implements a new dependency tracking schemed that should be
-able to handle automatic dependency tracking using any compiler (not
-just gcc) and any make (not just GNU @command{make}). In addition,
-the new scheme should be more reliable than the old one, as
-dependencies are generated on the end user's machine. Alexandre Oliva
-creates depcomp for this purpose.
-
address@hidden Tracking Evolution}, for more details about the
-evolution of automatic dependency tracking in Automake.
-
address@hidden 1999-11-21 The @code{user-dep-branch} is merged into the main
trunk.
-
-This was a huge problem since we also had patches going in on the
-trunk. The merge took a long time and was very painful.
-
address@hidden 2000-05-10
-
-Since September 1999 and until 2003, Akim Demaille will be zealously
-revamping Autoconf.
-
address@hidden
-I think the next release should be called "3.0"address@hidden
-Let's face it: you've basically rewritten address@hidden
-Every weekend there are 30 new address@hidden
-I don't see how we could call this "2.15" with a straight address@hidden
--- Tom Tromey on @email{autoconf@@gnu.org}
address@hidden quotation
-
-Actually Akim works like a submarine: he will pile up patches while he
-works off-line during the weekend, and flush them in batch when he
-resurfaces on Monday.
-
address@hidden 2001-01-24
-
-On this Wednesday, Autoconf 2.49c, the last beta before Autoconf 2.50
-is out, and Akim has to find something to do during his week-end :)
-
address@hidden 2001-01-28
-
-Akim sends a batch of 14 patches to @email{automake@@gnu.org}.
-
address@hidden
-Aiieeee! I was dreading the day that the Demaillator turned his
-sights on address@hidden and now it has arrived! -- Tom Tromey
address@hidden quotation
-
-It's only the beginning: in two months he will send 192 patches. Then
-he would slow down so Tom can catch up and review all this. Initially
-Tom actually read all these patches, then he probably trustingly
-answered OK to most of them, and finally gave up and let Akim apply
-whatever he wanted. There was no way to keep up with that patch rate.
-
address@hidden
-Anyway the patch below won't apply since it predates Akim's
-sourcequake; I have yet to figure where the relevant passage has
-been moved :) -- Alexandre Duret-Lutz
address@hidden quotation
-
-All these patches were sent to and discussed on
address@hidden@@gnu.org}, so subscribed users were literally drowning in
-technical mails. Eventually, the @email{automake-patches@@gnu.org}
-mailing list was created in May.
-
-Year after year, Automake had drifted away from its initial design:
-construct @file{Makefile.in} by assembling various @file{Makefile}
-fragments. In 1.4, lots of @file{Makefile} rules are being emitted at
-various places in the @command{automake} script itself; this does not
-help ensuring a consistent treatment of these rules (for instance
-making sure that user-defined rules override Automake's own rules).
-One of Akim's goal was moving all these hard-coded rules to separate
address@hidden fragments, so the logic could be centralized in a
address@hidden fragment processor.
-
-Another significant contribution of Akim is the interface with the
-``trace'' feature of Autoconf. The way to scan @file{configure.in} at
-this time was to read the file and grep the various macro of interest
-to Automake. Doing so could break in many unexpected ways; @command{automake}
-could miss some definition (for instance @samp{AC_SUBST([$1], [$2])}
-where the arguments are known only when M4 is run), or conversely it
-could detect some macro that was not expanded (because it is called
-conditionally). In the CVS version of Autoconf, Akim had implemented
-the @option{--trace} option, which provides accurate information about
-where macros are actually called and with what arguments. Akim will
-equip Automake with a second @file{configure.in} scanner that uses
-this @option{--trace} interface. Since it was not sensible to drop the
-Autoconf 2.13 compatibility yet, this experimental scanner was only
-used when an environment variable was set, the traditional
-grep-scanner being still the default.
-
address@hidden 2001-04-25 Gary address@hidden releases Libtool 1.4
-
-It has been more than two years since Automake 1.4, CVS Automake has
-suffered lot's of heavy changes and still is not ready for release.
-Libtool 1.4 had to be distributed with a patch against Automake 1.4.
-
address@hidden 2001-05-08 Automake 1.4-p1
address@hidden 2001-05-24 Automake 1.4-p2
-
-Gary address@hidden, the principal Libtool maintainer, makes a ``patch
-release'' of Automake:
-
address@hidden
-The main purpose of this release is to have a stable automake
-which is compatible with the latest stable libtool.
address@hidden quotation
-
-The release also contains obvious fixes for bugs in Automake 1.4,
-some of which were reported almost monthly.
-
address@hidden 2001-05-21 Akim Demaille releases Autoconf 2.50
-
address@hidden 2001-06-07 Automake 1.4-p3
address@hidden 2001-06-10 Automake 1.4-p4
address@hidden 2001-07-15 Automake 1.4-p5
-
-Gary continues his patch-release series. These also add support for
-some new Autoconf 2.50 idioms. Essentially, Autoconf now advocates
address@hidden over @file{configure.in}, and it introduces a new
-syntax for @code{AC_OUTPUT}ing files.
-
address@hidden 2001-08-23 Automake 1.5
-
-A major and long-awaited release, that comes more than two years after
-1.4. It brings many changes, among which:
address@hidden
address@hidden The new dependency tracking scheme that uses @command{depcomp}.
-Aside from the improvement on the dependency tracking itself
-(@pxref{Dependency Tracking Evolution}), this also streamlines the use
-of @command{automake}-generated @file{Makefile.in}s as the @file{Makefile.in}s
-used during development are now the same as those used in
-distributions. Before that the @file{Makefile.in}s generated for
-maintainers required GNU @command{make} and GCC, they were different
-from the portable @file{Makefile} generated for distribution; this was
-causing some confusion.
-
address@hidden Support for per-target compilation flags.
-
address@hidden Support for reference to files in subdirectories in most
address@hidden variables.
-
address@hidden Introduction of the @code{dist_}, @code{nodist_}, and
@code{nobase_}
-prefixes.
address@hidden Perl 4 support is finally dropped.
address@hidden itemize
-
-1.5 did break several packages that worked with 1.4. Enough so that
-Linux distributions could not easily install the new Automake version
-without breaking many of the packages for which they had to run
address@hidden
-
-Some of these breakages were effectively bugs that would eventually be
-fixed in the next release. However, a lot of damage was caused by
-some changes made deliberately to render Automake stricter on some
-setup we did consider bogus. For instance, @samp{make distcheck} was
-improved to check that @samp{make uninstall} did remove all the files
address@hidden install} installed, that @samp{make distclean} did not omit
-some file, and that a VPATH build would work even if the source
-directory was read-only. Similarly, Automake now rejects multiple
-definitions of the same variable (because that would mix very badly
-with conditionals), and @samp{+=} assignments with no previous
-definition. Because these changes all occurred suddenly after 1.4 had
-been established for more than two years, it hurt users.
-
-To make matter worse, meanwhile Autoconf (now at version 2.52) was
-facing similar troubles, for similar reasons.
-
address@hidden 2002-03-05 Automake 1.6
-
-This release introduced versioned installation (@pxref{API
-Versioning}). This was mainly pushed by Havoc Pennington, taking the
-GNOME source tree as motive: due to incompatibilities between the
-autotools it's impossible for the GNOME packages to switch to Autoconf
-2.53 and Automake 1.5 all at once, so they are currently stuck with
-Autoconf 2.13 and Automake 1.4.
-
-The idea was to call this version @file{automake-1.6}, call all its
-bug-fix versions identically, and switch to @file{automake-1.7} for
-the next release that adds new features or changes some rules. This
-scheme implies maintaining a bug-fix branch in addition to the
-development trunk, which means more work from the maintainer, but
-providing regular bug-fix releases proved to be really worthwhile.
-
-Like 1.5, 1.6 also introduced a bunch of incompatibilities, intentional or
-not. Perhaps the more annoying was the dependence on the newly
-released Autoconf 2.53. Autoconf seemed to have stabilized enough
-since its explosive 2.50 release and included changes required to fix
-some bugs in Automake. In order to upgrade to Automake 1.6, people
-now had to upgrade Autoconf too; for some packages it was no picnic.
-
-While versioned installation helped people to upgrade, it also
-unfortunately allowed people not to upgrade. At the time of writing,
-some Linux distributions are shipping packages for Automake 1.4, 1.5,
-1.6, 1.7, 1.8, and 1.9. Most of these still install 1.4 by default.
-Some distribution also call 1.4 the ``stable'' version, and present
-``1.9'' as the development version; this does not really makes sense
-since 1.9 is way more solid than 1.4. All this does not help the
-newcomer.
-
address@hidden 2002-04-11 Automake 1.6.1
-
-1.6, and the upcoming 1.4-p6 release were the last release by Tom.
-This one and those following will be handled by Alexandre
-Duret-Lutz. Tom is still around, and will be there until about 1.7,
-but his interest into Automake is drifting away towards projects like
address@hidden
-
-Alexandre has been using Automake since 2000, and started to
-contribute mostly on Akim's incitement (Akim and Alexandre have been
-working in the same room from 1999 to 2002). In 2001 and 2002 he had
-a lot of free time to enjoy hacking Automake.
-
address@hidden 2002-06-14 Automake 1.6.2
-
address@hidden 2002-07-28 Automake 1.6.3
address@hidden 2002-07-28 Automake 1.4-p6
-
-Two releases on the same day. 1.6.3 is a bug-fix release.
-
-Tom Tromey backported the versioned installation mechanism on the 1.4
-branch, so that Automake 1.6.x and Automake 1.4-p6 could be installed
-side by side. Another request from the GNOME folks.
-
address@hidden 2002-09-25 Automake 1.7
-
-This release switches to the new @file{configure.ac} scanner Akim
-was experimenting in 1.5.
-
address@hidden 2002-10-16 Automake 1.7.1
address@hidden 2002-12-06 Automake 1.7.2
address@hidden 2003-02-20 Automake 1.7.3
address@hidden 2003-04-23 Automake 1.7.4
address@hidden 2003-05-18 Automake 1.7.5
address@hidden 2003-07-10 Automake 1.7.6
address@hidden 2003-09-07 Automake 1.7.7
address@hidden 2003-10-07 Automake 1.7.8
-
-Many bug-fix releases. 1.7 lasted because the development version
-(upcoming 1.8) was suffering some major internal revamping.
-
address@hidden 2003-10-26 Automake on screen
-
-Episode 49, `Repercussions', in the third season of the `Alias' TV
-show is first aired.
-
-Marshall, one of the characters, is working on a computer virus that he
-has to modify before it gets into the wrong hands or something like
-that. The screenshots you see do not show any program code, they show
-a @file{Makefile.in} @code{generated by automake}...
-
address@hidden 2003-11-09 Automake 1.7.9
-
address@hidden 2003-12-10 Automake 1.8
-
-The most striking update is probably that of @command{aclocal}.
-
address@hidden now uses @code{m4_include} in the produced
address@hidden when the included macros are already distributed
-with the package (an idiom used in many packages), which reduces code
-duplication. Many people liked that, but in fact this change was
-really introduced to fix a bug in rebuild rules: @file{Makefile.in}
-must be rebuilt whenever a dependency of @file{configure} changes, but
-all the @file{m4} files included in @file{aclocal.m4} where unknown
-from @command{automake}. Now @command{automake} can just trace the
address@hidden to discover the dependencies.
-
address@hidden also starts using the @option{--trace} Autoconf option
-in order to discover used macros more accurately. This will turn out
-to be very tricky (later releases will improve this) as people had
-devised many ways to cope with the limitation of previous
address@hidden versions, notably using handwritten
address@hidden: @command{aclocal} must make sure not to redefine a
-rule that is already included by such statement.
-
-Automake also has seen its guts rewritten. Although this rewriting
-took a lot of efforts, it is only apparent to the users in that some
-constructions previously disallowed by the implementation now work
-nicely. Conditionals, Locations, Variable and Rule definitions,
-Options: these items on which Automake works have been rewritten as
-separate Perl modules, and documented.
-
address@hidden 2004-01-11 Automake 1.8.1
address@hidden 2004-01-12 Automake 1.8.2
address@hidden 2004-03-07 Automake 1.8.3
address@hidden 2004-04-25 Automake 1.8.4
address@hidden 2004-05-16 Automake 1.8.5
-
address@hidden 2004-07-28 Automake 1.9
-
-This release tries to simplify the compilation rules it outputs to
-reduce the size of the Makefile. The complaint initially come from
-the libgcj developers. Their @file{Makefile.in} generated with
-Automake 1.4 and custom build rules (1.4 did not support compiled
-Java) is address@hidden The one generated by 1.8 was over address@hidden 1.9
gets it
-down to address@hidden
-
-Aside from this it contains mainly minor changes and bug-fixes.
-
address@hidden 2004-08-11 Automake 1.9.1
address@hidden 2004-09-19 Automake 1.9.2
-
-Automake has ten years. This chapter of the manual was initially
-written for this occasion.
-
address@hidden 2007-10-29 Automake repository moves to @code{savannah.gnu.org}
and uses
-git as primary repository.
-
address@hidden table
-
address@hidden Dependency Tracking Evolution
address@hidden Dependency Tracking in Automake
-
-Over the years Automake has deployed three different dependency
-tracking methods. Each method, including the current one, has had
-flaws of various sorts. Here we lay out the different dependency
-tracking methods, their flaws, and their fixes. We conclude with
-recommendations for tool writers, and by indicating future directions
-for dependency tracking work in Automake.
-
address@hidden
-* First Take on Dependencies:: Precomputed dependency tracking
-* Dependencies As Side Effects:: Update at developer compile time
-* Dependencies for the User:: Update at user compile time
-* Techniques for Dependencies:: Alternative approaches
-* Recommendations for Tool Writers:: What tool writers can do to help
-* Future Directions for Dependencies:: Languages Automake does not know
address@hidden menu
-
address@hidden First Take on Dependencies
address@hidden First Take on Dependency Tracking
address@hidden Description
-
-Our first attempt at automatic dependency tracking was based on the
-method recommended by GNU @command{make}. (@pxref{Automatic
-Prerequisites, , Generating Prerequisites Automatically, make, The GNU
-make Manual})
-
-This version worked by precomputing dependencies ahead of time. For
-each source file, it had a special @file{.P} file that held the
-dependencies. There was a rule to generate a @file{.P} file by
-invoking the compiler appropriately. All such @file{.P} files were
-included by the @file{Makefile}, thus implicitly becoming dependencies
-of @file{Makefile}.
-
address@hidden Bugs
-
-This approach had several critical bugs.
-
address@hidden
address@hidden
-The code to generate the @file{.P} file relied on @command{gcc}.
-(A limitation, not technically a bug.)
address@hidden
-The dependency tracking mechanism itself relied on GNU @command{make}.
-(A limitation, not technically a bug.)
address@hidden
-Because each @file{.P} file was a dependency of @file{Makefile}, this
-meant that dependency tracking was done eagerly by @command{make}.
-For instance, @samp{make clean} would cause all the dependency files
-to be updated, and then immediately removed. This eagerness also
-caused problems with some configurations; if a certain source file
-could not be compiled on a given architecture for some reason,
-dependency tracking would fail, aborting the entire build.
address@hidden
-As dependency tracking was done as a pre-pass, compile times were
-doubled--the compiler had to be run twice per source file.
address@hidden
address@hidden dist} re-ran @command{automake} to generate a
address@hidden that did not have automatic dependency tracking (and
-that was thus portable to any version of @command{make}). In order to
-do this portably, Automake had to scan the dependency files and remove
-any reference that was to a source file not in the distribution.
-This process was error-prone. Also, if @samp{make dist} was run in an
-environment where some object file had a dependency on a source file
-that was only conditionally created, Automake would generate a
address@hidden that referred to a file that might not appear in the
-end user's build. A special, hacky mechanism was required to work
-around this.
address@hidden itemize
-
address@hidden Historical Note
-
-The code generated by Automake is often inspired by the
address@hidden style of a particular author. In the case of the first
-implementation of dependency tracking, I believe the impetus and
-inspiration was Jim Meyering. (I could be mistaken. If you know
-otherwise feel free to correct me.)
-
address@hidden Dependencies As Side Effects
address@hidden Dependencies As Side Effects
address@hidden Description
-
-The next refinement of Automake's automatic dependency tracking scheme
-was to implement dependencies as side effects of the compilation.
-This was aimed at solving the most commonly reported problems with the
-first approach. In particular we were most concerned with eliminating
-the weird rebuilding effect associated with make clean.
-
-In this approach, the @file{.P} files were included using the
address@hidden command, which let us create these files lazily. This
-avoided the @samp{make clean} problem.
-
-We only computed dependencies when a file was actually compiled. This
-avoided the performance penalty associated with scanning each file
-twice. It also let us avoid the other problems associated with the
-first, eager, implementation. For instance, dependencies would never
-be generated for a source file that was not compilable on a given
-architecture (because it in fact would never be compiled).
-
address@hidden Bugs
-
address@hidden
address@hidden
-This approach also relied on the existence of @command{gcc} and GNU
address@hidden (A limitation, not technically a bug.)
address@hidden
-Dependency tracking was still done by the developer, so the problems
-from the first implementation relating to massaging of dependencies by
address@hidden dist} were still in effect.
address@hidden
-This implementation suffered from the ``deleted header file'' problem.
-Suppose a lazily-created @file{.P} file includes a dependency on a
-given header file, like this:
-
address@hidden
-maude.o: maude.c something.h
address@hidden example
-
-Now suppose that you remove @file{something.h} and update @file{maude.c}
-so that this include is no longer needed. If you run @command{make},
-you will get an error because there is no way to create
address@hidden
-
-We fixed this problem in a later release by further massaging the
-output of @command{gcc} to include a dummy dependency for each header
-file.
address@hidden itemize
-
address@hidden Dependencies for the User
address@hidden Dependencies for the User
address@hidden Description
-
-The bugs associated with @samp{make dist}, over time, became a real
-problem. Packages using Automake were being built on a large number
-of platforms, and were becoming increasingly complex. Broken
-dependencies were distributed in ``portable'' @file{Makefile.in}s,
-leading to user complaints. Also, the requirement for @command{gcc}
-and GNU @command{make} was a constant source of bug reports. The next
-implementation of dependency tracking aimed to remove these problems.
-
-We realized that the only truly reliable way to automatically track
-dependencies was to do it when the package itself was built. This
-meant discovering a method portable to any version of make and any
-compiler. Also, we wanted to preserve what we saw as the best point
-of the second implementation: dependency computation as a side effect
-of compilation.
-
-In the end we found that most modern make implementations support some
-form of include directive. Also, we wrote a wrapper script that let
-us abstract away differences between dependency tracking methods for
-compilers. For instance, some compilers cannot generate dependencies
-as a side effect of compilation. In this case we simply have the
-script run the compiler twice. Currently our wrapper script
-(@command{depcomp}) knows about twelve different compilers (including
-a "compiler" that simply invokes @command{makedepend} and then the
-real compiler, which is assumed to be a standard Unix-like C compiler
-with no way to do dependency tracking).
-
address@hidden Bugs
-
address@hidden
address@hidden
-Running a wrapper script for each compilation slows down the build.
address@hidden
-Many users don't really care about precise dependencies.
address@hidden
-This implementation, like every other automatic dependency tracking
-scheme in common use today (indeed, every one we've ever heard of),
-suffers from the ``duplicated new header'' bug.
-
-This bug occurs because dependency tracking tools, such as the
-compiler, only generate dependencies on the successful opening of a
-file, and not on every probe.
-
-Suppose for instance that the compiler searches three directories for
-a given header, and that the header is found in the third directory.
-If the programmer erroneously adds a header file with the same name to
-the first directory, then a clean rebuild from scratch could fail
-(suppose the new header file is buggy), whereas an incremental rebuild
-will succeed.
-
-What has happened here is that people have a misunderstanding of what
-a dependency is. Tool writers think a dependency encodes information
-about which files were read by the compiler. However, a dependency
-must actually encode information about what the compiler tried to do.
-
-This problem is not serious in practice. Programmers typically do not
-use the same name for a header file twice in a given project. (At
-least, not in C or C++. This problem may be more troublesome in
-Java.) This problem is easy to fix, by modifying dependency
-generators to record every probe, instead of every successful open.
-
address@hidden
-Since Automake generates dependencies as a side effect of compilation,
-there is a bootstrapping problem when header files are generated by
-running a program. The problem is that, the first time the build is
-done, there is no way by default to know that the headers are
-required, so make might try to run a compilation for which the headers
-have not yet been built.
-
-This was also a problem in the previous dependency tracking implementation.
-
-The current fix is to use @code{BUILT_SOURCES} to list built headers
-(@pxref{Sources}). This causes them to be built before any other
-build rules are run. This is unsatisfactory as a general solution,
-however in practice it seems sufficient for most actual programs.
address@hidden itemize
-
-This code is used since Automake 1.5.
-
-In GCC 3.0, we managed to convince the maintainers to add special
-command-line options to help Automake more efficiently do its job. We
-hoped this would let us avoid the use of a wrapper script when
-Automake's automatic dependency tracking was used with @command{gcc}.
-
-Unfortunately, this code doesn't quite do what we want. In
-particular, it removes the dependency file if the compilation fails;
-we'd prefer that it instead only touch the file in any way if the
-compilation succeeds.
-
-Nevertheless, since Automake 1.7, when a recent @command{gcc} is
-detected at @command{configure} time, we inline the
-dependency-generation code and do not use the @command{depcomp}
-wrapper script. This makes compilations faster for those using this
-compiler (probably our primary user base). The counterpart is that
-because we have to encode two compilation rules in @file{Makefile}
-(with or without @command{depcomp}), the produced @file{Makefile}s are
-larger.
-
address@hidden Techniques for Dependencies
address@hidden Techniques for Computing Dependencies
-
-There are actually several ways for a build tool like Automake to
-cause tools to generate dependencies.
-
address@hidden @asis
address@hidden @command{makedepend}
-This was a commonly-used method in the past. The idea is to run a
-special program over the source and have it generate dependency
-information. Traditional implementations of @command{makedepend} are
-not completely precise; ordinarily they were conservative and
-discovered too many dependencies.
address@hidden The tool
-An obvious way to generate dependencies is to simply write the tool so
-that it can generate the information needed by the build tool. This is
-also the most portable method. Many compilers have an option to
-generate dependencies. Unfortunately, not all tools provide such an
-option.
address@hidden The file system
-It is possible to write a special file system that tracks opens,
-reads, writes, etc, and then feed this information back to the build
-tool. @command{clearmake} does this. This is a very powerful
-technique, as it doesn't require cooperation from the
-tool. Unfortunately it is also very difficult to implement and also
-not practical in the general case.
address@hidden @code{LD_PRELOAD}
-Rather than use the file system, one could write a special library to
-intercept @code{open} and other syscalls. This technique is also quite
-powerful, but unfortunately it is not portable enough for use in
address@hidden
address@hidden table
-
address@hidden Recommendations for Tool Writers
address@hidden Recommendations for Tool Writers
-
-We think that every compilation tool ought to be able to generate
-dependencies as a side effect of compilation. Furthermore, at least
-while @command{make}-based tools are nearly universally in use (at
-least in the free software community), the tool itself should generate
-dummy dependencies for header files, to avoid the deleted header file
-bug. Finally, the tool should generate a dependency for each probe,
-instead of each successful file open, in order to avoid the duplicated
-new header bug.
-
address@hidden Future Directions for Dependencies
address@hidden Future Directions for Dependencies
-
-Currently, only languages and compilers understood by Automake can
-have dependency tracking enabled. We would like to see if it is
-practical (and worthwhile) to let this support be extended by the user
-to languages unknown to Automake.
-
address@hidden Releases
address@hidden Release Statistics
-
-The following table (inspired by @samp{perlhist(1)}) quantifies the
-evolution of Automake using these metrics:
-
address@hidden @asis
address@hidden Date, Rel
-The date and version of the release.
address@hidden am
-The number of lines of the @command{automake} script.
address@hidden acl
-The number of lines of the @command{aclocal} script.
address@hidden pm
-The number of lines of the @command{Perl} supporting modules.
address@hidden @file{*.am}
-The number of lines of the @file{Makefile} fragments. The number in
-parentheses is the number of files.
address@hidden m4
-The number of lines (and files) of Autoconf macros.
address@hidden doc
-The number of pages of the documentation (the Postscript version).
address@hidden t
-The number of test cases in the test suite. Of those, the number in
-parentheses is the number of generated test cases.
address@hidden table
-
address@hidden {8888-88-88} {8.8-p8} {8888} {8888} {8888} {8888 (88)} {8888
(88)} {888} {888 (88)}
address@hidden Date @tab Rel @tab am @tab acl @tab pm @tab @file{*.am}
@tab m4 @tab doc @tab t
address@hidden 1994-09-19 @tab CVS @tab 141 @tab @tab @tab 299
(24) @tab @tab @tab
address@hidden 1994-11-05 @tab CVS @tab 208 @tab @tab @tab 332
(28) @tab @tab @tab
address@hidden 1995-11-23 @tab 0.20 @tab 533 @tab @tab @tab 458
(35) @tab @tab 9 @tab
address@hidden 1995-11-26 @tab 0.21 @tab 613 @tab @tab @tab 480
(36) @tab @tab 11 @tab
address@hidden 1995-11-28 @tab 0.22 @tab 1116 @tab @tab @tab 539
(38) @tab @tab 12 @tab
address@hidden 1995-11-29 @tab 0.23 @tab 1240 @tab @tab @tab 541
(38) @tab @tab 12 @tab
address@hidden 1995-12-08 @tab 0.24 @tab 1462 @tab @tab @tab 504
(33) @tab @tab 14 @tab
address@hidden 1995-12-10 @tab 0.25 @tab 1513 @tab @tab @tab 511
(37) @tab @tab 15 @tab
address@hidden 1996-01-03 @tab 0.26 @tab 1706 @tab @tab @tab 438
(36) @tab @tab 16 @tab
address@hidden 1996-01-03 @tab 0.27 @tab 1706 @tab @tab @tab 438
(36) @tab @tab 16 @tab
address@hidden 1996-01-13 @tab 0.28 @tab 1964 @tab @tab @tab 934
(33) @tab @tab 16 @tab
address@hidden 1996-02-07 @tab 0.29 @tab 2299 @tab @tab @tab 936
(33) @tab @tab 17 @tab
address@hidden 1996-02-24 @tab 0.30 @tab 2544 @tab @tab @tab 919
(32) @tab 85 (1) @tab 20 @tab 9
address@hidden 1996-03-11 @tab 0.31 @tab 2877 @tab @tab @tab 919
(32) @tab 85 (1) @tab 29 @tab 17
address@hidden 1996-04-27 @tab 0.32 @tab 3058 @tab @tab @tab 921
(31) @tab 85 (1) @tab 30 @tab 26
address@hidden 1996-05-18 @tab 0.33 @tab 3110 @tab @tab @tab 926
(31) @tab 105 (1) @tab 30 @tab 35
address@hidden 1996-05-28 @tab 1.0 @tab 3134 @tab @tab @tab 973
(32) @tab 105 (1) @tab 30 @tab 38
address@hidden 1997-06-22 @tab 1.2 @tab 6089 @tab 385 @tab @tab 1294
(36) @tab 592 (20) @tab 37 @tab 126
address@hidden 1998-04-05 @tab 1.3 @tab 6415 @tab 422 @tab @tab 1470
(39) @tab 741 (23) @tab 39 @tab 156
address@hidden 1999-01-14 @tab 1.4 @tab 7240 @tab 426 @tab @tab 1591
(40) @tab 734 (20) @tab 51 @tab 197
address@hidden 2001-05-08 @tab 1.4-p1 @tab 7251 @tab 426 @tab @tab 1591
(40) @tab 734 (20) @tab 51 @tab 197
address@hidden 2001-05-24 @tab 1.4-p2 @tab 7268 @tab 439 @tab @tab 1591
(40) @tab 734 (20) @tab 49 @tab 197
address@hidden 2001-06-07 @tab 1.4-p3 @tab 7312 @tab 439 @tab @tab 1591
(40) @tab 734 (20) @tab 49 @tab 197
address@hidden 2001-06-10 @tab 1.4-p4 @tab 7321 @tab 439 @tab @tab 1591
(40) @tab 734 (20) @tab 49 @tab 198
address@hidden 2001-07-15 @tab 1.4-p5 @tab 7228 @tab 426 @tab @tab 1596
(40) @tab 734 (20) @tab 51 @tab 198
address@hidden 2001-08-23 @tab 1.5 @tab 8016 @tab 475 @tab 600 @tab 2654
(39) @tab 1166 (29) @tab 63 @tab 327
address@hidden 2002-03-05 @tab 1.6 @tab 8465 @tab 475 @tab 1136 @tab 2732
(39) @tab 1603 (27) @tab 66 @tab 365
address@hidden 2002-04-11 @tab 1.6.1 @tab 8544 @tab 475 @tab 1136 @tab 2741
(39) @tab 1603 (27) @tab 66 @tab 372
address@hidden 2002-06-14 @tab 1.6.2 @tab 8575 @tab 475 @tab 1136 @tab 2800
(39) @tab 1609 (27) @tab 67 @tab 386
address@hidden 2002-07-28 @tab 1.6.3 @tab 8600 @tab 475 @tab 1153 @tab 2809
(39) @tab 1609 (27) @tab 67 @tab 391
address@hidden 2002-07-28 @tab 1.4-p6 @tab 7332 @tab 455 @tab @tab 1596
(40) @tab 735 (20) @tab 49 @tab 197
address@hidden 2002-09-25 @tab 1.7 @tab 9189 @tab 471 @tab 1790 @tab 2965
(39) @tab 1606 (28) @tab 73 @tab 430
address@hidden 2002-10-16 @tab 1.7.1 @tab 9229 @tab 475 @tab 1790 @tab 2977
(39) @tab 1606 (28) @tab 73 @tab 437
address@hidden 2002-12-06 @tab 1.7.2 @tab 9334 @tab 475 @tab 1790 @tab 2988
(39) @tab 1606 (28) @tab 77 @tab 445
address@hidden 2003-02-20 @tab 1.7.3 @tab 9389 @tab 475 @tab 1790 @tab 3023
(39) @tab 1651 (29) @tab 84 @tab 448
address@hidden 2003-04-23 @tab 1.7.4 @tab 9429 @tab 475 @tab 1790 @tab 3031
(39) @tab 1644 (29) @tab 85 @tab 458
address@hidden 2003-05-18 @tab 1.7.5 @tab 9429 @tab 475 @tab 1790 @tab 3033
(39) @tab 1645 (29) @tab 85 @tab 459
address@hidden 2003-07-10 @tab 1.7.6 @tab 9442 @tab 475 @tab 1790 @tab 3033
(39) @tab 1660 (29) @tab 85 @tab 461
address@hidden 2003-09-07 @tab 1.7.7 @tab 9443 @tab 475 @tab 1790 @tab 3041
(39) @tab 1660 (29) @tab 90 @tab 467
address@hidden 2003-10-07 @tab 1.7.8 @tab 9444 @tab 475 @tab 1790 @tab 3041
(39) @tab 1660 (29) @tab 90 @tab 468
address@hidden 2003-11-09 @tab 1.7.9 @tab 9444 @tab 475 @tab 1790 @tab 3048
(39) @tab 1660 (29) @tab 90 @tab 468
address@hidden 2003-12-10 @tab 1.8 @tab 7171 @tab 585 @tab 7730 @tab 3236
(39) @tab 1666 (31) @tab 104 @tab 521
address@hidden 2004-01-11 @tab 1.8.1 @tab 7217 @tab 663 @tab 7726 @tab 3287
(39) @tab 1686 (31) @tab 104 @tab 525
address@hidden 2004-01-12 @tab 1.8.2 @tab 7217 @tab 663 @tab 7726 @tab 3288
(39) @tab 1686 (31) @tab 104 @tab 526
address@hidden 2004-03-07 @tab 1.8.3 @tab 7214 @tab 686 @tab 7735 @tab 3303
(39) @tab 1695 (31) @tab 111 @tab 530
address@hidden 2004-04-25 @tab 1.8.4 @tab 7214 @tab 686 @tab 7736 @tab 3310
(39) @tab 1701 (31) @tab 112 @tab 531
address@hidden 2004-05-16 @tab 1.8.5 @tab 7240 @tab 686 @tab 7736 @tab 3299
(39) @tab 1701 (31) @tab 112 @tab 533
address@hidden 2004-07-28 @tab 1.9 @tab 7508 @tab 715 @tab 7794 @tab 3352
(40) @tab 1812 (32) @tab 115 @tab 551
address@hidden 2004-08-11 @tab 1.9.1 @tab 7512 @tab 715 @tab 7794 @tab 3354
(40) @tab 1812 (32) @tab 115 @tab 552
address@hidden 2004-09-19 @tab 1.9.2 @tab 7512 @tab 715 @tab 7794 @tab 3354
(40) @tab 1812 (32) @tab 132 @tab 554
address@hidden 2004-11-01 @tab 1.9.3 @tab 7507 @tab 718 @tab 7804 @tab 3354
(40) @tab 1812 (32) @tab 134 @tab 556
address@hidden 2004-12-18 @tab 1.9.4 @tab 7508 @tab 718 @tab 7856 @tab 3361
(40) @tab 1811 (32) @tab 140 @tab 560
address@hidden 2005-02-13 @tab 1.9.5 @tab 7523 @tab 719 @tab 7859 @tab 3373
(40) @tab 1453 (32) @tab 142 @tab 562
address@hidden 2005-07-10 @tab 1.9.6 @tab 7539 @tab 699 @tab 7867 @tab 3400
(40) @tab 1453 (32) @tab 144 @tab 570
address@hidden 2006-10-15 @tab 1.10 @tab 7859 @tab 1072 @tab 8024 @tab 3512
(40) @tab 1496 (34) @tab 172 @tab 604
address@hidden 2008-01-19 @tab 1.10.1 @tab 7870 @tab 1089 @tab 8025 @tab 3520
(40) @tab 1499 (34) @tab 173 @tab 617
address@hidden 2008-11-23 @tab 1.10.2 @tab 7882 @tab 1089 @tab 8027 @tab 3540
(40) @tab 1509 (34) @tab 176 @tab 628
address@hidden 2009-05-17 @tab 1.11 @tab 8721 @tab 1092 @tab 8289 @tab 4164
(42) @tab 1714 (37) @tab 181 @tab 732 (20)
address@hidden multitable
-
-
@c ========================================================== Appendices
@page
hooks/post-receive
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GNU Automake
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