[PATCH 3/7] elisp: use suffix rules, get rid of 'elisp-comp' script (mostly a rewrite)

[Stefano Lattarini]

From: Jack Kelly <address@hidden>

Motivated by automake bug#11806.

Traditionally, automake byte-compiled emacs-lisp '.el' files by invoking
'elisp-comp' on all of them in a bulk; this involved complex timestamping
and file-locking logic.  It was also brittle in any slightly-unusual
setup, because 'elisp-comp' operated by copying all of the elisp files
to be compiled into a temporary sub-directory and compiling them in there,
the copying the resulting byte-compile files back in the build directory.

This patch removes all of that juggling and chicanery in favour of
defining a much simpler '.el.elc' suffix rule.  Not only this is simpler,
but it also interacts better with "make -jN" calls, which are becoming
more and more common and useful on today's increasingly multicore systems.

* Makefile.am (dist_script_DATA): Remove 'elisp-comp'.
* automake.in (@common_files): Likewise.
(handle_emacs_lisp): Do not require 'elisp-comp'.
* doc/automake.texi: Remove references to 'elisp-comp'.
* lib/am/lisp.am: Define elisp compilation via a suffix rule; this
basically amounts to a complete re-write of the lisp byte-compilation
rules.
* lib/elisp-comp: Remove.
* t/add-missing.tap: Remove elisp-comp test.
* t/dist-auxdir-many-subdirs.sh: Remove reference to elisp-comp.
* t/primary-prefix-invalid-couples.tap: Likewise.
* t/primary-prefix-valid-couples.sh: Likewise.
* t/lisp4.sh: Remove reference to elc-stamp.
* t/lisp5.sh: Likewise.
* t/lisp6.sh: Likewise.
* t/lisp3.sh: Likewise.  Also remove the recompilation check that
involves a (message) call.
* t/lisp7.sh: Remove check for "Warnings can be ignored".  Remove
reference to elc-stamp.
* t/lisp8.sh: Likewise.
* t/lispdry.sh: Remove references to elc-stamp.

Acked-by: Stefano Lattarini <address@hidden>
Signed-off-by: Stefano Lattarini <address@hidden>
---
 Makefile.am                          |    1 -
 automake.in                          |    4 +-
 doc/automake.texi                    |    4 --
 lib/am/lisp.am                       |   69 +++++--------------------
 lib/elisp-comp                       |   93 ----------------------------------
 t/add-missing.tap                    |   11 ----
 t/dist-auxdir-many-subdirs.sh        |    3 --
 t/lisp3.sh                           |   10 ----
 t/lisp4.sh                           |    1 -
 t/lisp5.sh                           |    1 -
 t/lisp6.sh                           |    5 --
 t/lisp7.sh                           |    2 -
 t/lisp8.sh                           |    4 --
 t/lispdry.sh                         |    4 +-
 t/primary-prefix-invalid-couples.tap |    1 -
 t/primary-prefix-valid-couples.sh    |    1 -
 16 files changed, 16 insertions(+), 198 deletions(-)
 delete mode 100755 lib/elisp-comp

diff --git a/Makefile.am b/Makefile.am
index a5332d3..26a04a1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -135,7 +135,6 @@ dist_script_DATA = \
   lib/mdate-sh \
   lib/missing \
   lib/mkinstalldirs \
-  lib/elisp-comp \
   lib/ylwrap \
   lib/depcomp \
   lib/compile \
diff --git a/automake.in b/automake.in
index 15d545d..92ad9a6 100644
--- a/automake.in
+++ b/automake.in
@@ -231,7 +231,7 @@ my @common_files =
     (qw(ABOUT-GNU ABOUT-NLS AUTHORS BACKLOG COPYING COPYING.DOC COPYING.LIB
        COPYING.LESSER ChangeLog INSTALL NEWS README THANKS TODO
        ar-lib compile config.guess config.rpath
-       config.sub depcomp elisp-comp install-sh libversion.in mdate-sh
+       config.sub depcomp install-sh libversion.in mdate-sh
        missing mkinstalldirs py-compile texinfo.tex ylwrap),
      @libtool_files, @libtool_sometimes);
 
@@ -4999,8 +4999,6 @@ sub handle_emacs_lisp
 
   require_variables ($elfiles[0][0], "Emacs Lisp sources seen", TRUE,
                     'EMACS', 'lispdir');
-  require_conf_file ($elfiles[0][0], FOREIGN, 'elisp-comp');
-  &define_variable ('elisp_comp', "$am_config_aux_dir/elisp-comp", INTERNAL);
 }
 
 # Handle Python
diff --git a/doc/automake.texi b/doc/automake.texi
index 9ef7e9f..a34b401 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -2281,9 +2281,6 @@ generate not only the desired output but also dependency 
information
 that is then used by the automatic dependency tracking feature
 (@pxref{Dependencies}).
 
address@hidden elisp-comp
-This program is used to byte-compile Emacs Lisp code.
-
 @item install-sh
 This is a replacement for the @command{install} program that works on
 platforms where @command{install} is unavailable or unusable.
@@ -2929,7 +2926,6 @@ Automake will look for various helper scripts, such as
 @file{config.guess},
 @file{config.sub},
 @file{depcomp},
address@hidden,
 @file{compile},
 @file{install-sh},
 @file{ltmain.sh},
diff --git a/lib/am/lisp.am b/lib/am/lisp.am
index 4a96eb0..0d355f5 100644
--- a/lib/am/lisp.am
+++ b/lib/am/lisp.am
@@ -22,60 +22,19 @@ endif %?INSTALL%
 ## Building.  ##
 ## ---------- ##
 
-elc-stamp: $(LISP)
-       @echo 'WARNING: Warnings can be ignored. :-)'
-       @rm -f elc-temp && touch elc-temp
-       if test "$(EMACS)" != no; then \
-## Make sure "$@" isn't empty initially.
-         set x; \
-## Populate "$@" with elisp files (found in the current directory
-## or in $srcdir).
-         list='$(LISP)'; for p in $$list; do \
-           if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
-           set x "$$@" "$$d$$p"; shift; \
-         done; \
-## Finally call elisp-comp for all files.
-         shift; \
-         abs_srcdir="$(abs_srcdir)" EMACS="$(EMACS)" $(SHELL) \
-           $(elisp_comp) "$$@" || exit 1; \
-       else : ; fi
-       @mv -f elc-temp $@
-
-## Do not use $(ELCFILES) as target, because it may have been emptied
-## by the user (to disable byte-compilation), and POSIX does not allow
-## an empty target.
-$(am__ELCFILES): elc-stamp
-## Recover from the removal of address@hidden
-##
-## Do not call "make elc-stamp" if emacs is not available, because it would
-## be useless.
-##
-## If "make -n" is called, do not execute any command in the recipe that
-## changes the tree; however, invoke the recursive make for debuggability.
-       @if $(am__make_dryrun); then dry=:; else dry=; fi; \
-       if test "$(EMACS)" != no && test ! -f $@; then \
-## If "make -j" is used and more than one file has been erased, several
-## processes can execute this block.  We have to make sure that only
-## the first one will run "$(MAKE) $(AM_MAKEFLAGS) elc-stamp", and the
-## other ones will wait.
-##
-## There is a race here if only one child of make receive a signal.
-## In that case the build may fail.  We remove elc-stamp when we receive
-## a signal so we are sure the build will succeed the next time.
-         $$dry trap 'rm -rf elc-lock elc-stamp' 1 2 13 15; \
-         if $$dry mkdir elc-lock 2>/dev/null; then \
-## This code is being executed by the first process.
-           $$dry rm -f elc-stamp; \
-           $(MAKE) $(AM_MAKEFLAGS) elc-stamp; \
-           $$dry rmdir elc-lock; \
-         else \
-## This code is being executed by the follower processes.
-## Wait until the first process is done.
-           while test -d elc-lock && test -z "$$dry"; do sleep 1; done; \
-## Succeed if and only if the first process succeeded.
-           $$dry test -f elc-stamp; exit $$?; \
-         fi; \
-       else : ; fi
+.el.elc:
+## We add $(abs_builddir) and $(abs_srcdir) to load-path, so that any
+## .el files that $< depends upon can be found (including generated
+## ones). The destination file is normally determined by appending "c"
+## to the input (which would put it in $(srcdir)), so we override
+## that, too.
+       if test "$(EMACS)" != "no"; then \
+         $(EMACS) -q --batch \
+           --eval "(setq load-path (cons \"$(abs_builddir)\" load-path))" \
+           --eval "(setq load-path (cons \"$(abs_srcdir)\" load-path))" \
+           --eval "(defun byte-compile-dest-file (f) \"address@hidden")" \
+           --eval "(unless (byte-compile-file \"$<\") (kill-emacs 1))"; \
+       else :; fi
 
 
 ## ------------ ##
@@ -144,7 +103,7 @@ endif %?INSTALL%
 
 .PHONY clean-am: clean-lisp
 clean-lisp:
-       -rm -f elc-stamp $(ELCFILES)
+       -rm -f $(ELCFILES)
 
 
 ## -------------- ##
diff --git a/lib/elisp-comp b/lib/elisp-comp
deleted file mode 100755
index 5e888bd..0000000
--- a/lib/elisp-comp
+++ /dev/null
@@ -1,93 +0,0 @@
-#!/bin/sh
-# Copyright (C) 1995-2012 Free Software Foundation, Inc.
-
-scriptversion=2012-07-05.17; # UTC
-
-# Franc,ois Pinard <address@hidden>, 1995.
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# As a special exception to the GNU General Public License, if you
-# distribute this file as part of a program that contains a
-# configuration script generated by Autoconf, you may include it under
-# the same distribution terms that you use for the rest of that program.
-
-# This file is maintained in Automake, please report
-# bugs to <address@hidden> or send patches to
-# <address@hidden>.
-
-case $1 in
-  '')
-     echo "$0: No files.  Try '$0 --help' for more information." 1>&2
-     exit 1;
-     ;;
-  -h | --h*)
-    cat <<\EOF
-Usage: elisp-comp [--help] [--version] FILES...
-
-This script byte-compiles all '.el' files listed as FILES using GNU
-Emacs, and put the resulting '.elc' files into the current directory,
-so disregarding the original directories used in '.el' arguments.
-
-This script manages in such a way that all Emacs LISP files to
-be compiled are made visible between themselves, in the event
-they require or load-library one another.
-
-Report bugs to <address@hidden>.
-EOF
-    exit $?
-    ;;
-  -v | --v*)
-    echo "elisp-comp $scriptversion"
-    exit $?
-    ;;
-esac
-
-if test -z "$EMACS" || test "$EMACS" = "t"; then
-  # Value of "t" means we are running in a shell under Emacs.
-  # Just assume Emacs is called "emacs".
-  EMACS=emacs
-fi
-
-tempdir=elc.$$
-
-# Cleanup the temporary directory on exit.
-trap 'ret=$?; rm -rf "$tempdir" && exit $ret' 0
-do_exit='(exit $ret); exit $ret'
-trap "ret=129; $do_exit" 1
-trap "ret=130; $do_exit" 2
-trap "ret=141; $do_exit" 13
-trap "ret=143; $do_exit" 15
-
-mkdir $tempdir
-cp "$@" $tempdir
-
-(
-  cd $tempdir
-  echo "(setq load-path (cons nil (cons \"$abs_srcdir\" load-path)))" > script
-  $EMACS -batch -q -l script -f batch-byte-compile *.el || exit $?
-  mv *.elc ..
-) || exit $?
-
-(exit 0); exit 0
-
-# Local Variables:
-# mode: shell-script
-# sh-indentation: 2
-# eval: (add-hook 'write-file-hooks 'time-stamp)
-# time-stamp-start: "scriptversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
-# time-stamp-time-zone: "UTC"
-# time-stamp-end: "; # UTC"
-# End:
diff --git a/t/add-missing.tap b/t/add-missing.tap
index c47382b..f15657a 100755
--- a/t/add-missing.tap
+++ b/t/add-missing.tap
@@ -343,17 +343,6 @@ rm -f foo.texi
 
 check_ <<'END'
 == Name ==
-elisp-comp
-== Files ==
-elisp-comp
-== configure.ac ==
-AM_PATH_LISPDIR
-== Makefile.am ==
-lisp_LISP = foo.el
-END
-
-check_ <<'END'
-== Name ==
 py-compile
 == Files ==
 py-compile
diff --git a/t/dist-auxdir-many-subdirs.sh b/t/dist-auxdir-many-subdirs.sh
index d509836..4937a14 100755
--- a/t/dist-auxdir-many-subdirs.sh
+++ b/t/dist-auxdir-many-subdirs.sh
@@ -56,8 +56,6 @@ END
     foo_SOURCES = foo.c
     ## For py-compile.
     python_PYTHON = bar.py
-    ## For elisp-comp.
-    lisp_LISP = baz.el
     ## For test-driver.
     TESTS =
 END
@@ -67,7 +65,6 @@ END
     missing
     depcomp
     py-compile
-    elisp-comp
     test-driver
   '
 
diff --git a/t/lisp3.sh b/t/lisp3.sh
index 5b95715..a752151 100755
--- a/t/lisp3.sh
+++ b/t/lisp3.sh
@@ -47,7 +47,6 @@ $MAKE
 test -f am-one.elc
 test -f am-two.elc
 test -f am-three.elc
-test -f elc-stamp
 
 # Make sure we can recover from a deletion.
 rm -f am-one.elc
@@ -79,15 +78,6 @@ test -f _inst/$dir/site-lisp/am-three.elc
 $MAKE uninstall
 find _inst | $EGREP '\.elc?$' && exit 1
 
-# Make sure we build all files when any of them change.
-# (We grep a message to make sure the compilation happens.)
-unique=0a3346e2af8a689b85002b53df09142a
-$sleep
-echo "(message \"$unique\")(provide 'am-three)" > am-three.el
-$MAKE >output 2>&1 || { cat output; exit 1; }
-cat output
-grep $unique output
-
 # It should also work for VPATH-builds.
 $MAKE distcheck
 
diff --git a/t/lisp4.sh b/t/lisp4.sh
index b8cb796..41dc873 100755
--- a/t/lisp4.sh
+++ b/t/lisp4.sh
@@ -32,7 +32,6 @@ test:
        test ! -f am-one.elc
        test ! -f am-two.elc
        test ! -f am-three.elc
-       test ! -f elc-stamp
 
 install-test: install
        test -f "$(lispdir)/am-one.el"
diff --git a/t/lisp5.sh b/t/lisp5.sh
index 4d0499c..c154e3c 100755
--- a/t/lisp5.sh
+++ b/t/lisp5.sh
@@ -31,7 +31,6 @@ test:
        test ! -f am-one.elc
        test ! -f am-two.elc
        test ! -f am-three.elc
-       test ! -f elc-stamp
 
 install-test: install
        test -f "$(lispdir)/am-one.el"
diff --git a/t/lisp6.sh b/t/lisp6.sh
index e877d5a..c84917c 100755
--- a/t/lisp6.sh
+++ b/t/lisp6.sh
@@ -57,7 +57,6 @@ $MAKE
 test -f am-one.elc
 test ! -e am-two.elc
 test -f am-three.elc
-test -f elc-stamp
 
 $MAKE install
 test -f lisp/am-one.el
@@ -73,7 +72,6 @@ $MAKE distclean
 test ! -e am-one.elc
 test ! -e am-two.elc
 test ! -e am-three.elc
-test ! -e elc-stamp
 
 ./configure --with-lispdir="$cwd/lisp" want_two=1
 
@@ -81,7 +79,6 @@ $MAKE
 test -f am-one.elc
 test -f am-two.elc
 test -f am-three.elc
-test -f elc-stamp
 
 # Let's mutilate the source tree, to check the recover rule.
 rm -f am-*.elc
@@ -89,7 +86,6 @@ $MAKE
 test -f am-one.elc
 test -f am-two.elc
 test -f am-three.elc
-test -f elc-stamp
 
 $MAKE install
 test -f lisp/am-one.el
@@ -105,6 +101,5 @@ $MAKE distclean
 test ! -e am-one.elc
 test ! -e am-two.elc
 test ! -e am-three.elc
-test ! -e elc-stamp
 
 :
diff --git a/t/lisp7.sh b/t/lisp7.sh
index 4553298..7efa27f 100755
--- a/t/lisp7.sh
+++ b/t/lisp7.sh
@@ -39,12 +39,10 @@ $AUTOMAKE --add-missing
 
 $MAKE >stdout || { cat stdout; exit 1; }
 cat stdout
-test 1 -eq $(grep -c 'Warnings can be ignored' stdout)
 
 test ! -e am-one.elc
 test ! -e am-two.elc
 test ! -e am-three.elc
-test -f elc-stamp
 
 $MAKE distcheck
 
diff --git a/t/lisp8.sh b/t/lisp8.sh
index 6e6b901..7464c68 100755
--- a/t/lisp8.sh
+++ b/t/lisp8.sh
@@ -42,12 +42,10 @@ $AUTOMAKE --add-missing
 $MAKE -j >>stdout || { cat stdout; exit 1; }
 
 cat stdout
-test 1 -eq $(grep -c 'Warnings can be ignored' stdout)
 
 test -f am-one.elc
 test -f am-two.elc
 test -f am-three.elc
-test -f elc-stamp
 
 rm -f am-*.elc
 
@@ -56,10 +54,8 @@ rm -f am-*.elc
 $MAKE -j >>stdout || { cat stdout; exit 1; }
 
 cat stdout
-test 1 -eq $(grep -c 'Warnings can be ignored' stdout)
 test -f am-one.elc
 test -f am-two.elc
 test -f am-three.elc
-test -f elc-stamp
 
 :
diff --git a/t/lispdry.sh b/t/lispdry.sh
index f7de071..765942d 100755
--- a/t/lispdry.sh
+++ b/t/lispdry.sh
@@ -42,9 +42,8 @@ $MAKE
 test -f am-one.elc
 test -f am-two.elc
 test -f am-three.elc
-test -f elc-stamp
 
-rm -f am-*.elc elc-stamp
+rm -f am-*.elc
 
 chmod a-w .
 
@@ -53,6 +52,5 @@ $MAKE -n
 test ! -e am-one.elc
 test ! -e am-two.elc
 test ! -e am-three.elc
-test ! -e elc-stamp
 
 :
diff --git a/t/primary-prefix-invalid-couples.tap 
b/t/primary-prefix-invalid-couples.tap
index dadf38d..86d7665 100755
--- a/t/primary-prefix-invalid-couples.tap
+++ b/t/primary-prefix-invalid-couples.tap
@@ -29,7 +29,6 @@ oIFS=$IFS # Saved for later.
 : > ar-lib
 : > ltmain.sh
 : > texinfo.tex
-: > elisp-comp
 : > py-compile
 : > config.guess
 : > config.sub
diff --git a/t/primary-prefix-valid-couples.sh 
b/t/primary-prefix-valid-couples.sh
index 778d1a1..1890369 100755
--- a/t/primary-prefix-valid-couples.sh
+++ b/t/primary-prefix-valid-couples.sh
@@ -41,7 +41,6 @@ END
 echo '@setfilename foo' > foo.texi
 : > texinfo.tex
 : > py-compile
-: > elisp-comp
 : > ar-lib
 
 # Setup Makefile.am.
-- 
1.7.9.5