Make "make" do a bootstrap if needed.

* src/Makefile.in (emacs${EXEEXT}): Link the new emacs to bootstrap-emacs.
(bootstrapclean): Remove.
(.el.elc): New rule.
(PRECOMP): New var.
(../lisp/subdirs.el): Remove.
(bootstrap-emacs${EXEEXT}): Remove subdirs.el and charpro.el dependency.
(witness-emacs): New target.
(mostlyclean): Remove witness-emacs as well.
(../lisp/loaddefs.el, ${lisp} ${SOME_MACHINE_LISP}):
Add witness-emacs dependency.
* lisp/loadup.el: Don't add emacs-<VERS> name when bootstrapping.
* lisp/Makefile.in (emacs-deps): Remove.
($(lisp)/cus-load.el, $(lisp)/finder-inf.el): Re-add.
(all): Use them.
(autogen-clean): Remove.
* Makefile.in (maybe_bootstrap, src/bootstrap-emacs${EXEEXT})
(bootstrap-build): Remove.
(top_bootclean): New var.
(top_distclean, bootstrap-clean): Use it.
(bootstrap): Don't recheck config.  Make normally.

2 files changed, 53 insertions, 12 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 83405f2e414..c3476f667d8 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2008-06-21  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * Makefile.in (emacs${EXEEXT}): Link the new emacs to bootstrap-emacs.
+        (bootstrapclean): Remove.
+        (.el.elc): New rule.
+        (PRECOMP): New var.
+        (../lisp/subdirs.el): Remove.
+        (bootstrap-emacs${EXEEXT}): Remove subdirs.el and charpro.el dependency.
+        (witness-emacs): New target.
+        (mostlyclean): Remove witness-emacs as well.
+        (../lisp/loaddefs.el, ${lisp} ${SOME_MACHINE_LISP}):
+        Add witness-emacs dependency.
+
 2008-06-20  Chong Yidong  <cyd@stupidchicken.com>
 
         * font.c (Ffont_face_attributes): Omit key-attribute pairs not
diff --git a/src/Makefile.in b/src/Makefile.in
index 85b1c6c0f34..7f93441039a 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -912,6 +912,9 @@ emacs${EXEEXT}: temacs${EXEEXT} ${etc}DOC ${lisp} ${SOME_MACHINE_LISP}
         ln temacs${EXEEXT} emacs${EXEEXT}
 #else
         LC_ALL=C $(RUN_TEMACS) -batch -l loadup dump
+        @: This new Emacs is as functional and more efficient then
+        @: bootstrap-emacs, so let us replace it.
+        -ln -f emacs${EXEEXT} bootstrap-emacs${EXEEXT}
 #endif /* ! defined (CANNOT_DUMP) */
         -./emacs -q -batch -f list-load-path-shadows
 
@@ -1268,12 +1271,10 @@ ${emacsapp}Contents/MacOS/Emacs: emacs${EXEEXT}
         cd ${emacsapp}Contents/MacOS/; cp ../../../../src/emacs${EXEEXT} Emacs${EXEEXT}
 #endif
 
-bootstrapclean:
-        rm -f bootstrap-emacs${EXEEXT} emacs-${version}${EXEEXT}
 mostlyclean:
         rm -f temacs${EXEEXT} prefix-args${EXEEXT} core *.core \#* *.o libXMenu11.a liblw.a
         rm -f ../etc/DOC
-        rm -f bootstrap-emacs${EXEEXT} emacs-${version}${EXEEXT}
+        rm -f bootstrap-emacs${EXEEXT} emacs-${version}${EXEEXT} witness-emacs
         rm -f buildobj.lst
 clean: mostlyclean
         rm -f emacs-*.*.*${EXEEXT} emacs${EXEEXT}
@@ -1319,22 +1320,49 @@ tags: TAGS TAGS-LISP $(lwlibdir)TAGS
 
 
 /* Bootstrapping.  */
-
-bootstrap: bootstrap-emacs${EXEEXT}
-
-../lisp/subdirs.el:
-        cd $(lispsource); $(MAKE) update-subdirs
-
-../lisp/loaddefs.el: bootstrap-emacs${EXEEXT}
-        cd $(lispsource); $(MAKE) autoloads EMACS=../src/bootstrap-emacs${EXEEXT}
+/* Bootstrapping right is difficult because of the circular dependencies.
+   Furthermore, we have to deal with the fact that many compilation targets
+   such as loaddefs.el or *.elc can typically be produced by any old
+   Emacs executable, so we would like to avoid rebuilding them whenever
+   we build a new Emacs executable.
+   To solve the circularity, we use 2 different Emacs executables,
+   "emacs" is the main target and "bootstrap-emacs" is the one used
+   to build the *.elc and loaddefs.el files.
+   To solve the freshness issue, we use a third file "witness-emacs"
+   which is used to witness the fact that there is a bootstrap-emacs
+   executable.  */
+
+/* These suffix rules do not allow additional dependencies, sadly, so
+   adding a bootstrap-emacs%{EXEEXT} dependency does not work --Stef */
+.el.elc:
+        cd ${lispsource}; $(MAKE) $(MFLAGS) $@ EMACS=../src/bootstrap-emacs${EXEEXT}
+
+/* Files that need to be compiled early to speed up further compilation.  */
+PRECOMP=../lisp/emacs-lisp/bytecomp.elc ../lisp/emacs-lisp/byte-opt.elc
+${PRECOMP}: witness-emacs
+
+/* Since the .el.elc rule cannot specify an extra dependency, we do it here.
+   The byte-compiler dependency is not necessary, but it substantially
+   speeds up byte-compilation of the other files.
+   Of course, it also has the downside of forcing a recompilation of all
+   those files whenever a file in $PRECOMP changes.  */
+${lisp} ${SOME_MACHINE_LISP}: witness-emacs ${PRECOMP}
+
+../lisp/loaddefs.el: witness-emacs
+        cd $(lispsource); $(MAKE) $(MFLAGS) autoloads EMACS=../src/bootstrap-emacs${EXEEXT}
 
 /* Dump an Emacs executable named bootstrap-emacs containing the
    files from loadup.el in source form.  */
 
-bootstrap-emacs${EXEEXT}: temacs${EXEEXT} ${lispsource}international/charprop.el ../lisp/subdirs.el
+bootstrap-emacs${EXEEXT}: temacs${EXEEXT}
 #ifdef CANNOT_DUMP
         ln temacs${EXEEXT} bootstrap-emacs${EXEEXT}
 #else
         $(RUN_TEMACS) --batch --load loadup bootstrap
         mv -f emacs${EXEEXT} bootstrap-emacs${EXEEXT}
 #endif /* ! defined (CANNOT_DUMP) */
+
+witness-emacs:
+        cd $(lispsource); $(MAKE) $(MFLAGS) update-subdirs
+        $(MAKE) $(MFLAGS) bootstrap-emacs${EXEEXT}
+        touch witness-emacs