Fix race in 'make info/dir', and speed it up.

* Makefile.in (AWK, srcdir_doc_info_dir_inputs, info_dir_inputs):
New macros.
(clean): Remove info-dir.*.
(info_dir_deps): Depend on make-info-dir too.
Fix bug with wildcards that weren't expanded.
(${srcdir}/info/dir): Make sure info directory exists.
Don't call pwd; just redirect make-info-dir's stdout to temp file.
* build-aux/make-info-dir: Send output to stdout.
Take input file names from args.
Fix a "FIXME inefficient looping" by using awk's associative arrays.
Basically, this rewrites the script from scratch, and speeds up
'make info/dir' from 2.6s to 0.07s on my platform.

3 files changed, 74 insertions, 80 deletions

diff --git a/ChangeLog b/ChangeLog
index 1772536c29a..534a34d103f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2014-10-23  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Fix race in 'make info/dir', and speed it up.
+	* Makefile.in (AWK, srcdir_doc_info_dir_inputs, info_dir_inputs):
+	New macros.
+	(clean): Remove info-dir.*.
+	(info_dir_deps): Depend on make-info-dir too.
+	Fix bug with wildcards that weren't expanded.
+	(${srcdir}/info/dir): Make sure info directory exists.
+	Don't call pwd; just redirect make-info-dir's stdout to temp file.
+	* build-aux/make-info-dir: Send output to stdout.
+	Take input file names from args.
+	Fix a "FIXME inefficient looping" by using awk's associative arrays.
+	Basically, this rewrites the script from scratch, and speeds up
+	'make info/dir' from 2.6s to 0.07s on my platform.
+
 2014-10-20  Glenn Morris  <rgm@gnu.org>
 
 	* Merge in all changes up to 24.4 release.
diff --git a/Makefile.in b/Makefile.in
index dee3f7167a1..57d97d7eafc 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -80,6 +80,7 @@ AUTOCONF = @AUTOCONF@
 AUTOMAKE = @AUTOMAKE@
 AUTOHEADER = @AUTOHEADER@
 ACLOCAL = @ACLOCAL@
+AWK = @AWK@
 
 EXEEXT=@EXEEXT@
 
@@ -817,6 +818,7 @@ clean: $(clean_dirs:=_clean)
 	  [ ! -d $$dir ] || $(MAKE) -C $$dir clean; \
 	done
 	-rm -f etc/emacs.tmpdesktop etc/emacs.tmpappdata
+	-rm -rf info-dir.*
 
 ### `bootclean'
 ###      Delete all files that need to be remade for a clean bootstrap.
@@ -935,13 +937,19 @@ ps: $(PSS)
 
 info-dir: ${srcdir}/info/dir
 
-## Not strictly necessary, but speeds things up a bit by stopping
-## the info-dir rule from running when not needed.
 ## Hopefully doc/misc/*.texi is not too long for some systems?
-info_dir_deps = ${srcdir}/build-aux/dir_top \
-	${srcdir}/doc/emacs/emacs.texi \
-	${srcdir}/doc/lispintro/emacs-lisp-intro.texi \
-	${srcdir}/doc/lispref/elisp.texi ${srcdir}/doc/misc/*.texi
+srcdir_doc_info_dir_inputs = \
+  ${srcdir}/doc/emacs/emacs.texi \
+  ${srcdir}/doc/lispintro/emacs-lisp-intro.texi \
+  ${srcdir}/doc/lispref/elisp.texi \
+  $(sort $(wildcard ${srcdir}/doc/misc/*.texi))
+info_dir_inputs = \
+  ../build-aux/dir_top \
+  $(subst ${srcdir}/doc/,,${srcdir_doc_info_dir_inputs})
+info_dir_deps = \
+  ${srcdir}/build-aux/make-info-dir \
+  ${srcdir}/build-aux/dir_top \
+  ${srcdir_doc_info_dir_inputs}
 
 ## It would be much simpler if info/dir was only created in the
 ## installation location by the install-info rule, but we also
@@ -950,10 +958,12 @@ info_dir_deps = ${srcdir}/build-aux/dir_top \
 ## but then we would need to depend on info-real, which would
 ## slow down parallelization.
 ${srcdir}/info/dir: ${info_dir_deps}
+	${MKDIR_P} ${srcdir}/info
 	tempfile=info-dir.$$$$; \
 	rm -f $${tempfile}; \
-	thisdir=`pwd`; \
-	(cd ${srcdir} && ./build-aux/make-info-dir $${thisdir}/$${tempfile}); \
+	(cd ${srcdir}/doc && \
+	 AWK='${AWK}' ../build-aux/make-info-dir ${info_dir_inputs} \
+	) >$$tempfile && \
 	${srcdir}/build-aux/move-if-change $${tempfile} ${srcdir}/info/dir
 
 INSTALL_DVI = install-emacs-dvi install-lispref-dvi \
diff --git a/build-aux/make-info-dir b/build-aux/make-info-dir
index 3f927382ded..10a0b75fd6a 100755
--- a/build-aux/make-info-dir
+++ b/build-aux/make-info-dir
@@ -31,76 +31,44 @@
 ## installation directory.  It does not handle info/dir being present
 ## but missing some entries.
 
-### Code:
-
-if test $# -ne 1; then
-    echo "Specify destination file"
-    exit 1
-fi
-
-outfile=$1
-
-echo "Creating $outfile..."
-
-if test -f "$outfile"; then
-    echo "$outfile already present"
-    exit 1
-fi
-
 ## Header contains non-printing characters, so this is more
-## reliable than using echo.
-basefile=build-aux/dir_top
-
-if test ! -f "$basefile"; then
-    echo "$basefile not found"
-    exit 1
-fi
-
-
-cp $basefile $outfile
-
-
-## FIXME inefficient looping.
-## What we should do is loop once over files, collecting topic and
-## direntry information for each.  Then loop over topics and write
-## out the results.  But that seems to require associative arrays,
-## and I do not know how to do that with portable sh.
-## Could use Emacs instead of sh, but till now info generation does
-## not require Emacs to have been built.
-for topic in "Texinfo documentation system" "Emacs" "Emacs lisp" \
-    "Emacs editing modes" "Emacs network features" "Emacs misc features" \
-    "Emacs lisp libraries"; do
-
-    cat - <<EOF >> $outfile
-
-$topic
-EOF
-    ## Bit faster than doc/*/*.texi.
-    for file in doc/emacs/emacs.texi doc/lispintro/emacs-lisp-intro.texi \
-        doc/lispref/elisp.texi doc/misc/*.texi; do
-
-        ## FIXME do not ignore w32 if OS is w32.
-        case $file in
-            *-xtra.texi|*efaq-w32.texi|*doclicense.texi) continue ;;
-        esac
-
-        dircat=`sed -n -e 's/@value{emacsname}/Emacs/' -e 's/^@dircategory //p' $file`
-
-        ## TODO warn about unknown topics.
-        ## (check-info in top-level Makefile does that.)
-        test "$dircat" = "$topic" || continue
-
-
-        sed -n -e 's/@value{emacsname}/Emacs/' \
-            -e 's/@acronym{\([A-Z]*\)}/\1/' \
-            -e '/^@direntry/,/^@end direntry/ s/^\([^@]\)/\1/p' \
-            $file >> $outfile
-
-    done
-done
-
-echo "Created $outfile"
-
-exit 0
-
-### make-info-dir ends here
+## reliable than using awk.
+cat <"${1?}" || exit
+shift
+
+exec "${AWK-awk}" '
+  function detexinfo() {
+    gsub(/@value{emacsname}/, "Emacs")
+    gsub(/@[^{]*\{/, "")
+    gsub(/}/, "")
+  }
+  BEGIN {
+    ntopics = 0
+    topic[ntopics++] = "Texinfo documentation system"
+    topic[ntopics++] = "Emacs"
+    topic[ntopics++] = "Emacs lisp"
+    topic[ntopics++] = "Emacs editing modes"
+    topic[ntopics++] = "Emacs network features"
+    topic[ntopics++] = "Emacs misc features"
+    topic[ntopics++] = "Emacs lisp libraries"
+    topic[ntopics] = "Unknown category"
+  }
+  /^@dircategory / {
+    sub(/^@dircategory /, "")
+    detexinfo()
+    for (dircat = 0; dircat < ntopics && topic[dircat] != $0; dircat++)
+      continue;
+  }
+  /^@direntry/, /^@end direntry/ {
+    # FIXME do not ignore w32 if OS is w32.
+    if ($0 !~ /^@/ && $0 !~ /w32/) {
+      detexinfo()
+      data[dircat] = data[dircat] $0 "\n"
+    }
+  }
+  END {
+    for (dircat = 0; dircat <= ntopics; dircat++)
+      if (data[dircat])
+        printf "\n%s\n%s", topic[dircat], data[dircat]
+  }
+' "${@?}"