alternative from mk/jpeg.buildlink3.mk
This allows selection of an alternative jpeg library (namely the x86 MMX,
SSE, SSE2 accelerated libjpeg-turbo) via JPEG_DEFAULT=libjpeg-turbo, and
follows the current standard model for alternatives (fam, motif, fuse etc).
The mechanical edits were applied via the following script:
#!/bin/sh
for d in */*; do
[ -d "$d" ] || continue
for i in "$d/"Makefile* "$d/"*.mk; do
case "$i" in *.orig|*"*"*) continue;; esac
out="$d/x"
sed -e 's;graphics/jpeg/buildlink3\.mk;mk/jpeg.buildlink3.mk;g' \
-e 's;BUILDLINK_PREFIX\.jpeg;JPEGBASE;g' \
< "$i" > "$out"
if cmp -s "$i" "$out"; then
rm -f "$out"
else
echo "Edited $i"
mv -f "$i" "$i.orig" && mv "$out" "$i"
fi
done
done
This changes the buildlink3.mk files to use an include guard for the
recursive include. The use of BUILDLINK_DEPTH, BUILDLINK_DEPENDS,
BUILDLINK_PACKAGES and BUILDLINK_ORDER is handled by a single new
variable BUILDLINK_TREE. Each buildlink3.mk file adds a pair of
enter/exit marker, which can be used to reconstruct the tree and
to determine first level includes. Avoiding := for large variables
(BUILDLINK_ORDER) speeds up parse time as += has linear complexity.
The include guard reduces system time by avoiding reading files over and
over again. For complex packages this reduces both %user and %sys time to
half of the former time.
