gen_build_files.sh: rewrite with sed

The shell parsing of files is incredibly slow on many systems.  With
one report, the process was taking a minute or two which made people
thing the build was hung.  So rewrite the craziness with sed and proper
shell functions.  On an idle system, this cut the runtime by half.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Mike Frysinger 2010-11-16 07:29:12 -05:00
parent b78d561ec7
commit f718e3a0db

View File

@ -9,43 +9,54 @@ mkdir include 2>/dev/null
srctree="$1"
status() { printf ' %-8s%s\n' "$1" "$2"; }
gen() { status "GEN" "$@"; }
chk() { status "CHK" "$@"; }
generate()
{
local src="$1" dst="$2" header="$3" insert="$4"
#chk "${dst}"
(
echo "${header}"
if grep -qs '^INSERT$' "${src}"; then
sed -n '1,/^INSERT$/p' "${src}"
echo "${insert}"
sed -n '/^INSERT$/,$p' "${src}"
else
if [ -n "${insert}" ]; then
echo "ERROR: INSERT line missing in: ${src}" 1>&2
fi
cat "${src}"
fi
) | sed '/^INSERT$/d' > "${dst}.tmp"
if ! cmp -s "${dst}" "${dst}.tmp"; then
gen "${dst}"
mv "${dst}.tmp" "${dst}"
else
rm -f "${dst}.tmp"
fi
}
# (Re)generate include/applets.h
src="$srctree/include/applets.src.h"
dst="include/applets.h"
s=`sed -n 's@^//applet:@@p' -- "$srctree"/*/*.c "$srctree"/*/*/*.c`
old=`cat "$dst" 2>/dev/null`
# Why "IFS='' read -r REPLY"??
# This atrocity is needed to read lines without mangling.
# IFS='' prevents whitespace trimming,
# -r suppresses backslash handling.
new=`echo "/* DO NOT EDIT. This file is generated from applets.src.h */"
while IFS='' read -r REPLY; do
test x"$REPLY" = x"INSERT" && REPLY="$s"
printf "%s\n" "$REPLY"
done <"$src"`
if test x"$new" != x"$old"; then
echo " GEN $dst"
printf "%s\n" "$new" >"$dst"
fi
generate \
"$srctree/include/applets.src.h" \
"include/applets.h" \
"/* DO NOT EDIT. This file is generated from applets.src.h */" \
"${s}"
# (Re)generate include/usage.h
src="$srctree/include/usage.src.h"
dst="include/usage.h"
# We add line continuation backslash after each line,
# and insert empty line before each line which doesn't start
# with space or tab
# (note: we need to use \\\\ because of ``)
s=`sed -n -e 's@^//usage:\([ \t].*\)$@\1 \\\\@p' -e 's@^//usage:\([^ \t].*\)$@\n\1 \\\\@p' -- "$srctree"/*/*.c "$srctree"/*/*/*.c`
old=`cat "$dst" 2>/dev/null`
new=`echo "/* DO NOT EDIT. This file is generated from usage.src.h */"
while IFS='' read -r REPLY; do
test x"$REPLY" = x"INSERT" && REPLY="$s"
printf "%s\n" "$REPLY"
done <"$src"`
if test x"$new" != x"$old"; then
echo " GEN $dst"
printf "%s\n" "$new" >"$dst"
fi
generate \
"$srctree/include/usage.src.h" \
"include/usage.h" \
"/* DO NOT EDIT. This file is generated from usage.src.h */" \
"${s}"
# (Re)generate */Kbuild and */Config.in
{ cd -- "$srctree" && find . -type d; } | while read -r d; do
@ -55,42 +66,25 @@ fi
dst="$d/Kbuild"
if test -f "$src"; then
mkdir -p -- "$d" 2>/dev/null
#echo " CHK $dst"
s=`sed -n 's@^//kbuild:@@p' -- "$srctree/$d"/*.c`
old=`cat "$dst" 2>/dev/null`
new=`echo "# DO NOT EDIT. This file is generated from Kbuild.src"
while IFS='' read -r REPLY; do
test x"$REPLY" = x"INSERT" && REPLY="$s"
printf "%s\n" "$REPLY"
done <"$src"`
if test x"$new" != x"$old"; then
echo " GEN $dst"
printf "%s\n" "$new" >"$dst"
fi
generate \
"${src}" "${dst}" \
"# DO NOT EDIT. This file is generated from Kbuild.src" \
"${s}"
fi
src="$srctree/$d/Config.src"
dst="$d/Config.in"
if test -f "$src"; then
mkdir -p -- "$d" 2>/dev/null
#echo " CHK $dst"
s=`sed -n 's@^//config:@@p' -- "$srctree/$d"/*.c`
old=`cat "$dst" 2>/dev/null`
new=`echo "# DO NOT EDIT. This file is generated from Config.src"
while IFS='' read -r REPLY; do
test x"$REPLY" = x"INSERT" && REPLY="$s"
printf "%s\n" "$REPLY"
done <"$src"`
if test x"$new" != x"$old"; then
echo " GEN $dst"
printf "%s\n" "$new" >"$dst"
fi
generate \
"${src}" "${dst}" \
"# DO NOT EDIT. This file is generated from Config.src" \
"${s}"
fi
done
# Last read failed. This is normal. Don't exit with its error code:
exit 0