gen_build_files: don't pass 200k+ strings as params. Closes 4321

Also removes one grep per generated file.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/scripts/gen_build_files.sh b/scripts/gen_build_files.sh
index e518a90..1a3d3e9 100755 (executable)
--- a/scripts/gen_build_files.sh
+++ b/scripts/gen_build_files.sh
@@ -19,25 +19,20 @@ chk() { status "CHK" "$@"; }
 
 generate()
 {
-       local src="$1" dst="$2" header="$3" insert="$4"
+       # NB: data to be inserted at INSERT line is coming on stdin
+       local src="$1" dst="$2" header="$3"
        #chk "${dst}"
-       (
+       {
                # Need to use printf: different shells have inconsistent
-               # rules re handling of "\n" in echo params,
-               # and ${insert} definitely contains "\n".
-               # Therefore, echo "${header}" would not work:
+               # rules re handling of "\n" in echo params.
                printf "%s\n" "${header}"
-               if grep -qs '^INSERT$' "${src}"; then
-                       sed -n '1,/^INSERT$/p' "${src}"
-                       printf "%s\n" "${insert}"
-                       sed -n '/^INSERT$/,$p' "${src}"
-               else
-                       if [ -n "${insert}" ]; then
-                               printf "%s\n" "ERROR: INSERT line missing in: ${src}" 1>&2
-                       fi
-                       cat "${src}"
-               fi
-       ) | sed '/^INSERT$/d' > "${dst}.tmp"
+               # print everything up to INSERT line
+               sed -n '/^INSERT$/q;1,/^INSERT$/p' "${src}"
+               # copy stdin to stdout
+               cat
+               # print everything after INSERT line
+               sed -n '/^INSERT$/{:l;n;p;bl}' "${src}"
+       } >"${dst}.tmp"
        if ! cmp -s "${dst}" "${dst}.tmp"; then
                gen "${dst}"
                mv "${dst}.tmp" "${dst}"
@@ -47,24 +42,21 @@ generate()
 }
 
 # (Re)generate include/applets.h
-s=`sed -n 's@^//applet:@@p' "$srctree"/*/*.c "$srctree"/*/*/*.c`
-generate \
+sed -n 's@^//applet:@@p' "$srctree"/*/*.c "$srctree"/*/*/*.c \
+| generate \
        "$srctree/include/applets.src.h" \
        "include/applets.h" \
-       "/* DO NOT EDIT. This file is generated from applets.src.h */" \
-       "${s}"
+       "/* DO NOT EDIT. This file is generated from applets.src.h */"
 
 # (Re)generate 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`
-generate \
+sed -n -e 's@^//usage:\([ \t].*\)$@\1 \\@p' -e 's@^//usage:\([^ \t].*\)$@\n\1 \\@p' "$srctree"/*/*.c "$srctree"/*/*/*.c \
+| generate \
        "$srctree/include/usage.src.h" \
        "include/usage.h" \
-       "/* DO NOT EDIT. This file is generated from usage.src.h */" \
-       "${s}"
+       "/* DO NOT EDIT. This file is generated from usage.src.h */"
 
 # (Re)generate */Kbuild and */Config.in
 { cd -- "$srctree" && find . -type d; } | while read -r d; do
@@ -75,11 +67,10 @@ generate \
        if test -f "$src"; then
                mkdir -p -- "$d" 2>/dev/null
 
-               s=`sed -n 's@^//kbuild:@@p' "$srctree/$d"/*.c`
-               generate \
+               sed -n 's@^//kbuild:@@p' "$srctree/$d"/*.c \
+               | generate \
                        "${src}" "${dst}" \
-                       "# DO NOT EDIT. This file is generated from Kbuild.src" \
-                       "${s}"
+                       "# DO NOT EDIT. This file is generated from Kbuild.src"
        fi
 
        src="$srctree/$d/Config.src"
@@ -87,11 +78,10 @@ generate \
        if test -f "$src"; then
                mkdir -p -- "$d" 2>/dev/null
 
-               s=`sed -n 's@^//config:@@p' "$srctree/$d"/*.c`
-               generate \
+               sed -n 's@^//config:@@p' "$srctree/$d"/*.c \
+               | generate \
                        "${src}" "${dst}" \
-                       "# DO NOT EDIT. This file is generated from Config.src" \
-                       "${s}"
+                       "# DO NOT EDIT. This file is generated from Config.src"
        fi
 done