1 files changed, 51 insertions, 52 deletions

diff --git a/scripts/gen_build_files.sh b/scripts/gen_build_files.sh
index 09a95b507..03831f501 100755
--- a/scripts/gen_build_files.sh
+++ b/scripts/gen_build_files.sh
@@ -9,43 +9,58 @@ 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}"
+        (
+                # 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:
+                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"
+        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 -- "$srctree" && find . -type d; } | while read -r d; do
@@ -55,40 +70,24 @@ fi
         dst="$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