Changeset 2725 in MondoRescue for branches/2.2.9/mindi-busybox/scripts/trylink

Timestamp:

Feb 25, 2011, 9:26:54 PM (13 years ago)

Author:

Bruno Cornec

Message:

• Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3

File:

• branches/2.2.9/mindi-busybox/scripts/trylink (modified) (2 diffs)

branches/2.2.9/mindi-busybox/scripts/trylink

@@ -3 +3 @@
 debug=false
 
+# Linker flags used:
+#
+# Informational:
+# --warn-common
+# -Map $EXE.map
+# --verbose
+#
+# Optimizations:
+# --sort-common                 reduces padding
+# --sort-section alignment      reduces padding
+# --gc-sections                 throws out unused sections,
+#                               does not work for shared libs
+# -On                           Not used, maybe useful?
+#
+# List of files to link:
+# $l_list                       == --start-group -llib1 -llib2 --end-group
+# --start-group $O_FILES $A_FILES --end-group
+#
+# Shared library link:
+# -shared                       self-explanatory
+# -fPIC                         position-independent code
+# --enable-new-dtags            ?
+# -z,combreloc                  ?
+# -soname="libbusybox.so.$BB_VER"
+# --undefined=lbb_main          Seed name to start pulling from
+#                               (otherwise we'll need --whole-archive)
+# -static                       Not used, but may be useful! manpage:
+#                               "... This option can be used with -shared.
+#                               Doing so means that a shared library
+#                               is being created but that all of the library's
+#                               external references must be resolved by pulling
+#                               in entries from static libraries."
+
+
 try() {
-    added="$1"
-    shift
-    $debug && echo "Trying: $* $added"
-    "$@" $added 2>busybox_ld.err
-}
+    printf "%s\n" "Output of:" >$EXE.out
+    printf "%s\n" "$*" >>$EXE.out
+    printf "%s\n" "==========" >>$EXE.out
+    $debug && echo "Trying: $*"
+    $@ >>$EXE.out 2>&1
+    return $?
+}
+
+check_cc() {
+    local tempname="/tmp/temp.$$.$RANDOM"
+    # Can use "-o /dev/null", but older gcc tend to *unlink it* on failure! :(
+    # "-xc": C language. "/dev/null" is an empty source file.
+    if $CC $1 -shared -xc /dev/null -o "$tempname".o >/dev/null 2>&1; then
+    echo "$1";
+    else
+    echo "$2";
+    fi
+    rm "$tempname".o 2>/dev/null
+}
+
+check_libc_is_glibc() {
+    local tempname="/tmp/temp.$$.$RANDOM"
+    echo "\
+    #include <stdlib.h>
+    /* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */
+    #if defined(__GLIBC__) && !defined(__UCLIBC__)
+    syntax error here
+    #endif
+    " >"$tempname".c
+    if $CC "$tempname".c -c -o "$tempname".o >/dev/null 2>&1; then
+    echo "$2";
+    else
+    echo "$1";
+    fi
+    rm "$tempname".c "$tempname".o 2>/dev/null
+}
+
+EXE="$1"
+CC="$2"
+CFLAGS="$3"
+LDFLAGS="$4"
+O_FILES="$5"
+A_FILES="$6"
+LDLIBS="$7"
+
+# The --sort-section option is not supported by older versions of ld
+SORT_SECTION=`check_cc "-Wl,--sort-section,alignment" ""`
+
+START_GROUP="-Wl,--start-group"
+END_GROUP="-Wl,--end-group"
+INFO_OPTS="-Wl,--warn-common -Wl,-Map,$EXE.map -Wl,--verbose"
+
+# gold may not support --sort-common (yet)
+SORT_COMMON=`check_cc "-Wl,--sort-common" ""`
+
+# Static linking against glibc produces buggy executables
+# (glibc does not cope well with ld --gc-sections).
+# See sources.redhat.com/bugzilla/show_bug.cgi?id=3400
+# Note that glibc is unsuitable for static linking anyway.
+# We are removing -Wl,--gc-sections from link command line.
+GC_SECTIONS=`(
+. ./.config
+if test x"$CONFIG_STATIC" = x"y"; then
+    check_libc_is_glibc "" "-Wl,--gc-sections"
+else
+    echo "-Wl,--gc-sections"
+fi
+)`
+
+# The --gc-sections option is not supported by older versions of ld
+if test -n "$GC_SECTIONS"; then
+    GC_SECTIONS=`check_cc "$GC_SECTIONS" ""`
+fi
 
 # Sanitize lib list (dups, extra spaces etc)
-#echo "BBOX_LIB_LIST=$BBOX_LIB_LIST"
-BBOX_LIB_LIST=`echo "$BBOX_LIB_LIST" | xargs -n1 | sort | uniq | xargs`
+LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs`
 
 # First link with all libs. If it fails, bail out
-echo "Trying libraries: $BBOX_LIB_LIST"
-l_list=`echo "$BBOX_LIB_LIST" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
-test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
-try "$l_list" "$@" \
+echo "Trying libraries: $LDLIBS"
+# "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
+l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
+test "x$l_list" != "x" && l_list="$START_GROUP $l_list $END_GROUP"
+try $CC $CFLAGS $LDFLAGS \
+    -o $EXE \
+    $SORT_COMMON \
+    $SORT_SECTION \
+    $GC_SECTIONS \
+    $START_GROUP $O_FILES $A_FILES $END_GROUP \
+    $l_list \
 || {
-    echo "Failed: $* -Wl,--start-group $l_list -Wl,--end-group"
-    cat busybox_ld.err
+    echo "Failed: $l_list"
+    cat $EXE.out
     exit 1
 }
@@ -27 +135 @@
 # Now try to remove each lib and build without it.
 # Stop when no lib can be removed.
-while test "$BBOX_LIB_LIST"; do
-    $debug && echo "Trying libraries: $BBOX_LIB_LIST"
+while test "$LDLIBS"; do
+    $debug && echo "Trying libraries: $LDLIBS"
     all_needed=true
-    for one in $BBOX_LIB_LIST; do
-    without_one=`echo " $BBOX_LIB_LIST " | sed "s/ $one / /g" | xargs`
+    last_needed=false
+    for one in $LDLIBS; do
+    without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs`
+    # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
     l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
-    test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
+    test x"$l_list" != x"" && l_list="$START_GROUP $l_list $END_GROUP"
     $debug && echo "Trying -l options: '$l_list'"
-    if try "$l_list" "$@"; then
-        echo "Library $one is not needed"
-        BBOX_LIB_LIST="$without_one"
-        all_needed=false
+    try $CC $CFLAGS $LDFLAGS \
+        -o $EXE \
+        $SORT_COMMON \
+        $SORT_SECTION \
+        $GC_SECTIONS \
+        $START_GROUP $O_FILES $A_FILES $END_GROUP \
+        $l_list
+    if test $? = 0; then
+        echo " Library $one is not needed, excluding it"
+        LDLIBS="$without_one"
+        all_needed=false
+        last_needed=false
     else
-        echo "Library $one is needed"
+        echo " Library $one is needed, can't exclude it (yet)"
+        last_needed=true
     fi
     done
     # All libs were needed, can't remove any
     $all_needed && break
-    # If there is no space char, the list has just one lib.
-    # I'm not sure that in this case lib really is 100% needed.
-    # Let's try linking without it anyway... thus commented out.
-    #{ echo "$BBOX_LIB_LIST" | grep -q ' '; } || break
+    # Optimization: was the last tried lib needed?
+    if $last_needed; then
+    # Was it the only one lib left? Don't test again then.
+    { echo "$LDLIBS" | grep -q ' '; } || break
+    fi
 done
 
 # Make the binary with final, minimal list of libs
-echo "Final link with: $BBOX_LIB_LIST"
-l_list=`echo "$BBOX_LIB_LIST" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
-test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group -Wl,--verbose"
+echo "Final link with: ${LDLIBS:-<none>}"
+l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
+test "x$l_list" != "x" && l_list="$START_GROUP $l_list $END_GROUP"
 # --verbose gives us gobs of info to stdout (e.g. linker script used)
 if ! test -f busybox_ldscript; then
-    try "$l_list -Wl,--verbose" "$@" >busybox_ld.out
+    try $CC $CFLAGS $LDFLAGS \
+        -o $EXE \
+        $SORT_COMMON \
+        $SORT_SECTION \
+        $GC_SECTIONS \
+        $START_GROUP $O_FILES $A_FILES $END_GROUP \
+        $l_list \
+        $INFO_OPTS \
+    || {
+    cat $EXE.out
+    exit 1
+    }
 else
     echo "Custom linker script 'busybox_ldscript' found, using it"
-    # Add SORT_BY_ALIGNMENT to linker script (found in busybox_ld.out):
+    # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out):
     #  .rodata         : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) }
     #  *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
     #  *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
-    # This will eliminate most of the data padding (~3kb).
-    try "$l_list -Wl,--verbose -Wl,-T -Wl,busybox_ldscript" "$@" >busybox_ld.out
-fi
+    # This will eliminate most of the padding (~3kb).
+    # Hmm, "ld --sort-section alignment" should do it too.
+    try $CC $CFLAGS $LDFLAGS \
+        -o $EXE \
+        $SORT_COMMON \
+        $SORT_SECTION \
+        $GC_SECTIONS \
+        -Wl,-T,busybox_ldscript \
+        $START_GROUP $O_FILES $A_FILES $END_GROUP \
+        $l_list \
+        $INFO_OPTS \
+    || {
+    cat $EXE.out
+    exit 1
+    }
+fi
+
+. ./.config
+
+sharedlib_dir="0_lib"
+
+if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then
+    mkdir "$sharedlib_dir" 2>/dev/null
+    test -d "$sharedlib_dir" || {
+    echo "Cannot make directory $sharedlib_dir"
+    exit 1
+    }
+    ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null
+
+    EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped"
+    try $CC $CFLAGS $LDFLAGS \
+        -o $EXE \
+        -shared -fPIC \
+        -Wl,--enable-new-dtags \
+        -Wl,-z,combreloc \
+        -Wl,-soname="libbusybox.so.$BB_VER" \
+        -Wl,--undefined=lbb_main \
+        $SORT_COMMON \
+        $SORT_SECTION \
+        $START_GROUP $A_FILES $END_GROUP \
+        $l_list \
+        $INFO_OPTS \
+    || {
+    echo "Linking $EXE failed"
+    cat $EXE.out
+    exit 1
+    }
+    $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER"
+    chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER"
+    echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER"
+fi
+
+if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
+    EXE="$sharedlib_dir/busybox_unstripped"
+    try $CC $CFLAGS $LDFLAGS \
+        -o $EXE \
+        $SORT_COMMON \
+        $SORT_SECTION \
+        $GC_SECTIONS \
+        $START_GROUP $O_FILES $END_GROUP \
+        -L"$sharedlib_dir" -lbusybox \
+        $INFO_OPTS \
+    || {
+    echo "Linking $EXE failed"
+    cat $EXE.out
+    exit 1
+    }
+    $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox"
+    echo "busybox linked against libbusybox: $sharedlib_dir/busybox"
+fi
+
+if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then
+    echo "Linking individual applets against libbusybox (see $sharedlib_dir/*)"
+    gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \
+    | grep -v "^#" \
+    | grep -v "^$" \
+    > applet_lst.tmp
+    while read name main junk; do
+
+    echo "\
+void lbb_prepare(const char *applet, char **argv);
+int $main(int argc, char **argv);
+
+int main(int argc, char **argv)
+{
+    lbb_prepare(\"$name\", argv);
+    return $main(argc, argv);
+}
+" >"$sharedlib_dir/applet.c"
+
+    EXE="$sharedlib_dir/$name"
+    try $CC $CFLAGS $LDFLAGS "$sharedlib_dir/applet.c" \
+        -o $EXE \
+        $SORT_COMMON \
+        $SORT_SECTION \
+        $GC_SECTIONS \
+        -L"$sharedlib_dir" -lbusybox \
+        -Wl,--warn-common \
+    || {
+        echo "Linking $EXE failed"
+        cat $EXE.out
+        exit 1
+    }
+    rm -- "$sharedlib_dir/applet.c" $EXE.out
+    $STRIP -s --remove-section=.note --remove-section=.comment $EXE
+
+    done <applet_lst.tmp
+fi
+
+# libbusybox.so is needed only for -lbusybox at link time,
+# it is not needed at runtime. Deleting to reduce confusion.
+rm "$sharedlib_dir"/libbusybox.so 2>/dev/null
+exit 0 # or else we may confuse make