From 367a55c7d7e31a8162e795edc343277f8eb35f38 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sat, 15 Jul 2017 14:52:26 +0200 Subject: build system: FEATURE_LIBBUSYBOX_STATIC - try to pull libc/libm into libbusybox It variously fails with different toolchains I tried... Signed-off-by: Denys Vlasenko --- Config.in | 43 ++++++++++++++++++++----------------------- scripts/trylink | 18 ++++++++++++------ 2 files changed, 32 insertions(+), 29 deletions(-) diff --git a/Config.in b/Config.in index cfb3aa0ee..82baed50a 100644 --- a/Config.in +++ b/Config.in @@ -386,29 +386,26 @@ config BUILD_LIBBUSYBOX Build a shared library libbusybox.so.N.N.N which contains all busybox code. - This feature allows every applet to be built as a tiny - separate executable. Enabling it for "one big busybox binary" - approach serves no purpose and increases code size. - You should almost certainly say "no" to this. - -### config FEATURE_FULL_LIBBUSYBOX -### bool "Feature-complete libbusybox" -### default n if !FEATURE_SHARED_BUSYBOX -### depends on BUILD_LIBBUSYBOX -### help -### Build a libbusybox with the complete feature-set, disregarding -### the actually selected config. -### -### Normally, libbusybox will only contain the features which are -### used by busybox itself. If you plan to write a separate -### standalone application which uses libbusybox say 'Y'. -### -### Note: libbusybox is GPL, not LGPL, and exports no stable API that -### might act as a copyright barrier. We can and will modify the -### exported function set between releases (even minor version number -### changes), and happily break out-of-tree features. -### -### Say 'N' if in doubt. + This feature allows every applet to be built as a really tiny + separate executable linked against the library: + + $ size 0_lib/l* + text data bss dec hex filename + 939 212 28 1179 49b 0_lib/last + 939 212 28 1179 49b 0_lib/less + 919138 8328 1556 929022 e2cfe 0_lib/libbusybox.so.1.N.M + + This is useful on NOMMU systems which are not capable + of sharing executables, but are capable of sharing code + in dynamic libraries. + +config FEATURE_LIBBUSYBOX_STATIC + bool "Pull in all external references into libbusybox" + default n + depends on BUILD_LIBBUSYBOX + help + Make libbusybox library independent, not using or requiring + any other shared libraries. config FEATURE_INDIVIDUAL bool "Produce a binary for each applet, linked against libbusybox" diff --git a/scripts/trylink b/scripts/trylink index 9f288c141..ba2d265bc 100755 --- a/scripts/trylink +++ b/scripts/trylink @@ -91,7 +91,9 @@ fi START_GROUP="-Wl,--start-group" END_GROUP="-Wl,--end-group" -INFO_OPTS="-Wl,--warn-common -Wl,-Map,$EXE.map -Wl,--verbose" +INFO_OPTS() { + echo "-Wl,--warn-common -Wl,-Map,$EXE.map -Wl,--verbose" +} # gold may not support --sort-common (yet) SORT_COMMON="-Wl,--sort-common" @@ -194,7 +196,7 @@ if ! test -f busybox_ldscript; then $GC_SECTIONS \ $START_GROUP $O_FILES $A_FILES $END_GROUP \ $l_list \ - $INFO_OPTS \ + `INFO_OPTS` \ || { cat $EXE.out exit 1 @@ -225,7 +227,7 @@ else -Wl,-T,busybox_ldscript \ $START_GROUP $O_FILES $A_FILES $END_GROUP \ $l_list \ - $INFO_OPTS \ + `INFO_OPTS` \ || { cat $EXE.out exit 1 @@ -244,10 +246,14 @@ if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then } ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null + # Yes, "ld -shared -static" is a thing. It's a shared library which is itself static. + LBB_STATIC="" + test "$CONFIG_FEATURE_LIBBUSYBOX_STATIC" = y && LBB_STATIC="-Wl,-static" + EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped" try $CC $CFLAGS $LDFLAGS \ -o $EXE \ - -shared -fPIC \ + -shared -fPIC $LBB_STATIC \ -Wl,--enable-new-dtags \ -Wl,-z,combreloc \ -Wl,-soname="libbusybox.so.$BB_VER" \ @@ -256,7 +262,7 @@ if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then $SORT_SECTION \ $START_GROUP $A_FILES $END_GROUP \ $l_list \ - $INFO_OPTS \ + `INFO_OPTS` \ || { echo "Linking $EXE failed" cat $EXE.out @@ -277,7 +283,7 @@ if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then $START_GROUP $O_FILES $END_GROUP \ -L"$sharedlib_dir" -lbusybox \ $l_list \ - $INFO_OPTS \ + `INFO_OPTS` \ || { echo "Linking $EXE failed" cat $EXE.out -- cgit v1.2.3