| Message ID | 1468767958-19572-1-git-send-email-gustavo.zacarias@free-electrons.com |
|---|---|
| State | Rejected |
| Headers | show |
Gustavo, All, On 2016-07-17 12:05 -0300, gustavo.zacarias@free-electrons.com spake thusly: > From: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > > This option tells the linker to only link to the libraries containing > symbols that are actually used. > > It requires libtool patches to fully clean the needed chain, these are > used by major distributions such as Debian and Gentoo. > https://wiki.debian.org/ToolChain/DSOLinking > https://wiki.gentoo.org/wiki/Project:Quality_Assurance/As-needed OK, I read both of the above, and I do understand the technicalities behind --as-needed. However, I fail to see what it would bring to Buidlroot. One key point of --as-needed is to not pull in an unneeded library into an executable, in case it does not need it, especially in the case that this library is a second-order depedency by way of another library, e.g.: foo: NEEDED: libbar.so NEEDED: libbuz.so libbar.so: NEEDED: libbuz.so but where foo does not use any symbol from libbuz.so. This purportedly allows to update second-order libraries (libbuz, above) when there is an ABI change in those libs, and only have to rebuild first-order libs (libbar, above) without to rebuild the executable itself. Another key point is that the dynamic loader will not have to load unncessary libraries,thus reducing startup time. However, I fail to see how that can be any usefull in the context of Buildroot. First, we do not support partial updates, and only catter to full-system updates. Thus the first point is moot IMHO. Second, the default behaviour of the dynamic linker is to do lazy binding, i.e. to only resolve sumbols at the time they are first needed, and thus only loading libraries to resolve a missing symbol (unless I'm mistaken...) So, what would that bring to us? Regards, Yann E. MORIN. > Introduce a BR2_AS_NEEDED global enable option (default=no, marked as > experimental) that generally disables the libtool patching and avoids > the extra LDFLAGS (-Wl,--as-needed). > > Also add a per-package PACKAGE_AS_NEEDED (default=yes) option to work > around problematic packages that might not behave too well with > as-needed linking. > > For the libtool patching use a guess (automatic) method since > version-matching doesn't work accurately with some packages that ship > patched/modified ltmain.sh scripts, normally based on 2.4. In some of > these cases the as-needed-v2.2.6.patch works, and in other cases the > as-needed-v2.4.2.patch is necessary and the exact condition can't be > found in a deterministic way. If for some reason none of the patches > applies to a particular package this will only affect said package and > shouldn't have any consequence even if passing -Wl,--as-needed LDFLAGS. > > Example for a simple defconfig: > BR2_arm=y > BR2_AS_NEEDED=y > BR2_TOOLCHAIN_EXTERNAL=y > BR2_PACKAGE_GSTREAMER1=y > BR2_PACKAGE_GST1_PLUGINS_BAD=y > > With as-needed disabled: > $ readelf -a libgstbadvideo-1.0.so|grep "(NEEDED)"|wc -l > 10 > > With as-needed enabled: > $ readelf -a libgstbadvideo-1.0.so|grep "(NEEDED)"|wc -l > 8 > > Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > --- > Config.in | 6 +++++ > package/Makefile.in | 5 ++++ > package/pkg-autotools.mk | 43 ++++++++++++++++++++++++++++++ > support/libtool/as-needed-v1.5.26.patch | 46 +++++++++++++++++++++++++++++++++ > support/libtool/as-needed-v1.5.patch | 38 +++++++++++++++++++++++++++ > support/libtool/as-needed-v2.2.6.patch | 46 +++++++++++++++++++++++++++++++++ > support/libtool/as-needed-v2.4.2.patch | 46 +++++++++++++++++++++++++++++++++ > support/libtool/as-needed-v2.4.3.patch | 46 +++++++++++++++++++++++++++++++++ > 8 files changed, 276 insertions(+) > create mode 100644 support/libtool/as-needed-v1.5.26.patch > create mode 100644 support/libtool/as-needed-v1.5.patch > create mode 100644 support/libtool/as-needed-v2.2.6.patch > create mode 100644 support/libtool/as-needed-v2.4.2.patch > create mode 100644 support/libtool/as-needed-v2.4.3.patch > > diff --git a/Config.in b/Config.in > index 7bb2a01..e8b0477 100644 > --- a/Config.in > +++ b/Config.in > @@ -739,6 +739,12 @@ config BR2_REPRODUCIBLE > This is labeled as an experimental feature, as not all > packages behave properly to ensure reproducibility. > > +config BR2_AS_NEEDED > + bool "Link target binaries/libraries as-needed (experimental)" > + help > + Tell the linker to link in the produced binary/library only > + the libraries containing symbols that are actually used. > + > endmenu > > source "toolchain/Config.in" > diff --git a/package/Makefile.in b/package/Makefile.in > index afd5d3a..b190363 100644 > --- a/package/Makefile.in > +++ b/package/Makefile.in > @@ -144,6 +144,11 @@ TARGET_CXXFLAGS = $(TARGET_CFLAGS) > TARGET_FCFLAGS = $(TARGET_ABI) $(TARGET_OPTIMIZATION) $(TARGET_DEBUGGING) > TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS)) > > +# $(PKG)_AS_NEEDED gets expanded too early for ifeq usage, so use subst instead > +ifeq ($(BR2_AS_NEEDED),y) > +TARGET_LDFLAGS += -Wl,$(subst NO,--no,$(subst YES,-,$($(PKG)_AS_NEEDED)))-as-needed > +endif > + > ifeq ($(BR2_BINFMT_FLAT),y) > TARGET_CFLAGS += $(if $($(PKG)_FLAT_STACKSIZE),-Wl$(comma)-elf2flt=-s$($(PKG)_FLAT_STACKSIZE),\ > -Wl$(comma)-elf2flt) > diff --git a/package/pkg-autotools.mk b/package/pkg-autotools.mk > index 75e2df0..de00628 100644 > --- a/package/pkg-autotools.mk > +++ b/package/pkg-autotools.mk > @@ -55,6 +55,26 @@ define UPDATE_CONFIG_HOOK > endef > > # > +# Hook to patch libtool to make it work properly for as-needed linking > +# > +define LIBTOOL_AS_NEEDED_PATCH_HOOK > + @$(call MESSAGE,"Patching libtool as-needed") > + $(Q)for i in `find $($(PKG)_SRCDIR) -name ltmain.sh`; do \ > + if patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v2.4.3.patch >/dev/null ; then\ > + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v2.4.3.patch; \ > + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v2.4.2.patch >/dev/null ; then\ > + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v2.4.2.patch; \ > + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v2.2.6.patch >/dev/null ; then\ > + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v2.2.6.patch; \ > + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v1.5.26.patch >/dev/null ; then\ > + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v1.5.26.patch; \ > + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v1.5.patch >/dev/null ; then\ > + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v1.5.patch; \ > + fi \ > + done > +endef > + > +# > # Hook to patch libtool to make it work properly for cross-compilation > # > define LIBTOOL_PATCH_HOOK > @@ -111,6 +131,17 @@ endef > > define inner-autotools-package > > +# > +# as-needed is only patched/enabled for target packages > +# > +ifndef $(2)_AS_NEEDED > + ifeq ($(4),target) > + $(2)_AS_NEEDED ?= YES > + else > + $(2)_AS_NEEDED ?= NO > + endif > +endif > + > ifndef $(2)_LIBTOOL_PATCH > ifdef $(3)_LIBTOOL_PATCH > $(2)_LIBTOOL_PATCH = $$($(3)_LIBTOOL_PATCH) > @@ -244,6 +275,12 @@ $(2)_PRE_CONFIGURE_HOOKS += AUTORECONF_HOOK > ifneq ($$($(2)_LIBTOOL_PATCH),NO) > $(2)_PRE_CONFIGURE_HOOKS += LIBTOOL_PATCH_HOOK > endif > +# Don't patch packages that skip as-needed > +ifeq ($(BR2_AS_NEEDED),y) > +ifneq ($$($(2)_AS_NEEDED),NO) > +$(2)_PRE_CONFIGURE_HOOKS += LIBTOOL_AS_NEEDED_PATCH_HOOK > +endif > +endif > $(2)_DEPENDENCIES += host-automake host-autoconf host-libtool > > else # ! AUTORECONF = YES > @@ -252,6 +289,12 @@ else # ! AUTORECONF = YES > ifneq ($$($(2)_LIBTOOL_PATCH),NO) > $(2)_POST_PATCH_HOOKS += LIBTOOL_PATCH_HOOK > endif > +# Don't patch packages that skip as-needed > +ifeq ($(BR2_AS_NEEDED),y) > +ifneq ($$($(2)_AS_NEEDED),NO) > +$(2)_PRE_CONFIGURE_HOOKS += LIBTOOL_AS_NEEDED_PATCH_HOOK > +endif > +endif > > endif > > diff --git a/support/libtool/as-needed-v1.5.26.patch b/support/libtool/as-needed-v1.5.26.patch > new file mode 100644 > index 0000000..6a347ca > --- /dev/null > +++ b/support/libtool/as-needed-v1.5.26.patch > @@ -0,0 +1,46 @@ > +Conveniently fetched from Gentoo, these are basically the same as used > +by Debian. > +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed > + > +Upstream status: unknown > + > +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > + > +--- a/ltmain.sh.orig 2009-04-18 16:51:52.000000000 +0200 > ++++ b/ltmain.sh 2009-04-18 16:55:05.000000000 +0200 > +@@ -1812,10 +1812,15 @@ > + done > + IFS="$save_ifs" > + arg=`$echo "X$arg" | $Xsed -e "s/^ //"` > + ;; > + > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ deplibs="$deplibs $arg" > ++ continue > ++ ;; > ++ > + -Wl,*) > + args=`$echo "X$arg" | $Xsed -e "$sed_quote_subst" -e 's/^-Wl,//'` > + arg= > + save_ifs="$IFS"; IFS=',' > + for flag in $args; do > +@@ -2152,10 +2157,19 @@ > + fi > + for deplib in $libs; do > + lib= > + found=no > + case $deplib in > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ if test "$linkmode,$pass" = "prog,link"; then > ++ compile_deplibs="$deplib $compile_deplibs" > ++ finalize_deplibs="$deplib $finalize_deplibs" > ++ else > ++ deplibs="$deplib $deplibs" > ++ fi > ++ continue > ++ ;; > + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe|-threads) > + if test "$linkmode,$pass" = "prog,link"; then > + compile_deplibs="$deplib $compile_deplibs" > + finalize_deplibs="$deplib $finalize_deplibs" > + else > diff --git a/support/libtool/as-needed-v1.5.patch b/support/libtool/as-needed-v1.5.patch > new file mode 100644 > index 0000000..15e255c > --- /dev/null > +++ b/support/libtool/as-needed-v1.5.patch > @@ -0,0 +1,38 @@ > +Conveniently fetched from Gentoo, these are basically the same as used > +by Debian. > +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed > + > +Upstream status: unknown > + > +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > + > +--- a/ltmain.sh.orig 2006-03-29 15:45:36.000000000 +0200 > ++++ b/ltmain.sh 2006-03-29 16:39:30.000000000 +0200 > +@@ -1754,6 +1754,11 @@ > + arg=`$echo "X$arg" | $Xsed -e "s/^ //"` > + ;; > + > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ deplibs="$deplibs $arg" > ++ continue > ++ ;; > ++ > + -Wl,*) > + args=`$echo "X$arg" | $Xsed -e "$sed_quote_subst" -e 's/^-Wl,//'` > + arg= > +@@ -2094,6 +2099,15 @@ > + lib= > + found=no > + case $deplib in > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ if test "$linkmode,$pass" = "prog,link"; then > ++ compile_deplibs="$deplib $compile_deplibs" > ++ finalize_deplibs="$deplib $finalize_deplibs" > ++ else > ++ deplibs="$deplib $deplibs" > ++ fi > ++ continue > ++ ;; > + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe) > + if test "$linkmode,$pass" = "prog,link"; then > + compile_deplibs="$deplib $compile_deplibs" > diff --git a/support/libtool/as-needed-v2.2.6.patch b/support/libtool/as-needed-v2.2.6.patch > new file mode 100644 > index 0000000..f27c100 > --- /dev/null > +++ b/support/libtool/as-needed-v2.2.6.patch > @@ -0,0 +1,46 @@ > +Conveniently fetched from Gentoo, these are basically the same as used > +by Debian. > +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed > + > +Upstream status: unknown > + > +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > + > +--- a/ltmain.sh.orig 2009-04-18 14:37:16.000000000 +0200 > ++++ b/ltmain.sh 2009-04-18 14:40:08.000000000 +0200 > +@@ -4721,10 +4721,15 @@ > + IFS="$save_ifs" > + func_stripname ' ' '' "$arg" > + arg=$func_stripname_result > + ;; > + > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ deplibs="$deplibs $arg" > ++ continue > ++ ;; > ++ > + -Wl,*) > + func_stripname '-Wl,' '' "$arg" > + args=$func_stripname_result > + arg= > + save_ifs="$IFS"; IFS=',' > +@@ -5075,10 +5080,19 @@ > + > + for deplib in $libs; do > + lib= > + found=no > + case $deplib in > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ if test "$linkmode,$pass" = "prog,link"; then > ++ compile_deplibs="$deplib $compile_deplibs" > ++ finalize_deplibs="$deplib $finalize_deplibs" > ++ else > ++ deplibs="$deplib $deplibs" > ++ fi > ++ continue > ++ ;; > + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe|-threads) > + if test "$linkmode,$pass" = "prog,link"; then > + compile_deplibs="$deplib $compile_deplibs" > + finalize_deplibs="$deplib $finalize_deplibs" > + else > diff --git a/support/libtool/as-needed-v2.4.2.patch b/support/libtool/as-needed-v2.4.2.patch > new file mode 100644 > index 0000000..0ef0d99 > --- /dev/null > +++ b/support/libtool/as-needed-v2.4.2.patch > @@ -0,0 +1,46 @@ > +Conveniently fetched from Gentoo, these are basically the same as used > +by Debian. > +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed > + > +Upstream status: unknown > + > +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > + > +--- a/ltmain.sh.orig 2012-08-19 10:18:57.929178597 +0200 > ++++ b/ltmain.sh 2012-08-19 10:31:43.409388998 +0200 > +@@ -5798,10 +5798,15 @@ > + IFS="$save_ifs" > + func_stripname ' ' '' "$arg" > + arg=$func_stripname_result > + ;; > + > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ deplibs="$deplibs $arg" > ++ continue > ++ ;; > ++ > + -Wl,*) > + func_stripname '-Wl,' '' "$arg" > + args=$func_stripname_result > + arg= > + save_ifs="$IFS"; IFS=',' > +@@ -6158,10 +6163,19 @@ > + > + for deplib in $libs; do > + lib= > + found=no > + case $deplib in > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ if test "$linkmode,$pass" = "prog,link"; then > ++ compile_deplibs="$deplib $compile_deplibs" > ++ finalize_deplibs="$deplib $finalize_deplibs" > ++ else > ++ deplibs="$deplib $deplibs" > ++ fi > ++ continue > ++ ;; > + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe \ > + |-threads|-fopenmp|-openmp|-mp|-xopenmp|-omp|-qsmp=*) > + if test "$linkmode,$pass" = "prog,link"; then > + compile_deplibs="$deplib $compile_deplibs" > + finalize_deplibs="$deplib $finalize_deplibs" > diff --git a/support/libtool/as-needed-v2.4.3.patch b/support/libtool/as-needed-v2.4.3.patch > new file mode 100644 > index 0000000..25e6dfc > --- /dev/null > +++ b/support/libtool/as-needed-v2.4.3.patch > @@ -0,0 +1,46 @@ > +Conveniently fetched from Gentoo, these are basically the same as used > +by Debian. > +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed > + > +Upstream status: unknown > + > +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > + > +--- a/ltmain.sh > ++++ b/ltmain.sh > +@@ -7225,10 +7225,15 @@ > + IFS=$save_ifs > + func_stripname ' ' '' "$arg" > + arg=$func_stripname_result > + ;; > + > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ deplibs="$deplibs $arg" > ++ continue > ++ ;; > ++ > + -Wl,*) > + func_stripname '-Wl,' '' "$arg" > + args=$func_stripname_result > + arg= > + save_ifs=$IFS; IFS=, > +@@ -7609,10 +7614,19 @@ > + > + for deplib in $libs; do > + lib= > + found=false > + case $deplib in > ++ -Wl,--as-needed|-Wl,--no-as-needed) > ++ if test "$linkmode,$pass" = "prog,link"; then > ++ compile_deplibs="$deplib $compile_deplibs" > ++ finalize_deplibs="$deplib $finalize_deplibs" > ++ else > ++ deplibs="$deplib $deplibs" > ++ fi > ++ continue > ++ ;; > + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe \ > + |-threads|-fopenmp|-openmp|-mp|-xopenmp|-omp|-qsmp=*) > + if test prog,link = "$linkmode,$pass"; then > + compile_deplibs="$deplib $compile_deplibs" > + finalize_deplibs="$deplib $finalize_deplibs" > -- > 2.7.3 > > _______________________________________________ > buildroot mailing list > buildroot@busybox.net > http://lists.busybox.net/mailman/listinfo/buildroot
On 17/07/16 18:01, Yann E. MORIN wrote: > OK, I read both of the above, and I do understand the technicalities > behind --as-needed. > > However, I fail to see what it would bring to Buidlroot. > > One key point of --as-needed is to not pull in an unneeded library into > an executable, in case it does not need it, especially in the case that > this library is a second-order depedency by way of another library, > e.g.: > > foo: > NEEDED: libbar.so > NEEDED: libbuz.so > > libbar.so: > NEEDED: libbuz.so > > but where foo does not use any symbol from libbuz.so. This purportedly > allows to update second-order libraries (libbuz, above) when there is > an ABI change in those libs, and only have to rebuild first-order libs > (libbar, above) without to rebuild the executable itself. Hi Yann. Indeed this is not the point of the new option. > Another key point is that the dynamic loader will not have to load > unncessary libraries,thus reducing startup time. But this is. > However, I fail to see how that can be any usefull in the context of > Buildroot. > > First, we do not support partial updates, and only catter to full-system > updates. Thus the first point is moot IMHO. Agreed. > Second, the default behaviour of the dynamic linker is to do lazy > binding, i.e. to only resolve sumbols at the time they are first needed, > and thus only loading libraries to resolve a missing symbol (unless I'm > mistaken...) > > > So, what would that bring to us? Yes, that's what lazy binding does... but it's still based on DT_NEEDED entries, hence instead of scanning 10 libraries at required time in my example it will only need to scan 8 to resolve required symbols. For more complex applications that use many nested libraries the savings can be bigger. Example diff between non-as-needed gst-launch-1.0 and as-needed version: libgstreamer-1.0.so.0 libgobject-2.0.so.0 -libgmodule-2.0.so.0 libglib-2.0.so.0 -librt.so.1 -libdl.so.2 libgcc_s.so.1 libpthread.so.0 libc.so.6 Most of the time even with lazy bindings any given binary will need to resolve symbols unless we are building statically. Regards.
Hello, On Sun, 17 Jul 2016 12:05:57 -0300, gustavo.zacarias@free-electrons.com wrote: > From: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> > > This option tells the linker to only link to the libraries containing > symbols that are actually used. > > It requires libtool patches to fully clean the needed chain, these are > used by major distributions such as Debian and Gentoo. > https://wiki.debian.org/ToolChain/DSOLinking > https://wiki.gentoo.org/wiki/Project:Quality_Assurance/As-needed > > Introduce a BR2_AS_NEEDED global enable option (default=no, marked as > experimental) that generally disables the libtool patching and avoids > the extra LDFLAGS (-Wl,--as-needed). > > Also add a per-package PACKAGE_AS_NEEDED (default=yes) option to work > around problematic packages that might not behave too well with > as-needed linking. > > For the libtool patching use a guess (automatic) method since > version-matching doesn't work accurately with some packages that ship > patched/modified ltmain.sh scripts, normally based on 2.4. In some of > these cases the as-needed-v2.2.6.patch works, and in other cases the > as-needed-v2.4.2.patch is necessary and the exact condition can't be > found in a deterministic way. If for some reason none of the patches > applies to a particular package this will only affect said package and > shouldn't have any consequence even if passing -Wl,--as-needed LDFLAGS. Just like Yann, I don't understand the usefulness of --as-needed support. If a library A is not using symbols from a library B it is linked against, why is library A linked against library B in the first place ? The way you present it makes me understand that --as-needed is a workaround for broken package build systems, which end up producing binaries (programs or libraries) incorrect linked to too many libraries, that are in fact not all needed. In addition to this, it is not really clear what are the benefits of having less NEEDED entries (i.e practical number of performance improvements). Since the complexity is quite huge for something that 1/ looks like a workaround and 2/ isn't associated to concrete performance improvements, I don't think we want to merge this at this point. Of course, feel free to come back with some more details on why --as-needed is useful (why it's not a workaround, and prove it's really useful in practice). Thanks a lot, Thomas
>>>>> "Gustavo" == Gustavo Zacarias <gustavo.zacarias@free-electrons.com> writes: Hi, >> So, what would that bring to us? > Yes, that's what lazy binding does... but it's still based on > DT_NEEDED entries, hence instead of scanning 10 libraries at required > time in my example it will only need to scan 8 to resolve required > symbols. > For more complex applications that use many nested libraries the > savings can be bigger. > Example diff between non-as-needed gst-launch-1.0 and as-needed version: > libgstreamer-1.0.so.0 > libgobject-2.0.so.0 > -libgmodule-2.0.so.0 > libglib-2.0.so.0 > -librt.so.1 > -libdl.so.2 > libgcc_s.so.1 > libpthread.so.0 > libc.so.6 So what is E.G. the time differences when running time gst-launch-1.0 fakesrc num-buffers=1 ! fakesink on a "normal" machine with/without these patches? (Notice that gstreamer searches plugins and creates cache file first time it is run).
diff --git a/Config.in b/Config.in index 7bb2a01..e8b0477 100644 --- a/Config.in +++ b/Config.in @@ -739,6 +739,12 @@ config BR2_REPRODUCIBLE This is labeled as an experimental feature, as not all packages behave properly to ensure reproducibility. +config BR2_AS_NEEDED + bool "Link target binaries/libraries as-needed (experimental)" + help + Tell the linker to link in the produced binary/library only + the libraries containing symbols that are actually used. + endmenu source "toolchain/Config.in" diff --git a/package/Makefile.in b/package/Makefile.in index afd5d3a..b190363 100644 --- a/package/Makefile.in +++ b/package/Makefile.in @@ -144,6 +144,11 @@ TARGET_CXXFLAGS = $(TARGET_CFLAGS) TARGET_FCFLAGS = $(TARGET_ABI) $(TARGET_OPTIMIZATION) $(TARGET_DEBUGGING) TARGET_LDFLAGS = $(call qstrip,$(BR2_TARGET_LDFLAGS)) +# $(PKG)_AS_NEEDED gets expanded too early for ifeq usage, so use subst instead +ifeq ($(BR2_AS_NEEDED),y) +TARGET_LDFLAGS += -Wl,$(subst NO,--no,$(subst YES,-,$($(PKG)_AS_NEEDED)))-as-needed +endif + ifeq ($(BR2_BINFMT_FLAT),y) TARGET_CFLAGS += $(if $($(PKG)_FLAT_STACKSIZE),-Wl$(comma)-elf2flt=-s$($(PKG)_FLAT_STACKSIZE),\ -Wl$(comma)-elf2flt) diff --git a/package/pkg-autotools.mk b/package/pkg-autotools.mk index 75e2df0..de00628 100644 --- a/package/pkg-autotools.mk +++ b/package/pkg-autotools.mk @@ -55,6 +55,26 @@ define UPDATE_CONFIG_HOOK endef # +# Hook to patch libtool to make it work properly for as-needed linking +# +define LIBTOOL_AS_NEEDED_PATCH_HOOK + @$(call MESSAGE,"Patching libtool as-needed") + $(Q)for i in `find $($(PKG)_SRCDIR) -name ltmain.sh`; do \ + if patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v2.4.3.patch >/dev/null ; then\ + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v2.4.3.patch; \ + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v2.4.2.patch >/dev/null ; then\ + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v2.4.2.patch; \ + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v2.2.6.patch >/dev/null ; then\ + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v2.2.6.patch; \ + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v1.5.26.patch >/dev/null ; then\ + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v1.5.26.patch; \ + elif patch -p1 --dry-run -f -s -d $${i%/*} <support/libtool/as-needed-v1.5.patch >/dev/null ; then\ + $(APPLY_PATCHES) $${i%/*} support/libtool as-needed-v1.5.patch; \ + fi \ + done +endef + +# # Hook to patch libtool to make it work properly for cross-compilation # define LIBTOOL_PATCH_HOOK @@ -111,6 +131,17 @@ endef define inner-autotools-package +# +# as-needed is only patched/enabled for target packages +# +ifndef $(2)_AS_NEEDED + ifeq ($(4),target) + $(2)_AS_NEEDED ?= YES + else + $(2)_AS_NEEDED ?= NO + endif +endif + ifndef $(2)_LIBTOOL_PATCH ifdef $(3)_LIBTOOL_PATCH $(2)_LIBTOOL_PATCH = $$($(3)_LIBTOOL_PATCH) @@ -244,6 +275,12 @@ $(2)_PRE_CONFIGURE_HOOKS += AUTORECONF_HOOK ifneq ($$($(2)_LIBTOOL_PATCH),NO) $(2)_PRE_CONFIGURE_HOOKS += LIBTOOL_PATCH_HOOK endif +# Don't patch packages that skip as-needed +ifeq ($(BR2_AS_NEEDED),y) +ifneq ($$($(2)_AS_NEEDED),NO) +$(2)_PRE_CONFIGURE_HOOKS += LIBTOOL_AS_NEEDED_PATCH_HOOK +endif +endif $(2)_DEPENDENCIES += host-automake host-autoconf host-libtool else # ! AUTORECONF = YES @@ -252,6 +289,12 @@ else # ! AUTORECONF = YES ifneq ($$($(2)_LIBTOOL_PATCH),NO) $(2)_POST_PATCH_HOOKS += LIBTOOL_PATCH_HOOK endif +# Don't patch packages that skip as-needed +ifeq ($(BR2_AS_NEEDED),y) +ifneq ($$($(2)_AS_NEEDED),NO) +$(2)_PRE_CONFIGURE_HOOKS += LIBTOOL_AS_NEEDED_PATCH_HOOK +endif +endif endif diff --git a/support/libtool/as-needed-v1.5.26.patch b/support/libtool/as-needed-v1.5.26.patch new file mode 100644 index 0000000..6a347ca --- /dev/null +++ b/support/libtool/as-needed-v1.5.26.patch @@ -0,0 +1,46 @@ +Conveniently fetched from Gentoo, these are basically the same as used +by Debian. +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed + +Upstream status: unknown + +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> + +--- a/ltmain.sh.orig 2009-04-18 16:51:52.000000000 +0200 ++++ b/ltmain.sh 2009-04-18 16:55:05.000000000 +0200 +@@ -1812,10 +1812,15 @@ + done + IFS="$save_ifs" + arg=`$echo "X$arg" | $Xsed -e "s/^ //"` + ;; + ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ deplibs="$deplibs $arg" ++ continue ++ ;; ++ + -Wl,*) + args=`$echo "X$arg" | $Xsed -e "$sed_quote_subst" -e 's/^-Wl,//'` + arg= + save_ifs="$IFS"; IFS=',' + for flag in $args; do +@@ -2152,10 +2157,19 @@ + fi + for deplib in $libs; do + lib= + found=no + case $deplib in ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ if test "$linkmode,$pass" = "prog,link"; then ++ compile_deplibs="$deplib $compile_deplibs" ++ finalize_deplibs="$deplib $finalize_deplibs" ++ else ++ deplibs="$deplib $deplibs" ++ fi ++ continue ++ ;; + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe|-threads) + if test "$linkmode,$pass" = "prog,link"; then + compile_deplibs="$deplib $compile_deplibs" + finalize_deplibs="$deplib $finalize_deplibs" + else diff --git a/support/libtool/as-needed-v1.5.patch b/support/libtool/as-needed-v1.5.patch new file mode 100644 index 0000000..15e255c --- /dev/null +++ b/support/libtool/as-needed-v1.5.patch @@ -0,0 +1,38 @@ +Conveniently fetched from Gentoo, these are basically the same as used +by Debian. +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed + +Upstream status: unknown + +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> + +--- a/ltmain.sh.orig 2006-03-29 15:45:36.000000000 +0200 ++++ b/ltmain.sh 2006-03-29 16:39:30.000000000 +0200 +@@ -1754,6 +1754,11 @@ + arg=`$echo "X$arg" | $Xsed -e "s/^ //"` + ;; + ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ deplibs="$deplibs $arg" ++ continue ++ ;; ++ + -Wl,*) + args=`$echo "X$arg" | $Xsed -e "$sed_quote_subst" -e 's/^-Wl,//'` + arg= +@@ -2094,6 +2099,15 @@ + lib= + found=no + case $deplib in ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ if test "$linkmode,$pass" = "prog,link"; then ++ compile_deplibs="$deplib $compile_deplibs" ++ finalize_deplibs="$deplib $finalize_deplibs" ++ else ++ deplibs="$deplib $deplibs" ++ fi ++ continue ++ ;; + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe) + if test "$linkmode,$pass" = "prog,link"; then + compile_deplibs="$deplib $compile_deplibs" diff --git a/support/libtool/as-needed-v2.2.6.patch b/support/libtool/as-needed-v2.2.6.patch new file mode 100644 index 0000000..f27c100 --- /dev/null +++ b/support/libtool/as-needed-v2.2.6.patch @@ -0,0 +1,46 @@ +Conveniently fetched from Gentoo, these are basically the same as used +by Debian. +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed + +Upstream status: unknown + +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> + +--- a/ltmain.sh.orig 2009-04-18 14:37:16.000000000 +0200 ++++ b/ltmain.sh 2009-04-18 14:40:08.000000000 +0200 +@@ -4721,10 +4721,15 @@ + IFS="$save_ifs" + func_stripname ' ' '' "$arg" + arg=$func_stripname_result + ;; + ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ deplibs="$deplibs $arg" ++ continue ++ ;; ++ + -Wl,*) + func_stripname '-Wl,' '' "$arg" + args=$func_stripname_result + arg= + save_ifs="$IFS"; IFS=',' +@@ -5075,10 +5080,19 @@ + + for deplib in $libs; do + lib= + found=no + case $deplib in ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ if test "$linkmode,$pass" = "prog,link"; then ++ compile_deplibs="$deplib $compile_deplibs" ++ finalize_deplibs="$deplib $finalize_deplibs" ++ else ++ deplibs="$deplib $deplibs" ++ fi ++ continue ++ ;; + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe|-threads) + if test "$linkmode,$pass" = "prog,link"; then + compile_deplibs="$deplib $compile_deplibs" + finalize_deplibs="$deplib $finalize_deplibs" + else diff --git a/support/libtool/as-needed-v2.4.2.patch b/support/libtool/as-needed-v2.4.2.patch new file mode 100644 index 0000000..0ef0d99 --- /dev/null +++ b/support/libtool/as-needed-v2.4.2.patch @@ -0,0 +1,46 @@ +Conveniently fetched from Gentoo, these are basically the same as used +by Debian. +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed + +Upstream status: unknown + +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> + +--- a/ltmain.sh.orig 2012-08-19 10:18:57.929178597 +0200 ++++ b/ltmain.sh 2012-08-19 10:31:43.409388998 +0200 +@@ -5798,10 +5798,15 @@ + IFS="$save_ifs" + func_stripname ' ' '' "$arg" + arg=$func_stripname_result + ;; + ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ deplibs="$deplibs $arg" ++ continue ++ ;; ++ + -Wl,*) + func_stripname '-Wl,' '' "$arg" + args=$func_stripname_result + arg= + save_ifs="$IFS"; IFS=',' +@@ -6158,10 +6163,19 @@ + + for deplib in $libs; do + lib= + found=no + case $deplib in ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ if test "$linkmode,$pass" = "prog,link"; then ++ compile_deplibs="$deplib $compile_deplibs" ++ finalize_deplibs="$deplib $finalize_deplibs" ++ else ++ deplibs="$deplib $deplibs" ++ fi ++ continue ++ ;; + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe \ + |-threads|-fopenmp|-openmp|-mp|-xopenmp|-omp|-qsmp=*) + if test "$linkmode,$pass" = "prog,link"; then + compile_deplibs="$deplib $compile_deplibs" + finalize_deplibs="$deplib $finalize_deplibs" diff --git a/support/libtool/as-needed-v2.4.3.patch b/support/libtool/as-needed-v2.4.3.patch new file mode 100644 index 0000000..25e6dfc --- /dev/null +++ b/support/libtool/as-needed-v2.4.3.patch @@ -0,0 +1,46 @@ +Conveniently fetched from Gentoo, these are basically the same as used +by Debian. +https://gitweb.gentoo.org/repo/gentoo.git/tree/eclass/ELT-patches/as-needed + +Upstream status: unknown + +Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com> + +--- a/ltmain.sh ++++ b/ltmain.sh +@@ -7225,10 +7225,15 @@ + IFS=$save_ifs + func_stripname ' ' '' "$arg" + arg=$func_stripname_result + ;; + ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ deplibs="$deplibs $arg" ++ continue ++ ;; ++ + -Wl,*) + func_stripname '-Wl,' '' "$arg" + args=$func_stripname_result + arg= + save_ifs=$IFS; IFS=, +@@ -7609,10 +7614,19 @@ + + for deplib in $libs; do + lib= + found=false + case $deplib in ++ -Wl,--as-needed|-Wl,--no-as-needed) ++ if test "$linkmode,$pass" = "prog,link"; then ++ compile_deplibs="$deplib $compile_deplibs" ++ finalize_deplibs="$deplib $finalize_deplibs" ++ else ++ deplibs="$deplib $deplibs" ++ fi ++ continue ++ ;; + -mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe \ + |-threads|-fopenmp|-openmp|-mp|-xopenmp|-omp|-qsmp=*) + if test prog,link = "$linkmode,$pass"; then + compile_deplibs="$deplib $compile_deplibs" + finalize_deplibs="$deplib $finalize_deplibs"