RUSTFLAGS Linker Flags Order

[LukeMauldin]

Linker flags specified by RUSTFLAGS are added to end of the command. Need a way to add at beginning.

I have a simple rust program that compiles against multiple vendor provided shared libraries. I need to link against the shared libraries with the --no-as-needed flag because the dependencies of the shared libaries are not setup correctly. I do not have the source code to the libraries and I cannot recompile them.

This is an example of linking a simple C++ program against the libraries. Notice the --no-as-needed flag is at the start of the command.

/usr/bin/gcc -m64 -L/apps/tc9/lib -L/apps/tc9/lib/oracle -L/usr/lib -L/usr/lib64 -L/usr/lib /apps/tc9/lib/itk_main.o main.o -Wl,--no-as-needed -L/apps/tc9/lib -luser_exits -lgdis -leintstub -lnxmgr_im -linternal_exits -lae -laie -lappr -larchive -lvis -lvm -lbackup -lbmf -lbob -lbom -lcae -lcfm -lconfig -lcxpom -ldmi -lmgc -lecm -leint -lepm -lfclasses -lform -lgrm -ltcinit -ltc -lsml -ltccore -ltctrushape -lqsearch -litk -lbase_utils -lics -llov -lme -lmld -lobjio -love -lproperty -lps -lpublication -lpie -lai -lqry -lres -lreq -ladsfoundation -ltcsoacorestrong -lsa -lschmgt -lschmgt_bridge -lss -lvispublish -lsub_mgr -lclientcache -ltextsrv -lrdv -lTcCrypto -ltcsso -lcollabctx -lmechatronics -ldocmgtapp -lcontmgmt -lserver_exits -linternal_server_exits -ltcgsoap -laiwebservice -ltcxsd -lconfigurator -ltcsoacommon -ltcsoaclient -ltcgateway -ltcsoaserver -ltcserverutil -lvalidation -lcp -ltcmultisitetypes -ltcmultisitestrong -ltcsoaworkflow -ltcsoaworkflowtypes -ltcsoaworkflownative -ltc_utils -ltccoreext -lrbf -lce -lclips -lclipsutil -lgms -ltie -lbriefcase -lvisualization -lnxclone -lvendormanagementdispatch -lccdm -lproductvariant -lfunctionality -licsie -lcondvalidation -lsmartuibldr -lfnd0soadiagramming -lfnd0soadiagrammingtypes -ltcsoacoretypes -ltcsoacore -ltcsoaprojectmanagement -ltcsoaprojectmanagementtypes -ltcsoaprojectmanagementnative -lbmidebase -lpdi_corba_server -lict -lcba -lsharedcache -lsharedcachetypes -lbooleanmath -lcbaext -lcfilter -lfnd0booleansolve -ldispatcher -lmeta -lmetaframework -lsecore -lfoundationdispatch -lcmdispatch -lcm -lFnd0nweditor -lusagewc -lusage -lconstants -lmfg -lmfgbvr -lssrsccuaclient -lscmccdispatch -lextensionframework -ldocmgt -lissuemgmt -lfunctionality -lcondvalidation -lFnd0profiler -lFnd0formulamgmt -larm -lpom -lsyss -lugmath -lplmxmlSDK -lplmxmlExtensions -lplmContainerSDK -licui18n341 -lxerces270 -lxalan110 -lc -lm -ldl -lnsl -lelf -lresolv -lclntsh -ldb2 -lstdc++ -Wl,--unresolved-symbols=ignore-in-shared-libs -o main_ubuntu

I have set the RUSTFLAGS variable via ./.cargo/config:

[build]
rustflags = [
"-C", "link-arg=-Wl,--unresolved-symbols=ignore-all",
"-C", "link-arg=-Wl,--no-as-needed"
]

I then ran cargo build -Z print-link-args and below is the command that rust is using to link the program. Notice the --no-as-needed is added at the end which the linker ignores.

"cc" "-Wl,--as-needed" "-Wl,-z,noexecstack" "-m64" "-L" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.10imwdy594ztd6bq.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.16d1j1qvoz2m2jvs.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.1fyaisel7xwy8gol.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.1m1fmcgm6riw3k8x.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.1ofvdi3023mvvvco.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.1sxelb0w7h73vp0e.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.26gzaqs5j4288ipr.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.2b1t8ich07w2gvrl.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.2roea1mze8w2afh0.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.3j13xg5n5tgud8iy.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.3sx17r8001u8o3w5.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.4113mge63r7rocsc.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.419w4t766q8u6dci.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.45cnk29n205b6w8p.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.49ob1frj11j54voq.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.4lo6dh84os25q8en.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.4td2c64b2g0tc0pa.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.4ulw9y80xwlyly7h.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.4zvsimlxb9npcpqm.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.9ud5haptujyqskc.rcgu.o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.agcn0tji9vk7e22.rcgu.o" "-o" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps/tclogin-1d2993c5e8dcf6e2.4kzuzfmqupnpce59.rcgu.o" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/home/mauldinl@gvl.is.l-3com.com/code/rust/tclogin/target/debug/deps" "-L" "/apps/tc9/lib" "-L" "/apps/tc9/lib/oracle" "-L" "/usr/lib/x86_64-linux-gnu" "-L" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-lgdis" "-leintstub" "-lnxmgr_im" "-linternal_exits" "-lae" "-laie" "-lappr" "-larchive" "-lvis" "-lvm" "-lbackup" "-lbmf" "-lbob" "-lbom" "-lcae" "-lcfm" "-lconfig" "-lcxpom" "-ldmi" "-lmgc" "-lecm" "-leint" "-lepm" "-lfclasses" "-lform" "-lgrm" "-ltcinit" "-ltc" "-lsml" "-ltccore" "-ltctrushape" "-lqsearch" "-litk" "-lbase_utils" "-lics" "-llov" "-lme" "-lmld" "-lobjio" "-love" "-lproperty" "-lps" "-lpublication" "-lpie" "-lai" "-lqry" "-lres" "-lreq" "-ladsfoundation" "-ltcsoacorestrong" "-lsa" "-lschmgt" "-lschmgt_bridge" "-lss" "-lvispublish" "-lsub_mgr" "-lclientcache" "-ltextsrv" "-lrdv" "-lTcCrypto" "-ltcsso" "-lcollabctx" "-lmechatronics" "-ldocmgtapp" "-lcontmgmt" "-lserver_exits" "-linternal_server_exits" "-ltcgsoap" "-laiwebservice" "-ltcxsd" "-lconfigurator" "-ltcsoacommon" "-ltcsoaclient" "-ltcgateway" "-ltcsoaserver" "-ltcserverutil" "-lvalidation" "-lcp" "-ltcmultisitetypes" "-ltcmultisitestrong" "-ltcsoaworkflow" "-ltcsoaworkflowtypes" "-ltcsoaworkflownative" "-ltc_utils" "-ltccoreext" "-lrbf" "-lce" "-lclips" "-lclipsutil" "-lgms" "-ltie" "-lbriefcase" "-lvisualization" "-lnxclone" "-lvendormanagementdispatch" "-lccdm" "-lproductvariant" "-lfunctionality" "-licsie" "-lcondvalidation" "-lsmartuibldr" "-lfnd0soadiagramming" "-lfnd0soadiagrammingtypes" "-ltcsoacoretypes" "-ltcsoacore" "-ltcsoaprojectmanagement" "-ltcsoaprojectmanagementtypes" "-ltcsoaprojectmanagementnative" "-lbmidebase" "-lpdi_corba_server" "-lict" "-lcba" "-lsharedcache" "-lsharedcachetypes" "-lbooleanmath" "-lcbaext" "-lcfilter" "-lfnd0booleansolve" "-ldispatcher" "-lmeta" "-lmetaframework" "-lsecore" "-lfoundationdispatch" "-lcmdispatch" "-lcm" "-lFnd0nweditor" "-lusagewc" "-lusage" "-lconstants" "-lmfg" "-lmfgbvr" "-lssrsccuaclient" "-lscmccdispatch" "-lextensionframework" "-ldocmgt" "-lissuemgmt" "-lFnd0profiler" "-lFnd0formulamgmt" "-lpom" "-lsyss" "-lugmath" "-lplmxmlSDK" "-lplmxmlExtensions" "-lplmContainerSDK" "-licui18n341" "-lxerces270" "-lxalan110" "-lc" "-lm" "-ldl" "-lnsl" "-lelf" "-lresolv" "-lclntsh" "-ldb2" "-licuuc341" "-licudata341" "-lTcCryptoUtil" "-lpoco" "-lTAO" "-lACE" "-lFnd0propertyrenderer" "-lnnz10" "-ltccurl" "-lTcMemBinding64" "-lTcMemCppBinding64" "-lstdc++" "-Wl,--start-group" "-Wl,-Bstatic" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-de5969744423fb69.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-349473e71495321d.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libbacktrace_sys-586a1c8092fef75c.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-132eea50c4719d58.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_demangle-ceaa2d4e2e4490ea.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-b0584d127f427a22.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-8570ae25713836c4.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-4ea1c8a0d2fa277d.rlib" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-c04ea2c3b5f80e64.rlib" "-Wl,--end-group" "/home/mauldinl@gvl.is.l-3com.com/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-a3371a772297084a.rlib" "-Wl,-Bdynamic" "-ldl" "-lrt" "-lpthread" "-lgcc_s" "-lc" "-lm" "-lrt" "-lpthread" "-lutil" "-lutil" "-Wl,--unresolved-symbols=ignore-all" "-Wl,--no-as-needed"

I need a way to either specify that the RUSTFLAGS should come at the beginning of the command OR a way to explictly inform rust to link to --no-as-needed

Meta

rustc --version --verbose:
rustc 1.33.0-nightly (e2f221c 2019-01-15)
binary: rustc
commit-hash: e2f221c
commit-date: 2019-01-15
host: x86_64-unknown-linux-gnu
release: 1.33.0-nightly
LLVM version: 8.0

OS: Ubuntu 18.04

[LukeMauldin]

Any update on this issue?

[LaurentMazare]

I ran into a similar issue today trying to link some libraries that end up needing -Wl,--no-as-needed at the beginning of the linker flags rather than at the end.
@LukeMauldin did you find a way around this?

[petrochenkov]

I have submitted an RFC about controlling as-needed in a more fine-grained way - rust-lang/rfcs#2951.
(This doesn't address this specific issue but seems relevant anyway.)

-Z pre-link-args may help with this right now, but it's unstable.

[petrochenkov]

Closing this issue, the as-needed modifier was implemented about 9 months ago, and #81490 tracks its stabilization.