meson: do not link libsystemd_static into libcore #8813
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(or in terms of the names of the actual files on disk, do not link libsystemd-shared-238.a into libcore.a). libsystemd_static is linked into libsystemd_shared, which in turn means that anything that links to libcore and libsystemd_shared will get libsystemd_static twice: $ cc -o systemd 'systemd@exe/src_core_main.c.o' -Wl,--no-undefined -Wl,--as-needed -Wl,-z,relro -Wl,-z,now -pie -DVALGRIND -Wl,--start-group src/core/libcore.a src/shared/libsystemd-shared-238.a src/shared/libsystemd-shared-238.so -pthread -lrt -lseccomp -lselinux -lmount -lblkid -Wl,--end-group -lseccomp -lpam -L/lib64 -laudit -lkmod -lmount -lrt -lcap -lacl -lcryptsetup -lgcrypt -lip4tc -lip6tc -lseccomp -lselinux -lidn -llzma -llz4 -lblkid '-Wl,-rpath,$ORIGIN/src/shared' -Wl,-rpath-link,/home/zbyszek/src/systemd/build/src/shared This propagation of the dependency seems correct (in the sense that meson is doing the expected thing based on the given configuration). Linking was done this way in the original meson conversion. I was probably trying to get everything to compile and link, I'm not sure why this particular choice was made. In the meantime, meson has gotten better at propagating dependencies, so it's possible that this had slightly different effect in the original conversion, but I did not verify this. Either way, I think we should drop this. With the patch: $ cc -o systemd 'systemd@exe/src_core_main.c.o' -Wl,--no-undefined -Wl,--as-needed -Wl,-z,relro -Wl,-z,now -pie -DVALGRIND -Wl,--start-group src/core/libcore.a src/shared/libsystemd-shared-238.so -pthread -lrt -lseccomp -lselinux -lmount -Wl,--end-group -lblkid -lrt -lseccomp -lpam -L/lib64 -laudit -lkmod -lselinux -lmount '-Wl,-rpath,$ORIGIN/src/shared' -Wl,-rpath-link,/home/zbyszek/src/systemd/build/src/shared This is more correct because we're not linking the same code twice. With the patch, libystemd_static is used in exactly four places: - src/shared/libsystemd-shared-238.so - src/udev/libudev.so.1.6.10 - pam_systemd.so - test-bus-error (compared to a bunch more executables before, including systemd, systemd-analyze, test-hostname, test-ns, etc.) Size savings are also noticable: $ size /var/tmp/inst?/usr/lib/systemd/libsystemd-shared-238.so text data bss dec hex filename 2397826 578488 15920 2992234 2da86a /var/tmp/inst1/usr/lib/systemd/libsystemd-shared-238.so 2397826 578488 15920 2992234 2da86a /var/tmp/inst2/usr/lib/systemd/libsystemd-shared-238.so $ size /var/tmp/inst?/usr/lib/systemd/systemd text data bss dec hex filename 1858790 261688 9320 2129798 207f86 /var/tmp/inst1/usr/lib/systemd/systemd 1556358 258704 8072 1823134 1bd19e /var/tmp/inst2/usr/lib/systemd/systemd $ du -s /var/tmp/inst? 52216 /var/tmp/inst1 50844 /var/tmp/inst2 google/oss-fuzz#1330 (comment) might be related.
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(or in terms of the names of the actual files on disk, do not link
libsystemd-shared-238.a into libcore.a).
libsystemd_static is linked into libsystemd_shared, which in turn means that
anything that links to libcore and libsystemd_shared will get libsystemd_static
twice:
$ cc -o systemd 'systemd@exe/src_core_main.c.o' -Wl,--no-undefined -Wl,--as-needed -Wl,-z,relro -Wl,-z,now -pie -DVALGRIND -Wl,--start-group src/core/libcore.a src/shared/libsystemd-shared-238.a src/shared/libsystemd-shared-238.so -pthread -lrt -lseccomp -lselinux -lmount -lblkid -Wl,--end-group -lseccomp -lpam -L/lib64 -laudit -lkmod -lmount -lrt -lcap -lacl -lcryptsetup -lgcrypt -lip4tc -lip6tc -lseccomp -lselinux -lidn -llzma -llz4 -lblkid '-Wl,-rpath,$ORIGIN/src/shared' -Wl,-rpath-link,/home/zbyszek/src/systemd/build/src/shared
This propagation of the dependency seems correct (in the sense that meson is
doing the expected thing based on the given configuration). Linking was done
this way in the original meson conversion. I was probably trying to get
everything to compile and link, I'm not sure why this particular choice was
made. In the meantime, meson has gotten better at propagating dependencies, so
it's possible that this had slightly different effect in the original
conversion, but I did not verify this. Either way, I think we should drop this.
With the patch:
$ cc -o systemd 'systemd@exe/src_core_main.c.o' -Wl,--no-undefined -Wl,--as-needed -Wl,-z,relro -Wl,-z,now -pie -DVALGRIND -Wl,--start-group src/core/libcore.a src/shared/libsystemd-shared-238.so -pthread -lrt -lseccomp -lselinux -lmount -Wl,--end-group -lblkid -lrt -lseccomp -lpam -L/lib64 -laudit -lkmod -lselinux -lmount '-Wl,-rpath,$ORIGIN/src/shared' -Wl,-rpath-link,/home/zbyszek/src/systemd/build/src/shared
This is more correct because we're not linking the same code twice.
With the patch, libystemd_static is used in exactly four places:
(compared to a bunch more executables before, including systemd,
systemd-analyze, test-hostname, test-ns, etc.)
Size savings are also noticable:
$ size /var/tmp/inst?/usr/lib/systemd/libsystemd-shared-238.so
text data bss dec hex filename
2397826 578488 15920 2992234 2da86a /var/tmp/inst1/usr/lib/systemd/libsystemd-shared-238.so
2397826 578488 15920 2992234 2da86a /var/tmp/inst2/usr/lib/systemd/libsystemd-shared-238.so
$ size /var/tmp/inst?/usr/lib/systemd/systemd
text data bss dec hex filename
1858790 261688 9320 2129798 207f86 /var/tmp/inst1/usr/lib/systemd/systemd
1556358 258704 8072 1823134 1bd19e /var/tmp/inst2/usr/lib/systemd/systemd
$ du -s /var/tmp/inst?
52216 /var/tmp/inst1
50844 /var/tmp/inst2
google/oss-fuzz#1330 (comment) might be related.