[Bug ld/24815] ld fails to find symbols from DT_NEEDED entries
https://sourceware.org/bugzilla/show_bug.cgi?id=24815
--- Comment #8 from Ismael Luceno ---
# For completeness, this is from the glibc system that's otherwise equal to the
musl-libc one:
$ gcc -v test.c -lxml2 2>&1 | awk
'$1~/collect2$/{for(i=1;i<=NF;i++)print$i;exit}'
/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/collect2
-plugin
/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/liblto_plugin.so
-plugin-opt=/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/lto-wrapper
-plugin-opt=-fresolution=/tmp/ccweSB2s.res
-plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lgcc_s
-plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lgcc_s
--build-id
--eh-frame-hdr
--hash-style=gnu
-m
elf_x86_64
-dynamic-linker
/lib/ld-linux-x86-64.so.2
-pie
/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/Scrt1.o
/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/crti.o
/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/crtbeginS.o
-L/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0
-L/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../x86_64-pc-linux-gnu/lib/../lib
-L/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib
-L/lib/../lib
-L/usr/lib/../lib
-L/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../x86_64-pc-linux-gnu/lib
-L/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../..
/tmp/ccQzormI.o
-lxml2
-lgcc
--push-state
--as-needed
-lgcc_s
--pop-state
-lc
-lgcc
--push-state
--as-needed
-lgcc_s
--pop-state
/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/crtendS.o
/usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/crtn.o
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[Bug ld/24815] ld fails to find symbols from DT_NEEDED entries
https://sourceware.org/bugzilla/show_bug.cgi?id=24815 --- Comment #9 from Ismael Luceno --- (In reply to Fangrui Song from comment #7) > -Wl,-t,-y,lzma_end is also useful > > When linking an executable, something like --no-allow-shlib-undefined is the > default (the opposite allow-shlib-undefine is used when linking a DSO), if > all of libxml2.so's DT_NEEDED libs are loaded, there can be an undefined > reference. # With glibc: $ gcc test.c -lxml2 -Wl,-t,-y,lzma_end /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/Scrt1.o /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/crti.o /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/crtbeginS.o /tmp/ccDXrw7S.o /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/libxml2.so /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/libgcc_s.so /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/libgcc_s.so.1 /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/libc.so /lib/libc.so.6 /usr/lib/libc_nonshared.a /lib64/ld-linux-x86-64.so.2 /usr/lib/libc_nonshared.a /lib64/ld-linux-x86-64.so.2 /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/libgcc_s.so /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/libgcc_s.so.1 /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/crtendS.o /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../lib/crtn.o /usr/lib/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../x86_64-pc-linux-gnu/bin/ld: /lib/liblzma.so.5: definition of lzma_end # With musl-libc: $ gcc test.c -lxml2 -Wl,-t,-y,lzma_end /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/Scrt1.o /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/crti.o /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/crtbeginS.o /tmp/ccnhkcpO.o /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libxml2.so /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libgcc_s.so /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libgcc_s.so.1 /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libc.so /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libgcc_s.so /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libgcc_s.so.1 /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/libgcc.a /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/crtendS.o /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/crtn.o /usr/bin/ld: /lib/liblzma.so.5: definition of lzma_end /usr/bin/ld: /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libxml2.so: undefined reference to `lzma_properties_decode@XZ_5.0' /usr/bin/ld: /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libxml2.so: undefined reference to `lzma_code@XZ_5.0' /usr/bin/ld: /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libxml2.so: undefined reference to `lzma_auto_decoder@XZ_5.0' /usr/bin/ld: /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libxml2.so: undefined reference to `lzma_end@XZ_5.0' collect2: error: ld returned 1 exit status -- You are receiving this mail because: You are on the CC list for the bug. ___ bug-binutils mailing list bug-binutils@gnu.org https://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/24815] ld fails to find symbols from DT_NEEDED entries
https://sourceware.org/bugzilla/show_bug.cgi?id=24815 --- Comment #10 from Szabolcs Nagy --- > /usr/bin/ld: /lib/liblzma.so.5: definition of lzma_end ... > /usr/bin/ld: > /usr/lib/gcc/x86_64-pc-linux-musl/9.1.0/../../../../lib/libxml2.so: > undefined reference to `lzma_end@XZ_5.0' you need to check the symbol versions and symbol table. readelf -sW /lib/liblzma.so.5 |grep lzma_end -- You are receiving this mail because: You are on the CC list for the bug. ___ bug-binutils mailing list bug-binutils@gnu.org https://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/24815] ld fails to find symbols from DT_NEEDED entries
https://sourceware.org/bugzilla/show_bug.cgi?id=24815 Ismael Luceno changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #11 from Ismael Luceno --- Nevermind. The issue was on the libxml2 build. -- You are receiving this mail because: You are on the CC list for the bug. ___ bug-binutils mailing list bug-binutils@gnu.org https://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug ld/24836] --as-needed leaves unused direct dependencies
https://sourceware.org/bugzilla/show_bug.cgi?id=24836 --- Comment #11 from crusader.mike at gmail dot com --- > ... it would be possible ... a lot of work for little gain Well, in my case (which I believe isn't very rare) majority of functionality is locked in a few large static libs (of dubious quality) and all minor tools link them and (due to various effects) end up having dummy dependencies, forcing me to package unnecessary libs in deliverables (plus some waste at runtime). Fixing this is not huge, but nice to have. In terms of work -- what about associating a counter with every lib, which goes up for every resolved symbol and goes down for every symbol marked for garbage collection? At the end -- remove all DT_NEEDED entries with counter at 0. Well, (since I am ignorant wrt ld implementation) it is probably a dumb idea, so I 'll leave this problem with those who know what they are doing. > ... to do better than just removing DT_NEEDED entries would basically require > iterating the link What do you mean by "to do better"? > ... that should help explain the various destructor ... Thank you, Alan. Now it makes sense. Can you comment on #7? I.e. why elf executable ends up having large .dynsym table? is there a way to to trim it down only to stuff used by it's shared libs? Thank you. -- You are receiving this mail because: You are on the CC list for the bug. ___ bug-binutils mailing list bug-binutils@gnu.org https://lists.gnu.org/mailman/listinfo/bug-binutils
