ALT Linux Bugzilla – Full Text Bug Listing
| Summary: | libtool --mode=link g++ -export-symbols-regex does not work as expected | ||
|---|---|---|---|
| Product: | Sisyphus | Reporter: | at <at> |
| Component: | libtool_1.5 | Assignee: | Dmitry V. Levin <ldv> |
| Status: | NEW --- | QA Contact: | qa-sisyphus |
| Severity: | normal | ||
| Priority: | P2 | CC: | jackie.rosen |
| Version: | unstable | ||
| Hardware: | all | ||
| OS: | Linux | ||
Retested with libtool_1.5-1.5.24-alt3: The libtool --mode=link g++ command now works, but -export-symbols-regex option still works strange. According to discussion in http://sourceware.org/ml/binutils/2001-12/msg00143.html thread, libtool should use -version-script instead of -retain-symbols-file. There is a famous rant in the DSO howto on this subject: "there is hope libtool will learn about converting the export lists into the anonymous version maps we have seen in the previous section when the GNU linker is used. At that point libtool will become useful. Until then relying on its -export-symbols option is misleading at best." |
when using g++, -export-symbols does not work as expected. $ cat test.c extern "C" void _test() { return; } extern "C" void test() { return; } $ -- created sample file. $ libtool --tag=CXX --mode=compile g++ -c test.c -o test.lo g++ -c test.c -fPIC -DPIC -o .libs/test.o g++ -c test.c -o test.o >/dev/null 2>&1 $ -- complited sample file. $ libtool --mode=link gcc -o libtest.la -rpath /usr/lib -version-info 0:0:0 -export-symbols-regex '^test' test.lo rm -fr .libs/libtest.a .libs/libtest.exp .libs/libtest.la .libs/libtest.lai .libs/libtest.so .libs/libtest.so.0 .libs/libtest.so.0.0.0 .libs/libtest.ver generating symbol list for `libtest.la' /usr/bin/nm -B .libs/test.o | sed -n -e 's/^.*[ ]\([ABCDGIRSTW][ABCDGIRSTW]*\)[ ][ ]*\([_A-Za-z][_A-Za-z0-9]*\)$/\1 \2 \2/p' | /bin/sed 's/.* //' | sort | uniq > .libs/libtest.exp grep -E -e "^test" ".libs/libtest.exp" > ".libs/libtest.expT" mv -f ".libs/libtest.expT" ".libs/libtest.exp" echo "{ global:" > .libs/libtest.ver cat .libs/libtest.exp | sed -e "s/\(.*\)/\1;/" >> .libs/libtest.ver echo "local: *; };" >> .libs/libtest.ver gcc -shared .libs/test.o -Wl,-soname -Wl,libtest.so.0 -Wl,-version-script -Wl,.libs/libtest.ver -o .libs/libtest.so.0.0.0 (cd .libs && rm -f libtest.so.0 && ln -s libtest.so.0.0.0 libtest.so.0) (cd .libs && rm -f libtest.so && ln -s libtest.so.0.0.0 libtest.so) ar cru .libs/libtest.a test.o ranlib .libs/libtest.a creating libtest.la (cd .libs && rm -f libtest.la && ln -s ../libtest.la libtest.la) $ -- linked with gcc, and it worked ok. Note: .libs/libtest.ver file is created and -version-script -Wl,.libs/libtest.ver is passed to the linker. Now I am going to link with g++: $ libtool --mode=link g++ -o libtest.la -rpath /usr/lib -version-info 0:0:0 -export-symbols-regex '^test' test.lo rm -fr .libs/libtest.a .libs/libtest.exp .libs/libtest.la .libs/libtest.lai .libs/libtest.so .libs/libtest.so.0 .libs/libtest.so.0.0.0 .libs/libtest.ver generating symbol list for `libtest.la' /usr/bin/nm -B .libs/test.o | sed -n -e 's/^.*[ ]\([ABCDGIRSTW][ABCDGIRSTW]*\)[ ][ ]*\([_A-Za-z][_A-Za-z0-9]*\)$/\1 \2 \2/p' | /bin/sed 's/.* //' | sort | uniq > .libs/libtest.exp grep -E -e "^test" ".libs/libtest.exp" > ".libs/libtest.expT" mv -f ".libs/libtest.expT" ".libs/libtest.exp" g++ -shared -nostdlib /usr/lib/gcc/i586-alt-linux/3.4.4/../../../crti.o /usr/lib/gcc/i586-alt-linux/3.4.4/crtbeginS.o .libs/test.o -L/usr/lib/gcc/i586-alt-linux/3.4.4 -L/usr/lib/gcc/i586-alt-linux/3.4.4/../../.. -lstdc++ -lm -lc -lgcc_s /usr/lib/gcc/i586-alt-linux/3.4.4/crtendS.o /usr/lib/gcc/i586-alt-linux/3.4.4/../../../crtn.o -Wl,-soname -Wl,libtest.so.0 -Wl,-retain-symbols-file -Wl,.libs/libtest.exp -o .libs/libtest.so.0.0.0 i586-alt-linux-g++: /usr/lib/gcc/i586-alt-linux/3.4.4/../../../crti.o: No such file or directory i586-alt-linux-g++: /usr/lib/gcc/i586-alt-linux/3.4.4/crtbeginS.o: No such file or directory i586-alt-linux-g++: /usr/lib/gcc/i586-alt-linux/3.4.4/crtendS.o: No such file or directory i586-alt-linux-g++: /usr/lib/gcc/i586-alt-linux/3.4.4/../../../crtn.o: No such file or directory $ -- it failed, but it does not really matter for now. Note two things: .libs/libtest.ver is not created; and -version-script is not passed to the linker. -Wl,-retain-symbols-file -Wl,.libs/libtest.exp is used instead. Now see what happens if I fix the command and use -Wl,-retain-symbols-file: $ cat .libs/libtest.exp test $ g++ -shared -nostdlib .libs/test.o -Wl,-soname -Wl,libtest.so.0 -Wl,-retain-symbols-file -Wl,.libs/libtest.exp -o .libs/libtest.so.0.0.0 $ nm -D .libs/libtest.so.0.0.0 00001244 A __bss_start U __gxx_personality_v0 00001244 A _edata 00001244 A _end 000001cc T _test 000001d2 T test $ You see "_test" is still exported! However, what I was trying to achieve with -export-symbols-regex '^test' is exactly the opposite: "_test" must not be exported. Thus I infer that -export-symbols does not work as expected.