binutils-gdb/ld/testsuite/ld-elf/pr26978a.d

#source: pr26978a.s
#source: pr26978b.s
#target: [check_shared_lib_support]
#as:
#ld: -shared --version-script=pr26979.ver
#readelf: -sW

#failif
#...
.*foo@v1
#pass
PR26978, Inconsistency for strong foo@v1 and weak foo@@v1 Prior to this patch ld -shared --version-script=pr26979.ver pr26978a.o pr26978b.o results in ld: pr26978b.o: in function `foo_v1': (.text+0x0): multiple definition of `foo@v1' ld: pr26978b.o:(IND+0x0): multiple definition of `foo' while ld -shared --version-script=pr26979.ver pr26978b.o pr26978a.o results in no error, but some odd dynamic symbols. ... 0 NOTYPE GLOBAL DEFAULT 7 foo@v1 ... 0 NOTYPE WEAK DEFAULT 7 foo@@v1 When linking an undecorated reference to foo against such a shared library, ld complains about multiple definitions of foo@v1 while gold creates a dynamic reference to foo@v1. That results in foo@v1 being used at runtime. While we could error in both cases, it is reasonable to say foo@v1 and foo@@v1 are in fact the same symbol. (Same name, same version. The only real difference is that foo@@v1 satisfies a reference to plain foo, while foo@v1 does not.) Just as merging a weak undecorated sym with a strong sym results in the strong sym prevailing, so should the strong foo@v1 prevail. And since there is a definition that satisfies plain foo, the foo@@v1 variety of dynamic symbol should be emitted at the foo@v1 value. That makes the testcase that currently links continue to produce a shared library, and that shared library can now be used by both ld and gold with the same runtime behaviour as when using gold with the odd dynamic symbol library. bfd/ PR 26978 * elflink.c (_bfd_elf_add_default_symbol): Handle the case where a new weak sym@@ver should be overridden by an existing sym@ver. (elf_link_add_object_symbols): Don't _bfd_elf_add_default_symbol for a new weak sym@ver when sym@@ver already exists. * linker.c (link_action): Choose MIND for previous indirect, current def, rather than MDEF. (_bfd_generic_link_add_one_symbol <MIND>): Handle redefinition of weak indirect symbol. ld/ * testsuite/ld-elf/pr26978a.d, * testsuite/ld-elf/pr26978a.s, * testsuite/ld-elf/pr26978b.d, * testsuite/ld-elf/pr26978b.s: New tests. 2020-12-02 10:33:23 +08:00			`#source: pr26978a.s`
			`#source: pr26978b.s`
			`#target: [check_shared_lib_support]`
			`#as:`
			`#ld: -shared --version-script=pr26979.ver`
			`#readelf: -sW`

			`#failif`
			`#...`
			`.*foo@v1`
			`#pass`