On Mon, Feb 16, 2015 at 5:25 AM, Uros Bizjak <ubiz...@gmail.com> wrote: > Hello! > >> 2015-02-12 H.J. Lu <hongjiu...@intel.com> >> Richard Henderson <r...@redhat.com> >> >> PR rtl/32219 >> * cgraphunit.c (cgraph_node::finalize_function): Set definition >> before notice_global_symbol. >> (varpool_node::finalize_decl): Likewise. >> * varasm.c (default_binds_local_p_2): Rename from >> default_binds_local_p_1, add weak_dominate argument. Use direct >> returns instead of assigning to local variable. Unify varpool and >> cgraph paths via symtab_node. Reject undef weak variables before >> testing visibility. Reorder tests for simplicity. >> (default_binds_local_p): Use default_binds_local_p_2. >> (default_binds_local_p_1): Likewise. >> (decl_binds_to_current_def_p): Unify varpool and cgraph paths >> via symtab_node. >> (default_elf_asm_output_external): Emit visibility when specified. > > It looks like this patch broke alphaev68-linux-gnu [1]. There are many > failures of the type: > > /tmp/cck7V7MR.o: In function > `__static_initialization_and_destruction_0(int, int)':^M > (.text+0x3ac): relocation truncated to fit: GPRELHIGH against symbol > `std::__cxx11::basic_string<char, std::char_traits<char>, > std::allocator<char> >::~basic_string()@@GLIBCXX_3.4.21' defined in > .text section in > /space/uros/gcc-build/alphaev68-unknown-linux-gnu/./libstdc++-v3/src/.libs/libstdc++.so^M > /space/homedirs/uros/local/bin/ld: /tmp/cck7V7MR.o: gp-relative > relocation against dynamic symbol
It could be related to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65064 Before this bug fix, all common symbols don't bind locally, which is one of PR 32219 bugs. After this fix, common symbols bind locally. It may cause problems on targets with small data sections and common symbols aren't in small data section: 1. Since common symbols bind locally, backend may assume they are in small data section and lead to link-time failure. 2. Backend assume common symbols are never in small data section. But a definition in small data section may override a common symbol, which still binds lcoally, and turn a reference to common symbol to reference to small data section. This also may lead to link-time failure. Those targets can't assume common symbols are in small data section since it may change at link-time. The most conservative solution is to make common symbol doesn't bind locally for targets which defines TARGET_IN_SMALL_DATA_P. -- H.J.
