This is basically the same as https://stackoverflow.com/questions/76580329/hide-symbols-from-executable I pasted it below in its entirety. If this is primarily a binutils question I will paste it there, but I *think* it is mostly a gcc related question. ------8< ------8< ------8< ------8< ------8< ------8< ------8< ------ <https://stackoverflow.com/posts/76580329/timeline> I use gcc 9.2.0 to compile c++ program for arm. I use boost 1.71.0 (mainly asio). My final executable works fine, but even after stripping readelf -W prog --dyn-syms shows e.g. these entries: 904: 000dc518 1 OBJECT UNIQUE DEFAULT 25 _ZN5boost4asio6detail30execution_context_service_baseINS1_16resolver_serviceINS0_2ip3tcpEEEE2idE 912: 000dc498 1 OBJECT UNIQUE DEFAULT 25 _ZN5boost4asio6detail30execution_context_service_baseINS1_18signal_set_serviceEE2idE 943: 000dc46c 4 OBJECT UNIQUE DEFAULT 25 _ZN5boost4asio6detail17posix_global_implINS0_14system_contextEE11static_ptr_E 951: 000dc4b0 1 OBJECT UNIQUE DEFAULT 25 _ZN5boost4asio6detail12service_baseINS1_14strand_serviceEE2idE 990: 000dc48c 4 OBJECT UNIQUE DEFAULT 25 _ZGVN5boost4asio6detail10call_stackINS1_14strand_service11strand_implEhE4top_E 1005: 0009a484 38 OBJECT WEAK DEFAULT 15 _ZTSN5boost4asio22service_already_existsE 1006: 000a3808 87 OBJECT WEAK DEFAULT 15 _ZTSN5boost16exception_detail10clone_implINS0_19error_info_injectorINS_12bad_any_castEEEEE 1024: 0009ad9c 65 OBJECT WEAK DEFAULT 15 _ZTSN5boost16exception_detail19error_info_injectorISt11logic_errorEE 1038: 0009ee34 128 OBJECT WEAK DEFAULT 15 _ZTSN5boost4asio6detail30execution_context_service_baseINS1_22deadline_timer_serviceINS0_11time_traitsINS_10posix_time5ptimeEEEEEEE 1045: 0009ade0 84 OBJECT WEAK DEFAULT 15 _ZTSN5boost16exception_detail10clone_implINS0_19error_info_injectorISt11logic_errorEEEE As far as I can tell, these symbols are known to the compiler/linker, as their Ndx is not UND (so undefined), which means their presence in the symbol table is not necessary. Since the whole program has 690kB and as strings shows these entries in the symbol table take more or less 140kB, I'd like to remove them. Currently I am compiling using the following compiler/linker options: -fvisibility=hidden -fvisibility-inlines-hidden -flto -Wl,--exclude-libs,ALL -Wl,-r,--discard-all -Wl,-flto Without these options the binary is >1.3MB. I have two questions: 1. Why are these symbols WEAK? These symbols are not from an external library (static or dynamic), they come from templates (so from include files) and there is no need for them to be defined as WEAK as far as I can tell. 2. How can I remove them from the symbols table? Note: I neither want nor can define visibility by hand - modifying boost to this end is tedious, also if we ever upgrade it I'd have to do it again. So it is not an option. Using objcopy with any option (-x, --localize-hidden, --strip-unneeded) does nothing, as the symbol table is not modified whatsoever. I guess all these functions/methods are used. I guess they must be marked differently by linker (ld in my case), otherwise nothing can be done as they are strictly required. ------8< ------8< ------8< ------8< ------8< ------8< ------8< ------ <https://stackoverflow.com/posts/76580329/timeline> -- Jędrzej Dudkiewicz I really hate this damn machine, I wish that they would sell it. It never does just what I want, but only what I tell it.
