Does NOT refer to relocatability as what it means talking about “Position Independent Code”, relocation tables for dynamically linked libraries, … • It is about the application of Data Orientation heterogeneous types (as in the C++ for C# Delegate we worked on at Snap) • Managers that do relocation! • Concerns about the forward and backward maps 37Zoo Type Erasure 38Key Successes • Breaking

@ciura_victor - Regular, Revisited X Slide Title Object Relocation https://github.com/facebook/folly/blob/master/folly/docs/FBVector.md#object-relocation One particularly sensitive topic about handling C++ @ciura_victor - Regular, Revisited X Slide Title Object Relocation https://github.com/facebook/folly/blob/master/folly/docs/FBVector.md#object-relocation In contrast, a relocatable value would preserve its Object Relocation https://github.com/facebook/folly/blob/master/folly/docs/FBVector.md#object-relocation2023 Victor Ciura | @ciura_victor - Regular, Revisited X Slide Title Object Relocation https://github

try to link a shared lib from obj files not built with fPIC and using global vars: error: relocation R_X86_64_PC32 against symbol `global' can not be used when making a shared object; recompile with (a Huawei Company) ofekshilon@gmail.com OfekShilon 5253More Rabbit Holes for the Curious • Relocation details • Weak linkage • Versioning (both of libraries and of API) • Granularity • COMDAT, -ffunction-sections bagrintsev.me/CPP/dsohowto.pdf • Eli Benderski: • https://eli.thegreenplace.net/2011/08/25/load-time-relocation-of-shared-libraries/ • https://eli.thegreenplace.net/2011/11/03/position-independent-code-pic

1. 跑全量用例 (cd src; ./all.bash -v) 2. commit信息 cmd/link: fix loadelf failed on MIPS family The relocation of MIPS64 family ELF is different with other architecture according to the document from Linux-MIPS 1. 跑全量用例 (cd src; ./all.bash -v) 2. commit信息 cmd/link: fix loadelf failed on MIPS family The relocation of MIPS64 family ELF is different with other architecture according to the document from Linux-MIPS 1. 跑全量用例 (cd src; ./all.bash -v) 2. commit信息 cmd/link: fix loadelf failed on MIPS family The relocation of MIPS64 family ELF is different with other architecture according to the document from Linux-MIPS

... (Darwin) N Do not generate a relocation section. PXXX Minimum iOS deployment version needed (iphonesim) XXX is one of 8.0, 8.0.2, etc. R Generate a relocation section. T Generate a TOOL application . (Darwin) -WN Do not generate relocation code, needed for debugging (Windows) -WP Minimum iOS deployment version: 8.0, 8.0.2, ... (iphonesim) -WR Generate relocation code (Windows) -WX Enable executable APPENDIX C. COMPILER MESSAGES Warning: To allow debugging for win32 code you need to disable relocation with -WN option Stabs debug info is wrong for relocatable DLL or EXES. Use -WN if you want to

a physical aspect of a program • Relocation is done at load time Dynamic loading • Ask for additional functionalities • Often involve library discovery • Relocation is done at run time • May be capable

about the ELF file, which can sometimes be useful for introspecting generated section headers, relocation entries and the symbol table. In the unlikely case where clang and LLVM need to be compiled from the flag dwarfris (dwarf relocation in section) disables DWARF cross-section relocations between DWARF and the ELF’s symbol table since libdw does not have proper BPF relocation support, and therefore tools be able to properly dump structures from the object. elfutils (>= 0.173) implements proper BPF relocation support and therefore the same can be achieved without the -mattr=dwarfris option. Dumping the

Total size of ElfNN_Rela relocations. */ DT_RELAENT DynTag = 9 /* Size of each ElfNN_Rela relocation entry. */ DT_STRSZ DynTag = 10 /* Size of string table. */ DT_SYMENT DynTag relocations. */ DT_RELENT DynTag = 19 /* Size of each ElfNN_Rel relocation. */ DT_PLTREL DynTag = 20 /* Type of relocation used for PLT. */ DT_DEBUG DynTag = 21 /* Reserved (not (i ProgType) String() string type R_386 type R_386 int Relocation types for 386. const ( R_386_NONE R_386 = 0 /* No relocation. */ R_386_32 R_386 = 1 /* Add symbol value

about the ELF file, which can sometimes be useful for introspecting generated section headers, relocation entries and the symbol table. In the unlikely case where clang and LLVM need to be compiled from the flag dwarfris (dwarf relocation in section) disables DWARF cross-section relocations between DWARF and the ELF’s symbol table since libdw does not have proper BPF relocation support, and therefore tools be able to properly dump structures from the object. elfutils (>= 0.173) implements proper BPF relocation support and therefore the same can be achieved without the -mattr=dwarfris option. Dumping the

about the ELF file, which can sometimes be useful for introspecting generated section headers, relocation entries and the symbol table. In the unlikely case where clang and LLVM need to be compiled from the flag dwarfris (dwarf relocation in section) disables DWARF cross-section relocations between DWARF and the ELF’s symbol table since libdw does not have proper BPF relocation support, and therefore tools be able to properly dump structures from the object. elfutils (>= 0.173) implements proper BPF relocation support and therefore the same can be achieved without the -mattr=dwarfris option. Dumping the