How symbols work and why we need them
summary
Shows how ELF on Linux implements C/C++ linkage with three symbol tables (symtab, dynsym and debug), how relocations let the linker fix calls, and why the compiler emits separate sections per weak/inline entity so the linker can discard duplicates; demonstrates building an executable that returns 42, using objdump, nm, readelf and strip and GCC, and shows strip removing symbols causes an undefined reference; notes the surprising ~20 section headers in a tiny object file and explains weak and unique symbols and -fvisibility=hidden.
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chapters (8)
- 0:00Symbols and purpose
- 3:56Global variables example
- 13:03Object file sections
- 20:49Linkage in C/C++
- 39:13Dynamic linking
- 51:13Symbol tables in libraries
- 55:06Program elements need symbols
- 1:00:02Summary of symbols
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