dynamic symbol table

http://timetobleed.com/dynamic-symbol-table-duel-elf-vs-mach-o-round-2/

1. symbol table 符号表

     只是对debug有用。strip会去除符号表

     The symbol table does not need to be mapped into a running process and is only useful for debugging. The symbol table (and other sections) may be removed from an object when you use strip.

2. dynamic symbol table 动态符号表

     动态符号表是加载动态库时能导出的函数表，例如dlopen后，dlsym能查找到的函数

    动态符号表是符号表的subset

     shared objects in both Mach-O and ELF have a symbol table listing only functions that are exporteed by the object.

    The dynamic symbol table in ELF objects is stored in a section named dynsym. The indexes stored in the st_name field (from the structure listed above) are indexes into the string table in a section named dynstr. dynstr is a string table specifically for entries in the dynamic symbol table.