what the different with LC_Symtab and LC_DYSYMTAB ? about macho-kit

[DeVaukz]

LC_SYMTAB only provides the locations of the symbol and string tables. LC_DYSYMTAB provides much more information including where to find the rebasing information plus the ranges of local, external, and undefined symbols within the symbol table, and much more. Checkout the comments for struct dysymtab_command in <mach-o/loader.h>

[vedon]

@DeVaukz Thank you ! Is the LC_DYSYMTAB contain the LC_SYMTAB？ LC_SYMTAB is the subset of the LC_DYSYMTAB?

[DeVaukz]

No. They are separate but LC_SYMTAB must be present if LC_DYSYMTAB is present.

[vedon]

@DeVaukz ok ,I get that .If i have one symbol ,could you have any idea to confirm the range of the symbol in assembly ? Just like the pic show?

[DeVaukz]

Symbols relate a name to a specific address, not a range. You would need to parse the assembly code beginning at the address associated with the target function's symbol, stopping when you encounter another prolog (which signifies the beginning of a new function) in order to find the end of your target function.

[vedon]

@DeVaukz thx ! I know how to deal with this