jcc_rewrite_pass.hpp

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#pragma once
#include <obf/pass.hpp>
 
namespace theo::obf {
/// <summary>
/// jcc rewrite pass which rewrites rip relative jcc's so that they are position
/// independent.
///
/// given the following code:
///
///     jnz label1
///     ; other code goes here
/// label1:
///     ; more code here
///
/// the jnz instruction will be rewritten so that the following code is
/// generated:
///
///     jnz br2
/// br1:
///     jmp [rip] ; address after this instruction contains the address
///               ; of the instruction after the jcc.
/// br2:
///     jmp [rip] ; address after this instruction contains the address of where
///               ; branch 2 is located.
///
/// its important to note that other passes will encrypt (transform) the address
/// of the next instruction. There is actually no jmp [rip] either, push/ret is
/// used.
/// </summary>
class jcc_rewrite_pass_t : public pass_t {
  explicit jcc_rewrite_pass_t() : pass_t(decomp::sym_type_t::instruction) {}
 
 public:
  static jcc_rewrite_pass_t* get();
  void run(decomp::symbol_t* sym);
};
}  // namespace theo::obf