PreProcess.cpp
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#include "llvm/Pass.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Instructions.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/IR/CFG.h"
#include <fstream>
#include <iostream>
using namespace llvm;
namespace {
struct PreProcess : public FunctionPass {
static char ID;
PreProcess() : FunctionPass(ID) { }
bool runOnFunction(Function &F) override {
Module* mod = F.getParent();
std::vector<Instruction *> instructions;
std::vector<BasicBlock *> RetBlocks;
bool inserted = false;
std::ofstream functionFile("functions.txt", std::ios_base::app);
if (functionFile.is_open()) {
if (!F.getName().contains("__cxx") && !F.getName().contains("_GLOBAL"))
functionFile << F.getName().str() << "\n";
functionFile.close();
}
if (!F.getName().contains("__cxx") && !F.getName().contains("_GLOBAL")) {
for (auto &BB : F) {
for (auto &I : BB) {
if (I.getOpcode() == Instruction::Ret) {
instructions.push_back(&I);
}
}
}
for (auto &I : instructions) {
BasicBlock *BB = I->getParent();
// One Instruction Basic Block has only one ret instructions
if (!BB->size() < 2)
{
BasicBlock *retblock = BB->splitBasicBlock(I->getIterator(), "obfuscatedreturn");
} else {
BB->setName("obfuscatedreturn");
}
}
}
return true;
}
}; // end of struct Hello
} // end of anonymous namespace
char PreProcess::ID = 0;
static RegisterPass<PreProcess> X("preprocess", "Hello World Pass",
false /* Only looks at CFG */,
false /* Analysis Pass */);