Пример #1
0
 private static boolean removePhiList(MethodNode mth, List<PhiInsn> insnToRemove) {
   if (insnToRemove.isEmpty()) {
     return false;
   }
   for (BlockNode block : mth.getBasicBlocks()) {
     PhiListAttr phiList = block.get(AType.PHI_LIST);
     if (phiList == null) {
       continue;
     }
     List<PhiInsn> list = phiList.getList();
     for (PhiInsn phiInsn : insnToRemove) {
       if (list.remove(phiInsn)) {
         for (InsnArg arg : phiInsn.getArguments()) {
           SSAVar sVar = ((RegisterArg) arg).getSVar();
           if (sVar != null) {
             sVar.setUsedInPhi(null);
           }
         }
         InstructionRemover.remove(mth, block, phiInsn);
       }
     }
     if (list.isEmpty()) {
       block.remove(AType.PHI_LIST);
     }
   }
   insnToRemove.clear();
   return true;
 }
Пример #2
0
 private static void renameVar(MethodNode mth, SSAVar[] vars, int[] vers, BlockNode block) {
   SSAVar[] inputVars = Arrays.copyOf(vars, vars.length);
   for (InsnNode insn : block.getInstructions()) {
     if (insn.getType() != InsnType.PHI) {
       for (InsnArg arg : insn.getArguments()) {
         if (!arg.isRegister()) {
           continue;
         }
         RegisterArg reg = (RegisterArg) arg;
         int regNum = reg.getRegNum();
         SSAVar var = vars[regNum];
         if (var == null) {
           throw new JadxRuntimeException(
               "Not initialized variable reg: "
                   + regNum
                   + ", insn: "
                   + insn
                   + ", block:"
                   + block
                   + ", method: "
                   + mth);
         }
         var.use(reg);
       }
     }
     RegisterArg result = insn.getResult();
     if (result != null) {
       int regNum = result.getRegNum();
       vars[regNum] = mth.makeNewSVar(regNum, vers, result);
     }
   }
   for (BlockNode s : block.getSuccessors()) {
     PhiListAttr phiList = s.get(AType.PHI_LIST);
     if (phiList == null) {
       continue;
     }
     int j = s.getPredecessors().indexOf(block);
     if (j == -1) {
       throw new JadxRuntimeException("Can't find predecessor for " + block + " " + s);
     }
     for (PhiInsn phiInsn : phiList.getList()) {
       if (j >= phiInsn.getArgsCount()) {
         continue;
       }
       int regNum = phiInsn.getResult().getRegNum();
       SSAVar var = vars[regNum];
       if (var == null) {
         continue;
       }
       var.use(phiInsn.getArg(j));
       var.setUsedInPhi(phiInsn);
     }
   }
   for (BlockNode domOn : block.getDominatesOn()) {
     renameVar(mth, vars, vers, domOn);
   }
   System.arraycopy(inputVars, 0, vars, 0, vars.length);
 }
Пример #3
0
 private static boolean removeUselessPhi(MethodNode mth) {
   List<PhiInsn> insnToRemove = new ArrayList<PhiInsn>();
   for (SSAVar var : mth.getSVars()) {
     // phi result not used
     if (var.getUseCount() == 0) {
       InsnNode assignInsn = var.getAssign().getParentInsn();
       if (assignInsn != null && assignInsn.getType() == InsnType.PHI) {
         insnToRemove.add((PhiInsn) assignInsn);
       }
     }
   }
   for (BlockNode block : mth.getBasicBlocks()) {
     PhiListAttr phiList = block.get(AType.PHI_LIST);
     if (phiList == null) {
       continue;
     }
     for (PhiInsn phi : phiList.getList()) {
       removePhiWithSameArgs(phi, insnToRemove);
     }
   }
   return removePhiList(mth, insnToRemove);
 }
Пример #4
0
 private static void removePhiWithSameArgs(PhiInsn phi, List<PhiInsn> insnToRemove) {
   if (phi.getArgsCount() <= 1) {
     insnToRemove.add(phi);
     return;
   }
   boolean allSame = true;
   SSAVar var = phi.getArg(0).getSVar();
   for (int i = 1; i < phi.getArgsCount(); i++) {
     if (var != phi.getArg(i).getSVar()) {
       allSame = false;
       break;
     }
   }
   if (allSame) {
     // replace
     insnToRemove.add(phi);
     SSAVar assign = phi.getResult().getSVar();
     for (RegisterArg arg : new ArrayList<RegisterArg>(assign.getUseList())) {
       assign.removeUse(arg);
       var.use(arg);
     }
   }
 }