From 1739af6d37e1c5cca5aaeaaf81d2c1d4c8c95fa7 Mon Sep 17 00:00:00 2001
From: nanlioniya <huangp585@gmail.com>
Date: Thu, 1 May 2025 14:47:18 +0800
Subject: [PATCH] pass with validation

---
 lab6/llvm-pass.so.cc | 116 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 98 insertions(+), 18 deletions(-)

diff --git a/lab6/llvm-pass.so.cc b/lab6/llvm-pass.so.cc
index 6c6e17e..d1112fe 100644
--- a/lab6/llvm-pass.so.cc
+++ b/lab6/llvm-pass.so.cc
@@ -1,34 +1,114 @@
 #include "llvm/Passes/PassPlugin.h"
 #include "llvm/Passes/PassBuilder.h"
 #include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Value.h"
 
 using namespace llvm;
 
+namespace {
 struct LLVMPass : public PassInfoMixin<LLVMPass> {
-  PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM);
-};
-
-PreservedAnalyses LLVMPass::run(Module &M, ModuleAnalysisManager &MAM) {
-  LLVMContext &Ctx = M.getContext();
-  IntegerType *Int32Ty = IntegerType::getInt32Ty(Ctx);
-  FunctionCallee debug_func = M.getOrInsertFunction("debug", Int32Ty);
-  ConstantInt *debug_arg = ConstantInt::get(Int32Ty, 48763);
-
-  for (auto &F : M) {
-    errs() << "func: " << F.getName() << "\n";
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM) {
+    // 尋找 main 函數
+    Function *MainFunc = M.getFunction("main");
+    if (!MainFunc) {
+      return PreservedAnalyses::all();
+    }
 
+    LLVMContext &Ctx = M.getContext();
+    
+    // 創建全局字符串常量 "deubg mode"
+    Constant *DebugStr = ConstantDataArray::getString(Ctx, "deubg mode", true);
+    GlobalVariable *DebugGV = new GlobalVariable(
+        M, DebugStr->getType(), true, GlobalValue::PrivateLinkage, DebugStr, "debug_str");
+    
+    // 創建全局字符串常量 "hayaku... motohayaku!"
+    Constant *HayakuStr = ConstantDataArray::getString(Ctx, "hayaku... motohayaku!", true);
+    GlobalVariable *HayakuGV = new GlobalVariable(
+        M, HayakuStr->getType(), true, GlobalValue::PrivateLinkage, HayakuStr, "hayaku_str");
+    
+    // 獲取 printf 函數
+    FunctionType *PrintfTy = FunctionType::get(
+        Type::getInt32Ty(Ctx), Type::getInt8PtrTy(Ctx), true);
+    FunctionCallee PrintfFunc = M.getOrInsertFunction("printf", PrintfTy);
+    
+    // 在 main 函數入口處插入代碼
+    BasicBlock &EntryBB = MainFunc->getEntryBlock();
+    IRBuilder<> Builder(&EntryBB, EntryBB.getFirstInsertionPt());
+    
+    // 打印 "deubg mode"
+    Value *FormatStr = Builder.CreateGlobalStringPtr("%s\n", "format");
+    Value *GEPIndices[] = {
+      ConstantInt::get(Type::getInt32Ty(Ctx), 0),
+      ConstantInt::get(Type::getInt32Ty(Ctx), 0)
+    };
+    Value *DebugPtr = Builder.CreateInBoundsGEP(DebugGV->getValueType(), DebugGV, GEPIndices, "debug_str_ptr");
+    Builder.CreateCall(PrintfFunc, {FormatStr, DebugPtr});
+    
+    // 創建常量 48763 (替換 argc)
+    ConstantInt *MagicNum = ConstantInt::get(Type::getInt32Ty(Ctx), 48763);
+    
+    // 獲取 main 函數參數
+    auto ArgIt = MainFunc->arg_begin();
+    Argument *ArgC = &*ArgIt; // 第一個參數是 argc
+    ++ArgIt;
+    Argument *ArgV = &*ArgIt; // 第二個參數是 argv
+    
+    // 創建臨時變量存儲 48763
+    AllocaInst *TempArgC = Builder.CreateAlloca(Type::getInt32Ty(Ctx), nullptr, "temp_argc");
+    Builder.CreateStore(MagicNum, TempArgC);
+    
+    // 替換所有 argc 的使用
+    for (auto UI = ArgC->use_begin(), UE = ArgC->use_end(); UI != UE;) {
+      Use &U = *UI++;
+      User *User = U.getUser();
+      
+      // 替換為從臨時變量加載的值
+      Value *LoadedArgC = Builder.CreateLoad(Type::getInt32Ty(Ctx), TempArgC, "loaded_argc");
+      U.set(LoadedArgC);
+    }
+    
+    // 修改 argv[1]
+    // 創建指向 "hayaku... motohayaku!" 的指針
+    Value *HayakuPtr = Builder.CreateInBoundsGEP(HayakuGV->getValueType(), HayakuGV, GEPIndices, "hayaku_str_ptr");
+    
+    // 計算 argv[1] 的地址
+    Value *IndexOne = ConstantInt::get(Type::getInt32Ty(Ctx), 1);
+    Value *ArgVPtr = Builder.CreateGEP(ArgV->getType()->getPointerElementType(), ArgV, IndexOne, "argv_1_ptr");
+    
+    // 將 "hayaku... motohayaku!" 存入 argv[1]
+    Builder.CreateStore(HayakuPtr, ArgVPtr);
+    
+    return PreservedAnalyses::none();
   }
-  return PreservedAnalyses::none();
+};
 }
 
-extern "C" ::llvm::PassPluginLibraryInfo LLVM_ATTRIBUTE_WEAK
+// 註冊 Pass
+extern "C" LLVM_ATTRIBUTE_WEAK ::llvm::PassPluginLibraryInfo
 llvmGetPassPluginInfo() {
-  return {LLVM_PLUGIN_API_VERSION, "LLVMPass", "1.0",
+  return {
+    LLVM_PLUGIN_API_VERSION, "LLVMPass", LLVM_VERSION_STRING,
     [](PassBuilder &PB) {
-      PB.registerOptimizerLastEPCallback(
-        [](ModulePassManager &MPM, OptimizationLevel OL) {
+      PB.registerPipelineParsingCallback(
+        [](StringRef Name, ModulePassManager &MPM,
+           ArrayRef<PassBuilder::PipelineElement>) {
+          if (Name == "llvm-pass") {
+            MPM.addPass(LLVMPass());
+            return true;
+          }
+          return false;
+        });
+      
+      // 註冊為優化器的開始步驟
+      PB.registerPipelineStartEPCallback(
+        [](ModulePassManager &MPM, OptimizationLevel) {
           MPM.addPass(LLVMPass());
         });
-    }};
+    }
+  };
 }
-