test f

Author: SapphireLinXu

lab6/llvm-pass.so.cc

@@ -1,50 +1,65 @@
 #include "llvm/Passes/PassPlugin.h"
 #include "llvm/Passes/PassBuilder.h"
 #include "llvm/IR/IRBuilder.h"
-using namespace llvm;
-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);
-
-  FunctionType *debugTy = FunctionType::get(Type::getVoidTy(Ctx), {Int32Ty}, false);
-  FunctionCallee debug_func = M.getOrInsertFunction("debug", debugTy);
-  ConstantInt *debug_arg = ConstantInt::get(Int32Ty, 48763);
-
-  for (auto &F : M) {
-    //errs() << "func: " << F.getName() << "\n";
-    if(F.getName() != "main" || F.isDeclaration())
-    	continue;
-
-    errs() << "func: " << F.getName() << "\n";
-
-    auto ArgIter = F.arg_begin();
-    Argument *argcArg = &*ArgIter++;
-    Argument *argvArg = &*ArgIter;
 
-    Instruction *InsertPt = &*F.getEntryBlock().getFirstInsertionPt();
-    IRBuilder<> Builder(InsertPt);
+namespace {
+using namespace llvm;
 
-    Builder.CreateCall(debug_func, {debug_arg});
+class CustomModulePass : public PassInfoMixin<CustomModulePass> {
+public:
+  PreservedAnalyses run(Module &Module, ModuleAnalysisManager &AnalysisManager);
+};
 
-    for(auto &BB : F){
-    	for(auto &I : BB){
-    		for(unsigned i = 0; i < I.getNumOperands(); ++i){
-    		if(I.getOperand(i) == argcArg){
-    			I.setOperand(i, debug_arg);
-    		}
-    		}
-    	}
+PreservedAnalyses CustomModulePass::run(Module &Module, ModuleAnalysisManager &AnalysisManager) {
+  LLVMContext &Context = Module.getContext();
+  
+  // Create types
+  auto *I32Type = Type::getInt32Ty(Context);
+  
+  // Setup debug function
+  FunctionType *DebugFunctionType = FunctionType::get(Type::getVoidTy(Context), {I32Type}, false);
+  FunctionCallee DebugFunction = Module.getOrInsertFunction("debug", DebugFunctionType);
+  
+  // Magic number constant
+  ConstantInt *MagicNumber = ConstantInt::get(I32Type, 48763);
+  
+  // Process functions in module
+  for (Function &CurrentFunction : Module) {
+    // Skip non-main functions and declarations
+    if (CurrentFunction.getName() != "main" || CurrentFunction.isDeclaration())
+      continue;
+      
+    errs() << "Processing function: " << CurrentFunction.getName() << "\n";
+    
+    // Get function arguments
+    auto ArgIterator = CurrentFunction.arg_begin();
+    Argument *ArgCount = &*ArgIterator++;
+    Argument *ArgVector = &*ArgIterator;
+    
+    // Insert at the beginning of function entry block
+    IRBuilder<> IRB(&*CurrentFunction.getEntryBlock().begin());
+    
+    // Insert call to debug function
+    IRB.CreateCall(DebugFunction, {MagicNumber});
+    
+    // Replace all uses of argc with magic number
+    for (BasicBlock &Block : CurrentFunction) {
+      for (Instruction &Inst : Block) {
+        for (unsigned OpIdx = 0; OpIdx < Inst.getNumOperands(); ++OpIdx) {
+          if (Inst.getOperand(OpIdx) == ArgCount) {
+            Inst.setOperand(OpIdx, MagicNumber);
+          }
+        }
+      }
     }
-
-    Value *idx1 = ConstantInt::get(Int32Ty, 1);
-    Value *argv1Ptr = Builder.CreateInBoundsGEP(argvArg->getType()->getPointerElementType(), argvArg, idx1);
-    Value *strPtr = Builder.CreateGlobalStringPtr("hayaku... motohayaku!");
-    Builder.CreateStore(strPtr, argv1Ptr);
-
-    //Builder.CreateStore(debug_arg, argcArg);
-
+    
+    // Modify argv[1]
+    Value *IndexOne = ConstantInt::get(I32Type, 1);
+    Value *SecondArgPtr = IRB.CreateInBoundsGEP(ArgVector->getType()->getPointerElementType(), 
+                                                ArgVector, IndexOne);
+    Value *MessagePtr = IRB.CreateGlobalStringPtr("hayaku... motohayaku!");
+    IRB.CreateStore(MessagePtr, SecondArgPtr);
   }
-  return PreservedAnalyses::none();
+  
+  return PreservedAnalyses::none();
+}