1 //===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/Analysis/Loads.h" 10 #include "llvm/Analysis/Passes.h" 11 #include "llvm/IR/DataLayout.h" 12 #include "llvm/IR/InstIterator.h" 13 #include "llvm/IR/Instructions.h" 14 #include "llvm/IR/LLVMContext.h" 15 #include "llvm/IR/Module.h" 16 #include "llvm/InitializePasses.h" 17 #include "llvm/Pass.h" 18 #include "llvm/Support/ErrorHandling.h" 19 #include "llvm/Support/raw_ostream.h" 20 using namespace llvm; 21 22 namespace { 23 struct MemDerefPrinter : public FunctionPass { 24 SmallVector<Value *, 4> Deref; 25 SmallPtrSet<Value *, 4> DerefAndAligned; 26 27 static char ID; // Pass identification, replacement for typeid 28 MemDerefPrinter() : FunctionPass(ID) { 29 initializeMemDerefPrinterPass(*PassRegistry::getPassRegistry()); 30 } 31 void getAnalysisUsage(AnalysisUsage &AU) const override { 32 AU.setPreservesAll(); 33 } 34 bool runOnFunction(Function &F) override; 35 void print(raw_ostream &OS, const Module * = nullptr) const override; 36 void releaseMemory() override { 37 Deref.clear(); 38 DerefAndAligned.clear(); 39 } 40 }; 41 } 42 43 char MemDerefPrinter::ID = 0; 44 INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs", 45 "Memory Dereferenciblity of pointers in function", false, true) 46 INITIALIZE_PASS_END(MemDerefPrinter, "print-memderefs", 47 "Memory Dereferenciblity of pointers in function", false, true) 48 49 FunctionPass *llvm::createMemDerefPrinter() { 50 return new MemDerefPrinter(); 51 } 52 53 bool MemDerefPrinter::runOnFunction(Function &F) { 54 const DataLayout &DL = F.getParent()->getDataLayout(); 55 for (auto &I: instructions(F)) { 56 if (LoadInst *LI = dyn_cast<LoadInst>(&I)) { 57 Value *PO = LI->getPointerOperand(); 58 if (isDereferenceablePointer(PO, LI->getType(), DL)) 59 Deref.push_back(PO); 60 if (isDereferenceableAndAlignedPointer( 61 PO, LI->getType(), MaybeAlign(LI->getAlignment()), DL)) 62 DerefAndAligned.insert(PO); 63 } 64 } 65 return false; 66 } 67 68 void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const { 69 OS << "The following are dereferenceable:\n"; 70 for (Value *V: Deref) { 71 V->print(OS); 72 if (DerefAndAligned.count(V)) 73 OS << "\t(aligned)"; 74 else 75 OS << "\t(unaligned)"; 76 OS << "\n\n"; 77 } 78 } 79