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