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/MemDerefPrinter.h"
10#include "llvm/Analysis/Loads.h"
11#include "llvm/Analysis/Passes.h"
12#include "llvm/IR/InstIterator.h"
13#include "llvm/IR/Instructions.h"
14#include "llvm/IR/Module.h"
15#include "llvm/InitializePasses.h"
16#include "llvm/Pass.h"
17#include "llvm/Support/raw_ostream.h"
18
19using namespace llvm;
20
21PreservedAnalyses MemDerefPrinterPass::run(Function &F,
22                                           FunctionAnalysisManager &AM) {
23  OS << "Memory Dereferencibility of pointers in function '" << F.getName()
24     << "'\n";
25
26  SmallVector<Value *, 4> Deref;
27  SmallPtrSet<Value *, 4> DerefAndAligned;
28
29  const DataLayout &DL = F.getParent()->getDataLayout();
30  for (auto &I : instructions(F)) {
31    if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
32      Value *PO = LI->getPointerOperand();
33      if (isDereferenceablePointer(PO, LI->getType(), DL))
34        Deref.push_back(PO);
35      if (isDereferenceableAndAlignedPointer(PO, LI->getType(), LI->getAlign(),
36                                             DL))
37        DerefAndAligned.insert(PO);
38    }
39  }
40
41  OS << "The following are dereferenceable:\n";
42  for (Value *V : Deref) {
43    OS << "  ";
44    V->print(OS);
45    if (DerefAndAligned.count(V))
46      OS << "\t(aligned)";
47    else
48      OS << "\t(unaligned)";
49    OS << "\n";
50  }
51  return PreservedAnalyses::all();
52}
53