1 //===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===//
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
7 //===----------------------------------------------------------------------===//
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"
22 struct MemDerefPrinter : public FunctionPass {
23 SmallVector<Value *, 4> Deref;
24 SmallPtrSet<Value *, 4> DerefAndAligned;
26 static char ID; // Pass identification, replacement for typeid
27 MemDerefPrinter() : FunctionPass(ID) {
28 initializeMemDerefPrinterPass(*PassRegistry::getPassRegistry());
30 void getAnalysisUsage(AnalysisUsage &AU) const override {
33 bool runOnFunction(Function &F) override;
34 void print(raw_ostream &OS, const Module * = nullptr) const override;
35 void releaseMemory() override {
37 DerefAndAligned.clear();
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)
48 FunctionPass *llvm::createMemDerefPrinter() {
49 return new MemDerefPrinter();
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))
59 if (isDereferenceableAndAlignedPointer(
60 PO, LI->getType(), MaybeAlign(LI->getAlignment()), DL))
61 DerefAndAligned.insert(PO);
67 void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const {
68 OS << "The following are dereferenceable:\n";
69 for (Value *V: Deref) {
71 if (DerefAndAligned.count(V))
74 OS << "\t(unaligned)";