1 //===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "llvm/Analysis/Passes.h"
11 #include "llvm/ADT/SetVector.h"
12 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
13 #include "llvm/IR/CallSite.h"
14 #include "llvm/IR/DataLayout.h"
15 #include "llvm/IR/InstIterator.h"
16 #include "llvm/IR/LLVMContext.h"
17 #include "llvm/IR/Module.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> Vec;
25
26 static char ID; // Pass identifcation, replacement for typeid
MemDerefPrinter__anon18c459ce0111::MemDerefPrinter27 MemDerefPrinter() : FunctionPass(ID) {
28 initializeMemDerefPrinterPass(*PassRegistry::getPassRegistry());
29 }
getAnalysisUsage__anon18c459ce0111::MemDerefPrinter30 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;
releaseMemory__anon18c459ce0111::MemDerefPrinter35 void releaseMemory() override {
36 Vec.clear();
37 }
38 };
39 }
40
41 char MemDerefPrinter::ID = 0;
42 INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs",
43 "Memory Dereferenciblity of pointers in function", false, true)
44 INITIALIZE_PASS_END(MemDerefPrinter, "print-memderefs",
45 "Memory Dereferenciblity of pointers in function", false, true)
46
createMemDerefPrinter()47 FunctionPass *llvm::createMemDerefPrinter() {
48 return new MemDerefPrinter();
49 }
50
runOnFunction(Function & F)51 bool MemDerefPrinter::runOnFunction(Function &F) {
52 const DataLayout &DL = F.getParent()->getDataLayout();
53 for (auto &I: inst_range(F)) {
54 if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
55 Value *PO = LI->getPointerOperand();
56 if (PO->isDereferenceablePointer(DL))
57 Vec.push_back(PO);
58 }
59 }
60 return false;
61 }
62
print(raw_ostream & OS,const Module * M) const63 void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const {
64 OS << "The following are dereferenceable:\n";
65 for (auto &V: Vec) {
66 V->print(OS);
67 OS << "\n\n";
68 }
69 }
70