llvm-project/llvm/lib/Analysis/MemDerefPrinter.cpp

76 lines
2.4 KiB
C++

//===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
struct MemDerefPrinter : public FunctionPass {
SmallVector<Value *, 4> Deref;
SmallPtrSet<Value *, 4> DerefAndAligned;
static char ID; // Pass identification, replacement for typeid
MemDerefPrinter() : FunctionPass(ID) {
initializeMemDerefPrinterPass(*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
}
bool runOnFunction(Function &F) override;
void print(raw_ostream &OS, const Module * = nullptr) const override;
void releaseMemory() override {
Deref.clear();
DerefAndAligned.clear();
}
};
}
char MemDerefPrinter::ID = 0;
INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs",
"Memory Dereferenciblity of pointers in function", false, true)
INITIALIZE_PASS_END(MemDerefPrinter, "print-memderefs",
"Memory Dereferenciblity of pointers in function", false, true)
FunctionPass *llvm::createMemDerefPrinter() {
return new MemDerefPrinter();
}
bool MemDerefPrinter::runOnFunction(Function &F) {
const DataLayout &DL = F.getParent()->getDataLayout();
for (auto &I: instructions(F)) {
if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
Value *PO = LI->getPointerOperand();
if (isDereferenceablePointer(PO, DL))
Deref.push_back(PO);
if (isDereferenceableAndAlignedPointer(PO, LI->getAlignment(), DL))
DerefAndAligned.insert(PO);
}
}
return false;
}
void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const {
OS << "The following are dereferenceable:\n";
for (Value *V: Deref) {
V->print(OS);
if (DerefAndAligned.count(V))
OS << "\t(aligned)";
else
OS << "\t(unaligned)";
OS << "\n\n";
}
}