1 //===- ObjCARCAnalysisUtils.cpp -------------------------------------------===//
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 // This file implements common infrastructure for libLLVMObjCARCOpts.a, which
10 // implements several scalar transformations over the LLVM intermediate
11 // representation, including the C bindings for that library.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "llvm/Analysis/ObjCARCAnalysisUtils.h"
16 #include "llvm/Analysis/AliasAnalysis.h"
17 #include "llvm/Support/CommandLine.h"
18
19 using namespace llvm;
20 using namespace llvm::objcarc;
21
22 /// A handy option to enable/disable all ARC Optimizations.
23 bool llvm::objcarc::EnableARCOpts;
24 static cl::opt<bool, true> EnableARCOptimizations(
25 "enable-objc-arc-opts", cl::desc("enable/disable all ARC Optimizations"),
26 cl::location(EnableARCOpts), cl::init(true), cl::Hidden);
27
IsPotentialRetainableObjPtr(const Value * Op,AAResults & AA)28 bool llvm::objcarc::IsPotentialRetainableObjPtr(const Value *Op,
29 AAResults &AA) {
30 // First make the rudimentary check.
31 if (!IsPotentialRetainableObjPtr(Op))
32 return false;
33
34 // Objects in constant memory are not reference-counted.
35 if (AA.pointsToConstantMemory(Op))
36 return false;
37
38 // Pointers in constant memory are not pointing to reference-counted objects.
39 if (const LoadInst *LI = dyn_cast<LoadInst>(Op))
40 if (AA.pointsToConstantMemory(LI->getPointerOperand()))
41 return false;
42
43 // Otherwise assume the worst.
44 return true;
45 }
46