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 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