1//===-- InstrinsicInst.cpp - Intrinsic Instruction Wrappers ---------------===// 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// This file implements methods that make it really easy to deal with intrinsic 11// functions. 12// 13// All intrinsic function calls are instances of the call instruction, so these 14// are all subclasses of the CallInst class. Note that none of these classes 15// has state or virtual methods, which is an important part of this gross/neat 16// hack working. 17// 18// In some cases, arguments to intrinsics need to be generic and are defined as 19// type pointer to empty struct { }*. To access the real item of interest the 20// cast instruction needs to be stripped away. 21// 22//===----------------------------------------------------------------------===// 23 24#include "llvm/IR/IntrinsicInst.h" 25#include "llvm/IR/Constants.h" 26#include "llvm/IR/GlobalVariable.h" 27#include "llvm/IR/Metadata.h" 28using namespace llvm; 29 30//===----------------------------------------------------------------------===// 31/// DbgInfoIntrinsic - This is the common base class for debug info intrinsics 32/// 33 34static Value *CastOperand(Value *C) { 35 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) 36 if (CE->isCast()) 37 return CE->getOperand(0); 38 return nullptr; 39} 40 41Value *DbgInfoIntrinsic::StripCast(Value *C) { 42 if (Value *CO = CastOperand(C)) { 43 C = StripCast(CO); 44 } else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) { 45 if (GV->hasInitializer()) 46 if (Value *CO = CastOperand(GV->getInitializer())) 47 C = StripCast(CO); 48 } 49 return dyn_cast<GlobalVariable>(C); 50} 51 52static Value *getValueImpl(Value *Op) { 53 auto *MD = cast<MetadataAsValue>(Op)->getMetadata(); 54 if (auto *V = dyn_cast<ValueAsMetadata>(MD)) 55 return V->getValue(); 56 57 // When the value goes to null, it gets replaced by an empty MDNode. 58 assert(!cast<MDNode>(MD)->getNumOperands() && "Expected an empty MDNode"); 59 return nullptr; 60} 61 62//===----------------------------------------------------------------------===// 63/// DbgDeclareInst - This represents the llvm.dbg.declare instruction. 64/// 65 66Value *DbgDeclareInst::getAddress() const { 67 if (!getArgOperand(0)) 68 return nullptr; 69 70 return getValueImpl(getArgOperand(0)); 71} 72 73//===----------------------------------------------------------------------===// 74/// DbgValueInst - This represents the llvm.dbg.value instruction. 75/// 76 77const Value *DbgValueInst::getValue() const { 78 return const_cast<DbgValueInst *>(this)->getValue(); 79} 80 81Value *DbgValueInst::getValue() { return getValueImpl(getArgOperand(0)); } 82