llvm-project/llvm/lib/IR/IntrinsicInst.cpp

82 lines
2.7 KiB
C++

//===-- InstrinsicInst.cpp - Intrinsic Instruction Wrappers ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements methods that make it really easy to deal with intrinsic
// functions.
//
// All intrinsic function calls are instances of the call instruction, so these
// are all subclasses of the CallInst class. Note that none of these classes
// has state or virtual methods, which is an important part of this gross/neat
// hack working.
//
// In some cases, arguments to intrinsics need to be generic and are defined as
// type pointer to empty struct { }*. To access the real item of interest the
// cast instruction needs to be stripped away.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Metadata.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
/// DbgInfoIntrinsic - This is the common base class for debug info intrinsics
///
static Value *CastOperand(Value *C) {
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
if (CE->isCast())
return CE->getOperand(0);
return nullptr;
}
Value *DbgInfoIntrinsic::StripCast(Value *C) {
if (Value *CO = CastOperand(C)) {
C = StripCast(CO);
} else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
if (GV->hasInitializer())
if (Value *CO = CastOperand(GV->getInitializer()))
C = StripCast(CO);
}
return dyn_cast<GlobalVariable>(C);
}
static Value *getValueImpl(Value *Op) {
auto *MD = cast<MetadataAsValue>(Op)->getMetadata();
if (auto *V = dyn_cast<ValueAsMetadata>(MD))
return V->getValue();
// When the value goes to null, it gets replaced by an empty MDNode.
assert(!cast<MDNode>(MD)->getNumOperands() && "Expected an empty MDNode");
return nullptr;
}
//===----------------------------------------------------------------------===//
/// DbgDeclareInst - This represents the llvm.dbg.declare instruction.
///
Value *DbgDeclareInst::getAddress() const {
if (!getArgOperand(0))
return nullptr;
return getValueImpl(getArgOperand(0));
}
//===----------------------------------------------------------------------===//
/// DbgValueInst - This represents the llvm.dbg.value instruction.
///
const Value *DbgValueInst::getValue() const {
return const_cast<DbgValueInst *>(this)->getValue();
}
Value *DbgValueInst::getValue() { return getValueImpl(getArgOperand(0)); }