1//===-- llvm/MC/MCValue.h - MCValue class -----------------------*- C++ -*-===//
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 contains the declaration of the MCValue class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_MC_MCVALUE_H
14#define LLVM_MC_MCVALUE_H
15
16#include "llvm/MC/MCExpr.h"
17#include "llvm/MC/MCSymbol.h"
18#include "llvm/Support/DataTypes.h"
19#include <cassert>
20
21namespace llvm {
22class MCAsmInfo;
23class raw_ostream;
24
25/// This represents an "assembler immediate".
26///
27///  In its most general form, this can hold ":Kind:(SymbolA - SymbolB +
28///  imm64)".  Not all targets supports relocations of this general form, but we
29///  need to represent this anyway.
30///
31/// In general both SymbolA and SymbolB will also have a modifier
32/// analogous to the top-level Kind. Current targets are not expected
33/// to make use of both though. The choice comes down to whether
34/// relocation modifiers apply to the closest symbol or the whole
35/// expression.
36///
37/// Note that this class must remain a simple POD value class, because we need
38/// it to live in unions etc.
39class MCValue {
40  const MCSymbolRefExpr *SymA = nullptr, *SymB = nullptr;
41  int64_t Cst = 0;
42  uint32_t RefKind = 0;
43
44public:
45  MCValue() = default;
46  int64_t getConstant() const { return Cst; }
47  const MCSymbolRefExpr *getSymA() const { return SymA; }
48  const MCSymbolRefExpr *getSymB() const { return SymB; }
49  uint32_t getRefKind() const { return RefKind; }
50
51  /// Is this an absolute (as opposed to relocatable) value.
52  bool isAbsolute() const { return !SymA && !SymB; }
53
54  /// Print the value to the stream \p OS.
55  void print(raw_ostream &OS) const;
56
57  /// Print the value to stderr.
58  void dump() const;
59
60  MCSymbolRefExpr::VariantKind getAccessVariant() const;
61
62  static MCValue get(const MCSymbolRefExpr *SymA,
63                     const MCSymbolRefExpr *SymB = nullptr,
64                     int64_t Val = 0, uint32_t RefKind = 0) {
65    MCValue R;
66    R.Cst = Val;
67    R.SymA = SymA;
68    R.SymB = SymB;
69    R.RefKind = RefKind;
70    return R;
71  }
72
73  static MCValue get(int64_t Val) {
74    MCValue R;
75    R.Cst = Val;
76    R.SymA = nullptr;
77    R.SymB = nullptr;
78    R.RefKind = 0;
79    return R;
80  }
81
82};
83
84} // end namespace llvm
85
86#endif
87