1//===- MCSymbolMachO.h -  ---------------------------------------*- C++ -*-===//
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#ifndef LLVM_MC_MCSYMBOLMACHO_H
10#define LLVM_MC_MCSYMBOLMACHO_H
11
12#include "llvm/ADT/Twine.h"
13#include "llvm/MC/MCSymbol.h"
14
15namespace llvm {
16class MCSymbolMachO : public MCSymbol {
17  /// \brief We store the value for the 'desc' symbol field in the
18  /// lowest 16 bits of the implementation defined flags.
19  enum MachOSymbolFlags : uint16_t { // See <mach-o/nlist.h>.
20    SF_DescFlagsMask                        = 0xFFFF,
21
22    // Reference type flags.
23    SF_ReferenceTypeMask                    = 0x0007,
24    SF_ReferenceTypeUndefinedNonLazy        = 0x0000,
25    SF_ReferenceTypeUndefinedLazy           = 0x0001,
26    SF_ReferenceTypeDefined                 = 0x0002,
27    SF_ReferenceTypePrivateDefined          = 0x0003,
28    SF_ReferenceTypePrivateUndefinedNonLazy = 0x0004,
29    SF_ReferenceTypePrivateUndefinedLazy    = 0x0005,
30
31    // Other 'desc' flags.
32    SF_ThumbFunc                            = 0x0008,
33    SF_NoDeadStrip                          = 0x0020,
34    SF_WeakReference                        = 0x0040,
35    SF_WeakDefinition                       = 0x0080,
36    SF_SymbolResolver                       = 0x0100,
37    SF_AltEntry                             = 0x0200,
38
39    // Common alignment
40    SF_CommonAlignmentMask                  = 0xF0FF,
41    SF_CommonAlignmentShift                 = 8
42  };
43
44public:
45  MCSymbolMachO(const StringMapEntry<bool> *Name, bool isTemporary)
46      : MCSymbol(SymbolKindMachO, Name, isTemporary) {}
47
48  // Reference type methods.
49
50  void clearReferenceType() const {
51    modifyFlags(0, SF_ReferenceTypeMask);
52  }
53
54  void setReferenceTypeUndefinedLazy(bool Value) const {
55    modifyFlags(Value ? SF_ReferenceTypeUndefinedLazy : 0,
56                SF_ReferenceTypeUndefinedLazy);
57  }
58
59  // Other 'desc' methods.
60
61  void setThumbFunc() const {
62    modifyFlags(SF_ThumbFunc, SF_ThumbFunc);
63  }
64
65  bool isNoDeadStrip() const {
66    return getFlags() & SF_NoDeadStrip;
67  }
68  void setNoDeadStrip() const {
69    modifyFlags(SF_NoDeadStrip, SF_NoDeadStrip);
70  }
71
72  bool isWeakReference() const {
73    return getFlags() & SF_WeakReference;
74  }
75  void setWeakReference() const {
76    modifyFlags(SF_WeakReference, SF_WeakReference);
77  }
78
79  bool isWeakDefinition() const {
80    return getFlags() & SF_WeakDefinition;
81  }
82  void setWeakDefinition() const {
83    modifyFlags(SF_WeakDefinition, SF_WeakDefinition);
84  }
85
86  bool isSymbolResolver() const {
87    return getFlags() & SF_SymbolResolver;
88  }
89  void setSymbolResolver() const {
90    modifyFlags(SF_SymbolResolver, SF_SymbolResolver);
91  }
92
93  void setAltEntry() const {
94    modifyFlags(SF_AltEntry, SF_AltEntry);
95  }
96
97  bool isAltEntry() const {
98    return getFlags() & SF_AltEntry;
99  }
100
101  void setDesc(unsigned Value) const {
102    assert(Value == (Value & SF_DescFlagsMask) &&
103           "Invalid .desc value!");
104    setFlags(Value & SF_DescFlagsMask);
105  }
106
107  /// \brief Get the encoded value of the flags as they will be emitted in to
108  /// the MachO binary
109  uint16_t getEncodedFlags(bool EncodeAsAltEntry) const {
110    uint16_t Flags = getFlags();
111
112    // Common alignment is packed into the 'desc' bits.
113    if (isCommon()) {
114      if (unsigned Align = getCommonAlignment()) {
115        unsigned Log2Size = Log2_32(Align);
116        assert((1U << Log2Size) == Align && "Invalid 'common' alignment!");
117        if (Log2Size > 15)
118          report_fatal_error("invalid 'common' alignment '" +
119                             Twine(Align) + "' for '" + getName() + "'",
120                             false);
121        Flags = (Flags & SF_CommonAlignmentMask) |
122                (Log2Size << SF_CommonAlignmentShift);
123      }
124    }
125
126    if (EncodeAsAltEntry)
127      Flags |= SF_AltEntry;
128
129    return Flags;
130  }
131
132  static bool classof(const MCSymbol *S) { return S->isMachO(); }
133};
134}
135
136#endif
137