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