1 //===- MCSectionCOFF.h - COFF Machine Code Sections -------------*- 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 //
10 // This file declares the MCSectionCOFF class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_MC_MCSECTIONCOFF_H
15 #define LLVM_MC_MCSECTIONCOFF_H
16 
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/MC/MCSection.h"
19 #include "llvm/Support/COFF.h"
20 
21 namespace llvm {
22 class MCSymbol;
23 
24 /// MCSectionCOFF - This represents a section on Windows
25   class MCSectionCOFF : public MCSection {
26     // The memory for this string is stored in the same MCContext as *this.
27     StringRef SectionName;
28 
29     // FIXME: The following fields should not be mutable, but are for now so
30     // the asm parser can honor the .linkonce directive.
31 
32     /// Characteristics - This is the Characteristics field of a section,
33     /// drawn from the enums below.
34     mutable unsigned Characteristics;
35 
36     /// The COMDAT symbol of this section. Only valid if this is a COMDAT
37     /// section. Two COMDAT sections are merged if they have the same
38     /// COMDAT symbol.
39     MCSymbol *COMDATSymbol;
40 
41     /// Selection - This is the Selection field for the section symbol, if
42     /// it is a COMDAT section (Characteristics & IMAGE_SCN_LNK_COMDAT) != 0
43     mutable int Selection;
44 
45   private:
46     friend class MCContext;
MCSectionCOFF(StringRef Section,unsigned Characteristics,MCSymbol * COMDATSymbol,int Selection,SectionKind K,MCSymbol * Begin)47     MCSectionCOFF(StringRef Section, unsigned Characteristics,
48                   MCSymbol *COMDATSymbol, int Selection, SectionKind K,
49                   MCSymbol *Begin)
50         : MCSection(SV_COFF, K, Begin), SectionName(Section),
51           Characteristics(Characteristics), COMDATSymbol(COMDATSymbol),
52           Selection(Selection) {
53       assert ((Characteristics & 0x00F00000) == 0 &&
54         "alignment must not be set upon section creation");
55     }
56     ~MCSectionCOFF() override;
57 
58   public:
59     /// ShouldOmitSectionDirective - Decides whether a '.section' directive
60     /// should be printed before the section name
61     bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
62 
getSectionName()63     StringRef getSectionName() const { return SectionName; }
getCharacteristics()64     unsigned getCharacteristics() const { return Characteristics; }
getCOMDATSymbol()65     MCSymbol *getCOMDATSymbol() const { return COMDATSymbol; }
getSelection()66     int getSelection() const { return Selection; }
67 
68     void setSelection(int Selection) const;
69 
70     void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
71                               const MCExpr *Subsection) const override;
72     bool UseCodeAlign() const override;
73     bool isVirtualSection() const override;
74 
classof(const MCSection * S)75     static bool classof(const MCSection *S) {
76       return S->getVariant() == SV_COFF;
77     }
78   };
79 
80 } // end namespace llvm
81 
82 #endif
83