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
21namespace llvm {
22class 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    const 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;
47    MCSectionCOFF(StringRef Section, unsigned Characteristics,
48                  const MCSymbol *COMDATSymbol, int Selection, SectionKind K)
49        : MCSection(SV_COFF, K), SectionName(Section),
50          Characteristics(Characteristics), COMDATSymbol(COMDATSymbol),
51          Selection(Selection) {
52      assert ((Characteristics & 0x00F00000) == 0 &&
53        "alignment must not be set upon section creation");
54    }
55    ~MCSectionCOFF();
56
57  public:
58    /// ShouldOmitSectionDirective - Decides whether a '.section' directive
59    /// should be printed before the section name
60    bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
61
62    StringRef getSectionName() const { return SectionName; }
63    std::string getLabelBeginName() const override {
64      return SectionName.str() + "_begin";
65    }
66    std::string getLabelEndName() const override {
67      return SectionName.str() + "_end";
68    }
69    unsigned getCharacteristics() const { return Characteristics; }
70    const MCSymbol *getCOMDATSymbol() const { return COMDATSymbol; }
71    int getSelection() const { return Selection; }
72
73    void setSelection(int Selection) const;
74
75    void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
76                              const MCExpr *Subsection) const override;
77    bool UseCodeAlign() const override;
78    bool isVirtualSection() const override;
79
80    static bool classof(const MCSection *S) {
81      return S->getVariant() == SV_COFF;
82    }
83  };
84
85} // end namespace llvm
86
87#endif
88