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 {
22
23/// MCSectionCOFF - This represents a section on Windows
24  class MCSectionCOFF : public MCSection {
25    // The memory for this string is stored in the same MCContext as *this.
26    StringRef SectionName;
27
28    // FIXME: The following fields should not be mutable, but are for now so
29    // the asm parser can honor the .linkonce directive.
30
31    /// Characteristics - This is the Characteristics field of a section,
32    /// drawn from the enums below.
33    mutable unsigned Characteristics;
34
35    /// Selection - This is the Selection field for the section symbol, if
36    /// it is a COMDAT section (Characteristics & IMAGE_SCN_LNK_COMDAT) != 0
37    mutable int Selection;
38
39    /// Assoc - This is name of the associated section, if it is a COMDAT
40    /// section (Characteristics & IMAGE_SCN_LNK_COMDAT) != 0 with an
41    /// associative Selection (IMAGE_COMDAT_SELECT_ASSOCIATIVE).
42    mutable const MCSectionCOFF *Assoc;
43
44  private:
45    friend class MCContext;
46    MCSectionCOFF(StringRef Section, unsigned Characteristics,
47                  int Selection, const MCSectionCOFF *Assoc, SectionKind K)
48      : MCSection(SV_COFF, K), SectionName(Section),
49        Characteristics(Characteristics), Selection(Selection), Assoc(Assoc) {
50      assert ((Characteristics & 0x00F00000) == 0 &&
51        "alignment must not be set upon section creation");
52      assert ((Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) ==
53              (Assoc != 0) &&
54        "associative COMDAT section must have an associated section");
55    }
56    ~MCSectionCOFF();
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
63    StringRef getSectionName() const { return SectionName; }
64    virtual std::string getLabelBeginName() const {
65      return SectionName.str() + "_begin";
66    }
67    virtual std::string getLabelEndName() const {
68      return SectionName.str() + "_end";
69    }
70    unsigned getCharacteristics() const { return Characteristics; }
71    int getSelection() const { return Selection; }
72    const MCSectionCOFF *getAssocSection() const { return Assoc; }
73
74    void setSelection(int Selection, const MCSectionCOFF *Assoc = 0) const;
75
76    virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
77                                      raw_ostream &OS,
78                                      const MCExpr *Subsection) const;
79    virtual bool UseCodeAlign() const;
80    virtual bool isVirtualSection() const;
81
82    static bool classof(const MCSection *S) {
83      return S->getVariant() == SV_COFF;
84    }
85  };
86
87} // end namespace llvm
88
89#endif
90