1 //===- MCSectionCOFF.h - COFF Machine Code Sections -------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the MCSectionCOFF class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_MC_MCSECTIONCOFF_H
15 #define LLVM_MC_MCSECTIONCOFF_H
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/MC/MCSection.h"
19 #include "llvm/Support/COFF.h"
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;
29 // FIXME: The following fields should not be mutable, but are for now so
30 // the asm parser can honor the .linkonce directive.
32 /// Characteristics - This is the Characteristics field of a section,
33 /// drawn from the enums below.
34 mutable unsigned Characteristics;
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
39 const MCSymbol *COMDATSymbol;
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;
45 /// Assoc - This is name of the associated section, if it is a COMDAT
46 /// section (Characteristics & IMAGE_SCN_LNK_COMDAT) != 0 with an
47 /// associative Selection (IMAGE_COMDAT_SELECT_ASSOCIATIVE).
48 mutable const MCSectionCOFF *Assoc;
51 friend class MCContext;
52 MCSectionCOFF(StringRef Section, unsigned Characteristics,
53 const MCSymbol *COMDATSymbol, int Selection,
54 const MCSectionCOFF *Assoc, SectionKind K)
55 : MCSection(SV_COFF, K), SectionName(Section),
56 Characteristics(Characteristics), COMDATSymbol(COMDATSymbol),
57 Selection(Selection), Assoc(Assoc) {
58 assert ((Characteristics & 0x00F00000) == 0 &&
59 "alignment must not be set upon section creation");
60 assert ((Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) ==
62 "associative COMDAT section must have an associated section");
67 /// ShouldOmitSectionDirective - Decides whether a '.section' directive
68 /// should be printed before the section name
69 bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
71 StringRef getSectionName() const { return SectionName; }
72 std::string getLabelBeginName() const override {
73 return SectionName.str() + "_begin";
75 std::string getLabelEndName() const override {
76 return SectionName.str() + "_end";
78 unsigned getCharacteristics() const { return Characteristics; }
79 int getSelection() const { return Selection; }
80 const MCSectionCOFF *getAssocSection() const { return Assoc; }
82 void setSelection(int Selection,
83 const MCSectionCOFF *Assoc = nullptr) const;
85 void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
86 const MCExpr *Subsection) const override;
87 bool UseCodeAlign() const override;
88 bool isVirtualSection() const override;
90 static bool classof(const MCSection *S) {
91 return S->getVariant() == SV_COFF;
95 } // end namespace llvm