src/llvm/include/llvm/MC/MCSectionCOFF.h

   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;
  47     MCSectionCOFF(StringRef Section, unsigned Characteristics,
  48                   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     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