Home | History | Annotate | Download | only in MC
      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 
     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