1 //===- MCSection.h - 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 MCSection class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_MC_MCSECTION_H
15 #define LLVM_MC_MCSECTION_H
16 
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/MC/SectionKind.h"
19 #include "llvm/Support/Compiler.h"
20 
21 namespace llvm {
22 class MCAsmInfo;
23 class MCContext;
24 class MCExpr;
25 class MCSymbol;
26 class raw_ostream;
27 
28 /// Instances of this class represent a uniqued identifier for a section in the
29 /// current translation unit.  The MCContext class uniques and creates these.
30 class MCSection {
31 public:
32   enum SectionVariant { SV_COFF = 0, SV_ELF, SV_MachO };
33 
34 private:
35   MCSection(const MCSection &) = delete;
36   void operator=(const MCSection &) = delete;
37 
38   MCSymbol *Begin;
39   mutable MCSymbol *End;
40 
41 protected:
MCSection(SectionVariant V,SectionKind K,MCSymbol * Begin)42   MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
43       : Begin(Begin), End(nullptr), Variant(V), Kind(K) {}
44   SectionVariant Variant;
45   SectionKind Kind;
46 
47 public:
48   virtual ~MCSection();
49 
getKind()50   SectionKind getKind() const { return Kind; }
51 
getVariant()52   SectionVariant getVariant() const { return Variant; }
53 
getBeginSymbol()54   MCSymbol *getBeginSymbol() const { return Begin; }
55   MCSymbol *getEndSymbol(MCContext &Ctx) const;
56   bool hasEnded() const;
57 
58   virtual void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
59                                     const MCExpr *Subsection) const = 0;
60 
61   /// Return true if a .align directive should use "optimized nops" to fill
62   /// instead of 0s.
63   virtual bool UseCodeAlign() const = 0;
64 
65   /// Check whether this section is "virtual", that is has no actual object
66   /// file contents.
67   virtual bool isVirtualSection() const = 0;
68 };
69 
70 } // end namespace llvm
71 
72 #endif
73