• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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/Casting.h"
20 
21 namespace llvm {
22   class MCContext;
23   class MCAsmInfo;
24   class raw_ostream;
25 
26   /// MCSection - Instances of this class represent a uniqued identifier for a
27   /// section in the current translation unit.  The MCContext class uniques and
28   /// creates these.
29   class MCSection {
30   public:
31     enum SectionVariant {
32       SV_COFF = 0,
33       SV_ELF,
34       SV_MachO
35     };
36 
37   private:
38     MCSection(const MCSection&);      // DO NOT IMPLEMENT
39     void operator=(const MCSection&); // DO NOT IMPLEMENT
40   protected:
MCSection(SectionVariant V,SectionKind K)41     MCSection(SectionVariant V, SectionKind K) : Variant(V), Kind(K) {}
42     SectionVariant Variant;
43     SectionKind Kind;
44   public:
45     virtual ~MCSection();
46 
getKind()47     SectionKind getKind() const { return Kind; }
48 
getVariant()49     SectionVariant getVariant() const { return Variant; }
50 
51     virtual void PrintSwitchToSection(const MCAsmInfo &MAI,
52                                       raw_ostream &OS) const = 0;
53 
54     /// isBaseAddressKnownZero - Return true if we know that this section will
55     /// get a base address of zero.  In cases where we know that this is true we
56     /// can emit section offsets as direct references to avoid a subtraction
57     /// from the base of the section, saving a relocation.
isBaseAddressKnownZero()58     virtual bool isBaseAddressKnownZero() const {
59       return false;
60     }
61 
62     // UseCodeAlign - Return true if a .align directive should use
63     // "optimized nops" to fill instead of 0s.
64     virtual bool UseCodeAlign() const = 0;
65 
66     /// isVirtualSection - Check whether this section is "virtual", that is
67     /// has no actual object file contents.
68     virtual bool isVirtualSection() const = 0;
69 
classof(const MCSection *)70     static bool classof(const MCSection *) { return true; }
71   };
72 
73 } // end namespace llvm
74 
75 #endif
76