1//===- MCSectionMachO.h - MachO 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 MCSectionMachO class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_MC_MCSECTIONMACHO_H
15#define LLVM_MC_MCSECTIONMACHO_H
16
17#include "llvm/ADT/StringRef.h"
18#include "llvm/MC/MCSection.h"
19#include "llvm/Support/MachO.h"
20
21namespace llvm {
22
23/// MCSectionMachO - This represents a section on a Mach-O system (used by
24/// Mac OS X).  On a Mac system, these are also described in
25/// /usr/include/mach-o/loader.h.
26class MCSectionMachO : public MCSection {
27  char SegmentName[16];  // Not necessarily null terminated!
28  char SectionName[16];  // Not necessarily null terminated!
29
30  /// TypeAndAttributes - This is the SECTION_TYPE and SECTION_ATTRIBUTES
31  /// field of a section, drawn from the enums below.
32  unsigned TypeAndAttributes;
33
34  /// Reserved2 - The 'reserved2' field of a section, used to represent the
35  /// size of stubs, for example.
36  unsigned Reserved2;
37
38  MCSectionMachO(StringRef Segment, StringRef Section,
39                 unsigned TAA, unsigned reserved2, SectionKind K);
40  friend class MCContext;
41public:
42
43  StringRef getSegmentName() const {
44    // SegmentName is not necessarily null terminated!
45    if (SegmentName[15])
46      return StringRef(SegmentName, 16);
47    return StringRef(SegmentName);
48  }
49  StringRef getSectionName() const {
50    // SectionName is not necessarily null terminated!
51    if (SectionName[15])
52      return StringRef(SectionName, 16);
53    return StringRef(SectionName);
54  }
55
56  std::string getLabelBeginName() const override {
57    return StringRef(getSegmentName().str() + getSectionName().str() + "_begin");
58  }
59
60  std::string getLabelEndName() const override {
61    return StringRef(getSegmentName().str() + getSectionName().str() + "_end");
62  }
63
64  unsigned getTypeAndAttributes() const { return TypeAndAttributes; }
65  unsigned getStubSize() const { return Reserved2; }
66
67  MachO::SectionType getType() const {
68    return static_cast<MachO::SectionType>(TypeAndAttributes &
69                                           MachO::SECTION_TYPE);
70  }
71  bool hasAttribute(unsigned Value) const {
72    return (TypeAndAttributes & Value) != 0;
73  }
74
75  /// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
76  /// This is a string that can appear after a .section directive in a mach-o
77  /// flavored .s file.  If successful, this fills in the specified Out
78  /// parameters and returns an empty string.  When an invalid section
79  /// specifier is present, this returns a string indicating the problem.
80  /// If no TAA was parsed, TAA is not altered, and TAAWasSet becomes false.
81  static std::string ParseSectionSpecifier(StringRef Spec,       // In.
82                                           StringRef &Segment,   // Out.
83                                           StringRef &Section,   // Out.
84                                           unsigned  &TAA,       // Out.
85                                           bool      &TAAParsed, // Out.
86                                           unsigned  &StubSize); // Out.
87
88  void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
89                            const MCExpr *Subsection) const override;
90  bool UseCodeAlign() const override;
91  bool isVirtualSection() const override;
92
93  static bool classof(const MCSection *S) {
94    return S->getVariant() == SV_MachO;
95  }
96};
97
98} // end namespace llvm
99
100#endif
101