1//===- lib/MC/MCSectionCOFF.cpp - COFF Code Section Representation --------===//
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#include "llvm/MC/MCSectionCOFF.h"
11#include "llvm/MC/MCAsmInfo.h"
12#include "llvm/MC/MCContext.h"
13#include "llvm/MC/MCSymbol.h"
14#include "llvm/Support/COFF.h"
15#include "llvm/Support/raw_ostream.h"
16using namespace llvm;
17
18MCSectionCOFF::~MCSectionCOFF() {} // anchor.
19
20// ShouldOmitSectionDirective - Decides whether a '.section' directive
21// should be printed before the section name
22bool MCSectionCOFF::ShouldOmitSectionDirective(StringRef Name,
23                                               const MCAsmInfo &MAI) const {
24  if (COMDATSymbol)
25    return false;
26
27  // FIXME: Does .section .bss/.data/.text work everywhere??
28  if (Name == ".text" || Name == ".data" || Name == ".bss")
29    return true;
30
31  return false;
32}
33
34void MCSectionCOFF::setSelection(int Selection) const {
35  assert(Selection != 0 && "invalid COMDAT selection type");
36  this->Selection = Selection;
37  Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
38}
39
40void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI,
41                                         raw_ostream &OS,
42                                         const MCExpr *Subsection) const {
43
44  // standard sections don't require the '.section'
45  if (ShouldOmitSectionDirective(SectionName, MAI)) {
46    OS << '\t' << getSectionName() << '\n';
47    return;
48  }
49
50  OS << "\t.section\t" << getSectionName() << ",\"";
51  if (getCharacteristics() & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
52    OS << 'd';
53  if (getCharacteristics() & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
54    OS << 'b';
55  if (getCharacteristics() & COFF::IMAGE_SCN_MEM_EXECUTE)
56    OS << 'x';
57  if (getCharacteristics() & COFF::IMAGE_SCN_MEM_WRITE)
58    OS << 'w';
59  else if (getCharacteristics() & COFF::IMAGE_SCN_MEM_READ)
60    OS << 'r';
61  else
62    OS << 'y';
63  if (getCharacteristics() & COFF::IMAGE_SCN_LNK_REMOVE)
64    OS << 'n';
65  if (getCharacteristics() & COFF::IMAGE_SCN_MEM_SHARED)
66    OS << 's';
67  OS << '"';
68
69  if (getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT) {
70    OS << ",";
71    switch (Selection) {
72      case COFF::IMAGE_COMDAT_SELECT_NODUPLICATES:
73        OS << "one_only,";
74        break;
75      case COFF::IMAGE_COMDAT_SELECT_ANY:
76        OS << "discard,";
77        break;
78      case COFF::IMAGE_COMDAT_SELECT_SAME_SIZE:
79        OS << "same_size,";
80        break;
81      case COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH:
82        OS << "same_contents,";
83        break;
84      case COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE:
85        OS << "associative,";
86        break;
87      case COFF::IMAGE_COMDAT_SELECT_LARGEST:
88        OS << "largest,";
89        break;
90      case COFF::IMAGE_COMDAT_SELECT_NEWEST:
91        OS << "newest,";
92        break;
93      default:
94        assert (0 && "unsupported COFF selection type");
95        break;
96    }
97    assert(COMDATSymbol);
98    COMDATSymbol->print(OS, &MAI);
99  }
100  OS << '\n';
101}
102
103bool MCSectionCOFF::UseCodeAlign() const {
104  return getKind().isText();
105}
106
107bool MCSectionCOFF::isVirtualSection() const {
108  return getCharacteristics() & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA;
109}
110