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