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
24  // FIXME: Does .section .bss/.data/.text work everywhere??
25  if (Name == ".text" || Name == ".data" || Name == ".bss")
26    return true;
27
28  return false;
29}
30
31void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI,
32                                         raw_ostream &OS) const {
33
34  // standard sections don't require the '.section'
35  if (ShouldOmitSectionDirective(SectionName, MAI)) {
36    OS << '\t' << getSectionName() << '\n';
37    return;
38  }
39
40  OS << "\t.section\t" << getSectionName() << ",\"";
41  if (getKind().isText())
42    OS << 'x';
43  if (getKind().isWriteable())
44    OS << 'w';
45  else
46    OS << 'r';
47  if (getCharacteristics() & COFF::IMAGE_SCN_MEM_DISCARDABLE)
48    OS << 'n';
49  OS << "\"\n";
50
51  if (getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT) {
52    switch (Selection) {
53      case COFF::IMAGE_COMDAT_SELECT_NODUPLICATES:
54        OS << "\t.linkonce one_only\n";
55        break;
56      case COFF::IMAGE_COMDAT_SELECT_ANY:
57        OS << "\t.linkonce discard\n";
58        break;
59      case COFF::IMAGE_COMDAT_SELECT_SAME_SIZE:
60        OS << "\t.linkonce same_size\n";
61        break;
62      case COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH:
63        OS << "\t.linkonce same_contents\n";
64        break;
65    //NOTE: as of binutils 2.20, there is no way to specifiy select largest
66    //      with the .linkonce directive. For now, we treat it as an invalid
67    //      comdat selection value.
68      case COFF::IMAGE_COMDAT_SELECT_LARGEST:
69    //  OS << "\t.linkonce largest\n";
70    //  break;
71      default:
72        assert (0 && "unsupported COFF selection type");
73        break;
74    }
75  }
76}
77
78bool MCSectionCOFF::UseCodeAlign() const {
79  return getKind().isText();
80}
81
82bool MCSectionCOFF::isVirtualSection() const {
83  return getCharacteristics() & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA;
84}
85