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"
15 using namespace llvm;
16
~MCSectionCOFF()17 MCSectionCOFF::~MCSectionCOFF() {} // anchor.
18
19 // ShouldOmitSectionDirective - Decides whether a '.section' directive
20 // should be printed before the section name
ShouldOmitSectionDirective(StringRef Name,const MCAsmInfo & MAI) const21 bool 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
setSelection(int Selection,const MCSectionCOFF * Assoc) const31 void MCSectionCOFF::setSelection(int Selection,
32 const MCSectionCOFF *Assoc) const {
33 assert(Selection != 0 && "invalid COMDAT selection type");
34 assert((Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) ==
35 (Assoc != 0) &&
36 "associative COMDAT section must have an associated section");
37 this->Selection = Selection;
38 this->Assoc = Assoc;
39 Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
40 }
41
PrintSwitchToSection(const MCAsmInfo & MAI,raw_ostream & OS,const MCExpr * Subsection) const42 void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI,
43 raw_ostream &OS,
44 const MCExpr *Subsection) const {
45
46 // standard sections don't require the '.section'
47 if (ShouldOmitSectionDirective(SectionName, MAI)) {
48 OS << '\t' << getSectionName() << '\n';
49 return;
50 }
51
52 OS << "\t.section\t" << getSectionName() << ",\"";
53 if (getKind().isText())
54 OS << 'x';
55 if (getKind().isWriteable())
56 OS << 'w';
57 else
58 OS << 'r';
59 if (getCharacteristics() & COFF::IMAGE_SCN_MEM_DISCARDABLE)
60 OS << 'n';
61 OS << "\"\n";
62
63 if (getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT) {
64 switch (Selection) {
65 case COFF::IMAGE_COMDAT_SELECT_NODUPLICATES:
66 OS << "\t.linkonce one_only\n";
67 break;
68 case COFF::IMAGE_COMDAT_SELECT_ANY:
69 OS << "\t.linkonce discard\n";
70 break;
71 case COFF::IMAGE_COMDAT_SELECT_SAME_SIZE:
72 OS << "\t.linkonce same_size\n";
73 break;
74 case COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH:
75 OS << "\t.linkonce same_contents\n";
76 break;
77 case COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE:
78 OS << "\t.linkonce associative " << Assoc->getSectionName() << "\n";
79 break;
80 case COFF::IMAGE_COMDAT_SELECT_LARGEST:
81 OS << "\t.linkonce largest\n";
82 break;
83 case COFF::IMAGE_COMDAT_SELECT_NEWEST:
84 OS << "\t.linkonce newest\n";
85 break;
86 default:
87 assert (0 && "unsupported COFF selection type");
88 break;
89 }
90 }
91 }
92
UseCodeAlign() const93 bool MCSectionCOFF::UseCodeAlign() const {
94 return getKind().isText();
95 }
96
isVirtualSection() const97 bool MCSectionCOFF::isVirtualSection() const {
98 return getCharacteristics() & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA;
99 }
100