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/BinaryFormat/COFF.h"
12 #include "llvm/MC/MCSymbol.h"
13 #include "llvm/Support/raw_ostream.h"
14 #include <cassert>
15
16 using namespace llvm;
17
18 MCSectionCOFF::~MCSectionCOFF() = default; // anchor.
19
20 // ShouldOmitSectionDirective - Decides whether a '.section' directive
21 // should be printed before the section name
ShouldOmitSectionDirective(StringRef Name,const MCAsmInfo & MAI) const22 bool 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
setSelection(int Selection) const34 void 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
PrintSwitchToSection(const MCAsmInfo & MAI,const Triple & T,raw_ostream & OS,const MCExpr * Subsection) const40 void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
41 raw_ostream &OS,
42 const MCExpr *Subsection) const {
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 (getCharacteristics() & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
51 OS << 'd';
52 if (getCharacteristics() & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
53 OS << 'b';
54 if (getCharacteristics() & COFF::IMAGE_SCN_MEM_EXECUTE)
55 OS << 'x';
56 if (getCharacteristics() & COFF::IMAGE_SCN_MEM_WRITE)
57 OS << 'w';
58 else if (getCharacteristics() & COFF::IMAGE_SCN_MEM_READ)
59 OS << 'r';
60 else
61 OS << 'y';
62 if (getCharacteristics() & COFF::IMAGE_SCN_LNK_REMOVE)
63 OS << 'n';
64 if (getCharacteristics() & COFF::IMAGE_SCN_MEM_SHARED)
65 OS << 's';
66 if ((getCharacteristics() & COFF::IMAGE_SCN_MEM_DISCARDABLE) &&
67 !isImplicitlyDiscardable(SectionName))
68 OS << 'D';
69 OS << '"';
70
71 if (getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT) {
72 if (COMDATSymbol)
73 OS << ",";
74 else
75 OS << "\n\t.linkonce\t";
76 switch (Selection) {
77 case COFF::IMAGE_COMDAT_SELECT_NODUPLICATES:
78 OS << "one_only";
79 break;
80 case COFF::IMAGE_COMDAT_SELECT_ANY:
81 OS << "discard";
82 break;
83 case COFF::IMAGE_COMDAT_SELECT_SAME_SIZE:
84 OS << "same_size";
85 break;
86 case COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH:
87 OS << "same_contents";
88 break;
89 case COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE:
90 OS << "associative";
91 break;
92 case COFF::IMAGE_COMDAT_SELECT_LARGEST:
93 OS << "largest";
94 break;
95 case COFF::IMAGE_COMDAT_SELECT_NEWEST:
96 OS << "newest";
97 break;
98 default:
99 assert(false && "unsupported COFF selection type");
100 break;
101 }
102 if (COMDATSymbol) {
103 OS << ",";
104 COMDATSymbol->print(OS, &MAI);
105 }
106 }
107 OS << '\n';
108 }
109
UseCodeAlign() const110 bool MCSectionCOFF::UseCodeAlign() const {
111 return getKind().isText();
112 }
113
isVirtualSection() const114 bool MCSectionCOFF::isVirtualSection() const {
115 return getCharacteristics() & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA;
116 }
117