1//===- lib/MC/MCSectionELF.cpp - ELF 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/MCSectionELF.h" 11#include "llvm/MC/MCAsmInfo.h" 12#include "llvm/MC/MCContext.h" 13#include "llvm/MC/MCExpr.h" 14#include "llvm/MC/MCSymbol.h" 15#include "llvm/Support/ELF.h" 16#include "llvm/Support/raw_ostream.h" 17 18using namespace llvm; 19 20MCSectionELF::~MCSectionELF() {} // anchor. 21 22// Decides whether a '.section' directive 23// should be printed before the section name. 24bool MCSectionELF::ShouldOmitSectionDirective(StringRef Name, 25 const MCAsmInfo &MAI) const { 26 27 if (isUnique()) 28 return false; 29 30 return MAI.shouldOmitSectionDirective(Name); 31} 32 33static void printName(raw_ostream &OS, StringRef Name) { 34 if (Name.find_first_not_of("0123456789_." 35 "abcdefghijklmnopqrstuvwxyz" 36 "ABCDEFGHIJKLMNOPQRSTUVWXYZ") == Name.npos) { 37 OS << Name; 38 return; 39 } 40 OS << '"'; 41 for (const char *B = Name.begin(), *E = Name.end(); B < E; ++B) { 42 if (*B == '"') // Unquoted " 43 OS << "\\\""; 44 else if (*B != '\\') // Neither " or backslash 45 OS << *B; 46 else if (B + 1 == E) // Trailing backslash 47 OS << "\\\\"; 48 else { 49 OS << B[0] << B[1]; // Quoted character 50 ++B; 51 } 52 } 53 OS << '"'; 54} 55 56void MCSectionELF::PrintSwitchToSection(const MCAsmInfo &MAI, 57 raw_ostream &OS, 58 const MCExpr *Subsection) const { 59 60 if (ShouldOmitSectionDirective(SectionName, MAI)) { 61 OS << '\t' << getSectionName(); 62 if (Subsection) { 63 OS << '\t'; 64 Subsection->print(OS, &MAI); 65 } 66 OS << '\n'; 67 return; 68 } 69 70 OS << "\t.section\t"; 71 printName(OS, getSectionName()); 72 73 // Handle the weird solaris syntax if desired. 74 if (MAI.usesSunStyleELFSectionSwitchSyntax() && 75 !(Flags & ELF::SHF_MERGE)) { 76 if (Flags & ELF::SHF_ALLOC) 77 OS << ",#alloc"; 78 if (Flags & ELF::SHF_EXECINSTR) 79 OS << ",#execinstr"; 80 if (Flags & ELF::SHF_WRITE) 81 OS << ",#write"; 82 if (Flags & ELF::SHF_EXCLUDE) 83 OS << ",#exclude"; 84 if (Flags & ELF::SHF_TLS) 85 OS << ",#tls"; 86 OS << '\n'; 87 return; 88 } 89 90 OS << ",\""; 91 if (Flags & ELF::SHF_ALLOC) 92 OS << 'a'; 93 if (Flags & ELF::SHF_EXCLUDE) 94 OS << 'e'; 95 if (Flags & ELF::SHF_EXECINSTR) 96 OS << 'x'; 97 if (Flags & ELF::SHF_GROUP) 98 OS << 'G'; 99 if (Flags & ELF::SHF_WRITE) 100 OS << 'w'; 101 if (Flags & ELF::SHF_MERGE) 102 OS << 'M'; 103 if (Flags & ELF::SHF_STRINGS) 104 OS << 'S'; 105 if (Flags & ELF::SHF_TLS) 106 OS << 'T'; 107 108 // If there are target-specific flags, print them. 109 if (Flags & ELF::XCORE_SHF_CP_SECTION) 110 OS << 'c'; 111 if (Flags & ELF::XCORE_SHF_DP_SECTION) 112 OS << 'd'; 113 114 OS << '"'; 115 116 OS << ','; 117 118 // If comment string is '@', e.g. as on ARM - use '%' instead 119 if (MAI.getCommentString()[0] == '@') 120 OS << '%'; 121 else 122 OS << '@'; 123 124 if (Type == ELF::SHT_INIT_ARRAY) 125 OS << "init_array"; 126 else if (Type == ELF::SHT_FINI_ARRAY) 127 OS << "fini_array"; 128 else if (Type == ELF::SHT_PREINIT_ARRAY) 129 OS << "preinit_array"; 130 else if (Type == ELF::SHT_NOBITS) 131 OS << "nobits"; 132 else if (Type == ELF::SHT_NOTE) 133 OS << "note"; 134 else if (Type == ELF::SHT_PROGBITS) 135 OS << "progbits"; 136 else if (Type == ELF::SHT_X86_64_UNWIND) 137 OS << "unwind"; 138 139 if (EntrySize) { 140 assert(Flags & ELF::SHF_MERGE); 141 OS << "," << EntrySize; 142 } 143 144 if (Flags & ELF::SHF_GROUP) { 145 OS << ","; 146 printName(OS, Group->getName()); 147 OS << ",comdat"; 148 } 149 150 if (isUnique()) 151 OS << ",unique," << UniqueID; 152 153 OS << '\n'; 154 155 if (Subsection) { 156 OS << "\t.subsection\t"; 157 Subsection->print(OS, &MAI); 158 OS << '\n'; 159 } 160} 161 162bool MCSectionELF::UseCodeAlign() const { 163 return getFlags() & ELF::SHF_EXECINSTR; 164} 165 166bool MCSectionELF::isVirtualSection() const { 167 return getType() == ELF::SHT_NOBITS; 168} 169