1 //===- lib/MC/MCSectionELF.cpp - ELF Code Section Representation ----------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #include "llvm/MC/MCSectionELF.h"
10 #include "llvm/ADT/Triple.h"
11 #include "llvm/BinaryFormat/ELF.h"
12 #include "llvm/MC/MCAsmInfo.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/Support/ErrorHandling.h"
15 #include "llvm/Support/raw_ostream.h"
20 // Decides whether a '.section' directive
21 // should be printed before the section name.
22 bool MCSectionELF::ShouldOmitSectionDirective(StringRef Name,
23 const MCAsmInfo &MAI) const {
27 return MAI.shouldOmitSectionDirective(Name);
30 static void printName(raw_ostream &OS, StringRef Name) {
31 if (Name.find_first_not_of("0123456789_."
32 "abcdefghijklmnopqrstuvwxyz"
33 "ABCDEFGHIJKLMNOPQRSTUVWXYZ") == Name.npos) {
38 for (const char *B = Name.begin(), *E = Name.end(); B < E; ++B) {
39 if (*B == '"') // Unquoted "
41 else if (*B != '\\') // Neither " or backslash
43 else if (B + 1 == E) // Trailing backslash
46 OS << B[0] << B[1]; // Quoted character
53 void MCSectionELF::PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
55 const MCExpr *Subsection) const {
56 if (ShouldOmitSectionDirective(SectionName, MAI)) {
57 OS << '\t' << getSectionName();
60 Subsection->print(OS, &MAI);
67 printName(OS, getSectionName());
69 // Handle the weird solaris syntax if desired.
70 if (MAI.usesSunStyleELFSectionSwitchSyntax() &&
71 !(Flags & ELF::SHF_MERGE)) {
72 if (Flags & ELF::SHF_ALLOC)
74 if (Flags & ELF::SHF_EXECINSTR)
76 if (Flags & ELF::SHF_WRITE)
78 if (Flags & ELF::SHF_EXCLUDE)
80 if (Flags & ELF::SHF_TLS)
87 if (Flags & ELF::SHF_ALLOC)
89 if (Flags & ELF::SHF_EXCLUDE)
91 if (Flags & ELF::SHF_EXECINSTR)
93 if (Flags & ELF::SHF_GROUP)
95 if (Flags & ELF::SHF_WRITE)
97 if (Flags & ELF::SHF_MERGE)
99 if (Flags & ELF::SHF_STRINGS)
101 if (Flags & ELF::SHF_TLS)
103 if (Flags & ELF::SHF_LINK_ORDER)
106 // If there are target-specific flags, print them.
107 Triple::ArchType Arch = T.getArch();
108 if (Arch == Triple::xcore) {
109 if (Flags & ELF::XCORE_SHF_CP_SECTION)
111 if (Flags & ELF::XCORE_SHF_DP_SECTION)
113 } else if (T.isARM() || T.isThumb()) {
114 if (Flags & ELF::SHF_ARM_PURECODE)
116 } else if (Arch == Triple::hexagon) {
117 if (Flags & ELF::SHF_HEX_GPREL)
125 // If comment string is '@', e.g. as on ARM - use '%' instead
126 if (MAI.getCommentString()[0] == '@')
131 if (Type == ELF::SHT_INIT_ARRAY)
133 else if (Type == ELF::SHT_FINI_ARRAY)
135 else if (Type == ELF::SHT_PREINIT_ARRAY)
136 OS << "preinit_array";
137 else if (Type == ELF::SHT_NOBITS)
139 else if (Type == ELF::SHT_NOTE)
141 else if (Type == ELF::SHT_PROGBITS)
143 else if (Type == ELF::SHT_X86_64_UNWIND)
145 else if (Type == ELF::SHT_MIPS_DWARF)
146 // Print hex value of the flag while we do not have
147 // any standard symbolic representation of the flag.
149 else if (Type == ELF::SHT_LLVM_ODRTAB)
151 else if (Type == ELF::SHT_LLVM_LINKER_OPTIONS)
152 OS << "llvm_linker_options";
153 else if (Type == ELF::SHT_LLVM_CALL_GRAPH_PROFILE)
154 OS << "llvm_call_graph_profile";
155 else if (Type == ELF::SHT_LLVM_DEPENDENT_LIBRARIES)
156 OS << "llvm_dependent_libraries";
157 else if (Type == ELF::SHT_LLVM_SYMPART)
158 OS << "llvm_sympart";
160 report_fatal_error("unsupported type 0x" + Twine::utohexstr(Type) +
161 " for section " + getSectionName());
164 assert(Flags & ELF::SHF_MERGE);
165 OS << "," << EntrySize;
168 if (Flags & ELF::SHF_GROUP) {
170 printName(OS, Group->getName());
174 if (Flags & ELF::SHF_LINK_ORDER) {
175 assert(AssociatedSymbol);
177 printName(OS, AssociatedSymbol->getName());
181 OS << ",unique," << UniqueID;
186 OS << "\t.subsection\t";
187 Subsection->print(OS, &MAI);
192 bool MCSectionELF::UseCodeAlign() const {
193 return getFlags() & ELF::SHF_EXECINSTR;
196 bool MCSectionELF::isVirtualSection() const {
197 return getType() == ELF::SHT_NOBITS;