1 | //===- lib/MC/MCSectionELF.cpp - ELF Code Section Representation ----------===// |
2 | // |
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 |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #include "llvm/MC/MCSectionELF.h" |
10 | #include "llvm/BinaryFormat/ELF.h" |
11 | #include "llvm/MC/MCAsmInfo.h" |
12 | #include "llvm/MC/MCExpr.h" |
13 | #include "llvm/Support/ErrorHandling.h" |
14 | #include "llvm/Support/raw_ostream.h" |
15 | #include "llvm/TargetParser/Triple.h" |
16 | #include <cassert> |
17 | |
18 | using namespace llvm; |
19 | |
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 { |
24 | if (isUnique()) |
25 | return false; |
26 | |
27 | return MAI.shouldOmitSectionDirective(SectionName: Name); |
28 | } |
29 | |
30 | static void printName(raw_ostream &OS, StringRef Name) { |
31 | if (Name.find_first_not_of(Chars: "0123456789_." |
32 | "abcdefghijklmnopqrstuvwxyz" |
33 | "ABCDEFGHIJKLMNOPQRSTUVWXYZ" ) == Name.npos) { |
34 | OS << Name; |
35 | return; |
36 | } |
37 | OS << '"'; |
38 | for (const char *B = Name.begin(), *E = Name.end(); B < E; ++B) { |
39 | if (*B == '"') // Unquoted " |
40 | OS << "\\\"" ; |
41 | else if (*B != '\\') // Neither " or backslash |
42 | OS << *B; |
43 | else if (B + 1 == E) // Trailing backslash |
44 | OS << "\\\\" ; |
45 | else { |
46 | OS << B[0] << B[1]; // Quoted character |
47 | ++B; |
48 | } |
49 | } |
50 | OS << '"'; |
51 | } |
52 | |
53 | void MCSectionELF::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T, |
54 | raw_ostream &OS, |
55 | const MCExpr *Subsection) const { |
56 | if (shouldOmitSectionDirective(Name: getName(), MAI)) { |
57 | OS << '\t' << getName(); |
58 | if (Subsection) { |
59 | OS << '\t'; |
60 | Subsection->print(OS, MAI: &MAI); |
61 | } |
62 | OS << '\n'; |
63 | return; |
64 | } |
65 | |
66 | OS << "\t.section\t" ; |
67 | printName(OS, Name: getName()); |
68 | |
69 | // Handle the weird solaris syntax if desired. |
70 | if (MAI.usesSunStyleELFSectionSwitchSyntax() && |
71 | !(Flags & ELF::SHF_MERGE)) { |
72 | if (Flags & ELF::SHF_ALLOC) |
73 | OS << ",#alloc" ; |
74 | if (Flags & ELF::SHF_EXECINSTR) |
75 | OS << ",#execinstr" ; |
76 | if (Flags & ELF::SHF_WRITE) |
77 | OS << ",#write" ; |
78 | if (Flags & ELF::SHF_EXCLUDE) |
79 | OS << ",#exclude" ; |
80 | if (Flags & ELF::SHF_TLS) |
81 | OS << ",#tls" ; |
82 | OS << '\n'; |
83 | return; |
84 | } |
85 | |
86 | OS << ",\"" ; |
87 | if (Flags & ELF::SHF_ALLOC) |
88 | OS << 'a'; |
89 | if (Flags & ELF::SHF_EXCLUDE) |
90 | OS << 'e'; |
91 | if (Flags & ELF::SHF_EXECINSTR) |
92 | OS << 'x'; |
93 | if (Flags & ELF::SHF_WRITE) |
94 | OS << 'w'; |
95 | if (Flags & ELF::SHF_MERGE) |
96 | OS << 'M'; |
97 | if (Flags & ELF::SHF_STRINGS) |
98 | OS << 'S'; |
99 | if (Flags & ELF::SHF_TLS) |
100 | OS << 'T'; |
101 | if (Flags & ELF::SHF_LINK_ORDER) |
102 | OS << 'o'; |
103 | if (Flags & ELF::SHF_GROUP) |
104 | OS << 'G'; |
105 | if (Flags & ELF::SHF_GNU_RETAIN) |
106 | OS << 'R'; |
107 | |
108 | // If there are os-specific flags, print them. |
109 | if (T.isOSSolaris()) |
110 | if (Flags & ELF::SHF_SUNW_NODISCARD) |
111 | OS << 'R'; |
112 | |
113 | // If there are target-specific flags, print them. |
114 | Triple::ArchType Arch = T.getArch(); |
115 | if (Arch == Triple::xcore) { |
116 | if (Flags & ELF::XCORE_SHF_CP_SECTION) |
117 | OS << 'c'; |
118 | if (Flags & ELF::XCORE_SHF_DP_SECTION) |
119 | OS << 'd'; |
120 | } else if (T.isARM() || T.isThumb()) { |
121 | if (Flags & ELF::SHF_ARM_PURECODE) |
122 | OS << 'y'; |
123 | } else if (Arch == Triple::hexagon) { |
124 | if (Flags & ELF::SHF_HEX_GPREL) |
125 | OS << 's'; |
126 | } else if (Arch == Triple::x86_64) { |
127 | if (Flags & ELF::SHF_X86_64_LARGE) |
128 | OS << 'l'; |
129 | } |
130 | |
131 | OS << '"'; |
132 | |
133 | OS << ','; |
134 | |
135 | // If comment string is '@', e.g. as on ARM - use '%' instead |
136 | if (MAI.getCommentString()[0] == '@') |
137 | OS << '%'; |
138 | else |
139 | OS << '@'; |
140 | |
141 | if (Type == ELF::SHT_INIT_ARRAY) |
142 | OS << "init_array" ; |
143 | else if (Type == ELF::SHT_FINI_ARRAY) |
144 | OS << "fini_array" ; |
145 | else if (Type == ELF::SHT_PREINIT_ARRAY) |
146 | OS << "preinit_array" ; |
147 | else if (Type == ELF::SHT_NOBITS) |
148 | OS << "nobits" ; |
149 | else if (Type == ELF::SHT_NOTE) |
150 | OS << "note" ; |
151 | else if (Type == ELF::SHT_PROGBITS) |
152 | OS << "progbits" ; |
153 | else if (Type == ELF::SHT_X86_64_UNWIND) |
154 | OS << "unwind" ; |
155 | else if (Type == ELF::SHT_MIPS_DWARF) |
156 | // Print hex value of the flag while we do not have |
157 | // any standard symbolic representation of the flag. |
158 | OS << "0x7000001e" ; |
159 | else if (Type == ELF::SHT_LLVM_ODRTAB) |
160 | OS << "llvm_odrtab" ; |
161 | else if (Type == ELF::SHT_LLVM_LINKER_OPTIONS) |
162 | OS << "llvm_linker_options" ; |
163 | else if (Type == ELF::SHT_LLVM_CALL_GRAPH_PROFILE) |
164 | OS << "llvm_call_graph_profile" ; |
165 | else if (Type == ELF::SHT_LLVM_DEPENDENT_LIBRARIES) |
166 | OS << "llvm_dependent_libraries" ; |
167 | else if (Type == ELF::SHT_LLVM_SYMPART) |
168 | OS << "llvm_sympart" ; |
169 | else if (Type == ELF::SHT_LLVM_BB_ADDR_MAP) |
170 | OS << "llvm_bb_addr_map" ; |
171 | else if (Type == ELF::SHT_LLVM_BB_ADDR_MAP_V0) |
172 | OS << "llvm_bb_addr_map_v0" ; |
173 | else if (Type == ELF::SHT_LLVM_OFFLOADING) |
174 | OS << "llvm_offloading" ; |
175 | else if (Type == ELF::SHT_LLVM_LTO) |
176 | OS << "llvm_lto" ; |
177 | else |
178 | report_fatal_error(reason: "unsupported type 0x" + Twine::utohexstr(Val: Type) + |
179 | " for section " + getName()); |
180 | |
181 | if (EntrySize) { |
182 | assert(Flags & ELF::SHF_MERGE); |
183 | OS << "," << EntrySize; |
184 | } |
185 | |
186 | if (Flags & ELF::SHF_LINK_ORDER) { |
187 | OS << "," ; |
188 | if (LinkedToSym) |
189 | printName(OS, Name: LinkedToSym->getName()); |
190 | else |
191 | OS << '0'; |
192 | } |
193 | |
194 | if (Flags & ELF::SHF_GROUP) { |
195 | OS << "," ; |
196 | printName(OS, Name: Group.getPointer()->getName()); |
197 | if (isComdat()) |
198 | OS << ",comdat" ; |
199 | } |
200 | |
201 | if (isUnique()) |
202 | OS << ",unique," << UniqueID; |
203 | |
204 | OS << '\n'; |
205 | |
206 | if (Subsection) { |
207 | OS << "\t.subsection\t" ; |
208 | Subsection->print(OS, MAI: &MAI); |
209 | OS << '\n'; |
210 | } |
211 | } |
212 | |
213 | bool MCSectionELF::useCodeAlign() const { |
214 | return getFlags() & ELF::SHF_EXECINSTR; |
215 | } |
216 | |
217 | bool MCSectionELF::isVirtualSection() const { |
218 | return getType() == ELF::SHT_NOBITS; |
219 | } |
220 | |
221 | StringRef MCSectionELF::getVirtualSectionKind() const { return "SHT_NOBITS" ; } |
222 | |