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Eugene Zelenkofa912a72017-02-27 22:45:06 +00001//===- llvm/CodeGen/TargetLoweringObjectFileImpl.cpp - Object File Info ---===//
Anton Korobeynikovab663a02010-02-15 22:37:53 +00002//
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// This file implements classes used to handle lowerings specific to common
11// object file formats.
12//
13//===----------------------------------------------------------------------===//
14
Chandler Carruth6bda14b2017-06-06 11:49:48 +000015#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
Chandler Carruthed0881b2012-12-03 16:50:05 +000016#include "llvm/ADT/SmallString.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000017#include "llvm/ADT/SmallVector.h"
Chandler Carruthed0881b2012-12-03 16:50:05 +000018#include "llvm/ADT/StringExtras.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000019#include "llvm/ADT/StringRef.h"
Chandler Carruthed0881b2012-12-03 16:50:05 +000020#include "llvm/ADT/Triple.h"
Zachary Turner264b5d92017-06-07 03:48:56 +000021#include "llvm/BinaryFormat/COFF.h"
22#include "llvm/BinaryFormat/Dwarf.h"
23#include "llvm/BinaryFormat/ELF.h"
24#include "llvm/BinaryFormat/MachO.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000025#include "llvm/CodeGen/MachineModuleInfo.h"
Chandler Carruthed0881b2012-12-03 16:50:05 +000026#include "llvm/CodeGen/MachineModuleInfoImpls.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000027#include "llvm/IR/Comdat.h"
Chandler Carruth9fb823b2013-01-02 11:36:10 +000028#include "llvm/IR/Constants.h"
29#include "llvm/IR/DataLayout.h"
30#include "llvm/IR/DerivedTypes.h"
31#include "llvm/IR/Function.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000032#include "llvm/IR/GlobalAlias.h"
33#include "llvm/IR/GlobalObject.h"
34#include "llvm/IR/GlobalValue.h"
Chandler Carruth9fb823b2013-01-02 11:36:10 +000035#include "llvm/IR/GlobalVariable.h"
Rafael Espindola894843c2014-01-07 21:19:40 +000036#include "llvm/IR/Mangler.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000037#include "llvm/IR/Metadata.h"
Chandler Carruth9fb823b2013-01-02 11:36:10 +000038#include "llvm/IR/Module.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000039#include "llvm/IR/Type.h"
Peter Collingbourne94d77862015-11-03 23:40:03 +000040#include "llvm/MC/MCAsmInfo.h"
Anton Korobeynikovab663a02010-02-15 22:37:53 +000041#include "llvm/MC/MCContext.h"
42#include "llvm/MC/MCExpr.h"
Chris Lattner87cffa92010-05-07 17:17:41 +000043#include "llvm/MC/MCSectionCOFF.h"
Chandler Carruthed0881b2012-12-03 16:50:05 +000044#include "llvm/MC/MCSectionELF.h"
45#include "llvm/MC/MCSectionMachO.h"
Dan Gohman18eafb62017-02-22 01:23:18 +000046#include "llvm/MC/MCSectionWasm.h"
Rafael Espindolaa83b1772011-04-16 03:51:21 +000047#include "llvm/MC/MCStreamer.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000048#include "llvm/MC/MCSymbol.h"
Rafael Espindolaa8695762015-06-02 00:25:12 +000049#include "llvm/MC/MCSymbolELF.h"
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +000050#include "llvm/MC/MCValue.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000051#include "llvm/MC/SectionKind.h"
Xinliang David Li5f04f922016-01-14 18:09:45 +000052#include "llvm/ProfileData/InstrProf.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000053#include "llvm/Support/Casting.h"
54#include "llvm/Support/CodeGen.h"
Martin Storsjo04b68442017-11-28 08:07:18 +000055#include "llvm/Support/Format.h"
Anton Korobeynikovab663a02010-02-15 22:37:53 +000056#include "llvm/Support/ErrorHandling.h"
57#include "llvm/Support/raw_ostream.h"
Chandler Carruth442f7842014-03-04 10:07:28 +000058#include "llvm/Target/TargetMachine.h"
Eugene Zelenkofa912a72017-02-27 22:45:06 +000059#include <cassert>
60#include <string>
61
Anton Korobeynikovab663a02010-02-15 22:37:53 +000062using namespace llvm;
Anton Korobeynikov31a92122010-02-21 20:28:15 +000063using namespace dwarf;
Anton Korobeynikovab663a02010-02-15 22:37:53 +000064
Peter Collingbourne89061b22017-06-12 20:10:48 +000065static void GetObjCImageInfo(Module &M, unsigned &Version, unsigned &Flags,
Saleem Abdulrasool4c474342017-06-05 21:26:39 +000066 StringRef &Section) {
Peter Collingbourne89061b22017-06-12 20:10:48 +000067 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
68 M.getModuleFlagsMetadata(ModuleFlags);
69
Saleem Abdulrasool4c474342017-06-05 21:26:39 +000070 for (const auto &MFE: ModuleFlags) {
71 // Ignore flags with 'Require' behaviour.
72 if (MFE.Behavior == Module::Require)
73 continue;
74
75 StringRef Key = MFE.Key->getString();
76 if (Key == "Objective-C Image Info Version") {
77 Version = mdconst::extract<ConstantInt>(MFE.Val)->getZExtValue();
78 } else if (Key == "Objective-C Garbage Collection" ||
79 Key == "Objective-C GC Only" ||
80 Key == "Objective-C Is Simulated" ||
81 Key == "Objective-C Class Properties" ||
82 Key == "Objective-C Image Swift Version") {
83 Flags |= mdconst::extract<ConstantInt>(MFE.Val)->getZExtValue();
84 } else if (Key == "Objective-C Image Info Section") {
85 Section = cast<MDString>(MFE.Val)->getString();
86 }
87 }
88}
89
Anton Korobeynikovab663a02010-02-15 22:37:53 +000090//===----------------------------------------------------------------------===//
91// ELF
92//===----------------------------------------------------------------------===//
Anton Korobeynikovab663a02010-02-15 22:37:53 +000093
Michael J. Spencer7bb27672018-07-16 00:28:24 +000094void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx,
95 const TargetMachine &TgtM) {
96 TargetLoweringObjectFile::Initialize(Ctx, TgtM);
97 TM = &TgtM;
Reid Klecknerfce7f732018-08-09 22:24:04 +000098
Lei Liu901a0a92018-08-13 06:06:53 +000099 CodeModel::Model CM = TgtM.getCodeModel();
Reid Klecknerfce7f732018-08-09 22:24:04 +0000100
101 switch (TgtM.getTargetTriple().getArch()) {
102 case Triple::arm:
103 case Triple::armeb:
104 case Triple::thumb:
105 case Triple::thumbeb:
106 if (Ctx.getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
107 break;
108 // Fallthrough if not using EHABI
109 LLVM_FALLTHROUGH;
110 case Triple::ppc:
111 case Triple::x86:
112 PersonalityEncoding = isPositionIndependent()
113 ? dwarf::DW_EH_PE_indirect |
114 dwarf::DW_EH_PE_pcrel |
115 dwarf::DW_EH_PE_sdata4
116 : dwarf::DW_EH_PE_absptr;
117 LSDAEncoding = isPositionIndependent()
118 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
119 : dwarf::DW_EH_PE_absptr;
120 TTypeEncoding = isPositionIndependent()
121 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
122 dwarf::DW_EH_PE_sdata4
123 : dwarf::DW_EH_PE_absptr;
124 break;
125 case Triple::x86_64:
126 if (isPositionIndependent()) {
Lei Liu901a0a92018-08-13 06:06:53 +0000127 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
128 ((CM == CodeModel::Small || CM == CodeModel::Medium)
129 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
Reid Klecknerfce7f732018-08-09 22:24:04 +0000130 LSDAEncoding = dwarf::DW_EH_PE_pcrel |
Lei Liu901a0a92018-08-13 06:06:53 +0000131 (CM == CodeModel::Small
132 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
Reid Klecknerfce7f732018-08-09 22:24:04 +0000133 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
Lei Liu901a0a92018-08-13 06:06:53 +0000134 ((CM == CodeModel::Small || CM == CodeModel::Medium)
135 ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
Reid Klecknerfce7f732018-08-09 22:24:04 +0000136 } else {
137 PersonalityEncoding =
Lei Liu901a0a92018-08-13 06:06:53 +0000138 (CM == CodeModel::Small || CM == CodeModel::Medium)
139 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
140 LSDAEncoding = (CM == CodeModel::Small)
141 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
142 TTypeEncoding = (CM == CodeModel::Small)
143 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
Reid Klecknerfce7f732018-08-09 22:24:04 +0000144 }
145 break;
146 case Triple::hexagon:
147 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
148 LSDAEncoding = dwarf::DW_EH_PE_absptr;
149 TTypeEncoding = dwarf::DW_EH_PE_absptr;
150 if (isPositionIndependent()) {
151 PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
152 LSDAEncoding |= dwarf::DW_EH_PE_pcrel;
153 TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
154 }
155 break;
156 case Triple::aarch64:
157 case Triple::aarch64_be:
158 // The small model guarantees static code/data size < 4GB, but not where it
159 // will be in memory. Most of these could end up >2GB away so even a signed
160 // pc-relative 32-bit address is insufficient, theoretically.
161 if (isPositionIndependent()) {
162 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
163 dwarf::DW_EH_PE_sdata8;
164 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
165 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
166 dwarf::DW_EH_PE_sdata8;
167 } else {
168 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
169 LSDAEncoding = dwarf::DW_EH_PE_absptr;
170 TTypeEncoding = dwarf::DW_EH_PE_absptr;
171 }
172 break;
173 case Triple::lanai:
174 LSDAEncoding = dwarf::DW_EH_PE_absptr;
175 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
176 TTypeEncoding = dwarf::DW_EH_PE_absptr;
177 break;
178 case Triple::mips:
179 case Triple::mipsel:
180 case Triple::mips64:
181 case Triple::mips64el:
182 // MIPS uses indirect pointer to refer personality functions and types, so
183 // that the eh_frame section can be read-only. DW.ref.personality will be
184 // generated for relocation.
185 PersonalityEncoding = dwarf::DW_EH_PE_indirect;
186 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
187 // identify N64 from just a triple.
188 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
189 dwarf::DW_EH_PE_sdata4;
190 // We don't support PC-relative LSDA references in GAS so we use the default
191 // DW_EH_PE_absptr for those.
192
193 // FreeBSD must be explicit about the data size and using pcrel since it's
194 // assembler/linker won't do the automatic conversion that the Linux tools
195 // do.
196 if (TgtM.getTargetTriple().isOSFreeBSD()) {
197 PersonalityEncoding |= dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
198 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
199 }
200 break;
201 case Triple::ppc64:
202 case Triple::ppc64le:
203 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
204 dwarf::DW_EH_PE_udata8;
205 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
206 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
207 dwarf::DW_EH_PE_udata8;
208 break;
209 case Triple::sparcel:
210 case Triple::sparc:
211 if (isPositionIndependent()) {
212 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
213 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
214 dwarf::DW_EH_PE_sdata4;
215 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
216 dwarf::DW_EH_PE_sdata4;
217 } else {
218 LSDAEncoding = dwarf::DW_EH_PE_absptr;
219 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
220 TTypeEncoding = dwarf::DW_EH_PE_absptr;
221 }
222 break;
223 case Triple::sparcv9:
224 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
225 if (isPositionIndependent()) {
226 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
227 dwarf::DW_EH_PE_sdata4;
228 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
229 dwarf::DW_EH_PE_sdata4;
230 } else {
231 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
232 TTypeEncoding = dwarf::DW_EH_PE_absptr;
233 }
234 break;
235 case Triple::systemz:
236 // All currently-defined code models guarantee that 4-byte PC-relative
237 // values will be in range.
238 if (isPositionIndependent()) {
239 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
240 dwarf::DW_EH_PE_sdata4;
241 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
242 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
243 dwarf::DW_EH_PE_sdata4;
244 } else {
245 PersonalityEncoding = dwarf::DW_EH_PE_absptr;
246 LSDAEncoding = dwarf::DW_EH_PE_absptr;
247 TTypeEncoding = dwarf::DW_EH_PE_absptr;
248 }
249 break;
250 default:
251 break;
252 }
Michael J. Spencer7bb27672018-07-16 00:28:24 +0000253}
254
Eric Christopheraadbabc2018-04-20 19:07:57 +0000255void TargetLoweringObjectFileELF::emitModuleMetadata(MCStreamer &Streamer,
256 Module &M) const {
Saleem Abdulrasoolb36fbbc2018-01-30 16:29:29 +0000257 auto &C = getContext();
258
259 if (NamedMDNode *LinkerOptions = M.getNamedMetadata("llvm.linker.options")) {
260 auto *S = C.getELFSection(".linker-options", ELF::SHT_LLVM_LINKER_OPTIONS,
261 ELF::SHF_EXCLUDE);
262
263 Streamer.SwitchSection(S);
264
265 for (const auto &Operand : LinkerOptions->operands()) {
266 if (cast<MDNode>(Operand)->getNumOperands() != 2)
267 report_fatal_error("invalid llvm.linker.options");
268 for (const auto &Option : cast<MDNode>(Operand)->operands()) {
269 Streamer.EmitBytes(cast<MDString>(Option)->getString());
270 Streamer.EmitIntValue(0, 1);
271 }
272 }
273 }
274
Saleem Abdulrasool4c474342017-06-05 21:26:39 +0000275 unsigned Version = 0;
276 unsigned Flags = 0;
277 StringRef Section;
278
Peter Collingbourne89061b22017-06-12 20:10:48 +0000279 GetObjCImageInfo(M, Version, Flags, Section);
Michael J. Spencer7bb27672018-07-16 00:28:24 +0000280 if (!Section.empty()) {
281 auto *S = C.getELFSection(Section, ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
282 Streamer.SwitchSection(S);
283 Streamer.EmitLabel(C.getOrCreateSymbol(StringRef("OBJC_IMAGE_INFO")));
284 Streamer.EmitIntValue(Version, 4);
285 Streamer.EmitIntValue(Flags, 4);
286 Streamer.AddBlankLine();
287 }
288
289 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
290 M.getModuleFlagsMetadata(ModuleFlags);
291
292 MDNode *CFGProfile = nullptr;
293
294 for (const auto &MFE : ModuleFlags) {
295 StringRef Key = MFE.Key->getString();
296 if (Key == "CG Profile") {
297 CFGProfile = cast<MDNode>(MFE.Val);
298 break;
299 }
300 }
301
302 if (!CFGProfile)
Saleem Abdulrasool4c474342017-06-05 21:26:39 +0000303 return;
304
Michael J. Spencer7bb27672018-07-16 00:28:24 +0000305 auto GetSym = [this](const MDOperand &MDO) -> MCSymbol * {
306 if (!MDO)
307 return nullptr;
308 auto V = cast<ValueAsMetadata>(MDO);
309 const Function *F = cast<Function>(V->getValue());
310 return TM->getSymbol(F);
311 };
312
313 for (const auto &Edge : CFGProfile->operands()) {
314 MDNode *E = cast<MDNode>(Edge);
315 const MCSymbol *From = GetSym(E->getOperand(0));
316 const MCSymbol *To = GetSym(E->getOperand(1));
317 // Skip null functions. This can happen if functions are dead stripped after
318 // the CGProfile pass has been run.
319 if (!From || !To)
320 continue;
321 uint64_t Count = cast<ConstantAsMetadata>(E->getOperand(2))
322 ->getValue()
323 ->getUniqueInteger()
324 .getZExtValue();
325 Streamer.emitCGProfileEntry(
326 MCSymbolRefExpr::create(From, MCSymbolRefExpr::VK_None, C),
327 MCSymbolRefExpr::create(To, MCSymbolRefExpr::VK_None, C), Count);
328 }
Saleem Abdulrasool4c474342017-06-05 21:26:39 +0000329}
330
Rafael Espindoladaeafb42014-02-19 17:23:20 +0000331MCSymbol *TargetLoweringObjectFileELF::getCFIPersonalitySymbol(
Eric Christopher4367c7f2016-09-16 07:33:15 +0000332 const GlobalValue *GV, const TargetMachine &TM,
Rafael Espindoladaeafb42014-02-19 17:23:20 +0000333 MachineModuleInfo *MMI) const {
Rafael Espindolace83fc32011-04-27 23:17:57 +0000334 unsigned Encoding = getPersonalityEncoding();
Eugene Zelenkofa912a72017-02-27 22:45:06 +0000335 if ((Encoding & 0x80) == DW_EH_PE_indirect)
Jim Grosbach6f482002015-05-18 18:43:14 +0000336 return getContext().getOrCreateSymbol(StringRef("DW.ref.") +
Tim Northoverb64fb452016-11-22 16:17:20 +0000337 TM.getSymbol(GV)->getName());
Eugene Zelenkofa912a72017-02-27 22:45:06 +0000338 if ((Encoding & 0x70) == DW_EH_PE_absptr)
Tim Northoverb64fb452016-11-22 16:17:20 +0000339 return TM.getSymbol(GV);
Logan Chienc0029812014-05-30 16:48:56 +0000340 report_fatal_error("We do not support this DWARF encoding yet!");
Rafael Espindolaa83b1772011-04-16 03:51:21 +0000341}
342
Mehdi Amini5c0fa582015-07-16 06:04:17 +0000343void TargetLoweringObjectFileELF::emitPersonalityValue(
344 MCStreamer &Streamer, const DataLayout &DL, const MCSymbol *Sym) const {
Rafael Espindola51d2d7a2011-06-13 03:09:13 +0000345 SmallString<64> NameData("DW.ref.");
346 NameData += Sym->getName();
Rafael Espindolaa8695762015-06-02 00:25:12 +0000347 MCSymbolELF *Label =
348 cast<MCSymbolELF>(getContext().getOrCreateSymbol(NameData));
Rafael Espindola39897762011-04-27 21:29:52 +0000349 Streamer.EmitSymbolAttribute(Label, MCSA_Hidden);
350 Streamer.EmitSymbolAttribute(Label, MCSA_Weak);
Rafael Espindola39897762011-04-27 21:29:52 +0000351 unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE | ELF::SHF_GROUP;
Eric Christopher36e601c2016-07-01 06:07:38 +0000352 MCSection *Sec = getContext().getELFNamedSection(".data", Label->getName(),
353 ELF::SHT_PROGBITS, Flags, 0);
Mehdi Amini5c0fa582015-07-16 06:04:17 +0000354 unsigned Size = DL.getPointerSize();
Rafael Espindola39897762011-04-27 21:29:52 +0000355 Streamer.SwitchSection(Sec);
Fangrui Songe73534462017-11-15 06:17:32 +0000356 Streamer.EmitValueToAlignment(DL.getPointerABIAlignment(0));
Rafael Espindola39897762011-04-27 21:29:52 +0000357 Streamer.EmitSymbolAttribute(Label, MCSA_ELF_TypeObject);
Jim Grosbach13760bd2015-05-30 01:25:56 +0000358 const MCExpr *E = MCConstantExpr::create(Size, getContext());
Rafael Espindolaa8695762015-06-02 00:25:12 +0000359 Streamer.emitELFSize(Label, E);
Rafael Espindola39897762011-04-27 21:29:52 +0000360 Streamer.EmitLabel(Label);
Rafael Espindolaa83b1772011-04-16 03:51:21 +0000361
Rafael Espindola39897762011-04-27 21:29:52 +0000362 Streamer.EmitSymbolValue(Sym, Size);
Rafael Espindolaa83b1772011-04-16 03:51:21 +0000363}
364
Rafael Espindola15b26692014-02-09 14:50:44 +0000365const MCExpr *TargetLoweringObjectFileELF::getTTypeGlobalReference(
Eric Christopher4367c7f2016-09-16 07:33:15 +0000366 const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
367 MachineModuleInfo *MMI, MCStreamer &Streamer) const {
Eugene Zelenkofa912a72017-02-27 22:45:06 +0000368 if (Encoding & DW_EH_PE_indirect) {
Anton Korobeynikove42af362012-11-14 01:47:00 +0000369 MachineModuleInfoELF &ELFMMI = MMI->getObjFileInfo<MachineModuleInfoELF>();
370
Eric Christopher4367c7f2016-09-16 07:33:15 +0000371 MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, ".DW.stub", TM);
Anton Korobeynikove42af362012-11-14 01:47:00 +0000372
373 // Add information about the stub reference to ELFMMI so that the stub
374 // gets emitted by the asmprinter.
Anton Korobeynikove42af362012-11-14 01:47:00 +0000375 MachineModuleInfoImpl::StubValueTy &StubSym = ELFMMI.getGVStubEntry(SSym);
Craig Topperc0196b12014-04-14 00:51:57 +0000376 if (!StubSym.getPointer()) {
Tim Northoverb64fb452016-11-22 16:17:20 +0000377 MCSymbol *Sym = TM.getSymbol(GV);
Anton Korobeynikove42af362012-11-14 01:47:00 +0000378 StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
379 }
380
381 return TargetLoweringObjectFile::
Jim Grosbach13760bd2015-05-30 01:25:56 +0000382 getTTypeReference(MCSymbolRefExpr::create(SSym, getContext()),
Eugene Zelenkofa912a72017-02-27 22:45:06 +0000383 Encoding & ~DW_EH_PE_indirect, Streamer);
Anton Korobeynikove42af362012-11-14 01:47:00 +0000384 }
385
Eric Christopher4367c7f2016-09-16 07:33:15 +0000386 return TargetLoweringObjectFile::getTTypeGlobalReference(GV, Encoding, TM,
387 MMI, Streamer);
Anton Korobeynikove42af362012-11-14 01:47:00 +0000388}
389
Sam Clegg12fd3da2017-10-20 21:28:38 +0000390static SectionKind getELFKindForNamedSection(StringRef Name, SectionKind K) {
Eric Christopher1f5eb862018-05-16 20:34:00 +0000391 // N.B.: The defaults used in here are not the same ones used in MC.
Rafael Espindola0d018b12011-05-24 03:10:31 +0000392 // We follow gcc, MC follows gas. For example, given ".section .eh_frame",
393 // both gas and MC will produce a section with no flags. Given
Bill Wendlingd1634052012-07-19 00:04:14 +0000394 // section(".eh_frame") gcc will produce:
395 //
396 // .section .eh_frame,"a",@progbits
Xinliang David Li4a5ddf82017-04-14 17:48:40 +0000397
Vedant Kumar1a6a2b62017-04-15 00:09:57 +0000398 if (Name == getInstrProfSectionName(IPSK_covmap, Triple::ELF,
399 /*AddSegmentInfo=*/false))
Xinliang David Li5f04f922016-01-14 18:09:45 +0000400 return SectionKind::getMetadata();
401
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000402 if (Name.empty() || Name[0] != '.') return K;
403
Eric Christopherf31e91e2018-05-18 02:39:57 +0000404 // Default implementation based on some magic section names.
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000405 if (Name == ".bss" ||
406 Name.startswith(".bss.") ||
407 Name.startswith(".gnu.linkonce.b.") ||
408 Name.startswith(".llvm.linkonce.b.") ||
409 Name == ".sbss" ||
410 Name.startswith(".sbss.") ||
411 Name.startswith(".gnu.linkonce.sb.") ||
412 Name.startswith(".llvm.linkonce.sb."))
413 return SectionKind::getBSS();
414
415 if (Name == ".tdata" ||
416 Name.startswith(".tdata.") ||
417 Name.startswith(".gnu.linkonce.td.") ||
418 Name.startswith(".llvm.linkonce.td."))
419 return SectionKind::getThreadData();
420
421 if (Name == ".tbss" ||
422 Name.startswith(".tbss.") ||
423 Name.startswith(".gnu.linkonce.tb.") ||
424 Name.startswith(".llvm.linkonce.tb."))
425 return SectionKind::getThreadBSS();
426
427 return K;
428}
429
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000430static unsigned getELFSectionType(StringRef Name, SectionKind K) {
Petr Hosek12903552016-09-20 20:21:13 +0000431 // Use SHT_NOTE for section whose name starts with ".note" to allow
432 // emitting ELF notes from C variable declaration.
433 // See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77609
434 if (Name.startswith(".note"))
435 return ELF::SHT_NOTE;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000436
437 if (Name == ".init_array")
Rafael Espindolaaea49582011-01-23 04:28:49 +0000438 return ELF::SHT_INIT_ARRAY;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000439
440 if (Name == ".fini_array")
Rafael Espindolaaea49582011-01-23 04:28:49 +0000441 return ELF::SHT_FINI_ARRAY;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000442
443 if (Name == ".preinit_array")
Rafael Espindolaaea49582011-01-23 04:28:49 +0000444 return ELF::SHT_PREINIT_ARRAY;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000445
446 if (K.isBSS() || K.isThreadBSS())
Rafael Espindolaaea49582011-01-23 04:28:49 +0000447 return ELF::SHT_NOBITS;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000448
Rafael Espindolaaea49582011-01-23 04:28:49 +0000449 return ELF::SHT_PROGBITS;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000450}
451
Rafael Espindola8bc9ccc2015-02-25 00:52:15 +0000452static unsigned getELFSectionFlags(SectionKind K) {
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000453 unsigned Flags = 0;
454
455 if (!K.isMetadata())
Rafael Espindola0e7e34e2011-01-23 04:43:11 +0000456 Flags |= ELF::SHF_ALLOC;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000457
458 if (K.isText())
Rafael Espindola0e7e34e2011-01-23 04:43:11 +0000459 Flags |= ELF::SHF_EXECINSTR;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000460
Prakhar Bahuguna52a7dd72016-12-15 07:59:08 +0000461 if (K.isExecuteOnly())
462 Flags |= ELF::SHF_ARM_PURECODE;
463
Rafael Espindolac85e0d82011-06-07 23:26:45 +0000464 if (K.isWriteable())
Rafael Espindola0e7e34e2011-01-23 04:43:11 +0000465 Flags |= ELF::SHF_WRITE;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000466
467 if (K.isThreadLocal())
Rafael Espindola0e7e34e2011-01-23 04:43:11 +0000468 Flags |= ELF::SHF_TLS;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000469
Rafael Espindola8bc9ccc2015-02-25 00:52:15 +0000470 if (K.isMergeableCString() || K.isMergeableConst())
Rafael Espindola0e7e34e2011-01-23 04:43:11 +0000471 Flags |= ELF::SHF_MERGE;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000472
473 if (K.isMergeableCString())
Rafael Espindola0e7e34e2011-01-23 04:43:11 +0000474 Flags |= ELF::SHF_STRINGS;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000475
476 return Flags;
477}
478
David Majnemerdad0a642014-06-27 18:19:56 +0000479static const Comdat *getELFComdat(const GlobalValue *GV) {
480 const Comdat *C = GV->getComdat();
481 if (!C)
482 return nullptr;
483
484 if (C->getSelectionKind() != Comdat::Any)
485 report_fatal_error("ELF COMDATs only support SelectionKind::Any, '" +
486 C->getName() + "' cannot be lowered.");
487
488 return C;
489}
490
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000491static const MCSymbolELF *getAssociatedSymbol(const GlobalObject *GO,
492 const TargetMachine &TM) {
493 MDNode *MD = GO->getMetadata(LLVMContext::MD_associated);
494 if (!MD)
495 return nullptr;
496
Evgeniy Stepanovf7e8acf2017-05-08 23:46:20 +0000497 const MDOperand &Op = MD->getOperand(0);
498 if (!Op.get())
499 return nullptr;
500
501 auto *VM = dyn_cast<ValueAsMetadata>(Op);
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000502 if (!VM)
503 report_fatal_error("MD_associated operand is not ValueAsMetadata");
504
505 GlobalObject *OtherGO = dyn_cast<GlobalObject>(VM->getValue());
506 return OtherGO ? dyn_cast<MCSymbolELF>(TM.getSymbol(OtherGO)) : nullptr;
507}
508
Nick Desaulniers47bab692018-10-12 16:35:44 +0000509static unsigned getEntrySizeForKind(SectionKind Kind) {
510 if (Kind.isMergeable1ByteCString())
511 return 1;
512 else if (Kind.isMergeable2ByteCString())
513 return 2;
514 else if (Kind.isMergeable4ByteCString())
515 return 4;
516 else if (Kind.isMergeableConst4())
517 return 4;
518 else if (Kind.isMergeableConst8())
519 return 8;
520 else if (Kind.isMergeableConst16())
521 return 16;
522 else if (Kind.isMergeableConst32())
523 return 32;
524 else {
525 // We shouldn't have mergeable C strings or mergeable constants that we
526 // didn't handle above.
527 assert(!Kind.isMergeableCString() && "unknown string width");
528 assert(!Kind.isMergeableConst() && "unknown data width");
529 return 0;
530 }
531}
532
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000533MCSection *TargetLoweringObjectFileELF::getExplicitSectionGlobal(
Peter Collingbourne67335642016-10-24 19:23:39 +0000534 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
535 StringRef SectionName = GO->getSection();
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000536
Javed Absarb16d1462017-06-05 10:09:13 +0000537 // Check if '#pragma clang section' name is applicable.
538 // Note that pragma directive overrides -ffunction-section, -fdata-section
539 // and so section name is exactly as user specified and not uniqued.
540 const GlobalVariable *GV = dyn_cast<GlobalVariable>(GO);
541 if (GV && GV->hasImplicitSection()) {
542 auto Attrs = GV->getAttributes();
543 if (Attrs.hasAttribute("bss-section") && Kind.isBSS()) {
544 SectionName = Attrs.getAttribute("bss-section").getValueAsString();
545 } else if (Attrs.hasAttribute("rodata-section") && Kind.isReadOnly()) {
546 SectionName = Attrs.getAttribute("rodata-section").getValueAsString();
547 } else if (Attrs.hasAttribute("data-section") && Kind.isData()) {
548 SectionName = Attrs.getAttribute("data-section").getValueAsString();
549 }
550 }
551 const Function *F = dyn_cast<Function>(GO);
552 if (F && F->hasFnAttribute("implicit-section-name")) {
553 SectionName = F->getFnAttribute("implicit-section-name").getValueAsString();
554 }
555
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000556 // Infer section flags from the section name if we can.
557 Kind = getELFKindForNamedSection(SectionName, Kind);
558
David Majnemerdad0a642014-06-27 18:19:56 +0000559 StringRef Group = "";
Rafael Espindola8bc9ccc2015-02-25 00:52:15 +0000560 unsigned Flags = getELFSectionFlags(Kind);
Peter Collingbourne67335642016-10-24 19:23:39 +0000561 if (const Comdat *C = getELFComdat(GO)) {
David Majnemerdad0a642014-06-27 18:19:56 +0000562 Group = C->getName();
563 Flags |= ELF::SHF_GROUP;
564 }
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000565
566 // A section can have at most one associated section. Put each global with
567 // MD_associated in a unique section.
568 unsigned UniqueID = MCContext::GenericSectionID;
569 const MCSymbolELF *AssociatedSymbol = getAssociatedSymbol(GO, TM);
570 if (AssociatedSymbol) {
571 UniqueID = NextUniqueID++;
572 Flags |= ELF::SHF_LINK_ORDER;
573 }
574
575 MCSectionELF *Section = getContext().getELFSection(
576 SectionName, getELFSectionType(SectionName, Kind), Flags,
Nick Desaulniers47bab692018-10-12 16:35:44 +0000577 getEntrySizeForKind(Kind), Group, UniqueID, AssociatedSymbol);
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000578 // Make sure that we did not get some other section with incompatible sh_link.
579 // This should not be possible due to UniqueID code above.
Eric Christopher76cfef42018-06-21 07:15:14 +0000580 assert(Section->getAssociatedSymbol() == AssociatedSymbol &&
581 "Associated symbol mismatch between sections");
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000582 return Section;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000583}
584
Rafael Espindola25d2c202015-02-11 14:44:17 +0000585/// Return the section prefix name used by options FunctionsSections and
586/// DataSections.
David Majnemer102ff692014-06-24 16:01:53 +0000587static StringRef getSectionPrefixForGlobal(SectionKind Kind) {
Rafael Espindola25d2c202015-02-11 14:44:17 +0000588 if (Kind.isText())
Rafael Espindola68fa2492015-02-17 20:48:01 +0000589 return ".text";
Rafael Espindola25d2c202015-02-11 14:44:17 +0000590 if (Kind.isReadOnly())
Rafael Espindola68fa2492015-02-17 20:48:01 +0000591 return ".rodata";
Rafael Espindola25d2c202015-02-11 14:44:17 +0000592 if (Kind.isBSS())
Rafael Espindola68fa2492015-02-17 20:48:01 +0000593 return ".bss";
Rafael Espindola25d2c202015-02-11 14:44:17 +0000594 if (Kind.isThreadData())
Rafael Espindola68fa2492015-02-17 20:48:01 +0000595 return ".tdata";
Rafael Espindola25d2c202015-02-11 14:44:17 +0000596 if (Kind.isThreadBSS())
Rafael Espindola68fa2492015-02-17 20:48:01 +0000597 return ".tbss";
Rafael Espindola449711c2015-11-18 06:02:15 +0000598 if (Kind.isData())
Rafael Espindola68fa2492015-02-17 20:48:01 +0000599 return ".data";
Chris Lattner5b212a32010-04-13 00:36:43 +0000600 assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
Rafael Espindola68fa2492015-02-17 20:48:01 +0000601 return ".data.rel.ro";
Chris Lattner5b212a32010-04-13 00:36:43 +0000602}
603
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000604static MCSectionELF *selectELFSectionForGlobal(
605 MCContext &Ctx, const GlobalObject *GO, SectionKind Kind, Mangler &Mang,
606 const TargetMachine &TM, bool EmitUniqueSection, unsigned Flags,
607 unsigned *NextUniqueID, const MCSymbolELF *AssociatedSymbol) {
Rafael Espindola8bc9ccc2015-02-25 00:52:15 +0000608
Rafael Espindola9075f772015-02-20 23:28:28 +0000609 StringRef Group = "";
Peter Collingbourne67335642016-10-24 19:23:39 +0000610 if (const Comdat *C = getELFComdat(GO)) {
Rafael Espindola9075f772015-02-20 23:28:28 +0000611 Flags |= ELF::SHF_GROUP;
612 Group = C->getName();
613 }
614
Eric Christopher7a70be62018-08-01 01:29:30 +0000615 // Get the section entry size based on the kind.
616 unsigned EntrySize = getEntrySizeForKind(Kind);
617
Rafael Espindola8bc9ccc2015-02-25 00:52:15 +0000618 SmallString<128> Name;
Rafael Espindolaa05b3b72015-01-28 17:54:19 +0000619 if (Kind.isMergeableCString()) {
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000620 // We also need alignment here.
621 // FIXME: this is getting the alignment of the character, not the
622 // alignment of the global!
Peter Collingbourne67335642016-10-24 19:23:39 +0000623 unsigned Align = GO->getParent()->getDataLayout().getPreferredAlignment(
624 cast<GlobalVariable>(GO));
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000625
Rafael Espindolaba31e272015-01-29 17:33:21 +0000626 std::string SizeSpec = ".rodata.str" + utostr(EntrySize) + ".";
Rafael Espindola8bc9ccc2015-02-25 00:52:15 +0000627 Name = SizeSpec + utostr(Align);
628 } else if (Kind.isMergeableConst()) {
629 Name = ".rodata.cst";
630 Name += utostr(EntrySize);
631 } else {
632 Name = getSectionPrefixForGlobal(Kind);
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000633 }
Dehao Chen302b69c2016-10-18 20:42:47 +0000634
Peter Collingbourne67335642016-10-24 19:23:39 +0000635 if (const auto *F = dyn_cast<Function>(GO)) {
Dehao Chen302b69c2016-10-18 20:42:47 +0000636 const auto &OptionalPrefix = F->getSectionPrefix();
637 if (OptionalPrefix)
638 Name += *OptionalPrefix;
639 }
Dehao Chenf84b6302016-02-23 03:39:24 +0000640
Reid Kleckner97837b72016-05-02 23:22:18 +0000641 unsigned UniqueID = MCContext::GenericSectionID;
Eric Christopherad36c742018-08-01 01:03:34 +0000642 if (EmitUniqueSection) {
643 if (TM.getUniqueSectionNames()) {
644 Name.push_back('.');
645 TM.getNameWithPrefix(Name, GO, Mang, true /*MayAlwaysUsePrivate*/);
646 } else {
647 UniqueID = *NextUniqueID;
648 (*NextUniqueID)++;
649 }
Rafael Espindola8ca44f02015-04-04 18:02:01 +0000650 }
Eric Christopherad36c742018-08-01 01:03:34 +0000651 // Use 0 as the unique ID for execute-only text.
Prakhar Bahuguna52a7dd72016-12-15 07:59:08 +0000652 if (Kind.isExecuteOnly())
653 UniqueID = 0;
Rafael Espindola4491d0d2015-02-26 23:55:11 +0000654 return Ctx.getELFSection(Name, getELFSectionType(Name, Kind), Flags,
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000655 EntrySize, Group, UniqueID, AssociatedSymbol);
Rafael Espindola4491d0d2015-02-26 23:55:11 +0000656}
657
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000658MCSection *TargetLoweringObjectFileELF::SelectSectionForGlobal(
Peter Collingbourne67335642016-10-24 19:23:39 +0000659 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
Rafael Espindola4491d0d2015-02-26 23:55:11 +0000660 unsigned Flags = getELFSectionFlags(Kind);
661
662 // If we have -ffunction-section or -fdata-section then we should emit the
663 // global value to a uniqued section specifically for it.
664 bool EmitUniqueSection = false;
665 if (!(Flags & ELF::SHF_MERGE) && !Kind.isCommon()) {
666 if (Kind.isText())
667 EmitUniqueSection = TM.getFunctionSections();
668 else
669 EmitUniqueSection = TM.getDataSections();
670 }
Peter Collingbourne67335642016-10-24 19:23:39 +0000671 EmitUniqueSection |= GO->hasComdat();
Rafael Espindola4491d0d2015-02-26 23:55:11 +0000672
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000673 const MCSymbolELF *AssociatedSymbol = getAssociatedSymbol(GO, TM);
674 if (AssociatedSymbol) {
675 EmitUniqueSection = true;
676 Flags |= ELF::SHF_LINK_ORDER;
677 }
678
679 MCSectionELF *Section = selectELFSectionForGlobal(
680 getContext(), GO, Kind, getMangler(), TM, EmitUniqueSection, Flags,
681 &NextUniqueID, AssociatedSymbol);
682 assert(Section->getAssociatedSymbol() == AssociatedSymbol);
683 return Section;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000684}
685
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000686MCSection *TargetLoweringObjectFileELF::getSectionForJumpTable(
Eric Christopher4367c7f2016-09-16 07:33:15 +0000687 const Function &F, const TargetMachine &TM) const {
Rafael Espindola29786d42015-02-12 17:16:46 +0000688 // If the function can be removed, produce a unique section so that
689 // the table doesn't prevent the removal.
690 const Comdat *C = F.getComdat();
691 bool EmitUniqueSection = TM.getFunctionSections() || C;
692 if (!EmitUniqueSection)
693 return ReadOnlySection;
694
Rafael Espindola4491d0d2015-02-26 23:55:11 +0000695 return selectELFSectionForGlobal(getContext(), &F, SectionKind::getReadOnly(),
Evgeniy Stepanov51c962f722017-03-17 22:17:24 +0000696 getMangler(), TM, EmitUniqueSection,
697 ELF::SHF_ALLOC, &NextUniqueID,
698 /* AssociatedSymbol */ nullptr);
Rafael Espindola29786d42015-02-12 17:16:46 +0000699}
700
Rafael Espindoladf195192015-02-17 23:34:51 +0000701bool TargetLoweringObjectFileELF::shouldPutJumpTableInFunctionSection(
702 bool UsesLabelDifference, const Function &F) const {
703 // We can always create relative relocations, so use another section
704 // that can be marked non-executable.
705 return false;
706}
707
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000708/// Given a mergeable constant with the specified size and relocation
709/// information, return a section that it should be placed in.
Mehdi Amini5c0fa582015-07-16 06:04:17 +0000710MCSection *TargetLoweringObjectFileELF::getSectionForConstant(
David Majnemera3ea4072016-02-21 01:30:30 +0000711 const DataLayout &DL, SectionKind Kind, const Constant *C,
712 unsigned &Align) const {
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000713 if (Kind.isMergeableConst4() && MergeableConst4Section)
714 return MergeableConst4Section;
715 if (Kind.isMergeableConst8() && MergeableConst8Section)
716 return MergeableConst8Section;
717 if (Kind.isMergeableConst16() && MergeableConst16Section)
718 return MergeableConst16Section;
David Majnemer964b70d2016-02-22 22:23:11 +0000719 if (Kind.isMergeableConst32() && MergeableConst32Section)
720 return MergeableConst32Section;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000721 if (Kind.isReadOnly())
722 return ReadOnlySection;
723
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000724 assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
725 return DataRelROSection;
726}
727
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000728static MCSectionELF *getStaticStructorSection(MCContext &Ctx, bool UseInitArray,
729 bool IsCtor, unsigned Priority,
730 const MCSymbol *KeySym) {
Rafael Espindolac4b42532014-09-04 23:03:58 +0000731 std::string Name;
732 unsigned Type;
733 unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE;
Rafael Espindolac4b42532014-09-04 23:03:58 +0000734 StringRef COMDAT = KeySym ? KeySym->getName() : "";
735
736 if (KeySym)
737 Flags |= ELF::SHF_GROUP;
Anton Korobeynikov7722a2d2012-01-25 22:24:19 +0000738
Rafael Espindolaca3e0ee2012-06-19 00:48:28 +0000739 if (UseInitArray) {
Rafael Espindola7c7d7b92014-09-05 00:02:50 +0000740 if (IsCtor) {
741 Type = ELF::SHT_INIT_ARRAY;
742 Name = ".init_array";
743 } else {
744 Type = ELF::SHT_FINI_ARRAY;
745 Name = ".fini_array";
746 }
Rafael Espindolac4b42532014-09-04 23:03:58 +0000747 if (Priority != 65535) {
748 Name += '.';
749 Name += utostr(Priority);
750 }
Rafael Espindolaca3e0ee2012-06-19 00:48:28 +0000751 } else {
Rafael Espindolac4b42532014-09-04 23:03:58 +0000752 // The default scheme is .ctor / .dtor, so we have to invert the priority
753 // numbering.
Rafael Espindola7c7d7b92014-09-05 00:02:50 +0000754 if (IsCtor)
755 Name = ".ctors";
756 else
757 Name = ".dtors";
Martin Storsjo04b68442017-11-28 08:07:18 +0000758 if (Priority != 65535)
759 raw_string_ostream(Name) << format(".%05u", 65535 - Priority);
Rafael Espindolac4b42532014-09-04 23:03:58 +0000760 Type = ELF::SHT_PROGBITS;
Rafael Espindolaca3e0ee2012-06-19 00:48:28 +0000761 }
Rafael Espindolac4b42532014-09-04 23:03:58 +0000762
Rafael Espindolaba31e272015-01-29 17:33:21 +0000763 return Ctx.getELFSection(Name, Type, Flags, 0, COMDAT);
Rafael Espindola7c7d7b92014-09-05 00:02:50 +0000764}
765
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000766MCSection *TargetLoweringObjectFileELF::getStaticCtorSection(
Rafael Espindola7c7d7b92014-09-05 00:02:50 +0000767 unsigned Priority, const MCSymbol *KeySym) const {
768 return getStaticStructorSection(getContext(), UseInitArray, true, Priority,
769 KeySym);
Anton Korobeynikov7722a2d2012-01-25 22:24:19 +0000770}
771
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000772MCSection *TargetLoweringObjectFileELF::getStaticDtorSection(
Rafael Espindola0766ae02014-06-06 19:26:12 +0000773 unsigned Priority, const MCSymbol *KeySym) const {
Rafael Espindola7c7d7b92014-09-05 00:02:50 +0000774 return getStaticStructorSection(getContext(), UseInitArray, false, Priority,
775 KeySym);
Rafael Espindolaca3e0ee2012-06-19 00:48:28 +0000776}
777
Peter Collingbourne265ebd72016-04-22 20:40:10 +0000778const MCExpr *TargetLoweringObjectFileELF::lowerRelativeReference(
Eric Christopher4367c7f2016-09-16 07:33:15 +0000779 const GlobalValue *LHS, const GlobalValue *RHS,
Peter Collingbourne265ebd72016-04-22 20:40:10 +0000780 const TargetMachine &TM) const {
781 // We may only use a PLT-relative relocation to refer to unnamed_addr
782 // functions.
Peter Collingbourne96efdd62016-06-14 21:01:22 +0000783 if (!LHS->hasGlobalUnnamedAddr() || !LHS->getValueType()->isFunctionTy())
Peter Collingbourne265ebd72016-04-22 20:40:10 +0000784 return nullptr;
785
786 // Basic sanity checks.
787 if (LHS->getType()->getPointerAddressSpace() != 0 ||
788 RHS->getType()->getPointerAddressSpace() != 0 || LHS->isThreadLocal() ||
789 RHS->isThreadLocal())
790 return nullptr;
791
792 return MCBinaryExpr::createSub(
Tim Northoverb64fb452016-11-22 16:17:20 +0000793 MCSymbolRefExpr::create(TM.getSymbol(LHS), PLTRelativeVariantKind,
Peter Collingbourne265ebd72016-04-22 20:40:10 +0000794 getContext()),
Tim Northoverb64fb452016-11-22 16:17:20 +0000795 MCSymbolRefExpr::create(TM.getSymbol(RHS), getContext()), getContext());
Peter Collingbourne265ebd72016-04-22 20:40:10 +0000796}
797
Rafael Espindolaca3e0ee2012-06-19 00:48:28 +0000798void
799TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) {
800 UseInitArray = UseInitArray_;
Rafael Espindola46fa2312016-08-29 12:33:42 +0000801 MCContext &Ctx = getContext();
802 if (!UseInitArray) {
803 StaticCtorSection = Ctx.getELFSection(".ctors", ELF::SHT_PROGBITS,
804 ELF::SHF_ALLOC | ELF::SHF_WRITE);
Rafael Espindolaca3e0ee2012-06-19 00:48:28 +0000805
Rafael Espindola46fa2312016-08-29 12:33:42 +0000806 StaticDtorSection = Ctx.getELFSection(".dtors", ELF::SHT_PROGBITS,
807 ELF::SHF_ALLOC | ELF::SHF_WRITE);
808 return;
809 }
810
811 StaticCtorSection = Ctx.getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
812 ELF::SHF_WRITE | ELF::SHF_ALLOC);
813 StaticDtorSection = Ctx.getELFSection(".fini_array", ELF::SHT_FINI_ARRAY,
814 ELF::SHF_WRITE | ELF::SHF_ALLOC);
Anton Korobeynikov7722a2d2012-01-25 22:24:19 +0000815}
816
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000817//===----------------------------------------------------------------------===//
818// MachO
819//===----------------------------------------------------------------------===//
820
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +0000821TargetLoweringObjectFileMachO::TargetLoweringObjectFileMachO()
822 : TargetLoweringObjectFile() {
823 SupportIndirectSymViaGOTPCRel = true;
824}
825
Rafael Espindola46fa2312016-08-29 12:33:42 +0000826void TargetLoweringObjectFileMachO::Initialize(MCContext &Ctx,
827 const TargetMachine &TM) {
828 TargetLoweringObjectFile::Initialize(Ctx, TM);
Rafael Espindola412a5292016-08-29 12:47:22 +0000829 if (TM.getRelocationModel() == Reloc::Static) {
Rafael Espindola46fa2312016-08-29 12:33:42 +0000830 StaticCtorSection = Ctx.getMachOSection("__TEXT", "__constructor", 0,
831 SectionKind::getData());
832 StaticDtorSection = Ctx.getMachOSection("__TEXT", "__destructor", 0,
833 SectionKind::getData());
834 } else {
835 StaticCtorSection = Ctx.getMachOSection("__DATA", "__mod_init_func",
836 MachO::S_MOD_INIT_FUNC_POINTERS,
837 SectionKind::getData());
838 StaticDtorSection = Ctx.getMachOSection("__DATA", "__mod_term_func",
839 MachO::S_MOD_TERM_FUNC_POINTERS,
840 SectionKind::getData());
841 }
Reid Klecknerfce7f732018-08-09 22:24:04 +0000842
843 PersonalityEncoding =
844 dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
845 LSDAEncoding = dwarf::DW_EH_PE_pcrel;
846 TTypeEncoding =
847 dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
Rafael Espindola46fa2312016-08-29 12:33:42 +0000848}
849
Eric Christopheraadbabc2018-04-20 19:07:57 +0000850void TargetLoweringObjectFileMachO::emitModuleMetadata(MCStreamer &Streamer,
851 Module &M) const {
Daniel Dunbar95856122013-01-18 19:37:00 +0000852 // Emit the linker options if present.
Peter Collingbourne89061b22017-06-12 20:10:48 +0000853 if (auto *LinkerOptions = M.getNamedMetadata("llvm.linker.options")) {
Saleem Abdulrasoole0f0c0e2016-04-30 18:15:34 +0000854 for (const auto &Option : LinkerOptions->operands()) {
Daniel Dunbar95856122013-01-18 19:37:00 +0000855 SmallVector<std::string, 4> StrOptions;
Saleem Abdulrasoole0f0c0e2016-04-30 18:15:34 +0000856 for (const auto &Piece : cast<MDNode>(Option)->operands())
857 StrOptions.push_back(cast<MDString>(Piece)->getString());
Daniel Dunbar95856122013-01-18 19:37:00 +0000858 Streamer.EmitLinkerOptions(StrOptions);
859 }
Bill Wendling06df7722012-02-14 21:28:13 +0000860 }
861
Saleem Abdulrasool4c474342017-06-05 21:26:39 +0000862 unsigned VersionVal = 0;
863 unsigned ImageInfoFlags = 0;
864 StringRef SectionVal;
Peter Collingbourne89061b22017-06-12 20:10:48 +0000865
866 GetObjCImageInfo(M, VersionVal, ImageInfoFlags, SectionVal);
Saleem Abdulrasool4c474342017-06-05 21:26:39 +0000867
Bill Wendling734909a2012-02-15 22:36:15 +0000868 // The section is mandatory. If we don't have it, then we don't have GC info.
Saleem Abdulrasool4c474342017-06-05 21:26:39 +0000869 if (SectionVal.empty())
870 return;
Bill Wendling06df7722012-02-14 21:28:13 +0000871
Bill Wendling734909a2012-02-15 22:36:15 +0000872 StringRef Segment, Section;
873 unsigned TAA = 0, StubSize = 0;
874 bool TAAParsed;
875 std::string ErrorCode =
876 MCSectionMachO::ParseSectionSpecifier(SectionVal, Segment, Section,
877 TAA, TAAParsed, StubSize);
Bill Wendlinga0009ee2012-02-15 22:47:53 +0000878 if (!ErrorCode.empty())
Bill Wendling734909a2012-02-15 22:36:15 +0000879 // If invalid, report the error with report_fatal_error.
Bill Wendlinga0009ee2012-02-15 22:47:53 +0000880 report_fatal_error("Invalid section specifier '" + Section + "': " +
881 ErrorCode + ".");
Bill Wendling06df7722012-02-14 21:28:13 +0000882
Bill Wendling734909a2012-02-15 22:36:15 +0000883 // Get the section.
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000884 MCSectionMachO *S = getContext().getMachOSection(
Rafael Espindola449711c2015-11-18 06:02:15 +0000885 Segment, Section, TAA, StubSize, SectionKind::getData());
Bill Wendling734909a2012-02-15 22:36:15 +0000886 Streamer.SwitchSection(S);
887 Streamer.EmitLabel(getContext().
Jim Grosbach6f482002015-05-18 18:43:14 +0000888 getOrCreateSymbol(StringRef("L_OBJC_IMAGE_INFO")));
Bill Wendling06df7722012-02-14 21:28:13 +0000889 Streamer.EmitIntValue(VersionVal, 4);
Bill Wendlingf1b14b72012-04-24 11:03:50 +0000890 Streamer.EmitIntValue(ImageInfoFlags, 4);
Bill Wendling06df7722012-02-14 21:28:13 +0000891 Streamer.AddBlankLine();
892}
893
David Majnemerdad0a642014-06-27 18:19:56 +0000894static void checkMachOComdat(const GlobalValue *GV) {
895 const Comdat *C = GV->getComdat();
896 if (!C)
897 return;
898
899 report_fatal_error("MachO doesn't support COMDATs, '" + C->getName() +
900 "' cannot be lowered.");
901}
902
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000903MCSection *TargetLoweringObjectFileMachO::getExplicitSectionGlobal(
Peter Collingbourne67335642016-10-24 19:23:39 +0000904 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000905 // Parse the section specifier and create it if valid.
906 StringRef Segment, Section;
Stuart Hastings12d53122011-03-19 02:42:31 +0000907 unsigned TAA = 0, StubSize = 0;
908 bool TAAParsed;
David Majnemerdad0a642014-06-27 18:19:56 +0000909
Peter Collingbourne67335642016-10-24 19:23:39 +0000910 checkMachOComdat(GO);
David Majnemerdad0a642014-06-27 18:19:56 +0000911
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000912 std::string ErrorCode =
Peter Collingbourne67335642016-10-24 19:23:39 +0000913 MCSectionMachO::ParseSectionSpecifier(GO->getSection(), Segment, Section,
Stuart Hastings12d53122011-03-19 02:42:31 +0000914 TAA, TAAParsed, StubSize);
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000915 if (!ErrorCode.empty()) {
Chris Lattner2104b8d2010-04-07 22:58:41 +0000916 // If invalid, report the error with report_fatal_error.
Peter Collingbourne67335642016-10-24 19:23:39 +0000917 report_fatal_error("Global variable '" + GO->getName() +
Benjamin Kramer1f97a5a2011-11-15 16:27:03 +0000918 "' has an invalid section specifier '" +
Peter Collingbourne67335642016-10-24 19:23:39 +0000919 GO->getSection() + "': " + ErrorCode + ".");
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000920 }
921
922 // Get the section.
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000923 MCSectionMachO *S =
924 getContext().getMachOSection(Segment, Section, TAA, StubSize, Kind);
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000925
Stuart Hastingsb4863a42011-02-21 17:27:17 +0000926 // If TAA wasn't set by ParseSectionSpecifier() above,
927 // use the value returned by getMachOSection() as a default.
Stuart Hastings12d53122011-03-19 02:42:31 +0000928 if (!TAAParsed)
Stuart Hastingsb4863a42011-02-21 17:27:17 +0000929 TAA = S->getTypeAndAttributes();
930
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000931 // Okay, now that we got the section, verify that the TAA & StubSize agree.
932 // If the user declared multiple globals with different section flags, we need
933 // to reject it here.
934 if (S->getTypeAndAttributes() != TAA || S->getStubSize() != StubSize) {
Chris Lattner2104b8d2010-04-07 22:58:41 +0000935 // If invalid, report the error with report_fatal_error.
Peter Collingbourne67335642016-10-24 19:23:39 +0000936 report_fatal_error("Global variable '" + GO->getName() +
Benjamin Kramer1f97a5a2011-11-15 16:27:03 +0000937 "' section type or attributes does not match previous"
938 " section specifier");
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000939 }
940
941 return S;
942}
943
Rafael Espindola0709a7b2015-05-21 19:20:38 +0000944MCSection *TargetLoweringObjectFileMachO::SelectSectionForGlobal(
Peter Collingbourne67335642016-10-24 19:23:39 +0000945 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
946 checkMachOComdat(GO);
Bill Wendling25b61db2013-11-17 10:53:13 +0000947
948 // Handle thread local data.
949 if (Kind.isThreadBSS()) return TLSBSSSection;
950 if (Kind.isThreadData()) return TLSDataSection;
951
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000952 if (Kind.isText())
Peter Collingbourne67335642016-10-24 19:23:39 +0000953 return GO->isWeakForLinker() ? TextCoalSection : TextSection;
Arnold Schwaighoferc31c2de2013-08-08 21:04:16 +0000954
955 // If this is weak/linkonce, put this in a coalescable section, either in text
956 // or data depending on if it is writable.
Peter Collingbourne67335642016-10-24 19:23:39 +0000957 if (GO->isWeakForLinker()) {
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000958 if (Kind.isReadOnly())
Arnold Schwaighoferc31c2de2013-08-08 21:04:16 +0000959 return ConstTextCoalSection;
Steven Wud0804aa2018-04-10 20:16:35 +0000960 if (Kind.isReadOnlyWithRel())
961 return ConstDataCoalSection;
Arnold Schwaighoferc31c2de2013-08-08 21:04:16 +0000962 return DataCoalSection;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000963 }
964
965 // FIXME: Alignment check should be handled by section classifier.
Chris Lattneref2f8042010-03-07 04:28:09 +0000966 if (Kind.isMergeable1ByteCString() &&
Peter Collingbourne67335642016-10-24 19:23:39 +0000967 GO->getParent()->getDataLayout().getPreferredAlignment(
968 cast<GlobalVariable>(GO)) < 32)
Chris Lattneref2f8042010-03-07 04:28:09 +0000969 return CStringSection;
Michael J. Spencerfbdab0d2010-10-27 18:52:20 +0000970
Chris Lattneref2f8042010-03-07 04:28:09 +0000971 // Do not put 16-bit arrays in the UString section if they have an
972 // externally visible label, this runs into issues with certain linker
973 // versions.
Peter Collingbourne67335642016-10-24 19:23:39 +0000974 if (Kind.isMergeable2ByteCString() && !GO->hasExternalLinkage() &&
975 GO->getParent()->getDataLayout().getPreferredAlignment(
976 cast<GlobalVariable>(GO)) < 32)
Chris Lattneref2f8042010-03-07 04:28:09 +0000977 return UStringSection;
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000978
Rafael Espindolab43d51d2014-08-28 20:13:31 +0000979 // With MachO only variables whose corresponding symbol starts with 'l' or
980 // 'L' can be merged, so we only try merging GVs with private linkage.
Peter Collingbourne67335642016-10-24 19:23:39 +0000981 if (GO->hasPrivateLinkage() && Kind.isMergeableConst()) {
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000982 if (Kind.isMergeableConst4())
983 return FourByteConstantSection;
984 if (Kind.isMergeableConst8())
985 return EightByteConstantSection;
Rafael Espindola1f3de492014-02-13 23:16:11 +0000986 if (Kind.isMergeableConst16())
Anton Korobeynikovab663a02010-02-15 22:37:53 +0000987 return SixteenByteConstantSection;
988 }
989
990 // Otherwise, if it is readonly, but not something we can specially optimize,
991 // just drop it in .const.
992 if (Kind.isReadOnly())
993 return ReadOnlySection;
994
995 // If this is marked const, put it into a const section. But if the dynamic
996 // linker needs to write to it, put it in the data segment.
997 if (Kind.isReadOnlyWithRel())
998 return ConstDataSection;
999
1000 // Put zero initialized globals with strong external linkage in the
1001 // DATA, __common section with the .zerofill directive.
1002 if (Kind.isBSSExtern())
1003 return DataCommonSection;
1004
1005 // Put zero initialized globals with local linkage in __DATA,__bss directive
1006 // with the .zerofill directive (aka .lcomm).
1007 if (Kind.isBSSLocal())
1008 return DataBSSSection;
Michael J. Spencerfbdab0d2010-10-27 18:52:20 +00001009
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001010 // Otherwise, just drop the variable in the normal data section.
1011 return DataSection;
1012}
1013
Mehdi Amini5c0fa582015-07-16 06:04:17 +00001014MCSection *TargetLoweringObjectFileMachO::getSectionForConstant(
David Majnemera3ea4072016-02-21 01:30:30 +00001015 const DataLayout &DL, SectionKind Kind, const Constant *C,
1016 unsigned &Align) const {
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001017 // If this constant requires a relocation, we have to put it in the data
1018 // segment, not in the text segment.
Rafael Espindola449711c2015-11-18 06:02:15 +00001019 if (Kind.isData() || Kind.isReadOnlyWithRel())
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001020 return ConstDataSection;
1021
1022 if (Kind.isMergeableConst4())
1023 return FourByteConstantSection;
1024 if (Kind.isMergeableConst8())
1025 return EightByteConstantSection;
Rafael Espindola1f3de492014-02-13 23:16:11 +00001026 if (Kind.isMergeableConst16())
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001027 return SixteenByteConstantSection;
1028 return ReadOnlySection; // .const
1029}
1030
Rafael Espindola15b26692014-02-09 14:50:44 +00001031const MCExpr *TargetLoweringObjectFileMachO::getTTypeGlobalReference(
Eric Christopher4367c7f2016-09-16 07:33:15 +00001032 const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
1033 MachineModuleInfo *MMI, MCStreamer &Streamer) const {
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001034 // The mach-o version of this method defaults to returning a stub reference.
1035
Anton Korobeynikov31a92122010-02-21 20:28:15 +00001036 if (Encoding & DW_EH_PE_indirect) {
1037 MachineModuleInfoMachO &MachOMMI =
1038 MMI->getObjFileInfo<MachineModuleInfoMachO>();
1039
Eric Christopher4367c7f2016-09-16 07:33:15 +00001040 MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", TM);
Anton Korobeynikov31a92122010-02-21 20:28:15 +00001041
1042 // Add information about the stub reference to MachOMMI so that the stub
1043 // gets emitted by the asmprinter.
Rafael Espindola712f9572016-05-17 16:01:32 +00001044 MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(SSym);
Craig Topperc0196b12014-04-14 00:51:57 +00001045 if (!StubSym.getPointer()) {
Tim Northoverb64fb452016-11-22 16:17:20 +00001046 MCSymbol *Sym = TM.getSymbol(GV);
Chris Lattner2ea586b2010-03-15 20:37:38 +00001047 StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
Anton Korobeynikov31a92122010-02-21 20:28:15 +00001048 }
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001049
1050 return TargetLoweringObjectFile::
Jim Grosbach13760bd2015-05-30 01:25:56 +00001051 getTTypeReference(MCSymbolRefExpr::create(SSym, getContext()),
Eugene Zelenkofa912a72017-02-27 22:45:06 +00001052 Encoding & ~DW_EH_PE_indirect, Streamer);
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001053 }
1054
Eric Christopher4367c7f2016-09-16 07:33:15 +00001055 return TargetLoweringObjectFile::getTTypeGlobalReference(GV, Encoding, TM,
1056 MMI, Streamer);
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001057}
1058
Rafael Espindoladaeafb42014-02-19 17:23:20 +00001059MCSymbol *TargetLoweringObjectFileMachO::getCFIPersonalitySymbol(
Eric Christopher4367c7f2016-09-16 07:33:15 +00001060 const GlobalValue *GV, const TargetMachine &TM,
Rafael Espindoladaeafb42014-02-19 17:23:20 +00001061 MachineModuleInfo *MMI) const {
Rafael Espindola08704342011-04-27 23:08:15 +00001062 // The mach-o version of this method defaults to returning a stub reference.
1063 MachineModuleInfoMachO &MachOMMI =
1064 MMI->getObjFileInfo<MachineModuleInfoMachO>();
1065
Eric Christopher4367c7f2016-09-16 07:33:15 +00001066 MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", TM);
Rafael Espindola08704342011-04-27 23:08:15 +00001067
1068 // Add information about the stub reference to MachOMMI so that the stub
1069 // gets emitted by the asmprinter.
Bill Wendlinge4cc3322011-11-29 01:43:20 +00001070 MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(SSym);
Craig Topperc0196b12014-04-14 00:51:57 +00001071 if (!StubSym.getPointer()) {
Tim Northoverb64fb452016-11-22 16:17:20 +00001072 MCSymbol *Sym = TM.getSymbol(GV);
Rafael Espindola08704342011-04-27 23:08:15 +00001073 StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
1074 }
1075
1076 return SSym;
1077}
1078
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001079const MCExpr *TargetLoweringObjectFileMachO::getIndirectSymViaGOTPCRel(
1080 const MCSymbol *Sym, const MCValue &MV, int64_t Offset,
1081 MachineModuleInfo *MMI, MCStreamer &Streamer) const {
Benjamin Kramerdf005cb2015-08-08 18:27:36 +00001082 // Although MachO 32-bit targets do not explicitly have a GOTPCREL relocation
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001083 // as 64-bit do, we replace the GOT equivalent by accessing the final symbol
1084 // through a non_lazy_ptr stub instead. One advantage is that it allows the
1085 // computation of deltas to final external symbols. Example:
1086 //
1087 // _extgotequiv:
1088 // .long _extfoo
1089 //
1090 // _delta:
1091 // .long _extgotequiv-_delta
1092 //
1093 // is transformed to:
1094 //
1095 // _delta:
1096 // .long L_extfoo$non_lazy_ptr-(_delta+0)
1097 //
1098 // .section __IMPORT,__pointers,non_lazy_symbol_pointers
1099 // L_extfoo$non_lazy_ptr:
1100 // .indirect_symbol _extfoo
1101 // .long 0
1102 //
1103 MachineModuleInfoMachO &MachOMMI =
1104 MMI->getObjFileInfo<MachineModuleInfoMachO>();
1105 MCContext &Ctx = getContext();
1106
1107 // The offset must consider the original displacement from the base symbol
1108 // since 32-bit targets don't have a GOTPCREL to fold the PC displacement.
1109 Offset = -MV.getConstant();
1110 const MCSymbol *BaseSym = &MV.getSymB()->getSymbol();
1111
1112 // Access the final symbol via sym$non_lazy_ptr and generate the appropriated
1113 // non_lazy_ptr stubs.
1114 SmallString<128> Name;
1115 StringRef Suffix = "$non_lazy_ptr";
Mehdi Amini5c0fa582015-07-16 06:04:17 +00001116 Name += MMI->getModule()->getDataLayout().getPrivateGlobalPrefix();
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001117 Name += Sym->getName();
1118 Name += Suffix;
Jim Grosbach6f482002015-05-18 18:43:14 +00001119 MCSymbol *Stub = Ctx.getOrCreateSymbol(Name);
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001120
1121 MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(Stub);
1122 if (!StubSym.getPointer())
1123 StubSym = MachineModuleInfoImpl::
1124 StubValueTy(const_cast<MCSymbol *>(Sym), true /* access indirectly */);
1125
1126 const MCExpr *BSymExpr =
Jim Grosbach13760bd2015-05-30 01:25:56 +00001127 MCSymbolRefExpr::create(BaseSym, MCSymbolRefExpr::VK_None, Ctx);
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001128 const MCExpr *LHS =
Jim Grosbach13760bd2015-05-30 01:25:56 +00001129 MCSymbolRefExpr::create(Stub, MCSymbolRefExpr::VK_None, Ctx);
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001130
1131 if (!Offset)
Jim Grosbach13760bd2015-05-30 01:25:56 +00001132 return MCBinaryExpr::createSub(LHS, BSymExpr, Ctx);
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001133
1134 const MCExpr *RHS =
Jim Grosbach13760bd2015-05-30 01:25:56 +00001135 MCBinaryExpr::createAdd(BSymExpr, MCConstantExpr::create(Offset, Ctx), Ctx);
1136 return MCBinaryExpr::createSub(LHS, RHS, Ctx);
Bruno Cardoso Lopes618c67a2015-03-06 13:49:05 +00001137}
1138
Peter Collingbourne94d77862015-11-03 23:40:03 +00001139static bool canUsePrivateLabel(const MCAsmInfo &AsmInfo,
1140 const MCSection &Section) {
1141 if (!AsmInfo.isSectionAtomizableBySymbols(Section))
1142 return true;
1143
1144 // If it is not dead stripped, it is safe to use private labels.
1145 const MCSectionMachO &SMO = cast<MCSectionMachO>(Section);
1146 if (SMO.hasAttribute(MachO::S_ATTR_NO_DEAD_STRIP))
1147 return true;
1148
1149 return false;
1150}
1151
1152void TargetLoweringObjectFileMachO::getNameWithPrefix(
Eric Christopher4367c7f2016-09-16 07:33:15 +00001153 SmallVectorImpl<char> &OutName, const GlobalValue *GV,
Peter Collingbourne94d77862015-11-03 23:40:03 +00001154 const TargetMachine &TM) const {
Peter Collingbourne67335642016-10-24 19:23:39 +00001155 bool CannotUsePrivateLabel = true;
1156 if (auto *GO = GV->getBaseObject()) {
1157 SectionKind GOKind = TargetLoweringObjectFile::getKindForGlobal(GO, TM);
1158 const MCSection *TheSection = SectionForGlobal(GO, GOKind, TM);
1159 CannotUsePrivateLabel =
1160 !canUsePrivateLabel(*TM.getMCAsmInfo(), *TheSection);
1161 }
Eric Christopher4367c7f2016-09-16 07:33:15 +00001162 getMangler().getNameWithPrefix(OutName, GV, CannotUsePrivateLabel);
Peter Collingbourne94d77862015-11-03 23:40:03 +00001163}
1164
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001165//===----------------------------------------------------------------------===//
1166// COFF
1167//===----------------------------------------------------------------------===//
1168
Chris Lattner87cffa92010-05-07 17:17:41 +00001169static unsigned
Renato Golinef3eb062016-06-27 14:42:20 +00001170getCOFFSectionFlags(SectionKind K, const TargetMachine &TM) {
Chris Lattner87cffa92010-05-07 17:17:41 +00001171 unsigned Flags = 0;
Renato Golinef3eb062016-06-27 14:42:20 +00001172 bool isThumb = TM.getTargetTriple().getArch() == Triple::thumb;
Chris Lattner87cffa92010-05-07 17:17:41 +00001173
Anton Korobeynikove4152302010-07-06 15:24:56 +00001174 if (K.isMetadata())
Chris Lattner02844932010-05-07 21:49:09 +00001175 Flags |=
Daniel Dunbar329d2022010-07-01 20:07:24 +00001176 COFF::IMAGE_SCN_MEM_DISCARDABLE;
Chris Lattner87cffa92010-05-07 17:17:41 +00001177 else if (K.isText())
1178 Flags |=
Daniel Dunbar329d2022010-07-01 20:07:24 +00001179 COFF::IMAGE_SCN_MEM_EXECUTE |
Michael J. Spencer0f83d962010-10-27 18:52:29 +00001180 COFF::IMAGE_SCN_MEM_READ |
Renato Golinef3eb062016-06-27 14:42:20 +00001181 COFF::IMAGE_SCN_CNT_CODE |
1182 (isThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0);
David Majnemerb8dbebb2014-09-20 07:31:46 +00001183 else if (K.isBSS())
Chris Lattner02844932010-05-07 21:49:09 +00001184 Flags |=
Daniel Dunbar329d2022010-07-01 20:07:24 +00001185 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
1186 COFF::IMAGE_SCN_MEM_READ |
1187 COFF::IMAGE_SCN_MEM_WRITE;
Anton Korobeynikovc6b40172012-02-11 17:26:53 +00001188 else if (K.isThreadLocal())
1189 Flags |=
1190 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1191 COFF::IMAGE_SCN_MEM_READ |
1192 COFF::IMAGE_SCN_MEM_WRITE;
David Majnemerb8dbebb2014-09-20 07:31:46 +00001193 else if (K.isReadOnly() || K.isReadOnlyWithRel())
Chris Lattner87cffa92010-05-07 17:17:41 +00001194 Flags |=
Daniel Dunbar329d2022010-07-01 20:07:24 +00001195 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1196 COFF::IMAGE_SCN_MEM_READ;
Chris Lattner87cffa92010-05-07 17:17:41 +00001197 else if (K.isWriteable())
1198 Flags |=
Daniel Dunbar329d2022010-07-01 20:07:24 +00001199 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1200 COFF::IMAGE_SCN_MEM_READ |
1201 COFF::IMAGE_SCN_MEM_WRITE;
Chris Lattner87cffa92010-05-07 17:17:41 +00001202
1203 return Flags;
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001204}
1205
Benjamin Kramer6cbe6702014-07-07 14:47:51 +00001206static const GlobalValue *getComdatGVForCOFF(const GlobalValue *GV) {
David Majnemerdad0a642014-06-27 18:19:56 +00001207 const Comdat *C = GV->getComdat();
1208 assert(C && "expected GV to have a Comdat!");
1209
1210 StringRef ComdatGVName = C->getName();
1211 const GlobalValue *ComdatGV = GV->getParent()->getNamedValue(ComdatGVName);
1212 if (!ComdatGV)
1213 report_fatal_error("Associative COMDAT symbol '" + ComdatGVName +
1214 "' does not exist.");
1215
1216 if (ComdatGV->getComdat() != C)
1217 report_fatal_error("Associative COMDAT symbol '" + ComdatGVName +
Hans Wennborgc0f0c512014-09-19 01:14:56 +00001218 "' is not a key for its COMDAT.");
David Majnemerdad0a642014-06-27 18:19:56 +00001219
1220 return ComdatGV;
1221}
1222
1223static int getSelectionForCOFF(const GlobalValue *GV) {
1224 if (const Comdat *C = GV->getComdat()) {
1225 const GlobalValue *ComdatKey = getComdatGVForCOFF(GV);
1226 if (const auto *GA = dyn_cast<GlobalAlias>(ComdatKey))
1227 ComdatKey = GA->getBaseObject();
1228 if (ComdatKey == GV) {
1229 switch (C->getSelectionKind()) {
1230 case Comdat::Any:
1231 return COFF::IMAGE_COMDAT_SELECT_ANY;
1232 case Comdat::ExactMatch:
1233 return COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH;
1234 case Comdat::Largest:
1235 return COFF::IMAGE_COMDAT_SELECT_LARGEST;
1236 case Comdat::NoDuplicates:
1237 return COFF::IMAGE_COMDAT_SELECT_NODUPLICATES;
1238 case Comdat::SameSize:
1239 return COFF::IMAGE_COMDAT_SELECT_SAME_SIZE;
1240 }
1241 } else {
1242 return COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE;
1243 }
David Majnemerdad0a642014-06-27 18:19:56 +00001244 }
1245 return 0;
1246}
1247
Rafael Espindola0709a7b2015-05-21 19:20:38 +00001248MCSection *TargetLoweringObjectFileCOFF::getExplicitSectionGlobal(
Peter Collingbourne67335642016-10-24 19:23:39 +00001249 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
Michael J. Spencerf1aef752012-11-13 22:04:09 +00001250 int Selection = 0;
Renato Golinef3eb062016-06-27 14:42:20 +00001251 unsigned Characteristics = getCOFFSectionFlags(Kind, TM);
Peter Collingbourne67335642016-10-24 19:23:39 +00001252 StringRef Name = GO->getSection();
Rafael Espindola2d30ae22013-11-27 01:18:37 +00001253 StringRef COMDATSymName = "";
Peter Collingbourne67335642016-10-24 19:23:39 +00001254 if (GO->hasComdat()) {
1255 Selection = getSelectionForCOFF(GO);
David Majnemerdad0a642014-06-27 18:19:56 +00001256 const GlobalValue *ComdatGV;
1257 if (Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
Peter Collingbourne67335642016-10-24 19:23:39 +00001258 ComdatGV = getComdatGVForCOFF(GO);
David Majnemerdad0a642014-06-27 18:19:56 +00001259 else
Peter Collingbourne67335642016-10-24 19:23:39 +00001260 ComdatGV = GO;
David Majnemerdad0a642014-06-27 18:19:56 +00001261
1262 if (!ComdatGV->hasPrivateLinkage()) {
Tim Northoverb64fb452016-11-22 16:17:20 +00001263 MCSymbol *Sym = TM.getSymbol(ComdatGV);
David Majnemerdad0a642014-06-27 18:19:56 +00001264 COMDATSymName = Sym->getName();
1265 Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
1266 } else {
1267 Selection = 0;
1268 }
Michael J. Spencerf1aef752012-11-13 22:04:09 +00001269 }
Reid Kleckner97837b72016-05-02 23:22:18 +00001270
1271 return getContext().getCOFFSection(Name, Characteristics, Kind, COMDATSymName,
Nico Riecka37acf72013-07-06 12:13:10 +00001272 Selection);
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001273}
1274
Reid Kleckner13c9ee62018-06-21 20:27:38 +00001275static StringRef getCOFFSectionNameForUniqueGlobal(SectionKind Kind) {
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001276 if (Kind.isText())
Rafael Espindola2d30ae22013-11-27 01:18:37 +00001277 return ".text";
David Majnemera9bdb322014-04-08 22:33:40 +00001278 if (Kind.isBSS())
Rafael Espindola2d30ae22013-11-27 01:18:37 +00001279 return ".bss";
1280 if (Kind.isThreadLocal())
Rafael Espindola3c8e1472013-11-27 15:52:11 +00001281 return ".tls$";
David Majnemer597be2d2014-09-22 20:39:23 +00001282 if (Kind.isReadOnly() || Kind.isReadOnlyWithRel())
1283 return ".rdata";
1284 return ".data";
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001285}
1286
Rafael Espindola0709a7b2015-05-21 19:20:38 +00001287MCSection *TargetLoweringObjectFileCOFF::SelectSectionForGlobal(
Peter Collingbourne67335642016-10-24 19:23:39 +00001288 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
David Majnemer93389842014-03-23 17:47:39 +00001289 // If we have -ffunction-sections then we should emit the global value to a
1290 // uniqued section specifically for it.
David Majnemer273bff42014-03-25 06:14:26 +00001291 bool EmitUniquedSection;
1292 if (Kind.isText())
1293 EmitUniquedSection = TM.getFunctionSections();
1294 else
1295 EmitUniquedSection = TM.getDataSections();
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001296
Peter Collingbourne67335642016-10-24 19:23:39 +00001297 if ((EmitUniquedSection && !Kind.isCommon()) || GO->hasComdat()) {
Reid Kleckner13c9ee62018-06-21 20:27:38 +00001298 SmallString<256> Name = getCOFFSectionNameForUniqueGlobal(Kind);
1299
Renato Golinef3eb062016-06-27 14:42:20 +00001300 unsigned Characteristics = getCOFFSectionFlags(Kind, TM);
Chris Lattner02844932010-05-07 21:49:09 +00001301
Daniel Dunbar329d2022010-07-01 20:07:24 +00001302 Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
Peter Collingbourne67335642016-10-24 19:23:39 +00001303 int Selection = getSelectionForCOFF(GO);
David Majnemerdad0a642014-06-27 18:19:56 +00001304 if (!Selection)
1305 Selection = COFF::IMAGE_COMDAT_SELECT_NODUPLICATES;
1306 const GlobalValue *ComdatGV;
Peter Collingbourne67335642016-10-24 19:23:39 +00001307 if (GO->hasComdat())
1308 ComdatGV = getComdatGVForCOFF(GO);
David Majnemerdad0a642014-06-27 18:19:56 +00001309 else
Peter Collingbourne67335642016-10-24 19:23:39 +00001310 ComdatGV = GO;
David Majnemerdad0a642014-06-27 18:19:56 +00001311
Reid Kleckner97837b72016-05-02 23:22:18 +00001312 unsigned UniqueID = MCContext::GenericSectionID;
1313 if (EmitUniquedSection)
1314 UniqueID = NextUniqueID++;
1315
David Majnemerdad0a642014-06-27 18:19:56 +00001316 if (!ComdatGV->hasPrivateLinkage()) {
Tim Northoverb64fb452016-11-22 16:17:20 +00001317 MCSymbol *Sym = TM.getSymbol(ComdatGV);
David Majnemerdad0a642014-06-27 18:19:56 +00001318 StringRef COMDATSymName = Sym->getName();
Reid Kleckner2ef48662018-06-21 23:06:33 +00001319
1320 // Append "$symbol" to the section name when targetting mingw. The ld.bfd
1321 // COFF linker will not properly handle comdats otherwise.
1322 if (getTargetTriple().isWindowsGNUEnvironment())
1323 raw_svector_ostream(Name) << '$' << COMDATSymName;
1324
David Majnemerdad0a642014-06-27 18:19:56 +00001325 return getContext().getCOFFSection(Name, Characteristics, Kind,
Reid Kleckner97837b72016-05-02 23:22:18 +00001326 COMDATSymName, Selection, UniqueID);
David Majnemer7db449a2015-03-17 23:54:51 +00001327 } else {
1328 SmallString<256> TmpData;
Peter Collingbourne67335642016-10-24 19:23:39 +00001329 getMangler().getNameWithPrefix(TmpData, GO, /*CannotUsePrivateLabel=*/true);
David Majnemer7db449a2015-03-17 23:54:51 +00001330 return getContext().getCOFFSection(Name, Characteristics, Kind, TmpData,
Reid Kleckner97837b72016-05-02 23:22:18 +00001331 Selection, UniqueID);
David Majnemerdad0a642014-06-27 18:19:56 +00001332 }
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001333 }
1334
1335 if (Kind.isText())
David Majnemer3d96acb2013-08-13 01:23:53 +00001336 return TextSection;
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001337
Anton Korobeynikovc6b40172012-02-11 17:26:53 +00001338 if (Kind.isThreadLocal())
David Majnemer3d96acb2013-08-13 01:23:53 +00001339 return TLSDataSection;
Anton Korobeynikovc6b40172012-02-11 17:26:53 +00001340
David Majnemer597be2d2014-09-22 20:39:23 +00001341 if (Kind.isReadOnly() || Kind.isReadOnlyWithRel())
David Majnemerf76d6b32013-08-08 01:50:52 +00001342 return ReadOnlySection;
1343
David Majnemera9bdb322014-04-08 22:33:40 +00001344 // Note: we claim that common symbols are put in BSSSection, but they are
1345 // really emitted with the magic .comm directive, which creates a symbol table
1346 // entry but not a section.
1347 if (Kind.isBSS() || Kind.isCommon())
David Majnemer3d96acb2013-08-13 01:23:53 +00001348 return BSSSection;
1349
1350 return DataSection;
Anton Korobeynikovab663a02010-02-15 22:37:53 +00001351}
1352
David Majnemer7db449a2015-03-17 23:54:51 +00001353void TargetLoweringObjectFileCOFF::getNameWithPrefix(
Eric Christopher4367c7f2016-09-16 07:33:15 +00001354 SmallVectorImpl<char> &OutName, const GlobalValue *GV,
Peter Collingbourne94d77862015-11-03 23:40:03 +00001355 const TargetMachine &TM) const {
1356 bool CannotUsePrivateLabel = false;
David Majnemer7db449a2015-03-17 23:54:51 +00001357 if (GV->hasPrivateLinkage() &&
1358 ((isa<Function>(GV) && TM.getFunctionSections()) ||
1359 (isa<GlobalVariable>(GV) && TM.getDataSections())))
1360 CannotUsePrivateLabel = true;
1361
Eric Christopher4367c7f2016-09-16 07:33:15 +00001362 getMangler().getNameWithPrefix(OutName, GV, CannotUsePrivateLabel);
David Majnemer7db449a2015-03-17 23:54:51 +00001363}
1364
Rafael Espindola0709a7b2015-05-21 19:20:38 +00001365MCSection *TargetLoweringObjectFileCOFF::getSectionForJumpTable(
Eric Christopher4367c7f2016-09-16 07:33:15 +00001366 const Function &F, const TargetMachine &TM) const {
Rafael Espindolaab447e42015-03-11 19:58:37 +00001367 // If the function can be removed, produce a unique section so that
1368 // the table doesn't prevent the removal.
1369 const Comdat *C = F.getComdat();
1370 bool EmitUniqueSection = TM.getFunctionSections() || C;
1371 if (!EmitUniqueSection)
1372 return ReadOnlySection;
1373
1374 // FIXME: we should produce a symbol for F instead.
1375 if (F.hasPrivateLinkage())
1376 return ReadOnlySection;
1377
Tim Northoverb64fb452016-11-22 16:17:20 +00001378 MCSymbol *Sym = TM.getSymbol(&F);
Rafael Espindolaab447e42015-03-11 19:58:37 +00001379 StringRef COMDATSymName = Sym->getName();
1380
1381 SectionKind Kind = SectionKind::getReadOnly();
Reid Kleckner13c9ee62018-06-21 20:27:38 +00001382 StringRef SecName = getCOFFSectionNameForUniqueGlobal(Kind);
Renato Golinef3eb062016-06-27 14:42:20 +00001383 unsigned Characteristics = getCOFFSectionFlags(Kind, TM);
Rafael Espindolaab447e42015-03-11 19:58:37 +00001384 Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
Reid Kleckner97837b72016-05-02 23:22:18 +00001385 unsigned UniqueID = NextUniqueID++;
Rafael Espindolaab447e42015-03-11 19:58:37 +00001386
Reid Kleckner13c9ee62018-06-21 20:27:38 +00001387 return getContext().getCOFFSection(
1388 SecName, Characteristics, Kind, COMDATSymName,
1389 COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE, UniqueID);
Rafael Espindolaab447e42015-03-11 19:58:37 +00001390}
1391
Eric Christopheraadbabc2018-04-20 19:07:57 +00001392void TargetLoweringObjectFileCOFF::emitModuleMetadata(MCStreamer &Streamer,
1393 Module &M) const {
Peter Collingbourne89061b22017-06-12 20:10:48 +00001394 if (NamedMDNode *LinkerOptions = M.getNamedMetadata("llvm.linker.options")) {
Saleem Abdulrasoole0f0c0e2016-04-30 18:15:34 +00001395 // Emit the linker options to the linker .drectve section. According to the
1396 // spec, this section is a space-separated string containing flags for
1397 // linker.
1398 MCSection *Sec = getDrectveSection();
1399 Streamer.SwitchSection(Sec);
1400 for (const auto &Option : LinkerOptions->operands()) {
1401 for (const auto &Piece : cast<MDNode>(Option)->operands()) {
1402 // Lead with a space for consistency with our dllexport implementation.
1403 std::string Directive(" ");
1404 Directive.append(cast<MDString>(Piece)->getString());
1405 Streamer.EmitBytes(Directive);
1406 }
Reid Klecknerd973ca32013-04-25 19:34:41 +00001407 }
1408 }
Saleem Abdulrasool4c474342017-06-05 21:26:39 +00001409
1410 unsigned Version = 0;
1411 unsigned Flags = 0;
1412 StringRef Section;
1413
Peter Collingbourne89061b22017-06-12 20:10:48 +00001414 GetObjCImageInfo(M, Version, Flags, Section);
Saleem Abdulrasool4c474342017-06-05 21:26:39 +00001415 if (Section.empty())
1416 return;
1417
1418 auto &C = getContext();
1419 auto *S = C.getCOFFSection(
1420 Section, COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
1421 SectionKind::getReadOnly());
1422 Streamer.SwitchSection(S);
1423 Streamer.EmitLabel(C.getOrCreateSymbol(StringRef("OBJC_IMAGE_INFO")));
1424 Streamer.EmitIntValue(Version, 4);
1425 Streamer.EmitIntValue(Flags, 4);
1426 Streamer.AddBlankLine();
Reid Klecknerd973ca32013-04-25 19:34:41 +00001427}
Reid Klecknerfceb76f2014-05-16 20:39:27 +00001428
Rafael Espindola46fa2312016-08-29 12:33:42 +00001429void TargetLoweringObjectFileCOFF::Initialize(MCContext &Ctx,
1430 const TargetMachine &TM) {
1431 TargetLoweringObjectFile::Initialize(Ctx, TM);
1432 const Triple &T = TM.getTargetTriple();
1433 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
1434 StaticCtorSection =
1435 Ctx.getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1436 COFF::IMAGE_SCN_MEM_READ,
1437 SectionKind::getReadOnly());
1438 StaticDtorSection =
1439 Ctx.getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1440 COFF::IMAGE_SCN_MEM_READ,
1441 SectionKind::getReadOnly());
1442 } else {
1443 StaticCtorSection = Ctx.getCOFFSection(
1444 ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1445 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
1446 SectionKind::getData());
1447 StaticDtorSection = Ctx.getCOFFSection(
1448 ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1449 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
1450 SectionKind::getData());
1451 }
1452}
1453
Martin Storsjo04b68442017-11-28 08:07:18 +00001454static MCSectionCOFF *getCOFFStaticStructorSection(MCContext &Ctx,
1455 const Triple &T, bool IsCtor,
1456 unsigned Priority,
1457 const MCSymbol *KeySym,
1458 MCSectionCOFF *Default) {
Reid Klecknerf803b232018-09-07 23:07:55 +00001459 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
1460 // If the priority is the default, use .CRT$XCU, possibly associative.
1461 if (Priority == 65535)
1462 return Ctx.getAssociativeCOFFSection(Default, KeySym, 0);
1463
1464 // Otherwise, we need to compute a new section name. Low priorities should
1465 // run earlier. The linker will sort sections ASCII-betically, and we need a
1466 // string that sorts between .CRT$XCA and .CRT$XCU. In the general case, we
1467 // make a name like ".CRT$XCT12345", since that runs before .CRT$XCU. Really
1468 // low priorities need to sort before 'L', since the CRT uses that
1469 // internally, so we use ".CRT$XCA00001" for them.
1470 SmallString<24> Name;
1471 raw_svector_ostream OS(Name);
1472 OS << ".CRT$XC" << (Priority < 200 ? 'A' : 'T') << format("%05u", Priority);
1473 MCSectionCOFF *Sec = Ctx.getCOFFSection(
1474 Name, COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
1475 SectionKind::getReadOnly());
1476 return Ctx.getAssociativeCOFFSection(Sec, KeySym, 0);
1477 }
Martin Storsjo04b68442017-11-28 08:07:18 +00001478
1479 std::string Name = IsCtor ? ".ctors" : ".dtors";
1480 if (Priority != 65535)
1481 raw_string_ostream(Name) << format(".%05u", 65535 - Priority);
1482
1483 return Ctx.getAssociativeCOFFSection(
1484 Ctx.getCOFFSection(Name, COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1485 COFF::IMAGE_SCN_MEM_READ |
1486 COFF::IMAGE_SCN_MEM_WRITE,
1487 SectionKind::getData()),
1488 KeySym, 0);
1489}
1490
Rafael Espindola0709a7b2015-05-21 19:20:38 +00001491MCSection *TargetLoweringObjectFileCOFF::getStaticCtorSection(
Rafael Espindola0766ae02014-06-06 19:26:12 +00001492 unsigned Priority, const MCSymbol *KeySym) const {
Martin Storsjo04b68442017-11-28 08:07:18 +00001493 return getCOFFStaticStructorSection(getContext(), getTargetTriple(), true,
1494 Priority, KeySym,
1495 cast<MCSectionCOFF>(StaticCtorSection));
Reid Klecknerfceb76f2014-05-16 20:39:27 +00001496}
1497
Rafael Espindola0709a7b2015-05-21 19:20:38 +00001498MCSection *TargetLoweringObjectFileCOFF::getStaticDtorSection(
Rafael Espindola0766ae02014-06-06 19:26:12 +00001499 unsigned Priority, const MCSymbol *KeySym) const {
Martin Storsjo04b68442017-11-28 08:07:18 +00001500 return getCOFFStaticStructorSection(getContext(), getTargetTriple(), false,
1501 Priority, KeySym,
1502 cast<MCSectionCOFF>(StaticDtorSection));
Reid Klecknerfceb76f2014-05-16 20:39:27 +00001503}
Peter Collingbourneaef36592015-06-29 22:04:09 +00001504
1505void TargetLoweringObjectFileCOFF::emitLinkerFlagsForGlobal(
Eric Christopher4367c7f2016-09-16 07:33:15 +00001506 raw_ostream &OS, const GlobalValue *GV) const {
Bob Haarmandd4ebc12017-02-02 23:00:49 +00001507 emitLinkerFlagsForGlobalCOFF(OS, GV, getTargetTriple(), getMangler());
Peter Collingbourneaef36592015-06-29 22:04:09 +00001508}
Dan Gohman18eafb62017-02-22 01:23:18 +00001509
Saleem Abdulrasool99f479a2018-01-20 00:28:02 +00001510void TargetLoweringObjectFileCOFF::emitLinkerFlagsForUsed(
1511 raw_ostream &OS, const GlobalValue *GV) const {
1512 emitLinkerFlagsForUsedCOFF(OS, GV, getTargetTriple(), getMangler());
1513}
1514
Reid Kleckner98117a42018-06-12 18:56:05 +00001515const MCExpr *TargetLoweringObjectFileCOFF::lowerRelativeReference(
1516 const GlobalValue *LHS, const GlobalValue *RHS,
1517 const TargetMachine &TM) const {
1518 const Triple &T = TM.getTargetTriple();
1519 if (!T.isKnownWindowsMSVCEnvironment() &&
1520 !T.isWindowsItaniumEnvironment() &&
1521 !T.isWindowsCoreCLREnvironment())
1522 return nullptr;
1523
1524 // Our symbols should exist in address space zero, cowardly no-op if
1525 // otherwise.
1526 if (LHS->getType()->getPointerAddressSpace() != 0 ||
1527 RHS->getType()->getPointerAddressSpace() != 0)
1528 return nullptr;
1529
1530 // Both ptrtoint instructions must wrap global objects:
1531 // - Only global variables are eligible for image relative relocations.
1532 // - The subtrahend refers to the special symbol __ImageBase, a GlobalVariable.
1533 // We expect __ImageBase to be a global variable without a section, externally
1534 // defined.
1535 //
1536 // It should look something like this: @__ImageBase = external constant i8
1537 if (!isa<GlobalObject>(LHS) || !isa<GlobalVariable>(RHS) ||
1538 LHS->isThreadLocal() || RHS->isThreadLocal() ||
1539 RHS->getName() != "__ImageBase" || !RHS->hasExternalLinkage() ||
1540 cast<GlobalVariable>(RHS)->hasInitializer() || RHS->hasSection())
1541 return nullptr;
1542
1543 return MCSymbolRefExpr::create(TM.getSymbol(LHS),
1544 MCSymbolRefExpr::VK_COFF_IMGREL32,
1545 getContext());
1546}
1547
1548static std::string APIntToHexString(const APInt &AI) {
1549 unsigned Width = (AI.getBitWidth() / 8) * 2;
1550 std::string HexString = utohexstr(AI.getLimitedValue(), /*LowerCase=*/true);
1551 unsigned Size = HexString.size();
1552 assert(Width >= Size && "hex string is too large!");
1553 HexString.insert(HexString.begin(), Width - Size, '0');
1554
1555 return HexString;
1556}
1557
1558static std::string scalarConstantToHexString(const Constant *C) {
1559 Type *Ty = C->getType();
1560 if (isa<UndefValue>(C)) {
1561 return APIntToHexString(APInt::getNullValue(Ty->getPrimitiveSizeInBits()));
1562 } else if (const auto *CFP = dyn_cast<ConstantFP>(C)) {
1563 return APIntToHexString(CFP->getValueAPF().bitcastToAPInt());
1564 } else if (const auto *CI = dyn_cast<ConstantInt>(C)) {
1565 return APIntToHexString(CI->getValue());
1566 } else {
1567 unsigned NumElements;
1568 if (isa<VectorType>(Ty))
1569 NumElements = Ty->getVectorNumElements();
1570 else
1571 NumElements = Ty->getArrayNumElements();
1572 std::string HexString;
1573 for (int I = NumElements - 1, E = -1; I != E; --I)
1574 HexString += scalarConstantToHexString(C->getAggregateElement(I));
1575 return HexString;
1576 }
1577}
1578
1579MCSection *TargetLoweringObjectFileCOFF::getSectionForConstant(
1580 const DataLayout &DL, SectionKind Kind, const Constant *C,
1581 unsigned &Align) const {
Martin Storsjo9dafd6f2018-07-26 10:48:20 +00001582 if (Kind.isMergeableConst() && C &&
1583 getContext().getAsmInfo()->hasCOFFComdatConstants()) {
1584 // This creates comdat sections with the given symbol name, but unless
1585 // AsmPrinter::GetCPISymbol actually makes the symbol global, the symbol
1586 // will be created with a null storage class, which makes GNU binutils
1587 // error out.
Reid Kleckner98117a42018-06-12 18:56:05 +00001588 const unsigned Characteristics = COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
1589 COFF::IMAGE_SCN_MEM_READ |
1590 COFF::IMAGE_SCN_LNK_COMDAT;
1591 std::string COMDATSymName;
1592 if (Kind.isMergeableConst4()) {
1593 if (Align <= 4) {
1594 COMDATSymName = "__real@" + scalarConstantToHexString(C);
1595 Align = 4;
1596 }
1597 } else if (Kind.isMergeableConst8()) {
1598 if (Align <= 8) {
1599 COMDATSymName = "__real@" + scalarConstantToHexString(C);
1600 Align = 8;
1601 }
1602 } else if (Kind.isMergeableConst16()) {
1603 // FIXME: These may not be appropriate for non-x86 architectures.
1604 if (Align <= 16) {
1605 COMDATSymName = "__xmm@" + scalarConstantToHexString(C);
1606 Align = 16;
1607 }
1608 } else if (Kind.isMergeableConst32()) {
1609 if (Align <= 32) {
1610 COMDATSymName = "__ymm@" + scalarConstantToHexString(C);
1611 Align = 32;
1612 }
1613 }
1614
1615 if (!COMDATSymName.empty())
1616 return getContext().getCOFFSection(".rdata", Characteristics, Kind,
1617 COMDATSymName,
1618 COFF::IMAGE_COMDAT_SELECT_ANY);
1619 }
1620
1621 return TargetLoweringObjectFile::getSectionForConstant(DL, Kind, C, Align);
1622}
1623
1624
Dan Gohman18eafb62017-02-22 01:23:18 +00001625//===----------------------------------------------------------------------===//
1626// Wasm
1627//===----------------------------------------------------------------------===//
1628
Sam Cleggea7cace2018-01-09 23:43:14 +00001629static const Comdat *getWasmComdat(const GlobalValue *GV) {
Dan Gohmand934cb82017-02-24 23:18:00 +00001630 const Comdat *C = GV->getComdat();
1631 if (!C)
Sam Cleggea7cace2018-01-09 23:43:14 +00001632 return nullptr;
Dan Gohmand934cb82017-02-24 23:18:00 +00001633
Sam Cleggea7cace2018-01-09 23:43:14 +00001634 if (C->getSelectionKind() != Comdat::Any)
1635 report_fatal_error("WebAssembly COMDATs only support "
1636 "SelectionKind::Any, '" + C->getName() + "' cannot be "
1637 "lowered.");
1638
1639 return C;
Dan Gohmand934cb82017-02-24 23:18:00 +00001640}
1641
Sam Clegge1694f92017-12-07 02:55:51 +00001642static SectionKind getWasmKindForNamedSection(StringRef Name, SectionKind K) {
1643 // If we're told we have function data, then use that.
1644 if (K.isText())
1645 return SectionKind::getText();
1646
1647 // Otherwise, ignore whatever section type the generic impl detected and use
1648 // a plain data section.
1649 return SectionKind::getData();
1650}
1651
Dan Gohman18eafb62017-02-22 01:23:18 +00001652MCSection *TargetLoweringObjectFileWasm::getExplicitSectionGlobal(
1653 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
Sam Clegg277f8982018-06-14 18:48:19 +00001654 // We don't support explict section names for functions in the wasm object
1655 // format. Each function has to be in its own unique section.
1656 if (isa<Function>(GO)) {
1657 return SelectSectionForGlobal(GO, Kind, TM);
1658 }
1659
Sam Clegg759631c2017-09-15 20:54:59 +00001660 StringRef Name = GO->getSection();
Sam Cleggea7cace2018-01-09 23:43:14 +00001661
Sam Clegge1694f92017-12-07 02:55:51 +00001662 Kind = getWasmKindForNamedSection(Name, Kind);
Sam Cleggea7cace2018-01-09 23:43:14 +00001663
1664 StringRef Group = "";
1665 if (const Comdat *C = getWasmComdat(GO)) {
1666 Group = C->getName();
1667 }
1668
1669 return getContext().getWasmSection(Name, Kind, Group,
1670 MCContext::GenericSectionID);
Dan Gohman18eafb62017-02-22 01:23:18 +00001671}
1672
Sam Clegg2176a9f2017-09-12 18:31:24 +00001673static MCSectionWasm *selectWasmSectionForGlobal(
1674 MCContext &Ctx, const GlobalObject *GO, SectionKind Kind, Mangler &Mang,
1675 const TargetMachine &TM, bool EmitUniqueSection, unsigned *NextUniqueID) {
Dan Gohmand934cb82017-02-24 23:18:00 +00001676 StringRef Group = "";
Sam Cleggea7cace2018-01-09 23:43:14 +00001677 if (const Comdat *C = getWasmComdat(GO)) {
1678 Group = C->getName();
1679 }
Dan Gohmand934cb82017-02-24 23:18:00 +00001680
1681 bool UniqueSectionNames = TM.getUniqueSectionNames();
1682 SmallString<128> Name = getSectionPrefixForGlobal(Kind);
1683
1684 if (const auto *F = dyn_cast<Function>(GO)) {
1685 const auto &OptionalPrefix = F->getSectionPrefix();
1686 if (OptionalPrefix)
1687 Name += *OptionalPrefix;
1688 }
1689
1690 if (EmitUniqueSection && UniqueSectionNames) {
1691 Name.push_back('.');
1692 TM.getNameWithPrefix(Name, GO, Mang, true);
1693 }
1694 unsigned UniqueID = MCContext::GenericSectionID;
1695 if (EmitUniqueSection && !UniqueSectionNames) {
1696 UniqueID = *NextUniqueID;
1697 (*NextUniqueID)++;
1698 }
Sam Clegg12fd3da2017-10-20 21:28:38 +00001699 return Ctx.getWasmSection(Name, Kind, Group, UniqueID);
Dan Gohmand934cb82017-02-24 23:18:00 +00001700}
1701
Dan Gohman18eafb62017-02-22 01:23:18 +00001702MCSection *TargetLoweringObjectFileWasm::SelectSectionForGlobal(
1703 const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
Dan Gohmand934cb82017-02-24 23:18:00 +00001704
1705 if (Kind.isCommon())
1706 report_fatal_error("mergable sections not supported yet on wasm");
1707
1708 // If we have -ffunction-section or -fdata-section then we should emit the
1709 // global value to a uniqued section specifically for it.
1710 bool EmitUniqueSection = false;
Dan Gohman18eafb62017-02-22 01:23:18 +00001711 if (Kind.isText())
Dan Gohmand934cb82017-02-24 23:18:00 +00001712 EmitUniqueSection = TM.getFunctionSections();
1713 else
1714 EmitUniqueSection = TM.getDataSections();
1715 EmitUniqueSection |= GO->hasComdat();
1716
1717 return selectWasmSectionForGlobal(getContext(), GO, Kind, getMangler(), TM,
Sam Clegg2176a9f2017-09-12 18:31:24 +00001718 EmitUniqueSection, &NextUniqueID);
Dan Gohman18eafb62017-02-22 01:23:18 +00001719}
1720
1721bool TargetLoweringObjectFileWasm::shouldPutJumpTableInFunctionSection(
1722 bool UsesLabelDifference, const Function &F) const {
1723 // We can always create relative relocations, so use another section
1724 // that can be marked non-executable.
1725 return false;
1726}
1727
1728const MCExpr *TargetLoweringObjectFileWasm::lowerRelativeReference(
1729 const GlobalValue *LHS, const GlobalValue *RHS,
1730 const TargetMachine &TM) const {
1731 // We may only use a PLT-relative relocation to refer to unnamed_addr
1732 // functions.
1733 if (!LHS->hasGlobalUnnamedAddr() || !LHS->getValueType()->isFunctionTy())
1734 return nullptr;
1735
1736 // Basic sanity checks.
1737 if (LHS->getType()->getPointerAddressSpace() != 0 ||
1738 RHS->getType()->getPointerAddressSpace() != 0 || LHS->isThreadLocal() ||
1739 RHS->isThreadLocal())
1740 return nullptr;
1741
1742 return MCBinaryExpr::createSub(
1743 MCSymbolRefExpr::create(TM.getSymbol(LHS), MCSymbolRefExpr::VK_None,
1744 getContext()),
1745 MCSymbolRefExpr::create(TM.getSymbol(RHS), getContext()), getContext());
1746}
1747
Sam Cleggb2b019f2017-10-03 11:20:28 +00001748void TargetLoweringObjectFileWasm::InitializeWasm() {
1749 StaticCtorSection =
Sam Clegg12fd3da2017-10-20 21:28:38 +00001750 getContext().getWasmSection(".init_array", SectionKind::getData());
Sam Cleggbafe6902017-12-15 00:17:10 +00001751}
1752
1753MCSection *TargetLoweringObjectFileWasm::getStaticCtorSection(
1754 unsigned Priority, const MCSymbol *KeySym) const {
1755 return Priority == UINT16_MAX ?
1756 StaticCtorSection :
1757 getContext().getWasmSection(".init_array." + utostr(Priority),
1758 SectionKind::getData());
1759}
1760
1761MCSection *TargetLoweringObjectFileWasm::getStaticDtorSection(
1762 unsigned Priority, const MCSymbol *KeySym) const {
1763 llvm_unreachable("@llvm.global_dtors should have been lowered already");
1764 return nullptr;
Dan Gohman18eafb62017-02-22 01:23:18 +00001765}