1 //===-- llvm/CodeGen/TargetLoweringObjectFileImpl.cpp - Object File Info --===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements classes used to handle lowerings specific to common
11 // object file formats.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/ADT/StringExtras.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
20 #include "llvm/IR/Constants.h"
21 #include "llvm/IR/DataLayout.h"
22 #include "llvm/IR/DerivedTypes.h"
23 #include "llvm/IR/Function.h"
24 #include "llvm/IR/GlobalVariable.h"
25 #include "llvm/IR/Module.h"
26 #include "llvm/MC/MCContext.h"
27 #include "llvm/MC/MCExpr.h"
28 #include "llvm/MC/MCSectionCOFF.h"
29 #include "llvm/MC/MCSectionELF.h"
30 #include "llvm/MC/MCSectionMachO.h"
31 #include "llvm/MC/MCStreamer.h"
32 #include "llvm/MC/MCSymbol.h"
33 #include "llvm/Support/Dwarf.h"
34 #include "llvm/Support/ELF.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include "llvm/Target/Mangler.h"
38 #include "llvm/Target/TargetMachine.h"
39 #include "llvm/Target/TargetOptions.h"
41 using namespace dwarf;
43 //===----------------------------------------------------------------------===//
45 //===----------------------------------------------------------------------===//
48 TargetLoweringObjectFileELF::getCFIPersonalitySymbol(const GlobalValue *GV,
50 MachineModuleInfo *MMI) const {
51 unsigned Encoding = getPersonalityEncoding();
52 switch (Encoding & 0x70) {
54 report_fatal_error("We do not support this DWARF encoding yet!");
55 case dwarf::DW_EH_PE_absptr:
56 return Mang->getSymbol(GV);
57 case dwarf::DW_EH_PE_pcrel: {
58 return getContext().GetOrCreateSymbol(StringRef("DW.ref.") +
59 Mang->getSymbol(GV)->getName());
64 void TargetLoweringObjectFileELF::emitPersonalityValue(MCStreamer &Streamer,
65 const TargetMachine &TM,
66 const MCSymbol *Sym) const {
67 SmallString<64> NameData("DW.ref.");
68 NameData += Sym->getName();
69 MCSymbol *Label = getContext().GetOrCreateSymbol(NameData);
70 Streamer.EmitSymbolAttribute(Label, MCSA_Hidden);
71 Streamer.EmitSymbolAttribute(Label, MCSA_Weak);
72 StringRef Prefix = ".data.";
73 NameData.insert(NameData.begin(), Prefix.begin(), Prefix.end());
74 unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE | ELF::SHF_GROUP;
75 const MCSection *Sec = getContext().getELFSection(NameData,
78 SectionKind::getDataRel(),
80 unsigned Size = TM.getDataLayout()->getPointerSize();
81 Streamer.SwitchSection(Sec);
82 Streamer.EmitValueToAlignment(TM.getDataLayout()->getPointerABIAlignment());
83 Streamer.EmitSymbolAttribute(Label, MCSA_ELF_TypeObject);
84 const MCExpr *E = MCConstantExpr::Create(Size, getContext());
85 Streamer.EmitELFSize(Label, E);
86 Streamer.EmitLabel(Label);
88 Streamer.EmitSymbolValue(Sym, Size);
91 const MCExpr *TargetLoweringObjectFileELF::
92 getTTypeGlobalReference(const GlobalValue *GV, Mangler *Mang,
93 MachineModuleInfo *MMI, unsigned Encoding,
94 MCStreamer &Streamer) const {
96 if (Encoding & dwarf::DW_EH_PE_indirect) {
97 MachineModuleInfoELF &ELFMMI = MMI->getObjFileInfo<MachineModuleInfoELF>();
99 SmallString<128> Name;
100 Mang->getNameWithPrefix(Name, GV, true);
103 // Add information about the stub reference to ELFMMI so that the stub
104 // gets emitted by the asmprinter.
105 MCSymbol *SSym = getContext().GetOrCreateSymbol(Name.str());
106 MachineModuleInfoImpl::StubValueTy &StubSym = ELFMMI.getGVStubEntry(SSym);
107 if (StubSym.getPointer() == 0) {
108 MCSymbol *Sym = Mang->getSymbol(GV);
109 StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
112 return TargetLoweringObjectFile::
113 getTTypeReference(MCSymbolRefExpr::Create(SSym, getContext()),
114 Encoding & ~dwarf::DW_EH_PE_indirect, Streamer);
117 return TargetLoweringObjectFile::
118 getTTypeGlobalReference(GV, Mang, MMI, Encoding, Streamer);
122 getELFKindForNamedSection(StringRef Name, SectionKind K) {
123 // N.B.: The defaults used in here are no the same ones used in MC.
124 // We follow gcc, MC follows gas. For example, given ".section .eh_frame",
125 // both gas and MC will produce a section with no flags. Given
126 // section(".eh_frame") gcc will produce:
128 // .section .eh_frame,"a",@progbits
129 if (Name.empty() || Name[0] != '.') return K;
131 // Some lame default implementation based on some magic section names.
132 if (Name == ".bss" ||
133 Name.startswith(".bss.") ||
134 Name.startswith(".gnu.linkonce.b.") ||
135 Name.startswith(".llvm.linkonce.b.") ||
137 Name.startswith(".sbss.") ||
138 Name.startswith(".gnu.linkonce.sb.") ||
139 Name.startswith(".llvm.linkonce.sb."))
140 return SectionKind::getBSS();
142 if (Name == ".tdata" ||
143 Name.startswith(".tdata.") ||
144 Name.startswith(".gnu.linkonce.td.") ||
145 Name.startswith(".llvm.linkonce.td."))
146 return SectionKind::getThreadData();
148 if (Name == ".tbss" ||
149 Name.startswith(".tbss.") ||
150 Name.startswith(".gnu.linkonce.tb.") ||
151 Name.startswith(".llvm.linkonce.tb."))
152 return SectionKind::getThreadBSS();
158 static unsigned getELFSectionType(StringRef Name, SectionKind K) {
160 if (Name == ".init_array")
161 return ELF::SHT_INIT_ARRAY;
163 if (Name == ".fini_array")
164 return ELF::SHT_FINI_ARRAY;
166 if (Name == ".preinit_array")
167 return ELF::SHT_PREINIT_ARRAY;
169 if (K.isBSS() || K.isThreadBSS())
170 return ELF::SHT_NOBITS;
172 return ELF::SHT_PROGBITS;
177 getELFSectionFlags(SectionKind K) {
181 Flags |= ELF::SHF_ALLOC;
184 Flags |= ELF::SHF_EXECINSTR;
187 Flags |= ELF::SHF_WRITE;
189 if (K.isThreadLocal())
190 Flags |= ELF::SHF_TLS;
192 // K.isMergeableConst() is left out to honour PR4650
193 if (K.isMergeableCString() || K.isMergeableConst4() ||
194 K.isMergeableConst8() || K.isMergeableConst16())
195 Flags |= ELF::SHF_MERGE;
197 if (K.isMergeableCString())
198 Flags |= ELF::SHF_STRINGS;
204 const MCSection *TargetLoweringObjectFileELF::
205 getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
206 Mangler *Mang, const TargetMachine &TM) const {
207 StringRef SectionName = GV->getSection();
209 // Infer section flags from the section name if we can.
210 Kind = getELFKindForNamedSection(SectionName, Kind);
212 return getContext().getELFSection(SectionName,
213 getELFSectionType(SectionName, Kind),
214 getELFSectionFlags(Kind), Kind);
217 /// getSectionPrefixForGlobal - Return the section prefix name used by options
218 /// FunctionsSections and DataSections.
219 static const char *getSectionPrefixForGlobal(SectionKind Kind) {
220 if (Kind.isText()) return ".text.";
221 if (Kind.isReadOnly()) return ".rodata.";
222 if (Kind.isBSS()) return ".bss.";
224 if (Kind.isThreadData()) return ".tdata.";
225 if (Kind.isThreadBSS()) return ".tbss.";
227 if (Kind.isDataNoRel()) return ".data.";
228 if (Kind.isDataRelLocal()) return ".data.rel.local.";
229 if (Kind.isDataRel()) return ".data.rel.";
230 if (Kind.isReadOnlyWithRelLocal()) return ".data.rel.ro.local.";
232 assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
233 return ".data.rel.ro.";
237 const MCSection *TargetLoweringObjectFileELF::
238 SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
239 Mangler *Mang, const TargetMachine &TM) const {
240 // If we have -ffunction-section or -fdata-section then we should emit the
241 // global value to a uniqued section specifically for it.
242 bool EmitUniquedSection;
244 EmitUniquedSection = TM.getFunctionSections();
246 EmitUniquedSection = TM.getDataSections();
248 // If this global is linkonce/weak and the target handles this by emitting it
249 // into a 'uniqued' section name, create and return the section now.
250 if ((GV->isWeakForLinker() || EmitUniquedSection) &&
253 Prefix = getSectionPrefixForGlobal(Kind);
255 SmallString<128> Name(Prefix, Prefix+strlen(Prefix));
256 MCSymbol *Sym = Mang->getSymbol(GV);
257 Name.append(Sym->getName().begin(), Sym->getName().end());
258 StringRef Group = "";
259 unsigned Flags = getELFSectionFlags(Kind);
260 if (GV->isWeakForLinker()) {
261 Group = Sym->getName();
262 Flags |= ELF::SHF_GROUP;
265 return getContext().getELFSection(Name.str(),
266 getELFSectionType(Name.str(), Kind),
267 Flags, Kind, 0, Group);
270 if (Kind.isText()) return TextSection;
272 if (Kind.isMergeable1ByteCString() ||
273 Kind.isMergeable2ByteCString() ||
274 Kind.isMergeable4ByteCString()) {
276 // We also need alignment here.
277 // FIXME: this is getting the alignment of the character, not the
278 // alignment of the global!
280 TM.getDataLayout()->getPreferredAlignment(cast<GlobalVariable>(GV));
282 const char *SizeSpec = ".rodata.str1.";
283 if (Kind.isMergeable2ByteCString())
284 SizeSpec = ".rodata.str2.";
285 else if (Kind.isMergeable4ByteCString())
286 SizeSpec = ".rodata.str4.";
288 assert(Kind.isMergeable1ByteCString() && "unknown string width");
291 std::string Name = SizeSpec + utostr(Align);
292 return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
299 if (Kind.isMergeableConst()) {
300 if (Kind.isMergeableConst4() && MergeableConst4Section)
301 return MergeableConst4Section;
302 if (Kind.isMergeableConst8() && MergeableConst8Section)
303 return MergeableConst8Section;
304 if (Kind.isMergeableConst16() && MergeableConst16Section)
305 return MergeableConst16Section;
306 return ReadOnlySection; // .const
309 if (Kind.isReadOnly()) return ReadOnlySection;
311 if (Kind.isThreadData()) return TLSDataSection;
312 if (Kind.isThreadBSS()) return TLSBSSSection;
314 // Note: we claim that common symbols are put in BSSSection, but they are
315 // really emitted with the magic .comm directive, which creates a symbol table
316 // entry but not a section.
317 if (Kind.isBSS() || Kind.isCommon()) return BSSSection;
319 if (Kind.isDataNoRel()) return DataSection;
320 if (Kind.isDataRelLocal()) return DataRelLocalSection;
321 if (Kind.isDataRel()) return DataRelSection;
322 if (Kind.isReadOnlyWithRelLocal()) return DataRelROLocalSection;
324 assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
325 return DataRelROSection;
328 /// getSectionForConstant - Given a mergeable constant with the
329 /// specified size and relocation information, return a section that it
330 /// should be placed in.
331 const MCSection *TargetLoweringObjectFileELF::
332 getSectionForConstant(SectionKind Kind) const {
333 if (Kind.isMergeableConst4() && MergeableConst4Section)
334 return MergeableConst4Section;
335 if (Kind.isMergeableConst8() && MergeableConst8Section)
336 return MergeableConst8Section;
337 if (Kind.isMergeableConst16() && MergeableConst16Section)
338 return MergeableConst16Section;
339 if (Kind.isReadOnly())
340 return ReadOnlySection;
342 if (Kind.isReadOnlyWithRelLocal()) return DataRelROLocalSection;
343 assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
344 return DataRelROSection;
348 TargetLoweringObjectFileELF::getStaticCtorSection(unsigned Priority) const {
349 // The default scheme is .ctor / .dtor, so we have to invert the priority
351 if (Priority == 65535)
352 return StaticCtorSection;
355 std::string Name = std::string(".init_array.") + utostr(Priority);
356 return getContext().getELFSection(Name, ELF::SHT_INIT_ARRAY,
357 ELF::SHF_ALLOC | ELF::SHF_WRITE,
358 SectionKind::getDataRel());
360 std::string Name = std::string(".ctors.") + utostr(65535 - Priority);
361 return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
362 ELF::SHF_ALLOC |ELF::SHF_WRITE,
363 SectionKind::getDataRel());
368 TargetLoweringObjectFileELF::getStaticDtorSection(unsigned Priority) const {
369 // The default scheme is .ctor / .dtor, so we have to invert the priority
371 if (Priority == 65535)
372 return StaticDtorSection;
375 std::string Name = std::string(".fini_array.") + utostr(Priority);
376 return getContext().getELFSection(Name, ELF::SHT_FINI_ARRAY,
377 ELF::SHF_ALLOC | ELF::SHF_WRITE,
378 SectionKind::getDataRel());
380 std::string Name = std::string(".dtors.") + utostr(65535 - Priority);
381 return getContext().getELFSection(Name, ELF::SHT_PROGBITS,
382 ELF::SHF_ALLOC |ELF::SHF_WRITE,
383 SectionKind::getDataRel());
388 TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) {
389 UseInitArray = UseInitArray_;
394 getContext().getELFSection(".init_array", ELF::SHT_INIT_ARRAY,
397 SectionKind::getDataRel());
399 getContext().getELFSection(".fini_array", ELF::SHT_FINI_ARRAY,
402 SectionKind::getDataRel());
405 //===----------------------------------------------------------------------===//
407 //===----------------------------------------------------------------------===//
409 /// emitModuleFlags - Emit the module flags that specify the garbage collection
411 void TargetLoweringObjectFileMachO::
412 emitModuleFlags(MCStreamer &Streamer,
413 ArrayRef<Module::ModuleFlagEntry> ModuleFlags,
414 Mangler *Mang, const TargetMachine &TM) const {
415 unsigned VersionVal = 0;
416 unsigned ImageInfoFlags = 0;
417 StringRef SectionVal;
419 for (ArrayRef<Module::ModuleFlagEntry>::iterator
420 i = ModuleFlags.begin(), e = ModuleFlags.end(); i != e; ++i) {
421 const Module::ModuleFlagEntry &MFE = *i;
423 // Ignore flags with 'Require' behavior.
424 if (MFE.Behavior == Module::Require)
427 StringRef Key = MFE.Key->getString();
428 Value *Val = MFE.Val;
430 if (Key == "Objective-C Image Info Version")
431 VersionVal = cast<ConstantInt>(Val)->getZExtValue();
432 else if (Key == "Objective-C Garbage Collection" ||
433 Key == "Objective-C GC Only" ||
434 Key == "Objective-C Is Simulated")
435 ImageInfoFlags |= cast<ConstantInt>(Val)->getZExtValue();
436 else if (Key == "Objective-C Image Info Section")
437 SectionVal = cast<MDString>(Val)->getString();
440 // The section is mandatory. If we don't have it, then we don't have GC info.
441 if (SectionVal.empty()) return;
443 StringRef Segment, Section;
444 unsigned TAA = 0, StubSize = 0;
446 std::string ErrorCode =
447 MCSectionMachO::ParseSectionSpecifier(SectionVal, Segment, Section,
448 TAA, TAAParsed, StubSize);
449 if (!ErrorCode.empty())
450 // If invalid, report the error with report_fatal_error.
451 report_fatal_error("Invalid section specifier '" + Section + "': " +
455 const MCSectionMachO *S =
456 getContext().getMachOSection(Segment, Section, TAA, StubSize,
457 SectionKind::getDataNoRel());
458 Streamer.SwitchSection(S);
459 Streamer.EmitLabel(getContext().
460 GetOrCreateSymbol(StringRef("L_OBJC_IMAGE_INFO")));
461 Streamer.EmitIntValue(VersionVal, 4);
462 Streamer.EmitIntValue(ImageInfoFlags, 4);
463 Streamer.AddBlankLine();
466 const MCSection *TargetLoweringObjectFileMachO::
467 getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
468 Mangler *Mang, const TargetMachine &TM) const {
469 // Parse the section specifier and create it if valid.
470 StringRef Segment, Section;
471 unsigned TAA = 0, StubSize = 0;
473 std::string ErrorCode =
474 MCSectionMachO::ParseSectionSpecifier(GV->getSection(), Segment, Section,
475 TAA, TAAParsed, StubSize);
476 if (!ErrorCode.empty()) {
477 // If invalid, report the error with report_fatal_error.
478 report_fatal_error("Global variable '" + GV->getName() +
479 "' has an invalid section specifier '" +
480 GV->getSection() + "': " + ErrorCode + ".");
484 const MCSectionMachO *S =
485 getContext().getMachOSection(Segment, Section, TAA, StubSize, Kind);
487 // If TAA wasn't set by ParseSectionSpecifier() above,
488 // use the value returned by getMachOSection() as a default.
490 TAA = S->getTypeAndAttributes();
492 // Okay, now that we got the section, verify that the TAA & StubSize agree.
493 // If the user declared multiple globals with different section flags, we need
494 // to reject it here.
495 if (S->getTypeAndAttributes() != TAA || S->getStubSize() != StubSize) {
496 // If invalid, report the error with report_fatal_error.
497 report_fatal_error("Global variable '" + GV->getName() +
498 "' section type or attributes does not match previous"
499 " section specifier");
505 const MCSection *TargetLoweringObjectFileMachO::
506 SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
507 Mangler *Mang, const TargetMachine &TM) const {
509 // Handle thread local data.
510 if (Kind.isThreadBSS()) return TLSBSSSection;
511 if (Kind.isThreadData()) return TLSDataSection;
514 return GV->isWeakForLinker() ? TextCoalSection : TextSection;
516 // If this is weak/linkonce, put this in a coalescable section, either in text
517 // or data depending on if it is writable.
518 if (GV->isWeakForLinker()) {
519 if (Kind.isReadOnly())
520 return ConstTextCoalSection;
521 return DataCoalSection;
524 // FIXME: Alignment check should be handled by section classifier.
525 if (Kind.isMergeable1ByteCString() &&
526 TM.getDataLayout()->getPreferredAlignment(cast<GlobalVariable>(GV)) < 32)
527 return CStringSection;
529 // Do not put 16-bit arrays in the UString section if they have an
530 // externally visible label, this runs into issues with certain linker
532 if (Kind.isMergeable2ByteCString() && !GV->hasExternalLinkage() &&
533 TM.getDataLayout()->getPreferredAlignment(cast<GlobalVariable>(GV)) < 32)
534 return UStringSection;
536 if (Kind.isMergeableConst()) {
537 if (Kind.isMergeableConst4())
538 return FourByteConstantSection;
539 if (Kind.isMergeableConst8())
540 return EightByteConstantSection;
541 if (Kind.isMergeableConst16() && SixteenByteConstantSection)
542 return SixteenByteConstantSection;
545 // Otherwise, if it is readonly, but not something we can specially optimize,
546 // just drop it in .const.
547 if (Kind.isReadOnly())
548 return ReadOnlySection;
550 // If this is marked const, put it into a const section. But if the dynamic
551 // linker needs to write to it, put it in the data segment.
552 if (Kind.isReadOnlyWithRel())
553 return ConstDataSection;
555 // Put zero initialized globals with strong external linkage in the
556 // DATA, __common section with the .zerofill directive.
557 if (Kind.isBSSExtern())
558 return DataCommonSection;
560 // Put zero initialized globals with local linkage in __DATA,__bss directive
561 // with the .zerofill directive (aka .lcomm).
562 if (Kind.isBSSLocal())
563 return DataBSSSection;
565 // Otherwise, just drop the variable in the normal data section.
570 TargetLoweringObjectFileMachO::getSectionForConstant(SectionKind Kind) const {
571 // If this constant requires a relocation, we have to put it in the data
572 // segment, not in the text segment.
573 if (Kind.isDataRel() || Kind.isReadOnlyWithRel())
574 return ConstDataSection;
576 if (Kind.isMergeableConst4())
577 return FourByteConstantSection;
578 if (Kind.isMergeableConst8())
579 return EightByteConstantSection;
580 if (Kind.isMergeableConst16() && SixteenByteConstantSection)
581 return SixteenByteConstantSection;
582 return ReadOnlySection; // .const
585 /// shouldEmitUsedDirectiveFor - This hook allows targets to selectively decide
586 /// not to emit the UsedDirective for some symbols in llvm.used.
587 // FIXME: REMOVE this (rdar://7071300)
588 bool TargetLoweringObjectFileMachO::
589 shouldEmitUsedDirectiveFor(const GlobalValue *GV, Mangler *Mang) const {
590 /// On Darwin, internally linked data beginning with "L" or "l" does not have
591 /// the directive emitted (this occurs in ObjC metadata).
592 if (!GV) return false;
594 // Check whether the mangled name has the "Private" or "LinkerPrivate" prefix.
595 if (GV->hasLocalLinkage() && !isa<Function>(GV)) {
596 // FIXME: ObjC metadata is currently emitted as internal symbols that have
597 // \1L and \0l prefixes on them. Fix them to be Private/LinkerPrivate and
598 // this horrible hack can go away.
599 MCSymbol *Sym = Mang->getSymbol(GV);
600 if (Sym->getName()[0] == 'L' || Sym->getName()[0] == 'l')
607 const MCExpr *TargetLoweringObjectFileMachO::
608 getTTypeGlobalReference(const GlobalValue *GV, Mangler *Mang,
609 MachineModuleInfo *MMI, unsigned Encoding,
610 MCStreamer &Streamer) const {
611 // The mach-o version of this method defaults to returning a stub reference.
613 if (Encoding & DW_EH_PE_indirect) {
614 MachineModuleInfoMachO &MachOMMI =
615 MMI->getObjFileInfo<MachineModuleInfoMachO>();
617 SmallString<128> Name;
618 Mang->getNameWithPrefix(Name, GV, true);
619 Name += "$non_lazy_ptr";
621 // Add information about the stub reference to MachOMMI so that the stub
622 // gets emitted by the asmprinter.
623 MCSymbol *SSym = getContext().GetOrCreateSymbol(Name.str());
624 MachineModuleInfoImpl::StubValueTy &StubSym =
625 GV->hasHiddenVisibility() ? MachOMMI.getHiddenGVStubEntry(SSym) :
626 MachOMMI.getGVStubEntry(SSym);
627 if (StubSym.getPointer() == 0) {
628 MCSymbol *Sym = Mang->getSymbol(GV);
629 StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
632 return TargetLoweringObjectFile::
633 getTTypeReference(MCSymbolRefExpr::Create(SSym, getContext()),
634 Encoding & ~dwarf::DW_EH_PE_indirect, Streamer);
637 return TargetLoweringObjectFile::
638 getTTypeGlobalReference(GV, Mang, MMI, Encoding, Streamer);
641 MCSymbol *TargetLoweringObjectFileMachO::
642 getCFIPersonalitySymbol(const GlobalValue *GV, Mangler *Mang,
643 MachineModuleInfo *MMI) const {
644 // The mach-o version of this method defaults to returning a stub reference.
645 MachineModuleInfoMachO &MachOMMI =
646 MMI->getObjFileInfo<MachineModuleInfoMachO>();
648 SmallString<128> Name;
649 Mang->getNameWithPrefix(Name, GV, true);
650 Name += "$non_lazy_ptr";
652 // Add information about the stub reference to MachOMMI so that the stub
653 // gets emitted by the asmprinter.
654 MCSymbol *SSym = getContext().GetOrCreateSymbol(Name.str());
655 MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(SSym);
656 if (StubSym.getPointer() == 0) {
657 MCSymbol *Sym = Mang->getSymbol(GV);
658 StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
664 //===----------------------------------------------------------------------===//
666 //===----------------------------------------------------------------------===//
669 getCOFFSectionFlags(SectionKind K) {
674 COFF::IMAGE_SCN_MEM_DISCARDABLE;
677 COFF::IMAGE_SCN_MEM_EXECUTE |
678 COFF::IMAGE_SCN_MEM_READ |
679 COFF::IMAGE_SCN_CNT_CODE;
682 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
683 COFF::IMAGE_SCN_MEM_READ |
684 COFF::IMAGE_SCN_MEM_WRITE;
685 else if (K.isThreadLocal())
687 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
688 COFF::IMAGE_SCN_MEM_READ |
689 COFF::IMAGE_SCN_MEM_WRITE;
690 else if (K.isReadOnly())
692 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
693 COFF::IMAGE_SCN_MEM_READ;
694 else if (K.isWriteable())
696 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
697 COFF::IMAGE_SCN_MEM_READ |
698 COFF::IMAGE_SCN_MEM_WRITE;
703 const MCSection *TargetLoweringObjectFileCOFF::
704 getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
705 Mangler *Mang, const TargetMachine &TM) const {
707 unsigned Characteristics = getCOFFSectionFlags(Kind);
708 SmallString<128> Name(GV->getSection().c_str());
709 if (GV->isWeakForLinker()) {
710 Selection = COFF::IMAGE_COMDAT_SELECT_ANY;
711 Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
712 MCSymbol *Sym = Mang->getSymbol(GV);
714 Name.append(Sym->getName().begin() + 1, Sym->getName().end());
716 return getContext().getCOFFSection(Name,
722 static const char *getCOFFSectionPrefixForUniqueGlobal(SectionKind Kind) {
727 if (Kind.isThreadLocal())
729 if (Kind.isWriteable())
735 const MCSection *TargetLoweringObjectFileCOFF::
736 SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
737 Mangler *Mang, const TargetMachine &TM) const {
739 // If this global is linkonce/weak and the target handles this by emitting it
740 // into a 'uniqued' section name, create and return the section now.
741 if (GV->isWeakForLinker()) {
742 const char *Prefix = getCOFFSectionPrefixForUniqueGlobal(Kind);
743 SmallString<128> Name(Prefix, Prefix+strlen(Prefix));
744 MCSymbol *Sym = Mang->getSymbol(GV);
745 Name.append(Sym->getName().begin() + 1, Sym->getName().end());
747 unsigned Characteristics = getCOFFSectionFlags(Kind);
749 Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
751 return getContext().getCOFFSection(Name.str(), Characteristics,
752 COFF::IMAGE_COMDAT_SELECT_ANY, Kind);
756 return getTextSection();
758 if (Kind.isThreadLocal())
759 return getTLSDataSection();
761 return getDataSection();