Create symbols marking the start of a section earlier.

This lets us pass the symbol to the constructor and avoid the mutable field.

This also opens the way for outputting the symbol only when needed, instead
of outputting them at the start of the file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231859 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCContext.h

@@ -258,23 +258,30 @@ namespace llvm {
     /// the operands to be valid.
     const MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
                                           unsigned TypeAndAttributes,
-                                          unsigned Reserved2, SectionKind K);
+                                          unsigned Reserved2, SectionKind K,
+                                          const char *BeginSymName = nullptr);
+
     const MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
                                           unsigned TypeAndAttributes,
-                                          SectionKind K) {
+                                          SectionKind K,
-      return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
+                                          const char *BeginSymName = nullptr) {
+      return getMachOSection(Segment, Section, TypeAndAttributes, 0, K,
+                             BeginSymName);
     }
 
     const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
-                                      unsigned Flags);
+                                      unsigned Flags,
+                                      const char *BeginSymName = nullptr);
 
     const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
                                       unsigned Flags, unsigned EntrySize,
-                                      StringRef Group);
+                                      StringRef Group,
+                                      const char *BeginSymName = nullptr);
 
     const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
                                       unsigned Flags, unsigned EntrySize,
-                                      StringRef Group, bool Unique);
+                                      StringRef Group, bool Unique,
+                                      const char *BeginSymName = nullptr);
 
     void renameELFSection(const MCSectionELF *Section, StringRef Name);
 
@@ -283,11 +290,13 @@ namespace llvm {
     const MCSectionCOFF *getCOFFSection(StringRef Section,
                                         unsigned Characteristics,
                                         SectionKind Kind,
-                                        StringRef COMDATSymName, int Selection);
+                                        StringRef COMDATSymName, int Selection,
+                                        const char *BeginSymName = nullptr);
 
     const MCSectionCOFF *getCOFFSection(StringRef Section,
                                         unsigned Characteristics,
-                                        SectionKind Kind);
+                                        SectionKind Kind,
+                                        const char *BeginSymName = nullptr);
 
     const MCSectionCOFF *getCOFFSection(StringRef Section);
 

include/llvm/MC/MCSection.h

@@ -34,11 +34,11 @@ private:
   MCSection(const MCSection &) = delete;
   void operator=(const MCSection &) = delete;
 
-  mutable const MCSymbol *Begin;
+  MCSymbol *Begin;
 
 protected:
-  MCSection(SectionVariant V, SectionKind K)
+  MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
-      : Begin(nullptr), Variant(V), Kind(K) {}
+      : Begin(Begin), Variant(V), Kind(K) {}
   SectionVariant Variant;
   SectionKind Kind;
 
@@ -49,12 +49,7 @@ public:
 
   SectionVariant getVariant() const { return Variant; }
 
-  const MCSymbol *getBeginSymbol() const { return Begin; }
+  MCSymbol *getBeginSymbol() const { return Begin; }
-
-  void setBeginSymbol(const MCSymbol &L) const {
-    assert(!Begin);
-    Begin = &L;
-  }
 
   virtual void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
                                     const MCExpr *Subsection) const = 0;

include/llvm/MC/MCSectionCOFF.h

@@ -45,8 +45,9 @@ class MCSymbol;
   private:
     friend class MCContext;
     MCSectionCOFF(StringRef Section, unsigned Characteristics,
-                  MCSymbol *COMDATSymbol, int Selection, SectionKind K)
+                  MCSymbol *COMDATSymbol, int Selection, SectionKind K,
-        : MCSection(SV_COFF, K), SectionName(Section),
+                  MCSymbol *Begin)
+        : MCSection(SV_COFF, K, Begin), SectionName(Section),
           Characteristics(Characteristics), COMDATSymbol(COMDATSymbol),
           Selection(Selection) {
       assert ((Characteristics & 0x00F00000) == 0 &&

include/llvm/MC/MCSectionELF.h

@@ -51,9 +51,10 @@ class MCSectionELF : public MCSection {
 private:
   friend class MCContext;
   MCSectionELF(StringRef Section, unsigned type, unsigned flags, SectionKind K,
-               unsigned entrySize, const MCSymbol *group, bool Unique)
+               unsigned entrySize, const MCSymbol *group, bool Unique,
-      : MCSection(SV_ELF, K), SectionName(Section), Type(type), Flags(flags),
+               MCSymbol *Begin)
-        Unique(Unique), EntrySize(entrySize), Group(group) {}
+      : MCSection(SV_ELF, K, Begin), SectionName(Section), Type(type),
+        Flags(flags), Unique(Unique), EntrySize(entrySize), Group(group) {}
   ~MCSectionELF();
 
   void setSectionName(StringRef Name) { SectionName = Name; }

include/llvm/MC/MCSectionMachO.h

@@ -35,8 +35,8 @@ class MCSectionMachO : public MCSection {
   /// size of stubs, for example.
   unsigned Reserved2;
 
-  MCSectionMachO(StringRef Segment, StringRef Section,
+  MCSectionMachO(StringRef Segment, StringRef Section, unsigned TAA,
-                 unsigned TAA, unsigned reserved2, SectionKind K);
+                 unsigned reserved2, SectionKind K, MCSymbol *Begin);
   friend class MCContext;
 public:
 

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -243,12 +243,10 @@ DwarfDebug::~DwarfDebug() { }
 
 // Switch to the specified MCSection and emit an assembler
 // temporary label to it if SymbolStem is specified.
-static void emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
+static void emitSectionSym(AsmPrinter *Asm, const MCSection *Section) {
-                           StringRef SymbolStem) {
   Asm->OutStreamer.SwitchSection(Section);
-  MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
+  MCSymbol *TmpSym = Section->getBeginSymbol();
   Asm->OutStreamer.EmitLabel(TmpSym);
-  Section->setBeginSymbol(*TmpSym);
 }
 
 static bool isObjCClass(StringRef Name) {
@@ -628,7 +626,7 @@ void DwarfDebug::endModule() {
   // If we aren't actually generating debug info (check beginModule -
   // conditionalized on !DisableDebugInfoPrinting and the presence of the
   // llvm.dbg.cu metadata node)
-  if (!TLOF.getDwarfInfoSection()->getBeginSymbol())
+  if (!TLOF.getDwarfInfoSection()->getBeginSymbol()->isInSection())
     return;
 
   // Finalize the debug info for the module.
@@ -1306,24 +1304,24 @@ void DwarfDebug::emitSectionLabels() {
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
 
   // Dwarf sections base addresses.
-  emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
+  emitSectionSym(Asm, TLOF.getDwarfInfoSection());
   if (useSplitDwarf()) {
-    emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
+    emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection());
-    emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
+    emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection());
   }
-  emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
+  emitSectionSym(Asm, TLOF.getDwarfAbbrevSection());
   if (useSplitDwarf())
-    emitSectionSym(Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
+    emitSectionSym(Asm, TLOF.getDwarfAbbrevDWOSection());
 
-  emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
+  emitSectionSym(Asm, TLOF.getDwarfLineSection());
-  emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
+  emitSectionSym(Asm, TLOF.getDwarfStrSection());
   if (useSplitDwarf()) {
-    emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
+    emitSectionSym(Asm, TLOF.getDwarfStrDWOSection());
-    emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
+    emitSectionSym(Asm, TLOF.getDwarfAddrSection());
-    emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
+    emitSectionSym(Asm, TLOF.getDwarfLocDWOSection());
   } else
-    emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
+    emitSectionSym(Asm, TLOF.getDwarfLocSection());
-  emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
+  emitSectionSym(Asm, TLOF.getDwarfRangesSection());
 }
 
 // Emit the debug info section.
@@ -1364,9 +1362,9 @@ void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
 }
 
 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
-                           StringRef TableName, StringRef SymName) {
+                           StringRef TableName) {
   Accel.FinalizeTable(Asm, TableName);
-  emitSectionSym(Asm, Section, SymName);
+  emitSectionSym(Asm, Section);
 
   // Emit the full data.
   Accel.emit(Asm, Section->getBeginSymbol(), this);
@@ -1375,27 +1373,27 @@ void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
 // Emit visible names into a hashed accelerator table section.
 void DwarfDebug::emitAccelNames() {
   emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
-            "Names", "names_begin");
+            "Names");
 }
 
 // Emit objective C classes and categories into a hashed accelerator table
 // section.
 void DwarfDebug::emitAccelObjC() {
   emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
-            "ObjC", "objc_begin");
+            "ObjC");
 }
 
 // Emit namespace dies into a hashed accelerator table.
 void DwarfDebug::emitAccelNamespaces() {
   emitAccel(AccelNamespace,
             Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
-            "namespac", "namespac_begin");
+            "namespac");
 }
 
 // Emit type dies into a hashed accelerator table.
 void DwarfDebug::emitAccelTypes() {
   emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
-            "types", "types_begin");
+            "types");
 }
 
 // Public name handling.

lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -371,7 +371,7 @@ class DwarfDebug : public AsmPrinterHandler {
 
   /// \brief Emit a specified accelerator table.
   void emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
-                 StringRef TableName, StringRef SymName);
+                 StringRef TableName);
 
   /// \brief Emit visible names into a hashed accelerator table section.
   void emitAccelNames();

lib/MC/MCContext.cpp

@@ -236,11 +236,10 @@ MCSymbol *MCContext::LookupSymbol(const Twine &Name) const {
 // Section Management
 //===----------------------------------------------------------------------===//
 
-const MCSectionMachO *MCContext::getMachOSection(StringRef Segment,
+const MCSectionMachO *
-                                                 StringRef Section,
+MCContext::getMachOSection(StringRef Segment, StringRef Section,
-                                                 unsigned TypeAndAttributes,
+                           unsigned TypeAndAttributes, unsigned Reserved2,
-                                                 unsigned Reserved2,
+                           SectionKind Kind, const char *BeginSymName) {
-                                                 SectionKind Kind) {
 
   // We unique sections by their segment/section pair.  The returned section
   // may not have the same flags as the requested section, if so this should be
@@ -257,14 +256,19 @@ const MCSectionMachO *MCContext::getMachOSection(StringRef Segment,
   if (Entry)
     return Entry;
 
+  MCSymbol *Begin = nullptr;
+  if (BeginSymName)
+    Begin = createTempSymbol(BeginSymName);
+
   // Otherwise, return a new section.
   return Entry = new (*this) MCSectionMachO(Segment, Section, TypeAndAttributes,
-                                            Reserved2, Kind);
+                                            Reserved2, Kind, Begin);
 }
 
 const MCSectionELF *MCContext::getELFSection(StringRef Section, unsigned Type,
-                                             unsigned Flags) {
+                                             unsigned Flags,
-  return getELFSection(Section, Type, Flags, 0, "");
+                                             const char *BeginSymName) {
+  return getELFSection(Section, Type, Flags, 0, "", BeginSymName);
 }
 
 void MCContext::renameELFSection(const MCSectionELF *Section, StringRef Name) {
@@ -282,7 +286,8 @@ void MCContext::renameELFSection(const MCSectionELF *Section, StringRef Name) {
 
 const MCSectionELF *MCContext::getELFSection(StringRef Section, unsigned Type,
                                              unsigned Flags, unsigned EntrySize,
-                                             StringRef Group, bool Unique) {
+                                             StringRef Group, bool Unique,
+                                             const char *BeginSymName) {
   // Do the lookup, if we have a hit, return it.
   auto IterBool = ELFUniquingMap.insert(
       std::make_pair(SectionGroupPair(Section, Group), nullptr));
@@ -302,8 +307,12 @@ const MCSectionELF *MCContext::getELFSection(StringRef Section, unsigned Type,
   else
     Kind = SectionKind::getReadOnly();
 
-  MCSectionELF *Result = new (*this)
+  MCSymbol *Begin = nullptr;
-      MCSectionELF(CachedName, Type, Flags, Kind, EntrySize, GroupSym, Unique);
+  if (BeginSymName)
+    Begin = createTempSymbol(BeginSymName);
+
+  MCSectionELF *Result = new (*this) MCSectionELF(
+      CachedName, Type, Flags, Kind, EntrySize, GroupSym, Unique, Begin);
   if (!Unique)
     Entry.second = Result;
   return Result;
@@ -311,22 +320,23 @@ const MCSectionELF *MCContext::getELFSection(StringRef Section, unsigned Type,
 
 const MCSectionELF *MCContext::getELFSection(StringRef Section, unsigned Type,
                                              unsigned Flags, unsigned EntrySize,
-                                             StringRef Group) {
+                                             StringRef Group,
-  return getELFSection(Section, Type, Flags, EntrySize, Group, false);
+                                             const char *BeginSymName) {
+  return getELFSection(Section, Type, Flags, EntrySize, Group, false,
+                       BeginSymName);
 }
 
 const MCSectionELF *MCContext::CreateELFGroupSection() {
-  MCSectionELF *Result =
+  MCSectionELF *Result = new (*this)
-      new (*this) MCSectionELF(".group", ELF::SHT_GROUP, 0,
+      MCSectionELF(".group", ELF::SHT_GROUP, 0, SectionKind::getReadOnly(), 4,
-                               SectionKind::getReadOnly(), 4, nullptr, false);
+                   nullptr, false, nullptr);
   return Result;
 }
 
-const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
+const MCSectionCOFF *
-                                               unsigned Characteristics,
+MCContext::getCOFFSection(StringRef Section, unsigned Characteristics,
-                                               SectionKind Kind,
+                          SectionKind Kind, StringRef COMDATSymName,
-                                               StringRef COMDATSymName,
+                          int Selection, const char *BeginSymName) {
-                                               int Selection) {
   // Do the lookup, if we have a hit, return it.
 
   SectionGroupTriple T(Section, COMDATSymName, Selection);
@@ -339,9 +349,13 @@ const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
   if (!COMDATSymName.empty())
     COMDATSymbol = GetOrCreateSymbol(COMDATSymName);
 
+  MCSymbol *Begin = nullptr;
+  if (BeginSymName)
+    Begin = createTempSymbol(BeginSymName);
+
   StringRef CachedName = std::get<0>(Iter->first);
-  MCSectionCOFF *Result = new (*this)
+  MCSectionCOFF *Result = new (*this) MCSectionCOFF(
-      MCSectionCOFF(CachedName, Characteristics, COMDATSymbol, Selection, Kind);
+      CachedName, Characteristics, COMDATSymbol, Selection, Kind, Begin);
 
   Iter->second = Result;
   return Result;
@@ -349,8 +363,9 @@ const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
 
 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
                                                unsigned Characteristics,
-                                               SectionKind Kind) {
+                                               SectionKind Kind,
-  return getCOFFSection(Section, Characteristics, Kind, "", 0);
+                                               const char *BeginSymName) {
+  return getCOFFSection(Section, Characteristics, Kind, "", 0, BeginSymName);
 }
 
 const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {

lib/MC/MCObjectFileInfo.cpp

@@ -184,27 +184,27 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
   // Debug Information.
   DwarfAccelNamesSection =
       Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "names_begin");
   DwarfAccelObjCSection =
       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "objc_begin");
   // 16 character section limit...
   DwarfAccelNamespaceSection =
       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "namespac_begin");
   DwarfAccelTypesSection =
       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "types_begin");
 
   DwarfAbbrevSection =
       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "section_abbrev");
   DwarfInfoSection =
       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "section_info");
   DwarfLineSection =
       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "section_line");
   DwarfFrameSection =
       Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
                            SectionKind::getMetadata());
@@ -222,16 +222,16 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
                            SectionKind::getMetadata());
   DwarfStrSection =
       Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "info_string");
   DwarfLocSection =
       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "section_debug_loc");
   DwarfARangesSection =
       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
                            SectionKind::getMetadata());
   DwarfRangesSection =
       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
-                           SectionKind::getMetadata());
+                           SectionKind::getMetadata(), "debug_range");
   DwarfDebugInlineSection =
       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
                            SectionKind::getMetadata());
@@ -455,10 +455,12 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
   COFFDebugSymbolsSection = nullptr;
 
   // Debug Info Sections.
-  DwarfAbbrevSection =
+  DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
-      Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0);
+                                          "section_abbrev");
-  DwarfInfoSection = Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0);
+  DwarfInfoSection =
-  DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
+      Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
+  DwarfLineSection =
+      Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0, "section_line");
   DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
   DwarfPubNamesSection =
       Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
@@ -468,44 +470,46 @@ void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
       Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
   DwarfGnuPubTypesSection =
       Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
-  DwarfStrSection =
+  DwarfStrSection = Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
-      Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
+                                       ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "",
-                         ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
+                                       "info_string");
-  DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
+  DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
+                                       "section_debug_loc");
   DwarfARangesSection =
       Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
   DwarfRangesSection =
-      Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0);
+      Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
 
   // DWARF5 Experimental Debug Info
 
   // Accelerator Tables
   DwarfAccelNamesSection =
-      Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0);
+      Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
   DwarfAccelObjCSection =
-      Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0);
+      Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
-  DwarfAccelNamespaceSection =
+  DwarfAccelNamespaceSection = Ctx->getELFSection(
-      Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0);
+      ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
   DwarfAccelTypesSection =
-      Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0);
+      Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
 
   // Fission Sections
-  DwarfInfoDWOSection =
+  DwarfInfoDWOSection = Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS,
-      Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
+                                           0, "section_info_dwo");
-  DwarfTypesDWOSection =
+  DwarfTypesDWOSection = Ctx->getELFSection(
-      Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
+      ".debug_types.dwo", ELF::SHT_PROGBITS, 0, "section_types_dwo");
-  DwarfAbbrevDWOSection =
+  DwarfAbbrevDWOSection = Ctx->getELFSection(
-      Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
+      ".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0, "section_abbrev_dwo");
-  DwarfStrDWOSection =
+  DwarfStrDWOSection = Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
-      Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
+                                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1,
-                         ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
+                                          "", "skel_string");
   DwarfLineDWOSection =
       Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
   DwarfLocDWOSection =
-      Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0);
+      Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
   DwarfStrOffDWOSection =
       Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
-  DwarfAddrSection = Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0);
+  DwarfAddrSection =
+      Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
 
   StackMapSection =
       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
@@ -581,17 +585,18 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
       ".debug_abbrev",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "section_abbrev");
   DwarfInfoSection = Ctx->getCOFFSection(
       ".debug_info",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "section_info");
   DwarfLineSection = Ctx->getCOFFSection(
       ".debug_line",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "section_line");
+
   DwarfFrameSection = Ctx->getCOFFSection(
       ".debug_frame",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
@@ -621,12 +626,12 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
       ".debug_str",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "info_string");
   DwarfLocSection = Ctx->getCOFFSection(
       ".debug_loc",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "section_debug_loc");
   DwarfARangesSection = Ctx->getCOFFSection(
       ".debug_aranges",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
@@ -636,12 +641,12 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
       ".debug_ranges",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "debug_range");
   DwarfInfoDWOSection = Ctx->getCOFFSection(
       ".debug_info.dwo",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "section_info_dwo");
   DwarfTypesDWOSection = Ctx->getCOFFSection(
       ".debug_types.dwo",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
@@ -651,12 +656,12 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
       ".debug_abbrev.dwo",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "section_abbrev_dwo");
   DwarfStrDWOSection = Ctx->getCOFFSection(
       ".debug_str.dwo",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "skel_string");
   DwarfLineDWOSection = Ctx->getCOFFSection(
       ".debug_line.dwo",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
@@ -666,7 +671,7 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
       ".debug_loc.dwo",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "skel_loc");
   DwarfStrOffDWOSection = Ctx->getCOFFSection(
       ".debug_str_offsets.dwo",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
@@ -676,27 +681,27 @@ void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
       ".debug_addr",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "addr_sec");
   DwarfAccelNamesSection = Ctx->getCOFFSection(
       ".apple_names",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "names_begin");
   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
       ".apple_namespaces",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "namespac_begin");
   DwarfAccelTypesSection = Ctx->getCOFFSection(
       ".apple_types",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "types_begin");
   DwarfAccelObjCSection = Ctx->getCOFFSection(
       ".apple_objc",
       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
           COFF::IMAGE_SCN_MEM_READ,
-      SectionKind::getMetadata());
+      SectionKind::getMetadata(), "objc_begin");
 
   DrectveSection = Ctx->getCOFFSection(
       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,

lib/MC/MCSectionMachO.cpp

@@ -70,8 +70,10 @@ ENTRY(nullptr /*FIXME*/,     S_ATTR_LOC_RELOC)
 };
 
 MCSectionMachO::MCSectionMachO(StringRef Segment, StringRef Section,
-                               unsigned TAA, unsigned reserved2, SectionKind K)
+                               unsigned TAA, unsigned reserved2, SectionKind K,
-  : MCSection(SV_MachO, K), TypeAndAttributes(TAA), Reserved2(reserved2) {
+                               MCSymbol *Begin)
+    : MCSection(SV_MachO, K, Begin), TypeAndAttributes(TAA),
+      Reserved2(reserved2) {
   assert(Segment.size() <= 16 && Section.size() <= 16 &&
          "Segment or section string too long");
   for (unsigned i = 0; i != 16; ++i) {

lib/Target/NVPTX/NVPTXSection.h

@@ -26,7 +26,7 @@ namespace llvm {
 class NVPTXSection : public MCSection {
   virtual void anchor();
 public:
-  NVPTXSection(SectionVariant V, SectionKind K) : MCSection(V, K) {}
+  NVPTXSection(SectionVariant V, SectionKind K) : MCSection(V, K, nullptr) {}
   virtual ~NVPTXSection() {}
 
   /// Override this as NVPTX has its own way of printing switching