[WebAssembly] Remove flags from MCSectionWasm

[sbc100]

Summary

Looks like these were copied from the ELF sections but
don't apply to Wasm and were not used anywhere.

Also remove unused wasm methos in MCContext.

[sbc100]

remove debugging

[sunfish]

I can confirm that this was all copied from ELF. At a glance, these seem fine to remove.

include/llvm/MC/MCContext.h

public:
     /// Gets or creates a section equivalent to Sec that is associated with the
     /// section containing KeySym. For example, to create a debug info section
     /// associated with an inline function, pass the normal debug info section
     /// as Sec and the function symbol as KeySym.
     MCSectionCOFF *
     getAssociativeCOFFSection(MCSectionCOFF *Sec, const MCSymbol *KeySym,
                               unsigned UniqueID = GenericSectionID);
 
-    MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
-                                  unsigned Flags) {
-      return getWasmSection(Section, Type, Flags, nullptr);
-    }
-
-    MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
-                                  unsigned Flags, const char *BeginSymName) {
-      return getWasmSection(Section, Type, Flags, "", BeginSymName);
+    MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type) {
+      return getWasmSection(Section, Type, nullptr);
     }
 
     MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
-                                  unsigned Flags, const Twine &Group) {
-      return getWasmSection(Section, Type, Flags, Group, nullptr);
-    }
-
-    MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
-                                  unsigned Flags, const Twine &Group,
                                   const char *BeginSymName) {
-      return getWasmSection(Section, Type, Flags, Group, ~0, BeginSymName);
+      return getWasmSection(Section, Type, "", ~0, BeginSymName);
     }
 
     MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
-                                  unsigned Flags, const Twine &Group,
-                                  unsigned UniqueID) {
-      return getWasmSection(Section, Type, Flags, Group, UniqueID, nullptr);
+                                  const Twine &Group, unsigned UniqueID) {
+      return getWasmSection(Section, Type, Group, UniqueID, nullptr);
     }
 
+    private:
     MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
-                                  unsigned Flags, const Twine &Group,
-                                  unsigned UniqueID, const char *BeginSymName);
+                                  const Twine &Group, unsigned UniqueID,
+                                  const char *BeginSymName);
 
     MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
-                                  unsigned Flags, const MCSymbolWasm *Group,
-                                  unsigned UniqueID, const char *BeginSymName);
-
-    /// Get a section with the provided group identifier. This section is
-    /// named by concatenating \p Prefix with '.' then \p Suffix. The \p Type
-    /// describes the type of the section and \p Flags are used to further
-    /// configure this named section.
-    MCSectionWasm *getWasmNamedSection(const Twine &Prefix, const Twine &Suffix,
-                                       unsigned Type, unsigned Flags);
-
-    MCSectionWasm *createWasmRelSection(const Twine &Name, unsigned Type,
-                                        unsigned Flags,
-                                        const MCSymbolWasm *Group);
-
-    void renameWasmSection(MCSectionWasm *Section, StringRef Name);
+                                  const MCSymbolWasm *Group, unsigned UniqueID,
+                                  const char *BeginSymName);
+    public:
 
     // Create and save a copy of STI and return a reference to the copy.
     MCSubtargetInfo &getSubtargetCopy(const MCSubtargetInfo &STI);
 
     /// @}
 
     /// \name Dwarf Management
     /// @{

include/llvm/MC/MCSectionWasm.h

 
 /// This represents a section on wasm.
 class MCSectionWasm final : public MCSection {
 private:
   /// This is the name of the section.  The referenced memory is owned by
   /// TargetLoweringObjectFileWasm's WasmUniqueMap.
   StringRef SectionName;
 
-  /// This is the sh_type field of a section, drawn from the enums below.
+  /// This is the type of the section, from the enums in BinaryFormat/Wasm.h
   unsigned Type;
 
-  /// This is the sh_flags field of a section, drawn from the enums below.
-  unsigned Flags;
-
   unsigned UniqueID;
 
   const MCSymbolWasm *Group;
 
   // The offset of the MC function/data section in the wasm code/data section.
   // For data relocations the offset is relative to start of the data payload
   // itself and does not include the size of the section header.
   uint64_t SectionOffset;
 
   friend class MCContext;
-  MCSectionWasm(StringRef Section, unsigned type, unsigned flags, SectionKind K,
+  MCSectionWasm(StringRef Section, unsigned type, SectionKind K,
                 const MCSymbolWasm *group, unsigned UniqueID, MCSymbol *Begin)
       : MCSection(SV_Wasm, K, Begin), SectionName(Section), Type(type),
-        Flags(flags), UniqueID(UniqueID), Group(group), SectionOffset(0) {
-  }
+        UniqueID(UniqueID), Group(group), SectionOffset(0) {}
 
   void setSectionName(StringRef Name) { SectionName = Name; }
 
 public:
   ~MCSectionWasm();
 
   /// Decides whether a '.section' directive should be printed before the
   /// section name
   bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const;
 
   StringRef getSectionName() const { return SectionName; }
   unsigned getType() const { return Type; }
-  unsigned getFlags() const { return Flags; }
-  void setFlags(unsigned F) { Flags = F; }
   const MCSymbolWasm *getGroup() const { return Group; }
 
   void PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                             raw_ostream &OS,
                             const MCExpr *Subsection) const override;
   bool UseCodeAlign() const override;
   bool isVirtualSection() const override;
 

include/llvm/Target/TargetLoweringObjectFile.h

class TargetLoweringObjectFile : public MCObjectFileInfo {
   /// Name-mangler for global names.
   Mangler *Mang = nullptr;
 
 protected:
   bool SupportIndirectSymViaGOTPCRel = false;
   bool SupportGOTPCRelWithOffset = true;
 
   /// This section contains the static constructor pointer list.
-  MCSection *StaticCtorSection;
+  MCSection *StaticCtorSection = nullptr;
 
   /// This section contains the static destructor pointer list.
-  MCSection *StaticDtorSection;
+  MCSection *StaticDtorSection = nullptr;
 
 public:
   TargetLoweringObjectFile() = default;
   TargetLoweringObjectFile(const TargetLoweringObjectFile &) = delete;
   TargetLoweringObjectFile &
   operator=(const TargetLoweringObjectFile &) = delete;
   virtual ~TargetLoweringObjectFile();
 

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

 }
 
 MCSection *TargetLoweringObjectFileWasm::getExplicitSectionGlobal(
     const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
   llvm_unreachable("getExplicitSectionGlobal not yet implemented");
   return nullptr;
 }
 
-static MCSectionWasm *
-selectWasmSectionForGlobal(MCContext &Ctx, const GlobalObject *GO,
-                           SectionKind Kind, Mangler &Mang,
-                           const TargetMachine &TM, bool EmitUniqueSection,
-                           unsigned Flags, unsigned *NextUniqueID) {
+static MCSectionWasm *selectWasmSectionForGlobal(
+    MCContext &Ctx, const GlobalObject *GO, SectionKind Kind, Mangler &Mang,
+    const TargetMachine &TM, bool EmitUniqueSection, unsigned *NextUniqueID) {
   StringRef Group = "";
   if (getWasmComdat(GO))
     llvm_unreachable("comdat not yet supported for wasm");
 
   bool UniqueSectionNames = TM.getUniqueSectionNames();
   SmallString<128> Name = getSectionPrefixForGlobal(Kind);
 
   if (const auto *F = dyn_cast<Function>(GO)) {
     const auto &OptionalPrefix = F->getSectionPrefix();
     if (OptionalPrefix)
       Name += *OptionalPrefix;
   }
 
   if (EmitUniqueSection && UniqueSectionNames) {
     Name.push_back('.');
     TM.getNameWithPrefix(Name, GO, Mang, true);
   }
   unsigned UniqueID = MCContext::GenericSectionID;
   if (EmitUniqueSection && !UniqueSectionNames) {
     UniqueID = *NextUniqueID;
     (*NextUniqueID)++;
   }
-  return Ctx.getWasmSection(Name, /*Type=*/0, Flags,
-                            Group, UniqueID);
+  return Ctx.getWasmSection(Name, /*Type=*/0, Group, UniqueID);
 }
 
 MCSection *TargetLoweringObjectFileWasm::SelectSectionForGlobal(
     const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
 
   if (Kind.isCommon())
     report_fatal_error("mergable sections not supported yet on wasm");
 
   // If we have -ffunction-section or -fdata-section then we should emit the
   // global value to a uniqued section specifically for it.
   bool EmitUniqueSection = false;
   if (Kind.isText())
     EmitUniqueSection = TM.getFunctionSections();
   else
     EmitUniqueSection = TM.getDataSections();
   EmitUniqueSection |= GO->hasComdat();
 
   return selectWasmSectionForGlobal(getContext(), GO, Kind, getMangler(), TM,
-                                    EmitUniqueSection, /*Flags=*/0,
-                                    &NextUniqueID);
+                                    EmitUniqueSection, &NextUniqueID);
 }
 
 bool TargetLoweringObjectFileWasm::shouldPutJumpTableInFunctionSection(
     bool UsesLabelDifference, const Function &F) const {
   // We can always create relative relocations, so use another section
   // that can be marked non-executable.
   return false;
 }

lib/MC/MCContext.cpp

return getCOFFSection(Sec->getSectionName(), Characteristics,
                           Sec->getKind(), KeySym->getName(),
                           COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE, UniqueID);
   }
 
   return getCOFFSection(Sec->getSectionName(), Characteristics, Sec->getKind(),
                         "", 0, UniqueID);
 }
 
-void MCContext::renameWasmSection(MCSectionWasm *Section, StringRef Name) {
-  StringRef GroupName;
-  assert(!Section->getGroup() && "not yet implemented");
-
-  unsigned UniqueID = Section->getUniqueID();
-  WasmUniquingMap.erase(
-      WasmSectionKey{Section->getSectionName(), GroupName, UniqueID});
-  auto I = WasmUniquingMap.insert(std::make_pair(
-                                     WasmSectionKey{Name, GroupName, UniqueID},
-                                     Section))
-               .first;
-  StringRef CachedName = I->first.SectionName;
-  const_cast<MCSectionWasm *>(Section)->setSectionName(CachedName);
-}
-
-MCSectionWasm *MCContext::createWasmRelSection(const Twine &Name, unsigned Type,
-                                               unsigned Flags,
-                                               const MCSymbolWasm *Group) {
-  StringMap<bool>::iterator I;
-  bool Inserted;
-  std::tie(I, Inserted) =
-      RelSecNames.insert(std::make_pair(Name.str(), true));
-
-  return new (WasmAllocator.Allocate())
-      MCSectionWasm(I->getKey(), Type, Flags, SectionKind::getReadOnly(),
-                    Group, ~0, nullptr);
-}
-
-MCSectionWasm *MCContext::getWasmNamedSection(const Twine &Prefix,
-                                              const Twine &Suffix, unsigned Type,
-                                              unsigned Flags) {
-  return getWasmSection(Prefix + "." + Suffix, Type, Flags, Suffix);
-}
-
 MCSectionWasm *MCContext::getWasmSection(const Twine &Section, unsigned Type,
-                                         unsigned Flags,
                                          const Twine &Group, unsigned UniqueID,
                                          const char *BeginSymName) {
   MCSymbolWasm *GroupSym = nullptr;
   if (!Group.isTriviallyEmpty() && !Group.str().empty())
     GroupSym = cast<MCSymbolWasm>(getOrCreateSymbol(Group));
 
-  return getWasmSection(Section, Type, Flags, GroupSym, UniqueID, BeginSymName);
+  return getWasmSection(Section, Type, GroupSym, UniqueID, BeginSymName);
 }
 
 MCSectionWasm *MCContext::getWasmSection(const Twine &Section, unsigned Type,
-                                         unsigned Flags,
                                          const MCSymbolWasm *GroupSym,
                                          unsigned UniqueID,
                                          const char *BeginSymName) {
   StringRef Group = "";
   if (GroupSym)
     Group = GroupSym->getName();
   // Do the lookup, if we have a hit, return it.
   auto IterBool = WasmUniquingMap.insert(
       std::make_pair(WasmSectionKey{Section.str(), Group, UniqueID}, nullptr));
   auto &Entry = *IterBool.first;
   if (!IterBool.second)
     return Entry.second;
 
   StringRef CachedName = Entry.first.SectionName;
 
   SectionKind Kind = SectionKind::getText();
 
   MCSymbol *Begin = nullptr;
   if (BeginSymName)
     Begin = createTempSymbol(BeginSymName, false);
 
   MCSectionWasm *Result = new (WasmAllocator.Allocate())
-      MCSectionWasm(CachedName, Type, Flags, Kind, GroupSym, UniqueID, Begin);
+      MCSectionWasm(CachedName, Type, Kind, GroupSym, UniqueID, Begin);
   Entry.second = Result;
   return Result;
 }
 
 MCSubtargetInfo &MCContext::getSubtargetCopy(const MCSubtargetInfo &STI) {
   return *new (MCSubtargetAllocator.Allocate()) MCSubtargetInfo(STI);
 }
 

lib/MC/MCObjectFileInfo.cpp

void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                                             COFF::IMAGE_SCN_MEM_READ,
                                         SectionKind::getReadOnly());
 }
 
 void MCObjectFileInfo::initWasmMCObjectFileInfo(const Triple &T) {
   // TODO: Set the section types and flags.
-  TextSection = Ctx->getWasmSection(".text", 0, 0);
-  DataSection = Ctx->getWasmSection(".data", 0, 0);
+  TextSection = Ctx->getWasmSection(".text", 0);
+  DataSection = Ctx->getWasmSection(".data", 0);
 
   // TODO: Set the section types and flags.
-  DwarfLineSection = Ctx->getWasmSection(".debug_line", 0, 0);
-  DwarfStrSection = Ctx->getWasmSection(".debug_str", 0, 0);
-  DwarfLocSection = Ctx->getWasmSection(".debug_loc", 0, 0);
-  DwarfAbbrevSection = Ctx->getWasmSection(".debug_abbrev", 0, 0, "section_abbrev");
-  DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", 0, 0);
-  DwarfRangesSection = Ctx->getWasmSection(".debug_ranges", 0, 0, "debug_range");
-  DwarfMacinfoSection = Ctx->getWasmSection(".debug_macinfo", 0, 0, "debug_macinfo");
-  DwarfAddrSection = Ctx->getWasmSection(".debug_addr", 0, 0);
-  DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", 0, 0);
-  DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", 0, 0);
-  DwarfInfoSection = Ctx->getWasmSection(".debug_info", 0, 0, "section_info");
-  DwarfFrameSection = Ctx->getWasmSection(".debug_frame", 0, 0);
-  DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", 0, 0);
-  DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", 0, 0);
+  DwarfLineSection = Ctx->getWasmSection(".debug_line", 0);
+  DwarfStrSection = Ctx->getWasmSection(".debug_str", 0);
+  DwarfLocSection = Ctx->getWasmSection(".debug_loc", 0);
+  DwarfAbbrevSection = Ctx->getWasmSection(".debug_abbrev", 0, "section_abbrev");
+  DwarfARangesSection = Ctx->getWasmSection(".debug_aranges", 0);
+  DwarfRangesSection = Ctx->getWasmSection(".debug_ranges", 0, "debug_range");
+  DwarfMacinfoSection = Ctx->getWasmSection(".debug_macinfo", 0, "debug_macinfo");
+  DwarfAddrSection = Ctx->getWasmSection(".debug_addr", 0);
+  DwarfCUIndexSection = Ctx->getWasmSection(".debug_cu_index", 0);
+  DwarfTUIndexSection = Ctx->getWasmSection(".debug_tu_index", 0);
+  DwarfInfoSection = Ctx->getWasmSection(".debug_info", 0, "section_info");
+  DwarfFrameSection = Ctx->getWasmSection(".debug_frame", 0);
+  DwarfPubNamesSection = Ctx->getWasmSection(".debug_pubnames", 0);
+  DwarfPubTypesSection = Ctx->getWasmSection(".debug_pubtypes", 0);
 
   // TODO: Define more sections.
 }
 
 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
                                             MCContext &ctx,
                                             bool LargeCodeModel) {
   PositionIndependent = PIC;