[MC] Add MCSection::NonUniqueID and delete one MCContext::getELFSection overload

Author: MaskRay

llvm/include/llvm/MC/MCContext.h

@@ -435,14 +435,8 @@ namespace llvm {
     MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
                                 unsigned Flags, unsigned EntrySize,
                                 const Twine &Group) {
-      return getELFSection(Section, Type, Flags, EntrySize, Group, ~0);
-    }
-
-    MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
-                                unsigned Flags, unsigned EntrySize,
-                                const Twine &Group, unsigned UniqueID) {
-      return getELFSection(Section, Type, Flags, EntrySize, Group, UniqueID,
-                           nullptr);
+      return getELFSection(Section, Type, Flags, EntrySize, Group,
+                           MCSection::NonUniqueID, nullptr);
     }
 
     MCSectionELF *getELFSection(const Twine &Section, unsigned Type,

llvm/include/llvm/MC/MCSection.h

@@ -38,6 +38,8 @@ template <> struct ilist_alloc_traits<MCFragment> {
 /// current translation unit.  The MCContext class uniques and creates these.
 class MCSection {
 public:
+  static constexpr unsigned NonUniqueID = ~0U;
+
   enum SectionVariant { SV_COFF = 0, SV_ELF, SV_MachO, SV_Wasm, SV_XCOFF };
 
   /// Express the state of bundle locked groups while emitting code.

llvm/include/llvm/MC/MCSectionELF.h

@@ -81,7 +81,7 @@ class MCSectionELF final : public MCSection {
   bool UseCodeAlign() const override;
   bool isVirtualSection() const override;
 
-  bool isUnique() const { return UniqueID != ~0U; }
+  bool isUnique() const { return UniqueID != NonUniqueID; }
   unsigned getUniqueID() const { return UniqueID; }
 
   const MCSection *getLinkedToSection() const {

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -1670,8 +1670,9 @@ bool AsmPrinter::doFinalization(Module &M) {
           GV.getVisibility() != GlobalValue::DefaultVisibility)
         continue;
 
-      OutStreamer->SwitchSection(OutContext.getELFSection(
-          ".llvm_sympart", ELF::SHT_LLVM_SYMPART, 0, 0, "", ++UniqueID));
+      OutStreamer->SwitchSection(
+          OutContext.getELFSection(".llvm_sympart", ELF::SHT_LLVM_SYMPART, 0, 0,
+                                   "", ++UniqueID, nullptr));
       OutStreamer->emitBytes(GV.getPartition());
       OutStreamer->EmitZeros(1);
       OutStreamer->EmitValue(

llvm/lib/MC/MCContext.cpp

@@ -433,8 +433,8 @@ MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
 
 MCSectionELF *MCContext::createELFGroupSection(const MCSymbolELF *Group) {
   return createELFSectionImpl(".group", ELF::SHT_GROUP, 0,
-                              SectionKind::getReadOnly(), 4, Group, ~0,
-                              nullptr);
+                              SectionKind::getReadOnly(), 4, Group,
+                              MCSection::NonUniqueID, nullptr);
 }
 
 MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,

llvm/lib/Target/ARM/ARMTargetObjectFile.cpp

@@ -49,7 +49,7 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
     // Since we cannot modify flags for an existing section, we create a new
     // section with the right flags, and use 0 as the unique ID for
     // execute-only text
-    TextSection = Ctx.getELFSection(".text", Type, Flags, 0, "", 0U);
+    TextSection = Ctx.getELFSection(".text", Type, Flags, 0, "", 0U, nullptr);
   }
 }