[llvm-objcopy][NFC] Add a helper method RelocationSectionBase::getNamePrefix()

Refactor handleArgs() to use that method.

Differential Revision: https://reviews.llvm.org/D110350

llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp

@@ -618,27 +618,16 @@ static Error handleArgs(const CommonConfig &Config, const ELFConfig &ELFConfig,
         // .rela.prefix.plt since GNU objcopy does so.
         const SectionBase *TargetSec = RelocSec->getSection();
         if (TargetSec && (TargetSec->Flags & SHF_ALLOC)) {
-          StringRef prefix;
-          switch (Sec.Type) {
-          case SHT_REL:
-            prefix = ".rel";
-            break;
-          case SHT_RELA:
-            prefix = ".rela";
-            break;
-          default:
-            llvm_unreachable("not a relocation section");
-          }
-
           // If the relocation section comes *after* the target section, we
           // don't add Config.AllocSectionsPrefix because we've already added
           // the prefix to TargetSec->Name. Otherwise, if the relocation
           // section comes *before* the target section, we add the prefix.
           if (PrefixedSections.count(TargetSec))
-            Sec.Name = (prefix + TargetSec->Name).str();
+            Sec.Name = (RelocSec->getNamePrefix() + TargetSec->Name).str();
           else
-            Sec.Name =
-                (prefix + Config.AllocSectionsPrefix + TargetSec->Name).str();
+            Sec.Name = (RelocSec->getNamePrefix() + Config.AllocSectionsPrefix +
+                        TargetSec->Name)
+                           .str();
         }
       }
     }

llvm/tools/llvm-objcopy/ELF/Object.cpp

@@ -893,6 +893,17 @@ Error SymbolTableSection::accept(MutableSectionVisitor &Visitor) {
   return Visitor.visit(*this);
 }
 
+StringRef RelocationSectionBase::getNamePrefix() const {
+  switch (Type) {
+  case SHT_REL:
+    return ".rel";
+  case SHT_RELA:
+    return ".rela";
+  default:
+    llvm_unreachable("not a relocation section");
+  }
+}
+
 Error RelocationSection::removeSectionReferences(
     bool AllowBrokenLinks, function_ref<bool(const SectionBase *)> ToRemove) {
   if (ToRemove(Symbols)) {

llvm/tools/llvm-objcopy/ELF/Object.h

@@ -745,6 +745,8 @@ public:
   const SectionBase *getSection() const { return SecToApplyRel; }
   void setSection(SectionBase *Sec) { SecToApplyRel = Sec; }
 
+  StringRef getNamePrefix() const;
+
   static bool classof(const SectionBase *S) {
     return S->OriginalType == ELF::SHT_REL || S->OriginalType == ELF::SHT_RELA;
   }