[llvm-readobj] Replace arch-specific ObjDumper methods by the single `printArchSpecificInfo`

[atanasyan]

Summary

Initially llvm-readobj supports multiple command line options like --arm-attributes and --mips-plt-got for display ELF arch-specific information. Now all these options are superseded by the --arch-specific one. It makes sense to have a single printArchSpecificInfo method in the base ObjDumper, and hide all ELF/target specific details in the ELFDumper::printArchSpecificInfo override.

[peter.smith]

I'm fine with this change if the others have no objections.

[MaskRay]

I'm happy with the change, which makes the scope of arch-specific features narrower.

llvm/tools/llvm-readobj/ELFDumper.cpp

public:
   void printProgramHeaders(bool PrintProgramHeaders,
                            cl::boolOrDefault PrintSectionMapping) override;
   void printHashTable() override;
   void printGnuHashTable() override;
   void printLoadName() override;
   void printVersionInfo() override;
   void printGroupSections() override;
 
-  void printAttributes() override;
-  void printMipsPLTGOT() override;
-  void printMipsABIFlags() override;
-  void printMipsReginfo() override;
-  void printMipsOptions() override;
+  void printArchSpecificInfo() override;
 
   void printStackMap() const override;
 
   void printHashHistogram() override;
 
   void printCGProfile() override;
   void printAddrsig() override;
 
return checkDRI({ObjF->getELFFile()->base() + P->p_offset, P->p_filesz,
                      EntSize, ObjF->getFileName()});
   }
 
   DynRegionInfo createDRIFrom(const Elf_Shdr *S) {
     return checkDRI({ObjF->getELFFile()->base() + S->sh_offset, S->sh_size,
                      S->sh_entsize, ObjF->getFileName()});
   }
 
+  void printAttributes();
+  void printMipsPLTGOT();
+  void printMipsABIFlags();
+  void printMipsReginfo();
+  void printMipsOptions();
+
   std::pair<const Elf_Phdr *, const Elf_Shdr *>
   findDynamic(const ELFFile<ELFT> *Obj);
   void loadDynamicTable(const ELFFile<ELFT> *Obj);
   void parseDynamicTable();
 
   StringRef getSymbolVersion(StringRef StrTab, const Elf_Sym *symb,
                              bool &IsDefault) const;
   void LoadVersionMap() const;
if (!NumSyms)
     reportError(createError("No dynamic symbol section"), ObjF->getFileName());
   W.printHexList("Values", GnuHashTable->values(NumSyms));
 }
 
 template <typename ELFT> void ELFDumper<ELFT>::printLoadName() {
   W.printString("LoadName", SOName);
 }
 
+template <class ELFT> void ELFDumper<ELFT>::printArchSpecificInfo() {
+  const ELFFile<ELFT> *Obj = ObjF->getELFFile();
+  switch (Obj->getHeader()->e_machine) {
+  case EM_ARM:
+    printAttributes();
+    break;
+  case EM_MIPS:
+    printMipsABIFlags();
+    printMipsOptions();
+    printMipsReginfo();
+    printMipsPLTGOT();
+    break;
+  default:
+    break;
+  }
+}
+
 template <class ELFT> void ELFDumper<ELFT>::printAttributes() {
   W.startLine() << "Attributes not implemented.\n";
 }
 
 namespace {
 
 template <> void ELFDumper<ELF32LE>::printAttributes() {
   const ELFFile<ELF32LE> *Obj = ObjF->getELFFile();

llvm/tools/llvm-readobj/ObjDumper.h

public:
   virtual void printVersionInfo() {}
   virtual void printGroupSections() {}
   virtual void printHashHistogram() {}
   virtual void printCGProfile() {}
   virtual void printAddrsig() {}
   virtual void printNotes() {}
   virtual void printELFLinkerOptions() {}
   virtual void printStackSizes() {}
-
-  // Only implemented for ARM ELF at this time.
-  virtual void printAttributes() { }
-
-  // Only implemented for MIPS ELF at this time.
-  virtual void printMipsPLTGOT() { }
-  virtual void printMipsABIFlags() { }
-  virtual void printMipsReginfo() { }
-  virtual void printMipsOptions() { }
+  virtual void printArchSpecificInfo() { }
 
   // Only implemented for PE/COFF.
   virtual void printCOFFImports() { }
   virtual void printCOFFExports() { }
   virtual void printCOFFDirectives() { }
   virtual void printCOFFBaseReloc() { }
   virtual void printCOFFDebugDirectory() { }
   virtual void printCOFFResources() {}

llvm/tools/llvm-readobj/llvm-readobj.cpp

handleAllErrors(
       createFileError(Input, std::move(Err)), [&](const ErrorInfoBase &EI) {
         errs() << "\n";
         WithColor::warning(errs(), ToolName) << EI.message() << "\n";
       });
 }
 
 } // namespace llvm
 
-static bool isMipsArch(unsigned Arch) {
-  switch (Arch) {
-  case llvm::Triple::mips:
-  case llvm::Triple::mipsel:
-  case llvm::Triple::mips64:
-  case llvm::Triple::mips64el:
-    return true;
-  default:
-    return false;
-  }
-}
 namespace {
 struct ReadObjTypeTableBuilder {
   ReadObjTypeTableBuilder()
       : Allocator(), IDTable(Allocator), TypeTable(Allocator),
         GlobalIDTable(Allocator), GlobalTypeTable(Allocator) {}
 
   llvm::BumpPtrAllocator Allocator;
   llvm::codeview::MergingTypeTableBuilder IDTable;
if (opts::HashTable)
     Dumper->printHashTable();
   if (opts::GnuHashTable)
     Dumper->printGnuHashTable();
   if (opts::VersionInfo)
     Dumper->printVersionInfo();
   if (Obj->isELF()) {
     if (opts::ELFLinkerOptions)
       Dumper->printELFLinkerOptions();
-    if (opts::ArchSpecificInfo) {
-      if (Obj->getArch() == llvm::Triple::arm)
-        Dumper->printAttributes();
-      else if (isMipsArch(Obj->getArch())) {
-        Dumper->printMipsABIFlags();
-        Dumper->printMipsOptions();
-        Dumper->printMipsReginfo();
-        Dumper->printMipsPLTGOT();
-      }
-    }
+    if (opts::ArchSpecificInfo)
+      Dumper->printArchSpecificInfo();
     if (opts::SectionGroups)
       Dumper->printGroupSections();
     if (opts::HashHistogram)
       Dumper->printHashHistogram();
     if (opts::CGProfile)
       Dumper->printCGProfile();
     if (opts::Addrsig)
       Dumper->printAddrsig();