llvm-objdump: don't print relocations in non-relocatable files.

This matches the behavior of GNU objdump.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215844 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Object/COFF.h

@@ -462,6 +462,8 @@ public:
   std::error_code getHintName(uint32_t Rva, uint16_t &Hint,
                               StringRef &Name) const;
 
+  bool isRelocatableObject() const override;
+
   static inline bool classof(const Binary *v) { return v->isCOFF(); }
 };
 

include/llvm/Object/ELFObjectFile.h

@@ -224,6 +224,8 @@ public:
 
   std::pair<symbol_iterator, symbol_iterator>
   getELFDynamicSymbolIterators() const override;
+
+  bool isRelocatableObject() const override;
 };
 
 // Use an alignment of 2 for the typedefs since that is the worst case for
@@ -945,6 +947,10 @@ ELFObjectFile<ELFT>::getELFDynamicSymbolIterators() const {
   return std::make_pair(dynamic_symbol_begin(), dynamic_symbol_end());
 }
 
+template <class ELFT> bool ELFObjectFile<ELFT>::isRelocatableObject() const {
+  return EF.getHeader()->e_type == ELF::ET_REL;
+}
+
 inline std::error_code getELFRelocationAddend(const RelocationRef R,
                                               int64_t &Addend) {
   const ObjectFile *Obj = R.getObjectFile();

include/llvm/Object/MachO.h

@@ -219,6 +219,8 @@ public:
   static bool isValidArch(StringRef ArchFlag);
   static Triple getHostArch();
 
+  bool isRelocatableObject() const override;
+
   static bool classof(const Binary *v) {
     return v->isMachO();
   }

include/llvm/Object/ObjectFile.h

@@ -302,6 +302,9 @@ public:
     return object_error::invalid_file_type;
   }
 
+  /// True if this is a relocatable object (.o/.obj).
+  virtual bool isRelocatableObject() const = 0;
+
   /// @returns Pointer to ObjectFile subclass to handle this type of object.
   /// @param ObjectPath The path to the object file. ObjectPath.isObject must
   ///        return true.

lib/Object/COFFObjectFile.cpp

@@ -979,6 +979,10 @@ COFFObjectFile::getRelocationValueString(DataRefImpl Rel,
   return object_error::success;
 }
 
+bool COFFObjectFile::isRelocatableObject() const {
+  return !DataDirectory;
+}
+
 bool ImportDirectoryEntryRef::
 operator==(const ImportDirectoryEntryRef &Other) const {
   return ImportTable == Other.ImportTable && Index == Other.Index;

lib/Object/MachOObjectFile.cpp

@@ -1688,6 +1688,10 @@ void MachOObjectFile::ReadULEB128s(uint64_t Index,
   }
 }
 
+bool MachOObjectFile::isRelocatableObject() const {
+  return getHeader().filetype == MachO::MH_OBJECT;
+}
+
 ErrorOr<std::unique_ptr<MachOObjectFile>>
 ObjectFile::createMachOObjectFile(std::unique_ptr<MemoryBuffer> &Buffer) {
   StringRef Magic = Buffer->getBuffer().slice(0, 4);

test/Object/objdump-reloc-shared.test

@@ -0,0 +1,5 @@
+RUN: llvm-objdump -r %p/Inputs/elf-reloc-no-sym.x86_64 \
+RUN:              | FileCheck %s
+
+; CHECK: elf-reloc-no-sym.x86_64:       file format ELF64-x86-64
+; CHECK-NOT: {{.}}

tools/llvm-objdump/llvm-objdump.cpp

@@ -562,6 +562,11 @@ static void DisassembleObject(const ObjectFile *Obj, bool InlineRelocs) {
 static void PrintRelocations(const ObjectFile *Obj) {
   StringRef Fmt = Obj->getBytesInAddress() > 4 ? "%016" PRIx64 :
                                                  "%08" PRIx64;
+  // Regular objdump doesn't print relocations in non-relocatable object
+  // files.
+  if (!Obj->isRelocatableObject())
+    return;
+
   for (const SectionRef &Section : Obj->sections()) {
     if (Section.relocation_begin() == Section.relocation_end())
       continue;