[Object] Deduplicate the three createError functions

[teemperor]

Summary

The Object library currently has three identical functions that translate a Twine into
a parser error. Until recently these functions have coexisted peacefully, but since
D110320 Clang with enabled modules is now diagnosing that we have several definitions
of createError in Object.

This patch just merges them all and puts them into Object's Error.h where the error
code for parse_failed is also defined which seems cleaner and unbreaks the bots.

[jhenderson]

llvm/include/llvm/Object/Error.h

85

I'm not sure you want the static keyword here? The inline keyword is enough to prevent ODR violations.

[teemperor]

• Remove static

llvm/include/llvm/Object/Error.h

85

Thanks! (this is actually just ELF.h version copied here, but the static can indeed go).

[jhenderson]

LGTM!

llvm/include/llvm/Object/ELF.h

 getElfArchType(StringRef Object) {
   if (Object.size() < ELF::EI_NIDENT)
     return std::make_pair((uint8_t)ELF::ELFCLASSNONE,
                           (uint8_t)ELF::ELFDATANONE);
   return std::make_pair((uint8_t)Object[ELF::EI_CLASS],
                         (uint8_t)Object[ELF::EI_DATA]);
 }
 
-static inline Error createError(const Twine &Err) {
-  return make_error<StringError>(Err, object_error::parse_failed);
-}
-
 enum PPCInstrMasks : uint64_t {
   PADDI_R12_NO_DISP = 0x0610000039800000,
   ADDIS_R12_TO_R2_NO_DISP = 0x3D820000,
   ADDI_R12_TO_R2_NO_DISP = 0x39820000,
   ADDI_R12_TO_R12_NO_DISP = 0x398C0000,
   PLD_R12_NO_DISP = 0x04100000E5800000,
   MTCTR_R12 = 0x7D8903A6,
   BCTR = 0x4E800420,

llvm/include/llvm/Object/Error.h

 
 /// isNotObjectErrorInvalidFileType() is used when looping through the children
 /// of an archive after calling getAsBinary() on the child and it returns an
 /// llvm::Error.  In the cases we want to loop through the children and ignore the
 /// non-objects in the archive this is used to test the error to see if an
 /// error() function needs to called on the llvm::Error.
 Error isNotObjectErrorInvalidFileType(llvm::Error Err);
 
+inline Error createError(const Twine &Err) {
+  return make_error<StringError>(Err, object_error::parse_failed);
+}
+
 } // end namespace object.
 
 } // end namespace llvm.
 
 namespace std {
 template <>
 struct is_error_code_enum<llvm::object::object_error> : std::true_type {};
 }
 
 #endif

llvm/lib/Object/COFFModuleDefinition.cpp

static bool isDecorated(StringRef Sym, bool MingwDef) {
   // as decorated, i.e. don't add any more leading underscores.
   // We can't check for a leading underscore here, since function names
   // themselves can start with an underscore, while a second one still needs
   // to be added.
   return Sym.startswith("@") || Sym.contains("@@") || Sym.startswith("?") ||
          (!MingwDef && Sym.contains('@'));
 }
 
-static Error createError(const Twine &Err) {
-  return make_error<StringError>(StringRef(Err.str()),
-                                 object_error::parse_failed);
-}
-
 class Lexer {
 public:
   Lexer(StringRef S) : Buf(S) {}
 
   Token lex() {
     Buf = Buf.trim();
     if (Buf.empty())
       return Token(Eof);

llvm/lib/Object/XCOFFObjectFile.cpp

static Expected<const T *> getObject(MemoryBufferRef M, const void *Ptr,
   return reinterpret_cast<const T *>(Addr);
 }
 
 static uintptr_t getWithOffset(uintptr_t Base, ptrdiff_t Offset) {
   return reinterpret_cast<uintptr_t>(reinterpret_cast<const char *>(Base) +
                                      Offset);
 }
 
-static Error createError(const Twine &Err) {
-  return make_error<StringError>(Err, object_error::parse_failed);
-}
-
 template <typename T> static const T *viewAs(uintptr_t in) {
   return reinterpret_cast<const T *>(in);
 }
 
 static StringRef generateXCOFFFixedNameStringRef(const char *Name) {
   auto NulCharPtr =
       static_cast<const char *>(memchr(Name, '\0', XCOFF::NameSize));
   return NulCharPtr ? StringRef(Name, NulCharPtr - Name)