Be a bit more consistent about using ErrorOr when constructing Binary objects.

The constructors of classes deriving from Binary normally take an error_code
as an argument to the constructor. My original intent was to change them
to have a trivial constructor and move the initial parsing logic to a static
method returning an ErrorOr. I changed my mind because:

* A constructor with an error_code out parameter is extremely convenient from
  the implementation side. We can incrementally construct the object and give
  up when we find an error.
* It is very efficient when constructing on the stack or when there is no
  error. The only inefficient case is where heap allocating and an error is
  found (we have to free the memory).

The result is that this is a much smaller patch. It just standardizes the
create* helpers to return an ErrorOr.

Almost no functionality change: The only difference is that this found that
we were trying to read past the end of COFF import library but ignoring the
error.

llvm-svn: 199770

1 files changed, 10 insertions, 35 deletions

diff --git a/llvm/lib/Object/Binary.cpp b/llvm/lib/Object/Binary.cpp
index f1da11ceab5..4f35d975262 100644
--- a/llvm/lib/Object/Binary.cpp
+++ b/llvm/lib/Object/Binary.cpp
@@ -19,7 +19,6 @@
 
 // Include headers for createBinary.
 #include "llvm/Object/Archive.h"
-#include "llvm/Object/COFF.h"
 #include "llvm/Object/MachOUniversal.h"
 #include "llvm/Object/ObjectFile.h"
 
@@ -45,24 +44,14 @@ StringRef Binary::getFileName() const {
 ErrorOr<Binary *> object::createBinary(MemoryBuffer *Source) {
   OwningPtr<MemoryBuffer> scopedSource(Source);
   sys::fs::file_magic type = sys::fs::identify_magic(Source->getBuffer());
-  error_code EC;
   switch (type) {
-    case sys::fs::file_magic::archive: {
-      OwningPtr<Binary> Ret(new Archive(scopedSource.take(), EC));
-      if (EC)
-        return EC;
-      return Ret.take();
-    }
+    case sys::fs::file_magic::archive:
+      return Archive::create(scopedSource.take());
     case sys::fs::file_magic::elf_relocatable:
     case sys::fs::file_magic::elf_executable:
     case sys::fs::file_magic::elf_shared_object:
-    case sys::fs::file_magic::elf_core: {
-      OwningPtr<Binary> Ret(
-          ObjectFile::createELFObjectFile(scopedSource.take()));
-      if (!Ret)
-        return object_error::invalid_file_type;
-      return Ret.take();
-    }
+    case sys::fs::file_magic::elf_core:
+      return ObjectFile::createELFObjectFile(scopedSource.take());
     case sys::fs::file_magic::macho_object:
     case sys::fs::file_magic::macho_executable:
     case sys::fs::file_magic::macho_fixed_virtual_memory_shared_lib:
@@ -72,28 +61,14 @@ ErrorOr<Binary *> object::createBinary(MemoryBuffer *Source) {
     case sys::fs::file_magic::macho_dynamic_linker:
     case sys::fs::file_magic::macho_bundle:
     case sys::fs::file_magic::macho_dynamically_linked_shared_lib_stub:
-    case sys::fs::file_magic::macho_dsym_companion: {
-      OwningPtr<Binary> Ret(
-          ObjectFile::createMachOObjectFile(scopedSource.take()));
-      if (!Ret)
-        return object_error::invalid_file_type;
-      return Ret.take();
-    }
-    case sys::fs::file_magic::macho_universal_binary: {
-      OwningPtr<Binary> Ret(new MachOUniversalBinary(scopedSource.take(), EC));
-      if (EC)
-        return EC;
-      return Ret.take();
-    }
+    case sys::fs::file_magic::macho_dsym_companion:
+      return ObjectFile::createMachOObjectFile(scopedSource.take());
+    case sys::fs::file_magic::macho_universal_binary:
+      return MachOUniversalBinary::create(scopedSource.take());
     case sys::fs::file_magic::coff_object:
     case sys::fs::file_magic::coff_import_library:
-    case sys::fs::file_magic::pecoff_executable: {
-      OwningPtr<Binary> Ret(
-          ObjectFile::createCOFFObjectFile(scopedSource.take()));
-      if (!Ret)
-        return object_error::invalid_file_type;
-      return Ret.take();
-    }
+    case sys::fs::file_magic::pecoff_executable:
+      return ObjectFile::createCOFFObjectFile(scopedSource.take());
     case sys::fs::file_magic::unknown:
     case sys::fs::file_magic::bitcode:
     case sys::fs::file_magic::windows_resource: {