[llvm-objcopy] Introduce dispatch mechanism based on the input

In this diff we introduce dispatch mechanism based on 
the type of the input (archive, object file, raw binary) 
and the format (coff, elf, macho).
We also move the ELF-specific code into the namespace llvm::objcopy::elf.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D53311

llvm-svn: 345217

1 files changed, 9 insertions, 6 deletions

diff --git a/llvm/tools/llvm-objcopy/Object.cpp b/llvm/tools/llvm-objcopy/Object.cpp
index d677579ea23..5b2138436d5 100644
--- a/llvm/tools/llvm-objcopy/Object.cpp
+++ b/llvm/tools/llvm-objcopy/Object.cpp
@@ -28,8 +28,10 @@
 #include <utility>
 #include <vector>
 
-using namespace llvm;
-using namespace llvm::objcopy;
+namespace llvm {
+namespace objcopy {
+namespace elf {
+
 using namespace object;
 using namespace ELF;
 
@@ -1165,7 +1167,9 @@ template <class ELFT> void ELFWriter<ELFT>::writeEhdr() {
   Ehdr.e_machine = Obj.Machine;
   Ehdr.e_version = Obj.Version;
   Ehdr.e_entry = Obj.Entry;
-  Ehdr.e_phnum = size(Obj.segments());
+  // We have to use the fully-qualified name llvm::size
+  // since some compilers complain on ambiguous resolution.
+  Ehdr.e_phnum = llvm::size(Obj.segments());
   Ehdr.e_phoff = (Ehdr.e_phnum != 0) ? Obj.ProgramHdrSegment.Offset : 0;
   Ehdr.e_phentsize = (Ehdr.e_phnum != 0) ? sizeof(Elf_Phdr) : 0;
   Ehdr.e_flags = Obj.Flags;
@@ -1597,9 +1601,6 @@ void BinaryWriter::finalize() {
   SecWriter = llvm::make_unique<BinarySectionWriter>(Buf);
 }
 
-namespace llvm {
-namespace objcopy {
-
 template class BinaryELFBuilder<ELF64LE>;
 template class BinaryELFBuilder<ELF64BE>;
 template class BinaryELFBuilder<ELF32LE>;
@@ -1614,5 +1615,7 @@ template class ELFWriter<ELF64LE>;
 template class ELFWriter<ELF64BE>;
 template class ELFWriter<ELF32LE>;
 template class ELFWriter<ELF32BE>;
+
+} // end namespace elf
 } // end namespace objcopy
 } // end namespace llvm