Hook up llc's -filetype=obj to use MCStreamer if an MCCodeEmitter is available.
Remove most of old Mach-O Writer support, it has been replaced by MCMachOStreamer

Further refactoring to completely remove MachOWriter and drive the object file
writer with the AsmPrinter MCInst/MCSection logic is forthcoming.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93527 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 2b5fd2c..758c81d 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Assembly/PrintModulePass.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/FileWriters.h"
 #include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
 #include "llvm/Target/TargetOptions.h"
@@ -115,12 +116,11 @@
       return FileModel::Error;
     return FileModel::AsmFile;
   case TargetMachine::ObjectFile:
-    if (getMachOWriterInfo())
+    if (!addObjectFileEmitter(PM, OptLevel, Out))
       return FileModel::MachOFile;
     else if (getELFWriterInfo())
-      return FileModel::ElfFile;
+      return FileModel::ElfFile; 
   }
-
   return FileModel::Error;
 }
 
@@ -137,6 +137,17 @@
   return false;
 }
 
+bool LLVMTargetMachine::addObjectFileEmitter(PassManagerBase &PM,
+                                             CodeGenOpt::Level OptLevel,
+                                             formatted_raw_ostream &Out) {
+  MCCodeEmitter *Emitter = getTarget().createCodeEmitter(*this);
+  if (!Emitter)
+    return true;
+  
+  PM.add(createMachOWriter(Out, *this, getMCAsmInfo(), Emitter));
+  return false;
+}
+
 /// addPassesToEmitFileFinish - If the passes to emit the specified file had to
 /// be split up (e.g., to add an object writer pass), this method can be used to
 /// finish up adding passes to emit the file, if necessary.