Subzero: Add basic ELFObjectWriter (text section, symtab, strtab, headers)

src/IceGlobalContext.h

Index: src/IceGlobalContext.h
diff --git a/src/IceGlobalContext.h b/src/IceGlobalContext.h
index 43f65ad8fe8a747cfddb85b2a0dd7faac3f59e18..90ca9ab7ec260913202d493f9ea985826954135d 100644
--- a/src/IceGlobalContext.h
+++ b/src/IceGlobalContext.h
@@ -22,6 +22,7 @@
 
 #include "IceDefs.h"
 #include "IceClFlags.h"
+#include "IceELFObjectWriter.h"
 #include "IceIntrinsics.h"
 #include "IceRNG.h"
 #include "IceTimerTree.h"
@@ -75,8 +76,8 @@ class GlobalContext {
 
 public:
   GlobalContext(llvm::raw_ostream *OsDump, llvm::raw_ostream *OsEmit,
-                VerboseMask Mask, TargetArch Arch, OptLevel Opt,
-                IceString TestPrefix, const ClFlags &Flags);
+                ELFStreamer *ELFStreamer, VerboseMask Mask, TargetArch Arch,
+                OptLevel Opt, IceString TestPrefix, const ClFlags &Flags);
   ~GlobalContext();
 
   // Returns true if any of the specified options in the verbose mask
@@ -146,15 +147,26 @@ public:
     return ALLOW_DISABLE_IR_GEN ? getFlags().DisableIRGeneration : false;
   }
 
-  // Allocate data of type T using the global allocator.
+  // Allocate one instance of data of type T using the global allocator.
   template <typename T> T *allocate() { return Allocator.Allocate<T>(); }
 
+  // Allocate an N element array of data of bytes using the global allocator.
+  template uint8_t *allocateBytes(size_t N, size_t Align) {
+    return reinterpret_cast<uint8_t *>(Allocator.Allocate(N, Align));
+  }
+
   const Intrinsics &getIntrinsicsInfo() const { return IntrinsicsInfo; }
 
   // TODO(wala,stichnot): Make the RNG play nicely with multithreaded
   // translation.
   RandomNumberGenerator &getRNG() { return RNG; }
 
+  ELFObjectWriter *getObjectWriter() const { return ObjectWriter.get(); }
+
+  const GlobalDeclarationList &getGlobalDeclarations() const {
+    return GlobalDeclarations;
+  }
+
   // Reset stats at the beginning of a function.
   void resetStats() { StatsFunction.reset(); }
   void dumpStats(const IceString &Name, bool Final = false);
@@ -209,10 +221,11 @@ private:
   const ClFlags &Flags;
   bool HasEmittedFirstMethod;
   RandomNumberGenerator RNG;
+  std::unique_ptr<ELFObjectWriter> ObjectWriter;
   CodeStats StatsFunction;
   CodeStats StatsCumulative;
   std::vector<TimerStack> Timers;
-  std::vector<GlobalDeclaration *> GlobalDeclarations;
+  GlobalDeclarationList GlobalDeclarations;
 
   // Private helpers for mangleName()
   typedef llvm::SmallVector<char, 32> ManglerVector;