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

src/IceGlobalContext.cpp

 //===- subzero/src/IceGlobalContext.cpp - Global context defs -------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines aspects of the compilation that persist across
@@ skipping 85 matching lines @@
   TypePool<IceType_f64, double, ConstantDouble> Doubles;
   TypePool<IceType_i1, int8_t, ConstantInteger32> Integers1;
   TypePool<IceType_i8, int8_t, ConstantInteger32> Integers8;
   TypePool<IceType_i16, int16_t, ConstantInteger32> Integers16;
   TypePool<IceType_i32, int32_t, ConstantInteger32> Integers32;
   TypePool<IceType_i64, int64_t, ConstantInteger64> Integers64;
   TypePool<IceType_i32, RelocatableTuple, ConstantRelocatable> Relocatables;
   UndefPool Undefs;
 };
 
-GlobalContext::GlobalContext(llvm::raw_ostream *OsDump,
-                             llvm::raw_ostream *OsEmit, VerboseMask Mask,
+GlobalContext::GlobalContext(Ostream *OsDump, Ostream *OsEmit,
+                             ELFStreamer *ELFStr, VerboseMask Mask,
                              TargetArch Arch, OptLevel Opt,
                              IceString TestPrefix, const ClFlags &Flags)
     : StrDump(OsDump), StrEmit(OsEmit), VMask(Mask),
       ConstPool(new ConstantPool()), Arch(Arch), Opt(Opt),
       TestPrefix(TestPrefix), Flags(Flags), HasEmittedFirstMethod(false),
-      RNG("") {
+      RNG(""), ObjectWriter() {
   // Pre-register built-in stack names.
   newTimerStackID("Total across all functions");
   newTimerStackID("Per-function summary");
+  if (Flags.UseELFWriter) {
+    ObjectWriter.reset(new ELFObjectWriter(*this, *ELFStr));
+  }
 }
 
 // Scan a string for S[0-9A-Z]*_ patterns and replace them with
 // S<num>_ where <num> is the next base-36 value.  If a type name
 // legitimately contains that pattern, then the substitution will be
 // made in error and most likely the link will fail.  In this case,
 // the test classes can be rewritten not to use that pattern, which is
 // much simpler and more reliable than implementing a full demangling
 // parser.  Another substitution-in-error may occur if a type
 // identifier ends with the pattern S[0-9A-Z]*, because an immediately
@@ skipping 353 matching lines @@
 }
 
 TimerMarker::TimerMarker(TimerIdT ID, const Cfg *Func)
     : ID(ID), Ctx(Func->getContext()),
       Active(Func->getFocusedTiming() || Ctx->getFlags().SubzeroTimingEnabled) {
   if (Active)
     Ctx->pushTimer(ID);
 }
 
 } // end of namespace Ice