Refactor llvm2ice so that Ice can be built while reading bitcode.

src/IceConverter.h

+//===- subzero/src/IceConverter.h - Converts LLVM to ICE --------*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the LLVM to ICE converter.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICECONVERTER_H
+#define SUBZERO_SRC_ICECONVERTER_H
+
+#include "IceGlobalContext.h"
+
+namespace llvm {

[Jim Stichnoth, 2014/06/26 23:50:12]

Could we just declare like this:
  class llvm::Module;
?

[Karl, 2014/06/27 16:15:22]

The problem is that doesn't work (you can't use a namespace that hasn't been
referred to in the file). When I compile it I get:

   error: ‘Module’ in namespace ‘llvm’ does not name a type

That's why I put it inside a namespace.

+class Module;
+}
+
+namespace Llvm2Ice {
+
+class Converter {
+public:
+  Converter(Ice::GlobalContext *Ctx,
+            bool DisableInternal,
+            bool SubzeroTimingEnabled,
+            bool DisableTranslation)
+      : Ctx(Ctx),
+        DisableInternal(DisableInternal),
+        SubzeroTimingEnabled(SubzeroTimingEnabled),
+        DisableTranslation(DisableTranslation)
+  {}
+  /// Converts the LLVM Module to ICE. Returns exit status 0 if successful,
+  /// Nonzero otherwise.
+  int convertToIce(llvm::Module *Mod);
+private:
+  Ice::GlobalContext *Ctx;
+  bool DisableInternal;
+  bool SubzeroTimingEnabled;
+  bool DisableTranslation;
+};
+
+}
+
+#endif  // SUBZERO_SRC_ICECONVERTER_H