Subzero: Embed the revision string into translated output.

src/IceRevision.h

+//===- subzero/src/IceRevision.h - Revision string embedding ----*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Declares the function for returning the Subzero revision string.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICEREVISION_H
+#define SUBZERO_SRC_ICEREVISION_H
+
+namespace Ice {
+
+// Returns the Subzero revision string, which is meant to be essentially the git
+// hash of the repo when Subzero was built.
+//
+// Note: It would be possible to declare this a constexpr char[] and put its
+// definition right here in the include file.  But since the git hash is passed
+// to the compiler on the command line, and compilation is directed through a
+// Makefile, lack of recompilation could lead to different files seeing
+// inconsistent revision strings.
+const char *getSubzeroRevision();
+
+} // end of namespace Ice
+
+#endif // SUBZERO_SRC_ICEREVISION_H